产出不确定条件下农产品供应链内部融资研究

农产品供应链的研究较少考虑农户资金不足,供应链内部融资手段实现产销均衡的情况.文章针对二级农产品供应链产出不确定,构建核心企业为资金约束农户提供内部融资的模型,通过求解最优化的农产品订购量、投产量并进行算例分析,提出内部融资服务规则及最优生产运作策略.结果表明:在不考虑农户缺货成本和残值收益情况下,存在资金约束的农户倾向投入少于订购量的投产量来减少成本投入和还款金额,实现自己期望收益最优;资金约束条件下采取分散决策,供应链成员存在最优的投产量和订购量使得自身期望收益实现最优;资金约束条件下,文章设计的融资模式使得销售商的期望收益随着农户自有资金的增加而减少.     

碳交易机制下资金约束制造商替代产品的最优生产策略研究

碳交易机制和资金约束在很大程度上影响企业的生产决策,但很少有文献研究碳排放和资金双约束下企业对普通与低碳两种替代品生产决策问题。因此,本文在碳交易机制下讨论了资金约束下制造商两种产品的生产决策问题。本文采用基于有无碳交易和银行融资划分四种情形,基于报童模型构建优化模型分析制造商的最优决策。研究发现:(1)无融资情形下,如果制造商的初始资金很少,则制造商生产更多的普通产品;如果制造商的初始资金很多,则制造商生产更多的低碳产品;(2)在银行融资情形下,当利率较小时,制造商生产更多的低碳产品;当利率较大时,制造商生产更多的普通产品;(3)在银行融资情形下,如果碳排放配额较大,无碳交易机制时的融资量和融资成本高于有碳交易机制时的融资量和融资成本;如果碳排放配额较低则结论相反。     

低碳约束下湖南省产业结构优化研究

在湖南省"十二五"规划工业产业节能减排的背景下,如何在碳减排目标的基础上,实现产业结构优化,成为湖南省面临的重大挑战.本文构建低碳约束下湖南省主导产业选择指标体系,计算并选取湖南省无低碳约束和有低碳约束下的主导产业.进一步,本文设计无低碳约束、弱低碳约束和强低碳约束三种情景模拟,分析不同的低碳约束条件对湖南省主导产业选择的影响.本文结论如下:1)无低碳约束条件下,湖南省主导产业包括有色金属冶炼及压延加工业等碳生产力较低的行业,低碳约束条件下,湖南省主导产业包括食品制造业等碳生产力较高的行业.这表明,考虑低碳约束条件,湖南省主导产业由碳生产力较低的行业向碳生产力较高的行业转变.2)情景模拟结果表明,一些传统支柱型产业仍是湖南省产业结构优化中需重点发展的产业,且随着低碳政策的深化和节能减排目标的扩大,战略性产业如医药制造业成为主导产业,在产业结构优化中发挥中坚作用.     

预付款融资下期权契约的协调研究

本文研究零售商占主导、供应商自有资金有限的二级供应链如何通过契约实现协调的问题。在预付款融资的基础上加入期权契约方法,构建用于预付款融资的期权契约模型,并求解出该模型下所能协调供应链的契约参数与此时零售商供应商双方的最优决策系统。研究表明当供应商自有资金大于等于某临界值时通过预付款融资下的期权契约可实现供应链协调。若小于则无法通过该契约协调,并且供应商自有资金约束越大,零售商最优订购数量越多,同时供应商的最优生产数量随着自有资金的减少而减少,供应链的参与者及整个供应链的利润也随着供应商自有资金的减少单调递减;另外,相比于无融资下的期权契约,预付款模式能提高零售商、供应商以及整个供应链的收益。     

考虑RFID应用的资金约束供应链订购决策研究

RFID技术的应用在有效降低商品库存损耗率的同时,也增加了供应链企业的运营成本,尤其是具有资金压力的供应链中小企业。在零售商具有资金约束的二级供应链下分析RFID技术的应用对资金约束供应链绩效的影响,通过构建贸易信贷下基于批发价合同的Stackelberg博弈模型,对比采用RFID前后资金约束供应链成员的均衡决策及期望收益,探讨了该供应链采用RFID的必要条件。结果显示当RFID标签成本低于某个阈值,或RFID库存损耗恢复率高于某个阈值时,供应链成员会选择采用RFID。此外,当RFID单位标签成本或零售商标签成本分摊系数较低,或RFID库存损耗恢复率较高时,制造商会提供比不采用RFID时更高的批发价;在采用RFID的条件下,零售商订购数量低于不采用RFID时的数量。通过设计收益分享契约实现了采用RFID时资金约束供应链的协调。     

基于状态不确定性的动态滤波算法

本文将不确定性表示为状态约束,融入平差模型,建立基于状态参数不确定性的滤波模型.首先从无状态约束条件下的平差准则中推导出无约束滤波算法,该算法与卡尔曼滤波算法是一致的.然后扩展到不等式约束和椭球约束的平差准则,推导出基于状态约束的动态滤波算法.通过实例计算,对不同状态约束的动态滤波模型进行比较.结果表明基于状态不确定性的动态滤波算法要优于卡尔曼滤波算法,且简便高效,具有显示表达式.     

资金约束条件下订单农业供应链的融资定价问题研究

在农产品产出不确定以及零售市场价格受随机产出率影响的条件下,研究了由一个风险中性型公司和一个风险规避型农户组成的订单农业供应链受农户资金约束时的融资与定价问题.研究结果表明,农户在受资金约束条件下存在融资的必要,农户向银行融资后其期望收益明显得到提高.研究还表明农户向银行融资后,公司和农户的最佳决策以及最大收益与银行贷款利率密切相关.为具体实践中在资金约束条件下订单农业供应链的融资与定价决策提供了一些参考依据.     

资金成本下延迟支付期限的收益分享契约

针对由单一制造商和单一零售商组成的供应链系统,建立了随机需求下考虑有资金成本延迟支付期限的收益分享契约模型,研究两种决策(分散化和集中化)下,延迟支付期限是如何影响资金约束零售商的最优订货数量以及供应链系统的利润.分析表明,不管是分散化还是集中化决策,考虑有资金成本延迟支付期限的收益分享契约使供应链系统的最优订货量和利润都增大.最后,运用数值分析验证了结论.     

NHPP软件可靠性模型参数的保序估计

许多主要的非齐次泊过程松模型的故障强度都满足顺序约束条件.在顺序约束条件下,本文提出了故障强度的约束极大似然估计(RML),并讨论了其性质.利用故障强度的RML,获得了软件可靠性模型参数的加权最小二乘估计.     

市场约束条件下的非寿险费率厘定

在非寿险费率厘定中,经常遇到的一个实际问题是某些风险类别的费率不能过高或不能过低。在这种约束条件下,传统的广义线性模型将不能直接用于费率厘定。本文给出了一种在一般线性约束条件下,如何应用迭代算法对常用的广义线性模型进行调整,从而得到满足特定约束条件的费率厘定结果。本文的实证研究结果表明,该方法具有灵活性和现实可行性,能够解决非寿险费率厘定中常见的市场约束问题。     

A Stochastic Capital Rationing Model

This paper addresses the issue of optimal project selection for capital expenditures assuming uncertain budgetary allocations. A critical review of the historical development of capital budgeting models indicates two major deficiencies: (i) deterministic models ignore the uncertain nature of capital budgeting problems; and (ii) those models which do incorporate the concept of uncertainty have serious computational problems when applied to larger problems. A stochastic capital rationing model (SCRM) is proposed which makes use of recent developments in stochastic programmes with recourse. This model remains computationally tractable despite the explicit incorporation of uncertainty and the application of theoretically sound penalties for constraint violations. Two problems are introduced which illustrate the model's superiority over comparable deterministic formulations. By varying both the probability distributions of the stochastic constraints and the borrowing rates, it was possible to identify the impact these factors have on project selections.     

Radial DEA models without inputs or without outputs

In this paper we consider radial DEA models without inputs (or without outputs), and radial DEA models with a single constant input (or with a single constant output). We demonstrate that (i) a CCR model without inputs (or without outputs) is meaningless; (ii) a CCR model with a single constant input (or with a single constant output) coincides with the corresponding BCC model; (iii) a BCC model with a single constant input (or a single constant output) collapses to a BCC model without inputs (or without outputs); and (iv) all BCC models, including those without inputs (or without outputs), can be condensed to models having one less variable (the radial efficiency score) and one less constraint (the convexity constraint).     

Capital structure of real estate assets: Theory and empirical evidence

This paper presents a model which intends to explain the capital structure of real estate assets. The model is cast in classical portfolio choice framework, but special attention is paid to the liquidity constraint. The test of this model on two assets with different capital structures (new housing and old housing in France) revealed the importance of return indicators as well as liquidity constraint in the household's financing decisions.     

A single facility stochastic location problem undera-distance

In this paper we consider a stochastic facility location model in which the weights of demand points are not deterministic but independent random variables, and the distance between the facility and each demand point isA-distance. Our objective is to find a solution which minimizes the total cost criterion subject to a chance constraint on cost restriction. We show a solution method which solves the problem in polynomial order computational time. Finally the case of rectilinear distance, which is used in many facility location models, is discussed.     

地区经济发展的不平衡与经济增长

本文用两部门内生增长模型分析了在地区经济发展不平衡的情况下 ,经济发展的长期趋势 .在这个模型中 ,假定物质资本和人力资本可以不受限制的自由流动 ,技术是外生给定的 .研究发现 ,地区差别使发达地区的经济发展更快 ,落后地区的经济发展更慢 ;发达地区将有更高的均衡利率 .最后 ,文章给出了具体的政策建议 ,并对某些政策给予了评价 .     

股权融资管制与公司资本结构:模型与模拟

股权融资管制带来的摩擦会如何影响公司的资本结构及资本结构调整？本文建立了股权融资管制摩擦模型,并使用计算机实验模拟的方法,研究股权再融资管制带来的摩擦对公司目标资本结构以及资本结构调整的影响,同时探讨资本结构调整速度模型的适用性。研究发现,外部股权融资管制程度不仅影响公司的目标资本结构,也影响公司资本结构调整的速度,研究结论为观测资本市场融资摩擦提供了一种独特视角。此外,观察分析当前使用的资本结构调整模型,本文发现该模型忽略了变量之间的强约束条件,会导致模型设定偏误。     

Expanded models of the project portfolio selection problem with loss in divisibility

This research develops three new models for the project portfolio selection problem with multiple periods. To reflect some real situations, three loss assumptions are considered for the interruption of project execution for the first time. The mathematical representations of the loss assumptions are provided and proved. Besides, the workload constraint, capital flow constraint, cardinality constraint, and precedence relationship are incorporated into the models. One benchmark example and one real-world application case are used to demonstrate the capability and characteristics of the proposed models.     

Competitive facility location on decentralized supply chains

This paper addresses a novel competitive facility location problem about a firm that intends to enter an existing decentralized supply chain comprised of three tiers of players with competition: manufacturers, retailers and consumers. It first proposes a variational inequality for the supply chain network equilibrium model with production capacity constraints, and then employs the logarithmic-quadratic proximal prediction–correction method as a solution algorithm. Based on this model, this paper develops a generic mathematical program with equilibrium constraints for the competitive facility location problem, which can simultaneously determine facility locations of the entering firm and the production levels of these facilities so as to optimize an objective. Subsequently, a hybrid genetic algorithm that incorporates with the logarithmic-quadratic proximal prediction–correction method is developed for solving the proposed mathematical program with an equilibrium constraint. Finally, this paper carries out some numerical examples to evaluate proposed models and solution algorithms.     

Arbitrage and the tax code

We provide a detailed characterization of arbitrage-free asset prices in the presence of capital gains and income taxes. The distinguishing feature of our analysis is that we impose on the model two important features of the tax code: the limited use of capital losses and the inability to wash sell. We show that under remarkably mild conditions, the lack of pre-tax arbitrage implies the lack of post-tax arbitrage with the limited use of capital losses. The conditions are that the risk free interest rate be positive and that tax rates on interest income exceed capital gains tax rates. The result also holds when only a wash sale constraint is imposed and no investor holds a portfolio with a large capital loss. We allow investors to face different tax rates and have different bases for the calculation of capital gains taxes. The characterizations we provide have important implications for both asset pricing and portfolio choice. Our results imply that models that use arbitrage-free pre-tax models continue for derivative pricing and hedging are also arbitrage free in a world with taxes. Similarly, portfolio choice models with taxes typically specify pre-tax arbitrage free price processes and then analyze portfolio choice in the presence of taxes. In these models, it is unclear if portfolio recommendations are based on risk-return tradeoffs or on the arbitrage opportunities present in the model. Our results imply that if the above features of the tax code are modeled explicitly, then we can isolate the post-tax risk-return tradeoffs.     

Covering location problem of emergency service facilities in an uncertain environment

In practical location problems on networks, the response time between any pair of vertices and the demands of vertices are usually indeterminate. This paper employs uncertainty theory to address the location problem of emergency service facilities under uncertainty. We first model the location set covering problem in an uncertain environment, which is called the uncertain location set covering model. Using the inverse uncertainty distribution, the uncertain location set covering model can be transformed into an equivalent deterministic location model. Based on this equivalence relation, the uncertain location set covering model can be solved. Second, the maximal covering location problem is investigated in an uncertain environment. This paper first studies the uncertainty distribution of the covered demand that is associated with the covering constraint confidence level α. In addition, we model the maximal covering location problem in an uncertain environment using different modelling ideas, namely, the (α, β)-maximal covering location model and the α-chance maximal covering location model. It is also proved that the (α, β)-maximal covering location model can be transformed into an equivalent deterministic location model, and then, it can be solved. We also point out that there exists an equivalence relation between the (α, β)-maximal covering location model and the α-chance maximal covering location model, which leads to a method for solving the α-chance maximal covering location model. Finally, the ideas of uncertain models are illustrated by a case study.