IJISA Vol. 3, No. 1, Feb. 2011
Cover page and Table of Contents: PDF (size: 129KB)
The demands placed by designers on workpiece performance and functionality are increasing rapidly. Important aspects of manufacturing’s contribution to the fulfillment of these demands are the conditions at the work piece edges. However, Burrs are often created on the workpiece edges in micro-machining. In many cases, time consuming and expensive deburring processes have to be applied in order to ensure the desired part functionality. Burrs make troubles on production lines in terms of deburring cost, quality of products and cutting tool wear. To prevent problems caused by burrs in micro-machining, prediction and control of burr size is desirable. Experimental studies show that burr formation in micro-milling is a highly complex process depending on a number of parameters such as material properties, tool geometry and cutting parameters. It is very difficult to establish the relationship between burr sizes and cutting conditions. A web-based micro-machining burr expert system for burr sizes prediction and control was developed using ASP.NET platform. Burrs types and sizes prediction and cutting conditions optimization for burr controlling which based on the reasoning method of BP neural networks are realized. Operation results show that the system is reliable. It provides a new technology for burrs modelling and controlling.[...] Read more.
The main goal of this paper is to analyze the flutter boundary, transient loads of a supersonic fin, and the flutter with perturbation. Reduced order mode (ROM) based on Volterra Series is presented to calculate the flutter boundary, and CFD/CSD coupling is used to compute the transient aerodynamic load. The Volterra-based ROM is obtained using the derivative of unsteady aerodynamic step-response, and the infinite plate spline is used to perform interpolation of physical quantities between the fluid and the structural grids. The results show that inertia force plays a significant role in the transient loads, the moment cause by inertia force is lager than the aerodynamic force, because of the huge transient loads, structure may be broken by aeroelasticity below the flutter dynamic pressure. Perturbations of aircraft affect the aeroelastic response evident, the reduction of flutter dynamic pressure by rolling perturbation form 15.4% to 18.6% when Mach from 2.0 to 3.0. It is necessary to analyze the aeroelasticity behaviors under the compositive force environment.[...] Read more.
The principle of field synergy is to simulate the comfortableness of room in this study. The parameters U, V, W and input position of wind are calculated to simulate comfortableness of room. Temperature and velocity fields are simulated by COMSOL Multiphysics software. Comfortable degree is calculated by field synergy mean square root method in this research. The simulation result shows that field synergy angle decreases while comfortable degree increases. It is very obvious that the right input position of wind leads lower field synergy angle.[...] Read more.
This paper introduces the establishment and simplification of the temperature field and the general calculation method of temperature stress of the prestressed concrete box girders. Three kinds of sunshine temperature gradient models were loaded to a real bridge respectively, and got stress and displacement curves. Research data of several prestressed concrete box girders were selected from different regions of China to compare the relative error of the calculated and measured value. We indicate that the study of temperature field and thermal stress of prestressed concrete box girders is necessary, and will help engineers to solve the problem in structure design.[...] Read more.
This paper introduces the status of parallel-type Electrostatic Fabric Filter was researched, and the factors influencing collection efficiency were analyzed in this paper. Using software Gambit, which also meshed the calculating region, a three-dimensional structure model of the precipitator was established. And then the numerical simulation of the air distribution characteristic was carried on with the software of fluent 6.2, which sets the boundary conditions, standard k-ε 2-equation model and SIMPLE algorithm; Then draw the path line and contour chart of the cross-section, obtained the mean square deviation value, analyzed the airflow distribution situation and the reasons for why its uneven. By setting an appropriate opening rate for the airflow distribution plates and collection plates to improve the air distribution. The results show that the airflow distribution can be uniformed by improving the opening rate of the collection plates. The numerical simulation result is more reasonable and can be used as the reference of optimizing the structural design of Electrostatic Fabric Filter.[...] Read more.
The mechanism of a recycling system about discarded products is running with a few critical roles and processes. To identify the relationship and collaborate the activities involved in this recycling circle are the very significant work in practice. For the sake the paper explores and identifies the critical drivers underlying the system, based on which a framework is established to explore the relationship among relevant activities consisted of collection, remanufacturing and resale, as well as companies and customers’ behaviours. A dynamic quantitative model is designed to simulate this vigorous relation, which demonstrates and verifies the rule of this relationship with details about the recycling activities. The information will benefit practitioners a lot in terms of the recycling operation planning under different situation.[...] Read more.
It is significant to scientifically carry out the urban earthquake disaster reduction. According to the features of China urban earthquake disaster reduction, this paper designed the urban earthquake disaster reduction information management system, which proposed a system design idea, system composition and function structure. The system adopted the object-oriented language VB6.0 and the component set ArcGIS Engine provided by ESRI for development. We applied a variety of information techniques (GIS and database) for spatial information acquisition, analysis and computing, and drew up function modules corresponding to inquiry, spatial analysis, risk analysis and data management. By using this system we can achieve scientific management about the earthquake disaster information in storage and transportation engineering, draw up kinds of earthquake emergency decisions intellectually and make them visual, which improved the efficiency and velocity of earthquake emergency evidently, and assisted the decision-making system effectively for the earthquake emergency work.[...] Read more.
Service integration and supply on-demand coming from cloud computing can significantly improve the utilization of computing resources and reduce power consumption of per service, and effectively avoid the error of computing resources. However, cloud computing is still facing the problem of intrusion tolerance of the cloud computing platform and sensitive data of new enterprise data center. In order to address the problem of intrusion tolerance of cloud computing platform and sensitive data in new enterprise data center, this paper constructs a virtualization intrusion tolerance system based on cloud computing by researching on the existing virtualization technology, and then presents a method of intrusion tolerance to protect sensitive data in cloud data center based on virtual adversary structure by utilizing secret sharing. This system adopts the method of hybrid fault model, active and passive replicas, state update and transfer, proactive recovery and diversity, and initially implements to tolerate F faulty replicas in N=2F+1 replicas and ensure that only F+1 active replicas to execute during the intrusion-free stage. The remaining replicas are all put into passive mode, which significantly reduces the resource consuming in cloud platform. At last we prove the reconstruction and confidentiality property of sensitive data by utilizing secret sharing.[...] Read more.