• Magazine of the Korean Society of Agricultural Engineers
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• v.27 no.2
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• pp.23-37
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• 1985

This studies were carried out to get characteristics of frequency distribution, probable flood flows according to the return periods, and the correlation between return periods and those length of records affect the Risk of failure in the annual maximum series of the main river systems in Korea. Especially, Risk analysis according to the levels were emphasized in relation to the design frequency factors for the different watersheds. Twelve watersheds along Han, Geum, Nak Dong, Yeong San and Seom Jin river basin were selected as studying basins. The results were analyzed and summarized as follows. 1. Type 1 extremal distribution was newly confirmed as a good fitted distribution at selected watersheds along Geum and Yeong San river basin. Three parameter lognormal Seom Jin river basin. Consequently, characteristics of frequency distribution for the extreme value series could be changed in connection with the watershed location even the same river system judging from the results so far obtained by author. 2. Evaluation of parameters for Type 1 extremal and three parameter lognormal distribution based on the method of moment by using an electronic computer. 3. Formulas for the probable flood flows were derived for the three parameter lognormal and Type 1 extremal distribution. 4. Equations for the risk to failure could be simplified as $\frac{n}{N+n}$ and $\frac{n}{T}$ under the condition of non-parametric method and the longer return period than the life of project, respectively. 5. Formulas for the return periods in relation to frequency factors were derived by the least square method for the three parameter lognormal and Type 1 extremal distribution. 6. The more the length of records, the lesser the risk of failure, and it was appeared that the risk of failure was increasing in propotion to the length of return periods even same length of records. 7. Empirical formulas for design frequency factors were derived from under the condition of the return periods identify with the life of Hydraulic structure in relation to the risk level. 8. Design frequency factor was appeared to be increased in propotion to the return periods while it is in inverse proportion to the levels of the risk of failure. 9. Derivation of design flood including the risk of failure could be accomplished by using of emprical formulas for the design frequency factor for each watershed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.732-738
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• 2020

This study examined the effects of hospice & palliative care education programs for nursing students, in terms of spiritual well-being and knowledge concerning advance directives. This is a quasi-experimental study of non-equivalent control groups, and includes a pre-test and post-test design. Data was collected between September to December 2018, enrolling third grade nursing college students attending a university in C city: 22 subjects in the experimental group and 27 subjects in the control group. The experimental group was provided the education as a regular subject, 2 hours a week for 7 weeks, for a total of 14 hours. Ed. Notes: I suggest you maintain any one unit for mentioning time. Hence, I changed 120 mins to 2 hours. Data were analyzed by X2 test, Fisher's exact, t-test, independent t-test, and paired t-test, using the SPSS 21.0 program. After attending the program, spiritual well-being showed a significant increase (t=2.80, p=0.009). However, there was no significant difference between groups in knowledge regarding advance directives (t=1.33, p=0.190). Our results indicate that the hospice & palliative care education program helps nursing students improve their score of spiritual well-being. We believe that these results contribute basic data for the future development of hospice-palliative care curriculum.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.103-103
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• 2012

본 연구에서는 시험포장($1276.6m^2$)에서의 지표피복 BMPs (Best Management Practices) 시나리오를 적용하여 얻은 평균 유출저감율을 HSPF 모델에 적용하여 유역차원에서의 비점원오염 저감효과를 평가하고자 한다. 본 연구에서는 별미천 유역($1.21km^2$)을 대상으로 모형의 적용을 위한 입력자료로 기상자료와 지형자료를 구축하였으며 기상자료로 수원, 양평, 이천 기상관측소 자료를 구축하였으며, 지형자료로 격자크기 2m의 DEM (Digital Elevation Model)과 토지이용도는 2006년 5월 1일 QuickBird 영상을 제공받아 기존 환경부, 건교부, USGS의 토지피복분류체계 및 현장조사를 통하여 QuickBird 영상으로부터 추출 가능한 정밀농업정보에 대한 항목을 결정하였으며, 정사보정된 QuickBird 영상을 스크린 디지타이징 기법(On-Screen Digitizing Method)을 이용하여 총 21개 토지이용항목의 정밀토지이용도를 구축하였다. 실제모니터링으로 측정된 자료를 바탕으로 수위-유량곡선 산정 및 오염부하곡선을 선정, 2011년 6월 8일부터 10월 31일 분석기간으로 HSPF 모델링을 실시하였으며 모의결과 월별 통계에 따른 적용성 분석으로 RMSE (Root Mean Square Error) 는 1.15 ~ 1.76(mm/day), $R^2$는 0.62 ~ 0.78, Nash-Sutcliffe model efficiency (NSE)는 0.62 ~ 0.76로 모의치는 실측치와 유의성이 있는 것으로 분석되었다. 또한, Sediment, T-N, T-P의 $R^2$는 각각 0.72, 0.62, 0.63으로 상관성을 보이는 것으로 분석되었다. 시험포장으로부터 얻어진 event별 볏짚을 이용한 지표피복시나리오적용 후 밭에서의 평균 유출 약 10 % 유출율 감소 조건과 실제 평균 비점원오염 저감효과 89.7 % ~ 99.4 %의 결과로부터 지표피복효과의 침투효과를 HSPF 모델로 적용하기 위해 침투량(INFILT)를 조절하여 평균유출 약 10 %가 감소되는 16.0 mm/hr 값을 선정하였다. 그 결과, Sediment. T-N, T-P의 평균 저감율은 각각 87.2 %, 28.5 %, 85.1 %로 나타났으며 이는 시험포장에서의 실제 평균 비점오염 저감효과 89.7 % ~ 99.4 %에 근접함을 알 수 있었다. 이 결과로부터 침투량 조절에 따른 지표피복(침투짚단)효과는 Sediment, T-P에서 저감효율이 80 % 이상으로 높았지만 T-N은 약 30 %로 낮은 저감율을 보임으로써 저감효과가 크지 않음을 나타냈다.

• Journal of Trauma and Injury
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• v.21 no.2
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• pp.115-119
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• 2008

Purpose: Abrupt abstinence from alcohol in cause of chronic alcohol addiction can trigger alcohol withdrawal syndrome. The authors studied the effect of post-operative alcohol withdrawal syndrome in patients who require intensive care due to trauma. Methods: For the study group, we selected 70 patients who had undergone emergency surgery from May 2003 to March 2007 due to trauma and who had been treated with prophylactic thiamine. Data was collected retrospectively. We excluded those who extended their hospital stay for other than traumatic causes, those who died within 3 days of surgery after trauma, those who transferred to other institutions, and those who received a psychiatric diagnosis. Patient groups were determined by the existence or the non-existence of withdrawal syndrome. Age, sex, injury mechanism, mortality, complications, durations of hospital stay and intensive care, use of mechanical ventilator, and sedative use were investigated. A Chi-square test and The Mann-Whitney method were used for statistical analysis in this study. Results: Twenty-four (24) patients from the 58 who had an ISS of 16 or more showed alcohol withdrawal syndrome, and men were shown to be affected with the syndrome significantly more than women. Although ISS was higher in the group with alcohol withdrawal syndrome, statistically, the difference was not significant (P<0.08). The total hospital stay in the patient group with alcohol withdrawal syndrome was on average 10 days longer. However, the difference was not significant (P<0.054). The duration of intensive care in the patient group with alcohol withdrawal syndrome was significantly longer (P<0.029). The patients with alcohol withdrawal syndrome showed no significant difference in the duration of mechanical ventilator use (P<0.783), or in the duration of sedative use (P<0.284). Respiratory distress, pneumonia, upper airway infection, sepsis, acute renal failure, and mortality in the alcohol withdrawal syndrome group were investigated, but no statistically significant difference were noted. Conclusion: We found that the duration of intensive care in chronic alcohol abusers was longer due to the development of alcohol withdrawal syndrome. We also discovered that, when the patients overcame the symptoms of alcohol withdrawal syndrome after intensive care, no difference was found in the frequency of developing complications, the morbidity, and the mortality. Therefore, we conclude that intensive care in trauma patients who are chronic alcohol abusers decreases the incidence of complications found in patients with post-operative alcohol withdrawal syndrome and does not adversely impact the prognoses for those patients.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.7-8
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• 2010

The surface conductive layer (SCL) of chemical vapor deposition (CVD) diamonds has attracting much interest. However, neither photoemission electron microscopic (PEEM) nor micro-spectroscopic (PEEMS) information is available so far. Since SCL retains in an ultra-high vacuum (UHV) condition, PEEM or PEEMS study will give an insight of SCL, which is the subject of the present study. The sample was made on a Ib-type HTHP diamond (001) substrate by non-doping CVD growthin a DC-plasma deposition chamber. The SCL properties of the sample in air were; a few tens K/Sq. in sheet resistance, ${\sim}180\;cm^2/vs$ in Hall mobility, ${\sim}2{\times}10^{12}/cm^2$ in carrier concentration. The root-square-mean surface roughness (Rq) of the sample was ~0.2nm as checked by AFM. A $2{\times}1$ LEED pattern and a sheet resistance of several hundreds K/Sq. in UHV were checked in a UHV chamber with an in-situ resist-meter [1]. The sample was then installed in a commercial PEEM/S apparatus (Omicron FOCUS IS-PEEM) which was composed of electro-static-lens optics together with an electron energy-analyzer. The presence of SCL was regularly monitored by measuring resistance between two electrodes (colloidal graphite) pasted on the two ends of sample surface. Figure 1 shows two PEEM images of a same area of the sample; a) is excited with a Hg-lamp and b) with a Xe-lamp. The maximum photon energy of the Hg-lamp is ~4.9 eV which is smaller that the band gap energy ($E_G=5.5\;eV$) of diamond and the maximum photon energy of the Xe-lamp is ~6.2 eV which is larger than $E_G$. The image that appear with the Hg-lamp can be due to photo-excitation to unoccupied states of the hydrogen-terminated negative electron affinity (NEA) diamond surface [2]. Secondary electron energy distribution of the white background of Figs.1a) and b) indeed shows that the whole surface is NEA except a large black dot on the upper center. However, Figs.1a) and 1b) show several features that are qualitatively different from each other. Some of the differences are the followings: the two main dark lines A and B in Fig.1b) are not at all obvious and the white lines B and C in Fig.1b) appear to be dark lines in Fig.1a). A PEEMS analysis of secondary electron energy distribution showed that all of the features A-D have negative electron affinity with marginal differences among them. These differences can be attributed to differences in the details of energy band bending underneath the surface present in SCL [3].

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.156-162
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• 2016

This study was conducted to investigate the effects of a death education program on self-esteem, spiritual well-being, and pain in adults. This investigations employed a nonequivalent control group non-synchronized design, and was performed in C hospital located in Chungju, Chungcheongbukdo province, Korea from January 4-13, 2016. The study included 48 participants who agreed to enrolled. Participants were randomly divided into an experimental and a control group of 22 and 26 applicants each. Participants (n=22) in the experimental group participated in the death education program for 2 hours, three times a week for 2 weeks. The effects of treatment were measured using a structured questionnaire to evaluate self-esteem, spiritual well-being, and pain before and after 2 weeks of intervention. Data were analyzed using a t-test, chi-squared test, Fisher's Exact-test and a paired t-test. The experimental group showed significantly increased self-esteem (P<0.002) and spiritual well-being (P<0.015), and significantly reduced pain (P<0.014) compared to the control group after 2 weeks of intervention. Overall, the death education program was shown to be an effective nursing intervention for adults; therefore, of its use in various fields should be considered.

• Journal of Nutrition and Health
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• v.38 no.6
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• pp.445-454
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• 2005

The purpose of this study was to compare the validity of obese index among body mass index (BMI), waist to hip ratio (WHR), and waist circumference (WC) and to determine which is the best in relation to cardiovascular disease (CVD) risk in Korean elderly more than 65 ages. Data from the 1998 Korean Health and Nutrition Survey were used (n=1017). Anthropometric indices and CVD risk factors were measured, and chi-square test, analysis of variance following duncan's multiple range test, partial correlation analysis, and Receiver Operator Characteristic (ROC) curves were used in the analysis. Anthropometric values were decreased in both male and female when ages were goes up. In female elderly, it specially showed the characteristics of upper body fat and systolic blood pressure risk (p<0.05). Among life style factors the current smokers were prevalent in obese male (p<0.05), but not prevalent in female having obese or upper body fat. Also, person with upper body obesity have more exercise than that of normal group (p<0.01). Mean BMI values of the current smoker was lower than that of normal group in both sexes (p<0.01). Mean BMI value of person with other risk factors were higher than that of normal groups (p<0.05). Among 7 CVD risk factors in partial correlation analysis, WC had the highest correlation coefficient in 5 in male, whereas BMI in 4 in female. In ROC analyses of 12 risk factors and health conditions, the largest area under curve of obese indices for risk factors were WC>WHR>BMI in male and BMI>WHR>WC in female. The optimal cutoff values of each index (BMI : WHR : WC) for one or more risk factors were 19.02 : 0.84 : 71.3 in male and 19.04 : 0.88 : 85.6 in female. In conclusion, Most Korean elderly showed non-obese and abdominal obesity likewise other Asians. Also CVD risk factors were prevalent in Korean elderly within normal limits of obese indices. Therefore the upper body fat indices reflected in the aged whose muscle mass is replaced by fat must be used as an indicator of CVD risk together with BMI. Although WHR was the worst index based on partial correlation analysis and so located between BMI and WC in ROC curve analysis in both sexes, it need to be use with WC to screen the cardiovascular risk group.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.25 no.4
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• pp.45-56
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• 2012

Objective : This study was done to investigate the correlation between general quality of life(QOL) and disease specific QOL of tinnitus patients. Methods : 2009 National health and nutrition survey(NHNS) data were employed for analyzing the mean estimates of total population and tinnitus sub-group patients, and predicting the regression equation of mapping between EQ-5D and disease severity. Baseline statistical analyses and normality tests were done by using Student t-test, Chi-square test, Shapiro-Wilk test and ladder test. Hierarchial regression analyses were performed using related variables and predicted the optimal regression equations. Statistical significance was achieved if the probability was less than 5%. Results : Firstly, the standardized prevalence of tinnitus patient in South Korea was 18.69% and over 90th age-group was relatively higher than other groups. Mean value of domestic QOL measured by EQ-5D was estimated as 0.9486 and QOL of tinnitus subgroup(0.9169) was lower than the non-tinnitus subgroup(0.9559), significantly. Stratified by age and sex, QOLs of all sub-groups with tinnitus were lower than without tinnitus sub-groups significantly. Regression equations from 2009 NHNS data were developed using hierarchial regression analysis which is as follows. $$Y_{EQ-5D}=0.9224-0.0079{\times}T1-0.0261{\times}T2-0.0951{\times}T3+\sum_{i=1}^{n}{\beta}_i{\times}X_i\\{\hspace{95}}(0.0106){\hspace{3}}(0.0037){\hspace{30}}(0.0072){\hspace{30}}(0.0038)$$ ($X_i$=Other explanatory variables except Tinnitus QOL1, 2, 3, ${\beta}$= Regression Coefficient of Model 4) Conclusion : We confirmed the correlation among THI and EQ-5D and HUI-III, and developed the inference for regression equation of EQ-5D.

• Wind and Structures
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• v.28 no.2
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• pp.71-87
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• 2019

The yaw and interference effects of blades affect aerodynamic performance of large wind turbine system significantly, thus influencing wind-induced response and stability performance of the tower-blade system. In this study, the 5MW wind turbine which was developed by Nanjing University of Aeronautics and Astronautics (NUAA) was chosen as the research object. Large eddy simulation on flow field and aerodynamics of its wind turbine system with different yaw angles($0^{\circ}$, $5^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$ and $45^{\circ}$) under the most unfavorable blade position was carried out. Results were compared with codes and measurement results at home and abroad, which verified validity of large eddy simulation. On this basis, effects of yaw angle on average wind pressure, fluctuating wind pressure, lift coefficient, resistance coefficient,streaming and wake characteristics on different interference zone of tower of wind turbine were analyzed. Next, the blade-cabin-tower-foundation integrated coupling model of the large wind turbine was constructed based on finite element method. Dynamic characteristics, wind-induced response and stability performance of the wind turbine structural system under different yaw angle were analyzed systematically. Research results demonstrate that with the increase of yaw angle, the maximum negative pressure and extreme negative pressure of the significant interference zone of the tower present a V-shaped variation trend, whereas the layer resistance coefficient increases gradually. By contrast, the maximum negative pressure, extreme negative pressure and layer resistance coefficient of the non-interference zone remain basically same. Effects of streaming and wake weaken gradually. When the yaw angle increases to $45^{\circ}$, aerodynamic force of the tower is close with that when there's no blade yaw and interference. As the height of significant interference zone increases, layer resistance coefficient decreases firstly and then increases under different yaw angles. Maximum means and mean square error (MSE) of radial displacement under different yaw angles all occur at circumferential $0^{\circ}$ and $180^{\circ}$ of the tower. The maximum bending moment at tower bottom is at circumferential $20^{\circ}$. When the yaw angle is $0^{\circ}$, the maximum downwind displacement responses of different blades are higher than 2.7 m. With the increase of yaw angle, MSEs of radial displacement at tower top, downwind displacement of blades, internal force at blade roots all decrease gradually, while the critical wind speed decreases firstly and then increases and finally decreases. The comprehensive analysis shows that the worst aerodynamic performance and wind-induced response of the wind turbine system are achieved when the yaw angle is $0^{\circ}$, whereas the worst stability performance and ultimate bearing capacity are achieved when the yaw angle is $45^{\circ}$.

• Journal of Korean society of Dental Hygiene
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• v.19 no.5
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• pp.651-664
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• 2019

Objectives: This study surveyed the application of Comprehensive Dental Hygiene Care (CDHC), based on non-surgical periodontal therapy within the educational curricula of Korean universities and examined whether they recognized the need for CDHC. Methods: This study analyzed data from professors of dental hygiene practicum related subjects in 75 Korean universities. The collected data were analyzed using a Chi-square test, a Mann-Whitney U-test, and a Kruskal Wallis test via SPSS (Ver. 21.0). Results: First, the application scope of CDHC was higher in four-year universities than three-year ones with the scope of several characteristics increasing along with enrollment quota. The application scope of dental hygiene plans and actions increased with the number of patient practices in terms of periodontal evaluations. Second, the needs of the dental hygiene courses were more than 4 points in all characteristics. Although four-year universities exhibited higher points than three-year ones, there was no significant difference found except other test. Finally, all universities based their dental hygiene courses on case histories, oral and maxillofacial information, hard tissue modules, periodontal issues, and other tests, with needs also being high. Meanwhile, the application scope of the dental hygiene course evaluations was lowest in all characteristics. Conclusions: There were no significant differences in dental hygiene curricula among the universities. However, highly qualified and standardized educational courses and lectures should be developed by the Korean evaluation center for dental hygiene curricula using various studies as the basis of theory and practical classes, the total number of terms, number of case studies used, number of students per class, ratio of students to professor, and so on.