The model of a paper machine is very complex and difficult to describe completely by a mathematical model. There are a lot of parameters in both the wet and dry end of the machine and there is a very large time delay ...
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The model of a paper machine is very complex and difficult to describe completely by a mathematical model. There are a lot of parameters in both the wet and dry end of the machine and there is a very large time delay in the system which effects the quality of the paper being produced. Although the PID controller is widely used for these types of applications, it is often not tuned very well. In this work, a newly developed algorithm (Munro, The systematic design of PID controllers, IEE Colloquium in Robust Control: Theory, Software and Applications, Austin Court, Birmingham, 1999) is used for tuning the PTD controller. Along with this controller, a Smith-predictive controller is applied to the plant and the transient and steady-state behaviours of these controllers are compared. Hardware and software implementations of the closed-loop control are also presented in the paper. (C) 2001 Elsevier Science Ltd. All rights reserved.
A tractor performance program that predicts the performance of two-wheel-drive (2WD) and four-wheel-drive/mechanical-front-wheel-drive (4WD/MFWD) tractors on agricultural soils for both bias-ply and radial tires was d...
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A tractor performance program that predicts the performance of two-wheel-drive (2WD) and four-wheel-drive/mechanical-front-wheel-drive (4WD/MFWD) tractors on agricultural soils for both bias-ply and radial tires was developed to meet the user requirements for both educational and research programs. The program was written in visual C + + programming language as a new method of predicting 2WD and 4WD/MFWD tractor performance. The program provides an intuitive user interface by linking databases such as tractor specifications, tire data (front. bias-ply. and radial), and traction equation coefficients to predict the performance of a selected tractor and model. The program has been proven to be user friendly and efficient. (C) 2001 Elsevier Science B.V. All rights reserved.
The theory of visual programming languages (VPLs) is very crucial for understanding the visual programming approach. It includes basically formal models for specifying VPLs and the corresponding parsing algorithms. Th...
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The theory of visual programming languages (VPLs) is very crucial for understanding the visual programming approach. It includes basically formal models for specifying VPLs and the corresponding parsing algorithms. This paper presents a grammatical formalism and an efficient parsing algorithm for visual languages. The proposed formalism, called modified relation grammar (MRG), is a restricted form of the relation grammar (RG). MRG restricts the form of productions and distributes the evaluation rules among various production rules, which makes the grammar more readable. The paper also presents an efficient O(n) parsing algorithm for MRG. The paper includes a number of examples to demonstrate the proposed formalism, It also includes a discussion on the expressive power of the proposed grammar and the correctness of its parsing algorithm. Finally, the paper compares the proposed grammar and its parsing algorithm with a similar restricted form of the RG. (C) 2001 Elsevier Science Inc. All rights reserved.
The use of metaphor can be a potential aid to the novice modeler in several ways. Metaphor can imbue abstract ideas with concrete properties, thereby making the abstract ideas more accessible. The analogies suggested ...
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The use of metaphor can be a potential aid to the novice modeler in several ways. Metaphor can imbue abstract ideas with concrete properties, thereby making the abstract ideas more accessible. The analogies suggested by metaphor might also aid reasoning about modeling and implementation problems. Another potential benefit of metaphor in modeling is the improvement of mental retention of model architecture and functionality. Traditionally models and programs have been produced in a two-dimensional (2-D) or textual medium. However these media may be inferior to a three-dimensional (3-D) medium in the development and use of metaphor, as the concrete properties that metaphors often provide are real-world phenomena, which are naturally 3-0. We developed an example of the use of metaphors in modeling and 3-0 simulation. The example consists of a simplified operating system task scheduler;along with associated hardware devices, developed in a VRML environment using VRML PROTO nodes. These nodes are designed as modular objects based on real-world metaphors. We were able to construct a set of metaphors and prototypes that may, if extended, ease the modeling and design of agent-oriented systems for novices. A proposed extension of one metaphor presented in the research is the synthetic human agent.
Spreadsheets are among the most common form of software in use today. Unlike more traditional forms of software however, spreadsheets are created and maintained by end users with little or no programming experience. A...
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ISBN:
(纸本)0769511899;0769511902
Spreadsheets are among the most common form of software in use today. Unlike more traditional forms of software however, spreadsheets are created and maintained by end users with little or no programming experience. As a result, a high percentage of these "programs" contain errors. Unfortunately, software engineering research has for the most part ignored this problem. We have developed a methodology that is designed to aid end users in developing, testing, and maintaining spreadsheets. The methodology communicates testing information and information about the impact of cell changes to users in a manner that does not require an understanding of formal testing theory or the behind the scenes mechanisms. This paper presents the results of an empirical study that shows that, during maintenance, end users using our methodology were more accurate in making changes and did a significantly better job of validating their spreadsheets than end users without the methodology.
This paper presents an object-oriented architecture, called the Model-View-Shape (MVS) architecture, for constructing an Integrated visual programming Environment (IVPE), whose constituent tools deal with (fine-graine...
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In this paper, we deal with editing tabular forms for program specifications based on a particular graph grammar HNGG [2]. First, we formalize syntax-directed editing methods by extending of the notion of the Cornell ...
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In this paper, we deal with editing tabular forms for program specifications based on a particular graph grammar HNGG [2]. First, we formalize syntax-directed editing methods by extending of the notion of the Cornell Program Synthesizer [8] to attribute NCE graph grammars (cf. [1]). Next, we discuss the algorithms of the editing methods.
This paper presents an object-oriented architecture, called the Model-View-Shape (MVS) architecture, for constructing an Integrated visual programming Environment (IVPE), whose constituent tools deal with (fine-graine...
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This paper presents an object-oriented architecture, called the Model-View-Shape (MVS) architecture, for constructing an Integrated visual programming Environment (IVPE), whose constituent tools deal with (fine-grained) language semantics, as well as a mass of graphics-drawing activities. This architecture enforces a layered and loosely-coupled structure, so that the user-interface part of components may be more independent, maintainable, and reusable than those proposed in the original model-view-controller architecture. An MVS class hierarchy, systematically constructed using C++, can be reused and extended with new semantics to rapidly develop new tools for an existing IVPE, or even an IVPE supporting more than one language, The present editors developed can be used to construct programs by specifying the associated flow information in explicit (visual) or implicit (textual) ways, while the (incremental) flow analysers can help analyse incomplete program fragments to locate and inform the user of possible errors or anomalies during programming. (C) 1998 John Wiley & Sons, Ltd.
This paper presents a visual environment for building process simulators which is specifically aimed at integrating the construction of a model and the organizational of the corresponding simulation code, providing th...
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This paper presents a visual environment for building process simulators which is specifically aimed at integrating the construction of a model and the organizational of the corresponding simulation code, providing the user with easy and extensive control of both phases. The environment relies entirely on a graphical programming language, which permits easy creation of flexible and effective user interfaces for the simulators. It adopts a modular approach, so as to simplify its maintenance and extension. A real-size case is treated to demonstrate the capacity of the proposed environment.
The design and implementation of a new visual programming language is a difficult task. The article presents a new meta tool which eases the initial design phase. The approach differs from existing techniques as it is...
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ISBN:
(纸本)0818685859
The design and implementation of a new visual programming language is a difficult task. The article presents a new meta tool which eases the initial design phase. The approach differs from existing techniques as it is based on an easy-to-use description language, each lexeme of which is represented as an individual node on the workplace and is described by a special code file. The broad aim of this research is to investigate how visual elements/techniques could be integrated into a concrete visual environment which supports the programming task Thus, the emphasis lies primarily on the visualisation of structures or relationships rather than on implementation details. To keep the ongoing research as open as possible, the separation of the underlying semantics from the visual representation is of great importance.
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