• 한국통신학회논문지
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• 제34권7A호
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• pp.515-522
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• 2009

본 논문에서는 채널 부호회된 OFDM (orthogonal frequency division multiplexing) 시스템을 위한 공간 변조를 이용한 새로운 전송 기법을 제안한다. 공간 변조라 불리는 개루프 (open-loop) 방식의 다중 안테나 기술은 업력 데이터를 안테나 인텍스(index) 신호와 데이터 신호로 나누고, 안테나 인텍스 신호에 따라 다수의 송신안테나 중 하나의 송신안테나를 선택하여 데이터 신호를 전송한다. 공간 변조는 수신기에서 송신된 신호가 어떤 안테나로부터 보내졌는지를 의미하는 안테나 인텍스를 검출해야 하는데, 이를 위해서 채널 행렬의 직교성이 보장되어야 한다. 실제 채널은 무시하지 못할 정도의 채널 상관도로 인해 직교성을 유지하지 못한다. 또한 기존 공간 변조를 위한 수신기는 경판정 방식을 취하고 있으므로, 실제 시스템에 이를 활용하기가 어렵다. 본 논문에서는 기존의 공간 변조 기법이 연판정 수신을 할 수 있도록 소프트 출력 디맵퍼 (soft-output demapper)를 유도하고, 기존 기법의 수신 성능을 개선하기 위해 새로운 구조의 전송 기법을 제안한다.

• 한국경영과학회지
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• 제41권3호
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• pp.59-74
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• 2016

Electricity sales are directly measured from individual consumers, which could minimize the time gap between data collection and public announcement. Furthermore, industrial electricity sales are highly linked with production and output. Therefore, industrial electricity consumption can be used to track production and output in real time. By using the high-frequency data of industrial electricity sales, this study develops the daily electricity business index (DEBI) to capture the daily economic status. The steps used to formulate DEBI are as follows: (1)selection of the explanatory variables and period, (2) amendment of the seasonal adjustment to eliminate daily temperature and effective day effects, (3) estimation of the weighted value via variables by using PCA, (4) calculation of DEBI and commencement of validation tests. Our empirical analysis and the Hodrick-Prescott filter analysis show that DEBI is highly related to existing economic indices.

• Spatial Information Research
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• 제20권6호
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• pp.69-76
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• 2012

본 연구에서는 산업연관분석을 통해 공간정보산업의 특징을 도출하였다. 이를 위하여 공간정보산업을 재분류하고 이에 맞게 산업연관표를 수정하여 공간정보산업을 분석하였으며 생산유발계수, 영향력계수, 감응력계수를 도출하였다. 그 결과 공간정보산업은 생산유발효과는 작으나 전방연쇄효과가 매우 큰 산업으로 확인되었다. 이를 기반으로 공간정보산업 육성을 위한 정책의 방향성을 '산업생태계 조성, 고도화와 활용도 향상 병행, 장기적 관점 수립'으로 제시하였다.

• 동아시아경상학회지
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• 제9권1호
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• pp.41-51
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• 2021

Purpose - The purpose of this study is to propose strategies of improving efficiency of 20 listed port companies in China based on analysis of their input-output indexes from 2014 to 2018. Research design, data, and methodology - In this paper, the relevant input-output indicators of 20 listed port companies in China from 2014 to 2018 were adopted. Data derived from the company annual reports announced by Shanghai stock exchange and Shenzhen stock exchange. Comprehensive efficiency and pure technical efficiency were measured from output perspective by DEA and Malmquist index, and efficiency changes and regional efficiency were analyzed. Result - The results showed that the efficiency value of 20 listed port companies in China fluctuated and increased during 2014-2018, regional efficiency was unbalanced, and change of MPI was influenced by internal factors and external factors. Listed port companies affected by internal and external factors needed to make appropriate response to internal and external factors. Conclusion - The research conclusion can provide important reference information about management and planning for port companies in China and related areas. However, this paper is limited to the availability of data. So the improvement scheme for listed companies in inefficient regional ports needs further study, such as using AHP method.

• 동력기계공학회지
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• 제3권4호
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• pp.69-78
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• 1999

In the single-input and single-output system, the parameter of plant is scalar polynomial, but in the multiple input and multiple output, it accompanies, being matrix polynomial, the consideration of observable controlability index or problems non-commutation in matrix polynomial as well as degree, and it is more complex to deal with. Therefore, it is thought that a full research on the single-input and single-output system is not sufficient. This paper proposes that problems of minimum variance self-tuning regulator by using numerical calculation example of multivariable system and pole assignment self-tuning regulator.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.322-326
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• 1989

This paper describes design procedure of suboptimal control to minimize a performance index which is represented as sum of square output error and the heat input power in arc welding process. Heat input and temperature of a fixed point on the surface of the material are concerned as input and output of the process, repectively. The suboptimal control law considered here in is a proportional plus integral type and is implemented by using only the output variables available from sensor which is also optimally located in a fixed point w.r.t. a moving weld touch.

• 한국정보관리학회:학술대회논문집
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• 한국정보관리학회 2015년도 제22회 학술대회 논문집
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• pp.23-27
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• 2015

한 논문에 대하여 참고문헌의 인용빈도로 원 논문을 평가하는 outgrow index와, 인용논문의 인용빈도로 원 논문을 평가하는 single paper h-index를 비교해보았다. KCI 문헌정보학 분야 논문을 대상으로 시험 적용해본 결과 outgrow index의 값과 single paper h-index의 값이 비례하지 않음을 알 수 있었다. 한 논문을 outgrow index와 single paper h-index로 분석하여 다면적인 논문 평가 도구로 활용될 가능성을 검토해본다.

• 통상정보연구
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• 제18권1호
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• pp.235-258
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• 2016

본 연구는 산업연관표를 중심으로 2011년~2013년 기간의 실측표기준의 투입산출물표(Input-output Table)를 사용하여 동 기간의 국내 해외직접투자(FDI) 유입액을 한국표준산업분류(KSIC 30부문)기준으로 재분류 및 통합하여 적용한 결과 3개년 평균 국내 외국인직접투자 유입액은 15조 3,000억원이고, 평균총생산유발액은 45조 8,000억원으로 추계되었다. 국내 외국인직접투자 유입의 특징은 감응도계수 및 영향력계수가 큰 산업인 화학제품, 전기 및 전자기기, 금속제품에 편중되어 있다. 특히 중간재로 활용되는 감응도계수가 큰 산업에 국내 외국인직접투자 유치가 이루어지면 국내 경제적 산업파급효과가 큰 것으로 나타난다.

• Journal of Information Science Theory and Practice
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• 제5권2호
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• pp.48-61
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• 2017

This paper uses 601 cited papers of Pakistani LIS researchers with the purpose to examine the individual performance of these Library and Information Science (LIS) researchers in terms of their research output and its impact on the LIS (national/international) literature by using various bibliometric indicators. A list of 139 authors was compiled with the help of the Library, Information Science, and Technology Abstracts (LISTA) and some other sources. Data were collected from Google Scholar and SPSS version 20 was utilized in order to identify the relationship between self-citations and various performance indices of the authors. The average citations received per paper vary from 1.80 to 10.08. About half of the papers were single-authored whereas less than one-fifth were by three or more authors. The authors who worked in collaboration produced more papers and received more citations. The h-index, g-index, hI-index, hI-norm, and e-index were used to determine the rank for each author. The intra-group citations grid revealed the volume of self-citations and a small group who cite each other more due to close academic and social relationships. The correlations between self-citations and the impact indices used revealed significant differences. Findings are useful for concerned institutions regarding award, promotions, etc. Further, future research should seriously consider the self-citations and social networking of authors while examining their citations-based research performance.

• 센서학회지
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• 제29권3호
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• pp.172-179
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• 2020

We studied an integrated-optic biosensor configuration that operates at a wavelength of 0.63 ㎛ based on the evanescent-wave and two horizontal mode power coupling of Si₃N₄ rib-optical waveguides formed on a Si/SiO₂/Si₃N₄/SiO₂ multilayer thin films. The sensor consists of a single-mode input waveguide, followed by a two-mode section which acts as the sensing region, and a Y-branch output for separating the two output waveguides. The coupling between the two propagating modes in the sensing region produces a periodically repeated optical power exchanges along the propagation. A light power was steered from one output channel to the other due to the change in the cladding layer (bio-material) refractive index, which affected the effective refractive index (phase-shift) of two modes through evanescent-wave. Waveguide analyses based on the rib optical waveguide dimensions were performed using various numerical computational software. Sensitivity values of 12~23 and 65~165 au/RIU, respectively for the width and length of 4 ㎛, and 3841.46 and 26250 ㎛ of the two-mode region corresponding to the refractive index range 1.36~1.43 and 1.398~1.41, respectively, were obtained.