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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.
281

The dynamic, resource-constrained shortest path problem on an acyclic graph with application in column generation and literature review on sequence-dependent scheduling

Zhu, Xiaoyan 25 April 2007 (has links)
This dissertation discusses two independent topics: a resource-constrained shortest-path problem (RCSP) and a literature review on scheduling problems involving sequence-dependent setup (SDS) times (costs). RCSP is often used as a subproblem in column generation because it can be used to solve many practical problems. This dissertation studies RCSP with multiple resource constraints on an acyclic graph, because many applications involve this configuration, especially in column genetation formulations. In particular, this research focuses on a dynamic RCSP since, as a subproblem in column generation, objective function coefficients are updated using new values of dual variables at each iteration. This dissertation proposes a pseudo-polynomial solution method for solving the dynamic RCSP by exploiting the special structure of an acyclic graph with the goal of effectively reoptimizing RCSP in the context of column generation. This method uses a one-time “preliminary” phase to transform RCSP into an unconstrained shortest path problem (SPP) and then solves the resulting SPP after new values of dual variables are used to update objective function coefficients (i.e., reduced costs) at each iteration. Network reduction techniques are considered to remove some nodes and/or arcs permanently in the preliminary phase. Specified techniques are explored to reoptimize when only several coefficients change and for dealing with forbidden and prescribed arcs in the context of a column generation/branch-and-bound approach. As a benchmark method, a label-setting algorithm is also proposed. Computational tests are designed to show the effectiveness of the proposed algorithms and procedures. This dissertation also gives a literature review related to the class of scheduling problems that involve SDS times (costs), an important consideration in many practical applications. It focuses on papers published within the last decade, addressing a variety of machine configurations - single machine, parallel machine, flow shop, and job shop - reviewing both optimizing and heuristic solution methods in each category. Since lot-sizing is so intimately related to scheduling, this dissertation reviews work that integrates these issues in relationship to each configuration. This dissertation provides a perspective of this line of research, gives conclusions, and discusses fertile research opportunities posed by this class of scheduling problems. since, as a subproblem in column generation, objective function coefficients are updated using new values of dual variables at each iteration. This dissertation proposes a pseudo-polynomial solution method for solving the dynamic RCSP by exploiting the special structure of an acyclic graph with the goal of effectively reoptimizing RCSP in the context of column generation. This method uses a one-time
282

Dynamic Simulation and Economic Analysis of an Isolated Hybrid Wind Diesel System

Selony, Wilson 24 June 2008 (has links)
An isolated hybrid system comprised of a dispatchable and a non-dispatchable power generation sources, is proposed to supply the load of a remote village in the west region of Haiti. The wind speed data and load data of this remote village are used to study the system. The non-dispatchable generation comes from a nature-dependent wind turbine, and the dispatchable one is a diesel generator. Using MATLAB/Simulink, dynamic simulations are performed to investigate the interaction between these two power sources for the load management, and the voltage and frequency behaviors during wind speed and load variations. Economic analyses of the system are also conducted. The cost of energy (COE), energy payback time (PBT), internal rate of return (IRR) and avoided cost (AC) of CO2¬, NOx and PM (Particles Materials) of the hybrid system are computed, and results are compared with those of the baseline diesel only case. Simulation results show that the wind turbine and the diesel generator can be operated suitably in parallel, and the economic analyses show the positive benefits of wind generation in reducing COE and increasing the avoided cost (AC) of emitted pollutions.
283

Sole electoral district two ticket system research political influence---Elects take seventh session of legislator as the example

Yeh, I-jung 22 July 2008 (has links)
none
284

The contribution of non-native structure with recombinant cobrotoxin to its immunoreactivity toward anti-cobrotoxin antibodies

Ding, Sheng-che 30 June 2009 (has links)
To induce the production of antibodies, exogenous antigens are taken up and degraded in antigen presenting cells in vivo. Since this process inevitably lead to distort antigen¡¦s structure, it is likely that some arising antibodies following immunization may not react appropriately with native protein. In the present study, comparative studies on the reactivity of cobrotoxin and recombinant cobrotoxin toward anti-cobrotoxin antibodies were carried out. CD spectra and acrylamide quenching of Trp fluorescence showed that global structure of recombinant cobrotoxin was different from that of native toxin. Results of ELISA and dot blotting assay revealed that recombinant cobrotoxin had a superior reactivity toward anti-cobrotoxin antibodies than native toxin did. Reactivity with antibody fractions specifically against N-terminal region or C-terminal region of cobrotoxin also showed the same results. The binding of recombinant cobrotoxin with antibodies was stronger than that of cobrotoxin as revealed by ammonium thiocyanate elution assay. Recombinant protein was susceptible to reduce its antigenicity after tryptic digestion compared to cobrotoxin. Distorting disulfide linkages at C-terminus caused a marked decrease in immunoreactivity of recombinant cobrotoxin, indicating that anti-cobrotoxin antibodies mostly recognized conformation-dependent epitopes. Moreover, cobrotoxin and recombinant cobrotoxin showed a similar immunoreactivity under denaturing condition. Taken together, these results suggest that native conformation with cobrotoxin may unfavorably impede the interaction of some epitope(s) with anti-cobrotoxin antibodies.
285

Attribution of Profits to Dependent Agent Permanent Establishments : The dual taxpayer approach versus the single taxpayer approach

Hasanbegovic, Jasmina January 2009 (has links)
<p>Business profits constitute the main part of income derived through international business and these profits are only to be taxed in the home state of the enterprise. However, if the enterprise conducts business in a host state through a PE, the profits attributable to the PE are taxable in the host state. Article 7 of the OECD Model Tax determines the profits attributable to the PE.</p><p>Nevertheless, Member States have interpreted Article 7 of the OECD Model Tax Convention in various ways. In order to provide consensus the OECD adopted an authorised OECD approach for attributing profits to PEs.</p><p>The first part of the purpose of this thesis is to study the Swedish approach for attributing profits to dependent agent PEs in relation to the authorised OECD approach. An enterprise from the home state can be considered to have a dependent agent PE in the host state if it conducts business in the host state through a dependent agent located therein. This is provided that the agent has the authority to conclude contracts in the name of the enterprise and exercises this authority regularly.</p><p>Under the authorised OECD approach for profit attribution to dependent agent PEs it is possible to allocate profits to the PE in excess of the arm’s length remuneration paid to the dependent agent. Thereby, the OECD has adopted the dual taxpayer approach as the authorised OECD approach.</p><p>According to the author’s opinion the Swedish perspective regarding profit attribution to dependent agent PEs differs from the authorised OECD approach as the dual taxpayer approach so far has not been applied in Sweden. Furthermore, it differs as the attribution of capital to PEs is not allowed according to case law and as far as the recognition of internal dealings is concerned.</p><p>When the OECD adopted the dual taxpayer approach as the authorised OECD approach another method was available; the single taxpayer approach. In line with this approach no further profits in excess of the arm’s length remuneration to the dependent agent can be attributed to the dependent agent PE. However, the single taxpayer approach was rejected as the authorised OECD approach, which has lead to disagreement within the international tax community.</p><p>Therefore, the second part of the purpose of this thesis is to study to what extent the authorised OECD approach is sustained. This is done by analysing reactions to the single and dual taxpayer approach among business and academic circles.</p><p>The author believes that reactions against the dual taxpayer approach mainly arise in situations when an enterprise in the host state gives rise to a dependent agent PE. Therefore, the authorised OECD approach should have recognised that different types of dependent agent PEs might arise and the approach is only sustained to the extent that a person belonging to the foreign enterprise leads to the existence of a dependent agent PE.</p>
286

Channel Quality Information Reporting and Channel Quality Dependent Scheduling in LTE

Eriksson, Erik January 2007 (has links)
<p>Telecommunication systems are under constant development. Currently 3GPP is working on an evolution of the 3G-standard, under the name 3G Long Term Evolution (LTE). Some of the goals are higher throughput and higher peak bit rates. A crucial part to achieve the higher performance is channel dependent scheduling (CDS). CDS is to assign users when they have favorable channel conditions. Channel dependent scheduling demands accurate and timely channel quality reports. These channel quality indication (CQI) reports can possibly take up a large part of the allocated uplink. This thesis report focuses on the potential gains from channel dependent scheduling in contrast to the loss in uplink to reporting overhead.</p><p>System simulations show that the gain from channel dependent scheduling is substantial but highly cell layout dependent. The gain with frequency and time CDS, compered to CDS in time domain only, is also large, around 20\%. With a full uplink it can still be a considerable gain in downlink performance if a large overhead is used for channel quality reports. This gives a loss in uplink performance, and if the uplink gets to limited it will severely affect both uplink and downlink performance negatively.</p><p>How to schedule and transmit CQI-reports is also under consideration. A suggested technique is to transmit the CQI reports together with uplink data. With a web traffic model simulations show that a high uplink load is required to get the reports often enough. The overhead also gets unnecessary large, if the report-size only depends on the allocated capacity.</p>
287

Functions of Cdk1-cyclin B in regulating the early embryonic mitoses in Drosophila /

Ji, Jun-Yuan, January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 136-153).
288

Learning when to ask : the quantity and type of implementation data as a function of when the data are collected in a program evaluation /

Bensenberg, Michelle. January 2000 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 279-285). Available also in a digital version from Dissertation Abstracts.
289

Local structure and dynamics of complex fluids

Carmer, James Lee 15 January 2014 (has links)
There is a well-known connection between the structure and dynamics that is present in molecular and colloidal systems. Using this connection as a guide we are able to design interparticle potentials that optimizes the diffusivity of a single particle. While structure-dynamic correlations provide the insight that diffusion could be enhanced, the effect of this enhancement on the dynamics of neighboring particles is more difficult to quantify. A novel method for calculating position-dependent dynamics is introduced that can be easily implemented into existing simulation protocols. The computational requirements are very low compared to existing methods and this technique can also be applied to a wide variety of systems, including experiments where particle trajectories can be determined. Using this method, the position-dependent diffusivity of solvent particles in the vicinity of a tracer particle can be measured. This information allows for determination of the microscopic changes that take place as a result of the optimization discussed above. To study the effect of a non-continuum solvent, we design a system that eliminates inhomogeneous structuring near an interface. Hydrodynamic theory can predict the position-dependent diffusivity of a sphere in continuum solvent. Comparing these systems not only highlights the difference in position-dependent dynamics for continuum and non-continuum solvents, but is a starting point to study what happens to dynamics when structure is reintroduced. This allows us to answer many other questions about the relationships between structure and dynamics. While these connections have been studied extensively for average properties, they have not been explored for their position-dependent counterparts. For bulk fluids, the insertion probability and two-body excess entropy has proven useful for predicting average dynamic properties. We develop expressions for the position-dependent versions of both of these quantities. We show that when using the appropriate reference state the position-dependent diffusivity can be qualitatively related to the insertion probability. / text
290

Ontogenetic and mechanistic explanations of within-sex behavioral variation in a lizard with temperature- dependent sex determination

Huang, Victoria 25 February 2014 (has links)
The leopard gecko (Eublepharis macularius) is a reptile species in which embryonic temperature contributes both to sex determination and within- sex polymorphisms. Its life history makes the leopard gecko a model system for seeking ontogenic and proximate explanations for within-sex variation in sexually dimorphic behavior and neurophysiology, necessary attributes for reproductive success. For my dissertation I have incorporated the role of androgens that potentially modulate incubation temperature effects on behavioral and brain variation, which I approached using embryo and adult leopard geckos. First, I found that that the bias of same-sex clutch siblings is primarily incubation temperature- dependent and any maternal or genetic effects on same-sex clutch siblings are secondary. Second, I found that testosterone concentrations in the yolk-albumen were higher in eggs of late development than early development at 26 °C, a female-producing incubation temperature, but did not differ from eggs incubated at another female-biased temperature. This increase in testosterone concentrations during the temperature sensitive period in putative females is a finding opposite of reported trends in most other reptiles studied to date. Further, I found that the embryonic environment influences male sociosexual investigation in the absence of gonadal hormones. Lastly, in adult males of 32.5 °C, a male-biased incubation temperature, I found that the phosphoprotein DARPP-32 that is activated by the D1 dopamine receptor in limbic brain regions is correlated to this sociosexual investigatory behavior. Neurons immunopositive for phosphorylated DARPP-32 were not only less dense in the nucleus accumbens of males who spent more time with other males, but also more dense in the preoptic area of males who spent more time with females. The use of phosphorylated DARPP-32 as marker for sociosexual exposure is novel in a lizard species. Taken together, in support of previous studies, these results show that differences in embryonic environment stem primarily from incubation temperature, can explain behavioral differences in adulthood in the absence of hormones, and, in concert with hormonal manipulation, can influence neuronal marker sensitivity to sociosexual exposure. / text

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