• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.2
• /
• pp.488-494
• /
• 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.

• Journal of Digital Contents Society
• /
• v.13 no.3
• /
• pp.291-299
• /
• 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 Power Electronics
• /
• v.18 no.1
• /
• pp.137-146
• /
• 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.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2000.10a
• /
• pp.7-10
• /
• 2000

능동형 데이터베이스 시스템은 사용자가 정의한 rule의 집합이 해당 event 가 발생하는 순간 능동적으로 일련의 행위를 수행하도록 정의된 시스템이다. 그러나. 이처럼 서로 긴밀한 관계를 갖는 rule들이 능동적으로 수행되는 과정에 종료되지 않고 무한히 순환하여 수행하는 경우가 발생할 수 있다. 이처럼 무한히 순환하여 수행할 수 있는 가능성을 분석하는 것이 Termination Analysis 이다. 본 논문은 compile time 에 rule 의 termination 을 예측하는 방법에 대한 연구로, Java Language 를 rule definition language로 사용하며, composite event의 경우도 지원하도록 기존의 Termination analysis 방법을 확장하였다.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.12
• /
• pp.195-202
• /
• 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 Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.6
• /
• pp.115-122
• /
• 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
• /
• v.3 no.4
• /
• pp.49-54
• /
• 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.

• Journal of The Korean Astronomical Society
• /
• v.36 no.spc1
• /
• pp.7-12
• /
• 2003

We have studied the magnetic helicity of active regions by using the data from (1) the photo-electric magnetograph of the Okayama Observatory (1983-1995) and (2) the video magnetograph of NAOJ/Mitaka (1992-2000). The latitude distribution of helicity showed a tendency that the regions in the north (south) hemisphere have negative (positive) helicities, respectively, which is already known as the hemispheric sign rule. If we look into the sign of helicity as a function of time, the sign rule was less definite or was reversed sometimes in the sunspot minimum phase. We also studied the relation between the magnetic helicity and the sunspot tilt angles, and found that these two quantities are positively correlated, which is opposite to the expectation of a theoretical model. The implications of this cycle-phase dependence of helicity signs and the correlation between magnetic he Ii city and sunspot tilt angles are discussed.

• Transactions on Control, Automation and Systems Engineering
• /
• v.4 no.3
• /
• pp.212-216
• /
• 2002

A practical issue is studied to improve the performance of a new energy based method of achieving stable, high performance haptic interface control. The issue is related to resetting the amount of energy accumulated in the Passivity Observer for faster operation. A heuristic method is derived and experimentally tested for the resetting and it is shown to help the PC to operate sooner when the system gets active. Experimental results are presented for the “Excalibur” haptic device.

• The Journal of the Korea Contents Association
• /
• v.19 no.4
• /
• pp.12-29
• /
• 2019

The purpose of this study is to develop the scenario for implementation of the rule-based counseling chatbot and to verify its usefulness. For this purpose, counseling scenario for exploring problems triggering depression and establishing early counseling relationships was built and user evaluations for the rule-base counseling chatbot were conducted on 10 counseling psychologists. As a result, clear counseling structuring, appropriate use of selective and narrative responses, and active listening were identified as important components of counseling chatbot. To the next step, the usefulness of counseling chatbot developed in the previous step was examined with 78 college students. As a result, active listening was found to be an important factor in improving user satisfaction and positive mood change. In addition, through qualitative analysis of user evaluation, the unique advantages of counseling chatbot were identified and the limitations of counseling chatbot that should be overcome were identified. Based on the results of the study, the implications of the study and suggestions for future research were discussed.