Push-Kanban – a kanban-based production control concept for job shops

Job-shop production in an individual and small-batch manufacturing environment demands producing simultaneously different products in many customised versions and in small numbers. The associated variability of the time-phased work content leads to a high degree of complexity and turbulence in the manufacturing process of such a production type. Therefore, production control becomes significantly more complicated, and many theories on how to cope fail in the real world. Despite the many technological and conceptual advances in the field of job-shop control over the past few decades, there is still a remarkable lack of practical control approaches for job-shop production. For this reason the Push-Kanban production control concept will be introduced in this article. It combines robust push scheduling along with a kanban-driven, decentralised inventory control mechanism to create a holistic control approach, integrating all production control tasks. Thus, it offers a feasible option for controlling job-shop production in industrial practice. This article examines the effectiveness of the concept by means of a simulation study based on real data.     

"广松哲学"的发生学研究

日本哲学家广松涉认为,中国与日本可以相互协作,发掘出与欧洲的“实体主义”相对应的、在亚洲生长起来的“关系主义”思想,并将之体系化。当今,我们面临着近代世界观的全面的解体期,必须扬弃“近代”世界观的根本图式本身,从认识论的立场来说,就是要超越近代的“主观-客观”图式,建构新的认识论。同时,可以从对近代世界观的超越这一观点来重新理解马克思,从而探讨超越“人本主义”与“科学主义”对立的途径。     

Performance characteristics of the adjusted r2 algorithm for determining the start of the terminal disposition phase and comparison with a simple r2 algorithm and a visual inspection method

The adjusted r² algorithm is a popular automated method for selecting the start time of the terminal disposition phase (t_z) when conducting a noncompartmental pharmacokinetic data analysis. Using simulated data, the performance of the algorithm was assessed in relation to the ratio of the slopes of the preterminal and terminal disposition phases, the point of intercept of the terminal disposition phase with the preterminal disposition phase, the length of the terminal disposition phase captured in the concentration‐time profile, the number of data points present in the terminal disposition phase, and the level of variability in concentration measurement. The adjusted r² algorithm was unable to identify t_z accurately when there were more than three data points present in a profile's terminal disposition phase. The terminal disposition phase rate constant (λ_z) calculated based on the value of t_z selected by the algorithm had a positive bias in all simulation data conditions. Tolerable levels of bias (median bias less than 5%) were achieved under conditions of low measurement variability. When measurement variability was high, tolerable levels of bias were attained only when the terminal phase time span was 4 multiples of t_1/2 or longer. A comparison of the performance of the adjusted r² algorithm, a simple r² algorithm, and t_z selection by visual inspection was conducted using a subset of the simulation data. In the comparison, the simple r² algorithm performed as well as the adjusted r² algorithm and the visual inspection method outperformed both algorithms. Recommendations concerning the use of the various t_z selection methods are presented.     

Criteria for reporting noncompartmental estimates of half‐life and area under the curve extrapolated to infinity

Various criteria have been proposed for determining the reliability of noncompartmental pharmacokinetic estimates of the terminal disposition phase half‐life (t_1/2) and the extrapolated area under the curve (AUC_extrap). This simulation study assessed the performance of two frequently used reportability rules: the terminal disposition phase regression adjusted‐r² classification rule and the regression data point time span classification rule. Using simulated data, these rules were assessed in relation to the magnitude of the variability in the terminal disposition phase slope, the length of the terminal disposition phase captured in the concentration‐time profile (data span), the number of data points present in the terminal disposition phase, and the type and level of variability in concentration measurement. The accuracy of estimating t_1/2 was satisfactory for data spans of 1.5 and longer, given low measurement variability; and for spans of 2.5 and longer, given high measurement variability. Satisfactory accuracy in estimating AUC_extrap was only achieved with low measurement variability and spans of 2.5 and longer. Neither of the classification rules improved the identification of accurate t_1/2 and AUC_extrap estimates. Based on the findings of this study, a strategy is proposed for determining the reportability of estimates of t_1/2 and area under the curve extrapolated to infinity.     

Our common future: a rapidly growing and rapidly aging humankind

Abstract

Physical inactivity, diabetes, hypertension, dyslipidemia, smoking and obesity were associated with imbalance in oxidative stress, leading to endothelial dysfunction. Such dysfunction is present in both cardiovascular disease (CVD) and erectile dysfunction (ED). ED is the persistent inability to achieve or sustain an erection sufficient for satisfactory sexual performance and is one of the first manifestations of endothelial damage in men with CVD risk factors. The purpose of this article is to review the results of studies involving physical activity, CVD, endothelial dysfunction and ED in order to verify its applicability for improving the health and quality of life of men with such disorders. There is consistent evidence that endothelial damage is intimately linked to ED, and this manifestation seems to be associated with the appearance CVDs. On the other hand, physical activity has been pointed out as an important clinical strategy in the prevention and treatment of CVDs and ED mainly associated with improvement of endothelial function. However, further experimental and clinical prospective investigations are needed to test the role of physical exercises in the modulation of endothelial function and their implications on erectile function and the appearance of CVDs.     

THE PERFORMANCE EFFECTS OF WISE AND UNWISE MANAGERIAL DISMISSALS

The decision to dismiss a coach is challenging because poor performance tends to coincide with both bad luck and low coaching ability. We differentiate between dismissals following actual poor performance on the pitch (wise dismissals) and dismissals following seemingly poor performance due to bad luck (unwise dismissals). To categorize dismissals, we use “expected goals,” which are less vulnerable to random variation in match outcomes. Using data from European football, we find that wise dismissals increase subsequent performance compared to a control group of nondismissals with similarly poor performance on the pitch. However, unwise dismissals do not improve subsequent performance compared to a control group with similar strings of bad luck. (JEL D81, J44, L83)     

Job Shop Scheduling With Deadlines

In this paper we deal with a variant of the Job ShopScheduling Problem. We consider the addition of release dates anddeadlines to be met by all jobs. The objective is makespanminimization if there are no tardy jobs, and tardiness minimizationotherwise. The problem is approached by using a Shifting Bottleneckstrategy. The presence of deadlines motivates an iterative use of aparticular one machine problem which is solved optimally. Theoverall procedure is heuristic and exhibits a good trade-off betweencomputing time and solution quality.     

How do private entrepreneurs transform local social capital into economic capital? Four case studies from rural Denmark

Bourdieu's (1986) General Theory of the Economy of Practices assumes that people perpetually transform tangible and intangible forms of capital according to certain ‘laws of conversion’. On this background, and combining sociology and micro-economics, we analyze specific strings of capital conversion in time and space. More specifically, we raise the question: How do private entrepreneurs transform local social capital into economic capital? We combine in-depth interviews with four private entrepreneurs in rural Denmark with Prisoner's Dilemma game theory. Thus each of our cases illustrates one of the outcomes in the PD matrix. In this way we explain why only one of the four entrepreneurs succeeds in capitalizing social capital.     

Logical Constraints as Cardinality Rules: Tight Representation

We derive by means of disjunctive programming the convex hull representation of logical conditions called cardinality rules given by Hong and Hooker (1999), and specify an efficient separation algorithm for the family of inequalities defining the convex hull. We then extend both the convex hull characterization and the efficient separation procedure to more general logical conditions.