• Journal of Nutrition and Health
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• v.9 no.1
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• pp.16-24
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• 1976

To determine patterns of preference for and consumption of milk and milk products in Seoul city, a study was conducted of 724 girls and 587 boys ranging in age from elementary school to collage level, from July to August, 1974. Findings are summarized as follows: In general, milk and milk products were liked by both children and adults. A contrasting low tendency to purchase such products was due to socioeconomics, habitual, and educational factors, as well as a lack of adequate nutritional information, especially with regard to milk. Knowledge of the value of milk as a source of calcium was lacking, especially among boys. The majority of homemakers understood that milk was nutritious, but not specifically as the best source of calcium for their families. Milk, especially in beverage form, was commonly regarded as food for the infant and small child. Grandparents would not drink it. Such a beliefe is similar to that found in under-developed or developing nations. The need for nutrition education must be emphasized. Milk and milk products are expensive foods, particularly for the low income family; but even in higher income levels, consumption was limited. Milk was consumed mostly by the younger family members, less by the older. Among the children, preference, knowledge, and concern with the nutritional value of milk increased with age of subjects. It is presumed that awareness improved with increasing length of school education. Greater frequency of milk intolerance was found with decreasing age of respondents: about 10 percent had some form of milk intolerance. This percentage will be found to be much higher in villages where milk is less familiar. This study indicated that respondents liked ice cream best of all the milk products. For beverage, they preferred cider and cola in summer, coffee and milk in winter. Smaller families consumed more milk than larger families. Household consumption of condensed milk was very low, mostly as coffeemate. Among households interviewed, as many had regular as irregular delivery of dairy milk. Average consumption ranged 0.5 to 1.5 Hop. Engel indices of these families ranged 20 to 60. Use of milk at home was very simple. Not many methods of preparation were found. The milk was used mostly as beverage. In order to improve the nutritional level of Korean children and adults who especially need additional calcium, milk and milk products are recommended as the best source of calcium. Nutrition education of children and their parents should receive greater emphasis.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.730-736
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• 2014

Test standards for electrical and electronic equipment required for ship operations is applying the IEC-60533 standard. However, although a test procedure and a specified regulation are clearly defined in the deck and bridge zone and general power distribution zone, they are not regulated in the special power distribution zone with ship propulsion system. For these reasons, the costs for additional research and development have been invested. In this paper, we was measured power noise in a special power distribution zone in ship and we were compared and analyzed values measured. The actual experiments are performed on the ship of Korea Maritime and Ocean University. As a result, the acquired data on Hanbada shows that loop antenna with low frequency band(160kHz) and ultra log antenna with high frequency band(1.97GHz)occur about 6-8dB differences and about 8.7 difference respectively. Also, the acquired data on Hannara shows that each loop antenna of 1MHz, 11MHz, and 25MHz occurs about 7dB difference about 4-5dB differences respectively. so standard of Special distribution zone must be specified by comparative analysis of data obtained by the experiment more.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.682-687
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• 1999

The destruction of tissues by volume increase at food freezing is accepted as one of the factor responsible for quality damage. For this reason, the internal pressure developed in meats were investigated with a pressure transducer during freezing, frozen storage and thawing. Increasement of 6.33% for volume and $942.17\;kg/cm^2$ for density at $-20^{\circ}C$ for beef were shown. In quick and slow freezing of beef, internal pressure reached to highest point after reached to the lowest point at initial of the zone of ice crystal formation. The internal pressure was approximately $8{\sim}10\;psig$ and pressure difference was about 1 psig, which was bigger in immersion freezing than that of still-air freezing. During frozen storage of pork, internal pressure of $1.84{\sim}2.32\;psig$ occurred repeatedly as a function of sample weight at material temperature difference of ${\pm}1^{\circ}C$. The internal pressure during thawing of pork was decreased slowly after rapid increase to the maximum for less than 5min at the beginning of thawing. Internal pressure value at thawing was higher than that at freezing in most cases. Internal pressure of beef with thermal equalized freezing was about $1{\sim}4\;psig$, which was lower than that of non-thermal equalized freezing. Also, freezing time was shortened to $10{\sim}20%$.

• Magazine of the Korean Society of Agricultural Engineers
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• v.35 no.4
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• pp.55-66
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• 1993

Upon freezing a soil swells due to phase change and its compression stress increase a lot. As the soil undergo thawing, however, it becomes a soft soil layer because the 'soil changes from a solid state to a plastic state. These changes are largely dependent on freezing temperature and repeated freezing-thawing cycle as well as the density of the soil and applied loading condition. This study was initiated to describe the effect of the freezing temperature and repeated freezing-thawing cycle on the unconfined compressive strength. Soil samples were collected at about 20 sites where soil structures were installed in Kangwon provincial area and necessary laboratory tests were conducted. The results could be used to help manage effectively the field structures and can be used as a basic data for designing and constructing new projects in the future. The results were as follows ; 1. Unconfined compressive strength decreased as the number of freezing and thawing cycle went up. But the strength increased as compression speed, water content and temperature decreased. The largest effect on the strength was observed at the first freezing and thawing cycle. 2. Compression strain went up with the increase of deformation speed, and was largely influenced by the number of the freezing-thawing cycle. 3. Secant modulus was responded sensitivefy to the material of the loading plates, increased with decrease of temperature down to - -10$^{\circ}$C, but was nearly constant below the temperature. Thixotropic ratio characteristic became large as compression strain got smaller and was significantly larger in the controlled soil than in the soil treated with freezing and thawing processes 4. Vertical compression strength of ice crystal(development direction) was 3 to 4 times larger than that of perpendicular to the crystal. The vertical compression strength was agreed well with Clausius-Clapeyrons equation when temperature were between 0 to 5C$^{\circ}$, but the strength below - 5$^{\circ}$C were different from the equation and showed a strong dependency on temperature and deformation speed. When the skew was less then 20 degrees, the vertical compression strength was gradually decreased but when the skew was higher than that, the strength became nearly constant. Almost all samples showed ductile failure. As considered above, strength reduction of the soil due to cyclic freezing-thawing prosses must be considered when trenching and cutting the soil to construct soil structures if the soil is likely subject to the processes. Especially, if a soil no freezing-thawing history, cares for the strength reduction must be given before any design or construction works begin. It is suggested that special design and construction techniques for the strength reduction be developed.

• Korean Journal of Community Nutrition
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• v.18 no.5
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• pp.442-456
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• 2013

This study was performed to investigate the dietary habits, body satisfaction and nutritional knowledge according to body image of middle school girl students (n = 284). The subjects were classified as lean, normal and fat groups according to body image. The weight, body mass index (BMI) and the score of body image were significantly higher in the students who recognized their body image as 'fat'. The satisfaction of present body image was significantly lower in students who recognized their body image as 'lean'. The interest in weight control and experience of weight control were significantly higher in students who recognized their body image as 'fat'. The necessity of nutrition education was higher in all groups (lean 67.2%, normal 59.0% and fat 52.8%). The products used to feel sweetened were sweetened ice (68.7%), processed milk (68.3%), confectionery (62.3%), carbonated beverage (55.3%), fermented milk (38.0%) and none (6.0%). The frequency of consumption of fruit juices and fried food was significantly higher in 'normal' compared to 'fat'. There was no significant difference in the frequency of consumption of snack and nutritional knowledge among the three groups. In the multiple regression analysis, the score of body image was negatively associated with the frequency of snack consumption in the 'lean'. The score of body image was positively associated with identification of nutrition labels and an interest in weight control but was negatively associated with satisfaction of present body image in the 'fat'. Based on these results, we conclude that, the middle school girl students need correct recognition of body image and continuous and practical nutrition education in order to maintain healthy dietary habits.

• Journal of Life Science
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• v.27 no.5
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• pp.591-599
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• 2017

It is well established that endurance performance is negatively affected by environmental heat stress. Numerous scientific investigations have attempted to improve performance in the heat with pre-cooling and per-cooling for endurance athletes. Some cooling strategies are more logistically challenging than others, and thus are often impractical for use in training or competition. The purpose of this study was to review the literature on the use of cooling interventions in the improvement of performance and recovery from exercise-induced heat stress. We undertook an examination that focused on the effects of pre-cooling and per-cooling on the improvement in endurance performance and the effects of post-exercise cooling on recovery. The benefits for pre-cooling and per-cooling strategies undertaken in the laboratory setting could be employed by athletes who compete in hot environmental conditions to improve performance. Most laboratory studies have shown improvements in endurance performance following pre-cooling and per-cooling, and in recovery following post-cooling. Cooling strategies such as cooling vest, neck cooling collar, menthol and ice slurry are practically relevant to sports field. Cooling interventions that can be applied frequently to reduce thermal strain prior to, during and directly after training appear to be the best effective strategy to improve performance and recovery. Future research is warranted to investigate the effectiveness of practical pre-cooling and per-cooling strategies in competition or field settings.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.1055-1061
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• 2014

Innovative freezing technology is currently applied to preserve foodstuffs for long-term storage. Generally, the quality of frozen food is closely related to the types of freezing and thawing processes. In this study, we characterized the physicochemical properties of onions depending on freezing rate. When onions were frozen at $-40^{\circ}C$, freezing rates were 0.1, 0.5, and $0.7^{\circ}C/min$ depending on air-blast quick freezer mode. Onions were thawed by microwave irradiation at 400 W. Hardness of onion dramatically decreased after freezing and thawing compared with blanched onion. However, the fastest freezing rate did not affect hardness. Thawing loss of onion decreased with a faster freezing rate. For morphological observation, onion frozen at a faster rate showed a smaller ice-crystal size. Vitamin C content decreased upon blanching or freezing, but there was no significant difference according to freezing rate. Although free sugar content also decreased upon blanching and freezing, its highest content was at $0.7^{\circ}C/min$ freezing. Among organic acids, malic acid content was highest at $0.7^{\circ}C/min$ freezing. Based on this study, it could be suggested that a faster freezing rate is effective to improve frozen food quality in accordance with preventing tissue damage or minimizing destruction of nutrients.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.4
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• pp.651-659
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• 2015

This study was conducted to investigate the effects of addition of dandelion leaf, root and whole part extract on the quality and sensory characteristics of ground pork meat. Four types of ground pork were evaluated: 10% ice water added (control), 10% dandelion leaf extract added (DL), 10% dandelion root extract added (DR), and dandelion whole part extract added (DW). There was no significant difference in $L^*$, $b^*$, VBN content, moisture, protein, fat and ash of raw and cooked ground pork, cooking yield, water holding capacity, moisture retention, fat retention, reduction in diameter, total free amino acid, taste, texture, juiciness, or overall acceptability. The total polyphenol content of the control, DL, DR, and DW groups were 2.07, 6.49, 3.85 and 5.77 mg/100 g, respectively. Total phenol content of DL was significantly higher than those of the other samples. The pH was highest in the control. The TBARS values of the control, DL, DR and DW were 0.52, 0.20, 0.31, and 0.24 mg MA/kg, respectively, and TBARS values of the control were significantly higher than those of the other samples. Flavor was highest in DL. We suggest that dandelion leaf extracts may be a useful ingredient in ground pork to improve color, flavor, and antioxidant potential.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.2
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• pp.173-179
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• 2020

Electric vehicles (EVs) using lithium secondary batteries (LIBs) with excellent power and long-term cycle performance are gaining interest as the successors of internal combustion engine (ICE) vehicles. However, there are few systematic researches for fast charging to satisfy customers' needs. In this study, we compare the degradation of LIB where its composition is LiNi_0.5Co_0.2Mn_0.3/Graphite with the constant current and constant power-charging method. The charging speed was set to 1C, 2C, 3C and 4C in the constant current mode and the value of constant power was calculated based on the energy at each charging speed. Therefore, by analyzing the battery degradation based on the same charging energy but different charging method; CP charging method can slow down the battery degradation at a high rate of 3C through the voltage curve, capacity retention and DC-IR. However, when the charging rate was increased by 4C or more, the deviation between the LIBs dominated the degradation than the charging method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.216-220
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• 2002

The microbiological examinations of food service operations were conducted for the hygienic evaluation at four elementary schools in Busan, Korea. Total one hundred and seventy two swabbed samples using sponge were collected from the surface of environments, utensils and equipments of food service facilities and analyzed by measuring the total, coliform and psychrotrophic count. Sampling sites were the surfaces of floors, drains, walls, knives, cutting boards, rubber gloves, vinyl aprons, plastic containers, carriers, shelves, trays, dry shelves, electric tray dryer, food containers, soup containers, rice cookers, frying pans, boiling cookers, refrigerators, dumb waiters and dishwashers. The swabbed samples kept in an ice-parked box were transported to a laboratory and analyzed. The results demonstrated that the degree of contamination depended on the sampling sites. Averages of total counts of surface swab samples were ranged from 0.62 to 7.79 Log CFU/200 cm$^2$. The level of coliforms were ranged from not detectable to 5.26 Log CFU/200 cm$^2$, and those of psychrotrophs from not detectable to 6.15 Log CFU/200 cm$^2$. The severely contaminated sites were dumb waiters, drains, rice cookers, knives, plastic containers and floors. Also cutting boards, rubber gloves, carriers, drying shelves, vinyl aprons, boiling cookers, soup containers, frying pans and refrigerators were highly contaminated with the level of abode 3.5 Log CFU/200 cm$^2$. Therefore, those sites should be focused and controlled according to control points of sanitation standard operating procedures (SSOP). Also, periodic microbiological examination in addition to visual examination is recommended on these highly contaminated sites indicated above results at food service operations in elementary school.