• Elastomers and Composites
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• v.47 no.2
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• pp.96-103
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• 2012

This paper reviews recent technologies for recycling poly (ethylene terephthalate) wastes. Wide application and non-biodegradability of the PET creates huge amounts of waste and disposal, leading to an environmental problem and economic loss. Chemical recycling can be a promising technology to deal with these problems by converting the waste into useful feedstock material for polyester production. Chemical recycling of polyethylene terephthalate are processes where the PET polymer chain is destructed by the impact of glycol (MEG) causing glycolysis, methanol causing methanolysis or water causing hydrolysis. After intensive purification polyester oligomers or the monomers MEG, dimethyl telephthalate (DMT) or purified terephthalic acid (PTA) are received which are re-used to produce polyester products.

• Journal of the Korean Geographical Society
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• v.39 no.2
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• pp.256-268
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• 2004

Korea remains one of the few countries in the world that has not participated in any formal regionalism except its first FTA with chile which was just recently concluded. The lack or regionalism in Northeast Asia reflects post-war national policies that favored international export markets as an engine of economic growth. Based on a survey of 50 firms in Korea, this paper examines the relationship between regionalism and multilateralism in terms of computer industry. The results show that the industry favors international rather than regional markets for its continued export growth. According to the results, accelerated trade liberalization measures through the mutilateralism of the WTO dilute the demand for and negative impacts from regionalism. Overall, the results suggest that the Korean computer industry supports a trading system with a strong multilateral commitment based on non-discrimination.

• Fire Science and Engineering
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• v.19 no.4 s.60
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• pp.87-92
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• 2005

The PASCON of the flame resistance and the economic feasibility was prepared by non-halogenate flame retardant system. Prepared PASCON samples contained various flame retardants were subjected to flame tests(KS M 3015). We have studied that the effect of various flame retardants on the inflammability of PASCON and the effect of synergist on the flame resistance. As results, PASCON contained red-phosphorus as flame retardant exhibited excel lent flame retardancy. Also, the improvement of flame resistance is achieved by addition of 2.5phr synergist in the red-phosphorus(RP)/magnesium hydroxide(MH) system.

• Journal of Arbitration Studies
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• v.31 no.2
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• pp.47-76
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• 2021

India is one of the fast growing country in the world. For the acceleration of economic growth of India, it is indispensable for Indian government to construct infrastructure, such as railroad, airport, harbor, power plant, and water management system. For example, Modi, prime minister of federal government of India proclaimed that Indian government plans to construct 100 smart cities in 2015. In recent times, India is expected to be the largest recipient of Public-Private Partnership(PPP) type projects in the world. Owing to PPP, it is possible for India to pursue her objective to transform the whole economy into digital economy beyond agricultural society. One of major problem related with implementation of PPP type projects is the growth of disputes concomitant to the rising phenomena of PPP type projects in order to build infrastructure in India. Because of this, non-negligible number of projects has been cancelled during last two decades. This study investigates seven failure cases of PPP in India. Those include Nabi mumbai airport, Dabhol power plant, Munbai water project, and Kolkata subway project. Main types of dispute resolution are mediation or conciliation, dispute review board, arbitration, expert adjudication in PPP.

• Journal of the Korean Society of School Health
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• v.32 no.2
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• pp.77-87
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• 2019

Purpose: This study was conducted to examine the prevalence of current smoking and the factors that influence current smoking among male high school students in Korea according to school type. Methods: Data were extracted from the Korea Youth Risk Behavior Web-Based Survey (2017) and multiple logistic regression was used based on complex sample analysis. The study sample comprised of 15,777 male high school students: 12,583 from general high schools (GHS) and 3,194 from specialized vocational high schools (SVHS). Results: The prevalence of current smoking was significantly higher in SVHS students (19.6%) compared to GHS students (12.6%). Low academic achievement, depressive symptoms, current drinking, and high household economic status were commonly associated with current smoking in male students from both school types. However, exposure to secondhand smoking at home, non-exposure to anti-smoking advertisement, exposure to tobacco advertisement, participation in smoking prevention or cessation education were related to current smoking in GHS students, while living in rural area was associated with current smoking in SVHS students. Conclusion: To reduce current smoking among male high school students, it is necessary to develop smoking prevention policies reflecting the factors associated with current smoking that are different by school type.

• Journal of the Korean Society of Safety
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• v.33 no.6
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• pp.58-65
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• 2018

The life span of the porcelain insulator was made to be 30 years, but currently many of the 154kV NGK porcelain insulators using in Korea are found to have passed the production life. Accidents caused by aged mechanical breakdown can lead to disruption of power supply in some areas, large economic losses, and casualties. Therefore, ultrasonic method, which is one of the non - destructive test methods, is applied as a method for evaluating the integrity of porcelain insulators. In this study, the experiment on the interface of cap was conducted and the difference between the energy difference and the attenuation coefficient of the reflected wave was derived according to the interface state of the steel - cement. The results of this study are expected to be used as the basic data of the ultrasonic testing to evaluate the interface condition of the porcelain insulator cap.

• Advances in concrete construction
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• v.10 no.6
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• pp.515-526
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• 2020

Cold-mixed asphalt mixture is a widely recommended asphalt pavement materials with potentially economic and environmental benefits. Due to the reduction of natural non-renewable mineral resources, powder minerals with similar properties are considered as new mineral fillers in asphalt mixtures. This study explored the feasibility of using cement to replace natural limestone powder (LP) in emulsified asphalt concrete modified by styrene-butadiene styrene copolymer. The experimental tests, including compressive strength, Marshall stability as well as moisture susceptibility test, were used to investigate the mechanical properties, the Marshall stability, flow value, as well as the moisture damage. In addition, the influence of material composition on the performance of asphalt concrete is explained by the microstructure evolution of the pore structure, the interface transition zone (ITZ), and the micromorphology. Due to mineralogical reactivity of cement, its replacement part of LP improved the mechanical properties, Marshall stability, but it will reduce the moisture susceptibility and flow value. This is because with the increase of the cement substitution rate, the pore structure of the asphalt concrete is refined, the width of ITZ becomes smaller, and the microstructure is more compact. In addition, asphalt concrete with a larger nominal particle size (AC-16) has relatively better performance.

• The Journal of Fisheries Business Administration
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• v.53 no.2
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• pp.42-57
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• 2022

The purpose of this study was to estimate the economic values of whale watching. The data used in this study were collected with 1,599 coastal tourists and the questionnaire included contingent valuation method questions. The results show that coastal tourists obtained the benefits of about KRW 15,970 from whale watching. Further analyses were conducted to check the differences of willingness to pay for whale watching based on the three variables as follows: previous experience of whale watching and participation intention in whale watching tourism, and previous experience of cruise trips. The results indicate that the respondents, who already participated or intended to participate in this type of tourism activity, were willing to pay higher than those, who did not participated or had no intention of participation, respectively. These results imply that whale watching could be a feasible alternative to the direct consumption of whale meat. Based on the study results, we provide policy and management-related implications for whale watching programs.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.7
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• pp.185-196
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• 2022

The purpose of this study is to examine the effects of split ratings on earnings management through cost adjustments based on asymmetric cost behaviors. Using a sample of 2,027 Korean firm-year observations over the 2002-2019 period, we analyze whether a firm deliberately reduces discretionary costs, such as selling, general, and administrative (SG&A) expenses, to improve profits when it receives multiple ratings from credit rating agencies (CRAs). While examining earnings management incentives in the presence of split ratings, we also investigate the moderating effects of Chaebols, Korea's unique corporate governance structure. We find that split-rating firms show less stickiness in SG&A costs compared to non-split-rating firms when sales decrease. This result implies the deliberate reduction of discretionary costs to improve earnings in the presence of split ratings, which are more likely to change in future credit assessments. We also find that the incentives for earnings management of split-rating firms are limited in Chaebol firms, which have high levels of socio-economic surveillance and support affiliated firms through the internal market of corporate groups. This study contributes to existing research by identifying new determinants of cost behavior by using the framework of asymmetric cost behavior in relation to earnings management incentives.

• ALGAE
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• v.38 no.1
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• pp.71-80
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• 2023

The oomycete pathogens Pythium porphyrae, causing red rot disease, and Olpidiopsis spp. causing Olpidiopsis-blight, cause serious economic losses to Pyropia sea farms in Korea. During the washing step for Pyropia processing, these pathogens proliferate rapidly, significantly reducing the quality of the final product. To develop non-acidic treatments for these pathogens, various calcium salts were tested against the infectivity of P. porphyrae and Olpidiopsis pyropiae on Pyropia gametophytes, and calcium propionate was the most effective. When Pyropia blades were immersed in 10 mM calcium propionate for 1 h after inoculation with the oomycete pathogen, infection rate of both oomycete pathogens on day 2 was significantly lower (7.1%) than control (>95%). Brief incubation of Pyropia blades in calcium propionate also reduced the spread of infection. The infected area of Pyropia thallus was reduced to 14.3% of the control in 2 days after treatment with 100 mM calcium propionate for 30 s. In field experiments conducted in actual aquaculture farms, it has been shown that a brief 30 s wash every two weeks with 100 mM calcium propionate can effectively reduce the spread of oomycetes throughout the entire culture period. The above results suggest that calcium propionate can be a useful means for controlling the spread of oomycetes not only during laver processing but also during aquaculture.