Common Data Structure Research Articles

Development of "Data-Free-Way" Distributed Database System for Advanced Nuclear Materials.

A distributed database system named “Data-Free-Way (DFW)” is under development by a cooperation among three Japanese national research organizations to support the creation of advanced nuclear materials. The development of DFW started in 1990 as a five-year program with a support from Science and Technology Agency of Japan. Before starting the program, a preliminary survey of both domestic and foreign databases of nuclear materials had been made for two years. Then, subjects for the construction of DFW were extracted. To meet the subjects, the development and construction programs were established. The DFW is constructed on the computer network which connects engineering workstations in the separate organizations. A relational database management system is used, a distributed material database is equipped on the hardware with specially designed common data structure. Data storage has been carried out continuously in each organization. The equipment of useful user-interface systems, such as retrieval, data entry and process supporting and image data handling systems, have also been constructed to make it friendly for users. The collection of nuclear material data from three research organizations and its mutual usage have become possible by the construction of DFW.

Sampling the Leaves of a Tree with Equal Probabilities

Abstract In the computer sciences, trees are among the most common data structures. Knuth proposed a method of sampling the leaves of a tree with known but unequal probabilities; he used the sample to estimate the behavior of backtrack algorithms. This article proposes two methods for sampling leaves with equal probabilities.

Computer-aided interactive plastic design of frames

A computer method for analysis and design of plane frames is presented. The method is meant primarily for plastic collapse analysis. Optimal design and elastic-plastic deformation analysis capabilities are provided as options on the same computational platform such that all activities share common internal data structures. A specific feature is the interfacing of user input with analysis calculations, resulting in an interactive design system. Four sequential levels of input data are considered: frame topology, geometry, member sections and loading. Separate calculation modules are activated at each level of input, permitteng interactive data modifications; computational work that needs to be repeated to obtain the new solution is that of the modification level and the following levels if any.

SIMPLE ALGORITHMS FOR ENUMERATING INTERPOINT DISTANCES AND FINDING k NEAREST NEIGHBORS

We present an O(n log n+k log k) time and O(n+k) space algorithm which takes as input a set of n points in the plane and enumerates the k smallest distances between pairs of points in nondecreasing order. We also present an O(n log n+kn log k) solution to the problem of finding the k nearest neighbors for each of n points. Both algorithms are conceptually very simple, are easy to implement, and are based on a common data structure: the Delaunay triangulation. Variants of the algorithms work for any convex distance function metric.

Computer-assisted generation of multi-leaf collimator settings for conformation therapy.

Techniques for the automatic set up of the individual leaf positions of a Philips multi-leaf collimator system to cover a defined target volume are described. Tumour outline data for multi-field treatments may be obtained from one of two techniques, either from simulator images or from cross-sectional computed tomography (CT) slices. In the first technique, simulator images are digitized directly from image intensifier video signals or from conventional film radiographs using a CCD camera. Corrections for image distortion are carried out before reformatting the digitized images to a common data structure. Target outlines are subsequently traced interactively on the digital image to create an outline file. In the second technique, target volumes are defined on several individual CT slices and these are then used to obtain projected graphical views from any desired angle. In both techniques, a scaled graphical representation of leaf positions is then displayed and set relative to the outer edge of the target outline. Both techniques allow interactive repositioning of single leaves when required, or the operator can specify a margin around the projected target volume. Leaf prescription data files are created and are transferred via a Decnet-OSI-Opennet network link to an Intel microcomputer, which is used to drive the device itself. Examples of both techniques are given.

4989132 Object-oriented, logic, and database programming tool with garbage collection

A programming tool is provided which integrates an object-oriented programming language system, a logic programming language system, and a database in such a manner that logic terms can be treated as objects in the object-oriented programming language system, objects can be treated as logic terms in the logic programming language system, and logic terms and objects are stored in the database in a common data structure format. Automatic management of the database is provided which is transparent to the user.

RES, an expert system for the set-up and interpretation of a ruggedness test in HPLC method validation: Part 2: The ruggedness expert system

An expert system is described for the design and diagnosis of the results of a ruggedness test in HPLC method validation. It advises on the selection of relevant factors and an appropriate experimental design and it translates the statistical results into chemically relevant results. If the test fails, the program can advise on how to improve the HPLC method. The basis of the program is a Common Data Structure which represents all objects that are important in HPLC. Linked to this Common Data Structure are modules that manipulate objects. The modules represent major steps in a ruggedness test. An expert system on factor choice and a program on solving resolution problems are integrated in this program as modules. The program is designed to advise on a complete ruggedness test, from factor choice to improvement of the method.

Routing area compaction based on iterative construction

Abstract In this paper, an iterative‐construction based layout approach composed of three algorithms: net‐forest routing, track assignment, and block position refinement, is presented. These algorithms, unlike the conventional methods implemented separately with a sequence of tools, are linked with a common data structure — H‐V model of corner‐stitching. Thus, they have maximal compatibility. Given an initial non‐overlapping placement, the approach always generates a more compact final layout. Several layout examples in the literature are tested to prove the effectiveness of our approach; these experimental results show that our approach is better than the 1‐D compactors and some of the 2‐D compactors.

A design of expert system architecture for communications engineering simulation

Simulation expert system architecture for communications simulation including the features of common data structure, top- down information driven technique, optimization, and expert system approach is addressed. The concepts can be combined to implement a very user-friendly simulation system for either a novice or experienced user. The architecture block diagram of the simulator is discussed to highlight the important functions. Complete or partial features addressed can be adopted in any simulator design.

New iterative construction approach to routing with compacted area

The new iterative construction approach presented in this paper consists of three algorithms, namely, channel expansion routing, track assignment, and module location refinement. These algorithms, contrary to the conventional methods implemented with a sequence of tools separately, are linked with a common data structure which guarantees a maximal compatibility. With an initial nonoverlapping placement as input, the iterative construction approach generates a final layout with more compacted area than the layout result from the one-dimensional compactor or some of two-dimensional compactors. Several layout examples in the literature are tested to show the effectiveness of our approach.

The run-time efficiency of parallel asynchronous algorithms

The problem studied is similar to the problems found in multiprocessor operating systems. The lockout problem in multiprocessor operating systems is a direct result of multiple processors attempting to process common data structures asynchronously. There are numerous such shared data structures. The models developed are applicable to the study of contention for software and hardware resources in multiprocessor operating systems. The authors introduce an approximate analytical model to evaluate the performance of asynchronous processes found in asynchronous algorithms, including the combined effects of software lockout on critical sections and on job queues, and of shared-memory access conflicts. Because of the strong similarities between the two effects, the same model can be used for both, leading to a uniform and elegant formulation. The models are combined to find the run-time efficiency of asynchronous iterations. >

Expert system for precision testing in validation of liquid chromatographic methods

After a liquid chromatographic method has been developed, it must be validated to establish its limitations in daily use. Method validation is becoming increasingly important as stricter rules are applied by regulatory authorities. Precision testing is a vital step in this validation; both intralaboratory testing and interlaboratory testing are needed. In an intralaboratory test, repeatability and ruggedness tests are usually done. Expert systems are available for both tests. Here they are integrated to form an intralaboratory precision-testing expert system; special integration architecture is described. Important features of the integrated system are a supervisor containing planning knowledge about the tests and a common data structure containing all the objects necessary for an expert system in this area.

Radiation therapy treatment planning using concurrent programming

Concurrent programming can be applied to the problem of computer graphic simulation of radiation treatment of tumors (radiation treatment planning). Running several tasks or programs simultaneously on behalf of a single user provides a big improvement over the traditional sequential approach, in which editing a treatment plan and computing and displaying dose distributions are separate operations which must be invoked by explicit commands. With our system, the user sees isodose contours being updated automatically and continuously as the plan is edited; this greatly facilitates plan optimization. The complexity of parallel processing has resulted in a ‘conventional wisdom” which discourages this technique. The usual approach is to have parallel processes share a common global data structure, which makes interaction hard to control and discourages modularity and data abstraction. We have developed an alternative approach based on message streams which instead enhances modularity and data abstraction while still providing the advantages of parallel processing. The system is very reliable and is used routinely in a practical clinical environment.

Parallel computers for graphics applications

Specialized computer architectures can provide better price/performance for executing image processing and graphics applications than general purpose designs. Two processors are presented that use parallel SIMD data paths to support common graphics data structures as primitive operands in arithmetic expressions. A variant of the C language has been implemented to allow high level language coding of user applications on these processors. High level programming support is designed into the processor architecture that implements parallel object data typing and parallel conditional evaluation in hardware.

Parallel computers for graphics applications

Specialized computer architectures can provide better price/performance for executing image processing and graphics applications than general purpose designs. Two processors are presented that use parallel SIMD data paths to support common graphics data structures as primitive operands in arithmetic expressions. A variant of the C language has been implemented to allow high level language coding of user applications on these processors. High level programming support is designed into the processor architecture that implements parallel object data typing and parallel conditional evaluation in hardware.

Parallel computers for graphics applications

Specialized computer architectures can provide better price/performance for executing image processing and graphics applications than general purpose designs. Two processors are presented that use parallel SIMD data paths to support common graphics data structures as primitive operands in arithmetic expressions. A variant of the C language has been implemented to allow high level language coding of user applications on these processors. High level programming support is designed into the processor architecture that implements parallel object data typing and parallel conditional evaluation in hardware.

N-Expression implementations for integrated symbolic and numeric processing

Despite a growing interest in the integration of the symbolic, and numeric processing, the corresponding language and architecture types are still considered largely incompatible. A most serious incompatibility accrues from the diversity of the data structures they manipulate. In symbolic processing, data structures tend to be complex Symbolic-Expressions scattered through memory. These structures, known as S-Expressions, are implemented by using the binary list and its algebra of programs. In numeric applications the most common data structure is a linearly allocated array or vector. Array processing involves an entirely different algebra of operations, therefore effecting incompatabilities both at the language and architecture levels. This paper presents a brief formal semantics for the N-Expression, followed by a detailed account of how the N-Expression can be implemented in the linear computer memory, and concludes by presenting some experimental results from its implementation on a network of software-implemented microcomputers. The N-Expression attempts to support symbolic and numeric processing in a uniform way through the n-ary list and its algebra of programs. The n-ary list subsumes both the binary list (S-Expression) and the array type. Its algebra of programs is founded on a set of primitive operations that fall into three groups for: accessing, traversing and reorganising the n-ary list. For implementation the n-ary list in the linear computer memory, three novel schemes are discussed and evaluated for efficiency. The first scheme is based on a tree representing (e.g. paged memory) and shows performance speed ups of between 4–6 times over symbolic processing systems that use the traditional binary list (e.g. CDR-Coded lisp cells) to implement structured memory. The second scheme is based on a nested parentheses representation (e.g. delimited string) and shows a performance improvement factor of between 1.2–2 times over the binary list (e.g. CDR-Coding). The third scheme is based on the Dewey Decimal Notation (e.g. tabular representation for the n-ary list) and shows performance speed ups of between 5–7 times over the binary list (CDR-Coding).

Teaching programming algorithms aided by computer graphics

Effects of operations on abstract data objects are often difficult for students to comprehend. Visual models can be helpful to students, when the connections among the data object models, virtual machine representations of data objects, and algorithms operating on the data objects are made clear to the students. This paper discusses the design criteria used to develop a series of Pascal programs, implemented on widely used microcomputers, which make use of graphics to illustrate the effects of programming algorithms on common data structures. These programs were designed to be used in classroom demonstrations and by individual students working in the computing laboratory. 1 A non-machine specific design of an algorithm teacher is proposed. It is a programmed environment to help students in a beginning computer science course learn problem solving skills. This paper provides an overview of the problem, a motivation and justification, followed by a brief description of what the program should provide the student.

Developing computer animation packages (panel)

Specialized computer architectures can provide better price/performance for executing image processing and graphics applications than general purpose designs. Two processors are presented that use parallel SIMD data paths to support common graphics data structures as primitive operands in arithmetic expressions. A variant of the C language has been implemented to allow high level language coding of user applications on these processors. High level programming support is designed into the processor architecture that implements parallel object data typing and parallel conditional evaluation in hardware.

Developing computer animation packages (panel)

Specialized computer architectures can provide better price/performance for executing image processing and graphics applications than general purpose designs. Two processors are presented that use parallel SIMD data paths to support common graphics data structures as primitive operands in arithmetic expressions. A variant of the C language has been implemented to allow high level language coding of user applications on these processors. High level programming support is designed into the processor architecture that implements parallel object data typing and parallel conditional evaluation in hardware.