关联规则分析中兴趣度量Lift与Conviction的关系探讨及教育数据验证

关联规则分析是数据挖掘中最常用的研究方法之一。在关联关系的发现过程中兴趣度量是关联规则发现的理论基础,它可以度量规则的重要程度,其中Lift和Conviction这两个度量在数据分析中被广泛应用于筛选关联规则。本文对这两种兴趣度量进行了研究。首先,提出并证明了当后项集固定时,Conviction取值随Lift取值单调增加,且Conviction (Lift)是一个凸函数。然后,证明了当Confidence固定时,Conviction取值随Lift取值单调增加,且Conviction (Lift)是一个凹函数。最后,综合以上两个方面,得到一个重要结论:当后项集保持不变或当Confidence固定时,根据Conviction和Lift筛选出来的规则都是相同的。最后,利用某高校数学类专业三个年级的成绩数据进行了定理及相应结论的验证。

复合水泥正交试验因素权重分析及正态检验研究

针对河套地区普遍存在的粉质粘土,利用水泥固化土的固化原理,掺加粉煤灰、氢氧化钙、氢氧化钠等添加剂,形成具有一定强度、一定耐久性的复合水泥土,研究分析复合水泥土的力学性质,通过对试验数据用正交表进行整体设计、进行数据正态验证、数据的方差分析,得出复合水泥土最优配合比及应用统计学原理验证后的水泥土各影响因素的权重。

Molecular reconstruction model based on structure oriented lumping and group contribution methods

Molecular management is a promising technology to face challenges in the refining industry, such as more stringent requirements for product oil and heavier crude oil, and to maximize the value of every molecule in petroleum fractions. To achieve molecular management in refining processes, a novel model that is based on structure oriented lumping(SOL) and group contribution(GC) methods was proposed in this study. SOL method was applied to describe a petroleum fraction with structural increments, and GC method aimed to estimate molecular properties. The latter was achieved by associating rules between SOL structural increments and GC structures. A three-step reconstruction algorithm was developed to build a representative set of molecules from partial analytical data. First, structural distribution parameters were optimized with several properties. Then, a molecular library was created by using the optimized parameters. In the final step, maximum information entropy(MIE) method was applied to obtain a molecular fraction. Two industrial samples were used to validate the method, and the simulation results of the feedstock properties agreed well with the experimental data.

Cluster-Based Content Download and Forwarding Scheme for Highway VANETs

The recent advances in wireless communication technology enable high-speed vehicles to download data from roadside units(RSUs). However, the data download volume of individual vehicle is rather restricted due to high mobility and limited transmission range of vehicles, bringing users poor performance. To address this issue, we exploit the combination of both clustering and carry-and-forward schemes in this paper. Our scheme coordinates the cooperation of multiple infrastructures, cluster formation in the same direction and data forwarding of reverse vehicles to facilitate the target vehicle to download large-size content in dark areas. The process of data dissemination and achievable data download volume are then derived and analyzed theoretically. Finally, we conduct extensive simulations to verify the performance of the proposed scheme. Results show significant benefits of the proposed scheme in terms of increasing data download volume and throughput.

Design, Analysis and Installation of Offshore Instrumented Moored Data Buoy System

This paper discusses the analysis done on the meteorological ocean buoy mooring used for monitoring the Indian seas. Based on the extreme environmental parameters experienced by the buoys, mooring loads are analyzed using offshore dynamic analysis software. The results obtained are validated with the tension recorder installed in one of the moorings, and the results are found to comply with an accuracy of better than 1%. The successful on demand performance of the mooring during major cyclones in the Bay of Bengal and the vital meteorological and oceanographic information provided by the buoy during these disastrous cyclonic events validates the mooring design, and proves the data availability for societal needs. The time critical data assimilated in the cyclone prediction models have given confidence to improve the country＇s weather prediction and climate modelling capabilities.

The Proposal of Data Warehouse Validation

The analysis of relevant standards and guidelines proved the lack of information on actions and activities concerning data warehouse testing. The absence of the complex data warehouse testing methodology seems to be crucial particularly in the phase of the data warehouse implementation. The aim of this article is to suggest basic data warehouse testing activities as a final part of data warehouse testing methodology. The testing activities that must be implemented in the process of the data warehouse testing can be split into four logical units regarding the multidimensional database testing, data pump testing, metadata and OLAP （Online Analytical Processing） testing. Between main testing activities can be included： revision of the multidimensional database scheme, optimizing of fact tables number, problem of data explosion, testing for correctness of aggregation and summation of data etc.

Development of Multilevel Meteorological Data Acquisition System for Radiation Emergency Decision Support

This paper describes a development of multilevel meteorological data acquisition system implemented at Kalpakkam coastal site for atmospheric dispersion and model validation studies. Meteorological data are one of the most important inputs into any air dispersion model. As a part of atmospheric dispersion modeling studies and developing a methodology to forecast the site-specific dispersion characteristics, the real time monitoring of meteorological parameters assumes significance. This is achieved by erecting met towers instrumented at multilevel and single level at different locations with sensors for measuring various meteorological parameters. Real-world data logging applications involve not only just acquiring and recording signals, but also combination of offline analysis, display, report generation and data sharing. This paper covers development of low cost compact MMDAS （modular meteorological data acquisition system）, its performance evaluation, field deployment test and data comparison analysis with fast response and high accuracy internationally acclaimed sonic anemometer. The system is based on embedded modules from Advantech and is designed to acquire analogue and digital signals from a multilevel instrumented met tower. The collected data are transferred from remote base station to central server for storage and further processing using wireless interface. MMDAS has many advantages like cost effectiveness, less complex signal conditioning electronics and easy maintenance. This system has good application during radiation emergency as well as site specific meteorological data collection and model validation studies.

基于正交试验的复合水泥土配合比应用及方差验证研究

文章通过对试验数据用正交表进行整体设计、进行数据正态验证、数据的方差分析,得出复合水泥土最优配合比及应用统计学原理验证后的水泥土各影响因素的权重。