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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.
431

Study of Green Management Continuity from Parent companies to Joint Ventures - Case Study of two Petrochemical companies

Jung, Pei 13 August 2008 (has links)
The Industrial Revolution which began at the end of the 18th century opened a new chapter in human history. Since the steam engine was invented by Watt, technology advances and innovations have taken place continuously. This has brought unprecedented prosperity to mankind. However, highly developed technology has led to environmental pollution and an damage the natural ecology and human life. The issue is only now attracting attention. In the face of undeniable environmental damage, every large petrochemistry company has realized that the trend toward greater environmental responsibility cannot be ignored and needs to be seriously considered. Due to global complications, however, there are different priorities and strategies among countries in th way their enterprises approach environmental protection issues. This research paper is focused on the continuity of green management from multi-national oil corporations down to the joint-venture subsidiaries. Two JV subsidiaries and three parent companies are included in this study. This research is based on a non-quantitative study, by means of face-to-face interviews and information collection, in an attempt to understand the policy details and implementation of green management continuity from parent companies to their subsidiaries. This research tackles the following issues: (1) How the multi-national oil corporations extend and control the green management of their subsidiaries (2) Differences among the multinational oil corporations regarding green management (3) Comparing multinational oil corporations, how local oil companies control the green management of their subsidiaries (4) Where Petrochemical industry corporations manage environmental protection and safety within the same department, what is the degree of interaction between these two functions The search has revealed: (1) In terms of influence on environmental protection implementation, the local environmental regulation are obviously more influential than the direction handed down by the parent companies of multi-national corporations. (2) In terms of influence on environmental protection implementation, the influence of local neighborhood consciousness is also greater than that exercised by the parent companies of multi-national corporations. (3) In term of green management control and coordination with subsidiaries, multi-national corporations are made adept than local companies. (4) Multi-national corporations handle environmental protection issues based on risk management (5) Multi-national corporations emphasis safety before environmental protection issues.
432

The implementation of H.264 algorithm with parallel extended MMX instruction set

Shen, Cheng-Ying 20 August 2008 (has links)
The H.264 Protocol is an important method for the multimedia transmission and calculation, but it is difficult to work smoothly on the embedded systems because of the low clock in the working environment of the embedded system .Although many new multimedia instruction sets have been developed, the immediate multimedia calculation is still difficult to implement on the embedded system. So this paper uses the ¡§Multimedia Operation Register¡¨, a SIMD architecture, to implement H.264 algorithm on the embedded system to improve the performance of handling multimedia calculation. Multimedia Operation Register, which performs the parallel execution of the multi-data-streaming, uses the bit slice concept to design operation pair combining bit storage cell and bit computation. According to the characteristic , which is the address having constant distance between more than two data being used saved in the Memory, this paper using the striping addressing mode , which can cooperate with the parallel execution of multi-data-streaming , to load the data having strode addresses from the Memory in one instructions. On the other hand, this paper designs a new instruction set based on the Intel MMX instruction set and the operation feature of multimedia calculation. When a designer uses single-data-steaming to implement the H.264 Protocol by the multimedia instruction sets, he will use more interactions to do the same thing in every block. Now this paper can use fewer interactions to do the same thing because the Multimedia Operation Register can use the parallel execution of the multi-data-stream to calculate the data in many different blocks to implement H.264 Protocol at the same time. On the other hand, this paper can reallocate the number of the registers to the arithmetic unit which will be used smartly by changing the working mode. This paper also saves much execution time of some actions such as the transpose of the matrix, the data resorting and the SAD (Sum of Absolute Differences) calculation by using new instructions. In order to reduce the times of memory access, this paper uses the method which rotates the data between two registers to let the data been used as possible as it can. So the coding efficiency can be improved explosively by using all the methods which have been introduced. The conclusion in this paper shows that the parallel execution of the multi-data-streaming will be a very important method to handle multimedia calculation. And this paper advances an innovative architecture to implement the parallel execution of the multi-data- streaming. According to the simulation in 5th chapter, the speedup of handling H.264 Protocol by Multimedia Operation Register is more than four times with MMX instruction set. In the SAD calculation, it even can have ten times advanced then MMX instruction set. At last the efficacy is even better than the latest multimedia instruction set -¡§SSE4¡¨.
433

The Applications of Pulse Shaping in Ultra-broad Bandwidth Pulse Characterization and Multi-pulse Generation

Liu, Shin-Cheng 04 November 2008 (has links)
This thesis utilize pulse shaping in characterization of ultra-broad bandwidth laser pulse and multi-pulse generation. Using angle-dithering technique, time-integrating phase-matching bandwidth can be increased significantly even with a thin crystal. We also characterize the pulse by angle-dithered MIIPS( intrapulse interference phase scan ) technique. An addition advantage of using a thick crystal is increased signal strength. In addition, we provide a method to generate multi-pulses and proceed Michelson interferometeric autocorrelator by controlling the spectral amplitude and phase of the pulse. To compare with the past method, the efficiency was obtained from 33% to 80% , and the stability and time resolution of delay time can be improved. We expect this method applied to narrow-band frequency-tunable THz wave genetration will be better.
434

A Multi-phase Approach for Disulfide Bond Prediction

Chung, Wei-Chun 25 July 2009 (has links)
Disulfide bond information can help the prediction of protein secondary structure, tertiary structure and all-atom coordinates. Most of previous works focused on either state classification or connectivity prediction with some assumption that some constraints were added to make the problem solvable in reality. In this thesis, we propose a multi-phase approach to solve the problem. Our method can export the number of bonds and achieve 90.7% accuracy in the state classification. For the connectivity prediction problem, we use the number of bonds we predict as a base to decide bond pairs. For overcoming the ratio imbalance of samples, we propose a down-sampling method to reducing processing time. Finally, we perform the weighted graph matching algorithm to obtain the bonding pattern, which achieves 63.5% accuracy. We also achieve 48% accuracy for the thorough prediction. Our method is validated by the datasets derived from SWISS-PROT and PDB. The results are better than the previous works.
435

Scalable analysis and design of service systems

Zhang, Bo 29 March 2011 (has links)
In this dissertation, we develop analytical and computational tools for performance analysis and design of large-scale service systems. The dissertation consists of three main chapters. The first chapter is devoted to devising efficient task assignment policies for large-scale service system models from a rare event analysis standpoint. Specifically, we study the steady-state behavior of multi-server queues with general job size distributions under size-interval task assignment (SITA) policies. Assuming Poisson arrivals and the existence of the alpha-th moment of the job size distribution for some alpha> 1, we show that if the job arrival rate and the number of servers increase to infinity with the traffic intensity held fixed, a SITA policy parameterized by alpha minimizes in a large deviation sense the steady-state probability that the total number of jobs in the system is greater than or equal to the number of servers. The optimal large deviation decay rate can be arbitrarily close to the one for the corresponding probability in an infinite-server queue, which only depends on the system traffic intensity but not on any higher moments of the job size distribution. This supports in a many-server asymptotic framework the common wisdom that separating large jobs from small jobs protects system performance against job size variability. In the second chapter, we study constraint satisfaction problems for a Markovian parallel-server queueing model with impatient customers, motivated by large telephone call centers. To minimize the staffing level subject to different service-level constraints, we propose refined square-root staffing (SRS) rules, which preserve the insightfulness and computational scalability of the celebrated SRS principle and yet achieve a stronger form of optimality. In particular, using asymptotic series expansion techniques, we first develop refinements to a set of asymptotic performance approximations recently used in analyzing large call centers, namely, the Quality and Efficiency Driven (QED) diffusion approximations. We then use the improved performance approximations to explicitly characterize the error of conventional SRS and further obtain the refined SRS rules. Finally, we demonstrate how the explicit form of the staffing refinements enables an analytical assessment of the accuracy of conventional SRS and its underlying QED approximation. In the third chapter, we study a fluid model for many-server Markovian queues in changing environments, which can be used to model large-scale service systems with customer abandonments and time-varying arrivals. We obtain the stationary distribution of the fluid model, which refines and is shown to converge, as the environment changing rate vanishes in a proper way, to a simple discrete bimodal approximation. We also prove that the fluid model arises as a law of large number limit in a many-server asymptotic regime.
436

Quantum chemical calculations of non-linear optical absorption

Cronstrand, Peter January 2004 (has links)
<p>This thesis represents a quantum chemical treatise ofvarious types of interactions between radiation and molecularsystems, with special emphasis on the nonlinear opticalprocesses of Multi-Photon Absorption and Excited StateAbsorption. Excitation energies, transition dipole moments,two-photon and three-photon tensor elements have beencalculated from different approaches; density functional theoryand<i>ab-initio</i>theory, employing different orders ofcorrelation treatment with the purpose to provide accuratevalues as well as evaluate the quality of the lower ordermethods. A combined study of the Multi-Photon Absorption andExcited State Absorption processes is motivated partly becausethey both contribute to the total optical response of a systemsubjected to intense radiation, but also because of theirconnection through so-called sum-over-states expressions. Thelatter feature is exploited in a generalized few-states model,which incorporates the polarization of the light and thedirections of the transition dipole moments constructing anexcitation channel, which thereby enables a more comprehensivecomparison of the attained transition dipole moments withexperimental data. Moreover, by decomposing a complex nonlinearresponse process such as Two-Photon Absorption into moreintuitive quantities, generalized few-states models may alsoenable a more elaborate interpretation of computed orexperimental results from which guidelines can be extracted inorder to control or optimize the property of interest. Ageneral conclusion originating from these models is that thetransition dipole moments in an excitation channel should bealigned in order to maximize the Two-Photon Absorptionprobability. The computational framework employed is responsetheory which through the response functions (linear, quadratic,cubic) offers alternative routes for evaluating the propertiesin focus; either directly and untruncated through the singleresidue of the quadratic or cubic response func- tions orthrough various schemes of truncated sum-over-statesexpressions where the key ingredients, transition dipolemoments, can be identified from the single residue of thelinear response function and double residue of the quadraticresponse function. The range of systems treated in the thesisstretches from diatomics, such as carbon monoxide and lithiumhydride, via small to large fundamental organic molecules, suchas formaldehyde, tetrazine and the trans-polyenes, to largechro- mophores, such as<i>trans</i>-stilbene, cumulenes, dithienothiophene,paracyclophane and organo-metallic systems, such as theplatinum(II)ethynyl compounds.</p>
437

OFFSHORE WIND FARM DECOMMISSIONING: INTRODUCING A MULTI-CRITERIA DECISION AID APPROACH

Kerkvliet, Hans January 2015 (has links)
The objective of this Thesis is to develop a methodological framework to guide the decision maker in selecting a decommissioning method for offshore wind farms which is supported by the majority of relevant stakeholders. Initially, a literature review has been conducted to find out which methods are available to decommission an off-shore wind farm and which criteria can influence the outcome.Two methods have been found in literature, namely partial and total removal of the foundation. Furthermore, twenty one (21) criteria have been found which could influence the results. These criteria can be divided in four categories which are economical, environmental, social and technical.Subsequently, a methodological framework was developed that included four steps. First, the possible decommissioning methods should be identified. Following on that, information should be collected and stakeholders should be selected. Subsequently, criteria should be selected and as last a multi criteria decision aid method should be used. It is expected that this procedure would lead to a decommissioning method which is supported by most of the stakeholders.To validate the methodological framework, a case study in the Netherlands has been selected. For this case study, four (4) stakeholders were identified and eleven (11) criteria were assessed. The outranking multi-criteria decision aid method PROMETHEE II was selected and results were obtained. Analyzing the results, it was possible to conclude that only one stakeholder preferred the total removal method while the other three stakeholders preferred the partial removal method.
438

High Bandwidth Control of a Small Aerial Vehicle / Hög bandbreddsreglering av en liten luftfarkost

Blomberg, Magnus January 2015 (has links)
Small aerial vehicles such as quad-rotors have been widely used commercially, for research and for hobby for the last decade with use still growing. The high interest is mainly due to the vehicles being small, simple, cheap and versatile. Among rigid body dynamics fast dynamics exist cohering to motors and other fast actuators. A linear quadratic control design technique is here investigated. The design technique suggests that the linear quadratic controller can be designed with penalties on the slow states only. The fast dynamics are modeled but the states are not penalised in the linear quadratic design. The design technique is here applied and evaluated. The results show that this in several cases is a suitable design technique for linear quadratic control design. MATLAB and Simulink have been widely used for design and implementation of control systems. With additional toolboxes these control systems can be compiled to and run on remote computers. Small, lightweight computers with high computational capacity are now easily accessible. In this thesis an avionics solution based on a small, powerful computer is presented. Simulink models can be compiled and transferred to the computer from the Simulink environment. The result is a user friendly way of rapid prototyping and evaluation of control systems.
439

Cooperation in self-organized heterogeneous swarms

Moritz, Ruby Louisa Viktoria 23 March 2015 (has links) (PDF)
Cooperation in self-organized heterogeneous swarms is a phenomenon from nature with many applications in autonomous robots. I specifically analyzed the problem of auto-regulated team formation in multi-agent systems and several strategies to learn socially how to make multi-objective decisions. To this end I proposed new multi-objective ranking relations and analyzed their properties theoretically and within multi-objective metaheuristics. The results showed that simple decision mechanism suffice to build effective teams of heterogeneous agents and that diversity in groups is not a problem but can increase the efficiency of multi-agent systems.
440

Cost-effectiveness of a line probe assay test compared to standard drug susceptibility testing for the detection of multi-drug resistant tuberculosis in a South African HIV population

Reddy, Millidhashni, 1980- 06 February 2012 (has links)
Over the last few years the World Health Organization (WHO) has endorsed several tests for the rapid detection of multidrug-resistant tuberculosis (MDR-TB) in resource-poor settings. The objective of this study was to compare the cost-effectiveness of a line probe assay test (less than one week for results) to conventional (bacterial culture) drug susceptibility testing (one month for results) for the detection of MDR-TB in an HIV-positive South African population by estimating the incremental cost-effectiveness ratio (ICER) per disability-adjusted life-year (DALY) averted. Costs of testing, drug treatment, hospitalization, as well as estimates for mortality, treatment success, and failure rates were obtained from literature sources, the South African Department of Health, the WHO, the Foundation of Innovative Diagnostics (FIND), and expert opinion. The willingness-to-pay threshold for a DALY averted was pre-set at 3 times the 2009 GDP per capita (about $17,400) for South Africa. In the base-case scenario for a prevalence of 30% of MDR-TB among HIV-positive patients, the average cost per person for the line probe assay testing strategy was $3,539/0.458 DALY averted and the conventional testing approach was $3,011/0.430 DALY averted. The base-line ICER was about $18,800 per DALY averted – about $1,400 above the pre-set threshold. In sensitivity analyses, the model was robust to changes in prevalence (+ 50%); costs (+ 10%), and probabilities of death, success and failure (+ 20%). However, when the treatment success rate for the line probe assay test was increased to 60% (one of the targets set by WHO in TB treatment) the ICER was below the willingness-to-pay level (i.e., cost-effective). The probabilistic sensitivity analysis showed there is a 70% chance that the additional cost of the line probe assay, compared with conventional testing, was less than $30,000 per DALY averted. However, the model may have underestimated the benefits of the line probe assay because it did not account for a decrease in the transmission of the disease due to earlier treatment nor did it measure any benefits more than a year after testing. / text

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