[Book review] Theory of Games and Economic Behaviour

Tony Mann provides a review of the book: Theory of Games and Economic Behavior, John von Neumann and Oskar Morgenstern, Princeton University Press, 1944.

The effect of thermal cycle profiles on solder joint damage

The relationship between the damage caused at different thermal cycles is very important. The whole of accelerated thermal cycle testing is based on the premise that damage at one cycle is representative of damage at a different cycle. In this paper, the relative damage caused by six thermal cycle profiles are predicted using Finite Element (FE) modelling and the results validated against experiments. Both creep strain and strain energy density were used as damage indicators and creep strain was found to correlate better with experiment. The validated FE model is then used to investigate the effect of altering each of the thermal profile parameters (ramp and swell times, hot and cold temperatures). The components used for testing are surface mount resistors - 1206, 0805 and 0603. The solders investigated are eutectic SnAgCu and eutectic SnAg.

Effect of reflow profile and thermal cycle ageing on the intermetallic formation and growth in lead-free soldering

The formation and growth of intermetallic compound layer thickness is one of the important issues in search for reliable electronic and electrical connections. Intermetallic compounds (IMCs) are an essential part of solder joints. At low levels, they have a strengthening effect on the joint; but at higher levels, they tend to make solder joints more brittle. If the solder joint is subjected to long-standing exposure of high temperature, this could result in continuous growth of intermetallic compound layer. The brittle intermetallic compound layer formed in this way is very much prone to fracture and cold therefore lead to mechanical and electrical failure of the joint. Therefore, the primary aim of this study is to investigate the growth of intermetallic compound layer thickness subjected to five different reflow profiles. The study also looks at the effect of three different temperature cycles (with maximum cycle temperature of 25 0C, 40 0C and 60 0C) on intermetallic compound formation and their growth behaviour.. Two different Sn-Ag-Cu solder pastes (namely paste P1 and paste P2) which were different in flux medium, were used for the study. The result showed that the growth of intermetallic compound layer thickness was a function of ageing temperature. It was found that the rate of growth of intermetallic compound layer thickness of paste P1 was higher than paste P2 at the same temperature condition. This behaviour could be related to the differences in flux mediums of solder paste samples used.

A life cycle model for product-service systems design

Western manufacturing companies are developing innovative ways of delivering value that competes with the low cost paradigm. One such strategy is to deliver not only products, but systems that are closely aligned with the customer value proposition. These systems are comprised of integrated products and services, and are referred to as Product-Service Systems (PSS). A key challenge in PSS is supporting the design activity. In one sense, PSS design is a further extension of concurrent engineering that requires front-end input from the additional downstream sources of product service and maintenance. However, simply developing products and service packages is not sufficient: the new design challenge is the integrated system. This paper describes the development of a PSS data structure that can support this integrated design activity. The data structure is implemented in a knowledge base using the Protégé knowledge base editor.

The Olympic Games and urban displacement: the case of Beijing

Urban spectacles such as the Olympic Games have been long perceived as being able to impose desired effects in the city that act as host. This kind of urban boost may include the creation of new jobs and revenue for local community, growth in tourism and convention business, improvements to city infrastructure and environment, and the stimulation of broad reform in the social, political and institutional realm. Nevertheless at the other end of the debate, the potentially detrimental impacts of Olympic urban development, particularly on disadvantaged and vulnerable groups, have also been increasingly noticed in recent years and subsequently cited by a number of high profile anti-Olympic groups to campaign against Olympic bids and awards. The common areas of concern over Olympic-related projects include the cost and debts risk, environmental threat, the occurrence of social imbalance, and disruption and disturbance of existing community life. Among these issues, displacement of low income households and squatter communities resulting from Olympic-inspired urban renewal are comparatively under-explored and have emerged as an imperative area for research inquiry. This is particularly the case where many other problems have become less prominent. Changing a city’s demographic landscape, particularly displacing lower income people from the area proposed for a profitable development is a highly contentious matter in its own right. Some see it as a natural and inevitable outgrowth of the process of urban evolution, without which cities cannot move towards a more attractive location for consumption-based business. Others believe it reflects urban crises and conflicts, highlighting the market failures, polarization and injustice. Regardless of perception,these phenomena are visible everywhere in post-industrial cities and particularly cannot be ignored when planning for the Olympic Games and other mega-events. The aim of this paper is to start the process of placing the displacement issue in the context of Olympic preparation and to seek a better understanding of their interrelations. In order to develop a better understanding of this issue in terms of cause, process, influential factors and its implication on planning policy, this paper studies the topic from both theoretic and empirical angles. It portrays various situations where the Olympics may trigger or facilitate displacement in host cities during the preparation of the Games, identifies several major variables that may affect the process and the overall outcome, and explores what could be learnt in generic terms for planning Olympic oriented infrastructure so that ill-effects to the local community can be effectively controlled. The paper concludes that the selection of development sites, the integration of Olympic facilities with the city’s fabric, the diversity of housing type produced for local residents and the dynamics of the new socioeconomic structure.