Master Scheduling in Assemble-To-Order Environments: A Capacitated Multiobjective Lot-Sizing Model

Basic characteristics of an assemble-to-order environment make effective master scheduling extremely difficult. Limited resource capacities and dynamic customer end-item demand contribute to the complexity of the master production scheduling problem. To gain flexibility and responsiveness within this system, the master production schedule (MPS) focuses at the component level. This research proposes a master scheduling technique for manufactured components which combines a multiobjective capacitated multi-item/multi-stage lot-sizing model with an interactive multiple objective optimization solution procedure. To evaluate the model's performance as a realistic and practical master scheduling tool, this study focuses on the National Cash Register (NCR) electronics manufacturing facility in Columbia, South Carolina.     

Why adult children return home

This article examines the question of why more young adults are living with their parents. The expectation of the 1960s and 1970s that grown children establish separate residence, even before marriage, began to erode in the 1980s. We asked a small, convenience sample of parents and coresident adult children to respond to two possible interpretations of the trend: (1) that children return home due to economic hardship, or (2) that children return home because they feel entitled to a particular standard of living. Parents and children concluded that economic factors drive adult children home again, but few of the adult children in this study had come home because of genuine economic hardship.     

A comparison of objective and subjective measures of clinical competence

The purpose of this study was to determine if objective performance measures from a simulated patient practical examination were related to faculty subjective assessments of surgery students' performance. Another purpose was to determine if those students performing well on a simulated patient practical examination were the same students awarded honor ratings by faculty. Faculty ratings of students (n = 72) on history taking ability, physical exam skills, problem identification, use of investigations, problem integration, patient management, and patient relations skills were correlated with objective measures on these same criteria achieved on a practical exam employing three simulated patient cases. Correlations were also calculated to study the relationship between practical exam scores and honor rating recipients. Results indicated significant relationships between faculty subjective ratings and practical exam outcomes on all practical examination skills except physical exam skills and patient management skills. Findings also indicated the performance of honor students on the practical examination was significantly better than non-honor students on two skills: history-taking and patient relations. The implications of these research findings are discussed.     

SOCIAL ATOMISM, HOLISM, AND TRUST

The metatheoretical difference between social atomism and social holism is clarified by analysis of the generic necessity of trust. A theoretical approach to trust can be traced from Durkheim, Simmel, Parsons, and the recent work of Luhmann and Barber. Trust functions as a deep assumption underwriting social order and is not reducible to individual characteristics. Changes in trust alter social relationships. The study of power, exchange, family, and politics illustrates how trust constitutes social reality as emergent and holistic. This helps us understand the formation of interpersonal relationships, the difference between economic and social exchange, and the discrepancy between attitudes toward society and toward particular institutional actors.     

The Practical Significance of Measurement Error in Pulmonary Function Testing Conducted in Research Settings

Conventional spirometry produces measurement error by using repeatability criteria (RC) to discard acceptable data and terminating tests early when RC are met. These practices also implicitly assume that there is no variation across maneuvers within each test. This has implications for air pollution regulations that rely on pulmonary function tests to determine adverse effects or set standards. We perform a Monte Carlo simulation of 20,902 tests of forced expiratory volume in 1 second (FEV₁), each with eight maneuvers, for an individual with empirically obtained, plausibly normal pulmonary function. Default coefficients of variation for inter‐ and intratest variability (3% and 6%, respectively) are employed. Measurement error is defined as the difference between results from the conventional protocol and an unconstrained, eight‐maneuver alternative. In the default model, average measurement error is shown to be ～5%. The minimum difference necessary for statistical significance at p < 0.05 for a before/after comparison is shown to be 16%. Meanwhile, the U.S. Environmental Protection Agency has deemed single‐digit percentage decrements in FEV₁ sufficient to justify more stringent national ambient air quality standards. Sensitivity analysis reveals that results are insensitive to intertest variability but highly sensitive to intratest variability. Halving the latter to 3% reduces measurement error by 55%. Increasing it to 9% or 12% increases measurement error by 65% or 125%, respectively. Within‐day FEV₁ differences ≤5% among normal subjects are believed to be clinically insignificant. Therefore, many differences reported as statistically significant are likely to be artifactual. Reliable data are needed to estimate intratest variability for the general population, subpopulations of interest, and research samples. Sensitive subpopulations (e.g., chronic obstructive pulmonary disease or COPD patients, asthmatics, children) are likely to have higher intratest variability, making it more difficult to derive valid statistical inferences about differences observed after treatment or exposure.     

A remark on a social choice problem

If preferences are continuous monotone complete preorders, then there is a continuous social choice aggregation rule which respects unanimity and is anonymous. The simple proof of this result involves a straightforward application of well-known properties of the closed convergence topology.     

Does the Organization of Emotional Expression Change Over Time? Facial Expressivity From 4 to 12 Months

Differentiation models contend that the organization of facial expressivity increases during infancy. Accordingly, infants are believed to exhibit increasingly specific facial expressions in response to stimuli as a function of development. This study tested this hypothesis in a sample of 151 infants (83 boys and 68 girls) observed in 4 situations (tickle, sour taste, arm restraint, and masked stranger) at 4 and 12 months of age. Three of the 4 situations showed evidence of increasing specificity over time. In response to tickle, the number of infants exhibiting joy expressions increased and the number exhibiting interest, surprise, and surprise blends decreased from 4 to 12 months. In tasting a sour substance, more infants exhibited disgust and fewer exhibited joy and interest expressions, and fear and surprise blends over time. For arm restraint, more infants exhibited anger expressions and anger blends and fewer exhibited interest and surprise expressions and surprise blends over time. In response to a masked stranger, however, no evidence of increased specificity was found. Overall, these findings suggest that infants increasingly exhibit particular expressions in response to specific stimuli during the 1st year of life. These data provide partial support for the hypothesis that facial expressivity becomes increasingly organized over time.     

OBLIGATED CLINICAN SELF-DISCLOSURE: JONE THERAPITS'S INTERVENTIONS FOLLOWING A FAMILY MEMBERS'S PUBLICIZED MURDER*

This article describes a family therapist's management of the sudden collision between profesional and personal boundaries following the publicized murder of her spouse. Reasons are offered to explain why it is becoming difficult for all clinicians to control the process of self-disclosure in therapy. Strategies used to meet the demands of affirming professional distance while maintaining therapeutic effectiveness are described. Brief recommendations are proposed for therapists in group, medical, rural, inpatient, and underserved settings. It is hoped that this case study will generate further discussion and assist health care providers who may face this challenge in the future.