Design of cellular cofferdams by the ccell computer program

CCELL is a computer program for the analysis and design of cellular cofferdams and mooring cells. The theoretical basis of the program is explained in sufficient detail to enable a designer to determine if the program is appropriate for his or her needs. Two design examples are presented.     

Time-dependent analysis of segmental bridges

The computer program TIMEDEP is presented for the time-dependent analysis of segmental bridges. Loadings considered at each stage of construction include self-weight, time-dependent effects, temperature, and construction loads. The program is intended to be used for routine day-to-day design and operates on the IBM Personal Computer as well as on most other mainframe computers. Five numerical examples illustrate the usefulness of the program. Documentation, sample input and output, and a FORTRAN source listing are also provided.     

Optimum topology and shape design of prestressed concrete bridge girders using a genetic algorithm

The purpose of this study is to optimize the topology and shape of prestressed concrete bridge girders. An optimum design approach that uses a genetic algorithm (GA) for this purpose is presented. The cost of girders is the optimum design criterion. The design variables are the cross-sectional dimensions of the prefabricated prestressed beams, the cross-sectional area of the prestressing steel and the number of beams in the bridge cross-section. Stress, displacement and geometrical constraints are considered in the optimum design. AASHTO Standard Specifications for Highway Bridges are taken into account when calculating the loads and designing the prestressed beams. A computer program is coded in Visual Basic for this optimization. Many design examples from various applications have been optimized using this program. Several of these examples are presented to demonstrate the efficiency of the algorithm coded in the study.     

C语言循环结构教学浅析

循环结构是C语言程序设计中最复杂、最重要,也是使用最多的一种程序流程控制结构,是程序设计课程教学的重点与难点内容之一,是进行复杂程序设计的基础.针对高职学生的实际情况,通过讲授典型实例,使用启发式引导,循序渐进分析循环结构程序设计过程,旨在帮助学生更好地掌握C语言循环结构的实质,提高利用循环结构解决实际问题的能力.     

PREOPT-W: Off-line optimization of binary gradient separations in HPLC by simulation—IV. Phase 3

Off-line gradient optimization by means of the PREOPT-W simulation program is described and illustrated with examples based on real data. The influence of the main factors such as the type of simplex strategy used, optimization objective function and gradient duration as well as other minor, although important, factors like the definition of initial gradient shape and advances used in the design of the initial simplex are discussed. Additional features of the simulation program such as vertex revision and gradient manipulator are also outlined, emphasizing the multiple possibilities at the hands of the chromatographer when developing a gradient separation for very complex mixtures with the help of PREOP-W.     

Example‐based Authoring of Procedural Modeling Programs with Structural and Continuous Variability

Procedural models are a powerful tool for quickly creating a variety of computer graphics content. However, authoring them is challenging, requiring both programming and artistic expertise. In this paper, we present a method for learning procedural models from a small number of example objects. We focus on the modular design setting, where objects are constructed from a common library of parts. Our procedural representation is a probabilistic program that models both the discrete, hierarchical structure of the examples as well as the continuous variability in their spatial arrangements of parts. We develop an algorithm for learning such programs from examples, using combinatorial search over program structures and variational inference to estimate continuous program parameters. We evaluate our method by demonstrating its ability to learn programs from examples of ornamental designs, spaceships, space stations, and castles. Experiments suggest that our learned programs can reliably generate a variety of new objects that are perceptually indistinguishable from hand‐crafted examples.     

Computer aided plastic design of unbraced frameworks

A computer program for the plastic design of two-dimensional unbraced steel frameworks is described. The program is an extension of a set of programs developed at Lehigh University, and uses the subassemblage method of analysis to analyse each story of the framework. In the program described, member sizes are determined firstly on the basis of strength alone, and then an optimal set of increments in the member sizes is determined to satisfy suitable constraints on sway deflections under working load conditions. Mathematical programming procedures are involved in this incrementing process. Some design examples are presented, and the program is compared with other approaches reported in the literature.     

A program package for simulation of coupled chemical reactions in flow reactors

A program package KINSIMI for an interactive simulation of homogeneous isothermal reactor systems with an arbitrary elementary kinetics has been developed. The simulation of ideal reactors, tanks-in-series, normal axial dispersion reactors and segregated and maximum mixed tanks-in-series and axial dispersion reactors can be performed with the program package. For the ideal reactors and tanks-in-series both step responses and steady states can be computed. For the axial dispersion, segregation and maximum mixedness models the treatment is limited to a steady state stimulation. For the segregation model, empirical batch reactor kinetics can be used in the computation of continuous reactor performance. The corresponding mathematical models and the numerical algorithms are discussed. Two examples of the application of the package are given. The program package can be used for reactor design as well as for educational purposes in illustrating the influence of different reaction mechanisms and flow patterns on the conversion and product distribution.     

A new applications manual for the Storm Water Management Model (SWMM)

The EPA Storm Water Management Model (SWMM) is a widely used program for simulating urban runoff quantity and quality. Its existing documentation includes a User's Manual that describes how to run the program and a Reference Manual that covers its theory and algorithms. A new manual, the “SWMM Applications Manual”, has been added to this collection. It contains nine worked-out examples addressing common stormwater management and design problems encountered in practice. The manual will be especially useful for new SWMM users who need additional guidance in applying this powerful tool to urban drainage design and analysis.     

ODMixed: A tool to obtain optimal designs for heterogeneous longitudinal studies with dropout

ODMixed is a computer program to obtain optimal designs for linear mixed models of longitudinal studies. These designs account for heterogeneous correlated errors and for data with dropout. Designs are compared by using relative efficiencies, e.g., between a D-optimal design for homogeneous data and another for heterogeneous data or between a D-optimal design for complete data against another that optimizes designs when data is missing at random. Two examples are worked out to illustrate how researchers could use this computer program to profit of optimal design theory at the planning stage of longitudinal studies.     

Control–structural design optimization for vibration of piezoelectric intelligent truss structures

Based on the design sensitivity analysis for structural dynamics in time domain, an integrated control–structural design optimization method is proposed to the vibration control of piezoelectric intelligent truss structure. In this investigation, the objective function and constraint functions include not only the conventional design indexes of structure but also the vibration control indexes and the feedback control variables. The structural design variables are optimized simultaneously with the vibration control system. The sensitivity relations for the control–structure optimization model are derived by using a new method, and the sequential linear programming algorithm is used to solve this kind of optimization problem. The numerical examples given in the paper demonstrate the effectiveness of methods and the program.     

PLC控制程序的设计方法——西门子SR功能模块的应用

通过典型的PLC控制程序的编程实例,阐述了西门子SR功能模块在PLC控制程序设计中的应用,构建了PLc控制程序设计的基本步骤,总结出了程序设计的基本方法与技巧.     

基于COM的SolidWorks级进模CAD常用接口

在日趋复杂的应用程序设计过程中，组件化程序设计思想得到了极大发展，基于这一思想进行了级进模CAD系统组件设计。讨论了在组件化程序设计思想上发展的COM技术及其在SolidWorks中的应用，并且用级进模CAD系统中的示例程序，说明COM程序开发过程。     

递归程序设计方法的分析探讨

递归是设计程序的一种重要方法,文中对递归的定义及递归的基本条件进行了分析,给出了递归程序设计的基本方法,并结合数据结构中二叉树遍历和单链表结点输出的实例进行了验证,最后对递归程序进行了深度分析,说明了递归是一种有效的程序设计方法。     

并行程序Petri网模型的结构性质

正确性是并行程序的基础,但是由于它的复杂性,其验证要比串行程序困难得多,因此有必要进行建模并研究其性质.从程序的角度出发,在将基于消息传递的并行程序转换为Petri网模型之后,证明了与并行正确的并行程序对应的Petri网模型应当满足的结构性质,包括强连通性、S-不变量、T-不变量、受控死锁性质以及守恒性,并举例说明了这些性质在并行程序验证中的应用.这些性质可用于并行程序的事前验证,而且避免了使用动态性质进行验证时的状态爆炸问题,从而提高并行程序设计和验证效率.同时这些方法具有良好的可推广性.     

Design of airfoils in incompressible viscous flows by numerical optimization

A method is outlined for the design of airfoils in incompressible viscous flows by numerical optimization wherein a reduced number of design coordinates are used to define the airfoil shape. The optimization problem is formulated as a nongradient search in a finite constrained parameter space. The approach is to define the airfoil as a linear combination of basic shapes which may be analytically or numerically defined. The design problem is to determine the participation of each of these basic shapes in defining the optimum airfoil. The aerodynamic analysis program is specially developed to fit the requirements of the optimization program and is based on the vortex singularity method for inviscid flow analysis and the momentum integral method for boundary layer analysis. Four examples have been worked out to illustrate the proposed design method. In these, modifications to four different airfoil geometries are made to achieve either a minimum drag coefficient or a minimum pitching moment coefficient under prescribed constraints. The results show that significant drag or pitching moment reduction is possible through shape manipulation alone.     

Programming high-performance parallel computations: formal models and graphics processing units

This article presents a line of development of formal design methods that is based on the concepts of algebraic programming and algebraic dynamic program models using rewriting rules for the automated design of efficient programs for graphics processing units. The developed formal methods are illustrated by examples that show high efficiency of transformations.