• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.709-711
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• 2005

본 논문에서는 알파벳 대문자 영상에 다양한 특징을 추출하고 이를 신경망을 이용하여 영문 알파벳을 구분하는 방법을 제안하고자 한다. 제안된 방식은 비교적 간단한 연산을 통해 입력된 영상에 대한 정보를 추출하여 신경망에 대입을 함으로서, 빠른 결과를 얻는 것과 동시에 알파벳 이미지가 아닌 알파벳 내에 들어있는 패턴들을 이용하여 알파벳을 구분함으로서 노이즈에 강한 장점을 나타내고 있다. 다양한 필체를 이용하여 실험을 수행하였고, 현재 사용 중인 상용 프로그램과 본 논문에서 제안한 방법의 적중률을 비교하였다.

• Journal of Korean Society for Geospatial Information Science
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• v.11 no.1 s.24
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• pp.77-82
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• 2003

Geographic information system extends several teamed circles so for and took in application step. Specially, GIS is applying much in civil engineering works field, and is trying to express terrain numerically and look for true value. It is very important that express terrain, can become important parameter to do three-dimensional analysis in later. We are using irregularity triangulation network mainly to express these terrain. In this study, calculated volume of topography by irregularity triangulation by developed formula.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3106-3108
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• 2000

본 논문은 고압배전선을 이용한 가입자망 개발에 필수적으로 상용되는 고압배전선용 커플러 개발에 관한 것이다. 개발된 고압배전선용 커플링 장치는 고압용 커패시터와 초크코일 및 커플링 트랜스포머로 구성되어 있다. 특히 개발된 커플링 트랜스포머는 1Mhz - 40Mhz 주파수 대역에서 0.1dB 이하의 손실을 가지는 광대역 저손실 특성을 가지는 것으로 평가되었다. 개발된 커플링 장치는 앞으로 전력선 가입자망 구성 및 임피던스 측정장치에 활용하고자 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.267-269
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• 2020

입모양 인식(Lip Reading) 기술은 입술 움직임을 통해 발화를 분석하는 기술이다. 본 논문에서는 일상적으로 사용하는 10개의 상용구에 대해서 발화자의 안면 움직임 분석을 통해 실시간으로 분류하는 연구를 진행하였다. 시간상의 연속된 순서를 가진 영상 데이터의 특징을 고려하여 3차원 합성곱 신경망 (Convolutional Neural Network)을 사용하여 진행하였지만, 실시간 시스템 구현을 위해 연산량 감소가 필요했다. 이를 해결하기 위해 차 영상을 이용한 2차원 합성곱 신경망과 LSTM 순환 신경망 (Long Short-Term Memory) 결합 모델을 설계하였고, 해당 모델을 이용하여 실시간 시스템 구현에 성공하였다.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.223-228
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• 2008

Recently, various types of wireless access networks, such as WLAN, WiBro and HSDPA, etc, have been successfully deployed by commercial service providers (i.e., KT, KTF). In this situation, there are many efforts to provide high quality of services to guarantee seamless mobility between heterogeneous networks. The IP layer mobility protocols are efficient mechanisms to provide seamless mobility between IP based heterogeneous networks as well as homogeneous networks. However, to apply IP mobility protocols in real heterogeneous networks (i.e., WiBro and HSDPA), we must consider not only the basic features of techniques of wireless access networks (i.e., Data rate, Coverage, Quality of Service) but also the problem of real environment of service provider (i.e., Expanse cost to change the access network). Due to this reason, it is difficult to satisfy required conditions by using only one IP mobility protocol in real heterogeneous networks. Therefore, in this paper, we propose an efficient mobility protocol to solve the complex problems that are occurred in real heterogeneous networks. The proposed protocol, so-called, "Hybrid Mobile IP" tries to provide a synergy effect by integrating Client Mobile IPv4 (CMIPv4) and Proxy Mobile IPv4 (PMIPv4), and using the two mobility protocols selectively according to the situation of real heterogeneous networks.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.9
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• pp.41-48
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• 2004

In this work, a domain-wise hash structure is developed for efficient data handling, and by using the developed domain-wise hash structure, an automatic triangular mesh generation algorithm is proposed. To generate the optimal nodal points and triangles efficiently, the advancing layer method and Delaunay triangulation method are utilized. To investigate the performance of the proposed algorithm, benchmarking tests are carried out for various models including convex, concave and complicated shapes through the developed object oriented C++ mesh generation code.

• The Transactions of the Korea Information Processing Society
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• v.5 no.11
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• pp.2930-2942
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• 1998

POTS(Plain Old Telephone Service) is the most popular telecommunication service and should be supported in the future BUSDN that is based on the ATM technology. Therefore, the interwoking system between ATM network and PSTN is needed, which provides telephone service between client of ATM network and subscriber of PSTN. In this paper, the interwoking system between ATM network and PSTN is designed and implemented. The interwoking system consists of PSTN I/F module, signaling processing module, voice sampling module, voice regeneration module, transmission module and ATM I/F module. The PSTN I/F module and ATM I/F module are implemented using the existing commercial H/W products. However, the other 4 modules are implemented for the WIN95 environments by software. The test environment is also implemented and the interworking system is operated without problems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.277-283
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• 2019

Advances in technology have allowed the development and commercialization of various parts; however this has shortened the discontinuation cycle of the components. This means that repair and logistic support of weapon system which is applied to thousands of part components and operated over the long-term is difficult, which is the one of main causes of the decrease in the availability of weapon system. To improve this problem, the United States has created a special organization for this problem, whereas in Korea, commercial tools are used to predict and manage DMSMS. However, there is rarely a method to predict life cycle of parts that are not presented DMSMS information at the commercial tools. In this study, the structured and unstructured data of parts of a commercial tool were gathered, preprocessed, and embedded using neural network algorithm. Then, a method is suggested to predict the life cycle risk (LC Risk) and year to end of life (YTEOL). In addition, to validate the prediction performance of LC Risk and YTEOL, the prediction value is compared with descriptive statistics.

• Journal of Korea Multimedia Society
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• v.9 no.7
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• pp.854-863
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• 2006

As WiBro service providers which provide a wireless multimedia communication service are selected, the commercial service will emerge in the near future. Although the use of efficient multicast technology for multimedia will be essentially required, it would be difficult to design the overall communication network in the early stage by using IP multicast due to technological or commercial issues. Application layer multicast schemes or hybrid multicast schemes also should be considered. In this paper, we propose a hybrid multicast scheme and evaluate its performance against typical IP multicast schemes on modelling of the WiBro network for one of WiBro service providers. We also propose a simulation method for the hybrid multicast on the simulation network for performance evaluation. If the number of mobile nodes reaches a certain point, the performance difference between the hybrid multicast and IP multicast is reduced significantly. We show that hybrid multicast technology can be applied for WiBro service without much performance degradation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.5
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• pp.541-548
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• 2013

This paper presents a vector network analysis system for 2-port scattering parameters of microwave devices using some basic microwave instruments/devices such as signal generators, vector voltmeter, directional couplers and frequency mixers. The analytical model and implementation method for scattering parameter measurements - which can replace the vector network analyzers - are presented. The performance of the implemented system is evaluated through 1- and 2-port scattering parameter measurements, respectively. The vector volt signals which determine the scattering parameters are detected in two distinct methods depending on the frequency band of interests; a direct-detection method with a single signal generator and vector voltmeter for relatively low band and a heterodyne method to frequency down-mix associated with an additional signal source as well as frequency mixers for high band are used, respectively. Using these two methods, scattering parameters of UHF and X bands are evaluated and their performances are verified through a comercial vector network analyzer.