RVERL: Run-time Verification of Real-time and Reactive Programs using Event-based Real-Time Logic Approach

2007 ◽  
Author(s):  
Saeed Jalili ◽  
Mehdi MirzaAghaei
Keyword(s):  
Real Time ◽  
Time Logic ◽  
Logic Approach ◽  
Run Time ◽  
Event Based ◽  
Reactive Programs

AN EVENT-BASED REAL-TIME LOGIC FOR THE SPECIFICATION AND ANALYSIS OF REAL-TIME SYSTEMS

1993 ◽  
Vol 02 (01) ◽  
pp. 71-91 ◽  
Author(s):  
HORNG-YUAN CHEN ◽  
JEFFREY J.P. TSAI ◽  
YAODONG BI
Keyword(s):  
Real Time ◽  
Temporal Logic ◽  
Programming Language ◽  
Target System ◽  
Real Time Systems ◽  
Testing And Debugging ◽  
Time Logic ◽  
Prolog Programming ◽  
Event Based ◽  
Time Systems

Research on real-time systems now focuses on formal approaches to specify and analyze the behavior of real-time systems. Temporal logic is a natural candidate for this since it can specify properties of event and state sequences. However, “pure” temporal logic cannot specify “quantitative” aspect of time. The concepts of eventuality, fairness, etc. are essentially “qualitative” treatment of time. The pure temporal logic makes no reference to absolute time. For real-time systems, the pure qualitative specification and analysis of time are inadequate. In this paper, we present a modification of temporal logic—Event-based Real-time Logic (ERL), based on our event-based conceptual model. The ERL provides a high-level framework for specifying timing properties of real-time systems, and it can be implemented using Prolog programming language. In our approach to testing and debugging of real-time systems, the ERL is used to specify both expected behavior (specification) and actual behavior (execution traces) of the target system and to verify that the target system achieves the specification. In this paper, a method is presented to implement the ERL using Prolog programming language for testing and debugging real-time systems.

scholarly journals Comparison of Searching Behaviour of Three Evolutionary Algorithms Applied to Water Distribution System Design Optimization

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 695 ◽  
Author(s):  
Weiwei Bi ◽  
Yihui Xu ◽  
Hongyu Wang
Keyword(s):  
Evolutionary Algorithms ◽  
Real Time ◽  
Distribution System ◽  
Optimization Design ◽  
Distribution Systems ◽  
Water Distribution ◽  
Optimal Solutions ◽  
Great Ability ◽  
Searching Behaviour ◽  
Run Time

Over the past few decades, various evolutionary algorithms (EAs) have been applied to the optimization design of water distribution systems (WDSs). An important research area is to compare the performance of these EAs, thereby offering guidance for the selection of the appropriate EAs for practical implementations. Such comparisons are mainly based on the final solution statistics and, hence, are unable to provide knowledge on how different EAs reach the final optimal solutions and why different EAs performed differently in identifying optimal solutions. To this end, this paper aims to compare the real-time searching behaviour of three widely used EAs, which are genetic algorithms (GAs), the differential evolution (DE) algorithm and the ant colony optimization (ACO). These three EAs are applied to five WDS benchmarking case studies with different scales and complexities, and a set of five metrics are used to measure their run-time searching quality and convergence properties. Results show that the run-time metrics can effectively reveal the underlying searching mechanisms associated with each EA, which significantly goes beyond the knowledge from the traditional end-of-run solution statistics. It is observed that the DE is able to identify better solutions if moderate and large computational budgets are allowed due to its great ability in maintaining the balance between the exploration and exploitation. However, if the computational resources are rather limited or the decision has to be made in a very short time (e.g., real-time WDS operation), the GA can be a good choice as it can always identify better solutions than the DE and ACO at the early searching stages. Based on the results, the ACO performs the worst for the five case study considered. The outcome of this study is the offer of guidance for the algorithm selection based on the available computation resources, as well as knowledge into the EA’s underlying searching behaviours.

A Fast 3-D Visualization Methodology Using Characteristic Views of Objects

1998 ◽  
Vol 08 (01) ◽  
pp. 97-114 ◽  
Author(s):  
Soochan Hwang ◽  
Sang-Young Cho ◽  
Taehyung Wang ◽  
Phillip C.-Y. Sheu
Keyword(s):  
Finite Number ◽  
Real Time ◽  
Time Complexity ◽  
Object Oriented ◽  
Equivalence Classes ◽  
Visualization Method ◽  
Tree Algorithm ◽  
Projected Image ◽  
Characteristic Views ◽  
Run Time

This paper describes a 3-D visualization method based on the concept of characteristic views (CVs). The idea of characteristic views was derived based on the observation that the infinite possible views of a 3-D object can be grouped into a finite number of equivalence classes so that within each class all the views are isomorphic in the sense that they have the same line-junction graphs. To visualize the changes of scenes in real time, the BSP tree algorithm is known to be efficient in a static environment in which the viewpoint can be changed easily. However, if a scene consists of many objects and each object consists of many polygons, the time complexity involved in traversing a BSP tree increases rapidly so that the original BSP tree algorithm may not be efficient. The method proposed in this paper is object-oriented in the sense that, for all viewpoints, at the preprocessing stage the ordering for displaying the objects is determined. At run time, the objects are displayed based on a pre-calculated ordering according to the viewpoint. In addition, a CV is used as a basic 2-D projected image of a 3-D object.

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