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.

Mathematical model-building is one kind of mathematical thinking, which uses mathematical signs and methods to build a mathematical tool which can describe and solve practical problem. However, System Dynamic is to solve complicated non-linear dynamic problem. It uses the model-building software of diagram interface to make dynamic simulation. Behind the dynamic simulation is the calculation of a set of mathematical equation. The purpose of this research is , by the transition between Mathematics Model and System Dynamic Model, to discuss the mathematical principle of System Dynamic ,and to avoid distorting model and making the model validation harder due to the model-builder's misusing function. Using the conclusion of the transition will help validating the model and raising the reliability and the efficiency of the model. From the conclusion of this research, we find out that System Dynamic is non-linear dynamic mathematical model. Both are exchangeable. From the transition, we also find that the graph function used in the process of System Dynamic model-building is a piecewise-linear- approximate function. The numerical value setting of the graph function can influence the system action. After the transition from System Dynamic model to mathematical model, we can use some other mathematical software to draw the phase-plane-plot or phase-portrait-plot. It will analyze clearly the system action in any situation, and validate the correction of model construction.

Several reports research the best prediction power of the credit risk models for different industries. The structural models use firm¡¦s information for firms¡¦ structural variables, such as asset value and asset volatility, to determine the time of default, but it suffer from some drawbacks, which represent the main reasons behind their relatively poor empirical performance. It require estimates for the parameters of the firm¡¦s asset value, which is nonobservable. Moody's KMV model is well known and useful among them, but it ignores recovery rate and difference in financial structure and industry. The reduced-form models fundamentally differ from typical structural models in the degree of predictability of the default. Reduced-form models use market data and assume the probability of default is exogenously generated. However, the basel committee for banking supervision proposed that risk is endogenous. The purpose of this paper is using quantile and threshold regression to introduce a new approach which is based on the Moody¡¦s KMV model, the Lu and Kuo ( 2005) and the Altman, Brooks Brady, Resti and Sironi (2005) to the evaluation of the endogenous probability of default and the endogenous recovery rate.

Thesis (Ph. D.)--University of Oregon, 2000. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 199-204). Also available for download via the World Wide Web; free to UO users.

Usage of simulation models is an essential part in many modern engineering disci- plines. Computer models of complex physical systems can be used to expedite the design of control systems and reduce the number of physical tests. Model valida- tion tries to answer the question if the model is a good enough representation of the physical system. This thesis describes techniques to visualize multi-dimensional validation results and the search for an automated validation process. The work is focused on a simulation model of the Primary Environmental Control System of Gripen E, but can be applied on validation results from other simulation models. The result from the thesis can be divided into three major components, static validation, dynamic validation and model coverage. To present the results from the static validation different multi-dimensional visualization techniques are in- vestigated and evaluated. The visualizations are compared to each other and to properly depict the static validation status of the model, a combination of visual- izations are required. Two methods for validation of the dynamic performance of the model are examined. The first method uses the singular values of an error model estimated from the residual. We show that the singular values of the error model relay important information about the model’s quality but interpreting the result is a considerable challenge. The second method aims to automate a visual inspection procedure where interesting quantities are automatically computed. Coverage is a descriptor of how much of the applicable operating conditions that has been validated. Two coverage metrics, volumetric coverage and nearest neigh- bour coverage, are examined and the strengths and weaknesses of these metrics are presented. The nearest neighbour coverage metric is further developed to account for validation performance, resulting in a total static validation quantity.

This report describes the major steps used in the Army’s LSS methodology, provides a brief overview of the Unaccompanied Personnel Housing and the Army Family Housing and briefly describes some of the initial steps intended to start improving the process. In the improvement phase, two detailed models (The EOQ Model and the Hadley and Whitin (Q,r) Model) used for inventory management are discussed. This report also provides a series of recommendations that include suggestions for baseline inventory levels, some ideas for future data collection, example improvements to some data input sheets as well as a few tasks for UPH and AFH managers to reduce cost and improve the overall efficiency of the system. / text

This report discusses two examples of the use of Poincare disc models and their different relationships to Euclidean geometry. The topics include light reflection in hyperbolic geometry and the Hyperbolic Pythagorean Theorem; all in relation to the Poincare unit disc and Poincare upper half plane model. / text

The Capacitance Resistance Model (CRM) is a reservoir model based on a data-driven approach. It stems from the continuity equation and takes advantage of the usually abundant rate data to achieve a synergy of analytical model and data-driven approach. Minimal information (rates and bottom-hole pressure) is required to inexpensively characterize the reservoir. Important information, such as inter-well connectivity, reservoir compressibility effects, etc., can be easily and readily evaluated. The model also suggests optimal injection schemes in an effort to maximize ultimate oil recovery, and hence can assist real time reservoir analysis to make more informed management decisions. Nevertheless, an important limitation in the current CRM model is that it only treats the reservoir flow as single-phase flow, which does not favor capturing physics when the saturation change is large, such as for an immature water flood. To overcome this limitation, we develop a two-phase flow coupled CRM model that couples the pressure equation (fluid continuity equation) and the saturation equation (oil mass balance). Through this coupling, the model parameters such as the connectivity, the time constant, temporal oil saturation, etc., are estimated using nonlinear multivariate regression to history match historical production data. Incorporating the physics of two-phase displacement brings several advantages and benefits to the CRM model, such as the estimation of total mobility change, more accurate prediction of oil production, broader model application range, and better adaptability to complicated field scenarios. Also, the estimated saturation within the drainage volume of each producer can provide insights with respect to the field remaining oil saturation distribution. Synthetic field case studies are carried out to demonstrate the different capabilities of the coupled CRM model in homogeneous and heterogeneous reservoirs with different geological features. The physical meanings of model parameters are well explained and validated through case studies. The results validate the coupled CRM model and show improved accuracy in model parameters obtained through the history match. The prediction of oil production is also significantly improved compared to the current CRM model. A more reliable oil rate prediction enables further optimization to adjust injection strategies. The coupled CRM model has been shown to be fast and stable. Moreover, sensitivity analyses are conducted to study and understand the impact of the input information (e.g., relative permeability, viscosity) upon the output model parameters (e.g., connectivity, time constants). This analysis also proves that the model parameters from the two-phase coupled model can combine both reservoir compressibility and mobility effects. / text

This research is about liquid-liquid chromatography modelling. While the main focus was on liquid-liquid chromatography, where the stationary and mobile phases are both liquid, theory of different types of chromatography, including the currently most used techniques, were considered as well. The main goal of this research was to develop a versatile liquid-liquid separation model, able to model all potential operating scenarios and modes of operation. A second goal was to create effective and usable interfaces to such a model, implying primarily information visualisation, and secondarily educative visualisation. The first model developed was a model based on Counter-Current Distribution. Next a new more elemental model was developed, the probabilistic model, which better models continuous liquid-liquid chromatography techniques. Finally, a more traditional model was developed using transport theory. These models were used and compared to experimental data taken from literature. The models were demonstrated to model all main liquid-liquid chromatography techniques, incorporated the different modes of operation, and were able to accurately model many sample components and complex sample injections. A model interface was developed, permitting functional and effective model configuration, exploration and analysis using visualisation and interactivity. Different versions of the interface were then evaluated using questionnaires, group interviews and Insight Evaluation. The visualisation and interactivity enhancements have proven to contribute understanding and insight of the underlying chromatography process. This also proved the value of the Insight Evaluation method, providing valuable qualitative evaluation results desired for this model interface evaluation. A prototype of a new graphical user interface developed, and showed great potential for combining model parameter input and exploring the liquid-liquid chromatography processes. Additionally, a new visualisation method was developed that can accurately visualise different modes of operation. This was used to create animations, which were also evaluated. The results of this evaluation show the new visualisation helps understanding of the liquid-liquid chromatography process amongst CCC novices. The model software will be a valuable tool for industry for predicting, evaluating and validating experimental separations and production processes. While effective models already existed, the use of interactive visualisation permits users to explore the relationship between parameters and performances in a simpler yet more powerful way. It will also be a valuable tool for academia for teaching & training, both staff and students, on how to use the technology. Prior to this work no such tool existed or existing tools were limited in their accessibility and educational value.

Most companies have some sort of business model showing how they operate their activities,resources, cost and revenues etcetera. What is becoming increasingly emphasised in today'sbusiness is however to integrate sustainability within the business model. Our research willtherefore investigate how companies are attempting to make their business model moresustainable. We have chosen to focus on the mobile phone industry as reports have shown thatthey are a significant contributor to carbon emissions and electronic waste. With this in mind ourresearch question is formulated as follows:"How is the mobile phone industry attempting to innovate their business models towardssustainability?"As we attempt to understand how the mobile phone industry is attempting to innovate towardsgreater sustainability, we have chosen to perform a qualitative study. The material we usedconsisted of reports and web pages as well as interviews with manufacturers of mobile phonesand MNO’s. To analyse the material we had collected, we chiefly utilised a list of materialconcerns specific to the aforementioned mobile phone industry stakeholders, a proposedarchetype system for classifying attempts to innovate the business model to become moresustainable and finally a tool for graphically presenting a business model and its inner workings.Our conclusions show what the companies we have interviewed are attempting to innovate intheir business model. The innovations focus mainly on their partnerships, activities, resourcesand value propositions. By performing this study we contribute to the still young research area ofsustainable business model innovation through providing a snapshot of what our interviewedcompanies are attempting to innovate at the time of our study. Furthermore it also contributes tothe empirical use of the proposed sustainable business model innovation archetypes as we applythem to empirical data in an attempt to classify the data. Through performing both of theseactions we also contribute a proposed way of classifying sustainable business model innovationwithin a business model through the combining of the archetypes and the business model canvas.