Meteorological satellite is one kind of applied satellite that has tremendous benefit to both economic and society. The development of polar orbit meteorological satellite in China has experienced the processes from experiment to application. This paper introduces briefly the development and performance of the FY-1 polar meteorological satellite,and the success of space borne 10 channels scanning radiometer and the long life,high reliable polar satellite platform are described. Moreover, the general information of the new generation polar FY-3 meteorological satellite is presented. The technology specialty of the satellite is summarized.
Work on faster-than-light (superluminal) research has been going on in USA, Europe and PRC since the early work of O. M. Bilanuik and E. C. Sudarshan in 1962 and that of a good working with G. Feinberg at Columbia University in 1967.
According to the original article of A. Einstein in 1905, velocities greater than that of light have no possibility of existence. However, an interesting phenomenon related to the Einstein's article in 1907 have been found, in which the possibility of sending signals in superluminal communication was not completely negated. In this paper, the author tries to bring about split-up to the different subjects of velocity's study，and then, suggests the definition of General Information Velocity (GIV) to make better discussion of those velocity concepts. After rethinking superluminal research in 1962—2003，the author obtains the conclusion that the “faster than the speed of light in vacuum” is a realizable scientific statement.
The ground structure's intelligent and automatical creating is researched. The ground structures of truss structures are intelligently and automatically created by using collateral ANFIS (Adaptive-Network-Based Fuzzy Inference Systems). The essentials of this method is to form a mapping between configurations of the trusses existed and those to be found. The ground structure is inferred by the mechanism contained in sample trusses. To produce appropriate data format of ANFIS, the topology configuration of trusses is described as a series of decimal fraction. The simulation shows the efficiency of this system.
Factorials experiment and velocity single-factor experiment are applied in the dry high-speed milling experiments of Martensitic stainless steel 2Crl3, which is used in aerospace industry. Based on the analysis of cutting regimes, influences on milling force, the spectrum analysis and wavelet analysis are applied on the random cutting force signals. This study shows that in high speed milling of Martensitic stainless process, the interaction of depth of cut and feed per tooth has significant effect on the cutting force; the interaction of feed per tooth and depth of cut introduces a lower frequency periodic signal; this low frequency signal coupled with high frequency signal could remarkably increase the amplitude of cutting force signals.
As an expansion of LAN, the WLAN reduce the cost of building a network infrastructure, to enjoy the mobile, high-quality, multimedia services. The 802.11 standard for wireless networks includes a Wired Equivalent Privacy (WEP) protocol, which is used to protect link-layer communications from eavesdropping and other attacks. Several serious security flaws in this protocol have been discovered and some solutions have been proposed to enhance WEP security. However, it is doubtful whether they can provide enough security as these solutions lack precisely security analysis. In this paper, concrete security analyses of various enhancing mechanisms are given. Results show that these mechanisms indeed increase security and bring significant, provable security gains in WLAN environment. The authors quantify the security as a function of the security of the primitives used, thereby enabling a user to decide how to construct an enhanced mechanism for desired demands.
A MIMO-GPC stability theorem based on frequency domain is presented in the paper. The closed-loop feedback structure of MIMO-GPC is proposed. Nyquist array methodology is used to analyze the stability of MIMO-GPC. The parameters of MIMO-GPC can be determined by stability criterion.
As a new design pattern, virtual optimization design is a multiple subjects crossed synthetical technique and will become the trend of modern mechanical products design. It can avoid the repeated processes from design to trial-manufacture and test. The designers can analyze and optimize the product structures in virtual visualization environment. The design cycle is shortened and the cost is reduced. The paper analyzes the peculiarity of virtual optimization design, and puts forward the thought and procedure to implement virtual optimization design. Finally, the example to optimize the NC lathe headstock is studied.
Based on grey system theory and fuzzy theory, uncertain decision making problems and several relative articles were studied, then points out the advantage and shortage of them when dealing with grey fuzzy set were pointed out. In this paper, using optimization theory and the maximum entropy formulism, a method for multi-attribute group decision making based on the theory of grey fuzzy relation is established. Furthermore, two practical algorithms are given, in which attribute weights are known or unknown respectively. Finally, an example demonstrates the validity of this method.
In this paper, a fuzzy model algorithm for a rule-base self-extraction and simplification is introduced. The method consistes of three steps: The first step is to classify the out-in space by constructing a fuzzy partition validity index, then the optimal number of dusters and, hence, the optimal number of rules are obtained; The second step is to construct the initial fuzzy system based on the optimal number of rules and neural networks; The third step is to get the function of computing similarity of fuzzy sets by fuzzy similarity analysis method. The similar fuzzy sets are merged to create a common fuzzy set in rule base based on threshold value. Thus a fuzzy system with interpretability and simplicity is obtained. At last, the fuzzy rules of productivity factor of China is extracted by the fuzzy system.
The management of subway tunnel fire smoke is an important component in city public safety. In this paper, on the basis of theoretical analysis of the main factors affecting fire smoke flow in a subway tunnel, the ventilation and exhaust system were considered as a whole and the effects of buoyancy and thermal resistance were introduced. Further, a mathematical model was established to express the relationships between the critical environments, critical velocities, air speeds, smoke speeds and fire intensities. The results can provide instructions for tunnel smoke managements and emergency handling.
By analyzing certain fuzzy models for production scheduling, the author proposes a general novel fuzzification method based on fuzzy programming for batching production processes and offers a modeling method with fuzzy coefficients. Two fuzzy algorithms based on genetic algorithm, i. e. , fuzzy simulation and SFA algorithm, are adopted to solve the fuzzy model. The selection of membership function is flexible, and a proper expression of fuzziness is adopted. Finally, a numerical example demonstrates that the modeling method is valid.
The frame, function and achievement method of knowledge sub-database in computer aided equipment design system based on I-deas are introduced according to the principle of Knowledge Based Engineering. The relations among the sub-databases are analyzed. Finally, the integration of the knowledge database and equipment design and management system is described in the computer aided equipment design system based on I-deas.
Fluid jet principle is used in many processes. This paper introduces four patented new technologies developed based on fluid jet principle for oil field development. They are the methods of removal of formation plug, spent-acid flow-back by pressure decrease on one-trip, wellhead adding water, and removal of sludge from settling tank. The applications in more than 200 wells (or sets) show that these fluid jet new technologies have great prospects in oilfield production with their simplicity of technological process, convenient operation and low cost. This-paper describes mainly the technical principles, field utilization results and features of them.
The GFRP plate was epoxy-bonded to the tension flanges of RC beam, which can effectively improve the bending strength and the lateral stiffness of the RC beam. In this paper, the pulling force of GFRP plate and the deflection of the plated beam have been analyzed when the plated beam bears three different loads. The results can guide experiment and study in the future.
This article narrates Virtual Enterprise's CRM system's characteristics, and analyzes its information flow. And on the basis of information flow, a distributed running system is given which is managed and coordinated by coordination enterprise of VE CRM. Moreover, a reference model of function module of VE CRM's coordination enterprise is constructed and a technique framework of Virtual Enterprise's CRM is brought forward.
In this paper, the development course and basic principle of MRP Ⅱ /ERP are discussed, and then the structure and function of MRP Ⅱ/ERP system are analyzed. At last, the key point of implementation of MRP Ⅱ /ERP system is illuminated and the future of MRP Ⅱ /ERP system is anticipated.
Fabrication of micro-channels is a key technique for production of analysis chip. The principles of selecting material, the fabrication of mold used in molding replication and every directly fabricating methods were compared and discussed. Some available methods of microfabrication for production of analysis chip were proposed.