• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.4
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• pp.266-273
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• 2008

Natural gas hydrates are ice-like solid substances, which are composed of water and natural gas, mainly methane. They have three kinds of crystal structures of five polyhedra formed by hydrogen-bonded water molecules, and are stable at high pressures and low temperatures. They contain large amounts of organic carbon and widely occur in deep oceans and permafrost regions. Therefore, they are expected as a potential energy resource in the future. Especially, $1m^3$ natural gas hydrate contains up to $172Nm^3$ of methane gas, de pending on the pressure and temperature of production. Such large volumes make natural gas hydrates can be used to store and transport natural gas. In this study, three-phase equilibrium conditions for forming natural gas hydrate were numerically obtained in pure water and single electrolyte solution containing 3 wt% NaCl. The results show that the predictions match the previous experimental values very well, and it was found that NaCl acts as an inhibitor. Also, help gases such that ethane, propane, i-butane, and n-butane reduce the hydrate formation pressure at the same temperature.

• Journal of the Korean Dietetic Association
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• v.18 no.3
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• pp.234-247
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• 2012

The purpose of this study was to investigate the consumption and perception of high caloric-low nutrient dense foods in middle school students in the Daegu. Among 550 questionnaires distributed to students in Daegu, 528 (256 boys and 272 girls) were analyzed. A little higher than 80% of students ate snacks everyday, and 43.4%, 29.0%, and 8.1% ate snacks once, twice, and three times or more per day, respectively. Snacks and foods most frequently consumed were ice cream, fried noodles, drinks, cookies, and baked goods. Energy supply from snacks was 104.8~356.9 Kcal/intake while that from meal substitution foods was 520.7~980 Kcal/intake. Students' knowledge score of high caloric-low nutrient dense foods was $6.51{\pm}3.02$ out of 10 points. Sixty percent of students did not read nutrition labels, but 67.9% of them thought that they need nutrition education by nutrition teachers. Students recognized the criteria of high caloric-low nutrient dense foods as well as proper food selection for essential educational items, It was concluded that effective education should be implemented in middle schools by nutrition teachers for students to develop good habits in selecting snacks and foods.

• Journal of the Korean Dietetic Association
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• v.15 no.1
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• pp.10-21
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• 2009

The objective of this research was to assess the dietary habits, food frequency, and nutrition knowledge of young children who like sweets in the Busan area; the study was conducted using survey method with questionnaires. One hundred eighty three children, aged 8 to 9 years, were divided into two groups: the sweet preference group (SPG) and the control group, based on the subjects' scores for sweets-related dietary habits, sweets preference, and sweets frequency. For dietary habits, the score for eating more snacks than meals was significantly higher in the SPG group than the control group. The SPG group members were also more likely to skip breakfast, have irregular meals, and consume instant and fast food more frequently (p<0.001) than the control group. Nutrition knowledge scores for proper snack intake and proper dietary attitude were significantly lower in the SPG than in the control group (p < 0.05). With regard to food frequency, the SPG consumed more bread, cake, chicken, ham, sausage, hamburger, and ice cream, but less fish, tofu, beans, kimchi, bean sprouts, and milk than the control group. Strong positive correlations were noted between sweets preference, sweets frequency, and sweets-related dietary habits, whereas all of them were correlated negatively with nutritional knowledge. Sweets frequency was related negatively to meal regularity, having breakfast, eating the adequate amount of meals, and recommended food frequency.

• Journal of Acupuncture Research
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• v.30 no.4
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• pp.125-138
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• 2013

Objectives : This study aimed to investigate temperature characteristics by heat transfer type of therapeutic modalities. Methods : We selected heating and cooling modalities that are frequently used in clinical by heat transfer type: conduction, convection, radiation, and conversion. We used ham as tissue model, and applied the modalities for 30 minutes. We measured real-time changed temperature($^{\circ}C$) of the surface, 2, 4, 6, 8, 10, 12, and 14 mm depth. Results : 1. In conduction-using hot pack, ice pack, and CryoStamp heating-cooling combination therapy unit($40^{\circ}C/{\sim}15^{\circ}C$), the surface temperature sharply rose close to equilibrium in first 5 minutes. 2. In convection-using smokeless moxa, temperature slowly rose to the maximum at 25-minute elapsed time. But in another convection-using CRAiS cryotherapy device, result was similar to that of conduction. 3. In radiation-using infrared lamp, result was similar to that of conduction, but not reached equilibrium during applying time. 4. In conversion-using ultrasound device, temperature was the highest at 6 mm depth, and not reached equilibrium during applying time. Conclusions : We could comprehend temperature characteristics and proper use of modalities by heat transfer type. It would be necessary to consider in vivo physical conditions in further studies.

• The Korea Journal of Herbology
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• v.32 no.6
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• pp.9-15
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• 2017

Objectives : Traditional medicines isolated from natural products often have positive effects in the prevention and healing of various immune disorders, such as allergy and atopic inflammation. Scrophulariae Radix (SR) been used in oriental medicine used for treatment of acute and chronic inflammatory diseases. Mast cells are known to play important roles in the initiation of allergic reactions. In this study, we investigated the effects of SR ethanol extract on inflammatory responses in IgE-stimulated RBL-2H3 mast cells. Methods : Rat basophilic leukemia RBL-2H3 cells were purchased from Korean Cell Line Bank (KCLB No. 22256). Cell viability was measured by MTT assay. Assays for ${\beta}-Hexosaminidase$ Secretion : RBL-2H3 cells were sensitized with dinitrophenyl-ImmunoglobulinE (DNP IgE). The next antigen DNP-BSA ($25ng/m{\ell}$) was added for 10 minutes and the reaction was terminated after 5 minutes in the ice bath. To determine ${\beta}-Hexosaminidase$ release, supernatants were aliquoted into 96-well plates. Samples were mixed with substrate solution and incubated for 1 h at $37^{\circ}C$. Absorbance was measured with a spectrophotometer at 405 nm. IL-4 and tumor necrosis $factor-{\alpha}$($TNF-{\alpha}$) concentrations in cell culture supernatants were measured using enzyme-linked immunosorbent assay (ELISA) kits. Results : The cytotoxicity of SRE in RBL-2H3 cells was less than 5%. SRE inhibited DNP-IgE-imduced degranulation of mast cells in RBL-2H3 cells. Also significantly decreased the levels of inflammatory cytokine, IL-4 and TNF-alpha. In this study, the SRE showed potential anti-allergic and antiinflammatory. Conclusions : These results indicate that SRE could be inhibit the allergic response through suppressing the mast cell activation.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.563-575
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• 2003

The purpose of this study was to investigate differences in craniofacial characteristics of professional sportsmen who have practiced since their prepubertal periods. From the standardized lateral and P-A cephalograms of 137 sportsmen, 7 angular, 19 linear, 4 ratio, and 2 index measurements were measured and evaluated by means of statistical methods. The samples were divided into three groups: Group 1; ice hockey(n=17), foot-ball(n=27), basketball(n=16) Group 2; baseball(n=16), gymnastics(n=13), and Group 3; judo(n=18), ssireum(n=10), weight lift(n=20). The results were as follows: It seemed obvious that the cephalic indices of the 3 groups exhibited brachycephalic headform (Group 1; $0.85{\pm}0.04$, Group 2; $0.84{\pm}0.04$, Group 3; $0.83{\pm}0.06$) and there was no statistical difference among the groups (p>0.05). The facial indices of the Group 1 ($0.93{\pm}0.05$) and Group 2 ($0.93{\pm}0.04$) exhibited definite leptoprosopic facial forms while the Group 3 ($0.90{\pm}0.04$) showed more or less euryprosopic facial form, and there appeared significant difference between the Group 1 and 3 (p<0.05), and also between the Group 2 and 3 (p<0.05). There appeared strong relationships between the facial indices and the facial axis angle, mandibular plane angle, total craniofacial height, total facial height, upper anterior dental height, lower anterior dental height, mandibular length, lower anterior facial height ratio, and especially with lower anterior facial height (p<0.001). It seemed that most of the vertical facial measurements of the Group 1 and 2 appeared to be larger than those of the Group 3.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.12
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• pp.1102-1139
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• 2002

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2000 and 2001 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD technologies were widely applied for developing facilities and their systems. (2) Most of papers related with heat transfer analysis and heat exchanger shows dealt with convection, evaporation, and channel flow for the design application of heat exchanger. The numerical heat transfer simulation studies have been peformed and reported to show heat transfer characteristics. Experimental as well as numerical studies on heat exchanger were reported, while not many papers are available for the system analysis including heat exchanger. (3) A review of the recent studies on heat pump system shows that performance analysis and control of heat pump have been peformed by various simulations and experiments. The research papers on multi-type heat pump system increased significantly. The studies on heat pipe have been examined experimently for change of working characteristics and strut lure. Research on the phase change has been carried out steadily and operation strategies of encapsulated ice storage tank are reported experimentally in several papers. (4) A review of recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. Evaporation and condensation heat transfer characteristics are investigated for tube shapes and new alternative refrigerants. Studies on components of refrigeration/air conditioning system are carried to examine efficiency for various compressors and performance of new expansion devices. In addition to thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out, however research works on two-phase flow seemed to be insufficient. (5) A review of the recent studies on absorption cooling system indicates that heat and mass transfer phenomena have been investigated to improve absorber performance. Various experimental data have been presented and several simulation models have been proposed. A review of the recent studies on duct and ventilation shows that ventilation indices have been proposed to quantify the ventilation performance in buildings and tunnels. Main efforts have been focused on the applications of ventilation effectiveness in practice, either numerically using computational fluid dynamics or experimentally using tracer gas techniques. (6) Based on a review of recent studies on indoor thermal environment and building service systems, research issues have mainly focused on many innovative ideas such as underfloor air-conditioning system, personal environmental modules, radiant floor cooling and etc. Also, the new approaches for minimizing energy consumption as well as improving indoor environmental conditions through predictive control of HVAC systems, various activities of building energy management and cost-benefit analysis for economic evaluation were highlighted.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1234-1268
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• 2004

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2002 and 2003 has been carried out. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment/design. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation in diverse facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat transfer, humidity was also interesting to promote comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing research topics. Well developed CFD technologies were widely applied for analysis and design of various facilities and their systems. (2) Heat transfer characteristics of enhanced finned tube heat exchangers and heat sinks were extensively investigated. Experimental studies on the boiling heat transfer, vortex generators, fluidized bed heat exchangers, and frosting and defrosting characteristics were also conducted. In addition, the numerical simulations on various heat exchangers were performed and reported to show heat transfer characteristics and performance of the heat exchanger. (3) A review of the recent studies shows that the performance analysis of heat pump have been made by various simulations and experiments. Progresses have been made specifically on the multi-type heat pump systems and other heat pump systems in which exhaust energy is utilized. The performance characteristics of heat pipe have been studied numerically and experimentally, which proves the validity of the developed simulation programs. The effect of various factors on the heat pipe performance has also been examined. Studies of the ice storage system have been focused on the operational characteristics of the system and on the basics of thermal storage materials. Researches into the phase change have been carried out steadily. Several papers deal with the cycle analysis of a few thermodynamic systems which are very useful in the field of air-conditioning and refrigeration. (4) Recent studies on refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement when new alternative refrigerants are applied. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and new alternative refrigerants including natural refrigerants. Efficiency of various compressors and performance of new expansion devices are also dealt with for better design of refrigeration/air conditioning system. In addition to the studies related with thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out. It should be noted that the researches on two-phase flow are constantly carried out. (5) A review of the recent studies on absorption refrigeration system indicates that heat and mass transfer enhancement is the key factor in improving the system performance. Various experiments have been carried out and diverse simulation models have been presented. Study on the small scale absorption refrigeration system draws a new attention. Cooling tower was also the research object in the respect of enhancement its efficiency, and performance analysis and optimization was carried out. (6) Based on a review of recent studies on indoor thermal environment and building service systems, it is noticed that research issues have mainly focused on several innovative systems such as personal environmental modules, air-barrier type perimeterless system with UFAC, radiant floor cooling system, etc. New approaches are highlighted for improving indoor environmental conditions and minimizing energy consumption, various activities of building energy management and cost-benefit analysis for economic evaluation.

• 한국노년학
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• v.40 no.1
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• pp.111-130
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• 2020

This qualitative study aims to understand family members' caregiving experience for middle-aged and elderly breast cancer survivors at early stages. A total of four families of breast cancer survivors were given focus group interviews(FGI), and an additional family was interviewed individually. The thematic analyses of the FGI and individual in-depth interview discussions revealed the following four themes: first, day-to-day feelings like walking on thin ice (entangled emotions with each treatment stage, regret of watching a survivor's pain, fear of recurrence and death, concerns of changes in family relationships, and various feelings experienced as a daughter), second, caregiving has become a mainstay in my life (unfamiliar and unskilled care, losing my life), third, beginning to recover and different experiences between a survivor and a family caregiver (not understanding a survivor's pain from the abyss, forgetting that the survivor is still a cancer patient and that treating him or her casually), and fourth, moving forward (hope that things will be better, taking care of myself to prevent exhaustion). Based on the results of this study, we proposed social welfare services and policy measures to reflect the psychosocial needs of family caregivers of breast cancer survivors and support family caregivers during the care process.

• Ocean and Polar Research
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• v.26 no.1
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• pp.87-101
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• 2004

This paper delineated the ecology including movement (departure from the rookery and returning to the rookery), egg-laying, and hatch of the penguins occurred in the cold years and a less cold year in the vicinity of King Sejong Station, King George Island off the Antarctic Peninsula. The years of 1988, 1991, 1992, and 1995 were selected as cold years and the year of 2001 was selected as a less cold year based on the mean annual temperature of the years. Gentoo Penguin (Pygoscelis papua) left their rookery in May, meanwhile some remained around the station. They returned in middle-September in the less cold .year, and returned in late-September to early-October in the cold years. Chinstrap Penguin (Pygoscelis antarctica) left their rookery in early-April in the cold years as well as in the less cold year without exception. They returned to the rookery in late-October to early-November in cold years, meanwhile in early-October in the less cold year. This difference in the returning of this bird seems to be related with the exposed sea water, i.e., sea ice condition to feed in the sea. The global warming will lead to the appearance of birds which breed in the Sub-Antarctic. For example, one pair of King Penguin (Aptenodytes patagonicus) was observed in the Maxwell Bay in austral summer. And a pair of snide-like bird was recently observed for the first time in November 2001 at the penguin rookery located in the Barton Peninsula, King George Island. And it will also lead to the disappearance of an Emperor Penguin (Aptenodytes forsteri) which appeared in the full winter when Maxwell Bay and Marian Cove were frozen. It seems that the behaviour of the penguins observed around the station shows the complex effects of the ecology of the birds in combination with the natural environments, which include feeding strategy and areas, animal Instincts, exposed terrain related to weather conditions, and globa1 warming. It is necessary to take further observation and carry out systematic researches on the birds including penguins around the station which show the ecology of the birds as well as the environmental changes.