• 한국대기환경학회지
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• 제23권4호
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• pp.478-486
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• 2007

Numerical analysis had been performed to understand flow characteristics of the flue gas and slurry in the absorber of a flue gas desulphurization (FGD) system using computational fluid dynamics (CFD) technique. Two-fluid(Euler-Lagrangian) model had been employed to simulate physical phenomenon, which slurry particles injected through slurry spray nozzles fall down and bump into the flue gas inflowing through inlet duct. It was not necessary to adopt pre-defined pressure drop inside the absorber because interaction between flue gas and slurry particles was considered. Hundreds of slurry spray nozzles were considered with the spray velocity at the nozzles, swirl velocity and spreading angle. The results note that the flow disturbance of flue gas is found at the bottom of the absorber, and the current rising with high speed stream is observed in the opposite region of the inflow duct. The high speed stream is reduced as the flue gas goes up, because the high speed stream of flue gas dumps falling slurry particles due to momentum exchange between flue gas and slurry particles. In spite of some disproportion in slurry distribution inside the absorber, escape of slurry particles from the absorber facility is not observed. The pressure drop inside the absorber is mainly occurred at the bottom section.

• Geomechanics and Engineering
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• 제20권4호
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• pp.359-370
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• 2020

Prestressed ground anchors are important structural elements in geotechnical engineering. Despite their widespread usage, the design process is often significantly simplified. One of the major drawbacks of commonly used design methods is the assumption that skin friction is mobilized uniformly along an anchor's fixed length, one consequence of which is that a progressive failure phenomenon is neglected. The following paper introduces an alternative design approach - a computer algorithm employing the load-transfer method. The method is modified for the analysis of anchors and combined with a procedure for the derivation of load-transfer functions based on commonly available laboratory tests. The load-transfer function is divided into a pre-failure (hardening) and a post-failure (softening) segment. In this way, an aspect of non-linear stress-strain soil behavior is incorporated into the algorithm. The influence of post-grouting in terms of radial stress update, diameter enlargement, and grout consolidation is included. The axial stiffness of the anchor body is not held constant. Instead, it gradually decreases as a direct consequence of tensile cracks spreading in the grout material. An analysis of the program's operation is performed via a series of parametric studies in which the influence of governing parameters is investigated. Finally, two case studies concerning three investigation anchor load tests are presented.

• 연구논문집
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• 통권29호
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• pp.5-15
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• 1999

Present study deals with performance analysis of an inert gas generator (IGG) which is to be used as an effective mean to suppress the fire. The IGG uses a turbo jet cycle gas turbine engine to generate inert gas for fire extinguishing. It is generally known that a lesser degree of oxygen content in the product of combustion will increase the effectiveness of fire suppressing. An inert gas generator system with water injection will bring advantages of suffocating and cooling effects which are considered as vital factors for fire extinguishing. As the inert gas is injected to the burning site, it lowers the oxygen content of the air surrounding the flame as well as reduces the temperature around the fire as the vapour in the inert gas evaporates during the time of spreading. Some important aspects of influencing parameters, such as, air excess coefficient. $\alpha$, compressor pressure ratio, $ pi_c$, air temperature before combustion chamber, $T_2$, gas temperature after combustion chamber, $T_3$, mass flow rate of water injection, $M_w$, etc., on the performance of IGG system are investigated. Calculations of total amount of water needed to reduce the turbine exit temperature to pre-set nozzle exit temperature employing a heat exchanger were made to compare the economics of the system. A heat exchanger with two step cooling by water and steam is considered to be better than water cooling only. Computer programs were developed to perform the cycle analysis of the IGG system and heat exchanger considered in the present study.

• 한국학교보건학회지
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• 제24권1호
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• pp.1-11
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• 2011

Purpose: This study is a non-equivalent control group pre-post design, which attempted to observe the effects of Basic Life Support Education on undergraduate students' CPR Knowledge and Attitude. Methods: The subjects were 96 undergraduates in Jeonbuk. They were divided into two groups: an experimental group of 46 students and a control group of 50 students. The BLS education was given by three BLS instructors certified by the American Heart Association using a DVD. Data were collected from October 20 to November 15, 2010 and analyzed, using the ${\chi}^2$ test, t-test, and ANCOVA. Results: There were significant differences between the experimental group and the control group in the levels of CPR Knowledge and Attitude. The 1st hypothesis, that the CPR knowledge scores for the experimental group would be higher than those of the control group, was supported (F=157.58, p=.000). The 2nd hypothesis, that the CPR attitude scores for the experimental group would be higher than those of the control group, was supported (F=23.78, p=.000). Conclusion: This study showed that BLS education had a positive influence on undergraduate students' knowledge and attitudes toward CPR. We expect that BLS education will contribute to spreading knowledge of CPR and reducing mortality among heart attack victims, and we can see from this study how CPR training in combination with theory and clinical practice develops knowledge and practical ability.

• 한국멀티미디어학회논문지
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• 제24권7호
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• pp.849-859
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• 2021

Prostate cancer (PCa) is a fatal disease that occurs in men. In general, PCa cells are found in the prostate gland. Early diagnosis is the key to prevent the spreading of cancers to other parts of the body. In this case, deep learning-based systems can detect and distinguish histological patterns in microscopy images. The histological grades used for the analysis were benign, grade 3, grade 4, and grade 5. In this study, we attempt to use transfer learning and fine-tuning methods as well as different model architectures to develop and compare the models. We implemented MobileNet, ResNet50, and DenseNet121 models and used three different strategies of freezing layers techniques of fine-tuning, to get various pre-trained weights to improve accuracy. Finally, transfer learning using MobileNet with the half-layer frozen showed the best results among the nine models, and 90% accuracy was obtained on the test data set.

• 한국토양비료학회지
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• 제24권1호
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• pp.35-40
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• 1991

유기물(볏짚)의 병용과 부숙이 탄산석회에 의한 갯흙의 제염에주는 영향을 밝히기 위하여 컬럼시험을 한 결과는 아래와 같다. 1. 볏짚과 탄산석회를 미리 시용하여 부숙시켰을 경우는 투수속도가 빨라졌으나 석고처리에는 미치지 못했으며, 제염(Na) 효과는 $CaCO_3$단용 또는 $CaCO_3$+볏짚분(미부숙)을 따르지 못하였다. 부식된 볏짚에 흡착되어 제염이 늦어진 것으로 판단되었다. 2. Na와 Mg를 치환 침출하기에 충분하지 못한(1/3) $CaCO_4$를 시용했을 경우와 $CaCO_3$만을 시용했을 경우는 표층에 Mg를 집적시키고 그 직하층에서 Mg 를 용탈하여 아랫층에 집적시켰으니, 볏짚분이 병용된 처리에서는 이런 용탈현상없이 물리세탈만이 일어났다. 3. $Na^+$의 제염은 세탈용액의 염농도와 비례하는 것으로 보여서, 상충토가 세탈되여 하충토양용액의 염농도가 높아졌을 경우는 염농도가 높아진 층에서 $Na^+$의 치환제거가 많다. 이 말은 염류의 공급원이 세탈되면 표층토의 Na제염이 부진하다는 것을 의미한다.

• 보건교육건강증진학회지
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• 제20권3호
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• pp.61-76
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• 2003

Substance abuse among teenagers has been spreading widely and become a serious social problem. However, teachers hardly realize its importance. Recently, substance abuse prevention programs show a tendency towards one time education. This study aims to research the effect of substance abuse prevention on high school students using the Life Skills Training Program. Two classes(36 students in the experimental group, 35 in the control group) at W High School in Daejeon were randomly sampled for this study from May to June 2002. Substance knowledge and attitude, problem solving, and assertiveness were examined as Pre and Post-Tests. The data was analyzed using frequencies, t-test, means, and covariance(ANCOVA). The results of this study were as follows； 1. Compared with the control group, substance knowledge in the experimental group was significantly improved(F＝176.317, P＝.000). And compared with the control group, substance attitudes in the experimental group were improved significantly.(F＝207.682, P＝.000). 2. Compared with the control group, cognitions to problem solving in the experimental group was significantly improved(F＝100.937, P＝.000). 3. Compared with the control group, assertiveness behaviors in the experimental group were increased significantly(F＝207.255, P＝.000). The study showed that Substance Abuse Prevention of High School Students was effective in improving substance knowledge and attitude, cognition to problem solving, and assertiveness behavior. Some suggestions based on the result are as follows； 1. Substance abuse preventive programs must be practiced properly and systematically with high school students in their regular classes. 2. Various preventive education programs must be developed for substance abuse where high school students can join in a community center, such as Community Welfare Center, Alcoholic Counseling Center, and Mental Health Center. 3. For the furthering of substance abuse preventive education, there must be continued research about not only students with problems of substance misuse and abuse, but also students without them. 4. There must be early determination of students with problems of substance misuse to be able provide school social workers with the opportunity for intervention.

• 한국학교보건학회지
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• 제19권2호
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• pp.117-125
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• 2006

Purpose : The purpose of this study is to test the effect of the web-b ased alcohol preventive education for ndicate the model of alcohol preventive education for students spreading al over the family and the comunity.Methods : This study was performed on the 1 public and 1 private eleme ntary school students who are the six grade in Seongdong-gu, Seoul. The number of experimental gr oup was 117 and control group's number was 131, totaled 248. eeks. The pre- and the post-test for web-based alcohol preventive education were tested about knowle dge and attitude toward drinking by questionnaire. The data analysis was done using SPS/Win 12.0 p rogram.Results：The results of this study are as follows;1. Compared with control group, experimental group which was educated the web-based alcohol preventive icant diference in the knowledge toward drinking.2. Compared with control group, also the experimental group w as improved with significant diference in attitude toward drinking after the education.3. In control group, female students' knowledge of drinking w as more increased than male students. And the he group which experienced drinking.Conclusions : The web-based alcohol preventi ve education is worth as a int ervention to get positive influence for the health education. Especially in female studen ts who didn't met with drinking, early education for alcohol prevention is very important. Therefore i t will be helpful that coperate with district ofice ithin the comunity for becoming established the controled drinking pattern.

• 디지털융복합연구
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• 제11권3호
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• pp.95-100
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• 2013

최근 케이팝(K-POP)이 전 세계에서 인기를 얻고 있다. 케이팝 음악은 반복되는 가사와 멜로디를 사용하여 만든 후크송(Hook Song)을 기반으로 하고 있다. 음악의 특징은 단순하고 경쾌한 리듬과 비트감, 따라 부르기 쉬운 멜로디, 흥미로운 노랫말 그리고 멋진 댄스 실력으로 선보이는 군무라고 할 수 있다. 케이팝은 유튜브, 페이스북, 트위터와 같은 다양한 소셜 네트워킹 서비스를 통해 다양한 국가에 확산되고 있다. 케이팝은 디지털 음악 시장이 지배하면서 강한 인상을 줄 수 있는 음악을 만들다보니 음악의 길이가 점점 짧아지는 경향을 보였으며, 60초의 미리 듣기 기능으로 인해 후렴구를 앞에서 사용하는 노래들이 증가하였다. 그러나 음악의 구성과 가사의 의미가 모호해지는 경우가 발생하였고 문제가 제기되었다. 본 논문에서는 케이팝 음악의 특징을 살펴보고, 케이팝에서 사용하고 있는 후크송 음악제작의 세 가지 방향을 제시한다. 마지막으로 싸이의 강남스타일 음악을 본 논문에서 제시한 세 가지 기준으로 비교하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1532-1548
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• 2008

The tunnel type spillways is under construction to increasing water reservoir capacity in Dae-am dam. The tunnel outlet was planned to be made after installing slope stabilization system on natural slope there. Generally, the tunnel outlet is made perpendicularly to the slope, but in this case, it had to be made obliquely to the slope for not interrupting flow of river. Because of excavation in condition of natural slope caused to deflecting earth pressure, the outlet couldn't be made. So, artificial ground made with concrete that it was constructed in the outside of tunnel for producing the arching effect which enables to make a outlet. We were planned tunnel excavation was carried out after artificial ground made. Artificial ground made by poor mix concrete of which it was planned that the thickness was at least 3.0m height from outside of tunnel lining and 30cm of height per pouring. Spreading and compaction was planned utilized weight of 15 ton roller machine. In order to access of working truck, slope of artificial ground was designed 1:1.0 and applied 2% slope in upper pert of it for easily drainage of water. In addition to, upper pert of artificial ground was covered with soil, because of impaction of rock fall from upper slope was made minimum. The tunnel excavation of the artificial ground was designed application with special blasting method that it was Super Wedge and control blasting utilized with pre-percussion hole.