跨文化比较中模子的确认及应用——叶维廉诗学理论支点分析

国际比较文学领域曾习惯于把西方的批评模子用在源于不同文化的文学研究和批评中。叶维廉则在经验性的实践中确认了东西方具有不同的思维、美学和批评模子。对模子应用的具体关注和思考 ,是叶维廉诗学理论的支点。他的模子应用理论从解决跨中西文化比较研究及批评理论的具体运用问题入手 ,为跨文化诗学比较提供了方法论上的依据 ,为我们进一步思考中国传统诗学的独特价值开启了一条可行之路。     

Age,Trend, and Cohort Effects in a Macro Model of Canadian Expenditure Patterns

A quadratic almost ideal demand system allowing for age, cohort, and trend effects is developed at the macro level. The model is estimated by maximum likelihood, using a three-tier iterative/search method applied to pooled 1961–1992 time series for five regions of Canada and six categories of expenditure. Hypothesis tests indicate support for the model specification. Elasticities are compared with those reported in other studies, with special attention to food. Effects of demographic and trend variables on elasticities and expenditure shares are investigated. An overall conclusion is that such effects can be very important in a macro demand system.     

Measuring work stressors: The role of frequency,duration, and demand

Abstract

In recent years a number of authors have suggested that progress towards a better understanding of the stressor-stress relationship can only be achieved by altering the way in which work stress is investigated. One strategy is to investigate what it is we are measuring when we assess work stressors. More particularly there is a need to use rating scales that measure demand associated with work roles rather than just imply it. Dimensions such as frequency, duration, and level of demand were measured in addition to the traditional method of simply asking individuals to indicate whether they agree/disagree that stressors are present at work. The results point to the incremental increase in variance explained when these additional facets are measured over and above the variance explained by traditional methods. This result confirms the ned to develop a better understanding of the concept of demand, the difference between chronic and acute stressors, and the interaction effects of the different facets.     

The impact of distributions of uncertain lumpy demand on inventories

Most studies on inventory management under demand uncertainty analyse the detrimental effects of demand variability (i.e. its coefficient of variation). In contrast, the consequences of the shape of demand distribution (e.g. its multi-modality and asymmetry) have received only minor attention. The aim of the present paper is to assess the impact of the shape of demand distribution on inventories. In particular, it considers contexts in which demand distributions have more than one 'mode' and are asymmetric, thus making requirements lumpy. The analysis is based on a simulation model which, in order to ensure comparable conditions, keeps all the other factors constant (i.e. ceteris paribus), and compares different demand distributions with the same mean and coefficient of variation. Results show that that demand shape is a key driver of inventory investment. Specifically: (i) the magnitude of the impact of multi-modality and asymmetry is comparable to that of variability; (ii) multi-modality and asymmetry can have either a negative or positive effect depending on the target service level sought. The managerial implications of these findings are addressed in the conclusions.     

The resource constrained single-item inventory problem with demand-dependent unit cost

In this paper, we present an economic order quantity (EOQ) with both demand-dependent unit cost and restrictions. An analytical solution of the EQO is derived using a recent and simple method, which isthe geometric programming approach. The EOQ inventory model with demand-dependent unit cost without any restriction and the classical EOQ inventory model are obtained.     

A Parsimonious Macroeconomic Model for Asset Pricing

I study asset prices in a two‐agent macroeconomic model with two key features: limited stock market participation and heterogeneity in the elasticity of intertemporal substitution in consumption (EIS). The model is consistent with some prominent features of asset prices, such as a high equity premium, relatively smooth interest rates, procyclical stock prices, and countercyclical variation in the equity premium, its volatility, and in the Sharpe ratio. In this model, the risk‐free asset market plays a central role by allowing non‐stockholders (with low EIS) to smooth the fluctuations in their labor income. This process concentrates non‐stockholders' labor income risk among a small group of stockholders, who then demand a high premium for bearing the aggregate equity risk. Furthermore, this mechanism is consistent with the very small share of aggregate wealth held by non‐stockholders in the U.S. data, which has proved problematic for previous models with limited participation. I show that this large wealth inequality is also important for the model's ability to generate a countercyclical equity premium. When it comes to business cycle performance, the model's progress has been more limited: consumption is still too volatile compared to the data, whereas investment is still too smooth. These are important areas for potential improvement in this framework.     

航线网络中需求无约束估计的非参数选择模型

传统的航空客运需求无约束估计方法仅针对平行直达航班中的顾客需求“溢出”和“再 现”问题,未能考虑航空网络中直达和中转联程航班之间的网络替代效应． 基于顾客偏好排序列表定义了航空网络顾客类型集合,建立了考虑顾客策略行为的网络型非参数离散选择模型．考虑到网络环境下历史预售数据的不完备性,站在线上和线下交易平台的角度,分别建立了非截尾和截尾需求情况下的完备数据对数似然函数． 采用 EM 算法对顾客到达率和概率质量函数进行联合估计,并提出了网络环境下的顾客“初始需求”、“再现需求”和“溢出需求”无约束估计计算方法．通过数值模拟验证了所提方法的可行性和有效性,相较于现有方法能准确反映产品间网络替代效应对顾客选择行为影响,从而更加有效地避免对历史顾客“初始需求”的高估问题．     

董事会治理评价、治理指数与公司绩效实证研究

在优化中国上市公司董事会治理评价指标体系的基础上,对上市公司董事会治理状况进行指数化评价,并对董事会治理评价指数及其与公司绩效的关系进行实证分析.实证结果显示,董事会治理质量趋于改善,独立性有所增强,但整体治理指数仍然较低;行业因素、控股股东性质对董事会治理产生重要影响,即行业的竞争性越强董事会治理质量越高,当控股股东为职工持股会和民营企业时董事会治理指数较高;不同董事会治理机制间存在替代效应,董事会治理水平的提高对公司绩效产生显著的正向效应,由于替代效应的存在,单一董事会治理机制与公司绩效间的关系缺乏显著性和一致性,但作为一个整体,董事会治理质量的改善显著地提高公司绩效.据此提出改善中国上市公司董事会治理的政策建议.     

Optimal Control of Replenishment and Substitution in an Inventory System with Nonstationary Batch Demand

We study an inventory system in which a supplier supplies demand using two mutually substitutable products over a selling season of T periods, with a single replenishment opportunity at the beginning of the season. As the season starts, customer orders arrive in each period, for either type of products, following a nonstationary Poisson process with random batch sizes. The substitution model we consider combines the usual supplier‐driven and customer‐driven schemes, in that the supplier may choose to offer substitution, at a discount price, or may choose not to; whereas the customer may or may not accept the substitution when it is offered. The supplier's decisions are the supply and substitution rules in each period throughout the season, and the replenishment quantities for both products at the beginning of the season. With a stochastic dynamic programming formulation, we first prove the concavity of the value function, which facilitates the solution to the optimal replenishment quantities. We then show that the optimal substitution follows a threshold rule, and establish the monotonicity of the thresholds over time and with respect to key cost parameters. We also propose a heuristic exhaustive policy, and illustrate its performance through numerical examples.     

Rationing Capacity Between Two Product Classes*

In this paper, we study the capacity allocation problem faced by make-to-order manufacturing firms encountering expected total demand in excess of available capacity. Specifically, we focus on firms' manufacturing short-life-cycle or seasonal products such as high fashion apparel. Using a decision-theory-based approach, we develop a capacity allocation policy that allows such firms to discriminate between two classes of products (one yielding a higher profit contribution per unit of capacity allocated to it than the other), resulting in selective rejection of orders for the class with the lower unit contribution. The effectiveness of capacity rationing is investigated under a wide array of conditions characterized by variations in factors such as the ratio of unit profit contributions of the two product classes, the ratio of total available capacity to expected total demand, the ratio of expected demands between the two classes, and the variability in demand for each product class. The results indicate that capacity rationing is very effective in increasing the total profit, and could therefore serve as a valuable decision tool for managers in such firms.