上海市交通拥堵成本测算及对策研究

依据美国德克萨斯运输学院交通拥挤外部成本的经典测算模型，将交通运输拥挤成本分为时间延误成本、额外燃油消耗成本、环境污染物排放成本和噪音成本三个方面，对于2015年上海市工作日高峰期交通拥挤的外部成本进行了详细的测算。结果表明，交通拥堵的外部成本约占当年上海市GDP的0.63%。最后，对于交通拥堵成本较高的现状提出了包括对上海市部分高度拥堵路段或区域收取拥堵费、大力发展上海市公共交通和发展交通快慢型出行方式共存在内的相关政策和建议。     

单车场无时间窗甩挂运输车辆调度的启发式算法

考虑了牵引车空驶、带空挂车行驶和带重挂车行驶所引起的成本差异，定义了牵引车运行成本的概念，将总运行成本最小作为调度方案优劣的判别指标，并同时考虑牵引车数量最少。将牵引任务分为四种类型，定义了任务链、虚拟任务、链内交叉和链间交叉的概念，提出了一种求解该类单车场甩挂运输车辆调度无时间窗约束的启发式算法，包括初始调运方案、链内优化、空车调运交叉、牵引车数量优化和链间交叉。最后给出了仿真算例，算法优化后的最终方案与初始方案相比，牵引车数量减少，总运行成本降低，验证了算法的有效性和可行性。     

When was the U.S. housing downturn predictable? A comparison of univariate forecasting methods

This paper uses three classes of univariate time series techniques (ARIMA type models, switching regression models, and state-space/structural time series models) to forecast, on an ex post basis, the downturn in U.S. housing prices starting around 2006. The performance of the techniques is compared within each class and across classes by out-of-sample forecasts for a number of different forecast points prior to and during the downturn. Most forecasting models are able to predict a downturn in future home prices by mid 2006. Some state-space models can predict an impending downturn as early as June 2005. State-space/structural time series models tend to produce the most accurate forecasts, although they are not necessarily the models with the best in-sample fit.     

论历史逻辑

历史逻辑是以历史时间的历时性和共时性统一为基础的概念推论，研究关于叙述史中基本概念之间的意义关系和推论规则。过去、现在和未来是历史逻辑的基本范畴，“过去-现在-未来”三段式是历史逻辑的基本公式，它是概念逻辑推论三段式“正题-反题-合题”在历史逻辑中的具体形式。历史逻辑研究的目的，是根据特定历史时段的特殊性，建构以不同时段概念为逻辑变项的历史逻辑，预见未来的发展，规划现在的实践。     

The trade-off between fixed vehicle costs and time-dependent arrival penalties in a routing problem

This paper introduces the vehicle routing problem with soft time windows (VRPSTW) in which problem definition differs from ones previously defined in literature. Branch-and-price approach is employed, resulting in a set partitioning master problem and its new subproblem. Novel techniques are consequently developed to solve this new subproblem. Experimental results report the comparisons of these solution techniques under the branch-and-price framework. The VRPSTW solutions have further been compared to the state-of-the-art literature, signifying the superiority of the VRPSTW on this issue.     

Traffic evacuation time under nonhomogeneous conditions

During many manmade and natural crises such as terrorist threats, floods, hazardous chemical and gas leaks, emergency personnel need to estimate the time in which people can evacuate from the affected urban area. Knowing an estimated evacuation time for a given crisis, emergency personnel can plan and prepare accordingly with the understanding that the actual evacuation time will take longer. Given the urban area to be evacuated, street widths exiting the area's perimeter, the area's population density, average vehicle occupancy, transport mode share and crawl speed, an estimation of traffic evacuation time can be derived. Peak-hour traffic data collected at three, midblock, Mumbai sites of varying geometric features and traffic composition were used in calibrating a model that estimates peak-hour traffic flow rates. Model validation revealed a correlation coefficient of +0.98 between observed and predicted peak-hour flow rates. A methodology is developed that estimates traffic evacuation time using the model.     

Effects of time pressure,type of shopping,and store attributes on consumers’ satisfaction with grocery shopping

The aim of this study is to investigate whether satisfaction with grocery stores is affected by type of grocery shopping in conjunction with time pressure, and which attributes are important for satisfaction. Fictitious grocery stores are constructed according to a fractional factorial design by varying access, price level, supply quality/range, and service quality. In an Internet survey, 1023 Swedish consumers rated satisfaction with major vs. fill-in shopping imagining they were under high or low time pressure. The results showed that satisfaction is higher for fill-in shopping than major shopping, that time pressure has no effect on satisfaction, and that price level, service quality, and product quality/range are more important for satisfaction with major shopping, whereas access is more important for satisfaction with fill-in shopping. It is also found that the importance of attributes for satisfaction depends on type of shopping more than on individual characteristics.     

Noisy signaling in discrete time

This paper characterizes the equilibrium set of a dynamic noisy-signaling model in discrete time. A seller privately knows the quality of her asset. She can exert a costly effort to generate stochastic returns. Buyers stochastically arrive over time and, after observing the history of returns, they make price offers. In our model, the equilibrium behavior of the buyers is discontinuous: they only make acceptable (high) offers if the posterior about the quality is above a given threshold. As a result, the recursive nature of the model replicates the discontinuity, giving the equilibrium continuation payoff a complex self-replicating structure that may take the form of a devil’s staircase.     

Tourists’ impulse buying behavior at duty-free shops: the moderating effects of time pressure and shopping involvement

This study investigates the consumer behavior of tourists at duty-free shops who experience different limitations on shopping than do consumers at general shopping malls. The target for sampling was outbound tourists who shopped in two hotel duty-free shops in Seoul, Korea. The final analysis used data from 343 respondents and the results revealed (1) the more positive the emotions felt by tourists, the more impulsive buying behavior occurs; (2) time pressure during shopping reinforces negative emotions, resulting in increased affective impulse buying; and (3) increased shopping involvement directly increases cognitive impulse buying.     

When nature calls: The role of customer toilets in retail stores

The scarce previous literature indicates that the customer toilet facilities influence shopping value and should be a concern for retailers. However, customer toilets are often inadequately capitalised in retail stores. This study aims to provide a scientifically robust argument about the critical role of customer toilets in retail stores. The explanatory survey data (n=655) from a Finnish out-of-town department store is examined to explore (1) the importance that consumers place on the customer toilets and (2) the effect of toilet usage on actual shopping behaviour. The results support the assumptions of previous literature by suggesting that customer toilets are considered as an important store attribute and, more importantly, the use of toilets is associated with prolonged in-store time which, in turn, increases spending. The findings offer both academic and managerial contribution and encourage academics and practitioners to regard customer toilets as more than mere an unwanted property expense and discover their full marketing potential.