• Journal of Institute of Control, Robotics and Systems
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• v.16 no.1
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• pp.25-32
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• 2010

The paper proposes a hierarchical fault detection method for the high voltage equipment using a microphone array which detects the location of fault and the thermal imaging and CCD cameras which verifies the fault and stores the image, respectively. There are partial arc discharges on the faulty insulators, which generates a specific pattern of sound. Detecting the signal using the microphone array, the location of the faulty insulator can be estimated. The 6th band-pass filter was applied to remove noise signal from wind or external influence. When the mobile robot carries the thermal and CCD cameras to the possible place of the fault insulator, the fault insulators or power transmission wires can be detected by the thermal images, which are caused by the aging or natural erosion. Finally, the CCD camera captures the image of the fault insulator for the record. The detection scheme of fault location using the microphone array and the thermal images have been proved to be effective through the real experiments. As a result of this research, it becomes possible to use a mobile robot with the integrated sensors to detect the fault insulators instead of a human being.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.121-126
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• 2004

An efficient multi face detection technique is proposed based on hierarchical context-free attention operators in which multiple faces are efficiently detected from a noisy and complex background. A noise-tolerant generalized symmetry transform (NTSGT) is applied hierarchically, as a context free attention operator, to the input pyramidal image for the high speed global location of the regions of face candidates (ROFCs) with a single mask. For the face verification, local NTGST is applied within each ROFC to confirm the existence of the detailed facial features. First, by globally applying NTGST which introduces the average pyramid method and focusing to the input image with complex background, ROFCs with recognizable resolution are detected robustly. Morphological operations are applied only to the each detected ROFCs to emphasize the facial features like eyes and lips. Then, eyes are detected by locally appling NTGST to the ROFCs and only faces are detected by verifying the existence of the geometrical features of the faces relatively to the location of eyes. The experimental results show that the proposed method can efficiently detect multiple faces from a noisy or complex background with 93.5% detection rate.

• Journal of the Korea Society of Computer and Information
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• v.10 no.1 s.33
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• pp.201-208
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• 2005

Recently, the container terminal requires the study of method to increase efficiency through change of its operation method. Loading plan is a very important part to increase the efficiency of container terminal. Loading Plan is largely divided into two cases, deciding loading location and loading scheduling and this Paper proposes a more efficient method of container loading scheduling. Container loading scheduling is a problem of combination optimization to consider several items of loading location and operation equipments. etc. An existing method of cluster composition that decides the order of container loading scheduling has a restriction to increase the efficiency of work owing to rehandling problem. Therefore, we Propose a more efficient method of container loading scheduling which composes containers with identical attribution, based on ship loading list and yard map, into stack units of cluster, applying to hierarchical clustering method, and defines the restriction of working order. In this process, we can see a possible working path among clusters by defining the restriction of working order and search efficiency will be increased because of restricted search for working path.

• Journal of KIISE:Software and Applications
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• v.36 no.12
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• pp.1028-1033
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• 2009

This paper presents a real-time hand gesture recognition approach for controlling a computer. We define hand gestures as continuous hand postures and their movements for easy expression of various gestures and propose a Two-layered Bayesian Network (TBN) to recognize those gestures. The proposed method can compensate an incorrectly recognized hand posture and its location via the preceding and following information. In order to vertify the usefulness of the proposed method, we implemented a Virtual Mouse interface, the gesture-based interface of a physical mouse device. In experiments, the proposed method showed a recognition rate of 94.8% and 88.1% for a simple and cluttered background, respectively. This outperforms the previous HMM-based method, which had results of 92.4% and 83.3%, respectively, under the same conditions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4B
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• pp.424-434
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• 2004

Ubiquitous network consists of various devices using several heterogeneous protocols and requires seamless communication between devices. This paper proposes a new hierarchical event service and multiple event server architecture to implement the service under ubiquitous environment. The proposed event service classifies devices by logical and physical location to abstract the idiosyncrasy of used protocols, and reduces network load. Due to the design consideration, the proposed architecture removes transfer of duplicated event data effectively. As a result, we can guarantee the reliable event delivery. The prototype multiple event server architecture was implemented according to the proposed idea and evaluated its performance under a home network test bed.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.5
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• pp.457-461
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• 2008

Previous studies on overlay ad hoc multi-casting are mainly divided into two categories: hierarchical structure-based multicast schemes and non-hierarchical structure-based multicast schemes. They do not reflect their real-time location information for routing updates. This can be a cause of low performance on energy consumption, throughput, and latency. For improving the problems, we propose an implicit cluster based overlay ad hoc multicast scheme with analysis of related work, and then we evaluate performance through computer simulation.

• Journal of Navigation and Port Research
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• v.45 no.2
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• pp.54-60
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• 2021

The aim of this study is to determine the critical factors and construction requirements for a new deep-water seaport system in the Lach Huyen area in northern Vietnam. In this study, the Analytic Hierarchical Process (AHP ) method was used to evaluate the importance of the criteria and subcriteria. The results were as follows: the principal criterion "geographical location (0.151)" ranked as the most important criterion for building a new deep-water port system, which is affected by the subcriteria "direct sea route with mega-vessel" and "good liner connectivity index". The principal criterion "port competency (0.145)" ranked second; thus, it can be concluded that good competitiveness of a port' will provide many benefits to the port and the region. Regarding the implication, the established evaluation framework can be used for port construction to make a more reasonable judgment. In a future study, the scope of evaluation factors should be widened, involving participation of broader stakeholders, such as shipping companies, forwarders, and logistics companies.

• Journal of Industrial Convergence
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• v.19 no.1
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• pp.7-15
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• 2021

The purpose of this study is to investigate factors affecting conflict of teachers in school. Researchers selected independent variables in personal, school, and local levels and analyzed their influence on conflict of faculty and staff, students and parents, and educational policy. We used 561 survey responses of teachers working in S City Office of Education and conducted hierarchical multiple regression analysis using SPSS 24.0. For results, we found out that variables such as career in the level of person, homeroom teacher and status in the level of school, and location in the level of region were statistically significant. Researchers suggested possible solutions which can be considered by school district and school officials.

• Annual Conference of KIPS
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• 2007.11a
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• pp.1073-1076
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• 2007

HMIPv6 (Hierarchical Mobile IPv6)는 MAP (Mobility Anchor Point)을 이용하여 이동노드를 효율적으로 관리하는 방안을 제시하였다. MAP 에 걸리는 부하는 HMIPv6 로 구성된 네트워크에 진입한 이동노드가 어느 MAP 을 선정하느냐에 따라 달라진다. MAP 을 선정하는 방법으로 이동노드의 이동속도나 MAP 과 이동노드의 거리를 고려하여 선택하는 방법 등이 연구되었다. 하지만 이들은 각각 이동속도 측정을 위한 추가적인 비용이 발생하거나 특정 MAP 에 몰리는 현상을 효과적으로 해결하지 못하는 문제점이 있다. 본 논문은 HMIPv6 로 구성된 네트워크에서 네트워크 관리지역의 중앙부분을 지나는 이동노드가 바깥부분을 지나는 이동노드보다 해당 네트워크에 오래 머무른다는 사실에 착안하여 지역정보 기반의 MAP 선정기법을 제안한다. 제안하는 기법은 우선 네트워크 관리지역 내에 분포된 MAP 들을 지역정보에 기반하여 계층적으로 구성한다. 그 다음, 중앙부분을 지나는 이동노드에게 보다 넓은 지역을 담당하는 높은 레벨의 MAP 을 선정하고 바깥부분을 지나는 이동노드에게 보다 좁은 지역을 담당하는 낮은 레벨의 MAP 을 선정한다. 이로써 전체적으로 발생하는 바인딩 업데이트 비용을 줄이고 MAP 의 로드밸런싱 효과를 얻는다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11B
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• pp.960-968
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• 2006

HMIPv6 improved the handover management of basic MIPv6 by introducing the new protocol agent MAP. In this new protocol, MAP instead of the Mobile Node intercepts all packets and redirects the packets to CoA of the Mobile Node. However, this process may degrade the network performance due to the centralization phenomenon of registration occurring in the hierarchical MAP structure. ffe propose two schemes to improve real time traffic performance. First proposal is a MAP selection mettled in which MAP is selected based on traffic characteristics. And we also propose differentiated traffic processing scheme with multi-level queues when Home Agent or Correspondent Nodes process Binding Update messages. Performances of the proposed scheme are analyzed. Analysis result shows that our model has good performance in the respect of location update cost and total cost of Mobile Nodes.