“冷冻侠”高灵能源

高灵能源有一个别致的英文名，叫做“IccBank”，字面翻译是“冰银行”。这个看似奇特的名称实际上是这家公司盈利模式最简单形象的表达。依靠蓄冷而盈利——高灵能源叮以在夜间将电力转化成“冷能源”储存起来，并在白天用电高峰时提供给它的用户。     

Hotelling was Right

This paper proves existence of a subgame perfect equilibrium in Hotelling's original (unidimensional city, linear transportation costs, uniform distribution of the consumers, two firms with identical and constant marginal cost, perfectly inelastic demand) location–price game such that in the location subgame the location choices of the firms are pure and identical. The result can be extended to variations of the original setup (multidimensional city, nonlinear transportation costs, nonuniform distribution of consumers, many firms with identical and constant marginal costs, two or more firms with nonidentical but constant marginal costs).     

The effect of lot-sizing on workload variability

Lot-sizing models which group demand requirements for one or more consecutive time periods into a single production run have received considerable attention in recent years. Material Requirements Planning (MRP) systems must, for instance, make a lot-size decision for each planned order release. Existing decision models attempt to minimize the sum of setup plus inventory holding costs. However, lot-sizing tends to increase the work center load variability, and, consequently, the costs associated with changing production levels from period to period should be incorporated into the economic analysis. This study is concerned, first of all, with analytically describing the relationship between dynamic lot-sizing models and workload variability. Secondly, in order to account for production level change costs we propose a simple modification to existing heuristic models. Lastly, we employ a simulation model to empirically extend these results to a typical MRP multiechelon production environment. An example is included to show clearly that with cost premiums for overtime and severance or guaranteed minimum costs for undertime the traditional lot-sizing techniques significantly underestimate actual costs and can lead to very costly policies.Mean, variance and coefficient of variation of period work time requirements are derived as a function of several algorithm characteristics. Average cycle time (number of periods covered by a single batch) is found to be the most influential factor in determining workload variability. Variance grows approximately in proportion to this cycle time with the proportionality constant being the square of average period workload. Cycle time and demand variability also contribute to workload variability. Results indicate that for a given average cycle time, the EOQ method will minimize workload variability. When N products utilize the same work center, the coefficient of load variation will be reduced by a factor of N^{?$\text{1}\text{2}$} unless requirements are positively correlated. Positive correlation would result when products have similar seasons or parent items. In this case grouping such products cannot help reduce variability.In order to incorporate production level change costs into existing heuristics we may simply introduce a term consisting of a penalty factor times average cycle time. The penalty factor represents the costs of period by period production level changes. Several popular heuristics are extended in this fashion, and it is found that solutions are still readily obtainable, requiring only modifications to setup or holding cost parameters.The effects of level change costs are examined via simulation for a specific yet typical environment. It is found that when setup costs are significant, traditional lot-sizing heuristics can provide cost savings and service level improvements as compared to lot-for-lot production. However, whereas for our model the obtainable profit improvement from lot-sizing was 25% in the case of freely variable capacity, actual improvements were only one half as large when reasonable hiring and firing practices and overtime and undertime costs were considered. Consequently, management needs to consider carefully labor costs and work center product relationships when determining a production scheduling method.     

Advertising as Information: Matching Products to Buyers

We consider communication of quality via cheap talk and dissipative advertising expenditures, when consumers have heterogeneous tastes for quality, and price information must be acquired through costly search. For search pods, cheap talk communicates quality when fixed costs are roughly constant across quality levels, while if fixed costs vary greatly with quality, then firms having the higher fixed-cost quality level use dissipative advertising. For experience goods, quality can be communicated by cheap talk in a range where low-quality firms have greater fixed costs, and low-quality firms use dissipative advertising if their fixed costs are greater still.     

Short interval forecasting of emergency phone call (911) work loads

There has been an increasing emphasis over the last 5 to 10 years to improve productivity in the Service Sector of the U.S. economy. Much of the improvement obtained by these managers has come about through better scheduling of the work force in these organizations. Effective scheduling of this personnel requires good estimates of demand, which may exhibit substantial variations between days for certain times of the year. The Indianapolis Police Department (IPD) Communications area is one such organization that exhibits varying workloads and is interested in improving staff scheduling of dispatch operators.This article explores the use of six different forecasting techniques for predicting daily emergency call workloads for the IPD's communications area. Historical call volume data are used to estimate the model parameters. A hold-out sample of five months compares forecasts and actual daily call levels. The forecast system utilizes a rolling horizon approach, where daily forecasts are made for the coming month from the end of the prior month. The forecast origin is then advanced to the end of the month, where the current month's actual call data are added to the historical database, new parameters are estimated, and then the next month's daily estimates are generated. Error measures of residual standard deviation, mean absolute percent error, and bias are used to measure performance. Statistical analyses are conducted to evaluate if significant differences in performance are present among the six models.The research presented in this article indicates that there are clearly significant differences in performance for the six models analyzed. These models were tailored to the specific structure and this work suggests that the short interval forecasting problems faced by many service organizations has several structural differences compared to the typical manufacturing firm in a made-to-stock environment. The results also suggests two other points. First, simple modeling approaches can perform well in complex environments that are present in many service organizations. Second, special tailoring of the forecasting model is necessary for many service firms. Historical data patterns for these organizations tend to be more complex than just trend and seasonal elements, which are normally tracked in smoothing models. These are important conclusions for both managers of operating systems and staff analysts supporting these operating systems. The design of an appropriate forecasting system to support effective staff planning must consider the nature, scope, and complexity of these environments.     

To lead or to wait? An application to internationalization strategies under demand uncertainty

We examine the exports versus foreign direct investment (FDI) decision under demand uncertainty for an asymmetric cost duopoly. One of the firms can lead entry before demand realization or retain flexibility enjoying an informational advantage. When the time value of information is small and for sufficiently low investment costs, follow‐the‐leader behavior in FDI arises. Relatively high investment (fixed) costs result in follow‐the‐leader exporting behavior. When the time value of information becomes significant, the potential leader will opt for a wait‐and‐see strategy. For intermediate values of investment costs, the efficient firm invests, while the rival chooses to export.     

Misallocation,informality, and human capital: Understanding the role of institutions

The aim of this paper is to quantify the role of formal-sector institutions in shaping the demand for human capital and the level of informality. We propose a firm dynamics model where firms face capital market imperfections and costs of operating in the formal sector. Formal firms have a larger set of production opportunities and the ability to employ skilled workers, but informal firms can avoid the costs of formalization. These firm-level distortions give rise to endogenous formal and informal sectors and, more importantly, affect the demand for skilled workers. The model predicts that countries with a low degree of debt enforcement and high costs of formalization are characterized by relatively lower stocks of skilled workers, larger informal sectors, low allocative efficiency, and measured TFP. Moreover, we find that the interaction between entry costs and financial frictions (as opposed to the sum of their individual effects) is the main driver of these differences. This complementarity effect derives from the introduction of skilled workers, which prevents firms from substituting labor for capital and in turn moves them closer to the financial constraint.     

Performance measures that work

Measuring white-collar productivity is difficult in any setting but the complex operations of hospitals--where work load can vary hour to hour--are now being measured for peak efficiency. By developing standards and working with formulas and computer models, HR professionals are measuring productivity and predicting staffing needs.     

A hybrid machine learning model for forecasting a billing period’s peak electric load days

Many models have been studied for forecasting the peak electric load, but studies focusing on forecasting peak electric load days for a billing period are scarce. This focus is highly relevant to consumers, as their electricity costs are determined based not only on total consumption, but also on the peak load required during a period. Forecasting these peak days accurately allows demand response actions to be planned and executed efficiently in order to mitigate these peaks and their associated costs. We propose a hybrid model based on ARIMA, logistic regression and artificial neural networks models. This hybrid model evaluates the individual results of these statistical and machine learning models in order to forecast whether a given day will be a peak load day for the billing period. The proposed model predicted 70% (40/57) of actual peak load days accurately and revealed potential savings of approximately USD $80,000 for an American university during a one-year testing period.     

The effect of international staffing practices on subsidiary staff retention in multinational corporations

This paper contributes to the scarce body of research on employee turnover in multinational corporations' foreign subsidiaries and addresses some key issues related to dealing with turnover of local staff. Based on a literature review, I conceptualize locals' perceived career prospects and their organizational identification as key variables mediating the relationship between international staffing practices and local staff turnover. In a second step, the paper develops instruments that help international firms to retain their subsidiary staff. Specifically, I focus on how international staffing practices need to be configured to ensure employee retention and I derive moderating factors. My arguments are integrated into a framework for the effect of international staffing practices on subsidiary staff retention in multinational corporations.     

Allocation and routing of mobile computed tomography equipment

We consider the problem of allocating and routing mobile medical equipment to hospitals, as faced by an equipment leasing company. The equipment is leased to hospitals across the United States for periods ranging from a few weeks to many months. The problem is to satisfy the requirements of hospitals with different demand schedules given the equipment available. The objective is to maximize total revenues generated less the transportation costs incurred. The problem is here modeled as a network flow formulation. A spreadsheet-based decision support system was developed and implemented in a firm with no expertise or prior experience in such modeling efforts. Details of the system and its implementation are provided.     

Antecedents and consequences of the introduction of flexible benefit plans in China

The present study had two aims. The first was to explore the extent of flexible benefit plans (flex plans) within China and to make predictions about future trends. The second aim was to examine the relationships between the use of flex plans and two measures of labour market performance: the ability to attract essential employees and the level of labour turnover. The results from a survey of 324 firms in China reflecting a response rate of 32.4% showed that although there are presently a limited number of firms that adopt flex plans, the number is likely to increase in the next few years. Second, the probability of the adoption of flex plans was not found to vary with the mode of ownership and firm location. Third, flex plans were found to be adopted by firms for several practical reasons including their perceived role in cost containment, improved recruitment and retention, enhancement of job satisfaction and labour productivity. The take-up of such plans, however, was found to be inhibited by perceived administrative burdens and costs, and the limited number of staff qualified in benefit provision. Finally, the adoption of flex plans was significantly related to labour turnover and improved recruitment capacity.     

Policy modes,firms and the natural environment

This paper examines how different environmental policy types differentially impact firms and why firms vary in their responses to such policies. Based on the mechanisms embedded in policy instruments to create incentives for firms to comply, the characteristics of benefits/costs that policies impose on firms and the institutional context in which policy instruments were created and are sustained, the paper identifies five policy categories. These are category I (command and control), category II (market based), category III (mandatory information disclosures), category IV (business–government partnerships) and category V (private voluntary codes). Different policy types often bestow asymmetrical benefits/costs on firms. Some benefits/costs may constitute ‘private/club goods’ while others may constitute ‘public goods’. Drawing insights from public policy literature, the paper argues that firms can be expected to favor policies whose benefits have the characteristics of private/club goods but the costs of public goods. Thus, understanding the nature of benefits/costs (private/club versus public) and the magnitude of their excludability is critical in explaining the variations in firms' responses. To understand how managers perceive the nature of benefits/costs (monetary as well as non‐monetary), the paper draws on theories and perspectives in the business and public policy field. In doing so, the paper examines the ‘demand’ and the ‘supply’ sides as well as the market and non‐market environments of a given policy. Thus, the paper makes a case for a multi‐theoretic approach to understand variations in managerial assessments of benefits/costs, and consequently variations in their responses to various policy types. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.     

Staffing venture capital firms' international operations

International staffing is relatively unexplored for service firms as much of the literature focuses on manufacturing firms. We draw on the knowledge-based perspective to analyze three key issues related to venture capital firms' international staffing: composition of the international staffing pool; reasons for the deployment of expatriates; and the process through which staff co-ordinate international decision-making, respectively. These research questions are investigated in an exploratory study combining a survey and qualitative interviews. The results suggest that the recruitment of local executives is significantly more important than the deployment of expatriates, and expatriation is significantly more important for transferring knowledge than for other motives suggested in the literature. In VC firms, investment committees play a key role in international decision-making, which allows them to manage challenges that otherwise would require deployment of expatriates. Implications of these results for future IHRM research and for the management of venture capital firms are discussed.     

政治联系、市场化进程与权益资本成本——来自中国民营上市公司的经验证据

以中国民营上市公司为样本,文章实证检验不同市场环境下政治联系对企业权益资本成本的影响,研究发现:政治联系对权益资本成本的影响在不同地区是有差异的;在市场化程度较低地区,由于政府干预导致企业经营业绩有较高的不确定性,有政治联系企业承担着较高的权益资本成本;在市场化程度较高地区,政府干预相对较少,政治联系更多地体现为一种荣誉或良好的政商关系,此时有政治联系企业享有较低的权益资本成本;当上市公司存在控股股东利益输送时,投资者预期到无法共享政治联系为企业带来的利益,此时有政治联系企业要承担较高的权益资本成本。本研究为厘清政治联系对企业和投资者的利弊影响提供了一个有益的视角。     

Modeling regional electric power markets and market power

This paper develops a nonlinear, mathematical programming model for estimating production decisions in an open access, regional power market. Our approach allows one to estimate competitive power market equilibrium prices, which in turn offers empirical conclusions about marginal generation facilities, transmission interconnection congestion, and most importantly, load pockets and market power. Sensitivity analyses are conducted by subjecting the model to changes in production costs, peak hour demand, power imports, and transmission interconnection price assumptions. We then consider the issue of a firm's ability to exercise market power and the implications it may have on regional equilibrium power prices. The Louisiana power market is used as a case study for our work. Copyright © 2001 John Wiley & Sons, Ltd.     

Quality investment timing by the startup and the established firm

This study investigates quality investment timing decisions of the established firm and the startup by a duopoly model, where firms can position quality early (demand uncertainty is high) or late (uncertainty has been resolved), possibly at different costs. The startup positions quality to maximize its survival probability, whereas the established firm maximizes profits. Results indicate that the startup positions quality earlier than the established firm when the demand uncertainty is high and costs do not decline sharply over time. Additionally, policy analysis shows that subsidies work better than direct funds in encouraging quality innovation of the startup.     

Contraction flexibility,operating leverage,and financial leverage

This study investigates the impacts of contraction flexibility and operating leverage on financial leverage from the perspective of the agency conflict between shareholders and debtholders. In a continuous-time real option framework, we demonstrate that shareholders’ contraction flexibility may have an adverse effect on financial leverage, and that the substitution relation between operating leverage and financial leverage is persistent or pronounced in the presence of contraction flexibility. The evidence from Chinese listed firms not only supports our theoretical predictions well, but also offers a method to examine the agency conflict hypothesis. We suggest that the high proportion of bank loans or long-term debt in total liabilities can help levered firms alleviate the agency problem arising from contraction decisions.     

浅谈提高电网运行效率的技术手段

随着社会经济的飞速发展和人民物质生活水平的提高,对电力的需求也在迅速增长,用电负荷与十年前相比已不可同日而语,尤其是夏季高峰时期,设备经常是满载或过载运行。那么既要满足社会对电力的需求,又要保证设备的安全运行,这无疑是对我们电网的管理和设备的双重考验,也只有从管理入手,从整治设备入手,才有可能找寻出问题的症结,得出令人满意的结果。     

Patient equipment management: integrating a flexible alternative to purchase or lease

As hospital CSS and OR departments work together to manage patient equipment, alternatives to purchase are available that can provide them with needed flexibility and responsiveness. A rental equipment provider that can meet the standards demanded for quality health care can become a valuable asset when developing and refining a hospitalwide equipment management program. But in order to receive the level of quality and service they should expect, hospitals must continually communicate their changing needs while holding their providers accountable to established standards.