• Environmental and Resource Economics Review
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• v.21 no.3
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• pp.595-625
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• 2012

Recently environment-friendly pellet boilers have interests as emissions of greenhouse gases are regulated internationally and energy security becomes more important to oil addicted countries including Republic of Korea. But the Korean market for pellet boilers is on the initial stage due to the high production costs relative to other conventional boilers. Hence the Korean government has supported financially and promoted the pellet boiler business. In this sense, it would contribute market stratergy and effective promotion policy for both of the government and private companies if we can forecast market shares of pellet boilers appropriately. For this purpose, this study surveyed potential consumers' preferences on pellet boilers among various alternatives using a choice experiment reflecting intangible costs. As the market share of new technology increases, intangible costs decline. According to different intangible cost scenarios, we experimented people's preferences on oil, gas, electric, and pellet boilers. A multinomial logit model was employed to estimate coefficient parameters of common attributes for various alternative boilers. Based on the estimates, we forecasted market shares of individual boilers. We found that as intangible costs decline, the market share of pellet boiler increase substantically while market shares of electric and gas boilers decrease dramatically. The market share of oil boiler did not change significantly. Meanwhile, as people are more rich, more educated, and exposed to advertisement on pellet boilers, the likelihood of choosing the pellet boiler increases.

• Korean Chemical Engineering Research
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• v.47 no.4
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• pp.488-494
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• 2009

Zeolite 4A was prepared by new synthesis method, 2-step crystallization, for enhancement of oil absorption capacity. Vietnamese sand and $NaAlO_2$ solution from natural bauxite were used as raw materials in stead of conventional cullet and $Al(OH)_3$ to reduced the processing cost. Some dissolved organics in $NaAlO_2$ solution were removed by activated carbon. Synthetic method was progressed by 1) reacting the raw materials at $55^{\circ}C$, 4 hr with the ratio of Si/Al to 1.15, and 2) reacting at $65^{\circ}C$, 5 hr with reducing the ratio of Si/Al to 0.98. New method can easily control the particle size, aggregation, surface polarity, and enhanced the whiteness of the products. The prepared zeolite 4A shows excellent oil absorption capacity(O.A.C>50 ml/100 g) as well as equal value with calcium ion exchange capacity, and proves the 2-step crystallization is the economic and effective process for the preparation of zeolite 4A.

• Research in Plant Disease
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• v.14 no.2
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• pp.112-116
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• 2008

Powdery mildew of Paprika caused by Leveillula taurica has been a serious problem in greenhouse. It is an unusual endophytic powdery mildew because the mycelia grow inside the leaf, such that the pale yellow lesions on adaxial surfaces appear first and the white powdery lesion/signs develop later on the corresponding to the spots of the abaxial leaf surface, where the conidiophores are typically emerge through the stomatal opening. Although one foliar application of cooking oil and yolk mixture(COY) to the foliage was not practically effective enough, two or three, weekly application of COY to the foliage at either 0.3 or 0.5% concentration resulted in excellent control against powdery mildew with disease index less/lower than 1, respectively. This treatment could provide protection for three weeks, which, we believe, is not only cost-effective, but also environment-friendly. Powdery mildew fungus was affected by COY treatment quickly which is recognizable in three days. Net photosynthesis and evapotranspiration was remarkably reduced by powdery mildew infection compared to healthy leaves, suggesting that prevention and early protection is the most critical strategy for peak paprika fruit yield. Moreover, COY treatment did not adversely affect the photosynthesis and evapotranspiration of foliages.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.238-244
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• 2011

Biodiesel, mono-alkyl esters of long chain fatty acids, is one of the alternative fuels derived from renewable lipid feedstock, such as vegetable oils or animal fats. For decade, various lipases have been used for the production of biodiesel. However, the production of biodiesel by enzymatic catalyst has profound restriction in industry application due to high cost. To overcome these problems, many research groups have studied extensively on the selection of cheap oil sources, the screening of suitable lipases, and development of lipase immobilization methods. In this study, we produced biodiesel from plant oil using Proteus vulgaris lipase K80 expressed in Escherichia coli cells. The recombinant lipase K80 was not only expressed in high level but also had high specific lipase activity and high stability in various organic solvents. Lipase K80 could produce biodiesel from olive oil by 3-stepwise methanol feeding method. The immobilized lipase K80 also produced biodiesel using the same 3-stepwise method. The immobilized lipase could produce biodiesel efficiently from various plant oils and waste oils.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.3 s.55
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• pp.53-62
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• 2007

This paper presents a new vibration control method for long-span bridges using complex damper system. The new system presents simple mechanical configuration with oil and elasto-plastic dampers which have velocity and displacement dependency in vibration energy absorbing. This system can produce various damping forces according to the applied external forces by the velocity and displacement-dependent characteristics of the dampers. The oil damper dissipates vibration energy for relatively frequent and small amplitude like in the case for small to moderate earthquakes, whereas the elasto-plastic damper system works for rare and large amplitude vibration such as high seismic excitation. Thus, the proposed system exhibits the advantage of low cost with high performance since the roles of the two different dampers are effectively separated. A numerical model is established for the complex damper system, and the response characteristics and effectiveness of the proposed system are presented through numerical simulations. Numerical results show that the proposed complex damper system can significantly improve the seismic performance of long-span bridge structures with much more effective damping mechanism than single conventional passive damper systems.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.28-34
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• 2014

Automatic transmission fluid (ATF) is used for automatic transmissions in the vehicle as the characterized fluid. Recently, the vehicle manufacture usually guarantee for fluid change over 80000~100000 km mileage or no exchange, but most drivers usually change ATF below every 50000 km driving in Republic of Korea. It can cause to raise environmental contamination by used ATF and increase the cost of driving by frequently ATF change. In this study, we investigate the various physical properties such as flash point, fire point, pour point, kinematic viscosity, cold cranking simulator, total acid number, and metal component concentration for fresh and used ATF after driving (50000 km, 100000 km). The result showed that the total acid number, pour point, Fe, Al and Cu component had increased than fresh ATF, but 2 kind of used oil (50000 km and 100000km) had similar physical values and metal component concentration.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.6
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• pp.503-513
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• 2016

In order to reduce the green-house gas exhaustion, International Maritime Organization (IMO) has been reinforcing carbon gas regulations. Due to the regulations, a lot of competitions for designing Eco ship in the shipbuilding industry are progressing now. It is faced with the necessity of reducing hull weight by combining automated systems for optimal compartment arrangement with hull structural design. Most researches on optimum structural design method have been consistently in progress and applied to minimize weight and cost of mid-ship section in preliminary ship design stage based on analytical structural analysis method on fixed compartment arrangement. In order to reduce design period and to improve international technical competitiveness by shortening the period of hull structural design and enhancing design accuracy, it has been felt necessity to combine optimized compartment arrangement with optimum design of ship structure based on the international regulations and rules. So in this study, the automated design algorithm for longitudinal members has been developed to combine automated algorithm of compartment arrangement with hull structural design system for oil tanker. The SeaTrust-Hullscan software developed by Korean Register is used to perform ship structural design for mother ship and selected design cases. The effect of weight reduction is verified with comparison of ship weight between mother ship and the cases suggested in this study.

• Fisheries and Aquatic Sciences
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• v.25 no.9
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• pp.473-488
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• 2022

To have a better understanding of the impact of the PETRONAS oil and gas platform on commercial fisheries activities, Universiti Malaysia Terengganu (UMT) examined two approaches which are data collection from satellite and data collection from fishermen and anglers. By profiling the anglers who utilize reefed oil and gas structures for fishing, it can determine if the design and location of the reef platforms will benefit or negatively impacts those anglers and fisherman. Furthermore, this assessment will be contributing to the knowledge regarding the value of offshore oil and gas platforms as fisheries resources. Collectively, the apparent fishing activity data included, combined with the findings in the reefing viability index will help to inform PETRONAS's future decommissioning decisions and may help determine if the design and proposed locations for future rigs-to-reefs candidates would benefit commercial fishing groups, further qualifying them as appropriate artificial reef candidates. The method applied in this study is approaching by using a data satellite known as Google's Global Fishing Watch technology, which is one of the applications to measure commercial fishing efforts around the globe. The apparent commercial fishing effort around the selected twelve PETRONAS platforms was analyzed from January 2012 to December 2018. Using the data collection from fishermen which is the total estimation of commercial fish value cost (in Malaysia ringgit, MYR [RM]) in Peninsular Malaysia Asset, Sabah Asset, and Sarawak Operation region. The data were extracted every month from 2016 to 2018 from the National Oceanic and Atmospheric Administration database. Most of the selected platforms that show a high frequency of vessels around the year are platform KP-A, platform BG-A and platform PL-B. The estimated values of commercial fishes varied between platforms, with ranged from RM 10,209.92 to RM 89,023.78. Thus, platforms with high commercial fish value are selected for reefing in-situ and will serve multi-purposes and benefit the locals as well as the country. The current study has successfully assessed the potential reefing area of the Malaysian offshore environment with greater representativeness and this paper focused on its potential as a new fishing ground.

• Management & Information Systems Review
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• v.22
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• pp.137-165
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• 2007

It seems high time to increase productivity by adopting e-business to overcome challenges posed by both external factors including the appreciation of Korean won, oil hikes and fierce global competition and domestic issues represented by disparities between large corporations and small and medium enterprises (SMEs), Seoul metropolitan and local cities, and export and domestic demand all of which weaken future growth engines in the Korean economy. The demands of the globalization era are for innovative changes in businessprocess and industrial structure aiming for creating new values. To this end, e-business is expected to play a core role in the sophistication of the Korean economy through new values and innovation. In order to examine business performance in e-business-adopting industries, this study analyzed the home shopping industry by closely looking into the financial ratios including the ratio of net profit to sales, the ratio of operation income to sales, the ratio of gross cost to sales cost, the ratio of gross cost to selling, general and administrative (SG&A) expense, and return of investment (ROI). This study, for best outcome, referred to corporate financial statements as a main resource to calculate financial ratios by utilizing Data Analysis, Retrieval and Transfer System (DART) of the Financial Supervisory Service, one of the Korea's financial supervisory authorities. First of all, the result of the trend analysis on the ratio of net profit to sales is as following. CJ Home Shopping has registered a remarkable increase in its ratio of net profit rate to sales since 2002 while its competitors find it hard to catch up with CJ's stunning performances. This is partly due to the efficient management compared to CJ's value of capital. Such significance, if the current trend continues, will make the front-runner assume the largest market share. On the other hand, GS Home Shopping, despite its best organized system and largest value of capital among others, lacks efficiency in management. Second of all, the result of the trend analysis on the ratio of operation income to sales is as following. Both CJ Home Shopping and GS Home Shopping have, until 2004, recorded similar growth trend. However, while CJ Home Shopping's operating income continued to increase in 2005, GS Home Shopping observed its operating income declining which resulted in the increasing income gap with CJ Home Shopping. While CJ Home Shopping with the largest market share in home shopping industryis engaged in aggressive marketing, GS Home Shopping due to its stability-driven management strategies falls behind CJ again in the ratio of operation income to sales in spite of its favorable management environment including its large capital. Companies in the Group B were established in the same year of 2001. NS Home Shopping was the first in the Group B to shift its loss to profit. Woori Home Shopping has continued to post operating loss for three consecutive years and finally was sold to Lotte Group in 2007, but since then, has registered a continuing increase in net income on sales. Third of all, the result of the trend analysis on the ratio of gross cost to sales cost is as following. Since home shopping falls into sales business, its cost of sales is much lower than that of other types of business such as manufacturing industry. Since 2002 in gross costs including cost of sales, SG&A expense, and non-operating expense, cost of sales turned out to have remarkably decreased. Group B has also posted a notable decline in the same sector since 2002. Fourth of all, the result of the trend analysis on the ratio of gross cost to SG&A expense is as following. Due to its unique characteristics, the home shopping industry usually posts ahigh ratio of SG&A expense. However, more than 80% of SG&A expense means the result of lax management and at the same time, a sharp lower net income on sales than other industries. Last but not least, the result of the trend analysis on ROI is as following. As for CJ Home Shopping, the curve of ROI looks similar to that of its investment on fixed assets. As it turned out, the company's ratio of fixed assets to operating income skyrocketed in 2004 and 2005. As far as GS Home Shopping is concerned, its fixed assets are not as much as that of CJ Home Shopping. Consequently, competition in the home shopping industry, at the moment, is among CJ, GS, Hyundai, NS and Woori Home Shoppings, and all of them need to more thoroughly manage their costs. In order for the late-comers of Group B and other home shopping companies to advance further, the current lax management should be reformed particularly on their SG&A expense sector. Provided that the total sales volume in the Internet shopping sector is projected to grow over 20 trillion won by the year 2010, it is concluded that all the participants in the home shopping industry should put strategies on efficient management on costs and expenses as their top priority rather than increase revenues, if they hope to grow even further after 2007.

• Korean Journal of Agricultural Science
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• v.43 no.5
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• pp.761-768
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• 2016

Recently, swine production costs have increased due to increased feed cost, especially the price of corn and soybean meals. Soybean meal is traditionally an expensive ingredient, but the price of corn has dramatically increased because of increased biofuel production. This change has resulted in the swine industry looking for alternatives in order to reduce feed cost, resulting in decreased production costs. Thus, various alternatives have been used as feed ingredients to replace corn, soybean meal, or other expensive ingredients. One othercandidate may be palm kernel co-products that are a by-product of oil extraction from palm fruits. Palm kernel co-products have not been used in swine diets due to high fiber content and imbalanced amino acids compared with corn and soybean meal. However, recent studies showed that palm kernel co-products did not have any negative effects on growth performance of pigs when they replaced some proportions of corn and soybean meal. In addition, palm kernel co-products may provide some physiological properties to pigs by modifying gut microbiota and/or immunity of pigs, resulting in improvement of growth and health of pigs. Therefore, the value of palm kernel co-products were reviewed as one of the alternatives for corn, soybean meal, or other major ingredients in swine diets.