To see the other types of publications on this topic, follow the link: Correctional change.

Dissertations / Theses on the topic 'Correctional change'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Correctional change.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Fortin, Sylvie. "Attitude change in correctional groups." Thesis, University of Ottawa (Canada), 1995. http://hdl.handle.net/10393/10143.

Full text
Abstract:
Group polarization is a phenomenon in which moderate attitudes or opinions espoused by a social group tend to become more extreme in the course of interactions and discussions within the group. Using a modified form of the group polarization paradigm, the present study examined the conditions under which group polarization or related phenomena may operate within correctional treatment or discussion groups to inadvertently foster the amplification of procriminal attitudes or beliefs. Inmates at a correctional treatment facility were assigned to small discussion groups on the basis of their pre-experimental scores on psychometric tests measuring either identification with the inmate code (High vs. Low Inmate Solidarity) or antisocial/prosocial personality traits (High vs. Low Criminality). Each group then engaged in brief discussions of (a) topics preselected to elicit or trigger categorizations along a prosocial-procriminal dimension ("prototypical" topics), and (b) neutral topics. Group-mediated attitudinal shifts were affected by both the type of group composition and by the discussion topic. Only homogeneous groups of High Inmate Solidarity subjects showed significant strengthening of procriminal attitudes and this was the case only for discussions of prototypical topics, not for neutral topics. All other group compositions tended to exhibit shifts toward the mid-point of the rating (i.e., more neutral or ambivalent post-discussion attitudes), regardless of the type of topic discussed. The results are interpreted as providing evidence for Self-Categorization Theory, which posits that group-mediated attitude change is a phenomenon of conformity to local ingroup norms--representing what group members perceive to be the group consensus--and factors influencing the salience of ingroup-outgroup categorizations or group identity. The clinical implications of these findings for correctional treatment groups and implications for future research are discussed.
APA, Harvard, Vancouver, ISO, and other styles
2

Pealer, Jennifer A. "Correctional Rehabilitation and Therapeutic Communities: Reducing Recidivism Through Behavior Change (Routledge Innovations in Corrections)." Digital Commons @ East Tennessee State University, 2017. https://www.amzn.com/B06XPJB48M.

Full text
Abstract:
Drawing on original research on the effectiveness of a therapeutic community (TC) in reducing recidivism among juvenile male offenders, Correctional Rehabilitation and Therapeutic Communities: Reducing Recidivism Through Behavior Change provides a comprehensive review of the current state of drug treatment for the offending population, especially the link between juvenile offending and substance abuse. The book assesses the factors predicting successful completion of treatment as well as the methodological limitation of previous TC program reviews, and suggests policy implication and routes for future research. Using improvements such as multiple outcome criteria, long-term follow-up, matching groups on risk and needs, and the employment of a standardized instrument to measure program quality, Correctional Rehabilitation assesses the degree to which participation in the TC affects antisocial attitudes and reduces delinquency. Readers will explore how TCs can be designed to influence adolescent drug offenders and ultimately reduce recidivism. This book is essential reading for students, researchers, practitioners, and other stakeholders focusing on the development of treatment programs.
https://dc.etsu.edu/etsu_books/1145/thumbnail.jpg
APA, Harvard, Vancouver, ISO, and other styles
3

Forde, Hugh Anthony. "Evaluation of a stress inoculation training program at an Ohio male correctional institution." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1117557647.

Full text
Abstract:
Thesis (Ph.D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains ix, 129 p.; also includes graphics. Includes bibliographical references (p. 120-129). Available online via OhioLINK's ETD Center
APA, Harvard, Vancouver, ISO, and other styles
4

Madia, M. S. "The role of transformation in the provision and maintenance of personnel in the Department of Correctional Services Pretoria Central Prison /." Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-01312006-103832.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Chan, Wing-kit Eric. "An analysis of human resource management in correctional homes of the Social Welfare Department : implications for change /." Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18595753.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Varga, Carey Lee. "A quasi-experimental study to examine knowledge and stage of smoking change following a smoking intervention in a federal correctional setting." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq22412.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Rubtcova, Mariia. "The education system for children with disabilities in the modern Russia: problems of reforming correctional school education." Doctoral thesis, Universitat de Girona, 2019. http://hdl.handle.net/10803/668026.

Full text
Abstract:
Inclusive education is a pedagogic approach that has been developed in response to the demand for including children with disabilities in regular school education. The present work is devoted to the studying of the reforming characteristics of the Russian correctional school education and attempts have been made to include inclusive education in particular social context related to Russian secondary schools. This thesis presents a series of studies devoted to the issues of the correctional education reform and the development of inclusive education in St. Petersburg during the period 2012-2016. The first public demonstration against the reform of correctional education started in 2011 after the beginning of the neoliberal educational reforms of the government. Therefore, our first study in 2012 was devoted to the opinion poll of the St. Petersburg residents focused on the reform of correctional and inclusive education. In December, 2012, 396 structured interviews were carried out. They were repeated in March, 2014. It is interesting to note that the study showed a fairly high loyalty to inclusive education. Our second research devoted to stakeholders was conducted in 2014. The first stage was devoted to teachers of regular schools in order to understand the extent of their acquaintance and involvement in the process of implementing inclusive education. 196 questionnaires of respondents - teachers at regular school in 2012 and 343 in 2014 were achieved. The second stage was devoted to the opinion of students of teacher education. We have 276 questionnaires of student-future teachers in 2012 and 269 in 2015. The research revealed quite contradictory assessments and judgments. The results showed that the concept of inclusive education gradually integrates into the life of modern Russia but also requires efforts to fully implement it in the educational process.
La educación inclusiva es un enfoque pedagógico que se ha desarrollado en respuesta a la demanda de incluir alumnado con discapacidades en el sistema educativo ordinario. El presente trabajo está dedicado al estudio de las características de la reforma de la educación escolar especial en Rusia, planteando los avances desarrollados en relación a la educación inclusiva. Esta tesis presenta varios estudios dedicados a la reforma de la educación especial (Correctional Education) y el desarrollo de la educación inclusiva en San Petersburgo durante el período 2012-2016. La primera manifestación pública contra la reforma de la educación especial comenzó en 2011, después del inicio de las reformas educativas neoliberales del gobierno. Por esta razón, nuestro primer estudio en 2012 estuvo dedicado a la encuesta de opinión de los residentes de San Petersburgo centrada en la reforma de la educación correccional. En diciembre de 2012 se realizaron 396 entrevistas estructuradas. Se repitieron en marzo de 2014. Es interesante observar que el estudio mostró una adhesión considerablemente elevada a la educación inclusiva. Nuestra segunda investigación se llevó a cabo en 2014. La primera etapa se dedicó a los maestros de escuelas ordinarias para comprender el alcance de su conocimiento y participación en el proceso de implementación de la educación inclusiva. Se obtuvieron 196 cuestionarios procedentes de maestros en escuelas ordinarias en 2012 y 343 en 2014. La segunda etapa se dedicó a profundizar en la opinión de los alumnos de magisterio. Obtuvimos 276 cuestionarios de futuros maestros, actuales estudiantes en 2012 y 269 en 2015. La investigación reveló evaluaciones y juicios bastante contradictorios. Los resultados mostraron que el concepto de educación inclusiva se integra gradualmente en la vida de la Rusia moderna, pero también requiere esfuerzos para avanzar en su total implementación en el proceso educativo.
APA, Harvard, Vancouver, ISO, and other styles
8

Mayles, Philip Andrew. "Evaluating systemic change in the Virginia Department of Corrections : creating agents of change /." Full-text of dissertation on the Internet (63 KB), 2009. http://www.lib.jmu.edu/general/etd/2009/Masters/Mayles_PhilipA/maylespa_masters_11-30-2009.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Hodge, Miriam Christine. "Bias correction and change measurement in spatio-temporal data." Thesis, University of Canterbury. Department of Mathematics and Statistics, 2012. http://hdl.handle.net/10092/7540.

Full text
Abstract:
A simplistic view of a dataset is that it is collection of numbers. In fact data are much more than that and all data are collected at a set place and time. Often either the location, or the time, is fixed within the dataset and one or both are disregarded. When the place and time of the collection are incorporated into the analysis, the result is a spatio-temporal model. Spatio-temporal data are the focus of this thesis. The majority of the datasets used are radio tracking studies of animals where the objective is to measure the habitat use. Observations are made over a long period of time and a large area. The largest dataset analysed tracks over a hundred animals, in an area larger than 40 square miles, for multiple years. In this context understanding the spatio-temporal relationships between observations is essential. Even data that do not have an obvious spatial component can benefit from spatio-temporal analysis. For example, the data presented on volatility in the stock market do not have an obvious spatial component. The spatial component is the location in the market, not a physical location. Two different methods for measuring and correcting bias are presented. One method relies on direct modelling of the underlying process being observed. The underlying process is animal movement. A model for animal movement is constructed and used to estimate the missing observations that are thought to be the cause of the bias. The second method does not model the animal movement, but instead relies on a Bayesian Hierarchical Model with some simple assumptions. A long running estimation is used to calculate the most likely result without ever directly estimating the underlying equations. In the second section of the thesis two methods for measuring change from shifts in both spatial and temporal location are presented. The methods, Large Diffeomorphic Deformation Metric Mapping (LDDMM) and Diffeomorphic Demons (DD), were originally developed for anatomical data and are adapted here for nonparametric regression surfaces. These are the first applications of LDDMM and DD outside of computational anatomy.
APA, Harvard, Vancouver, ISO, and other styles
10

Devlin, Renee S. "Responsible Adult Culture: Cognitive and Behavioral Changes at a Community-Based Correctional Facility." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1211297932.

Full text
APA, Harvard, Vancouver, ISO, and other styles
11

Cripps, Emily Jane. "USING ASSESSMENT INSTRUMENTS TO PREDICT RECIDIVISM FOLLOWING A LIFESTYLE CHANGE PROGRAM." OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2493.

Full text
Abstract:
The vast number of individuals under correctional supervision in the United States has been an area of concern for decades. The correctional population as a whole is made up of approximately six million individuals, with approximately four million serving community sentences. It is essential to provide adequate services and resources to those serving community sentences due to the large number serving such sentences. To add to the concern is the immense number of offenders with mental illness under correctional supervision. Often, offenders with mental illness receive psychiatric services, but treatment programs that address the cause of criminal activity are neglected. The goal of this study is to examine scores from two assessment instruments measuring criminal thinking and the therapeutic alliance to determine their predictability for future criminal activity using a sample of thirty-five probationers with mental illness. Probationers completed both the Psychological Inventory of Criminal Thinking Styles and the Working Alliance Inventory in order to determine the extent of criminal cognitions and measure the relationship between therapist and patient and agreement towards the goals and tasks of therapy, respectively. Results indicate that probationers who score less favorably on each of the scales were more likely to obtain a new charge following completion of the program. Further, less Agreement on the Tasks of Therapy was a significant predictor for future criminal activity. This study adds to the correctional mental health treatment literature, and illuminates areas which can be improved and provides recommendations for future research.
APA, Harvard, Vancouver, ISO, and other styles
12

Devlin, Renee. "Responsible Adult Culture (RAC) cognitive and behavioral changes at a community-based correctional facility /." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1211297932.

Full text
APA, Harvard, Vancouver, ISO, and other styles
13

Armstrong, Deborah. "The Role of vision and refractive correction changes in dizziness." Thesis, University of Bradford, 2018. http://hdl.handle.net/10454/16956.

Full text
Abstract:
Dizziness is a common, multifactorial problem that causes reductions in quality of life and is a major risk factor for falls, but the role of vision is a very under-researched area. This study aimed to investigate any link between dizziness and vision and to establish if changes in spectacle lens correction could elicit dizziness symptoms. A link between dizziness and self-reported poor vision was indicated in the epidemiological literature as shown by a systematic review, provided lightheadedness was not included in the definition of dizziness. Cases of individuals who reported vision-related dizziness were investigated to determine potential areas of research for this thesis and subsequently two studies investigated the effects of refractive correction changes on dizziness status. The first study was limited by logistical problems, although it highlighted limitations in the short form of the Dizziness Handicap Inventory that was used to quantify dizziness. Results of an optometry practice recheck study found that oblique cylindrical changes were significantly more likely to be associated with dizziness symptoms than other spectacle lens changes. It also highlighted that optometrists do not ask/record about dizziness symptoms with only 4% of records including “dizziness” as a problem when 38% of patients reported dizziness symptoms when directly asked. All studies highlighted a need for a patient-reported outcome measure to be designed to assess vision-related dizziness. Literature review, interviews with experts and patients and focus groups led to the development of a pilot questionnaire and subsequently a 25-item Vision-Related Dizziness instrument, the VRD-25. This was validated using responses from 223 respondents, with 79 participants completing the questionnaire a second time to provide test-retest data. Two subscales of VRD-12-frequency (VRD-12f) and VRD-13-severity (VRD-13s) were shown to be unidimensional and had good psychometric properties, convergent validity and test-retest repeatability. The VRD-25 is the only patient-reported outcome measure developed to date to assess vision related dizziness and will hopefully provide the platform to further grow this under-researched area that seems likely to provide important clinical information.
College of Optometrists sponsored the research with a Postgraduate Research Scholarship
APA, Harvard, Vancouver, ISO, and other styles
14

Mispan, Muhamad Radzali. "Multi-sensor remote sensing data for change detection analysis : a case study from peninsular Malaysia." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338538.

Full text
APA, Harvard, Vancouver, ISO, and other styles
15

Patel, Sudhir. "An investigation of the optical zone of the human cornea and changes induced by excimer laser surgery." Thesis, Glasgow Caledonian University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316647.

Full text
APA, Harvard, Vancouver, ISO, and other styles
16

Liu, Wenjie. "Estimation and bias correction of the magnitude of an abrupt level shift." Thesis, Linköpings universitet, Statistik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-84618.

Full text
Abstract:
Consider a time series model which is stationary apart from a single shift in mean. If the time of a level shift is known, the least squares estimator of the magnitude of this level shift is a minimum variance unbiased estimator. If the time is unknown, however, this estimator is biased. Here, we first carry out extensive simulation studies to determine the relationship between the bias and three parameters of our time series model: the true magnitude of the level shift, the true time point and the autocorrelation of adjacent observations. Thereafter, we use two generalized additive models to generalize the simulation results. Finally, we examine to what extent the bias can be reduced by multiplying the least squares estimator with a shrinkage factor. Our results showed that the bias of the estimated magnitude of the level shift can be reduced when the level shift does not occur close to the beginning or end of the time series. However, it was not possible to simultaneously reduce the bias for all possible time points and magnitudes of the level shift.
APA, Harvard, Vancouver, ISO, and other styles
17

Mazzocco, Philip James. "Moderators of the effects of mental imagery on persuasion the cognitive resources model and the imagery correction model /." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1127050519.

Full text
Abstract:
Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xvi, 251 p.; also includes graphics. Includes bibliographical references (p. 157-174). Available online via OhioLINK's ETD Center
APA, Harvard, Vancouver, ISO, and other styles
18

Yang, Jung-A. "Projection of future storm surges around the Korean Peninsula considering climate change effect." Kyoto University, 2017. http://hdl.handle.net/2433/227603.

Full text
APA, Harvard, Vancouver, ISO, and other styles
19

Zhang, Feng. "Climate change assessment for the southeastern United States." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/45770.

Full text
Abstract:
Water resource planning and management practices in the southeastern United States may be vulnerable to climate change. This vulnerability has not been quantified, and decision makers, although generally concerned, are unable to appreciate the extent of the possible impact of climate change nor formulate and adopt mitigating management strategies. Thus, this dissertation aims to fulfill this need by generating decision worthy data and information using an integrated climate change assessment framework. To begin this work, we develop a new joint variable spatial downscaling technique for statistically downscaling gridded climatic variables to generate high-resolution, gridded datasets for regional watershed modeling and assessment. The approach differs from previous statistical downscaling methods in that multiple climatic variables are downscaled simultaneously and consistently to produce realistic climate projections. In the bias correction step, JVSD uses a differencing process to create stationary joint cumulative frequency statistics of the variables being downscaled. The functional relationship between these statistics and those of the historical observation period is subsequently used to remove GCM bias. The original variables are recovered through summation of bias corrected differenced sequences. In the spatial disaggregation step, JVSD uses a historical analogue approach, with historical analogues identified simultaneously for all atmospheric fields and over all areas of the basin under study. In the second component of the integrated assessment framework, we develop a data-driven, downward hydrological watershed model for transforming the climate variables obtained from the downscaling procedures to hydrological variables. The watershed model includes several water balance elements with nonlinear storage-release functions. The release functions and parameters are data driven and estimated using a recursive identification methodology suitable for multiple, inter-linked modeling components. The model evolves from larger spatial/temporal scales down to smaller spatial/temporal scales with increasing model structure complexity. For ungauged or poorly-gauged watersheds, we developed and applied regionalization hydrologic models based on stepwise regressions to relate the parameters of the hydrological models to observed watershed responses at specific scales. Finally, we present the climate change assessment results for six river basins in the southeastern United States. The historical (baseline) assessment is based on climatic data for the period 1901 through 2009. The future assessment consists of running the assessment models under all IPCC A1B and A2 climate scenarios for the period from 2000 through 2099. The climate assessment includes temperature, precipitation, and potential evapotranspiration; the hydrology assessment includes primary hydrologic variables (i.e., soil moisture, evapotranspiration, and runoff) for each watershed.
APA, Harvard, Vancouver, ISO, and other styles
20

Eden, Jonathan Michael. "Development of a correction approach for future precipitation changes simulated by General Circulation Models." Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/1514/.

Full text
Abstract:
Producing reliable estimates of changes in precipitation at local- and regional-scales remains an important challenge in climate change science. Statistical downscaling methods are often utilised to bridge the gap between the coarse resolution of General Circulation Models (GCMs) and the higher-resolutions at which information is required by the majority of end users. However, the skill of GCM precipitation, particularly in simulating temporal variability, is not fully understood and statistical downscaling typically adopts a ‘Perfect-Prog’ (short for perfect prognosis) approach in which the derivation of high-resolution precipitation projections is based on real world statistical relationships between large-scale atmospheric ‘predictors’ and local-scale precipitation. Here, a ‘nudged’ simulation of the ECHAM5 GCM is conducted in which the large-scale climatic state is forced towards historical observations of large-scale circulation and temperature for the period 1958-2001. By comparing simulated and observed precipitation it is possible to, for the first time, quantify GCM skill in simulating temporal variability of precipitation. Correlation between simulated and observed monthly mean precipitation is shown to be as strong as 0.8-0.9 in many parts of Europe, North America and Australia. A nudged simulation permits the development of an alternative approach to statistical downscaling, known as Model Output Statistics (MOS), to correct precipitation as simulated by ECHAM5. It is also shown that MOS correction offers greater skill than Perfect-Prog methods when estimating local-scale monthly mean precipitation. The strongest-performing MOS models are applied to ECHAM5 climate change simulations and are shown to produce high-resolution precipitation projections that support those of RCM simulations. The potential for extending the MOS approach to daily precipitation is also assessed, with recommendations made for further research and application.
APA, Harvard, Vancouver, ISO, and other styles
21

Switanek, Matthew B., Peter A. Troch, Christopher L. Castro, Armin Leuprecht, Hsin-I. Chang, Rajarshi Mukherjee, and Eleonora M. C. Demaria. "Scaled distribution mapping: a bias correction method that preserves raw climate model projected changes." COPERNICUS GESELLSCHAFT MBH, 2017. http://hdl.handle.net/10150/624439.

Full text
Abstract:
Commonly used bias correction methods such as quantile mapping (QM) assume the function of error correction values between modeled and observed distributions are stationary or time invariant. This article finds that this function of the error correction values cannot be assumed to be stationary. As a result, QM lacks justification to inflate/deflate various moments of the climate change signal. Previous adaptations of QM, most notably quantile delta mapping (QDM), have been developed that do not rely on this assumption of stationarity. Here, we outline a methodology called scaled distribution mapping (SDM), which is conceptually similar to QDM, but more explicitly accounts for the frequency of rain days and the likelihood of individual events. The SDM method is found to outperform QM, QDM, and detrended QM in its ability to better preserve raw climate model projected changes to meteorological variables such as temperature and precipitation.
APA, Harvard, Vancouver, ISO, and other styles
22

Crowley-Ames, Coleen, and Phyllis Paulette McNeal. "Successful outcomes of adult ex-offenders: "Catalyst to Change"." CSUSB ScholarWorks, 2003. https://scholarworks.lib.csusb.edu/etd-project/2287.

Full text
Abstract:
This descriptive, statistical survey research design sought to identify factors that motivate individuals to stay crime free after serving time in prison. The purpose of this research study was to examine the factors that played a significant role in recidivism.
APA, Harvard, Vancouver, ISO, and other styles
23

McAleese, Samantha A. "A Safe Space for a Second Chance: Exploring the Role of Performative Space in Delivering Education Programs to Justice-involved Adults in the Prison and the Community." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23139.

Full text
Abstract:
This thesis explores the structure and delivery of education programs to justice-involved adults in Canadian federal prisons and in the community. A series of semi-structured interviews as well as three volumes of the Journal for Prisoners on Prisons were analyzed using a qualitative approach to determine whether or not principles of adult education and components of performative space are present in current correctional education strategies. The findings suggest that while there are occurrences of both elements in the education that is provided to prisoners, the programs in the community are much more reflective of these adult learning standards. This project highlights the need for research into the area of adult correctional education, increased collaboration between the fields of criminology and education, and provides a framework from which future research can continue.
APA, Harvard, Vancouver, ISO, and other styles
24

Donpapob, Manee. "Impact of climate change on reservoir water storage and operation of large scale dams in Thailand." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/217151.

Full text
APA, Harvard, Vancouver, ISO, and other styles
25

Cho, Richard S. 1976. "Building a continuum of care through boundary spanning and organizational change : corrections and HIV/AIDS supported housing in Massachusetts." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/65256.

Full text
Abstract:
Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2000.
Includes bibliographical references (leaves 103-105).
In the current context of federal devolution, practitioners in supported housing systems and other diverse organizational contexts increasingly face the challenge of fostering coordination and managing conflicts of values and perspectives within organizations tied together in networks. Such coordination is problematic, just as conflicts are inevitable, within such networks and other inter-organizational systems because of the historically evolved structures and specialization of organizations. These specialized structures or 'domains' imply certain boundaries defining what activities can be considered internally coherent and consistent with organizational goals. Yet it is too often the case that these structures are "incomplete" in fulfilling all of society's needs. In situations where this is the case, "'gaps" can be said to exist between the domains of two organizations, and can have serious consequences for individuals and communities proximate to them. In this light, homelessness as a result of de-institutionalization, or unemployment among post-secondary school youth, may be seen as social problems generated by structural gaps between organizational domain boundaries. Solving these problems, I argue, requires that practitioners undertake roles in their own organizations that are 'boundary spanning.' Boundary spanning becomes a means of building ties across vast inter-organizational distances, inventing programmatic solutions to structural problems, and creating organizational change. In this thesis, I examine organizational change as it occurred within a specific interorganizational network of providers and institutions: a continuum of care for ex-offenders living with HIV/AIDS in Massachusetts. The case presented here is one in which I am both an observer/researcher and a practitioner. Reflecting upon the activities of myself and others working to expand access to HIV/AIDS supported and other housing opportunities, I analyze the attributes of our boundary spanning roles as examples of successful practice in creating organizational change towards our goal of homelessness prevention among ex offenders living with HIV/AIDS. From these attributes emerges a theory of practice for boundary spanning towards organizational change.
by Richard S. Cho.
M.C.P.
APA, Harvard, Vancouver, ISO, and other styles
26

Arnaud, David. "Analyse expérimentale des phénomènes instationnaires dans un compresseur multi-étages à forte charge aérodynamique." Ecully, Ecole centrale de Lyon, 2003. http://bibli.ec-lyon.fr/exl-doc/darnaud.pdf.

Full text
Abstract:
Ce travail s'inscrit dans le cadre d'un projet de recherche en collaboration avec SNECMA MOTEURS. La première partie de ce travail a consisté en la mise en place de la structure métrologique nécessaire à cette étude (nouvelles procédures informatiques, correction des distorsions générées sur les faisceaux laser par les accès optiques du compresseur, adaptation du procédé de synchronisation de façon à pouvoir mesurer l'ensemble des phénomènes instationnaires périodiques présents dans le compresseur). La deuxième partie de ce travail a concerné l'analyse des mesures dans différents plans inter-grilles. Le rôle important que jouent ces interactions est montré et leur structure spatiale, de type ondes tournantes, est analysée. Ces mesures constituent une importante base de données utilisables aussi bien pour la validation des codes de calcul que pour l'aide à la modélisation des phénomènes d'interaction rotor-stator
This work is a part of a research project in collaboration with SNECMA MOTEURS. The first part of this work consists in the set up of the metrology, essencial to this study (new data-processing procedures, study on the optical distortions on the laser beams by the optical accesses within the compressor, new synchronisation procedures with the rotation of the machine in order to permit the measurement on any periodic-insteady phenomena). The second part of this work relates to the analysis of measurements in a series of inter-grids planes. The significant role that these interactions have is showed and the measured flow structures, a set of spinning lobes, is analysed. These measurements constitute a significant data base, usable either for the validation of numerical simulation, either fot the modelling of the rotor-stator interactions phenomena
APA, Harvard, Vancouver, ISO, and other styles
27

Toan, Duong Duc. "Assessment of river discharge changes in the Indochina Peninsula region under a changing climate." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/195976.

Full text
APA, Harvard, Vancouver, ISO, and other styles
28

Liao, Michael W., and Michael W. Liao. "Investigating the Effect of Nanoscale Changes on the Chemistry and Energetics of Nanocrystals with a Novel Photoemission Spectroscopy Methodology." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/625558.

Full text
Abstract:
This dissertation explores the effect of nanometer-scale changes in structure on the energetics of photocatalytic and photovoltaic materials. Of particular interest are semiconductor nanocrystals (NCs), which have interesting chemical properties that lead to novel structures and applications. Chief among these properties are quantum confinement and the high surface area-to-volume ratio, which allow for chemical tuning of the energetics and structure of NCs. This tunable energetic landscape has led to increasing application of NCs in various areas of research, including solar energy conversion, light-emitting diode technologies, and photocatalysis. However, spectroscopic methods to determine the energetics of NCs have not been well developed, due to chemical complexities of relevant NCs such as polydispersity, capping ligand effects, core-shell structures, and other chemical modifications. In this work, we demonstrate and expand the utility of photoelectron spectroscopy (PES) to probe the energetics of NCs by considering the physical processes that lead to background and secondary photoemission to enhance photoemission from the sample of interest. A new methodology for the interpretation of UP spectra was devised in order to emphasize the minute changes to the UP spectra line shape that arise from nanoscopic changes to the NCs. We applied various established subtractions that correct for photon source satellites, secondary photoelectrons, and substrate photoemission. We then investigated the effect of ligand surface coverage on the surface chemistry and density of states at the top of valence band (VB). We systematically removed ligands by increasing numbers of purification steps for two diameters of NCs and found that doing so increased photoemission density at the top of the VB, which is due to undercoordinated surface atoms. Deeper VB structure was also altered, possibly due to reorganization of the atoms in the NC. Using the new UPS interpretation methodology, we examined the evolution of the valence band energy (EVB) of CdSe NCs as it was modified from spherical NC to rod to Au-NP tipped nanorod (NR). We also employed potential-modulated attenuated total reflectance spectroscopy (PM-ATR) to probe the conduction band energy (ECB) of the series. The EVB decreased with each modification, which is predicted with a band-bending model. This trend was also observed in the ECB, as revealed by spectroelectrochemistry, along with the appearance of new metal-semiconductor states in the band gap. UPS was finally used to investigate the even more complex Pt-NP tipped CdSe@CdS core@shell NR heterostructure. The addition of the CdS shell decreases the EVB relative to CdSe, as expected from common cation II-VI compounds. The Pt-NC increases the EVB, which, like the Au-CdSe NR, is predicted by employing a band-bending model. XPS revealed that PtSx-like chemical states were formed near the CdS-Pt interface. These experiments, along with the improved UP spectra interpretation methodology, demonstrate the wealth of information regarding surface chemistry and energetics that can be obtained with PES which can be applied to not only NCs, but also to metal oxide or molecular thin films.
APA, Harvard, Vancouver, ISO, and other styles
29

Teerawat, Ram-Indra. "DEVELOPMENT OF BIAS CORRECTION METHOD FOR GCM RUNOFF DATA AND ITS APPLICATION TO THE UPPER CHAO PHRAYA RIVER BASIN IN THAILAND." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263626.

Full text
APA, Harvard, Vancouver, ISO, and other styles
30

Elitas, Zeynep. "Reassessing The Trends In The Relative Supply Of College-equivalent Workers In The U.s.: A Selection-correction Approach." Phd thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615741/index.pdf.

Full text
Abstract:
Among better-educated employed workers, the fraction of full-time full-year (FTFY) workers is quite high and stable over time in the U.S. Among those with low education levels, however, this fraction is much lower and considerably more volatile. These observations suggest that the composition of unobserved skills is subject to sharp movements within low-educated employed workers, while the scale of these movements is potentially much smaller within high-educated ones. The standard college premium framework accounts for the observed shifts between education categories, but it cannot account for unobserved compositional changes within education categories. This thesis uses Heckman'
s two-step estimator on repeated Current Population Survey cross sections to calculate a relative supply series that corrects for unobserved compositional shifts due to selection in and out of the FTFY status. We find that the well-documented deceleration in the growth rate of relative supply of college-equivalent workers after mid-1980s becomes even more pronounced once we correct for selectivity. This casts further doubt on the relevance of the plain skill-biased technical change hypothesis. We conclude that what happens to the within-group skill composition for low-educated groups is critical for fully understanding the trends in the relative supply of college workers in the United States.
APA, Harvard, Vancouver, ISO, and other styles
31

Yamb, Elie Blaise Benjamin. "Mésalignement et dynamique de convergence du taux de change réel en zone CFA." Paris 1, 2007. https://tel.archives-ouvertes.fr/tel-00326328.

Full text
Abstract:
La thèse met en relief les mésalignements du taux de change réel pour un certain nombre de pays de la zone franc CFA. L'auteur utilise une relation de cointégration de long terme en appliquant la méthode des moindres carrés dynamiques pour déterminer les fondamentaux qui influences significativement le taux de change et par ricochet les mésalignements. Un modèle à correction d'erreur est utilisé à cet effet pour étudier la dynamique de convergence à l'équilibre du taux de change suite à des chocs exogènes et les réponses du taux de change réel consécutif aux chocs exogènes sont étudiées à travers les différentes fonctions de réponse impulsionnelle et de la décomposition de la variance.
APA, Harvard, Vancouver, ISO, and other styles
32

Yamb, Elie. "Mésalignement et dynamique de convergence du taux de change réel en zone CFA." Phd thesis, Université Panthéon-Sorbonne - Paris I, 2007. http://tel.archives-ouvertes.fr/tel-00326328.

Full text
Abstract:
La thèse étudie et met en évidence les mésalignements (déviation du taux de change réel par rapport à sa valeur d'équilibre) du taux de change pour un certain nombre de pays des deux zones franc CFA, à savoir la Côte d'Ivoire et le Mali pour l'UEMOA, le Tchad, la République Centrafricaine et le Cameroun pour la CEMAC. En fait, il s'agit de savoir si l'organisation des unions monétaires en change fixe avec l'euro, avec leurs règles monétaires et les règles de convergence budgétaires adoptées ne conduisent pas à une surévaluation structurelle et chronique des taux de change réels des pays qui seraient préjudiciables à leur croissance ou plus généralement à leur développement ceci en dépit des gains de crédibilité obtenus en matière d'inflation et les avantages en terme de risque pays que procure des règles strictes, mais claires et constantes au cours du temps. Cela dit le taux de change réel d'équilibre de long terme est apprécié dans la thèse en fonction des termes de l'échange, de la part des biens non échangeables et échangeables internationalement, de la balance courante, de la demande intérieure, des droits et taxes sur les importations et exportations, du degré d'ouverture et des dépenses publiques. Nous en arrivons à la conclusion selon laquelle les taux de change réels ont été en général surévalués (en moyenne sur la période 1965-2003) quoique de manière diverse selon les pays, ce qui justifie après coup la dévaluation de 1994, les mésalignements ne se résorbant pas plus vite dans les « petits pays » que dans les « grands ». Un développement en quatre parties est proposé : la première décrit l'évolution des économies des zones franc selon le régime de change (dévaluation de 1994, passage à l'euro en 1999), la situation de la dette (crise de la dette et politiques d'ajustement structurelles entre 1986 et 1994), la spécialisation du commerce extérieur et le taux de croissance du PIB. Le problème récurrent du déficit extérieur et les taux de croissance faibles sont également mis en exergue. La seconde partie passe en revue les théories du taux de change réel d'équilibre et se termine par une évaluation très précise et originale des taux de change réels. La troisième partie étudie et discute une spécification d'une forme réduite de taux de change réel d'équilibre dans l'esprit de la théorie d'Edwards et développe les modèles VAR et VAR à correction d'erreur qui permettent de penser l'évolution du taux de change vers sa valeur de long terme considérée comme une fonction des fondamentaux décrite par une relation de cointégration. La quatrième partie enfin présente les estimations complètes pour les cinq pays étudiés, les discutent et les utilisent pour produire les conclusions rappelées au début de ce résumé.
APA, Harvard, Vancouver, ISO, and other styles
33

Teutschbein, Claudia. "Hydrological Modeling for Climate Change Impact Assessment : Transferring Large-Scale Information from Global Climate Models to the Catchment Scale." Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-84197.

Full text
Abstract:
A changing climate can severely perturb regional hydrology and thereby affect human societies and life in general. To assess and simulate such potential hydrological climate change impacts, hydrological models require reliable meteorological variables for current and future climate conditions. Global climate models (GCMs) provide such information, but their spatial scale is too coarse for regional impact studies. Thus, GCM output needs to be downscaled to a finer scale either through statistical downscaling or through dynamic regional climate models (RCMs). However, even downscaled meteorological variables are often considerably biased and therefore not directly suitable for hydrological impact modeling. This doctoral thesis discusses biases and other challenges related to incorporating climate model output into hydrological studies and evaluates possible strategies to address them. An analysis of possible sources of uncertainty stressed the need for full ensembles approaches, which should become standard practice to obtain robust and meaningful hydrological projections under changing climate conditions. Furthermore, it was shown that substantial biases in current RCM simulations exist and that correcting them is an essential prerequisite for any subsequent impact simulation. Bias correction algorithms considerably improved RCM output and subsequent streamflow simulations under current conditions. In addition, differential split-sample testing was highlighted as a powerful tool for evaluating the transferability of bias correction algorithms to changed conditions. Finally, meaningful projections of future streamflow regimes could be realized by combining a full ensemble approach with bias correction of RCM output: Current flow regimes in Sweden with a snowmelt-driven spring flood in April will likely change to rather damped flow regimes that are dominated by large winter streamflows.
APA, Harvard, Vancouver, ISO, and other styles
34

Hoarau, Jean-François. "Le mésalignement du taux de change réel dans le cadre d'une petite économie ouverte : causes, procédures d'estimation et politiques de correction : une application à l'économie Australienne." La Réunion, 2004. http://elgebar.univ-reunion.fr/login?url=http://thesesenligne.univ.run/04_18_Hoarau.pdf.

Full text
Abstract:
Cette thèse étudie les différents aspects théoriques et opérationnels du mésalignement du taux de change réel pour une petite économie ouverte. La première partie s'intéresse à la définition théorique du mésalignement réel. À cet effet , nous développons une version améliorée du modèle NATREX, laquelle permet de mettre en évidence l'importance de certains paramètres structurels de l'économie modélisée et d'étudier de manière plus rigoureuse l'impact de certains fondamentaux réels sur le taux de change réel d'équilibre. La deuxième partie présente les aspects opérationnels liés au concept du mésalignement pour l'Australie sur la période 1976-2000. Nous déterminons d'abord des indicateurs empiriques de taux de change réel d'équilibre et de mésalignement, et la présence éventuelle de ruptures structurelles dans le comportement de ce dernier, pour le dollar australien. Nous montrons ensuite que la politique économique occupe une place de choix dans l'analyse des déséquilibres de change réels, puisqu'elle se révèle à la fois comme une cause et un remède au désalignement
This thesis aims at analysing the conceptual and operational aspects of the real exchange rate misalignment for a small open economy. The first part focuses on the theoretical definition of the real misalignment. For that purpose, we introduce a new version of the NATREX model which studies the importance of several crucial structural parameters and the effect of a set of fondamental determinants on the equilibrium real exchange rate. The second part deals with the operational aspects of the real misalignment for Australia over the period 1976-2000. On one hand, we determine by means of econometric tools some indicators for the equilibrium real exchange rate and the misalignment, and the possible presence of structural breaks in the misalignment behavior. On the hand, we show that economic policy holds a decisive place in the real exchange rate distortions analysis. Indeed, this one can be both a cause of and a cure for the misalignment
APA, Harvard, Vancouver, ISO, and other styles
35

Kriebel, Maximilian [Verfasser], Tim [Akademischer Betreuer] Clark, Tim [Gutachter] Clark, and Rainer [Gutachter] Fink. "1. Feynman-dispersion correction 2. Charge transport via imaginary time propagation / Maximilian Kriebel ; Gutachter: Tim Clark, Rainer Fink ; Betreuer: Tim Clark." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2020. http://d-nb.info/1211557510/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
36

Hart, Ingrid Anne Wilkinson. "A quantitative and qualitative exploration of changes in walking post-stroke and the impact of functional electrical stimulation for correction of dropped foot." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/393354/.

Full text
Abstract:
The research presented in this thesis explores changes in walking following a stroke, empirically at a group level and from the perspective of the individual. Walking does not appear to have been previously been systematically explored from the perspective of the individual stroke survivor. In the first phase of this research, quantitative methods were used to investigate existing gait rehabilitation interventions applied in a novel population. Problems with ‘dropped foot’ post-stroke are common and can result in trips, falls and restricted mobility. Electrical stimulation of the common peroneal nerve produces dorsiflexion and eversion to correct dropped foot and is associated with improved motor control and walking post-stroke, however most research studies have recruited people with chronic stroke to reduce sample variability. People who are less than six months post-stroke may gain added benefit from electrical stimulation as poor walking patterns may not yet have become habitual and the potential for motor recovery due to cortical reorganisation is greatest. A pilot parallel group partially single blinded randomised controlled clinical trial (n=20) identified statistically significant within group differences in mobility after the intervention period in both groups (maintained during follow-up). No statistically significant between group differences were observed apart from gait quality, which was slightly better in the intervention group. Participants in the intervention group also walked faster when stimulation was used than without it. The protocol was feasible and 144 participants per group would produce an adequately powered definitive study. Participants in the pilot clinical trial spoke about valued personal aspects of walking but these were not fully captured by the outcome measures and are not reflected in the published literature. To systematically explore changes in walking post-stroke in depth interviews with a subgroup of the original participants were undertaken using an interpretative phenomenological approach (n=4). The participants gave examples of post-stroke walking related changes in their self-perception, roles and their embodied experience of walking that are rarely mentioned in the rehabilitation literature, apart from in personal accounts written by people living with chronic illness. They spoke about walking within the context of activities that they identified as personally important. These participants valued being able to walk distances at a reasonable speed, being independent, safe and confident. They said that they missed their pre-stroke spontaneity, freedom, agility and their lost automatic body movement, which are not usually assessed in stroke rehabilitation research or reflected in published research. Areas for further work have been identified.
APA, Harvard, Vancouver, ISO, and other styles
37

Ratnayake, Mudiyanselage Kalpani Manurangi. "A MULTI-PROXY APPROACH TO RECONSTRUCTION OF HOLOCENE CLIMATE CHANGE: EVIDENCE FROM LAKE ERIE SEDIMENTARY ARCHIVES." Kent State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=kent1606763358671089.

Full text
APA, Harvard, Vancouver, ISO, and other styles
38

Oliveira, Jimmy Lima de. "Estimando o impacto do estoque de capital publico sobre o PIB per capita na presenÃa de mudanÃa estrutural." Universidade Federal do CearÃ, 2006. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1347.

Full text
Abstract:
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
O presente trabalho estima a elasticidade produto-gasto pÃblico para economia brasileira, no perÃodo de 1950 a 2003, utilizando um modelo vetorial de correÃÃo de erro (VECM) para controlar possÃveis mudanÃas estruturais nas sÃries. Quando existem mudanÃas estruturais, os vÃrios testes estatÃsticos de Dickey-Fuller sÃo viesados em direÃÃo da nÃo rejeiÃÃo de uma raiz unitÃria. Este viÃs significa que o teste de Dickey-Fuller à viesado em direÃÃo da hipÃtese nula de uma raiz unitÃria, mesmo se a sÃrie à estacionÃria dentro de cada subperÃodo. Sem controlar para mudanÃas estruturais, os testes de cointegraÃÃo podem apresentar resultados enganosos, e as estimativas obtidas podem ser viesadas.
Aiming to estimate the elasticity product-public expenditure to the Brazilian economy, during the period 1950-2003, it was used a vector error correction model (VECM) to control for possible structural changes in the series. When structural changes were observed, many of the Dickey-Fuller statistic tests are biased towards the non-rejection of the existence of a unit root. This bias means that the Dickey-Fuller test is biased towards the null hypothesis of unit root, even if the series is stationary within each sub period. Without controlling for structural changes, the cointegration tests may present deceiving results and the estimates obtained may be biased.
APA, Harvard, Vancouver, ISO, and other styles
39

Adam, Katiúcia Nascimento. "Incertezas e impactos de mudanças climáticas sobre o regime de vazões na Bacia Hidrográfica do Rio Uruguai." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/143109.

Full text
Abstract:
Mudanças climáticas podem afetar a distribuição espacial e temporal das variáveis hidrológicas, tendo como consequências alterações nos regimes de precipitação e vazão dos rios. Aumentos ou reduções no volume de escoamento de uma bacia hidrográfica podem, por exemplo, produzir danos aos ecossistemas, afetar a produção de alimentos, abastecimento de água, navegação e geração de energia. Atualmente buscam-se relações que permitam entender os processos de mudanças climáticas a fim avaliar os impactos e mitigá-los, assim como avaliar as incertezas inerentes ao processo de modelagem hidrológica de tais mudanças. Neste contexto este trabalho apresenta uma metodologia de quantificação e análise de incertezas para estudos de mudanças climáticas, tomando como estudo de caso a bacia hidrográfica do Rio Uruguai (BHRU) com área aproximada de 110,000 Km². Para tanto três fontes de incerteza foram analisadas e comparadas: o modelo hidrológico, técnicas de remoção de viés e modelos climáticos. O modelo hidrológico MGB-IPH foi avaliado quanto ao processo de parametrização, utilizando diferentes períodos de simulação para calibração: (i) Período de calibração 1 – MGB/P1: representando a série completa de observações de 1960-1990 com verificação no período de 1992-1999; (ii) Período de calibração 2 - MGB/P2: calibração em período seco e verificação de período de cheias (iii) Período de calibração 3 – MGB/P3: calibração em período característico de cheias e verificação de período de estiagem. Três diferentes técnicas de remoção de viés foram aplicadas para analisar o grau de incerteza que a escolha de um determinado método de correção pode agregar ao resultado final: (i) RV1 - Técnica de Mapeamento Quantil-Quantil; (ii) RV2 - Técnica de Escalonamento Linear e (iii) RV3 - Técnica Delta change. Os modelos climáticos globais (GMC’s) foram analisados quanto a sua estrutura, comparando projeções de cinco diferentes modelos: MPEH5 (ECHAM5/MPIOM), GFCM21 (GFDL-CM2.1), MRCGCM (MRI-CGCM2.3.2), HADCM3 (UKMO-HadCM3) e NCCCSM (CCSM3). Adicionalmente, também foram analisadas as projeções climáticas de cinco diferentes versões do modelo climático regional (RCM) ETA/CPTEC: CT20, CT40, LOW, MID e HIGH. Inicialmente os resultados das simulações provenientes de cada uma destas fontes foram comparados de maneira isolada e em seguida de maneira combinada. Portanto, a metodologia foi dividida em Etapa (1) e Etapa (2). A Etapa (1) teve por objetivo responder a seguinte pergunta: Qual dentre as fontes de incerteza selecionadas agrega maior variação ao resultado final? Ou seja, qual destas fontes propaga maior incerteza em termos de impactos de mudanças climáticas na BHRU? Os resultados obtidos por cada uma das fontes de incerteza foram comparados em termos de anomalias de vazões médias de longo período (QMLP), máximas e mínimas anuais. Na Etapa (2) foi realizada a análise total de incerteza, ou seja, a análise combinada dos resultados obtidos na Etapa (1). As anomalias de vazões foram apresentadas utilizando as curvas de distribuição acumulada (CDF’s) e a incerteza total expressa pela diferença entre os percentis 5% e 95%. Considerando os resultados obtidos para as vazões médias de longo período (QMLP), as fontes podem ser ordenadas de forma decrescente, em relção ao grau de incerteza que propagam: modelos climáticos globais > modelos climáticos regionais > técnicas de remoção de viés > modelo hidrológico. Para as vazões extremas os RCM’s apresentam as maiores variações de anomalias se comparadas às dos modelos hidrológicos e técnicas de remoção de viés, inclusive para ambos os extremos, máximos e mínimos. Esta variação se dá principalmente, pelos resultados de LOW e MID. Estas informações podem ajudar os gestores e tomadores de decisão no adequado gerenciamento e planejamento dos recursos hídricos sob condições de mudanças climáticas, assim como o entendimento da incerteza associada.
Climate change can affect the spatial and temporal distribution of hydrological variables, with the consequences of changes in precipitation regimes and river flows. Increase or decrease the flow of rivers, for example, can cause damage to ecosystems, affecting food production, water supply, navigation and power generation. Currently seeking to relationships that allow understand climate change processes in order to assess the impacts and mitigate them, and assess the uncertainties inherent in hydrologic modeling process of such climate change. This thesis aimed at the development of a methodology for quantification and analysis of uncertainties for climate change studies in hydrology , taking as a case study the basin of the Uruguay River (BHRU) with a drainage area near 110,000 km². For that three sources of uncertainty were analyzed and compared: the hydrologic model, bias removal techniques and climate models. The hydrological model MGB-IPH was evaluated for parameterization, using different simulation periods for calibration: (i) MGB /P1: full range with calibration period (1960-1990) and validate (1992-1999); (ii) MGB / P2: calibrated in the period of dry and validated in the flood season (iii) MGB/P3: calibrated in the period of floods and validated in the dry season. Three different bias correction methods were applied to analyze the degree of uncertainty that the choice of a particular method of correction can add to the final result: (i) RV1 - Quantil-Quantil Mapping; (ii) RV2 - Linear Scaling, and (iii) RV3 - Delta Change Technique. Global climate models (GMC's) were analyzed for their structure, comparing projections of five different models: MPEH5 (ECHAM5/MPI-OM), GFCM21 (GFDLCM2.1), MRCGCM (MRI-CGCM2.3.2), HADCM3 (UKMO-HadCM3) e NCCCSM (CCSM3). Additionaly, climate projections from five different versions of the regional climate model (RCM) ETA / CPTEC were also analyzed: CT20, CT40, LOW, MID e HIGH. Initially the simulation results from each of the sources of uncertainty were compared individually (single propagation) and then in a combined way (multi propagation). Therefore, the methodology was divided in Step (1) and Step (2). Step (1) aimed to answer: Which of the selected sources of uncertainty adds more variation to the final result? Which of these sources propagates greater uncertainty in terms of impacts of climate change on BHRU? The results for each of the sources of uncertainty were compared in terms of long-term mean flow (QMLP), maximum and minimum annual flow. In Step (2) total uncertainty analysis was performed, therefore the combined analysis of the results obtained in Step (1). The anomalies in discharge were presented using the cumulative distribution function (CDF's) and the total uncertainty expressed by the difference between the percentiles 5% and 95%. Throughout the application of the proposed methodology it was concluded that: (i) for the extremes (maximum and minimum) annual discharges the largest source of uncertainty are the projections of the RCM's, followed by the the bias removal technique and finally the hydrological model; (ii) for the QMLP the largest source of uncertainty are followed global climate models, then the regional climate models. This information can help managers and decision makers in the proper management and planning of water resources under climate change conditions, as well as the understanding of the associated uncertainty.
APA, Harvard, Vancouver, ISO, and other styles
40

Zou, Ziqiang. "A sharp interface method for low Mach two-phase flows with phase change Toward asymptotic-preserving low-Mach correction for sharp interface two-phase flows with capillary effects An Accurate Sharp Interface Method for Two-Phase Compressible Flows at Low-Mach Regime." Thesis, université Paris-Saclay, 2020. https://tel.archives-ouvertes.fr/tel-03178310.

Full text
Abstract:
Une approche d'interface raide est présentée pour le calcul des écoulements diphasiques avec tension superficielle et changement de phase en régime à faible nombre de Mach. Pour développer un tel modèle, où de légers effets compressibles sont pris en compte ainsi que des fermetures thermodynamiques correctes, le liquide et le gaz sont considérés comme compressibles et décrits par un solveur compressible précis. Ce solveur compressible adopte une technique de décomposition appelée "décomposition du transport acoustique" qui décompose le système Euler en deux parties: acoustique et transport. Sur la base du sous-système acoustique, un solveur de Riemann approximatif qui tient compte des effets de tension superficielle et de changement de phase est développé. L'interface de l'écoulement diphasique est capturée par la méthode de Level Set et considérée comme raide. La problème de la capture d'interface de la méthode Level Set dans le cadre Eulérien est le point clé des simulations d'écoulement diphasique, et dans ce travail, nous proposons et adoptons des approches d'ordre élevé pour l'advection de l'interface, la redistanciation et l'estimation de la courbure. En régime à faible nombre de Mach, les solveurs compressibles conventionnels perdent en précision et une correction à faible Mach est alors nécessaire pour réduire la dissipation numérique. Pour une méthode d'interface raide, l'interface est traitée comme la discontinuité de contact via la méthode Ghost Fluid. Sans une région lisse à l'interface, une telle discontinuité existant à l'interface présente un énorme défi pour la conception d'un schéma numérique. La correction à faible Mach bien connue dans la littérature pourrait conduire à une erreur de troncature significative, en particulier pour les écoulements diphasiques avec de grands rapports de densité et de vitesse du son. Pour retrouver une bonne propriété de préservation asymptotique, nous proposons une nouvelle correction à faible Mach avec une analyse asymptotique rigoureuse. Plusieurs cas de test numériques ont été utilisés pour valider la présente approche numérique et montrer ses bonnes performances
A sharp interface approach is presented for computing two-phase flows with surface tension and phase change in low Mach regime. To develop such a model, where slight compressible effects are taken into account as well as correct thermodynamical closures, both the liquid and the gas are considered compressible and described by a precise compressible solver. This compressible solver adopt a splitting technique called "acoustic-transport splitting" which splits the Euler system into two parts: acoustic and transport. Based on the acoustic subsystem, an approximate Riemann solver that accounts for surface tension and phase change effects is developed. The interface between two-phase flows is captured by the Level Set method that is considered to be sharp. The interface capturing issue of the Level Set method within the Eulerian framework is the key point of the two-phase flow simulations, and in this work we propose and adopt high-order approaches for interface advection, redistancing and curvature estimation. In low Mach regime, conventional compressible solvers lose accuracy and a low Mach correction is then necessary to reduce the numerical dissipation. For a sharp interface method, the interface is treated as the shock-wave contact discontinuity via the Ghost Fluid method. Without a smooth region at the interface, such discontinuity existing at the interface presents a huge challenge to the design of a numerical scheme. The well-known low Mach fix in literature could lead to significant truncation error, especially for two-phase flows with large density and sound speed ratios. To recover a good asymptotic-preserving property, we propose a new low Mach correction with rigorous asymptotic analysis. Several numerical test cases have been employed to validate the present numerical approach and enlighten its good performance
APA, Harvard, Vancouver, ISO, and other styles
41

Dabo, Marcelin. "Commande prédictive généralisée non linéaire à temps continu des systèmes complexes." Phd thesis, Université de Rouen, 2010. http://tel.archives-ouvertes.fr/tel-00497319.

Full text
Abstract:
Nous abordons, dans cette thèse, la poursuite asymptotique de trajectoire basée sur la commande prédictive généralisée non linéaire à temps continu (NCGPC). L'application de cette technique de commande requiert la vérification d'assomptions précises. La NCGPC est caractérisée par deux paramètres : le degré relatif et l'horizon de prédiction, respectivement, intrinsèque et extrinsèque au système. Sa loi de commande résulte de la minimisation d'un critère quadratique basée sur l'erreur de prédiction (jusqu'à un ordre égal au degré relatif) entre la(es) sortie(s) choisie(s) et le(es) signal(aux) de référence correspondant(s). Elle linéarise le système non linéaire en boucle fermée dans un nouvel espace de coordonnées et lui garantit la stabilité (degré relatif inférieur ou égal à quatre) de facto. Au-delà de quatre, il y a instabilité. Pour résoudre ce problème, Chen et al. ont introduit un troisième paramètre, qui est l'ordre des dérivées successives de la commande par rapport au temps, choisi de sorte que sa différence avec le degré relatif soit inférieure à quatre. Nous proposons dans ce travail, deux approches qui vérifient les mêmes assomptions mentionnées ci-dessus et dont les points communs sont la modification du critère avec le maintien à zéro de l'ordre des dérivées successives de la commande et la garantie de la stabilité pour le système linéaire bouclé résultant. La première approche consiste au rajout d'un terme linéaire en commande au critère, tandis que la deuxième consiste au rajout d'une matrice de correction "intelligente" à la matrice de prédiction du critère. Quelques propriétés de la NCGPC sont données pour des systèmes SISO de degré relatif un ou deux.
APA, Harvard, Vancouver, ISO, and other styles
42

Zhou, Yifan, Dániel Apai, Ben W. P. Lew, and Glenn Schneider. "A Physical Model-based Correction for Charge Traps in the Hubble Space Telescope’s Wide Field Camera 3 Near-IR Detector and Its Applications to Transiting Exoplanets and Brown Dwarfs." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/625388.

Full text
Abstract:
The Hubble Space Telescope Wide Field Camera 3 (WFC3) near-IR channel is extensively used in time-resolved observations, especially for transiting exoplanet spectroscopy as well as. brown dwarf and directly imaged exoplanet rotational phase mapping. The ramp effect is the dominant source of systematics in the WFC3 for time-resolved observations, which limits its photometric precision. Current mitigation strategies are based on empirical fits and require additional orbits to help the telescope reach a thermal equilibrium. We show that the ramp-effect profiles can be explained and corrected with high fidelity using charge trapping theories. We also present a model for this process that can be used to predict and to correct charge trap systematics. Our model is based on a very small number of parameters that are intrinsic to the detector. We find that these parameters are very stable between the different data sets, and we provide best-fit values. Our model is tested with more than 120 orbits (similar to 40 visits) of WFC3 observations. and is proved to be able to provide near photon noise limited corrections for observations made with both staring and scanning modes of transiting exoplanets as well as for starting-mode observations of brown dwarfs. After our model correction, the light curve of the first orbit in each visit has the same photometric precision as subsequent orbits, so data from the first orbit no longer need. to. be discarded. Near-IR arrays with the same physical characteristics (e.g., JWST/NIRCam) may also benefit from the extension of this model if similar systematic profiles are observed.
APA, Harvard, Vancouver, ISO, and other styles
43

Canty, Kenika Kiante'. "A Survey of Probation Officers' Opinions: Risk Assessments." ScholarWorks, 2015. https://scholarworks.waldenu.edu/dissertations/1684.

Full text
Abstract:
The U. S. criminal justice system has used risk assessment tools in an effort to reduce recidivism and risk assessment tools are now commonplace. Correctional organizations, however, have struggled with officers' resistance to these tools in spite of the evidence for their utility. There is limited research that explores the impact of resistance to organizational change within the context of correctional agencies. To address that gap, this correlational study used organizational change theory to examine officers' resistance to the use of risk assessment tools based on officers' opinions of the risk assessment tool being used in North Carolina. Data were collected through an online survey of 109 North Carolina probation and parole officers. Multiple linear regression analysis was used to examine the statistical relationship between officer use of risk assessment tools and the dependent variables which included officers' opinions of the risk assessment tool, knowledge of risk assessments, training for use of risk assessments, risk assessments in the sentencing process, and officers' length of time employed. Findings indicated that opinions of the risk assessment tool and training to use the tool statistically impact officers' use of the tool in daily supervision of offenders. Organizational change theory predicted these findings as officers' resistance to policy change was manifested in their opinions of that policy. Implications for positive social change include recommendations for corrections agencies to refine training regarding risk assessments in efforts to minimize officer resistance of properly applying risk assessment tools in daily job duties with the intended outcome of reducing recidivism, and therefore preventing future harms to the community.
APA, Harvard, Vancouver, ISO, and other styles
44

Bluteau, Hélène. "Contribution à l'amélioration de la qualité des mesures sur les machines à mesurer tridimensionnelles : surveillance, diagnostic et correction des défaillances." Cachan, Ecole normale supérieure, 1999. http://www.theses.fr/1999DENS0007.

Full text
Abstract:
Les travaux présentés dans ce mémoire sont centrés sur l'amélioration de la qualité des mesures réalisées sur machine à mesurer tridimensionnelle (MMT) en milieu industriel. En particulier nous nous intéressons au diagnostic et à la correction des défaillances de la chaine de mesure. Dans un premier temps, nous proposons un travail d'expertise des savoir-faire des utilisateurs sous la forme d'une analyse des modes de défaillance et de leur criticité (amdec) des maillons de la chaine de mesure, ainsi qu'une analyse d'un ensemble de procédures qualité industrielles usuelles. Une étude bibliographique des solutions présentées dans la littérature complète l'expertise menée. Suite à ces travaux, nous avons défini la structure et les fonctionnalités d'un superviseur de MMT adapté aux contraintes d'utilisation des MMT en milieu industriel. Nous proposons des indicateurs qualité, ainsi que des procédures adaptées pour leur évaluation. Le superviseur, enrichi avec les indicateurs et procédures expérimentés doit mener a la maitrise de la qualité des mesures réalisées sur MMT. Les indicateurs de qualité calculés et suivis pour la supervision, offrent des perspectives en vue de l'évaluation des incertitudes sur les mesures.
APA, Harvard, Vancouver, ISO, and other styles
45

Hernandez, Michael. "Applications of modern control in power electronics." Paris 11, 2010. http://www.theses.fr/2010PA112161.

Full text
Abstract:
Dans la première partie, cette dissertation continue le cadre pour l'analyse et la conception (probablement des compensateurs de facteur) de puissance (PF) non linéaire pour les systèmes électriques fonctionnant dans des régimes nonsinusoïdaux (mais périodiques) avec les charges non linéaires. En particulier, dans la prétention standard que le générateur est une source de tension sans l'impédance, nous avons caractérisé toutes les charges non linéaires dont le pf est amélioré avec un compensateur non linéaire indiqué. Et ce cadre est employé pour étudier le problème de lacompensation passive de pf d'un redresseur commandé par pont classique. Est donné le fonctionnement "à l'avance de phase" du redresseur qu'on s'attend à ce que la compensation capacitive améliore le pf. Il est cependant moins évident que ceci puisse également être réalisé (dans quelques conditions appropriées) avec des inducteurs. Dans la deuxième partie, on a proposé la méthodologie d’A pour concevoir les contrôleurs (PI) proportionnel-intégraux linéaires utilisés des applications de convertisseur de puissance et en assurant la stabilité asymptotique. La technique s’est fondée sur le fait de base que si un système d’affinage peut être rendu passif avec une commande constante, alors il est stabilisable avec pi. Un état structural a été imposé alors au convertisseur de puissance pour satisfaire l’ancienne propriété avec un résultat passif produit comme combinaison linéaire des états. Cette condition est technique et n’a aucune interprétation physique claire. Ce résultat est prolongé dans trois directions : d’abord, la condition mentionnée ci-dessus est enlevée ; en second lieu, une plus grande classe des convertisseurs (avec des sources extérieures de commutation) est considérée ; troisièmement, la résistance de charge est assumée qu’on propose l’inconnu et un contrôleur adaptatif de pi (avec trois estimateurs différents). La méthodologie est appliquée au problème de la compensation de facteur de puissance d’un redresseur triphasé de source de tension, avec des résultats de simulation proposés. En outre, pi adaptatif stable est conçu pour la régulation de tension de rendement d’un convertisseur quadratique de poussée montrant l’exécution au moyen de résultat expérimental. Dans la troisième partie quelques contrôleurs basés sur le concept de la commande de charge pour un convertisseur utilisé dans une mise sous tension la correction de facteur sont montrés. Le convertisseur se compose par le raccordement intercalé de deux convertisseurs ou plus de poussée reliée à la grille à l’aide d’un redresseur de diode non commandé. La commande de charge représente une solution bon marché pour garantir la mise en commun courante entre les différents convertisseurs impliqués, et est normalement employée en combination avec d’autres contrôleurs. Les deux contrôleurs sont d’abord conçus pour garantir le facteur de puissance de près d’un avec la tension CC Réglée, à laquelle la commande de charge est ajoutée pour distribuer le courant égal parmi les convertisseurs. En conclusion, on présente une simplification avec l’exécution semblable qui élimine l’utilisation des sondes courantes, excepté les transformateurs de courant exigés pour mettre en application la commande de charge, des résultats expérimentaux accomplissent cette cloison. La quatrième partie, présente l’exécution et la programmation d’une méthode pour dépister le point de puissance maximum (MPP) dans des applications (PV) photovoltaïques. Ce point de fonctionnement est d’intérêt spécial pendant qu’on l’exige pour extraire la puissance maximum disponible à partir des rangées photovoltaïques
In the first part, this dissertation continues with the framework for analysis and design of (possibly nonlinear) power factor (PF) compensators for electrical systems operating in non-sinusoidal (but periodic) regimes with nonlinear loads. In particular, under the standard assumption that the generator is a voltage source with no impedance, we characterized all nonlinear loads whose PF is improved with a given nonlinear compensator. And this framework is used to study the problem of passive PF compensation of a classical half-bridge controlled rectifier. Given the “phase advance” operation of the rectifier it is expected that capacitive compensation improves PF, it is however less obvious that this can also be achieved (under some suitable conditions) with inductors. In the second part, A methodology to design linear proportional-integral (PI) controllers used in power converter applications and ensuring asymptotic stability was proposed. The technique relied on the basic fact that if an affine system can be rendered passive with a constant control, then it is stabilizable with a PL A structural condition was imposed then on the power converter to satisfy the former property with a passive output generated as a linear combination of the states. This condition is technical and has no clear physical interpretation. This result is extended in three directions : first, the aforementioned condition is removed ; second, a larger class of converters (with switching external sources) is considered ; third, the load resistance is assumed unknown and an adaptive PI controller (with three different estimators) is proposed. The methodology is applied to the problem of power factor compensation of a 3-phase. Voltage source rectifier, with simulation results proposed. Also, a stable adaptive PI is designed for the output voltage regulation of a quadratic boost converter showing the performance by means of experimental result. In the third part some controllers based on the concept of charge control for a converter used in an application of power factor correction are shown. The converter is composed by the interleaved connection of two or more boost converters connected to the grid by means of a non controlled diode rectifier. Charge control represents a cheap solution to guarantee current sharing among the different converters involved, and is normally used in combination with other controllers. The two controllers are first designed to guarantee the power factor close to one with regulated DC voltage, to which charge control is added to distribute equal current among the converters. Finally, a simplification with similar performance is presented that eliminates the use of current sensors, except for the current transformers required to implement the charge control, experimental results complete this part. The fourth part presents the implementation and programming of a method to track the maximum power point (MPP) in photovoltaic (PV) applications. This operation point is of special interest as it is required to extract the maximum power available from the photovoltaic arrays
APA, Harvard, Vancouver, ISO, and other styles
46

Abouloifa, Abdelmajid. "Commande de convertisseurs statiques de puissance AC/DC en vue de la correction du facteur de puissance et du pilotage de la charge : développement d'une approche formelle pour la synthèse de régulateurs et l'analyse des performances." Caen, 2008. http://www.theses.fr/2008CAEN2072.

Full text
Abstract:
Cette thèse porte sur la commande des convertisseurs de puissance AC/DC fonctionnant en commutation à travers un générateur à modulation de largeur d’impulsions. L’intérêt de cette classe de convertisseurs réside dans son rendement énergétique élevé et sa capacité à fonctionner en mode de conduction continue minimisant ainsi les interférences électromagnétiques, conduites et rayonnées. L’objectif de commande est double : (i) régulation du signal de sortie (tension aux bornes d’une charge résistive, vitesse d’une charge motrice) ; (ii) assurer une connexion avec un facteur de puissance quasi-unitaire (PFC) entre le convertisseur et le réseau de puissance. Le problème est appréhendé en développant une stratégie de commande impliquant deux régulateurs montés en cascade. Le régulateur interne est conçu de telle sorte que le courant absorbé à l’entrée du convertisseur soit proportionnel à la tension sinusoïdale du réseau d’alimentation. L’entrée de référence de ce régulateur (le rapport de proportionnalité mentionné) est aussi le signal de commande du régulateur externe qui vise à réguler le signal de sortie (tension ou vitesse). Les régulateurs sont élaborés à partir du modèle non linéaire du système commandé, en utilisant différentes techniques de synthèse. Le système de commande en boucle fermée résultant s’avère non linéaire et temps variant. En utilisant des outils d’analyse appropriés, tels que ceux de stabilité et de moyennage, nous démontrons formellement que les objectifs de commande sont réalisables en moyenne avec une erreur qui dépend de la fréquence du réseau d’alimentation. Cette erreur est d’autant plus petite que la fréquence du réseau est plus élevée
This thesis deals with switched PWM AC/DC power converters. The interest of this type of converters lies in their high power efficiency and their ability to operate in continuous conduction mode minimizing thus electromagnetic interferences, both conducted and radiated. The control objective is twofold: (i) output signal regulation (output voltage for resistive type load, speed for motor type load); (ii) ensuring a unit power factor (PFC) connection between the converter and the power supply net. The problem is dealt with developing a control strategy involving two regulators in cascade. The inner regulator is designed to make the current absorbed by the converter proportional to the supply net voltage. The reference signal of this regulator is also the control signal of the outer regulator which aims at regulating the system output (voltage or speed). Both regulators are obtained from the nonlinear model of the converter, using different control techniques. The resulting closed-loop system turns out to be nonlinear and time-varying. Using suitable stability and averaging tools, it is formally demonstrated that the control objectives are achieved in the mean with an error that depends on the supply net frequency. The larger the net frequency is the smaller the error.
APA, Harvard, Vancouver, ISO, and other styles
47

Bartůněk, Tomáš. "Komparativní analýza vykazování změn účetních metod a oprav účetních chvb u velkých českých společností." Master's thesis, Vysoká škola ekonomická v Praze, 2017. http://www.nusl.cz/ntk/nusl-359785.

Full text
Abstract:
The following thesis deals with the development of the accounting of corrections of the accounting errors of previous years and changes in accounting methods from the beginning of financial accounting in the Czech Republic through the processing of many interpretations by the National Accounting Board, up to the current modification, which was an amendment to the Decree No. 500/2002 Coll., which transposed certain provisions of Act No. 563/1991 Coll., which came into force on January 1, 2013. Thanks to this decree, the account Restatements of retained earnings results, in the case of a correction of an error and a change in the accounting method, in a better understanding of the financial statements than it did before the issue was addressed through extraordinary costs or revenues in the current accounting period. In addition as practical part, this thesis composes also of a research from the financial statements of large Czech companies focusing on the frequency of use of the new item in the balance sheet for 2015, the reason of the using and explanation in supplement to the financial statements, including the method of settling the final balance of the account from previous years. The research also dealt with the auditor's response to the found deficiencies. The last part of the thesis is a comparative analysis of research conducted during the years of 2013, 2014 and 2015.
APA, Harvard, Vancouver, ISO, and other styles
48

Weydert, Carole. "Recherche d'un boson de Higgs chargé avec le détecteur ATLAS : de la théorie à l'expérience." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00629349.

Full text
Abstract:
Cette thèse se situe à mi-chemin entre la phénoménologie et la physique de particules expérimentale. Dans la première partie, nous décrivons un calcul de section efficace à order supérieur en développement perturbatif, ainsi que son implementation dans un générateur d'événements Monte Carlo. Nous présentons les corrections au premier order en chromodynamique quantique pour la production de boson de Higgs chargé en association avec un quark top au LHC, en utilisant le formalisme de soustraction de Catani et Seymour. Notre code indépendant nous a permis de valider les résultats donnés par MC@NLO, et nous avons réalisé des études concernant diverses contributions aux erreurs systématiques dues à la simulation d'événements. L'implémention du processus a été réalisée pour le générateur POWHEG. En raison de la quantité de données insuffisante disponible fin 2010 (le détecteur ATLAS a accumulé 35 pb-1 de données de collisions proton-proton), le processus de production de Higgs chargé n'a pas pu être étudié et nous nous sommes tournés vers la caractérisation de bruits de fonds. Dans ce contexte, il s'avère que la production de boson W en association avec un quark top est importante à connaître. Dans la seconde partie de cette thèse, nous mettons en place une analyse spécifique au canal Wt semileptonique, en incluant les effets statistiques et systématiques, pour lesquels nous nous concentrons plus particulièrement sur l'effet dû aux différentes paramétrisations du contenu des protons. Le processus Wt étant inobservable au Tévatron, nous pouvons pour la première fois donner une limite à la setion efficace de production.
APA, Harvard, Vancouver, ISO, and other styles
49

Daumard, Fabrice. "Contribution à la télédétection passive de la fluorescence chlorophyllienne des végétaux." Phd thesis, Ecole Polytechnique X, 2010. http://pastel.archives-ouvertes.fr/pastel-00563244.

Full text
Abstract:
Les travaux effectués durant cette thèse portent sur l'étude et l'utilisation d'une méthode de mesure passive pour la télédétection de la fluorescence chlorophyllienne induite par le rayonnement solaire à l'échelle du couvert végétal. Cette méthode est basée sur la mesure de la déformation des bandes d'absorption du spectre solaire dans le spectre d'irradiance, après interaction avec la végétation. Dans ce cadre, un nouvel algorithme permettant de mesurer la fluorescence a été élaboré. Il s'applique à des mesures faites dans quelques canaux autour des bandes d'absorption de l'oxygène atmosphérique. Son originalité est qu'il permet de tenir compte des variations de réflectance de la végétation qui perturbent l'estimation de la fluorescence. Dans le cadre de mesures à grande distance, une modélisation à l'aide du code de transfert radiatif MODTRAN a permis l'étude des effets atmosphériques affectant la mesure de la fluorescence. Nous avons établi que MODTRAN pouvait être utilisé pour corriger ces effets. Il a par ailleurs été montré qu'en plus de la connaissance des conditions atmosphériques, il était essentiel de pouvoir caractériser l'environnement de la cible. En effet, sa contribution, qui peut être supérieure au signal de fluorescence, est fortement variable spatialement. Une méthode opérationnelle de corrections des effets atmosphériques a été définie à partir de cette étude et appliquée à des mesures avionnées effectuées pendant la campagne ESA-CEFLES2. Les résultats de cette campagne mettent en évidence la grande variabilité spatiale et temporelle du signal de fluorescence. Une plateforme de mesure de la fluorescence à l'échelle du couvert a été mise en place et un nouveau capteur développé. Cette plateforme a permis de conduire des mesures établissant que la fluorescence mesurée dans le proche infrarouge pouvait être utilisée comme indicateur de biomasse, et que le rapport des fluorescences rouge/proche infrarouge, était porteur d'informations sur la structure de la végétation.
APA, Harvard, Vancouver, ISO, and other styles
50

Weinberger, David. "Detektionsmethoden für Gammastrahlung in der therapeutischen Medizin mit CdZnTe-Detektoren." Universitätsverlag der Technischen Universität Chemnitz, 2017. https://monarch.qucosa.de/id/qucosa%3A20912.

Full text
Abstract:
CdZnTe-Detektoren, zur direkten Messung von Gammastrahlung, die bei der Behandlung mit beschleunigten Teilchen entsteht, besitzen das Potential eine Reichweitenkontrolle zu ermöglichen und die Strahlendosis zu erfassen. Jedoch stellt die Identifizierung einzelner, energetisch nahe beieinander liegenden Photonenenergien, bei einem solchen Volumendetektor eine besondere Herausforderung dar. Die vorliegende Arbeit beschäftigt sich mit der Entwicklung von Methoden zur Korrektur der Signalformen am Volumenhalbleiter CdZnTe und der damit verbundenen Verbesserung der Energie- und Zeitinformation des Detektors. Dies ist wichtig für den Einsatz in der therapeutischen Medizin mit beschleunigten Teilchen, da Ladungsträger durch Gammastrahlung in unterschiedlichen Tiefen des Detektors generiert werden und einen tiefenabhängigen Fehler in der Detektorgenauigkeit erzeugen.
CdZnTe detectors, used for the direct measurement of gamma radiation generated during the treatment with accelerated particles, have the potential to provide a range control and to detect the radiation dose. However, the identification of individual energetically close photon energies in such a volume detector is a particular challenge. The present work deals with the development of methods for correcting the signal forms of the CdZnTe and the associated improvement of the energy and time information of the detector This is important for use in accelerated particle medicine because charge carriers are generated by gamma radiation at different depths of the detector and produce a depth dependent error in detector accuracy.
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography