• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.230-236
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• 1998

We have screened total 32 herbal drugs to find the highest activity against human cariogenic enzyme, glucosyltransferase (GTase) from the extracts of Magnoliae bark. The extracts were separated into three phases, i. e. water, n-butanol and ethylacetate according to their solvent polarity. Among them, ethylacetate fraction had approximately more than 70% of total activities, and the active principle was further isolated by prep. HPLC following silicagel column chromatography to yield single compound as white powder. The chemical structure of the compound was finally elucidated to be 4,4'-dihydroxy-3,3'-dimethoxylignan from the spectral data of FAB-MS. $^1H-\;and\;^{13}C-NMR$ spectrometries. The compound was also shown to have relatively strong antibacterial activity against ten types of cariogenic oral bacteria and one kind of Actinomyces sp.

• Journal of dental hygiene science
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• v.12 no.3
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• pp.217-225
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• 2012

The purpose of this study is to measure the relation of employment stress and self-esteem in some health college students and to consider a proper means for the solution. The population of the research is some randomly chosen health college students located in Seoul City during the period from May 10 to June 11 2010, and the sample of 295 students were recruited as the analysis object group. The data on general characteristics and employment stress were collected by a questionnaire survey. The collected data were analyzed with the SPSS WIN 12.0 program. The following shows the results of this study. 1. Employment stress was low in high group of satisfaction in campus life. It was statistically significant(p<0.001). 2. Mean scores of total self-esteem in study population were 3.1 and positive self-esteem level(3.76) were higher than negative ones (2.44)(p<0.001). 3. The relation between employment stress and selfesteem(r=0.132) revealed significant correlation. 4. In regression analysis, home economy, competence for a schoolwork, satisfaction in campus life, self-esteem(p<0.001) were proved as significant factors that is related to the employment stress. In other words, It is significant statistically that the lower home economy, competence for a schoolwork, satisfaction in campus life, self-esteem, the higher employment stress level. I suggest with the result of the study that for coping effectively employment stress of health college students, we will need to open an educational development considering self-esteem and an exclusive employment counsel window for better administrationwelfare service in campus, to expand industry-academic cooperation in community. Because of students are independent responsibility of employment, active effort must take precedence in order for the solution of problem by themselves. Also, we will need to create better academic environment and show more concern, consideration, love in family.

• The Korean Journal of Mycology
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• v.24 no.3 s.78
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• pp.214-222
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• 1996

This study was carried out to obtain the basic data on artificial culture of Phellinus linteus. The optimum condition for the mycelial growth was $25{\sim}30^{\circ}C$ and pH $6.0{\sim}7.0$. The carbon sources such as D-glucose, D-mannose and Dextrose were favorable to mycelial growth. As nitrogen sources, peptone, cassamino acid and glutamic acid appeared to be favorable. The optimum C/N ratio was about 20:1, when 2% of glucose was provided as a carbon source. The better organic acids and vitamin among tested ones were gallic, silicic acids and biotin. The mineral nutrients of $KH_2PO_4,\;FeSO_4{\cdot}7H_2O,\; MgSO_4{\cdot}7H_2O,\;ZnSO_4{\cdot}7H_2O$ were effective and the optimum concentrations were 0.05, 0.001, 0.02 and 0.003%, respectively.

• 한국유가공학회:학술대회논문집
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• 2004.06a
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• pp.21-39
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• 2004

Fermented milks have been recognized as healthy foods since ancient times, but those using intestinal bacteria such as Bifidobacterium and lactic acid bacteria (LAB) are even more valuable from the standpoint of view of maintaining health. They have also now come to be recognized as important in the field of preventive medicine. Although advances in the medical sciences in the last 50 years have significantly increased the human lift span, an unfortunate fact is that many of us are now living long enough to experience chronic disorders such as coronary heart disease, hypertension, osteoporosis, diabetes and cancer. In recent years there has been renewed interest in health promotion and disease prevention by incorporating probiotic bacteria into foods to counteract harmful bacteria in the intestinal tract. Therefore, there are now a wide variety of commercial products containing prospective probiotics that claim health-promoting effects, such reductions in large botvel carcinogens and mutagens, antitumor properties, cholesterol-lowering effects, increased lactose digestion, relief from con-stipation, stimulation of immunocomponent cells and enhancement of phagocytosis. Two well-known representative probiotic is LAB and Bifidobaclerium. Traditional probiotic dairy strains of LAB which have been designated as GRAS (Generally Recognized As Safe) bacteria have a long history of safe use and most strains are considered comestible microorganisms with no pathogenic potential. Accordingly, there is considerable interest in extending the range of foods containing probiotic organisms from dairy foods to infant formulas, baby foods, and pharmaceuticals. In addition, the ingestion of probiotics, prebiotics, and symbiotic as wll as combinations of pro- and prebiotics has recently aroused renewed interest as enhancing the beneficial relationship between the host and intestinal microflora in both healthy and diseased indivisuals. Non-communicable chronic diseases such as cancer, cerebral hemorrhage, is chemic heart disease, and diabetes mellitus has recently been recognized as adult diseases in Japan as well as other countries. and are considered to be inevitably associated with aging. These diseases occur as a result of individual life styles. The Japanes Government. Ministry of Health, Labor and Welfare has proposed substituting the term 'adult diseases' with 'lifestyle-related diseases'. It has emphasized the importance of prevention rather than treatment. since the well-known increase in the elderly population in Japan is predicted to result in a variety of socioeconomic problems. n this lecture on the Present status of fermented milk products in Japan, I will report a strategy for the development of fermented milk products in Japan from the standpoint of view of research in Japan on LAB and Bifidobacteria. They could play an important role in preserving human health by controlling intestinal microflora capable of producing toxic effects on the host.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.3_4
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• pp.34-47
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• 1995

It is experienced fact as a regular annual event that the structure to he designed on unreasonable flood for the agricultural structures including reservoirs have been brought not only loss of lives, but also enormous property damage. For the solution of this problem at issue, this study was conducted to develop an optimal runoff hydrograph model by comparison of the peak flows and time to peak between observed and simulated flows derived by linear time-invariant and linear time-variant models under the condition of having a short duration of heavy rainfall with uniform rainfall intensity at nine small watersheds which are within the range of 55.9 to 140.7 square kilometers in area in Han, Geum, Nagdong and Yeongsan Rivers. The results obtained through this study can be summarized as follows. 1. Storage constants and Gamma function arguments were calculated within the range of 1.2 to 6.42 and of 1.28 to 8.05 respectively by the moment method as the parameters for the analysis of runoff hydrograph based on linear time-invariant model. 2. Parameters for both linear time-invariant and linear time-variant models were calibrated with nine gaged watershed data, using a trial and error method. The resulting parameters including Gamma function argument, N and storage constant, K for linear time-invariant model were related statistically to watershed characteristic variables such as area, slope, length of main stream and the centroid length of the basin. 3. Average relative errors of the simulated peak discharge of calibrated runoff hydrographs by using linear time-variant and linear time-invariant models were shown to be 0.75 and 5.42 percent respectively to the peak of observed runoff hydrographs. Correlation coefficients for the statistical analysis in the same condition were shown to be 0.999 and 0.978 with a high significance respectively. Therefore, it can be concluded that the accuracy of a linear time-variant model is approaching more closely to the observed runoff hydrograph than that of a linear time-invariant model in the applied watersheds. 4. Average relative errors of the time to peak of calibrated runoff hydrographs by using linear time-variant and linear time-invariant models were shown to be 16.44 and 19.89 percent respectively to the time to peak of observed runoff hydrographs. Correlation coefficients in the same condition were also shown to be 0.999 and 0.886 with a high significance respectively. 5. It can be seen that the shape of simulated hydrograph based on a linear time- variant model is getting closer to the observed runoff hydrograph than that of a linear time-invariant model in the applied watersheds. 6. Two different models were verified with different rainfall-runoff events from data for the calibration by relative error and correlation analysis. Consequently, it can be generally concluded that verification results for the peak discharge and time to peak of simulated runoff hydrographs were in good agreement with those of calibrated runoff hydrographs.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.98-104
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• 1997

Soil pollution intensity at Mt. Namsan in Seoul city which was expected to show significant soil contamination due to long-term air pollution was evaluated by comparing soil chemical properties at Mt. Kyebangsan in Hongcheon area as a control, and the bacteria participating in nitrogen or sulfur mineralization were assayed simultaneously in order to evaluate the validity of N and/or S mineralization bacteria as an index of soil contamination. The soil of Mt. Namsan showed 10 times higher concentration of hydrogen ion compared to that of Mt. Kyebangsan, which indicated that the soil had relatively been acidified seriously. Especially, large amount of canons were thought to be leached out from the soil, while the amount of extractable Al was getting larger and larger, which result in serious problems in soil ecosystem of the mountain. I could infer from soil chemical properties of the four study sites that the major reason of soil acidification was SOx deposition. However, the sulfur-reducing bacteria were not significantly different between the two regions, which indicated that the microbial dynamics of the soil ecosystem was not controlled by simple factor, but by multiple factors. By the way, the dynamics of bacteria participating in denitrification process was different between the two regions, which was more active at Mt. Kyebangsan than at Mt. Namsan. Thus, the microbial assay for nitrogen mineralization is desirable to be examined as a tool for evaluating soil health or microbial activity in soil ecosystem.

• Korean Journal of Child Education & Care
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• v.18 no.1
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• pp.125-146
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• 2018

The purpose of this study was to examine the state of parent education experienced by parents and the state of child education at home relation to infant/preschooler abuse prevention. The subjects in this study were 302 selected parents who resided in I city and whose children were in infancy or early childhood. A survey was conducted, and frequency analysis or chi-square test was carried out after their answer sheets were gathered. The findings of the study were as follows: As for the state of parent education, the parents who received education related to infant/ preschooler abuse prevention accounted for 12.6 percent, and the parents who were taught about all the four types of abuse outnumbered the others who weren't. The parents received that education at institutions for early childhood education by experts in child abuse and early childhood education, and they replied they were satisfied with that education. As for the state of child education, the parents who replied they provided abuse prevention education for their children at home accounted for 25.2 percent, and they answered they taught about physical abuse and how to cope with abuse. They responded they started to conduct this education in their homes when their children were in infancy, and they did it frequently in daily life mainly through conversations. They told it's difficult for them to offer this education at home due to a shortage of abuse-related materials. And whether they offered that education for their children or not at home was significantly different according to whether they received parent education or not. Given the findings of the study, the necessity of the development of manuals for abuse prevention education that can easily be used at home without any modifications was suggested, and education on neglect and the revitalization of publicity are required as well.

• Journal of the Society of Disaster Information
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• v.8 no.4
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• pp.362-375
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• 2012

Tourist hotels are equipped with facilities such as accommodation and restaurants, exercise, recreation. Unspecified guests, visitors and management of tourist hotels are very vulnerable on the casualties and property losses due to fire peril exist. In this study, we analysis that the fire statistics status of tourist hotels from 2001 to 2010. And the 15 cases of a large hotel fire are reviewed. The total number of fires on hotel are consist of a hotel rooms fire(33.2%), a restaurant kitchen fire(11.8%). And the major causes of the fire are an electrical fire (40.8%), a cigarette fire (14.5%) and a hot-work fire (9.2%). In case study, the fire wall defect and combustible materials are major fire loss causes for 10year. Each tourist hotels are needed a development of suitable fire risk management and a field operations. A hotel is required an active fire risk management on a preventive inspection, an education and training, and a preventive maintenance. It is necessary that a fire wall maintenance to prevent of the spread of a fire and a sprinkler installation of whole area to protect fire. And it is very important an emergency response for evacuation of guest, and operate emergency procedures on a fire or emergency situation.

• Journal of Chest Surgery
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• v.2 no.2
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• pp.167-167
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• 1969

Two groups of esophagus graft were done in canine esophagus in 34 adult mongrel dogs. For the first group segmental replacement graft was done with fresh autologous pericardium tube, and for the second, patch graft was done utilizing fresh autologous pericardium, fresh homologous pericardium,and dacron piece. All eight dogs in the first segmental replacement graft group died 2 to 5 days after operation with severe empyema caused by anastomosis disruption. Among 26 patch graft dogs 2 died during operation and 7 died 13 to 18 days after operation. For the 17 long-term patch grafted survivors esophagography and postoperative weight check were done. Postoperative stool was collected and examined for dacron patch excretion. One, two, three, and four months postoperative long-term survivors were sacrificed to obtain specimens in each group respectively and the following observations were made.I. Survival; Autologous pericardium patch group showed no mortality but in homologous pericardium and dacron patch group only two thirds were long-term survivors. II. Postoperative swallowing; There was no case which demonstrated postoperative dysphagia. About half of the cases showed postoperative weight increase and in only 3 cases weight decrease followed operation. III. Dacron patch was excreted in the stool 8 to 23 days after operation. Animals which excreted dacron patch up to 9 days after operation all died of empyema due to anastomosis disruption.IV. Postoperative esophagogram; All esophagograms in each group showed no leakage of barium, no passage disturbances and no remarkable stenotic signs.V. Morphological findings; [A] Macroscopical findings; In one month group specimens of each group dense adhesion with surrounding structures was noted and luminal surface was smooth with contraction of the patched area. In two month groups anastomosis sutures were still exposed but patched area showed lesser abnormality. In three to four months groups sutures were covered completely and patched area showed only very slight signs of contraction. [B] Microscopic findings; In one month group luminal surface of the replaced tissue [transplanted tissue] showed almost complete epithelial covering that is composed of several layers of squamous cells with no evidence of keratinization. Basement membrane was also well distinct throughout. Slight to minimal inflammatory cells comprising of large mononuclears, lymphocytes and plasma cells were observed in the subepithelial fibrous stroma consisted entirely of loose fibrous tissue containing many newly formed capillaries and fibroblastic proliferation. Scattered suture granulomas were found, few of which became acutely inflamed. In two months group repairing process progressed with lesser degree of inflammatory cell infiltration and young capillary proliferation. Fibrous tissue was more matured showing even focal collagenization.Suture granuloma persisted but with lesser reactive changes. Epithelial covering was that of a mature non-keratinizing stratified squamous epithelium. In three and four months groups the replaced area showed essentially similar histological findings. However, subepithelial stroma still consisted entirely of connective tissue without evidence of smooth muscle regeneration. In this group, inflammatory cell infiltration was minimal or negligible. Among these patch materials autologous pericardium group showed the most satisfactory repairing process.The above mentioned results may signify the feasibility of autogenous pericardium patch graft in clinical esophageal surgery.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.456-456
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• 2010

CMOS 소자가 서브마이크론($0.1\;{\mu}m$) 이하로 스케일다운 되면서 단채널 효과(short channel effect), 게이트 산화막(gate oxide)의 누설전류(leakage current)의 증가와 높은 직렬저항(series resistance) 등의 문제가 발생한다. CMOS 소자의 구동전류(drive current)를 높이고, 단채널 효과를 줄이기 위한 가장 효율적인 방법은 소스 및 드레인의 얕은 접합(shallow junction) 형성과 직렬 저항을 줄이는 것이다. 플라즈마 도핑 방법은 플라즈마 밀도 컨트롤, 주입 바이어스 전압 조절 등을 통해 저 에너지 이온주입법보다 기판 손상 및 표면 결함의 생성을 억제하면서 고농도로 얕은 접합을 형성할 수 있다. 그리고 얕은 접합을 형성하기 위해 주입된 불순물의 활성화와 확산을 위해 후속 열처리 공정은 높은 온도에서 짧은 시간 열처리하여 불순물 물질의 활성화를 높여주면서 열처리로 인한 접합 깊이를 얕게 해야 한다. 그러나 접합의 깊이가 줄어듦에 따라서 소스 및 드레인의 표면 저항(sheet resistance)과 접촉저항(contact resistance)이 급격하게 증가하는 문제점이 있다. 이러한 표면저항과 접촉저항을 줄이기 위한 방안으로 실리사이드 박막(silicide thin film)을 형성하는 방법이 사용되고 있다. 본 논문에서는 (100) p-type 웨이퍼 He(90 %) 가스로 희석된 $PH_3$(10 %) 가스를 사용하여 플라즈마 도핑을 실시하였다. 10 mTorr의 압력에서 200 W RF 파워를 인가하여 플라즈마를 생성하였고 도핑은 바이어스 전압 -1 kV에서 60 초 동안 실시하였다. 얕은 접합을 형성하기 위한 불순물의 활성화는 ArF(193 nm) excimer laser를 통해 $460\;mJ/cm^2$의 에니지로 열처리를 실시하였다. 그리고 낮은 접촉비저항과 표면저항을 얻기 위해 metal sputter를 통해 TiN/Ti를 $800/400\;{\AA}$ 증착하고 metal RTP를 사용하여 실리사이드 형성 온도를 $650{\sim}800^{\circ}C$까지 60 초 동안 열처리를 실시하여 $TiSi_2$ 박막을 형성하였다. 그리고 $TiSi_2$의 두께를 측정하기 위해 TEM(Transmission Electron Microscopy)을 측정하였다. 화학적 결합상태를 분석하기 위해 XPS(X-ray photoelectronic)와 XRD(X-ray diffraction)를 측정하였다. 접촉비저항, 접촉저항과 표면저항을 분석하기 위해 TLM(Transfer Length Method) 패턴을 제작하여 I-V 특성을 측정하였다. TEM 측정결과 $TiSi_2$의 두께는 약 $580{\AA}$ 정도이고 morphology는 안정적이고 실리사이드 집괴 현상은 발견되지 않았다. XPS와 XRD 분석결과 실리사이드 형성 온도가 $700^{\circ}C$에서 C54 형태의 $TiSi_2$ 박막이 형성되었고 가장 낮은 접촉비저항과 접촉저항 값을 가진다.