visual computer languages exploit the natural language of diagrams and pictures to provide a simple and intelligible approach to programming. Unfortunately, it is difficult to provide them with a formal syntax and sem...
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visual computer languages exploit the natural language of diagrams and pictures to provide a simple and intelligible approach to programming. Unfortunately, it is difficult to provide them with a formal syntax and semantics. In this paper we show how the RCC spatial calculus can be used to provide an unambiguous, formal description of such languages by systematically describing the syntax of Pictorial Janus.
The main goal of the article is to evaluate the suitability of visual programming languages, i.e., Pictorial Janus (K. Kahn and V. Saraswat, 1990), for the modeling of complex systems and their control strategies. The...
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ISBN:
(纸本)081867508X
The main goal of the article is to evaluate the suitability of visual programming languages, i.e., Pictorial Janus (K. Kahn and V. Saraswat, 1990), for the modeling of complex systems and their control strategies. These systems can be seen as networks of communicating objects. Objects select strategies for suitable actions based on incoming messages. Our field of investigation is in computer integrated manufacturing considering the example of a car manufacturing cell. This color sorting assembly buffer (CSAB) schedules jobs in queues. The jobs represent car bodies scheduled in feeder lines for the enameling. Feeder lines collect raw bodies to blocks. Blocks are bodies which are to be enameled by the same color. This organization decreases the cost of expensive change-over-times when changing colors at the enamelling. Blocks of bodies are dislocated from the queue and enameled successively. Contradictory system goals, such as minimizing color changes and preserving the sequence of incoming jobs, have to be regarded by appropriate control strategies. Due to the complexity of this (NP complete) problem and to real time requirements for online control there are no optimal strategies on hand. Consequently, suitable heuristics have to be developed. Often they are designed applying a trial-and-error method. A modeling framework has to support the rapid prototyping of these systems as well as an expressive end user oriented representation. Both are essential requirements since end users need other visualization techniques than experienced designers due to their different knowledge and interests.
This paper discusses a software tool,called VANISH, which supports the rapid prototyping of interactive 2D and 3D information visualizations. VANISH supports rapid prototyping: through a special-purpose language tailo...
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ISBN:
(纸本)081867668X
This paper discusses a software tool,called VANISH, which supports the rapid prototyping of interactive 2D and 3D information visualizations. VANISH supports rapid prototyping: through a special-purpose language tailored for visualizations;through a software architecture that insulates visualization-specific code from changes in both the domain being visualized and the presentation toolkit used;and through the reuse of visualization techniques between application domains. The generality of VANISH is established by showing how it is able to re-create a wide variety of ''standard'' visualization techniques. VANISH's support for prototyping is shown through an extended example, where we build a C++ class browser, exploring many visualization alternatives in the process.
A weakness of many interactive visual programming languages (VPLs) is their static representations. Lack of an adequate static representation places a heavy cognitive burden on a VPL's programmers, because they mu...
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ISBN:
(纸本)081867508X
A weakness of many interactive visual programming languages (VPLs) is their static representations. Lack of an adequate static representation places a heavy cognitive burden on a VPL's programmers, because they must remember potentially long dynamic sequences of screen displays in order to understand a previously-written program. Building upon the cognitive dimensions developed for programminglanguages by cognitive psychologists Green and others, the authors have developed a set of concrete benchmarks for VPL designers to use when designing new static representations. These benchmarks provide design-time information that can be used to improve a VPL's static representation.
visual programming languages use graphics to visualize and aid in the understanding of programs. We describe the graphical techniques used in the MAP environment to visualize the workspace, data, programs and program ...
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ISBN:
(纸本)081867508X
visual programming languages use graphics to visualize and aid in the understanding of programs. We describe the graphical techniques used in the MAP environment to visualize the workspace, data, programs and program executions. Meta information is one approach to supplementing the basic functionality provided in the visualprogramming environment. We introduce meta-commands, commands to control visual characteristics of program objects, and describe the MAP meta-commands for color, folding, render and transparency. We show how these meta-commands can be used to affect graphical representation of programs and their executions and as a way to optimize the recording of program executions, and present examples of how a programmer can use these techniques to build, execute and analyze programs.
Due to its iterative nature, the execution of the maximum likelihood expectation maximization (ML-EM) reconstruction algorithm requires a long computation time. To overcome this problem, multiprocessor machines could ...
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ISBN:
(纸本)0819415421
Due to its iterative nature, the execution of the maximum likelihood expectation maximization (ML-EM) reconstruction algorithm requires a long computation time. To overcome this problem, multiprocessor machines could be used. In this paper, a parallel implementation of the algorithm for positron emission tomography (PET) images is presented. To cope with the difficulties involved with parallel programming a programming environment based on a visual language has been used.
Software engineering for real-time applications is known to be a hard problem. For years, many people have been taking different eteps to tackle this problem. One of these steps was the introduction of visual language...
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Software engineering for real-time applications is known to be a hard problem. For years, many people have been taking different eteps to tackle this problem. One of these steps was the introduction of visuallanguages. visuallanguages have the potential to ease programming as they are more expressive than the conventional textual languages (Shu, 1988). In the domain of real time applications, the use of visuallanguages is mainly restricted to software design languages. Automatic code generators are used to generate a code skeleton, which is filled in with fairly ‘coarse grained’ hand written textual program fragments. In this paper we present a method to extend existing visual design languages to visual programming languages with a much more powerful visual component.
Traditionally, interactive applications have been difficult to build, modify and extend. These integrated applications provide bounded bounded functionality, have a single thread of control and a fixed user interface ...
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ISBN:
(纸本)9780897912754
Traditionally, interactive applications have been difficult to build, modify and extend. These integrated applications provide bounded bounded functionality, have a single thread of control and a fixed user interface that must anticipate everything the user will *** workstations allow several processes to share the screen. With proper communication between processes, it is possible to escape previous models for application development and *** is a high-level visual language we use on an IRIS workstation that lets users dynamically build and modify graphics applications. To do this, a system designer disintegrates complex applications into modular components. By interactively connecting simple components, the user constructs a complete graphics application that matches the needs of a task. A connection manager controls the flow of data between individual components. As a result, we replace the usual user-machine dialog with a dynamic live performance that is orchestrated by the user.
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