Optimal Purchase and Transportation Cost Lot Sizing for a Single Item

A review of the literature indicates that the traditional approach for evaluating quantity discount offerings for purchased items has not adequately considered the effect that transportation costs may have on the optimal order quantity; despite the general fact that purchased materials must bear transportation charges. The transportation cost structure for less-than-truckload (LTL) shipments reflects sizable reductions in freight rates when the shipment size exceeds one of the nominal rate breakpoints. However, the shipper must also be aware of the opportunity to reduce total freight costs by artificially inflating the actual shipping weight to the next rate breakpoint, in order that a lower marginal tariff is achieved for the entire shipment. Such over-declared shipments result in an effective freight rate schedule that is characterized by constant fixed charge segments in addition to the nominal marginal rates. Over-declared shipments are economical when the shipment volume is less than the rate breakpoint, but greater than a cost indifference point between the two adjacent marginal rates. This paper presents a simple analytical procedure for finding the order quantity that minimizes total purchase costs which reflect both transportation economies and quantity discounts. After first solving for the series of indifference points that apply to a particular freight rate schedule, a total purchase cost expression is presented that properly accounts for the actual transportation cost structure. The optimal purchase order quantity will be one of the four following possibilities: (1) the valid economic order quantity (EOQ), QC; (2) a purchase price breakpoint in excess of QC; (3) a transportation rate breakpoint in excess of QC; and (4) a modified EOQ which provides an over-declared shipment in excess of QC. Finally, an algorithm which systematically explores these four possibilities is presented and illustrated with a numerical example.     

RESOURCE PLANNING FOR MULTIPLE PROJECTS *

This paper is concerned with the estimation of the resource requirements to service multiple projects that use many types of resources. It reports on a systematic procedure to determine the low cost levels of these resources, focusing on the two following characteristics: (1) the comparative cost of standard time to overtime in the utilization of these resources for the economical completion of the projects, and (2) the impact of highly expensive equipment in the determination of the economic levels of the manpower resources that combine with the equipment to form a crew. A numerical example is also presented to illustrate the method. Resource planning is of particular interest in the area of multiproject scheduling, since most of the commonly utilized heuristic solution approaches focus on the allocation of a limited set of available resources. In the corporate strategic planning functions, resource planning is particularly important for capital investment, training and development, and procurement scheduling.     

AN EVALUATION OF FORECAST ERROR IN MASTER PRODUCTION SCHEDULING FOR MATERIAL REQUIREMENTS PLANNING SYSTEMS.

Typical forecast-error measures such as mean squared error, mean absolute deviation and bias generally are accepted indicators of forecasting performance. However, the eventual cost impact of forecast errors on system performance and the degree to which cost consequences are explained by typical error measures have not been studied thoroughly. The present paper demonstrates that these typical error measures often are not good predictors of cost consequences in material requirements planning (MRP) settings. MRP systems rely directly on the master production schedule (MPS) to specify gross requirements. These MRP environments receive forecast errors indirectly when the errors create inaccuracies in the MPS. Our study results suggest that within MRP environments the predictive capabilities of forecast-error measures are contingent on the lot-sizing rule and the product components structure When forecast errors and MRP system costs are coanalyzed, bias emerges as having reasonable predictive ability. In further investigations of bias, loss functions are evaluated to explain the MRP cost consequences of forecast errors. Estimating the loss functions of forecast errors through regression analysis demonstrates the superiority of loss functions as measures over typical forecast error measures in the MPS.     

论孙中山民权思想对中国传统民本思想的继承和展开

作者通过对中国传统民本思想与孙中山民权思想在追求的目标、人群划分的理论及君子与先知先觉者的社会义务三大方面的具体对比,认为孙中山的民权思想在价值法则上继承了中国传统的民本思想资源,是民本思想在当时社会背景下的自然展开,从而厘清了孙中山民权思想的渊源。     

日本电影产业的经济学分析

运用一个国内市场的经济学模型,来阐释美日两国电影产业之间不断变化的竞争平衡关系,可以验证如下假设,即日本的国产电影市场份额减少是因为对美国电影消费的增长速度超过对日本本国电影的消费速度。根据美日媒体产业发展的数据资料（1955－2000）得出的结论支持了这一经济学假设。     

Children’s Resilience-Related Beliefs as a Predictor of Positive Child Development in the Face of Adversities: Implications for Interventions to Enhance Children’s Quality of Life

This paper reports the findings of a longitudinal childhood resilience study which investigated the relationship between resilience-related beliefs and positive child development. Three waves of data collection (T1, T2, and T3) were completed in January 2005, July 2005, and January 2006 with a sample of 843 grade 4 pupils, drawn from six primary schools in Hong Kong, and their parents or guardians. At T1, parents/guardians responded to a 24-item inventory of life adversities affecting their children since birth; at T1 and T3, they completed a 25-item Parental Assessment of Child’s Habit, which provided parental evaluation of children’s performance at home and in school. At T1, T2, and T3, children responded to a 58-item Child and Youth Resilience Measure, a 9-item scale on Chinese cultural beliefs about adversity, and an 11-item Chinese Resilience Measure for Children and Adolescents in Hong Kong. Regression analyses, based on linear mixed models, controlling for gender, T1 and T2 scores, personal variables, and random effects of schools, were conducted to test and validate the hypothesis that children’s resilience beliefs are predictive of positive child development, and that this predictive relationship is stronger with increasing adversity in children’s lives. Implications of these findings for the development of resilience-based interventions to enhance the quality of life of children facing adversities are examined.     

A Multilevel Analysis of Factors Related to Poverty in Welfare States

This study aims to investigate factors contributing to poverty, one of the most significant social problems in Western societies. To this end, 13 countries that have made a variety of efforts to reduce poverty, and therefore experienced similar development processes related to welfare, were selected. To overcome the methodological limitations of previous studies, the study utilized a Hierarchical Generalized Linear Model to simultaneously analyze individual-level and state-level factors that might affect the poverty status of a household, employing household data from the fifth wave of Luxembourg Income Study and Comparative Welfare State data. By comparing the magnitude of individual- and state-level effects in the analysis process, the model can empirically illuminate which of the two levels is more responsible for households’ destitution. Furthermore, by analyzing the level of and characteristics of poverty in each country, this study examines whether there are discrepancies in the level of poverty across types of welfare states and what factors contribute to these discrepancies.     

Quality of College Life (QCL) of Students: Further Validation of a Measure of Well-being

This paper reports a study designed to further validate a measure of quality of college life (QCL) of university students (Sirgy, Grzeskowiak, Rahtz, Soc Indic Res 80(2), 343–360, 2007). Two studies were conducted: a replication study and an extension study. The replication study involved surveys of 10 different college campuses in different countries. The results of the replication study provided additional nomological (predictive) validation support of the measure based on a theoretical model mapping out the antecedents and consequences of satisfaction with college life. With respect to the extension study, the focus was to further test the nomological validity of the QCL measure by arguing and empirically demonstrating that the consequence of QCL is life satisfaction. The extension study involved a survey of three college campuses in different countries. The results were also supportive of the nomological validity of the QCL measure.     

What Encourages Nonprofits' Adoption of Good Governance Policies?

This study examines how nonprofits' external environments and organizational characteristics explain their likelihood of having written policies for good governance. Findings from the 2010 data of the National Center for Charitable Statistics show that state requirements for registration and annual reporting are not related to a nonprofit's likelihood of adopting such written policies. The results instead indicate that organizations that engage in lobbying activities and operate in metropolitan areas are more likely to have good governance standards. Most of all, the analysis shows that organizational resources, both financial and human, explain differences in the adoption of these policies. These findings suggest that the nonprofit community should collectively invest in building the infrastructure that helps smaller organizations develop good governance policies and, hence, stay competitive.     

Contributions of Child Sexual Abuse,Self-Blame,Posttraumatic Stress Symptoms,and Alcohol Use to Women’s Risk for Forcible and Substance-Facilitated Sexual Assault

Child sexual abuse and adult sexual assault have been linked to increased self-blame, posttraumatic stress symptoms, and alcohol use. The current study aims to examine (a) whether these constructs explain women’s risk for later adult sexual assault and revictimization, (b) whether such factors differentially confer risk for specific types of adult sexual assault (i.e., substance-facilitated and forcible), and (c) if self-blame confers risk indirectly through other risk factors. Multiple types of self-blame, posttraumatic stress, and alcohol use were examined among 929 female college students as serial mediators of the relationship between child sexual abuse and adult sexual assault and as risk factors for sexual revictimization among child sexual abuse survivors. In the model predicting risk for substance-facilitated adult sexual assault, child sexual abuse indirectly predicted greater risk for substance-facilitated adult sexual assault mediated through two separate paths: global blame-to-posttraumatic-stress and global blame-to-alcohol use. In the model predicting risk for forcible adult sexual assault, child sexual abuse directly predicted greater risk for forcible adult sexual assault, and this relation was mediated by the global blame-to-posttraumatic-stress path. Among child sexual abuse survivors, child sexual abuse specific characterological and behavioral self-blame directly predicted greater risk for forcible and substance-facilitated revictimization, but the pathways were not mediated by posttraumatic stress or alcohol use. Results emphasize the importance of assessing different types of self-blame in predicting posttraumatic stress symptoms as well as examining risk for sexual victimization and revictimization. Findings did not support hypotheses that increased posttraumatic stress would predict increased alcohol use but did indicate that heightened self-blame is consistently associated with heightened posttraumatic stress and that heightened global self-blame predicts increased alcohol use. Implications for future research and intervention are discussed.