• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1999년도 KOBA 방송기술 워크샵 KOBA Broadcasting Technology Workshop
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• pp.97.1-102
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• 1999

This paper porposes and efficient coding scheme for remote medical communication systems, or“telemedicine systems”. These systems require a technique which is able to transfer large volume of data such as X-ray images effectively. We have already developed a hierarchical image coding and transmission scheme (HITS), which achieves an efficient transmission of medical images simply[1]. In this paper, a new coding scheme for HITS is proposed, which used hierarchical context modeling for the purpose of improving the coding efficiency. The hierarchical context modeling divides wavelet coefficients into several sets by the value of a correspondent coefficient in their higher class, or“a parent”, optimizes a Golomb-Rice (GR) code parameter in each set, and then encodes the coefficients with the parameter. Computer simulation shows that the proposed scheme is effective with simple implementation. This is due to fact that a wavelet coefficient has dependence on its parent. As a result, high speed data transmission is achieved even if the telemedicine system consists of simple personal computers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.584-587
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• 1995

Recent development in the digital relay technology has introduced the adaptive relaying system which adopts the relays to the current operating states. This paper proposes the hierarchical digital protection system whose design has been based on 154 kV S/S. Applying the newest communication networking, the system provides the new protection capabilities improving the system reliability and speed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권3호
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• pp.997-1010
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• 2014

Today, as the hierarchical cellular system is getting more attention than before, some recent studies introduce delay based admission control (AC) scheme which delays the admission to the macro-embedded small cell for a relatively short time to prevent unnecessary handover caused by the short-term visitors of the small cell area. In such delay based ACs, when we use improper delay parameter, the system frequently makes incorrect handover decisions such as where unnecessary handover is allowed due to too short delaying, or where necessary handover is denied due to too long delaying. In order to avoid these undesirable situations as much as possible, we develop a new delay parameter decision method based on probabilistic cell residence time approximations. By the extensive numerical and analytical evaluations, we determine the proper delay parameter which prevents the incorrect handover decision as much as possible. We expect our delay parameter decision method can be useful system administration tips in hierarchical cellular system where delay based AC is adopted.

• 한국항행학회논문지
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• 제12권6호
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• pp.598-603
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• 2008

릴레이 시스템은 차세대 무선통신시스템에서 고속하향통신과 서비스 커버리지 확장을 실현하기 위한 주요 기술이다. 본 논문에서는 직교주파수다중화변조 기반에서 계층변조를 사용하는 릴레이 시스템을 위한 효율적인 전송방식을 제안한다. 본 전송방식은 기지국 전력의 큰 증가 없이 셀 외곽지역의 사용자들에게 셀 내에 위치한 사용자들과 같은 고속하향통신을 제공할 수 있다. 전산모의실험을 통해서 제안 전송방식의 성능을 계층변조가 적용되지 않은 기존 방식과 비교 분석하며, 그 결과 제안 전송방식이 일대일전송 및 일대다중전송의 경우 모두 기존방식에 비해서 기지국 전력사용 측면에서 우수한 성능을 보임을 확인한다.

• 한국시스템다이내믹스연구
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• 제8권2호
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• pp.253-273
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• 2007

To measure the effect of school zone on housing cost, Linear Regression Model is widely used, and school zone is known as a key determinant of housing cost in Korea. However, when the Hierarchical Linear Model (HLM) is applied with the same data, school effect on housing cost becomes statistically non-significant. It is because HLM effectively separates the effect of individual housing's attributes from the group effect. In sum, the housing cost of Kangnam, where good public schools are located, is apparently is higher than that of Kangbuk. However, the school effect on housing cost (Level 2) becomes non-significant when individual housing's attributes (Level 1) are controlled with HLM.

• 한국언어정보학회:학술대회논문집
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• 한국언어정보학회 2002년도 Language, Information, and Computation Proceedings of The 16th Pacific Asia Conference
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• pp.217-226
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• 2002

In this paper, we propose a method of generating a proper categorization of morphemes by giving a hierarchical part-of-speech system and a corpus tagged using this part-of-speech system. Our method use hierarchical information in the part-of-speech system and statistical information in the corpus to generate a category set. The statistical information is based on the context of occurrence of categories. First, we specify the format of given information. Then, we describe an algorithm to generate a proper categorization. Finally, we present the results of our experiments in applying this method. We obtained a moderately proper categorization and found several candidates for improvement .

• 한국멀티미디어학회논문지
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• 제16권7호
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• pp.862-869
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• 2013

In order to support a cell-independent traffic asymmetry, the conventional TDD system cannot avoid crossed time slot (CTS) interference. Moreover, the TDD/FDD hierarchical overlay cellular systems is taken into account as a generally accepted cell model in a heterogeneous radio environment. In this paper, we propose an interference resolving radio resource allocation technique in a TDD-OFDMA cellular system that overlays a FDD-CDMA cell. In our proposed scheme, we exploit under-used FDD-CDMA uplink resource by TDD mobile abiding by a region based time slot(TS) allocation which in turn mitigates CTS interference considerably. It is demonstrated that combined with under-used resource utilization scheme based on mobile's location, the proposed technique can reduce CTS interference considerably and support the asymmetric traffic in TDD system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.790-795
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• 1994

This paper describes multiple fault diagnosis method in complex system with hierarchical structure. Complex system is divided into subsystem, item, component. For diagnosing this hierarchical complex system, it is necessary to implement special neural network. We introducd to Hierarchical Artificial Neural Network(HANN) for this purpose. HANN consists of four level neural network, first level for symptom classification, second level for item fault diagnosis, third level for component symptom classification,forth level for component fault diagnosis. Each network is multi layer perceptron with 7 inputs, 30 hidden node and 7 outputs trainined by backpropagation. UNIX IPC(Inter Process Communication) is used for implementing HANN with multitasking and message transfer between processes in SUN workstation. We tested HANN in reactor system.

• Journal of Mechanical Science and Technology
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• 제20권10호
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• pp.1527-1533
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• 2006

Workflow systems have benefited the enterprise and customer in many aspects. But with the increasing complexity of the system, workflow design becomes a complicated and time-consuming process. In this paper, we model the system based on the Hierarchical Colored Petri Nets (HCPN) to avoid the complexity of the system, and the super nets of the model are abstracted as independent components to increase the flexibility, acceptability and maintainability of the system. Another important characteristic of this model is its convenience for reuse and workflow mining. The development process of the overhead traveling crane was given to demonstrate the proposed method.

• 한국산학기술학회논문지
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• 제7권2호
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• pp.182-187
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• 2006

본 논문은 통계 기반 접근 방식인 HMM(Hidden Markov model)과 생물학의 개체명에 관한 온톨로지 정보를 이용한 생물학 문서에서의 개체명(named entity) 경계 인식 방법을 제안한다. 제안하는 방법은 31개의 자질 정보를 이용한 평탄화 기법을 사용하며 생물학 개체명의 계층 정보를 이용하여 HMM의 자료 부족 문제를 완화시킬 수 있도록 하였다. 개체명 경계 인식의 학습과 실험을 위하여 GENIA 코퍼스 ver 2.1을 사용하였으며 개체명 경계 인식 실험을 수행한 결과 모든 부류를 사용한 경우보다 정확도 및 실행 속도가 개선됨을 확인하였다.