• 환경정책연구
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• 제9권2호
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• pp.135-155
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• 2010

본 논문의 목적은 강릉 남대천처럼 시민들과 매우 밀접한 관계에 있는 자연환경의 질이 악화될 경우 시민들의 후생에 얼마나 큰 영향을 미치는지를 조건부가치측정법을 통하여 평가하는데 있다. 분석 결과, 강릉 남대천은 상수원의 제공뿐만 아니라, 공익적 기능, 생태적 기능, 물놀이, 휴양 및 심미적 만족감을 제공하는 장소로서 중요하다고 인식되고 있으며 강릉 남대천의 수질을 개선하기 위한 총 지불의사액은 가구당 연간 117,040원이 도출되었다. 먼저 수질개선 부담금의 지불에 가구당 연평균 약 87,502원으로 나타났고, 자원봉사에 대한 기회비용 측면에서는 연평균 29,538원으로 나타났다. 위의 결과를 근거로 강릉시 전체로 확대할 경우 수질 악화에 의한 간접적인 후생변화는 연간 약 270억원으로 산출되었다. 이처럼 수질 악화에 의한 후생변화는 매우 크다고 볼 수 있다. 따라서 자연환경은 비가역적인 특징을 가지면서 한번 파괴되면 복원되는데 많은 시간과 비용이 수반되기 때문에, 자연환경의 변화는 궁극적으로 인간에게 영향을 미치게 된다. 그러므로 의사결정자들은 자연환경과 관련된 정책을 수립할 때 시장에서 평가되는 부분뿐만 아니라 시장에서 거래가 되지 않는 간접적인 부분까지도 충분히 고려하여야 정책의 효율성과 후생 증대의 목표를 동시에 달성할 수 있다.

• 한국화재소방학회논문지
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• 제31권1호
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• pp.42-49
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• 2017

본 논문은 가속열화에 따른 페놀수지 절연재료의 트래킹 특성에 관한 연구이다. 페놀수지 절연재료의 절연열화를 위해 가속수명 시험방법 중 아레니우스 방정식을 이용한 가속열화 실험을 진행하여 등가연수 0년, 10년, 20년, 30년, 40년 된 실험시료를 제작하였다. 그 후 가속열화된 실험시료를 대상으로 KS C IEC 60112 기준에 의한 트래킹 실험을 진행하였다. 가속열화에 따른 페놀수지의 트래킹 특성 측정결과 염화암모늄 0.1% 적하 시 등가수명 0년을 기준으로 위험성이 등가수명 10년 1.38배, 20년 1.45배, 30년 1.62배, 40년 1.94배 증가하는 것으로 나타났다. 염화암모늄 0.01% 적하 시 등가수명 년을 기준으로 위험성이 등가수명 10년 1.39배, 20년 1.52배, 30년 1.99배, 40년 5.30배 증가하는 것으로 나타났다. 실험 결과 노후화에 따른 절연열화가 오래될수록 트래킹 위험성이 커지는 것으로 나타났으며, 특히 등가수명 40년의 경우 그 위험성이 크게 증가하는 것으로 관측되었다. 따라서 노후화에 따른 절연열화 등의 위험성을 고려하여 제도적으로 권장 교체주기를 마련해 주는 것이 전기화재 발생 가능성 및 위험성을 최소화할 수 있을 것으로 생각된다.

• 한국화재소방학회논문지
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• 제33권2호
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• pp.114-123
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• 2019

본 논문은 IV 및 HIV 절연전선의 가속열화에 따른 절연피복의 성능변화에 관한 연구이다. IV 및 HIV 절연전선의 절연열화를 가정하기 위해 가속수명시험 모형 중 아레니우스 방정식을 이용한 가속수명시험을 진행하였고, 등가수명 0년, 10년, 20년, 30년, 40년 실험시료를 제작하였다. IV 및 HIV 절연전선의 가속열화가 진행됨에 따라 최대인장하중은 커지는 반면, 절연전선의 신장률, 파단시간, 유연성이 점차 감소되는 것으로 나타났다. 추가적인 주사전자현미경을 이용한 등가수명별 절연전선 표면 분석 결과 가속열화가 진행됨에 따라 시료 표면에 결정형 구조 및 천공 등의 현상이 발생되어 노후화에 따른 절연열화가 진행 될수록 절연체의 기계적 특성이 감소되는 것으로 나타났다. 따라서 절연성능 저하에 따른 전기화재 위험성을 사전에 예방하기 위해선 건축물 내에 설치되는 절연체의 성능저하를 고려한 제도적인 절연전선의 교체 및 보수시기의 마련이 필요할 것으로 생각된다.

• Journal of the Korean Wood Science and Technology
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• 제36권1호
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• pp.30-35
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• 2008

동해안 지역에서 산불로 고사된 소나무의 5년에 걸친 경시적 재질 변화를 역학성능을 중심으로 조사하였다. 고사에 따른 재질열화로 가장 크게 영향 받는 역학성능은 충격 휨 흡수에너지였다. 따라서 고사 초기의 재질변화를 예측하는 지표로 활용이 가능할 것으로 밝혀졌다. 고사 경과에 따라 변재의 재질열화가 심재에 비해 두드러지게 진행되었다. 열화의 정도는 충격 휨 흡수에너지가 가장 컸으며 압축강도가 가장 작았다. 고사 이후의 외관 변화와 역학성능의 열화진행 정도로 볼 때 산불피해 소나무의 유효한 활용을 위한 적정 벌채 시기는 산불발생 1년 이내가 바람직한 것으로 밝혀졌다.

• 한국암반공학회:학술대회논문집
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• 한국암반공학회 2008년도 국제학술회의
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• pp.3-16
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• 2008

The underground construction and mining are facing many geomechanics challenges stemming from, geological complexities and stress-driven rock mass degradation processes. Brittle failing rock at depth poses unique problems as stress-driven failure processes often dominate the tunnel behaviour. Such failure processes can lead to shallow unravelling or strainbursting modes of instability that cause difficult conditions for tunnel contractors. This keynote address focuses on the challenge of anticipating the actual behaviour of brittle rocks in laboratory testing, for empirical rock mass strength estimation, and by back-analysis of field observations. This paper summarizes lessons learned during the construction of deep Alpine tunnels and highlights implications that are of practical importance with respect to constructability. It builds on a recent presentation made at the $1^{st}$ Southern Hemisphere International Rock Mechanics Symposium held in Perth, Australia, in September this year, and includes results from recent developments.

• Korean Journal of Hydrosciences
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• 제2권
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• pp.115-126
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• 1991

The anaerobic digester with sludge from sewage treatment plant was operated in the laboratory for two year to investigate the enumeration and activity of methanogenic microorganisms. In this experimental study, the effects of HRT on the degradation characteristics of organic materials and on the number of methanogenic bacteria produced were investigated. By making the media with the repeated wxperiment, the number and activity of methanogenic bacteria were measured. The increase of the removal rate of organic acid in the digester was oberved at HRT of 2 days. The total number of methane forming bacteria estimated by the MPN method showed 2.3 $\times$ $ at HRT of 3 days, 7$\times$$ of 5 days and 7.9$\times$$ $/ml of 10 days. The optimum incubation time for measuring the number of methanogenic bacteria was found as more than four weeks. The PMA revealed 161ml CH$/l day at HRT of 10 days and the PUA 290mg COD/l day. At the incubation time 4.3 days, the maximum value of CH$ *59.1%) was found. At this time, $ was found as 15.3% and $ 25.6%.

• Asian-Australasian Journal of Animal Sciences
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• 제12권8호
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• pp.1241-1245
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• 1999

Nine two-year old sheep fitted with rumen and duodenum cannulas were used to study the effect of controlling protozoa flora on the degradation and utilization of dietary fibre and protein in the rumen and on nitrogenous flow to the duodenum. There were three groups in this experiment: defaunation (DF); partial defaunation (PDF); faunation (F) as control. Results showed that: 1,There were no differences between treatments in dietary DM degradation in the rumen, but defaunation and partial defaunation increased the quantity of nitrogenous material in the rumen and the flow of N to duodenum. 2, partial defaunation and defaunation improved the degradabilities of dietary NDF, ADF and HC, but there were no differences between the defaunated and partially defaunated groups. 3, Partial defaunation decreased the degradability of dietary protein in the rumen. There was no difference between defaunated and faunated groups. 4, Defaunation and partial defaunation increased the quantity of total N (TN) and microbial N (MCN) in the rumen and the amounts entering the duodenum. The protozoa N (PN) flow in the faunated group was higher than that in the partially defaunated group, and the amino acid pattern in the digesta at the proximal duodenum in the defaunated group was closer to the ideal amino acid pattern. 5, There were differences in the mole percent of acetic, propionic, total-VFAs and the non-glucogenic to glucogenic VFAs ratio (NGR) value in the rumen fluids. The order was as follows: mole percent of acetate: F>PDF>DF; mole percent of propionate: DF>PDF>F; total-VFAs: PDF>F>DF; NGR: F>PDF>DF.

• 수산해양기술연구
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• 제44권3호
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• pp.239-249
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• 2008

Trawlers have to a sufficient towing force due to it's characteristics of the high performance. The newly constructed trawler with the conventional propellers shows the sufficient towing force, so that the propeller and engine are optimized. In the 1970s, many trawlers were imported from overseas by Korean fisheries industries. But the engine output degradation with year by year caused the trawlers to decrease the towing speed of the vessels. On the previous studies, the nozzle propeller had not so good efficiency with increasing of resistance in high-speed cruising operation over 15knots. But the trawling operation is just required the higher thrust and towing force, so that the nozzle propeller is very profitable for the it's effectiveness. A new nozzle propeller was designed for the 4,462G/T trawler, Dong-San, operated by Dongwon Industries Co., Ltd. to improve the towing speed, and the model tests were performed. The model ship and model propeller are preciously manufactured and used model tests in basin. The resistance test and propeller open water test were performed for the cases of the half and full loads. The required engine horse power and RPM were evaluated analytically by the speed-power curve, when the trawler was equipped with the nozzle propeller. The results of tests showed that the towing speed 4.85knots on the design load waterline requires the 200 engine RPM and 2,567ps in the delivered horsepower.

• 산업경영시스템학회지
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• 제43권1호
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• pp.26-33
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• 2020

The plastic waste problem is deepening all over the world. Plastic wastes have serious impacts on our lives as well as environ- mental pollution. The production and use of plastics increases every year, but once they are produced, they usually roam the earth for hundreds or thousands of years to pollute the environment. Although there is growing interest in plastic issues around the world and environmental regulations are being tightened, but no clear solution has yet been found. This study suggests Environmental degradation index (EDI). EDI can help raise consumers' attention to plastic wastes. In addition, EDI will contribute to reduce them in the future. As far as we know, this is the first study. We developed EDI for the confectionery packaging. This study defines four factors that may affect the environment of confectionery packaging: greenhouse gas emissions, energy consumption, methane emissions, and packaging space ratio. Then we quantify the value of each element and compute EDI as the sum of the four component values. In order to evaluate the feasibility of EDI proposed in this study, confectionery-packaging materials distributed in Korea were collected and analyzed. First, the types of confectionery are classified into pies, biscuits, and snacks and basic data was collected. Then the values of the four components were calculated using existing research data on the environment. We can use the proposed EDI to determine how much a product packing affects the environment.

• 동남아시아연구
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• 제23권3호
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• pp.49-92
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• 2013

In May 2010, Indonesia and Norway signed a Letter of Intent on "Cooperation on Reducing Greenhouse Gas Emissions from Deforestation and Forest Degradation(REDD)." In the LoI, Norway agreed to offer Indonesia a sum of USD 1 billion with a view to encourage Indonesia to significantly contribute to the successful implementation of REDD+. On 20 May 2011, correspondingly, Indonesia announced the 2011 'Forest Moratorium' (the Presidential Instruction No. 10/2011) which was valid for the following consecutive two years. By means of the 2011 'Forest Moratorium', Indonesia aimed at significant reductions in greenhouse gas emissions from deforestation, forest degradation and peatland conversion. In so doing, it also sought to improve forest governance. Meanwhile, concerned stakeholders also raised various questions about the effectiveness of the 'Forest Moratorium'. As an extension of the 2011 'Forest Moratorium', Indonesia announced the 2013 'Forest Moratorium'(the Presidential Instruction No. 6/2013) for another two-year period on 13 May 2013. Indonesia's 'Forest Moratorium' is concerned with stakeholders at various levels, who may play a role of significant 'agent' in the process of implementing the 'Forest Moratorium'. This mechanism of the 'Forest Moratorium' should be understood in the light of forest governance. Employing stakeholder approach, therefore, this article attempts to analyze Indonesia's 'Forest Moratorium' in the light of forest governance. In this regard, it analyzes the detailed contents of the 'Forest Moratorium', the process of making the 'Forest Moratorium', current development of the Indicative Moratorium Map for suspension of new concessions on forest land, and contesting views of various stakeholders. At the same time, it also talks about how 'weak' forest governance had influence upon Indonesia's 'Forest Moratorium'. In so doing, this article consequently attempts to evaluate Indonesia's 'Forest Moratorium' and also put it into perspective in terms of improving forest governance. The 2013 'Forest Moratorium' fundamentally represents a radical policy that is designed to suspend new concessions on forest conversion for another two-year period and its detailed contents attempt to reflect on various stakeholders from related industries and environmental NGOs. However, there are challenging factors in the process of implementing the 'Forest Moratorium', that is, 'weak' forest governance and also a discrepancy between forest planning maps designated by central and regional governments. The announcement of the 2013 'Forest Moratorium', as an extension of the 2011 'Forest Moratorium', may functionally strengthen and improve Indonesia's forest governance. However, at the same time, there is a practical limit due to the fact that it is merely a Presidential Instruction that lacks legal binding.