Persistent Reusable Java Virtual Machine unter z/OS und Linux

Zusammenfassung Die Nutzung von Java zur Entwicklung von Anwendungen für Hochleistungstransaktionssysteme stellt besondere Anforderungen an die Isolation und das Leistungsverhalten in der transaktionalen Ausführung. In dem vorliegenden Beitrag wird eine neuartige Technologie beschrieben, die verbesserte Isolationseigenschaften und eine erhebliche Leistungssteigerung erm?glicht. Die Persistent Reusable Java Virtual Machine erweitert eine normale Java Virtual Machine um gemeinsam genutzte Klassen und um eine Reset-Funktionalit?t, die eine serielle Wiederverwendbarkeit erm?glicht. In einer Benchmark-Untersuchung unter z/OS wurde hiermit ein Performance-Gewinn um einen Faktor 325 im Vergleich mit einer normalen JVM erreicht. Für das Erstellen von Transaktionsanwendungen unter dem Betriebssystem z/OS sind Enterprise Java Beans damit eine ernstzunehmende Alternative zu bisherigen Programmiermodellen.

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The use of Java for the development of new applications in high-end transaction systems generates special isolation and performance requirements. A new technology offering improved isolation and a significant performance improvement is discussed in this article. The Persistent Reusable Java Virtual Machine extends a regular Java Virtual Machine by adding the facility to share classes and by providing a reset functionality, which permits serial reuse of the JVM. A z/OS benchmark demonstrated a performance improvement by a factor of 325, compared to a regular JVM. Thus the use of Enterprise Java Beans has to be considered as a serious alternative when developing new transactional applications under the z/OS operating system.

     

Themenheft: Electronic Commerce

Ohne Zusammenfassung     

Inside the College Writing Gap: Exploring the Mixed Messages of Remediation Support

This case study offers a qualitative perspective on a relationship between institutional structures and student outcomes. The data describe the conditions in 10 English remediation classrooms at one urban community college district. The study uses new literacies as a theoretical framework with which to understand how these conditions supported classroom-level teaching and learning. Findings suggest that classroom conditions undermined new literacies’ assumptions that college writing is a social practice. The authors discuss the implications of these findings for research to improve writing remediation policies.     

Lessons from the Legacy of Canada-China University Linkages

This article looks at a series of university linkages between Canadian and Chinese universities that were supported by the Canadian International Development Agency as a result of a development agreement signed in 1983 between the two governments. It first reviews relevant theoretical literature on higher education in a global context, and discusses the methodology adopted for the study. Then it provides an overview of a major program of collaboration in management education between 1983 and 1996, presenting views of leaders and participants on both sides. The next section overviews parallel linkages in the areas of education, engineering, agriculture, and medicine over the period from 1988 to 2001, and draws on the literature around university partnerships to identify factors that led, in some cases, to long-term sustainable relationships, but not in all. The final section of the paper reviews two major culminating linkages in environment and law, and suggests that these may have significant lessons for current and future cooperation between Chinese and Canadian universities in a new era of global geo-politics.     

Cultural stereotypes and professional self-socialisation in the transition from education to work

A key insight from studies of gender segregation is that the allocation of different groups to different positions in the labour market is strongly related to ascribed status. Shared gendered cultural beliefs generally portray men as more competent and of a higher status than women, and position some workers as more suited than others to perform different types of work and tasks. Yet, although much work has been done on status and gender segregation, this research tends to overlook the intersections of gender, race, and ethnicity. This study contributes to the literature by examining how skills and competence are valued in traditionally gender- segregated professions that have seen an increased influx of immigrants and ethnic minorities. Drawing on 66 qualitative interviews with Norwegian students, the study analyses, first, how gender, racial, and ethnic stereotyping of tasks and competencies affect the students’ aspirations in transition from education to work, and second, how the intersection between race, ethnicity, and gender plays out quite differently in different professions. Theoretically, I develop the concept of ‘professional self-socialisation’, which points to the process whereby individuals adapt and redefine their aspirations to the gendered, ethnic, and racial hierarchy of suitability within their profession.     

Methodik, Sprachen und Grundlagen des Software Engineering

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Adventures in Implementing a Testing Program

What are the ways in which a testing program can run aground? What are some suggestions for avoiding these problems?