• Journal of KIISE:Software and Applications
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• 제26권12호
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• pp.1393-1403
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• 1999

공간 데이타베이스 시스템을 통하여 공유되는 공간 데이타는 무결성이 적절하게 유지되지 않는 한 전체 응용 시스템의 행위를 예측할 수 없게 되므로 데이타의 무결성 확인 및 유지는 필수적이다. 특히 공공 GIS에 저장된 공간 데이타는 토지 이용도 평가, 도시 계획, 자원 관리, 시설물 관리, 안전 관리, 국방 등 국가 전체 및 지역의 중요한 정책 결정을 위한 다양한 응용 시스템들에 의해 이용되므로 적절한 공간 객체의 무결성 확인이 더욱 더 필요하다. 본 논문에서는 능동(active) DBMS의 능동 규칙(active rule) 기법을 이용하여 공간 객체의 무결성 확인을 지원하기 위한 규칙 관리 시스템을 제시한다. 능동 규칙을 이용한 공간 객체의 무결성 확인은 응용 프로그래머를 무결성 확인에 대한 부담으로부터 자유롭게 할 수 있다. 본 시스템은 특정 DBMS에 종속되지 않는 독립적인 외부 시스템으로 존재하며, 능동 규칙 관리기, 규칙 베이스, 그리고 활성규칙 생성기의 3 부분으로 구성된다. 사용자가 공간 데이타베이스 응용 프로그램을 통해 공간 객체를 조작하고자 할 때, 본 시스템은 데이타베이스 트랜잭션을 단위로 조작되는 모든 공간 객체의 무결성 확인을 위해 응용 프로그램에 삽입될 무결성 제약조건 규칙들을 효율적으로 관리하는 역할을 한다.Abstract It is necessary that the integrity of spatial data shared through the spatial database system is validated and appropriately maintained, otherwise the activity of whole application system is unpredictable. Specially, the integrity of spatial data stored in public GIS has to be validated, because those data are used by various applications which make a decision on an important policy of the region and/or whole nation such as evaluation of land use, city planning, resource management, facility management, risk management/safety supervision, national defense. In this paper, we propose rule management system to support validating the integrity of spatial object, using the technique of active rule technique from active DBMS. Validating data integrity using active rules allows database application programmer to be free from a burden on validation of the data integrity. This system is an independent, external system that is not subject to specific DBMS and consists of three parts, which are the active rule manager, the rule base, and the triggered rule generator. When an user tries to manipulate spatial objects through a spatial database application program, this system serves to efficiently manage integrity rules to be inserted into the application program to validate the integrity constraints of all the spatial objects manipulated by database transactions.

• Journal of the Korea Institute of Military Science and Technology
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• 제14권1호
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• pp.123-131
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• 2011

In this paper, modeling and design of a distributed detection system are considered for an active sonar sensor network. The sensor network has a parallel configuration and it consists of a fusion center and a set of receiver nodes. A system with two receiver nodes is considered to investigate a theoretical aspect of design. To be specific, AND rule and OR rule are considered as the fusion rules of the sensor network. For the fusion rules, it is shown that a threshold rule of each sensor node has uniformly most powerful properties. Optimum threshold for each sensor is obtained that maximizes the probability of detection given probability of false alarm. Numerical experiments were also performed to investigate the detection characteristics of a distributed detection system with multiple sensor nodes. The experimental results show how signal strength, false alarm probability, and the distance between nodes in a sensor field affect the system detection performances.

• Journal of Digital Contents Society
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• 제13권3호
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• pp.291-299
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• 2012

Ubiquitous computing is a technique to provide users with appropriate services, collecting the context information in somewhere by attached sensor. An intelligent system needs to automatically update services according to the user's various circumstances. To do this, in this paper, we propose a design of context ontology, trigger rule for mining service pattern related to users activity and an active mining architecture integrating trigger system. The proposed system is a framework for active mining user activity and service pattern by considering the relation between user context and object based on trigger system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제24권6호
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• pp.115-122
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• 2010

The main purpose of centralized monitoring system is to manage factory electrical installation efficiently by on-line data acquisition and supervisory control. The existing centralized system is only able to be managed by operator whenever electrical installation's faults are detected. Therefore, it may be possible for propagating the installation's faults when operator make the unexpected mistakes. To overcome the unexpected mistakes, in this paper, the author presents a centralized monitoring system for factory electrical installation using active database. by using active database production rule, stated system can minimize unexpected mistake and can operate centralized monitoring system efficiently. Test results on the five factory electrical installations show that performance is efficient and robust.

• Journal of the Korea Society of Computer and Information
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• 제25권12호
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• pp.195-202
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• 2020

The control system for the efficiency of resource utilization in sensor network environment based on object detection and environmental sensor requires active control function which based on sensor data acquisition and transmission functions and server's data analysis. Using active rule-based mobile agent middleware, this paper proposes a new distributed control framework that reduces the load of central sensor data server in sensor network environment by implementing remote data sensing and Zigbee-based communication with server and data analysis method of server. In addition, we implemented a power-saving system prototype using active rule-based distributed control methods that applied consumer's demand and environmental variables, and verified the validity of the proposed system through experiments and evaluations in the mobile agent middleware environment. The proposed system is a system framework that can efficiently autonomously control distributed objects in the sensor network environment, and it can be applied effectively to the development of demand response service based on optimal power control for the smart power system in the future.

• Journal of the Korea Society of Computer and Information
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• 제3권4호
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• pp.49-54
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• 1998

AS it takes a considerable time for database operations for processing the condition part of active rule, the operations have an important effect on the efficiency of active database system. The processing time of operations should be minimized in order to improve the efficiency of system. The previous works are limited to basic database operations and the partial aggregate functions. In this paper, the processing technique using the structuralization and the state table of relations is suggested. The processing time for basic database operations can be reduced with the structuralization of relations to classification tree and the introduction of deletion information table. With the introduction of binary search tree and relation state table, the aggregate function which has a big of processing cost can be processed effectively and the function of the active database system can be maximized.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 한국윤활학회 2001년도 제34회 추계학술대회 개최
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• pp.316-321
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• 2001

The paper presents the unbalance response of a rotor-bearing system supported by an active control bearing. The proportional, derivative and integral controls are employed for the control algorithm of an active control bearing to suppress the unbalance response of a rotor-bearing system. Results of analytical investigations on the unbalance responses of a rotor supported by an active control bearing are presented for various control gains. It is found that the unbalance response of a rotor can be greatly suppressed by the proportional, derivative or integral control of the bearing. The proportional control is more effective than the derivative control at low rotational speed, and the derivative control is more effective than the proportional control at high rotational speed. In the case of the integral control of the bearing , the unbalance response of a rotor is increased as a general rule. However, the integral control of the bearing is extremely superior to proportional or derivative control at very low rotational speed.

• Tribology and Lubricants
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• 제18권2호
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• pp.99-104
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• 2002

The paper presents the unbalance response of a rotor-bearing system supported by an active control bearing. The proportional, derivative and integral controls are investigated fur the control algorithm of an active control bearing to suppress the unbalance response of a rotor-bearing system. Results of analytical investigations on the unbalance responses of a rotor supported by an active control bearing are presented for various control gains. It is found that the unbalance response of a rotor can be greatly suppressed by the proportional, derivative or integral control of the bearing. The proportional control is more effective than the derivative control at low rotational speed, and the derivative control is more effective than the proportional control at high rotational speed. In the case of the integral control of the bearing, the unbalance response ova rotor is increased as a general rule. However, the integral control of the bearing is extremely superior to proportional or derivative control at very low rotational speed.

• Journal of Power Electronics
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• 제18권1호
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• pp.137-146
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• 2018

This paper describes a single pulse-width modulation control strategy using the Single Pulse-Width Modulation (SPWM) method with a soft-switching technique for a wide range of output voltages from a bidirectional Dual-Active Bridge (DAB) converter. This method selects two typical inductor current waveforms for soft-switching, and proposes a rule that makes it possible to achieve soft-switching without any compensation algorithm from the waveforms. In addition, both the step-up and step-down conditions are analyzed. This paper verifies that the leakage inductance is independent from the rule, which makes it easier to apply in DAB converters. An integrated algorithm, which includes step-up and step-down techniques, is proposed. The results of experiments conducted on a 50-kW prototype are presented. The system efficiency is experimentally verified to be from 85.6% to 97.5% over the entire range.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제17권2호
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• pp.488-494
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• 2013

For the activeness and autonomy of a sensor network, the efficient migration method of a mobile agent and the consistent naming services are the required components of a sensor network. Accordingly, this paper presented the implementation of backward migration of an active rule mobile agent applying the naming method based on RMI that used the meta_table including the informations about the components of a sensor network. This study implemented based on the extension of the forward migration[12], and the results of the various experiments present the efficacy of mobile agent middleware system and the possibility of constructing efficient sensor network application environment. And, the results of this study are able to enhance the adaptability on dynamic changes of environment in sensor network application development.