作者：
Lim, DJHanyang Univ
Sch Elect Engn & Comp Sci Kyungki 426791 South Korea
This paper describes a real-time control laboratory course for undergraduate students. To introduce the concept of real-time control with real-time programming in a feedback-control laboratory course, a commercial sof...
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This paper describes a real-time control laboratory course for undergraduate students. To introduce the concept of real-time control with real-time programming in a feedback-control laboratory course, a commercial software tool for a real-time operating system is adopted. Instead of using convenient graphical programming and automatic code generation methods, students in this course are required to write programs using C language to control and monitor analog dynamic simulators and experimental plants. Through step-by-step procedures, students are able to acquire the knowledge necessary for writing real-time programs to control dynamic systems.
We present a novel level-of-detail selection method for real-time rendering, which works on hierarchies of discrete and continuous representations. We integrate smoothly represented, point-rendered objects with discre...
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We present a novel level-of-detail selection method for real-time rendering, which works on hierarchies of discrete and continuous representations. We integrate smoothly represented, point-rendered objects with discrete polygonal, geometry and demonstrate our approach in a terrain-flyover application. In this testing application the digital elevation model is augmented with forests in accordance with satellite data. The vegetation is rendered as a continuous sequence of splats generated from a procedural description. Further, we discuss enhancements to our basic method to improve its scalability.
The article focuses on the realistic finite-element modeling and simulation of viscoelastic soft tissue behavior. The researchers both use linear and non-linear finite-element models (FEM) to develop real-time organ-f...
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The article focuses on the realistic finite-element modeling and simulation of viscoelastic soft tissue behavior. The researchers both use linear and non-linear finite-element models (FEM) to develop real-time organ-force models but linearity assumption is not valid for soft tissues. Linear FEM models cannot accurately simulate large organ deformations while non-linear FEM models display realistic deformations than linear FEMs. They conclude that material property of soft tissues are closer to the actual properties, and small identification assumption affects the computation of viscoelastic material coefficients.
Expression evaluation in programming languages is normally assumed to be deterministic;however, if an expression involves variables that are being modified by the environment of the process during its evaluation, the ...
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Expression evaluation in programming languages is normally assumed to be deterministic;however, if an expression involves variables that are being modified by the environment of the process during its evaluation, the result of the evaluation can be non-deterministic. Two common scenarios in which this occurs are concurrent programs within which processes share variables and real-time programs that interact to monitor and/or control their environment. In these contexts, although any particular evaluation of an expression gives a single result, there is a range of possible values that could be returned depending on the relative timing between modification of a variable by the environment and its access within the expression evaluation. To compare the semantics of non-deterministic expression evaluation, one can use the set of possible values the expression evaluation could return. This paper formalizes three approaches to non-deterministic expression evaluation, highlights their commonalities and differences, shows the relationships between the approaches and explores conditions under which they coincide. Modal operators representing that a predicate holds for all possible evaluations and for some possible evaluation are associated with each of the evaluation approaches, and the properties and relationships between these operators are investigated. Furthermore, a link is made to a new notation used in reasoning about interference.
Experimental research in music performance is now an established field with anumber of interesting advances relating to the understanding of the musical communication betweenperformer and listener (Palmer 1997; Gabrie...
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Experimental research in music performance is now an established field with anumber of interesting advances relating to the understanding of the musical communication betweenperformer and listener (Palmer 1997; Gabrielsson 1999). Research in this field includes thecommunication of structure (Friberg and Battel 2002), emotional expression (Juslin 2001), andmusicians'' body gestures (Davidson and Correia 2002; Wanderley et al. 2005; Dahl and Fribergforthcoming). From this research, it is evident that the performer has an important and essentialrole ''giving life'' to a composition by introducing gestural qualities, enhancing the musicalstructure, and providing a personal interpretation reflecting an expressive intention. For example,studies of emotional expression have shown that the same piece can communicate completely differentemotions by changing the performance.
This paper presents a navigation technique for a sonar-equipped mobile robot in which the local map is built in real-time and is used for local path planning. The mobile robot is navigated to the goal by the proposed ...
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This paper presents a navigation technique for a sonar-equipped mobile robot in which the local map is built in real-time and is used for local path planning. The mobile robot is navigated to the goal by the proposed technique even in the complicated environments in which the robot is often trapped in a deadlock by using a reactive technique. The obtained local map can be used to build and/or update the global map of the environment. It is used to plan a desirable path for the next run. In navigation experiments using a commercial mobile robot named Pioneer-1, the proposed technique with map-building was effective in several environments, especially in complicated environments compared to a reactive navigation technique without map-building. Furthermore, The proposed navigation technique was also effective even if an unknown obstacle was placed in the environment;that is, in dynamic environments.
This special issue is devoted to the synchronous approach to reactive and real-time programming. This introductory paper presents and discusses the application fields and the principles of synchronous programming. The...
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This special issue is devoted to the synchronous approach to reactive and real-time programming. This introductory paper presents and discusses the application fields and the principles of synchronous programming. The major concern of the synchronous approach is to base synchronous programming languages on mathematical models. This makes it possible to handle compilation, logical correctness proofs, and verifications of real-time programs in a formal way, leading to a clean and precise methodology for design and programming.
Addressing the challenge of packet transmission in a wireless soft realtime system, we present five splitting protocols that take packet deadlines into account. With them, connectionless service with real-time QoS gua...
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Addressing the challenge of packet transmission in a wireless soft realtime system, we present five splitting protocols that take packet deadlines into account. With them, connectionless service with real-time QoS guarantees at the MAC layer can be offered. Three protocols are blocked access and two are free access algorithms. Mathematical models are developed and results compared with simulations. As is the case with non real-time splitting algorithms, the blocked access versions offer higher success rates than the free access versions. We further show that of the two best performing blocked access protocols, under moderate to heavy loads, the Sliding Partition CRA outperforms the Two Cell CRA.
作者：
Vardanega, TEuropean Space Agcy
Res & Technol Ctr Estec Spacecraft Control & Data Syst Div NL-2201 AZ Noordwijk Netherlands
In the development of on-board real-time systems an important proportion of critical requirements tends to consolidate at a late stage during the establishment of the physical model of the system. This reflects the pr...
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In the development of on-board real-time systems an important proportion of critical requirements tends to consolidate at a late stage during the establishment of the physical model of the system. This reflects the progressive adaptation of the logical model to the features of the execution environment. This phenomenon will be exacerbated by the urge to halve the duration of the development schedule while inflating the size and complexity of the software product. These demands may be accommodated by the provision of a design framework capable of supporting the parallel and incremental definition of the logical and physical model.
A quantitative tool is presented to perform program-level valuation of commercial aircraft designs. The algorithm used expands on traditional net present value methods through the explicit consideration of market unce...
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A quantitative tool is presented to perform program-level valuation of commercial aircraft designs. The algorithm used expands on traditional net present value methods through the explicit consideration of market uncertainty and the ability of the firm to react to such uncertainty through real-time decision making throughout the course of the aircraft program. The algorithm links three separate models, performance, cost, and revenue, into a system-level analysis by viewing the firm as a decision-making agent facing continuous choices between several different operating modes. An optimization problem is set up and solved using a dynamic programming approach to find a set of operating mode decisions that maximizes the firm's expected value from the aircraft project. The result is a quantification of value that can be used to make program-level design trades and to gain insight into the effects of uncertainty on a particular aircraft design. Examples are drawn from the blended-wing-body aircraft concept to demonstrate the operation of the program valuation tool.
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