• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.1
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• pp.46-53
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• 2000

본 논문에서는 전원전압 센서 없는 단상 PWM 컨버터의 전류제어방법을 제안한다. 제안된 방법에서 전원전압은 슬라이딩 모드 관측기에 의해 추정되며 추정된 전원전압을 이용하여 컨버터의 입력 역률을 '1'로 하고 일정한 DC링크전압을 얻을 수 있다. 제안된 방법의 특징은 전원전압의 크기와 위상의 추정이 실제전류와 추정전류의 전류오차에 의해서 얻어질 수 있다. 제안된 방법은 DSP를 이용하여 구현하고, 실험결과는 제안된 방법의 정당성을 입증한다.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.143-144
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• 2014

"카카오톡"이 세계시장으로 확대하기를 위해서 중미일의 대표적인 모바일 SNS(Facebook, Wechat, Linkedln)와 대비를 통하여 GUI디자인을 중심으로 분석이 이루어져야 할 필요성이 있다. 연구결과를 통하여 본 카카오톡 GUI디자인의 특징과 문제점은 다음과 같다. 첫째, 굵은 선으로 아이콘 구성하는 방법이 전체 스타일에 영합하지만 화면이 복잡해 보이는 측면이 있다. 둘째, 서브메뉴에서 아이콘과 앱링크, 광고이미지 등 다양한 요소를 한꺼번에 놓으면 혼란한 측면이 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.460-462
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• 2003

본 논문은 현재 18M, 마이크로소프트, SAP등이 운용하고 있는 대표적인 공용 UBR(UDDI Business Registry) 노드들과 국내에서 개발된 K-UDDI, 일본의 NTT에서 운용하는 UBR노드에 대해 각각의 특징을 서로 비교해 본다. 또한 간단한 모니터링 프로그램을 구현하여, 각각의 UDDI 비즈니스 레지스트리에 등록되고 있는 전체 비즈니스 개체와 비즈니스 서비스 수의 증감 추이를 관찰하고, 등록된 비즈니스 개체별 링크된 WSDL파일의 유효함의 여부를 실행한 결과물을 통해 현재 운용중인 공용 UDDI 레지스트리의 활성화 정도를 분석해 본다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1327-1330
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• 2010

최근 전세계적으로 마이크로-블로그 형태의 소셜네트워크 서비스가 확산되어가고 있으며, 트위터(Twitter)란 이러한 가장 대표적인 소셜네트워크 서비스이다. 본 논문에서는 트위터를 매개로써 이루어지는 악성코드 유포 행위를 조사하기 위해 트위터에 올라오는 게시물(Tweet)들에서 약 93 만개의 링크를 임의 추출하여 다운받았고, 이중 7 개의 악성코드 배포 계정을 검출하여 해당 게시물과 계정의 특징을 조사하였다.

• Annual Conference on Human and Language Technology
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• 2019.10a
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• pp.170-172
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• 2019

개체명 연결이란 주어진 문장에 출현한 단어를 위키피디아와 같은 지식 기반 상의 하나의 개체에 연결하는 것을 의미한다. 문장에 나타나는 개체들은 주로 동일한 주제를 가지게 되는데 본 논문에서는 이러한 특징을 활용하기 위해서 개체들을 그래프상의 노드로 표현하고, 그래프 신경망을 이용하여 주변 노드의 정보를 통해 노드 표상을 업데이트한다. 한국어 위키피디아 링크 데이터를 사용하여 실험을 진행한 결과 개발 셋에서 82.09%, 평가 셋에서 81.87%의 성능을 보였다.

• The KIPS Transactions:PartB
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• v.13B no.2 s.105
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• pp.121-126
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• 2006

In this paper, we propose an approach to increase the power of clustering Web images by using high-level semantic features from text information relevant to Web images as well as low-level visual features of image itself. These high-level text features can be obtained from image URLs and file names, page titles, hyperlinks, and surrounding text. As a clustering engine, self-organizing map (SOM) proposed by Kohonen is used. In the SOM-based clustering using high-level text features and low-level visual features, the 200 images from 10 categories are divided in some suitable clusters effectively. For the evaluation of clustering powers, we propose simple but novel measures indicating the degrees of scattering images from the same category, and degrees of accumulation of the same category images. From the experiment results, we find that the high-level text features are more useful in SOM-based Web image clustering.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6A
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• pp.558-567
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• 2011

In this paper, we propose a partial full duplex relay scheme for 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution)-Advanced system using a Type 1 relay. The Type 1 relay as inband relay is prohibited to transmit and receive simultaneously because of self-interference. Therefore, the Type 1 relay cannot receive synchronization signals which are transmitted to eNB. To overcoming this problem, we propose the partial full duplex relay scheme which transmits to R-UE (Relay-User Equipment) and receives from eNB (evolved NodeB) simultaneously when eNB and the Type 1 relay transmit subframes which have synchronization signals. Additionally, for solving self-interference, the Type 1 relay transmitter and receiver antennas are sufficiently sufficiently isolated and self-interference cancellation is applied for the self-interference signal from the relay transmitter. Thus, the partial full duplex relay scheme can receive synchronization signals from eNB and solve the problems of conventional solutions and we propose the partial channel estimation scheme for partial full duplex relay scheme using SCI. By extensive computer simulation, we verify that the partial full duplex relay scheme is attractive and suitable for the Type 1 relay system.

• Journal of Korean Library and Information Science Society
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• v.48 no.4
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• pp.107-127
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• 2017

This study is to suggest the considerations in constructing BIBFRAME by analyzing change feature of BIBFRAME 2.0 under recognizing the needs of the detailed methods for BIBFRAME construction in Korea through literature review as research methods. First, it is to add or to describe expression level as the core entity in BIBFRAME 2.0. Second, it is to extend classes and properties as BIBFRAME vocabulary to reflect the RDA elements by testing the various materials. Third, preferred title and preferred name is to be described in BIBFRAME and Korean Cataloging Rules related to authorized access point is to be regulated. This study could contribute to develop BIBFRAME development and revision under revising BIBFRAME vocabularies ongoing.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.7-12
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• 2014

It has good features for social networking with friends SNS is maintained. However, various enterprises, individuals invading the inconvenience spammers have exposure to a number of users to tweet spam. The study was conducted in the existing research on these spam tweets. However, the results showed a more accurate classification and detection is difficult because of the lack of precision and different causes. In this paper, we describe how to classify the characteristics of spammers, classification criteria. Also has a link rate and difference between followers and following, these features were present classification criteria for spammers account. This experiment was performed according to the criteria. Randomized trial of spam and non-spam accounts were selected and account type was conducted according to the criteria 68% of the link ratio of spam accounts. Followers / Following ratio was 27581.5. Non-spam accounts was 6.12%. Followers / Following ratio was 1.26.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1C
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• pp.54-62
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• 2012

A Wi-Fi mesh network providing multi-hop wireless connections based on IEEE 802.11 PHY/MAC technology has recently received a significant attention as a network infrastructure that interconnects RFID systems and wireless sensor networks (WSNs). However, the current IEEE 802.11 contention-based MAC protocol cannot fully utilize the network capacity due to eithor frame collisions or unused network resources. In this paper, we propose a novel multi-channel scheduling MAC (MCS-MAC) protocol for Wi-Fi mesh networks. Under the secondary interference model of Wi-Fi mesh networks, the MCS-MAC protocol can maximize the network throughput via activation of collision-free links that has a maximal link weight. Through the simulations, we show that the throughput of the MCS-MAC protocol is at least three times higher than that of existing MAC protocols in Wi-Fi mesh networks.