Dimensions of variability in embedded operating systems     

Wolfgang Schr?der-Preikschat  Daniel Lohmann  Fabian Scheler  Olaf Spinczyk 《Informatik - Forschung und Entwicklung》2007,22(1):5-22

Design, implementation, and re-engineering of operating systems are still an ambitious undertaking. Despite, or even because, of the long history of theory and practice in this field, adapting existing systems to environments of different conditions and requirements as originally specified or assumed, in terms of functional and/or non-functional respects, is anything but simple. Especially this is true for the embedded systems domain which, on the one hand, calls for highly specialized and application-aware system abstractions and, on the other hand, cares a great deal for easily reusable implementations of these abstractions. The latter aspect becomes more and more important as embedded systems technology is faced with an innovation cycle decreasing in length. Software for embedded systems needs to be designed for variability, and this is in particular true for the operating systems of this domain. The paper discusses dimensions of variability that need to be considered in the development of embedded operating systems and presents approaches that aid construction and maintenance of evolutionary operating systems. CR subject classification  C.3; D.2.11; D.2.13; D.4.7  相似文献   

Die ODAWA-Methodik für den Entwurf von Data-Warehouse-Datenbanken     

Olaf Herden und Arne Harren 《Informatik - Forschung und Entwicklung》2004,19(2):87-96

Zusammenfassung. Zusammenfassung Der Softwaremarkt für Data-Warehouse-Systeme hat in den letzten Jahren stark zugenommen. Da Standards fehlen, bringen Softwaresysteme jeweils eigene multidimensionale Datenmodelle und (physische) Entwurfswerkzeuge mit, sodass der Entwurf von Data-Warehouse-Datenbanken verfrüht auf die eingesetzten Systeme zugeschnitten ist. In diesem Beitrag präsentieren wir ein werkzeuggestütztes Entwurfsvorgehen, das ausgehend von einem Drei-Ebenen-Entwurf die zielplattformunabhängige, konzeptionelle Modellierung multidimensionaler Data-Warehouse-Schemata und anschliesend eine Transformation und Optimierung dieser Schemata für konkrete Zielplattformen ermöglicht. Durch die konzeptionelle Modellierung wird gewährleistet, dass Implementierungsdetails nicht zu früh in den Entwurfsprozess einfliesen und stattdessen fachliche Anforderungen im Vordergrund stehen.CR Subject Classification: D.2.2, H.2.1Arne Harren: Die hier beschriebene Arbeit entstand während unserer gemeinsamen Tätigkeit am Oldenburger Forschungsinstitut OFFIS (http: //www.offis.de).Eingegangen am 25. Juli 2003 / Angenommen am 1. Juni 2004, Online publiziert 6. September 2004  相似文献   

Testing Visual Signals in Representative Surveys in Combination with Media Content Analyses of the 2002 German Federal Election Campaign     

Petersen  Thomas; Jandura  Olaf 《Int. Journal of Public Opinion Research》2007,19(1):89-96

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Relationship Reciprocation Modulates Resource Allocation in Adolescent Social Networks: Developmental Effects          下载免费PDF全文

Stephanie Burnett Heyes  Yeou‐Rong Jih  Per Block  Chii‐Fen Hiu  Emily A. Holmes  Jennifer Y. F. Lau 《Child development》2015,86(5):1489-1506

Adolescence is characterized as a period of social reorientation toward peer relationships, entailing the emergence of sophisticated social abilities. Two studies (Study 1: N = 42, ages 13–17; Study 2: N = 81, ages 13–16) investigated age group differences in the impact of relationship reciprocation within school‐based social networks on an experimental measure of cooperation behavior. Results suggest development between mid‐ and late adolescence in the extent to which reciprocation of social ties predicted resource allocation. With increasing age group, investment decisions increasingly reflected the degree to which peers reciprocated feelings of friendship. This result may reflect social‐cognitive development, which could facilitate the ability to navigate an increasingly complex social world in adolescence and promote positive and enduring relationships into adulthood.  相似文献   

What Can a Teacher Do to Support Students’ Interest in Science? A Study of the Constitution of Taste in a Science Classroom     

Per Anderhag  Karim Mikael Hamza  Per-Olof Wickman 《Research in Science Education》2015,45(5):749-784

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Managing research and innovation networks: Evidence from a government sponsored cross-industry program     

Per Levén  Jonny Holmström  Lars Mathiassen 《Research Policy》2014

Important innovations are increasingly produced based on research engagement and fertilization across industries. However, we know little about the challenges associated with managing innovation networks in specific contexts that involves researchers in cross-industry collaboration. Against this backdrop, we draw on theory on design and orchestration of innovation networks to analyze a large-scale government sponsored program, “ProcessIT Innovations” that was designed to increase competitiveness and accelerate economic growth in Northern Sweden. The program was initiated and led by firms from the traditionally strong local process industry and engaged local researchers and firms from the emerging IT industry. Based on our analyses, we offer two contributions. First, we provide a detailed analysis of the challenges related to configuration of the network, orchestration of partnerships between participants, and facilitation of innovation in dedicated development projects. Second, we propose a model of managing research and innovation networks through fertilization across industries and between firms and research institutions.  相似文献   

Mandatory coursework assignments can be,and should be,eliminated!     

John Haugan  Marius Lysebo  Per Lauvas 《European Journal of Engineering Education》2017,42(6):1408-1421

Formative assessment can serve as a catalyst for increased student effort and student learning. Yet, many engineering degree programmes are dominated by summative assessment and make limited use of formative assessment. The present case study serves as an example on how formative assessment can be used strategically to increase student effort and improve student learning. Within five courses of an engineering bachelor degree programme in Norway, the mandatory coursework assignments were removed and replaced by formative-only assessment. To facilitate the formative assessment, weekly student peer-assessment sessions were introduced. The main findings include an increase in student study hours and improved student performance on the examinations. Finally, interviews were conducted by an external consultant in an effort to identify key factors that attributed to the positive outcome.  相似文献   

On the effects of motivation on reading performance growth in secondary school   总被引：1，自引：0，他引：1  

Jan Retelsdorf  Olaf KöllerJens Möller 《Learning and Instruction》2011,21(4):550-559

This research aimed at identifying unique effects of reading motivation on reading performance when controlling for cognitive skills, familial, and demographic background. We drew upon a longitudinal sample of N = 1508 secondary school students from 5th to 8th grade. Two types of intrinsic reading motivation (reading enjoyment, reading for interest), one type of extrinsic reading motivation (competition), and reading self-concept were measured by self-report questionnaires. Cognitive skills (reasoning, decoding speed) and reading performance were assessed using standardized tests and background variables were collected using student and parent questionnaires. Applying latent growth curve modeling, positive unique effects of reading enjoyment and reading self-concept and a negative unique effect of competition on the initial level of reading performance were recorded. Moreover, a positive unique effect of reading for interest on reading performance growth was recorded. One may conclude that enhancing students’ interest might be fruitful in terms of nurturing reading performance.  相似文献   

RPL for accreditation in higher education – As a process of mutual understanding or merely lifeworld colonisation?     

Fredrik Sandberg  Per Andersson 《Assessment & Evaluation in Higher Education》2011,36(7):767-780

This article focuses on a process of recognition of prior learning (RPL) in higher education. It is based on experiences from a project carried out in collaboration between the University of Lund, Linköping University and two trade unions in Sweden. The aim of the project was to find ways of recognising prior learning for accreditation of course credits at university level. In the project and its analysis, Habermas’ theory of communicative action was used as theoretical underpinning. During the project we carried out a thematic analysis based on interviews. The analysis suggested that the participants had a mystified view of higher education that RPL must be considered a learning process and that the participants’ prior learning can be characterised as practical wisdom. These themes guided the development of the project. In a retrospective analysis, language proficiency seemed to play a significant role for the outcome of the process. The conclusion suggests that a more fair and valid assessment of the participant’s prior learning could be accomplished by focusing on RPL as a process of mutual understanding. However, a critical appraisal of the process suggests that RPL for accreditation is problematic and could be seen as a colonisation of the lifeworld.  相似文献   

Negative school factors and their influence on math and science achievement in TIMSS 2003     

Tina Vršnik Perše  Ana Kozina  Tina Rutar Leban 《Educational studies》2011,37(3):265-276

The aim of the present study was to conduct an analysis of TIMSS (Trends in International Mathematics and Science Study) 2003 database and to determine how negative school factors, such as aggression, are associated to the mathematical and science achievement of students. The analyses were conducted separately for national and international data. National analyses for Slovenia show significant associations between math and science achievement and the experience of aggressive behaviour. Students who experienced aggressive behaviour scored lower in math and science, both in the fourth and in the eighth grade. The results of the regression analysis show that negative factors, such as aggressive behaviour, are good predictors of educational achievement in Slovenia. International analyses for the selected countries (high‐ and low‐achieving countries from the whole TIMSS population) confirm that this type of finding is culturally impartial as well as valid for the level of achievement both in math and in science.  相似文献