Key Engineering Materials Vols. 474-476

Abstract: The design of the grain supply chain network is one of the important and challenging problems in the field of agri-food supply chain. Almost all researches mainly concerned with the problem in deterministic, stochastic or fuzzy environments. Different from them, we study the grain supply chain design problem by using uncertainty theory. This paper employs an uncertain programming tool to design the grain supply chain network and a α-cost minimization model is proposed. To solve the model, we design a hybrid intelligent algorithm which integrates 99-method and different evolution algorithm. Finally, a numerical example is presented to illustrate the effectiveness of the proposed model and algorithm.

Abstract: The author has designed a framework for building web sites using Microsoft’s .NET technology. The framework employs a design approach based upon the Model View Controller (MVC) design pattern. A framework in an object oriented system is a collection of classes that provide an abstract approach to solving a given problem.

Abstract: PLL is an important part of the RF front-end module,its performance is directly related to stability and accuracy of the RF base-band signal extracted. A FPGA-based all-digital PLL is implemented in this thesis, Hilbert digital phase detector (HDPD) ,Numerically controlled oscillator (NCO) and FIR digital loop filter module implemented using Verilog language ensure accuracy and stability to Sample input Baseband signal modulated. The experiments confirmed that the all-digital PLL designed in this thesis can overcome the defects of DPLL based on semi-analog circuits; and has high Operating frequency, exact capture time, precision adjustable, simple interface, and so on; can be widely used in radio frequency identification (RFID) and automatic control system.

Abstract: The article analyzed the old tongue deviation analysis method and introduced a new tongue deviation analysis method with auto-correction aiming at the shortcomings in the old method. This method overcomes the shortcoming that the old method utilized area symmetry to extract central axis and we utilizes the method of shape symmetry analysis to improve the accuracy. In comparison experiment, this method is more accurate than the old one and its efficiency is higher than the old one.

Abstract: With the continuous development of the Internet, it while brings each kind of beneficial information to the people , the hacker, viral as well as the malicious destruction and so on bad factor also multiplies along with it the spread, the network security and the reliability have become the focal point which various countries pay attention together .

Abstract: Virtual Private Network (VPN) refers to rely on the ISP (Internet service providers) and other NSP (Network service provider), in the public network, to establish a dedicated data communication network technologies. In the virtual private network, between any two nodes connected no dedicated network for the traditional end-to-end physical link, but to use a public network composed of dynamic resources. VPN technology can reduce the internal network building costs, improve user network operation and management flexibility, and enable communication between computers and private circuits on computer communications with the same security.

Abstract: The dynamics of fractional-order systems have attracted increasing attention in recent years. In this paper, we study the chaotic behaviors in a fractional-order modified van der Pol oscillator. We find that chaos exists in the fractional-order modified van der Pol oscillator with order less than 3. In addition, the lowest order we find for chaos to exist in such system is 2.4. Finally, a simple, but effective, linear feedback controller is also designed to stabilize the fractional order chaotic van der Pol oscillator.

Abstract: Empirical mode decomposition (EMD), a new self-adaptive signal processing method, has been recently developed for nonlinear and non-stationary time series analysis. In this paper, EMD method is described and applied in time-frequency analysis. Aiming at the problems of intrinsic mode function (IMF) criterion in the EMD method, neural network (NN) prediction model and wavelet packet transform (WPT) technology are simultaneously introduced into the EMD method to improve the border effect and to enhance the ability of signal analysis, and thus a hybrid EMD-based time-frequency analysis strategy is proposed. The simulated time series are exploited to verify the effectiveness of the proposed hybrid model. Experimental results indicate that the hybrid strategy gives a quite satisfactory performance when both NN prediction model and WPT method are employed.

Abstract: Dynamic ice storage system has advantages of energy-saving by using electricity price difference of the different period. Food in display cabinet requires small temperature fluctuation to prolong preservation time. Considering the questions of energy consumption and unable to adopt the traditional method of halting and running compressor to control center temperature fluctuation in display cabinet, the paper provides dynamic ice storage system to cool display cabinet. When the wind speed keeps in suitable space, according to environment temperature, humidity and wind change, self-adaptive adjusting cooling water pump flow can maintain the center temperature within a certain range, and reduce center temperature fluctuations in display cabinet by controlling inverter frequency using PLC. Experiments prove that when environment temperature change range is 20°C to 32°C, and relative humidity is 40% to 90%, if not adopting PLC control pump flow, the temperature difference is 2.5°C, on the contrary, temperature difference is 1.3°C.

Abstract: In this paper, it aiming at the functional features of containerization canning safety valves adopts the method of design of experiments (DOE) to conduct fast modeling on the working conditions of the safety valve spring, and cites the means of multi-objective optimization to optimize the spring designs, minimizing the maximum inner shear stresses of its winding coils and its weights. In the process of the study, a parametric finite-element spring model with three variable parameters has been used to generate arbitrary spring shapes within the pre-set scope of spring shapes.By the V-Optimal method, it generates a DOE input matrix with 30 input points. It obtains a two-third-order polynomial regression model through analyses and calculations, which can fully reflect the regression characteristics of the shear stresses and the weights of springs. This study shows that by means of DOE and multi-objective optimization, it enables to quickly design and optimize on safety valve springs.