Knowledge-based systems (KBSs) have been built and practically applied in various contexts for decades. Yet, they still challenge developers by their complexity: Apart from a sound knowledge base they likewise require comprehensive user interface (UI) and interaction design for supporting the task at hand optimally. However, current KBS-Engineering methodologies still mostly focus on knowledge base development, regarding UI/interaction design a more incidental, low priority task. Thus, the UI often is developed in a rather ad hoc manner, thereby neglecting the potential of experimental design and creating reusable solutions. The integration of (rapid) evolutionary prototyping activities with KBS Engineering offers the chance for incorporating UI/interaction design more prominently into the process while at the same time leveraging the overall development task; specifically, we propose Extensible Prototyping as a tailored prototyping approach and we suggest its integration with the Agile Process Model for knowledge-based systems in this paper. For practical support, we further introduce the customized prototyping and knowledge systems engineering tool ProKEt, and we report on practical experiences with applying both the approach and the tool. 相似文献
Degradation of steam generator tubes is occurring in Spanish nuclear power plants. Degradation causes are different and give occasion for leakages.
General Criteria of Design, technical specifications and availability are concepts which must be harmonized. Historic behaviour of certain tube defects together with experiments and studies made by the Spanish Owner Group of Pressurized Water Reactors and approved by Consejo de Seguridad Nuclear have led to a new plugging criterion based on the Leak-Before-Break concept and a new limit for leakages is in operation in some plants. 相似文献
The statnet suite of R packages contains a wide range of functionality for the statistical analysis of social networks, including the implementation of exponential-family random graph (ERG) models. In this paper we illustrate some of the functionality of statnet through a tutorial analysis of a friendship network of 1,461 adolescents. 相似文献
In our quest for fractionating lignocellulosic biomass and valorizing specific constitutive fractions, we have developed a strategy for the separation of 12 added value monomers generated during the hydrolytic based‐catalyzed depolymerization of a Steam Exploded Aspen Lignin. The separation strategy combines liquid‐liquid‐extraction (LLE), followed by vacuum distillation, liquid chromatography (LC) and crystallization. LLE, vacuum distillation and flash LC were tested experimentally. Batch vacuum distillation produced up to 4 fractions. Process simulation confirmed that a series of 4 vacuum distillation columns could produce 5 distinct monomer streams, 3 of which require further chromatography and crystallization for purification. 相似文献
The single mode condition in large cross section rib waveguides is of great interest because almost every kind of active and
passive integrated optoelectronic device or sensor is designed to sustain only the fundamental mode of propagation for better
matching with optical fibers. In this paper we present a criterion to determine the single mode condition for a large cross
section rib waveguides, by comparison between the numerical solutions found with Neumann boundary conditions and Dirichlet
boundaries conditions applied when solving the eigenvalues problem. 相似文献
The Spanish plant described in this study is a 982 MWe PWR plant with a three-loop primary circuit of piping made from centrifugally-cast stainless steel SA351 CF8A.
The licensee requested an exemption to GDC-4, from CSN, so as to avoid the postulation of guillotine rupture of the primary loop piping. The request was based on the generic work performed for a US PWR plant group to have such exemption to GDC-4. As the piping material in the Spanish plant is different from that in the plants included in the generic work, CSN performed a review of the applicability of the generic results to the Spanish plant. Also, aspects such as fatigue evaluation, net section collapse, crack growth and leak detection, specifically analyzed for the Spanish plant, were reviewed.
CSN found that fracture toughness test results from generic work are applicable to the Spanish plant; sufficient margin exists against unstable crack extension, and adequate leak detection capability exists with the leakage detection systems available in the plant.
Exemption to GDC-4 was approved and CSN authorized the licensee to remove protection devices against dynamic loads from guillotine breaks in the primary coolant loops. 相似文献
The conformations of two synthetic pentapeptides with antimicrobial activity and their 4-fluorophenylalanine (Pff)-containing analogues (ArXArXAr-NH(2); Ar=Phe, Pff; X=Lys, Arg) have been studied. NMR experiments carried out both in aqueous fluoroalcohol solutions and SDS micelles permitted their interactions with membrane-like environments to be explored. WaterLOGSY experiments and Mn(2+)-based paramagnetic probes were also applied to assess their orientations with respect to the SDS micelles. In addition, pulse-field gradient (PFG) diffusion NMR spectroscopy studies were conducted, under different experimental conditions (i.e., concentration, temperature) to characterize the possible changes in the peptides' aggregation states as a putative critical factor for their antimicrobial activity. Finally, molecular dynamics simulations on a variety of conformations showed the intrinsic flexibility of these peptides in both aqueous solutions and membrane-mimetic systems. 相似文献