Work Flow Policy and Within-Worker and Between-Workers Variability in Performance.

Work flow policies are shown to induce a change in average between-workers variability (worker heterogeneity) and within-worker variability in performance times. In a laboratory experiment, the authors measured the levels of worker heterogeneity and within-worker variability under an individual performance condition, a work sharing condition, and a fixed assignment condition. The work sharing policy increased the levels of worker heterogeneity and worker variability, whereas the fixed assignment policy decreased them. These effects, along with work flow policy main effects on mean performance times and variability are examined. This article represents an initial step in understanding effects that may be important in the selection of an operating policy, the ignorance of which may lead to costly misestimates of performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

安钢外贸工作探讨

结合实际情况,就如何搞好钢铁企业外贸工作进行了探讨,并介绍了近年来安钢开展进出口贸易的一些经验与体会。     

Work Flow Variation and Labor Productivity: Case Study

Different types of flow variation and how they affect construction project performance have been studied by previous researchers. One aspect that has not been well researched is how work flow variation and labor productivity are related in construction practice. To study that issue, 134?weeks of project production data were collected and analyzed to explore this relationship. Labor productivity was found to be positively correlated with Percent Plan Complete (PPC), a measure of work flow variation. The relationship between productivity and the ratio of total task completion to planned tasks, weekly workload, weekly work output, and weekly work hours was also studied, and no significant correlation was found. The results suggest that productivity is not improved by completing as many tasks as possible regardless of the plan, nor from increasing workload, work output, or the number of work hours expended. In contrast, productivity does improve when work flow is made more predictable. These findings can help project managers focus on actual drivers of productivity. It can also help consulting companies pinpoint responsibility for productivity losses in claims.     

温度对化学镀Ni-Fe-P合金性能的影响

研究了温度对化学镀Ni-Fe-P合金性能的影响,着重探讨了在不同温度下对其镀速、镀层硬度、镀层形貌、镀层成分以及耐腐蚀性的影响.结果表明：当温度在87℃时,镀层沉积速度最快,镀层硬度达到最大,镀层表面颗粒最均匀,镀层成分中含铁量、含硅量最大,而且该温度下的耐腐蚀性最好.     

Visualization of Work Flow to Support Lean Construction

Implementation of advanced production management techniques, such as lean construction concepts like filtering of work packages to stabilize work flows, pull flow of teams and materials, and in-process quality control, demands effective and timely flows of information both to and from the workface. The key requirement—making the process state transparent to all participants—is more difficult to achieve in construction than in manufacturing, because work crews move continuously within a physical environment that is itself changing. Novel computer-aided visualization tools can fulfill the needs that simpler tools, such as Kanban cards, fulfill in manufacturing. Two prototypes with user interfaces designed to facilitate process flow have been devised and implemented within the context of building information modeling (BIM) software systems. They demonstrate aspects of the synergy between BIM and lean construction. Given the dynamic and dispersed physical environments and the fractured contracting arrangements typical of construction, BIM-based visualization interfaces are important tools for providing process transparency.     

Impact of Resources and Strategies on Construction Company Performance

Globalized competition and customer needs forced construction companies to measure their performance beyond the financial measures such as profitability, turnover, etc. As qualitative determinants were added to measurement systems, their investigation and evaluation became a major area of research. In this study, the impact of “resources and capabilities,” “strategic decisions,” “project management competencies,” and “strength of relationships with other parties” on “company performance” was investigated. A questionnaire survey was administered to 73 Turkish contractors and the results of the survey were analyzed using structural equation modeling. The findings indicate that, as expected, resources and capabilities and strategic decisions have an important and direct impact on company performance, whereas project management competencies and strength of relationships with other parties impact company performance only indirectly, through their impact on companies’ resources and capabilities and strategic decisions.     

Measuring the Impact of Rework on Construction Cost Performance

Rework continues to affect both cost and schedule performance throughout the construction industry. The direct costs alone often tally to 5% of the total construction costs. Using the data obtained from 359 construction projects in the Construction Industry Institute database, this paper assesses the impacts of rework on construction cost performance for projects in various categories. In addition, it identifies the sources of this rework, permitting further analyses and the development of rework reduction initiatives. The results of this study establish that the impacts of rework differ according to project characteristics and that the sources of rework having the greatest impact are not significantly different among project categories. By recognizing the impacts of rework and its sources, the construction industry can reduce rework and ultimately improve project cost performance.     

Geographic Variability of Rainfall Erosivity Estimation and Impact on Construction Site Erosion Control Design

The Revised Universal Soil Loss Equation (RUSLE) is used often by erosion control planners to estimate the soil loss from urban construction sites when sizing sediment ponds and determining the soil loss under vegetative mats. This project used the existing, complete-year rainfall record for 27 sites in the state of Pennsylvania to compare the USDA isoerodent maps to the annual rainfall erosivity, R, values calculated using the USEPA equations for the National Resource Conservation Service Type II rainfall. The USDA and USEPA maps showed a general trend of increasing median annual R from west-to-east and north-to-south. A trend analysis relating the median R values calculated during this project to geographic location had similar, large-scale geographic trends as the USDA and USEPA maps. However, the R values more closely followed a combination of the annual rainfall pattern and topography (the Appalachian mountains bisect the state). Two case studies of the impacts of these calculations were developed to show the impact of using different values of R on the design of sediment ponds and predicting vegetation establishment. The results of these scenarios indicate that the source of data to predict R can affect the frequency and cost of sediment pond maintenance and may under-predict the protection level required of a vegetated erosion control mat.     

Impact of Limiters on Accuracy of High-Resolution Flow and Transport Models

High-resolution finite volume schemes used to predict mass transport and free surface flows utilize limiters such as Minmod, Double Minmod, and Superbee to prevent spurious oscillations commonly associated with second-order accurate schemes. These limiters effectively switch between the classical Lax-Wendroff, Warming-Beam, and Fromm schemes, or amplified versions of these schemes that artificially increase gradient magnitudes to minimize damping of high frequency solution components. A Von Neumann analysis illustrates that gradient or slope amplification reduces numerical dissipation, but also increases the phase error and should therefore be cautiously used. The Double Minmod limiter closely mimics the Fromm scheme and possesses better phase accuracy than the Minmod and Superbee limiters. Near sharp solution gradients, slope amplification used by the Double Minmod and Superbee limiters reduces artificial smearing. The Minmod limiter does not use slope amplification and therefore yields the most solution smearing. Results of model tests show that the combined attributes of the Double Minmod limiter yield more accurate predictions of mass transport and circulation zones in shallow water than those of other limiters such as Minmod and Superbee.     

Marine Outfall Performance. I: Introduction and Flow Restoration

Sewage outfalls are common inclusions in the infrastructure of coastal cities and towns. Near-ocean industries may also make use of such pipes. Keeping such a conduit operating properly is by no means a trivial matter, and this paper is the first of two dealing with this complex topic. Herein, the various failure and impairment mechanisms are summarized, and the need for careful underwater inspection is stressed. Examples are given of inspection, maintenance, and repair operations for various municipal facilities. The paper closes with presentation of two improvement procedures, pigging and sliplining.     

Impact of Shift Work on Labor Productivity for Labor Intensive Contractor

Generally, a contractor has three options in accelerating a construction schedule: working longer hours, increasing the number of workers, or creating an additional shift of workers. There has been a significant amount of research conducted on scheduled overtime on construction labor productivity. However, little information has been found in the literature addressing the labor inefficiency associated with working a second shift. This paper has qualitative and quantitative components. The qualitative part details why and how shift work affects labor productivity, and then addresses the appropriate use of shift work. The quantitative component determines the relationship between the length of shift work and labor efficiency. The results of the research show that shift work has the potential to be both beneficial and detrimental to the productivity of construction labor. Small amounts of well-organized shift work can serve as a very effective response to schedule compression. The productivity loss, obtained from the quantification model developed through this study, ranges from ?11 to 17% depending on the amount of shift work used.     

风险管理工作中的业务流程梳理法

随着我国社会主义市场经济体制的不断完善,风险管理逐步成为各经济单位管理的重点.各单位通过风险识别、风险衡量、风险评价等措施,并在此基础上优化各种风险管理技术,对风险实施有效的控制和妥善处理风险所导致损失的后果,期望达到以最少的成本获得最大安全保证的目标.业务流程是实现对组织现状的客观描述并得到业务模型,为管理改革提供客观依据,为提升风险管理工作的整体水平提供指导.本文着重分析业务流程法的优、劣势,结合实践工作探讨业务流程梳理后进一步的工作方向.     

Impact of Stress on the Performance of Construction Project Managers

The work of construction project managers (CPMs) is often highly stressful, due to time pressures, and due to the uncertainties and the dynamic social structure involved in construction projects. This study aims to investigate the impact of stress on the performance of CPMs. Correlation analysis and structural equation modeling are employed to uncover the relationships between different types of stress (i.e., objective stress, burnout, and physiological stress) and the work performances (i.e., task performance, interpersonal performance, and organizational performance) of CPMs. Data were collected from 108 CPMs who work in a variety of construction sectors, including prime contractors, subcontractors, developers, consultant firms, and the public sector. Results showed that (1) objective stress reduces the task performance of CPMs while burnout can have a positive effect on it; (2) interpersonal performance is maximized with a moderate level of objective stress (i.e., an inverted-U-shaped relationship between these two variables) and increases in line with the improvement of the task performance of individuals; and (3) organizational performance has U-shaped relationships with both burnout and physiological stresses and is worsened by objective stress. Last, it is suggested to stakeholders that regular reviews of job allocation, stress appraisals, stress management workshops, group or individual counseling, and psychological treatment or physiotherapy be carried out to optimize the stress and the performance of CPMs.     

高水膨胀材料浆体流动性能研究

为了研究新型充填材料——高水膨胀材料的流变性能,本试验针对浆体粘度、流变参数、凝结时间三个方面的特性,研究了浆体在静置、扰动状态下的性能变化规律及浆体浓度对浆体流动性能的影响。研究结果表明:浆体在静置和扰动状态下的流动性能有很大差别,扰动会阻止浆体固化的进行,使浆体更长时间的保持良好流动性,利于充填浆体的管道输送。     

Impact of the Decontrol of Silver Concentrate Processing Trade on China's Lead Market

正In early June,two lead factories of Henan Jinli,and Yuguang GoldLead announced they have obtained silver concentrate Processing Handbook.Market analysts considered that decontrol on contract processing of silver ore will aggravate the pressure on lead ingot supply in China.     

主盐浓度对化学镀Ni-Fe-P合金性能的影响

研究了镀液中主盐浓度对铜基体化学镀的影响,通过测定镀速、硬度、镀层形貌、自腐蚀电位,以确定主盐的最佳使用浓度.结果表明当主盐的浓度为25 g/L时,镀速、耐腐蚀性、硬度适宜,镀层分布均匀、紧凑、颗粒细小.     

Organizational Error Management Culture and Its Impact on Performance: A Two-Study Replication.

The authors argue that a high-organizational error management culture, conceptualized to include norms and common practices in organizations (e.g., communicating about errors, detecting, analyzing, and correcting errors quickly), is pivotal to the reduction of negative and the promotion of positive error consequences. Organizational error management culture was positively related to firm performance across 2 studies conducted in 2 different European countries. On the basis of quantitative and qualitative cross-sectional data from 65 Dutch organizations, Study 1 revealed that organizational error management culture was significantly correlated with both organizational goal achievement and an objective indicator of economic performance. This finding was confirmed in Study 2, using change-of-profitability data from 47 German organizations. The results suggest that organizations may want to introduce organizational error management as a way to boost firm performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of Aging Temperature on the Performance of a Nickel-Iron-Based Superalloy

In this study, the effects of aging temperature on the microstructure and properties of a nickel-iron (Ni-Fe)-based superalloy were investigated. On the one hand, owing to the increase in the size and particle spacing of Ni3Al (γ′) precipitate, long-term aging induced a significant drop in the alloy strength. Moreover, the increasing aging temperature from 700 °C to 750 °C further induced more than 75 MPa decline in the alloy yield strength. Furthermore, it led to a decrease in the critical stress because of dynamic recrystallization. On the other hand, the long-term aging increased the alloy’s ductility. The crack propagation along the grain boundary was inhibited, because of the decreasing grain boundary brittleness. Although the grain boundary precipitates changed from carbide to γ′ when the aging temperature increased, a distinct change in the alloy’s ductility was not observed. The transmission electron microscopy results showed that both precipitates were sheared by the grain boundary during the alloy deformation. These results confirm that aging temperature has less effect on alloy’s ductility.     

Zolpidem-Related Effects on Performance and Mood During Simulated Night-Shift Work.

The effects of zolpidem, a nonbenzodiazepine hypnotic, on psychomotor task performance, subjective effects, and food intake were examined during simulated shift work. Seven participants completed this 23-day, within-participant design, residential laboratory study. They received a single oral zolpidem dose (0, 5, or 10 mg) 1 hr before bedtime for 3 consecutive days under 2 shift conditions: day shift and night shift. When participants received placebo, next-day performance and subjective effects were disrupted, and food intake was decreased during the night shift. Zolpidem improved subjective reports of sleep quality and, to a lesser extent, next-day performance. Next-day mood, however, was worsened by zolpidem. Food intake was unaffected by zolpidem. These data indicate that shift changes produce performance impairments, mood alterations, and decreases in food intake, and that zolpidem attenuates some shift-change-related disruptions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Impact of Justice Climate and Justice Orientation on Work Outcomes: A Cross-Level Multifoci Framework.

In this article, which takes a person-situation approach, the authors propose and test a cross-level multifoci model of workplace justice. They crossed 3 types of justice (procedural, informational, and interpersonal) with 2 foci (organization and supervisor) and aggregated to the group level to create 6 distinct justice climate variables. They then tested for the effects of these variables on either organization-directed or supervisor-directed commitment, satisfaction, and citizenship behavior. The authors also tested justice orientation as a moderator of these relationships. The results, based on 231 employees constituting 44 work groups representing multiple organizations and occupations, revealed that 4 forms of justice climate (organization-focused procedural and informational justice climate and supervisor-focused procedural and interpersonal justice climate) were significantly related to various work outcomes after controlling for corresponding individual-level justice perceptions. In addition, some moderation effects were found. Implications for organizations and future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)