• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.9
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• pp.1854-1866
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• 1997

This paper proposes a new test case generation technique for a nondeterministic finite state machine by improving the existing UIO sequence generation method. First, a new conformance relationis defined, which is one of prerequisites for automatic test case generation. Because fof the nondeterministic property of torpocols, the output of the systems under test is not known deterministically to the tester. Therefore, tree-like test case generation method is introduced for adaptive testing, in which the next input is selected after observing the previous output. Since the test cases are generated with regarding the inputs and outputs as separate events and are represented in tree notation, the test cases are easily converted into TTCN, the international standard test suite specification language.

• The KIPS Transactions:PartA
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• v.18A no.5
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• pp.177-180
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• 2011

In this paper, we present a record-replay technique based on interrupt logging and reproduction. Race conditions have been considered as the main source of nondeterminism in conventional record-replay approaches. However, interrupts are another source of nondeterministic computer system behavior, which must be reproduced at accurate time points, let alone the order of interrupt occurrence. We show that an interrupt-based replayer can be efficiently and effectively implemented by using hardware performance counters and debugging functionality. Experiments also show that the runtime overhead of the interrupt-based replayer is sufficiently low.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4307-4325
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• 2016

With the aim of solving the problems of long processing times, high memory consumption and low event throughput in the current processing approaches in out-of-order RFID event streams, an efficient complex event processing method based on INFA-HTS (Improved Nondeterministic Finite Automaton-Hash Table Structure) is presented in this paper. The contribution of this paper lies in the fact that we use INFA and HTS to successfully realize the detection of complex events for out-of-order RFID event streams. Specifically, in our scheme, to detect the disorder of out-of-order event streams, we expand the traditional NFA model into a new INFA model to capture the related RFID primitive events from the out-of-order event stream. To high-efficiently manage the large intermediate capturing results, we use the HTS to store and process them. As a result, these problems in the existing methods can be effectively solved by our scheme. The simulation results of our experiments show that our proposed method in this paper outperforms some of the current general processing approaches used to process out-of-order RFID event streams.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.10a
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• pp.485-491
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• 1998

이산사건 시스템은 시간의 이산순간에 상태변화가 발생하는 시스템으로서 공정제어, Robotics, 교통시스템, Flexible Manufacturing System, 통신등 많은 분야의 시스템이 이산사건 시스템들이지만 아직도 포괄적이고 융통성 있는 제어이론이 연구되지 않았다. 본 연구는 특히 Real-Time Temporal Logic Framework(RTTL)에서 비결정적으로 발생되어지는 확정적인 사건들로써 유발되어지는 비결정적 이산사건 시스템의 모델링 방법을 제시하였다. 이 방법을 두 개의 machine들로 구성된 Flexible Manufacturing System(FMS)에 적용하여 설명하였다. 이 방법은 복잡한 이산사건 시스템의 모델링을 모듈화하여 간편하게 표현 할 수 있는 우수한 특성을 가지고 있다.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.1_2
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• pp.41-50
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• 2004

Detecting races is important for debugging shared-memory Parallel programs, because races result in unintended nondeterministic executions of the programs. Particularly, the first races to occur in an execution of a program must be detected because they can potentially affect other races that occur later. Previous on-the-fly techniques that detect such first races based on candidate events that are likely to participate in the first races monitor access events in order to collect the candidate events during a program execution, and try to report the races only from determining the concurrency relationships of the candidates. Such races reported in this way. however, are not guaranteed to be first races, because they are not determined by taking into account how they are affected with each other. This paper presents a new post-mortem technique that analyzes, on each nesting level, candidate events collected from an execution of a shared-memory program with nested parallelism in order to report only first races. This technique is efficient, because it guarantees that first races reported by analyzing a nesting level are the races that occur first at the level, and does not require more analyses to the higher nesting levels than the current level. The Proposed technique facilitates more practical and effective debugging than the previous techniques, because it guarantees to detect first races if candidate events are collected from an execution instance of the program with nested parallelism.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.989-997
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• 2018

Massive event stream brings us great challenges in its volume, velocity, variety, value and veracity. Picking up some valuable information from it often faces with long detection time, high memory consumption and low detection efficiency. Aiming to solve the problems above, an efficient complex event detection method based on NFA_HTS (Nondeterministic Finite Automaton_Hash Table Structure) is proposed in this paper. The achievement of this paper lies that we successfully use NFA_HTS to realize the detection of complex event from massive RFID event stream. Specially, in our scheme, after using NFA to capture the related RFID primitive events, we use HTS to store and process the large matched results, as a result, our scheme can effectively solve the problems above existed in current methods by reducing lots of search, storage and computation operations on the basis of taking advantage of the quick classification and storage technologies of hash table structure. The simulation results show that our proposed NFA_HTS scheme in this paper outperforms some general processing methods in reducing detection time, lowering memory consumption and improving event throughput.

• Journal of KIISE:Software and Applications
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• v.27 no.4
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• pp.370-383
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• 2000

This paper describes a new technique known as specification-based regression testing that is used for the revalidation of concurrent programs after changes are made to specifications. This type of regression testing requires sequencing constraint that specify precedence relations on the synchronization events. In order to extract sequencing constraint automatically, we use Message Sequence Charts(MSCs) that are considered partial and nondeterministic specifications. We show how to identify which sequencing constraint is affected by the modifications made to a specification rather than creating new sequencing constraint from scratch to reduce the cost of regression testing. We also describe how to determine that each affected sequencing constraint is satisfied by a program being tested.