Effect of a road safety training program on drivers' comparative optimism

Reducing comparative optimism regarding risk perceptions in traffic accidents has been proven to be particularly difficult (Delhomme, 2000). This is unfortunate because comparative optimism is assumed to impede preventive action. The present study tested whether a road safety training course could reduce drivers’ comparative optimism in high control situations. Results show that the training course efficiently reduced comparative optimism in high control, but not in low control situations. Mechanisms underlying this finding and implications for the design of road safety training courses are discussed.     

保罗·兰德的设计理念与表现手法探析

美国现代平面设计的开创者与奠基人保罗·兰德被誉为世界平面设计之父,他认为平面设计应简单、直观、准确地传达内容,应面向大众而不是某个阶层,应文雅而幽默并传递乐观精神。保罗·兰德常用拼贴、蒙太奇、极简化作为设计表现手法,形成了具有本民族特征的、系统的现代主义风格。     

Computer design and optimization of cryogenic refrigeration systems

This paper describes the design and optimization of a cryogenic refrigerator using the LBL computer program GEOTHM. This computer program has been used extensively to design and optimize geothermal power plants and power cycles of other types. GEOTHM can calculate the thermodynamics of a wide variety of cycles including refrigeration cycles. GEOTHM has an optimizer which permits single step multi-parameter optimization of a thermodynamic cycle. A refrigeration cycle may be optimized for minimum cost refrigeration, or maximum thermodynamic performance using up to 55 optimizable parameters. The use of the optimizer in GEOTHM is demonstrated on two liquid nitrogen refrigeration cycles which are optimized for minimum refrigeration cost and minimum input power.     

The optimism bias and traffic accident risk perception

Research suggests that people are excessively and unrealistically optimistic when judging their driving competency and accident risk. In this study, college-age drivers compared their risk of being involved in a variety of described traffic accidents relative to their peers. They also rated each of the accidents along a number of dimensions hypothesized as being related to optimism. In addition, subjects provided global estimates of their driving safety, skill, and accident likelihood. Significant optimism was evident for both the accidents and the global ratings. Optimism increased with driving experience and marginally with age. Those with more driving experience considered human factors to be more important in accident causation; those assigning more importance to human factors also rated themselves as more skillful drivers. For the specific accidents, perceived controllability was a strong predictor of optimism. The findings for controllability are interpreted in terms of other recent data and hypothesized explanations of the optimism bias. In general, it appears that optimism arises because people persistently overestimate the degree of control that they have over events.     

“五育并举”视角下学龄前乡村留守儿童益智玩具设计研究

目的 针对乡村留守儿童的早教问题,研究学龄前留守儿童益智玩具的设计策略。方法 基于“德、智、体、美、劳”的“五育”理念,系统分析学龄前留守儿童的教育问题及现有益智玩具的现状,并构建学龄前乡村留守儿童益智玩具设计的“五育”益智框架以及具体的设计原则,最后结合贫困乡村地区广西融水县的实地调研,对学龄前留守儿童益智玩具设计的“五育”益智设计原则进行相关设计实践。结论 从学龄前乡村留守儿童“五育”教育问题出发,提出关怀性、创造性、合作性、自然性、乐观性5个对应的设计原则,并通过实际案例验证了该设计原则具有一定指导意义。同时,也为乡村留守儿童益智产品的开发提供设计理论参考,进一步推动我国设计扶贫的工作。     

Robust supply chain networks design and ambiguous risk preferences

In this paper, a robust stochastic optimisation model for regret minimising is proposed for supply chain networks design. The model emphasises the ambiguity lying in both the risk preference and the probability distribution. A duality theory for the model is derived and the random utility functions are identified as the Lagrange multipliers. In addition, a tractable relaxation based on reformulation-linearisation technique is presented for the computational aspects of the model. The numerical experiments show that our regret minimising model can make a well balance between the conservativeness of a pure robust optimisation model and the optimism of risk-neutrality. We also present a case study to demonstrate the applicability of the proposed model.     

Perceived driving safety and seatbelt usage

Swedish and U.S. subjects judged their own driving skills and safety in relation to other drivers. As in earlier studies, most subjects showed an optimism bias: a tendency to judge oneself as safer and more skillful than the average driver, with a smaller risk of getting involved and injured in an accident. Different measures of the optimism effect were strongly correlated with one another, with driving experience and with the judged importance of human factors (as opposed to technical and chance factors) in causing accidents. Degree of optimism was positively, but weakly, correlated with reported seatbelt usage and worry about traffic accidents. Seatbelt usage was positively related to the extent to which belts are judged to be convenient and popular, and more modestly related to the belt's perceived contributions to safety. These results suggest that providing more information about the effectiveness of seatbelts may not be as efficient a way of increasing seatbelt usage as emphasizing other factors, such as comfort and social norms, which cannot be outweighed by optimism.     

抗毁性WDM网状光网络中的P圈快速构造算法

p圈法是抗毁性网状WDM光网络中一种十分优秀的保护算法,在p圈配置到网状光网络的过程中,圈构造算法是设计的第一步.文中提出了一种快速圈挖掘算法(FCMA),本算法基于k-最短路由算法构造最小p图,通过圈扩展算法获得更多性能优良圈,文中给了启发式算法的具体步骤.通过计算机仿真表明,该算法实现快速圈构造,性能优于其它同类算法,适合网状光网络中的p圈快速构造.     

Comparative simulation and investigation of ammonia-water: absorption cycles for heat pump applications

Several recent programs in absorption research have focused on technology for domestic heating and cooling utilizing natural gas. In residential and small commercial size applications, ammonia-water cycles offer the possibility of a gas-fired heat pump for both winter heating and summer cooling, at better year-round COPS than currently available by various alternatives. Several cycles have been considered for this purpose, ranging from the simplest single effect to the GAX (Generator-Absorber heat eXchange) with its different variations. Detailed calculations of ammonia-water systems are rather difficult, particularly in complex cycles such as the GAX. This may be the reason that relatively few simulation studies have been published to date that give more than design point performance. The objective of the present study has been a comprehensive investigation of various ammonia-water cycles, with operating conditions and different design parameters varied over a wide range to compare their performance. To this end, a modular simulation program (ABSIM) was employed, which makes it possible to simulate absorption cycles in varying configurations. The cycles investigated increase in complexity from the basic single-effect cycle, through the same cycle with an added precooler, through an added solution-cooled absorber and solution-heated generator, to the GAX and branched GAX cycles with different types of branching. Each cycle was formed on the basis of the previous one by adding one or two components at each stage, resulting in increasing complexity rewarded by improved performance. This kind of investigation enabled determination at each stage of the influence of the added components on the cycle. The results of the investigation show cooling CON ranging from about 0.5 for the simplest single-effect cycle to about 1.0 for the GAX cycle.     

Air separation plant design

This paper presents a general review of the design of air separation plants from the initial specifications to the final details. References to key sources for data and for design criteria are presented in lieu of lengthy discussions.The effect of the product quantities and purities on the selection of the process cycle are discussed and general design guidelines and specific examples of various types of air separation plants are given. Process cycles for large tonnange plants, unattended nitrogen generators, small oxygen generators for sewage plants, and for all-liquid plants are described. Unit operations used in these cycles and materials of construction are reviewed briefly.     

Design of flexible manpower line walk cycles for a fixed number of operators

Flexible manpower lines (FMLs) are a form of flow process line in which operators are allocated ‘walk cycles’, i.e. a repetitive sequence in which to load and unload machine tools. The effective design of such lines is normally achieved with the expectation that operators without full walk cycles, i.e. those that do not require a full Takt time to accomplish, can complete their walk cycles at an adjoining FML. However, an alternative FML design strategy is possible in cases where no adjoining FML exists or it is not possible for operators to move between work areas. This strategy involves determining the minimum Takt time and the associated operator walk cycles at which the FML can operate under a fixed number of operators. To solve this type of problem, a genetic algorithm that make use of a novel crossover operator has been developed that can design FMLs. The genetic algorithm is capable of generating, for a specific Takt time and fixed number of operators, FMLs with high-quality, near-optimal operator walk cycles. Solutions for the fixed manpower case were then identified by performing multiple genetic algorithm runs to find the best walk cycles at various Takt times.     

Refrigerant injection for heat pumping/air conditioning systems: Literature review and challenges discussions

This paper reviews the major research on refrigerant injection techniques in detail. Liquid and vapor refrigerant injection techniques are discussed and compared. The current research on refrigerant injection techniques falls into two categories: system level research and component level research. The system level research is focused on low ambient temperature heating, heat pump water heating, high ambient temperature cooling, cycle comparison, and control strategy development. Internal heat exchanger and flash tank cycles are the two typical cycles for refrigerant injection. These two cycles are discussed and compared in detail. The component level research is focused on employing different types of compressors, variable speed compressors, the injection process, and the flash tank. Different types of compressors employing refrigerant injection are presented. Based on the literature study, the potential future research directions are presented and discussed. The flash tank cycle control strategy and refrigerant charge management strategy are worth further research efforts. Compressor design can be improved in order to optimize the performance with refrigerant injection. The appropriate design of flash tanks plays a vital role in achieving appropriate two-phase flow patterns in the flash tank. Computational Fluid Dynamics (CFD) modeling can be a useful tool to facilitate the design of the flash tank.     

考虑生产过程时间的柔性作业车间调度优化

通过研究生产过程时间,重新细分和定义等待时间,建立包括运输时间、调整时间、故障时间、等待时间、加工时间在内的柔性作业车间生产过程的时间模型,研究了柔性作业车间调度优化问题并设计了混合遗传算法的求解算法。最后,采用经典柔性作业车间调度用例,验证和对比了柔性作业车间调度的结果。结果表明,基于生产过程时间模型研究柔性作业车间调度问题,其优化性能有较好的改进,具有更好的实际应用价值。     

Design considerations for refrigeration cycles

The Carnot COP, which assumes a thermodynamically ideal cycle in which no irreversibilities exist, is often considered to be a design goal for actual cycles. However, the Carnot COP does not consider heat transfer mechanisms. Heat transfer at a finite rate is necessarily an irreversible process and unavoidable in a refrigeration cycle. The lack of consideration of rate processes reduces the usefulness of the Carnot COP as a realistic design goal. In this paper, the limitations of both thermodynamics and heat transfer are considered to identify a more realistic design goal for the COP of refrigeration cycles. The consideration of heat transfer limitations leads to a design rule for the optimum distribution of heat exchange area between the low- and high-temperature heat exchangers.     

Young drivers' optimism bias for accident risk and driving skill: Accountability and insight experience manipulations

This study aimed to determine whether two brief, low cost interventions would reduce young drivers’ optimism bias for their driving skills and accident risk perceptions. This tendency for such drivers to perceive themselves as more skilful and less prone to driving accidents than their peers may lead to less engagement in precautionary driving behaviours and a greater engagement in more dangerous driving behaviour. 243 young drivers (aged 17–25 years) were randomly allocated to one of three groups: accountability, insight or control. All participants provided both overall and specific situation ratings of their driving skills and accident risk relative to a typical young driver. Prior to completing the questionnaire, those in the accountability condition were first advised that their driving skills and accident risk would be later assessed via a driving simulator. Those in the insight condition first underwent a difficult computer-based hazard perception task designed to provide participants with insight into their potential limitations when responding to hazards in difficult and unpredictable driving situations. Participants in the control condition completed only the questionnaire. Results showed that the accountability manipulation was effective in reducing optimism bias in terms of participants’ comparative ratings of their accident risk in specific situations, though only for less experienced drivers. In contrast, among more experienced males, participants in the insight condition showed greater optimism bias for overall accident risk than their counterparts in the accountability or control groups. There were no effects of the manipulations on drivers’ skills ratings. The differential effects of the two types of manipulations on optimism bias relating to one's accident risk in different subgroups of the young driver sample highlight the importance of targeting interventions for different levels of experience. Accountability interventions may be beneficial for less experienced young drivers but the results suggest exercising caution with the use of insight type interventions, particularly hazard perception style tasks, for more experienced young drivers typically still in the provisional stage of graduated licensing systems.     

Degradation of bond between FRP and RC beams

Beams and slabs externally reinforced with FRP are often in contact with moisture and temperature cycles that reduce the expected durability of the system. Bond degradation is a frequent cause of premature failure of structural elements and environmental conditions are known to relate to such failures. The study shows the effects of cycles of salt fog, temperature and moisture as well as immersion in salt water on the bending response of beams externally reinforced with GFRP or CFRP, especially on bond between FRP reinforcement and concrete. Temperature cycles (−10 °C; 10 °C) and moisture cycles were associated with failure in the concrete substrate, while salt fog cycles originated failure at the interface concrete–adhesive. Immersion in salt water and salt fog caused considerable degradation of bond between the GFRP strips and concrete. However, immersion did not lower the load carrying capacity of beams, unlike temperature cycles (−10 °C; 10 °C) that caused considerable loss. No significant differences were detected on the behavior of the systems strengthened with GFRP and CFRP, perhaps because the design of the tests impeded failure of the fibres.     

VLSI design for MPEG-4 shape coding using a contour-based binary motion estimation algorithm

An efficient architecture with the fast algorithm for MPEG-4 shape coding is proposed. The authors apply the fast shape coding algorithm, with contour-based binary motion estimation (CBBME), which is based on the properties of a boundary mask. By using the block-matching motion estimation and the extended approach on centre-biased motion vector distribution with shrinking of the search range, a large number of search points in BME can be skipped. Based on this algorithm, a dedicated architecture design using the proposed CBBME algorithm is developed. With certain optimisation and design considerations, the memory access and processing cycles can be reduced. The average number of clock cycles for the processing of one binary alpha block is only 1708, which is only 56% of the previous design. In addition, a prototyping chip for shape coding is implemented and verified. The die area is 2.4 x 2.4 mm² with TSMC 0.18 μm CMOS technology and the maximum clock frequency is 53 MHz.     

Current hurdles in the commercial development of inorganic membrane reactors

This article is a summary of a presentation which was given at the 4th International Conference on Catalysis in Membrane Reactors (ICCMR 2000), which was held 3–5 July 2000 in Zaragoza, Spain. At an earlier ICCMR meeting which was held during 1994 in Lyon, France there was some optimism that by now we would see some commercial implementations of catalytic membrane reactors. In the event this optimism has proved to be unfounded. Not only are there no immediate commercial prospects for catalytic membrane reactors, but we have yet to see any ceramic gas separation membranes in industrial use. This article will examine why this should be the case. It will also look at the underlying reasons, the progress made so far, and the problems which still need to be resolved.     

Enhanced ejector refrigeration cycles powered by low grade heat. Part 1. Systems characterization

Conventional and improved ejector refrigeration cycles are discussed. Special emphasis is given to the adaptation of these cycles for the utilization of low grade or waste heat. A compression enhanced ejector system is suggested as a mechanically efficient way to improve the ejector cycle. It is demonstrated that a combination of mechanical and thermal energies may provide a wide range of design alternatives which should yield a competitive refrigeration system. The paper provides an over-all view of the systems by discussing their principle of operation, expected performance and design considerations.