• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 10
  • 6
  • 4
  • 3
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 46
  • 11
  • 8
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 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.
21

Rangs, préséances, hiérarchie et constitution du royaume de Louis XIII à la Régence / Ranks, precedence, hierachy and the constitution of the realm from Louis XIII to the Régence

Fournier, Raphaël 03 December 2015 (has links)
Les conflits de rang sont en France aux XVIIème et XVIIIème siècle une source abondante de contentieux. Si leur dimension sociale et symbolique a été étudiée, leur dimension juridique a moins retenu l’attention. Une approche phénoménologique des rangs, des préséances, des hiérarchies, des conflits dont ils sont l’occasion et de leurs voies de règlement en montrent la nature conflictuelle, juridique et judiciaire. A l’examen, les cérémonies et les actes où s’exprime la puissance publique (audiences publiques des souverains, lits de justice, entrées royales et principales cérémonies de l’information), révèlent le caractère constitutionnel avant la lettre de cette matière, la perméabilité entretenue entre le signe de l’autorité, que l’on peut résumer par le rang, et l’autorité elle-même. En regard, les éléments de doctrine contemporains, pour précieux qu’ils soient, laissent perplexe. Pauvre ou silencieuse, la doctrine semble pécher par prudence. L’autorité du précédent y est tacitement reconnue tandis que la puissance discrétionnaire d’un souverain démiurge indiscrètement exaltée. Cependant, l’époque n’est pas pour autant privée de toute pensée des rangs adéquate à son objet. La littérature contemporaine montre que la hiérarchie constitue pour le public cultivé de l’époque un schème fondamental, une structure implicite du discours. Ce que la doctrine s’efforce de taire et que les sources contemporaines révèlent est le travail concurrent de deux matrices à l’oeuvre dans l’Etat royal à l’âge classique, la contradiction croissante entre la souveraineté et la hiérarchie. / Conflicts of rank in France in the 17th and 18th centuries were an abundant source of litigation. If their social and symbolic dimensions have already been studied, their legal dimension has attracted less attention. A phenomenological approach to ranks, precedencies, and hierarchies, as well as their ensuing conflicts and subsequent outcomes reveal their contentious, legal and judicial character. Upon examination, the ceremonies and acts during which public authority (the sovereigns' public audiences, parliamentary sessions presided over by the king, royal entrances, and the main ceremonies of information) expressed itself reveal a constitutional character before the very existence of such a document, as well as the permeability maintained between the sign of authority - as assumed by rank - and the authority itself. On the other hand, the elements of contemporary doctrine, as precious as they may be, remain perplexing. Poor or lacking, doctrine seems to be exceedingly cautious. The authority of the precedent is tacitly recognized whereas the demiurge sovereign's discretionary power indiscreetly exalted. However, the era was hardly lacking in any adequate thought as to ranks. The contemporary literature shows that the hierarchy constituted a fundamental scheme or an implicit structure of discourse for the educated public at the time. What doctrine seeks to silence and what contemporary sources reveal is the competition of two matrices at work in the royal State of the Classical Age, the growing contradiction between sovereignty and hierarchy.
22

Perceptual sound field synthesis concept for music presentation

Ziemer, Tim 24 April 2020 (has links)
A perceptual sound field synthesis approach for music is presented. Its signal processing implements critical bands, the precedence effect and integration times of the auditory system by technical means, as well as the radiation characteristics of musical instruments. Furthermore, interaural coherence, masking and auditory scene analysis principles are considered. As a result, the conceptualized sound field synthesis system creates a natural, spatial sound impression for listeners in extended listening area, even with a low number of loudspeakers. A novel technique, the “precedence fade”, as well as the interaural cues provided by the sound field synthesis approach, allow for a precise and robust localization.Simulations and a listening test provide a proof of concept. The method is particularly robust for signals with impulsive attacks and long quasi-stationary phases, as in the case of many instrumental sounds. It is compatible with many loudspeaker setups, such as 5.1 to 22.2, ambisonics systems and loudspeaker arrays for wave front synthesis. The perceptual sound field synthesis approach is an alternative to physically centered wave field synthesis concepts and conventional, perceptually motivated stereophonic sound and benefits from both paradigms.
23

Weighted Automata and Logics on Hierarchical Structures and Graphs

Dück, Stefan 04 January 2018 (has links)
Formal language theory, originally developed to model and study our natural spoken languages, is nowadays also put to use in many other fields. These include, but are not limited to, the definition and visualization of programming languages and the examination and verification of algorithms and systems. Formal languages are instrumental in proving the correct behavior of automated systems, e.g., to avoid that a flight guidance system navigates two airplanes too close to each other. This vast field of applications is built upon a very well investigated and coherent theoretical basis. It is the goal of this dissertation to add to this theoretical foundation and to explore ways to make formal languages and their models more expressive. More specifically, we are interested in models that are able to model quantitative features of the behavior of systems. To this end, we define and characterize weighted automata over structures with hierarchical information and over graphs. In particular, we study infinite nested words, operator precedence languages, and finite and infinite graphs. We show Büchi-like results connecting weighted automata and weighted monadic second order (MSO) logic for the respective classes of weighted languages over these structures. As special cases, we obtain Büchi-type equivalence results known from the recent literature for weighted automata and weighted logics on words, trees, pictures, and nested words. Establishing such a general result for graphs has been an open problem for weighted logics for some time. We conjecture that our techniques can be applied to derive similar equivalence results in other contexts like traces, texts, and distributed systems.
24

A Sequential Pattern Mining Driven Framework for Developing Construction Logic Knowledge Bases

Le, Chau, Shrestha, Krishna J., Jeong, H. D., Damnjanovic, Ivan 01 January 2021 (has links)
One vital task of a project's owner is to determine a reliable and reasonable construction time for the project. A U.S. highway agency typically uses the bar chart or critical path method for estimating project duration, which requires the determination of construction logic. The current practice of activity sequencing is challenging, time-consuming, and heavily dependent upon the agency schedulers' knowledge and experience. Several agencies have developed templates of repetitive projects based on expert inputs to save time and support schedulers in sequencing a new project. However, these templates are deterministic, dependent on expert judgments, and get outdated quickly. This study aims to enhance the current practice by proposing a data-driven approach that leverages the readily available daily work report data of past projects to develop a knowledge base of construction sequence patterns. With a novel application of sequential pattern mining, the proposed framework allows for the determination of common sequential patterns among work items and proposed domain measures such as the confidence level of applying a pattern for future projects under different project conditions. The framework also allows for the extraction of only relevant sequential patterns for future construction time estimation.
25

Scheduling Heuristics for Maximizing the Output Quality of Iris Task Graphs in Multiprocessor Environment with Time and Energy Bounds

Ravindran, Rajeswaran Chockalingapuram 01 January 2012 (has links) (PDF)
Embedded real time applications are often subject to time and energy constraints. Real time applications are usually characterized by logically separable set of tasks with precedence constraints. The computational effort behind each of the task in the system is responsible for a physical functionality of the embedded system. In this work we mainly define theoretical models for relating the quality of the physical func- tionality to the computational load of the tasks and develop optimization problems to maximize the quality of the system subject to various constraints like time and energy. Specifically, the novelties in this work are three fold. This work deals with maximizing the final output quality of a set of precedence constrained tasks whose quality can be expressed with appropriate cost functions. We have developed heuristic scheduling algorithms for maximizing the quality of final output of embedded applications. This work also dealswith the fact that the quality of output of a task in the system has noticeable effect on quality of output of the other dependent tasks in the system. Finally run time characteristics of the tasks are also modeled by simulating a distribution of run times for the tasks, which provides for averaged quality of output for the system rather than un-sampled quality based on arbitrary run times. Many real-time tasks fall into the IRIS (Increased Reward with Increased Service) category. Such tasks can be prematurely terminated at the cost of poorer quality output. In this work, we study the scheduling of IRIS tasks on multiprocessors. IRIS tasks may be dependent, with one task feeding other tasks in a Task Precedence Graph (TPG). Task output quality depends on the quality of the input data as well as on the execution time that is allowed. We study the allocation/scheduling of IRIS TPGs on multiprocessors to maximize output quality. The heuristics developed can effectively reclaim resources when tasks finish earlier than their estimated worst-case execution time. Dynamic voltage scaling is used to manage energy consumption and keep it within specified bounds.
26

Attention Modulates ERP Indices of the Precedence Effect

Zobel, Benjamin H. 07 November 2014 (has links) (PDF)
When presented with two identical sounds from different locations separated by a short onset asynchrony, listeners report hearing a single source at the location of the lead sound, a phenomenon called the precedence effect (Wallach et al., 1949; Haas, 1951). When the onset asynchrony is above echo threshold, listeners report hearing the lead and lag sounds as separate sources with distinct locations. Event-related potential (ERP) studies have shown that perception of separate sound sources is accompanied by an object-related negativity (ORN) 100-250 ms after onset and a late posterior positivity (LP) 300-500 ms after onset (Sanders et al., 2008; Sanders et al., 2011). The current study tested whether these ERP effects are modulated by attention. Clicks were presented in lead/lag pairs at and around listeners’ echo thresholds while in separate blocks they 1) attended to the sounds and reported if they heard the lag sound as a separate source, and 2) performed a difficult 2-back visual task. Replicating previous results, when attention was directed to the sounds, an ORN and LP were observed for click pairs 1 ms above compared to 1 ms below echo threshold. In contrast, when attention was directed away from the sounds to the visual task, neither the ORN nor the LP was evident. Instead, click pairs 1 ms above echo threshold elicited an anterior positivity 250-450 ms after onset. In addition, an effect resembling an ORN was found in comparing ERPs elicited by unattended click pairs with SOAs below attended echo threshold. These results indicate that attention modulates early perceptual processes in the precedence effect and may be critical for auditory object formation under these conditions.
27

Tight Flow-Based Formulations for the Asymmetric Traveling Salesman Problem and Their Applications to some Scheduling Problems

Tsai, Pei-Fang 15 June 2006 (has links)
This dissertation is devoted to the development of new flow-based formulations for the asymmetric traveling salesman problem (ATSP) and to the demonstration of their applicability in effectively solving some scheduling problems. The ATSP is commonly encountered in the areas of manufacturing planning and scheduling, and transportation logistics. The integration of decisions pertaining to production and shipping, in the supply chain context, has given rise to an additional and practical relevance to this problem especially in situations involving sequence-dependent setups and routing of vehicles. Our objective is to develop new ATSP formulations so that algorithms can be built by taking advantage of their relaxations (of integer variables, thereby, resulting in linear programs) to effectively solve large-size problems. In view of our objective, it is essential to have a formulation that is amenable to the development of an effective solution procedure for the underlying problem. One characteristic of a formulation that is helpful in this regard is its tightness. The tightness of a formulation usually refers to the quality of its approximation to the convex hull of integer feasible solutions. Another characteristic is its compactness. The compactness of a formulation is measured by the number of variables and constraints that are used to formulate a given problem. Our formulations for the ATSP and the scheduling problems that we address are both tight and compact. We present a new class of polynomial length formulations for the asymmetric traveling salesman problem (ATSP) by lifting an ordered path-based model using logical restrictions in concert with the Reformulation-Linearization Technique (RLT). We show that a relaxed version of this formulation is equivalent to a flow-based ATSP model, which, in turn, is tighter than the formulation based on the exponential number of Dantzig-Fulkerson-Johnson (DFJ) subtour elimination constraints. The proposed lifting idea is applied to derive a variety of new formulations for the ATSP, and a detailed analysis of these formulations is carried out to show that some of these formulations are the tightest among those presented in the literature. Computational results are presented to exhibit the relative tightness of our formulations and the efficacy of the proposed lifting process.> While the computational results demonstrate the efficacy of employing the proposed theoretical RLT and logical lifting ideas, yet it remains of practical interest to take due advantage of the tightest formulations. The key requirement to accomplish this is the ability to solve the underlying LP relaxations more effectively. One approach, to that end, is to solve these LP relaxations to (near-) optimality by using deflected subgradient methods on Lagrangian dual formulations. We solve the LP relaxation of our tightest formulation, ATSP6, to (near-) optimality by using a deflected subgradient algorithm with average direction strategy (SA_ADS) (see Sherali and Ulular [69]). We also use two nondifferentiable optimization (NDO) methods, namely, the variable target value method (VTVM) presented by Sherali et al. [66] and the trust region target value method (TRTV) presented by Lim and Sherali [46], on the Lagrangian dual formulation of ATSP6. The preliminary results show that the near-optimal values obtained by the VTVM on solving the problem in the canonical format are the closest to the target optimal values. Another approach that we use is to derive a set of strong valid inequalities based on our tighter formulations through a suitable surrogation process for inclusion within the more compact manageable formulations. Our computational results show that, when the dual optimal solution is available, the associated strong valid inequalities generated from our procedure can successfully lift the LP relaxation of a less tight formulation, such as ATSP2R¯, to be as tight as the tightest formulation, such as ATSP6. We extend our new formulations to include precedence constraints in order to enforce a partial order on the sequence of cities to be visited in a tour. The presence of precedence constraints within the ATSP framework is encountered quite often in practice. Examples include: disassembly optimization (see Sarin et al. [62]), and scheduling of wafers/ ICs on automated testing equipments in a semiconductor manufacturing facility (see Chen and Hsia [17]); among others. Our flow-based ATSP formulation can very conveniently capture these precedence constraints. We also present computational results to depict the tightness of our precedence-constrained asymmetric traveling salesman problem (PCATSP) formulations. We, then, apply our formulations to the hot strip rolling scheduling problem, which involves the processing of hot steel slabs, in a pre-specified precedence order, on one or more rollers. The single-roller hot strip rolling scheduling problem can be directly formulated as a PCATSP. We also consider the multiple-roller hot strip rolling scheduling problem. This gives rise to the multiple-asymmetric traveling salesman problem (mATSP). Not many formulations have been presented in the literature for the mATSP, and there are none for the mATSP formulations involving a precedence order among the cities to be visited by the salesmen, which is the case for the multiple-roller hot strip rolling scheduling problem. To begin with, we develop new formulations for the mATSP and show the validity of our formulations, and present computational results to depict their tightness. Then, we extend these mATSP formulations to include a pre-specified, special type of precedence order in which to process the slabs, and designate the resulting formulations as the restricted precedence-constrained multiple-asymmetric traveling salesman problem (rPCmATSP) formulations. We directly formulate the multiple-roller hot strip rolling scheduling problem as a rPCmATSP. Furthermore, we consider the hot strip rolling scheduling problem with slab selection in which not all slabs need to be processed. We model the single-roller hot strip rolling scheduling problem with slab selection as a multiple-asymmetric traveling salesman problem with exactly two traveling salesmen. Similarly, the multiple-roller hot strip rolling scheduling problem with slab selection is modeled as a multiple-asymmetric traveling salesman problem with (m+1) traveling salesmen. A series of computational experiments are conducted to exhibit the effectiveness of our formulations for the solution of hot strip rolling scheduling problems. Furthermore, we develop two mixed-integer programming algorithms to solve our formulations. These are based on Benders΄ decomposition [13] and are designated Benders΄ decomposition and Modified Benders΄ methods. In concert with a special type of precedence order presented in the hot strip rolling scheduling problems, we further introduce an adjustable density ratio of the associated precedence network and we use randomly generated test problems to study the effect of various density ratios in solving these scheduling problems. Our experimentation shows the efficacy of our methods over CPLEX. Finally, we present a compact formulation for the job shop scheduling problem, designated as JSCD (job shop conjunctive-disjunctive) formulation, which is an extension of our ATSP formulations. We use two test problems given in Muth and Thompson [53] to demonstrate the optimal schedule and the lower bound values obtained by solving the LP relaxations of our formulations. However, we observe that the lower bound values obtained by solving the LP relaxations of all variations of our JSCD formulation equal to the maximum total processing time among the jobs in the problem. / Ph. D.
28

A heuristic algorithm for the Capacitated Vehicle Routing Problem with Synchronized Pick-ups and Drop-offs : a case study for medications delivery and supervision in DR Congo

Clarke, John 08 1900 (has links)
Dans des contextes de post-urgence tels que le vit la partie occidentale de la République Démocratique du Congo (RDC), l’un des défis cruciaux auxquels font face les hôpitaux ruraux est de maintenir un niveau de médicaments essentiels dans la pharmacie. Sans ces médicaments pour traiter les maladies graves, l’impact sur la santé de la population est significatif. Les hôpitaux encourent également des pertes financières dues à la péremption lorsque trop de médicaments sont commandés. De plus, les coûts du transport des médicaments ainsi que du superviseur sont très élevés pour les hôpitaux isolés ; les coûts du transport peuvent à eux seuls dépasser ceux des médicaments. En utilisant la province du Bandundu, RDC pour une étude de cas, notre recherche tente de déterminer la faisabilité (en termes et de la complexité du problème et des économies potentielles) d’un problème de routage synchronisé pour la livraison de médicaments et pour les visites de supervision. Nous proposons une formulation du problème de tournées de véhicules avec capacité limitée qui gère plusieurs exigences nouvelles, soit la synchronisation des activités, la préséance et deux fréquences d’activités. Nous mettons en œuvre une heuristique « cluster first, route second » avec une base de données géospatiales qui permet de résoudre le problème. Nous présentons également un outil Internet qui permet de visualiser les solutions sur des cartes. Les résultats préliminaires de notre étude suggèrent qu’une solution synchronisée pourrait offrir la possibilité aux hôpitaux ruraux d’augmenter l’accessibilité des services médicaux aux populations rurales avec une augmentation modique du coût de transport actuel. / In post-emergency contexts such as in Western Democratic Republic of the Congo, also known as DR Congo, one of the crucial challenges that rural hospitals face is maintaining a pharmacy with essential medications and supplies. There is significant negative humanitarian impact when hospitals do not have essential medications for treatable life-threatening diseases; hospitals also incur financial losses when too much medication is ordered and it expires. Moreover, the cost of transporting medications and providing onsite supervision to remote hospitals is an extremely expensive endeavour. In some cases the transportation costs alone can surpass the cost of the medications. Using the province of Bandundu, DR Congo as a case study, we attempt to determine the feasibility (in terms of both problem complexity and potential savings) of a synchronized routing problem for medication delivery and on-site supervision visits. We propose a Capacitated Vehicle Routing Problem formulation that handles several novel requirements including activity-wise synchronization, precedence, and two activity frequencies. We implement a novel cluster-first, route-second heuristic with a geospatially-enabled database to solve the problem. We also present a Web-based tool to visualize the solutions in a map. The preliminary results of the research suggest that a synchronized solution could allow rural hospitals to increase the accessibility of medical services to rural populations with only a modest increase in transportation costs.
29

Inference for the K-sample problem based on precedence probabilities

Dey, Rajarshi January 1900 (has links)
Doctor of Philosophy / Department of Statistics / Paul I. Nelson / Rank based inference using independent random samples to compare K>1 continuous distributions, called the K-sample problem, based on precedence probabilities is developed and explored. There are many parametric and nonparametric approaches, most dealing with hypothesis testing, to this important, classical problem. Most existing tests are designed to detect differences among the location parameters of different distributions. Best known and most widely used of these is the F- test, which assumes normality. A comparable nonparametric test was developed by Kruskal and Wallis (1952). When dealing with location-scale families of distributions, both of these tests can perform poorly if the differences among the distributions are among their scale parameters and not in their location parameters. Overall, existing tests are not effective in detecting changes in both location and scale. In this dissertation, I propose a new class of rank-based, asymptotically distribution- free tests that are effective in detecting changes in both location and scale based on precedence probabilities. Let X_{i} be a random variable with distribution function F_{i} ; Also, let _pi_ be the set of all permutations of the numbers (1,2,...,K) . Then P(X_{i_{1}}<...<X_{i_{K}}) is a precedence probability if (i_{1},...,i_{K}) belongs to _pi_. Properties of these of tests are developed using the theory of U-statistics (Hoeffding, 1948). Some of these new tests are related to volumes under ROC (Receiver Operating Characteristic) surfaces, which are of particular interest in clinical trials whose goal is to use a score to separate subjects into diagnostic groups. Motivated by this goal, I propose three new index measures of the separation or similarity among two or more distributions. These indices may be used as “effect sizes”. In a related problem, Properties of precedence probabilities are obtained and a bootstrap algorithm is used to estimate an interval for them.
30

Återanställning genom bemanningsföretag / Reemployment through temporary agencies

Fagern, Danielly, Andersson, Carola January 2010 (has links)
<p><strong>Syfte: </strong>Syftet med studien är att undersöka hur användning av LAS företrädesrätt och bemanningsföretag har påverkat IF Metall och arbetsgivare inom tillverkningsindustrin.<strong> </strong></p><p><strong>Metod: </strong>Vi har genomfört en kvalitativ undersökning i form av intervjuer samt använt sekundärdata så som böcker, tidningsartiklar, forskningsrapporter och internetkällor.<strong> </strong></p><p><strong>Teoretiskt perspektiv: </strong>Vi har använt oss av Atkinsons teori, kapitalbindning, nyttomaximeringsteori, transaktionskostnadsteori samt psykologiskt och transaktionellt kontrakt.<strong> </strong></p><p><strong>Empiri: </strong>I empirin redovisas arbetsdomstolens domar om kringgående av LAS. Därefter följer redovisning av intervjuer som genomförts med IF Metall, Svenskt Näringsliv, Bemanningsföretagen och tre företag inom tillverkningsindustrin.<strong> </strong></p><p><strong>Slutsats: </strong>Vår undersökning visar att IF Metall och arbetsgivare enbart kan komma överens om ett kollektivavtal upprättas. Den nya förstärkta företrädesrätten tycks ha skapat än mer osämja arbetsgivare och IF Metall:s fackförbund emellan.</p>

Page generated in 0.1197 seconds