A SIMULATION ANALYSIS OF THE JAPANESE JUST-IN-TIME TECHNIQUE (WITH KANBANS) FOR A MULTILINE,MULTISTAGE PRODUCTION SYSTEM

The Japanese “just-in-time with kanban” technique reduces in-process inventory to absolute minimal levels, in concert with the Japanese belief that inventory is an unnecessary evil. Due to the success of Japanese firms that employ this type of system, American firms would like to import this technique and emulate Japanese successes. But this Japanese success may be attributable not only to the just-in-time with kanban technique but also to the production environment in which the technique is employed. This paper simulates the just-in-time with kanban technique for a multiline, multistage production system in order to determine its adaptability to an American production environment that might include such characteristics as variable processing times, variable master production scheduling, and imbalances between production stages. The results have practical implications for those firms considering adoption of the Japanese technique.     

SOME COMMENTS ON “A SYSTEMS PERSPECTIVE ON MATERIALS REQUIREMENTS PLANNING”*

We believe there are some serious deficiencies in the Morecroft article on MRP problems which appeared in a recent issue of this journal. The article, at the most, shows that MRP, inappropriately imposed on an existing production system, can result in undesirable system performance. This does not represent a new or startling conclusion. Four problem areas in the article are discussed, and suggested alternative approaches are offered.     

if条件句与充分条件性——if构块式理据的研究

多种不同的语义关系都可以进入if条件句,Sweetser提出三域进行分析;这一分析细致深入,但略嫌共性概括不足.充分条件性是if构块式大家族的背后同一理据的假设;据此,if条件句大家族分为两大构块式群,下分四小类.这个大家族是一个典型范畴,第一小类典型条件句作为充分条件假言判断的语言表达形式是最典型的成员,以下各小类向着边缘成员演变,构成了一个连续统.对if条件句的理解,要通过常规推理,将从句一主句的关系补足为充分条件同其结果的关系.if条件句的多种意义最后都可回归到充分条件性,这就是各类if条件句最后都可归入if构块式大家族的同一理据.这一研究再一次表明了含意本体论的常规关系和常规推理理论在研究构块式的理据方面可能起的作用.     

THE HARMS SHOE COMPANY: DEVELOPMENT OF A COMPUTER MODEL FOR THE CLASSROOM

This paper describes a case that examines five key topics in production and operations management [1]—forecasting, inventory control, transportation planning, aggregate planning, and the disaggregation of the aggregate plan—in an integrated, realistic manner for upper-level undergraduate business majors [3]. The case structure stresses the linkage of these interrelated subjects and supplements the regular classroom presentations dealing with them. The case relies on computer calculations at each stage to provide the information input for calculations at the next stage. It is a static model with a twelve-month planning horizon. Students complete several exercises and assume several roles as the case unfolds. They act on their own in filling some roles and as members of teams in performing others. They do not compete with each other, as the purpose of the case is to help them develop an appreciation of the factors that persons performing the role must consider.     

氧化石墨的合成及其结构研究

在Hummer法的基础上合成了氧化石墨、对氧化石墨的组成、分子结构及其还原性进行了测试与分析,结果表明,氧化石墨结构中含有大量的极性基因,这些基因的存在赋予了氧化石墨在极性溶剂中有良好的溶剂化能力。     

从胡文化“汉化”看生态环境的迁移对文化转型的影响

不同文化特质的形成 ,除受政治经济影响外 ,还受特定生态环境的制约。胡汉两大文化体系的差异 ,在很大程度上就是不同生态环境作用的结果。与此相应 ,文化的发展一旦脱离了与自身相适应的环境 ,就势必要出现势能上的劣势 ,并逐渐与异地文化相溶     

What are you thinking? Acculturation as an activating event for negative evaluative beliefs among Latinos/as

Negative evaluative beliefs and other cognitive structures have been tied to psychological distress across various populations but have not been sufficiently incorporated into acculturation models. The current study examines the relationships between acculturation and various activating events and mediating sources of support related to negative evaluative beliefs among people of Mexican descent (N = 319). Overall, model variables explained 26% of the variance in negative evaluative beliefs. Acculturation, marital commitment, and social capital associated with friends were negatively related to negative evaluative beliefs. Conversely, single relationship status, marital reward value, psychosocial stressors, and bridging social capital were positively related, and likely serve as activating events for negative evaluative beliefs. Identifying mechanisms related to psychological distress as well as supportive structures may help in constructing interventions that will address the specific needs of different groups. Future research should continue to explore appraisal and associated beliefs in acculturation models to understand why acculturative experiences may become stressful.     

Eye-tracking methodology: exploring the processing of question formats in web surveys

In social research, the use of agree/disagree (A/D) questions is a popular method for measuring attitudes. Research has shown that A/D questions require complex cognitive processing and are susceptible to response bias. Thus, some researchers recommend the use of item-specific (IS) questions. This study examines the processing of A/D and IS questions, using eye-tracking methodology. By recording respondents’ eye movements, how respondents process survey questions can be evaluated. The results reveal that IS questions cause more and longer fixations. However, this only applies to the response categories. There are no differences regarding the question stems. Altogether, it seems that IS response categories trigger deeper cognitive processing than A/D response categories.     

Parents’ perspectives of social support and social cohesion in urban contexts of diversity

Although provisions for young children are increasingly considered as ideal places to foster an inclusive and socially just society by embracing issues of social support and social cohesion, there is no in-depth understanding of the role these provisions can play in enabling supportive and cohesive encounters in contexts of diversity. Even more striking is the absence of parents’ voices in this discussion. Based on an analysis of qualitative interviews with 18 parents who use childcare services in urban contexts of diversity, our findings show the relevance of ephemeral contacts with diverse people that could offer bridging opportunities in terms of social connectedness to familiarise within diversity while decoding the other in urban contexts of diversity. However, neither bonding nor bridging contacts appear as self-evident. Our research shows that the role of childcare services might be vital in creating light and temporal communities as the prerequisite for social cohesion to flourish, in both individual as well as collective dimensions.