• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.243-246
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• 2010

Recently, global warming problem is a major issue in international community. The carbon dioxide ($CO_2$) emissions in the construction industry is one of the main factors causing a global warming problem. Accordingly, various researches on $CO_2$ emissions caused by the construction industry is needed and construction methods which is low $CO_2$ emissions should be developed. In this study, $CO_2$emission cost is compared with roof waterproofing types in construction phase. As a result, the $CO_2$ emission costs of asphalt waterproofing is the highest. This research is to provide basic information for selecting appropriate construction methods in aspect of low $CO_2$ emission cost.

• 한국지능시스템학회논문지
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• 제11권7호
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• pp.569-573
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• 2001

An approximate representation of discrete functions {f$_{i,j}\mid$｜i, j=-1, 0, 1, …, N+1}in two variables by a fuzzy system is described. We use the cubic B-splines as fuzzy sets for the input fuzzification and spike functions as the output fuzzy sets. The ordinal number of f$_{i,j}$ in the sorted list is taken to be the out put fuzzy set number in the (i, j) th entry of the fuzzy rule table. We show that the fuzzy system is an exact representation of the cubic spline function s(x, y)=$\sum_{N+1}^{{i,j}=-1}f_{i,j}B_i(x)B_j(y)$ and that the approximation error S(x, y)-f(x, y) is surprisingly O($h^2$) when f(x, y) is three times continuously differentiable. We prove that when f(x, y) is a gray scale image, then the fuzzy system is a smoothed representation of the image and the original image can be recovered exactly from its fuzzy system representation when it is a digitized image.e.

• 전기학회논문지
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• 제59권2호
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• pp.390-396
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• 2010

An 80MHz surface acoustic wave (SAW)-based gyroscope utilizing a progressive wave was developed on a piezoelectric substrate. The developed sensor consists of two SAW oscillators in which one is used for sensing element and has metallic dots in the cavity between input and output IDTs. The other is used for a reference element. Coupling of mode (COM) modeling was conducted to determine the optimal device parameters prior to fabrication. According to the simulation results, the device was fabricated and then measured on a rate table. When the device was subjected to an angular rotation, oscillation frequency differences between the two oscillators were observed because of the Coriolis force acting on the metallic dots. Depending on the angular rate, the difference of the oscillation frequency was modulated. The obtained sensitivity was approximately 52.35 Hz/deg.s within the angular rate range of 0~1000 deg/s. The performances of devices with three IDT structures for two kinds of piezoelectric substrates were characterized. Good thermal stability was also observed during the evaluation process.

• 한국정보전자통신기술학회논문지
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• 제2권2호
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• pp.37-43
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• 2009

본 논문에서는 저 전력 시스템에 적합한 고정 소수점 연산기로 구현된 다중 채널 디지털 보청기 알고리즘의 최적화 기법을 제시한다. 먼저 입력 신호를 고속 MDCT(modified discrete cosine transform) 방법을 사용하여 주파수 대역 분할함으로써 알고리듬의 복잡도를 최소화 하였고, MDCT 출력을 비선형 대역 분할 과정을 거쳐 채널별 그룹핑을 한 다음, 각 채널 신호를 난청인의 청각 손실 정도에 따라 구성한 라우드니스 보상 함수(loudness compensation function: LCF)표를 이용하여 이득을 조절하고, 최종적으로 TDAC 기법을 구현하는 IMDCT(Inverse MDCT) 변환을 거쳐 보상된 출력을 합성한다. 모든 과정은 16비트 정수 연산으로 구현되며, 이득을 계산하기 위해 측정되는 로그 단위의 연산 과정은 미리 계산된 테이블과 고속 탐색 알고리듬을 이용하여 구현된다. 구성된 보청기 알고리즘의 성능을 컴퓨터 시뮬레이션을 통해 평가하였다.

• 한국유기농업학회지
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• 제29권4호
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• pp.459-469
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• 2021

Until now, research on inter-Korean economic cooperation and economic integration has been limited to the areas of the two Koreas. However, Korea is connected with many countries in Asia through the global value chain. Thus, if inter-Korean trade deepens, it may affect the trade structure of neighboring countries. In order to establish a specific inter-Korean economic integration policy when North Korea becomes a normal state in the future, an analysis that reflects the trade structure including Northeast Asia must be preceded. Therefore, in this paper, the impact of inter-Korean trade on Korea, China and Japan was analyzed using the international input and output table containing actual trade data. The scope of analysis was limited to agriculture, reflecting North Korea's demand for economic cooperation. The results show that trade in the agricultural sector between the two Koreas did not have a significant effect of production and value added. but when China and Japan participate in trade with North Korea, the production effect was calculated to be as high as 4 million dollars in Korea and up to 10 million dollars in Japan. And China showed up to 520 million dollars. In addition, the value-added effect was calculated up to $1 million in Korea, up to $4 million in Japan, and up to $250 million in China.

• Journal of Korea Trade
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• 제23권4호
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• pp.103-114
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• 2019

Purpose - This paper investigates the structure of exports across countries in terms of value added. Exports value added is examined under two categories, domestic and overseas. Using a statistical classification method by distance based on these two value added categories, this paper estimates the similarity of exports value added across countries including Korea. Design/methodology - The model of study is to employ a generalized distance function and then derive the Manhattan and Euclidean distances. The paper also performs cluster analysis using the Partitioning Around Medoids (PAM) and hierarchical methods to classify the 44 sample countries considered in this study. Findings - Our main findings are as follows. The 44 countries can be classified under 5 groups by their domestic and overseas value added in exports. Korea has a sandwich global value chains (GVCs) position between Japan, China, and Taiwan in the East Asian region. Originality/value - Existing papers point out the double counting problem of trade statistics as the intermediate goods trade across borders increases. This paper addresses the double counting problem by using the World Input-Output Table. The paper shows the need to explore the similarity of value added in exports structure across countries and investigate the GVCs position and role of each country.

• 터널과지하공간
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• 제32권6호
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• pp.386-396
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• 2022

로드헤더에 미치는 변수의 영향력을 분석하기 위해 픽커터 절삭시험 관련 참고문헌들을 조사하였고, 수록된 데이터들을 수집하였다. 입력 인자는 일축압축강도, 절삭 깊이, 절삭 간격, 받음각, 비틀림각, 출력 인자는 비에너지, 절삭력, 수직력으로 결정했다. 입력 인자와 출력 인자로 분류 후 실험계획법을 작성하였고 분산분석을 이용해 변수들에 대한 기여도를 조사하였다. 그 결과, 절삭력과 비에너지에 가장 큰 영향을 미치는 요인은 일축압축강도와 절삭 간격으로 분석되었다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.77-77
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• 2020

2019년 12월 발병한 코로나19(COVID-19)는 높은 전파력을 바탕으로 세계적으로 대유행하면서 사람들의 생명, 건강을 비롯하여 생산·소비활동까지 위협하고 있다. 코로나19는 치료제 개발 전까지 실물경제에 직접적으로 타격을 주면서 국내외 경제 전반에 악영향을 지속적으로 미칠 것으로 예상된다. 특히 외부활동 및 소비심리 위축으로 숙박, 음식, 관광, 문화, 여행 등의 대면서비스 업종의 심각한 매출 감소 및 고용악화가 발생하고 있으며, 이 외 대부분의 산업에서도 생산과 소비활동이 위축되고 있다. 이러한 소비·생산활동의 위축은 각 산업에 필요한 중간재 수요, 특히 필수재인 물이용에도 영향을 미치게 된다. 이에 본 연구에서는 코로나19 확산으로 소비가 감소할 경우 전산업과 물산업에 미치는 경제적 손실을 1년간의 모든 실물거래 관계를 행렬로 기록한 통계표인 산업연관표(input-output table)을 활용하여 분석해보았다. 이를 위해 전월대비 3월 소비자심리지수 하락 폭을 참고하여 소비 감소에 따른 시나리오 분석을 산업연관분석을 통해 실시하다. 분석결과, 5개월 동안 소비가 20% 감소하는 경우 전산업과 물산업에서 각각 48.3조원과 886억원의 생산감소가 발생하며, 부가가치는 각각 21.7조원과 451억원이 감소하는 것으로 분석되었다.

• 한국정보시스템학회지:정보시스템연구
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• 제20권3호
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• pp.187-207
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• 2011

As the IT labor captures an increasing proportion of the total labor, it is important to analyze the contribution of IT labor to national economy. Although there has been abundant research about the effect of IT investments, it is difficult to find a research about IT labor's economic contribution. Most prior studies on the effect of IT investment have focused on the effect of IT capital investment. This paper empirically explores whether and how IT labor makes contribution to Korean economy. And also this paper examines the economic contribution of IT experts and semi-experts in Korean industries over the 2000 to 2007 period, using production function framework and panel data set for 24 industries constructed from 'Input-Output table' and 'Research on Wage Structure Survey'. Based on the full sample of 120 observations, this study finds that a 1% increase in IT labor wage is associated with 0.042190% increase in added value. In the case of non-manufacturing industries on the sample of 50 observations, this study finds that a 1% increase in IT labor wage is associated with 0.074908% increase in added value. And in the case of IT experts (separated from IT semi-experts), this study finds that a 1% increase in IT expert's labor wage is associated with 0.013957% increase in added value of all industry. This study provides implication for policy makers and managers. The results suggests that non-manufacturing industries can capture further benefits by increasing investment in IT labor. Building on this study, future research should examine the impact of IT labor at a more detailed industry level and the firm level.

• 전기학회논문지
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• 제65권1호
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• pp.97-102
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• 2016

In this paper, a bidirectional power supply charger is proposed. This system used a solar cell panel to generate electricity and used super capacitors to store these energies, which can be used for the robot cleaner or some other electronic products. This system include a phase-shift controlled bidirectional dual active bridge (DAB) converter, solar panel super capacitors and DSP controller. In the daytime it can charge to the super capacitors to store the energy generated by the solar cell panel and in the night it will release the energy stored in the super capacitors to loads. A prototype of the proposed bidirectional power supply charger system was designed which can achieve 18V to 30V input, 10V/20W output to super capacitors and 9V/6.5W output when it acts as a charger for the robot cleaner. The system is verified to be sTable and reliable by both the simulation and experimental results.