• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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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.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.7
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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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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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.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.2
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• pp.37-43
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• 2009

In this study, multi-channel digital hearing aid algorithm for low power system is proposed. First, MDCT(Modified Discrete Cosine Transform) method converts time domain of input speech signal into frequency domain of it. Output signal from MDCT makes a group about each channel, and then each channel signal adjusts a gain using LCF(Loudness Compensation Function) table depending on hearing loss of an auditory person. Finally, compensation signal is composed by TDAC and IMDCT. Its all of process make progress 16-bit fixed-point operation. We use fast-MDCT instead of MDCT for reducing system complexity and previously computed tables instead of log computation for estimating a gain. This algorithm evaluate through computer simulation.

• Korean Journal of Organic Agriculture
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• v.29 no.4
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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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• v.23 no.4
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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.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.386-396
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• 2022

To analyze the influence of variables of roadheaders, the linear cutting testing data of pick cutter were collected from the former literatures. The input factors were set up as uniaxial compressive strength, cutting depth, cutting spacing, attack angle, skew angle, and output factors were determined as specific energy, average cutting force, maximum cutting force, average vertical force, and maximum vertical force. After composing a table of the design of experiment (DOE). The contribution level of each factor was calculated by analysis of variance (ANOVA). As a result, the factors having greatest influence on cutting force and specific energy were uniaxial compressive strength and cutting spacing.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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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.

• The Journal of Information Systems
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• v.20 no.3
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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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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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.