• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 6
  • 6
  • 5
  • 5
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 59
  • 59
  • 15
  • 13
  • 11
  • 10
  • 10
  • 7
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 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.
1

The study of the Bioeconomics analysis Of Grey mullet in Taiwan

Cheng, Man-chun 29 January 2007 (has links)
Abstract This study is based on the theory of biology and economy to establish the open access model, dynamic optimization model and static optimization of fishery mathematical models, to discuss the problem of fishery management. To be aimed at getting the equilibrium of resource stock and effort, research data are mainly analyzed by comparative statues. In so doing, the amount of grey mullet, collect and analyze the estimation of exogenous variable. Then, we can use Mathematica program to calculate the equilibrium value resource stock and the effort, and do the sensitivity analysis by standing on the change of estimation of exogenous variable. The result of analysis is as follow: These three fishery mathematical models¡¦ resource stock and effort are consistency. In another view of CPUE, it is not obvious of the economic effect of open access model. We must strengthen the management in policy of fishing for grey mullet, to let the fisherman earn the highest economic benefits. Keyword: open access model static optimization model. dynamic optimization model.
2

The biological and economical analysis of the resource of the shrimp Acetes intrmedius in TungKang,PingTung.

Yang, Chung-hao 27 June 2008 (has links)
The fishery of the shrimp Acetes intermedius in the southwestern coast of Taiwan has long history , and it is the food of many species of fishes and large-scale shrimps . Shrimp Acetes has not only fallen on dead ears , but also been ignored its importantce of ecologyical status in the southwestern coast by the academia because of less harvest and output value in the past . It then comes into operation the management of catch , leading the price going up and output value increasing rapidly when the establishment of TungKang producer organization of the shrimp Acetes intrmedius in 1994 , and it also becomes the important seasonal fishery . According to as was mentioned above , the study is based on the theory of biology and economy to put out the open access model , static optimization model and dynamic optimization of fishery mathematical models , and further discuss the problem of fishery management. In connection with getting the equilibrium of resource stock and effort , research data from the substitution of real data are mainly analyzed by compareative statues on exogenous variable .By means of understanding the sensitivity of variation on endogenous variable depending on exogenous variable , we can provide the member of TungKang producer organization of the shrimp Acetes intrmedius with the control on harvest and preservation of stock . The study can get the fact that the management of TungKang producer organization of the shrimp Acetes intrmedius has the notion of sustainable administration by the deriveation of theoretical model and the simulate analysis of historyical data. I hope the management of TungKang producer organization of the shrimp Acetes intrmedius can be popularized.
3

none

Cheng, Shu-Shuo 25 June 2008 (has links)
In this study, Gordon Schaefer Model is used to evaluate for the optimal conduction of open access and dynamic optimization in equilibrium condition. The results of the models are further analyzed by the method of comparative static analysis. According to the Schnute's method, the intrinsic growth rate, the catchability coefficient and the environmental carrying capacity have been estimated in the way to evaluate the equilibrium values of the resource stock and the effort of yellowfin tuna. The result of the sensitivity analysis is based on the assumption that all parameters are varied within reasonable ranges. The results of comparative static analysis consist with the results of the sensitivity analysis that the fishing is comparatively cohered with the dynamic optimization model. This study aims to provide a useful reference for the policy making in sustainable development of the offshore fishery resources in Taiwan.
4

Efektivnost záloh na jednocestné nápojové obaly v hospodářské praxi České republiky / Effectiveness of a deposit system on one-way containers in Czech republic

Slavík, Jan January 2003 (has links)
The reasons of the contemporaly regulation in the waste management regarding the theoretical basis (on that the regulation is built) are the main objectives of this work. Because of high induced costs of the erroneous state measures built on wrong expectations in the economy and because of less effectiveness and efficiency of these measures this analysis is very important. The test of induced costs should be accomplished on the example of the deposit system on one-way containers (PET bottles and cans), which should be implemented into the public law in the Czech republic in next few years. Hardly any measure in the waste management is provoking so intensive diskussion, as the deposit system on some beverages does. What is the main reason? Especially the rise of abatement costs by subjects influenced by the deposit system and the influence on the system of separate collection. The deposit system and the separate collection are competitive systems because of the reciprocal relationship. Regarding the driving forces of the regulation the main goal of this work is the modelling of costs and benefits of the deposit system in the Czech republic and the analysis of the decision making proces of affected subjects.
5

Hydraulic Fracture Optimization with a Pseudo-3D Model in Multi-layered Lithology

Yang, Mei 2011 August 1900 (has links)
Hydraulic Fracturing is a technique to accelerate production and enhance ultimate recovery of oil and gas while fracture geometry is an important aspect in hydraulic fracturing design and optimization. Systematic design procedures are available based on the so-called two-dimensional models (2D) focus on the optimization of fracture length and width, assuming one can estimate a value for fracture height, while so-called pseudo three dimensional (p-3D) models suitable for multi-layered reservoirs aim to maximize well production by optimizing fracture geometry, including fracture height, half-length and width at the end of the stimulation treatment. The proposed p-3D approach to design integrates four parts: 1) containment layers discretization to allow for a range of plausible fracture heights, 2) the Unified Fracture Design (UFD) model to calculate the fracture half-length and width, 3) the PKN or KGD models to predict hydraulic fracture geometry and the associated net pressure and other treatment parameters, and, finally, 4) Linear Elastic Fracture Mechanics (LEFM) to calculate fracture height. The aim is to find convergence of fracture height and net pressure. Net pressure distribution plays an important role when the fracture is propagating in the reservoir. In multi-layered reservoirs, the net pressure of each layer varies as a result of different rock properties. This study considers the contributions of all layers to the stress intensity factor at the fracture tips to find the final equilibrium height defined by the condition where the fracture toughness equals the calculated stress intensity factor based on LEFM. Other than maximizing production, another obvious application of this research is to prevent the fracture from propagating into unintended layers (i.e. gas cap and/or aquifer). Therefore, this study can aid fracture design by pointing out: (1) Treating pressure needed to optimize fracture geometry, (2) The containment top and bottom layers of a multi-layered reservoir, (3) The upwards and downwards growth of the fracture tip from the crack center.
6

none

Wu, Hsiao-wen 27 July 2009 (has links)
In this study, the fundamental model of fish dynamic model- Gordon Schaefer Model is used to discuss the equilibrium levels for the Pacific Bluefin Tuna fishery of open access and dynamic optimization, and then to do the sensitivity analysis. By comparing the historical record of catch data with the equilibrium values of open access and dynamic optimization, we could know that the fish stocks and harvests of Pacific Bluefin Tuna are not in the condition of dynamic optimization. In order to ensure the sustainable development of Pacific Bluefin Tuna fishery, we have to take effective measures to preserve and manage the Pacific Bluefin Tuna resources. Finally, this study simulates and analyses the various management scenarios of the Pacific Bluefin Tuna fishery. The results of simulative analysis reveal that the optimal management of the Pacific Bluefin Tuna fishery would imply significant reallocation of the fishing gear shares. Furthermore, the net present value could increase substantially by reallocating the fishing gear shares.
7

Investigation and realization of the high school schedule optimization model in the internet environment / Optimizacinio mokyklos tvarkaraščio modelio sudarymas ir realizavimas interneto aplinkoje

Strukov, Denis 26 August 2010 (has links)
Every school, college and university has to deal with the scheduling task once or more times a year. The school schedule creation on its own is a very difficult task, furthermore, to make it convenient for students as well as for teachers makes it even more complex. The main aim of this paper is to present a flexible software system that is capable of creating a schedule for a secondary school using the latest technologies and distributed programming techniques. The literature analyzed in the paper is related to solving the tasks of school scheduling. Contemporary solutions are reviewed. The paper also contains analysis of existing commercial and non commercial solutions. The new software system is presented. Its advantages and disadvantages are analyzed. The optimization methods that can be used in school schedule optimization are analyzed and some of them are employed in the new software prototype in order to achieve better results. / Kiekviena mokykla arba universitetas kasmet susiduria su tvarkaraščio sudarymo problema. Tai yra labai sudėtinga bei daug laiko reikalaujanti užduotis. Šio darbo tikslas yra pristatyti lanksčią mokyklos tvarkaraščių sudarymo bei optimizavimo sistemą. Analizuojama literatūra, egzistuojantis komerciniai bei nekomerciniai sprendimai. Pristatoma nauja sistema. Analizuojami jos privalumai bei trukumai. Apžvelgiami optimizaciniai metodai kurie gali būti panaudoti mokyklos tvarkaraščiui pagerinti. Taip pat pristatoma nauja architektūra bei modelis.
8

Development of a Cloud-Based Dual-Objective Nonlinear Programming Model for Irrigation Water Allocation

Yan, Zehao January 2020 (has links)
Irrigation water allocation is essential to the management of agricultural water use in irrigation districts. Many irrigation optimization models were proposed from previous studies to provide decision support for water managers. In order to capture the complex nonlinear relationships and meet different water demands, more advanced multi-objective nonlinear programming models were developed in the past decade. However, it is still a challenging task to address varies uncertainties associated with irrigation optimization. Fuzzy programming, interval programming, and chance-constrained programming can be used to quantify uncertainties in simplified formats, but none of them can represent complex uncertainty in a composite format. In this thesis, a cloud-based dual objective nonlinear programming (CDONP) model is developed by implementing a cloud modeling method in an irrigation model to address the uncertainties of reference evapotranspiration (ET0) and surface water availability (SWA). The cloud modeling method is used to generate 2,000 data samples from historical data. The results show that the generated samples are consistent with historical data. Optimized allocation schemes are provided, and the performance of the CDONP model are discussed. This is the first Canadian study that used the cloud modeling method in irrigation water allocation. This method provides a solution to quantify composite uncertainties based on limited data, which represents a unique contribution to irrigation water allocation modeling. This study provides valuable decision support for agriculture management to improve water use efficiency. / Thesis / Master of Applied Science (MASc)
9

Integrated solid waste management model: the case of Central Ohio district

Prawiradinata, Rudy Soeprihadi 18 June 2004 (has links)
No description available.
10

Solving Multiple Objective Optimization Problem using Multi-Agent Systems: A case in Logistics Management

Pennada, Venkata Sai Teja January 2020 (has links)
Background: Multiple Objective Optimization problems(MOOPs) are common and evident in every field. Container port terminals are one of the fields in which MOOP occurs. In this research, we have taken a case in logistics management and modelled Multi-agent systems to solve the MOOP using Non-dominated Sorting Genetic Algorithm-II (NSGA-II). Objectives: The purpose of this study is to build AI-based models for solving a Multiple Objective Optimization Problem occurred in port terminals. At first, we develop a port agent with an objective function of maximizing throughput and a customer agent with an objective function of maximizing business profit. Then, we solve the problem using the single-objective optimization model and multi-objective optimization model. We then compare the results of both models to assess their performance. Methods: A literature review is conducted to choose the best algorithm among the existing algorithms, which were used previously in solving other Multiple Objective Optimization problems. An experiment is conducted to know how well the models performed to solve the problem so that all the participants are benefited simultaneously. Results: The results show that all three participants that are port, customer one and customer two have gained profits by solving the problem in multi-objective optimization model. Whereas in a single-objective optimization model, a single participant has achieved earnings at a time, leaving the rest of the participants either in loss or with minimal profits. Conclusion: We can conclude that multi-objective optimization model has performed better than the single-objective optimization model because of the impartial results among the participants.

Page generated in 0.1022 seconds