MATHEMATICAL MODEL FOR ACCESS MODE OF CONTENTION-COLLISION CANCELLATION IN A STAR LAN

I type system model of CCCAM(Contention-Collision Cancellation Access Mode)is studied through mathematical modelling and simulation. There are two innovations: (1) in the account; (2) the time at which customers depart after having been served successfully are chosen to be the embedded point, thereby "free period" is introduced reasonably. So the mathematical modelling and analysis result in this paper are significant for application of wire star LAN and wireless star LAN.

CONSTITUTE EQUATIONS OF 40Cr STEEL UNDER SUPERPLASTIC COMPRESSIVE DEFORMATION

The microstructure of 40Cr steel sample and its surface is ultra-fined through salt-bath cyclic quenching and high frequency hardening, then the superplasticity is studied under isothermal superplastic compressive deformation condition. The experimental results indicate that the stress-strain curves are shown to take place obvious superplastic flow characteristic at the temperature of 750-770℃ and at the initial strain rate of (1.7-5.0)×10-4 s-1. Its strain rate sensitivity is 0.30-0.38, the steady superplastic flow stress is 60-70MPa, the superplastic flow activation energy is 198-217kJ/mol, and it is close to α-Fe grain boundary self-diffusion activation energy. The super-plastic compressive constitute equations of this steel are correspondingly set up. Due to the finer microstructure of high frequency hardening, it appears bigger strain rate sensitivity value, smaller the steady superplastic flow stress and the superplastic flow activation energy, so it has better superplastic deformation capability.

Study in Soybean Yield Forecast Application Based on Hopfield ANN Model

Using the artificial nerve network′s knowledge, establish the estimate′s mathematics model of the soybean′s yield, and by the model we can increase accuracy of the soybean yield forecast.

Study on Plant Audio Generator of Microcomputerand Its Application

A type of plant audio generator was introduced in the paper including its circuit configuration, principle of working and used to deal with spinach in order to discuss effect of audio frequency on plant growth.

Non-Noether Conserved Quantity for Relativistic Nonholonomic System with Variable Mass

Using form invariance under special infinitesimal transformations in which time is not variable, the non-Noether conserved quantity of the relativistic nonholonomic system with variable mass is studied. The differential equations of motion of the system are established. The definition and criterion of the form invariance of the system under infinitesimal transformations are studied. The necessaxy and sufficient condition under which the form invariance is a Lie symmetry is given. The condition under which the form invariance can be led to a non-Noether conserved quantity and the form of the conserved quantity are obtained. Finally, an example is given to illustrate the application of the result.

Automatic Identification of Tomato Maturation Using Multilayer Feed Forward Neural Network with Genetic Algorithms (GA)

We set up computer vision system for tomato images. By using this system, the RGB value of tomato image was converted into HIS value whose H was used to acquire the color character of the surface of tomato. To use multilayer feed forward neural network with GA can finish automatic identification of tomato maturation. The results of experiment showed that the accuracy was up to 94%.

Using TCP/IP Programming to Realize the Communication among Different Network Platforms

This paper mainly introduces about how to use socket to design network program which can transfer data in different network platform in terms of TCP/IP Network Programming Standard.

Near-infrared Spectral Detection of the Content of Soybean Fat Acids Based on Genetic Multilayer Feed forward Neural Network

In the paper, a method of building mathematic model employing genetic multilayer feed forward neural network is presented, and the quantitative relationship of chemical measured values and near-infrared spectral data is established. In the paper, quantitative mathematic model related chemical assayed values and near-infrared spectral data is established by means of genetic multilayer feed forward neural network, acquired near-infrared spectral data are taken as input of network with the content of five kinds of fat acids tested from chemical method as output, weight values of multilayer feed forward neural network are trained by genetic algorithms and detection model of neural network of soybean is built. A kind of multilayer feed forward neural network trained by genetic algorithms is designed in the paper. Through experiments, all the related coefficients of five fat acids can approach 0.9 which satisfies the preliminary test of soybean breeding.

Optimal Filtering Algorithm for Stochastic 2-D FMM Ⅱ with Multiplicative Noise

A stochastic two dimensional Fornasini Marchesini’s Model Ⅱ (2 D FMM Ⅱ) with multiplicative noise is given, and a filtering algorithm for this model, which is optimal in the sense of linear minimum variance, is developed. The stochastic 2 D FMM Ⅱ with multiplicative noise can be reduced to a 1 D model, and the proposed optimal filtering algorithm for the stochastic 2 D FMM Ⅱ with multiplicative noise is obtained by using the state estimation theory of 1 D systems. An example is given to illustrate the validity of this algorithm.

An improved digital watermarking scheme combining with PKC

Digital watermarking is the enabling technology to prove ownership on such copyrighted product as software, documents, music, and video, monitor the usage of them, and even trace them back to the user with embedding of unique buyer identification(ID) as a part of watermark into them. This thread of detection will deter users from releasing unauthorized copies. A problem arises when the seller is dishonesty, he has a chance to use the digital watermarking with the buyer ID maliciously and make the buyer receive false-accusation. In this paper, an improved digital watermarking scheme is introduced to prevent false-accusation to an honest buyer, which is combined with the advantage of PKC(public key certificate) so that it fits the on-line transaction and helps to realize secure e-commerce. In addition, the extended application of this scheme is discussed.

Form Invariance of Raitzin＇s Canonical Equations of Relativistic Mechanical System

A form invariance of Raitzin's canonical equations of relativistic mechanical system is studied. First, the Raitzin's canonical equations of the system are established. Next, the definition and criterion of the form invariance in the system under infinitesimal transformations of groups are given. Finally, the relation between the form invariance and the conserved quantity of the system is obtained and an example is given to illustrate the application of the result.

Non-Noether Conserved Quantity of Nonholonomic System Having Variable Mass and Unilateral Constraints

Using the Lie Symmetry under infinitesimal transformations in which the time is not variable, the nonNoether conserved quantity of nonholonomic system having variable mass and unilateral constraints is studied. The differential equations of motion of the system are given. The determining equations of Lie symmetrical transformations of the system under infinitesimal transformations are constructed. The Hojman's conservation theorem of the system is established. Finally, we give an example to illustrate the application of the result.

Experimental Study on Extruded Beer Adjunct Used for Brewing Beer

The properties of saccharified and boiled worts between extruded and traditional non-extruded beer adjuncts were studied at the laboratory and a small beer brewing equipment(100 L) in this paper. Test results indicate that the main saccharification indices and filtration speeds of worts between extruded and traditional non-extruded beer adjuncts are similar basically. The collected rate of extracted material of worts of extruded beer adjuncts is 8% more than that of traditional non-extruded beer adjuncts. Fermentation time of worts of extruded beer adjuncts is 10 % less than that of traditional non-extruded beer adjuncts. The energy consumption of extruded beer adjuncts in saccharification process is 13 % less than that of traditional non-extruded beer adjuncts.

THE DDTCI SWITCH ALGORITHM FOR ABR TRAFFIC CONTROL IN ATM NETWORKS

For the issue of flow control for Available Bit Rate (ABR) traffic in ATM network,a new improved Explicit Rate (ER) algorithm named Dynamic Double Threshold Congestion Indication (DDTCI) algorithm is presented based on the Explicit Forward Congestion Indication (EFCI) Current Cell Rate (CCR) algorithm and Relative Rate (RR) algorithm. Different from the early ER algorithm, both the high-level and the low-level threshold is dynamically changing according to the state of the bottleneck node. We determinate the congestion state with the information of the two dynamic threshold, and control the cell rate of the source by feed back mechanism. Except for the well performance in both link utilization and fairness in distribution of available bandwidth, the improved algorithm can alleviate the fluctuation of sending rate dramatically. The mechanism is modeled by a fluid model, and the useful expressions are derived.Simulation results show up our conclusion.

Controllability and Observability of 2-DOF Permanent Magnet Maglev System with Linear Control

A new type of 2-DOF(degree of freedom) magnetic levitation system for multi-DOF levitation is proposed. In this system, the force of permanent magnets are used for levitation and controlled by adjusting the reluctance of the magnetic circuit. Using permanent magnets, the feature of this system is effective for saving energy and avoiding heat generation. First, the principle of the levitation system and typical reluctance control methods are described. Second, an experimental device based on the principle is introduced. Finally, the feasibility of this system is considered from linear control theory.

Application of Machine Vision Technique in Weed Identification

This paper mainly introduces some foreign research methods and fruits about weed identification by applying machine vision. This facet researches is lack in our country, this paper could be reference for domestic studies about weed identification.

Combine Gearbox Aided Design Based on Artificial Neural Networks

In the optimum design of the self-propelled combine gearbox, the knowledge of ANN is applied to overcome slow calculation and low design efficiency. We did the normative approach of the charts information,then solved the difficult problems in the design process and get satisfactory results. We also completed three-dimensional design of the gearbox in order to verify the rationality of the design visually.

Variation of Plant Electrophysiology in Cucumber under Different Water Status

AP and VP were measured in cucumbers under water sufficiency and water stress. The results indicated that, the AP would be evoked by electrical impulse, for water-stressed cucumber, its amplitude could reached more than 40 mV which was obviously greater than that (about 10-20 mV) of plant under well-watered, and no VP came out. Along with the intensity of light increased, the VP appeared going-up trend, and accompanied by evidently spiking electrical signal, for plant under water stress, the VP increased more clearly, but the change of spiking amplitude of AP (about 3 mV) was rather smaller than that (8-10 mV) of plant under well-watered.