• Journal of the Korea Society for Simulation
• /
• v.17 no.3
• /
• pp.75-83
• /
• 2008

A deadlock is a condition in which the excessive demand for the resources being used by others causes activities to stop and it is one of the important problems in process control system to detect and prevent deadlocks. While the reachability analyze methods or divide subnets for analyzing methods are well used, it requires a lot of times and effects to analyze the detection of the deadlock status. Furthermore, it could not be effective if the model is complex or huge. Therefore, it is necessary to develop a new and more efficient deadlock detection algorithm. In this paper, a deadlock detection conditions after analyzed the Petri Net using the transitive matrix has been proposed to solve these problems. For presenting the results, the suggested deadlock detection algorithm was also adapted to an illustrated FMS (Flexible Manufacturing System) model.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06a
• /
• pp.425-427
• /
• 2012

본 논문에서는 상황인지 시스템에서 규칙들간에 발생하는 충돌을 실행 이전에 탐지하기 위한 기법을 소개한다. 사용자가 새로운 규칙을 입력하면, 이벤트, 조건, 액션 정보를 단계적으로 분석하여, 동일한 이벤트가 상이한 서비스를 요구하는 규칙들을 탐지한다. 이는 실행 중에 발생되는 충돌을 감소시킴으로써, 동적 충돌 탐지 및 해결 대상을 감소시킨다. 제안된 기법은 규칙 기반 상황인지 미들웨어 상에 구현되었다.

• Journal of Korean Institute of Industrial Engineers
• /
• v.20 no.1
• /
• pp.53-69
• /
• 1994

Deadlock in flexible manufacturing systems (FMS) which refers to the stop state of job flow in the system can be commonly occurred in operating FMS. This state mainly due to bad movements of jobs and commonly job routings should be avoided to maximize the utilization of high-capital resources in this study, the deadlock generated from the conflict between flow objects competing to occupy space resources in FMS is investigated. Capacity Designated Directed Graph (CDG) is constructed to represent the space resources and flow object routings. From the characteristics of CDG, an algorithm for the detection of the deadlock possibility is proposed. Finally two deadlock avoidance rule are proposed and implemented in the control on Automated Guided Vehicle system in an FMS.

• Journal of Environmental Impact Assessment
• /
• v.3 no.1
• /
• pp.69-76
• /
• 1994

Environmental impact assessment methodology using geographical information systems (GIS) technologies is described. Brief characteristics of experience for evaluation of consequences of mineral fertilizers use in the Moscow region as well as authors' experience for detection of urban ecologically conflict territories (in Kirovsk and Apatity. Murmansk region, Subpolar Aretic). Possibilities of expert systems use for environmental impact assessment are demonstrated.

• Journal of Information Processing Systems
• /
• v.6 no.3
• /
• pp.375-384
• /
• 2010

Trajectory modeling is foundational for 4D-Route modeling, conflict detection and air traffic flow management. This paper proposes a novel algorithm based Vincenty's fomulas for trajectory calculation, combined with the Dijkstra algorithm and Vincenty's formulas. Using flight plan simulations our experimental results show that our method of En-route trajectory calculation exhibits much improved performance in accuracy.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.1159-1164
• /
• 2005

현재 철도청이 운용중인 열차운행관리 시스템(Railway Traffic Management System, RTMS)은 서울, 대전, 부산, 순천 그리고 영주 등으로 총 5개 지역본부로 분산되어 있어 업무의 중복을 줄이고, 자동화(Automation)된 열차집중제어장치(Central Traffic Control, CTC)를 구축하기 위해 지역본부를 대전으로 통합하는 프로젝트를 진행중이다. 본 논문은 철도청 사령실 통합 신호설비 구축 프로젝트에 의거하여 열차 경합을 검지 또는 예측하고 운영자에게 최소의 시간 내에 최적의 해소 대책을 제시함을 목적으로 하는 열차 경합 검지 시스템을 구현하는 과정에서 작성되었다. 여기에서는 열차 경합 검지에 대한 개요와 검지 가능한 경합 종류에 대해 기술하고, 실제 구현된 알고리즘의 기본적인 내용, 프로세스의 구성도 및 시뮬레이션 결과를 설명하려고 한다.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1466-1474
• /
• 2007

In large station with high density traffic, trains is hardly controlled by CTC but by station dispatcher because CTC has difficulties in monitoring all states of affairs happening within the station such as departs and arrivals of many trains from different lines and shunting trains between yards and platforms, etc. Therefore station dispatcher has to make quick decision about how to schedule all trains including trains to arrive and depart before long. And such decisions become harder when an unexpected delay occurs. This study suggests a mathematical model and algorithm about how to detect in advance and resolve efficiently the conflicts occurring within a station and it will be shown how to reduce delay using our approach by means of analysing the schedule of ChyungRyangRi station.

• Journal of Advanced Navigation Technology
• /
• v.16 no.1
• /
• pp.122-130
• /
• 2012

Airborne separation assurance is a key requirement for Free Flight. This paper is to propose autonomous flight algorithm, such as extended authority of delegation, efficiency of airspace issue to deal with the empirical solution for free flight, and to measure flight efficiency and conflict detection and resolution (CD&R) by utilizing flight performance data under the two circumstances of scenario with the modeling of proposed algorithm and potential field algorithm. The results show that the autonomous flight algorithm is superior to the potential field algorithm under the circumstances of free flight airspace in terms of algorithm performance, CD&R, and flight efficiency.

• Journal of Information Technology Services
• /
• v.6 no.2
• /
• pp.177-188
• /
• 2007

Policy-based Network Management (PBNM) has been presented as a paradigm for efficient and customizable management systems. The approach chosen is based on PBNM systems, which are a promising and novel approach to network management. These systems have the potential to improve the automation of network management processes. The Internet Engineering Task Force (IETF) has also used policy concepts and provided a framework to describe the concept as the Policy Core Information Model (PCIM) and its extensions. There are policy conflicts among the policies that are defined as the policy information model and they are not easily and effectively detected and resolved. In this paper, we present the brief description of PBNM and illustrate the concepts of policy core information model and its policy implementation for a network security. Especially we describe our framework for detecting and resolving the policy conflicts for network security.

• International Journal of Aeronautical and Space Sciences
• /
• v.14 no.3
• /
• pp.272-281
• /
• 2013

Traffic Collision Avoidance System (TCAS) is designed to enhance safety in aircraft operations, by reducing the incidences of mid-air collision between aircraft. The current version of TCAS provides only vertical resolution advisory to the pilots, if an aircraft's collision with another is predicted to be imminent, while efforts to include horizontal resolution advisory have been made, as well. This paper introduces a collision resolution algorithm, which includes both vertical and horizontal avoidance maneuvers of aircraft. Also, the paper compares between the performance of the proposed algorithm and that of algorithms with only vertical or horizontal avoidance maneuver of aircraft.