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21.
To provide responsive information services in a ubiquitous computing environment, service software and system development are indispensable. A component-based ubiquitous information system with a JAIN (Java APIs for Integrated Networks) platform to achieve seamless transmissions and reach-everywhere communications was designed in our research. In this development, numerous ubiquitous service modules were identified: location management, roaming, mobile IP and WAP networking. These component-based network modules were constructed using a component composition language with component specification and interface definition, running on top of a distributed service architecture using a JAIN platform to distribute the ubiquitous information services to mobile users. Two applications, Wireless-Application-Protocol (WAP) Mail and Video-on-Demand (VoD) services, show that the JAIN-like platform with the developed networking components effectively fills the gap for application developers between mobile appliances and various kinds of ubiquitous information services.  相似文献   
22.
The characteristics of high-quality tomato pulp (commercial def.: crushed or diced tomatoes with about 30% tomato juice as packing medium) canned with tomato juice pulp enriched by ultrafiltration as packing medium were compared with those covered with conventional vacuum-concentrated juice.
Both hot- and cold-break products were prepared and those containing 20% serum-reduced packing juice proved to be the best, showing no signs of syneresis on storage and with improvements in sensory properties, colour and non-enzymatic browning; some volatile components were reduced.  相似文献   
23.
The authors report results of a study into the role of components of first-language (L1; Dutch) and second-language (L2; English) reading comprehension. Differences in the contributions of components of L1 and L2 reading comprehension are analyzed, in particular processing speed in L1 and L2. Findings indicate that regression weights of the L1 and L2 components are different. Although correlations between most processing speed components and reading comprehension are substantial, there are no unique contributions to the explanation of either L1 or L2 reading comprehension when linguistic and metacognitive knowledge are accounted for. In addition, L1 reading comprehension is shown to have a large contribution to L2 reading comprehension, supporting theories of L1-L2 transfer of reading skills. Results are discussed from a developmental perspective. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
24.
双组分树脂冷压法制备摩擦材料   总被引:8,自引:0,他引:8  
研究甲、乙双组分液体树脂作为粘结剂制备制动摩擦材料的冷压工艺方法,甲组分树脂为硼改性腰果壳油树脂,乙组分树脂为三聚氰胺改性酚醛树脂。该工艺可使模压料在室温下具有良好的成型效果,在固化处理中不使用夹具,可以使成型料具有良好的保型效果。冷压制备的制动摩擦材料具有硬度低、摩擦系数稳定和恢复性好等特点。  相似文献   
25.
This paper derives the admissible decompositions for a time series dynamic linear model, assuming only that the model is observable. The decompositions depend on factorizations of the characteristic polynomial of the state evolution matrix G into relatively prime factors. This generalizes the method of West (1997 ) which considers one decomposition in the particular case where G is diagonalizable. Conditions are derived for a decomposition to be independent. These results show that no autoregressive process of order d has an independent decomposition for any integer d . Two illustrations of this procedure are discussed in detail.  相似文献   
26.
Abstract. This article proposes an extension to scalar component methodology for the identification and estimation of VARMA models. The complete methodology determines the exact positions of all free parameters in any VARMA model with a predetermined embedded scalar component structure. This leads to an exactly identified system of equations that is estimated using full information maximum likelihood.  相似文献   
27.
An upper-bound analysis of the pressure-assisted injection forging (PAIF) of thick-walled tubular components with hollow flanges was conducted to predict the maximum forming-pressure requirements. The polymeric pressurizing material and the pure aluminium work material employed were assumed to obey the von-Mises’ yield criterion, the two materials being divided into three and six zones, respectively, and described using kinematically admissible velocity fields. An upper-bound solution was derived based on this model. Experiments were conducted to validate the solution. The results suggest that the upper-bound analysis has sufficient accuracy for the prediction of the forming-pressure requirements. Subsequently, a parametric analysis was conducted to study the effects of variation of the principal parameters of the process and the geometry, such as tube thicknesses, flange dimensions and friction, on the forming-force requirements, which showed other useful applications of the upper-bound solutions.  相似文献   
28.
Fourteen commercial polyadipates and a polysebacate were analysed for their components of a molecular mass below 1000 Da, primarily with the aim of generating the background data for measuring the migration of this type of polymeric additives from plasticized PVC (e.g. cling films and gaskets of lids) into foods or food simulants. Since the composition of the material <1000 Da varies between the polyadipates, the main components must be identified to enable a correct quantification. Polyadipates differ in the diol used as linker, their termination (acid or alcohol) and in the end‐capping (free alcohols, acetylation, acylation with fatty acids, esterification with octanol/decanol). Gas chromatography (GC) provides good separation, but the material remaining in the column up to high temperatures decomposes and forms a hump in the rear part of the chromatogram. Examples of mass spectra are shown, the most indicative fragments pointed out and spectra of 159 components listed. The polyadipates and the sebacate are characterized by their structure, the main components <1000 Da and the fraction of material <1000 Da. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
29.
This paper proposes an efficient method to develop requirement specifications for Plant Control Software (PCSW) using software-component-based prototypes. Prior to this proposal, domain analyses were conducted on existing PCSWs, and their functions were classified into “similar functions” and “individual functions”. Then PCSW Software Components (PSC: PCSW Software Component, PSCs: PCSW Software Components) were developed to correspond to these functions. PSCs as parameter-style components were developed in order to satisfy the clients’ (we define clients as owners, managers and operators of plants) requirements. A support environment for developing requirement specifications was developed. The environment consists of the Prototype Development Tool (PDT), the Behavior Check Simulator (BCS) and the Requirement Specification Development Tool (RSDT). The method consists of four steps. In the first step, PDT is used to define the parameters to customize PSCs and to compose a PCSW prototype by setting these parameters to PSCs. In the second step, BCS is used to execute the composed PCSW prototype and check its behavior and relevancy against the clients’ expectations. In the third step, steps 1 and 2 are repeated until the behavior of the PCSW prototype satisfies the clients’ requirements. Finally, a requirement specification is developed from the PCSW prototype which fully reflects the clients’ requirements. In order to evaluate the proposed method, it has been applied in five development cases. A Requirement Coverage of 91%, a Requirement Revision Rate of 6%, a PSC Reuse Rate of 92% and a LOC Reuse Rate of 83% have been achieved. In addition, a reduction of 55% in the amount of time required to develop requirement specifications has been achieved. These results indicate that the proposed method has sufficient capability to develop an exhaustive and an adequate PCSW requirement specification. And the developed PSCs have sufficient functions and capability to compose PCSW prototypes, and the support environment is capable of shortening the time taken to develop requirement specifications.  相似文献   
30.
卷边槽钢压杆考虑板组约束作用的屈曲系数   总被引:1,自引:0,他引:1  
申红侠 《钢结构》2006,21(1):62-64,68
卷边槽钢压杆的局部屈曲具有相关性。《冷弯薄壁型钢结构技术规范》(GB50018-2002)提出适用于各种不同截面的板组约束系数的统一计算公式来考虑这种相关性。但由于板组组成的多样性,其是否合理,有待于进一步研究。借助ANSYS有限元分析软件,对卷边槽钢压杆局部屈曲进行分析,得到考虑板组约束作用的屈曲系数,并和国内外规范进行比较。结果表明,计算结果和英国规范吻合较好,我国规范偏于安全较多。借鉴英国规范的形式,给出考虑板组约束作用的屈曲系数的计算公式,这些公式可供进一步修订规范时参考。  相似文献   
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