• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.2
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• pp.73-85
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• 2016

Systematic and efficient forestry management is required because of the long-term low profitability of timber production and forest products. In this situation, non-timber forest products can be the solution to secure stable sources of income for workers in the forestry field. However, the existing studies for non-timber forest products focus on effective production and economic analysis and provide plans for increasing the income and improving the marketing system. Therefore, this research intends to analyze the spatial distribution as well as quantitative concentration of non-timber forest production. To achieve this goal, this study examined the regional concentration and dispersion of non-timber forest production in 2001, 2007, and 2014 using the coefficient of localization(CL) and location quotient(LQ) and investigated the change in spatial distribution using spatial statistics. The production of chestnuts generally showed a concentrated pattern in 2014 based on the outputs of the CL and LQ, but the result of spatial autocorrelation indicated a decrease in the spatial concentration. In addition, astringent persimmon showed more concentration from the output of CL than oak mushroom, but Moran's I suggests the opposite. Therefore, it is necessary to examine the spatial distribution to understand and improve the marketing system and intensify the production of forest products.

• KDI Journal of Economic Policy
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• v.19 no.4
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• pp.159-215
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• 1997

전기요금수준과 요금체계는 산업의 생산비와 가계의 소비생활패턴에 직접적인 영향을 미쳐, 생산활동 산업구조 소비형태에 변화를 초래한다. 또한 적정요금의 부과는 미래의 전력수요에 부응하는 전원개발의 비용확보와 이를 통한 전력수급 안정에 필수적인 사항이다. 전기요금체계가 경제적으로 효율적인 한계비용방식으로 장기적으로 전환되겠지만 이에는 상당한 시간이 필요하다고 예상되므로, 본 논문에서는 현재 한전이 택하고 있는 평균비용방식에 의거한 용도별 요금체계의 문제점을 지적하고 중단기적 개선방안을 제시한다. 현재 용도별 요금에서의 문제점을 지적하자면, 일반용요금은 평균비용에 비해 과다하게 높은 데 반해 농사용요금은 과다하게 낮다. 또한 일반용에서 계시별 구분을 적용받는 소비자가 너무 적으며 선택요금이 다양하지 못하다는 문제점이 있다. 주택용요금은 평균비용과 상당한 괴리가 있으며, 현재의 7단계분류는 보통 외국의 3단계 분류에 비해 복잡하며 단계별 누진율이 과다하게 높다. 주택용의 기본요금과 전력량요금이 모두 누진적이나 이에 대한 경제적 논거가 약하다. 전기요금의 중단기적 개선의 기본방향은 한계요금체계에의 근접화, 정책적 왜곡의 최소화, 수요관리 요금체계의 강화로 정리될 수 있다. 현재의 전기요금체계는 산업정책 소득정책 정치적 선택 등 정책적 요소를 혼용하고 있는데, 정부의 경제개입이 줄어드는 추세에 맞추어 전기가 필수재라는 요소 이외의 정책적 요소는 사라져야 한다. 또한 전기가 피크기의 수요에 맞추어 용량을 확보해야 하는 특성을 가지고 있으므로 피크기의 수요관리는 설비비용의 절약으로 소비자 모두에게 혜택을 줄 수 있다. 본 논문에서는 위의 기본방향을 기반으로 하여 구체적 개선방안으로 산업용 일반용 교육용의 전압별 통합, 산업용 일반용의 선택요금 및 차등폭 확대, 요금의 비용 근접화, 농사용내의 구분 단일화, 주택용의 체계 단순화, 누진율의 대폭 완화, 하계수요관리 요금의 도입, 계시별 차등요금시간대 단순화를 제안한다. 이러한 개선방안은 현재의 전기요금체계를 경제학적 논리기반에 근접화시키고 좀도 효율화 합리화시킬 수 있을 것이다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.99.1-99.1
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• 2017

$TiO_2$는 기계적, 화학적 안정성이 높아 가혹한 화학적 환경 또는 고온 운전 조건에서 훌륭한 내구성을 보여주어 산업적으로 일찍이 널리 이용되어 왔다. 예를 들어, 염소발생 (chlorine evolution reaction) 또는 산소발생반응은 (oxygen evolution reaction) 염소 또는 산소 라디칼에 전극이 지속적으로 노출되기에 강한 내부식성을 지닌 전극재가 요구되었고, 그 결과 $TiO_2$를 골조로 한 불용성전극 (dimensionally stable anode)이 개발되어 이용되고 있다. 그러나, $TiO_2$는 절연성이 높은 금속 산화물 재료이기 때문에 넓은 표면적 획득 및 촉매제 사용을 통해 소재의 단점을 극복해야만 한다. 넓은 반응 표면적 획득의 한 방법으로써 전기화학적 양극산화 (electrochemical anodization)를 통한 $TiO_2$ 나노튜브 제조법은 경제적이면서도 구조 제어도 간편한 방법이다. $TiO_2$ 나노튜브는 100nm 전후의 기공 크기를 가짐과 동시에 매우 높은 종횡비를 지니고 있어 넓은 반응 표면적 획득에 특히 유리하다. 그러나, 이 높은 종횡비는 촉매 도입을 어렵게 하는 저해요소가 되기도 한다. 이러한 문제를 해결하기 위하여 다양한 방법들이 연구되었으나 대부분이 번거롭거나 비싼 후단공정을 필요로 한다. 본 연구에서는 $TiO_2$ 나노튜브에 촉매를 도핑하기 위한 간단한 전기화학적 방법으로, 단일공정 양극산화법 (single-step anodization)과 전압충격법 (potential shock), 그리고 저전압충격법 (under potential shock)을 연구하였으며 이에 적용 가능한 촉매제의 종류를 소개한다. 또한, 촉매의 성질에 따른 응용분야와 그 성능평가 결과를 제시한다.

• Journal of the Korean GEO-environmental Society
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• v.6 no.3
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• pp.17-23
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• 2005

In Korea, the production of reclaimed concrete materials has been increased due to the increase in the concrete structures taken down every year. The reclaimed concrete materials have been reused as road materials. However, the studies on their mechanical and environmental properties have been very limited. The recycled rate of the materials is currently low in Korea. This paper presents the investigation of mechanical and environmental properties of the reclaimed concrete materials, as well as the comparisons with those of gravel. For the evaluation of the mechanical and environmental characteristics, following tests were conducted on both reclamed materials and gravel; liquid limit, plasticity index, CBR, sand equivalent test, abrasion test, pH test, and column leaching test. The test results showed that the reclaimed concretes satisfy the requirements for use as roadbase, subbase, and subgrade materials, except base materials. The pH of reclaimed concrete materials was less than 11 and the leaching test results satisfied the regulatory requirement of Waste Management Act in Korea. Based on the investigations, it appears that the reclaimed concrete materials are environmentally safe and applicable for use as road materials.

• Journal of the Korean Geotechnical Society
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• v.30 no.6
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• pp.51-59
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• 2014

Shallow landslides and debris flows are a common form of soil slope instability in South Korea. These events may be generally initiated as a result of intense rainfall or lengthening rainfall duration because of the effects of climate change. This paper presents the evaluation of rainfall-induced natural soil slope stability and reinforced soil slope instability under vertical load (railway or highway load) throughout South Korea based on quantitative analysis obtained from 58 sites rainfall observatories for 38 years. The slope stability was performed for infinite and geogrid-reinforced soil slopes by taking an average of maximum rainfall every ten years from 1973 to 2010. Seepage analysis is carried out on unsaturated soil slope using the maximum rainfall at each site, and then the factor of safety was calculated by coupled analysis using saturated and unsaturated strength parameters. The contour map of South Korea shows four stages in 10-year-time for the degree of landslide hazard. The safety factor map based on long term observational data will help prevent rainfall-induced soil slope instability for appropriate design of geotechnical structures regarding disaster protection.

• Journal of the Korean Wood Science and Technology
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• v.31 no.4
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• pp.8-15
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• 2003

This study was carried out to investigate the dimensional stability of wood treated with PEG for better utilization of domestic small-diameter logs. Four species of ring- porous wood(Quercus mongolica F_ISCH, Quercus variabilis B_LUME, Fraxinus rhynchophylla H_ANCE, Paulownia coreana U_YEKI,) and four species of diffuse-porous wood(Prunus sargentii R_EHDER, Betula davurica P_ALL, Populus tomentiglandulosa T. L_EE, Cornus controversa H_EMSLEY) were used for this experiment. The shrinkage of wood decreased with increasing the concentration of PEG. The shrinkage of diffuse- porous woods was lower than that of ring-porous woods. The weight gain increased in proportional to the PEG concentration. Diffuse-porous woods showed a little higher weight gain than ring-porous woods. Bulking effect also increased with increasing the PEG concentration, but was in inverse proportional to the molecular weight of PEG. Diffuse-porous woods showed higher bulking effect than ring-porous woods. Consequently, diffuse-porous woods showed better dimensional stability than ring- porous woods. It was considered that dimensional stability was affected by characteristics of wood such as vessel and tylosis, and density.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.121-127
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• 1985

This study was designed to gain practical data on the use of soil conditioners for more efficient water managements and to establish the optimum levels of structural properties for soil conditioning. A sandy loam and a silt loam soil were each treated with two different soil conditioners, hydrophobic Bitumen or hydrophilic Uresol. The perspex tube 34 cm long were packed homogeneously with air dried soil up to 2 cm below the top, then covered over 2 cm of treated or untreated aggregates. The infiltration rate into the soil columns was measured under simulated rainfall condition. The evaporation study was carried out in the wind tunnel, and the changes of soil moisture distribution of the columns following and during the evaporation were determined by a gamma ray scanner. The infiltration rate of water into the soil column was increased to 18.7-50.8% by the Uresol treatment but it was decreased to less than 25% of control by the Bitumen treatment. Evaporation was decreased to 22.0-68.1% by the Bitumen treatment and to 38.7-68.4% by the Uresol treatment. The water use efficiency of Uresol treated column was increased to more than twice as much as that of untreated soil. Aggregate stability and wetting angle were related to water infiltration and evaporation. A positive and highly significant logarismic relationship was found between the infiltration rate and stability index-wetting angle, evaporation rate and instability index-wetting angle. It was considered that the structural stability is more important than wetting angle. This is true because the structural stability is always positively correlated to water saving, however wettability is positively correlated to the infiltration, and negatively correlated to water saving during the evaporation.

• Journal of Korea Technology Innovation Society
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• v.17 no.2
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• pp.355-379
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• 2014

For the transition to the low carbon society, it is inevitable but difficult journey that the new energy technology spread co-exists with formal social system. The objective of offshore wind power plant that has been implemented by the government is to connect large capacity new renewable energy to the central electric power system. Therefore, for the successful introduction of offshore wind power system, the transition of the formal social technology system should be companied. This study analysis the energy system transition about niche strategy adjustment using Multiple Level Perspectives & Strategic Niche Management. It also multi level analyzes and structuralizes the process that new technology, as a research result, evolves through connecting and communicating with formal regime and landscape. Also, adjusting Strategic Niche Management, it diagnoses the obstructive factors in the initial stage of niche experiment and found the major reasons why offshore wind power test plant had been delayed. Through this study, it reaches to the practical implication that offshore niche technology could grow stably in the energy system and various policies.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.249-249
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• 2010

핵융합로에서는 디버터의 열부하에 대한 안전성을 고려하기 위해 열전도도 및 열 저항성이 높은 텅스텐이 대면 물질로 고려되고 있으며, 경제적인 측면과 실용성 측면에서 텅스텐블록을 직접 제작하여 사용하는 것보다 텅스텐코팅이 효과적이라는 의견이 지배적이다. 또한 ASDEX Upgrade 에서는 탄소블럭에 텅스텐을 코팅하여 챔버 외벽 및 디버터 영역까지 구성하여 캠페인을 진행하였고, 재료적인 측면에서 안정성을 확인 하였다. 따라서 본 연구에서는 디버터 및 챔버외벽 등에 대한 대면물질을 구성하기 위해 상압 열플라즈마 제트를 이용하여 고온에서의 용융 및 냉각을 통해 모재에 텅스텐 피막을 적층하는 과정을 수행하고 있다. 기존의 연구를 통해 일부 공정 변수에 대해서는 이미 적정한 범위의 공정조건을 확보하였고, 기공도와 산화도 및 부착력 등의 물성치에 대한 추가적인 향상을 위해 주요 공정 변수에 집중하여 최적의 조건을 탐색하는 과정이 진행 중이다. 이를 위해 출력증가실험의 일환으로서 기존 36kW급 플라즈마 토치 전력을 한 단계 끌어 올려 48kW급 전력까지 단계적으로 상승시킴으로써 이에 따른 물성치 변화를 검증하고 있다. 현재 44kW 급까지 실험이 수행되었으며, 이를 통해 공극률 감소 및 미세구조 변화에 대한 결과를 얻었다. 실제로 토치의 출력을 증가시킴으로서 텅스텐 피막의 물성치가 변화하는 메커니즘은 플라즈마 제트의 중심부 온도 및 축방향 속도에 의해 결정된다. 중심부 온도가 상승하게 될수록 코팅을 위해 분사되는 분말의 용융률은 증가하지만 분말 외벽에 산화텅스텐이 형성될 가능성은 증가하게 되며, 플라즈마 제트의 모재를 향상 축방향 속도가 증가할수록 용융 된 분말이 모재에 증착 시 형성하는 형태가 원형에 가깝게 되므로 기공이 감소하는 효과가 발생한다. 특히 용융된 분말의 증착 형태는 모재의 온도 및 분말의 입사속도에 결정적이 영향을 받게 되며, 결국 모재와 분말사이의 습윤성에 의한 분말 분산속도가 분말의 입사속도에 버금갈 경우 분말은 모재 위에서 효과적으로 원형으로 전이하며 적층하게 된다. 이러한 전이 현상은 앞에서 언급한 모재의 온도 등에 의해 결정적으로 영향을 받게 되며, 모재의 온도가 전이온도 이하일 경우 폭파형태에서 원형으로 분말의 증착 형태가 전이하게 된다. 이외에 추가적으로 진행하고 있는 연구는 코팅 전처리에 해당하는 분말 효과이며, 특히 탄화텅스텐 분말을 통한 재료적 auto-shroud 효과와 미세분말을 이용한 분말 표면열속의 증가에 따른 용융률 증가효과를 연구에 포함할 계획이다. 이러한 연구는 열적, 그리고 재료적 해석을 바탕으로 해석적 접근을 통해 이루어진다.

• Economic and Environmental Geology
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• v.11 no.4
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• pp.127-141
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• 1978

The major structures characteristic of the Taebaegsan sedimentary basin were regionally analyzed with special reference to its southeastern extension to the Yeonhwa-Ulchin district of economic interest in zinc-lead mineralization. The basin geometry, basement setting, sedimentary components, and the characteristics of deformation and igneous activity of the Taebaegsan basin differ basically from those of the adjacent mobile belt of the Ogcheon geosyncline, although the latter affected the basin's western side considerably. The subrectangular shape of the Taebaegsan basin reflects the checkered pattern of basement-block arrangement, and the carbonate-dominated lithologic components of the basin-fill indicate a cratonic depositional setting, which is comparable to some of the North American mid-continental craton. The Taebaegsan basin, however, has somewhat been less stable than the North American megacraton that is reflected in the former's thicker sedimentary fill and steeper faults of later deformation, showing a tendency to increase in thickness close to the basement-block boundaries, which may indicate contacts of possibly detached cratonic blocks of Precambrian age; these weak zones of block boundaries have been the loci of repeated sedimentation, deformation and related igneous intrusions. A series of downthrown or uplifted tilted blocks, in which the Cambro-Ordovician sedimentary wedges and the late Cretaceous to early Tertiary igneous intrusives are involved, occurs intermittently across the Yeonhwa-Ulchin district in a noticeable pattern of en echelon type. These sedimentary wedges are correlated to the Cambro-Ordovician section of the Hambaeg syncline to the west in stratigraphy and lithology, and are considered to have resulted from the northeastern and/or northwestern cross-faulting of the pre-existing syncline belt of easterly trend, extended from the main portion of the Hambaeg syncline. These structural junctions (or intersections) of the earlier syncline belt and the later cross-faults have been acted as a guide to ascending igneous materials and hydrothermal ore-forming fluids to form a zone of zinc-lead skarn deposits across the Yeonhwa-Ulchin district showing a stepwise recurrence of these deposits toward the east.