• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.98-102
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• 2001

We investigated the changes of chemical compositions during fermentation of salted anchovy by salting methods for the purpose of establishment of processing condition. Dehydration of anchovy meat occurred remarkably by dry salting compared with that by brine salting and salinity was higher in anchovy by brine salting than by dry salting. Dehydration and salinity were increased in more anchovy fermented at $20^{\circ}C$ than at $5^{\circ}C$. Total nitrogen content was lower in anchovy by brine salting than by dry salting. Amino nitrogen increased remarkably during fermentation of salted anchovy at $20^{\circ}C$, while increased slightly at$5^{\circ}C$. Amino nitrogen showed maximum value on 120 days in dry salting and on 30 days in brine salting at $20^{\circ}C$, respectively. The changes of VBN were similar to the changes of amino nitrogen. The brine salting accelerated hydrolysis of anchovy meat compared with that of dry salting at $20^{\circ}C$, and the hydrolysis were suppressed at $5^{\circ}C$, The POV increased rapidly in dry-salted anchovy than brine-salted anchovy. We suggested that the appropriate processing condition of salted anchovy is to ferment for 5-6 months at $5^{\circ}C$ by addition of $25\%$ salt after pre-salting of raw anchovy.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.1
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• pp.36-40
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• 2014

Korea's agricultural land is constantly being reduced. The reasons for this are due to the change of agricultural profitability and the policy conditions. The reduction of agricultural land in 2010 showed a decline trend by 14.4 % of paddy fields and 1.2% of uplands compared to areas from 2000. These reductions were mainly due to switch rice paddy fields into upland or greenhouse facility cultivation because of low profitability of rice products compared to farm products. In addition, the permit system of agricultural areas was relaxed in switching paddy fields and this accelerated the reduction of agricultural land. For this reason, more than 1% of agricultural land area has been reduced every year for last five years. Moreover, indiscreet fill and cover materials such as construction wastes were used in agricultural lands and caused land contamination which threatened foundation as sustainable agricultural lands. For these reasons, it is a desperate situation to conserve good agricultural lands. However, the standards of transported soils, filling soils and cutting soils in the Agricultural Land Act are qualitative and have a problem of causing complaints. Therefore, the following criteria (proposals) are proposed in the Agricultural Land Act; (1) Use the proper soils for crops (criterion), (2) Soil components and amounts should be proper as transported soils (range), and (3) Prohibiting usage of improper earth rocks or recycled aggregates in case of filling soils (kinds). The presented criteria (proposals) suggest following; (1) Use physio-chemically proper soils for crops (criterion), (2) In case of transported soils, i, exclude potential acid sulphate soils, ii, gravel content sould be less than 15%, and iii, Heavy metals and other contaminants should be less than the soil contamination warning limit from the Ministry of Environments, (3) In case of filling soils, 13 kinds of recycled wastes specified in the Wastes Control Act should not be used as filling soils, (4) Practice soil conservation technology in case of sloping areas, and (5) Follow proper fertilizer application standards for maturing paddy fields and uplands when cutting soils.

• Journal of Chest Surgery
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• v.29 no.1
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• pp.7-13
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• 1996

The conventional glutaraldehyde (GA) fixation method of tissue valves is considered to be responsible for accelerated valve degeneration. The release of toxic GA from the valve tissue is believed to limit endothelial cell (EC) ingrowth. Removal of toxic GA by reaction with L-glutamic acid and storage in a Paraben solution may offer good EC growth. To investigate the conditions for endothelialization of tissue valves, the growth properties of ECs on the conventionally and alternatively treated pericardial tissue were compared. Conventional preparation included zero-pressure fixation for 72 hours in phosphated-buffered saline (PBS) solution containing 0.5% GA at 4$^{\circ}C$ and storage into PBS containing 0.2% GA(group I). Alternatively treated pericardial tissues were divided into three postfixation treatment groups : (1) storage in PBS solution containing Paraben(group II), (2) treatment with PBS containing 8$^{\circ}C$ L-glutamic acid(PH 7.35) and storage in PBS solution containing Paraben (g oup III), (3) treatment with L-glutamic acid dissolved in distilled water (PH 3.5) (group IV). Pericardial tissue were transferred into the 24-well plate after storage for 4 weeks. ECs were harvested enzymatically from the bovine pulmonary artery and grown to confluence on culture flask surfaces. Detached ECs by trypsin were incubated into the each well of the 24-well plate including test pericardial tissues. Cells were detached by trypsin, 1, 2, 3, 5, 7 days after incubation and counted on the hemacytometer. Cell viability test was performed by frypan-blue exclusion method. Acute cell death in the group I were found even after prolonged washing. The group II showed prolonged cell survival compared with the group I. Both group III and group IV showed better cell growth than group II. There was no statistically significant difference between group III and group IV method in terms of EC growth. This results suggest that treatment by L-glutamic ac id and storage in a Paraben solution be a promising approach for improvement of durability of GA-treated tissue valves.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.603-610
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• 2018

The development of industry and the increase in the use of fossil fuels have accelerated the process of global warming and climate change, resulting in more frequent and intense natural disasters than ever before. Since electricity facilities are often installed outdoors, they are heavily influenced by natural disasters and the number of related accidents is increasing. In this paper, we analyzed the statistical status of domestic electrical fires, electric shock accidents, and electrical equipment accidents and hence analyzed the risk associated with climate change. Through the analysis of the electrical accidental data in connection with the various regional (metropolitan) climatic conditions (temperature, humidity), the risk rating and charts for each region and each equipment were produced. Based on this analysis, a basic electric risk prediction model is presented and a method of displaying an electric hazard prediction map for each region and each type of electric facilities through a website or smart phone app was developed using the proposed analysis data. In addition, efforts should be made to increase the durability of the electrical equipment and improve the resistance standards to prevent future disasters.

• Korean Journal of Weed Science
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• v.13 no.4
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• pp.234-249
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• 1993

Herbicide is an essential agricultural chemical in the modern agriculture. Due to its bioactivity, however, risk of herbicide use against non-target organisms should be seriously considered. Among the unfavorable aspects given by herbicide, the residue is the most important because herbicide residue in soil and agricultural product is closely related to human safety. The residue in soil and crop is dependent on conditions of soil, weather, herbicide use and crop cultivation, etc. In general, the residue in soil or agricultural product in Korea is known to be not serious at this moment, except for some problems like carry-over effect on succeeding crops. To secure safety of herbicide use for the health, soil ecology and other environment, researches on herbicide residue including monitoring survey should be done more frequently and extensively. Safety guide for herbicide usage should be kept by farmers and development of long toxic herbicide should be accelerated.

• Journal of Technology Innovation
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• v.22 no.4
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• pp.21-55
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• 2014

The rates of technological innovation and environmental change as well as market competition have recently accelerated, which makes it difficult for firms to satisfy the needs of their customers through existing product innovation or limited services. Some firms have attempted to find the solutions to this problem by conducting business model (BM) innovation. This study reviews the theoretical discussion to BM innovation and suggests propositions concerning the necessity of BM innovation and conditions of successful BM innovation. Furthermore, the study examines the applicability of the propositions and draws strategic implications by analysing the cases of two world-wide leading firms, AVL and ETAS, in the automobile R&D service sector. In particular, the study investigates how the firms with technological competence in the R&D service sector obtain market performance through BM innovation. Results of this study show that the case firms recognize the necessity of BM innovation based on product (or technology)-service fusion to effectively propose customer value and create corporate profit. Also, the firms exploit firm-specific complementary assets for successful BM innovation. This paper contributes to the literature of innovation management by promoting academic discussion concerning BM innovation in Korea and suggesting strategic implications for further development of R&D service sector and related firms in Korea.

• The Journal of the Petrological Society of Korea
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• v.12 no.4
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• pp.196-206
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• 2003

The geochemical and mineralogical investigation on the rocks and repair material comprising of the Sungryemun (The 1st National Treasure) has been made. Rock of the Sungryemun is highly weathered coarse-grained calc-alkali granite. The rock consists mainly of quartz, perthite, plagioclase and biotite with small amounts of orthoclase, muscovite, chlorite and sericite, which are major weathering products from perthite. For obtaining informations about degree of weathering, mineral composition of the original rock calculated by CIPW norm and weathered rock composition determined by XRD quantitative analysis were plotted on a ternary diagram of quartz-potash feldspar-plagioclase. Original rock compositions are plotted on the central granite area. whereas weathered ones are plotted on the granite area close to quartz. The result means that quartz is more abundant in weathered rock, due to selective chemical weathering of potash feldspar and plagioclase over quartz. On the whole, surface of the rocks were black-coated, exfoliated and highly fractured due to the physical and chemical weathering and heavy load has made the cracks in the lower parts of the stone construction. Also, cement and nails, which was used as repair material, during the repair work in the early 1960's, has accelerated the weathering process. Furthermore, weathered conditions of repair materials are very severe. Therefore, it is very urgent to establish of the conservation plan for the Sungryemun.

• Journal of the Korea Concrete Institute
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• v.29 no.3
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• pp.299-306
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• 2017

In this research, it was examined chloride ion penetration resistance of slag-replaced concrete and cementless slag concrete considering marine environmental exposure conditions of splash zone, tidal zone and immersion zone. In the design strength of grade 24 MPa, the specimens were tested to determine their compressive strength, scanning electron microscopy images and chloride migration coefficient. Further, chloride ion penetration depth and carbonation depth of specimens exposed to marine environment were measured. Experimental results confirm that chloride migration coefficient of specimens tended to decrease with increasing the replacement ratio of ground granulated blast-furnace slag in accelerated laboratory test. In addition, the specimens exposed to the tidal zone were found to be the greatest chloride ion penetration depth compared to splash zone and immersion zone. On the other hand, the chloride ion penetration depth of the specimens exposed to splash zone tended to increase with increasing the replacement ratio of ground granulated blast-furnace slag in contrast with the results for the tidal zone and immersion zone.

• Journal of Radiation Protection and Research
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• v.21 no.1
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• pp.51-58
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• 1996

Underground migration of $^{54}Mn,\;^{60}Co,\;^{85}Sr\;and\;^{137}Cs$ in paddy and upland conditions was studied through two years' greenhouse experiment. At early and late growth stages of rice, soybean, Chinese cabbage and radish, a mixed solution of the radionuclides was applied to the water or soil surfaces of the culture boxes filled with an acidic loamy-sandy soil for the upper 20cm. Soil was sampled in layers upto $15{\sim}20cm$ down after harvest. Soil concentrations of the radionuclides decreased exponentially with increasing soil depth and more than 80% of the radioactivities remained in top $3{\sim}4cm$. The mobility of the radionuclides decreased in the order of $^{85}Sr>^{54}Mn>^{60}Co{\geq}^{137}Cs$. Downward migrations of the radionuclides were the greatest in rice soil and the lowest in soybean soil which was fertilized with the least amount of N, P and K. Differences in depth profiles between two application times indicate that the amount of daily migration from $0{\sim}1cm$ layer to the lower area decreases with increasing time after deposition. By a simultaneous addition of KCl and lime following the earlier application, downward migration in soybean, Chinese cabbage and radish soils changed little or retarded more or less but that in rice soil accelerated a little.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.9
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• pp.784-793
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• 2017

A two-axis gimbal-type X-band antenna mounted on an observation satellite can efficiently transmit high-capacity image data to a ground station regardless of both the satellite position and the orbital motion. However, this X-band antenna induces unnecessary micro-jitter which can degrade the image quality of the high-resolution observation satellite. Therefore, to achieve the high-resolution image quality from the observation satellite, micro-jitters have been required to be isolated. In this study, to resolve aforementioned drawback, we proposed blade gear using a shape memory alloy (SMA) applied to azimuth stage of X-band antenna. To investigate the rotational basic characteristics of the proposed SMA blade gear, we performed rotational static loading test. Futhermore, to evaluate the cycle to failure of the gear, accelerated life test was conducted. The temperature test was conducted to confirm rotational basic characteristics at various temperature conditions. To verify the isolation performance for micro-jitter, we performed micro-jitter measurement test.