The school bus routing problem: A review

This paper aims to provide a comprehensive review of the school bus routing problem (SBRP). SBRP seeks to plan an efficient schedule for a fleet of school buses where each bus picks up students from various bus stops and delivers them to their designated schools while satisfying various constraints such as the maximum capacity of a bus, the maximum riding time of a student in a bus, and the time window of a school. This class of problem consists of different sub-problems involving data preparation, bus stop selection, bus route generation, school bell time adjustment, and bus scheduling. In this paper, the various assumptions, constraints, and solution methods used in the literature on SBRP are summarized. A list of issues requiring further research is also presented.     

基于Markov Chain Monte Carlo模型对医院出院病人调查表数据缺失的填补与分析

目的对医院出院病人调查表普遍存在的数据缺失进行填补与分析,以保证统计调查表的质量,为医院以及上级卫生部门了解现状,进行预策和决策提供技术支持和质量保证。方法运用SAS9.1,采用多重填补方法Markov Chain Monte Carlo(MCMC)模型对缺失数据进行多次填补并综合分析。结果MCMC填补10次的结果最优。结论(Multiple Imputation)MI方法在解决医院出院病人调查表数据缺失时有优势,发挥空间较大,且填补效率较高。     

Lazy structure-activity relationships (lazar) for the prediction of rodent carcinogenicity and Salmonella mutagenicity

lazar is a new tool for the prediction of toxic properties of chemical structures. It derives predictions for query structures from a database with experimentally determined toxicity data. lazar generates predictions by searching the database for compounds that are similar with respect to a given toxic activity and calculating the prediction from their activities. Apart form the prediction, lazar provides the rationales (structural features and similar compounds) for the prediction and a reliable condence index that indicates, if a query structure falls within the applicability domain of the training database. Leave-one-out (LOO) crossvalidation experiments were carried out for 10 carcinogenicity endpoints ({female|male} {hamster|mouse|rat} carcinogenicity and aggregate endpoints {hamster|mouse|rat} carcinogenicity and rodent carcinogenicity) and Salmonella mutagenicity from the Carcinogenic Potency Database (CPDB). An external validation of Salmonella mutagenicity predictions was performed with a dataset of 3895 structures. Leave-one-out and external validation experiments indicate that Salmonella mutagenicity can be predicted with 85% accuracy for compounds within the applicability domain of the CPDB. The LOO accuracy of lazar predictions of rodent carcinogenicity is 86%, the accuracies for other carcinogenicity endpoints vary between 78 and 95% for structures within the applicability domain.     

Spectral Database Systems: A Review

Abstract: Spectroscopy has been demonstrated to be an important method of analysis and detection. A spectral database system (SDBS) can not only satisfy the traditional requirements for spectral management but also provides several new functions, including spectra sharing on the website and web-based and real-time analysis and detection. Chemists and spectroscopists could analyze and detect pure materials and some mixtures rapidly with the help of standard SDBS, and now they are trying to improve these systems to fulfill rapid analysis for complex mixtures, even those as complex as agro-products. Overall, SDBS make it possible to analyze and detect unknown samples rapidly and nondestructively. This article focuses on significant progress in research on infrared (IR), near-infrared (NIR), and Raman SDBSs. Additionally, the drawbacks and obstacles of SDBSs are summarized and trends are discussed.     

Technology-motivated teaching of topics in number theory through a tool kit approach

This paper shows how the computational and graphical capabilities of spreadsheets allow for interactive analytic and geometric constructions from numerical modelling of homogeneous Diophantine equations of the second order. Suggested activities, designed for prospective teachers of mathematics and made possible by what is referred to in the paper as the tool kit approach, enable one to revisit classic mathematics concepts within the framework of computerized mathematical experiment.     

The GEISA spectroscopic database: Current and future archive for Earth and planetary atmosphere studies

The development of Gestion et Etude des Informations Spectroscopiques Atmosphériques (GEISA: Management and Study of Spectroscopic Information) was started over three decades at Laboratoire de Météorologie Dynamique (LMD) in France. GEISA is a computer accessible spectroscopic database, designed to facilitate accurate forward radiative transfer calculations using a line-by-line and layer-by-layer approach. More than 350 users have been registered for on-line use of the GEISA facilities. The current 2003 edition of GEISA (GEISA-03) is a system comprising three independent sub-databases devoted respectively to: line transition parameters, infrared and ultraviolet/visible absorption cross-sections, microphysical and optical properties of atmospheric aerosols.Currently, GEISA is involved in activities related to the assessment of the capabilities of IASI (Infrared Atmospheric Sounding Interferometer on board of the METOP European satellite) through the GEISA/IASI database derived from GEISA.The GEISA-03 content is presented, placing emphasis on molecular species of interest for Earth and planetary atmosphere studies, with details on the updated 2008 archive underway. A critical assessment on the needs, in terms of molecular parameters archive, related with recent satellite astrophysical missions is made. Detailed information on free on-line GEISA and GEISA/IASI access is given at http://ara.lmd.polytechnique.fr and http://ether.ipsl.jussieu.fr.     

合肥光源储存环温度监测系统

温度是影响电子束轨道稳定的重要因素之一, 大多数加速器都需要为其建立完备的冷却恒温系统及相应的监测系统. 描述了合肥光源基于EPICS(Experimental Physics and Industrial     

A convenient guideline to determine if two Y‐STR profiles are from the same lineage

Y chromosome STR loci are used in forensics primarily for identification purposes by determining the male lineages. The Henan province in China has established a large Y‐STR (>200 000 profiles) database for criminal investigations. A large proportion of the Y‐STR profiles in the database were generated using either the Applied Biosystems Yfiler^? or Yfiler^? Plus PCR Amplification kits. The additional loci in the Yfiler Plus kit as compared to the Yfiler kit results in a concomitant cumulative mutation rate increase across the loci. Therefore, in those cases when two profiles have one to a few mismatched loci, it is difficult to determine if they are from the same lineage. In this study, 7405 unrelated male profiles were manually selected from the database. Analysis showed higher power of discrimination than the corresponding Yfiler haplotypes. Further, the distributions of the number of mismatched loci and the mismatched steps were generated for father‐son, grandfather‐grandson, uncle‐nephew, and cousins (i.e. one, two, three, and four meioses, respectively) by exhaustive pairwise comparison of the unrelated profiles using a dynamic programming approach. The same distributions were generated for unrelated pairs with mutation rates of the loci. With the distributions, the false negative and false positive rates were determined. Two Yfiler profiles with ≤2 mismatched loci or ≤2 steps are more likely from the same lineage than unrelated lineages, and two Yfiler Plus profiles with ≤4 mismatched loci or ≤5 mismatched steps are more likely from the same lineage.     

Post-primary students’ images of mathematics: findings from a survey of Irish ordinary level mathematics students

A questionnaire survey was carried out as part of a PhD research study to investigate the image of mathematics held by post-primary students in Ireland. The study focused on students in fifth year of post-primary education studying ordinary level mathematics for the Irish Leaving Certificate examination – the final examination for students in second-level or post-primary education. At the time this study was conducted, ordinary level mathematics students constituted approximately 72% of Leaving Certificate students. Students were aged between 15 and 18 years. A definition for ‘image of mathematics’ was adapted from Lim and Wilson, with image of mathematics hypothesized as comprising attitudes, beliefs, self-concept, motivation, emotions and past experiences of mathematics. A questionnaire was composed incorporating 84 fixed-response items chosen from eight pre-established scales by Aiken, Fennema and Sherman, Gourgey and Schoenfeld. This paper focuses on the findings from the questionnaire survey. Students’ images of mathematics are compared with regard to gender, type of post-primary school attended and prior mathematical achievement.     

基于生产者/消费者设计模式的应力波信息采集系统的设计

以LabVIEW14.0为虚拟仪器软件开发平台,采用生产者/消费者设计模式的控制策略、技术数据管理流(TDMS)二进制文件储存策略和SQL数据库及事件结构相结合的实时更新策略,设计了集实时信息采集、储存、显示等功能于一体的应力波采集系统;3种控制策略相结合,解决了传统顺序结构设计模式下程序循环周期长、执行效率低的问题,而且解决了实时采集过程中数据的快速、大容量储存问题,实现了采集过程中采集参数的实时更新;实验结果表明该应力波采集系统具有响应速度快、执行效率高等优点。