工程项目中业主初始信任对合作的影响研究:承包商公平感知的中介作用

基于工程项目临时性社会网络组织的本质特征,从社会交换的视角,通过理论分析构建了以业主初始信任为前因、承包商对于合同的公平感知为中介、合作为结果的概念模型,并以68个财政投资项目为样本采集到162套有效数据,运用结构方程模型的方法进行实证检验。研究表明:业主初始信任对于承包商公平感知的形成具有显著的正向影响;承包商的程序公平正向影响其分配公平,二者均对合作具有显著的正向影响;承包商公平感知在业主初始信任与合作之间起到部分中介作用。     

Competitive analysis for make-to-order scheduling with reliable lead time quotation

This paper makes extended studies on the discrete problem of online scheduling and reliable lead time quotation (discrete Q-SLTQ) introduced by Keskinocak et al. (Manag. Sci. 47(2):264–279, 2001). We first relax the assumption on revenue function from a linear decreasing function to any decreasing function. We present an online deterministic strategy which is optimal in competitiveness for concave revenue functions. The above results are further extended to the continuous Q-SLTQ model where orders are released at arbitrary time points. For the discrete Q-SLTQ problem, if orders are with nonuniform lengths, we prove the nonexistence of online strategies with bounded competitive ratios; otherwise if orders are with unit length but various weights, we present an optimal online strategy.     

Exposure Reconstruction for the TCDD-Exposed NIOSH Cohort Using a Concentration- and Age-Dependent Model of Elimination

Recent studies demonstrating a concentration dependence of elimination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) suggest that previous estimates of exposure for occupationally exposed cohorts may have underestimated actual exposure, resulting in a potential overestimate of the carcinogenic potency of TCDD in humans based on the mortality data for these cohorts. Using a database on U.S. chemical manufacturing workers potentially exposed to TCDD compiled by the National Institute for Occupational Safety and Health (NIOSH), we evaluated the impact of using a concentration- and age-dependent elimination model (CADM) (Aylward et al., 2005) on estimates of serum lipid area under the curve (AUC) for the NIOSH cohort. These data were used previously by Steenland et al. (2001) in combination with a first-order elimination model with an 8.7-year half-life to estimate cumulative serum lipid concentration (equivalent to AUC) for these workers for use in cancer dose-response assessment. Serum lipid TCDD measurements taken in 1988 for a subset of the cohort were combined with the NIOSH job exposure matrix and work histories to estimate dose rates per unit of exposure score. We evaluated the effect of choices in regression model (regression on untransformed vs. ln-transformed data and inclusion of a nonzero regression intercept) as well as the impact of choices of elimination models and parameters on estimated AUCs for the cohort. Central estimates for dose rate parameters derived from the serum-sampled subcohort were applied with the elimination models to time-specific exposure scores for the entire cohort to generate AUC estimates for all cohort members. Use of the CADM resulted in improved model fits to the serum sampling data compared to the first-order models. Dose rates varied by a factor of 50 among different combinations of elimination model, parameter sets, and regression models. Use of a CADM results in increases of up to five-fold in AUC estimates for the more highly exposed members of the cohort compared to estimates obtained using the first-order model with 8.7-year half-life. This degree of variation in the AUC estimates for this cohort would affect substantially the cancer potency estimates derived from the mortality data from this cohort. Such variability and uncertainty in the reconstructed serum lipid AUC estimates for this cohort, depending on elimination model, parameter set, and regression model, have not been described previously and are critical components in evaluating the dose-response data from the occupationally exposed populations.     

Consumer-Phase Salmonella enterica serovar Enteritidis Risk Assessment for Egg-Containing Food Products

We describe a one-dimensional probabilistic model of the role of domestic food handling behaviors on salmonellosis risk associated with the consumption of eggs and egg-containing foods. Six categories of egg-containing foods were defined based on the amount of egg contained in the food, whether eggs are pooled, and the degree of cooking practiced by consumers. We used bootstrap simulation to quantify uncertainty in risk estimates due to sampling error, and sensitivity analysis to identify key sources of variability and uncertainty in the model. Because of typical model characteristics such as nonlinearity, interaction between inputs, thresholds, and saturation points, Sobol's method, a novel sensitivity analysis approach, was used to identify key sources of variability. Based on the mean probability of illness, examples of foods from the food categories ranked from most to least risk of illness were: (1) home-made salad dressings/ice cream; (2) fried eggs/boiled eggs; (3) omelettes; and (4) baked foods/breads. For food categories that may include uncooked eggs (e.g., home-made salad dressings/ice cream), consumer handling conditions such as storage time and temperature after food preparation were the key sources of variability. In contrast, for food categories associated with undercooked eggs (e.g., fried/soft-boiled eggs), the initial level of Salmonella contamination and the log10 reduction due to cooking were the key sources of variability. Important sources of uncertainty varied with both the risk percentile and the food category under consideration. This work adds to previous risk assessments focused on egg production and storage practices, and provides a science-based approach to inform consumer risk communications regarding safe egg handling practices.     

IT安全系统安全效能评估模型

建立了对IT安全系统的安全效能进行评估的安全效能评估模型,该模型具有简单、客观、节省资源和时间、量化了系统安全性、评估结果直观的特点,与通用评估准则不同,从另一个角度来评价IT安全系统的安全性.     

基于银行-资产双边网络模型的系统性风险及投资策略研究

受近几年的国际金融危机及金融全球化的影响,对金融系统的系统性风险的研究已成为国内外学者的关注热点。考虑到当前基于"银行-资产-银行"间接传播渠道的相关研究相对匮乏,本文基于银行-资产双边网络模型来分析银行系统性风险。首先,使用中国47家上市银行2018年的资产负债表数据构建了中国银行系统的双边网络模型,研究分析各类资产遭受冲击时外部冲击、降价出售效应及银行所持有的各类资产占银行总资产的比例对银行系统性风险的影响。然后,引入系统性冲击方式,通过设置具有不同属性的两大类资产并生成四种冲击事件来构建银行的投资策略模型,从资产视角探讨银行最优的投资策略。研究发现,外部冲击与降价出售效应这两个产生系统性风险的影响因素在一定区间值时会产生叠加效应,使银行系统性风险急剧增加;五种资产类中,贷款类资产对外部冲击最敏感;分析发现在各类资产冲击下都未倒闭的所有银行的资产组合具有一定的相似性;进一步研究发现银行系统中存在着最优的资产组合,使得银行在稳定的同时能获取最大收益,并且资产负债比越大的银行其风险承受能力越强,从而可以选择更激进的投资策略来追求高收益。     

单次服务过程中新老顾客质量感知波动的差异分析

服务经济时代,越来越多的顾客开始参与到多阶段化的服务活动中,服务质量管理需要区分新老顾客阶段感知服务质量的波动差异.本文旨在探讨单次服务过程中,面对同样变化幅度的传递服务质量,新顾客和老顾客感知服务质量波动的差异情况.在构建一个三阶段服务质量更新模型基础上,本文以酒店服务为模拟情境,设计了一个三阶段服务过程的行为实验进行分析.研究结果显示,新顾客感知服务质量的变化更容易受到传递服务质量变化的影响,老顾客则更多受到先前消费经验的左右;不同阶段感知服务质量共同影响总体服务质量,尤其是最后阶段感知服务质量的影响更为突出.服务企业应针对不同的顾客群体采取相应的服务质量管理策略.     

我国代工企业制造战略与人力资源管理系统的匹配对企业绩效的影响

通过配置理论总结了制造战略、HRM系统与企业绩效关系的假设,并以广东214家代工企业为研究对象,对假设进行实证检验.研究表明,采用大规模服务者和质量定制者战略的企业更倾向于内部型HRM系统,采用专业化承包者战略的企业更倾向于混合型HRM系统,采用对竞争漠不关心者战略的企业更倾向于市场型HRM系统.制造战略与HRM系统匹配的企业,其HRM绩效高于不匹配的企业.     

Dynamic selection of dispatching rules for job shop scheduling

Although the academic contribution to job shop scheduling is abundant, its impact on practice has been minimal. The most preferred approach to job shop scheduling in the industry is dispatching rules. A major criticism against dispatching rules is that there is no single universal rule. The effective choice of dispatching rules depends on the scheduling criterion and existing job shop conditions. In this paper, the authors have proposed a scheduling method based on the analytic hierarchy process, that dynamically selects the most appropriate dispatching rule from several candidate rules. The selection is based on the existing job shop conditions. This method is applied to two formal job shop problems, and the results for single dispatching rules are inferior to the method proposed in this paper.     

有限产能下单向替代的闭环供应链定价模型研究

本文分析存在产品替代策略的情况下,闭环供应链在有限产能及废旧物品回收数量有限条件下的最优定价策略,分别得出四种不同情形下的最优定价策略与利润情况。同时,分析产能限制及废旧物品回收数量限制两个条件对最优定价决策与利润水平的影响,并通过数值试验进行验证。