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21.
This paper examines the concept of Quality in Software Engineering, its different contexts and its different meanings to various people. It begins with a commentary on quality issues for systems development and various stakeholders' involvement. It revisits aspects and concepts of systems development methods and highlights the relevance of quality issues to the choice of a process model. A summarised review of some families of methods is presented, where their application domain, lifecycle coverage, strengths and weaknesses are considered. Under the new development era the requirements of software development change; the role of methods and stakeholders change, too. The paper refers to the latest developments in the area of software engineering and emphasises the shift from traditional conceptual modelling to requirements engineering and process metamodelling principles. We provide support for an emerging discipline in the form of a software process metamodel to cover new issues for software quality and process improvement. The widening of the horizons of software engineering both as a communication tool and as a scientific discipline (and not as a craft) is needed in order to support both communicative and scientific quality systems properties. In general, we can consider such a discipline as a thinking tool for understanding the generic process and as the origin of combining intuition and quality engineering to transform requirements to adequate human-centred information systems. We conclude with a schematic representation of a Generic Process Metamodel (GPM) indicating facets contributed by Software Engineering, Computer Science, Information Systems, Mathematics, Linguistics, Sociology and Anthropology. Ongoing research and development issues have provided evidence for influence from even more diverse disciplines.  相似文献   
22.
Modeling emergency evacuation for major hazard industrial sites   总被引:1,自引:0,他引:1  
A model providing the temporal and spatial distribution of the population under evacuation around a major hazard facility is developed. A discrete state stochastic Markov process simulates the movement of the evacuees. The area around the hazardous facility is divided into nodes connected among themselves with links representing the road system of the area. Transition from node-to-node is simulated as a random process where the probability of transition depends on the dynamically changed states of the destination and origin nodes and on the link between them. Solution of the Markov process provides the expected distribution of the evacuees in the nodes of the area as a function of time. A Monte Carlo solution of the model provides in addition a sample of actual trajectories of the evacuees. This information coupled with an accident analysis which provides the spatial and temporal distribution of the extreme phenomenon following an accident, determines a sample of the actual doses received by the evacuees. Both the average dose and the actual distribution of doses are then used as measures in evaluating alternative emergency response strategies. It is shown that in some cases the estimation of the health consequences by the average dose might be either too conservative or too non-conservative relative to the one corresponding to the distribution of the received dose and hence not a suitable measure to evaluate alternative evacuation strategies.  相似文献   
23.
The purpose of this study was to determine the effects of an educational program and structured support on breast self-examination (BSE) frequency, proficiency, and perceived control in middle-aged and older women at 6 and 12 months after instruction. Women were randomly assigned to one of three treatment groups: (a) no-support control group; (b) peer support group; and (c) selected partner support group. All women received the same instructional program. Women assigned to peer and selected partner support groups received additional reinforcement from their partners to perform BSE for the next 6 months. There were significant differences between the initial interview and 6-month scores on BSE frequency, expert and self-rating of proficiency, and perceived skill. Self and expert ratings of proficiency and perceived skill continued to increase at 12 months postinstruction. No significant differences were found among the three support treatment groups.  相似文献   
24.
The difficulties of achieving social acceptance for Software Quality Management systems have been underestimated in the past, and they will be exacerbated in the future by the globalization of the software market and the increasing use of cross-cultural development teams within multinational companies. Management that can take account of the cultural context of their endeavours will improve understanding, minimize risk and ensure a higher degree of success in improvement programs within the software industry.This paper addresses cross-cultural issues in Software Quality Management. Qualitative and quantitative research was carried out in five European countries by using a postal questionnaire. Empirical measures of organizational culture, national culture and their interdependence, are presented together with interim instruments developed for the purpose of classifying organizations. Verification of the statistical results from the survey was carried out by triangulation, which included qualitative research methods in the form of interviews and observation. Cultural factors, which may have bearing on successful adoption and implementation of Software Quality Management were identified, and an assessment model, has been developed for use by organizations developing software in different parts of the world. The intention is that the recommendations following from the assessment will lead to greater cultural awareness in addressing quality, and will provide stimulus for improvement. The model's aims is to predict to what degree there is a fit between the organizational and the national culture, and to give recommendations and guidelines for software process improvement.  相似文献   
25.
The selection of an appropriate non-hazardous solvent or solvent system is essential to determine the rheological properties and electrospinnability of the solution, the productivity, and the morphology of nanofibres. In this study, poly lactic acid (PLA) solutions were prepared in various pure solvents and binary-solvent systems to investigate the effect of different solution properties on nanofibre morphology and diameter. Viscosity, conductivity and surface tension of each solution were measured. Nanofibre morphology was observed by scanning electron microscopy (SEM). Of all the solvent systems used acetone/dimethylformamide gave the highest fibre productivity and finest defect-free nanofibres. Therefore this solvent system was studied in more detail, varying the solvent ratio. Also the polymer concentration in this solvent system was varied to investigate the effect on nanofibre morphology and solution properties. Morphological investigations were done in correlation with rheological measurements: beaded nanofibrous structures were collected from solutions with concentration around the critical chain entanglement concentration (Ce), while defect-free nanofibres were produced when the concentration was increased to about twice the entanglement concentration. Further investigation of the effect of the PLA concentration on the elastic (G′) and the plastic (G″) moduli showed a sudden increase of the elastic moduli (G′) at the critical chain entanglement concentration. The results showed that the solvent properties, boiling point, viscosity, conductivity and surface tension, have a significant effect on process productivity, morphology and diameter distribution of the PLA nanofibres.  相似文献   
26.
Software quality models have primarily been based on top down process improvement approaches. Such models are based on the fundamental principle of empowerment of all involved and foster a questioning attitude through the active exchange of ideas and criticism ensuring that the most appropriate approach for quality improvements is adopted. The holistic view of systems enables the incorporation of many viewpoints held by different parties within the same organisation and by the same party at different stages of development. In this paper the GEQUAMO (GEneric, multilayered and customisable) QUAlity MOdel is proposed. GEQUAMO encapsulates the requirements of different stakeholders in a dynamic and flexible manner so as to enable each stakeholder (developer, user or sponsor) to construct their own model reflecting the emphasis/weighting for each attribute/requirement. Using a combination of the CFD (Composite Features Diagramming Technique) developed by the author, and Kiviat diagrams a multilayered and dynamic model is constructed. Instances of models are presented together with the algorithm for the computation of the profiles. Indications of future work conclude the paper.  相似文献   
27.
Poly(vinyl chloride) (PVC) is produced via a nonaqueous polymerization process in which hexane is used as a diluent. This nonaqueous process can lead to significant energy savings, significant reductions in carbon dioxide emissions, and the elimination of wastewater. Various suspending agents have been used to evaluate their effects on the shape and morphology of PVC grains. The nonaqueous process leads to the formation of PVC grains with higher porosity than that of typical suspension PVC. The bulk density is slightly lower than that of suspension PVC, but the thermal stability seems to be similar. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   
28.
The use of computerized adaptive testing (CAT) has expanded rapidly over recent years mainly due to the advances in communication and information technology. Availability of advanced mobile technologies provides several benefits to e-learning by creating an additional channel of access with mobile devices such as PDAs and mobile phones. This paper describes the design issues that were considered for the development and the implementation of a CAT on mobile devices, the computerized adaptive test on mobile devices (CAT-MD). Throughout the development of the system, formative evaluation was an integral part of the design methodology. The recommendations, suggestions and the results of the formative evaluation were used to improve the system in order to make the assessment procedure more effective and efficient. These results of the formative evaluation are also presented here.  相似文献   
29.
Photochemically induced emission tuning for the definition of pixels emitting the three primary colors, red, green, blue (RGB), in a single conducting polymeric layer is investigated. The approach proposed is based on an acid‐induced emission shift of the (1‐[4‐(dimethylamino)phenyl]‐6‐phenylhexatriene) (DMA‐DPH) green emitter and acid‐induced quenching of the red fluorescent emitter (4‐dimethylamino‐4′‐nitrostilbene) (DANS). The two emitters are dispersed in the wide bandgap conducting polymer poly(9‐vinylcarbazole) (PVK), along with a photoacid generator (PAG). In the unexposed film areas, red emission is observed because of efficient energy transfer from PVK and DMA‐DPH to DANS. Exposure of selected areas of the film at different doses results in quenching of the red emitter's fluorescence and the formation of green, blue, or even other color‐emitting pixels, depending on the exposure dose and the relative concentrations of the different compounds in the film. Organic light‐emitting diodes having the PVK polymer containing the appropriate amounts of DMA‐DPH, DANS, and PAG as the emitting layer are fabricated and electroluminescence spectra are recorded. The time stability of induced emission spectrum changes and the color stability during device operation are also examined, and the first encouraging results are obtained.  相似文献   
30.
The purpose of the study was to assess a fluorimetric assay for the determination of total phospholipase A2 (PLA2) activity in biological samples introducing the innovation of immobilized substrates on crosslinked polymeric membranes. The immobilized C12‐NBD‐PtdCho, a fluorescent analogue of phosphatidylcholine, exhibited excellent stability for 3 months at 4 °C and was not desorbed in the aqueous reaction mixture during analysis. The limit of detection was 0.5 pmol FA (0.2 pg) and the linear part of the response curve extended from 1 up to 190 nmol FA/h/mL sample. The intra‐ and inter‐day relative standard deviations (%RSD), were ≤6 and ≤9 %, respectively. Statistical comparison with other fluorescent methods showed excellent correlation and agreement. Semiempirical calculations showed a fair amount of electrostatic interaction between the NBD‐labeled substrate and the crosslinked polyvinyl alcohol with the styryl pyridinium residues (PVA‐SbQ) material, from the plane of which, the sn‐2 acyl chain of the phospholipid stands out and is accessible by PLA2. Atomic Force Microscopy revealed morphological alterations of the immobilized substrate after the reaction with PLA2. Mass spectrometry showed that only C12‐NBD‐FA, the PLA2 hydrolysis product, was detected in the reaction mixture, indicating that PLA2 recognizes PVA‐SbQ/C12‐NBD‐PtdCho as a surface to perform catalysis.  相似文献   
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