Predation, scramble competition, and the vigilance group size effect in dark-eyed juncos (Junco hyemalis)

In socially feeding birds and mammals, as group size increases, individuals devote less time to scanning their environment and more time to feeding. This vigilance “group size effect” has long been attributed to the anti-predatory benefits of group living, but many investigators have suggested that this effect may be driven by scramble competition for limited food. We addressed this issue of causation by focusing on the way in which the scan durations of free-living dark-eyed juncos (Junco hyemalis) decrease with group size. We were particularly interested in vigilance scanning concomitant with the handling of food items, since a decrease in food handling times (i.e. scan durations) with increasing group size could theoretically be driven by scramble competition for limited food resources. However, we showed that food-handling scan durations decrease with group size in an environment with an effectively unlimited food supply. Furthermore, this food-handling effect was qualitatively similar to that observed in the duration of standard vigilance scans (scanning exclusive of food ingestion), and both responded to changes in the risk of predation (proximity of a refuge) as one might expect based upon anti-predator considerations. The group size effects in both food-handling and standard scan durations may reflect a lesser need for personal information about risk as group size increases. Scramble competition may influence vigilance in some circumstances, but demonstrating an effect of competition beyond that of predation may prove challenging. Received: 22 September 1998 / Received in revised form: 1 February 1999 / Accepted: 14 February 1999     

垃圾焚烧炉烟气净化系统的工艺分析

介绍了两种垃圾焚烧电厂烟气净化处理工艺,分析了垃圾焚烧烟气净化处理装置工艺流程及出口排放参数,提出目前适合的处理工艺及发展方向。     

Identification of managerial shaping factors in a petrochemical plant by resilience engineering and data envelopment analysis

Resilience engineering (RE) is a novel approach that is capable of controlling and limiting incidents and accidents. This study identifies managerial shaping factors in a petrochemical plant by RE and data envelopment analysis (DEA). To do this, a standard questionnaire containing resilient factors is completed by managers of a petrochemical plant. Then, the best DEA model is selected based on average efficiency and statistical test. In addition, sensitivity analysis are performed to identify the most important shaping factors. Reporting culture, management commitment, and preparedness are identified as the most important factors in this paper, respectively. Finally, the proposed model is validated and verified through statistical experiment. The proposed approach would help managers to have a comprehensive understanding of the plant with respect to the RE. To the best of our knowledge this is the first paper that examines resilient shaping factors in a petrochemical plant with respect to management and organization by DEA.     

A new methodology for the synthesis of an optimum flexible water networks

This paper presents a new optimization model for the synthesis of direct reuse/recycle water networks with data uncertainties. In this case, data uncertainties were originated from the varying parameters of the water sources and sinks, which fluctuate within a given range of values. The aim of the method is to design an optimum flexible water network (FWN) that ensures minimum fresh water consumption and yet fulfilling all process constraints and uncertain parameters. The resulting FWN also features the minimum number of pipelines, which will ease process operation and control. Due to the complexity of the problem, multistep solving method based on theorem of corner points has been developed. The FWN obtained using the proposed method also includes information on the maximum flow rate in the pipelines, which is essential for detailed network design stage. The resulting model is a mixed integer linear problem (MILP), which may be solved to obtain global optimum solution. Two case studies were used to elucidate the newly proposed method.     

Box Handling in the Loading and Unloading of Vans

The handling of 2,306 boxes being loaded or unloaded from vans onto or from 4-wheeled trolleys by 31 handlers in a warehouse were characterized. Handling was videotaped and characterized through an analysis grid completed by three trained observers. The following execution parameters were observed: nature of the exertion applied by the upper limbs, plane and direction of the exertion, resulting displacement of the box, grip, use of the lower limbs and the back. Results show that execution parameters used by handlers vary considerably from those usually recommended or studied. For example, symmetric grips were rarely used (4%). The grip was modified during the handling of half the boxes. Significant knee flexion was rarely observed (3% of exertions). Each box was moved by applying an average of . 3.5 different exertions. Exertions were mostly applied in a plane parallel to the shoulders; they were rarely executed in a strict sagittal plane (11%). The implication of these observations are discussed.     

Differences in urban and rural accident characteristics and medical service utilization for traffic fatalities in less-motorized societies

Introduction

Fatalities from traffic accidents in less-motorized societies are an important global issue. We aimed to characterize the geographic differences of fatalities in such societies to facilitate the development of targeted interventions.

Method

This study linked police reports, hospital data, and vital registration data from Taiwan with special reference to accident factors in pre-hospital deaths and medical care in hospital deaths.

Results

A higher percentage of pre-hospital deaths were observed following rural as compared to urban traffic accidents. The deaths due to rural accidents can be attributed to lower use of restraints (i.e., helmets or seat belts), lower percentage of motorcyclists, and more highway accidents. A higher percentage of victims in rural accidents were transported to distant medical centers rather than to local hospitals.

Conclusion

Specific interventions, such as intelligent emergency medical systems, campaigns for helmets and seat belt usage, enforcement of helmets and seat belt use, and speed control measures should be targeted to rural areas.

Impact on industry

Cooperation between the vehicle industry and emergency medical providers in rural traffic accident rescue teams may decrease the numbers of deaths in these regions.     

新型机车监控系统的研究

设计了一种基于GSM的机车监控系统。用无线电手机传输监控装置产生的原始数据至PC机 ,来达到实时监控机车运行状况的目的。实践表明 ,该系统简单灵活 ,传输可靠 ,具有良好的稳定性和可靠性。与现行车载监控装置相比 ,新型机车监控系统具有提高数据的实时性、减轻工作人员的劳动强度等优点     

道路交通安全知识提取方法及其递进式模型的研究

道路交通数据资源日益膨胀和复杂化 ,已经远远超出了人脑的记忆和分析能力。面对道路交通的海量数据 ,传统运用的DBMS和OLTP技术 ,已无法发现隐藏在数据背后的关系、规则和发展趋势等新的内容、知识和信息。因此 ,建立基于DMKD的智能道路交通安全决策支持系统是相关部门急需解决的重大课题。笔者重点介绍了数据挖掘、知识发现的概念 ,提出了基于DW +OLAP +DMKD的道路交通安全决策支持系统 ,通过道路交通系统的要素分析 ,介绍了一种面向属性的粗糙集方法提取规则 ,并阐述了一种递进式规则评价提炼过程。     

室内微污染有机废气的纳米光催化处理

室内装修产生的污染严重影响人们的身体健康，纳米和光催化技术是国际上新出现并普遍认为是最有应用化前景的高新技术，介绍了应用TiO2纳米光催化技术治理室内空气污染的方法，能在常温下高效、稳定地分解污染物，其处理效果明显，无二次污染，适合室内空气中有害污染物净化。     

基于DEA的江苏省环境效率研究

运用DEA方法中SBM模型对江苏省13个地级市2001～2007年间环境效率及其变化率进行分析.结果显示江苏省各地级市间环境效率差异明显,苏州、无锡、常州、盐城和宿迁5市处于前沿面上,其他市均是DEA非有效或弱有效.Mahnquist指数计算显示各地级市在研究期内变化率不大,但扬州市近年来环境效率持续降低.综合经济产出...