• International conference on construction engineering and project management
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• 2011.02a
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• pp.66-73
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• 2011

With rapid industrialization, electric power consumption has been increasing every year in Korea and in other countries. The provision of additional power stations to produce more electricity is one possible response to this steady increase in consumption. Another alternative is to improve the efficiency of existing stations through timely and effective maintenance works. Since the construction of a new power plant involves a large amount of capital as well as difficulties in the selection of sites, the improvement of existing power stations' efficiencies is often a preferred solution. Therefore, this paper focuses on maintenance project management to address this issue. Among several types of maintenance works, this paper concentrates on planned outage maintenance (POM). This focus arises from the critical impact of POM on other maintenance work, as well as the entire process of electricity production. Unlike other maintenance work, POM is done on the basis of mid and long-term plans. In addition, only POM works are conducted during the outage of all power plants. To evaluate the efficiency of POM works, budget data relating to 164 POM projects between 2001 and 2008 was collected from 7 sites in South Korea. Data envelopment analysis (DEA) was selected as a methodology for evaluation. From this analysis, comparative study was used to determine the categories of projects that had performed well, and those with the most optimized budget structures. Moreover, through discussion with industry, this research develops a feasible proposed method by which to enhance the efficiency of POM projects.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.1038-1046
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• 2013

With the aim of investigating the differences in the quality traits between Korean native chicken (Hanhyup, KNC) and broilers commonly used in two different traditional Korean cuisines, the chemical composition and sensory properties of breast and thigh meat from the two chicken strains were assessed. KNC for baeksuk (chicken meat braised in soup with various Oriental medicinal plants; KNL), KNC for samgyetang (similar to baeksuk but young chickens and ginseng are used; KNS), broiler for baeksuk (BL), and broiler for samgyetang (BS) were used as treatments in this study. KNL and KNS contained higher protein but lower fat content than BL and BS. The $L^*$ values of breast and thigh meat, but not the $a^*$ values, were significantly different between KNS and BS, whereas significant differences in both values were observed between KNL and BL. Compared to the other three types of chickens, KNS contained the highest total and insoluble collagen content, and KNL and BL showed higher inosine-5'-monophosphate content in their meat. Overall, KNL and KNS contributed darker, less tender meat with higher protein and less fat content together with more n-3 fatty acids, as opposed to their counterparts used for the same cuisines. Based on the results of the sensory analysis, even though there are some differences in physiochemical traits, different chicken sources do not differ in overall sensory quality. This information can help consumers to understand better the meat available for their preferred traditional cuisines.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.8 s.251
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• pp.965-975
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• 2006

High pressure turbine blades are one of the key components in fossil power plants operated at high temperature. The blade is usually made of 12Cr steel and its operating temperature is above $500^{\circ}C$. Long term service at this temperature causes material degradation accompanied by changes in microstructures and mechanical properties such as strength and toughness. Quantitative assessment of reduction of strength and toughness due to high temperature material degradation is required for residual life assessment of the blade components. Nondestructive technique is preferred. So far most of the research of this kind was conducted with low alloy steels such as carbon steel, 1.25Cr0.5Mo steel or 2.25Cr1Mo steel. High alloy steel was not investigated. In this study one of the high Cr steel, 12Cr steel, was selected for high temperature material degradation. Electrochemical polarization method was employed to measure degradation. Strength reduction of the 12Cr steel was represented by hardness and toughness reduction was represented by change of transition temperature, FATT. Empirical relationships between the electrochemical polarization parameter and significance of material degradation were established. These relationship can be used for assessing the strength and toughness on the aged high pressure blade components indirectly by using the electrochemical method.

• Membrane Journal
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• v.17 no.4
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• pp.277-286
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• 2007

The technology of seawater desalination has been received much attentions to solve the problem of water shortage through all over the world. In this study, it attempts to confirm the use-possibility of cellulose triacetate (CTA) for preparation of reverse osmosis membranes which have been highlighted as high efficiency and low energy consumption process for seawater desalination. The effects of casting dope parameters like an acetyl content, solvent, additives on the membrane performance were investigated. It was possible to produce the membranes which have high water flow rate and salt rejection with the increase of acetyl content and dioxane content among various dioxane/acetone ratios. Acetic acid and maleic acid were preferred for additives to produce high performance membranes. It was verified that $HOLLOSEP^{(R)}$ module which is commercialized CTA membrane by TOYOBO Co. can produce stable water production and high-quality water for long-term operation in the practice plants without any chemical treatments.

• Journal of Radiation Protection and Research
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• v.36 no.1
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• pp.44-51
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• 2011

Activation foil-based Bonner sphere spheres are used to obtain neutron energy spectra of nuclear power plants or accelerator-produced neutrons. The position and the foil mass dependence of response functions should be studied carefully before measurement of Bonner spheres. This study showed that the normal incidence to the foil surface made a large shift of responses while parallel and isotropic incidence made no position dependence. The correlation between foil mass and response was not linear. Therefore, the response functions of activation-foil based Bonner spheres should be calculated for every different foil mass and the direction of Bonner spheres for parallel incidence will be preferred for radioactive neutron source or accelerator target produced neutrons.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.311-316
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• 2015

This study was performed to ascertain the potential of egg plant for use as a trap plant to attract Bemisia tabaci adults compared to that of tomato. Choice tests were conducted to compare the preference of B. tabaci adults to horseweed, egg-plant, cucumber, and tomato. B. tabaci adults were found to be more sensitive to visual cues than to odor cues, and they preferred the egg-plant and cucumber to horseweed. The attraction rates of the egg-plant and cucumber to B. tabaci adults were 82.3% and 82.5% respectively, compared to that of tomato. Because egg-plants are easier to manage compared to cucumber, we excluded cucumber from subsequent experiment. The attraction rate of egg-plant to B. tabaci adults was >90% when the height of egg-plant was equal or more than that of the tomato plant.

• Journal of the Korea Convergence Society
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• v.12 no.4
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• pp.161-169
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• 2021

'Clean beauty' attracts attention with an increasing interest in cosmetics without harmful ingredients as people wear masks in the age of COVID-19. Thus, this study selected and analyzed clean beauty cosmetic brands circulated in Korea on/offline in 2020. This study extracted 36 clean beauty brands and selected 20 suitable brands through an experts' analysis. For an analysis of clean beauty cosmetic brand communication, components: naming, logo, color, package, and website were drawn to conduct a survey. Preferred were the words they come up with when they think of nature or health for naming; wordmarks in a simple form for logo; greenish or yellowish for color; the simple form aligned center on the container body for package; and the images of plants, animals, and humans for website. To sum up the components, utilizing natural, clean, and light images harmoniously, acted as a factor for preferring the clean beauty cosmetic brands.

• Korean Journal of Ichthyology
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• v.28 no.3
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• pp.186-191
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• 2016

Distribution status and threatened assessment of endangered species, Pungitius sinensis (Pisces: Gasterosteidae), were investigated from March to October 2015 in Gangwon-do and Gyeongsangbuk-do etc., Korea. During the study period, a total of 854 individual P. sinensis were collected from 21 of 71 sampling stations using skimming nets. P. sinensis appeared in 23 streams during the past 30 years. However, it was only collected in 12 streams. Therefore, its habitats and populations were drastically reduced. The preferred habitat of P. sinensis was pool of the lower stream with lots of aquatic plants. Given these evidences of small occupying areas ($84km^2$) and drastic reduction in its habitats and populations, P. sinensis is considered as an endangered (EN) [B2ab(ii,iii,iv,v)] species based on IUCN Red List categories and criteria.

• Korean journal of applied entomology
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• v.53 no.1
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• pp.65-71
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• 2014

Frankliniella occidentalis is attracted to flowers and is a major pest of chrysanthemums. Even when some chrysanthemum plants are not flowering, the ones that have already flowered attract F. occidentalis. Therefore, we investigated the efficacy of chrysanthemum as a trap plant that attract F. occidentalis by using an olfactometer. The numbers of F. occidentalis collected from the flowers of pink, wihte and yellow standard chrysanthemums on a tray with wet paper during the flowering period were 18.4, 56.6, and 52.6 respectively; the numbers of F. occidentalis collected from leaves were 7.8, 16.6, and 15.4 respectively. the numbers of F. occidentalis collected from the buds of pink, white and yellow standard chrysanthemums were 15.2, 45.8, and 41.6 respectively; the numbers of F. occidentalis collected from the leaves were 2, 8.8 and 3.4 respectively. In the Y-tube olfactometer test, the number of F. occidentalis attracted to the 2-way arms of the Y-tube was not significantly different for the yellow, red, violet and white flowers. In the four-choice olfactometer test, when the same visual cues and odor cues were provided, the frequency of F. occidentalis was higher in the yellow (10.7) flowers than in the red (1.3), violet (3.7) and white (2.0) flowers. When visual cues with disturbed odor cues, F. occidentalis preferred yellow (10.0) color over red (3.3), violet (1.3) and white (3.0) colors. When the same visual and odor cues, except for yellow visual cues, were provided, F. occidentalis preferred white (8.3) color over red (4.7), violet (4.7) and yellow (2.0) colors. Therefore, F. occidentalis were attracted to buds before the flowering of chrysanthemum plants and attracted to yellow flowers after the flowering.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.117-121
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• 1998

This experiment was conducted to investigate host preference, occurrence and intraplant distribution of Trialeurodes vaporariorum (Westwood) and Encarsia formosa (Gahan) in greenhouse. T vaporariorum preferred cucumber over tomamto. 7: vaporariorum adults distributed at upper part of cucumber plant. Nymphs also distributed at upper part in early growing stage of cucumber but became to distribute lower part after 40 days. E. formosa adults were found mainly at mid-upper part of plant but there was no significant difference in statistics all analysis among each parts and also mummy distributed mid-low part. E. formosa were released when five ir: vaporariorum were caught by yellow sticky trap per week in glasshouse. The treatment of one tag (50 mummies) of E. formosa per five plants controlled successfully the 7: vaporariorum population after 40 days.