Giants ＆ Newcomers

Silicon Valley is called golden place or dreamlandbe cause it's full of the biggest companies in the world,which create a great number of millionaires and job op-portunities.In all the famous companies,HP and Intel rank thetop two according a well-known local magazine.HP was founded in 1939 by Bill Hewlett and DavePackard,who had both graduated from Stanford Universityin 1934, as a manufacturer of test and measurement in-struments. Their first product was a precision audio oscil-lator,the …     

.com’s时代

对比是残酷的。一度被看作中 国国民经济象征的首钢，去年９月在上海股票交易所上市，股票价格在５元人民币左右，总市值１１１多个亿人民币，刚刚成立不久的ｃｈｉｎａ．ｃｏｍ，去年７月在美国Ｎａｓｄａｑ上市，股价８５美元左右，总市值超过３６亿美元，是首钢的３倍。首钢拥有１０万员工，ｃｈｉｎａ．ｃｏｍ有员工１００多人；首钢是国家投巨资兴建的特大型企业，ｃｈｉｎａ．ｃｏｍ所拥有资产中价值最高的是Ｃｈｉ－ｎａ． ｃｏｍ、 ｈｏｎｇｋｏｎｇ． ｃｏｍ、 ｔａｉｗａｎ． ｃｏｍ等几个城名。比特的分量重过了钢铁。对比是残酷…     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).     

In memory of V.A. Kotel’nikov

Obituary

In memory of V.A. Kotelnikov     

Culture in cycles: considering H.T. Odum’s ‘information cycle’

‘Culture’ remains a conundrum in anthropology. When recast in the mold of ‘information cycles,’ culture is transformed. New fault lines appear. Information is splintered into parallel or nested forms. Dynamics becomes cycling. Energy is essential. And culture has function in a directional universe. The ‘information cycle’ is the crowning component of H.T. Odum’s theory of general systems. What follows is an application of the information cycle to the cultural domains of discourse, social media, ritual, education, journalism, technology, academia, and law, which were never attempted by Odum. In information cycles, cultural information is perpetuated – maintained against Second Law depreciation. Conclusions are that culture is in fact a nested hierarchy of cultural forms. Each scale of information production is semi-autonomous, with its own evolutionary dynamics of production and selection in an information cycle. Simultaneously, each information cycle is channeled or entrained by its larger scale of information and ultimately human-ecosystem structuring.     

Bay网络V.90’我支持

北电网络Bay网络事业部日前宣布,在Versalar5399远程访问集中器(RAC)模块和Versalar 8000远程访问集中器系统中全面支持V.90技术。目前,Bay Networks正在其发布的所有远程访问设备中发售V.90调制解器标准,使世界各地的企业和服务供应商能够选择V.90性能。通过继续支持X2和K56flex 56K专有协议,Bay将继续致力开发基于标准的端到端网络技术,并在必要时为客户提供所需支持。 除支持所有56K实现技术外,Bay Versalar 5399和8000产品还具有一系列其它竞争优     

Some problems for Clark’s model. II. A solution for Merton’s portfolio problem1

The problem of finding the optimal control over the portfolio for an investor in (B, S)-market is considered. Clark’s model is taken as a model for the stock price evolution. The cases of risk-loving, risk-neutral, and risk-averse investors are considered.     

Work capacity and anticipation in A.A. Ukhtomsky’s concept of dominance

This paper presents the results of theoretical and experimental investigations of human activity and anticipation based on A.A. Ukhtomsky’s concept of brain dominance – a non-equilibrium system-forming factor in living systems. Facts on the stages of dominance formation are presented in relation to the creative abilities of the human brain and the role of fatigue as a “lever” for increasing systems’ work capacity on the basis of “trace exaltation”. Individually, specific features of dominantogenesis are compared with variations in behavioural types. On the basis of chronotopic EEG analysis, we delineate cortical dominants that underlie individual specifics of cognitive processes. The relation is shown between anticipation and the “expansion of dominants” – the broadening of “distal perception” in time and space, as framed by A.A. Ukhtomsky.     

N.N. Krasovskii’s extremal shift method and problems of boundary control

For the boundary-controlled dynamic system obeying a parabolic differential equation with the Neumann boundary condition, the problems of following the reference motion, following the reference control, and guaranteed control (at domination of the controller resource) were solved on the basis of the N.N. Krasovskii method of extremal shift from the theory of positional differential games.     

Correction to ‘Robustness of Adaptive Control of Robots’ by F. Ghorbel and M.W. Spong

In paper Robustness of Adaptive Control of Robots by Ghorbel and Spong, the adaptive control of flexible joint robots is investigated using a singular perturbation approach and composite Lyapunov theory. In this note, we correct a missing term from the boundary-layer system of that paper and then show that the stability analysis presented remains valid.     

Review of: ‘ Programmed Instruction in the British Armed Forces’. By D. WALLIS,K. D. DUNCAN and M. A. G. KNIGHT. ( H.M.S.O., 1966.) [Pp. iv+49.] 4s. 6d.

A mathematical model for studying head protection in static is presented and its application to the design of ice hockey helmets is discussed. Static load and dynamic impact tests indicate that dynamic tests are to be preferred when estimating the stiffness of the materials used ns helmet liners. Solutions to the differential equations governing the linear motion of the head under a sideboard collision provide information regarding the thickness of the energy absorbing helmet liner and the tolerance level to which the helmet can be expected to perform. The model also provides a useful estimate of the angular velocity of the head imparted by the rebound from the sideboard. Although the helmet cannot prevent angular motion of the head, an estimate of the expected angular velocity may indicate that additional measures must be taken to prevent head injury from such angular motion. The study also indicates that the problem of providing head protection in ice hockey is of such magnitude that a helmet alone cannot be expected to provide total protection and additional modification to the playing environment must also be undertaken.     

Centenary of Einstein’s general relativity. Its present extensions

This paper is a brief review of integrable models of gravitation and cosmology in four and more dimensions which make up one of the proper approaches to studying the basic issues and strong field objects, the early and present Universe, and black hole (BH) physics in particular. The main results within this approach, obtained in the recent years by the research group founded by K.P. Staniukovich, are presented. Absolute G measurements and problems of its possible time and range variations, which are reflections of the unification problem, are discussed within these models. The choice, nature, classification and precision of determination of fundamental physical constants and their role in the expected transition to new definitions of basic SI units, supposed to be based on fundamental physical constants and stable quantum phenomena, are described. A need for further absolute measurements of G, its possible range and time variations is stressed. Themultipurpose space project SEE is shortly described, aimed at measuring G and its stability in space and time with a progress of 2–3 orders of magnitude against the present accuracy. It may answer many important questions posed by gravitation, cosmology and unified theories. A project of a laboratory experiment to test possible deviations from Newton’s law of gravity is also presented.     

IT managers’ vs. IT auditors’ perceptions of risks: An actor–observer asymmetry perspective

With the growing role of information technology (IT), many organizations struggle with IT-related risks. Both IT managers and IT auditors are involved in assessing, monitoring, and reporting IT risks, but this does not necessarily mean that they share the same views. In this study, we draw upon the actor–observer asymmetry perspective to understand differences in IT managers’ vs. IT auditors’ perceptions of risks. Through a quasi-experiment with 76 employees of a financial institution, we found that IT managers and IT auditors showed the expected actor–observer differences. Implications for both research and practice are discussed.     

Security flaw of Hölbl et al.’s protocol

Recently, Hölbl et al. [M. Hölbl, T. Welzer, B. Brumen, Improvement of the Peyravian–Jeffries’s user authentication protocol and password change protocol, Computer Communications 31 (2008) 1945–1951] have proposed an improvement of Peyravian–Jeffries’s user authentication protocol and password change protocol [M. Peyravian, C. Jeffries, Secure remote user access over insecure networks, Computer Communications 29 (5–6) (2006) 660–667]. Peyravian–Jeffries’s scheme suffers from an active off-line password-guessing attack [J. Munilla, A. Peinado, Off-line password-guessing attack to Peyravian–Jeffries’s remote user authentication protocol, Computer Communications 30 (1) (2006) 52–54], and Hölbl et al. state that their improved protocol overcomes this weakness. However, we show in this paper that although this proposed protocol prevents this active attack, it remains vulnerable to a passive (simpler) off-line password-guessing attack.     

一起.com——SAPPHIRE ’99亚太区用户大会有感

身着功夫装的青年男女在节奏明快的现代音乐伴奏下,演绎着中国传统武术的魅力;杂技演员手捧笔记本电脑向观众展示着他们动中求静的高超技艺;朝气蓬勃的少女在光怪陆离的激光下翩翩起舞……11月1日,SAP公司在新加坡召开的SAPPHIRE‘99亚太区用户大会的开幕表演,让人们感到的是一浪高似一浪的热烈气氛。此次大会是1995年以     

“.com’s”是不是一条“虫”

科学技术的发展使科幻小说的情景成为现实,２０世 纪的人类自己制造出来的第一条大害虫──“千年虫”,让人类吃足了自己的苦头,据报道,全世界已为“千年虫”花费了５０００亿美金的代价,而且在继续付出代价。全球众多人士为对付“千年虫”更付出了精神和体力的双重损耗,在新千年到来之际全人类激动万分的时刻,却有不少人精神过度紧张地守候在各自的机房里,通宵未眠地准备与“千年虫”决一死战。让人类在第３个千年到来的喜庆之中蒙上了重重的阴影。 人类既然已经造出了一条害虫,也就可能再造出第二条、第三条害虫,危害性可能更大…     

Comment on Lee et al.’s group signature and e-auction scheme

Recently, Lee et al. used their new group signature with the function of authenticated encryption to design a sealed-bid auction scheme, and they claimed that their schemes are secure. In this paper, we show that if the group manager has a valid group signature of a member, without the member’s secret key, he can forge a group signature on arbitrary message on behalf of the member; then, if the registration manager (RM) and the auction manager (AM) conspired (with each other) in their auction scheme, they can forge a new bid on any goods on behalf of the bidder who has sent his/her bid to AM. Therefore, their group signature and auction scheme are insecure. Finally, we improve Lee et al.’s group signature scheme to overcome the modification attack and achieve the security requirements.     

Vulnerabilities assessment — Part 2. Getting in through the ‘Net’

In the first part of this article we defined a vulnerability and discussed how to determine the importance of vulnerabilities. We looked at many types of vulnerabilities. Most people think of a vulnerability as something that gets exploited by ‘hacking in’ to organizations and systems by strangers on the outside. We looked at several important vulnerabilities not usually given much consideration because of that preconception: legal vulnerabilities, personnel/human resources vulnerabilities, premises vulnerabilities, phone switch vulnerabilities, disaster recovery/contingency planning vulnerabilities, insurance vulnerabilities, policy vulnerabilities, password vulnerabilities, default value vulnerabilities and improper access control vulnerabilities. It was shown that it was neither possible nor effective to remove all vulnerabilities, but that proper analyses were necessary to determine which to treat.