• Journal of the Korean association of regional geographers
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• v.15 no.6
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• pp.752-762
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• 2009

This paper aims to investigate the characteristics of location and business-services networks of venture firms in Daegu region. The regional venture firms are small scale and consist of mainly R&D investment and license new-technology in the category of soft-ware. Since the mid-1990's the firms that were founded by people with higher education and career experience seek diverse growth strategies. those firms concentrate in some regions of dalseo-gu and buk-gu. There are a few difference by types of firm-business, but, on the whole, the princepal location factors of venture firms are accessibility of research institute and university, easy information availability, and use of moderate land. In regard to networks with client firms, the venture firms determine whether to transfer. The result of the characteristics of networks between regional venture firms and business-service enterprises is as follows; the regional venture firms utilize small number of business-service enterprises and use mainly information processing and other computer operation related services and professional, scientific and technical services. In business-service be used by regional venture firms, the frequency of information processing and other computer operation related services, research and development, business support services is much, while the frequency of professional, scientific and technical services is little. Business-service enterprises are distributed mostly in Daegu region and are used owing to lack of technology and knowledge.

• Economic and Environmental Geology
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• v.47 no.6
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• pp.625-633
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• 2014

The Aquistore project is the world's first commercial capture, transportation, utilization and storage project of post-combustion $CO_2$ from a coal-fired thermo electric power plant, and the proposed storage is a saline aquifer at a depth of about 3,500 m. Deep saline aquifer, compared to hydrocarbon reservoir, provides the great volumetric potential for storage of $CO_2$ anywhere in the world, therefore the research results from the project may be exported globally to other sites. Geological $CO_2$ storage characterization for saline aquifer instead of hydrocarbon reservoir needs to estimate the geophysical properties of subsurface geology. This study calculated the geophysical property of water-saturated formation by applying amplitude variation analysis developed from oil and gas exploration. We correlated horizon tops at the well logs to seismic traveltime of 1,815 and 1,857 ms as Winnipeg and Deadwood formations. Gradient analysis from seismic traces showed correlation coefficient of 45 - 81 % on amplitude variation with respect to incident angle. Crossplot of intercept and gradient shows the inverse proportional trend which represents typical water saturated sediments. Product attribute of intercept and gradient described the base of wet sediment. Poisson's ratio change attribute increased at the top of target area satisfying with wet sediment and decreased at the top of basement in a dry rock bed.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.225-234
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• 2015

Nowadays a Virtual Power Plant (VPP) represents an aggregation of distributed energy resource such as Distributed Generation (DG), Combined Heat and Power generation (CHP), Energy Storage Systems (ESS) and load in order to operate as a single power plant by using Information and Communication Technologies, ICT. The VPP has been developed and verified based on a single virtual plant platform which is connected with a number of various distributed energy resources. As the VPP's distributed energy resources increase, so does the number of data from distributed energy. Moreover, it is obviously inefficient in the aspects of technique and cost that a virtual plant platform operates in a centralized manner over widespread region. In this paper the concept of the large-scale VPP which can reduce a error probability of system's load and increase the robustness of data exchange among distributed energy resources will be proposed. In addition, it can directly control and supervise energy resource by making small size's virtual platform which can make a optimal resource scheduling to consider of variable and sensitive load in the large-scale VPP. It makes certain the result is verified by simulation.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.213-222
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• 2018

This study attempts to empirically investigate the excess returns of growth stocks in the Korean stock market comparing with those of value stocks. Recently, a few of IT and bio-pharmaceutical stocks with high growth potentials have accomplished dramatically high returns in the Korean stock market. Whereas, important prior studies in this line have observed negative excess returns from investment of growth stocks on average. And a few studies have reported that the distribution of excess returns from growth stocks is not normal but positively skewed. Empirical results of the present study are consistent with those of prior studies. Interestingly, the present study observed serial inverse correlation between excess returns of growth stocks and value stocks. Also, regardless of growth or value stocks, the stocks with higher PEG(=PER/ROE) showed higher excess returns.

• Tunnel and Underground Space
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• v.21 no.3
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• pp.225-234
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• 2011

In this study, an in situ heater test for investigating the thermo-mechanical behavior related to heat flow was carried out. It was the first in situ heater test in Korea. For the test, an adequate design of heater, observation sensors, and data logging system was developed and installed with a consideration of the site condition and the test purposes. It was possible to observe that steep joints are overwhelmingly developed in the test area from a joint survey. The major rock and rock mass properties at the test site could be determined from the thermal and mechanical laboratory tests using the rock cores from the site. From the measured rock temperature distribution, it was possible to observe the influence of the rock joints and the heat flow through tunnel wall. When the heater temperature was maintained as $90^{\circ}C$, the rock temperature at 0.3 m from the heater hole was increased up to $40^{\circ}C$.

• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1065-1074
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• 2011

During several decades, many researchers in the field of finance have studied Value at Risk (VaR) to measure the market risk. VaR indicates the worst loss over a target horizon such that there is a low, pre-specified probability that the actual loss will be larger (Jorion, 2006, p.106). In this paper, we compare conditional copula method with two conventional VaR forecasting methods based on simple moving average and exponentially weighted moving average for measuring the risk of the portfolio, consisting of two domestic stock indices. Through real data analysis, we conclude that the conditional copula method can improve the accuracy of portfolio VaR forecasting in the presence of high kurtosis and strong correlation in the data.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.50-50
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• 2019

최근 국지성 호우 및 하천 제방의 노후화로 인한 제방 붕괴 피해가 빈번히 발생하면서 제방의 안정성 및 표면 보강을 위한 다양한 연구가 시도되고 있다. 본 연구에서는 제방 붕괴에 따른 피해 최소화 및 대책을 수립하기 위한 방법으로 시멘트와 같은 지구온난화를 야기시키는 물질이 아닌 친환경 신소재 바이오폴리머를 흙과 혼합한 재료를 활용하여 제방의 내구성을 강화하기 위한 연구가 수행되고 있다. 이에 안동하천실증연구센터에서는 현장토를 사용하여 높이 1 m, 폭 3 m, 사면경사 1 : 2, 총 길이 5 m 의 중규모 제방모형을 제작하였으며, 공동연구기관인 카이스트에서 개발된 바이오폴리머와 흙을 적정 비율로 혼합한 바이오-소일을 제방 전면에 일정 두께로 피복하여 월류 발생에 따른 제방 안정성 평가 실험을 수행하였다. 1차 실험은 흙 제방 조건이며, 2 3차 실험은 제방 표면에 5 cm 두께로 신소재가 피복된 조건으로 안정된 결과 도출을 위해 반복 실험을 수행하였다. 제방 천단면 및 사면에서의 유속분포를 측정하기 위해 드론 및 비디오카메라를 활용한 LSPIV 기법을 적용하여 실험조건에 따른 표면유속과 월류 흐름이 제방 붕괴에 미치는 영향에 대해 비교분석하였다. 또한 그래픽 소프트웨어를 이용한 픽셀기반 영상분석 기법을 적용하여 시간에 따른 제방사면의 붕괴면적을 산정하여 신소재 피복에 따른 붕괴 지연효과 분석을 통한 신소재 활용 제방의 현장 적용가능성 및 안정성을 평가하였다. 본 연구결과, 흙 제방의 경우 월류 흐름 발생 직후 침식현상이 전개되어 유속분포가 집중되고 있었으며, 이후 발생하는 강한 수직흐름으로 인해 입자추적을 통한 분석이 더 이상 불가능하였다. 신소재 제방의 경우 월류 흐름 발생 직후 침식은 발생하지 않았으며 일정시간동안 유속분포가 유지되었다. 지속적인 월류 흐름으로 인해 제방 끝단에서 침식이 발생하였으며 이때 최대 유속은 3.3 m/s 로 나타났다. 또한 픽셀기반 분석을 통해 30초 단위로 표면손실률을 산정한 결과, 신소재 활용 제방(2, 3차)의 경우 같은 실험조건에도 불구하고 최종 붕괴시간은 약 3배의 차이를 보였으며, 양생 과정에서의 크랙 발생을 최소화한다면 월류 발생 시 상당한 붕괴지연효과가 있는 것으로 판단된다.

• Journal of the Korean Geographical Society
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• v.29 no.2
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• pp.202-215
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• 1994

This research aims to introduce the theoretical basis of the studies of tourism resources, by review the research trends of tourism resources in the geography field. The geographical approaches to tourism resouces can be subdicided into 3 categories according to the subject. First, the classification of tourism resource types and the approach on the spatial distribution may be enumerated. This subject has been the object of the most interest and discussion to the geographers for tourism up to now. And from the viewpoint of contents, it has been developed by classifying the types of tourism resoures, which is based on the establishment of the range and standard of tourism resources and the spatial classification of types based on the distribution feature of the area. Second, the approach about cognition, preference and interpretation on the tourism resources as the background to induce tourism phenomenon and decide the tourism destination. Judging from the fact that most of this subject is starting from the behavioural study and that the right understanding and interpretation of tourism resource is the important factor to decide the preference degree of tourists, we have to have much interest about the field of tourism geoaraphy. Third, the development of tourism resources which is showing the active study recently and its influence and effect attendant upon it may be enumerated. Today, as the economic value of tourism is become important internationally, tourism resources are recognized as the important factor to induce the industrialization of tourism. And in the series of analytical studies related to it the interest has been transferred from the economic benefit analysis attendant upon tourism development including tourism resource and to the cultural, educational, environmental and psychological influence, etc. As the result of composite examination, for the geographical studies about tourism resources, the spatial scale and the contents are being subdivided and specialized. And in the side of subject and method of study, it is developing into the positive study based on the concrete data and the measuring and analytical frame.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.11a
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• pp.55-56
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• 2001

지난 수년간 유럽을 중심으로 Carbonate의 PSD (Particle Size Distribution)가 도공지 의 백색도, 불투명도, Coverage등에 미치는 영향에 대하여 많은 연구가 진행되어 왔다. 현재 국내의 Coating Pigment System 역시 Carbonate 위주로 구성되어 있으나, 입자 분포에 따른 실증적 연구가 선진국에 비하여 부족한 상태이다. 본 연구는 최근 유럽에서 사용 중인 Narrow PSD Carbonate가 도공지 품질에 미치는 영향을 검토한 것으로서, 특히 Multiple Coating에서의 도공층 구조변화와 그에 따른 백지물성 및 인쇄적성의 변화를 연구한 것이다. 실험의 Case는 Broad PSD CaC03와 Narrow PSD CaC03를 비 교하였 다 .. Color F Formulation은 Pre Color에서 #1 Clay 30 p따t와 각각 CaC03 70 p따t를 사용하였다. 그리고 바인더와 첨가제는 동일하게 사용하였다 .. Top color Formulation 또한 동일하 게 사용하였다. 코팅방식은 speed 450rrνmin, pre rod coating, top blade coating 방식 으로 CLC (Cy lindrical Laboratory Coater)를 사용하여 코팅하였다. 백지품질은 백색도, 평활도 ,광택도, 거칠음도, Bum Out Test와 Coverage( SEM 사 진 Z -direction) 등을 측정하였다. 인쇄품질은 인쇄 광택도, 인쇄 Picking strength와 2 도 인쇄 농도를 측정하였다. 백색도는 Narrow PSD CaC03를 사용한 것이 Broad PSD CaC03를 사용한 것 대비 약1% 우수하였다. 이것은 Narrow PSD CaC03를 사용한 것이 filter cake이 많이 open 되 어 있어 dewatering이 빠르고, Wet void volume이 증가되 어 부동화점 의 농도가 낮 아져 원지 층으로 침 투되 는 pigment가 작고 표층에 잔류하는 pigment와 void volume의 증가로 인해 기공층이 증가한 것으로 판단된다. 그리고, 백지광택도, 거칠음도 등 또한 Narrow PSD CaC03를 사용한 것이 우수하였 다. 이는 Pre color에서 coverage의 개선으로 top color층의 도공량 uniformity가 개선 된 이유라고 생각한다. 그러나 인쇄품질은 백지와 비교하여 차이가 없었다. 이것은 top 칼라 Formulation이 동일하고, 인쇄시 잉크흡수 거동은 top color 층에 주로 영향을 받기 때문이라고 판단 된다. 향후에는 인쇄품질의 향상을 위하여 Case 2의 CaC03 100% 사용가능성 및 Pre Color 는 Case 2로 고정하고, Top칼라를 변경하는 방법을 또한 생각할 필요가 있다고 판단된다.

• Environmental and Resource Economics Review
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• v.17 no.3
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• pp.1-29
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• 2008

The goal of this study is to analyze the effects of the second energy tax reform of the transportation sector in Korea. For this purpose, we estimated the elasticities of energy demand(for gasoline, diesel and LPG) by using the ARDL(Auto-Regressive Distributed Lag) Model during the period of 1997 and 2005. We have the empirical results that the demand for diesel would decrease as much as of 382 million barrel per year and the demand for LPG would increase as much as of 20 million barrel per year since 2007. The second energy tax reform would also result in the decrease of 27,346 ton of air pollutants and 0.96 million ton of carbon dioxide per year. This shows that the second energy tax reform would have achieved its own policy goals by reducing energy demand and improving the quality of environment.