• Child Health Nursing Research
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• v.5 no.2
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• pp.185-197
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• 1999

In the family life cycle, the most important task the families with school children should perform is ‘child education’ and ‘socialization’ However, economic stress on poor families with school children presents multiple problems through the shortage of resources necessary for child education and socialization, inappropriateness of family appraisal, and the insufficiency of the control channels for the efficient management of these confined resources and appropriate appraisal. The objectives of this article are : First, to report research on the actual conditions of the poor families in one area of Cheju and on the relevant health welfare policy, and to examine the appropriateness of the direction and the substance of this policy in terms of the intervention in economic stress on the poor families under the categories of resource management and control of appraisal. Second, to analyze qualitative data extracted from the memoirs of single-parent families living in several areas of Korea under the conceptual framework constructed by literature review in order to get a better understanding of the stress which poor families with school children have experienced. And third, to confirm the factors that can be risk factor but, at the same time, strength to these poor families from presented data and to use them as the basic data from which an intervention model can be developed, based on resource management and control of appraisal. The findings of this article are : First, while the number of absolute poor families in one area of Cheju is increasing and, as a result, the danger of the possibility that multiple problems will occur is also growing, the supporting level of the current policy is no more than a direct resource offer and there is no evidence that resource management is being professionally carried out. When it comes to control of appraisal, due to absence of the professional human resources in this matter, policy performances such as technical education training can have a negative impact. Second, a conceptual framework introduced in this article, ; Economic Pressure → Helplessness → Poor self-esteem → Marital Conflict → Parent-Child financial conflict → Inappropriate socialization → Poor child social competence : is partly verified. And third, judging from the results of the qualitative data, it is confirmed that the healing families, having overcome poverty, show several positive characteristics including : hope, strength, and social support. These findings are identified with the factors of resiliency considered above. According to these results, this article suggests the following. The anti -poverty policy in the future should focus not only on a direct resource offer but also on resource management and the control of appraisal that can magnify its effects. In particular, close attention should be paid to school children since they are in the most crucial period for socialization. Moreover, an emotional labor is such an essential resource for intervention that skilled nurses should play pivotal roles.

• Sleep Medicine and Psychophysiology
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• v.4 no.2
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• pp.147-155
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• 1997

To assess the reliability of chronobiological models of sleep/wake regulation, it is necerssary that the models predict the data which has been studied in sleep research, and they should be generalized across all ages. To date, many adult human data on such models have accumulated, yet it is evident that a comprehensive theory of the biorhythmic aspects of sleep/wake states has not established. Circadian rhythms such as the time going to bed, sleep onset, slow wave sleep pressure, periodicity of REM sleep, daytime performance, and early evening alertness are resumed everyday. Even in adult humans, sleep is inherently polyphasic. In both the disentrained and entrained states, naps when allowed tend to recur in a temporally lawful manner. The monophasic sleep pattern of most industrial societies therefore appears to be purely of social origin. The endogenous biorhythmic nature of circasemidian sleep tendency is supported by the ubiquity of the phenomenon across all ages. The NREM/REM sleep cycle within sleep with its inherent physiological, endocrine, and neurochemical fluctuations represents the best-documented ultradian sleep rhythms. Also, a daytime ultradian variation in sleepiness with a periodicity similar to nocturnal NREM/REM cycle(BRAC hypothesis) is suggested. This review article provides a brief synoptic review of the evidences for circadian, circasemidian, and ultradian sleep/wake rhythms, and then the authour will suggest the issues which expedite fuller modeling of sleep/wake system, to be further discussed.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.842-846
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• 2016

It's possible for a human to breathe under water, but the amount of dissolved oxygen in the water is small and a large amount of water is necessary to obtain sufficient dissolved oxygen from water. So, large separation system with large water pumps, having large surface areas, and large battery sources are needed. Exhalation gases are used to solve this problem. Theses gases contain some oxygen, nitrogen, and carbon dioxide; they contain less oxygen and more carbon dioxide compared to air. Therefore, reduction of the amount of carbon dioxide is necessary. If exhalation gases are employed appropriately, the separation device can be made more compact. Inlet water mixed with exhalation gases is supplied into the separation device, and dissolved gases are separated from the mixed water as it passes through the device. The inlet part of a typical separation system with a water delivery pump before the membrane module has more than one atmosphere. Hence, a compressor is used to mix the exhalation gases. In this study, the pressure at the inlet due to the use of a suction pump after the membrane module was less than one atmosphere; hence, compressors were not required. Separation characteristics were studied using a separation device without a compressor. The use of exhalation gases led to an increase in the amount of dissolved gases being separated. As the amount of inlet exhalation gases was increased, the separation of dissolved gases was increased as well.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.2 s.51
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• pp.141-146
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• 2005

Unstable cosmetic active ingredients could rapidly break down in chemical and photochemical process. Therefore, it has become a very important issue to encapsulate active ingredient for the stabilization. 7-Dehydrocholesterol (7-DHC), a precursor of vitamin $D_3$, has been shown to increase levels of protein and mRNA for heat shock protein in normal human epidermal keratinocytes. However, topical dermal application of 7-DHC is restricted due to its poor solubility and chemical unstability. In this study, 7-DHC was incorporated into nano-emulsion (NE), solid lipid nano-particle (SLN), and chitosan coated solid lipid nano-particle (CASLN), respectively. In order to prepare NE and SLN dispersion, high-pressure homogenization at temperature above the melting point of lipid was used Hydrogenated lecithin and polysorbate 60 were used as stabilizer for NE and SLN. CASLN was prepared by high speed homogenizing after adding chitosan solution to the SLN dispersion and showed positively charged particle properties. Decomposition rate of 7-DHC in NE, SLN and CASLN was studied as a function of time at different temperature. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies were performed to characterize state of lipid modification. It appeared that CASLN is the most effective to stabilize 7-DHC and may be used for a useful topical dermal delivery system.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.2
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• pp.93-99
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• 2008

Until now, (-)-epigallocatechin-3-gallate(EGCG) is known as the most powerful antioxidant among green tea catechins having many beneficial effects on human skin. Considering that the content of catechins is variable according to many conditions such as solvent, temperature and pressure, we prepared the heat-epimerized-EGCG-mixture (HE-EGCG-mix) containing high content of gallocatechin-3-gallate(GCG) by epimerization during autoclaving process and found out its optimal condition for maximizing conversion from EGCG to GCG. To investigate the effects of EGCG and HE-EGCG-mix on skin barrier function, we performed in vivo experiments with hairless mice. We found that HE-EGCG-mix has more potent stimulating activity than EGCG for the production of involucrin 7(INV7) and for recovery of barrier function in SKH-1 mice. Also, we found that GCG stimulates $PPAR-{\alpha}$ transactivation more effectively than EGCG in vitro by transient transfection assay for $PPAR-{\alpha}$ activation activity. These imply that HE-EGCG-mix consisting of high content of GCG should stimulate more efficiently recovery of skin barrier through PPAR-mediated-kerationocyte differentiation than EGCG. In conclusion, our study may provide a possibility that GCG, the C-2 epimer of EGCG, could be a potentially effective agent for development of new cosmetics or health foods for recovery of skin barrier.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.433-439
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• 2020

This study compared and analyzed the change of air consumption according to water depth with human characteristics and theoretical values. The experimental results are as follows. First, subjects A and B showed similar rise rates depending on the water depth. Second, subject C had a significantly higher rate of increase in air consumption at 25m underwater because the body responded sensitively to deep water pressure, which increased air consumption because breathing was faster than other participants. Third, the subjects D and E showed significantly lower overall air consumption. D and E were 37 and 35 years of age, respectively, the youngest, strongest and most experienced in deep sea diving at the time of military service. Fourth, the average air consumption per minute of the test subjects increased from 5m in water to 1.45 times, 10m in water to 1.85 times, and 20m in water to 2.8 times. This seems to be a result of different experiences, physical fitness, the degree of adaptation of the body to underwater, and different breathing techniques. Lastly, the difference between the experimental average value and the theoretical value appears to be the result of using more or less air than the theoretical value depending on the experiences and physical strength of each of the 5 rescuers, the degree of adaptation of the body underwater, and the method of underwater breathing.

• Journal of Sericultural and Entomological Science
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• v.46 no.1
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• pp.1-5
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• 2004

Rutin has many beneficial effects on human health. It was established that rutin antagonizes the increase of capillary fragility associated with hemorrhagic disease, reduces high blood pressure, decreases the permeability of the vessels, and has an antiedema effect, reduces the risk of arteriosclerosis, and shows antioxidant activity. Rutin analysis with mulberry fruits was carried out by high-performance liquid chromatography (HPLC) to reveal the possibility of source of functional food. As a result, mean content of fifty accessions was 0.14±0.050% DW. Among the tested fifty accessions, 'Sabangso' was showed the highest rutin in 0.29%DW, whereas 'Simseol' was the lowest content in 0.05% DW. Also, we researched the change of rutin content according to harvested date. The rutin contents of earlier harvested groups were higher than later harvested groups. Simultaneously, fruity characteristics as well as rutin content were researched and analyzed to select the functional mulberry varieties for the production of fruit. From the six accessions which were contained high rutin content, we selected three suitable varieties such as 'Ficus', 'Kangsun', and 'Palcheongsipyung'.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.728-734
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• 2001

The purpose of this study was to investigate the effects of Er:YAG laser on cutting of efficacy of enamel and dentin in primary and permanent teeth. We used the enamel and dentin specimens of human teeth which contain the physiologic saline and maintain the pulpal pressure in dentinal tubules. Each specimen was exposed to Er:YAG laser with non-contact mode under different treatment condition of irradiation energy, pulse repetition rate. We investigated the cutting efficacy of Er:YAG laser by Scanning Intensity Microscopy, and obtained following results. 1. Cutting volume of enamel and dentin in primary and permanent teeth were increased by increasing the irradiation energy, pulse repetition rate. 2. Cutting volume of primary teeth was larger than that of permanent teeth. 3. Cutting volume of dentin was larger than that of enamel in primary and permanent teeth. From these results, Er:YAG laser would be more effective in cutting dentin than enamel, and in cutting primary teeth than permanent teeth for clinical application.

• The Korean Journal of Mycology
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• v.34 no.2
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• pp.105-111
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• 2006

Tremella fuciformis, one of edible and medicinal mushroom belonging to Tremellaceae of Basidiomycota, has been known to have a curative effect on sarcoma 180 of mice and lowering high blood pressure of human beings. Neutral salt soluble [0.9% NaCl (Fr. NaCl)], hot water soluble (Fr. HW) and methanol soluble (Fr. MeOH) substances were extracted from Tremella fuciformis. In vitro cytotoxicity tests, Fr. HW and Fr. NaCl were not cytotoxic against cancer cell lines such as NIH3T3, Sarcoma 180, and HT-29 at the concentration of $2000{\mu}g/ml$, while Fr. MeOH was cytotoxic to NIH3T3 and Sarcoma 180. Intraperitoneal injection with Fr. NaCl showed antitumor effect with life prolongation of 53% in mice inoculated with Sarcoma 180. Fr. NaCl improved the immunopotentiation activity of B lymphocyte by increasing the alkaline phosphatase activity by $3.0{\sim}8.1$ folds, respectively. Intraperitoneal injection with Fr. NaCl increased the numbers of peritoneal exudated cells and circulating leukocytes by 7.4 folds and 1.6 folds, respectively, than in the control group. The antitumor effect of T. fuciformis against Sarcoma 180 of mice was likely due to immunopotentiation activity.

• Nuclear Engineering and Technology
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• v.47 no.6
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• pp.678-699
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• 2015

Although the harsh space environment imposes many severe challenges to space pioneers, space exploration is a realistic and profitable goal for long-term humanity survival. One of the viable and promising options to overcome the harsh environment of space is nuclear propulsion. Particularly, the Nuclear Thermal Rocket (NTR) is a leading candidate for nearterm human missions to Mars and beyond due to its relatively high thrust and efficiency. Traditional NTR designs use typically high power reactors with fast or epithermal neutron spectrums to simplify core design and to maximize thrust. In parallel there are a series of new NTR designs with lower thrust and higher efficiency, designed to enhance mission versatility and safety through the use of redundant engines (when used in a clustered engine arrangement) for future commercialization. This paper proposes a new NTR design of the second design philosophy, Korea Advanced NUclear Thermal Engine Rocket (KANUTER), for future space applications. The KANUTER consists of an Extremely High Temperature Gas cooled Reactor (EHTGR) utilizing hydrogen propellant, a propulsion system, and an optional electricity generation system to provide propulsion as well as electricity generation. The innovatively small engine has the characteristics of high efficiency, being compact and lightweight, and bimodal capability. The notable characteristics result from the moderated EHTGR design, uniquely utilizing the integrated fuel element with an ultra heat-resistant carbide fuel, an efficient metal hydride moderator, protectively cooling channels and an individual pressure tube in an all-in-one package. The EHTGR can be bimodally operated in a propulsion mode of $100MW_{th}$ and an electricity generation mode of $100MW_{th}$, equipped with a dynamic energy conversion system. To investigate the design features of the new reactor and to estimate referential engine performance, a preliminary design study in terms of neutronics and thermohydraulics was carried out. The result indicates that the innovative design has great potential for high propellant efficiency and thrust-to-weight of engine ratio, compared with the existing NTR designs. However, the build-up of fission products in fuel has a significant impact on the bimodal operation of the moderated reactor such as xenon-induced dead time. This issue can be overcome by building in excess reactivity and control margin for the reactor design.