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排序方式: 共有466条查询结果,搜索用时 15 毫秒
1.
张庆华 《数字社区&智能家居》2014,(7):4381-4383
该文介绍了基于B/S资料信息管理系统的设计和开发,重点阐述了资料信息管理系统的开发设计的难点和要点,同时提供了部分数据库表信息和代码。 相似文献
2.
唐洁 《电脑编程技巧与维护》2010,(1):39-50,57
通过笔者指导开发网络办公自动化(OA)系统的经验,详细剖析基于ASP.NET3.5技术的OA系统搭建过程,对OA系统的核心功能开发作了细致描述。 相似文献
3.
依照国家标准GB/T22239-2008采集数据,使得风险评估的数据采集有了可靠依据。基于GB/T22239-2008的网络风险评估模型在评估时采用专家意见和模糊综合评估、云重心判别法相结合的方法,解决了信息安全风险评估过程中定性与定量评估不能很好结合的问题,并给出了应用实例,是一种兼具科学性、综合性和可操作性的综合评估方法。 相似文献
4.
从播控管理系统的需求分析入手,构建了系统各功能模块,建立数据库,对系统登录、用户权限管理、播控资源管理等模块做了分析与设计。系统对播控信息数据进行统一管理,完成了信息的收集、统计、汇总和分析等功能,实现了对电视播控事务科学、高效的管理。 相似文献
5.
随着卫星重力测量技术的不断完善和发展,使得利用重力场模型进行GPS点高程转换的精度和可靠性都获得了极大提升。文章利用SRTM、DTM2006.0模型和EGM2008模型求得阳山矿区GPS点剩余高程异常,并进行残余高程异常拟合,建立阳山矿区剩余高程异常转换计算方法。在对阳山矿区22个D级GPS点,48个E级GPS点的高程数据进行比较后,发现此方法转换最高精度能达到2.8 cm,最差精度为4.4cm,平均精度为3.2 cm,从而证明了此方法可以提高阳山矿区GPS高程转换的精度。 相似文献
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The flow fields in a dual Rushton impeller stirred tank with diameter of 0.48 m (T) were measured by using Particle Image Velocimetry (PIV). Three different size impellers were used in the experiments with diameters of D = 0.33T, 0.40T and 0.50T, respectively. The multi-block and 360° ensemble-averaged approaches were used to measure the radial and axial angle-resolved velocity distributions. Three typical flow patterns, named, merging flow, parallel flow and diverging flow, were obtained by changing the clearance of the bottom impeller above the tank base (C1) and the spacing between the two impellers (C2). The results show that while C1 is equal to D, the parallel flow occurs as C2≥0.40T, C2≥0.38T and C2≥0.32T and the merging flow occurs as C2≤0.38T, C2≤0.36T and C2≤0.27T for the impellers with diameter of D=0.33T, 0.40T and 0.50T, respectively. When C2 is equal to D, the diverging flow occurs in the value of C1≤0.15T for all three impellers. The flow numbers of these impellers were calculated for the parallel flow. Trailing vortices generated by the lower impeller for the diverging flow were shown by the 10° angle-resolved velocity measurements. The peak value of turbulence kinetic energy ( k/V^2tip = 0.12-0.15 or above) appears along the center of the impeller discharging stream. 相似文献
8.
To overcome the problem that soft sensor models cannot be updated with the process changes, a soft sensor modeling algorithm based on hybrid fuzzy c-means (FCM) algorithm and incremental support vector machines (ISVM) is proposed. This hybrid algorithm FCMISVM includes three parts: samples clustering based on FCM algorithm, learning algorithm based on ISVM, and heuristic sample displacement method. In the training process, the training samples are first clustered by the FCM algorithm, and then by training each clustering with the SVM algorithm, a sub-model is built to each clustering. In the predicting process, when an incremental sample that represents new operation information is introduced in the model, the fuzzy membership function of the sample to each clustering is first computed by the FCM algorithm. Then, a corresponding SVM sub-model of the clustering with the largest fuzzy membership function is used to predict and perform incremental learning so the model can be updated on-line. An old sample chosen by heuristic sample displacement method is then discarded from the sub-model to control the size of the working set. The proposed method is applied to predict the p-xylene (PX) purity in the adsorption separation process. Simulation results indicate that the proposed method actually increases the model’s adaptive abilities to various operation conditions and improves its generalization capability. 相似文献
9.
This article presents an acetylene production process by partial oxidation/combustion of natural gas. The thermodynamic performance and exergy analysis in the process are investigated using the flow-sheeting program Aspen Plus. The results indicate that the most important destruction of exergy is found to occur in the reactor and water quenching scrubber, amounting to 8.23% and 10.39%, respectively, of the entire system. Based on the results of thermodynamic and exergy analysis, the acetylene reactor has been retrofitted. The improvement ratios of molar 02 to CH4 and molar CO to CN4 are 0.65 and 0.20, respectively. An improvement of the acetylene production system is proposed. Adopting the improvement operation conditions and using oil to realize the reaction heat recovery, the feedstock of natural gas is reduced by 9.88% and the exergy loss in the retrofitting process is decreased by 19.71% compared to the original process. 相似文献
10.