• International journal of advanced smart convergence
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• 제11권4호
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• pp.41-46
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• 2022

This study is a Ku-band array antenna for the manufacture of low-orbit satellite communication terminals, designed to have miniaturization, high gain, and wide beam width. The transmission of low-orbit satellite communication has a right-rotating circularly polarized wave, and the reception has a left-rotating circularly polarized wave. The 4×8 array antenna was separated for transmission and reception, and it was combined with the RF circuit part of the transmitter and receiver, and was terminated in the form of a waveguide for RF signal impedance matching in the form of a transition from the microstrip line to the waveguide. The 30° beam width of the receiver maximum gain of 19 dBi and the 29° beam width of the transmitter maximum gain of 18 dBi are shown. Through this antenna configuration, the system was configured to suit the low-orbit satellite transmission/reception characteristics.

• Journal of information and communication convergence engineering
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• 제12권2호
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• pp.67-74
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• 2014

In multi-hop communication systems, two-way relaying is one of the solutions to mitigate the spectral efficiency loss caused by a half-duplex transmission. In this paper, a simple two-way relaying scheme is proposed for two-hop two-user multiple input multiple output (MIMO) systems. In the proposed system, a base station and a relay station (RS), both equipped with two antennas, form a point-to-point MIMO channel, while the RS and two single-antenna mobile users form a point-to-multipoint multiuser (MU)-MIMO channel. Numerical examples show that the proposed system achieves a significant sum rate gain as compared to a one-way relaying system as the distance between a relay and the two users decreases. We also show that although we can expand the proposed scheme to more than two users, its performance gain as compared to that of one-way relaying decreases with an increase in the number of users.

• 한국어교육
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• 제29권3호
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• pp.197-225
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• 2018

The purpose of this study is to compare the difference in the interactions between beginning language learners and heritage learners on their forms based on the interaction hypothesis. In this study, three types of information gap activities were used to analyze Language Related Episodes (LREs) while investigating the interaction patterns in language use between four pairs (eight learners) of foreign learners and four pairs (eight learners) of English-speaking heritage learners. The result indicated that foreign learners had a high focus on form during interaction. In particular, they had a tendency to focus on vocabulary rather than grammar, and they conducted self-repair by examining and mostly adjusting their speech to postposition and tense. However, in the problem-solving process, they showed a limited ability in interaction, and thus directly asked others to settle the problem or resorted to using English due to their lack of ability to employ various communication strategies. However, heritage learners had a relatively low focus on form compared to foreign learners. Yet, they also focused more on vocabulary rather than grammar and conducted self-repair in interaction, especially for vocabulary. In addition, they were skillful at using various communication strategies such as indirect expressions, use of alternative words, evasion, and delaying, to expand speech and prevent communication breakdown. They focused less on grammar and mostly did not provide negative feedback in interaction.

• International journal of advanced smart convergence
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• 제10권4호
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• pp.273-277
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• 2021

As society gradually enters a virtual, non-face-to-face society, the use of online content is increasing as well. In particular, as smartphones are thoroughly established in our daily life, the platforms of webtoons, mobile broadcasting, and education are shifting from personal computers to smartphones. Recently, the development of the Over-The-Top media service (OTT service) enabled streaming services of various media contents through the internet and activation of IPTV. Therefore, the rapid increase of popularity of short-form content is a natural phenomenon with smartphone platforms with fast, improvised, and endless communication. Lately, TikTok became the favored platform with prosumers, defined as people who are both producers and consumers. In this study, I studied the experiential response of YouTube and TikTok users as representative examples of a short-form content platform developed after the 2000s, the flourishing years of digital content with a length of 30 seconds.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.485-489
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• 2006

In last decades, several linearization methods for the AOA measurements have been proposed, for example, Gauss-Newton method and closed-form solution. Gauss-Newton method can achieve high accuracy, but the convergence of the iterative process is not always ensured if the initial guess is not accurate enough. Closed-form solution provides a non-iterative solution and it is less computational. It does not suffer from convergence problem, but estimation error is somewhat larger. This paper proposes a self-tuning weighted least square AOA algorithm that is a modified version of the conventional closed-form solution. In order to estimate the error covariance matrix as a weight, two-step estimation technique is used. Simulation results show that the proposed method has smaller positioning error compared to the existing methods.

• 한국정보통신학회논문지
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• 제12권6호
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• pp.1082-1086
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• 2008

MIMO기술은 대역폭과 전력에 의해 제한을 받는 무선네트워크의 데이터 전송률을 증대시켜주는 효과적인 기술이다. 송수신단사이의 데이터 전송률은 채널용량에 의해 결정되며, MIMO기술은 이 채널용량을 적절히 이용함으로써 무선채널에서의 통신신뢰도를 높이는 이점을 가지고 있다. 본 논문은 Confluent Hypergeometric Function를 이용하여 새로운 공식 인 closed form capacity formula를 유도한다.

• ETRI Journal
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• 제31권4호
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• pp.454-456
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• 2009

The maximum likelihood linear spectral transformation (ML-LST) using a numerical iteration method has been previously proposed for robust speech recognition. The numerical iteration method is not appropriate for real-time applications due to its computational complexity. In order to reduce the computational cost, the objective function of the ML-LST is approximated and a closed-form solution is proposed in this paper. It is shown experimentally that the proposed closed-form solution for the ML-LST can provide rapid speaker and environment adaptation for robust speech recognition.

• International journal of advanced smart convergence
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• 제2권1호
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• pp.12-17
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• 2013

This paper introduces the fuzzy scatter partition-based fuzzy inference system to construct the model for nonlinear process to analyze nonlinear characteristics. The fuzzy rules of fuzzy inference systems are generated by partitioning the input space in the scatter form using Fuzzy C-Means (FCM) clustering algorithm. The premise parameters of the rules are determined by membership matrix by means of FCM clustering algorithm. The consequence part of the rules is represented in the form of polynomial functions and the parameters of the consequence part are estimated by least square errors. The proposed model is evaluated with the performance using the data widely used in nonlinear process. Finally, this paper shows that the proposed model has the good result for high-dimension nonlinear process.

• 정보처리학회논문지D
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• 제9D권2호
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• pp.267-276
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• 2002

트리 구조를 기반으로 하는 기존의 XML 문서 편집은 사용자고 하여금 XML에 대한 사전 지식을 필요로 한다. 그러나 XML 문서의 작성과 활용이 보편화되기 위해서는 이러한 문서 편집 방식에서 벗어나 누구나 쉽게 작성할 수 있는 환경이 제공되어야 한다. 본 논문에서는 트리 방식의 문서 편집뿐만 아니라 문서의 양식에 근거한 form을 기반으로 하는 편집 환경도 지원하는 새로운 XML 문서 편집기를 제안한다. 특히, form을 이용한 문서 편집은 기업이나 관공서 등과 같이 정형화된 양식을 이용하여 다량의 XML 문서를 작성하는 경우에 아주 효과적이다. Form 자체는 HTML 문서로 표현이 되고 이러한 HTML form은 template XML 문서와 XSL 문서를 이용한 XSLT 적용을 통해 자동적으로 생성된다. 생성된 HTML form은 내장된 브라우저를 통해 사용자에게 보여지며, foam에 입력된 사용자 데이터는 XML 문서로 변환되어 XML 저장소에 저장된다.

• 한국의류학회지
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• 제36권9호
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• pp.966-978
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• 2012

Fashion exhibitions in museums and galleries is a form of fashion communication media. This thesis examines the messages, objects, and space of fashion exhibitions as fashion communication media as well as analyzes the method of fashion communication. This thesis first provides a theoretical study on fashion exhibition and conducts a case study of the 2012 Nora Noh Retro Exhibition La Vie en Rose (2012/5/23-6/2, Horim GNB Gallery, Seoul), dedicated to the first Korean female fashion designer. The message of the exhibition was the fashion philosophy and the fashion style of the designer as well as the intention of the curator. The objects presented were the dresses kept by the loyal customers of the brand, and the homage items by designers of present generation. The space designs of the exhibition were the layout and total coordination of the opening event. The methods of fashion communication for the fashion exhibition, in the case of the La Vie en Rose exhibition, were communicated (1) from the past to the present, (2) from designers to celebrities and (3) from the designer to the celebrity and the viewers. From the past to the present, the designer's style throughout the 60 years of her fashion career is conveyed to the present generation fashion people, in the form of homage designs and collaboration works. From designers to celebrities, her fashion philosophy was delivered in the form of movie and stage costumes. Some present generation celebrities tried reinterpretations of the garment. From the designer to the celebrity and the viewers of the exhibition, the intention of the curator and the designer were individualized and internalized by the viewers.