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| Registros recuperados: 112 | |
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| Wu, Jinzhuo; Sperow, Mark; Wang, Jingxin. |
| A mixed-integer programming model is developed to assess the economic feasibility of siting a woody biomass-based ethanol facility in the central Appalachian hardwood region. The model maximizes the net present value (NPV) of a facility over its economic life. Model inputs include biomass availability, biomass handling system type, plant investment and capacity, transportation logistics, feedstock and product pricing, project financing, and taxes. Four alternative woody biomass handling systems, which include all processes from stand to plant, are considered. Eleven possible plant locations were identified based on site selection requirements. Results showed that the optimal plant location was in Buckhannon, West Virginia. The NPV of the plant with a... |
| Tipo: Journal Article |
Palavras-chave: Biofuels; Economic analysis; Ethanol; Optimization; Woody biomass; Crop Production/Industries. |
| Ano: 2010 |
URL: http://purl.umn.edu/99118 |
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| Kumarappan, Subbu; Ivanic, Rasto. |
| When the lignocellulosic biofuels industry reaches maturity and many types of biomass sources become economically viable, management of multiple feedstock supplies – that vary in their yields, density (tons per unit area), harvest window, storage and seasonal costs, storage losses, transport distance to the production plant – will become increasingly important for the success of individual enterprises. The manager’s feedstock procurement problem is modeled as a multi-period sequence problem to account for dynamic management over time. The case is illustrated with a hypothetical 53 million annual US gallon cellulosic ethanol plant located in south west Kansas that requires approximately 700,000 metric dry tons of biomass. The problem is framed over 40... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Cellulosic ethanol; Feedstock; Switchgrass; Miscanthus; Corn stover; Optimization; Biofuels; Biomass; Energy; Renewable; Agribusiness. |
| Ano: 2009 |
URL: http://purl.umn.edu/49407 |
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| Sharma, Rakesh Kumar; Sankhayan, Prem Lall; Singh, Ranveer. |
| Cropping pattern in the Himalayan region of India has undergone a significant change in the recent past. Introduction of horticultural crops of vegetables, fruits and flowers have led to more intensive agriculture. Such a change, resulting in higher incomes and improvements of the overall living conditions has, however, been accompanied with increased income risk. This emphasises a need for proper analysis of the cropping pattern, at an appropriate scale, such as, a micro watershed. This was achieved by constructing a dynamic non-linear programming model incorporating appropriate objective function, constraints and crop and livestock activity budgets along with risk component present in the gross returns. The model was then solved under alternate policy... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Cropping pattern; Gross margins; Himachal Pradesh; Optimization; Covariance; Crop Production/Industries; Farm Management; Research Methods/ Statistical Methods; Resource /Energy Economics and Policy; Risk and Uncertainty; C61; Q12; Q15. |
| Ano: 2009 |
URL: http://purl.umn.edu/51404 |
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| Laxminarayan, Ramanan; Simpson, R. David. |
| When the application of pesticides places selective evolutionary pressure on pest populations, it can be useful to plant refuge areas-crop areas intended to encourage the breeding of pests that are susceptible to the pesticide. Renewed interest in refuge areas has arisen with recent advances in biotechnology and genetically modified (GM) crops. In this paper, we use a simple model of the evolution of pest resistance to characterize the socially optimal refuge strategy for managing pest resistance. We demonstrate some interesting analogies with other models of renewable resource management, such as those of fisheries. Among the analogous results are findings that maintaining what we might call "maximal sustainable susceptibility" is typically not... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Pest resistance; Biotechnology; Optimization; Research and Development/Tech Change/Emerging Technologies; Q1; Q2. |
| Ano: 2000 |
URL: http://purl.umn.edu/10914 |
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| Maung, Thein A.; Gustafson, Cole R.. |
| This study examines the impact of stochastic harvest field time, corn cob and stover harvest technologies, increases in farm size, and alternative tillage practices on profit maximizing potential of corn cob and stover collection in North Dakota. Using three mathematical programming models, we analyze farmers’ harvest activities under 1) corn grain only harvest option, 2) simultaneous corn grain and cob harvest(one-pass) option 3) separate corn grain and stover harvest (two-pass) option. Under the first corn grain only option, farmers are able to complete harvesting corn grain and achieve maximum net income in a fairly short amount of time with existing combine technology. However, under the simultaneous corn grain and cob one-pass harvest option, our... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Cob; Stover; Harvest field time; Optimization; Farm size; Tillage; Crop Production/Industries; Production Economics. |
| Ano: 2011 |
URL: http://purl.umn.edu/103613 |
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| Lin, Xue; Jia, Xian-wei. |
| This paper reviews the connotation of agricultural listed company and the related researches on capital structure theory of enterprises in China. Based on this, research hypothesis is put forward. Capital structure has positive correlation with the scale, growth and debt paying ability of agricultural listed company, and has negative correlation with the profitability, operating capability and cash capacity. Taking 37 agricultural listed companies as the research samples, a total of 15 financial indices reflecting the growth, profitability, enterprise scale, operating capacity, cash capability and debt paying ability are selected to conduct factor analysis. Based on the principle of eigenvalue greater than 1, five factors are ascertained, which can explain... |
| Tipo: Thesis or Dissertation |
Palavras-chave: Agricultural listed company; Capital structure; Influencing factor; Optimization; China; Agribusiness; Industrial Organization. |
| Ano: 2009 |
URL: http://purl.umn.edu/54074 |
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| Keplinger, Keith O.; Hauck, Larry M.. |
| A model of manure utilization is developed and applied to four types of transportable manure. Model results highlight important response differences among manure types and generally illustrate the diseconomies of manure production. For example, as manure production increases, manure value decreases and excess phosphate applications increase, thereby increasing the potential for phosphorus runoff. Policy scenarios limiting the manure application rate reduce manure value and excess phosphate application. Increasing the ratio of land using manure increases manure value while reducing excess phosphate application. Buildup of soil nutrients reduces manure value, but either increases or decreases excess phosphate application depending on the scenario. |
| Tipo: Journal Article |
Palavras-chave: Linear programming; Manure application; Manure transportation; Manure utilization; Manure value; Optimization; Farm Management. |
| Ano: 2006 |
URL: http://purl.umn.edu/8611 |
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| Roucan-Kane, Maud; Martens, Bobby J.; Preckel, Paul V.. |
| Retail shelf space allocation remains a central issue in grocery retailing. A literature review produced many studies on retail shelf space allocation, but none which evaluated shelf space allocation using three major factors at once: space, vertical height, and price. In this study, shelf space allocation was modeled from the perspective of a retailer maximizing profit using space, vertical height, and price. Using benchmarking, the results show how shelf configuration affects consumer demand and retailer profit. Parameters for the model were based on experience-based intuition. Although the initial results are not valuable at this point, the method and results create a rationale and motivation to gather primary data. Once primary data is collected, this... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Shelf space allocation; Retail; Optimization; Grocery; Elasticity; GAMS; Ketchup; Marketing; C61; L81. |
| Ano: 2007 |
URL: http://purl.umn.edu/7330 |
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| Louis, Garrick; Shih, Jhih-Shyang. |
| Most of the United States have laws mandating the recycling of municipal solid waste (MSW). In order to comply, municipalities recycle quotas of materials, without regard to fluctuating prices. An inventory system is proposed that allows municipalities to be sensitive to materials prices as they recycle in accordance with state mandates. A dynamic model is developed; it uses historical secondary material prices as exogenous inputs to minimize the net present value of MSW recycling system cost. The model provides a cost-effective method for municipalities to achieve their MSW recycling targets. The savings is approximately $1.43 per ton of MSW generated based on total MSW management costs of $13.5 per ton. The model also allows one to investigate the... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Municipal solid waste; Recycling; Inventory; Optimization; Environmental Economics and Policy; Q2. |
| Ano: 2002 |
URL: http://purl.umn.edu/10459 |
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| Sohngen, Brent; Sedjo, Roger A.. |
| In this paper, we compare and contrast two types of timber models that have been used for public policy analysis. These models have been variously used to predict price, inventory and market welfare impacts under different exogenous forces that impact timber markets. The framework and theory for each model type is presented and discussed. We then thoroughly test the two model types across six potential exogenous shocks to timber markets, ranging from instantaneous demand shocks to gradual supply adjustments. Our comparison indicates that these models predict potentially important differences in timber market behavior. These differences are important to consider for those who do public policy analysis. |
| Tipo: Working or Discussion Paper |
Palavras-chave: Timber markets; Models; Dynamic adjustment; Optimization; Resource /Energy Economics and Policy; C62; Q21; Q23. |
| Ano: 1996 |
URL: http://purl.umn.edu/10467 |
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| Hoe, Lam Weng; Saiful Hafizah, Jaaman; Zaidi, Isa. |
| Risk is one of the important parameters in portfolio optimization problem. Since the introduction of the mean-variance model, variance has become the most common risk measure used by practitioners and researchers in portfolio optimization. However, the mean-variance model relies strictly on the assumptions that assets returns are multivariate normally distributed or investors have a quadratic utility function. Many studies have proposed different risk measures to overcome the drawbacks of variance. The purpose of this paper is to discuss and compare the portfolio compositions and performances of four different portfolio optimization models employing different risk measures, specifically the variance, absolute deviation, minimax and semi-variance. Results... |
| Tipo: Journal Article |
Palavras-chave: Portfolio; Optimization; Risk measures; Variance.; Financial Economics; CO2; C61; G11. |
| Ano: 2010 |
URL: http://purl.umn.edu/95934 |
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| Laxminarayan, Ramanan. |
| The increasing resistance of harmful biological organisms (bacteria, parasites, and pests) to selection pressure from the widespread use of control agents such as antibiotics, antimalarials, and pesticides is a serious problem in both medicine and agriculture. Modeling resistance-or, conversely, the effectiveness of these control agents as a biological resource-yields insights into how these agents should be optimally managed to maximize their economic benefit to society. This paper uses a model of evolution of bacterial resistance to antibiotics-in which resistance places an evolutionary disadvantage on the resistant organism-to develop a simple sequential algorithm of optimal antibiotic use. Although the solution to this problem follows the... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Antibiotic resistance; Natural resource; Optimization; Health Economics and Policy; I0; Q0. |
| Ano: 2001 |
URL: http://purl.umn.edu/10479 |
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| Registros recuperados: 112 | |
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