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1
Ordoñez, García Arturo. "Effects of architectural design variables on energy and environmental performance of office buildings." Doctoral thesis, Universitat Rovira i Virgili, 2016. http://hdl.handle.net/10803/395212.
Full textAbstract:
Aquesta
tesi
aborda
la
comprensió
dels
efectes
que
les
principals
variables
de
disseny
arquitectònic
tenen
en
les
prestacions
energètiques,
mediambientals
i
econòmiques
dels
edificis
d'oficines,
mitjançant
l'exploració
d'alguns
dels
mètodes
d'anàlisi
que
ofereixen
un
major
potencial
en
l'actualitat.
Busca
contribuir
al
desenvolupament
d'enfocaments,
mètodes
i
eines
que
facilitin
la
presa
de
decisions
durant
el
procés
de
disseny
arquitectònic,
especialment
en
les
primeres
etapes.
També
està
dirigit
a
generar
informació
que
ajudi
a
millorar
els
criteris
aplicats
en
el
desenvolupament
de
codis
energètics
i
sistemes
de
certificació
de
sostenibilitat.
La
investigació
ha
consistit
en
quatre
parts
principals:
•
La
primera
part
consisteix
en
el
desenvolupament
d'un
projecte
paramètric
basat
en
els
programes
EnergyPlus
i
jEPlus.
•
La
segona
part
consisteix
en
una
anàlisi
d'optimització
mitjançant
algoritmes
evolutius.
L'anàlisi
es
va
realitzar
amb
el
programa
jEPlus
+
EA,
i
està
destinat
a
identificar
les
solucions
de
disseny
arquitectònic
que
produeixen
impactes
mediambientals
i
econòmics
més
baixos.
•
La
tercera
part
consisteix
en
l'aplicació
dels
dos
mètodes
d'anàlisi
de
sensibilitat,
Morris
i
Sobol,
per
tal
d'establir
la
importància
relativa
de
cada
variable
de
disseny
arquitectònic
en
les
prestacions
dels
edificis.<br>Esta
tesis
aborda
el
estudio
de
los
efectos
que
las
principales
variables
de
diseño
arquitectónico
tienen
en
el
desempeño
energético,
medioambiental
y
económico
de
los
edificios
de
oficinas,
mediante
la
exploración
de
algunos
de
los
métodos
de
análisis
que
ofrecen
un
mayor
potencial
en
la
actualidad.
Busca
contribuir
al
desarrollo
de
enfoques,
métodos
y
herramientas
que
faciliten
la
toma
de
decisiones
durante
el
proceso
de
diseño
arquitectónico,
especialmente
en
las
primeras
etapas.
También
busca
generar
información
que
ayude
a
mejorar
los
criterios
aplicados
en
el
desarrollo
de
códigos
energéticos
y
sistemas
de
certificación
de
sostenibilidad.
La
investigación
consistió
en
cuatro
partes
principales:
•
Desarrollo
de
un
proyecto
paramétrico
basado
en
los
programas
EnergyPlus
y
jEPlus,
con
el
objeto
de
identificar
y
caracterizar
las
variables
de
diseño
arquitectónico
más
significativas
•
Aplicación
de
un
análisis
de
optimización
mediante
algoritmos
evolutivos.
El
análisis
se
realizó
con
el
programa
jEPlus
+
EA.
•
Ejecución
de
dos
métodos
de
análisis
de
sensibilidad,
Morris
y
Sobol,
con
el
fin
de
establecer
la
importancia
relativa
de
cada
variable
de
diseño
arquitectónico
en
el
desempeño
energético,
medioambiental
y
económico
de
los
edificios<br>This
thesis
addresses
the
understanding
of
the
effects
that
main
architectural
design
variables
have
on
energy,
environmental
and
economic
performance
of
office
buildings,
exploring
some
of
the
analytical
methods
that
offer
greater
potential
nowadays.
It
is
aimed
to
contribute
to
the
development
of
approaches,
methods
and
tools
that
facilitate
the
decision-making
during
the
architectural
design
processes,
especially
in
the
early
stages.
It
is
also
aimed
to
generate
information
that
helps
to
improve
the
criteria
applied
in
the
development
of
building
energy
codes
and
sustainability
certifications.
The
research
consisted
of
four
major
parts:
•
Development
of
a
parametric
project
based
on
the
programs
EnergyPlus
and
jEPlus
software.
•
Implementation
of
Optimization
analysis
by
means
of
evolutionary
algorithms.
The
analysis
is
performed
with
the
program
jEPlus+EA.
•
Application
of
two
sensitivity
analysis
methods,
Morris
and
Sobol,
in
order
to
investigate
the
relative
importance
of
each
architectural
design
variable.
•
Implementation
of
artificial
neural
networks
to
create
meta-models
that
are
able
to
predict,
with
reasonable
accuracy,
the
energy,
environmental
and
economic
performance
of
buildings
2
Haq, Saif-ul. "Complex architectural settings : an investigation of spatial and cognitive variables through wayfinding behavior." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/23201.
Full text
3
Stark, Randall J. "Connectionist variable binding architectures." Thesis, University of Sussex, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260835.
Full text
4
Heath, Felicity. "Variable architecture polymers for DNA delivery." Thesis, University of Nottingham, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.539162.
Full text
5
Saheba, Asheshh (Asheshh Mohit) 1972. "Variable volume architecture : expanding the boundary." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/69761.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2001.<br>Includes bibliographical references (p. [88]-89).<br>Research into the creation of a Variable Volume Architecture is explored through a series of proposals and projects. An argument is established to develop the means and methods of achieving an architecture of transformation. The basis for developing such a stance is substantiated and clarified with the act of probing into constructs of various scales. The design and manufacturing of a full scale prototype is explored to bring bearing on the physical resolution of the proposal. The device is an acknowledgment of potential applications and uses. The material, spatial, and structural nature of the propositions are articulated and examined throughout the investigation. The morphology of the concepts presented is derived to bring clarity to issues towards an endeavor for creating a responsive architectural landscape.<br>by Asheshh Saheba.<br>S.M.
6
Braun, Weston D. "A high frequency variable load inverter architecture." Thesis, Massachusetts Institute of Technology, 2018. https://hdl.handle.net/1721.1/121623.
Full textAbstract:
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (pages 163-165).<br>This thesis presents a high frequency variable load inverter architecture along with a physical prototype and eciency optimizing controller. The inverter architecture consists of two constituent inverters, one connected directly through the load and the other connected through an immittance converter, which acts as a lossless power combiner. By controlling the amplitude and relative phase of the two constituent inverters the loading seen by each constituent inverter can be kept in a desirable range for wide variations in load impedance. This allows for the use of highly ecient zero voltage switching inverters that would otherwise be precluded in applications with widely varying load impedances, such as wireless power transfer and plasma generation. Previous solutions to the challenge of driving widely variable load impedances, such as the tunable matching network, have typically resulted in systems that are often bulky, expensive, and slow. The physical prototype developed for this project operates at 13.56MHz and can supply a maximum output power of 1kW into a 21:8 + 0:3j load at an eciency of 95:4%. The eciency optimizing controller utilizes a quasi-static model prediction approach which allows for optimization of system performance over any desirable parameter. The system is also capable of driving a wide range of capacitive and inductive loads at a high power level and with high efficiency.<br>by Weston D. Braun.<br>M. Eng.<br>M.Eng. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science
7
Lee, Anthony. "On auxiliary variables and many-core architectures in computational statistics." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:244040a7-f094-4d57-a78f-e154ed3b353c.
Full textAbstract:
Emerging many-core computer architectures provide an incentive for computational methods to exhibit specific types of parallelism. Our ability to perform inference in Bayesian statistics is often dependent upon our ability to approximate expectations of functions of random variables, for which Monte Carlo methodology provides a general purpose solution using a computer. This thesis is primarily concerned with exploring the gains that can be obtained by using many-core architectures to accelerate existing population-based Monte Carlo algorithms, as well as providing a novel general framework that can be used to devise new population-based methods. Monte Carlo algorithms are often concerned with sampling random variables taking values in X whose density is known up to a normalizing constant. Population-based methods typically make use of collections of interacting auxiliary random variables, each of which is in X, in specifying an algorithm. Such methods are good candidates for parallel implementation when the collection of samples can be generated in parallel and their interaction steps are either parallelizable or negligible in cost. The first contribution of this thesis is in demonstrating the potential speedups that can be obtained for two common population-based methods, population-based Markov chain Monte Carlo (MCMC) and sequential Monte Carlo (SMC). The second contribution of this thesis is in the derivation of a hierarchical family of sparsity-inducing priors in regression and classification settings. Here, auxiliary variables make possible the implementation of a fast algorithm for finding local modes of the posterior density. SMC, accelerated on a many-core architecture, is then used to perform inference for a range of prior specifications to gain an understanding of sparse association signal in the context of genome-wide association studies. The third contribution is in the use of a new perspective on reversible MCMC kernels that allows for the construction of novel population-based methods. These methods differ from most existing methods in that one can make the resulting kernels define a Markov chain on X. A further development is that one can define kernels in which the number of auxiliary variables is given a distribution conditional on the values of the auxiliary variables obtained so far. This is perhaps the most important methodological contribution of the thesis, and the adaptation of the number of particles used within a particle MCMC algorithm provides a general purpose algorithm for sampling from a variety of complex distributions.
8
Demaël, Jacques J. "On the generation of variable structure distributed architectures." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14510.
Full textAbstract:
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1989.<br>Includes bibliographical references (leaves 201-203).<br>by Jacques J. Demaël.<br>M.S.
9
Lissek, Hervé. "Les matériaux actifs à propriétés acoustiques variables." Le Mans, 2002. http://cyberdoc.univ-lemans.fr/theses/2002/2002LEMA1007.pdf.
Full textAbstract:
Ce travail s'intéresse au concept des matériaux actifs à propriétés acoustiques variables, destinés à des applications de type correction acoustique. Ce concept est basé sur un principe de contrôle actif d'impédance acoustique d'un transducteur électroacoustique par contre-réaction motionnelle hybride, qui associe une contre-réaction motionnelle, obtenue grâce à un pont d'impédances électriques, et une contre-réaction en pression à l'aide d'un microphone placé à proximité de l'actionneur. L'extrapolation du principe à celui de mur actif de matériaux actifs à propriétés acoustiques variables est ensuite envisagée. Une mise en oeuvre, sur des haut-parleurs électrodynamiques à bobine mobile traditionnels, a permis de valider le procédé dans une configuration unidimensionnelle (champ acoustique en ondes planes sous incidence normale), puis dans une disposition de type mur actif, soumis à un champ acoustique tridimensionnel complexe. Ces études théoriques et expérimentales ont également permis d'établir un cahier des charges pour un transducteur électroacoustique spécifique, dédié à l'application c matériaux actifs ". La recherche d'un type de transducteur dédié au concept de matériau actif a abouti à l'étude du cas du transducteur isodynamique, dont un modèle numérique a été développé. L'étude du fonctionnement de ce transducteur a mis en évidence de nombreux problèmes susceptibles de limiter les performances en tant que matériau actif à propriétés acoustiques variables, et a permis également d'élaborer un outil nous permettant de le dimensionner pour cette application. Sur la base de cette étude, différents prototypes ont pu être construits, permettant de vérifier d'une part la validité du modèle numérique, et d'autre part d'étudier les limites fonctionnelles du transducteur, afin d'y apporter des solutions pratiques. Les résultats obtenus sur des transducteurs isodynamiques utilisés en matériaux actifs dans une configuration unidimensionnelle, nous on permis d'estimer le travail restant à accomplir pour le développement de matériaux actifs à propriétés acoustiques variables, ce type de transducteur restant le mieux adapté au concept, tant en termes de résultats qu'en termes de coût de fabrication<br>This work deals with the concept of active materials with variable acoustic properties, dedicated to room acoustics applications. This concept is based on an acoustic impedance active control principle by hybrid motionnal feedback, applied on an electroacoustic transducer. This hybrid feedback associates a motionnal feedback, obtained by an electric impedance bridge, and a pressure feedback, obtained by a microphone placed in the neighbourhood of the actuator. After the concept of active material has been modelized and tested experimentally with single moving-coil loudspeaker, this principle is extended to the concept of active wall. A prototype of active wall with active moving coil loudspeakers is modelized and tested, in order to find specifications for a specific electroacoustic transducer dedicated to the « active materials » application. This work leads to the implementation of the isodynamic transducer, for which a numeric model is elaborated. The study of the electroacoustic behaviour of this transducer underlines several problems, likely to limit its performances as active material with variable acoustic properties, and lead us to develop a numeric tool for sizing the transducer for this application. On the basis of this study, many prototypes are build in order to, in one hand, validate the numeric model, and in the other hand, point out the limitations of the transducer to find practical solutions to improve its performances. The results obtained with such transducers as active materials, obtained for plane waves and normal incidence, help us estimate future works for the achievement of active materials with variable acoustic properties ; the isodynamic principle seems to be the must suitable for this concept, in terms of results as well as in terms of product costs
10
Xie, Ruinan. "Design and Manufacturing of Variable Stiffness Cellular Architecture." Thesis, North Dakota State University, 2017. https://hdl.handle.net/10365/31739.
Full textAbstract:
Cellular structures are highly evaluated due to their high material efficiency. Both theoretical and experimental studies have done on periodic cellular structures. However, the mechanical performance can be stochastically distributed in the cellular architecture. This thesis presents the design and manufacturing of variable stiffness cellular architecture to achieve optimized topology by changing the unit cell parameters. The author applies image analysis technique to extract and digitize the information from the performance distribution map. Two types of cellular cells are studied for their relationship of stiffness and relative density. The methods of voxelization for both cells are also given in this study. This proposed methodology is then implemented to design a customized mattress and compare with current existing mattress. With the study of the unit cells and voxelization technique, our designed mattress aligns body curve better which provides more recuperation of the body during sleep.
11
Fagge, Megan. "Variable learning environments." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39595.
Full textAbstract:
Research shows the environment affects the user both psychologically and physiologically. Teachers often alter their classrooms in order to effect these changes, for instance, by adding elements for warmth, offsetting harsh lighting, or using found objects to mark and divide space. Research and observed use communicate a need for a planned variety of spaces in function and in character.
The project is a redesign of Therrell High School in southwest Atlanta seeking to complement the new movement to small learning communities, which embeds programmatic variety in the public school system.
Therrell is divided into three small thematically described academies, which effectively function as three separate high schools: the School of Science, Technology, Engineering, and Math; the School of Health Sciences and Research; the School of Law, Government, and Public Policy.
The design focuses on the necessary variability of spaces inherent in small learning communities. These spaces seek to address the varied instructional strategies that accompany the thematic endeavors of each school and introduce variety in architectural character, thus accommodating variable needs and desires of students. The focus of the project is on the student and the nature of space that fosters positive experiences as well as positive learning outcomes.
12
Lee, Jeffrey C. "ARCHITECTURAL CONSIDERATIONS FOR A VARIABLE BIT RATE DATA ACQUISITION TELEMETRY ENCODER." International Foundation for Telemetering, 2007. http://hdl.handle.net/10150/604502.
Full textAbstract:
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada<br>Modern telemetry systems require flexible bit rate telemetry encoders in order to optimize mission formats for varying data rate requirements and/or signal to noise conditions given a fixed transmitter power. Implementing a variable bit rate telemetry encoder requires consideration of several possible architectural topologies that place different system requirements on data acquisition modules within the encoder in order to maintain adequate signal fidelity of sensor information. This paper focuses on the requirements, design considerations and tradeoffs associated with differing architectural topologies for implementing a variable bit rate encoder and the resulting implications on the encoder systems data acquisition units.
13
Hoskins, Mandi M. "Vari_Mobile: Variety, Variability, and Mobility in Crisis Architecture." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1053380997.
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14
Lane, Peter. "Simple synchrony networks : a new connectionist architecture applied to natural language parsing." Thesis, University of Exeter, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322386.
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15
Ekmekjian, Nazareth (Nazareth Vahe). "Architecture sandwiched : tuning anisotropy through variable thickness and hetereogeneous laminar assemblies." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99272.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Architecture, 2015.<br>Cataloged from PDF version of thesis. Page 61 blank.<br>Includes bibliographical references (pages 58-59).<br>Much of architecture's earliest material palettes and construction methods are often referred to today as legacy materials - those primarily consisting of various types of stone and masonry construction. While these materials are often conceptually thought of as being solid, monolithic, and even homogeneous, in actuality they rely on logics of assembly more akin to contemporary sandwich structures, which are laminar assemblies typically composed of two or more stressed skins and either a solid or cellular core that binds them together. While it is still common to use ancient materials in contemporary architecture, the construction methods and techniques used several hundred years ago are no longer appropriate for today's buildings. This thesis however, argues for a newfound relevance of their influence on contemporary and even future material selections and methods. Specifically, this thesis explores the potentials of composite sandwiches varying in thickness and material in search of architectural possibilities whose structural, formal, and aesthetic implications are a result of tuning multiple influences. Variable thickness is used here as a strategy for enabling a range of architectural and tectonic conditions, all within the same heterogeneous but integrated laminar assemblies. While most commercial products in the realm of composite sandwiches are of uniform thickness in section, this thesis suggests a method for constructing sandwiched elements with variable thickness. This is done primarily through a process of infill and backfill using expanding urethane foam as a medium which creates the so called "core" of the sandwich between two skins. This investigation works through a series of small scale prototypes, each of which focus on a particular tectonic, spatial, or structural condition. These mock ups are meant to serve as didactic artifacts, providing feedback with which to incorporate and speculate upon larger architectural propositions through drawing and representation. The end result is a set of architectural proposals which suggest the beginnings of new design methodologies.<br>by Nazareth Ekmekjian.<br>S.M.
16
Cooke, Timothy Graham. "Lightweight concrete : investigations into the production of variable density cellular materials." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78505.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2012.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 123-127).<br>This research focuses on the intersection between material composition and form in the development of a new type of concrete. As concrete is the most widely used building material in the world, innovation in this material has more potential to effect change in our built environment than innovation in any other. With the objective of minimizing raw material consumption and energy use, this work attempts to develop methods for creating a cellular lightweight concrete with variable density that can be cured at room temperature. Most aerated concretes traditionally require high temperature and high pressure curing; the goal of this research is to create a lower embodied energy product through the use of room temperature curing, while at the same time maximizing performance through variation of the density of the material through its section-essentially locating stronger material where it is needed. This more durable and versatile concrete product will be able to compete with traditional lightweight concretes, which provide benefits such as insulation, as well as normal-weight concrete, which is harder and stronger. The research aims to capitalize on the inherent heterogeneity of the material by producing a substance whose internal properties can be varied based on the needs of a specific part of a building. I am interested in replacing the concept of the "assembly" of materials to gain a desired function with a more unitary concept: the manipulation of a single material to meet a building's multiple needs. A desired outcome of the work is to reconceive how we put buildings together, not as assemblies of discrete elements but as monolithic yet malleable wholes.<br>by Timothy Graham Cooke.<br>S.M.
17
Hannachi, Marwa. "Placement des tâches matérielles de tailles variables sur des architectures reconfigurables dynamiquement et partiellement." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0297/document.
Full textAbstract:
Les systèmes adaptatifs basés sur les architectures FPGA (Field-Programmable Gate Arrays) peuvent bénéficier grandement de la grande flexibilité offerte par la reconfiguration partielle dynamique (DPR). Grâce au DPR, les tâches matérielles composant un système adaptatif peuvent être allouées et re-allouées à la demande ou en fonction de l'environnement dynamique. Les flots de conceptions disponibles et les outils commerciaux ont évolué pour répondre aux exigences des architectures reconfigurables qui sont toutefois limitées dans leurs fonctionnalités. Ces outils ne permettent pas un placement et une relocation efficaces de tâches matérielles de tailles variables. L'objectif principal de ces travaux de thèse consiste à proposer des nouvelles méthodologies et de nouvelles approches pour faciliter au concepteur la phase de conception d'un système adaptatif reconfigurable opérationnelle, valide, optimisé et adapté aux changements dynamiques de l'environnement. La première contribution de cette thèse porte sur la problématique de la relocation des tâches matérielles de tailles différentes. Une méthodologie de conception est proposée pour répondre à un problème majeur des mécanismes de relogement : le stockage d'une unique bitstream de configuration pour réduire les besoins de la mémoire et pour accroître la réutilisable des modules matériels générés. Une technique de partitionnement de la région reconfigurable est appliquée dans la méthodologie de relogement proposée pour augmenter l'efficacité d'utilisation des ressources matérielles dans le cas des tâches reconfigurables de tailles variables. Cette méthodologie prend en compte aussi la communication entre différentes régions reconfigurables et la région statique. Pour valider la méthode, plusieurs études de cas sont implémentées. Cette validation montre une utilisation efficace des ressources matérielles ainsi une réduction importante du temps de reconfiguration. La deuxième partie de cette thèse présente et détaille une formulation mathématique afin d'automatiser le floorplanning des zones reconfigurables dans les FPGAs. Les algorithmes de recherche présentés dans cette thèse sont basés sur la technique d'optimisation PLMNE (programmation linéaire mixte en nombres entiers). Ces algorithmes permettent de définir automatiquement l'emplacement, la taille et la forme de la zone reconfigurable dynamique. Nous nous intéressons principalement dans cette recherche à la satisfaction des contraintes de placement des zones reconfigurables et celles liées à la relocation. De plus, nous considérons l’optimisation des ressources matérielles dans le FPGA en tenant compte des tâches de tailles variables. Finalement, une évaluation de l'approche proposée est présentée<br>Adaptive systems based on Field-Programmable Gate Arrays (FPGA) architectures can benefit greatly from the high degree of flexibility offered by dynamic partial reconfiguration (DPR). Thanks to DPR, hardware tasks composing an adaptive system can be allocated and relocated on demand or depending on the dynamically changing environment. Existing design flows and commercial tools have evolved to meet the requirements of reconfigurables architectures, but that are limited in functionality. These tools do not allow an efficient placement and relocation of variable-sized hardware tasks. The main objective of this thesis is to propose a new methodology and a new approaches to facilitate to the designers the design phase of an adaptive and reconfigurable system and to make it operational, valid, optimized and adapted to dynamic changes in the environment. The first contribution of this thesis deals with the issues of relocation of variable-sized hardware tasks. A design methodology is proposed to address a major problem of relocation mechanisms: storing a single configuration bitstream to reduce memory requirements and increasing the reusability of generating hardware modules. A reconfigurable region partitioning technique is applied in this proposed relocation methodology to increase the efficiency of use of hardware resources in the case of reconfigurable tasks of variable sizes. This methodology also takes into account communication between different reconfigurable regions and the static region. To validate the design method, several cases studies are implemented. This validation shows an efficient use of hardware resources and a significant reduction in reconfiguration time. The second part of this thesis presents and details a mathematical formulations in order to automate the floorplanning of the reconfigurable regions in the FPGAs. The algorithms presented in this thesis are based on the optimization technique MILP (mixed integer linear programming). These algorithms allow to define automatically the location, the size and the shape of the dynamic reconfigurable region. We are mainly interested in this research to satisfy the constraints of placement of the reconfigurable zones and those related to the relocation. In addition, we consider the optimization of the hardware resources in the FPGA taking into account the tasks of variable sizes. Finally, an evaluation of the proposed approach is presented
18
Hannachi, Marwa. "Placement des tâches matérielles de tailles variables sur des architectures reconfigurables dynamiquement et partiellement." Electronic Thesis or Diss., Université de Lorraine, 2017. http://www.theses.fr/2017LORR0297.
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Les systèmes adaptatifs basés sur les architectures FPGA (Field-Programmable Gate Arrays) peuvent bénéficier grandement de la grande flexibilité offerte par la reconfiguration partielle dynamique (DPR). Grâce au DPR, les tâches matérielles composant un système adaptatif peuvent être allouées et re-allouées à la demande ou en fonction de l'environnement dynamique. Les flots de conceptions disponibles et les outils commerciaux ont évolué pour répondre aux exigences des architectures reconfigurables qui sont toutefois limitées dans leurs fonctionnalités. Ces outils ne permettent pas un placement et une relocation efficaces de tâches matérielles de tailles variables. L'objectif principal de ces travaux de thèse consiste à proposer des nouvelles méthodologies et de nouvelles approches pour faciliter au concepteur la phase de conception d'un système adaptatif reconfigurable opérationnelle, valide, optimisé et adapté aux changements dynamiques de l'environnement. La première contribution de cette thèse porte sur la problématique de la relocation des tâches matérielles de tailles différentes. Une méthodologie de conception est proposée pour répondre à un problème majeur des mécanismes de relogement : le stockage d'une unique bitstream de configuration pour réduire les besoins de la mémoire et pour accroître la réutilisable des modules matériels générés. Une technique de partitionnement de la région reconfigurable est appliquée dans la méthodologie de relogement proposée pour augmenter l'efficacité d'utilisation des ressources matérielles dans le cas des tâches reconfigurables de tailles variables. Cette méthodologie prend en compte aussi la communication entre différentes régions reconfigurables et la région statique. Pour valider la méthode, plusieurs études de cas sont implémentées. Cette validation montre une utilisation efficace des ressources matérielles ainsi une réduction importante du temps de reconfiguration. La deuxième partie de cette thèse présente et détaille une formulation mathématique afin d'automatiser le floorplanning des zones reconfigurables dans les FPGAs. Les algorithmes de recherche présentés dans cette thèse sont basés sur la technique d'optimisation PLMNE (programmation linéaire mixte en nombres entiers). Ces algorithmes permettent de définir automatiquement l'emplacement, la taille et la forme de la zone reconfigurable dynamique. Nous nous intéressons principalement dans cette recherche à la satisfaction des contraintes de placement des zones reconfigurables et celles liées à la relocation. De plus, nous considérons l’optimisation des ressources matérielles dans le FPGA en tenant compte des tâches de tailles variables. Finalement, une évaluation de l'approche proposée est présentée<br>Adaptive systems based on Field-Programmable Gate Arrays (FPGA) architectures can benefit greatly from the high degree of flexibility offered by dynamic partial reconfiguration (DPR). Thanks to DPR, hardware tasks composing an adaptive system can be allocated and relocated on demand or depending on the dynamically changing environment. Existing design flows and commercial tools have evolved to meet the requirements of reconfigurables architectures, but that are limited in functionality. These tools do not allow an efficient placement and relocation of variable-sized hardware tasks. The main objective of this thesis is to propose a new methodology and a new approaches to facilitate to the designers the design phase of an adaptive and reconfigurable system and to make it operational, valid, optimized and adapted to dynamic changes in the environment. The first contribution of this thesis deals with the issues of relocation of variable-sized hardware tasks. A design methodology is proposed to address a major problem of relocation mechanisms: storing a single configuration bitstream to reduce memory requirements and increasing the reusability of generating hardware modules. A reconfigurable region partitioning technique is applied in this proposed relocation methodology to increase the efficiency of use of hardware resources in the case of reconfigurable tasks of variable sizes. This methodology also takes into account communication between different reconfigurable regions and the static region. To validate the design method, several cases studies are implemented. This validation shows an efficient use of hardware resources and a significant reduction in reconfiguration time. The second part of this thesis presents and details a mathematical formulations in order to automate the floorplanning of the reconfigurable regions in the FPGAs. The algorithms presented in this thesis are based on the optimization technique MILP (mixed integer linear programming). These algorithms allow to define automatically the location, the size and the shape of the dynamic reconfigurable region. We are mainly interested in this research to satisfy the constraints of placement of the reconfigurable zones and those related to the relocation. In addition, we consider the optimization of the hardware resources in the FPGA taking into account the tasks of variable sizes. Finally, an evaluation of the proposed approach is presented
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Chapman, Gary Allen. "Design variables and the success of outdoor neighborhood recreational facilities." Thesis, The University of Arizona, 1999. http://hdl.handle.net/10150/278696.
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Today, park use is at an all-time high with the number of city parks increasing at a growing rate each year. Designing a successful outdoor neighborhood recreational facility insures that the surrounding population has an enjoyable, safe, and lasting space to recreate. This study properly illustrates the process in designing a successful neighborhood park. A demographic analysis, conducted in Southern California's Coachella Valley, identified three neighborhood parks as ideal study sites. Likewise, the review of existing literature, site observations, and the analysis of a carefully designed survey developed the appropriate methodology in meeting the intent of this study. As author, I wish to stress the importance of process. If the designer of a neighborhood facility is to meet the recreational goals of any community, he or she must first take action in understanding the appropriate process. Once this understanding is achieved, effective design guidelines may then be developed.
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Yang, Hye Soo. "Variable reality : interacting with the virtual book." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98617.
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Thesis: S.M., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2015.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 91-95).<br>This thesis presents Variable Reality, a wearable augmented reality-based system focused on creating a unique on-the-go reading experience that combines the readily accessible nature of digital books with the favorable physical spatiality of a paper book. The two types of Variable Reality books are the Augmented Book and the Virtual Book. They differ in the way they are displayed as the former augments virtual pages onto an actual book whereas the latter virtually augments a 3-D book on the palm of the user's hand. Designed to take the physical form of a book, Variable Reality books make use of human cognitive ability in storing and retrieving information in a spatial manner. Easy-to-use hand gestures naturally associated with reading activity are integrated with the system to help bring an intuitive user experience in reading.<br>by Hye Soo Yang.<br>S.M.
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Eaton, Scott Michael 1973. "The design and engineering of variable character morphology." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/61121.
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Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, September 2001.<br>"August 2001."<br>Includes bibliographical references (p. 79-82).<br>This thesis explores the technical challenges and the creative possibilities afforded by a computational system that allows behavioral control over the appearance of a character's morphology. Working within the framework of the Synthetic Character's behavior architecture, a system has been implemented that allows a character's internal state to drive changes in its morphology. The system allows for real-time, multi-target blending between body geometries, skeletons, and animations. The results reflect qualitative changes in the character's appearance and state. Through the thesis character sketches are used to demonstrate the potential of this integrated approach to behavior and character morphology.<br>Scott Michael Eaton.<br>S.M.
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Adjei, Eunice Akyereko. "Multi-objective optimisation of building design variables and its impact on office building performance : a case for Ghana." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/43345/.
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Multi-objective optimisation of building design variables is an appropriate and robust approach in assessing office building performance. Conversely, in developing country contexts like Ghana there is lack of credible building design variables from scientific and technical journals. The main research problem was low building performance assessment by building professionals in Ghana resulting in high cooling energy utilization and indoor environmental discomfort within the commercial building sector. Overall, the aim of the research was to use cost effective low energy technologies to optimize the building design variables to achieve recommended good practice for energy utilization of service equipment and indoor environmental performance in office building. Research questions addressed in this research included the following: 1. How does local building professionals’ practices impact on design variables used in performance assessment, and are occupants’ comfortable as well as satisfied with building performance in Ghana? 2. Are the building fabrics used in Ghana suitable for enhancing building performance? 3. How can the building performance design variables from survey questionnaires and experimental assessments be optimized? 4. Are the existing economic benefit assessment tools adequate for fast accurate decision making in comparing recommended good practice for cooling load by CIBSE Guides in hot-humid climate? The following creative and novel methodologies were used for this research: 1. Survey questionnaires using Bristol Online Survey Tool for the administration and acquisition of responses from participants. 2. Experimental assessment of selected fabrics from Ghana and creative parametric fabrics using both TCi Thermal Analyser and AutoPore IV mercury intrusion Porosimeter. 3. Computer simulations for optimised design variables using ESDL Tas. Finally, Design of creative comparator decision making tool for economic benefit assessment of the optimised computer simulations design variables. The selected significant findings from the application of the creative and novel methodologies in addition to the corresponding implications are summarised as follows: 1. An average of 16% of all building professionals do assess design variables associated with its practices with about 60% building professionals satisfied with Ghana building regulations, on the contrary, highly recommended for an improvement on the regulations. 2. Experimental assessment of representative selected Ghana building fabrics and enhanced parametric studies meets the thermo-physical properties outlined in the CIBSE Guide standards, with the range of thermal conductivity being 0.2 to 0.7W/m2K. 3. From the creative computer simulation outcomes, the cooling load of the base case is about 10 times more than the recommended good cooling load practice outlined in CIBSE Guides. The optimised computer simulation single wall layer building design model was achieved using optimum low transmittance building fabrics, optimum internal conditions and low chilled beam technology. 4. From the economic benefit assessment, an increasing trend of inverse correlation between difference in modification cost with cooling load reduction was observed. That is, for reduction in cooling load, there is an increasing cost in modification. For example, for reduction of cooling load of 40% from Case 1 to Case 3, there is a corresponding increase in modification cost of 79.4%. 5. Representative office occupants are generally satisfied and comfortable with building performance in Ghana. The above findings have compounded extreme implications on the local building professionals’ practices, leading to subsequently high cooling load, hence the rising energy utilization of service equipment in non-residential buildings. Finally, the overall aim of achieving the recommended good practice for service equipment energy utilization in commercial buildings was not accomplished for the cooling load. This is due to the difference in cooling load calendar used by CIBSE Guide and hot-humid climate, Ghana. In conclusion, an optimised low cost computer simulation of single wall layer envelope design, with cooling load of 120 kW/m2 for floor area and acceptable indoor environmental quality has been achieved in this research. It is strongly, recommended that, performance assessment should be incorporated into building permit issuing process using the designed creative feedback chart designed in this research.
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Blum, David H. (David Henry). "Analysis and characterization of ancillary service demand response strategies for variable air volume HVAC systems." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82162.
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Thesis (S.M. in Building Technology)--Massachusetts Institute of Technology, Dept. of Architecture, 2013.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (p. 113-119).<br>Output variability and prediction difficulties with respect to solar and wind electricity resources increase the requirement of grid-scale reserve capacity and add strain to existing firm generators used for reserves and other ancillary services. Residential and commercial buildings account for a large portion of the electricity consumed in the U.S. and can play a significant role in smart grids to help meet challenges brought about by intermittent renewable generation. High resolution power consumption and HVAC performance data measured in a real building was used to identify real-world operational qualities of VAV systems to be considered by building researchers and building practitioners. This includes the relative magnitude of building power loads, the direct and indirect relationships between environmental conditions and HVAC power consumption, the discrete operation of staged or cycled power loads, and the presence of HVAC operational faults. Also, three static pressure adjustment tests were performed over a one day period. Results showed that fan and terminal unit controllers responded within two minutes and system air flowrate was strongly related to power consumption. Dynamic models were created in order to simulate the performance of a VAV system providing spinning reserves by four different common demand response strategies: zone air dry bulb temperature setpoint adjustment (ZDBA), duct static pressure setpoint adjustment (SPA), supply air temperature adjustment (STA), and chilled water temperature adjustment (CWA). Simulations were run over ranges of implementation and cooling load intensities and the results were used to create characteristic curves for each strategy, which map performance in terms of system power consumption reduction, system airflow reduction, and zone temperature rise. Inflection points on the curves that delineate performance effectiveness are found to result from maximum or minimum terminal unit damper positions. In the future, the development of mathematical functional forms of these characterization curves could help predict and optimize the performance of VAV systems in providing ancillary services to electricity networks.<br>by David H. Blum.<br>S.M.in Building Technology
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Chen, Junxiang. "Study of 270VDC system application." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/9477.
Full textAbstract:
As increasing power requirement in more or all electric aircraft, electric power
system is required to be more efficient and lower in weight. Among the current
power generation technologies, 115V variable frequency (VF) system and
270VDC system are regarded as the two optimal options for future use in MEA
or AEA. Therefore, it is very important to compare their relative merits in order
to determine the optimal choice on the primary power type.
As the reviewed literature mainly represents the comparison between 270VDC
system and 115V constant frequency system, it is very necessary to conduct
the comparison between 270VDC system and 115V/VF system. The aim of this
study is to grasp the nature of these systems and evaluate these two systems in
terms of some engineering aspects.
Literature regarding the power generation technology is first investigated. Based
on initial comparison, the 270VDC brushless generating system and 115V VF
generating system are selected for this study. Before conducting system
architecture design and wiring system design, the load requirement analysis
and optimization are conducted. Finally, a comparison between these two
systems will be made in terms of weight, power off take, minimum voltampere
(VA) capacity requirement, voltage drop, reliability, life cycle cost and risk.
The results show that the 270VDC system is superior to the115V/VF system in
terms of weight and efficiency. With regards to system reliability, the 270VDC
system can be designed as either an active parallel system or a standby system
while the 115V/VF system can only be designed as a standby redundant
system. As far as risk is concerned, the 270VDC is more dangerous than the
115V/VF system in terms of arcing risk and corona discharge. All in all, the
270VDC system can be considered as the optimal choice for future use in AEA
or MEA.
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Adjoyan, Seza. "Describing Dynamic and Variable Software Architecture Based on Identified Services From Object-Oriented Legacy Applications." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTS022/document.
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L'Orienté Service (SOA) est un paradigme de conception qui facilite la construction d’applications extensibles et reconfigurables basées sur des artefacts réutilisables qui sont les services. Ceux-ci sont structurés via des interfaces bien définies et publiables et qui peuvent être dynamiquement découvertes.Beaucoup d’approches ont été proposées dans la littérature pour la réingénierie d’applications existantes développées dans des paradigmes pré-services, principalement l’orienté objet, vers SOA. L’objectif est de permettre de sauvegarder la valeur métier de ces d’applications tout en leur permettant de bénéficier des avantages de SOA. Le problème est que ces approches s'appuient sur des critères ad-hoc pour identifier correctement des services dans le code source des applications existantes.Par ailleurs, l'une des caractéristiques les plus distinctives d'une application orientée service est sa capacité de se reconfigurer dynamiquement et d'adapter son comportement en fonction de son contexte d'exécution. Cependant, dans les langages de description d'architecture (ADL) existants dont l’aspect de reconfiguration et pris en compte, les règles de reconfiguration sont représentées d'une manière ad-hoc; en général, elles ne sont pas modélisées d'une manière explicite mais enfouillées dans la description de l'architecture. D'une part, ceci engendre une difficulté de la gestion de la reconfiguration dynamique au niveau de l'architecture et d’autre part, la traçabilité de la description de la reconfiguration dynamique à travers les différents niveaux d'abstraction est difficile à représenter et à gérer.Afin de surmonter les problèmes précédents, nous proposons dans le cadre de cette thèse deux contributions. D'abord, nous proposons une approche d'identification de services basée sur un modèle de qualité où les caractéristiques des services sont étudiées, raffinées et réifiées en une fonction que nous utilisons pour mesurer la validité sémantique de ces services. La deuxième contribution consiste en une proposition d'un langage de description d'architecture orientée service (ADL) qui intègre la description de la variabilité architecturale. Dans cette ADL les services qui peuvent constituer l’architecture, les éléments de contexte dont les changements d’état sont à l’origine des changements architecturaux, les variantes des éléments architecturaux sélectionnées en fonction des états des éléments de contexte et le comportement architectural dynamique sont ainsi spécifiés de façon modulaire<br>Service Oriented Architecture (SOA) is an architectural design paradigm which facilitates building and composing flexible, extensible and reusable service-oriented assets. These latter are encapsulated behind well-defined and published interfaces that can be dynamically discovered by third-party services. Before the advent of SOA, several software systems were developed using older technologies. Many of these systems still afford a business value, however they suffer from evolution and maintenance problems. It is advantageous to modernize those software systems towards service-based ones. In this sense, several re-engineering techniques propose migrating object-oriented applications towards SOA. Nonetheless, these approaches rely on ad-hoc criteria to correctly identify services in object-oriented legacy source code.Besides, one of the most distinguishing features of a service-oriented application is the ability to dynamically reconfigure and adjust its behavior to cope with changing environment during execution. However, in existing architecture description languages handling this aspect, reconfiguration rules are represented in an ad-hoc manner; reconfiguration scenarios are often implicit. This fact hinders a full management of dynamic reconfiguration at architecture level. Moreover, it constitutes a challenge to trace dynamic reconfiguration description/management at different levels of abstraction.In order to overcome the aforementioned problems, our contributions are presented in two axes: First, in the context of migrating legacy software towards SOA, we propose a service identification approach based on a quality measurement model, where service characteristics are considered, refined to measurable metrics in order to measure the semantic correctness of identified services. The second axis is dedicated to an Architecture Description Language (ADL) proposition that describes a variant-rich service-based architecture. In this modular ADL, dynamic reconfigurations are specified at architecture level. Moreover, the description is enriched with context and variability information, in order to enable a variability-based self-reconfiguration of architecture in response to context changes at runtime
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Zakula, Tea. "Heat pump simulation model and optimal variable-speed control for a wide range of cooling conditions." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59209.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2010.<br>"June 2010."<br>Includes bibliographical references (p. 127-129).<br>The steady-state air-to-air heat pump model presented in this thesis was developed from the first principles. The main objective was to develop a heat pump model that can be used as a part of larger simulation models, and that will make a connection between simple models that do not describe equipment behavior accurately enough and complicated models that are computationally very expensive. The model consists of the evaporator, compressor and condenser sub-model, each modeling the steady-state behavior of a particular component. To confirm the model accuracy, simulation results are compared with the experimental data from the Mitsubishi "Mr. Slim"® heat pump. The reported COP prediction errors are up to 20% under-prediction when the evaporating temperature is more than 2 K under-predicted, and 10% when the evaporating temperatures are more accurately predicted (less then 2K underpredicted). The model is strongly sensitive on the evaporator temperature prediction errors, since they influence the compressor inlet density. A grid search optimization algorithm is used to find the heat pump optimal performance map. The map defines the optimal evaporator fan speed, condenser fan speed and compressor speed needed to achieve the lowest total power consumption for the given cooling rate, ambient and zone temperature.<br>by Tea Zakula.<br>S.M.
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Padma, Prasad Boopal. "A Reconfigurable FFT Architecture for Variable Length and Multi-Streaming WiMax Wireless OFDM Standards." Thesis, Linköpings universitet, Elektroniksystem, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-72983.
Full textAbstract:
This paper presents a reconfigurable FFT architecture for variable length andmultistreaming WiMax wireless standard. The architecture processes 1 streamof 2048-pt FFT, up to 2 streams of 1024-pt FFT or up to 4 streams of 512-ptFFT. The architecture consists of 11 SDF pipelined stages and radix-2 butterflyis calculated in each stage. The sampling frequency of the system is varied inaccordance with FFT length. The wordlength and buffer length in each stage isconfigurable depending on the FFT length. Latch-free clock gating technique isused to reduce power consumption.The architecture is synthesized for Virtex-6 XCVLX760 FPGA. Experimentalresults show that the architecture achieves the throughput as required by theWiMax standard and the design has additional features compared to the previousapproaches. The design used 1% of the total available FPGA resources andmaximum clock frequency of 313.67 MHz was achieved.
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Taffo, Tiam Raoul. "Modèles opérationnels de processus métier et d'exigences variables pour le développement de lignes de produits logiciels." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS268.
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Toute institution concernée par le développement de logiciels, qu’il s’agisse d’un éditeur ou d’un organisme de services, doit faire face au challenge de compétitivité : “ faire de l’économie, un «objet de première classe» en génie logiciel ”. Cet impératif de penser l’économie du logiciel, s’est traduit par l’objectif d’obtenir une meilleure maîtrise sur la productivité du développeur. La Réutilisation Logicielle (Software Reuse) est un moyen privilégié d’augmenter cette productivité, en particulier quand elle est systématisée. Deux types d’activités doivent être considérés pour améliorer la réutilisation logicielle, le développement pour la réutilisation (development for reuse) et le développement par la réutilisation (development by reuse). Plusieurs solutions ont été proposées pour contribuer au développement pour la réutilisation. L’approche lignes de produits se distingue par sa contribution au développement par la réutilisation, à travers l’assistance et l’automatisation de la sélection, la configuration, et la dérivation de nouveaux produits. Néanmoins, malgré que cette approche a positionné la réutilisation comme activité centrale dans son processus de développement, celle-ci reste difficile à réaliser dans beaucoup de situations. Par exemple, en raison de l’absence de spécification ou gestion de la variabilité qui peut se manifester dans chacun des artefacts de toutes les étapes du cycle de développement. Dans ce cadre, la problématique générale de cette thèse CIFRE consiste en l’industrialisation d’une usine logicielle par la systématisation de la réutilisation dans chacune de ses étapes et la maximisation de l’automatisation des transitions entre étapes. Afin de mieux supporter l’agilité des environnements métier, notre premier objectif est la spécification de la variabilité au sein des modèles de processus métier, de sorte que les modèles conçus soient directement utilisables dans les usines logicielles. Notre second objectif consiste à introduire la spécification de la variabilité lors de l'ingénierie des exigences permettant ainsi de systématiser leur réutilisation, et l’établissement des liens de traçabilité avec les modèles de processus métier variables précédents. Ainsi, un modèle d’architecture logicielle (orientée services) peut être généré au sein de l'usine logicielle, comme implémentation des processus métier modélisés précédemment et dans le respect des exigences spécifiées<br>Any organization involved in software engineering has to deal with reduction of production time and cost, in order to face the competitiveness challenge. This imperative of thinking the software economy resulted in the goal of getting better control on developer productivity. Software Reuse is a preferred way to increase the productivity, particularly when it is systematized. Two types of activities should be considered to improve software reuse, development for reuse and development by reuse. Several solutions have been proposed to contribute and improve development for reuse. For its part, product line approach is distinguished by its contribution to development by reuse through support and automation of selection, configuration, and derivation of new products. However, although this approach has positioned reuse as a core activity in its engineering process, it remains difficult to realize it in many situations. For example, due to lack of specification or management of variability which may occur in each artifacts from all steps of the engineering process. In this context, the general issue of this thesis consists in industrialization of software product line, by the contribution to systematization of reuse in each steps and automation of transitions between those steps. To better support the business agility, our first goal is the specification of variability within business process models, in order to make them directly usable into software factory. Our second goal is to introduce variability specification into requirements engineering, enabling systematic reuse of requirements models and establishing traceability links with previous models of variable business processes. Thus, an architecture model (service oriented) can be generated in software factory, as implementation of modeled business processes with compliance to specified requirements
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Gault, Gregory John 1959. "Predictor variables of public perceptions and preferences for landscape planning and management." Thesis, The University of Arizona, 1997. http://hdl.handle.net/10150/278625.
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Landscape perception research has attempted to explain how people see and perceive landscapes, as well as, why people tend prefer some landscapes over others. An understanding of public perceptions and preferences is important for making appropriate decisions in the planning and management of our landscapes. Landscape perception research has focused on four major paradigms--expert, psychophysical, cognitive, and experiential--and has shown a wide variety of variables related to the landscape perceptions and preferences of the public. A comprehensive review of journal literature published over the last fifteen years revealed a total of 32 variables that, through empirical study, have been found to be important predictors of people's preferences for landscape. These important predictor variables are grouped into five categories and characterized to assist planners, landscape managers, and decision-makers in selecting appropriate variables for landscape assessment and evaluation. Recommendations for selecting predictor variables are provided.
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DeSimone, Mark. "A standard simulation testbed for the evaluation of control algorithms & strategies related to variable air volume HVAC systems." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/37035.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1995.<br>Includes bibliographical references.<br>The parameters for a dynamic, computer simulation model were developed. The parameters characterize the physical and geometric properties of a building shell, the internal and external building loads, the buildings secondary systems, and the plant or primary energy source. The purpose of the model is to provide a standard testbed for the evaluation of control algorithms and strategies related to variable air volume HVAC systems. This work was conducted in collaboration with, and under subcontract to Loughborough University of Technology, Loughborough England. The prototype building is a four level commercial, multi-use building and activities in the building include classroom / educational space professorial and student offices, and office / administrative. The building contains three air-handling units; one unit and the volume it serves provides the basis for the testbed. The model volume is divided into thirty four zones, each with its own single duct, pressure independent V A V terminal box with hot water reheat. A perimeter heating system, composed of hot water convectors, radiators and baseboard heaters, augments the room comfort control system. Local loop control in the mechanical room and for all but one of the zones is micro-processor based pneumatic actuated. One prototype direct digital control terminal box system was in use for a classroom zone. DDC control systems and motor driven actuators were substituted in the testbed for the pneumatic equipment. Zoning in the volume was redistributed into six zones; the supply and return duct system was redesigned to accommodate the simplified zone configuration. A survey was conducted to determine the availability of sub-one-hour solar and collateral weather data. Historically, data in this frequency has been collected, but, not reported. A relatively new program called the Automated Surface Observing System (AS OS) and operated by the National Oceanic and Atmospheric Administration will eventually provide weather data at varying intervals down to one minute, depending on the type of information required. Daily and monthly summaries are available, however, resolution is reduced and averaged to one hour intervals. The SOLMET program, under the auspices of DOE, provides archived solar data at one hour intervals on CD Rom. Data is collected from twenty-six stations distributed around the United States. Collateral weather data is also provided with the solar data and for simulation purposes the SOLMET data provides the best resource.<br>by Mark DeSimone.<br>M.S.
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Marvie, Jean-Eudes. "Visualisation Interactive d'Environnements Virtuels Complexes à travers des Réseaux et sur des Machines à Performances Variables." Rennes, INSA, 2004. http://www.theses.fr/2004ISAR0011.
Full textAbstract:
Les solutions dédiées à la visualisation interactive d'environnements virtuels via des réseaux sont multiples. Celles-ci sont souvent dédiées à des problèmes particuliers et les architectures employées permettent rarement de les utiliser conjointement. Notre proposition, Magellan, fournit un cadre de travail ainsi qu'une application répartie générique permettant, grâce à une approche orientée composants, l'intégration aisée de ces solutions. Elle permet à l'utilisateur de développer librement, pour son composant, les modes de télé-chargement progressifs, la répartition des états et des schémas d'exécution ainsi que le mode de rendu adaptatif. Nous proposons ensuite une solution permettant d'effectuer le télé-chargement progressif et la visualisation de décors architecturaux ou urbains, ainsi que deux optimisations locales: l'une permettant la gestion adaptative de textures progressives et l'autre utilisant des modèles procéduraux pour la visualisation de vastes environnements urbains<br>Solutions dedicated to remote visualisation of virtual environnements are multiple. They are most often dedicated to specific problems and the different architectures that are proposed are rarely used jointly. Our solution, Magellan, provides a framework as well as a generic distributed application that allows, thanks to a component approach, the integration of these solutions. It allows the user to develop freely, for its component, the streaming modes, the distributions of the states and execution schemas as well as the adaptive rendering mode. We then propose a streaming solution dedicated to remote visualisation of architectural and urban sceneries. We finally present two new local optimisations: the first one handles the adaptive management of progressive texture maps and the other one makes use of procedural geometric models to optimize the remote visualisation of large urban models
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Marques, Nicolas. "Méthodologie et architecture adaptative pour le placement efficace de tâches matérielles de tailles variables sur des partitions reconfigurables." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0139/document.
Full textAbstract:
Les architectures reconfigurables à base de FPGA sont capables de fournir des solutions adéquates pour plusieurs applications vu qu'elles permettent de modifier le comportement d'une partie du FPGA pendant que le reste du circuit continue de s'exécuter normalement. Ces architectures, malgré leurs progrès, souffrent encore de leur manque d'adaptabilité fasse à des applications constituées de tâches matérielles de taille différente. Cette hétérogénéité peut entraîner de mauvais placements conduisant à une utilisation sous-optimale des ressources et par conséquent une diminution des performances du système. La contribution de cette thèse porte sur la problématique du placement des tâches matérielles de tailles différentes et de la génération efficace des régions reconfigurables. Une méthodologie et une couche intermédiaire entre le FPGA et l'application sont proposées pour permettre le placement efficace des tâches matérielles de tailles différentes sur des partitions reconfigurables de taille prédéfinie. Pour valider la méthode, on propose une architecture basée sur l'utilisation de la reconfiguration partielle afin d'adapter le transcodage d'un format de compression vidéo à un autre de manière souple et efficace. Une étude sur le partitionnement de la région reconfigurable pour les tâches matérielles de l'encodeur entropique (CAVLC / VLC) est proposée afin de montrer l'apport du partitionnement. Puis une évaluation du gain obtenu et du surcoût de la méthode est présentée<br>FPGA-based reconfigurable architectures can deliver appropriate solutions for several applications as they allow for changing the performance of a part of the FPGA while the rest of the circuit continues to run normally. These architectures, despite their improvements, still suffer from their lack of adaptability when confronted with applications consisting of variable size material tasks. This heterogeneity may cause wrong placements leading to a sub-optimal use of resources and therefore a decrease in the system performances. The contribution of this thesis focuses on the problematic of variable size material task placement and reconfigurable region effective generation. A methodology and an intermediate layer between the FPGA and the application are proposed to allow for the effective placement of variable size material tasks on reconfigurable partitions of a predefined size. To approve the method, we suggest an architecture based on the use of partial reconfiguration in order to adapt the transcoding of one video compression format to another in a flexible and effective way. A study on the reconfigurable region partitioning for the entropy encoder material tasks (CAVLC / VLC) is proposed in order to show the contribution of partitioning. Then an assessment of the gain obtained and of the method additional costs is submitted
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Marques, Nicolas. "Méthodologie et architecture adaptative pour le placement efficace de tâches matérielles de tailles variables sur des partitions reconfigurables." Electronic Thesis or Diss., Université de Lorraine, 2012. http://www.theses.fr/2012LORR0139.
Full textAbstract:
Les architectures reconfigurables à base de FPGA sont capables de fournir des solutions adéquates pour plusieurs applications vu qu'elles permettent de modifier le comportement d'une partie du FPGA pendant que le reste du circuit continue de s'exécuter normalement. Ces architectures, malgré leurs progrès, souffrent encore de leur manque d'adaptabilité fasse à des applications constituées de tâches matérielles de taille différente. Cette hétérogénéité peut entraîner de mauvais placements conduisant à une utilisation sous-optimale des ressources et par conséquent une diminution des performances du système. La contribution de cette thèse porte sur la problématique du placement des tâches matérielles de tailles différentes et de la génération efficace des régions reconfigurables. Une méthodologie et une couche intermédiaire entre le FPGA et l'application sont proposées pour permettre le placement efficace des tâches matérielles de tailles différentes sur des partitions reconfigurables de taille prédéfinie. Pour valider la méthode, on propose une architecture basée sur l'utilisation de la reconfiguration partielle afin d'adapter le transcodage d'un format de compression vidéo à un autre de manière souple et efficace. Une étude sur le partitionnement de la région reconfigurable pour les tâches matérielles de l'encodeur entropique (CAVLC / VLC) est proposée afin de montrer l'apport du partitionnement. Puis une évaluation du gain obtenu et du surcoût de la méthode est présentée<br>FPGA-based reconfigurable architectures can deliver appropriate solutions for several applications as they allow for changing the performance of a part of the FPGA while the rest of the circuit continues to run normally. These architectures, despite their improvements, still suffer from their lack of adaptability when confronted with applications consisting of variable size material tasks. This heterogeneity may cause wrong placements leading to a sub-optimal use of resources and therefore a decrease in the system performances. The contribution of this thesis focuses on the problematic of variable size material task placement and reconfigurable region effective generation. A methodology and an intermediate layer between the FPGA and the application are proposed to allow for the effective placement of variable size material tasks on reconfigurable partitions of a predefined size. To approve the method, we suggest an architecture based on the use of partial reconfiguration in order to adapt the transcoding of one video compression format to another in a flexible and effective way. A study on the reconfigurable region partitioning for the entropy encoder material tasks (CAVLC / VLC) is proposed in order to show the contribution of partitioning. Then an assessment of the gain obtained and of the method additional costs is submitted
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Mu’azu, Abbas Ibrahim. "Sustainable design strategy : assessment of the impact of design variables on energy consumption of office buildings in Abuja, Nigeria." Thesis, University of Portsmouth, 2015. https://researchportal.port.ac.uk/portal/en/theses/sustainable-design-strategy(93be196e-2d81-4284-8997-c67ea42cc942).html.
Full textAbstract:
Buildings account for about 40% of global energy consumption and contribute 30% of all CO2 emissions. This research project investigated extant office building development in Abuja, Nigeria with a view to establishing typical energy performances. Energy end uses were critically analysed to identify energy saving potentials. The research evaluated design variables that can be used to facilitate low energy building design and determine enhanced performances in the Nigerian and regional context. The research initially adopted a case study approach that involved fieldwork surveys and walk-through energy audits in which 22 office buildings were investigated belonging to four performance based categories developed for the research. Also, based on a building inventory survey form developed for this research, building information obtained included the buildings physical components, energy use management and energy end uses. This enabled typical energy performances of the office building categories to be deduced using three widely used indicators; the Energy Use Index (EUI), the Energy Cost Index (ECI) and the Carbon Emission Index (CEI). Also, disaggregated energy end use showed an average distribution pattern of air conditioning, lighting, equipment and building services in the ratio 59%, 15%, 43% and 4% respectively. This showed the potentials of energy savings by reducing cooling load. With the aid of computer based simulation (using IES-VE software) the research further evaluated the impacts of nine architectural design variables (identified from design guidance for low energy buildings as well as design recommendations for tropical climates) on building energy consumption using simplified models of the case study office building categories. From all these, an impact hierarchy of the design variables was deduced and the appropriate low energy design strategies were developed. This showed potential energy savings of up to 20% was achievable. Also benchmarks for enhanced building performance targets for all the categories were proposed for the furtherance of a sustainable built environment in a developing world context.
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Cuenot, Jérémy. "Architectures d'alimentation et de commande des actionneurs haute-vitesse connectés aux réseaux avioniques à tension variable." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0263/document.
Full textAbstract:
La révolution technologique majeure des nouveaux aéronefs repose sur une électrification intensive de nombreux constituants de l'appareil et le fait que la vitesse des génératrices électriques n'est plus fixe mais variable. Cette nouvelle manière de générer la puissance électrique engendre des variations de tension sur les réseaux DC. De plus, pour accroître la compacité des Machines Synchrones à Aimants Permanents (MSAP) à puissance donnée, on augmente autant que possible leur vitesse d'entrainement, en les associant pour certaines applications à des réducteurs mécaniques. La variation du niveau de tension du bus DC alimentant une MSAP haute vitesse implique son dimensionnement afin d'assurer sa contrôlabilité sur toute la plage de vitesse reportant d'importantes contraintes sur l'onduleur de tension. Pour pallier ce problème, une solution consiste à intercaler un convertisseur DC/DC entre le filtre d'entrée et l'onduleur de tension pour maintenir la tension DC d'entrée de l'onduleur à une valeur adaptée au fonctionnement de la MSAP et optimiser son dimensionnement. Cependant, cette solution augmente l'ordre du système, ce qui accroît la complexité de son contrôle, accentuée par les contraintes liées à la nature haute-fréquence des MSAP considérées.Les travaux menés dans cette thèse concernent l'étude, l'optimisation et le contrôle des structures d'alimentation des actionneurs haute vitesse connectés aux réseaux DC avioniques à tension variable. Il en résulte que pour les applications avioniques considérées, ces architectures d'alimentation intégrant un convertisseur DC/DC supplémentaire permettent de réduire sa masse et son volume sans dégrader le rendement global de la chaîne de conversion notamment avec les convertisseurs à source impédante qui permettent de supprimer structurellement les ondulations de courant en entrée du convertisseur. De plus, des stratégies de commande Pulse Amplitude Modulation employées avec des architectures de contrôle non-linéaires (platitude, passivité) permettent d'assurer le contrôle de ces MSAP haute-vitesse tout en assurant leur stabilité sur toute la plage de fonctionnement<br>The main technological revolution of the new aircrafts is based on intensive electrification of many components of the aircraft. Moreover, the speed of electrical generators is no longer fixed but variable. This new way of generating electrical power generates voltage variations on DC networks. Besides, to increase the compactness of the Permanent Magnet Synchronous Machines (PMSM) at a given power, their mechanical speed is increased as much as possible by combining them with mechanical reducers for certain applications. The variation of the voltage level of the DC bus supplying a high-speed PMSM implies its sizing in order to ensure its controllability over the entire speed range which carries significant stresses on the Voltage Source Inverter (VSI). To solve this problem, one solution consists in adding an extra DC / DC converter between the input filter and the VSI to maintain the inverter input voltage at a value adapted to the operating point of the PMSM and to optimize its dimensioning. However, this solution increases the order of the system, which increases the complexity of its control, accentuated by the constraints related to the high-frequency nature of the PMSMs considered. The work carried out in this thesis concerns the study, the optimization and the control of the power supply architecture of the high-speed actuators connected to variable-voltage avionic DC networks. As a result, for the avionics applications considered, these power supply architectures integrating an additional DC / DC converter make it possible to reduce the mass and the volume of the power supply structure without degrading the overall efficiency of the conversion chain, in particular by using the impedance-source converters which allow to cancel the DC input current ripples. In addition, Pulse Amplitude Modulation (PAM) control strategies used with non-linear control architectures (flatness, passivity) make it possible to control these high-speed PMSMs while ensuring their stability over the entire operating range
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Cuenot, Jérémy. "Architectures d'alimentation et de commande des actionneurs haute-vitesse connectés aux réseaux avioniques à tension variable." Electronic Thesis or Diss., Université de Lorraine, 2017. http://www.theses.fr/2017LORR0263.
Full textAbstract:
La révolution technologique majeure des nouveaux aéronefs repose sur une électrification intensive de nombreux constituants de l'appareil et le fait que la vitesse des génératrices électriques n'est plus fixe mais variable. Cette nouvelle manière de générer la puissance électrique engendre des variations de tension sur les réseaux DC. De plus, pour accroître la compacité des Machines Synchrones à Aimants Permanents (MSAP) à puissance donnée, on augmente autant que possible leur vitesse d'entrainement, en les associant pour certaines applications à des réducteurs mécaniques. La variation du niveau de tension du bus DC alimentant une MSAP haute vitesse implique son dimensionnement afin d'assurer sa contrôlabilité sur toute la plage de vitesse reportant d'importantes contraintes sur l'onduleur de tension. Pour pallier ce problème, une solution consiste à intercaler un convertisseur DC/DC entre le filtre d'entrée et l'onduleur de tension pour maintenir la tension DC d'entrée de l'onduleur à une valeur adaptée au fonctionnement de la MSAP et optimiser son dimensionnement. Cependant, cette solution augmente l'ordre du système, ce qui accroît la complexité de son contrôle, accentuée par les contraintes liées à la nature haute-fréquence des MSAP considérées.Les travaux menés dans cette thèse concernent l'étude, l'optimisation et le contrôle des structures d'alimentation des actionneurs haute vitesse connectés aux réseaux DC avioniques à tension variable. Il en résulte que pour les applications avioniques considérées, ces architectures d'alimentation intégrant un convertisseur DC/DC supplémentaire permettent de réduire sa masse et son volume sans dégrader le rendement global de la chaîne de conversion notamment avec les convertisseurs à source impédante qui permettent de supprimer structurellement les ondulations de courant en entrée du convertisseur. De plus, des stratégies de commande Pulse Amplitude Modulation employées avec des architectures de contrôle non-linéaires (platitude, passivité) permettent d'assurer le contrôle de ces MSAP haute-vitesse tout en assurant leur stabilité sur toute la plage de fonctionnement<br>The main technological revolution of the new aircrafts is based on intensive electrification of many components of the aircraft. Moreover, the speed of electrical generators is no longer fixed but variable. This new way of generating electrical power generates voltage variations on DC networks. Besides, to increase the compactness of the Permanent Magnet Synchronous Machines (PMSM) at a given power, their mechanical speed is increased as much as possible by combining them with mechanical reducers for certain applications. The variation of the voltage level of the DC bus supplying a high-speed PMSM implies its sizing in order to ensure its controllability over the entire speed range which carries significant stresses on the Voltage Source Inverter (VSI). To solve this problem, one solution consists in adding an extra DC / DC converter between the input filter and the VSI to maintain the inverter input voltage at a value adapted to the operating point of the PMSM and to optimize its dimensioning. However, this solution increases the order of the system, which increases the complexity of its control, accentuated by the constraints related to the high-frequency nature of the PMSMs considered. The work carried out in this thesis concerns the study, the optimization and the control of the power supply architecture of the high-speed actuators connected to variable-voltage avionic DC networks. As a result, for the avionics applications considered, these power supply architectures integrating an additional DC / DC converter make it possible to reduce the mass and the volume of the power supply structure without degrading the overall efficiency of the conversion chain, in particular by using the impedance-source converters which allow to cancel the DC input current ripples. In addition, Pulse Amplitude Modulation (PAM) control strategies used with non-linear control architectures (flatness, passivity) make it possible to control these high-speed PMSMs while ensuring their stability over the entire operating range
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Busquere, Jean-Pierre. "Développement et intégration de MEMS RF dans les architectures d'amplificateur faible bruit reconfigurables." Phd thesis, INSA de Toulouse, 2005. http://tel.archives-ouvertes.fr/tel-00446353.
Full textAbstract:
De nos jours, les modules hyperfréquences doivent de plus en plus présenter non seulement des performances électriques sans cesse améliorées mais aussi des fonctionnalités nouvelles ainsi que de fortes compacités, et des coûts de fabrication les plus réduits possibles. Les perspectives attractives apportées par l'utilisation des technologies SiGe permettent aujourd'hui d'envisager la réalisation de circuits intégrés jusqu'aux fréquences millimétriques tandis que, dans le même temps, le développement rapide des technologies MEMS RF permet de réaliser de nouvelles fonctionnalités au niveau des circuits radiofréquences. Dans la première partie de ce mémoire, nous proposons un concept d'amplificateur faible bruit reconfigurable en fréquence (HIPERLAN et BLUETOOTH), basé sur l'association des technologies SiGe et MEMS RF. Conception et performances simulées des amplificateurs élaborés à la fois pour une intégration monolithique et une autre par fil de souduresont alors présentées. La deuxième partie est entièrement consacrée à la conception et la réalisation des MEMS RF suivant les spécifications que nous avons établi lors de la première partie. Conception, réalisation et caractérisation des structures MEMS RF sont présentés, pour aboutir à l'obtention de performances situées à l'état de l'art pour des capacités autant séries que parallèles. La dernière partie, traite de l'assemblage entre les deux technologies MEMS et SiGe, avec trois études réalisées sur une intégration monolithique dite « Above IC », un assemblage par fils de soudure et un assemblage Flip Chip. Au final, des modules de test assemblés sont présentés et caractérisés
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Sander, Samuel Thomas. "Retargetable compilation for variable-grain data-parallel execution in image processing." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/13850.
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Marques, Nicolas. "Méthodologie et architecture adaptative pour le placement e cace de tâches matérielles de tailles variables sur des partitions recongurables." Phd thesis, Université de Lorraine, 2012. http://tel.archives-ouvertes.fr/tel-00823585.
Full textAbstract:
Les architectures reconfigurables à base de FPGA sont capables de fournir des solutions adéquates pour plusieurs applications vu qu'elles permettent de modifier le comportement d'une partie du FPGA pendant que le reste du circuit continue de s'exécuter normalement. Ces architectures, malgré leurs progrès, souffrent encore de leur manque d'adaptabilité face à des applications constituées de tâches matérielles de taille différente. Cette hétérogénéité peut entraîner de mauvais placements conduisant à une utilisation sous-optimale des ressources et par conséquent une diminution des performances du système. La contribution de cette thèse porte sur la problématique du placement des tâches matérielles de tailles différentes et de la génération efficace des régions reconfigurables. Une méthodologie et une couche intermédiaire entre le FPGA et l'application sont proposées pour permettre le placement efficace des tâches matérielles de tailles différentes sur des partitions reconfigurables de taille prédéfinie. Pour valider la méthode, on propose une architecture basée sur l'utilisation de la reconfiguration partielle afin d'adapter le transcodage d'un format de compression vidéo à un autre de manière souple et efficace. Une étude sur le partitionnement de la région reconfigurable pour les tâches matérielles de l'encodeur entropique (CAVLC / VLC) est proposée afin de montrer l'apport du partitionnement. Puis une évaluation du gain obtenu et du surcoût de la méthode est présentée.
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Riou, Cécile. "Architectures et apports de systèmes de vision light-field pour la vision par ordinateur." Thesis, Mulhouse, 2017. http://www.theses.fr/2017MULH0498/document.
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Cette thèse traite des caméras light-field en tant que caméra ayant des capacités 3D. Les images brutes, acquises avec ces systèmes, sont généralement inexploitables directement. L’obstacle majeur concernant l'utilisation de ces caméras réside dans la complexité du traitement des images acquises. Cette thèse vise à dépasser ces limitations en s'intéressant aux dispositifs multi-vues et multi-caméras. De plus, comme l'un des domaines d'application envisagé est la vision industrielle, les images sont acquises en lumière naturelle afin de conserver la possibilité d'effectuer des traitements conventionnels par vision sur les images. Le travail de thèse repose sur trois axes : l'étude et la conception optique de systèmes light-field multi-caméras et multi-vues, le calibrage de ces dispositifs et le développement d’algorithmes et enfin leur mise en application pour montrer les intérêts de ces caméras dans divers domaines<br>This thesis deals with light-field cameras as cameras having 3D capacities. The raw images. acquired with these systems, are generally unusable directly. The main obstacle about their use lies in the complex processing of the recorded images. This thesis aims to overcome these limitations by focusing on multi-views and multi-camera devices. Morcover, as one of the application domains is the industrial vision, the images are acquired in natural lightning in order to conserve the possibility to make conventional treatments by vision on the images. The work is based on three axis: the study and'the optical desien of light-field systems, the calibration of these devices and the development of algorithms to show the intercsts of these cameras in various fields
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Bocco, Andrea. "A variable precision hardware acceleration for scientific computing." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI065.
Full textAbstract:
La plupart des unités matérielles arithmétiques à virgule flottante (en anglais Floating-Point, FP) prennent en charge les formats et les opérations spécifiés dans le standard IEEE 754. Ces formats ont une longueur en bits fixe et sont définis sur 16, 32, 64 et 128 bits. Cependant, certaines applications, par exemple les solveurs de systèmes linéaires, ou encore la géométrie computationnelle, pourraient bénéficier de formats différents pour représenter les flottants sur différentes tailles, avec différents compromis entre les champs des exposant et mantisse. La classe des formats de précision variable (en anglais Variable Precision, VP) répond à ces exigences. L'objectif de cette recherche est de proposer un système de calcul VP capable d'augmenter la précision ou l'efficacité de calcul des problèmes en offrant une granularité plus fine des opérations FP. Ce travail propose un système de calcul FP à VP basé sur trois couches de calcul. La couche externe prend en charge les formats IEEE existants pour les variables d'entrée et de sortie. La couche interne utilise des registres de longueur variable pour les opérations de multiplication-addition à haute précision. Enfin, une couche intermédiaire prend en charge le chargement et le stockage des résultats intermédiaires dans la mémoire cache sans perte de précision, avec un format VP réglable dynamiquement. Le support des formats différents entre la représentation interne et le stockage en mémoire proche permets d'envisager des "grands vecteurs" en VP avec la possibilité d’avoir une haute précision de calcul dans la couche interne. L'unité à VP exploite le format FP UNUM de type I, en proposant des solutions pour remédier à certains de ses difficultés intrinsèques, telles que la latence variable de l'opération interne et l'empreinte mémoire variable des variables intermédiaires. Contrairement aux formats définis par IEEE 754, dans l'UNUM de type I, la taille d'un nombre est stockée dans la représentation elle-même. Ce travail propose une architecture de jeu d'instructions pour programmer le système de calcul VP qui suit la structure des couches de calcul susmentionnée. L'objectif de cette ISA est d'établir une séparation claire entre le format de la mémoire et celui à l'intérieur du coprocesseur. Avec cette ISA, le programmeur peut écrire des programmes VP de telle sorte que les instructions assembleur générées soient décorrélées de la taille et des formats des variables du programme. Cette décorrélation se fait en stockant les informations sur la taille, la précision et le format des variables du programme dans des registres d'état dédiés, à l'intérieur de l'unité VP. Ces registres d’état sont utilisés par une unité de chargement et de stockage (Load and Store Unit, LSU), étroitement couplée à l'unité de calcul VP, qui prend en charge la conversion des données entre les couches de calcul<br>Most of the Floating-Point (FP) hardware units support the formats and the operations specified in the IEEE 754 standard. These formats have fixed bit-length. They are defined on 16, 32, 64, and 128 bits. However, some applications, such as linear system solvers and computational geometry, benefit from different formats which can express FP numbers on different sizes and different tradeoffs among the exponent and the mantissa fields. The class of Variable Precision (VP) formats meets these requirements. This research proposes a VP FP computing system based on three computation layers. The external layer supports legacy IEEE formats for input and output variables. The internal layer uses variable-length internal registers for inner loop multiply-add. Finally, an intermediate layer supports loads and stores of intermediate results to cache memory without losing precision, with a dynamically adjustable VP format. The VP unit exploits the UNUM type I FP format and proposes solutions to address some of its pitfalls, such as the variable latency of the internal operation and the variable memory footprint of the intermediate variables. Unlike IEEE 754, in UNUM type I the size of a number is stored within its representation. The unit implements a fully pipelined architecture, and it supports up to 512 bits of precision, internally and in memory, for both interval and scalar computing. The user can configure the storage format and the internal computing precision at 8-bit and 64-bit granularity This system is integrated as a RISC-V coprocessor. The system has been prototyped on an FPGA (Field-Programmable Gate Array) platform and also synthesized for a 28nm FDSOI process technology. The respective working frequencies of FPGA and ASIC implementations are 50MHz and 600MHz. Synthesis results show that the estimated chip area is 1.5mm2, and the estimated power consumption is 95mW. The experiments emulated in an FPGA environment show that the latency and the computation accuracy of this system scale linearly with the memory format length set by the user. In cases where legacy IEEE-754 formats do not converge, this architecture can achieve up to 130 decimal digits of precision, increasing the chances of obtaining output data with an accuracy similar to that of the input data. This high accuracy opens the possibility to use direct methods, which are more sensitive to computational error, instead of iterative methods, which always converge. However, their latency is ten times higher than the direct ones. Compared to low precision FP formats, in iterative methods, the usage of high precision VP formats helps to drastically reduce the number of iterations required by the iterative algorithm to converge, reducing the application latency of up to 50%. Compared with the MPFR software library, the proposed unit achieves speedups between 3.5x and 18x, with comparable accuracy
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Charron, Gwenaël. "Contribution à la commande bilatérale et à la gestion des configurations singulières pour le suivi de trajectoire d'un système télé-opéré : application à la télé-échographie robotisée." Thesis, Orléans, 2011. http://www.theses.fr/2011ORLE2048.
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Les objectifs scientifiques de ces travaux de thèse reposent sur le développement d’une plateforme robotisée pour la réalisation d’un acte d’échographie à distance. Les contraintes de cet acte médical à distance ont conduit à la réalisation d’un robot sériel à cinq degrés de liberté. La présence d’une singularité centrale a conditionné la proposition d’une loi de commande cinématique pondérée dont l’objectif est d’assurer le meilleur suivi du geste médical et le maintien du plan ultrasonore à l’approche de la singularité. Cette loi de commande est basée sur une combinaison linéaire de l’inverse et de la pseudo-inverse de la matrice jacobienne de base du robot. Les réseaux haut débit sont nécessaires pour l’utilisation de la plateforme télé-opérée afin d’assurer une très bonne qualité des images échographiques reçues par l’expert. Cependant, ils sont soumis à de forts délais de transmission perturbant la stabilité du système robotique et le ressenti des interactions robot/patient. L’architecture de commande bilatérale passive proposée est basée sur le formalisme des variables d’ondes, et inclut les structures mécatroniques des postes maître et esclave, et les caractéristiques des liens de communication. Cette approche garantit, quels que soient les délais de transmission, la stabilité et la transparence de la plateforme télé-opérée. La prise en compte de l’ensemble des caractéristiques mécatroniques de la chaîne télé-opérée a permis de proposer une méthodologie pour l’adaptation d’impédance afin d’améliorer le rendu haptique au niveau du poste maître. Des expérimentations par satellite ont validé l’approche de la structure bilatérale et confirmé la stabilité et la transparence de la chaîne télé-opérée quels que soient les délais de communication<br>The scientific objectives of this PhD thesis work are based on the development of a robotic platform used to perform tele-echography act via satellite link. The constraints of the remote tele-echography procedure led to the development of a 5-DOF serial robot. The presence of a central singularity has conditioned the proposal of a weighted kinematic control law to ensure a better monitoring of medical procedure and ultrasonic plan when approaching the singularity. This control law is based on a linear combination of the inverse and pseudo-inverse of the Jacobian matrix. Broadband networks are required to provide high quality ultrasound images to the medical expert. However, they are subject to high transmission delays disrupting the stability of the robotic system and rendering of robot/patient interactions. The passive bilateral control architecture proposed is based on the wave variables approach ; it includes the mechatronic master and slave characteristics, and the communication links characteristics. This approach ensures stability and transparency of the tele-operated platform whatever the transmission time delay. A methodology for impedance matching taking into account the characteristics of mechatronic tele-operated chain has improved haptic rendering at the station master. Satellite experiments have validated the proposed wave variables bilateral structure and confirmed the stability and transparency of the tele-operated chain for any communication delays
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Häkkinen, J. (Juha). "Integrated RF building blocks for base station applications." Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:951426908X.
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Abstract
This thesis studies the level of performance achievable using today's standard IC processes in the integrated RF subcircuits of the modern GSM base station. The thesis concentrates on those circuit functions, i.e. I/Q modulators, variable gain amplifiers and frequency synthesizers, most relevant for integration in the base station environment as pinpointed by studying the receiver/transmitter architectures available today.
Several RF integrated circuits have been designed, fabricated and their level of performance measured. All main circuits were fabricated in a standard double-metal double-poly 1.2 and 0.8 μm BiCMOS process. Key circuit structures and their measured properties are: 90° phase shifter with ±1° phase error with VCC = 4.5…5.5 V and T = -10…+85 °C, I/Q modulator suitable for operation at output frequencies from 100 MHz to 1 GHz and baseband frequencies from 60 to 500 kHz (2.0 mm × 2.0 mm, 100 mA, 5.0 V) with LO suppression of 38 dBc and image rejection of 41 dBc, temperature compensated DC to 1.5 GHz variable gain amplifier (1.15 mm × 2.00 mm, 100 mA, 5.0 V) with a linear 50 dB gain adjustment range, maximum gain of 18.5 dB and gain variation of 1 dB up to 700 MHz over the whole operating conditions range of VCC = 4.5…5.5 V and T = -10…+85 °C, a complete bipolar semicustom synthesizer (90…122 mA, 5.0 V) and two complete full-custom BiCMOS synthesizer chips including all building blocks of a PLL-based synthesizer except for the voltage controlled oscillator and the loop filter. The synthesizers include circuit structures such as ∼2 GHz multi-modulus divider and low-noise programmable phase detector/charge pump (18.7 pA/√Hz at Iout = 500 μA) and have an exemplar phase noise performance of -110 dBc/Hz at 200 kHz offset.
One of the main problems of the integer-N PLL based synthesizer when used in a multichannel telecommunications system is the level of spurious signals at the output, when the synthesizer is optimised for fast frequency switching. Therefore, a method using only two current pulses to make the frequency step response of the loop faster, thus allowing a narrower loop bandwidth to be used for additional spur suppression, is proposed. The operation of the proposed speed-up method is analysed mathematically and verified by measurements of an existing RF-IC synthesizer operating at 800 MHz. Measurements show that simple current pulses can be used to speed up the channel switching of a practical RF synthesizer having a frequency step time in the tens of μs range. In the example, a 7.65 MHz frequency step was made seven times faster using the proposed method.
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Chenouard, Raphaël. "Résolution par satisfation de contraintes appliquée à l'aide à la décision en conception architecturale." Phd thesis, Ecole nationale supérieure d'arts et métiers - ENSAM, 2007. http://tel.archives-ouvertes.fr/tel-00482208.
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La conception architecturale de systèmes mécaniques et énergétiques permet d'étudier la faisabilité de concepts préalablement choisis pendant la phase de recherche de concepts. Elle fait partie de la phase de conception préliminaire et son achèvement vise à définir l'architecture globale qui sera étudiée pendant la phase de conception détaillée d'un produit. Les principales caractéristiques d'un produit (dimensions, choix de composants, de formes, de topologies ou de matériaux) sont alors fondamentales à ce stade de la conception. La conception architecturale nécessite aussi la prise en compte des comportements physiques et des interactions du produit, de ses composants et des milieux extérieurs, de critères économiques, environnementaux, etc. suivant les exigences du cahier des charges fonctionnel. Le concepteur définit un modèle mathématique exprimant cette connaissance liée au produit. Ce modèle peut être traité à l'aide d'un solveur de Problèmes de Satisfaction de Contraintes numériques (CSP). Ce type de solveur traite de manière générique des problèmes formulés à l'aide de contraintes, de variables et de domaines. Nous proposons de nouveaux algorithmes et de nouvelles heuristiques qui prennent en compte des besoins spécifiques au concepteur en conception préliminaire, comme : la classification des variables, les précisions relatives aux valeurs de certaines variables, les contraintes par morceaux. Les études de faisabilité de plusieurs systèmes mécaniques et énergétiques ont été réalisées avec succès. Les nouveaux algorithmes ont permis de diminuer significativement les temps de calculs, mais ils ont aussi permis d'améliorer la qualité des solutions calculées au regard des besoins du concepteur.
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Kodipyaka, Sumedha. "Reconfigurable architecture for h.264/avc variable block size motion estimation based on motion activity and adaptive search range." Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4636.
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Motion Estimation (ME) technique plays a key role in the video coding systems to achieve high compression ratios by removing temporal redundancies among video frames. Especially in the newest H.264/AVC video coding standard, ME engine demands large amount of computational capabilities due to its support for wide range of different block sizes for a given macroblock in order to increase accuracy in finding best matching block in the previous frames. We propose scalable architecture for H.264/AVC Variable Block Size (VBS) Motion Estimation with adaptive computing capability to support various search ranges, input video resolutions, and frame rates. Hardware architecture of the proposed ME consists of scalable Sum of Absolute Difference (SAD) arrays which can perform Full Search Block Matching Algorithm (FSBMA) for smaller 4x4 blocks. It is also shown that by predicting motion activity and adaptively adjusting the Search Range (SR) on the reconfigurable hardware platform, the computational cost of ME required for inter-frame encoding in H.264/AVC video coding standard can be reduced significantly. Dynamic Partial Reconfiguration is a unique feature of Field Programmable Gate Arrays (FPGAs) that makes best use of hardware resources and power by allowing adaptive algorithm to be implemented during run-time. We exploit this feature of FPGA to implement the proposed reconfigurable architecture of ME and maximize the architectural benefits through prediction of motion activities in the video sequences ,adaptation of SR during run-time, and fractional ME refinement. The implemented ME architecture can support real time applications at a maximum frequency of 90MHz with multiple reconfigurable regions. When compared to reconfiguration of complete design, partial reconfiguration process results in smaller bitstream size which allows FPGA to implement different configurations at higher speed.; The proposed architecture has modular structure, regular data flow, and efficient memory organization with lower memory accesses. By increasing the number of active partial reconfigurable modules from one to four, there is a 4 fold increase in data re-use. Also, by introducing adaptive SR reduction algorithm at frame level, the computational load of ME is reduced significantly with only small degradation in PSNR (0.1dB).<br>ID: 028732077; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2010.; Includes bibliographical references.<br>M.S.<br>Masters<br>Department of Electrical Engineering and Computer Science<br>Engineering and Computer Science
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Sun, Zhuo. "A Method and Tool for Finding Concurrency Bugs Involving Multiple Variables with Application to Modern Distributed Systems." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3896.
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Concurrency bugs are extremely hard to detect due to huge interleaving space. They are happening in the real world more often because of the prevalence of multi-threaded programs taking advantage of multi-core hardware, and microservice based distributed systems moving more and more applications to the cloud. As the most common non-deadlock concurrency bugs, atomicity violations are studied in many recent works, however, those methods are applicable only to single-variable atomicity violation, and don't consider the specific challenge in distributed systems that have both pessimistic and optimistic concurrency control. This dissertation presents a tool using model checking to predict atomicity violation concurrency bugs involving two shared variables or shared resources. We developed a unique method inferring correlation between shared variables in multi-threaded programs and shared resources in microservice based distributed systems, that is based on dynamic analysis and is able to detect the correlation that would be missed by static analysis. For multi-threaded programs, we use a binary instrumentation tool to capture runtime information about shared variables and synchronization events, and for microservice based distributed systems, we use a web proxy to capture HTTP based traffic about API calls and the shared resources they access including distributed locks. Based on the detected correlation and runtime trace, the tool is powerful and can explore a vast interleaving space of a multi-threaded program or a microservice based distributed system given a small set of captured test runs. It is applicable to large real-world systems and can predict atomicity violations missed by other related works for multi-threaded programs and a couple of previous unknown atomicity violation in real world open source microservice based systems. A limitation is that redundant model checking may be performed if two recorded interleaved traces yield the same partial order model.
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Esteveny, Laure. "Vers un actionnement sûr pour la radiologie interventionnelle robotisée." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAD015/document.
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En radiologie interventionnelle, l’assistance robotisée permet de limiter l’exposition du praticien aux rayons X et d’apporter plus de précision pour effectuer des opérations complexes. La présence de robots dans un environnement humain pose alors la question de la sécurité du patient et de l’équipe médicale, que ce soit lors d’interactions ou de manipulations. Dans cette thèse, nous nous intéressons dans un premier temps aux problématiques de sûreté. Une structure d’actionnement intrinsèquement sûre est proposée. Le prototype réalisé permet d’effectuer des tâches de positionnement en mode automatique. Parallèlement, une stratégie de guidage basée sur une approche passive est proposée. Un système à raideur variable permet d’imposer un effort résistif variable à l’utilisateur en vue de contraindre son geste. Dans une deuxième partie, nous étudions la possibilité d’intégrer de tels systèmes sur un dispositif à plusieurs degrés de liberté, répondant au problème de placement d’aiguille<br>In the context of interventional radiology, robotic-assisted surgery limits practitioners’ exposure to radiations and brings more accuracy to perform complex interventions. However, the presence of robot in the environment is a potential danger for the patient and the medical staff in case of unexpected interactions and manipulations.In this PhD thesis, we first focus on safety problems. An intrinsically safe mechanism is proposed. The achieved prototype allows to follow both planned trajectories and moving environments.Secondly, a guidance mechanism based on a passive approach is suggested. With a variable stiffness system, using a compliant mechanism, a resistive force is applied to the user which allows him to be guided in his gesture.Based on medical needs, we then study the possibility to integrate and generalize such systems to multiple degrees of freedom
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Dussault, Jean-Michel. "Évaluation des performances écoénergétiques des technologies de fenestration intelligente à opacité variable." Thesis, Université Laval, 2012. http://www.theses.ulaval.ca/2012/29313/29313.pdf.
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Polowinski, Jan. "Semi-Automatic Mapping of Structured Data to Visual Variables." Master's thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-108497.
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While semantic web data is machine-understandable and well suited for advanced filtering, in its raw representation it is not conveniently understandable to humans. Therefore, visualization is needed. A core challenge when visualizing the structured but heterogeneous data turned out to be a flexible mapping to Visual Variables. This work deals with a highly flexible, semi-automatic solution with a maximum support of the visualization process, reducing the mapping possibilities to a useful subset. The basis for this is knowledge, concerning metrics and structure of the data on the one hand and available visualization structures, platforms and common graphical facts on the other hand — provided by a novel basic visualization ontology. A declarative, platform-independent mapping vocabulary and a framework was developed, utilizing current standards from the semantic web and the Model-Driven Architecture (MDA)<br>Während Semantic-Web-Daten maschinenverstehbar und hervorragend filterbar sind, sind sie — in ihrer Rohform — nicht leicht von Menschen verstehbar. Eine Visualisierung der Daten ist deshalb notwendig. Die Kernherausforderung dabei ist eine flexible Abbildung der strukturierten aber heterogenen Daten auf Visuelle Variablen. Diese Arbeit beschreibt eine hochflexible halbautomatische Lösung bei maximaler Unterstützung des Visualisierungsprozesses, welcher die Abbildungsmöglichkeiten, aus denen der Nutzer zu wählen hat, auf eine sinnvolle Teilmenge reduziert. Die Grundlage dafür sind einerseits Metriken und das Wissen über die Struktur der Daten und andererseits das Wissen über verfügbare Visualisierungsstrukturen, -plattformen und bekannte grafische Fakten, welche durch eine neuentwickelte Visualisierungsontologie bereitgestellt werden. Basierend auf Standards des Semantic Webs und der Model-getriebenen Architektur, wurde desweiteren ein deklaratives, plattformunabhängiges Visualisierungsvokabular und -framework entwickelt
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Athanasiadis, Nikolaos P. "Modelling, control and design of Flexible AC Transmission Systems (FACTS), custom power devices and variable speed drives for transmission and distribution architectures." Thesis, University of Strathclyde, 1999. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21441.
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The main tasks of power electronics in power transmission and distribution systems is to process and control the flow of electric energy by supplying voltages and currents in a form that is suitable for user loads. In recent years, the field of power electronics has experienced a large growth. Electric utilities expected that by the year 2000 over half of the electrical load may be supplied through power electronic systems. In order to take advantage of this highly developed technology a number of detailed modelling procedures and simulation facilities are needed. The work in this thesis is concentrated on modelling, control and design of various power electronic based models for use within transmission and distribution systems. The overall objective is to provide effective methods and tools for assessing the impact of the latest technology based on power electronic devices in the reinforcement of power system networks. The thesis clarifies modelling and control of various variable speed drive models, such as the six-step, PWM and vector control and gives a detailed account of the systematic derivation of equations that are necessary for the dynamic and transient analysis of a multi-machine multi-node power system with associated adjustable speed drives. Simulation of Flexible AC Transmission Systems (FACTS) models has also been developed for a number of devices including: the SVC (Static Var Compensator), the STATCON (Static Condenser) and the UPFC (Unified Power Flow Controller). The methodologies for development of the models are described and a number of case studies are included in order to give a broad overview of the applications and to prove the usefulness of the results. The last part of the thesis includes simulation, control and design of Custom Power Devices for use within distribution system architectures. It starts with a complete control system strategy for the modelling of a solid-state switch and continues with the modelling of a Dynamic Voltage Restorer model, using an innovative control system. The creation of the power electronics models library provides several opportunities for future developments, which are discussed in the concluding sections of the thesis.