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1
Poellabauer, Christian. "Q-Fabric: System Support for Continuous Online Quality Management." Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-04082004-134256/unrestricted/poellabauer%5Fchristian%5F200405%5Fphd.pdf.
Texte intégralRésumé :
Thesis (Ph. D.)--Computing, Georgia Institute of Technology, 2004.<br>Pande, Santosh, Committee Member ; Pu, Calton, Committee Member ; Schwan, Karsten, Committee Chair ; Franke, Hubertus, Committee Member ; Eisenhauer, Greg, Committee Member. Vita. Includes bibliographical references (leaves 158-169).
2
Howe, Dustin. "Quantile Regression Deep Q-Networks for Multi-Agent System Control." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505241/.
Texte intégralRésumé :
Training autonomous agents that are capable of performing their assigned job without fail is the ultimate goal of deep reinforcement learning. This thesis introduces a dueling Quantile Regression Deep Q-network, where the network learns the state value quantile function and advantage quantile function separately. With this network architecture the agent is able to learn to control simulated robots in the Gazebo simulator. Carefully crafted reward functions and state spaces must be designed for the agent to learn in complex non-stationary environments. When trained for only 100,000 timesteps, the agent is able reach asymptotic performance in environments with moving and stationary obstacles using only the data from the inertial measurement unit, LIDAR, and positional information. Through the use of transfer learning, the agents are also capable of formation control and flocking patterns. The performance of agents with frozen networks is improved through advice giving in Deep Q-networks by use of normalized Q-values and majority voting.
3
Lynd, Justin. "A characterization of the 2-fusion system of L_4(q)." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1337790920.
Texte intégral
4
Kjellström, Ingrid. "Utvärdering av skillnader vid karaktärisering och klassificering av bergkvalitet : En jämförelse mellan förundersökning, prognos och byggskede i projket Citybanan." Thesis, KTH, Jord- och bergmekanik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176273.
Texte intégralRésumé :
Detta examensarbete genomfördes i samarbete med Trafikverket och analyserar möjliga orsaker till avvikelser mellan karaktärisering utförd på kärnborrhål vid förundersökningar, uppförande av ingenjörsgeologisk prognos och karaktärisering och klassificering utförd i tunnel vid byggnadsskedet för Citybanan. Två av projektets delentreprenader utvärderades – Norrströms- och Norrmalmtunneln. Totalt analyserades 4596 löpmeter tunnel (Norrströmstunneln) och 2557 meter (Norrmalmstunneln) i syfte att identifiera varför och vart i processen som avvikelser uppstod. Den utförda studien tyder på att inom de två undersökta delentreprenaderna uppstod en skillnad i resultat mellan karaktärisering utförd i kärnborrhål och karaktärisering och klassificering utförd i tunnel. Övergripande visar resultat från karaktäriseringen i samband med tunnelkartering generellt sämre bergförhållanden jämfört med det som prognostiserats. Skillnaderna otsvarade sämre förhållande uttryckt i 5 (för Norrströmstunneln) respektive 7,5 enheter (Norrmalm) i RMR-systemet från borrhål till tunnelkaraktärisering. Analysen av det utvärderade resultatet indikerar att avvikelserna mellan karaktärisering på borrkärnor jämfört med karaktärisering och klassificering utförd i tunnel antagligen till viss del beror på den använda metodiken vid karaktärisering och klassificering av bergkvaliten med RMR- och Q-systemet. Detta på grund av att parametrarna i systemen inte bestäms på exakt samma sätt vid karaktärisering i förundersökningsskede och karaktärisering och klassificering i byggnadsskede. Dessutom indikeras att anvisningarna för karteringsrutiner vid karaktärisering och klassificering hanteras olika av karterande geologer vid tunneldrivning. Baserat på resultaten från den utförda analysen diskuteras även om det för vissa parametrar för karaktärisering och klassificering finns ett behov av uppdatering i den använda metodiken. Detta för att få förundersökningsprocessen att samspela med det arbete som sker i en tunnel. Resultaten tyder också på att geologerna vid tunnelkartering har en tendens till att kartera sämre bergförhållanden jämfört med det som är prognostiserat samt att vissa egenskaper hos berget kan vara lättare att beskriva på plats i tunneln än vid karaktärisering av berget från en borrkärna. Genom att harmonisera processen för beskrivning av ingående parametrar i de system som används vid karaktärisering mellan förundersökning och karaktärisering och klassificering i byggskede kan skillnader mellan stegen reduceras och risken för prognosavvikelser kan minska för tunnelprojekt i framtiden.<br>This thesis was carried out in cooperation with the Swedish Transport Administration and analyzes the possible causes of differing rock mass quality assessed in boreholes, engineering geological forecast and tunnel mapping. Two contracts from the City Line project where investigated - in total has 4596 meters (the Norrström tunnel) and 2557 meters (the Norrmalm tunnel) of tunnel mapped during construction been analyzed. The purpose was to identify the reason and where differences in the process of rock evaluation arose. The performed study indicates that in the two investigated tunnels it arose a difference in the results between the characterization performed in boreholes and the subsequent geological forecast compared with the characterization in the tunnel. The assessed rock mass quality became generally successively poorer as the process progresses. This was particulary the case when comparing the geological forecast with tunnel mapping during construction The differences corresponded to a difference of a downgrade of 5 (for the Norrström tunnel) and 7,5 units (the Norrmalm tunnel) in the RMR-system from bore holes to tunnel mapping. The analysis of the evaluated results indicates that the differences between the characterization of boreholes and geological forecasts compared to the characterization and classification performed in the tunnel is probably due to the methodology in the characterization and classification of rock quality with the RMR- and Q system. This is because the parameters of the ystems is not determined exactly in the characterization of the preliminary investigation stage and the characterization and classification in the construction stage. Also the instructions for mapping routines for the characterization and classification are handled differently by the mapping made by geologists during tunneling. Based on the results of the analysis it is recommended that the way in which some parameters in the systems of characterization and classification of rock are determined should be updated. This is in order to standardize the process for characterizing the rock mass when mapping boreholes, creating geological forecast and conducting tunnel mapping. It is also indicated that geologists tend to conservatively scale down the rock quality in the tunnel and that certain features of the rock is easier to determine in the tunnel than during characterization of bore holes. By harmonizing the description of parameters of the systems used in the characterization of bore holes and characterization and classification in the construction stage, differences between the steps can be reduced for projects in the future.
5
Francis, Gerald. "An Algorithm and System for Measuring Impedance in D-Q Coordinates." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/26462.
Texte intégralRésumé :
This dissertation presents work conducted at the Center for Power Electronics Systems (CPES) at Virginia Polytechnic Institute and State University.
Chapter 1 introduces the concept of impedance measurement, and discusses previous work on this topic. This chapter also addresses issues associated with impedance measurement.
Chapter 2 introduces the analyzer architecture and the proposed algorithm. The algorithm involves locking on to the voltage vector at the point of common coupling between the analyzer and the system via a PLL to establish a D-Q frame. A series of sweeps are performed, injecting at least two independent angles in the D-Q plane, acquiring D- and Q-axis voltages and currents for each axis of injection at the point of interest.
Chapter 3 discusses the analyzer hardware and the criteria for selection. The hardware built ranges from large-scale power level hardware to communication hardware implementing a universal serial bus. An eight-layer PCB was constructed implementing analog signal conditioning and conversion to and from digital signals with high resolution. The PCB interfaces with the existing Universal Controller hardware.
Chapter 4 discusses the analyzer software. Software was written in C++, VHDL, and Matlab to implement the measurement process. This chapter also provides a description of the software architecture and individual components.
Chapter 5 discusses the application of the analyzer to various examples. A dynamic model of the analyzer is constructed, considering all components of the measurement system. Congruence with predicted results is demonstrated for three-phase balanced linear impedance networks, which can be directly derived based on stationary impedance measurements. Other impedances measured include a voltage source inverter, Vienna rectifier, six-pulse rectifier and an autotransformer-rectifier unit.<br>Ph. D.
6
Soto, Santibanez Miguel Angel. "BUILDING AN ARTIFICIAL CEREBELLUM USING A SYSTEM OF DISTRIBUTED Q-LEARNING AGENTS." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/194811.
Texte intégralRésumé :
About 400 million years ago sharks developed a separate co-processor in their brains that not only made them faster but also more precisely coordinated. This co-processor, which is nowadays called cerebellum, allowed sharks to outperform their peers and survive as one of the fittest. For the last 40 years or so, researchers have been attempting to provide robots and other machines with this type of capability. This thesis discusses currently used methods to create artificial cerebellums and points out two main shortcomings: 1) framework usability issues and 2) building blocks incompatibility issues. This research argues that the framework usability issues hinder the production of good quality artificial cerebellums for a large number of applications. Furthermore, this study argues that the building blocks incompatibility issues make artificial cerebellums less efficient that they could be, given our current technology. To tackle the framework usability issues, this thesis research proposes the use of a new framework, which formalizes the task of creating artificial cerebellums and offers a list of simple steps to accomplish this task. Furthermore, to tackle the building blocks incompatibility issues, this research proposes thinking of artificial cerebellums as a set of cooperating q-learning agents, which utilize a new technique called Moving Prototypes to make better use of the available memory and computational resources. Furthermore, this work describes a set of general guidelines that can be applied to accelerate the training of this type of system. Simulation is used to show examples of the performance improvements resulting from the use of these guidelines. To illustrate the theory developed in this dissertation, this paper implements a cerebellum for a real life application, namely, a cerebellum capable of controlling a type of mining equipment called front-end loader. Finally, this thesis proposes the creation of a development tool based on this formalization. This research argues that such a development tool would allow engineers, scientists and technicians to quickly build customized cerebellums for a wide range of applications without the need of becoming experts on the area of Artificial Intelligence, Neuroscience or Machine Learning.
7
SILVA, MARCELO PETERSOHN CORDEIRO DA. "APPROACHES FOR MODELS WITH SERVICE LEVELS IN INVENTORY CONTROL SYSTEM (Q,R)." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=18554@1.
Texte intégralRésumé :
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO<br>O nível de serviço fill rate é uma alternativa viável de quantificação do
custo de falta em um modelo de estoque para o Sistema de Controle (Q, R).
Aproximações deste modelo são importantes para tornar mais simples a busca por
sua solução. Uma aproximação é proposta e outras duas são analisadas.
Experimentos foram feitos com as três aproximações para verificar o erro da
solução encontrada em relação à solução resultante do modelo exato. Foram
analisados os casos em que as aproximações são aceitáveis.<br>The fill rate service level is a viable alternative to quantify the penalty cost
in a inventory model for control system (Q, R). Approximations of this model are
important to make a simplest solution. An approximation is proposed and two
other are analyzed. Experiments were made with the three approximations to
check the error of the solution in relation to the resulting solution of the exact
model. So, we defined cases where the approximations are acceptable.
8
Chapman, Kevin L. "A Distributed Q-learning Classifier System for task decomposition in real robot learning problems." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-03042009-041449/.
Texte intégral
9
Brofsky, Steven Andrew. "An In Vitro Evaluation of the Elements Apex Locator Using the Endo Q System." VCU Scholars Compass, 2004. http://scholarscompass.vcu.edu/etd/1033.
Texte intégralRésumé :
The objective of this study was two-fold: 1) to determine the accuracy of the Elements Apex Locator and 2) to compare the accuracy of the alginate and Endo Q models as in-vitro apex locator testing devices. Twenty teeth were decoronated at the CEJ and triplicate measurements were made using the Elements Apex Locator. All measurements were made to the apex reading of the apex locator. True length was established by visualizing the file tip at the apex with a dental operating microscope. Measurements were then taken with the teeth mounted in an alginate model and then in the Endo Q model. The two models were compared using a repeated-measure ANOVA. Statistically significant differences occurred between the alginate and Endo Q models. The results showed that in 95% (n=19) of the cases, an accurate location to within + 0.5 mm of the apical foramen was obtained with the Endo Q model and 55% (n=11) with the alginate model. With a + 1.0 mm tolerance level, an accuracy of 95% (n=19) was found with the use of the alginate model. In conclusion, it seems that the Endo Q system was more suitable for testing the electronic apex locator than the alginate model. The Elements Apex Locator with the use of the Endo Q model was highly accurate in locating to within + 0.5 mm of the apical foramen (Mean deviation = .17 mm).
10
Featherkile, B. Nadine 1937. "STRUCTURING AN ENGINEERING AND AN ECOLOGICAL SYSTEM BY Q-ANALYSIS (POLYHEDRAL DYNAMICS, DROSOPHILA, SONORAN DESERT)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/276346.
Texte intégral
11
Jansson, Malin, and Nadja Levin. "Kritiska framgångsfaktorer vid implementering och uppgradering av ett ERP-system: En fallstudie av företaget Q-Med." Thesis, Uppsala University, Department of Business Studies, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-127087.
Texte intégralRésumé :
<p>Enterprise Resource Planning (ERP) Systems har utvecklats till att bli en av de mest attraktiva lösningar för informationshantering på företag. För att kunna nå de fördelar som systemet erbjuder är det viktigt att implementeringen sker med framgång. Forskning som behandlar ERP-implementering gör ofta detta genom att undersöka kritiska faktorer för framgång. Vid en litteraturgenomgång identifierades 20 kritiska faktorer vilka sedan utmynnades till fem. Dessa fem undersöktes sedan genom två fallstudier på det biomedicinska företaget Q-Med i Uppsala. I denna undersökning identifierades på vilket sätt fem utvalda faktorer varit kritiska vid implementeringen och uppgraderingen av ERP-systemet på Q-Med, och skillnader mellan dessa belystes. Vidare diskuteras varje faktors betydelse för framgång vid en ERP- implementering och uppgradering.</p>
12
Roberts, Peter Morse. "Seismic Q and velocity structure for the magma-hydrothermal system of the Valles Caldera, New Mexico." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/58021.
Texte intégralRésumé :
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1989.<br>Science copy is bound in 2 v.<br>Includes bibliographical references (leaves 326-332).<br>by Peter Morse Roberts.<br>Ph.D.
13
Christofolletti, Caio. "Correlação entre as classificações geomecânicas RMR e Q e sua relevância geológica." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/44/44141/tde-09102014-134001/.
Texte intégralRésumé :
O maciço granítico Teles Pires localizado ao norte do estado do Mato Grosso será escavado para a construção de três túneis de desvio utilizados na construção de uma usina hidrelétrica. Para a realização desta escavação, foram realizadas investigações geológicas a fim de se conhecer a condição do substrato rochoso e suas propriedades geomecânicas. Por meio da utilização das classificações geomecânicas RMR e Q, o maciço rochoso foi analisado de modo a se definir as possíveis áreas de instabilidade que poderiam surgir durante as escavações. A utilização de classificações geomecânicas é uma prática difundida na Geologia de Engenharia e utilizada pela maioria das empresas para prever o tipo de tratamento a ser utilizado durante e após a escavação dos túneis. Os métodos abordados neste trabalho levam em consideração parâmetros semelhantes entre si, seguindo cada um uma metodologia distinta. Por considerarem somente alguns parâmetros, as classificações geomecânicas devem ser utilizadas juntamente com as análises de campo e as interpretações geológicas. Neste trabalho, foram analisadas as correlações entre estas duas classificações assim como o quanto elas refletem o contexto geológico ao qual o maciço está inserido.<br>The Teles Pires granitic massif located north of Mato Grosso State will be excavated for the construction of three detour tunnels used in the construction of a hydroelectric plant. For the realization of this excavation, geological investigations were performed in order to know the condition of the bedrock and its geomechanical properties. Through the use of geomechanical classifications RMR and Q, the rock mass has been analyzed in order to define potential areas of instability that could arise during the excavations. The use of geomechanical classifications are a widespread practice in Engineering Geology and used by most companies to predict the type of treatment to be used during and after excavation of the tunnels. The methods discussed in this paper take into consideration parameters similar to each other, each following a distinct methodology. By considering only a few parameters, geomechanical classifications should be used along with field analysis and geological interpretations. In this study, we analyze the correlations between these two classifications as well as how they reflect the geological context to which the mass is inserted.
14
Wen, Bo. "Stability Analysis of Three-Phase AC Power Systems Based on Measured D-Q Frame Impedances." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51202.
Texte intégralRésumé :
Small-signal stability is of great concern for distributed power systems with a large number of regulated power converters. These converters are constant-power loads (CPLs) exhibit a negative incremental input resistance within the output voltage regulation bandwidth. In the case of dc systems, design requirements for impedances that guarantee stability have been previously developed and are used in the design and specification of these systems. In terms of three-phase ac systems, a mathematical framework based on the generalized Nyquist stability criterion (GNC), reference frame theory, and multivariable control is set forth for stability assessment. However, this approach relies on the actual measurement of these impedances, which up to now has severely hindered its applicability. Addressing this shortcoming, this research investigates the small-signal stability of three-phase ac systems using measured d-q frame impedances. Prior to this research, negative incremental resistance is only found in CPLs as a results of output voltage regulation. In this research, negative incremental resistance is discovered in grid-tied inverters as a consequence of grid synchronization and current injection, where the bandwidth of the phase-locked loop determines the frequency range of the negative incremental resistance behavior, and the power rating of inverter determines the magnitude of the resistance. Prior to this research, grid synchronization stability issue and sub-synchronous oscillations between grid-tied inverter and its nearby rectifier under weak grid condition are reported and analyzed using characteristic equation of the system. This research proposes a more design oriented analysis approach based on the negative incremental resistance concept of grid-tied inverters. Grid synchronization stability issues are well explained under the framework of GNC. Although stability and its margin of ac system can be addressed using source and load impedances in d-q frame, method to specify the shape of load impedances to assure system stability is not reported. This research finds out that under unity power factor condition, three-phase ac system is decoupled. It can be simplified to two dc systems. Load impedances can be then specified to guarantee system stability and less conservative design.<br>Ph. D.
15
Dalmia, Sidharth. "Design and implementation of high-Q passive devices for wireless applications using System-On-Package (SOP) based organic technologies." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/15689.
Texte intégral
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Temizel, Guvenc. "Intermetallic Phase Formation At Fe-al Film Interefaces." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607589/index.pdf.
Texte intégralRésumé :
This thesis presents the formation mechanism of intermetallics formed at Fe-Al film interfaces. Al thin films with different initial film thicknesses were coated on low carbon steel substrates by physical vapor deposition (PVD). By annealing the system at different temperatures and for different time intervals, several intermetallic phases were observed. X-Ray, SEM and EDS studies showed that intermetallic phases FeAl2 and Fe2Al5 are most dominant phases which were observed and they formed sequentially on the contrary of intermetallics which formed synchronous in bulk materials.
17
Polat, Aydin Goze. "Modeling Neurons That Can Self Organize Into Building Blocks And Hierarchies: An Exploration Based On Visual Systems." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614712/index.pdf.
Texte intégralRésumé :
Cell-cell and cell-environment interactions are controlled by a set of local rules that dictate cell behavior. With such local rules, emergence of computationally meaningful building blocks and hierarchies can be observed. For example, at the cellular level organization in the visual system, receptive field of a retinal ganglion cell displays an activation inhibition behavior that can be modeled as Mexican Hat wavelet or Difference of Gaussians. This precise organization is the product of a harmonious collaboration of different cell types located at the lower levels in a hierarchical structure for each ganglion cell. Moreover, a similar hierarchical organization is observed at higher levels in the visual system. This thesis investigates the visual system from several perspectives in an effort to explore the biological/computational principles underlying these local rules. The investigation results in a hybrid computer model that can combine the advantages of evolutionary and developmental principles to explore the effects of local rules on cellular differentiation, retinal mosaics, layered structures and network topology.
18
Gunsel, H. Sinem. "Ammunition Transfer System Optimization Problem." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614166/index.pdf.
Texte intégralRésumé :
Ammunition Transfer System (ATS) is the electro-mechanical system of the Ammunition Resupply Vehicle (ARV) which will be used to meet T-155 mm Firtina howitzers&rsquo<br>ammunition demand for tactical requirements of higher firing rate by off-road mobility and survivability. The transfer of ammunitions from ARV to Firtina is to be optimized for an effective improvement of firing rate.
In this thesis the transferring order of carried ammunitions is being optimized to minimize the total ammunition transferring time. This transfer problem is modeled as a modification of Travelling Salesman Problem (TSP). The given locations of the ammunitions are treated as cities to be visited and the gripper of ATS is treated as the traveling salesman. By GAMS<br>the small-size problems are solved optimally but large-size ones get only local optimum. A heuristic algorithm that contains nearest neighbor heuristics as construction method and 2-opt exchange heuristic as improvement method is developed to obtain same or better solutions obtained by GAMS with less computational time.
19
Kuckelsberg, Denise [Verfasser], Stefan [Gutachter] Herlitze, and Ulf [Gutachter] Eysel. "Funktionelle Charakterisierung spannungsabhängiger P/Q-Typ-Calciumkanäle im serotonergen System der Maus (Mus musculus) / Denise Kuckelsberg. Gutachter: Stefan Herlitze ; Ulf Eysel." Bochum : Ruhr-Universität Bochum, 2016. http://d-nb.info/1109051506/34.
Texte intégral
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Gregůrek, Jakub. "Řešení speciálních modelů zásob firmy Dencop Lighting." Master's thesis, Vysoká škola ekonomická v Praze, 2008. http://www.nusl.cz/ntk/nusl-4402.
Texte intégralRésumé :
The thesis is focused on finding optimal solution of stock company Dencop Lighting spol. s.r.o. At the very beginning of the thesis there is a brief characteristic of Dencop Lighting, their market aims and goals. After this view we are going to introduce you warehouse systems. There are analysis of products, their selection, flows and potentials for company. After completing product analysis we are going to focus on key factors of optimalization. There are mentioned many ways of optimalization with their advantages and disadvantages. Deterministic and stochastic methods are included as well. For better illusion in real live you can find added CD at the bottom of the thesis. Using guide of this software with detailed information about functions is in last pages of the thesis.
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Mitrovski, Michael K. "Energy and system size dependence of Q- [Xi-] and Q̄+ [anti-Xi+] production in relativistic heavy-ion collisions at the CERN SPS." [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=984895655.
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Gokel, Julia Maria [Verfasser]. "Sprachliche Indizien für inneres System bei Q. Cervidius Scaevola. : (Abt. A: Abhandlungen zum Römischen Recht und zur Antiken Rechtsgeschichte). / Julia Maria Gokel." Berlin : Duncker & Humblot, 2014. http://d-nb.info/1238430368/34.
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Adil, Fatime Zehra. "Development Of An Optical System Calibration And Alignment Methodology Using Shack-hartmann Wavefront Sensor." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615591/index.pdf.
Texte intégralRésumé :
Shack-Hartmann wavefront sensors are commonly used in optical alignment, ophthalmology,
astronomy, adaptive optics and commercial optical testing. Wavefront error measurement yields
Zernike polynomials which provide useful data for alignment correction calculations.
In this thesis a practical alignment method of a helmet visor is proposed based on the wavefront error
measurements. The optical system is modeled in Zemax software in order to collect the Zernike
polynomial data necessary to relate the error measurements to the positioning of the visor. An
artificial neural network based computer program is designed and trained with the data obtained from
Zernike simulation in Zemax software and then the program is able to find how to invert the
misalignments in the system. The performance of this alignment correction method is compared with
the optical test setup measurements.
24
Zerman, Erel. "Multi-item Inventory-routing Problem For An Fmcg Company." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608927/index.pdf.
Texte intégralRésumé :
In this study, inventory&ndash<br>routing system of a company operating in Fast Moving Consumer Goods (FMCG) industry is analyzed. The company has decided to redesign distribution system by locating regional warehouses between production plants and customers. The warehouses in the system are all allowed to hold stock without any capacity restriction. The customers are replenished by the warehouse to which they have been assigned. Customer stocks are continuously monitored by the warehouse and deliveries are to be scheduled. In this multi&ndash<br>item, two-echelon inventory&ndash<br>distribution system, main problem is synchronizing inventory and distribution decisions. An integrated Mixed Integer Programming optimization model for inventory and distribution planning is proposed with the aim of optimally coordinating inventory management and vehicle routing. The model determines the replenishment periods of items and amount of delivery to each customer<br>and constructs the delivery routes with the objective of cost minimization. The integrated model is coded in GAMS and solved by CPLEX. The integrated inventory-routing model is simulated with retrospective data of the company. Computational results on test problems are provided to show the effectiveness of the model developed in terms of the performance measures defined. Moreover, the feasible solution obtained for a period is compared to the realized inventory levels and distribution schedules. Computational results seem to indicate a substantial advantage of the integrated inventory-routing system over the existing distribution system.
25
Katirci, Argun. "Automation And Verification Of Ankara Wind Tunnel." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/12607692/index.pdf.
Texte intégralRésumé :
All the operational and measurement systems of Ankara Wind Tunnel was modified to
operate automatically under the control of a central computer system programmed using
the Lab View programming language.
A cruciform air-to-air missile with triangular canard control and a trapezoidal wing
model was tested by a 35mm diameter internal balance at Mach 0.2 and data was
compared with the test data of the same model&rsquo<br>s test that was performed at NASA
Langley Research Center.
26
Sultani, Jasim Farhood. "Modelling, design and implementation of D-Q control in single-phase grid-connected inverters for photovoltaic systems used in domestic dwellings." Thesis, De Montfort University, 2013. http://hdl.handle.net/2086/9631.
Texte intégralRésumé :
This thesis focuses on the single-phase voltage-source inverter for use in photovoltaic (PV) electricity generating systems in both stand-alone and grid-tied applications. In many cases, developments in single-phase PV systems have followed developments in three-phase systems. Time-variant systems are more difficult to control than time-invariant systems. Nevertheless, by using suitable transformation techniques, time-variant systems can often be modelled as time-invariant systems. After the transformation, the control signals that are usually time-variant (often varying sinusoidally in time) become time-invariant at the fundamental frequency, and are hence much easier to deal with. With this approach, synchronous rotating frame control techniques have been previously proposed for high performance three-phase inverter applications. The transformation theory cannot be applied directly in single-phase systems without modification, and the d-q components would not be time-invariant in situations where harmonics, resonances or unbalance is present. Single-phase inverter controller designs based on the use of a synchronous rotating reference frame have been proposed, but such designs do not always perform as well as expected. This thesis aims to improve single-phase voltage-source inverters. The main objective is to address, in terms of cost, efficiency, power management and power quality, the problems found with single-phase designs based on a synchronous rotating frame single-phase inverter controller. Consequently, this thesis focuses on a novel controller approach in order to obtain a more reliable and flexible single-phase inverter. As the first step, this thesis investigates the single-phase inverter switching gate-drive algorithms and develops a form of space-vector pulse-width-modulation (SVPWM) in order to reduce total harmonic distortion. The results of the new SVPWM algorithm demonstrate its superior performance when compared with sinusoidal pulse-width-modulation (SPWM) which is often used with single-phase inverters. The second step, which is further reviewed and presented in this thesis, is the modelling of the single-phase inverter control based on the synchronous rotating frame. A mathematical analysis is conducted to determine the mechanism of the coupling that exists between the voltage phase and amplitude terms, and a new transformation strategy is proposed based on using the voltage phase as a reference at the Park transformation stages, and the current phase as a reference for the current at the transformation stages. The line-frequency components of the feedback signals are transformed to time-invariant components, thus eliminating the ripple and reducing the computational burden associated with the controller stage. Consequently, the inverter feedback controller stage is designed so that the coupling terms are decoupled within the controller itself. The effectiveness of the techniques proposed in this thesis are demonstrated by simulation using the MATLAB/SIMULINK environment. The proposed technique was also investigated through a practical implementation of the control system using a Digital Signal Processor (DSP) and a single-phase inverter. This practical system was tested up to 1 kW only (limited by the available inverter hardware). Nevertheless, the correlation between the simulation and the practical results is high and this gives confidence that the developed mechanism will allow the 2.5kW goal to be achieved. Practical test cases illustrate the effectiveness of the models. In addition, the comparisons between experimental and simulation results permit the system's behaviour and performance to be accurately evaluated. With the development of the new controller, small-scale single-phase renewable energy systems will become more useful in the field of power quality management through their ability to separately control the phase and amplitude of the output voltage. Consequently, incorporation of this type of generator within the national electrical distribution network, as distributed generators (DG) at low-voltage level, can assist with power quality management at the consumer side of the grid. In addition, such a generator can also operate in stand-alone mode if the grid becomes unavailable. The third step in this thesis investigates small-scale single-phase renewable energy systems operating as decentralized distributed generators within a local network. This operation is achieved by controlling the inverter side using the quantities measured at the common coupling point between the grid and the inverter, without requiring other extensive communications. Thus, the small-scale single-phase renewable energy distributed generator systems will contain only a local controller at each installation.
27
Cisneros, Francia Sergio Clemente, Véliz Ysela Lorena Gutiérrez, Petrovich Luis Alberto Rodriguez, and Sánchez Jesús Emilio Sierra. "La solvencia económica y su relación con la implementación de las prácticas de Buen Gobierno Corporativo en los bancos en el Perú desde el año 2012 hasta el año 2018." Master's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2016. http://hdl.handle.net/10757/626722.
Texte intégralRésumé :
En el Perú, el sistema financiero es fundamental para fomentar el desarrollo económico, por lo que la adopción de las buenas prácticas de gobierno corporativo tiene un impacto positivo, permitiendo la estabilidad del sistema, generando nuevas inversiones y el desarrollo del mercado de capitales.
La presente investigación, tiene como principal objetivo analizar si existe una relación entre la adopción de las prácticas de buen gobierno corporativo y el grado de solvencia económica que mantienen los Bancos del Sistema Financiero Peruano.
La investigación busca obtener evidencia con relación causal entre variables y su efecto. Además, fue necesario realizar una investigación de tipo cuantitativa, utilizando el scoring establecido por el índice de buen gobierno corporativo, y la medición de solvencia económica.
Se analizaron diversos modelos de medición de solvencia y valor económico como; el Modelo Z de Altman, el Valor Económico Agregado y la Q de Tobin, determinándose como indicador el modelo Z de Altman lo que permite ser una herramienta útil en la evaluación de la viabilidad de las empresas. Además de ser considerado por expertos como un modelo de calificación para mercados emergentes como el Perú.
La investigación comprende desde el año 2012 al 2018 y se analizaron a 15 Instituciones Financieras.
Finalmente, los resultados hallados permiten asociar el buen uso de prácticas del gobierno corporativo con un impacto positivo para el fortalecimiento de la solvencia económica en el Sector Financiero del Perú.<br>In Peru, the financial system is essential to promote economic development, so the adoption of good corporate governance practices has a positive impact, allowing the stability of the system, generating new investments and the development of the capital market.
The main objective of this research is to analyze whether there is a relationship between the adoption of good corporate governance practices and the degree of economic solvency maintained by the Banks of the Peruvian Financial System.
The research seeks to obtain evidence with a causal relationship between variables and their effect. In addition, a quantitative investigation was necessary using the scoring established by the good corporate governance Index, and the measurement of economic solvency.
Various solvency and economic value measurement models were analyzed, such as the Altman Z Model, the Added Economic Value and the Tobin Q. The Altman Z model was the indicator chosen, which allows it to be a useful tool in the evaluation of the viability of the companies. In addition, many experts consider it as a rating model for emerging markets such as Peru.
The research includes the periods from 2012 to 2018 and 15 Financial Institutions were analyzed.
Finally, the results found allow us to associate the good use of corporate governance Practices with a positive impact for the strengthening of economic solvency in the Financial Sector of Peru.<br>Trabajo de investigación
28
Gadre, Aditya Shrikant. "Learning Strategies in Multi-Agent Systems - Applications to the Herding Problem." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/36116.
Texte intégralRésumé :
<p> "Multi-Agent systems" is a topic for a lot of research, especially research involving strategy, evolution and cooperation among various agents. Various learning algorithm schemes have been proposed such as reinforcement learning and evolutionary computing.
</p><p>
In this thesis two solutions to a multi-agent herding problem are presented. One solution is based on Q-learning algorithm, while the other is based on modeling of artificial immune system.
</p><p>
Q-learning solution for the herding problem is developed, using region-based local learning for each individual agent. Individual and batch processing reinforcement algorithms are implemented for non-cooperative agents. Agents in this formulation do not share any information or knowledge. Issues such as computational requirements, and convergence are discussed.
</p><p>
An idiotopic artificial immune network is proposed that includes individual B-cell model for agents and T-cell model for controlling the interaction among these agents. Two network models are proposed--one for evolving group behavior/strategy arbitration and the other for individual action selection.</p>
A comparative study of the Q-learning solution and the immune network solution is done on important aspects such as computation requirements, predictability, and convergence.<br>Master of Science
29
Singh, Amarjit Kumar. "Development of Computer Aided Heat Treatment Planning System for Quenching & Tempering (CHT - q/t) and Industrial Application of CHT-bf & CHT-cf." Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-050306-224714/.
Texte intégral
30
Baybas, Gizem. "Spatial Decision Support System For Archaeological Application: A Case Study For Kaunos Archaeological Site." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615648/index.pdf.
Texte intégralRésumé :
Geographically located materials are used by the archaeology to analyze and explain the socio-cultural aspects of ancient life. Thus, Geographical Information Systems (GIS) have started to be used in archaeology for many applications. Although, cooperation of GIS and archaeology is considered as beneficial, it has become insufficient to meet the requirements of archaeologists about excavation study. Therefore, the aim of this thesis is to develop Spatial Decision Support System (SDSS) which includes both the GIS tools and analyses and<br>analytical modeling capabilities in order to satisfy the needs of archaeologists. Moreover, to develop a specialized system for specific archaeological excavation site is aimed. In this study, Kaunos is selected as a case study area and in order to furnish this aim, firstly, needs of archaeologists working in the excavation study of Kaunos are analyzed. Secondly, GIS tools and analyses are determined which meet the requirements of archaeologists. Finally, SDSS for Kaunos Archaeological Excavation Site is developed. It is composed of four components namely<br>Database Management, Model Management, Dialog Management and Stakeholder Components. Analyses are conducted under the Model Management Component and results are visualized in Dialog Management Component. Result maps help and assist archaeologists in terms of interpreting and examining the socio-cultural, economical and demographical characteristics of Kaunos.
31
Aliyev, Elshan. "Development Of Expert System For Artificial Lift Selection." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615578/index.pdf.
Texte intégralRésumé :
During the reservoir production life reservoir pressure will decline. Also after water breakthrough the fluid column weight will increase as hydrostatic pressure will increase because of increased water and oil mixture density. In this case, reservoir pressure may not be enough to lift up the fluid from bottom to the surface. These reasons decrease or even may cause to stop flowing of fluids from the well. Some techniques must be applied to prevent the production decline. Artificial lift techniques are applied to add energy to the produced fluids. It increases production rate by reducing down-hole pressure and so that by increasing the drawdown. Artificial lift techniques increase production either by pumping the produced fluid from the bottom to the surface or reduce bottom-hole pressure by reducing the fluid column weight as a result of decreased fluid mixture density. Artificial lift is used worldwide in approximately 85% of the wells, thus its impact in overall efficiency and profitability of production operations cannot be overemphasized.
The most important problem is how to select optimum artificial lift techniques by taking into consideration the reservoir, well, environmental conditions. Selection of poor technique could cause decrease in efficiency and low profitability. As a result, it will lead to high operating expenses. Several techniques have been developed for selection of optimum artificial lift techniques. Expert Systems (ES) is the most suitable technique used in these selection techniques. Because the use and availability of required parameters is easy. Also in this selection method most of the artificial lift techniques are analyzed rather than other selection techniques. Expert Systems program mainly consist of three modules: (1) Expert Module, (2) Design Module, and (3) Economic Module. By entering required data to the system, program automatically suggests the feasible artificial lift techniques those might be used referring to given data. In this thesis work the artificial lift selection criteria and Expert Systems available in the literature have been studied. A Microsoft Windows based program has been developed to predict suitability of artificial lift methods for a given set of wells and produced fluid parameters. For the selected artificial lift method (i.e. sucker rod pump, ESP, gas lift, hydraulic pump, PCP) the program is able to perform basic calculations for the given data. Different case studies have been performed by running the program with actual data from fields. Well data of Venezuela, Azerbaijan and Iranian oil fields has been used in case studies. The results have been compared with previous studies those have been done on these fields with other selection techniques and current artificial lift techniques are being applied in selected wells. The obtained program results have been overlap with current real field application and previous studies.
32
Grube, Boris. "A trigger control system for COMPASS and a measurement of the transverse polarization of L [lambda] and Q [xi] hyperons from quasi-real photo-production." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=98014714X.
Texte intégral
33
Roux, Christian-Eric [Verfasser], and Klaus [Akademischer Betreuer] Blaum. "High-resolution mass spectrometry: The trap design and detection system of Pentatrap and new Q-values for neutrino studies / Christian-Eric Roux ; Betreuer: Klaus Blaum." Heidelberg : Universitätsbibliothek Heidelberg, 2012. http://d-nb.info/1177039915/34.
Texte intégral
34
Dumbar, Burcu. "Analysis Of Local Sectoral Policies Via System Dynamics Approach: The Case Of Alanya Tourism Sector." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610684/index.pdf.
Texte intégralRésumé :
The purpose of this work is indicating System Dynamics Approach to be an appropriate tool for analysis of policies suggested for local sectors. Local sectors are very important for stability of the country&rsquo<br>s economy as well as welfare of the local community. Therefore, feasible and effective policies should be created and implemented in order to contribute to the local sectoral development. But before any policy implementation, policy analysis is required on to evaluate whether effectiveness and feasibility would be ensured in alternative policies. In this study, firstly the issues of Local Sectoral Dynamics and Policies are examined and specifically, the situation in Alanya Tourism Sector is studied. Afterwards, in accordance with policy analysis steps, problems of Alanya Tourism Sector are detailed and alternative policies that would aid in solution of the problem are idenfined. For evaluation of alternative policies, Dynamics of Alanya Tourism Sector are modeled by System Dynamics approach and the &lsquo<br>Formal Model&rsquo<br>is implemented in Stella 9.0.1. The model is simulated for all policy alternatives and the policy outcomes of each alternative are forecasted. Finally the performance of each policy are evaluated using the previously established criteria and combined policies having more superior outcomes than the present ones are created.
35
Benhalima, Mehdi. "Evaluation of the differences in characterization and classification of the rock mass quality : A comparison between pre-investigation, engineering geological forecast and tunnel mapping in the Northern Link project and the Cityline project." Thesis, KTH, Jord- och bergmekanik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-195743.
Texte intégralRésumé :
In the construction of a tunnel, the characterization of the rock mass is performed in three different steps, in the pre-investigations, in the engineering geological forecast and in the tunnel mapping during construction. There has in previous work been observed that discrepancies exist between the results from these different steps, with a tendency to assign poorer rock mass quality in the tunnel mapping than in the pre-investigations and in the engineering geological forecast. One example is the work done by Kjellström [1] on the Cityline where the divergence in rock mass quality was analyzed between the different steps. If a divergence exists between the engineering geological forecast and the actual conditions observed in the tunnel mapping, it will influence both planning and budget. It is therefore important that the engineering geological forecast is as close as possible to the actual rock mass conditions in the field. The aim of this thesis was, using the case study of the Northern Link, to analyze those discrepancies in the rock mass quality estimated in the characterization and in the classification between the mapping of drill cores, the engineering geological forecast and the tunnel mapping thus complementing the work by Kjellström [1]. The aim was also identifying which parameters included in the Q-system that causes these discrepancies The analysis of the results showed that it is difficult to make the engineering geological forecast and the actual mapping match for every single meter, but that the overall correlation between them was good. The methodology used in the characterization and classification in the different phases (drill-core mapping, engineering geological forecast, tunnel mapping) may to some extent explain this divergence. The parameters Jr, Jn and Ja, included in the Q-system were the ones identified as having the largest influence on the discrepancies. In future work, it is recommended that focus is given on these parameters. A way to improve future engineering geological forecast for tunnel contracts would be to have a better follow up of the engineering geological forecast and to have standardized guidelines on how to assess clearly the value of the Q parameters in each phase (for the drill cores as well as for the actual mapping). The reduction of those differences would then lead to a better planning and budget management in future tunnel projects in Sweden.
36
Atak, Erman. "Incentive, Subsidy, Penalty Mechanisms And Pooled, Unpooled Allocation Of Production Capacity In Service Parts Management Systems." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613408/index.pdf.
Texte intégralRésumé :
In this thesis, two systems are analyzed in order to gain insight to the following
issues: (i) Effect of incentive, subsidy and penalty designs on decentralized system,
(ii) effect of using production facility as pooled capacity (pooled system) and
dedicated capacity (unpooled system) on capacity utilization and system profit.
Regarding the first issue, three models are defined<br>decentralized model, centralized
model and decentralized model with incentive, subsidy, penalty designs. In all
models, there are two dealers and one item is under consideration and lateral
transshipments are allowed. Dealers operate with four inventory level decision
(strategies) that consists of base stock level, rationing level, transshipment request
level and customer rejection level. Under the decentralized system, a dealer sets its
operating strategy according to the strategy of the other dealer and maximizes its
own infinite horizon discounted expected profit. In the centralized system, a central
authority (say manufacturer) exists, which considers the system-wide infinite
horizon discounted expected profit, and makes all decisions. Under decentralized
system with incentive, subsidy, penalty designs, manufacturer tries different designs
on decentralized system namely revenue sharing, holding cost subsidy, request
rejection penalty, transportation cost subsidy and commission subsidy in order to
v
align decentralized system with centralized system. According to the results
obtained, this alignment works best with nearly 40% revenue sharing percentage,
low rejection penalty, high transportation cost subsidy under low transportation cost
and commission subsidy under very low or very high commissions. Holding cost
subsidy, on the other hand, is not a good strategy since it declines decentralized
system profit. Considering the second issue, two systems are examined<br>pooled
system and unpooled system. Both systems are centrally managed. In the pooled
system, all capacity is dynamically allocated to either dealer considering
maximization of system profit. In the unpooled system, capacity is shared among
dealers and dealers are always allocated same percentage of the capacity. Infinite
horizon average expected profit is maximized in both systems. The dealer having
lower holding cost is allocated higher capacity in both pooled and unpooled system<br>however, exceptions exist in the unpooled system under low arrival rate. Highrevenue
dealer is always allocated higher capacity in both pooled and unpooled
system. Arrival rate affects both systems such that total capacity utilization increases
with increasing arrival rate. From the profit point of view, pooled system has great
advantage under low demand rate in general.
37
Schönström, Linus. "Programming a TEM for magnetic measurements : DMscript code for acquiring EMCD data in a single scan with a q-E STEM setup." Thesis, Uppsala universitet, Tillämpad materialvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-306167.
Texte intégralRésumé :
Code written in the DigitalMicrograph® scripting language enables a new experimental design for acquiring the magnetic dichroism in EELS. Called the q-E STEM setup, it provides simultaneous acquisition of the dichroic pairs of spectra (eliminating major error sources) while preserving the real-space resolution of STEM. This gives the setup great potential for real-space maps of magnetic momenta which can be instrumental in furthering the understanding of e.g. interfacial magnetic effects. The report includes a thorough presentation of the created acquisition routine, a detailed outline of future work and a fast introduction to the DMscript language.
38
Paiva, ?verton de Oliveira. "Melhoria na converg?ncia do algoritmo Q-Learning na aplica??o de sistemas tutores inteligentes." UFVJM, 2016. http://acervo.ufvjm.edu.br/jspui/handle/1/1386.
Texte intégralRésumé :
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Previous issue date: 2016<br>O uso sistemas computacionais como complemento ou substitui??o da sala de aula ? cada vez
mais comum na educa??o e os Sistemas Tutores Inteligentes (STIs) s?o uma dessas alternativas.
Portanto ? fundamental desenvolver STIs capazes tanto de ensinar quanto aprender informa??es
relevantes sobre o aluno atrav?s de t?cnicas de intelig?ncia artificial. Esse aprendizado acontece
por meio da intera??o direta entre o STI e o aluno que ? geralmente demorada. Esta disserta??o
apresenta a inser??o da metaheur?sticas Lista Tabu e GRASP com o objetivo de acelerar esse
aprendizado. Para avaliar o desempenho dessa modifica??o, foi desenvolvido um simulador de
STI. Nesse sistema, foram realizadas simula??es computacionais para comparar o desempenho
da tradicional pol?tica de explora??o aleat?ria e as metaheur?sticas propostas Lista Tabu e
GRASP. Os resultados obtidos atrav?s dessas simula??es e os testes estat?sticos aplicados
indicam fortemente que a introdu??o de meta-heur?sticas adequadas melhoram o desempenho
do algoritmo de aprendizado em STIs.<br>Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Educa??o, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016.<br>Using computer systems as a complement or replacement for the classroom experience is an
increasingly common practice in education and Intelligent Tutoring Systems (ITS) are one of
these alternatives. Therefore, it is crucial to develop ITS that are capable of both teaching and
learning relevant information about the student through artificial intelligence techniques. This
learning process occurs by means of direct, and generally slow, interaction between the ITS and
the student. This dissertation presents the insertion of meta-heuristic Tabu search and GRASP
with the purpose of accelera ting learning. An ITS simulator was developed to evaluate the
performance of this change. Computer simulations were conducted in order to compare the
performance of traditional randomized search methods with the meta-heuristic Tabu search.
Results obtained from these simulations and statistical tests strongly indicate that the
introduction of meta-heuristics in exploration policy improves the performance of the learning
algorithm in ITS.
39
Fogla, Prahlad. "Improving the Efficiency and Robustness of Intrusion Detection Systems." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19772.
Texte intégralRésumé :
With the increase in the complexity of computer systems, existing security measures are not enough to prevent attacks. Intrusion detection systems have become an integral part of computer security to detect attempted intrusions. Intrusion detection systems need to be fast in order to detect intrusions in real time. Furthermore, intrusion detection systems need to be robust against the attacks which are disguised to evade them.
We improve the runtime complexity and space requirements of a host-based anomaly detection system that uses q-gram matching. q-gram matching is often used for approximate substring matching problems in a wide range of application areas, including intrusion detection. During the text pre-processing phase, we store all the q-grams present in the text in a tree. We use a tree redundancy pruning algorithm to reduce the size of the tree without losing any information. We also use suffix links for fast linear-time q-gram search during query matching. We compare our work with the Rabin-Karp based hash-table technique, commonly used for multiple q-gram matching.
To analyze the robustness of network anomaly detection systems, we develop a new class of polymorphic attacks called polymorphic blending attacks, that can effectively evade payload-based network anomaly IDSs by carefully matching the statistics of the mutated attack instances to the normal profile. Using PAYL anomaly detection system for our case study, we show that these attacks are practically feasible. We develop a formal framework which is used to analyze polymorphic blending attacks for several network anomaly detection systems. We show that generating an optimal polymorphic blending attack is NP-hard for these anomaly detection systems. However, we can generate polymorphic blending attacks using the proposed approximation algorithms. The framework can also be used to improve the robustness of an intrusion detector. We suggest some possible countermeasures one can take to improve the robustness of an intrusion detection system against polymorphic blending attacks.
40
Soydas, Belma. "Characterization Of Zeolite Membranes By Gas Permeation." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610603/index.pdf.
Texte intégralRésumé :
Zeolite membranes are attractive materials to separate gas and liquid mixtures.
MFI is a widely studied zeolite type due to its ease of preparation and
comparable pore size with the molecular size of many substances. In this
study MFI type membranes were synthesized over porous &<br>#945<br>-Al2O3 supports
and characterized with XRD, SEM and gas permeation measurements.
In the first part of this study the effect of soda concentration of the synthesis
solution on the membrane morphology and crystal orientation was investigated.
The synthesis was carried out from solutions with a molar composition of (0-
6.5)Na2O:25SiO2:6.9TPABr:1136H2O at 150oC. At soda concentrations
between 0.45 and 1.8 the membrane layers with (h0h)/c-directed orientation
were obtained. At lower and higher soda concentrations membrane layer
formed from randomly oriented crystals. The (h0h)/c-oriented membranes
showed H2/n-C4H10 ideal selectivities of 478 and 36 at 25°<br>C and 150°<br>C,
respectively.In the second part, MFI membranes were synthesized from mixtures with
different concentrations of template molecules. Tetrapropylammonium
hydroxide, tetrapropylammonium bromide or mixture of both types were used
as template. The nucleation period, the size of MFI crystals, membrane
thickness decreased as the tetrapropylammonium hydroxide concentration
increased. Besides conversion of SiO2 in the synthesis solution to MFI passed
through a maximum with increasing concentration of tetrapropylammonium
hydroxide in the synthesis solution. When tetrapropylammonium bromide
was used as template thicker membranes were obtained.
In the third part MFI type membranes with a thickness of 1.5-2 &<br>#956<br>m were
synthesized by mid-synthesis addition of silica to the synthesis medium. The
membranes synthesized with and without mid-synthesis addition of silica have
n-C4H10/i-C4H10 ideal selectivities of 47 and 8 at 100oC, respectively. The
change of composition during the synthesis increases the crystal growth rate
and the size of the crystals forming the membrane, thus better quality
membranes can be obtained by mid-synthesis addition of silica to the synthesis
medium.
In the last part of this study, thin MFI type zeolite membranes were synthesized
in a recirculating flow system at 95°<br>C on the inner side of the tubular &<br>#945<br>-
alumina supports. A membrane synthesized by two consecutive synthesis steps
had a separation selectivity of 38 and 86 for equimolar mixtures of n-
C4H10/CH4 and n-C4H10/N2 at 25oC, respectively. The membrane selectively
permeated large n-C4H10 over small CH4 and N2, suggesting that the separation
is essentially adsorption-based and the membrane has few nonselective
intercrystalline pores.
41
Vincent, Christopher. "An enquiry into the role of values in the attrition of teachers of physical science subjects." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/an-enquiry-into-the-role-of-values-in-the-attrition-of-teachers-of-physical-science-subjects(ef976337-009c-455b-b080-0dd7ee5c831f).html.
Texte intégralRésumé :
This thesis enquires into the role of values in the attrition of teachers of physical science subjects in the formative years of their teaching careers. Recruitment and attrition have contributed to a shortage of these teachers in English schools (Bousted, 2016), and while recruitment has benefited from increased investment (Gov.uk, 2017), attrition has largely gone unaddressed. In belief system theory, values are considered to be intrinsically linked to the behaviours people exhibit (Ajzen and Fishbein, 1980). As the behaviour of interest in this thesis is the departure of these teachers from the profession, it was decided that the values informing this behaviour should be investigated. Values are also components of an organisation's culture, which is linked to job commitment and satisfaction (Branson, 2008). It is therefore possible that when the values of these teachers and those in school culture are aligned, this will contribute to reduced attrition. Based on the works of Rokeach (1973) and Schwartz (2012), an adapted value scale using Q-method was developed to measure the value systems of student teachers and those contributing to school culture as determined by secondary school department leaders. The measurement and comparison of these value systems showed: values held by these teachers in the formative years of their careers evolve, and ITT guides this; physical science and non-physical science student teacher value systems were shown in some instances to be similar, and in others to be noticeably different; one of the two physical science student teacher value systems was in most instances aligned with the value systems identified as being present in English secondary school culture; misalignment showed that physical science specialists place less emphasis on having a sense of belonging and on benevolence oriented values; when compared with the values in English secondary school culture, teachers in the formative years of their careers, regardless of their specialism, have the potential to overemphasise the importance of conformity oriented values. It is suggested that these combined factors contribute to the attrition of teachers of physical science subjects in the formative years of their careers.
42
ZHUANG, MEI-XIN, and 莊美幸. "A study of parallel coordinates system and multivariate Q-Q pots." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/28773538160379229156.
Texte intégralRésumé :
碩士<br>國立中正大學<br>應用數學研究所<br>80<br>1. 前言
2. 平行坐標系統的探討
2.1 有關的多變量資料圖形的顯示法
2.2 平行坐標幾何
2.3 齊次坐標系統
2.4 平行坐標幾何的深入探討
2.5 推廣到RN的結果
3. 用平行坐標顯示法解釋統計的資料分析
4. Q-Q 圖
4.1 介紹
4.2 從匹配的觀點看多變量Q-Q 圖
4.3 以多變量匹配為根據的Q-Q 圖之顯示法
5. 用多變量顯示法呈現Q-Q 圖的構想
6. 結論與建議
附錄
參考文獻
43
Chen, Ying-Yu, and 陳盈伃. "HARQ by Fuzzy Q-learning for MIMO HSDPA System." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/35166226138337746429.
Texte intégralRésumé :
碩士<br>國立交通大學<br>電信工程系所<br>97<br>Multiple input multiple output high speed downlink packet access (MIMO HSDPA) system is proposed by 3rd generation partnership project (3GPP) to provide higher transmission data rate and more resource utilization. An important QoS requirement defined in spec is to choose a suitable MCS based on the channel quality indicator while maintaining the initial block error rate (BLER) smaller than 0.1. Therefore, we proposed a fuzzy Q-learning based MIMO HARQ (FQLM-HARQ) scheme for MIMO HSDPA system to solve this problem. The FQLM-HARQ scheme can take the advantage from both fuzzy logic and Q-learning. Here, the HARQ scheme is modeled as a Markov decision process (MDP). The fuzzy rule is designed to separate different parts according to the BLER performance and the Q-learning algorithm can learn the optimal MCS under different environment. After learning, we can expect the MIMO HSDPA system with higher throughput while not violating the BLER requirement.
From simulation results, the proposed FQLM-HARQ scheme can achieve higher system throughput and endeavor to maintain the BLER requirement with channel quality indicator delay consideration. Comparing to other traditional schemes, the FQLM-HARQ scheme can accommodate well in channel variation.
44
Chen, Fei-Ting, and 陳非霆. "Convolutional Deep Q-learning for ETF Automated Trading System." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/f8asxa.
Texte intégralRésumé :
碩士<br>國立政治大學<br>應用數學系<br>106<br>In this paper, we used DCQN model, which is combined with reinforcement learning and CNN to train a trading system and hope the trading system could judge whether buy or sell ETFs. Since ETFs is a derivative financial good with high stability and related fee, the system does not perform real-time trading and it performs every 20 trading day. The system predicts value of action based on data in the last 20 opening days to maximize our future rewards.
DQN is a reinforcement learning model, using deep learning to predict value of actions in model. Combined with the RL's mechanism, which updates value of actions, and deep learning, which has a strong ability of learning, to finish an artificial intelligence. We got a perfect effect.
45
Tsai, Cheng-Yu, and 蔡承佑. "Online Learning System Using Q&A management mechanism." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/90277341659478981179.
Texte intégralRésumé :
碩士<br>國立中央大學<br>資訊工程研究所<br>98<br>Students usually turn to on-line information when they
study. Thus they can make up for the infertility of the
textbook contents, solving their questions and acquiring
more complete knowledge. However, sometimes students can
not find satisfying solution on the web, then except for
asking somebody in real-life, they can also post a
question on the forum and discuss with others in the forum
to come up with a proper answer.
However, because the forum is independent from the
textbook, discussions that aimed at some particular
concepts in the textbook is scattered all over the whole
forum. Even if students use keywords to search, they
always find other matterless discussions and have to spend
much time picking up useful discussion-threads they really
interested in. Moreover, when students post new questions,
they must frequently go back to the threads to check if
someone has answered their questions. And, when they need
to keep discussing with others in some threads, each time
they should search out the threads in the forum before
that.
Tracing the progression of discussion threads waste
much time and effort, inducing students’ unwillingness to
ask questions and discuss in an on-line forum. Hence we
propose a framework to combine Q&A management mechanism
with the textbook content. In such way, students can
easily find related discussions in the forum when they
read textbook, and they can subscribe interested threads
and monitor the status and progression of the threads.
These information help students to decide which thread is
worth reading in current context.
46
CHIA-LINGCHIANG and 姜佳伶. "Convergence Improvement of Q-learning Based on Personalized Recommendation System." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/d5fu9d.
Texte intégralRésumé :
碩士<br>國立成功大學<br>電機工程學系<br>106<br>Benefiting from vast improvements in computer technology, cooperation between humankind and computers has made the goal of enhancing workplace efficiency and convenience a reality by exploiting Artificial Intelligence. Among the many sub-research fields of Artificial Intelligence, Reinforcement Learning (RL) exploits the concept of reward/penalty in human learning so that the feedback signals of the environment can be used for self-learning without previous knowledge. The basic elements of RL include state, action, environment, learning agent, and reward/penalty. Although RL has been applied to many research fields, there are difficulties when implementing it in real world applications. One difficulty is the tradeoff between exploration and exploitation for the agent of RL in choosing a proper action—an improper action may lead to learning failure or an increase in learning cost. The other difficulty is that the learning agent of RL needs to interact with the environment to attain this real-time reward/penalty; however, the learning time consumed in the interaction process may be too long. In order to overcome the aforementioned difficulties, this thesis proposes an approach that employs a personalized recommendation system to provide a feedforward candidate action for RL to implement self-adaptive learning through teaching. A cliff-walking computer simulation and a visual tracking experiment using a pan/tilt camera are both conducted to assess the performance of the proposed approach. Experimental results show that this personalized recommendation system-based RL is able to improve the effectiveness and practicality of RL.
47
Wang, Chen-Ming, and 王誠明. "Improve Natural Language Q&A System based on scenario Study." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/75830561725258202131.
Texte intégralRésumé :
碩士<br>元智大學<br>資訊工程學系<br>91<br>People tend to find data or information through net surfing as computers and networks become more and more popular. Computer system analyzes user queries and searches for the demanded data or information. However, usually computer system provides only query input with fixed input column, while Q&A (Question and Answer) system merely uses the fixed-column query inputs as keywords to search and then to return the found data as results. This kind of Q&A system lacks of flexibility that user cannot express query condition adequately with limited input columns.
To solve the problem discussed above, it is necessary that Q&A system have the ability to deal with natural language input, one language that is most familiar to users so that query conditions can be expressed exactly and adequately. Yet, computer analysis cannot handle the semantics ambiguity of natural language input without the aid of scenario, which will lead to misinterpretation. “Language communication is not just a language communication”. Human brain explains semantics ambiguity by the aid of scenario such as background knowledge, speaker’s body language, etc, which computer system does not have.
Since scenario seems to have significant role in natural language analysis while there are only question strings provided by user in a Q&A system, we try to understand the scenario from lateral information of those question strings. For instance, length of string, keyword, use amount of proper noun, the relationship between subject of sentence and user, preceding sentences, etc… may be used to gather statistics and to analyze the scenario. According to the scenario, an appropriate natural language logic handling is applied while parsing and comparing the natural language.
Proper update to keyword database, weight of keyword, syntactical and morphologic features similarity comparison algorithm, is also performed then. This mechanism approaches the logic of human brain in the way that, not only one natural language analysis rule is applied stiffly to any user, but, an appropriate analysis rule is selected based on natural language query and its corresponding scenario and then is applied to distinct users, and thus may reduce analysis error.
48
Zih-LingLiu and 劉子菱. "Optimal Design of a Markovian (s, Q) Inventory System with Backorder." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/dn9j44.
Texte intégral
49
WANG, CHING-HSIEN, and 汪靜嫻. "The decentralized Q&A system for social and mobile networks." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/k7zvnq.
Texte intégralRésumé :
碩士<br>國立中正大學<br>資訊管理學系碩士在職專班<br>107<br>This research can be used to analyze user’s question and answer behavior. The current decentralized concept is a method that is commonly used on the Internet. From a question-and-answer-based websites to a mobile social networking apps, users have become accustomed to lightweight and fast user experience. Based on the social network-based website, this study proposes an effective way to make Q&A more efficient, enabling social networking sites to achieve lightweight, low cost, and fast response. The low computational cost makes the research system suitable for mobile devices. By using keyword, this system can infer the suitable respondents who are willing to contribute their correct answers between the neighboring nodes, and can forward the question to the node that can further to answer the question, improving the overall quality of the answer.
Keyword: light Q&A system
50
Liu, Yu-Cherng, and 劉禹成. "Compensation of I/Q Imbalance for OFDM system Using Frequency Dependent Equalizer." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/33133188648208116588.
Texte intégral