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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
471

Compilation de réseaux de Petri : modèles haut niveau et symétries de processus / Compilation of Petri nets : high-level models and process symmetries

Fronc, Lukasz 28 November 2013 (has links)
Cette thèse s'intéresse à la vérification de systèmes automatisables par model-checking. La question sous-jacente autour de laquelle se construit la contribution est la recherche d'un compromis entre différents objectifs potentiellement contradictoires : la décidabilité des systèmes à vérifier, l'expressivité des formalismes de modélisation, l'efficacité de la vérification, et la certification des outils utilisés. Dans ce but, on choisit de baser la modélisation sur des réseaux de Petri annotés par des langages de programmation réels. Cela implique la semi-décidabilité de la plupart des questions puisque la responsabilité de la terminaison est remise entre les mains du modélisateur (tout comme la terminaison des programmes est de la responsabilité du programmeur). Afin d'exploiter efficacement ces annotations, on choisit ensuite une approche de compilation de modèle qui permet de générer des programmes efficaces dans le langage des annotations, qui sont alors exécutées de la manière la plus efficace. De plus, la compilation est optimisée en tirant partie des spécificités de chaque modèle et nous utilisons l'approche de model-checking explicite qui autorise cette richesse d'annotations tout en facilitant le diagnostique et en restant compatible avec la simulation (les modèles compilés peuvent servir à de la simulation efficace). Enfin, pour combattre l'explosion combinatoire, nous utilisons des techniques de réductions de symétries qui permettent de réduire les temps d'exploration et l'espace mémoire nécessaire. / This work focuses on verification of automated systems using model-checking techniques. We focus on a compromise between potentially contradictory goals: decidability of systems to be verified, expressivity of modeling formalisms, efficiency of verification, and certification of used tools. To do so, we use high level Petri nets annotated by real programming languages. This implies the semi-decidability of most of problems because termination is left to the modeler (like termination of programs is left to the programmer). To handle these models, we choose a compilation approach which produces programs in the model annotation language, this allows to execute them efficiently. Moreover, this compilation is optimizing using model peculiarities. However, this rich expressivity leads to the use of explicit model-checking which allows to have rich model annotations but also allows to easily recover errors from verification, and remains compatible with simulation (these compiled models can be used for efficient simulation). Finally, to tackle the state space explosion problem, we use reduction by symmetries techniques which allow to reduce exploration times and state spaces.
472

律师事务所合伙人的激励机制设计和组织设计对其业务的影响

January 2019 (has links)
abstract: 中国律师制度自“文化大革命”结束后恢复至今,已有近四十年。中国律师行业伴随着中国改革开放的进程,得到了飞速的发展,当然,同时也面临着诸多的问题。重要的问题之一便是,中国律师事务所采用“加盟制合伙人”模式和采用“权益制合伙人”模式之争。本文试图从回顾企业边界的三大理论出发,提出“加盟制合伙人”模式和 “权益制合伙人”模式与合伙人律师的业务专业化程度、业务复杂化程度以及大客户和律师事务所规模关系的四个假设,通过实证分析的方式,试图以企业边界三大理论解释前述四个假设中的关系,并以此期望对律师行业的发展有所启发。 / Dissertation/Thesis / Doctoral Dissertation Business Administration 2019
473

Bayesian hierarchical normal intrinsic conditional autoregressive model for stream networks

Liu, Yingying 01 December 2018 (has links)
Water quality and river/stream ecosystems are important for all living creatures. To protect human health, aquatic life and the surrounding ecosystem, a considerable amount of time and money has been spent on sampling and monitoring streams and rivers. Water quality monitoring and analysis can help researchers predict and learn from natural processes in the environment and determine human impacts on an ecosystem. Measurements such as temperature, pH, nitrogen concentration, algae and fish count collected along the network are all important factors in water quality analysis. The main purposes of the statistical analysis in this thesis are (1) to assess the relationship between the variable measured in the water (response variable) and other variables that describe either the locations on/along the stream network or certain characteristics at each location (explanatory variable), and (2) to assess the degree of similarity between the response variable values measured at different locations of the stream, i.e. spatial dependence structure. It is commonly accepted that measurements taken at two locations close to each other should have more similarity than locations far away. However, this is not always true for observations from stream networks. Observations from two sites that do not share water flow could be independent of each other even if they are very close in terms of stream distance, especially those observations taken on objects that move passively with the water flow. To model stream network data correctly, it is important to quantify the strength of association between observations from sites that do not share water.
474

Criteria for generalized linear model selection based on Kullback's symmetric divergence

Acion, Cristina Laura 01 December 2011 (has links)
Model selection criteria frequently arise from constructing estimators of discrepancy measures used to assess the disparity between the data generating model and a fitted approximating model. The widely known Akaike information criterion (AIC) results from utilizing Kullback's directed divergence (KDD) as the targeted discrepancy. Under appropriate conditions, AIC serves as an asymptotically unbiased estimator of KDD. The directed divergence is an asymmetric measure of separation between two statistical models, meaning that an alternate directed divergence may be obtained by reversing the roles of the two models in the definition of the measure. The sum of the two directed divergences is Kullback's symmetric divergence (KSD). A comparison of the two directed divergences indicates an important distinction between the measures. When used to evaluate fitted approximating models that are improperly specified, the directed divergence which serves as the basis for AIC is more sensitive towards detecting overfitted models, whereas its counterpart is more sensitive towards detecting underfitted models. Since KSD combines the information in both measures, it functions as a gauge of model disparity which is arguably more balanced than either of its individual components. With this motivation, we propose three estimators of KSD for use as model selection criteria in the setting of generalized linear models: KICo, KICu, and QKIC. These statistics function as asymptotically unbiased estimators of KSD under different assumptions and frameworks. As with AIC, KICo and KICu are both justified for large-sample maximum likelihood settings; however, asymptotic unbiasedness holds under more general assumptions for KICo and KICu than for AIC. KICo serves as an asymptotically unbiased estimator of KSD in settings where the distribution of the response is misspecified. The asymptotic unbiasedness of KICu holds when the candidate model set includes underfitted models. QKIC is a modification of KICo. In the development of QKIC, the likelihood is replaced by the quasi-likelihood. QKIC can be used as a model selection tool when generalized estimating equations, a quasi-likelihood-based method, are used for parameter estimation. We examine the performance of KICo, KICu, and QKIC relative to other relevant criteria in simulation experiments. We also apply QKIC in a model selection problem for a randomized clinical trial investigating the effect of antidepressants on the temporal course of disability after stroke.
475

A Mathematical Model of the Dispersion of a Concentrated Substance for Use in the Great Salt Lake's South Arm

Rughellis, Anthony O. 01 May 1978 (has links)
The ability to predict the dispersion of substances in the Great Salt Lake is a requisite towards making responsible management decisions relating to uses of the lake. The lake is a complex terminal body of water and will require a fairly sophisticated mathematical model to properly simulate the dispersion process in the lake. This finite element convection-dispersion model is a first step towards developing a comprehensive model. The model provides a finite element solution to the two-dimensional convection-dispersion equation and is capable of simulating steady or unsteady-state situations. It utilizes a known velocity field, dispersion coefficients, an introduced substance concentration, substance decay rates, and the region geometry to produce a solution to a given convection-dispersion problem. At the present time, a quantitative verification of the model has not been done, but qualitative use of the model indicates that it yields reasonable solutions satisfying continuity to convection-dispersion problems. Problems tested utilize a uniform flow field and various methods of introducing a substance, such as internal injections, established concentration gradients, and diffusers. This model affords the options in the approximating techniques of linear or quadratic interpolation functions, the Galerkin or "upwinding" methods of weigh ted residuals, and a linearly or quadratically varying velocity field. The model must use a continuous flow field to produce a credible solution. The model does need improvement in its ability to conserve mass in unsteady-state problems when introducing a substance into the modeled region and allowing dispersive transport at the boundaries. Proper nodal spacing (mesh size) is also important because a relatively coarse mesh size can result in poor approximations in some areas of the region modeled.
476

Model upravljanja održavanjem sistema dizaličnog transporta / Maintenance Management Model of CraneTransport System‘

Brkić Aleksandar 18 September 2014 (has links)
<p>Iako se poslednjih godina sve veća paţnja<br />pridaje tehnikama odrţavanja na bazi rizika, i<br />metode tehniĉke dijagnostike implementiraju<br />u sve većem obimu, a dizalice, kao grupa<br />naj&scaron;ire primenjenih sredstava u rukovanju<br />materijalima, uĉestvuju sa ĉak jednom<br />trećinom u svim smrtnim sluĉajevima<br />pojedinih grana industrije, razvoj modela<br />odrţavanja konkretnih tehniĉkih sistema van<br />polja nuklearne i petrohemijske industrije ne<br />napreduje dovoljno brzo. Shodno tome,<br />predmet disertacije je postavka i potvrda<br />dovoljno taĉnog i dovoljno jednostavnog<br />modela odrţavanja sistema dizaliĉnog<br />transporta za &scaron;iru industrijsku primenu.<br />Novopostavljen model odrţavanja sistema<br />dizaliĉnog transporta, sadrţi dva modula -<br />tehniĉki i &bdquo;menadţment― modul. Shodno<br />predloţenom tehniĉkom modulu modela<br />odrţavanja sistema dizaliĉnog transporta,<br />sprovedena je eksperimentalna provera<br />tehniĉkog modula modela in site na dva<br />sistema dizaliĉnog transporta na<br />hidroelektrani &bdquo;HE Đerdap 1― u Kladovu kao<br />i provera faktora &bdquo;menadţment― modula<br />primenom metoda statistiĉke analize<br />(faktorska i analiza pouzdanosti) na uzorku 51<br />preduzeća u cilju dobijanja modifikacionog<br />faktora. Vrednosti modifikacionog faktora<br />odredjuju zahvat tehniĉkog faktora (postupak<br />procene tehniĉkog faktora u celini, vizuelna<br />kontrolu stanja konstrukcije i mehanizama<br />dizalica i statiĉki i dinamiĉki proraĉun modela<br />konstrukcije dizalica ili samo vizuelna<br />kontrola).</p> / <p>Although in recent years, more attention is<br />given to risk-based techniques of<br />maintenance, and methods of technical<br />diagnostics are implemented in an increasing<br />extent, and cranes, as a group of the most<br />widely used resources in material handling,<br />account for one third of all deaths in certain<br />industries, development of specific<br />maintenance models of technical systems<br />outside the field of nuclear and petrochemical<br />industries is not progressing fast enough.<br />Accordingly , the subject of this dissertation is<br />the setting and confirmation of sufficiently<br />accurate and sufficiently simple maintenance<br />model for cranes system transportation for<br />general industrial applications. The newly<br />appointed maintenance model for cranes<br />system transportation, contains two modules -<br />technical and &quot;management&quot; module.<br />According to the proposed technical module<br />of maintenance model for cranes system<br />transportation the experimental verification is<br />carried out on the two cranes systems in<br />power plant &quot;Djerdap 1 &quot; in Kladovo while<br />&#39;management&#39; module factors are proved using<br />the methods of statistical analysis ( factor<br />analysis and reliability) on the sample sized<br />51 in order to obtain the modification factor.<br />The values of modification factor determine<br />the level of technical factors needed (process<br />evaluation of technical factors as a whole, the<br />visual control condition of the structure and<br />mechanisms of cranes and static and dynamic<br />analysis model construction crane or solely<br />visual inspection).</p> / null
477

Parameter estimation of smooth threshold autoregressive models.

Nur, Darfiana January 1998 (has links)
This thesis is mainly concerned with the estimation of parameters of a first-order Smooth Threshold Autoregressive (STAR) model with delay parameter one. The estimation procedures include classical and Bayesian methods from a parametric and a semiparametric point of view.As the theoretical importance of stationarity is a primary concern in estimation of time series models, we begin the thesis with a thorough investigation of necessary or sufficient conditions for ergodicity of a first-order STAR process followed by the necessary and sufficient conditions for recurrence and classification for null-recurrence and transience.The estimation procedure is started by using Bayesian analysis which derives posterior distributions of parameters with a noninformative prior for the STAR models of order p. The predictive performance of the STAR models using the exact one-step-ahead predictions along with an approximation to multi-step-ahead predictive density are considered. The theoretical results are then illustrated by simulated data sets and the well- known Canadian lynx data set.The parameter estimation obtained by conditional least squares, maximum likelihood, M-estimator and estimating functions are reviewed together with their asymptotic properties and presented under the classical and parametric approaches. These estimators are then used as preliminary estimators for obtaining adaptive estimates in a semiparametric setting. The adaptive estimates for a first-order STAR model with delay parameter one exist only for the class of symmetric error densities. At the end, the numerical results are presented to compare the parametric and semiparametric estimates of this model.
478

Logistics technology transfer model

Al Hajri, Abdullah Said, Mechanical & Manufacturing Engineering, Faculty of Engineering, UNSW January 2008 (has links)
A consecutive number of studies on the adoption trend of logistics technology since 1988 revealed that logistics organizations are not in the frontier when it comes to adopting new technology and this delayed adoption creates an information gap. In the advent of supply chain management and the strategic position of logistics, the need for accurate and timely information to accompany the logistics executives became more important than ever before. Given the integrative nature of logistics technology, failure to implement the technology successfully could result in writing off major investments in developing and implementing the technology or even in abandoning the strategic initiatives underpinned by these innovations. Consequently, the need to employ effective strategies and models to cope with these uncertainties is rather crucial. This thesis addresses the aspect of uncertainty in implementation success by process and factor research models. Process research approach focuses on the sequence of events in the technology transfer process that occurs over time. It explains the story that explains the degree of association between these sequences and implementation success. Through content analysis, this research gathers, extracts, and categorizes process data of actual stories of logistics technology adoption and implementations in organizations that are published in literature. The extracted event sequences are then analyzed using optimal matching from natural science and grouped using cluster analysis. Four patterns were revealed that organizations follow to transfer logistics technology namely, formal minimalist, mutual adaptation, development concerned, and organizational roles dispenser. Factors that contribute to successful implementation in each pattern were defined as the crucial and necessary events that characterized and differentiated each pattern from others. The factor approach identifies the potential predictors of successful technology implementation and tests empirical association between predictors and outcomes. This research develops a logistics technology success model. In developing the model, various streams of research were investigated including logistics, information systems, and organizational psychology. The model is tested using a questionnaire survey study. The data were collected from Australian companies which have recently adopted and implemented logistics technology. The results of a partial least squares structured equation modeling provide strong support for the model constructs and valuable insights to logistics/supply chain managers. The last study reports a convergent triangulation study using multiple case study of three Australian companies which have implemented logistics technology. A within and a cross case analysis of the three cases provide cross validation for the results of the other two studies. The results provided high predictive validity for the two models. Furthermore, the case study approach was so beneficial in explaining and contextualizing the linkages of the factor-based model and in confirming the importance of the crucial events in the process-based model. The thesis concludes with a research and managerial implications chapter which is devoted for logistics/supply chain managers and researchers.
479

Resoure allocation in selected Australian universities

Eedle, Elizabeth Margaret, n/a January 2007 (has links)
Australian universities are multi-million dollar operations employing tens of thousands of people. They attract revenue from a variety of government and non-government sources, and yet, as non-profit organisations they are judged by governments, peers and their communities on their performance in teaching and research rather than on a financial bottom line. In order to achieve these results, university managers must make decisions on how to allocate available funding throughout the university. Faced with competing demands on scarce funds, how do university managers make these choices? One option is to use a resource allocation model to 'crunch the numbers'. Resource allocation models can incorporate a number of elements - student and staff numbers, weightings and performance data, for example - to allocate available funds. These allocation models are used in different ways in different universities, but serve the same basic purpose of assisting decision-making on how much to allocate to different sections of the organisation. Such models operate within a process and context that includes the strategic aims of the University, the organisation structure, its committees and culture. This thesis contains case studies of resource allocation models and processes used in three Australian universities. It examines the methods used for resource allocation at the first and second levels within each university; that is, from the Vice-Chancellor to Dean (or equivalent), and from Dean to Head of School (or equivalent). Observations and conclusions are drawn on the models used, the processes surrounding the models, and the continuity between the two layers of allocations. The research finds all the case-study universities operate models at multiple levels in their organisations, and that there is a concerning lack of consistency and flow-through at these different levels. The messages that the university leadership intends to send through the allocations may be lost to managers one-process removed from them. The research also concludes that transparency is the most important element of the resource allocation process. University staff dealing with allocation processes will accept the results, even if they are not ideal, if they can understand how and why decisions were made. As a professional doctorate thesis, the aim is to provide a practical aid to people with responsibility for resource allocation in universities.
480

數據相關之二階製程管制 / Two-step Process Control for Autocorrelated data

陳維倫, Chen, Wei-Lun Unknown Date (has links)
Most products are produced by several process steps and have more than one interested quality characteristics. If each step of the process is independent, and the observations taken from the process are also independent then we may use Shewhart control chart at each step. However, in many processes, most production steps are dependent and the observations taken from the process are correlated. In this research, we consider the process has two dependent steps and the observations taken from the process are correlated over time. We construct the individual residual control chart to monitor the previous process and the cause-selecting control chart to monitor the current process. Then simulate all the states occur in the process and present the individual residual control chart and the cause-selecting control chart of the simulations. Furthermore compare the proposed control charts with the Hotelling T2 control chart. At last, we give an example to illustrate how to construct the proposed control From the proposed control charts, we can determine which step of the process is out of control easily. If there is a signal in the individual residual control chart, it means the previous process is out of control. If there is a signal in the cause-selecting control chart, it means the current process is out of control. The Hotelling T2 control chart only indicate the process is out of control but does not detect which step of the process is out of control.

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