Computer-aided design of structures using LISP

An experimental knowledge-based expert system, called SSPG. is presented for design of stiffened steel plate girders, using the LISP programming language. Employing previously acquired knowledge of the optimum span-to-web depth ratios, SSPG is capable of yielding a “practical” minimum weight design without performing a costly formal optimization. This research indicates the effectiveness of the LISP language for computer-aided design of structures where not only subjective knowledge and heuristics are needed but also substantial numerical computations are involved.     

Efficient search of combinatorial maps using signatures

In this paper, we address the problem of computing canonical representations of n-dimensional combinatorial maps and of using them for efficiently searching for a map in a database. We define two combinatorial map signatures: the first one has a quadratic space complexity and may be used to decide an isomorphism with a new map in linear time whereas the second one has a linear space complexity and may be used to decide an isomorphism in quadratic time. We show that these signatures can be used to efficiently search for a map in a database.     

Computer-aided construction of nucleic acid restriction maps using defined vectors

A new algorithm is described that will rapidly produce restriction maps of cloned DNA fragments. Information concerning the vector is stored as a data file and used in constructing probable maps. As the program is based upon a permutation analysis it has two primary uses. First, preliminary restriction maps can be created from fragment length data as a starting point for further analysis. Second, existing maps can be confirmed as being highly probable, and other probable maps examined to ensure certain combinations have not been overlooked. Although primarily designed for linear vectors, the program can be used to calculate circular maps.     

Substring search and repeat search using factor oracles

We present some simple but useful properties of factor oracles, and propose fast algorithms for indexed full-text search and finding repeated substrings. Some experiments are given to demonstrate the performance of our algorithms.     

Hydrophobicity and functionality maps of farnesyltransferase.

Farnesyltransferase (FTase) catalyzes the attachment of a 15-carbon isoprenoid moiety, farnesyl, through a thioether linkage to a cysteine near the C-terminus of oncogenic Ras proteins. These transform animal cells to a malignant phenotype when farnesylated. Hence, FTase is an interesting target for the development of antitumor agents. In this work we first investigate the active site of FTase by mapping its hydrophobic patches. Then the program SEED is used to dock functional groups into the active site by an exhaustive search and efficient evaluation of the binding energy with solvation. The electrostatic energy is SEED is based on the continuum dielectric approximation and consists of screened intermolecular energy and protein and fragment desolvation terms. The results are found to be consistent with the sequence variability of the tetrapeptide substrate. The distribution of functional groups (functionality maps) on the substrate binding site allows for identification of modifications of the tetrapeptide sequence that are consistent with potent peptidic inhibitors. Furthermore, the best minima of benzene match corresponding moieties of an inhibitor in clinical trials. The functionality maps are also used to design a library of disubstituted indoles that might prevent the binding of the protein substrates.     

Visualizing search results and document collections using topic maps

This paper explores visualizations of document collections, which we call topic maps. Our topic maps are based on a topic model of the document collection, where the topic model is used to determine the semantic content of each document. Using two collections of search results, we show how topic maps reveal the semantic structure of a collection and visually communicate the diversity of content in the collection. We describe techniques for assessing the validity and accuracy of topic maps, and discuss the challenge of producing useful two-dimensional maps of documents.     

A novel method of S-box design based on discrete chaotic maps and cuckoo search algorithm

Multimedia Tools and Applications - Substitution-boxes (S-boxes) are unique nonlinear elements, which are used to achieve the property of confusion in modern symmetric ciphers and offer resistance...     

Robust control system design using random search and geneticalgorithms

Random search and genetic algorithms find compensators to minimize stochastic robustness cost functions. Statistical tools are incorporated in the algorithms, allowing intelligent decisions to be based on “noisy” Monte Carlo estimates. The genetic algorithm includes clustering analysis to improve performance and is significantly better than the random search for this application. The algorithm is used to design a compensator for a benchmark problem, producing a control law with excellent stability and performance robustness     

Computer-aided design and optimization of induction motors

A method of computer-aided design and optimization of induction motors is proposed. The method uses the digital computer in an interactive mode; the objective is the best use of man and machine. A definition of a 'good' design is attempted and the resulting ramifications discussed.     

Optimum design of steel frames using harmony search algorithm

In this article, harmony search algorithm was developed for optimum design of steel frames. Harmony search is a meta-heuristic search method that has been developed recently. It bases on the analogy between the performance process of natural music and searching for solutions to optimization problems. The objective of the design algorithm is to obtain minimum weight frames by selecting suitable sections from a standard set of steel sections such as American Institute of Steel Construction (AISC) wide-flange (W) shapes. Strength constraints of AISC load and resistance factor design specification and displacement constraints were imposed on frames. The effectiveness and robustness of harmony search algorithm, in comparison with genetic algorithm and ant colony optimization-based methods, were verified using three steel frames. The comparisons showed that the harmony search algorithm yielded lighter designs.     

A method of control system design using global search

A method is presented that eliminates the problem of the conventional quadratic performance criterion not being effective for some real-world systems because the performance parameters are seldom related to meaningful quantities. Globally searching the performance index allows the index to have local minimums as well as discontinuities, so it can be defined in meaningful terms. This ability to define meaningful performance indexes potentially can reduce the design time and produce better controls for nonlinear systems. The method has been implemented and tested with a simulated nonlinear system. Comparison to optimal control theory shows that the methodology has merit. Gains occur because the controller can be nonlinear and the system can be efficiently optimized to have the desired characteristics     

Computer-aided design of a CPW-fed slot antenna for MM-wave applications

This article presents a comprehensive parametric study with experimental characterization of an inductively coupled CPW-fed slot antenna on a GaAs substrate for MMIC applications. The length, width, and feed inset of the antenna are varied and their influences on the input impedance, bandwidth, and gain are investigated. The parametric study reveals that the slot length is the prime factor for determining the resonant frequency, while the width is used for fine-tuning of resonant frequency and gain-bandwidth product. For the fixed slot dimensions, the feed inset tremendously affects both resonant frequency and input match. The manufactured antenna resonates at 22.4 GHz with a 6.1% impedance bandwidth, 2% gain bandwidth, 2.5-dBi boresight gain, and 5-dB front-to-back (F/B) radiation level. The antenna exhibits bidirectional radiation patterns with almost omnidirectional patterns in the E-plane and a wide beamwidth of 84° 3-dB beam width in the H-plane. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14, 4–14, 2004     

An efficient digital search algorithm by using a double-arraystructure

An efficient digital search algorithm that is based on an internal array structure called a double array, which combines the fast access of a matrix form with the compactness of a list form, is presented. Each arc of a digital search tree, called a DS-tree, can be computed from the double array in 0(1) time; that is to say, the worst-case time complexity for retrieving a key becomes 0(k) for the length k of that key. The double array is modified to make the size compact while maintaining fast access, and algorithms for retrieval, insertion, and deletion are presented. If the size of the double array is n+cm, where n is the number of nodes of the DS-tree, m is the number of input symbols, and c is a constant particular to each double array, then it is theoretically proved that the worst-case times of deletion and insertion are proportional to cm and cm², respectively, and are independent of n. Experimental results of building the double array incrementally for various sets of keys show that c has an extremely small value, ranging from 0.17 to 1.13     

Computer-aided design of chiral ligands. Part I. Database search methods to identify chiral ligand types for asymmetric reactions

The utility of database searching to identify chiral ligand motifs is outlined. The key elements of three known chiral ligands have been described as bond vectors. The CAVEAT program was then used to screen the Cambridge Structural Database (CSD), portions of the Chemical Abstracts Services three-dimensional database (CAS-3D), and the TRIAD tricyclic structure database for scaffolds containing these elements. Scaffolds corresponding to the known starting points were identified indicating that this method can be used to identify chiral ligand structural motifs. In addition, alternate structural motifs were found that suggested alternative possible ligands.     

Evaluating maps produced by urban search and rescue robots: lessons learned from RoboCup

This paper presents the map evaluation methodology developed for the Virtual Robots Rescue competition held as part of RoboCup. The procedure aims to evaluate the quality of maps produced by multi-robot systems with respect to a number of factors, including usability, exploration, annotation and other aspects relevant to robots and first responders. In addition to the design choices, we illustrate practical examples of maps and scores coming from the latest RoboCup contest, outlining strengths and weaknesses of our modus operandi. We also show how a benchmarking methodology developed for a simulation testbed effortlessly and faithfully transfers to maps built by a real robot. A number of conclusions may be derived from the experience reported in this paper and a thorough discussion is offered.     

Symbol design: a user-centered method to design pen-based interfaces and extend the functionality of pointer input devices

A method called “SymbolDesign” is proposed that can be used to design user-centered interfaces for pen-based input devices. It can also extend the functionality of pointer input devices, such as the traditional computer mouse or the Camera Mouse, a camera-based computer interface. Users can create their own interfaces by choosing single-stroke movement patterns that are convenient to draw with the selected input device, and by mapping them to a desired set of commands. A pattern could be the trace of a moving finger detected with the Camera Mouse or a symbol drawn with an optical pen. The core of the SymbolDesign system is a dynamically created classifier, in the current implementation an artificial neural network. The architecture of the neural network automatically adjusts according to the complexity of the classification task. In experiments, subjects used the SymbolDesign method to design and test the interfaces they created, for example, to browse the web. The experiments demonstrated good recognition accuracy and responsiveness of the user interfaces. The method provided an easily-designed and easily-used computer input mechanism for people without physical limitations, and, with some modifications, has the potential to become a computer access tool for people with severe paralysis.