• Journal of Ecology and Environment
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• 제35권3호
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• pp.243-249
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• 2012

Biomass expansion factors, which convert timber volume (or dry weight) to biomass, are used for estimating the forest biomass and accounting for the carbon budget at a regional or national scale. We estimated the biomass conversion and expansion factors (BCEF), biomass expansion factors (BEF), root to shoot ratio (R), and ecosystem biomass expansion factor (EBEF) for Quercus mongolica Fisch. and Quercus variabilis Bl. forests based on publications in Korea. The mean BCEF, BEF, and R for Q. mongolica was 1.0383 Mg/$m^3$ (N = 27; standard deviation [SD], 0.5515), 1.3572 (N = 27; SD, 0.1355), and 0.2017 (N = 32; SD, 0.0447), respectively. The mean BCEF, BEF, and R for Q. variabilis was 0.7164 Mg/$m^3$ (N = 17; SD, 0.3232), 1.2464 (N = 17; SD, 0.0823), and 0.1660 (N = 8; SD, 0.0632), respectively. The mean EBEF, as a simple method for estimating the ground vegetation biomass, was 1.0216 (N = 7; SD, 0.0232) for Q. mongolica forest ecosystems, and 1.0496 (N = 8; SD, 0.0725) for Q. variabilis forest ecosystems. The biomass expansion factor values in this study may be better estimates of forest biomass in Q. mongolica or Q. variabilis forests of Korea compared with the default values given by the Intergovernmental Panel on Climate Change (IPCC).

• 한국기후변화학회지
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• 제6권3호
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• pp.175-184
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• 2015

In this study GC and PAS were used to calculate $N_2O$ concentration of exhaust gas from Wood Chip combustion system. Fuel supplied to the incinerator was collected and analyzed and then the analysis result was used to calculate $N_2O$ emissions. Tier 3 and Tier 4 Method were used to calculate the $N_2O$ emissions. Plant's Specific emission factor of $N_2O$ by Tier 3 Method was 0.35 kg/TJ, while default emission factor of Wood?Wood Waste proposed by 2006 IPCC G/L was 4 kg/TJ. So the $N_2O$ emission factor of this study was 3.65 kg/TJ lower compared to the IPCC G/L. The total emissions calculated by Plant's specific emission factor was 4.22 kg during the measuring period, but by Tier 4 Method it was 7.88 kg. This difference in emissions was caused by the difference of continuous measuring and intermittent sampling. It would be necessary to apply continuous measuring to calculate emissions of $Non-CO_2$ gas whose the density distribution is relatively high. However currently, according to the target management guideline of greenhouse gas and energy, the continuous measuring method to calculate greenhouse gas emission is applied only to $CO_2$. Therefore for reliable greenhouse gas emission calculation it would be necessary to apply continuous measuring to calculate $Non-CO_2$ gas emission.

• 자원리싸이클링
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• 제22권6호
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• pp.3-11
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• 2013

본 연구는 사용종료매립지 정비를 위한 폐기물 처리과정에서 가연성폐기물의 처리 방법별 온실가스 발생량을 IPCC에서 제시하고 있는 기본배출계수(default emission factor)를 활용하여 산정하고 그 결과 비교를 통해 온실가스 감축량을 산정하였다. 대상 매립지로부터 굴착한 폐기물의 성상을 조사한 결과 토사류가 64.96%로 가장 많은 비율을 차지하고 있었으며, 다음으로 비닐/플라스틱류가 19.18%의 비율을 차지하고 있어 전체 폐기물 중 토사류의 비율이 매우 높은 것으로 나타났다. 음식물류, 목초류, 종이류와 같이 생분해가 용이한 폐기물이 거의 발견되지 않은 점 등이 일반적인 비위생매립지의 굴착폐기물과 성상이 유사하였다. 전체 폐기물의 겉보기 밀도는 평균 $0.74t/m^3$으로 확인되었다. 폐기물을 매립으로 처리하는 경우 약 60,542 $tCO_2$, 소각을 통해 폐기물 처리 시 9,933 $tCO_2$의 온실가스가 배출되며 폐기물 고형연료 생산 시에는 33,738 $tCO_2$의 온실가스가 감축되는 것으로 산정되어 폐기물 고형연료 생산이 온실가스 감축에 도움이 되는 것으로 확인되었다.

• 한국해안·해양공학회논문집
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• 제24권5호
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• pp.333-342
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• 2012

파랑 모델에서 시공간적인 해상도의 변경은 결과에 많은 영향을 끼친다. 본 연구에서는 모델 입력장의 해상도 변경, 파랑 모델의 해상도 변경 그리고 물리적 옵션에 따른 모델의 민감도를 분석하였다. 모델의 분석을 위해서 전지구 부이관측자료와 위성자료를 이용하였다. 고해상도의 입력장을 사용할 경우 유의파고를 과대 산정하는 경향을 보였고, RSME는 약간 감소하였다. 고해상도의 파랑 모델을 수행할 경우 평균편향 및 RMSE가 약간 증가하였다. 또한, 유효 해상풍 계수를 기존의 값인 1.4보다 작게 설정할 경우 편향과 RMSE가 모두 감소하였다.

• Toxicological Research
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• 제17권
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• pp.41-45
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• 2001

The methods used for risk assessment from exposure to chemicals are well established. in most cases where toxicity other than carcinogenesis is being considered, the standard method relies on establishing the No Observed Adverse Effect Level (NOAEL) in the most sensitive animal toxicity study and using an appropriate safety factor (SF) to determine the exposure which would be associated with an acceptable risk. For carcinogens a different approach is used because it has been argued there is no threshold of effect. Thus mathematical equations are used to extrapolate from the high doses used in ani-mal experiments. These methods have been strongly criticised in recent years on several grounds. The most cogent criticisms are a) the equations are not based on a thorough understanding of the mechanisms of carcinogenesis and b) the outcome of a risk assessment based on such models varies more as a consequence of changes to the assumptions and equation used than it does from the data derived from carcinogenicity experiments. Other criticisms include the absence of any measure of the variance on the risk assessment and the selection of default values that are very conservative. Recent advances in the application of risk assessment emphasise that measures of both the exposure and the hazard should be considered as a distribution of values. The outcome of such a risk assessment provides an estimate of the distribution of the risks.

• The Journal of Asian Finance, Economics and Business
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• 제7권7호
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• pp.85-93
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• 2020

In peer-to-peer (P2P) loan markets, as most lenders are unskilled and inexperienced ordinary individuals, it is important to know the characteristics of borrowers that significantly impact their repayment performance. This study investigates the effects and importance of borrowers' past repayment performance track record within the platform to identify its predictive power. To this end, I analyze the detailed loan repayment data from two leading P2P lending platforms in Korea using a Cox proportional hazard, multiple linear regression, and logit models. Furthermore, the predictive power of the factors proxied by borrowers' track records are evaluated through the receiver operating characteristic (ROC) curves. As a result, it is found that the borrowers' past track record within the platform have the most important impact on the repayment performance of their current loans. In addition, this study also reveals that the borrowers' track record is much more predictive of their repayment performance than any other factor. The findings of this study emphasize that individual lenders must take into account the quality of borrowers' past transaction history when making a funding decision, and that platform operators should actively share the borrowers' past records within the markets with lenders.

• 디지털융복합연구
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• 제10권11호
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• pp.595-601
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• 2012

서사예술이 주로 인간에 대하여 사실적이고 가능성 있는 허구를 서술한 것이라고 볼 때 인물은 서사의 핵심구조이며 작중세계를 구축하는 가장 중요한 요소이다. 또 서사구조의 이야기를 성립시키면서 구성을 이끄는 행위의 주체이다. 이러한 관점에서 인물의 제시는 작가의 작품에 대한 기본적 태도이며 드라마 자체에 질서를 부여하는 작업이기 때문에 드라마의 미학적 구조는 결국 작중인물을 통하여 인식된다. 드라마를 미학적 쾌락과 미학적 이해의 정규 혼합물이라고 볼 때 작중인물을 통해 캐릭터를 창조하는 것은 서사구조에 대한 본질을 연구하는 지름길이 된다.

• 한국실내디자인학회논문집
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• 제21권6호
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• pp.260-270
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• 2012

The demographic and environmental changes such as the decrease of the population growth rate and the increase of the population of the senior citizens, which become issues of the modern society, are bringing numerous changes of many aspects like national economy, community, and culture. These social phenomena give impacts on the school facilities as well. Thus owing to the decrease of the number of the students, the number of the newly constructed schools has been decreased drastically, and moreover the merger of the schools cause many schools to be default. Meanwhile, the school facilities have been expanded into the functions of the local community centers, and the various educational activities demand the diversity and flexibility of the spaces. These factors add more burdens to the current schools. Therefore the school facilities are needed to adopt a flexible and relevant change necessary for using the spaces in accordance with the changed needs of the times, and are needed to reinvented continuously not to limit the educational and social activities because of the degradation of the school facilities. Yet because there are no proper criteria for doing the task, problems related to the relevance of the task and the unnecessary investment are raised. So through this study I tried to demonstrate the standardized index in terms of the sequential priority of upgrading the facilities among the schools.

• 한국대기환경학회지
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• 제27권4호
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• pp.405-415
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• 2011

The objective of this study was to compare greenhouse gas emissions from road transportation by calculation methods (Tier 1, Teir 2, and Tier 3). Tier 1 based on 2006 IPCC guidelines default emission factor and amount of fuel consumption. The Tier 2 approach is the same as Tier 1 except that country-specific carbon contents of the fuel sold in road transport are used. Tier 2 based on emission factor of guidelines for local government greenhouse gas inventories (Korea Environment Corporation), the fuel consumption per one vehicle, and the registered motor vehicles. The Tier 3 approach requires detailed, country-specific data to generate activity-based emission factors for vehicle subcategories (National Institute of Environmental Research) and may involve national models. Tier 3 calculates emissions by multiplying emission factors by vehicle activity levels (e.g., VKT) for each vehicle subcategory and possible road type. VKT was estimated by using GIS road map and traffic volume of the section. The GHG average emission rate by the Tier 1 was 728,857 $tonCO_2eq$/yr, while Tier 2 and Tier 3 were 864,757 $tonCO_2eq$/yr and 661,710 $tonCO_2eq$/yr, respectively. Tier 3 was underestimated by 10.1 and 20.7 percent for the GHG emission observed by Tier 1 and Tier 2, respectively. Based on this study, we conclude that Tier 2 is reasonable GHG emissions than Tier 1 or Tier 3. But, further study is still needed to accurate GHG emission from Tier 3 method by expanding the traffic survey area and developing the model of local road traffic.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제7권2호
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• pp.33-40
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• 2018

네트워크 대역폭이 큰 환경에서는 대역폭 활용률을 극대화함으로써 전송효율성을 높이는 것이 매우 중요한 이슈이다. 종단간 전송효율성은 네트워크, 데이터 전송 노드 그리고 기관 내 네트워크 보안정책 등 구성요소에 따라 크게 영향을 받는다. Science DMZ는 이러한 복합적인 구성요소들의 최적의 해결 방안을 통해 전송성능을 극대화하기 위한 혁신적인 네트워크 구조이다. 이 중에서 데이터 전송 노드는 스토리지, 네트워크 인터페이스, 운영체제, 전송응용 도구에 따라 전송성능에 크게 영향을 주는 핵심 요소이다. 하지만 고속네트워크 환경에서는 데이터 전송 노드를 구성하는 요소들의 적절한 튜닝이 수행되어야 높은 전송효율성을 제공할 수 있다. 본 논문에서는 100Gbps 데이터 전송 노드의 튜닝 요소를 통한 전송성능 향상 방안에 대해 제안한다. 성능측정결과 점보프레임, CPU governor 튜닝을 통해 100Gbps 네트워크 환경에서 전송효율성을 크게 개선할 수 있음을 확인하였다. Iperf를 통한 네트워크 성능테스트 결과 default에 비해 300%의 성능향상을 보였으며 NVMe SSD의 경우 하드디스크와 비교해 140%의 성능개선을 확인하였다.