时变路网无能力约束车辆路径优化

讨论了一类时变路网下的无能力约束车辆配送路径优化问题,建立了基于时变路网的以配送总耗时最短为优化目标的无能力约束车辆配送路径优化模型。提出了基于实时Dijkstra算法的模型求解方法。数值算例表明考虑路网时变特性得到的优化配送方案将更加符合配送实际。     

Discovering latent commercial networks from online financial news articles

Unlike most online social networks where explicit links among individual users are defined, the relations among commercial entities (e.g. firms) may not be explicitly declared in commercial Web sites. One main contribution of this article is the development of a novel computational model for the discovery of the latent relations among commercial entities from online financial news. More specifically, a CRF model which can exploit both structural and contextual features is applied to commercial entity recognition. In addition, a point-wise mutual information (PMI)-based unsupervised learning method is developed for commercial relation identification. To evaluate the effectiveness of the proposed computational methods, a prototype system called CoNet has been developed. Based on the financial news articles crawled from Google finance, the CoNet system achieves average F-scores of 0.681 and 0.754 in commercial entity recognition and commercial relation identification, respectively. Our experimental results confirm that the proposed shallow natural language processing methods are effective for the discovery of latent commercial networks from online financial news.     

直觉梯形模糊几何集成算子及其在群决策中的应用

文章首先定义了直觉梯形模糊数及其运算法则,基于这些运算法则,给出了直觉梯形模糊几何集成算子,即直觉梯形模糊加权几何(IT-WG)算子、直觉梯形模糊有序加权几何(IT-OWG)算子以及直觉梯形模糊混合几何(IT-HG)算子。在此基础上,提出了在属性权重已知的情形下专家评价值以直觉梯形模糊信息给出的多属性群决策方法。最后以产品最优设计方案的选择为实例进行分析,所得结果验证了该方法的有效性。     

多轴轮式车辆操纵稳定性试验研究

汽车操纵稳定性试验和评价方法不能完全适用于多轴车辆,制定和完善多轴车辆的操纵稳定性试验方法具有现实意义。针对某前四轮转向四轴车辆,制定了操纵稳定性试验方案,进行了定半径稳态回转试验、蛇行试验和转向盘转角脉冲输入试验,对该车稳态与瞬态转向特性进行了评价,为多轴车辆操纵稳定性试验与评价的科学化与规范化奠定了基础。     

基于迭代列消元法的线性分组码参数盲识别

针对线性分组码参数盲识别容错性能差的问题,提出基于迭代列消元法的线性分组码参数盲识别方法。首先对截获矩阵应用迭代列消元法,将其相关列对应各个窗内的转移矩阵中的列向量作为候选校验向量,再根据截获矩阵对偶码空间归一化维数来识别码字长度和同步时刻,最后将对偶码字进行初等行变换识别校验矩阵。仿真结果证明,与以往盲识别方法相比,所提方法容错性能好,适用于各种码率的线性分组码的码字长度、同步时刻和生成多项式识别。     

E-Shopping Patterns of Chinese and US Millennials

A conceptually based taxonomy of 22 distinct forms of e-shopping vehicles is proposed. A modification of the UTAUT and UTAUT2 models is introduced to explain how vehicles are interrelated in regard to consumer reliance upon them for their e-purchasing. A survey of over 1,000 millennial university students, 697 Chinese and 306 US, revealed strong support in both samples for the hypothesized six dimensional pattern underlying consumer vehicular reliance. Further, differences between Chinese and US samples lay not in the nature of the dimensions, but rather in the strength of reliance upon each dimension. Thus, the study demonstrates the utility of the concept/measure of shopper vehicular reliance, VPR (Vehicle Purchasing Reliance) for both practitioners and scientists. In cross-national comparisons, observed differences between samples in strength of reliance supported four of five hypotheses predicated on previously established national distinctions a) in trust and b) in the cultural value of individualism-collectivism.     

创业导向、外部知识获取与创业机会识别

创业活动是创新、就业和经济增长的重要来源。企业家通过持续探索创造新业务,促进社会和经济的发展和繁荣。本文基于资源基础理论和知识基础理论,以大众创业浪潮为研究背景,深入揭示创业导向、外部知识获取与创业机会识别之间的关系,并以中国246份创业新企业为样本进行了实证研究。研究结果表明：创业导向对新企业的机会识别和外部知识获取均具有积极影响;外部知识获取在创业导向和新企业的机会识别之间起到部分中介作用;此外,市场知识获取比技术知识获取对创业机会识别的影响更为突出。     

基于效应的随机灰规划模型和应用

为了解决同时含有随机因素和灰色因素的不确定规划问题,通过结合区间灰数所属区间两个端点的随机性,给出随机区间灰数和随机区间灰函数的定义,提出了随机灰规划模型。通过综合效应函数理论用随机变量期望值和方差综合量化表示灰数所属区间的两个端点值。应用该理论对综合量化后的两个端点值继续进行综合量化,从而将随机灰规划转化为确定型规划问题。应用遗传算法进行求解。通过综合效应函数的理念,综合随机变量的期望和方差,同时综合区间灰数的区间因素,将随机灰规划数学模型转化为确定型规划模型即基于效应的随机灰规划模型。通过选取不同的综合效应函数,得到了关于不同决策意识下的随机灰规划的最优解。这个方法可为决策者进行不确定决策提供参考。     

A novel decision support model for satisfactory restaurants utilizing social information: A case study of TripAdvisor.com

Decision support models for satisfactory restaurants have attracted numerous researchers' attention. Many extant models do not consider the active, neutral and passive information in online reviews all at once. Moreover, they ignore the effect of interdependence among criteria on tourists' decision-making. To cover these defects, this study proposes a restaurant decision support model using social information for tourists on TripAdvisor.com. The model introduces fuzzy sets to denote online reviews and utilizes Bonferroni mean to consider interdependence among criteria. Furthermore, it uses a novel similarity measurement which can handle sparse data in fuzzy environments. To validate the model, we conduct a case study of TripAdvisor.com which compares the proposed model with four other models. The performance of each model is evaluated by the metric called the mean absolute error. The study shows that the proposed model can effectively support tourists' decision-making and it performs better than the other four models.     

Assessing greenhouse gas emissions from electric vehicle operation in Australia using temporal vehicle charging and electricity emission characteristics

ABSTRACT

Significant interest exists in the potential for electric vehicles (EVs) to be a source of greenhouse gas (GHG) abatement. In order to establish the extent to which EVs will deliver abatement, however, a realistic understanding of the electricity and transport sector GHG emissions impacts arising from different approaches to integrating EVs into the power system is required. A key issue in this regard is the extent to which GHG emissions are a function of where and when EV charging will be enabled (or disabled) by the provision of recharging infrastructure and implementation of charging management strategies by the electricity industry. This article presents an investigation of the GHG emissions arising from electricity and gasoline consumption by plug-in hybrid EVs under a range of standard EV-power system integration scenarios. An assessment framework is presented, and GHG emissions from EV use are assessed for the New South Wales (NSW) and South Australian (SA) pools of the Australian National Electricity Market (NEM) using retrospective electricity system generation data for 2011. Results highlight that there is a range of possible outcomes depending on the integration scenario and emissions accounting approach used. This range illustrates value of a temporally explicit assessment approach in capturing the temporal alignment of electricity sector emission intensity and EV charging. Results also show the importance of a clean electricity generation mix in order for EVs to provide a GHG abatement benefit beyond what would be achieved by a hybrid (but non-plug-in) vehicle. The extent to which overnight charging in NSW is observed to produce higher emissions relative to unmanaged charging also illustrates a possible trade-off between GHG emissions and benefits for electricity industry from EV charging at times of low demand.