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.     

Assembly Line Balancing Using Genetic Algorithms with Heuristic-Generated Initial Populations and Multiple Evaluation Criteria*

We use genetic algorithms (GA) to solve the assembly line balancing (ALB) problem. Inparticular, we show how this technique can be used to generate feasible line balances, improve upon solutions obtained by other heuristics reported in the literature, and utilizeany one or more evaluation criteria that can be expressed in functional form. The procedure is demonstrated with two examples: (1) intimating the improvement of heuristic-generated ALB solutions by including them in the GA initial population, and (2) the possibility of balancing assembly lines with multiple criteria and side constraints. These examples suggest that GA can be a powerful tool in ALB. To investigate the utility of GA on single-criterion problems, an experiment is conducted that compares both the GA approach and conventional heuristics. Results indicate that the GA solutions are significantly improved over the heuristic solutions under the conditions studied. It is also found that the presence of heuristic-generated conventional solutions in the GA initial population leads to statistically preferred results.     

Wealth Inequality in Black and White: Cultural and Structural Sources of the Racial Wealth Gap

Using data from the 2013 Survey of Consumer Finances, this research examines competing and complementary cultural and structural explanations of the sources of racial differences in wealth. We use OLS regression and quantile regression to identify the major individual-level sources of wealth differences between African Americans and whites. Whites have more favorable wealth characteristics than do African Americans on all of the variables in the analysis: gender of household head, bankruptcies, spending patterns, stock ownership, business ownership, home ownership, inheritance, educational attainment, income, occupation, age, and number of children. Cultural factors, having a female-headed family, spending patterns, and inheritance account for little of the racial wealth gap. Racial differences in income, stock ownership, and business ownership account for much of the explained racial wealth gap. Moreover, compared with whites, African Americans receive significantly lower wealth returns to education, age, income, stock ownership, and business ownership. We discuss the implications of our findings.     

全球采购的一些日常问题

在公司走上国际性供应链的舞台之前,应该考虑启动 全球范围的供货商网要付出什么代价 通过确定更具有成本效益的供货 商,全球资源供应能够得到巨大 的节约。但是在公司走上国际性 供应链的舞台之前,他们也应该考虑启动 全球范围的供货商网要付出什么代价。这 似乎很俗,但是如果管理不当,一些日常问 题都可以吞噬你的利润,威胁到你的服务 水平。     

Physical fitness effects on substance abuse risk factors and use patterns

In this study, seventy-four adolescents in either a school, community or hospital based drug intervention program received and eight to nine week structured fitness activity class as an integrated element of their respective prevention or treatment program. Prepost assessments indicated significant gains in the field fitness tests of one mile run, 1 minute situp, 1 minute pushup, percent fat and flexibility for the total sample. Based upon prepost change on the one mile run time (less than 1:00) subjects were categorized as improvers (n = 38) and non-improvers (n = 36). Improvers demonstrated a significant increase in the self concept risk factor (Piers Harris Self Concept Scale) and a significant decrease in anxiety and depression risk factors (General Well-Being Scale) compared to the non-improvers. At posttest, the improvers self reported substance use patterns were significantly lower compared to the non-improvers for percentage of the sample who were multiple drug users and alcohol uses per week and were significantly higher for the percentage of the sample demonstrating total abstinence. These findings are suggestive of the usefulness of physical training as a supplemental intervention for adolescent substance abusers.     

谁会促进你的事业？

你必须分清谁的工作重点与你一致,谁跟你不一致谁会帮助你得到你想要的结果?对每个经理人来说,这都是一个关键问题。要回答这个问题,你必须能够分清谁的工作重点与你相一致,谁跟你不一致。但我们中很少有人使用自己可以支配的工具这样去做。运用同理心进行思考与哈佛商学院教授霍华德·史蒂文森合著《自己敲开机会的门》一书的艾琳·夏皮罗(Eileen Shapiro)称,要确定谁最有可     

Larkin Street Youth Services: helping kids get off the street for good (1982-2007)

Larkin Street Youth Services is a pioneering nonprofit organization that was established in 1981 to serve the growing urban homeless and runaway youth population. What began as a neighborhood effort has evolved into a $12 million organization over the course of its 25-year history. Larkin Street Youth Services delivers a continuum of services to homeless youth including counseling, housing, education, employment, and HIV services. The agency has received significant local and national attention for the success of its targeted program model and continuum of care services. The history of Larkin Street Youth Services provides an example of the important role of internal operations in an agency's ability to re-invent itself and respond to a larger community need.     

IT security planning under uncertainty for high-impact events

While many IT security incidents result in relatively minor operational disruptions or minimal recovery costs, occasionally high-impact security breaches can have catastrophic effects on the firm. Unfortunately, measuring security risk and planning for countermeasures or mitigation is a difficult task. Past research has suggested risk metrics which may be beneficial in understanding and planning for security incidents, but most of these metrics are aimed at identifying expected overall loss and do not directly address the identification of, or planning for, sparse events which might result in high-impact loss. The use of an upper percentile value or some other worst-case measure has been widely discussed in the literature as a means of stochastic optimization, but has not been applied to this decision domain. A key requirement in security planning for any threat scenario, expected or otherwise, is the ability to choose countermeasures optimally with regard to tradeoffs between countermeasure cost and remaining risk. Most of the planning models in the literature are qualitative, and none that we are aware of allow for the optimal determination of these tradeoffs. Therefore, we develop a model for optimally choosing countermeasures to block or mitigate security attacks in the presence of a given threat level profile. We utilize this model to examine scenarios under both expected threat levels and worst-case levels, and develop budget-dependent risk curves. These curves demonstrate the tradeoffs which occur if decision makers divert budgets away from planning for ordinary risk in an effort to mitigate the effects of potential high-impact outcomes.