Department of Civil and Environmental Engineering Copyright (c) 2013 Carnegie Mellon University All rights reserved. http://repository.cmu.edu/cee Recent documents in Department of Civil and Environmental Engineering en-us Sat, 26 Jan 2013 11:36:44 PST 3600 A Bibliography on Knowledge-Based Expert Systems in Engineering http://repository.cmu.edu/cee/64 http://repository.cmu.edu/cee/64 Wed, 23 May 2012 12:57:25 PDT The number of papers published in the applications of knowledge-based expert systems (KBES) to engineering problems in the last decade reflects the interest being shown in the engineering community. The intent of this report is to provide an annotated bibliography of the applications of KBES in engineering. The first four sections deal with applications in Civil (including Architecture and Geology), Chemical, Electrical and Computer, and Mechanical Engineering. Some papers which are common to engineering design, in general, are outlined in Section 5. A number of domain independent tools are discussed in Section 6. Section 7 contains a list of books for general reading. A list of relevant conferences and journals is provided in Section a

The bibliography is by no means complete and the author would appreciate pointers to other literature in the area for inclusion in a future update. A forthcoming special issue of ACM SIGART newsletter on applications of Artificial Intelligence to engineering problems will have further references. Some of these references are taken from NTIS citations from the INSPEC data base; these references contain the word [NTIS]..

]]> Duvvuru Sriram Equations aren't enough : information modeling in design http://repository.cmu.edu/cee/63 http://repository.cmu.edu/cee/63 Wed, 09 May 2012 13:34:47 PDT Abstract: "Arguing that design is a social process, we expand the meaning of modeling and analysis to include all activities facilitating continual refinement and criticism of the design requirements, process, and solutions. We do not assume any a priori methods for modeling or analysis: rather, we provide a framework and an approach to study designers and give them whatever modeling and analysis capabilities they choose. Our approach is the basis for a support tool, n-dim, currently under development."

]]> Eswaran Subrahmanian et al. A variational finite element method for stationary nonlinear fluid-solid interaction http://repository.cmu.edu/cee/62 http://repository.cmu.edu/cee/62 Wed, 09 May 2012 13:34:42 PDT Abstract: "We consider the problem of the interaction of a stationary viscous fluid with an elastic solid that undergoes large displacement. The fluid is modeled by the stationary incompressible Navier-Stokes equations in an Eulerian frame of reference, while a Lagrangian reference frame and large displacement - small strain theory is used for the solid. A variational formulation of the problem is developed that insures satisfaction of continuity of interface tractions and velocities. The variational formulation is approximated by a Galerkin finite element method, yielding a system of nonlinear algebraic equations in unknown fluid velocities and pressures and solid displacements. A Newton-like method is introduced for solution of the discrete system. The method employs a modified Jacobian that enables decomposition into separate fluid and solid subdomains. This domain decomposition avoids possible ill- conditioning of the Jacobian, as well as the need to compute and store geometric coupling terms between fluid and interface shape. The capability of the methodology is illustrated by solution of a problem of the flow- induced large displacement of an elastic infinite cylinder."

]]> Omar Ghattas et al. Risks associated with chlorination http://repository.cmu.edu/cee/61 http://repository.cmu.edu/cee/61 Wed, 09 May 2012 13:34:38 PDT Abstract: "This paper examines the risks of using and not using chlorine chemicals in the water disinfection process. Water disinfection has been termed by some as the most significant public health measure of this century. When the consideration of eliminating chlorine completely surfaces, one must take a step back and try to understand more completely the risks of such a decision. This paper presents the risks associated with chlorination and its by-products. This paper also discusses with [sic] the results of not chlorinating and presents several actual consequences experienced by several countries."

]]> Bryan H. Walker et al. An information model for the preliminary design of buildings http://repository.cmu.edu/cee/60 http://repository.cmu.edu/cee/60 Wed, 09 May 2012 13:34:32 PDT Abstract: "The report outlines an information model that organizes the wealth of data used and generated during the conceptual design stage of buildings. The building is represented as an assembly of entities with relationships among them. Each entity represents a meaningful concept to design participants such as a beam, a room or a structural frame. Each entity contains data about its design aspect, its function aspect and its behavior aspect. Furthermore, each entity stores its geometry, its topological relationships with other entities, its containment relationships (made-of and part-of), a reference to the technology (knowledge and procedures) that is used to derive it, and a set of classifiers. The geometry and topological relationships for the entity are obtained from a non-manifold skeletal geometrical representation common across all views. Representation of multiple views is supported by dividing the attributes of an entity into small cohesive subsets, which we call components. These components are then used as construction blocks to present different views of the entity. The goal of this representation is twofold: to store the design data as it is generated during the conceptual design and to support case-based reasoning."

]]> Hugues Rivard et al. Computer-based advisors for environmentally coscious [i.e. conscious], "green" product design http://repository.cmu.edu/cee/59 http://repository.cmu.edu/cee/59 Wed, 09 May 2012 13:34:27 PDT Abstract: "Many corporations have explicit goals to produce environmentally conscious, 'green' products to reduce harmful emissions, energy use and material waste. Numerous regulations on allowable materials and product disposal exist, and additional regulations can be expected. However, while a significant (and growing) literature on 'green design' exists, there are few computer-based aids to give direct guidance to designers concerning the environmental implications of their designs. In this paper, we report on several experimental systems intended to provide such assistance. One system intended to provide direct design advice is described in more detail. It was developed by including additional analysis algorithms and adding rules to an existing knowledge based expert system design advisor intended to provide critiques of the design of plastic parts to be produced from injection molding."

]]> Antonio Diaz-Calderon et al. System design for municipal solid waste recycling http://repository.cmu.edu/cee/58 http://repository.cmu.edu/cee/58 Wed, 09 May 2012 13:34:22 PDT Abstract: "Municipal solid waste recycling is alleged to save precious landfill capacity and lower the use of raw materials. The Environmental Protection Agency and 42 states have set msw recycling goals of 25-70 percent. We examine the volume and composition of household waste, the cost of landfilling and incinerating the waste, and the cost of collection and sorting recyclable materials. The additional cost of collection and cost of sorting are far greater than the revenue from selling recyclable materials or landfilling the waste. None of the examined changes in collection, including drop-off collection, make recycling costs attractive. For Pittsburgh and other cities, recycling significant fractions of municipal solid waste obtained from households harms the environment compared to placing it in a modern landfill."

]]> Chris Hendrickson et al. A machine learning decision support system for collaborative design http://repository.cmu.edu/cee/57 http://repository.cmu.edu/cee/57 Wed, 09 May 2012 13:34:18 PDT Abstract: "The research described in this paper is motivated by the complexity surrounding the development of decision support systems (DSSs) for collaborative design processes. If one realizes that each design agent engaged in a collaborative design process may have a unique theory of product behavior, a distinct language of communication, and a specific model of decision making, the complexity of building a DSS for such a design process is obvious. In this paper, we propose that machine learning is probably the only feasible approach to build a DSS for certain classes of collaborative design problems. We discuss high-level requirements for such a DSS and then propose a conceptual solution to build such a DSS based on a machine learning approach."

]]> Nenad Ivezic et al. Shape optimization of Navier-Stokes flows with application to optimal design of artificial heart components http://repository.cmu.edu/cee/56 http://repository.cmu.edu/cee/56 Wed, 09 May 2012 13:34:13 PDT Abstract: "We consider the problem of shape optimization of systems governed by the stationary incompressible Navier-Stokes equations under flow and geometric constraints. Our motivation stems from the problem of optimal design of artificial heart components. An [sic] continuation-SQP algorithm is developed to efficiently couple Newton-based optimization and flow solution. The main feature of the algorithm is to decompose the optimization problem into a sequence of subproblems characterized by increasing Reynolds numbers, and then apply continuation schemes on the design field, Hessian matrix, Lagrange multipliers, and flowfield. As an application we consider the optimum design of the shape of a two dimensional tube -- a simplification of a blood flow cannula that is a component of an artificial heart. Representative numerical results show a factor of four improvement in efficiency over a standard SQP algorithm."

]]> Omar Ghattas et al. Massively parallel aerodynamic shape optimization http://repository.cmu.edu/cee/55 http://repository.cmu.edu/cee/55 Wed, 09 May 2012 13:34:08 PDT Abstract: "We consider the problem of finding the shape of an airfoil which produces a pressure distribution closest to a desired one. The flow is modeled by the nonlinear potential equations of compressible flow. The problem is formulated as an optimization problem constrained by a discrete approximation to a nonlinear boundary value problem. We present a new parallel infeasible path method for this class of optimization problem. The method is based on a null space representation tailored to the structure of the constraint Jacobian matrix. The resulting null space projections formally involve inverses of the stiffness matrix. The algorithm requires only two stiffness matrix solves per optimization iteration, in contrast to a conventional path-following method, which resolves the full physics at each iteration. The algorithm has been implemented on a CM-2, and requires no new data structures or communication patterns beyond those needed for numerical solution of the boundary value problem. We discuss numerical evidence for the superiority of the new method relative to a conventional path-following approach."

]]> Carlos E. Orozco et al. Infeasible path methods for an aerodynamic shape optimization problem http://repository.cmu.edu/cee/54 http://repository.cmu.edu/cee/54 Wed, 09 May 2012 13:34:03 PDT Abstract: "We consider optimal design problems of systems governed by suitable discretizations of nonlinear partial differential equations. We present and examine a coordinate basis infeasible path method tailored to such design problems. We employ a particular null space representation which exploits the structure of the constraint Jacobian. The resulting method avoids resolution of the nonlinear behavior for each design iterate. Three variants of the method are developed which require the solution of either two or three linear systems involving the stiffness matrix of the discrete boundary value problem. The method is used to solve an aerodynamic design problem governed by nonlinear potential flow. Numerical results demonstrate a substantial performance improvement."

]]> Omar Ghattas et al. Structural design of tall buildings knowledge acquisition study report http://repository.cmu.edu/cee/53 http://repository.cmu.edu/cee/53 Wed, 09 May 2012 13:33:58 PDT Abstract: "A knowledge acquisition study in the domain of tall building design was conducted. Domain experts, five structural engineers and one architect, were interviewed. The experts were asked a set of questions divided into design process and design content questions, and asked to simulate a design scenario. The experts were also shown, and asked to critique, a prototype implementation of a design grammar. In this report we describe our objectives in gathering domain knowledge, our techniques for analyzing the interviews, and the resulting domain knowledge acquired from the analysis of the interviews."

]]> Steven Meyer et al. Viscous flow-finite elasticity interaction : variational formulation and finite element approximation http://repository.cmu.edu/cee/52 http://repository.cmu.edu/cee/52 Wed, 09 May 2012 13:33:52 PDT Abstract: "We consider the problem of the interaction of a stationary viscous fluid with an elastic solid that undergoes large deformation. The fluid is modeled by the stationary incompressible Navier- Stokes equations in an Eulerian frame of reference, while a Lagrangian reference frame and large deformation-small strain theory is used for the solid. A variational formulation of the problem is developed that insures satisfaction of continuity of interface tractions and velocities. The variational formulation is approximated by a Galerkin finite element method, yielding a system of nonlinear algebraic equations in unknown fluid velocities and pressures and solid displacements. A Newton-like method is introduced for solution of the discrete system. The method employs a modified Jacobian that enables decomposition into separate fluid and solid subdomains. This domain decomposition avoids possible ill-conditioning of the Jacobian, as well as the need to compute and store geometric coupling terms between fluid and interface shape. The capability of the methodology is illustrated by solution of a problem of the flow-induced large deformation of an elastic infinite cylinder."

]]> Omar Ghattas et al. Integrating spatial and functional data in a prototype solids grammar of tall building design http://repository.cmu.edu/cee/51 http://repository.cmu.edu/cee/51 Wed, 09 May 2012 13:33:47 PDT Abstract: "Spatial grammars and solids modeling have both contributed to the expansion of computer representable abstractions from numerical and symbolic data into the realm of spatial data. Spatial grammars, such as Stiny's shape grammars, have focused on representing and transforming this spatial data. However, to date spatial and non-spatial data have not been fully integrated into an engineering design process. We describe a grammar which uses a solids modeling representation with object-attribute-value labels. The objects in this label data structure are any of the topological elements of the solids model. Through this enriched representation we demonstrate the extensibility of the grammar formalism into engineering disciplines bound by functional constraints. The grammar presented is a prototype implementation intended to demonstrate the relevant domain variables as well as the nature of their interaction in driving the design process. We describe the grammar and discuss the lessons we have learned from its development and critique."

]]> Steven Meyer et al. The mechanical strength critic in CASE http://repository.cmu.edu/cee/50 http://repository.cmu.edu/cee/50 Mon, 30 Apr 2012 10:11:37 PDT Abstract: "This paper describes the mechanical strength critic in CASE (Computer Aided Simultaneous Engineering) (Rehg et al., 1988a; Regh et al., 1988b: Sapossnek et al., 1989). The mechanical strength critic is composed of two expert systems and several other supporting programs. The first expert system, the Model Generation (MG), generates a complete model for finite element analysis based on geometry, loading, boundary conditions, and performance criteria that are input by the designer. The second expert system draws the relevant results from the finite element analysis and checks for compliance with the performance specifications.If there are violations of the criteria, a set of recommendations for changes in the design are given by the Strength Critic expert system (SC) based on the assumptions of the behavior of the model made in MG and the results calculated in the analysis. The implementation of these changes are left to the designer, as he should also consider simultaneously other recommendations from other critics in the CASE project."

]]> Moshe Eisenberger et al. A framework for modeling and communicating abstractions of constructed facilities http://repository.cmu.edu/cee/49 http://repository.cmu.edu/cee/49 Mon, 30 Apr 2012 10:11:35 PDT Abstract: "Management of information about constructed facilities in a computer-integrated environment is a challenging task bacause this information evolves from and is viewed by many different disciplines throughout the facility's lifecycle. We present a general framework formodeling and reasoning about the components of a constructed facility at any desired level of abstraction, and communicating the informationacross disciplines at any stage in the lifecycle of the facility, as well as across stages. Our research has been motivated by an objectivesimilar to that of STEP, which intends to establish an international protocol for the exchange of CAD data.The descriptive information about a facility is divided into two separate but linked groups: spatial and non-spatial attributes. The primary emphasis of this research is to provide a single, uniform representation and reasoning paradigm for dealing with the various spatial abstractions of the facility components regardless of their geometric dimensionalities."

]]> M. Kiumarse. Zamanian et al. Representing and recording design intent : a progress report http://repository.cmu.edu/cee/48 http://repository.cmu.edu/cee/48 Mon, 30 Apr 2012 10:11:33 PDT Abstract: "This research outlines a design methodology for recording the intent behind decisions in a design process. The design problem isdescribed as a conjunction of design objectives, which are high level descriptions of the requirements that the design artifact must meet (functional, financial, constructability, maintainability, disposability etc.). We use a combination of informal text, first-order predicate logic and arithmetic constraints to express design objectives. Importance can be associated with objectives. In this design process, the objectives can be addressed in some order by focussing on a subset of them. Objectives are achieved by a process of refinement which may result in a set of alternative bindings for the design variables involved, or, in alternative decompositions for the objectives.Assumptions may be made in the generation of the alternatives. The alternatives are evaluated with respect to other objectives and one alternative is selected. The design is completed when the current set of objectives is satisfied. Thus, the designer does not manipulate the form of the artifact itself; rather, the designer manipulates the objectives and selects alternatives, thereby revealing the intent behind the decisions. We also describe a representation for the record of this design process. The record can be used to identify the objectives and assumptions responsible for design decisions and for identifying the objectives and assumptions affected when decisions are modified. Weare developing an interactive computer-based environment in the domain of residential and small office buildings to demonstrate this approach."

]]> Rajaram Ganeshan et al. A sparse approach to simultaneous analysis and design of geometrically nonlinear structures http://repository.cmu.edu/cee/47 http://repository.cmu.edu/cee/47 Mon, 30 Apr 2012 10:11:30 PDT Abstract: "The problem of increasing the efficiency of the optimization process for nonlinear structures has been examined by several authors in the last ten years. One of the methods that has been proposed to improve the efficiency of this process considers the equilibrium equations as equality constraints of the nonlinear mathematical programming problem. The efficiency of this method, commonly called simultaneous, as compared to the more traditional approach of nesting the analysis and design phases, is reexamined in this paper. It is shown that, when projected Lagrangian methods are used, the simultaneous method is computationally more efficient than the nested provided the sparsity of at least the Jacobian matrix is exploited.The basic structure of the Hessian and Jacobian matrices for geometrically nonlinear behavior of truss structures is given and numerical results are presented for a series of large problems using both dense and sparse projected Lagrangian methods."

]]> Omar Ghattas et al. Detection and evaluation of orientation features for CAD part models http://repository.cmu.edu/cee/46 http://repository.cmu.edu/cee/46 Mon, 30 Apr 2012 10:11:28 PDT Abstract: "Current design for assembly methodologies stress the importance of part features related to acquisition and orientation in determining time values and error rates. This paper discusses an approach to detecting and evaluating features of CAD modelled parts which contribute to assembly difficulty. An evaluation basis is described and algorithms are developed which return an index of difficulty with respect to orientation features and degree of symmetry for two- and three-dimensional parts. Limitations of the method are discussed with examples."

]]> Mohammad I. Kilani et al. Adjacency structures as mappings between function and structure in discrete static systems http://repository.cmu.edu/cee/45 http://repository.cmu.edu/cee/45 Mon, 30 Apr 2012 10:11:25 PDT Abstract: "One view of the design process is that design is a mapping from functional requirements to artifact description. This article presents initial work on a method for mapping between functional requirements and a description of the physical structure of discrete static systems. The representation consists of a set of atomic elements, a hierarchy of compound components from the domain, and the composition ofa graph of adjacent atomic elements. Through forward or backward chaining, this method may be used in a parsing mode to discover the behavior and function of a given system, or in a generative mode to suggest instances of systems which can be used to satisfy the desired functionality.Parsing discovers the behavior of the system in terms of the compound components by matching on subgraphs within the overall adjacency graph. Generation hierarchically instantiates subgraphs which satisfy the initial functional requirements and the requirements propagated by previously instantiated components. The graph is composed from a geometric model, but the method is independent of the specific representation used by the geometric modeler. We focus on the domain of structural systems in buildings to describe this method."

]]> Steven Meyer et al.