• Magazine of the Korean Society of Agricultural Engineers
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• v.22 no.1
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• pp.53-66
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• 1980

The research work is concerned with the analytical and experimental studies on the heat transfer phenomenon around the underground concrete digester used for biogas production Systems. A mathematical and computational method was developed to estimate heat losses from underground cylindrical concrete digester used for biogas production systems. To test its feasibility and to evaluate thermal parameters of materials related, the method was applied to six physical model digesters. The cylindrical concrete digester was taken as a physical model, to which the model,atical model of heat balance can be applied. The mathematical model was transformed by means of finite element method and used to analyze temperature distribution with respect to several boundary conditions and design parameters. The design parameters of experimental digesters were selected as; three different sizes 40cm by 80cm, 80cm by 160cm and l00cm by 200cm in diameter and height; two different levels of insulation materials-plain concrete and vermiculite mixing in concrete; and two different types of installation-underground and half-exposed. In order to carry out a particular aim of this study, the liquid within the digester was substituted by water, and its temperature was controlled in five levels-35。 C, 30。 C, 25。 C, 20。C and 15。C; and the ambient air temperature and ground temperature were checked out of the system under natural winter climate conditions. The following results were drawn from the study. 1.The analytical method, by which the estimated values of temperature distribution around a cylindrical digester were obtained, was able to be generally accepted from the comparison of the estimated values with the measured. However, the difference between the estimated and measured temperature had a trend to be considerably increased when the ambient temperature was relatively low. This was mainly related variations of input parameters including the thermal conductivity of soil, applied to the numerical analysis. Consequently, the improvement of these input data for the simulated operation of the numerical analysis is expected as an approach to obtain better refined estimation. 2.The difference between estimated and measured heat losses was shown to have the similar trend to that of temperature distribution discussed above. 3.It was found that a map of isothermal lines drawn from the estimated temperature distribution was very useful for a general observation of the direction and rate of heat transfer within the boundary. From this analysis, it was interpreted that most of heat losses is passed through the triangular section bounded within 45 degrees toward the wall at the bottom edge of the digesten Therefore, any effective insulation should be considered within this region. 4.It was verified by experiment that heat loss per unit volume of liquid was reduced as the size of the digester became larger For instance, at the liquid temperature of 35˚ C, the heat loss per unit volume from the 0. 1m$^3$ digester was 1, 050 Kcal/hr m$^3$, while at for 1. 57m$^3$ digester was 150 Kcal/hr m$^3$. 5.In the light of insulation, the vermiculite concrete was consistently shown to be superior to the plain concrete. At the liquid temperature ranging from 15。 C to 350 C, the reduction of heat loss was ranged from 5% to 25% for the half-exposed digester, while from 10% to 28% for the fully underground digester. 6.In the comparison of heat loss between the half-exposed and underground digesters, the heat loss from the former was fr6m 1,6 to 2, 6 times as much as that from the latter. This leads to the evidence that the underground digester takes advantage of heat conservation during winter.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.4
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• pp.289-299
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• 2011

We studied the characteristics of pollutant concentrations in 9 streams that flow into Shihwa Lake in order to provide the scientific data for effective implementation of total pollution loads management system (TPLMS) of the Lake. Suspended solid (SS), chemical oxygen demand (COD), dissolved nutrients ($NO_2$, $NO_3$, $NH_4$, $PO_4$ and $SiO_2$), total phosphorus (TP) and total nitrogen (TN) in stream water from industrial complexes, urban and agricultural regions were determined. Pollutant concentrations in December were higher than that in other sampling periods. COD concentration from industrial complex region with average of 12.6 mg/L was 2 times higher those from urban region (6.6 mg/L) and agricultural region (5.9 mg/L). TP concentration from industrial region also showed higher concentration than other regions. TN concentration in stream water was 5.89 mg/L for industrial region, 3.02 mg/L for urban region and 5.27 mg/L for agricultural region, respectively, suggesting inflow of TN due to fertilizer usage in agricultural field. Relative percentage of nitrogen compounds in TN follows the sequence: $NH_4$ (35.1%) > $NO_2$ (20.0%) > DON (22.8%) > PON (8.9%) > $NO_2$ (3.2%). Concentrations of dissolved nutrients, TP and TN in stream water were 3.2~37.2 times higher than that in Shihwa Lake seawater, therefore large amount of pollutants may be directly entered into Shihwa Lake without any treatment. For Gunja stream of industrial region, pollutants at midstream showed relatively higher concentration compared to upstream and downstream. It is necessary to manage the illegal discharging of sewage and waste water. Our results provide valuable informations on the estimation and reduction of total pollutant loads in the process of establishing adequately strategic and implemental plan of Shihwa Lake TPLMS.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1253-1259
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• 2003

Backgroud : Seizures in the neonate are relatively common and their clinical features are different from those in children and adults. The study aimed to provide the clinical profiles of neonatal seizure in our hospital. Methods : A total of 41 newborns with seizures were enrolled in this study over a period of three years. They were evaluated with special reference to risk factors, neurologic examinations, laboratory data, neuroimaging studies, EEG findings, seizure types, response to treatment, and prognosis, etc. Results : The average age at onset of seizures was $6.1{\pm}4.6days$ and the majority of patients(42%) had multifocal clonic seizure and 24% had subtle seizure. Factors that are known to increase risk of neonatal seizures include abnormal delivery history, birth asphyxia, and electrolyte imbalance, etc. However, they remain obscure in about 20% of cases. More than 50 percent showed abnormal lesions on neuroimaging studies such as brain hemorrhage, periventricular leukomalacia, brain infarction, cortical dysplasia, hydrocephalus, etc. and 17 out of 32 patients showed abnormal electroencephalographic patterns. Phenobarbital was tried as a first line antiepileptic drug and phenytoin was added if it failed to control seizures. The treatments were terminated in the majority of patients during the hospital stay. The overall prognosis was relatively good except for those with abnormal EEG background or congenital central nervous system malformations. Conclusion : Neonatal seizures may permanently disrupt brain development. Better understanding of their clinical profiles and appropriate management may lead to a reduction in neurological disability in later childhood.

• Journal of Nutrition and Health
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• v.48 no.3
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• pp.248-257
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• 2015

Purpose: The aim of this study was to estimate total sugar intake and sugar intake-related dietary habit and nutrient intake of middle school students. Methods: Subjects included 1,184 middle school students (476 males and 708 females) residing in Jeju. This research analyzed daily dietary intakes of subjects using the 24 hour recall method and surveyed the dietary habit related to total sugar intake using questionnaires. Descriptive analysis, chi-square test, t-test, and ANOVA, using the SAS program were used for analysis of data. Results: The average daily total sugar intake was 60.3 g (male 50.5 g, female 66.9 g). Total sugar intake per meal was 6.5 g (10.8%) from breakfast, 9.0 g (14.9%) from lunch, 11.8 g (19.6%) from dinner, and 33.0 g (54.7%) from snacks. Food groups that contribute to the majority of total sugar intake were grains and their products (23.0 g), milk (11.0 g), fruits and their products (7.3 g), sugars and sweets (6.1 g), and vegetables and their products (5.8 g). In terms of total sugar intakes by cooking methods, desserts showed a greater amount than main and side dishes, and indicated in order of amount as follows: bread and cookies (11.5 g), dairy products (7.5 g), ice cakes (6.2 g), beverages (5.3 g), and fruits (4.5 g). Total sugar consumption was high for rice and side dishes such as noodles (10.2 g), fried foods (2.9 g), stir-fried foods (2.0 g), and cooked rice with seasoning (1.7 g). The daily intake of natural sugar, added sugar, and natural and added sugar was 18.3 g, 35.8 g, and 6.2 g, respectively. The high sugar intake group, which was over 20% of the energy from total sugar intakes, consumed significantly less Fe, Zn, vitamin B6, niacin, and vitamin E than the low sugar intake group, which was below 20%. Conclusion: Total sugar intake of second graders of middle schools on Jeju Island was 60.3 g/day, mostly obtained from snacks (54.7%). Therefore, nutritional education for proper selection of better snacks and for reduction of dietary sugar intake is needed for middle school students.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.301-310
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• 2016

This is a nonequivalent control group non-synchronized experiment research to verify the effect of moxibustion therapy on efficient management of daily living disabilities and sleep patterns in elderly women with chronic low back pain. Total 12 sessions of moxibustion therapy were applied to elderly women(30 subjects in an experimental group and 30 subjects in a control group) in G City once a week for 12 weeks from March 15th to May $31^{st}$ 2015. Then the follow-up study was conducted 2 weeks after the post survey. For moxibustion, was applied to Shen-shu, Ashi point, Ta chang shu, Yang kuan and Yosu. 5 sheets of moxibustion were applied to 7 acupuncture points of Mugeukboyang moxibustion; Zu san li & Chu chi, Chung wan, Chung chi & Shui tao, Fei shu, Kao hung and Tien shu, Wijung respectively and experimental treatment was conducted. For assessing the degree of back pain, Visual Analog Scale(VAS) developed by Scott & Huskisson(1979) was used and for measuring the degree of daily living disability, Oswestry Disability Index, which was developed by Fairbank et al(1980) and translated and revised by Yim, Hyeon-sul et al.(1998), was used. For measuring sleep patterns, the sleep pattern measurement tool developed by Oh, Jin-su, Song, Mi-soon and Kim, Sin-mi(1998) was used. For data analysis, SPSS/WIN 18.0 was employed and Chi-square test, t-test and repeated measures ANOVA were performed. There were significant differences in pain score(F=2510.32, p<.001), daily living disability score(F=1937.82, p<.001) and sleep pattern score((F=15.54, p<.001) of elderly women that were provided with moxibustion therapy, compared to the control group. Therefore, it was found that moxibustion therapy made a positive contribution to reduction in pain and daily living disabilities and improvement in sleep quality. Based on this study finding, there is a need to apply moxibustion therapy to elderly people with chronic low back pain as a nursing intervention in future.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.402-409
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• 2002

The effects of protein-bound polysaccharides (A-PBP and L-PBP) that were extracted from the mycelia of two edible mushrooms, namely Agaricus blazai and Lentinus edodes, on serum cholesterol and body weight were investigated in mice and female volunteers. Six groups of Male Balb/c mice were fed six kinds of diet supplement- solutions composed of L-PBP, A-PBP, chitosan, and other fiber constituents, for 30 days under the normal diet. Ninety female volunteers were also supplemented for 8 weeks with six kinds of capsules including control and five test groups as the same manners (two times a day, 4 capsules). From 12 days after feeding of L-PBP (Group I) and A-PBP (Group II), the weight of mice began to reduce as compared with control, whereas that of Group III fed chitosan was decreased 15 days after feeding. Group W and Group V which were fed mixture of L-PBP, A-PBP, chitosan, and other dietary fiber, were more significant in lowering weight. After 4 weeks of the supplementation in women, their serum LDL-cholesterol level and body weights in Group I and II were reduced, but Croup 111 taken with chitosan capsule showed weaker effect than Group I and II. After 8 weeks, LDL-cholesterol content in the sera of Group I (132.5 mg/dL) and II(131.5 mg/dL) was decreased to ideal level (125.4 and 122.8 mg/dL) for healthy blood vessel. In the case of Group W supplemented with mixture of L-PBP, A-PBP, and chitosan, the weight-reduction effect (11.8%) and hypocholesterolemic effect (11.0%) was most significant, indicating their synergistic action. These data suggested that the weight-controlling and hypolipidemic effect of L-PBP and A-PBP was involved, at least in part, in absorption of cholesterol as their role of dietary fiber, as well as cholesterol metabolism.

• Journal of Nutrition and Health
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• v.48 no.2
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• pp.123-132
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• 2015

Purpose: The objective of this study was to examine whether Hamcho freeze-dried powder and Hamcho freeze-dried nano powder have an anti-obese effect on high fat diet-induced obese rats. Methods: Sprague Dawley rats were divided into 6 different groups, each of which was bred for 8 weeks with a different experimental diet: normal diet group (NC), high fat diet group (HFC), high fat diet + 2% Salicornia herbacea L. freeze-dried powder group (2% HS), high fat diet + 5% Salicornia herbacea L. freeze-dried powder group (5%HS), high fat diet + 1% Salicornia herbacea L. freeze-dried nano powder group (1% HSN), high fat diet + 2% Salicornia herbacea L. freeze-dried nano powder group (2% HSN). Results: The 5% HS group showed a weight loss effect in body weight, liver and adipose tissue by reducing the amount of dietary intake and food efficiency ratio. In addition, the 5% HS group showed a significant reduction of serum leptin concentration, while having a beneficial effect on the improvement of lipid metabolism such as increase the serum concentration of adiponectin. However, Hamcho freeze-dried nano powder did not show a weight loss effect. Conclusion: Overall data indicated that Hamcho seemed to have anti-obesity effects. In particular, consumption of 5% Hamcho freeze-dried powder might have beneficial effects on body weight, serum adiponectin level, and lipid profiles since it led to reduced body weight and growth of adipose tissues by suppressing dietary intakes. However conduct of further research studies is needed for analysis of active components and biochemical action mechanism of Hamcho.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.3
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• pp.197-201
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• 2007

Oil soluble licorice extract(licorice extract) is an officially approved cosmetic component as a whitening ingredient in Korea. The durability of licorice, during which the whitening effect can be maintained in optimum condition, must be accurately defined. Since the cosmetics durability under real condition is relatively longer than its development time. It is needed to predict the real durability interval from the experimental measurement under simulated operating conditions. We analyzed the relationship between the licorice lifetime and the high temperature condition by using Arrhenius equation. We have established the constant stress test with temperature of $50^{\circ}C$, $55^{\circ}C$, and $60^{\circ}C$ condition, within which no formulation change of licorice products is expected for the accelerated stress test. In this paper, the lifetime of licorice in cosmetics was defined as time period for its 10% contents reduction. We observed that the lifetime of licorice is 580 h at $50^{\circ}C$, 319 h at $55^{\circ}C$ and 166 h at $60^{\circ}C$. Using the above experimental data, we obtained the equation for the relationship between the licorice lifetime and temperature as follows; log(lifetime)=-35.0243 + 1.15322$\times$(11604.83/temperature). From this equation, the lifetime of licorice at $25^{\circ}C$ can be estimated as 26 months. The estimated result was verified by measuring full lifetime of licorice. In fact, there was no significant difference between the estimated lifetime and real measurement within 95 % significance level. This study can be applied to other useful cosmetic components for the fast estimation of the exact durability.

• Journal of Oral Medicine and Pain
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• v.35 no.3
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• pp.165-175
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• 2010

Valproic acid (VPA) is a well-known anticonvulsive agent and has been used in the treatment of epilepsy for almost 30 years. VPA emerged in 1997 as an antineoplastic agent as well, when findings indicated the substance inhibited proliferation and induced differentiation of primitive neuroectocdermal tumor cells in vivo (Cinatl et al., 1997). Antitmor activity of VPA is associated with its targeting histone deacetylases. Bile acids and their synthetic derivatives induced apoptosis in various kinds of cancer cells and anticancer effects. It has been reported that the synthetic chenodeoxycholic acid (CDCA) derivatives showed apoptosis-inducing activity on various cancer cells in vitro. This study was undertaken to investigate the synergistic apoptotic effect of co-treatment with the histone deacetylases inhibitor, VPA and a CDCA derivative, HS-1200 on human osteosarcoma (HOS) cells. Cell viability was evaluated by trypan-blue exclusion. Induction and augmentation of apoptosis were confirmed by Hoechst staining, flow cytometry (DNA hypoploidy and MMP change), Westen blot analysis and immunofluorescent staining. In this study, HOS cells co-treated with VPA and HS-1200 showed several lines of apoptotic manifestation such as nuclear condensations, the reduction of MMP, the decrease of DNA content, the release of cytochrome c into cytosol, the translocation of AIF onto nuclei, and activation of caspase-7, caspase-3 and PARP whereas each single treated HOS cells did not. Although the single treatment of 1 mM VPA or $25\;{\mu}M$ HS-1200 for 48 h did not induce apoptosis, the co-treatment of them induced prominently apoptosis. Therefore our data provide the possibility that combination therapy of VPA and HS-1200 could be considered as a novel therapeutic strategy for human osteosarcoma.

• Journal of the Korea Convergence Society
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• v.1 no.1
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• pp.41-47
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• 2010

This study was conducted to investigate determinent factors of the internet addiction that have influenced on middle school students. We randomly selected each one middle school in urban and rural areas, and conducted survey in 862 students of 2nd and 3rd grade from September 1 to 15, 2005. By using a statistical program called SPSS10.0, the data collected thereby were analyzed through a series of statistical methods including $x^2$-test, logistic regression analysis. The result of logistic regression analysis showed that the significant variables in urban area were resting time and using time a day. In rural area, sex, economic level, resting time and using time a day were significant variables. Higher status of internet addiction showed significant relationship with physical problems, anxiety, maladjustment to school, insufficient sleep time, fatigue in eyes, headache, pain in neck or shoulder, chronic fatigue, reduced vision, weight reduction, indigestion, xeroderma and adjustment to school. Especially, resting time and using time a day have dominant influence on internet addiction. And in case that the groups who showed high addiction tendency, there were negative health problem by physical, mental and social problem. To prevent internet addiction health education programs of right internet use and time, importance of rest, and health problems must be considered in internet addiction prevention policy.