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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.
201

Optimalizace pracovních sil / Workforce Optimisation

Pacinda, Štefan January 2011 (has links)
Title: Workforce Optimisation Author: Štefan Pacinda Department / Institute: Department of Theoretical Computer Science and Mathematical Logic (KTIML) Supervisor of the master thesis: doc. RNDr. Roman Barták Ph.D., KTIML Abstract: Workforce management deals with the problem of maintaining productive workforce for example in call centers, hospitals, transportation companies etc. It includes the problem of deciding which skills are necessarily at each given time and how many personnel with given skills is required. These decisions are followed by solving the problem of allocating particular employees to shifts while satisfying the skill demands but also other constraints derived for example from law regulations, trade unions agreements, and individual preferences. This thesis deals with workforce optimization, that is with the optimal assignment of personnel to shifts in order to cover the demand for resources that vary over time. In this paper the solved problem is described in all detail and modeled as mixed integer program. Implementation details are presented and exhaustive analysis and experiments on a real life problem instance are performed to assure that the aims of the work have been met. Keywords: Rostering, Workforce Management, Shift Scheduling
202

Metafory šílenství: umlčení mýtotvůrci a porouchané mozky. / Metaphors of Madness: Silenced Myth-Makers and Disordered Brains.

Müller, Matyáš January 2016 (has links)
The work has basically three aims: 1st to map the wide range of various approaches in the current debate about madness, 2nd to formulate a specific theory of madness, 3rd to identify general philosophical problems the topic brings about, (a 4th aim is also outlined: to understand the presented theory in terms of therapeutic potential). The central thesis of this work is that insanity is an inherently ambiguous and elusive phenomenon and that trying to understand it we are using various metaphors borrowed from other areas, and consequently forget their metaphorical nature. The work is generally motivated by an effort to reconcile conflicting approaches, to understand them as complementary. It also wants to avoid creating an all-embracing synthesis on the one hand, and purely relativistic and pragmatic viewpoint on the other hand. The first part identifies four levels on which particular approaches understand madness as a problem: the level of the individual, the level of the collective, the transpersonal level and the existential level. At the end of the part, I discuss the possibilities and risks of creating a theoretical framework that would enable to understand various contradictory approaches on a common basis. In the second part, I develop my own analysis of madness. It is based on a...
203

Padrões de crescimento do setor de culturas do estado do Espirito Santo / not available

Fassarella, Roberto Amadeu 04 September 1987 (has links)
O objetivo desta pesquisa é o de quantificar as fontes e diferenças regionais de crescimento do subsetor de cultivos da agricultura do Espírito Santo na década de 1970 e também identificar determinantes dessas mudanças. Para isso faz-se uso da versão modificada do modelo"Shift-share", que permite, comparando-se períodos, uma análise individual das culturas e também da influência de composição e distribuição regional sobre o desempenho global das lavouras. As culturas de exportação como café e o cacau apresentaram taxas relativamente elevadas de crescimento na produção. Para o cacau contribuiu para esse incremento na produção um efeito-rendimento elevado ao passo que o café, além do efeito-rendimento, o efeito-localização geográfica da produção / The objective of this research is to quantify the regional sources and differences in growth rates of the crop sector of the State of Espírito Santo, Brazil. The study covers the period of 1970 to 1980 and also intends to identify the causes of those changes. In order to achieve those objectives a modified version of the"shift-share"model isused. this procedure permits, by means of inter-period comparisons, a specific analysis of individual crops. The effects of regional composition and distribution on crop global perfomance, are also analysed. The exportation farmings such as coffee and cocoa presented relative high growth rate in crops. The yield effect and secondarily the geographical location effect contributed to the coffee growth crop
204

Mots visuels pour le calcul de pose / Visual words for pose computation

Bhat, Srikrishna 22 January 2013 (has links)
Nous abordons le problème de la mise en correspondance de points dans des images pour calculer la pose d'une caméra par l'algorithme Perspective-n-Point (PnP). Nous calculons la carte 3D, c'est-à-dire les coordonnées 3D et les caractéristiques visuelles de quelques points dans l'environnement grâce à une procédure d'apprentissage hors ligne utilisant un ensemble d'images d'apprentissage. Étant donné une nouvelle image nous utilisons PnP à partir des coordonnées 2D dans l'image de points 3D détectés à l'aide de la carte 3D. Pendant la phase d'apprentissage nous groupons les descripteurs SIFT extraits des images d'apprentissage pour obtenir des collections de positions 2D dans ces images de quelques-uns des points 3D dans l'environnement. Le calcul de SFM (Structure From Motion) est effectué pour obtenir les coordonnées des points correspondants 3D. Pendant la phase de test, les descripteurs SIFT associés aux points 2D projection d'un point 3D de la carte sont utilisés pour reconnaître le point 3D dans une image donnée. Le cadre de travail est semblable à celui des mots visuels utilisés dans différents domaines de la vision par ordinateur. Pendant l'apprentissage, la formation des mots visuelle est effectuée via l'identification de groupes et pendant les tests des points 3D sont identifiés grâce à la reconnaissance des mots visuels. Nous menons des expériences avec des méthodes de formation différentes (k-means et mean-shift) et proposons un nouveau schéma pour la formation des mots visuels pour la phase d'apprentissage. Nous utilisons différentes règles de mise en correspondance, y compris quelques-unes des méthodes standards de classification supervisée pour effectuer la reconnaissance des mots visuels pendant la phase de test. Nous évaluons ces différentes stratégies dans les deux étapes. Afin d'assurer la robustesse aux variations de pose entre images d'apprentissage et images de test, nous explorons différentes façons d'intégrer les descripteurs SIFT extraits de vues synthétiques générées à partir des images d'apprentissage. Nous proposons également une stratégie d'accélération exacte pour l'algorithme mean-shift / We address the problem of establishing point correspondences in images for computing camera pose through Perspective-n-Point (PnP) algorithm. We compute the 3D map i.e. 3D coordinates and visual characteristics of some of the points in the environment through an offline training stage using a set of training images. Given a new test image we apply PnP using the 2D coordinates of 3D points in the image detected by using the 3D map. During the training stage we cluster the SIFT descriptors extracted from training images to obtain 2D-tracks of some of the 3D points in the environment. Each 2D-track consists of a set of 2D image coordinates of a single 3D point in different training images. SfM (Structure from Motion) is performed on these 2D-tracks to obtain the coordinates of the corresponding 3D points. During the test stage, the SIFT descriptors associated the 2D-track of a 3D point is used to recognize the 3D point in a given image. The overall process is similar to visual word framework used in different fields of computer vision. During training, visual word formation is performed through clustering and during testing 3D points are identified through visual word recognition. We experiment with different clustering schemes (k-means and mean-shift) and propose a novel scheme for visual word formation for training stage. We use different matching rules including some of the popular supervised pattern classification methods to perform visual word recognition during test stage. We evaluate these various matching strategies in both stages. In order to achieve robustness against pose variation between train and test images, we explore different ways of incorporating SIFT descriptors extracted from synthetic views generated from the training images. We also propose an exact acceleration strategy for mean-shift computation
205

Electrogenic metals for elasmobranch bycatch mitigation

Unknown Date (has links)
Commercial longline fishing results in large amounts of incidental bycatch of elasmobranch fishes (sharks, skates, and rays). Teleost species lack electrosensory systems and development of technologies which target the ampullary organs of sharks provides an avenue to selectively deter elasmobranchs without affecting the catch rate of target teleosts. Electric field measurements and a controlled scientific longline study were conducted testing whether the lanthanide metal neodymium or zinc/graphite might reduce elasmobranch catch per unit effort (CPUE). Baited longline hooks were treated with neodymium and zinc/graphite and catch rates were compared to that of controls. Shark CPUE decreased by 60% on neodymium treated hooks and 80% on zinc/graphite treated hooks. The effectiveness of both treatments varied among species with significant reductions shown for Atlantic sharpnose sharks (Rhizoprionodon terranovae) but less dramatic differences for others. Zinc/graphite is potentially a viable tool for reduction of shark bycatch in a commercial longline fishery. / by Kieran Thomas Smith. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
206

Lanthanide metals as potential shark deterrents

Unknown Date (has links)
Sharks comprise a large portion of bycatch in pelagic longline fisheries worldwide. Lanthanide metals have been proposed as shark repellents. This study quantified the normalized voltage of lanthanide metals in seawater and found that there was no difference in normalized voltage among the six tested metals. Temperature and salinity had a significant effect on lanthanide normalized voltage. The output at 18ºC was significantly greater than at both 12 and 24ºC. The normalized voltage was significantly greater in freshwater than brackish or seawater. The dissolution rate for the lanthanides varied from -1.6 to -0.2g/h. As the metals dissolved the voltage remained constant. In a behavioral assay, neodymium was ineffective at repelling bonnethead sharks (Sphyrna tiburo) tested individually and in groups, and lemon sharks (Negaprion brevirostris) in groups. Due to high cost, fast dissolution rates, and lack of deterrent effects, lanthanide metals are not recommended for use in mitigating shark bycatch. / by Sara M. McCutcheon. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.
207

Staff scheduling by network programming.

January 1995 (has links)
by Kenneth Wing Chung Tang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 64-65). / LIST OF TABLES --- p.vi / LIST OF FIGURES --- p.vii / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 1.1 --- Staff Scheduling Overview --- p.2 / Chapter 1.1.1 --- Days-off scheduling --- p.7 / Chapter 1.1.2 --- Shift Scheduling --- p.8 / Chapter 1.1.3 --- Tour Scheduling --- p.9 / Chapter 1.2 --- Outline of The Work of The Thesis --- p.11 / Chapter 2. --- NETWORK MODEL FOR STAFF SCHEDULING --- p.13 / Chapter 2.1 --- The Basic Network Model --- p.13 / Chapter 2.1.1 --- General Idea --- p.13 / Chapter 2.1.2 --- Modeling Precedent Relationship Constraints by Arcs --- p.15 / Chapter 2.1.3 --- Modeling Shift Stretch Constraints by Nodes --- p.16 / Chapter 2.1.4 --- Modeling to Handle Side Constraints --- p.17 / Chapter 2.1.5 --- Mathematical Model --- p.21 / Chapter 2.2 --- Solving The Network Model With Side Constraints --- p.23 / Chapter 2.2.1 --- Basis Partitioning Network Simplex method --- p.23 / Chapter 2.2.2 --- A Two-Phase Heuristic for Schedules Construction --- p.29 / Chapter 3. --- APPLICA TION IN AN AIR CARGO TERMINAL --- p.55 / Chapter 3.1 --- Background And Problem Statement --- p.35 / Chapter 3.2 --- Generation of Staff Requirement Patterns --- p.38 / Chapter 3.3 --- A Typical Setting of Parameters --- p.41 / Chapter 3.4 --- Case One: Staff Requirement for Each Shift Is Fixed --- p.43 / Chapter 3.4.1 --- Conversion of hourly requirements to shift requirements --- p.43 / Chapter 3.4.2 --- Network Modeling --- p.44 / Chapter 3.4.3 --- An Example --- p.47 / Chapter 3.4.4 --- Computational result on different staff requirements --- p.49 / Chapter 3.5 --- Case Two: Staff Requirement for Each Shift Is Changing --- p.50 / Chapter 3.5.1 --- Network modeling --- p.51 / Chapter 3.5.2 --- An Example --- p.52 / Chapter 3.5.2.1 --- Overlapping shifts with one kind of break times --- p.54 / Chapter 3.5.2.2 --- Overlapping shifts with two kinds of break times --- p.56 / Chapter 3.5.2.3 --- Overtime work --- p.57 / Chapter 3.5.3 --- Computational results on different staff requirement patterns --- p.60 / Chapter 4. --- CONCLUSION --- p.62 / Chapter 5. --- BIBLIOGRAPHY --- p.64 / Chapter 6. --- APPENDIX --- p.66 / Chapter 6.1 --- Applying the heuristic to complete the incomplete schedules --- p.66 / Chapter 6.2 --- List of Schedules --- p.68 / Chapter 6.2.1 --- Terminologies --- p.68 / Chapter 6.2.2 --- The Optimal Schedules for Case One --- p.69 / Chapter 6.2.3 --- The Optimal Schedules for Case Two --- p.70 / Chapter 6.2.4 --- The Optimal Schedules with One-hour Break in One Shift --- p.71 / Chapter 6.2.5 --- The Optimal Schedules with Breaks after 4 and 3 Hours of Work --- p.72 / Chapter 6.2.6 --- The Optimal Schedules with Overtime Shifts --- p.73
208

Supported Pd and Pd/Alloy Membranes for Water-Gas Shift Catalytic Membrane Reactors

Augustine, Alexander Sullivan 08 April 2013 (has links)
This work describes the application of porous metal supported Pd-membranes to the water-gas shift catalytic membrane reactor in the context of its potential application to the Integrated Gasification Combined Cycle (IGCC) process. The objective of this work was to develop a better understanding of Pd-membrane fabrication techniques, water-gas shift catalytic membrane reactor operation, and long-term behavior of the Pd-membranes under water-gas shift conditions. Thin (1.5 - 16 um) Pd-membranes were prepared by electroless deposition techniques on porous metal supports by previously developed methods. Pd-membranes were installed into stainless steel modules and utilized for mixed gas separation (H2/inert, H2/H2O, dry syngas, and wet syngas) at 350 - 450C and 14.5 atma to investigate boundary layer mass transfer resistance and surface inhibition. Pd-membranes were also installed into stainless steel modules with iron-chrome oxide catalyst and tested under water-gas shift conditions to investigate membrane reactor operation in the high pressure (5.0 - 14.6 atma) and high temperature (300 - 500C) regime. After the establishment of appropriate operating conditions, long-term testing was conducted to determine the membrane stability through He leak growth analysis and characterization by SEM and XRD. Pd and Pd/Au-alloy membranes were also investigated for their tolerance to 1 - 20 ppmv of H2S in syngas over extended periods at 400C and 14.0 atma. Water-gas shift catalytic membrane reactor operating parameters were investigated with a focus on high pressure conditions such that high H2 recovery was possible without a sweep gas. With regard to the feed composition, it was desirable to operate at a low H2O/CO ratio for higher H2 recovery, but restrained by the potential for coke formation on the membrane surface, which occurred at a H2O/CO ratio lower than 2.6 at 400C. The application of the Pd-membranes resulted in high CO conversion and H2 recovery for the high temperature (400 - 500C) water-gas shift reaction which then enabled high throughput. Operating at high temperature also resulted in higher membrane permeance and less Pd-surface inhibition by CO and H2O. The water-gas shift catalytic membrane reactor was capable of stable CO conversion and H2 recovery (96% and 88% respectively) at 400C over 900 hours of reaction testing, and 2,500 hours of overall testing of the Pd-membrane. When 2 ppmv H2S was introduced into the membrane reactor, a stable CO conversion of 96% and H2 recovery of 78% were observed over 230 hours. Furthermore, a Pd90Au10-membrane was effective for mixed gas separation with up to 20 ppmv H2S present, achieving a stable H2 flux of 7.8 m3/m2-h with a moderate H2 recovery of 44%. The long-term stability under high pressure reaction conditions represents a breakthrough in Pd-membrane utilization.
209

A remodulation scheme for wavelength-division multiplexing passive optical network using time-interleaved differential phase shift keying modulation format.

January 2011 (has links)
Li, Pulan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 60-66). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview of wavelength division multiplexed passive optical network (WDM-PON) and colorless optical network unit (ONU) --- p.1 / Chapter 1.2 --- Implementation of colorless ONU --- p.4 / Chapter 1.3 --- Rayleigh backscattering in WDM-PON --- p.6 / Chapter 1.4 --- Motivation of this thesis --- p.9 / Chapter 1.5 --- Outline of this thesis --- p.11 / Chapter Chapter 2 --- Previous works of remodulation for WDM-PON --- p.12 / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.2 --- Devices utilized by colorless ONU in remodulation schemes --- p.13 / Chapter 2.2.1 --- Injection-locked Fabry-Perot laser diode at ONU --- p.13 / Chapter 2.2.2 --- Reflective semiconductor optical amplifier --- p.15 / Chapter 2.2.3 --- Reflective electro-absorption modulator and semiconductor optical amplifier (REAM-SOA) --- p.17 / Chapter 2.3 --- Modulation methods in remodulation schemes --- p.18 / Chapter 2.4 --- Summary --- p.23 / Chapter Chapter 3 --- A remodulation scheme based on time-interleaved DPSK modulation format --- p.25 / Chapter 3.1 --- Introduction --- p.25 / Chapter 3.2 --- Operation principle: time-interleaving technology for phase-modulated signal --- p.27 / Chapter 3.3 --- System architecture --- p.28 / Chapter 3.4 --- Experimental results and discussion --- p.31 / Chapter 3.5 --- Effect of timing misalignment on proposed remodulation scheme --- p.33 / Chapter 3.6 --- Summary --- p.35 / Chapter Chapter 4 --- Enhanced Tolerance to Rayleigh Backscattering in Remodulation Scheme Using Time-Interleaved DPSK Format --- p.37 / Chapter 4.1 --- Introduction --- p.37 / Chapter 4.2 --- Studies on Rayleigh backscattering suppression in optical domain --- p.39 / Chapter 4.2.1 --- RB suppression in carrier-distributed schemes --- p.39 / Chapter 4.2.2 --- RB suppression in remodulation schemes --- p.40 / Chapter 4.2 --- Experimental setup and results --- p.42 / Chapter 4.3 --- Discussion on RB suppression effect of the proposed scheme --- p.46 / Chapter 4.3.1 --- Theoretical study and simulation results --- p.46 / Chapter 4.3.2 --- Experimental demonstration of spectral relationship between signals and RB crosstalk --- p.49 / Chapter 4.4 --- Summary --- p.53 / Chapter Chapter 5 --- Conclusion and Future Works --- p.55 / Chapter 5.1 --- Conclusion of this thesis --- p.55 / Chapter 5.2 --- Future works --- p.57 / List of Publications --- p.59 / Bibliography --- p.60
210

Design and implementation of a high data rate QPSK demodulator for nanosatellites

Biyoghe, Joel S. January 2017 (has links)
Thesis (Master of Engineering in Electrical Engineering)--Cape Peninsula University of Technology, 2017. / This dissertation presents the development of a quadrature phase shift keying (QPSK) demodulator for nanosatellites that complies with both the limited resources associated with nanosatellites as well as the flexibility and configurability required for a software defined radio (SDR) platform. This research project is a component of a bigger project, which is to develop a high-speed receiver for nanosatellites, and aims to provide a practical solution to the need for communication technologies that support emerging nanosatellite applications, such as Earth observation and communications. The development of the QPSK demodulator follows an all-digital implementation approach. The main reason for selecting this approach is to have a system that is flexible and reconfigurable to comply with the SDR requirements. Another reason for selecting this approach is to comply with the low noise system, low power consumption as well as the small size and weight requirements associated with nanosatellites. The QPSK demodulator is implemented on an IGLOO2 Field Programmable Gate Array (FPGA), due to its robustness to radiation and high-speed capability. Initially, the techniques used to design each subsystem of the QPSK demodulator are selected. Then, algorithms to digitally implement the designed subsystems are produced. Thereafter, the code for the digital QPSK demodulator is written and verified in Matlab first. The simulation of the Matlab-based QPSK demodulator performs satisfactorily. Subsequently, the code to implement the QPSK demodulator on an FPGA (IGLOO2) has been written in Libero, using VHSIC Hardware Description Language (VHDL). The resulting FPGA-based QPSK demodulator has been emulated in Libero (an integration and development environment (IDE) for Microsemi FPGAs) using a test-bench as well as other analysis tools. The test-bench results are visualized using Modelsim. The results show that the demodulator can support data rates up to 13.25 Mbps if 16 samples-per-symbols are used, and up to 26.5 Mbps if 8 samples-per-symbols are used. It also has a very good bit-error-rate performance, which is simulated to be within a factor of 5 of the theoretical limit of QPSK modulation. Finally, the demodulator consumes less than 15 mW at the maximum operating speed. and has been coded to mitigate the effects of space radiation and noise contriution by the demodulator itself.

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