NPSNET-V. A new beginning for dynamically extensible virtualenvironments

At the Naval Postgraduate School (NPS) we, like others in the collaborative VE community, have extolled the virtues of persistent online virtual worlds for years. We previously addressed the infrastructure requirements of a large-scale, persistent online virtual world: runtime extensibility of both content and applications; scalability in world complexity and number of participants; and composability of heterogeneous content and applications. We follow those arguments with the first publication describing NPSNET-V     

新年伊始 TI加强C2000系列在PLC领域实力 TMS320F2806x Piccolo MCU能为可再生能源、PLC与电机控制提供浮点内核

<正>15年以来,德州仪器(TI)面向工业应用的C2000系列一直在电机、数字马达控制等实时控制领域贡献着自己的力量。TI的高性能浮点微控制器(MCU)Delfino系列(运算速度约在100～300 MIPS)及低端的Piccolo MCU系列(运算速度在40～60MIPS)覆盖的范围虽然很广,但是缺少运算速度在60～80 MIPS之间的实时处理MCU,为了弥补这一空缺,TI日前宣布推出15款最新低成本TMS320F2806x Piccolo浮点MCU,以提供能平衡低成本Piccolo与高性能Delfino的性能,为可再生能源、电力线通信(PLC)、电机控制、数字电源控制等提供浮点内核。     

A comparison of single- and dual-task measures to predict simulator performance of beginning student pilots

An experiment comparing the predictive validity of single- versus dual-task measures is reported. Two identical one-dimensional tracking tasks were used in the experiment. One task was controlled by the subject's left hand and the other by his right. Fifty-seven men first received two trials on each of the tasks alone followed by 25 dual-task trials. Finally, they again performed each task alone for one trial. The subjects subsequently worked through a short basic flight course consisting of ground instruction and practice in a GAT-2 simulator. After completing the course, the subjects performances on four level turns, four descents, and four descents followed by stalls were scored. Performance in the simulator was correlated with performance on each tracking trial. The predictive validity of the early single-task scores decreased with practice while the dual-task validity increased throughout the testing session. However, the predictive validity of the late single-task scores was almost as large as that of the late dual-task scores. Several analyses indicated that late single-task performance was more similar to late dual-task performance than to early single-task performance. A control theory analysis of the data revealed that a dual-task control strategy had been employed in the late single-task trials and probably accounted for the comparable predictive validities of late single-and dual-task scores.     

青啤分销从SCM入手实现战略转型

青岛啤酒股份有限公司是国家特大型企业,其前身是国营青岛啤酒厂,始建于1903年,是中国历史最悠久的啤酒生产企业。青啤是一个典型的依靠质量和销售制胜,将销售渠道管理作为核心能力之一的企业,其采用多级     

A new chaos detector

This paper proposes a new detector for chaos. It is simpler and numerically less intensive than previous methods. It is more robust than previous methods. It works well even with short data sets (200 time scalar points), in the presence of noise (as low as 4 dB signal to noise ratio in stationary additive white Gaussian noise), and with severe data level quantization (data quantized to five bits). The theory behind the new detector is given, and examples of its application to the Logistic, Henon, and Lozi Maps are shown. The new chaos detector is briefly compared to existing methods such as the estimation of the largest Lyapunov exponent, the correlation or attractor dimension, and the entropy of the data set. Conventional electrical engineering signal analysis tools (such as the Discrete Fourier Transform) fail to help in the detection of chaos. This failure is explored. Sinusoids and several types of noise are input to the detector and the outputs are recorded. The basis for a binary signaling scheme which uses chaotic sequences and the new chaos detector is briefly described.     

A new keyboard layout

'QWERTY' is the nickname for the inefficient standard typewriter keyboard, also used for Telex and many computer input terminals, dating from 1874. The ergonomically-designed Dvorak Simplified Keyboard (DSK) has been available for over 35 years and there is increasing international interest in its introduction; but DSK does not take metrication into account. There is a clear need for international agreement on a new design up-dating DSK for metrication. Agreement is in the interests of both keyboard users and their employers. An Alpha-Metric Keyboard (AMK) is proposed and its design and advantages are described.     

A new lifetime distribution

A new two-parameter distribution with decreasing failure rate is introduced. Various properties of the introduced distribution are discussed. The EM algorithm is used to determine the maximum likelihood estimates and the asymptotic variances and covariance of these estimates are obtained. Simulation studies are performed in order to assess the accuracy of the approximation of the variances and covariance of the maximum likelihood estimates and investigate the convergence of the proposed EM scheme. Illustrative examples based on real data are also given.     

一种新型的三参量传感器

单参量传感器（加速度计、速度计或位移计）只能输出一种参量。本文介绍一种三参量转换器,可与任何一种单参量传感器组成一套完整的三参量传感器,可同时输出加速度、速度和位移三种参量。分析了三参量转换器的基本原理及构成三参量传感器的方法,给出了实测数据和相关的技术指标。构成的新型三参量传感器已在工程振动、强地震动等领域的测量中得到应用,取得了满意的效果。     

A new realization theory

A realization theory that is based on the Kalman system theory and motivated by the Fuhrmann realization theory is presented. In the Fuhrmann realization theory, the realization state-space is defined by a natural polynomial module K_Q, which is related to a nonsingular polynomial matrix Q. The module K_Q is formed of all f where Q^-1f is strictly proper. In the realization theory proposed, the realization state-space is defined by a different module M_Q, which is formed of properly truncated, strictly proper formal power series of Q^-1f. The realization theory can be used to prove the dual-realization scheme induced by the Fuhrmann realization theory     

一个新的小额电子支付协议

在指出了目前最流行的小额电子支付协议PayWord的缺陷之后，设计了一个新的小额电子支付协议Pro-ofWord。与PayWord协议相比，ProofWord协议能更好地保护用户、商家和银行三方的利益，而其运行效率和Pay-Word协议基本相同。