The Effects of JIT on the Development of Productivity Norms

Low inventory, or just-in-time (JIT) manufacturing systems, enjoy increasing application worldwide, yet the behavioral effects of such systems remain largely unexplored. Operations Research (OR) models of low inventory systems typically make a simplifying assumption that individual worker processing times are independent random variables. This leads to predictions that low-inventory systems will exhibit production interruptions. Yet empirical results suggest that low-inventory systems do not exhibit the predicted productivity losses. This paper develops a model integrating feedback, goal-setting, group cohesiveness, task norms, and peer pressure to predict how individual behavior may adjust to alleviate production interruptions in low-inventory systems. In doing so we integrate previous research on the development of task norms. Findings suggest that low-inventory systems induce individual and group responses that cause behavioral changes that mitigate production interruptions

Fifty Years of Weathering the Storm: Are the Louisiana Gulf Coastal Parishes Prepared for Another Major Hurricane?

This study examines ten major storms that have affected Louisiana in the last fifty years, beginning with Hurricane Betsy in 1965. The goal is to determine if the nine coastal parishes are prepared adequately for another major hurricane impact. It examines storms that have affected the state physically, in terms of property and ecological damages. It also considers storms that provided non-physical influences, by way of mitigation policy changes and social, economical, ecological, and political policy alterations. The main focus is on the transformations, if any, of social vulnerability in light of emergency preparedness in the areas impacted, particularly along the Louisiana coast. I argue that, while the State has come a long way, Louisiana is not currently prepared adequately to handle another major storm by 2015. Furthermore, I offer recommendations for improvement in preparedness measures for the future

Fifty Years of Weathering the Storm: Are the Louisiana Gulf Coastal Parishes Prepared for Another Major Hurricane?

This study examines ten major storms that have affected Louisiana in the last fifty years, beginning with Hurricane Betsy in 1965. The goal is to determine if the nine coastal parishes are prepared adequately for another major hurricane impact. It examines storms that have affected the state physically, in terms of property and ecological damages. It also considers storms that provided non-physical influences, by way of mitigation policy changes and social, economical, ecological, and political policy alterations. The main focus is on the transformations, if any, of social vulnerability in light of emergency preparedness in the areas impacted, particularly along the Louisiana coast. I argue that, while the State has come a long way, Louisiana is not currently prepared adequately to handle another major storm by 2015. Furthermore, I offer recommendations for improvement in preparedness measures for the future

On the Interface Between Operations and Human Resources Management

Operations management (OM) and human resources management (HRM) have historically been very separate fields. In practice, operations managers and human resource managers interact primarily on administrative issues regarding payroll and other matters. In academia, the two subjects are studied by separate communities of scholars publishing in disjoint sets of journals, drawing on mostly separate disciplinary foundations. Yet, operations and human resources are intimately related at a fundamental level. Operations are the context that often explains or moderates the effects of human resource activities such as pay, training, communications and staffing. Human responses to operations management systems often explain variations or anomalies that would otherwise be treated as randomness or error variance in traditional operations research models. In this paper, we probe the interface between operations and human resources by examining how human considerations affect classical OM results and how operational considerations affect classical HRM results. We then propose a unifying framework for identifying new research opportunities at the intersection of the two fields

An experimental and modeling study of pH and related solutes in an irrigated anoxic coastal sediment

Macrofaunal irrigation is an important process in nearshore sediments, facilitating greater exchange between sediments and seawater and imparting significant lateral heterogeneity to the porewater profiles of many constituents. Like many macrofaunal activities, irrigation is a transient behavior, i.e. tubes and burrows are flushed periodically, at frequencies that generally are species-specific. As a result, transient concentrations within the dwelling arise, potentially impacting gradients, fluxes and reaction rates in the vicinity of the dwelling. We investigated the impact of periodic burrow irrigation on the distribution of several diagenetically important porewater constituents. Laboratory experiments evaluated irrigation periodicity using artificially irrigated tubes embedded in nearshore organic-rich sediments, and microdistributions of oxygen and pH in laboratory experiments were measured with microelectrodes. To help interpret our results, we also constructed a simplified time and space-dependent transport-reaction model for oxygen, pH and sulfide in irrigated sediments. Laboratory results show substantial differences in the pH field of sediments surrounding an irrigated tube as a function of irrigation frequency. Higher pH values, indicative of an overlying water signature, were observed in the vicinity of the tube wall with increasing duration of irrigation. Conversely, oxygen concentrations did not vary significantly with the amount of irrigation, most likely a result of extremely high sediment oxygen demand. Model results are consistent with laboratory findings in predicting differences in the measured variables as a function of irrigation frequency. However, the nature and extent of the model-predicted differences are often at variance with the experimental data. Overall, experimental and modeling results both suggest irrigation periodicity can substantially influence porewater distributions and diagenetic processes in sediments. Future studies should examine the influence of irrigation periodicity on the types and rates of reactions, and the attendant biological features, in the environment encompassing the tube or burrow wall

A modelling study of discontinuous biological irrigation

Irrigation of infaunal dwellings can lead to significant alteration of solute distributions in sediments. As a result, sediment-seawater fluxes of nutrients and dissolved carbon are greatly enhanced, and the biology of benthic communities is affected. The most realistic mathematical representation of irrigation and its effect on sediment geochemistry is Aller\u27s (1980) cylinder model. One critical assumption of this model is that burrows are irrigated continually, and that burrow water solute concentrations are identical to overlying water concentrations at all times. However, the vast majority of infaunal tube- and burrow-dwelling organisms irrigate periodically, i.e. in an on/off cycle. During periodic irrigation, the solute concentration at the tube wall may vary between the limits imposed by the flux from the porewater and the concentration in the overlying water. We introduce modifications to the cylinder model which allow for periodic irrigation. We assess how periodic irrigation affects solute profiles and fluxes of two chemical constituents, silica and ammonium, for different population densities (distance between burrows) and organism sizes (burrow radii). Silica and ammonium follow first and zeroth order reaction kinetics, respectively, and illustrate the behavior of two general reaction classes. Model results show that the effects of periodic irrigation vary with the class of reaction considered. For silica, radially-averaged profiles during discontinuous irrigation varied less than 15% from those with continuous irrigation for nearly all burrow sizes, burrow distances and reaction rate constants considered. However, we observed large temporal changes (as much as a factor of 6) in the areally-averaged silica flux over the irrigation cycle. Despite this time-dependence, the time-averaged silica flux was similar to that calculated for the continuous case. For ammonia, radially-averaged solute profiles were extremely sensitive to the duration of irrigation. In this case, the differences between discontinuous and continuous irrigation were greatest when the duration of irrigation was short (e.g. 5 min), and when the inter-burrow distance was small. As with silica, there was a strong time-dependence in areally-averaged ammonia flux when irrigation was periodic. However, the time-averaged ammonia flux is identical to the flux calculated for continuous irrigation. Our results suggest that irrigation behavior can affect the local burrow environment and this imposes a time dependence on solute fluxes

Seasonality in the Surface Energy Balance of Tundra in the Lower Mackenzie River Basin

This study details seasonal characteristics in the annual surface energy balance of upland and lowland tundra during the 1998–99 water year (Y2). It contrasts the results with the 1997–98 water year (Y1) and relates the findings to the climatic normals for the lower Mackenzie River basin region. Both years were much warmer than the long-term average, with Y1 being both warmer and wetter than Y2. Six seasons are defined as early winter, midwinter, late winter, spring, summer, and fall. The most rapid changes in the surface energy balance occur in spring, fall, and late winter. Of these, spring is the most dynamic, and there is distinct asymmetry between rates of change in spring and those in fall. Rates of change of potential insolation (extraterrestrial solar radiation) in late winter, spring, and fall are within 10% of one another, being highest in late winter and smallest in spring. Rates of change in air temperature and ground temperature are twice as large in spring as in fall and late winter, when they are about the same. Rates of change in components of the energy balance in spring are twice and 4 times as large as in fall and late winter, respectively. The timing of snowpack ripening and snowmelt is the major agent determining the magnitude of asymmetry between fall and spring. This timing is a result of interaction between the solar cycle, air temperature, and snowpack longevity. Based on evidence from this study, potential surface responses to a 18C increase in air temperature are small to moderate in most seasons, but are large in spring when increases range from 7% to 10% of average surface energy fluxes

Do girls have all the fun? Anxiety and enjoyment in the foreign language classroom

The present study focuses on gender differences in Foreign Language Enjoyment (FLE) and Foreign Language Classroom Anxiety (FLCA) among 1736 FL learners (1287 females, 449 males) from around the world. We used 21 items, rated on a Likert scale, reflecting various aspects of FLE (Dewaele & MacIntyre, 2014), and 8 items extracted from the FLCAS (Horwitz et al., 1986). An open question on FLE also provided us with narrative data. Previous research on the database, relying on an average measure of FLE and FLCA (Dewaele & MacIntyre, 2014) revealed significant gender differences. The present study looks at gender differences in FLE and FLCA at item level. Independent t-tests revealed that female participants reported having significantly more fun in the FL class, where they felt that they were learning interesting things, and they were prouder than male peers of their FL performance. However, female participants also experienced significantly more (mild) FLCA: they worried significantly more than male peers about their mistakes and were less confident in using the FL. Our female participants thus reported experiencing both more positive and more mild negative emotions in the FL classroom. We argue that this heightened emotionality benefits the acquisition and use of the FL

Greenway Medical Technologies: The Pace-Setting David of Electronic Health Records

This teaching case updates a previous study of Greenway Medical Technologies, a software company delivering electronic healthcare record (EHR) solutions to physicians. The current EHR marketplace is considered, including global trends as well as the impact of U.S. government funded monetary incentives. Greenway continues to build on its best-in-class software application and find ways to provide new enticements to medical practices and improvements to the broader medical community. The case also describes the EHR systems industry and explores the reasons for Greenway’s continued success and growth that surpasses its competitors

Evaluating the Efficacy of Elaborative Strategies for Remembering Expository Text

This study investigated whether elaborative interrogation would be an effective learning strategy for lengthy expository text. One hundred undergraduates (65 females and 35 males) comprised the study's five experimental groups: (a) unsupported elaborative interrogation, (b) self-study, (c) repetition, (d) elaborative interrogation with preunderlined main ideas, and (e) elaborative interrogation with preunderlined main ideas plus structured why questions. All students read an eight-page passage on childhood education, studied the main ideas (preidentified or not), used their instructed strategies, and completed a free recall and multiple-choice test. Of interest is that in unsupported conditions students had difficulty recognizing the main ideas in the passage. Elaborative interrogation was maximized when supported with preunderlined ideas and also was enhanced by providing specific why questions in addition to preunderlined ideas.Cette étude visait à déterminer si l'interrogation elaborative représenterait une stratégie d'apprentissage efficace pour de longues rédactions descriptives. Cent étudiants du premier cycle (65 femmes et 35 hommes) ont été répartis parmi les cinq groupes expérimentaux de l étude: (a) l'interrogation elaborative sans appui, (b) l'étude auto-dirigée, (c) la répétition, (d) l'interrogation elaborative avec les idées principales soulignées, et (e) l'interrogation elaborative avec les idées principales soulignées et des questions structurées sur l'adverbe "pourquoi". Tous les étudiants ont lu un texte de huit pages sur l'éducation des enfants, étudié les idées principales (soulignées ou non), mis en pratique les stratégies qu'on leur avait suggérées et complété un test de rappel libre et un test composé de questions à choix multiples. Il est intéressant de noter que les étudiants qui n'avaient pas reçu d'appui ont manifesté de la difficulté dans l'identification des idées principales. L'interrogation elaborative a profité le plus à ceux pour qui on avait souligné les idées principales. Le fait d'ajouter des questions précises structurées sur l'adverbe "pourquoi" a également rendu l'apprentissage plus efficace