• Journal of Computing Science and Engineering
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• 제9권1호
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• pp.9-19
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• 2015

The most important challenge in the region-based abstraction method as an approach to compute the state space of time Petri Nets (TPNs) for model checking is that the method results in a huge number of regions, causing a state explosion problem. Thus, region-based abstraction methods are not appropriate for use in developing practical tools. To address this limitation, this paper applies a modification to the basic region abstraction method to be used specially for computing the state space of TPN models, so that the number of regions becomes smaller than that of the situations in which the current methods are applied. The proposed approach is based on the special features of TPN that helps us to construct suitable and small region graphs that preserve the time properties of TPN. To achieve this, we use TPN-TCTL as a timed extension of CTL for specifying a subset of properties in TPN models. Then, for model checking TPN-TCTL properties on TPN models, CTL model checking is used on TPN models by translating TPN-TCTL to the equivalent CTL. Finally, we compare our proposed method with the current region-based abstraction methods proposed for TPN models in terms of the size of the resulting region graph.

• 한국항행학회논문지
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• 제1권1호
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• pp.70-80
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• 1997

본 논문에서는 CDMA 이동전파 환경에서 두 가지 비동기식 동기 추적 회로 즉, TCTL과 MCTL의 성능을 비교, 분석한다. 먼저, 두 가지 방식에 대해 안정 상태에서의 지터 분산을 펄스 성형 필터, 타이밍 오프셋, 신호 대 잡음 비 및 루우프 대역폭의 함수로 이론적으로 유도한다. 또한, 루우프 필터의 설계 방법에 대해 2차 동기 추적회로를 중심으로 고찰한다. 끝으로, 동기 추적 오차에 의한 BER 성능 저하를 ETRI 에 의해 IMT-2000용으로 설계된 CDMA 시스템의 역방향 링크에 대해 분석한다.