• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.7
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• pp.1567-1574
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• 2012

Since a migration method of the mobile agent is a factor that affects the overall performance of the entire distributed system, it is necessary to find efficient migration methods of the mobile agent within the sensor network and to collect and store data related to various components(server, sink and sensor node) of the sensor network, thereby providing consistent naming services. Accordingly, this paper presents design and implementation of MetaTable that is divided into MetaData where information on the sensor data server is stored and SubMetaData where various types of information on sink nodes and data on sensor nodes connected with the sink nodes is stored. Moreover, the paper also presented the implementation of forward migration of an active rule mobile agent applying the naming method based on RMI that used the meta_table and proposed the possibility of constructing efficient sensor network application environment. In this paper, for registration, release and retrieval methods suitable for new sensor network environment, we designed and implemented the naming agent by applying J2EE model based on RMI-IIOP(Internet Inter-ORB Protocol) technique.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.2
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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.

• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.121-128
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• 2005

A RC column-bent pier represents one of the most popular piers used in highway bridges. Seismic performance of reinforced concrete (RC) column-bent piers under bidirectional seismic loadings was experimentally investigated. Six column bent-piers were constructed with two circular supporting columns which were made in 400 mm diameter and 2,000 mm height. One single column specimen was additionally made to comparatively evaluate the seismic response of RC column-bent piers. Test parameters are different transverse reinforcement and loading pattern. These piers were tested under lateral load reversals with the axial load of $0.1 f_{ck}A_g$. Three specimens were subjected to bidirectional lateral load cycles which consisted of two main longitudinal loads and two sub transverse loads in one load cycle. Other three specimens were loaded in the opposite way. Test results indicated that lateral strength and ductility of the latter three specimens were generally bigger than those of the former three specimens. Plastic hinges were formed with the spall of cover concrete and the fracture of the longitudinal reinforcing steels in the bottom plastic hinge of two supporting columns for the former three specimens. Similar behavior was observed in the top and bottom parts of two supporting columns for the latter three specimens.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.3
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• pp.87-95
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• 2018

Recently, with the technological development of artificial intelligence, related market is expanding rapidly. In the artificial intelligence technology field, which is still in the early stage but still expanding, it is important to reduce uncertainty about research direction and investment field. Therefore, this study examined technology trends using text mining and topic modeling among big data analysis methods and suggested trends of core technology and future growth potential. We hope that the results of this study will provide researchers with an understanding of artificial intelligence technology trends and new implications for future research directions.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05a
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• pp.591-594
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• 2003

본 논문에서는 hopfield 신경망을 사용한 다양한 부분적인 패턴 복원에 관하여 연구하였다. 여섯 개의 $32{\times}32$ 비트맵 훈련패턴들은 한글자음 ㄱ, ㅁ, ㅂ, ㅇ, ㅊ, ㅍ, 그리고 남자와 여자 이미지로 구성되어 있다. 그리고 부분패턴들의 크기, 범위, 방향의 효과를 알아보기 위해서 훈련패턴에서 여덟 가지 형태의 테스트 패턴을 만든다. 한글 자음의 경우 유사 패턴이 많기 때문에 완전히 복원되지 못하였으나, 400회 정도 수렵된 후에는 테스트패턴들이 견본패턴과 비슷한 모양으로 복원되었다. 이 유사도를 측정하기 위해 해밍거리 (Hamming distance)를 이용하였다. 유사도를 측정하여 해밍거리가 가장 적은 것으로 본래의 이미지들 복원하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.1 s.41
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• pp.17-24
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• 2005

Response of reinforced concrete (RC) column-bent piers subjected to bidirectional seismic loadings was experimentally investigated. RC column-bent piers represent one of the most popular shapes of piers used in Korea highway bridges. Four column-bent piers were constructed in 400 mm diameter and 2,000 mm height. Each pier has two circular supporting columns. These piers were tested under bidirectional lateral load reversals with an axial load of $0.1f_{ck}A_g$. The test parameters included : different transverse reinforcement contents and lap-spliced longitudinal reinforcing steels. Test results indicate that the lap splice of longitudinal reinforcing steels have significantly influenced on hysteretic response of column-bent piers similar to previous test results for single columns with corresponding test parameters. Column capacity was changed with the level of transverse confinement. From the comparison of test result for single column under unidirectional loading, the damage of single column was concentrated on lower plastic hinge region but the damage of column-bent piers was scattered to upper and lower plastic hinge region.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.1
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• pp.24-34
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• 2001

The authors reconstruct a mooring type underwater positioning system to measure the movement of bag-net in a set-net by long base line mode with four transponders attached on the bag-net in latitudinal and a transponder fixed on the sea bed. To confirm the practical use of the system, the field experiments were carried out at the Jaran Bay, Kosung, Kyungnam Prov., on October 6, 2000 (neap tide) and November 28, 2000 (spring tide). And the vertical oscillation of bag-net was observed with three data loggers attached on the bottom of bag-net in longitudinal on November 28, 2000. The longitudinal movement range, the latitudinal one and the vertical one of the bag-net were 3.2 m, 3.4 m and 2.1 m. respectively. At the spring tide, these variations were 7.8 m, 7.8 m and 5.0 m, respectively. The vertical oscillation range about the bottom of the bag-net at near point of the slope net, at the middle part and at far point from the slope net were 3.2 m, 3.7 m and 8.4 m, respectively. The depth of the bottom net was decreased and its vertical oscillation appeared frequently when the current speed was more than 10 cm/s and the current direction was significantly different from the longitudinal axis of the bag-net. The variation of hydrophone coordinates measured by the transponder fixed on the sea bed presents that hydrophones equipped to the frame line of the set-net could be moved within several meters due to the tidal current. The fact indicates that the compensation of hydrophone coordinates is necessary to reduce the measuring errors. The position measuring errors of x, y and z axis of the system measured in the cage of aquaculture were 0.6 m, 0.8 m, and 1.2 m, respectively. And the errors of the transponders those were close to the base lines or placed in the baselines were smaller than those of others.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.3 s.49
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• pp.47-55
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• 2006

Seismic performance and retrofit of reinforced concrete (RC) two-column piers widely used at roadway bridges in Korea was experimentally evaluated. Ten two-column piers that were 400 mm in diameter and 2,000 mm in height were constructed. These piers were subjected to hi-directional cyclic loadings under a constant axial load of $0.1f_{ck}A_g$. Test parameters were the confinement steel ratio, loading pattern, lap splice of longitudinal reinforcing bars, and retrofitting method. Specimens with lap-spliced longitudinal bars were retrofitted with steel jacket, pre-stressing steel wire, and steel band. Test result showed that while the specimens subjected to bi-directional lateral cyclic loadings which consisted of two main amplitudes in the transverse axis and two sub amplitudes in longitudinal axis, referred to as a T-series cyclic loadings, exhibited plastic hinges both at the top and bottom parts of the column, the specimens subjected to bi-directional lateral cyclic loadings in an opposite way, referred to as a L-series cyclic loadings, exhibited a plastic hinge only at the bottom of the column. The displacement ductility of the specimen under the T-series loadings was bigger than that of the specimen under the L-series loadings. Specimen retrofitted with pre-stressing steel wires exhibited poor ductility due to the upward shift of the plastic hinge region because of over-reinforcement, but specimens retrofitted with steel jacket and steel band showed the required displacement ductility. Steel band can be an effective retrofitting scheme to improve the seimsic performance of RC bridge piers, considering its practical construction.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.67-72
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• 2004

최근 건설산업은 공공 및 민간부문의 발주물량 감소가 가시화되고 있으며, 최저가입제에 의한 사업수익율 하락 추세는 향후 건설업 붕괴위기, 건설산업 사양산업화라는 비관적 견해가 떠돌 만큼 건설업 전반이 심각한 위기를 맞고 있다. 정부는 재정 부족으로 인하여 SOC사업의 축소조정이 불가피하지만 국가경제의 악영향 해소와 신속한 경쟁력 회복을 위해 SOC사업에 대한 투자확대와 푹소범위 최소화의 필요성을 인식하고 있으며, 이에 재정부족과 SOC 확충이라는 두가지 문제를 해격하기 위해 민간투자사업이 활성화되고 있는 실정이다. 현재, 정부에 의해 주도되고 있는 민간투자사업의 제도 및 법률의 개정방향은 피간 건설업체가 주도하던 민자사업에 대하여 연기금 및 금융권으로의 전환을 예고하고 있으나, 현실적으로 금융권이 자체적으로 SOC 사업에 대한 투자를 위한 사업 타당성 분석이 어려운 실정이므로 이에 대한 대안으로 SOC 민간투자사업에 대한 노하우를 축적한 건설업체의 SOC 민간투자사업 분야에 아웃소싱 개닐념 도입, 특화하여 효율성을 극대화 시킴으로써 사업의 안정성 확보와 동시에 투자 수익 실현을 통하여 SOC 민간투자 활성화에 견인차 역학을 할 수 있는 전문운영회사의 도입에 대하여 논하고자 한다.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.82-87
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• 2011

The pulp infection of primary tooth is often caused by dental caries or trauma. But, if it is not managed properly, it can be produce the periapical lesion. The periapical lesion can cause some complications such as enamel hypoplasia, displacement, root dilaceration and impaction. Treatment options of displaced permanent successor are clinical and radiological follow-up after extraction of primary teeth, surgical opening, orthodontic traction, transplantation and extraction. In these cases, the premolars with abnormal eruption path caused by periapical lesion of the primary tooth have shown successful spontaneous eruption just as a result of extraction of infected primary tooth and space maintenance.