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51.
52.
This paper presents an algorithm that permits the search for dependencies among sets of data (univariate or multivariate time-series, or cross-sectional observations). The procedure is modeled after genetic theories and Darwinian concepts, such as natural selection and survival of the fittest. It permits the discovery of equations of the data-generating process in symbolic form. The genetic algorithm that is described here uses parts of equations as building blocks to breed ever better formulas. Apart from furnishing a deeper understanding of the dynamics of a process, the method also permits global predictions and forecasts. The algorithm is successfully tested with artificial and with economic time-series and also with cross-sectional data on the performance and salaries of NBA players during the 94–95 season. 相似文献
53.
Osama Y. Abudayyeh 《Advances in Engineering Software》1993,16(3):187-193
Effective management of construction projects depends on good access to and control of data, especially data pertaining to cost and schedule control functions. However, the proper design and development of automated mechanisms have not had the facility to acquire and store quality data in a timely manner. The purpose of this paper, then, is to discuss a prototype, automated data acquisition system that was developed to support an integrated project management system. The data acquisition system is composed of an integrated set of electronic forms used in conjunction with a bar coding data-entry tool. 相似文献
54.
The analysis of recently collected wind data at five sites in Saudi Arabia namely, Dhulum, Arar, Yanbu, Gassim and Dhahran is presented. The five sites represent different geographically and climatologically conditions. The data collected over a period spanned between 1995 and 2002 with different collection periods for each site. Daily, monthly and frequency profiles of the wind speed at the sites showed that Dhulum and Arar sites have higher wind energy potential with annual wind speed average of 5.7 and 5.4 m/s and speeds higher than 5 m/s for 60 and 47% of the time, respectively. The two sites are candidates for remote area wind energy applications. The costal site's, i.e. Yanbu and Dhahran wind speed data indicated that the two sites have lower annual wind speed averages and wind blows at speed higher than 5 m/s during afternoon hours. That makes the two sites candidates for grid connected wind systems for electrical load peak shaving. The data of Gassim site showed that the site has the lowest wind energy potential compared to the others. The annual energy produced by a Nordex N43 wind machine is estimated to be 1080, 990, 730, 454 and 833 MWh for Dhulum, Arar, Yanbu, Gassim and Dhahran, respectively. The analysis showed that the estimated annual energy produced by the machine based on 10 min averaged data is 2.5% higher than the estimated energy based on 30 min averaged data. 相似文献
55.
56.
基于中间件技术的HTML业务系统设计与实现 总被引:1,自引:0,他引:1
介绍了欧洲的MHP标准,并在HTML技术方面提出了改进方案。在此方案的基础上设计了一个基于HTML的从前端数据封装到终端数据接收的完整业务系统,并对其应用前景提出了一些看法。 相似文献
57.
从数据结构角度为旅游胜地设计导游系统。向游人提供景点的信息查询服务,根据指定的景点提供相关的景点信息。任意给定起点和终点,查询两点之间的最短路径。 相似文献
58.
Non-redundant data clustering 总被引:6,自引:6,他引:0
Data clustering is a popular approach for automatically finding classes, concepts, or groups of patterns. In practice, this
discovery process should avoid redundancies with existing knowledge about class structures or groupings, and reveal novel,
previously unknown aspects of the data. In order to deal with this problem, we present an extension of the information bottleneck
framework, called coordinated conditional information bottleneck, which takes negative relevance information into account by maximizing a conditional mutual information score subject to
constraints. Algorithmically, one can apply an alternating optimization scheme that can be used in conjunction with different
types of numeric and non-numeric attributes. We discuss extensions of the technique to the tasks of semi-supervised classification
and enumeration of successive non-redundant clusterings. We present experimental results for applications in text mining and
computer vision. 相似文献
59.
金永杰 《核电子学与探测技术》1989,9(1):10-17
本文所提出的投影域重建——再投影迭代算法可以恢复不完整的扇形束投影数据,从而实现从有限的投影数据重建图象。这种算法把滤波——反投影图象重建过程和再投影的过程纳入一个公式,仅在投影域上估算未知的投影数据,因此避免了重建过程和反投影过程中的插值运算,改善了收敛性,提高了计算精度,缩短了运算时间。模拟实验表明:即使有70%的投影数据丢失,经过两次迭代就能以令人满意的精度恢复丢失的投影数据。 相似文献
60.
Experimentally determined p,V,T data are reported for toluene, trichloromethane, dichloromethane, acetonitrile, aniline, and n-dodecane at 278, 288, 298, 313, and 323 K, except for dichloromethane, for which the highest temperature was 298 K. At each temperature, measurements were done at pressures up to about 280 MPa or (for aniline and n-dodecane) at a lower pressure slightly below the freezing pressure at the temperature of measurement. Values of the isobaric expansivity isothermal compressibility and (for toluene, trichloromethane, dichloromethane, and acetonitrile) internal pressure, derived from the p,V,T data, are presented. 相似文献