• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.5
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• pp.439-445
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• 2012

The COMS(Communication, Ocean, and Meteorological Satellite) is subjected to shock loads when the stage or fairing of a launch vehicle is separated and the satellite is separated from the launch vehicle during the launch vehicle flight. And, after the satellite is separated from the launcher, the COMS is subjected to shock loads when the solar array is deployed, Ka-Band communication antenna is deployed, and meteorological imager radiator cover is released. In order to validate the satellite safety against these shock loads on ground, shock tests were performed. In this paper, the shock tests performed in the course of the COMS development are described, and the method to assess the test result is presented with an example of Geostationary Ocean Color Imager(GOCI). In Ariane-5 launch vehicle, the clampband release shock for satellite separation is lower than the fairing or stage separation. In this paper, the extrapolation method to take into account the maximum shock load from the launch vehicle by using the satellite separation shock test result is also introduced.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.118-122
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• 2010

The study presents a standard time-temperature curve to evaluate the fire performance of subway tunnel structures. The central subway section is 135km long in Korea, the fourth longest in the world. The number of subway tunnels has been increasing rapidly and fire risk is proportional to the tunnel length. However, an adequate time-temperature curve for subway tunnel fires does not exist. Therefore, we studied a proposed foreign fire design model for which the heat rate is based on the traffic, and we present an appropriate time-temperature curve for Korean subway tunnels. The ISO 834 curve was used as a fire design model and the temperature distribution in the tunnel was estimated using numerical analysis. This led to a proposal for effective measures against subway tunnel fires.

• 재활복지
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• v.16 no.3
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• pp.421-437
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• 2012

The goal of this study is to provide the basic information for improvement of domestic standards on the powered scooter and the electric wheelchair considering using environments in the nation. The international standards and domestic standards have been analyzed and compared, in order to propose improved domestic standards. Based on the research, the items and standards for general and functional recommendations, electric features, and other suggestions have been reexamined so that the improvements on test item and standards have been identified, corrected, and summarized including max. speed, brake system, lights and so on. We have been preparing the reference data for the improvement of standards on the powered scooter and the electric wheelchair through the comparison & analysis on the international and domestic standards.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.674-680
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• 2005

The purposes of this study were to compare the effect of several reheating treatments (heating in the frying pan, convection oven and microwave oven) on sensory characteristics and to evaluate the safety during storage period of cook/chill Pajeon. The sensory evaluations were made on 5 sensory attributes by a 9-member panel using quantitative descriptive analysis (QDA). The fresh cooked Pajeon and the Pajeon reheated in the frying pan obtained a significantly (p<0.01) higher score in taste than the ones reheated in a convection oven and microwave oven. The reheated cook/chill Pajeon had a significantly (p<0.01) lower score in flavor than the freshed cooked one. Regardless of the reheating methods, sensory scores in texture of the Pajeon reheated at $v$ for 1 day were not different from that of fresh cooked one. However, the scores of the reheated ones in a convection oven and in a microwave oven decreased with storage time up to 5 days at $3^{\circ}C$. On the other hand, the Pajeon reheated in the frying pan, even after 3 days' storage at $3^{\circ}C$, was not found to be inferior to the freshed cook one in every quality attributes except flavor. Therefore, the reheating treatment in frying pan may be superior to those in a convection oven and a microwave oven. The safety of Pajeon was also evaluated by measuring total count, coliform count, psychrotrophic count, acid value and peroxide value during 5 days of storage periods at $4^{\circ}C$. Total counts of Pajeon was ranged from not detectable to $5.2\times10^2$ CFU/g. The coliform and psychrotroph were not detected at all experiments. The acid values were ranged from 1.90 to 4.03 mg of KOH/g of fat until 5 days at $4^{\circ}C$. And the peroxide values were ranged from 3.63 to 12.50 meq of peroxide/kg of fat until 5 days of storage period. Therefore, these results demonstrated that Pajeon is microbiologically and chemically safe during 5 days of storage period at refligeration temperature.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.334-346
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• 2022

There is a lack of knowledge and information on the understanding and application of the Process Safety Management (PSM) system, recognized as a major cause of industrial accidents in small-and medium-sized workplaces. Hence, it is necessary to prepare a protocol to secure the practical and continuous levels of implementation for PSM and eliminate human errors through tracking management. However, insufficient research has been conducted on this. Therefore, this study investigated and analyzed the various violations in the administrative measures, based on the regulations announced by the Ministry of Employment and Labor, in approximately 200 small-and medium-sized PSM workplaces with fewer than 300 employees across in korea. This study intended to contribute to the prevention of major industrial accidents by developing a facility maintenance web program that removed human errors in small-and medium-sized workplaces. The major results are summarized as follows. First, It accessed the web via a QR code on a smart device to check the equipment's specification search function, cause of failure, and photos for the convenience of accessing the program, which made it possible to make requests for the it inspection and maintenance in real time. Second, it linked the identification of the targets to be changed, risk assessment, worker training, and pre-operation inspection with the program, which allowed the administrator to track all the procedures from start to finish. Third, it made it possible to predict the life of the equipment and verify its reliability based on the data accumulated through the registration of the pictures for improvements, repairs, time required, cost, etc. after the work was completed. It is suggested that these research results will be helpful in the practical and systematic operation of small-and medium-sized PSM workplaces. In addition, it can be utilized in a useful manner for the development and dissemination of a facility maintenance web program when establishing future smart factories in small-and medium-sized PSM workplaces under the direction of the government.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.850-856
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• 2005

The sensory and safety of cook-chilled Buchu-jeon were evaluated to provide to foodservice operation during chilled storage for 5 days. The sensory evaluations of cook-chilled Buchu-jeon were conducted according to 3 reheating methods which was frying pan, steam/convection oven and microwave oven. The sensory evaluations were made on 4 sensory attributes (taste, odor, color, and texture) by a 9-member panel using quantitative descriptive analysis (QDA). The Buchu-jeon reheated in the steam/convection oven, after 1 day storage at $3^{\circ}C$, obtained higher score in taste, odor and texture than the ones reheated in a frying pan and microwave oven. Three reheating methods didn't show any difference in taste, odor, color, and texture of Buchu-jeon at $3^{\circ}C$ for 3 days. The Buchun-jeon reheated in microwave oven at $3^{\circ}C$ for 5 days had a significant $(p\leq0.05)$ lower score odor and color than the ones reheated in frying pan and steam/convection oven. The safety of Buchu-jeon was also evaluated by measuring total count, coliform count, psychrotrophic count, acid value and peroxide value during 5 days of storage periods at $4^{\circ}C$C. Total counts of Pajeon was ranged from $5.0\times10^{1}$ CFU/g to $2.2\times10^{2}$ CFU/g and the coliform and psychrotroph were not detected at most experiments. The acid values were ranged from 1.80 to 2.18 mg of KOH/g of fat until 5 days at $4^{\circ}C$. And the peroxide values were ranged from 4.44 to 17.87 meq of peroxide/kg of fat until 5 days of storage period. Therefore, these results demonstrated that the cook-chilled Buchu-jeon is microbiologically and chemically safe during 5 days of storage period at refrigeration temperature.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.2
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• pp.111-118
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• 2016

Acne vulgaris is a chronic inflammatory condition characterized by comedo, papule, cyst, nodule and postinflammatory hyperpigmentation. Meanwhile, it is also induced by adverse event of drugs. Among them, acneiform folliculitis is a side effect of epidermal growth factor receptor (EGFR) inhibitor, which is an anticancer agent, and its incidence may occur in upward of 75 ~ 100% of cases. The main method of acne vulgaris treatment is oral antibiotics, retinoids, topical medication and so on. However, it is limitation that teratogenicity caused by retinoids and antibiotic resistance increased by using antibiotics. In this study, we aimed to evaluate the clinical efficacy and safety of topical recombinant human (rh) EGF in treating facial acne vulgaris. Twenty three Koreans (age: 10 ~ 29 years) with mild to moderate acne vulgar participated in the study and applied topical rhEGF cream (trouble control EGF) with 3 products (trouble control clarifying cleansing foam, trouble control all-clear filling toner, redroll calming moisture) on their face twice daily for four weeks. Several assessment methods were applied: Acne lesion counts score by investigator's global assessment, efficacy and satisfaction score by subjects. Skin sebum output level, hydration level and redness level were also measured at each visit. At the final visit, skin sebum level, transepidermal water loss, skin redness statistically decreased and acne lesions (comedone, papule) were statistically reduced. No severe side effects were observed during the study. In conclusion, topical rhEGF seems to be an effective and safe adjuvant treatment option for mild acne vulgaris.

• Journal of Radiation Protection and Research
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• v.39 no.1
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• pp.7-13
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• 2014

Phosphate rock, phosphogypsum, and products in phosphate processing facility contain naturally occurring radioactive materials (NORM). Therefore, they may give rise to enhanced radiation dose to workers due to inhalation of airborne particulates. Internal dose due to particle inhalation varies depending on particle properties. The objective of the present study was to characterize particle properties at the largest phosphate processing facility in Korea. A cascade impactor was employed to sample airborne particulates at various processing areas in the plant. The collected samples were used for characterization of particle size distribution, particle concentration in the air, and shape analysis. Aerodynamic diameters of airborne particulates ranged 0.03-100 ${\mu}m$ with the highest concentration at the particle size range of 4.7-5.8 ${\mu}m$ (geometric mean = 5.22 ${\mu}m$) or 5.8-9.0 ${\mu}m$ (geometric mean = 7.22 ${\mu}m$). Particle concentrations in the air varied widely by sampling area up to more than two orders of magnitude. The large variation resulted from the variability of mechanical operations and building ventilations. The airborne particulates appeared as spheroids or rough spherical fragments across all sampling areas and sampled size intervals. Average mass densities of phosphate rocks, phosphogypsums, and fertilizers were 3.1-3.4, 2.1-2.6, and 1.7 $gcm^{-3}$, respectively. Radioactivity concentration of uranium series in phosphate rocks varied with country of origin, ranging 94-866 $Bqkg^{-1}$. Among the uranium series, uranium was mostly concentrated on products, including phosphoric acid or fertilizers whereas radium was concentrated on byproducts or phosphogypsum. No significant radioactivity of $^{226}Ra$ and $^{228}Ra$ were found in fertilizer. However, $^{40}K$ concentration in fertilizer was up to 5,000 Bq $g^{-1}$. The database established in this study can be used for the accurate risk assessment of workers due to inhalation of airborne particles containing NORM. In addition, the findings can be used as a basic data for development of safety standard and guide and for practical radiation safety management at the facility.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.76-83
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• 2006

In order to investigate the impacts of non-selective herbicide, glufosinate-ammonium (ammonium 4-[hydroxy(methyl)phosphinoyl] -DL-homoalaninate, GLA) to the non-target organisms, earthworm was exposed to GLA in the field soil for a month, and microbial populations in the soil were investigated after application of GLA. Simultaneously, the residues of GLA and its metabolite, 3-MPP were analyzed in the same soil. Meanwhile, to elucidate the influence of GLA to the growth of non-target crops incase of inter-furrow application, the amounts of carotenoid, chlorophyll, amino acid, proteins and sugars in the leaves of potato and chinese cabbage grown in the same field were investigated. In result, the dead earthworm was not observed during the test period, and the increasing rates of bodyweight were $9.410{\sim}11.603%$ in GLA-treated plots and 5.645% in GLA-untreated plots. The populations of fungi, bacteria and actinomycetes in the GLA-treated soils were $6.2{\times}10^4$, $1.5{\times}10^6$ and $5.7{\times}10^4$, respectively. They maintained relatively similar levels to the control which were $3.7{\times}10^4$, $3.7{\times}10^5$ and $3.7{\times}10^4$, respectively. In residue analysis, the limit of detection of GLA was 0.02 mg $kg^{-1}$, that of 3-MPP was the same level, and the half-life of GLA was 15 days in sandy clay loam soil. This result indicates that GLA was degraded very quickly in field soil. On the other hand, the amounts of physiological, biochemical components such as carotenoid, amino acid, chlorophyll, protein and sugar were ranged from 90.0 to 104.3% in potato and from 99.0 to 112.7% in chinese cabbage. Comparing with hand-weeded plots, it is indicated that GLA had not affected to the growth of non-target crops when applied at inter-furrow in crops-growing field.

• Journal of Nutrition and Health
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• v.44 no.1
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• pp.61-73
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• 2011

The aim of this study was to develop a reliable dietary questionnaire to assess human exposure to food-borne hazards. Eleven food-borne hazards were chosen as a priority control list through a literature review and advisory committees. The 11 food-borne hazards were phthalate, aflatoxin, bisphenol A, polycyclic aromatic hydrocarbons, dioxin, polychlorinated biphenyls, mercury, lead, cadmium, arsenic, and acrylamide. The characteristics, exposure level, and paths of these hazards were reviewed, and questionnaire items were identified to assess human exposure from the literature. A questionnaire was developed for each selected food based on its characteristics. Based on the items in the individual questionnaires, a comprehensive questionnaire, which contained demographic characteristics, job information, socioeconomic factors, health related lifestyles, and dietary behaviors, was developed. A 99-item food frequency questionnaire (FFQ) to assess food-borne hazard exposure was also developed. The FFQ included frequency of food intake during the previous year, container type for purchasing and storing food, and cooking method. The questionnaire developed in this study could be applied to assess dietary factors during an exposure assessment of food-borne hazards in a large population. A validation study for the questionnaire is needed before applying it to surveys.