A new deterministic quadratic parametric algorithm is introduced for curve estimation. A parametric biquadratic algorithm for surface estimation, based on the one for curve estimation is also presented. Our algorithm ...
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A new deterministic quadratic parametric algorithm is introduced for curve estimation. A parametric biquadratic algorithm for surface estimation, based on the one for curve estimation is also presented. Our algorithm does not assume that the surface to be estimated, based on a given set of data in the three-dimensional space, has a continuous first derivative, nor does it assume that the data satisfy the assumption of stationarity or the intrinsic hypothesis. The grid formed by the given data does not have to be equidistant;in other words the distance between neighboring points in the two-dimensional domain does not have to be the same. Also since the algorithm leads to parametric equations for the patches of the surface, the estimating surface does not need to be a function. Appropriate parameters are introduced in the blending functions of the parametric equations to produce tension. The algorithm does not require inversion of matrices and is faster than splines and kriging. The estimated surface passes through the given data points. Error analysis based on estimating surfaces of known functions from a sample of data and then comparing to their value, are made. A comparison with biqubic natural splines based on data generated from known functions is also given.
The two-dimensional method of Langdon and Rissanen for compression of black and white images is extended to handle the exact lossless compression of grey-wale images. Neighbouring pixel values are used to define conte...
The two-dimensional method of Langdon and Rissanen for compression of black and white images is extended to handle the exact lossless compression of grey-wale images. Neighbouring pixel values are used to define contexts and probabilities associated with these contexts are used to compress the image. The problem of restricting the number of contexts, both to limit the storage requirements and to be able to obtain sufficient data to generate meaningful probabilities, is addressed. Investigations on a variety of images are carried out using the JPEG lossless mode predictors. Results indicate that a one pass arithmetic encoder using restricted contexts can lead to effective lossless image compression algorithms.
Wafer packing is a process of combining multiple chip designs on the same wafer such that the fabrication cost can be shared by several designs and hence reduced. This technique is widely used for designs that require...
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Wafer packing is a process of combining multiple chip designs on the same wafer such that the fabrication cost can be shared by several designs and hence reduced. This technique is widely used for designs that require a small number of dies or chips. It is essential to have computer algorithms to decide how to allocate designs to wafers in order to reduce the total fabrication cost. Based on different wafer fabrication techniques, two versions of the wafer packing problem are formulated. We study different variations for each version. We present algorithms to find optimal solutions for these variations which are polynomial-time solvable. We also present heuristic algorithms for those proven to be NP-hard. The effectiveness of the proposed algorithms is demonstrated by experimental results.
We have developed a graphical user interface that supports the development of data-parallel programs for distributed-memory MIMD computers. The name of the tool is Intercom, since it facilitates programmer interaction...
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This paper presents an overview of HyperLecture, a hypertextual, gesturally-controlled lecture presentation system originally designed for teaching introductory computer programming. HyperLecture provides genuinely us...
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Even for the programmer, computer software can be a mysterious black box. But what if the programmer were able to give the box a good shake and listen to things rattle inside? Are there tools like the doctor's ste...
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ISBN:
(纸本)9051991339
Even for the programmer, computer software can be a mysterious black box. But what if the programmer were able to give the box a good shake and listen to things rattle inside? Are there tools like the doctor's stethoscope that can help programmers listen to the heartbeat of their software? These are the kinds of questions we decided to explore by building LogoMedia, a sound-enhanced programming environment. LogoMedia supports the ability to associate non-speech audio with program events while the code is being developed. These associations cause subsequent test runs of the program to generate and manipulate sounds which can aid in the comprehension and analysis of the program's behavior.
The integration of the US Army's existing combat modeling tool, JANUS(A), with the real-time three-dimensional graphics display offered by NPSNET is discussed. A scripting tool capable of rendering JANUS(A) scenar...
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Current user interface builders provide only low-level assistance, because they have knowledge of neither the application, nor the principles by which interface elements are combined effectively. We have developed a f...
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ISBN:
(纸本)9051991339
Current user interface builders provide only low-level assistance, because they have knowledge of neither the application, nor the principles by which interface elements are combined effectively. We have developed a framework that unites the knowledge components essential for effective user interface presentation design. The framework consists of an application model (both a data model and a control model), a design process model that supports top-down iterative development, and graphic design knowledge that is used both to place dialog box elements such that their application dependent logical relationships are visually reinforced and to control design symmetry and balance. To demonstrate the framework's viability, we have constructed a tool based on encapsulated design knowledge that establishes high-level style preferences and provides expert assistance for the dialog box presentation design and menu structuring.
VIEW is an exploratory visualization system for studying the structures of molecules. The system supports a high degree of complex user interaction with the image. Visualizations are constructed by selecting drawing t...
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ISBN:
(纸本)0897916018
VIEW is an exploratory visualization system for studying the structures of molecules. The system supports a high degree of complex user interaction with the image. Visualizations are constructed by selecting drawing tools from a library. Each tool uses parameters obtained from interactive selection of on-screen geometry by the user, and from a molecular database. The system is based on a tight coupling of on-screen geometry with the underlying database. Using these links, tools can create true-scale drawing elements that are constrained to database values. VIEW is highly extensible by the user or a paraprogrammer associated with the user. Drawing tools are written in a C-like programming language with constructs for managing databases, constructs for creating and altering geometry, as well as standard statements such as If-Else and For loops. An event-definition mechanism allows the user to describe actions to be performed when keys are depressed or dials turned. In addition, the user is able to specify conditional events actions that are to be taken whenever a user-defined condition becomes true. These conditions are automatically evaluated by the system as part of event processing. Such conditional events allow simple simulations to be readily programmed. Applications of conditional events have included animations of protein binding activity, and an interactive "flashlight" which highlights structures as a cursor is steered through a molecule. The system includes a development environment complete with a WYSIWYG editor, an interactive debugger, and a set of innovative graphical debugging features. VIEW has been installed for over a year in a protein crystallography laboratory at Duke University. Graduate students and faculty have used the system both for exploring molecular structures and for producing presentation graphics. These users have developed their own set of tools and made extensive use of the tool library. In January 1993, a beta-version of the software
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