Fit performance of several programs used for non-linear least squares problems

Seven computerprograms for non-linear regression or curve fitting problems are compared. The comparison of the programs, running in different computing centra, is restricted to the fit performance. Six model functions are fitted according to the least squares criterion to data series, arising from practical work. The special least squares minimization programs turned out to be better suited for these problems than general optimizing programs.     

发言摘登

这次会议讨论的是一个很重要的题目──国企转型与企业文化构建。我们现在对企业文化的认识,如果同10年前相比,可以说是跨越了一个世纪。当时感觉企业文化是个新鲜东西,并不知道它有多大用途,好像很时髦,多数人对它的认识还是狭窄的、浮面的。10年后的今天,经过理论界的探索研究,特别是经过企业界的创新实践,使得我们对企业文化的认识有了很大的发展。中外企业文化杂志社利用庆祝创刊10周年的机会,组织大家共同研讨国企转型与企业文化构建,这个题目选得非常好。当前,企业文化在中国的需求,很重要的一点就是与国企转型联系在了一起。企业文化…     

Factors that influence the consumption of food outside the home in Brazil

The food sector has taken on an unprecedented dynamism in recent years. The processing and distribution of food, although heavily influenced by tradition, have seen intensive innovations, leading to changes in the way individuals consume. One of these changes is the consistent growth of the habit of eating outside the home. Consuming food outside the home involves a number of practices such as eating at commercial establishments that specialize in food (restaurants, fast food restaurants and snack bars) and those that offer food as a part of their services (hotels, in‐flight meals), and non‐commercial alternatives such as the homes of family and friends. In order to describe the eating habits of consumers in the town of Lavras in Minas Gerais State, Brazil, especially when it comes to eating outside the home, a quantitative study was conducted, with 413 questionnaires being distributed by convenience sampling. Among the main results are: (a) a search for variety as a motivator for eating outside the home; (b) convenience as an important element on many occasions of consumption; (c) more intensive consumption and more favourable attitudes towards eating out on the part of younger people, people with higher incomes, no children and a higher degree of schooling; (d) importance of paying for food by the kilo. When compared with a study conducted in England, important similarities were identified in socio‐demographic influences, although the cultural factors are notable when it comes to dishes and the types of eating establishment. The growing habit of eating out has therefore become a worldwide phenomenon, but with cultural and regional differences that have led to different rhythms in terms of change and the way food is supplied. The recovery of embedded cultural habits, with increased value being given to slow food, traditional dishes and tradition itself, appears to co‐exist with a productivity model of food courts, pasteurization and accessible prices. The occasion for consumption, which may be understood as the dichotomies of ‘weekday versus weekend’ or ‘convenience versus leisure’, is an important element that influences consumer behaviours. The undertaking of a cross‐cultural comparative study can be seen as an important step in this field of research.     

Has the Internet Eliminated Regional Price Differences? Evidence from the Used Car Market

We study the effects of the Internet on regional price differences. Comparing two Dutch regions, we find that before the rise of the Internet, price differences of used cars between those regions amounted to some 11–15%, controlling for mileage, age, fuel type and engine volume. These price differences have completely disappeared after the rise of the Internet, in particular a website that allows consumers to make detailed comparisons between almost all used cars for sale in the Netherlands.     

Capitalization of Flood Insurance and Risk Perceptions in Housing Prices: An Empirical Agent‐Based Model Approach

Federally regulated or insured lenders in the United States are mandated to require flood insurance on properties that are located in areas at high risk of flooding. Despite the existence of this mandatory flood insurance requirement, take‐up rates for flood insurance have been low, and the federal government's exposure to uninsured property losses from flooding remains substantial. Meanwhile, the value of capital at risk varies significantly with flood events and changing risk perceptions, which necessitates mechanisms that stabilize these dynamics. In this article we discuss how a scenario of complete insurance uptake, under various risk attitudes, affects the value of properties in the 100‐year and 500‐year flood zones. Our results indicate that an increase in flood insurance uptake may provide such a mechanism by lowering the value of capital at risk in the flood zone consistently, independent of homeowners' risk attitudes. We apply an empirical adaptive agent‐based model to examine the capitalization of insurance costs, risk premiums, and their interaction in housing prices. Our approach combines widely‐used empirical hedonic analysis with the computational economic framework. We highlight the usefulness of our method in capturing the marginal implicit price of homeowners' preferences that may change over time and separately assess the effect of various factors and policies on property values, illustrating the agent‐based modeling as a valuable complement to traditional hedonic analysis.     

PAALiativ: Technik als Chance?

Assistenztechnologie im Wohnumfeld — Die Terminalphase des Lebens in h?uslicher Umgebung verbringen zu k?nnen entspricht dem Wunsch der meisten Menschen. In Oldenburg startete mit PAALiativ ein Projekt, mit dem exemplarisch nach M?glichkeiten der technischen Unterstützung für ein selbstbestimmtes Leben Schwerstkranker gesucht wird.     

Süchtige Sammler

Wohnungsdesorganisation bei Sucht - Chaotische Wohnverh?ltnisse lassen sich oft auf eine Suchterkrankung zurückführen. Dabei kann man einen deutlichen Unterschied zwischen Wohnungen von Menschen mit einer Kaufsucht und denen von Menschen mit psychischen St?rungen und Verhaltensst?rungen durch psychotrope Substanzen beobachten.