摘要：To promote the application of Mg alloy to motorcycle wheel to reduce weight, the fatigue analyses of wheels made of A356, AM60B and redesigned AM60B under the same service condition were carried out, revealing that the peak stress is reduced by 25.6% and stress distribution becomes more uniform in Mg-alloy wheel due to its lower elastic modulus in comparison with Al alloys. The service stress level of redesigned Mg wheel is relaxed further because of its optimized structure by altering the spoke configuration and increasing the fillet between spoke and ring, satisfying the desired reliability with 30% weight saving.
摘要：The platform consists of three layers: the management service layer administers the infrastructure of the whole platform; the integration service layer provides the core integration functions and the user service layer satisfies the enterprise integration demands. For the purpose of accommodating the characteristics of mold making companies, an event-driven enterprise service bus working as the heart of the platform is realized. A prototype system combining Web services, Business Process Execution Language (BPEL) and Web Ontology Language (OWL) is implemented. The clients and suppliers and the applications of mold making company are integrated in a loosely-coupled way through the services provided by the platform. Meanwhile the sharing of data and knowledge, and the coordination of business process are realized. By adopting the platform, a new approach is provided to solve the problem of design and manufacture integration for intra and inter mold making companies.
摘要：In order to meet the needs of practical design, an interpolation technique is employed to constrain the shape of surfaces. The method of preserving positivity on the interpolation surface and constraint on interpolating data is also developed. The advantage of this new method is that it can be used to constrain the shape of an interpolating surface only by selecting suitable parameters, and numerical examples are presented to show the performance of the method.
摘要：A methodology is implemented to find the optimum reduced weight configuration design of an operating structure of a civil aircraft vertical tail fin. FE (finite element) based topology optimization is executed to find the optimum material distribution of initial design space of rib by maximizing the stiffness. Loads pertinent to the operating and ground conditions are estimated and applied, considering the orientation of structural assembly members and built-in supports offered in the main structure. Manufacturing constraints are incorporated into the optimization loop to generate pragmatic and manufacturable design configuration. The topologically optimized configuration is then converted to CAD viable design through data reduction and smoothing by converting to ISO-surfaces. A methodology is also devised to modify the topological optimized voids and material layout precisely with splines and fillets to construct manufacturable features and avoid stress concentrations. The resulting novel design proposal is then analyzed and validated against stipulated loads, constraints and other design needs. Results validate the new design proposal as more reliable, having reduced weight and enhanced structural performance.
摘要：A method of enhancing power system stability for a single machine to infinite bus power system is presented. The technique used compromises the effectiveness of Proportional-Integral-Derivative controller (PID). In order to satisfy the damping characteristics for the proposed power system over a wide range of operating interval, rotational speed, torque angle and terminal voltage signals of the synchronous machine are utilized as control signals of the system. It is well known that these variables have significant effects on damping the generators shaft mechanical oscillations, it'll be so easy to validate the most suitable controller as seen from the simulation results.
摘要：The aerodynamic design of a strategic weapon is of interest, especially when the radar signatures are included in the conceptual design phase. The basics of stealth configurations and stealth mechanisms for missiles are reviewed. The Radar Cross Sections (RCS) of some generic missiles are predicted and compared to analyze the trade-offs involved between low RCS and aerodynamic performance. The consideration of RCS prediction in the conceptual design phase gives a quick insight into the stealth performance prior to detailed design.
摘要：A job shop scheduling problem with a combination processing in complex production environment is proposed. Based on the defining of "non-elastic combination processing relativity" and "virtual process",the problem can be simplified and transformed to a traditional one. On the basis of the dispatching rules select engine and considered factors of complex production environment,a heuristic method is designed. The algorithm has been applied to a mould enterprise in Shenzhen for half a year. The practice showed that by using the method suggested the number of delayed orders was decreased about 20% and the productivity was increased by 10 to 20%.
摘要：Reachability is a key criterion in maintenance design, and human arm is the main object in reachability analysis. The human arm's DOF is reduced, and applying military standards and human physiological constraints, the simplified arm model of 7-DOF using D-H method is built up. Particle Swarm Optimization (PSO) is used to acquire the shoulder, arm and hand posture with adaptive fitness function. A detailed reachability analysis is accomplished for disassembling the bolts from crank shaft is given as an example to validate the feasibility of using reachability analysis on maintenance design.
摘要：To meet the requirements and functions of spacecraft dynamic simulation and emulation according to different flight periods, the realization of real time system with different configurations, control of the development cycle and examples of application are presented in detail. On the basis of the satellite dynamic simulation technology, distributed network integrated with the component testing platforms is used to construct a multi-level bus network system. The system takes into full consideration the configuration flexibility, real time characteristics and extendibility. Test results show that both the software algorithm and the hardware integration of the system are correct and effective. The system could be used not only as the effective tool of designing and developing the components and whole assembly of satellites and missiles, but also for the dynamic simulation and emulation in all phases of a spacecraft developmentcycle.
摘要：A layered simulation model with stairstep contour is built from AutoCAD through extruding each successive section contour having been compensated in dimensions to meet the application requirements of the RP part. In such a way the shape and size tolerance of the RP product could be verified beforehand promptly and precisely.
摘要：Face-to-face Videoconferencing is a popular option for many large organizations because it minimizes the need for travel. Instead of continually paying for traveling expenses, a company can either pay to set up a high speed network which has many usages (including videoconferencing) or they can rent time on an existing network. Employees will also no longer be burdened with the need to travel. While face-to-face videoconferencing performance is heavily influenced by the underlying hardware and software, a good video compression scheme can help make the best use of videoconferencing and provide a high quality picture. H.263 standard is now widely used for real-time video communications over a range of networks including the Internet. A frame work for better understanding the H.263 including the implementation of encoder and decoder for face-to-face videoconferencing is presented. This software was written in C++ language, running under the Microsoft Windows operating system.
摘要：Introducing basic design methodology for developing backstepping nonlinear controller for vibration control system. With a simplified second-order system model of nonlinear vibration system (Duffing’s equation), where, the process has illustrated the backstepping design step-by-step. Backstepping is a novel nonlinear design tool, which is based on constructing the Lyapunov function for the closed-loop systems and guarantees the stability and tracking performance through energy dissipation. In general, this nonlinear control design approach generates aggressive control effort to reduce the tracking error presented in this control system and significantly improve the system bandwidth. The effectiveness of the design scheme is shown through the computer simulation.
摘要：The generalized regression neural network-one kind of RBF neural network, is chosen to construct the inverse-kinematics model for the shotcrete robot which has redundant degree-of–freedom. The inverse-kinematics model of the object is trained by the general learning method. In constructing model process, different partition methods is tried to divide the joint space and different diffusion coefficient value to train the neural network. The influence of the spread coefficient to the approach ability is also studied. The simulation method is adopted to test the performance of the neural network. The simulation result turns out to be satisfactory.
摘要：Aiming at the geometrical features of different containment relationships in Rapid Prototyping (RP), a general method of achieving the RP layer’s cusp distribution of the positive, negative and mixed tolerance is proposed to meet the part’s different applications. The procedure is executed by projecting the current and the next section of the CAD model onto a horizontal plane, computing the union and the intersection of the sections to get the outer and the inner boundary, and then blending the boundaries using a rotary vector through a proper inner point in the intersection to achieve the current layer’s scanning contour. The method can realize the layer’s cusp distribution of the mixed tolerance with unequal cusp height, expanding the connotation of the mixed tolerance.
摘要：A complete and detail method is described to get digitally reconstructed radiographs (DRRs). Casting rays to traverse CT images, computing CT values of resample points by interpolation, then converting CT value to its attenuation coefficient by using simplified segment function. Finally, DRRs enhancement is made to get the better display of region of interest (ROI), and a new way is adopted to adjust the customization coefficient. The experimental results show that the proposed method is effective in generating the satisfied DRRs.
摘要：The cyclic symmetry and local fine-mesh technology were adopted in the establishment of numerical simulation model for inner gear spin-forming. And the processing experiment was proceeded to verify the reliability of the established model. The simulation result indicates that besides radial and axial flows, there also exists rather large tangential flow, which results in an increase of forming force in tangential direction. Furthermore, the un-uniform deformation of metal during spin-forming would cause forming defects, such as underfill in tooth fillet region and indentation on the outside spun part.
摘要：Moving target detection (MTD) technique is designed to filtering out the clutters. The basis of the MTD digital signal processor is a bank of Doppler filters designed using FFT algorithm. For high pulse repetition frequency (HPRF), it leads to a long time calculations and great complexity in hardware implementation. Frequency domain detector is represented by Welch method Realized Doppler filters bank which will reduce the time calculation. The proposed method enhances the target detection capabilities by providing higher detection probabilities or lower false alarm rates. The performance of the two systems, the traditional MTD-I and Welch method are compared from the viewpoint of probability of detection (Pd), probability of false alarm (Pfa). Computer simulation results are presented to support the superiority of the proposed technique.
摘要：Coordinates of the key facial feature points can be captured by motion capture system OPTOTRAK with real-time character and high accuracy. The facial model is considered as an undirected weighted graph. By iteratively subdividing the related triangle edges, the geodesic distance between points on the model surface is finally obtained. The RBF (Radial Basis Functions) interpolation technique based on geodesic distance is applied to generate deformation of the facial mesh model. Experimental results demonstrate that the geodesic distance can explore the complex topology of human face models perfectly and the method can generate realistic facial expressions.
摘要：In order to solve the problem of low precision and complication of three-dimensional modeling about micro-segment gear, one method of setting up the accurate 3D model is introduced. At first, the equation of the profile curve and the dedendum transition curve is set up, and the coordinates of the whole tooth profile are calculated by the program developed by Dephi software. And then the data of coordinates is imported to Catia, three-dimensional modeling can be got through the operations of rotating, mirror, incision and array. The method used in this paper is accurate and simple, which supplies the academic basis of CAE analysis and virtual design for micro-segment gear and relevant products.
摘要：A 3D-view is helpful to instantly grasp what is presented in a drawing. There exist a variety of ways to present the same part with 3D-views. To facilitate the choice of an optimum one among them, the work divides composite solid models into three categories, so as to convey the originality of design concisely and accurately by using the least " engineering language".
摘要：Data clustering is a significant information retrieval technique in today’s data intensive society. Over the last few decades a vast variety of huge number of data clustering algorithms have been designed and implemented for all most all data types. The quality of results of cluster analysis mainly depends on the clustering algorithm used in the analysis. Architecture of a versatile, less user dependent, dynamic and scalable data clustering machine is presented. The machine selects for analysis, the best available data clustering algorithm on the basis of the credentials of the data and previously used domain knowledge. The domain knowledge is updated on completion of each session of data analysis.
摘要：Design of scheduling decision mechanism is a key issue of scheduling decision method and strategy for agile manufacturing system. Effective scheduling decision mechanism helps to improve the operational agility of manufacturing system. Several scheduling decision mechanisms are discussed, including scheduling forecasting mechanism, cooperation mechanism and cell scheduling mechanism. Also soft decision mechanism is put forward as a promising prospect for agile manufacturing system, and some key techniques in soft decision mechanism are introduced.
摘要：Blends of polyamide 6 and polycarbonate were prepared by a Brabender mixer ( PLV- 151) at 240 Co with 30 rpm for time 15, 8 and 6 minutes respectively. The thermal properties of blends with constituent ratio of 100/0, 60/40 and 20/80 are examined by Differential scanning calorimetry. DSC measures the temperatures and heat flow associated with transitions in materials as a function of time and temperature. The melting point temperature (Tm), crystalline temperature (Tc), and glass transition temperature (Tg) are observed..
摘要：Linear Quadratic Regulator (LQR) is modern linear control that is suitable for multivariable state feedback and is known to yield good performance for linear systems or for nonlinear systems where the nonlinear aspects are presented. The fuzzy control is known to have the ability to deal with nonlinearities without having to use advanced mathematics. The LQR integrated fuzzy control (LQRIFC) simultaneously makes use of the good performance of LQR in the region close to switching curve, and the effectiveness of fuzzy control in region away from switching curve. A new analysis of the fuzzy system behavior presented helps to make possible precise integration of LQR features into fuzzy control. The LQRIFC is verified by simulation to suppress the uncertainty instability more effectively than the LQR besides minimizing the time of the mission proposed.
摘要：Flight path and plane maneuver are controlled by joystick. Collision detection is supported to verify the bumping of plane against surrounding objects. Crash of plane is highlighted by generating explosive flames.
摘要：Solving large radial basis function (RBF) interpolation problem with non-customized methods is computationally expensive and the matrices that occur are typically badly conditioned. In order to avoid these difficulties, we present a fitting based on radial basis functions satisfying side conditions by least squares, although compared with interpolation the method loses some accuracy, it reduces the computational cost largely. Since the fitting accuracy and the non-singularity of coefficient matrix in normal equation are relevant to the uniformity of chosen centers of the fitted RBF, we present a choice method of uniform centers. Numerical results confirm the fitting efficiency.
摘要：Influence of strip self-rotating plastic spiral elements inserted in a tube on heat transfer enhancement is studied experimentally. The strip consists of 100 self-rotating spiral elements made of plastic polycarbonate inserted in the inner tube of a concentric tube heat exchanger with a view to generating swirl flow that helps to increase the heat transfer rate of the tube. Cold water flows in the annulus whereas the hot water flows in the inner tube. The obtained experimental data are compared with the data obtained from plain tube .Experimental results confirmed that the use of self-rotating plastic spiral elements leads to higher overall heat transfer coefficient than the plain tube. This technology is not only useful for heat transfer enhancement but also can be used for self cleaning deposition fouling in heat exchanger when the flow velocity is higher than 0.2 m/sec.
摘要：The angular position controller is applied to electro-hydraulic servo actuator system (EHSAS) to control the output of the rotary actuator. It works as a compensator based on the frequency response of the EHSAS. Its design model is verified on the state-space model of EHSAS by using simulation program SIMULINK. Real data used to test the system. Simulation results give a good agreement for the controller and also for the state-space model.
摘要：Necessary and sufficient conditions for the relationship of weights and control points of two parametrically and geometrically coincident rational Bézier or NURBS curves are discussed in detail. The method is based on the reduction of matrices and transformation between rational Bézier curves and NURBS curves.
