Case-based intelligent computer aided design system of welding machinery

The procedure during complex system plan design of welding position-locating machine is studied in this paper. The main difficulties in designing welding position-locating machine utilizing computer are discussed as well. A method of case-based intelligent CAD system for welding position-locating machine ( WMICAD) is put forward through wide research on design methodology. Object-oriented programming method is also applied to Ms system. The basic idea and realizing method are described.

Computer Aided Design and Performance Analysis of Inverse Fluidized Bed Biofilm Reactors with Special Reference to Bioplastic Synthesis

Poly Laevo Lactic Acid (PLLA), in spite of being an excellent bioplastic, has exorbitantly high market price due to the high cost of raw material (lactose, glucose, sucrose). Hence, its manufacture is being attempted starting from waste effluents such as cheese whey and molasses. Earlier studies on the same in fluidized bed and semifluidized bed biofilm reactors yielded encouraging results. The present study therefore involves design and analysis of inverse fluidized bed biofilm reactors for lactic acid synthesis. The performance features of the bioreactor have been studied both mathematically as well as experimentally. The inverse fluidized bed biofilm reactor has been found to provide more than 75% conversion of sucrose/lactose even at high capacities (high feed flow rates) exceeding 56,000 L/hr, within a reasonably low reactor volume. The fractional substrate conversion increases, though sluggishly, with increase in feed flow rate due to bed expansion and also with increase in cell mass concentration in biofilm due to enhancement in intrinsic rate of bioconversion. The inverse fluidized bed biofilm reactor of proposed design could be safely recommended for the commercial synthesis of polymer grade lactic acid from waste effluents such as cheese whey and molasses. The low operating cost of the bioreactor (due to downflow mode of operation) enhances the economy of the process. This would also help in significantly lowering the market price of the green plastic (PLLA) and shall promote its large scale manufacture and utilisation.

COMPUTER AIDED DESIGN OF AIRCRAFT CABIN LAYOUT

The reasonability of cabin layout is studied according to the ergonomic theory on micro-computer. This system includes the anthropometric model,modeling of aircraft seats and cabin,interactive ergonomic analyses on effect.

The Implementation Methods for Computer Aided Design and Analysis on Color-Woven Fabrics

Methods for computer aided design and analysis on color-woven fabrics are presented. The relation of color pattern, colored warp, colored weft and the model for regular weave texture are given based on their formative principle. Some efficient algorithms are developed to determine the color order of warp and weft threads which yields a given color pattern and regular weave texture. Finally, the design system structure and data process flowing are introduced.

The Creative Design Research of Product Appearance Based on Human-machine Interaction and Interface

Today’s product creative design has rendered many fe atures and has brought a great change in our everyday life, there are many new c hallenges in its traditional theory and principle. According to the traditional design theory, the FBS design model pays more attention to the function and stru cture of the product. But this model still couldn’t strengthen the relation bet ween product appearance design and human-machine design effectively. This paper adopt converse design thinking and presents an improved design thinking methodo logy based on C: FBS for product appearance design and give a general summarizat ion for the features, methods and technology based on human-machine interaction and interface. Meanwhile it also combines with the behavior design of product r elated IT fields and constructs a new outline to improve the design of product a ppearance supported by the technology of computer aided design. So the new metho d about design thinking for computer aided design, the new abstract product design model and the key problem of design thinking based on human-machine inte raction and interface are addressed in this paper. This kind of creative design theory that is driven by human-machine interaction and interface will help the development of CAD software system and the research of product design and manufa cture. Additionally, this paper gives some beneficial characters to address the theory based on human-machine interaction and interface. Meanwhile, combining with the developing of computer technology, the trends of design thinking based on t he technology of human-machine interaction and interface are also analyzed and discussed at the end of this paper.

VIRTUAL FUEL-PUMP DESIGN

Some concepts of virtual product are discussed. The key technologies ofvirtual fuel-pump development are in detail analysed, which include virtual fuel-pump productmodeling, intelligent simulation, distributed design environment, and virtual assembly. The virtualfuel-pump development prototype system considers requirement analysis, concept design, injectionpreferment analysis, detailed design, and assembly analysis.

Object-Oriented Design for FDTD Visual Scientific Computing

A scheme for general purposed FDTD visual scientific computing software is introduced in this paper using object-oriented design (OOD) method. By abstracting the parameters of FDTD grids to an individual class and separating from the iteration procedure, the visual software can be adapted to more comprehensive computing problems. Real-time gray degree graphic and wave curve of the results can be achieved using DirectX technique. The special difference equation and data structure in dispersive medium are considered, and the peculiarity of parameters in perfectly matched layer are also discussed.

OPTIMIZATION DESIGN OF HELICOPTER FOR PRELIMINARY PARAMETERS

A new design method for prehminary parameters is proposed. The analyticmodels of the optimization design are established according to the requirements of helicopter flight performance- stability, engine and weight. The optinial preliminary projectof design to meet the requirements of critenon for helicopter design is worked out byapplying the computer and optimization techniques. The inethod can be used for theanalysis of helicopters for prehminary parameters that are used in practice and for theanalysis of sensibility for preliminary parameters, too. The method is shown to be veryuseful by the example and application in the new design of helicopters.

Study of Piezoresistive Micro Electro-Mechanical Accelerometer Design Platform

According to the inland micro electro-mechanical system （MEMS） process technique level, a design platform of piezoresistive micro electro-mechanical accelerometer is given. This platform is much more adaptable to the inland designer compared with the current MEMS CAD software. The design flow is presented in detail, and the key techique in the platform is analyzed amply. The structure design methodology is exemplified in the design of a piezoresistive accelerometer, and the accelerometer is the optimized structure for the given performance requirements. The accelerometer is now being manufactured.

An Interactive Evolutionary Environment for Creative Design

A creative and/or innovative computer aided design environment is developed around the concept of an evolutionary optimization algorithm. Designs are generated within a set of prescribed design frameworks using a problem specific encoding and modified through operations including recombination, crossover and mutation. Evaluation of all candidate designs is performed by a user through a graphical user interface. A set of problems involving the creation of graphic images is presented. The examples include the generation of a set of two dimensional polygonal shapes, fractal images, path generation from a multi-degree freedom mechanical planar linkage and a mathematically prescribed pattern generation from a graphic design application utilized in quilting. Post design evaluation of the user input to the process provides insight into the individuals design strategy as well as determination of common user attributes in the creative design process.

Development of a 3D Conceptual Design Environment Using a Head Mounted Display Virtual Reality System

Engineering design is a resource intensive process with over half of a product’s total cost being attributed to design stage decisions. Developing product designs often involves creating complex 3D models in a 2D environment, a non-trivial task. This paper details a proof of concept VR environment displayed in a commodity HMD, specifically the HTC Vive. The environment allows a user to create full-scale, 3D, product geometry at the conceptual phase of the design process. The conceptual design environment contains a World-in-Miniature (WIM) model for enhanced usability. This method allows a user to efficiently manipulate full-scale geometry by adjusting the corresponding parts on a WIM model. Free-form mesh deformation was also implemented to provide designers with flexibility and efficiency not found in traditional design packages. Vital design metrics (e.g., cost, weight, and center of mass) were incorporated to allow a user to perform preliminary design analysis to assess product feasibility. Throughout the development process, the unique challenges and affordances associated with commodity HMDs were identified, explored, and discussed in this paper. Ultimately, the VR application discussed in this paper allows the user to easily create, assess, and view conceptual 3D designs without the constraints of traditional CAD software.

Advanced Computer-aided Design and Analysis for Synchronous Reluctance-Permanent Magnet Machines

This paper presents an advanced computer aided design (CAD) package for the synthesis, analysis, and optimization of synchronous reluctance combined with permanent magnet (SR PM) machines. The distinguishing features of the CAD package are that it allows a wide range of design options and parameter variations for the new type of machines, calculations of optimization for maximum efficiency and higher power density, and various performance. The package as described in the main text permits the integration of the machine design with an electronic controller, along with the simulation of the whole system. Through the optimal design, characteristic calculations, and system simulations, the CAD package offers a superior design for the SR PM machines, and presents a feasibility frontier outlined by the design.

Computer Aided Design System for Developing Musical Fountain Programs

A computer aided design system for developing musical fountain programs was developed with multiple functions such as intelligent design, 3-D animation, manual modification and synchronized motion to make the development process more efficient. The system first analyzed the music form and sentiment using many basic features of the music to select a basic fountain program. Then, this program is simulated with 3-D animation and modified manually to achieve the desired results. Finally, the program is transformed to a computer control program to control the musical fountain in time with the music. A prototype system for the musical fountain was also developed. It was tested with many styles of music and users were quite satisfied with its performance. By integrating various functions, the proposed computer aided design system for developing musical fountain programs greatly simplified the design of the musical fountain programs.

Global Continuity Adjustment and Local Shape Optimization Technique for Complex Trimmed Surface Model

Smoothly stitching multiple surfaces mainly represented by B-spline or NURBS together is an extremely important issue in complex surfaces modeling and reverse engineering. In recent years, a lot of progress has been made in smooth join of non-trimmed surface patches, while there has been seldom research on smoothly stitching trimmed surface patches together. This paper studies the problem of global continuity adjustment, damaged hole repair and local shape optimization for complex trimmed surface model, and presents a uniform scheme to deal with continuity adjustment of trimmed surfaces and geometric repair of local broken region. Constrained B-spline surface refitting technique and trim calculation are first utilized to achieve global G^1 continuity, and then local shape optimization functional is adopted to reduce fitting error and improve local quality of refitted surface patch. The proposed approach is applied to a discontinuity ship hull surface model with an irregular hole, and the result demonstrates the validation of our method. Furthermore, on the premise of global continuity, the proposed locally repairing damaged surface model provides a better foundation for following research work, such as topology recovery technique for complex surface model after geometric repair.

Application of digital positioning guide plates for the surgical extraction of multiple impacted supernumerary teeth:A case report and review of literature

BACKGROUND An extra tooth in the normal tooth sequence in any region of the dental arch is regarded as a supernumerary tooth(SNT).Due to the large variation in location and morphology,the extraction of impacted SNTs is an extensive and complex procedure with high risks of several complications.This report presents a rare case of seven impacted SNTs in the bilateral upper and lower arch that were successfully extracted with the use of digital positioning guide plates.CASE SUMMARY In January 2022,a 21-year-old male was referred to our department with a chief complaint of pain in relation to tooth#36.Clinical examination showed a deep carious lesion with pulpal involvement in tooth#36 and lingual swelling of the bilateral mandibular posterior area.Radiographic examination revealed seven deeply impacted SNTs in the bilateral posterior area and bilateral impacted mandibular third molars.Based on these findings,the patient was diagnosed with bilateral,multiple impacted SNTs and tooth#36 chronic pulpitis.A root canal treatment and an all-ceramic crown restoration for tooth#36 were performed.An individualized digital positioning guide plate was designed by computer-aided design/computer-aided manufacturing technology and cone-beam computed tomography for extraction of the impacted SNTs.During the operation,the digital positioning guide plate allowed rapid positioning and exposure of the SNTs while avoiding adjacent important anatomical structures.At 3-month follow-up,regeneration of bone and soft tissues was visible.CONCLUSION The application of digital positioning guide plates is useful for the individualized and minimalized extraction of impacted supernumerary teeth.

Approximate merging of B-spline curves and surfaces

Applying the distance function between two B-spline curves with respect to the L2 norm as the approximate error, we investigate the problem of approximate merging of two adjacent B-spline curves into one B-spline curve. Then this method can be easily extended to the approximate merging problem of multiple B-spline curves and of two adjacent surfaces. After minimizing the approximate error between curves or surfaces, the approximate merging problem can be transformed into equations solving. We express both the new control points and the precise error of approximation explicitly in matrix form. Based on homogeneous coordinates and quadratic programming, we also introduce a new framework for approximate merging of two adjacent NURBS curves. Finally, several numerical examples demonstrate the effectiveness and validity of the algorithm.

Structural Indexing for 3D Solid Digital Library

In a very large digital library that support computer aided collaborative design, an indexing process is crucial whenever the retrieval process has to select among many possible designs. In this paper, we address the problem of retrieving important design and engineering information by structural indexing. A design is represented by a model dependency graph, therefor, the indexing problem is to determine whether a graph is present or absent in a database of model dependency graphs. we present a novel graph indexing method using polynomial characterization of a model dependency graph and on hashing. Such an approach is able to create an high efficient 3D solid digital library for retrieving and extracting solid geometric model and engineering information.

A Novel Method for Solving Ordinary Differential Equations with Artificial Neural Networks

This research work investigates the use of Artificial Neural Network (ANN) based on models for solving first and second order linear constant coefficient ordinary differential equations with initial conditions. In particular, we employ a feed-forward Multilayer Perceptron Neural Network (MLPNN), but bypass the standard back-propagation algorithm for updating the intrinsic weights. A trial solution of the differential equation is written as a sum of two parts. The first part satisfies the initial or boundary conditions and contains no adjustable parameters. The second part involves a feed-forward neural network to be trained to satisfy the differential equation. Numerous works have appeared in recent times regarding the solution of differential equations using ANN, however majority of these employed a single hidden layer perceptron model, incorporating a back-propagation algorithm for weight updation. For the homogeneous case, we assume a solution in exponential form and compute a polynomial approximation using statistical regression. From here we pick the unknown coefficients as the weights from input layer to hidden layer of the associated neural network trial solution. To get the weights from hidden layer to the output layer, we form algebraic equations incorporating the default sign of the differential equations. We then apply the Gaussian Radial Basis function (GRBF) approximation model to achieve our objective. The weights obtained in this manner need not be adjusted. We proceed to develop a Neural Network algorithm using MathCAD software, which enables us to slightly adjust the intrinsic biases. We compare the convergence and the accuracy of our results with analytic solutions, as well as well-known numerical methods and obtain satisfactory results for our example ODE problems.

Application Study on 3D Modeling of Axial Compressor Blades Based on CFD and CAD

A new method for design of turbomachinery blades is presented. The parameters of a compressor blade are created from the Computational Fluid Dynamics （CFD） software CFX-BladeGen, and are inputted to the Computer Aided Design （CAD） software UG for building a curve surface model to create an entity model in UG. The result shows that the blade model is favorable from the entity effect and reflection analysis and the model process is useful for the CAD model creation of turbomachinery blades.