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51.
52.
Dipl.-Inf. Marina Berkovich Prof.?Dr. Jan Marco Leimeister Prof.?Dr. Helmut Krcmar 《WIRTSCHAFTSINFORMATIK》2011,53(6):357-370
In recent years, manufacturing companies and service providers have moved towards offering customer-specific problem solutions. These integrated bundles usually consist of hardware, software, and service components and are called product service systems (PSS) or hybrid products. Since the success of the resulting solution depends on the understanding of all requirements, requirements engineering (RE) has become a key factor. The article analyzes the state of the art of RE for PSS based on an extensive literature review in the domains of product-, software-, and service engineering. For this, criteria are derived from the characteristics of PSS and from the task area of RE in the life cycle of PSS. Based on these criteria we analyze the most established RE approaches for their suitability for PSS. An important finding is that integrated/interdisciplinary approaches for RE are missing. Moreover, the maturity of RE approaches in the three domains varies significantly. All analyzed approaches heavily rely on concepts and solution characteristics of their own domain so that a transfer to other domains is hardly possible. This literature review lays the foundation for successful RE for PSS and especially for future research aiming at combining and integrating RE approaches and models of product-, software-, and service engineering. Such requirement models could connect concepts of single domains and enable an integrated and seamless RE for PSS. 相似文献
53.
City councils hold meetings several times a week. There is a need for computer support at certain meetings. This paper examines the potential for group support systems for use in city council meetings and shows in what ways they can be helpful in pre-meeting and post-meeting activities. The study is based on 17 computer-supported city council meetings, carried out in Stuttgart, Kornwestheim and other cities as part of the Cuparla Project between 1996 and 1998. Three of these meetings are described in the paper as brief case studies. Following this, all 17 meeting sequences are evaluated and analysed. Guidelines have been developed from the results of the study for the introduction of group support systems in city council meetings. 相似文献
54.
Abstract— Coatings of indium tin oxide (ITO) nanoparticles on different flexible polymer substrates were investigated with respect to the achievable sheet resistance and their electrical behavior under oscillatory bending. As substrate materials, polyethyleneterephthalate (PET), polyethylenenaphthalate (PEN), polyetheretherketone (PEEK), and polyimide (PI) were chosen, the surface resistances on the different polymer substrates were compared as a function of annealing temperature and surface topography. The surface topography, which has a strong influence on the surface resistance, was characterized by means of a white‐light confocal (WL‐CF) microscope. On the PET substrate, which exhibits the smoothest surface, the coating of ITO nanoparticles shows the lowest sheet resistance of 2 kΩ/□ for a layer thickness of 3 μm and an annealing temperature of 200°C. Furthermore, the electrical behavior of coatings of ITO nanoparticles under oscillatory bending was investigated using a special device. These coatings show a cyclic change of the conductivity which can be explained by an alternating compression and extension of crack flanks under the applied stress. Due to the growing number of cracks with increasing number of cycles, a decrease of the conductivity is observed in the bent state as well as in the balanced state. For a small bending radii, the decrease of the conductivity is stronger due to more cracks caused by the higher tensile stresses in the layer. The electrical behavior of the coatings of the annealed ITO nanoparticles on PET films under oscillatory bending was compared with commercially available sputtered ITO coatings. The annealed coatings of ITO nanoparticles demonstrate better electrical properties under oscillatory bending than coatings of sputtered ITO. The different electrical behavior under oscillatory bending can be related to differences in crack formation. 相似文献
55.
Helmut Neukirchen Benjamin Zeiss Jens Grabowski 《International Journal on Software Tools for Technology Transfer (STTT)》2008,10(4):309-326
Experience with the development and maintenance of large test suites specified using the Testing and Test Control Notation (TTCN-3) has shown that it is difficult to construct tests that are concise with respect to quality aspects such as maintainability
or usability. The ISO/IEC standard 9126 defines a general software quality model that substantiates the term “quality” with
characteristics and subcharacteristics. The domain of test specifications, however, requires an adaption of this general model.
To apply it to specific languages such as TTCN-3, it needs to be instantiated. In this paper, we present an instantiation
of this model as well as an approach to assess and improve test specifications. The assessment is based on metrics and the
identification of code smells. The quality improvement is based on refactoring. Example measurements using our TTCN-3 tool
TRex demonstrate how this procedure is applied in practise.
B. Zeiss is supported by a Ph.D. scholarship from Siemens AG, Corporate Technology. 相似文献
56.
Helmut Reimer 《Datenschutz und Datensicherheit - DuD》2008,32(11):766-767
Ohne Zusammenfassung 相似文献
57.
58.
Lawrence E. Matson Helmut Erhart Moonyong Lee Robert A. Rapp 《Metallurgical and Materials Transactions A》1984,15(12):2241-2246
In situ oxidation of polycrystalline iron at 1200 °C and
atm has revealed symmetrical square growth pits in the wustite scale. The pit walls are nominally oriented with the {110}
planes of the wustite lattice but are dissociated into macro- and microledges consisting of {100}-type planes. Such growth
pits intrude into the wustite scale at the gas/oxide interface, and at the oxide/metal interface small oxide nodules intrude
into the metal. After sufficiently long oxidation times at 1200 °C, rate control should shift from oxidant arrival to cation
volume diffusion, and pits are then destabilized and a planar morphology is achieved. 相似文献
59.
60.
Groenesteijn L Ellegast RP Keller K Krause F Berger H de Looze MP 《Applied ergonomics》2012,43(2):320-328
In the present study, we investigated the effect of office tasks on posture and movements in field settings, and the comfort rating for chair characteristics and correlation with type of task. The tasks studied were: computer work, telephoning, desk work and conversation. Postures, movements, chair part inclinations and comfort rating data were collected from 12 subjects. Computer work showed the lowest physical activity, together with upright trunk and head position and low backrest inclination. Conversation shows the highest activity of head legs and low back together with the highest cervical spine extension. In contrast, desk work provoked the most cervical spine flexion and showed the second lowest activity. The telephoning tasks showed medium activity and the highest kyphosis. Conversation showed the highest backrest inclination. Positive comfort relations were found for computer work and a "swing system" chair, for telephoning and an active longitudinal seat rotation, and for desk work and a chair with a three-dimensionally moveable seat. 相似文献