In this paper, we consider a risk model in which two types of individual claims, main claims and by-claims, are defined. Every by-claim is induced by the main claim randomly and may be delayed for one time period with...In this paper, we consider a risk model in which two types of individual claims, main claims and by-claims, are defined. Every by-claim is induced by the main claim randomly and may be delayed for one time period with a certain probability. The dividend policy that certain amount of dividends will be paid as long as the surplus is greater than a constant dividend barrier is also introduced into this delayed claims risk model. By means of the probability generating functions, formulae for the expected present value of total dividend payments prior to ruin are obtained for discrete-type individual claims. Explicit expressions for the corresponding results are derived for K n claim amount distributions. Numerical illustrations are also given.展开更多
A cost sensitivity analysis was performed for an industrial membrane bioreactor to quantify the effects of hydraulic retention times and related operational parameters on cost.Different hydraulic retention times(72-24...A cost sensitivity analysis was performed for an industrial membrane bioreactor to quantify the effects of hydraulic retention times and related operational parameters on cost.Different hydraulic retention times(72-24 h)were subjected to a flat-sheet membrane bioreactor updated from an existing 72 h oxidation ditch treating antibiotic production wastewater.Field experimental data from the membrane bioreactor,both full-scale(500 m/d)and pilot(1.0 m3/d),were used to calculate the net present value(NPV),incorporating both capital expenditure(CAPEX)and operating expenditure.The results showed that the tank cost was estimated above membrane cost in the 38.2%,where capital expenditure contributed 24.2%more than operational expenditure.Tank construction cost was decisive in determining the net present value contributed 62.1%to the capital expenditure.The membrane bioreactor has the advantage of a longer lifespan flat-sheet membrane,while flux decline was tolerable.The antibiotics decreased to 1.87±0.33 mg/L in the MBR effluent.The upgrade to the membrane bioreactor also benefited further treatments by 10.1%-44.7%lower direct investment.展开更多
Since the implementation of several pilot production tests were in natural gas hydrate(NGH) reservoirs in terrestrial and marine settings, the study of NGH has entered a new stage of technological development for indu...Since the implementation of several pilot production tests were in natural gas hydrate(NGH) reservoirs in terrestrial and marine settings, the study of NGH has entered a new stage of technological development for industrial exploitation. Prior to the industrial exploitation of any given NGH reservoir, the economic feasibility should be examined. The first step of economic evaluation of a NGH reservoir is to know whether its resource amount meets the requirement for industrial exploitation. Unfortunately, few relevant studies have been conducted in this regard. In this study, the net present value(NPV) method is employed to estimate the economic critical resources required for the industrial exploitation of NGHs under different production scenarios. Sensitivity analysis is also performed in order to specify the effects of key factors, such as the number of production wells, gas price, technological improvement and tax incentive, on the economic critical resources. The results indicate that China requires the lowest economic critical resource for a NGH reservoir to be industrially exploited, ranging from 3.62 to 24.02 billion m3 methane. Changes in gas price and tax incentives also play significant roles in affecting the threshold and timeline for the industrial exploitation of NGH.展开更多
As a result of advances in horizontal comple- tions and multi-stage hydraulic fracturing, the U.S. has been able to economically develop several decades of worth of natural gas. However, a considerable concern has ris...As a result of advances in horizontal comple- tions and multi-stage hydraulic fracturing, the U.S. has been able to economically develop several decades of worth of natural gas. However, a considerable concern has risen on the economic viability of shale gas development for reasons associated with the fast production declines as well as recent down-turns of natural gas prices besides rises in the costs of new technologies. Therefore, an economic analysis is required to investigate the profitability of the re- fracturing treatment of unconventional gas resources. Net present value of cash flows and internal rate of return are calculated for a range of gas prices considering 20 years of natural gas production from a typical unconventional shale gas reservoir. A systematic comparison is then accom- plished for three scenarios: (1) re-fracturing versus no re- fracturing, (2) combination of re-fracturing and drilling new wells, and (3) time-dependent re-fracturing treatment. Further, this paper incorporates the cost of re-fracturing treatment, the cost of drilling a new horizontal well, the water treatment cost, as well as the current and future price of natural gas in the model. The findings of this work would help the future re-stimulation development plans of the emerging unconventional shale gas plays.展开更多
Extensions of Merton’s model(EMM)considering the firm’s payments and generating new types of firm value distribution are suggested.In the open log-value/time space,these distributions evolve from initially normal to...Extensions of Merton’s model(EMM)considering the firm’s payments and generating new types of firm value distribution are suggested.In the open log-value/time space,these distributions evolve from initially normal to negatively skewed ones,and their means are concave-down functions of time.When payments are set to zero or proportional to the firm value,EMM turns into the Geometric Brownian model(GBM).We show that risk-neutral probabilities(RNPs)and the no-arbitraging principle(NAP)follow from GBM.When firm’s payments are considered,RNPs and NAP hold for the entire market for short times only,but for long-term investments,RNPs and NAP just temporarily hold for individual stocks as far as mean year returns of the firms issuing those stocks remain constant,and fail when the mean year returns decline.The developed method is applied to firm valuation to derive continuous-time equations for the firm present value and project NPV.展开更多
Multilateral wells promise cost savings to oil and fields as they have the potential to reduce overall drilling distances and minimize the number of slots required for the surface facility managing the well.However,dr...Multilateral wells promise cost savings to oil and fields as they have the potential to reduce overall drilling distances and minimize the number of slots required for the surface facility managing the well.However,drilling a multilateral well does not always increase the flow rate when compared to two single-horizontal wells due to competition in production inside the mother-bore.Here,a holistic approach is proposed to find the optimum balance between single and multilateral wells in an offshore oil development.In so doing,the integrated approach finds the highest Net Present Value(NPV)configuration of the field considering drilling,subsurface,production and financial analysis.The model employs stochastic perturbation and Markov Chain Monte-Carlo methods to solve the global maximising-NPV problem.In addition,a combination of Mixed-Integer Linear Programming(MILP),an improved Dijkstra algorithm and a Levenberg-Marquardt optimiser is proposed to solve the rate allocation problem.With the outcome from this analysis,the model suggests the optimum development including number of multilateral and single horizontal wells that would result in the highest NPV.The results demonstrate the potential for modelling to find the optimal use of petroleum facilities and to assist with planning and decision making.展开更多
Agroforestry and beekeeping are widely promoted as prospective Nature-</span></span><span><span><span style="font-family:""> </span></span></span><span...Agroforestry and beekeeping are widely promoted as prospective Nature-</span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Based Income Generating Activities (NIGAs) to improve livelihoods while at </span><span style="font-family:Verdana;">the same time enhancing biodiversity conservation in degrading</span><span style="font-family:Verdana;"> agro-ecologies. These activities can diversify and increase famers’ incomes and support in</span><span style="font-family:Verdana;">stinctive biota and fauna resilience. However, evidence to showcase and compare their long-term benefits is scant. We use the case of Uluguru</span><span style="font-family:Verdana;"> Mountains in Tanzania to evaluate and compare viability of agroforestry and beekeeping projects using the Cost</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Benefit Analysis (CBA) approach. The results of analysis yielded positive NPVs for both agroforestry and beekeeping projects at discount rates not higher than 8.2% and 8.5% respectively. Overall, the comparison of economic viability between agroforestry and beekeeping projects revealed that the former was relatively more profitable than the later in terms of both the NPV and Benefit</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Cost Ratio (BCR) criteria. However, the Internal Rate of Return (IRR) for beekeeping was slightly higher than that of agroforestry. Yet, we underscore the fact that these two projects can jointly be implemented to enhance livelihoods of farmers and support biodiversity conservation in the study </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">area </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">and other parts with similar agro-ecologies in developing countries. However, farmers in these agro-ecologies need to be supported by governments and non-government development partners in terms of training and inspiration to shift from orthodox farming to sustainable NIGAs.展开更多
The formulas of premiums and premium reserves of a kind of mixed whole life insurance were obtained by the methods of actuarial science. Then we take a typical policy of whole life insurance in present Chinese market ...The formulas of premiums and premium reserves of a kind of mixed whole life insurance were obtained by the methods of actuarial science. Then we take a typical policy of whole life insurance in present Chinese market as an example to analyze its expense design and predict its market prospects.展开更多
Reducing emissions due to deforestation is considered a low-cost option for mitigating climate change.However,the recent literature suggests higher opportunity costs because of specific deforestation drivers,which ren...Reducing emissions due to deforestation is considered a low-cost option for mitigating climate change.However,the recent literature suggests higher opportunity costs because of specific deforestation drivers,which render reducing emissions from deforestation and forest degradation(REDD+)for mitigating climate change an uncertain,less attractive,and controversial option.Indonesia is one of the largest greenhouse gas emitters.Since 1989,53.80%of its oil palm expansion has come from forestlands,which has generated a significant amount of carbon emissions.This study uses official data and results from the relevant literature to estimate the costs of oil palm-based deforestation under various scenario assumptions,including different output prices,yields,time horizons,and discount rates.We also calculate the additional cost to preserve a 1-ha forest.We demonstrate that the average opportunity cost from avoiding oil palm-based deforestation is 24.42 USD/tCO_(2)eq in Indonesia,approximately 1.3 times the 2011 EUA carbon price.Additional sums of around 5,466.90–11,042.96 USD/ha should be provided to landowners for the deforestation avoidance caused by oil palm expansion.Special attention should be given to the extensive oil palm expansion in Indonesia and the resulting high opportunity costs for achieving the REDD+target.展开更多
Considering the important changes in the Swiss energy sector, especially in renewable energy(RE)technologies, new revenue possibilities for small and medium sized enterprises(SMEs) emerge. However, the adaption of RE-...Considering the important changes in the Swiss energy sector, especially in renewable energy(RE)technologies, new revenue possibilities for small and medium sized enterprises(SMEs) emerge. However, the adaption of RE-technologies for Swiss enterprises relies on tangible financial returns, based on complex calculations. This article analyses business opportunities(BOs) of eight Swiss SMEs considering the net present value of RE-investments in an uncertain economic environment. We identify two profitable BOs for Swiss SMEs and three which are not profitable. Further, the article demonstrates that the profitability of such investments remains mostly positive even under economic uncertainties. Surprisingly the profitability does not change significantly if the SME receives a subsidy or not. The support instrument of the Swiss Government has not a ponderous impact on the decision to invest in RE-technologies or not. Therefore, the article emphasizes the importance of including SME in the Swiss attempt to decentralize the energy market.展开更多
<span style="font-family:Verdana;">This work presents the results of the characterization of a standalone photovoltaic system for the electrification of a household located in rural area in the western...<span style="font-family:Verdana;">This work presents the results of the characterization of a standalone photovoltaic system for the electrification of a household located in rural area in the western region of Cameroon: Nziih-Bafou in Dschang (5.35</span><span style="white-space:normal;background-color:#FFFFFF;font-family:Verdana;">°</span><span style="font-family:Verdana;">N, 10.05</span><span style="white-space:normal;background-color:#FFFFFF;font-family:Verdana;">°</span><span style="font-family:Verdana;">E and 1900 m). In order to cope with the</span><span "=""> </span><span style="font-family:Verdana;">maintenance charges and reduce the investment cost, a small mill was added to the appliances of the household for income generation. The assessment of the energy demand was made by taking into account the reactive energy due to the heavy</span><span "=""> </span><span style="font-family:Verdana;">consumption of energy by the mill’s motor, especially during ignition. The sizing of all the system’s components was carried out with the prospect of determining an optimum design in accordance with daily electricity demand, site irradiance profile and climatic conditions. In this context, tilt angles applicable to the PV structure and that allow</span><span "=""> </span><span style="font-family:Verdana;">to receive the maximum irradiance as a function of the periods of the year were determined using the Hay model.</span><span "=""> </span><span style="font-family:Verdana;">This approach provides the system with incident irradiance greater than or at the limit equal to that received by a horizontal surface on the same site</span><span "=""> </span><span style="font-family:Verdana;">compared to the case of a single tilt angle where the irradiance on the inclined plane is often lower than that</span><span "=""> </span><span "=""><span style="font-family:Verdana;">on the horizontal. The economic analysis of the PV system showed an </span><span style="font-family:Verdana;">initial cost of $4448</span></span><span "=""> </span><span style="font-family:Verdana;">and the Life Cost Cycle amounted to $24,495. This</span><span style="font-family:Verdana;"> amount corresponds to a present cost per kilowatt hour of $0.44. The Net Present Value</span><span "=""> </span><span style="font-family:Verdana;">(NPV) of the project ($7793) over its lifetime (20 years)</span><span "=""> </span><span style="font-family:Verdana;">shows a payback period of less than 4 years.</span>展开更多
Externality;the term can define as a positive or negative impact from either production or consumption of goods or services.Services provided by particular location have very specific dependency on spatial characteris...Externality;the term can define as a positive or negative impact from either production or consumption of goods or services.Services provided by particular location have very specific dependency on spatial characteristics of that region.A region’s distinct characteristics make it ecologically unique from other such regions.Ecosystem services are offered by these regions thus differ according to these unique ecological features.In this particular study,artificially imposed expansion of coastal shrimp farming towards the inland and its impact over paddy cultivation have been addressed.Optimization of the extent of this manipulative coastal expansion has been supported by little modification of a previously described model.Here the investment prediction for both shrimp and paddy farming has been investigated by calculating net present value(NPV).Shrimp farming has very specific externality on local ecosystem services.In this particular case,some contradictory results are presented and with respect to positive or negative externality;but the externalities are strong.NPV results indicate that there is no long-term profitability in case of shrimp farming.Hence,an overall externality of shrimp farming has been described in context of this study.展开更多
Historically the price of a forest estate has, at least in Sweden, been closely related to the financial return from the estate, but this connection no longer seems to be that strong, other factors that previously had...Historically the price of a forest estate has, at least in Sweden, been closely related to the financial return from the estate, but this connection no longer seems to be that strong, other factors that previously had limited influence on prices now add to the price. Factors like site productivity and age distribution affect the financial return of a forest estate but is it obvious that these factors still influence prices as they once did? Over the last 20 years, the price of forest estates has increased dramatically. If development of prices has led to a weakened connection between return and price, could this be explained by the fact that previously price affecting factors have less weight when valuing forest estates? The purpose of the study was therefore to investigate how a number of factors influence the forest estate price;including site productivity and age distribution. The results shows that neither site productivity, nor age distribution have a significant impact on the forest estate price. What mainly influence the prices seems to be the standing forest volume on the estate and region. The development of the prices seems not only to have influenced the relationship between the return from the forest and the prices, but also minimized the influence of factors like age distribution and site productivity. This means that estates that are bought within the same region, at the same price per cubic meter, can have considerably different potential to gain financial return.展开更多
To comprehensively assess fi'actionated spacecraft, an assessment tool is developed based on lifecycle simulation under uncertainty driven by modular evolutionary stochastic models. First, fractionated spacecraft nom...To comprehensively assess fi'actionated spacecraft, an assessment tool is developed based on lifecycle simulation under uncertainty driven by modular evolutionary stochastic models. First, fractionated spacecraft nomenclature and architecture are clarified, and assessment criteria are analyzed. The mean and standard deviation of risk adjusted lifecycle cost and net present value (NPV) are defined as assessment metrics. Second, fractionated spacecraft sizing models are briefly described, followed by detailed discussion on risk adjusted lifecycle cost and NPV models. Third, uncertainty sources over fractionated spacecraft life- cycle are analyzed and modeled with probability theory. Then the chronological lifecycle simulation process is expounded, and simulation modules are developed with object oriented methodology to build up the assessment tool. The preceding uncertainty models are integrated in these simulation modules, hence the random object status can be simulated and evolve with lifecycle timeline. A case study to investigate the fractionated spacecraft for a hypothetical earth observation mission is carried out with the proposed assessment tool, and the results show that fractionation degree and launch manifest have great influence on cost and NPV, and generally fractionated spacecraft is more advanced than its monolithic counterpart under uncertainty effect. Finally, some conclusions are given and future research topics are highlighted.展开更多
In this paper, we investigate a Sparre Andersen risk model perturbed by diffusion with phase-type inter-claim times. We mainly study the distribution of maximum surplus prior to ruin. A matrix form of integro-differen...In this paper, we investigate a Sparre Andersen risk model perturbed by diffusion with phase-type inter-claim times. We mainly study the distribution of maximum surplus prior to ruin. A matrix form of integro-differential equation for this quantity is derived, and its solution can be expressed as a linear combination of particular solutions of the corresponding homogeneous integro-differential equations. By using the divided differences technique and nonnegative real part roots of Lundberg's equation, the explicit Laplace transforms of particular solutions are obtained. Specially, we can deduce closed-form results as long as the individual claim size is rationally distributed. We also give a concise matrix expression for the expected discounted dividend payments under a barrier dividend strategy. Finally, we give some examples to present our main results.展开更多
The present research work has been carried out on biomass based on 10 kW capacity gasifier power generation system installed at College of Agricultural Engineering and Technology,Dr.Panjabrao Deshmukh Agricultural Uni...The present research work has been carried out on biomass based on 10 kW capacity gasifier power generation system installed at College of Agricultural Engineering and Technology,Dr.Panjabrao Deshmukh Agricultural University(Dr.PDKV),Akola Maharashtra,India.The main objectives were to evaluate various costs and benefits involved in the power generation system.The costs of energy per unit were calculated for the first year of operation.The economics of gasifier based power generation system and thereby the feasibility of the system was examined by estimating per unit cost,Net Present Value(NPV),Benefit Cost Ratio(BCR),Internal Rate of Return(IRR)and payback period.The discount cash flow method was used to find out the IRR.In the present analysis,three costs viz.,installed capital cost,operation and maintenance cost,and levelised replacement cost were examined for the evaluation of the power generation per unit.Discount rate on investment in case of subsidy(Case I)and in case without subsidy(Case II)for installation cost of system was considered as 12.75%.The BCR comes in Case I for operating duration of 22 h,20 h,and 16 h are 1.24,1.18,and 1.13,respectively.Similarly for Case II BCR comes 1.44,1.38,and 2.39.The IRR comes in Case I for operating duration of 22 h,20 h,and 16 h are 26%,22%,and 19%,respectively.Similarly for Case II,IRR comes 52%,44%,and 39%for operating duration of 22 h,20 h,and 16 h,respectively.The payback period in the present analysis was worked out.The payback period for biomass based gasifier power generation system was observed to be for Case I from three to four years and for Case II it was one to two years.展开更多
This paper gives a new method into the evaluating system of teleeom investment projects, i.e. Real Option. This may overcome the defects resulted from employing Net Present Value (NPV), which is nova used in the eva...This paper gives a new method into the evaluating system of teleeom investment projects, i.e. Real Option. This may overcome the defects resulted from employing Net Present Value (NPV), which is nova used in the evaluation of telecom projects. A theoretical analysis of Real Option is provided, followed by an example of telecom investment project to illustrate the differences between the two methods.展开更多
This paper deals with the problem of project scheduling subject to multiple execution modes with non-renewable resources, and a model that handles some of monetary issues in real world applications.The objective is to...This paper deals with the problem of project scheduling subject to multiple execution modes with non-renewable resources, and a model that handles some of monetary issues in real world applications.The objective is to schedule the activities to maximize the expected net present value(NPV) of the project, taking into account the activity costs, the activity durations, and the cash flows generated by successfully completing an activity.Owing to the combinatorial nature of this problem, the current study develops a hybrid of branch-and-bound procedure and memetic algorithm to enhance both mode assignment and activity scheduling.Modifications for the makespan minimization problem have been made through a set of benchmark problem instances.Algorithmic performance is rated on the maximization of the project NPV and computational results show that the two-phase hybrid metaheuristic performs competitively for all instances of different problem sizes.展开更多
Carbon trading and carbon offset markets are potential policy options for mitigating greenhouse gas emissions and climate change. A price on carbon is expected to generate demand for carbon offsets. In a market-based ...Carbon trading and carbon offset markets are potential policy options for mitigating greenhouse gas emissions and climate change. A price on carbon is expected to generate demand for carbon offsets. In a market-based framework, the carbon price should be high enough to compensate for opportunity costs. We studied a highly-modified agricultural system in the Guanzhong–Tianshui economic region of China that is typical of many temperate agricultural zones in western China. We quantified the economic returns from agriculture and from carbon plantings(both monoculture and ecological plantings) under five carbon-price scenarios. The mean carbon sequestration is 34 Mg·hm^(–2)·a^(–1), and the average annual payment increased to 1146 CNY·hm^(–2) at a medium carbon price of 50 CNY·Mg^(–1) CO_2^(–e). Thus, areas of high priority for conservation and restoration may be restored relatively cheaply in the presence of a carbon market.Overall, however, less carbon is sequestered by ecological plantings(i.e., mixed native trees and shrubs) compared to agriculture.展开更多
基金The NSF (11201217) of Chinathe NSF (20132BAB211010) of Jiangxi Province
文摘In this paper, we consider a risk model in which two types of individual claims, main claims and by-claims, are defined. Every by-claim is induced by the main claim randomly and may be delayed for one time period with a certain probability. The dividend policy that certain amount of dividends will be paid as long as the surplus is greater than a constant dividend barrier is also introduced into this delayed claims risk model. By means of the probability generating functions, formulae for the expected present value of total dividend payments prior to ruin are obtained for discrete-type individual claims. Explicit expressions for the corresponding results are derived for K n claim amount distributions. Numerical illustrations are also given.
基金This work was supported by the National Key Research and Development Program of China(No.2016YFD0501405)National Natural Science Foundation of China(Grant No.21677161)Major Science&Technology Program for Water Pollution Control and Treatment of China(Nos.2017ZX07102-002 and 2018ZX07105-001).
文摘A cost sensitivity analysis was performed for an industrial membrane bioreactor to quantify the effects of hydraulic retention times and related operational parameters on cost.Different hydraulic retention times(72-24 h)were subjected to a flat-sheet membrane bioreactor updated from an existing 72 h oxidation ditch treating antibiotic production wastewater.Field experimental data from the membrane bioreactor,both full-scale(500 m/d)and pilot(1.0 m3/d),were used to calculate the net present value(NPV),incorporating both capital expenditure(CAPEX)and operating expenditure.The results showed that the tank cost was estimated above membrane cost in the 38.2%,where capital expenditure contributed 24.2%more than operational expenditure.Tank construction cost was decisive in determining the net present value contributed 62.1%to the capital expenditure.The membrane bioreactor has the advantage of a longer lifespan flat-sheet membrane,while flux decline was tolerable.The antibiotics decreased to 1.87±0.33 mg/L in the MBR effluent.The upgrade to the membrane bioreactor also benefited further treatments by 10.1%-44.7%lower direct investment.
基金the financial support provided by the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030003)supported by the Department of Science and Technology of Guangdong Province,as well as project(DD20221703)supported by the China Geological Survey。
文摘Since the implementation of several pilot production tests were in natural gas hydrate(NGH) reservoirs in terrestrial and marine settings, the study of NGH has entered a new stage of technological development for industrial exploitation. Prior to the industrial exploitation of any given NGH reservoir, the economic feasibility should be examined. The first step of economic evaluation of a NGH reservoir is to know whether its resource amount meets the requirement for industrial exploitation. Unfortunately, few relevant studies have been conducted in this regard. In this study, the net present value(NPV) method is employed to estimate the economic critical resources required for the industrial exploitation of NGHs under different production scenarios. Sensitivity analysis is also performed in order to specify the effects of key factors, such as the number of production wells, gas price, technological improvement and tax incentive, on the economic critical resources. The results indicate that China requires the lowest economic critical resource for a NGH reservoir to be industrially exploited, ranging from 3.62 to 24.02 billion m3 methane. Changes in gas price and tax incentives also play significant roles in affecting the threshold and timeline for the industrial exploitation of NGH.
文摘As a result of advances in horizontal comple- tions and multi-stage hydraulic fracturing, the U.S. has been able to economically develop several decades of worth of natural gas. However, a considerable concern has risen on the economic viability of shale gas development for reasons associated with the fast production declines as well as recent down-turns of natural gas prices besides rises in the costs of new technologies. Therefore, an economic analysis is required to investigate the profitability of the re- fracturing treatment of unconventional gas resources. Net present value of cash flows and internal rate of return are calculated for a range of gas prices considering 20 years of natural gas production from a typical unconventional shale gas reservoir. A systematic comparison is then accom- plished for three scenarios: (1) re-fracturing versus no re- fracturing, (2) combination of re-fracturing and drilling new wells, and (3) time-dependent re-fracturing treatment. Further, this paper incorporates the cost of re-fracturing treatment, the cost of drilling a new horizontal well, the water treatment cost, as well as the current and future price of natural gas in the model. The findings of this work would help the future re-stimulation development plans of the emerging unconventional shale gas plays.
基金The author is infinitely thankful to his friend and colleague M.Rubinstein for valuable discussions and an invariable interest to his work.The author is also thankful to C.Miller for his high estimation of the author’s efforts.Of course,all errors are author’s full responsibility.
文摘Extensions of Merton’s model(EMM)considering the firm’s payments and generating new types of firm value distribution are suggested.In the open log-value/time space,these distributions evolve from initially normal to negatively skewed ones,and their means are concave-down functions of time.When payments are set to zero or proportional to the firm value,EMM turns into the Geometric Brownian model(GBM).We show that risk-neutral probabilities(RNPs)and the no-arbitraging principle(NAP)follow from GBM.When firm’s payments are considered,RNPs and NAP hold for the entire market for short times only,but for long-term investments,RNPs and NAP just temporarily hold for individual stocks as far as mean year returns of the firms issuing those stocks remain constant,and fail when the mean year returns decline.The developed method is applied to firm valuation to derive continuous-time equations for the firm present value and project NPV.
文摘Multilateral wells promise cost savings to oil and fields as they have the potential to reduce overall drilling distances and minimize the number of slots required for the surface facility managing the well.However,drilling a multilateral well does not always increase the flow rate when compared to two single-horizontal wells due to competition in production inside the mother-bore.Here,a holistic approach is proposed to find the optimum balance between single and multilateral wells in an offshore oil development.In so doing,the integrated approach finds the highest Net Present Value(NPV)configuration of the field considering drilling,subsurface,production and financial analysis.The model employs stochastic perturbation and Markov Chain Monte-Carlo methods to solve the global maximising-NPV problem.In addition,a combination of Mixed-Integer Linear Programming(MILP),an improved Dijkstra algorithm and a Levenberg-Marquardt optimiser is proposed to solve the rate allocation problem.With the outcome from this analysis,the model suggests the optimum development including number of multilateral and single horizontal wells that would result in the highest NPV.The results demonstrate the potential for modelling to find the optimal use of petroleum facilities and to assist with planning and decision making.
文摘Agroforestry and beekeeping are widely promoted as prospective Nature-</span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Based Income Generating Activities (NIGAs) to improve livelihoods while at </span><span style="font-family:Verdana;">the same time enhancing biodiversity conservation in degrading</span><span style="font-family:Verdana;"> agro-ecologies. These activities can diversify and increase famers’ incomes and support in</span><span style="font-family:Verdana;">stinctive biota and fauna resilience. However, evidence to showcase and compare their long-term benefits is scant. We use the case of Uluguru</span><span style="font-family:Verdana;"> Mountains in Tanzania to evaluate and compare viability of agroforestry and beekeeping projects using the Cost</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Benefit Analysis (CBA) approach. The results of analysis yielded positive NPVs for both agroforestry and beekeeping projects at discount rates not higher than 8.2% and 8.5% respectively. Overall, the comparison of economic viability between agroforestry and beekeeping projects revealed that the former was relatively more profitable than the later in terms of both the NPV and Benefit</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Cost Ratio (BCR) criteria. However, the Internal Rate of Return (IRR) for beekeeping was slightly higher than that of agroforestry. Yet, we underscore the fact that these two projects can jointly be implemented to enhance livelihoods of farmers and support biodiversity conservation in the study </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">area </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">and other parts with similar agro-ecologies in developing countries. However, farmers in these agro-ecologies need to be supported by governments and non-government development partners in terms of training and inspiration to shift from orthodox farming to sustainable NIGAs.
文摘The formulas of premiums and premium reserves of a kind of mixed whole life insurance were obtained by the methods of actuarial science. Then we take a typical policy of whole life insurance in present Chinese market as an example to analyze its expense design and predict its market prospects.
基金supported by the National Natural Science Foundation of China(Program No.72073064)the National Natural Science Foundation of China Youth Science Fund Project(Program No.71703069)+1 种基金the“333 distinguished Talents Project”Foundation of Jiangsu Province in China(Grant No.BRA2018070)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Program No.KYCX20_0876).
文摘Reducing emissions due to deforestation is considered a low-cost option for mitigating climate change.However,the recent literature suggests higher opportunity costs because of specific deforestation drivers,which render reducing emissions from deforestation and forest degradation(REDD+)for mitigating climate change an uncertain,less attractive,and controversial option.Indonesia is one of the largest greenhouse gas emitters.Since 1989,53.80%of its oil palm expansion has come from forestlands,which has generated a significant amount of carbon emissions.This study uses official data and results from the relevant literature to estimate the costs of oil palm-based deforestation under various scenario assumptions,including different output prices,yields,time horizons,and discount rates.We also calculate the additional cost to preserve a 1-ha forest.We demonstrate that the average opportunity cost from avoiding oil palm-based deforestation is 24.42 USD/tCO_(2)eq in Indonesia,approximately 1.3 times the 2011 EUA carbon price.Additional sums of around 5,466.90–11,042.96 USD/ha should be provided to landowners for the deforestation avoidance caused by oil palm expansion.Special attention should be given to the extensive oil palm expansion in Indonesia and the resulting high opportunity costs for achieving the REDD+target.
文摘Considering the important changes in the Swiss energy sector, especially in renewable energy(RE)technologies, new revenue possibilities for small and medium sized enterprises(SMEs) emerge. However, the adaption of RE-technologies for Swiss enterprises relies on tangible financial returns, based on complex calculations. This article analyses business opportunities(BOs) of eight Swiss SMEs considering the net present value of RE-investments in an uncertain economic environment. We identify two profitable BOs for Swiss SMEs and three which are not profitable. Further, the article demonstrates that the profitability of such investments remains mostly positive even under economic uncertainties. Surprisingly the profitability does not change significantly if the SME receives a subsidy or not. The support instrument of the Swiss Government has not a ponderous impact on the decision to invest in RE-technologies or not. Therefore, the article emphasizes the importance of including SME in the Swiss attempt to decentralize the energy market.
文摘<span style="font-family:Verdana;">This work presents the results of the characterization of a standalone photovoltaic system for the electrification of a household located in rural area in the western region of Cameroon: Nziih-Bafou in Dschang (5.35</span><span style="white-space:normal;background-color:#FFFFFF;font-family:Verdana;">°</span><span style="font-family:Verdana;">N, 10.05</span><span style="white-space:normal;background-color:#FFFFFF;font-family:Verdana;">°</span><span style="font-family:Verdana;">E and 1900 m). In order to cope with the</span><span "=""> </span><span style="font-family:Verdana;">maintenance charges and reduce the investment cost, a small mill was added to the appliances of the household for income generation. The assessment of the energy demand was made by taking into account the reactive energy due to the heavy</span><span "=""> </span><span style="font-family:Verdana;">consumption of energy by the mill’s motor, especially during ignition. The sizing of all the system’s components was carried out with the prospect of determining an optimum design in accordance with daily electricity demand, site irradiance profile and climatic conditions. In this context, tilt angles applicable to the PV structure and that allow</span><span "=""> </span><span style="font-family:Verdana;">to receive the maximum irradiance as a function of the periods of the year were determined using the Hay model.</span><span "=""> </span><span style="font-family:Verdana;">This approach provides the system with incident irradiance greater than or at the limit equal to that received by a horizontal surface on the same site</span><span "=""> </span><span style="font-family:Verdana;">compared to the case of a single tilt angle where the irradiance on the inclined plane is often lower than that</span><span "=""> </span><span "=""><span style="font-family:Verdana;">on the horizontal. The economic analysis of the PV system showed an </span><span style="font-family:Verdana;">initial cost of $4448</span></span><span "=""> </span><span style="font-family:Verdana;">and the Life Cost Cycle amounted to $24,495. This</span><span style="font-family:Verdana;"> amount corresponds to a present cost per kilowatt hour of $0.44. The Net Present Value</span><span "=""> </span><span style="font-family:Verdana;">(NPV) of the project ($7793) over its lifetime (20 years)</span><span "=""> </span><span style="font-family:Verdana;">shows a payback period of less than 4 years.</span>
基金University Grants Commission(UGC)NET fellowship[Ref No.F.16-6(DEC.2016)/2017(NET)]University Grants Commission(UGC)for D S Kothari fellowship reference no.BL/17-18/0490.
文摘Externality;the term can define as a positive or negative impact from either production or consumption of goods or services.Services provided by particular location have very specific dependency on spatial characteristics of that region.A region’s distinct characteristics make it ecologically unique from other such regions.Ecosystem services are offered by these regions thus differ according to these unique ecological features.In this particular study,artificially imposed expansion of coastal shrimp farming towards the inland and its impact over paddy cultivation have been addressed.Optimization of the extent of this manipulative coastal expansion has been supported by little modification of a previously described model.Here the investment prediction for both shrimp and paddy farming has been investigated by calculating net present value(NPV).Shrimp farming has very specific externality on local ecosystem services.In this particular case,some contradictory results are presented and with respect to positive or negative externality;but the externalities are strong.NPV results indicate that there is no long-term profitability in case of shrimp farming.Hence,an overall externality of shrimp farming has been described in context of this study.
文摘Historically the price of a forest estate has, at least in Sweden, been closely related to the financial return from the estate, but this connection no longer seems to be that strong, other factors that previously had limited influence on prices now add to the price. Factors like site productivity and age distribution affect the financial return of a forest estate but is it obvious that these factors still influence prices as they once did? Over the last 20 years, the price of forest estates has increased dramatically. If development of prices has led to a weakened connection between return and price, could this be explained by the fact that previously price affecting factors have less weight when valuing forest estates? The purpose of the study was therefore to investigate how a number of factors influence the forest estate price;including site productivity and age distribution. The results shows that neither site productivity, nor age distribution have a significant impact on the forest estate price. What mainly influence the prices seems to be the standing forest volume on the estate and region. The development of the prices seems not only to have influenced the relationship between the return from the forest and the prices, but also minimized the influence of factors like age distribution and site productivity. This means that estates that are bought within the same region, at the same price per cubic meter, can have considerably different potential to gain financial return.
基金Foundation items: National Natural Science Foundation of China (50975280, 61004094) Program for New Century Excellent Talents in University (NCET-08-0149)+1 种基金 Fund of Innovation by Graduate School of National University of Defense Technology (B090102) Hunan Provincial Innovation Foundation for Postgraduate, China.
文摘To comprehensively assess fi'actionated spacecraft, an assessment tool is developed based on lifecycle simulation under uncertainty driven by modular evolutionary stochastic models. First, fractionated spacecraft nomenclature and architecture are clarified, and assessment criteria are analyzed. The mean and standard deviation of risk adjusted lifecycle cost and net present value (NPV) are defined as assessment metrics. Second, fractionated spacecraft sizing models are briefly described, followed by detailed discussion on risk adjusted lifecycle cost and NPV models. Third, uncertainty sources over fractionated spacecraft life- cycle are analyzed and modeled with probability theory. Then the chronological lifecycle simulation process is expounded, and simulation modules are developed with object oriented methodology to build up the assessment tool. The preceding uncertainty models are integrated in these simulation modules, hence the random object status can be simulated and evolve with lifecycle timeline. A case study to investigate the fractionated spacecraft for a hypothetical earth observation mission is carried out with the proposed assessment tool, and the results show that fractionation degree and launch manifest have great influence on cost and NPV, and generally fractionated spacecraft is more advanced than its monolithic counterpart under uncertainty effect. Finally, some conclusions are given and future research topics are highlighted.
基金Supported by National Basic Research Program of China (973 Program) 2007CB814905, National Natural Science Foundation of China (Grant No. 10871102), and the Keygrant Project of Chinese Ministry of Education (Grant No. 309009)
文摘In this paper, we investigate a Sparre Andersen risk model perturbed by diffusion with phase-type inter-claim times. We mainly study the distribution of maximum surplus prior to ruin. A matrix form of integro-differential equation for this quantity is derived, and its solution can be expressed as a linear combination of particular solutions of the corresponding homogeneous integro-differential equations. By using the divided differences technique and nonnegative real part roots of Lundberg's equation, the explicit Laplace transforms of particular solutions are obtained. Specially, we can deduce closed-form results as long as the individual claim size is rationally distributed. We also give a concise matrix expression for the expected discounted dividend payments under a barrier dividend strategy. Finally, we give some examples to present our main results.
文摘The present research work has been carried out on biomass based on 10 kW capacity gasifier power generation system installed at College of Agricultural Engineering and Technology,Dr.Panjabrao Deshmukh Agricultural University(Dr.PDKV),Akola Maharashtra,India.The main objectives were to evaluate various costs and benefits involved in the power generation system.The costs of energy per unit were calculated for the first year of operation.The economics of gasifier based power generation system and thereby the feasibility of the system was examined by estimating per unit cost,Net Present Value(NPV),Benefit Cost Ratio(BCR),Internal Rate of Return(IRR)and payback period.The discount cash flow method was used to find out the IRR.In the present analysis,three costs viz.,installed capital cost,operation and maintenance cost,and levelised replacement cost were examined for the evaluation of the power generation per unit.Discount rate on investment in case of subsidy(Case I)and in case without subsidy(Case II)for installation cost of system was considered as 12.75%.The BCR comes in Case I for operating duration of 22 h,20 h,and 16 h are 1.24,1.18,and 1.13,respectively.Similarly for Case II BCR comes 1.44,1.38,and 2.39.The IRR comes in Case I for operating duration of 22 h,20 h,and 16 h are 26%,22%,and 19%,respectively.Similarly for Case II,IRR comes 52%,44%,and 39%for operating duration of 22 h,20 h,and 16 h,respectively.The payback period in the present analysis was worked out.The payback period for biomass based gasifier power generation system was observed to be for Case I from three to four years and for Case II it was one to two years.
基金This workis supported by Ministry of Education P.R.C(03036)Key Laboratory of Information Management and Information Economics, Min-istry of Education P.R.C(F04-22) .
文摘This paper gives a new method into the evaluating system of teleeom investment projects, i.e. Real Option. This may overcome the defects resulted from employing Net Present Value (NPV), which is nova used in the evaluation of telecom projects. A theoretical analysis of Real Option is provided, followed by an example of telecom investment project to illustrate the differences between the two methods.
文摘This paper deals with the problem of project scheduling subject to multiple execution modes with non-renewable resources, and a model that handles some of monetary issues in real world applications.The objective is to schedule the activities to maximize the expected net present value(NPV) of the project, taking into account the activity costs, the activity durations, and the cash flows generated by successfully completing an activity.Owing to the combinatorial nature of this problem, the current study develops a hybrid of branch-and-bound procedure and memetic algorithm to enhance both mode assignment and activity scheduling.Modifications for the makespan minimization problem have been made through a set of benchmark problem instances.Algorithmic performance is rated on the maximization of the project NPV and computational results show that the two-phase hybrid metaheuristic performs competitively for all instances of different problem sizes.
基金supported by the National Natural Science Foundation of China (41371020)Fundamental Research Funds for the Central Universities (GK201502010)+2 种基金China Postdoctoral Science Foundation on the 58th Group (2015M582706)Postdoctoral Scientific Research Project Foundation of Shaanxi Province in 2015China 111 Project (B12007)
文摘Carbon trading and carbon offset markets are potential policy options for mitigating greenhouse gas emissions and climate change. A price on carbon is expected to generate demand for carbon offsets. In a market-based framework, the carbon price should be high enough to compensate for opportunity costs. We studied a highly-modified agricultural system in the Guanzhong–Tianshui economic region of China that is typical of many temperate agricultural zones in western China. We quantified the economic returns from agriculture and from carbon plantings(both monoculture and ecological plantings) under five carbon-price scenarios. The mean carbon sequestration is 34 Mg·hm^(–2)·a^(–1), and the average annual payment increased to 1146 CNY·hm^(–2) at a medium carbon price of 50 CNY·Mg^(–1) CO_2^(–e). Thus, areas of high priority for conservation and restoration may be restored relatively cheaply in the presence of a carbon market.Overall, however, less carbon is sequestered by ecological plantings(i.e., mixed native trees and shrubs) compared to agriculture.