Lower bounds on the information rate of secret sharing schemes with homogeneous access structure

We present some new lower bounds on the optimal information rate and on the optimal average information rate of secret sharing schemes with homogeneous access structure. These bounds are found by using some covering constructions and a new parameter, the k-degree of a participant, that is introduced in this paper. Our bounds improve the previous ones in almost all cases.     

Acculturation, Familism, Parental Monitoring, and Knowledge as Predictors of Marijuana and Inhalant Use in Adolescents.

The authors investigated relationships between marijuana and inhalant use and several cultural and demographic factors in Anglo American and Hispanic American adolescents (N=1,094). Outcome measures assessed lifetime and 30-day marijuana and inhalant use. Predictors and covariates used in logistic regression analyses were region, grade, gender, knowledge, acculturation, familism, and parental monitoring. Hispanic Americans exhibited higher usage across all measures. In this group, high acculturation was associated with low marijuana, but high inhalant, use. Across all participants, positive family relations and parental monitoring were strongly associated with attenuated marijuana use hut only among those most knowledgeable about drugs. Familism and monitoring were not associated with diminished usage among the less knowledgeable. For inhalants, monitoring combined with high knowledge or high familism was associated with diminished usage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

控制张紧力,延长钢丝绳芯胶带使用寿命

钢丝绳芯胶带是一种优质高效的运输带 ,影响它使用寿命的因素很多。本文重点介绍了张紧力对钢丝绳芯胶带的影响 ,阐述了实际工作中如何及时调节张紧力 ,并提供了几种调整张紧力的方法。     

The State of the Art in Text Filtering

This paper develops a conceptual framework for text filtering practice and research, and reviews present practice in the field. Text filtering is an information seeking process in which documents are selected from a dynamic text stream to satisfy a relatively stable and specific information need. A model of the information seeking process is introduced and specialized to define text filtering. The historical development of text filtering is then reviewed and case studies of recent work are used to highlight important design characteristics of modern text filtering systems. User modeling techniques drawn from information retrieval, recommender systems, machine learning and other fields are described. The paper concludes with observations on the present state of the art and implications for future research on text filtering. This revised version was published online in July 2006 with corrections to the Cover Date.     

N—ISDN走出低谷B—ISDN迈向市场

本文介绍了全球Ｎ－ＩＳＤＮ的商用情况和Ｂ－ＩＳＤＮ的发展趋势，展示出Ｎ－ＩＳＤＮ走了低谷、Ｂ－ＩＳＤＮ迈向市场的美好前景。     

集成光学干涉仪光纤陀螺

简述了集成光学干涉仪光纤陀螺（ＦＯＧ）的技术优势、发展概况和采用的技术途径，介绍了适用于不同技术条件要求的三种多功能集成光学芯片结构和相应的信息处理方法。简要地概括了目前国外ＦＯＧ的发展水平。     

我国石油开采与油井管生产概述

概略介绍了我国石油开采及其专用管材的需求情况以及油井管的生产规划和要求,对发展国内油井管特别是焊接油井管生产提出了建议。     

Data-logging: effects on practical science

Abstract This paper describes an investigation into the processes and effects of using electronic data-logging in practical science. A pilot study of classical laboratory work in schools was compared with similar tasks performed with data-logging systems. A more detailed exploration of pupils' performance was then conducted through an extensive series of observations in a range of secondary schools. The results reinforce previous indications of the potential benefits of data-logging, but such benefits must be viewed in the curriculum context of the type of measurement activity and the pedagogical context of teaching and learning objectives. The paper concludes with a discussion of the latter issues.     

强度型光纤传感器的信号检测系统

本文阐述了一种可提高强度型光纤传感器测量精度的检测系统。该系统利用同一检测电路交替检测信号、参考通道的输出信号，并将信号、参考两通道的检测结果相除，从而消除了因发光二极管光源波动及检测电路系统不稳定所带来的误差。采用同步相关技术抑制了噪声，提高了输出信噪比。实验证明，当时间常数ＲＣ为０．０５Ｓ时，采用该检测系统可获得优于千分之一的零点稳定性和优于２×１０３的输出信噪比。     

浅谈基于ISO9000的质量管理信息系统设计

讲述了一个军工产品承制单位基于ＩＳＯ９０００体系，建立质量管理信息系统的概况。