• 한국정보전자통신기술학회논문지
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• 제4권3호
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• pp.217-224
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• 2011

본 논문에서는 동적 데이터베이스 환경에서 발생할 수 있는 개인 정보 노출 문제를 해결할 수 있는 동적 데이터 보호 기법(Dynamic Data Protection Technique)을 제안하였다. 본 논문에서 제안한 DDPT은 다중 속성 일반화 알고리즘을 이용해 MAG(Multi-Attribute Generalization) 규칙을 생성하고, 그 MAG 규칙에 따라 k-anonymity를 만족하는 EC(Equivalence Class)를 생성한다. 그리고 데이터 변경 시 MAG 규칙에 따라 EC를 재구성 하도록 하여, EC의 변경으로 인한 식별 노출을 방지할 수 있다. 또한, ${\ell}$-diversity를 만족하는 EC의 정보손실 정도를 측정하고, 임계치 이하의 EC를 선정해서 데이터의 정확성을 유지함으로써 개인 정보 보호를 향상시켰다.

• Journal of Communications and Networks
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• 제12권4호
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• pp.358-365
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• 2010

We develop a low complexity cooperative diversity protocol for low energy adaptive clustering hierarchy (LEACH) based wireless sensor networks. A cross layer approach is used to obtain spatial diversity in the physical layer. In this paper, a simple modification in clustering algorithm of the LEACH protocol is proposed to exploit virtual multiple-input multiple-output (MIMO) based user cooperation. In lieu of selecting a single cluster-head at network layer, we proposed M cluster-heads in each cluster to obtain a diversity order of M in long distance communication. Due to the broadcast nature of wireless transmission, cluster-heads are able to receive data from sensor nodes at the same time. This fact ensures the synchronization required to implement a virtual MIMO based space time block code (STBC) in cluster-head to sink node transmission. An analytical method to evaluate the energy consumption based on BER curve is presented. Analysis and simulation results show that proposed cooperative LEACH protocol can save a huge amount of energy over LEACH protocol with same data rate, bit error rate, delay and bandwidth requirements. Moreover, this proposal can achieve higher order diversity with improved spectral efficiency compared to other virtual MIMO based protocols.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2002년도 정기총회 및 학술대회
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• pp.31-35
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• 2002

본 논문에서는 DVB-T 표준안의 모든 동작모드를 지원하며 임펄스 잡음 제거, 안테나 diversity 수신, 향상된 채널추정방법을 적용한 유럽향 디지털 TV 수신용 채널 칩셋의 설계에 관한 내용이다. 설계된 칩은 여러 개의 구성 블럭으로 구성되어있는데 여기에는 여러 가지의 향상된 알고리즘과 설계 아키텍쳐가 사용되었다. 가정용 가전기기들이 발생시키는 일정주기의 임펄스 잡음을 제거하기 위하여 임펄스 잡음 제거 블록을 AGC뒤에 사용하였다. 동기부는 대략적 주파수동기, 미세 주파수동기, 대략적 타이밍동기, 미세 타이밍 동기 등으로 이루어져 있으며 본 설계의 주파수 보상 영역은 $\pm$280Khz, 타이밍 보상 영역은 $\pm$500ppm이다. 파일럿 신호를 이용하여 채널추정과 보상을 수행하며 기존의 선형 보간기법과 함께 4개의 파일럿 신호를 이용한 보간기법을 사용하여 이동수신환경에 대응할 수 있도록 하였다. 이와 함에 수신성능을 개선할 수 있다고 알려진 안테나 diversity 기능을 채용하여 고정 및 이동 수신시의 수신성능을 향상시켰다. 안테나 diversity를 위해서 2개 이상의 수신 칩이 사용되며 이를 위해서 본 설계에서는 MRC(Maximum Ratio Combining)알고리즘을 사용하였다 본 설계는 5층 메탈 0.18um 공정을 사용하였으며 2.7Mbit 의 메모리 소자를 포함하여 대략 300 만 게이트의 회로크기를 갖으며 100 핀 PQFP로 제작되었다. 본 논문에서는 설계된 회로의 각 블록별 기능에 대한 설명과 함께 시뮬레이션 결과와 ASIC설계결과를 기술하였다.

• 대한전자공학회논문지TC
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• 제49권4호
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• pp.34-40
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• 2012

무선통신에서 페이딩은 피할 수 없는 문제이다. 그러므로 전송신호에 있어서는 BER 형태의 오류개념이 도입된다. 다른 페이딩 채널들 상에서 이러한 오류들의 동작을 인식하는 것이 필요하다. CoherentMPSK의 평균 BER에 대한 수학적인 해법을 얻기 위해서 몇 가지 기법들을 제안한다. 본 논문에서, 느리고 평탄한 라이시안 페이딩 채널 상에 diversity의 영향도 또한 분석되어진다. 여기서, 변조 지표 값 M은 변화하고 이 변화의 효과들 또한 묘사되어진다. 다양한 diversity값과 페이딩 파라미터에 따른 성능 곡선들은 믿을 수 있는 통신 시스템을 위하여 무선 채널을 설계하고 평가하는데 유용하다.

• Molecules and Cells
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• 제27권2호
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• pp.225-235
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• 2009

Antibody phage display provides a powerful and efficient tool for the discovery and development of monoclonal antibodies for therapeutic and other applications. Antibody clones from synthetic libraries with optimized design features have several distinct advantages that include high stability, high levels of expression, and ease of downstream optimization and engineering. In this study, a fully synthetic human scFv library with six diversified CDRs was constructed by polymerase chain reaction assembly of overlapping oligonucleotides. In order to maximize the functional diversity of the library, a ${\beta}$-lactamase selection strategy was employed in which the assembled scFv gene repertoire was fused to the 5'-end of the ${\beta}$-lactamase gene, and in-frame scFv clones were enriched by carbenicillin selection. A final library with an estimated total diversity of $7.6{\times}10^9$, greater than 70% functional diversity, and diversification of all six CDRs was obtained after insertion of fully randomized CDR-H3 sequences into this proofread repertoire. The performance of the library was validated using a number of target antigens, against which multiple unique scFv sequences with dissociation constants in the nanomolar range were isolated.

• 유통과학연구
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• 제19권11호
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• pp.17-25
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• 2021

Purpose: This study aims to examine the effect of gender diversity and institutional ownership on earnings management in distribution industry sub-sector companies listed on the Indonesia Stock Exchange in 2017-2018. Research design, data and methodology: This research is case study research, where the population in this study are all distribution sub-sector companies listed on the IDX in 2017-2018. The sample selection technique used was purposive sampling and obtained 74 companies with the 2017-2018 research period. Multiple linear regression analysis was used in this study, using Stata 17. Results: The results of this study indicate that: 1) Gender diversity has a negative effect on earnings management. 2) Institutional ownership has a negative effect on earnings management. Conclusions: This study contributes to the agency theory where gender diversity and institutional ownership can reduce the agency conflict that the shrinkage of earnings management. These results indicate that companies in which there are female directors will reduce earnings management practices, this is due to the attitude of female directors who tend to avoid risk. The results also show that institutional ownership will also lead to reduced levels of earnings management, because institutional investors will increase its oversight of the company.

• 아태비즈니스연구
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• 제12권4호
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• pp.211-225
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• 2021

Purpose - This study deals with the Openness to Diversity(OD) of soldiers in the military organization for efficient unit operation of the military organization composed of various soldier. The purpose of this study was to examine the effects of information and value OD on innovative behavior and the mediating effect of unit-members trust. Design/methodology/approach - The 269 samples of this study were surveyed on army soldiers. The Exploratory Factor Analysis (EFA), the multiple regression, bootstraping analysis were hired in order to analyze the data. Findings - The results showed that the information & value OD were positive(+) effect on innovative behavior. Unit-members trust showed a mediation effect between OD and innovative behavior. Research implications or Originality - First, according to Defense Reform 2.0, the military is expected to be composed of more diverse classes in the future. There is a theoretical contribution that examine their perception of diversity within the military. Second, OD was confirmed as a variable predicting the innovative behavior of soldiers and unit-memeber trust mediate the relationship between OD and invative behavior.

• Educational Technology International
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• 제14권1호
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• pp.55-74
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• 2013

The diversity of students is getting increased in the contemporary classroom. To deal with the diversity, differentiated instruction (DI) should be considered as a way of providing alternative approaches to content, process and product according to the students' readiness, interest, and learning needs. Teachers have problems and difficulties in supporting different student's needs. In fact, teachers need proven tools including framework, guidelines or computing systems to help to practice DI in real context. According to the activity theory, tools influence on how people act and think and even their social practice, playing a crucial role in mediating the activities with people. In DI practice, there are also some studies about physical and abstract tools, but they have been not widely utilized by teachers in real schools. It means that more innovative tool to promote DI might be required. Therefore, to design a better tool to mediate the DI activities with teacher, case studies were conducted. In order to elicit the design implications, two physical and two abstract tools for DI practice were analyzed as case studies. Through the analysis of the case studies, eight design implications better to facilitate DI practice were suggested. This study has implications in suggesting design guidelines for teachers' tools to facilitate their DI practice by analyzing case studies in DI practices for an innovative tool in the educational practice.

• 건축사
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• 통권587호
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• pp.136-143
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• 2018

• 대한전자공학회논문지TC
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• 제45권3호
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• pp.40-45
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• 2008

본 논문은 MIMO 시스템에서, 최대 전송률을 유지하면서 최대 다이버시티를 갖는 준직교 시공간 블록 부호 (QO-STBC : quasi orthogonal space time block codes)를 다차원 신호 공간에서 설계한다. QO-STBC 부호기 중 원형심볼(based-symbols)을 두 개의 신호 쌍으로 묶어서 변형된 새로운 신호를 전송하는 방식을 grouping QO-STBC 라고 한다. 이러한 grouping QO-STBC의 최대 다이버시티 조건을 기하학적으로 살펴보고, 다차원 신호 공간에서 신호를 설계하는 방법을 제안한다. 또한 다양한 신호 성상에 대하여 설계한 부호기의 성능을 분석하고 전산 모의실험을 통하여 성능분석의 타당성을 입증한다.