Utilization and maintenance in a model with scrapping

We consider a productive asset, called equipment or capital good, and we examine the properties of, as well as the interactions between, the operating policies, which are determined by its optimal utilization and maintenance, and the capital policy of scrapping, which defines the optimal time when the productive asset is retired from its current use. Starting with an abstract model and using the approach of optimal control, initially we characterize the various types of equipment by assigning to them a single total profit index, which indicates how the above policies affect the flow of operating revenues plus capital gains or losses. This index is a function of market-determined prices. So using it we then investigate how the operating and capital policies are influenced by the rate of discount, the price of new equipment, and the rise or fall of the price of new equipment relative to the value of its output. Among other interesting results, we find that the effects of these prices on the nature and interactions of optimal policies depend crucially on whether the equipment is of the usual profit making type, where output is the main source of revenue, or of the antique type, where the main source of revenue is capital gains.     

Product innovation with lumpy investment

The paper provides a framework that enables us to analyze the important topic of capital accumulation under technological progress. We describe an algorithm to solve Impulse Control problems, based on a (multipoint) boundary value problem approach. Investment takes place in lumps and we determine the optimal timing of technology adoptions as well as the size of the corresponding investments. Our numerical approach led to some guidelines for new technology investments. First, we find that investments are larger and occur in a later stadium when more of the old capital stock needs to be scrapped. Moreover, we obtain that the size of the firm’s investments increase when the technology produces more profitable products. We see that the firm in the beginning of the planning period adopts new technologies faster as time proceeds, but later on the opposite happens. Furthermore, we find that the firm does not invest such that marginal profit is zero, but instead marginal profit is negative.     

The acquisition of new technology and its impact on a firm's competitive position

The strategic decision concerning the optimal and dynamic acquisition of new technology is examined. The model focuses on a profit maximizing firm that optimally derives its price, level of output, and its level and composition of productive capacity over time. The acquisition of new technology and reduction of existing capacity may occur simultaneously, so that the composition of the firm's productive resources may be upgraded over time. It is assumed that the acquisition of new technology causes a reduction in production costs and a direct increase in the firm's demand. The demand experienced by the firm may be directly increased as a result of acquiring new technology due to benefits such as expanded product-mix or volume capabilities, improved quality of output, or improved customer service (shorter production lead time). In addition, it is shown that demand is indirectly increased due to the reduced production costs that enable the firm to charge a lower price. Therefore, the strategic impact of acquiring new technology is captured, since its effect on future demand and the firm's ability to meet the demand are considered. The importance of capturing the increased demand potential offered by the new technology is demonstrated through the analysis of numerical examples. In addition, the effect on the optimal solution caused by a variety of environmental conditions is examined. For example, the impact of technological innovation is observed by defining (i) the cost of acquiring technology as a decreasing function of time, and (ii) the effectiveness of new technology on reducing operating costs as an increasing function of time.     

A mean-risk index model for uncertain capital budgeting

This paper discusses the capital budgeting problem of projects using annual cash inflows, cash outflows and initial investment outlays given by experts’ evaluations when no historical data are available. Uncertain variables are used to describe the projects’ parameters. A profit risk index and a capital risk index are proposed, and a mean-risk index model is developed for optimal project selection. In addition, the deterministic forms of the model are given and a solution algorithm is provided. For the sake of illustration, a numerical example is also presented. The results of the example show that both profit risk index and capital risk index are important in investment risk control. However, when the profit risk control requirement is strong, the selected project portfolio may be insensitive to the capital risk constraint; when the profit risk control requirement is moderate, the capital risk constraint plays an important role. The results also show the tendency that when either the tolerable profit risk level or the tolerable capital risk level becomes higher, the obtained expected net present value of the project portfolio becomes larger, which is in agreement with the investment rule that the higher the risk, the higher the return.     

Determining the optimal constrained multi-item (Q, r) inventory policy by maximising risk-adjusted profit

^** Email: john.betts{at}infotech.monash.edu.au^*** Email: robertj{at}unimelb.edu.au The predominant approach to determining replenishment batchsizes for capital constrained multi-item inventories is to assumethat at some point in time the replenishment of all items willcoincide, and that batch sizes are small enough that the constraintis not violated when this event occurs. However, when an inventoryconsists of a large number of independently replenished components,the probability that all replenishments coincide is very small.The standard approach thus results in unnecessarily conservativebatch sizes that under-utilise the available resource, resultingin lower profit than would be the case if a small risk of violatingthe constraint was tolerated. In this paper, a new approachto determining constrained batch sizes is presented where, fora certain average investment, the probability of exceeding abinding, or fixed, constraint on capital is determined. Thisprobability is used to define an adjustment factor to be appliedto expressions for company profit so that an optimal trade-offbetween maximising profit and reducing risk of failure is obtainedsimply by optimising this adjusted profit. By optimising profitadjusted for the risk of exceeding the constraint, the new modelyields batch sizes that are larger, and result in greater profitabilitythan those recommended under traditional models.     

随机需求下有产能约束的技术创新策略研究

在随机需求和技术变革的环境下,基于有产能约束的单供应商-单零售商的供应链结构,研究供应商分销价格决策和技术创新策略以及零售商订货决策。建立了三阶段Stackelberg博弈模型,通过逆推方法求得了供应商最优分销价格和技术创新策略以及零售商最优订货量,深入探讨了供应商产能、新技术出现概率以及市场需求期望与波动分别对供应商、零售商和供应链整体利润的影响。结果表明当供应商产能不足时进行技术创新会提高供应商和供应链的利润,但零售商因间接承担供应商技术创新的投资成本而利润下降;当供应商产能过剩时进行技术创新则会降低供应商及供应链的利润,而零售商的利润增加。新技术出现概率增加会提高供应链各成员的利润;提高市场需求期望并减小市场波动对供应商及供应链有利,但可能会降低零售商的利润。     

市场利率环境下银企信贷信息共享信号传递博弈模型

在市场利率环境下,运用信号传递博弈理论,在成本倒挂情况下,采取利息补贴承诺的方法,设计一种以风险分担实现利润共享的契约机制,利润共享参数起到了传递信息的信号作用。研究结果表明,在该契约下企业没有撒谎的动机,契约参数是传达信息的信号。该契约机制下不仅可以实现信贷资金供求信息的共享,而且能够保证系统的协调,系统收益达到最优,使企业能够得到新产品生产所需资金,银行解决信贷资金的风险损失的问题。     

基于VaR的科技保险风险补偿问题研究

VaR(Value at Risk)是金融企业进行全面风险管理的有效工具,是保险公司“偿二代(C-ROSS)”量化资本要求采用的方法。本文利用VaR工具,在委托代理框架下,研究了科技保险风险补偿合同问题,阐述了科技保险风险补偿的理论依据。在对称信息与非对称信息情形下,获得了风险补偿合同的闭式解。本文结果显示,合同中固定补偿将起主导作用,最优边际补偿系数可正可负,且随保险公司置信水平增加而递减。     

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。     

基于技术创新的资金约束供应链融资策略分析

新兴技术进入竞争市场时,供应链成员往往存在资金约束,为了尽早占据市场份额、获得更高的利润流,上下游企业有意愿进行供应链的内外部融资。文章对上游企业存在资金约束、下游核心企业资金充裕的供应链融资策略进行决策分析。研究表明:上下游的融资策略会使上游企业得到帕累托改进,且随上游企业自有资金的增大,下游企业的利率阈值逐渐减小;存在最优融资利率使得下游企业的期望利润达到最大。在上下游企业财务不透明的前提下,存在下游企业的融资利率区间使上游企业有隐藏真实资金状况以期获得更低融资利率的动机,文章基于博弈论的信息甄别模型给出了相应的激励合同对上游企业的期望利润进行修正,诱使上游企业提供真实的资金状况。     

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.     

An optimal replenishment policy for deteriorating items with effective investment in preservation technology

In this paper, considering the amount invested in preservation technology and the replenishment schedule as decision variables, we formulate an inventory model with a time-varying rate of deterioration and partial backlogging. The objective is to find the optimal replenishment and preservation technology investment strategies while maximizing the total profit per unit time. For any given preservation technology cost, we first prove that the optimal replenishment schedule not only exists but is unique. Next, under given replenishment schedule, we show that the total profit per unit time is a concave function of preservation technology cost. We then provide a simple algorithm to figure out the optimal preservation technology cost and replenishment schedule for the proposed model. We use numerical examples to illustrate the model.     

基于生长价值跟踪的生鲜农产品采收销售模型

生鲜农产品的生长增值性对于提升渠道价值具有重要贡献。为此,将影响生鲜农产品需求的成熟度进行数学刻画并引入增值性变质库存模型,针对生鲜农产品育成育肥后定时采收销售和达到临界成熟后适时采收销售两种情形建立了农户利润模型,求解出了最优采收销售时间。研究得出,农户适时采收销售获得的利润更大;产品达到临界成熟后,农户无需再付出生产努力。     

风险收益不对等条件下中国对外直接投资合作模式的优化

针对对外直接投资所面临的资金短缺、进展不顺利的问题,在风险分担理论的基础上构建中国政府、东道国政府和社会资本的投资合作模型。目的在于设计出足够吸引社会资本投入,且保证中国对外直接投资顺利开展的风险分担模式。并通过数值模拟风险分担比例和利润分享比例对投资时机和投资价值的影响,证明了中国政府与社会资本间存在最优的风险分担比例,以及东道国政府与社会资本存在最优利润分享比例。     

Price subsidies and guaranteed buys of a new technology

We consider a problem of a government that wishes to stimulate the adoption of a new technology in order to replace an older, environmentally less desirable, technology. The new technology is manufactured by a monopolist firm which has learning-by-doing in its production process. The firm sells the new product to both private households and government institutions and wishes to determine an optimal pricing policy. The government has at its disposal two instruments: subsidizing the consumer price and making purchases of the new technology from the firm. We assume profit maximization on the part of the firm. The government wishes to maximize the cumulative number of units of the new technology sold to private households by the terminal date of the government program. The problem is set up as a Stackelberg differential game in which we identify an open-loop equilibrium, supposing that the government can credibly precommit to its subsidy and buying program.     

Irreversible capital accumulation under interest rate uncertainty

We consider the optimal sequential irreversible investment policy of a value maximizing firm facing decreasing returns to scale and interest rate uncertainty. We characterize the optimal accumulation policy and its value for a broad class of diffusion models of the short interest rate by focusing on the marginal investment decision and deriving the marginal value of capital explicitly. We also state a set of conditions under which there is a maximal capital stock above which the option to expand productive capacity further in the future becomes valueless. Hence, our results indicate that interest rate uncertainty may limit the size of an optimally investing firm.     

Intra-organizational Networks and Performance: A Review

Intra-organizational network research had its first heyday during the empirical revolution in social sciences before World War II when it discovered the informal group within the formal organization. These studies comment on the classic sociological idea of bureaucracy being the optimal organization. Later relational interest within organizational studies gave way to comparative studies on the quantifiable formal features of organizations. There has been a resurgence in intra-organizational networks studies recently as the conviction grows that they are critical to organizational and individual performance. Along with methodological improvements, the theoretical emphasis has shifted from networks as a constraining force to a conceptualization that sees them as providing opportunities and finally, as social capital. Because of this shift it has become necessary not only to explain the differences between networks but also their outcomes, that is, their performance. It also implies that internal and external networks should no longer be treated separately.Research on differences between intra-organizational networks centers on the influence of the formal organization, organizational demography, technology and environment. Studies on outcomes deal with diffusion and adaptation of innovation; the utilization of human capital; recruitment, absenteeism and turnover; work stress and job satisfaction; equity; power; information efficiency; collective decision making; mobilization for and outcomes of conflicts; social control; profit and survival of firms and individual performance.Of all the difficulties that are associated with intra-organizational network research, problems of access to organizations and incomparability of research findings seem to be the most serious. Nevertheless, future research should concentrate on mechanisms that make networks productive, while taking into account the difficulties of measuring performance within organizations, such as the performance paradox and the halo-effect.     

基于营运资金信息匹配平台的供应链金融动态折扣决策研究

当前逐渐受到实业界关注的一种新型供应链金融模式是基于营运资金信息匹配平台的动态折扣。本文针对两级供应链的动态折扣决策问题进行建模,揭示了动态折扣的应用对于改善供应链参与方现金流的影响机理。首先通过考虑供需双方动态折扣的独立决策,得出日折扣率的边界条件、双方效用最大时的日折扣率、买方混合还款方式下营运资金的最优准备方案和最低边界值;其次考虑供需双方动态折扣的最优决策,推导出在不同折扣率和利率关系下的最优还款策略,研究表明动态折扣可以明显提升供需双方的利润情况。     

确定性需求连续生产模型下的最优保理融资策略

保理是融资机构基于供应链上下游企业之间实际发生交易而给予供应链卖方企业的一种短期融资。基于连续生产模型研究了资金约束制造商的最优保理融资策略。考虑保理时间决策对融资成本和需求损失的影响,比较了固定期保理和即时保理两种策略下制造商的利润。研究发现,固定期保理策略下的最优保理时间随着其边际利润的增加而提前,而随着保理费率上升、应收款账期延长、自有资金增加而延迟。数值研究结果发现,保理商最优保理费率随着应收账款账期延长而降低。     

持股策略下随机需求低碳供应链融资决策均衡

随机市场需求且受制造商减排水平影响,考虑碳限额与交易机制,研究制造商进行单纯银行借贷和供应商投资持股的组合融资时的最优决策和利润情况,分析消费者低碳偏好、碳交易价格和供应商的投资持股比例对供应链的最优决策变量和利润的影响。研究发现:无资金约束、单纯银行借贷和组合融资下,消费者低碳偏好、碳交易价格和持股比例与制造商的减排水平和利润以及供应链系统的利润正相关,而供应商的批发价格和制造商的生产量与消费者低碳偏好正相关,与碳交易价格负相关,而持股比例与供应商的批发价格负相关,与制造商的生产量和减排水平正相关;持股策略下制造商的减排水平和生产量最大,无资金约束时次之,单纯银行借贷时最小;而无资金约束时供应商的批发价格最高,单纯银行借贷时次之,持股策略时最低;在持股比例满足一定条件下,供应商和制造商的利润优于单纯银行借贷时的利润,并且可以优于无资金约束时的利润,提高了供应链的竞争力和效率。