Fast probability integration by three-parameter normal tail approximation

A new method of fast probability integration is presented, based on a three-parameter normal tail approximation to a non-normal distribution function. Values of the distribution function, the probability density function and its derivative are matched at the approximation point with the approximating function. The approximation point is the known “design point”, used within the framework of second moment reliability theory. The proposed method is as fast as the available two-parameter algorithm, but is apparently more accurate.     

The Houston Growth Coalition In “Boom” and “Bust”

ABSTRACT: Although growth machine theory emphasizes the coalition's tactics and organization, it neglects adjustment to changing economic conditions. This article explores the changes in the strategy and organization of Houston's growth coalition during the peak growth of the 1970s and the decline of the 1980s. During the boom, the coalition focused not on additional growth but on easing the city's infrastructure problems. The coalition underwent several major changes during decline as it struggled to compete aggressively with other cities for various enterprises and to devise strategies for diversifying the economy. A growth coalition has the opportunity to establish the economic basis for future growth when the city's dominant industries reach maturity and decline.     

Psychosocial Factors and the “Sick Building-Syndrome”. A case-referent study

Abstract The significance of the psychosocial work environment for the prevalence of symptoms compatible with the “sick building syndrome” (SBS) was studied in a case-referent study including 464 office workers, half of whom had symptoms of SBS. A questionnaire was distributed to all subjects, and representatives of the organisations concerned were interviewed. The aim of the study was to investigate the importance of psychosocial and organisational factors in explaining the prevalence of SBS symptoms among office workers. The results showed that psychosocial work characteristics, such as workload and job satisfaction, as well as worry and reorganisation are factors that have a significant impact on the risk of developing the symptoms of SBS.     

Empfehlung Nr. 5 “Punktlastversuche an Gesteinsproben“ des Arbeitskreises 3.3 “Versuchstechnik Fels“ der Deutschen Gesellschaft für Geotechnik

Der Arbeitskreis AK 3.3 “Versuchstechnik Fels“ der Deutschen Gesellschaft für Geotechnik e. V. erarbeitet Empfehlungen für felsmechanische Labor‐ und Feldversuche sowie Messungen im Gebirge und an Bauwerken. Die vorliegende Neufassung der Empfehlung Nr. 5 behandelt den Punktlastversuch an Gesteinsprobekörpern und berücksichtigt die Weiterentwicklung der Versuchstechnik und ‐auswertung seit der gleichnamigen Empfehlung Nr. 5 von 1982. Es werden die Anforderungen an die Prüfeinrichtung und die Probekörper sowie die Vorgehensweisen für die Durchführung und Auswertung von Punktlastversuchen festgelegt. Die wesentliche Neuerung besteht darin, dass nicht mehr der Lastpunktabstand allein, sondern die Probekörperfläche zur Berechnung des Punktlastindex verwendet wird. Beim Punktlastversuch wird ein Indexwert für die Festigkeit eines Gesteins bestimmt, indem ein zylinderförmiger, quaderförmiger oder unregelmäßig geformter Probekörper zwischen zwei Lasteinleitungsspitzen bis zum Bruch belastet wird. In dieser Empfehlung werden der Zweck, die Begriffe, die Prüfeinrichtung, die Anforderungen an den Probekörper und die Versuchsdurchführung erläutert. Drei mögliche Optionen der Versuchsauswertung werden aufgezeigt, die Darstellung der Ergebnisse beschrieben und mit Hilfe von Beispielen illustriert. Abschließend wird erläutert, wie die einaxiale Druckfestigkeit aus der Punktlastfestigkeit abgeleitet werden kann. Recommendation No. 5 (revised) of the Commission on Rock Testing of the Deutsche Gesellschaft für Geotechnik e.V. — “point load tests on rock samples”. The Commission on Rock Testing of the Deutsche Gesellschaft für Geotechnik e.V. (German Geotechnical Society) is compiling instructions for rock tests conducted in the laboratory and in‐situ, and for performing monitoring of rock masses and civil engineering structures. The revised version of recommendation No. 5 deals with the point load test on rock samples and incorporates recent developments in testing machines and testing procedures since the first version from 1982. The requirements for the testing machines and the specimens are given, as well as the procedures to perform the tests and evaluate the data. The essential modification is the use of the sample area instead of the platen tip distance alone. The point load test is used to derive an index value for rock strength. Therefore rock specimens in the form of core, cut blocks or irregular lumps are loaded until failure between a pair of load tips. In this recommendation, scope, terms, apparatus, specimen requirements and procedure of the test are explained. Three possible options of test evaluation are given, the reporting of results described and illustrated by examples. Finally it is shown, how the uniaxial compressive strength can be derived by the point load strength.     

Environmental aesthetic design Identifying and achieving desired environmental effects, particularly “image” and “atmosphere”

Environmental aesthetic design is the process of determining aesthetic aspects of an environment still to be built. Aesthetic matters weigh heavily in the world of design and in the decisions of building designers, particularly architects. Yet, apart from its use within the specialized literature, the word aesthetic may mean whatever the user chooses it to mean. For the purposes of this paper an aesthetic effect of an environment is assumed to be a particular subjective quality that a designer may wish to give to, and a subjective response experienced by those who use, that environment. The paper proposes a simple procedure by which designers may establish aesthetic programmes (or briefs) for the “atmospheres” of environments and achieve their desired effects. The same procedure may be used to create a desired “image”.