• Journal of the Korean GEO-environmental Society
• /
• v.12 no.10
• /
• pp.13-22
• /
• 2011

In this study, features of correlation between S-velocity and N value are derived from 9 suspension PS layers in Chungcheong Buk-do. S-velocity to be measured on Chungcheong Buk-do is classified into 5 as conditions of stratum that are ; cohesive soil layer, sandy soil layer, gravel layer, weathering soil layer, weathered rock layer. Each correlation formulas between N value by SPT and S-velocity is proposed from these classifications. And correlation formula for whole soil body except weathered rock layer also is proposed for reference. Corelation formulas developed this study formed square expression considering existing formulas produced internationally. Strength parameter converted to linear if N value is more than 50. Features of proposed formula which came up with comparative analysis of international result of cohesive soil layer and sandy soil layer and gravel layer show similar to existing ones. But there is deference that result of correlation formula for weathered rock layer is a little smaller than domestic formula's one. Because correlations of weathered rock layer above the N value of 50 is converted into a linear formation.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2018.01a
• /
• pp.113-116
• /
• 2018

본 연구에서는 컴퓨팅 사고력 평가 도구 중 자기보고식 설문과 지필형 검사지인 비버 챌린지 간의 상관관계를 분석하고자 하였다. 두 평가 도구를 사용한 결과 간의 상관관계는 통계적으로 유의하지 않았다. 따라서 객관적인 측정을 위하여 자기보고식 설문에 대한 수정 및 보완이 필요하며, 비버 챌린지의 점수에 영향을 주는 난이도에 대한 고찰이 필요하다. 덧붙여 산출물 평가와 자기보고식 설문, 지필형 검사지 간의 상관관계를 분석할 필요가 있다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2016.05a
• /
• pp.411-411
• /
• 2016

본 연구에서는 유역 특성 인자와 지점 유량-유사량 관계식의 상관성 분석을 하였다. 대상 지점은 군남, 청미(이상 한강 유역), 향석, 동문, 선산, 동촌, 개진2(이상 낙동강 유역), 회덕, 합강(이상 금강 유역), 선암, 남평(이상 영산강 유역)을 선정하였다. 대상 지점의 상류에 댐이 있을 경우 유량-유사량 관계식이 왜곡될 가능성이 있기 때문에 이상 지점은 상류에 댐이 없는 곳으로 선정되었다. 이들 지점을 출구로 하는 유역을 정의하고 각 유역의 형상계수, 수면 폭, 단면적, 하천 총 길이 등을 조사하여 유량-유사량 관계식과 비교하였다. 분석 결과 수면 폭, 단면적, 하천 총 길이가 증가할수록 관계식의 계수는 감소하는 경향을 나타냈고 지수는 증가하는 형태를 나타내는 것을 알 수 있었다. 한편, 형상계수는 뚜렷한 상관관계를 나타내지 않았다. 유량-유사량의 경향성을 파악하기 위해 기존의 측정성과와 비교 분석하고자 하였다. 비교 분석한 결과 대부분 유사한 특성과 경향성을 나타내었으나 일부 다른 특성을 보인 지점도 존재하였다. 본 연구는 특정 지점의 유량-유사량 관계가 유역의 지형 특성에 영향을 받는 다는 것을 시사하는 초기 연구로 향후 추가 연구를 통해 그 영향을 규명할 필요성을 보여준다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2016.05a
• /
• pp.218-218
• /
• 2016

차량용 강우 센서는 강우측정이 어려운 지역의 강수량 측정이 가능하고, 실시간으로 강우정보를 생성해 내기 때문에 차세대 강우측정기로써 전망이 기대된다. 차량용 강우 센서는 일반적인 강우관측기와 달리 물 입자가 커질수록 빛의 산란이 크게 일어나는 현상을 이용한다. 산란이 크게 일어나면 강우 센서에 입력되는 값이 줄고 이는 강수가 높다는 것을 의미한다. 강우가 발생하면 자동차 전면 유리창에 부착된 강우 센서가 감지하는 우적량을 강우량으로 환산하는 방법을 통해 강우량을 산정한다. 강우가 쌓이고 나서 나중에 그 값을 측정하는 것이 아니라 즉시 그 값을 계산하여 강우량을 산출해야하기 때문에 단계가 복잡하다. 수식이 복잡할수록 오차가 발생할 확률도 크고 처리 속도도 느려지기 때문에 W-S-R 관계식을 이용하여 복잡한 수식을 간단하게 정리할 필요가 있다. AWS 기상관측소와의 비교 분석을 위해 차량에 우량계를 장착하였으며 W-S-R 관계식을 통하여 상관관계 분석하여 회귀식을 도출 한다. W-S-R 관계식이라 함은 와이퍼의 속도관계(W), 강우센서(S), 실제 강우(R)을 의미한다. 여기서 와이퍼의 속도관계는 와이퍼의 한 번 이동 했을 시 실제 강우는 실내강우발생 장비를 제작하여 10~80mm의 강우를 발생시키고 그 값은 우량계로 관측한다. 본 연구에서는 물 입자의 산란과 차량용 강우 센서 간의 관계식 도출과 W-S-R 관계식을 이용하여 실제 강우 정보와의 상관관계를 위한 분석을 통한 회귀식 개발을 목표로 한다.

• Fire Science and Engineering
• /
• v.24 no.6
• /
• pp.54-60
• /
• 2010

An experimental study has been carried out to determine the flow rate for a feasible N2 generator to extinguish the fire, and this study analogized the correlations to determine the flow rate for $N_2$ generator considered an Oxygen concentration, protected enclosure, discharging pressure and discharging time. We manufactured simple protected enclosure for analyzing fire-extinguishing performance of the $N_2$ generator. As a $N_2$ gas is exhausted on protected enclosure, a various of Oxygen concentration is measured to analyze fire-extinguishing performance experimentally. The correlations determined as an uncertainty analysis for the Oxygen concentration deviations of the theoretical and experimental value. The analogized correlations is Q = (21 $\times$ V)/($O_2+{\zeta}{\cdot}P$)-V. In case of $300m^3$ protected enclosure, 0.8 MPa discharging pressure and $40m^3$/min $N_2$ flow rate, the Oxygen concentration is decreased below 15% within 3 minutes.

• Nuclear Engineering and Technology
• /
• v.21 no.2
• /
• pp.73-88
• /
• 1989

Ten methods of the total two-phase pressure drop prediction based on five existing models and correlations have been examined for their accuracy and applicability to pressurized water reactor conditions. These methods were tested against 209 experimental data of local and bulk boiling conditions : Each correlations were evaluated for different ranges of pressure, mass velocity and Quality, and best performing models were identified for each data subsets. A computer code entitled 'K-TWOPD' has been developed to calculate the total two-phase pressure drop using the best performing existing correlations for a specific property range and a correction factor to compensate for the predicted error of the selected correlations. Assessment of this code shows that the present method fits all the available data within $\pm$11% at a 95% confidence level compared with $\pm$25%, for the existing correlations.

• International Journal of Highway Engineering
• /
• v.9 no.4
• /
• pp.205-213
• /
• 2007

Strength relationships are presented through experimental data from the concrete strength tests in this study. Various strength tests such as the compressive, flexural, and splitting tensile strength and the modulus of elasticity are included. An experimental work was performed to determine the various strength characteristics for various mix designs. Three different coarse aggregates such as granite, limestone, sandstone were used and included were fine aggregates such as natural sand, washed sand and crushed sand. Also included was cement amount as experimental variable. It was confirmed that each strength value with respect to curing time is to follow a typical strength development curve. With this somewhat reliable test results various strength relationships such as flexural strength-compressive strength, splitting tensile strength-compressive strength, modulus of elasticity-compressive strength, splitting tensile strength-flexural strength were analyzed through statistics. Experimental data were well fitted to the 0.5-power relationship of flexural strength and compressive strength which has been commonly accepted. The splitting tensile strength is expected to be best in the linear relationship from the flexural strength data. Finally splitting tensile strength was found to be proportional to the 0.87 power of the cylindrical compressive strength.

• Journal of the East Asian Society of Dietary Life
• /
• v.6 no.2
• /
• pp.167-176
• /
• 1996

This nutritional survey was conducted from July to August 1993, in order to investigate the nutrition knowledge, food habits, nutrient intake, and their correlation of high school girl students living in large city, middle and small city, and rural area. The subjects of this survey were 164 students living in large city, Seoul and Pusan, 289 students living in noddle and small city, Chonju and Iksan-City, and 252 students living in rural area, Samnye-Up and Kimje-Kun, Chonbuk-Province. The results obtained are summarized as follows: The perceived nutrition knowledge of large city, middle and small city, and rural area was 80.1%, 83.9%, and 76.0%, respectively, and their accuracy was 62.0%, 64.2%, 56.3% respectively The nutritional knowledge score of large city, middle and small city, and rural area was 14.90, 16.16, 12.84, respectively. The nutrition knowledge score was significant among large city, middle and small city, and rural area. The correlation coefficient between nutrition knowledge and food habits was significant among large city, and middle and small city students. The food habits score of rural area subjects were lowest. The correlation between food habit and calcium, vitamin 4 and vitamin C were significant among large city girls. In rural students the correlation between food habits and protein, phosphorus, iron, vitamin B1, vitamin B2, and vitamin C was significant.

• The Journal of the Korea Contents Association
• /
• v.13 no.8
• /
• pp.240-249
• /
• 2013

The aim of this study was to investigate the relationship among sexual attitudes, sexual knowledge and social support of middle school students. A cross-sectional, descriptive study was conducted. The subjects were 139 students at the freshman stage from a middle school. Data were collected from September 6th to December 10th, 2010 by using a structured questionnaire. The data were analyzed using SPSS/WIN 19.0 program. The subjects showed less opened sexual attitudes and lower level of sexual knowledge than high school students. Sexual attitudes and knowledge showed significant differences according to gender. And there were significant correlations between sexual attitudes and family support, sexual knowledge and social support respectively. These results suggest that the differentiated sexual education program have to be developed by considering student's gender. Also, family and school have important duties to increase sexual attitudes and knowledge of the middle school students.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.1
• /
• pp.46-52
• /
• 2013

The purpose of this study was to measure the serum lipid concentrations by gender and age, and to investigate the relationship between dietary behavior and serum lipid levels in Korean adults. The subjects consisted of 209 volunteers (121 men and 88 women) who visited a health promotion center. Their anthropometric and biochemical blood indices were measured, and data on lifestyles were obtained using structured questionnaires. The blood total cholesterol, LDL-cholesterol, and triglyceride concentrations increased significantly with age in women (p<0.01). The food habit score of men and women increased with age, and total food habit score was negatively correlated with BMI (p<0.05). The rate of skipping meals (p<0.001), overeating (p<0.05), eating instant food (p<0.001), and eating out (p<0.05) decreased significantly with age, and the intake rate of vegetables (p<0.001) and carbohydrates (p<0.05) significantly increased with it. The food intake frequency of 21 food items was also measured, and snacks (p<0.05), high fat foods (p<0.01) meats (p<0.05), and instant foods (p<0.01) were negatively correlated with HDL-cholesterol. Snacks (p<0.05) and high fat foods (p<0.01) were positively correlated with LDL-cholesterol. Snacks (p<0.05) and fats/oils (p<0.01) were positively correlated with triglycerides. These results suggest that the food habits and food intake frequency may be one of the important factors affecting serum lipid concentrations in Korean adults.