• 환경정책연구
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• 제14권3호
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• pp.41-73
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• 2015

온실가스의 국가감축목표 달성을 위한 시장 메커니즘의 핵심수단으로서 2015년 1월부터 국내에서도 배출권거래제가 시행되고 있다. 배출권 거래의 초기 거래실적은 해외사례에서도 높지 않은 편이지만, 성공적인 정책으로 발전되도록 배출권 시장이 보다 활성화될 필요가 있다. 이를 위해서는 현재 제1차 계획기간의 3개 이행연도별로 세분화되어 있지 않은 배출권 가격에 대해 적절한 가격 시그널이 마련되어야 한다. 이자율의 기간구조 개념과 선물가격 산정 방법인 보유비용 모델을 이용해 이행연도별 배출권 가격 산정 방법을 제시함으로써, 가격발견기능에 관한 시장 참여자의 합리적 기대 형성과 거래시장 활성화에 기여하고자 한다.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.186-192
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• 2007

In general, pulsation damper is installed in fuel rail for conventional MPI engine to decrease undesirable noise in vehicle cabin room. However, pulsation damper is so expensive that there are prevailing studies to reduce fuel pressure pulsations with integrated damping effect. This paper is one of basic studies for development of fuel rail to abate pulsations with self-damping effect. Primarily, the pressure pulsation characteristics was investigated with aspect ratio of cross section, wall thickness, and materials of fuel rail. A high aspect ratio or thin wall was found to absorb the pressure pulsations effectively. But volume effects on the fuel pressure pulsation reductions were not especially significant than cross section effects because volume increment rate is larger than pressure pulsation reduction rate. The fuel rail made of aluminum is effective for reduction of pressure pulsation than that of low-carbon steel. Pressure change period increases on the basis of same lengths of supply line and fuel rail as the volume is enlarged and/or the thickness of wall is thinned.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권2호
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• pp.41-49
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• 2022

To abate the environmental burdens arising from CO₂ emissions, biochar offers a strategic means to sequester carbons due to its recalcitrant nature. Also, biochar has a great potential for the use as carbon-based adsorbent because it is a porous material. As such, developing the surface properties of biochar increases a chance to produce biochar with great adsorption performance. Given that biochar is a byproduct in biomass pyrolysis, characteristics of biochar are contingent on pyrolysis operating parameters. In this respect, this work focused on the investigation of surface properties of biochar by controlling temperature and reaction medium in pyrolysis of pine sawdust as case study. In particular, CO₂ was used as reaction medium in pyrolysis process. According to pyrolytic temperature, the surface properties of biochar were indeed developed by CO₂. The biochar engineered by CO₂ showed the improved capability on CO₂ sorption. In addition, CO₂ has an effect on energy recovery by enhancing syngas production. Thus, this study offers the functionality of CO₂ for converting biomass into engineered biochar as carbon-based adsorbent for CO₂ sorption while recovering energy as syngas.

• Korean Chemical Engineering Research
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• 제56권4호
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• pp.453-460
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• 2018

원유 가격의 상승과 지구온난화로 인하여 재생 가능한 바이오매스를 이용하여 산업적으로 중요한 화합물을 생산하는 연구가 주목받고 있다. 특히, 3세대 바이오매스인 해조류는 비식량 자원, 높은 생산 수율, 온실가스 저감 등 장점을 가지고 있기에 연구 되어야 할 필요가 있다. 본 연구에서는 고체분석 방법을 이용하여 4종의 해조류 중에 미역이 가장 많은 당류를 함유하는 것을 확인하였다. 미역의 효과적인 전처리를 위해 반응표면분석법을 이용하였으며 이를 통해 고체의 부하 및 촉매의 농도 증가가 총 당의 추출률과 관계 있음을 확인하였다. 4종의 락토바실러스 균주에서 미역의 전처리물을 이용하여 젖산 생산 수행하였으며 L. alimentarius와 L. brevis가 해조류 이용한 젖산생산에 적합한 균주임을 확인하였다.

• 한국소음진동공학회논문집
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• 제25권1호
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• pp.5-12
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• 2015

According to the analysis of special medical examination and work environment monitoring data, the rate of C1 and D1 on noise hazard exceeded 90 % among those of total hazardous factors. The rate of company exceeding noise exposure limit was also more than 90 %. The analysis result shows that main ages diagnosed with C1 and D1 was age of 50s. The majority scale company having workers diagnosed with C1 and D1 was the companies employing 5~49 workers. Types of industries which have a large number of companies exceeding noise exposure limit were automobile and trailer manufacturing, metal processing industry and primary metal manufacturing. A large number of work processes exceeding noise exposure limit were forming and processing work, cutting and bending work and grinding. To reduce the number of company exceeding noise exposure limit, the reduction counterplan should be focused on the type of industry and the work process which exceeded noise exposure limit frequently. However, the reduction counterplan is preemptively necessary to the type of industry and the work process which exceeded noise exposure limit consecutively if the purpose of reduction counterplan is not to merely reduce the number of company exceeding noise exposure limit but to abate workers' suffering from noise.

• 대한한의학방제학회지
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• 제22권1호
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• pp.65-78
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• 2014

Objectives : The purpose of this study was to investigate the interpretation of the Ondam-tang(Ondam-tang, here-in-after referred to as "ODT") prescription in order to obtain the evidence for clinical applications. Methods : We have analyzed the interpretation on the ODT prescription through translations and comparisons based on classic books about the oriental medical prescriptions. Result : 1. ODT was first mentioned in the Jiyangfang(集驗方) which was quoted in the Waitaimiyao (外臺秘要). After that, in book Sanyinjiyibingzhengfanglun(三因極一病證方論), Chen-yan(陳言) completed and recorded in a book organizing prescriptions of ODT now in frequent use. 2. The Banha(半夏) removes the dam(痰-phlegm) and relieves emesis. The Jinpee(陳皮) encourages strengths, and the Bokryoung composes oneself and produces the water. The Licorice(甘草) relieves people's mind, and the Ginger relieves gastrointestinal problems and relieves emesis. Juk-yeo(竹茹) abate of the fever of the Sangcho(上焦). Jisil(枳實) encourages strength, controlling Samcho(三焦) as releasing the congestion of energy. In these ways, numerous symptoms resulted from the imbalances of the Gallbladder(膽) are treated. 3. Meaning of "on(溫-warm)" in ODT regains the original characteristic of the Gallbladder(膽). 4. Treatment mechanism of ODT is 'cooling the Gallbladder(膽)' and 'remedies Samcho(三焦)' and 'eliminates dam(痰)' and 'cure Kiwool(氣鬱-which is kind of depressions) and Saengyen(生涎-which is kind of phlegm)' and 'removes a mismatch between Gallbladder(膽) and Stomache(胃)'. Conclusion : In this study, we have demonstrated various methodologies. This paper will be useful to the future researchers and clinicians to conduct a study on herbal medicines such as the ODT.

• 한국대기환경학회지
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• 제29권6호
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• pp.811-817
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• 2013

A two-stage bioreactor system using sulfur-oxidizing bacteria was studied to abate high strength hydrogen sulfide ($H_2S$) from biogas. The two-stage bioreactor consisted of a $H_2S$ absorption column (0.5 L) and a microbial oxidation column (1 L) in series, and the liquid medium was continuously recirculated through the columns. The objectives of this study were to determine the feasibility of the bioreactor for biogas desulfurization and to investigate the effect of the medium circulation rate on the system performance. An averaged concentration of $H_2S$ introduced to the bioreactor was 530 ppm, corresponding to an overall loading rate of $44.4g/m^3/hr$. During the initial 20 days period at the medium recirculation rate of 8 reactor volumes per hour (12 L/hr), the dissolved oxygen (DO) concentration in the oxidation column was 6 mg/L, while the DO in the absorption column was 0.5 mg/L showing that the oxygen contents of the biogas stream was not altered. Because of the biological oxidation of $H_2S$ in the oxidation column, the sulfate concentration increased from 200 mg/L to 5,600 mg/L in the liquid medium. The removal efficiency of $H_2S$ was greater than 99% in the initial operation period. After the initial period, the medium recirculation rate between the two columns was stepwise changed eight times from 1.0 to 40 vol/hr (1.5~60 L/hr). At the recirculation rate of faster than 4 vol/hr, the $H_2S$ removal efficiencies were found to be high, but the efficiency declined at the lower recirculation rates than the threshold.

• 대한기계학회논문집B
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• 제21권11호
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• pp.1496-1508
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• 1997

The effects of porous wind fence on the pressure characteristics around a 2-dimensional prism model of triangular cross-section were investigated experimentally. The fence and prism model were embedded in a neutral atmospheric surface boundary layer over the city suburb. In this study, various fences of different porosity, back fence, inclination angle of prism and location of additional back prisms were tested to investigate their effects on the pressure and wall shear stress of the prism surface. The fence and prism had the same height of 40 mm and Reynolds number based on the model height was Re=3.9*10$^{4}$. The porous fence with porosity 40% was found to be the best wind fence for decreasing the mean and pressure fluctuations on the prism surface. By installing the fence of porosity 40%, the wall shear stress on the windward surface of prism was largely decreased up to 1/3 of that without the fence. This indicates that the porous fence is most effective to abate the wind erosion. Pressure fluctuations on the model surface were decreased more than half when a back fence was located behind the prism in addition to the front fence. With locating several back prisms and decreasing the inclination angle of triangular prism, the pressure fluctuations on the model surface were increased on the contrary.

• 한국시뮬레이션학회논문지
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• 제23권4호
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• pp.143-150
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• 2014

클라우드 컴퓨팅은 가정과 비즈니스 컴퓨팅에 있어 빠르게 확산되고 있다. 이러한 변화에 따라 수년 내에 다양한 클라우드 서비스를 제공하는 클라우드 서비스 공급자의 수가 폭발적으로 증가할 것으로 예측된다. 하지만 클라우드는 하나의 독립체가 아니고 서로 단절되어 있는 많은 응용 프로그램(SaaS)과 기반시설(IaaS), 상이한 플렛폼 서비스(PaaS)들의 집합으로 볼 수 있다. 클라우드 중개방법(brokering mechanism)은 산재되어 있는 서비스들의 집합을 통합하고 편리하게 유용한 서비스를 다양한 사용자에게 제공할 수 있게 하기 때문에 서로 상이한 클라우드 시장을 하나의 통상적 서비스로 변환시키는데 있어 필수적이다. 따라서 CSBs(클라우드 서비스 중개자들)는 사용자와 CSP(클라우드 서비스 제공자)사이의 거리를 최소화하고 예약과 on-demand 서비스의 비용을 최소화하는 운영전략을 찾을 필요가 있다. 이를 위하여 본 연구에서는 클라우드 서비스의 비용과 품질을 최적화하기 위해 예약 접근법을 고려한 수리적 모형을 제안한다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권1호
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• pp.265-270
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• 2015

Hepatocellular carcinoma (HCC) is amongst the top three cancer causes of death worldwide with hepatitis B and C viruses (HBV/HCV) as the main etiological agents. An up-to-date descriptive epidemiology of the burden of HBV/HCV-associated HCC in the Arab world is lacking. We therefore determined the burden of HBV/HCV-associated HCC deaths in the Arab world using the Global Burden of Disease (GBD) 2010 dataset. GBD 2010 provides, for the first time, deaths specifically attributable to viral-associated HCC. We analyzed the data for the 22 Arab countries by age, sex and economic status from 1990 to 2010 and compared the findings to global trends. Our analysis revealed that in 2010, an estimated 752,101 deaths occurred from HCC worldwide. Of these 537,093 (71%) were from HBV/HCV-associated HCC. In the Arab world, 17,638 deaths occurred from HCC of which 13,558 (77%) were HBV/HCV-linked. From 1990 to 2010, the burden of HBV and HCV-associated HCC deaths in the Arab world increased by 137% and 216% respectively, compared to global increases of 62% and 73%. Age-standardized death rates also increased in most of the Arab countries, with the highest rates noted in Mauritania and Egypt. Male gender and low economic status correlated with higher rates. These findings indicate that the burden of HBV/HCV-associated HCC in the Arab world is rising at a much faster rate than rest of the world and urgent public health measures are necessary to abate this trend and diminish the impact on already stretched regional healthcare systems.