• Journal of Environmental Policy
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• v.14 no.3
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• pp.41-73
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• 2015

The Korea Emissions Trading System that was launched in Jan. 2015 is expected to be a crucial policy measure to abate domestic $CO_2$ emission. For accomplishing its purpose, prior information on the price discovery process needs to be presented in order to facilitate the trading of spot allowances with different vintages. We develope a customized pricing method for Korean ETS using the concept of term structure and the cost of carry model.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.1
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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.

• Journal of Soil and Groundwater Environment
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• v.27 no.2
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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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• v.56 no.4
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• pp.453-460
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• 2018

Owing to rising oil prices and anthropogenic global warming, focused attempts are being made toward production of industrially important compounds by using renewable biomass. In this context, algal biomass as third-generation biomass is important because it doesn't compatible with food resource, has high yield, and helps abate greenhouse gases. Here, we investigate whether Undaria has the highest sugar content, which would make it the most suitable biomass for lactic acid production among the four algal biomasses tested. For effective pretreatment of Undaria, the response surface methodology was used. The amount of solid loaded and catalyst concentration were related to the extraction rate of total sugar. Lactic acid was produced by pretreatment of Undaria by using four Lactobacilli, and L. alimentarius and L. brevis were found to be suitable for lactic acid production.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.1
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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.

• Herbal Formula Science
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• v.22 no.1
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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.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.6
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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.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.11
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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.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.143-150
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• 2014

Cloud computing is fast becoming the wave of the future for both home and business computing. Because of this growing acceptance, we can expect an explosion of diverse cloud service providers in the coming years. However, the cloud is not a single entity, rather it is a set of many disconnected islands of application (SaaS), infrastructure (IaaS), and different platform (PaaS) services. Cloud brokering mechanisms are essential to transform the heterogeneous cloud market into a commodity-like service. Cloud service brokers (CSBs) are the new form of business entities to help to aggregate the scattered set of cloud services and make conveniently available to their diverse users. CSBs can reserve a certain percentage of their clients' (users') demand and satisfy the remaining portion in an on-demand basis. In doing so, they need to minimize cost of both reserved and on-demand instances as well as the distance of a link between the cloud service provider (CSP) and the user. The study proposes a reservation approach with a mixed integer model to optimizes the cloud service cost and quality.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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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.