A Review of: “TRENDS IN GENERAL SYSTEMS THEORY”, Edited by George J. Klir. John Wiley,New York, 1972, 462 pp.

The paper presents new refinements of homomorphisms that are needed in order to deal with partial algebraic systems; namely, weak, strong and Very strong homomorphisms and the laws of their compositions. Further, it describes loose and tight congruences and the canonical factorization of various kinds of homomorphisms. The results have important applications in cognitive modelling, general systems relational models, knowledge representation schemes in Expert Systems and formal methods of Software Engineering,     

著名专家J.J.HOPFIELD教授在南航讲学

世界著名神经元网络专家、神经元网络创始人之一,美国科学院士、加州理工学院计算与神经系主任、化学及生物学教授John J. Hopfield博士,应我国863高技术计划智能计算机专家组和南京航空学院的联合邀请,在南航作了为期2.5周“人工神经网络”讲座。Hopfield教授系统地讲授了神经网络基本原     

A review of: “Man in the Antarctic The Scientific Work of the International Biomedical Expedition to the Antarctic (IBEA)”, edited by J. RIVOLIER,R. GOLDSMITH,D. J. LUGG and A. J. W. TAYLOR,Taylor & Francis, 4 John Street,London WC1N 2ET (1988), pp. 222, £26·00, ISBN 0-85066-280-X

This study aimed to examine the effects of passive and non-computer work time on the estimation of computer use times by electronic activity monitoring. A total of 20 subjects with computers were monitored for 3 h. Average relative error for total computer use time estimation was about 4%, given that non-computer work time was 20% of the 3-h monitored period. No significant impact of passive computer use time was found in this study. Non-computer work time of 40% or less is suggested as criteria for the application of electronic activity monitoring to ensure reliability in the physical work loading assessment.

Statement of Relevance: This research studied the criteria of non-computer work time for the appropriate use of electronic activity monitoring to ensure reliability in the assessment of physical work loading. It is suggested that it should be set to 40% or less of the 3-h monitoring period.     

A Review of: “Exploration of the Solar System by Infrared Remote Sensing”. By R. A. HANEL,B. J. CONRATH,D. E. JENNINGS and R. E. SAMUELSON. (Cambridge: Cambridge University Press, 1992.) [Pp. 458.] Price £75.00.

Crop classification is a key issue for agricultural monitoring using remote-sensing techniques. Synthetic aperture radar (SAR) data are attractive for crop classification because of their all-weather, all-day imaging capability. The objective of this study is to investigate the capability of SAR data for crop classification in the North China Plain. Multi-temporal Envisat advanced synthetic aperture radar (ASAR) and TerraSAR data were acquired. A support vector machine (SVM) classifier was selected for the classification using different combinations of these SAR data and texture features. The results indicated that multi-configuration SAR data achieved satisfactory classification accuracy (best overall accuracy of 91.83%) in the North China Plain. ASAR performed slightly better than TerraSAR data acquired in the same time span for crop classification, while the combination of two frequencies of SAR data (C- and X-band) was better than the multi-temporal C-band data. Two temporal ASAR data acquired in late jointing and flowering periods achieved sufficient classification accuracy, and adding data to the early jointing period had little effect on improving classification accuracy. In addition, texture features of SAR data were also useful for improving classification accuracy. SAR data have considerable potential for agricultural monitoring and can become a suitable complementary data source to optical data.     

A review of: “Design of Modern Control Systems” Edited by D. J. BELL,P. A. COOK and N. MUNRO. (I.E. 13. Control Engineering Series 20) Peter Peregrinus Ltd, 1982, pp. 330. Price £19·50.

A nonlinear state-space model representing the robot dynamics and containing a disturbance term due to gravitational loading is presented. An adaptive model-following control problem satisfying the matching conditions is formulated using a suitable linear time-invariant reference model. The control input is designed to have two components: a non-adaptive linear component to do the task of model-following and a nonlinear unit-vector component based on hyperstability theory to do the adaptive task. An additional integral feedback term is further added and then the overall asymptotic hyperstability is established. Simulation experiments on the first three joints of a PUMA 560 robot manipulator have indicated the potential of our design approach.     

ASUS A6J

ASUSA6J是在之前的A6产品上进行硬件升级后的新品,因此在模具上保持了与原有A6产品的统一,这样做的好处在于延长了部分模块的使用周期。采用了新平台的A6J拥有更加强劲的性能,硬件方面的改善不仅来自于双核处理器,还包括新型的ATiMobilityRadeonX1600显示卡,ASUS毫不吝啬地为其     

Michael J. Miller 随身携带

你喜欢随身携带哪种机器?这一问题随着新的轻便型个人电脑在今年进入市场而变得更加复杂了。对于那些带着便携机经常四处奔波的人来说,更小、更轻的设备——即我们曾经说过的个人数字助理(PDAs),其历史可以追溯到Apple的Newton造成巨大轰动的年代——是一种奢望。但当时那些设备的用途与现在的差别甚大,而且只能提供很少     

谁是J.D.Edwards？

很多人觉得，沉稳、踏实的风格其实正是企业管理软件的用户所需要的，他们不喜欢冒险，他们更喜欢一个多年以来都在持续、稳定地专注于这一领域的厂商，比如J.D.Edwards。