• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4A
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• pp.497-505
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• 2008

Corrugated steel webs resist only shear force because of the accordion effects. The shear force in the web can cause three different buckling mode: local, global, and interactive shear buckling modes. The shear behavior of the corrugated steel webs have been investigated by several researchers. However, shear buckling behavior of the corrugated webs are not clearly explained yet. And, it lead the conservative design. This paper presents shear strength of trapezoidally corrugated steel webs. A series of the tests were also conducted to verified proposed shear strength. Firstly, local, global, and interactive shear buckling equations provided by previous researchers were rearranged as a simple form considering the profiles of the existing bridges with corrugated steel webs. And, global and interactive shear buckling coefficient, and shear buckling parameter for corrugated webs were suggested in this study. Inelastic buckling strength can be determined from buckling curves based on the proposed shear buckling parameter. From the test results of this study and those of previous researchers, it can be found that suggested shear strength provides good estimation of those of trapezoidally corrugated steel webs.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1B
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• pp.99-106
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• 2006

Due to both global warming and constructions of seadike/seawalls, continuously or abruptly rising tendencies of extreme high water levels have been detected at Kunsan and Mokpo harbors. This paper deals firstly with the separation of each effect, namely global warming effect and construction effect, on increases of water level quantitatively by a linear regression method. And then, it can be explained why and how the extreme high water levels had been risen just after constructions at both harbors. A numerical simulation of $M_2$ tidal constituent at Mokpo coastal zone shows that the tidal amplification by constructions is mainly due to the extinguishment of TCE at Mokpogu. The tidal flat effect makes the amplification more deepen at spring tide or extreme high tide, which results in the increase of inundation risk at Mokpo harbor. A frequency analysis method is applied, which is shown to be effective at such a site of having non-homogeneous tidal data due to constructions as Mokpo harbor.

• Applied Chemistry for Engineering
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• v.34 no.5
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• pp.472-478
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• 2023

The usage of jet fuel has been increasing with increasing passenger and logistics movements under globalization. CO₂, which is the main global warming gas from aircraft, was charged about 3.5% of total global CO₂ emissions and 12% of transportation fuel emissions. For these reasons, a lot of governments and the international civil aviation organization (ICAO) are trying to reduce CO₂ emissions via the introduction of bio-jet fuel. In this paper, we showed the jet fuel properties, specifications, and presentative production methods of bio-jet fuel such as alcohol to jet (ATJ), oil to jet (OTJ), gas to jet (GTJ) and sugar to jet (STJ). Also, we described the status of global and domestic bio-jet fuel usage and the policy plan for efficient distribution.

• Journal of Korean Society for Quality Management
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• v.31 no.3
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• pp.19-36
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• 2003

The manager of manufacturing industry just not to have known what to do related to the law of product liability(PL) that was put into operation in July 1, 2002. The law of PL is a public law about defective product, which was established in order to compensate consumer's damages of property and body caused by product, to make sound society by the safety products and to take international competitiveness. But the existing civil law has been having clause that compensation to be taken is limited. The law of PL is resolving this limitations and is characterized by the easy relief from damages of defective product. The decision in the case of Green-man has been a precedent since the court sentenced the manufacturer to liability. The law of PL has been in force in 27 countries, including all of the EU countries, Japan, Philippines and China. It has been shown that the corporations which meet the Global Standard, could survive in global competition. The economic effects by the law of PL are the increase of consumers relief production cost by the lawsuits. This paper will recommend more biref method that is able to cover PSMS by use of QMS. It will make domestic corporation improve in the plan, manufacture and sale of products to meet the Global Standard.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.24 no.4
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• pp.70-80
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• 2016

ICAO(International Civil Aviation Organization) established ICAO LPRs(Language Proficiency Requirements) which is an international standard of English for aviation to promote the aviation safety. The Republic of Korea government amended the aviation law on the 8th of November, 2005 and made EPTA(English Proficiency Test for Aviation) as a follow up action. Purpose of this research is analysing the problem of EPTA and improving it. This investigation takes a look at the current ICAO LPRs and compares the difference between EPTA and other global English proficiency requirements for aviation. The result indicated that there is a discordance between the standards of ICAO and EPTA. Also, the global English proficiency reqirements for aviation and EPTA had differences which required improvements. The study suggests to replace more job relevant questions in the EPTA and reform the level system of EPTA.

• Journal of Preventive Medicine and Public Health
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• v.54 no.4
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• pp.251-258
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• 2021

Hepatitis C infection is responsible for high morbidity and mortality rates globally as well as for significant indirect costs. The disease burden caused by the hepatitis C virus (HCV) is comparable to the one caused by human immunodeficiency virus or tuberculosis. Today, simple detection methods, highly effective and easy to administer therapies and efficient preventative measures are available to combat hepatitis C. Nevertheless, in most countries around the world, the World Health Organization target of eliminating this infectious disease and its consequences by 2030 are not being met. Significant gaps in care for hepatitis C sufferers still exist, the shortcomings ranging from education and treatment to aftercare. Hepatitis C infection was and still is not on the radar of most politicians and health authorities. National programmes and strategies to combat the disease exist or are being developed in many countries. However, for these to be implemented efficiently and successfully, clear political commitment, strong civil society actors, well-functioning public health structures and the relevant support from global donors are needed.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.98-100
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• 2007

Tropical forests have variety of biodiversity values, which provide invaluable services to the living being on earth. In the recent years, tropical forests are regarded as valuable global resources that act as sink for carbon dioxide in order to mitigate global climatic change. In many parts of the world, tropical forests are being rapidly cleared by various means. Soil organic carbon (SOC) is concentrated in the upper 12 inches of the soil. So it is readily depleted owing to the degradation activities. In the present study, it was aimed to assess the magnitude of disturbance in the availability of SOC in a semi- evergreen forest, situated in the Eastern Ghats of Tamil Nadu, India. The forest density of this region was mapped with QuickBird satellite data. Intensive field soil sampling and floristic study were conducted to estimate the SOC status in different density classes and to identify the species availability. The SOC density ranged from 274.06 t/ha to 147.84 t/ha in the very dense and degraded semi-evergreen forest respectively. The SOC content was also varied from 3.70 to 1.83 % in the very dense semi-evergreen and medium semi-evergreen forests respectively. The species composition in different density classes was also varied considerably. As a result of this study, it was identified that the disturbance to forests by various means not only affect the density of forests but also affect the below ground SOC status proportionately.

• Environmental Engineering Research
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• v.18 no.3
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• pp.145-150
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• 2013

Optimal preparation guidelines of a cathode catalyst layer by non-precious metal catalysts were evaluated based on electrochemical performance in single-chamber microbial fuel cells (MFCs). Experiments for catalyst loading rate revealed that iron(II) phthalocyanine (FePc) can be a promising alternative, comparable to platinum (Pt) and cobalt tetramethoxyphenylporphyrin (CoTMPP), including effects of substrate concentration. Results showed that using an optimal FePc loading of $1mg/cm^2$ was equivalent to a Pt loading of $0.35mg/cm^2$ on the basis of maximum power density. Given higher loading rates or substrate concentrations, FePc proved to be a better alternative for Pt than CoTMPP. Under the optimal loading rate, it was further revealed that 40 wt% of FePc to carbon support allowed for the best power generation. These results suggest that proper control of the non-precious metal catalyst layer and substrate concentration are highly interrelated, and reveal how those combinations promote the economic power generation of single-chamber MFCs.

• Asian Journal of Atmospheric Environment
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• v.8 no.1
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• pp.1-14
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• 2014

Migration of methane ($CH_4$) gas from landfills to the surrounding environment negatively affects both humankind and the environment. It is therefore essential to develop management techniques to reduce $CH_4$ emissions from landfills to minimize global warming and to reduce the human risks associated with $CH_4$ gas migration. Oxidation of $CH_4$ in landfill cover soil is the most important strategy for $CH_4$ emissions mitigation. $CH_4$ oxidation occurs naturally in landfill cover soils due to the abundance of methanotrophic bacteria. However, the activities of these bacteria are influenced by several controlling factors. This study attempts to review the important issues associated with the $CH_4$ oxidation process in landfill cover soils. The $CH_4$ oxidation process is highly sensitive to environmental factors and cover soil properties. The comparison of various biotic system techniques indicated that each technique has unique advantages and disadvantages, and the choice of the best technique for a specific application depends on economic constraints, treatment efficiency and landfill operations.

• Journal of Aerospace System Engineering
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• v.8 no.3
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• pp.34-40
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• 2014

Since the global economic crisis in year 2008, the world civil helicopter market has been growing recently. According to the market outlook in the next decade, the demand of civil helicopter will be driven by the demand of Private & Corporate, Oil & Gas, Off-shore and EMS(Emergency Medical Service) usages. On the other side, the demand of military market will be driven by the modification and upgrading for life extension or performance enhancement than the new helicopter development for replacing old models. To summarize these situations, the demand of MRO(Maintenance, Repair & Overhaul) market has also been on the rise because of the demand due to above several usages in civil side and the life-extension in military side. Through the MRO market analysis for characteristics, developmental trends and a supply chain, this paper describes that the potential of MRO business is considerably large as a propulsive power of domestic helicopter industry. And also, it proposes the construction direction of MRO network because the domestic industry must make the developmental awareness and reliability a stepping-stone towards own helicopter.