• 한국전자통신학회논문지
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• 제2권1호
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• pp.1-9
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• 2007

In this paper, a third-order harmonic mixer is designed using frequency multiplier theory for the Ka-band. The gate bias voltage is selected by frequency multiplier theory to maximize the third-order harmonic element ofthe fundamental LO frequency in the proposed mixer. The designed mixer has a gate mixer structure composed of a gate terminal input for the fundamental local signal ($f_{LO}$), RF signal (${RF}$) and a drain terminal output for the harmonic frequency ($3f_{LO}-f_{RF}$) respectively. The Ka-band harmonic mixer is designed and fabricated using a commercial GaAs MESFET device with a plastic package. The proposed mixer will provide a solution for the problems found in the high cost, complex circuitry in a conventional Ka-band mixer. The 33.5 GHz harmonic mixer has a -10 dB conversion gain by pumping 11.5 GHz LO with a +5 dBm level.

• 한국조명전기설비학회지:조명전기설비
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• 제10권3호
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• pp.47-54
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• 1996

본 논문에서는 정보설비용 개인 휴대 통신 장치 대역 통과 필터를 설계 제작하였다. 대역 통과 필터를 설계 제작하기 위하여 유전체 공진기 구조에 따른 특성을 분석하였다. J-인버터 이론을 이용한 대역 통과 필터의 설계 이론과 시뮬레이션 결과를 알아보았다. 설계 이론으로부터 구한 파라미터를 이용하여 실제 제작한 결과 미세 조정 후 특정한 결과와 시뮬레이션 결과와 일치함을 볼 수 있다.

• International Journal of Costume and Fashion
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• 제10권2호
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• pp.1-13
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• 2010

The purpose of this study is to investigate the behavioral complexities frequently arising in married couples with respect to clothing choices. Symbolic interaction theory was used to understand how spousal influence affects clothing selection after marriage. A convenient sample of nine married couples was interviewed for the data collection. A content analysis revealed how marriage affected their clothing choices, types of communication conveyed with their spouses about clothes and shopping patterns. The primary result indicated that individuals take their spouses' clothing preferences into consideration. Couples exhibited varying frequencies of communication about clothing choices and developed a variety of shopping patterns. As a result of the findings from this study, future research directions are suggested.

• International Journal of Internet, Broadcasting and Communication
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• 제8권1호
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• pp.1-6
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• 2016

Keeping a system in stable state is one of the important issues of control theory. The main goal of our basic research is stability of unmanned aerial vehicle (quadrotor). This type of system uses a variety of sensors to stabilize. In control theory and automatic control system to stabilize any system it is need to apply feedback control based on information from sensors. Our aim is to provide balance based on the 3D spatial information in real time. We used PID control method for stabilization of a seesaw balancing system and the article presents our experimental results. This paper presents the possibility of balancing of seesaw system based on feedback information from stereo vision system only.

• 조명전기설비학회논문지
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• 제23권11호
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• pp.34-43
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• 2009

SCADA (Supervisory Control and Data Acquisition) system has been used for remote measurement and control on the critical infrastructures as well as modem industrial facilities. As cyber attacks increase on communication networks, SCADA network has been also exposed to cyber security problems. Especially, SCADA systems of energy industry such as electric power, gas and oil are vulnerable to targeted cyber attack and terrorism Recently, many research efforts to solve the problems have made progress on SCADA network security. In this paper, flexible key distribution concept is proposed for improving the security of SCADA network using Multiagent System (MAS).

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권11호
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• pp.4573-4584
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• 2015

The traditional feature extraction algorithms for recognition of communication signals can hardly realize the balance between computational complexity and signals' interclass gathered degrees. They can hardly achieve high recognition rate at low SNR conditions. To solve this problem, a novel feature extraction algorithm based on Holder coefficient was proposed, which has the advantages of low computational complexity and good interclass gathered degree even at low SNR conditions. In this research, the selection methods of parameters and distribution properties of the extracted features regarding Holder coefficient theory were firstly explored, and then interval gray relation algorithm with improved adaptive weight was adopted to verify the effectiveness of the extracted features. Compared with traditional algorithms, the proposed algorithm can more accurately recognize signals at low SNR conditions. Simulation results show that Holder coefficient based features are stable and have good interclass gathered degree, and interval gray relation classifier with adaptive weight can achieve the recognition rate up to 87% even at the SNR of -5dB.

• 한국정보시스템학회지:정보시스템연구
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• 제8권1호
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• pp.109-129
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• 1999

This study deals with the problem of information dissemination in a communication network, which is defined to be the process whereby a set of messages, generated by an originator, is transmitted to all the members within the network. Since this type of message generally includes control data to manage the network or global information that all members should know, it is to be required to transmit it to all the members as soon as possible. In this study, it is assumed that a member can either transmit or receive a message and an informed member can transmit it to only one of its neighbors at time. This type of transmission is called 'local broadcasting' Several schemes of call sequencing are designed for a general-type network with nonuniform edge transmission times, and then computer simulations are performed. Some heuristics for information dissemination are proposed and tested. For this, optimal call sequence in a tree-type network, sequencing theory and graph theory are applied. The result shows that call sequencing based on the shortest path tree is the most desirable.

• 산업공학
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• 제14권1호
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• pp.54-58
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• 2001

In this study, we suggest a multi-generation Lotka-Volterra model, which is a competition model using game theory and complex system theory. The suggested model shows many improvements to weakness of a well known Bass model to forecast new technology in competitive markets. We show that the Lotka-Volterra model has strong power to forecast mobile communication services when it is used for competition of 1st generation mobile phone service and 2nd generation phone service in Korea. We finally use the model to forecast IMT-2000 service, the 3rd generation mobile communication service.

• 문화기술의 융합
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• 제5권1호
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• pp.205-210
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• 2019

디지털 디바이스와 네트워크의 발전에 의해 커뮤니케이션 기술은 용이해졌지만, 반대로 광고에 대한 소비자의 인식은 가장 부정적인 모습이다. 이런 배경에서 소셜 미디어를 이용한 브랜드 스토리텔링은 효율적인 마케팅 수단으로 주목받고 있다. 하지만 빠르게 성장하고 있는 VR(가상현실), AR(증강현실), 그리고 MR(혼합현실) 미디어 환경은 브랜드 스토리텔링 마케터들에게 새로운 가능성을 제공하고 있다. 본 연구는 서사몰입 이론을 중심으로 MR 미디어 서비스에 대한 논의를 통해 브랜드 마케팅의 방향과 시사점들을 제시하는데 목적을 가지고 있다.

• International Journal of Internet, Broadcasting and Communication
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• 제16권3호
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• pp.47-55
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• 2024

We examined how different types of brand personality play a role to develop a specific consumers' expectation toward a brand, and how this expectation works in various ways in different types of brand transgressions. Based on expectancy violation theory and brand transgression research, a 2 (brand personality types: sincerity vs. competence) × 2 (brand transgression types: morality-related vs. competence-related transgression) factorial design was employed. Corporate evaluations and purchase intention toward the brand were considered as dependent variables. We found that a brand having a sincerity personality is more vulnerable to a morality-related transgression. However, there is no difference in consumers' responses by transgression type for a brand with a competence personality. We identified that brand personality types and transgression types can be critical factors to influence consumers' responses in times of crisis. Theoretical and empirical implications are discussed.