• 한국도로학회논문집
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• 제6권4호
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• pp.101-108
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• 2004

노후콘크리트 포장 수명을 연장하기 위한 방안으로 아스팔트 덧씌우기가 일반적이나 반사균열을 억제하기 어렵다는 단점이 있다. 반사균열을 억제하기 위하여 줄눈부 보수, 응력 완화층 설치가 적용되는 경우가 있으나 반사균열의 진전 속도를 늦추는 제한적인 성공을 보여 왔다. 콘크리트포장 슬래브를 원위치에서 파쇄하여 기층재료로 활용하고 그 위에 덧씌우기 포장을 건설하는 러블라이제이션 공법은 기존 덧씌우기 보강 공법을 갖고 있는 반사균열 문제를 완벽하게 해결할 수 있는 장점을 가지고 있다. 러벌라이제이션 공법을 적용할 경우 파쇄된 노후 콘크리트 포장층 상부층은 40mm-70mm로 파쇄되나 하부층은 100mm이상 되는 경우가 일반적이다. 국내 고속도로와 같이 상대적으로 두꺼운 콘크리트 포장 슬래브를 사용하는 경우 전체 포장 두께를 파쇄하기에 어려움이 있다. 따라서 파쇄된 노후 콘크리트 포장층이 반사균열을 유발시키지 않는 도로기층으로써의 역활을 확보하기 위한 적정 파쇄 깊이를 파악하기 위하여 본 연구에서는 미국 DOT에서 제안한 일반적인 파쇄규격(40mm-70mm)을 기준으로 파쇄 깊이를 0cm, 10cm, 20cm,로 변화시켜가며 반사균열 실내 모사 실험을 수행하여 반사균열 저항 특성을 분석하고 적정파쇄 깊이를 검토하였다.

• 한국학교ㆍ지역보건교육학회지
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• 제13권2호
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• pp.59-76
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• 2012

Objectives: This study Development of a healthy college life, and effective for smoking cessation programs for education is to utilize as a basis for. Methods: The study employs frequency analysis, cross-analysis and correlation analysis through SPSS Win 17.0 on 296 (84.6% of total participants) from the entire participants of 350. The significance test is delivered with ${\chi}^2$-test. Results: 1) The participants consist of 47.7% (147) males and 52.3% (161) females. 78.2% (241) has experience of smoking cessation program at high school. 61.7% (190) has parents who are smoking. 40.9% (126) answers that they are currently smoking while 59.1% (182) answers that they are not. 2) When asked about their perception on quitting smoking, 81.2% (250) says that non-smokers are distressed by others' smoking. 74.0% (228) has unpleasant experience with cigarette smoke. 3) The analysis of the relation between smoking cessation program at high school and smoking shows that 63.8% of the ones who have experience of the program are non-smokers while 68.7% of those with no experience of the program are smokers. 4) Among those who have tried to quit smoking, 73.9% have experience of smoking cessation program at high school. 31.8% of these participants also reveal their interest in the cessation program. 5) In the analysis of the correlation between smoking habits, the experience of smoking cessation program at high school is closely related to non-smoking while current smoking habit is highly related to the strong interest in participation of cessation program. Also, the more interest they have in participating, the stronger needs they feel for smoking prevention program at college. Conclusion: Therefore, the last phase of education-related courses at the University of educated and credits granted through open non-smoking pledge, non-smoking club, non-smoking camps, training programs, such as smoking in non-smoking education and programs for students interested in openness and participation must be done will.

• 한국환경과학회지
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• 제25권11호
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• pp.1467-1474
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• 2016

In response to the water shortage problem, continued attempts are being made to secure consistent and reliable water sources. Among various solutions to this problem, wastewater effluent is an easy way to secure the necessary supply, since its annual output is consistent. Furthermore, wastewater effluent has the advantage of being able to serve various purposes, such as cleaning, sprinkling, landscaping, river management, irrigation, and industrial applications. Therefore, this study presents the possible use of reclaimed industrial wastewater treated with Birm filters and a UF membrane, along with an analysis on membrane fouling. The preprocessing stage, part of the reclamation process, used Birm filters to minimize membrane fouling. Since this study did not consider heavy metal levels in the treated water, the analyses did not include the criterion for irrigation water quality. However, the wastewater reclaimed by using Birm filters and a UF membrane met every other requirement for reclaimed water quality standards. This indicated that the treated water could be used for cleaning, channel flow for maintenance, recreational purposes, and industrial applications. The analysis on the fouling of the Birm filter and UF membrane required the study of the composition and recovery rate of the membrane. According to SEM and EDX analyses of the UF membrane, carbon and oxygen ion composition amounted to approximately 57%, whereas inorganic matter was not detected. Furthermore, the difference in the recovery rates of the distressed membrane between acidic and alkaline cleaning was more than ~78%, which indicated that organic rather than inorganic matter contributed to membrane fouling.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권1호
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• pp.57-61
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• 2010

In the presence of acute pericoronitis of mandilbular third molar, antibiotic therapy and early incision and drainage are the method of choice, followed by definitive surgical extraction of the tooth as soon as it becomes subacute. If excision of the overlying tissues is decided on, it should be done adequately. All overlying tissues must be throughly excised, and the crown portion of the unerupted tooth should be completely exposed. After excision has been completed, the wound should be managed with a surgical dressing. This should be allowed to remain approximately 7 days. And then, surgical extraction of the impacted mandibular third molar can be done usually. In this operation, there are many complications, such as, postoperative bleeding, infection, trismus, dysphasia and paresthesia. The surgeon are discredited and medicolegal problem may be occurred in the presence of many distressed complications. Therefore, the relatively nonsurgical treatment is the method of choice. So, authors selected the conservative treatment methods of incision and drainage, primary endodontic drainage, operculectomy without surgical extraction of the mandibular third molars. The results were more favorable without the postoperative complication in Wonju old offender prison.

• 한국도로학회논문집
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• 제14권5호
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• pp.31-45
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• 2012

PURPOSES: In Korea, rapid maintenance of distressed concrete pavement is required to prevent traffic jam of the highway. Asphalt concrete overlay has been used as a general maintenance method of construction for aged concrete pavement. AC overlay on existing concrete pavements experience various early distresses such as reflection crack, pothole and rutting, due to different physical characteristics between asphalt overlay and existing concrete pavement. Bonded concrete overlay(BCO) is a good alternative since it has advantages that can reduce various distresses during the service life since overlay material has similar properties with existing concrete pavements. Recently, BCO which uses the ultra rapid harding cement has been applied for maintenance of highway. BCO has advantage of structural performance since it does monolithic behave with existing pavement. Therefore, it is important to have a suitable bond strength criteria for securing performance of BCO. Bond strength criteria should be larger than normal tensile stress and horizontal shear stress occurred by traffic and environmental loading at bond interface. Normal tensile stress and horizontal shear stress need to estimated for the establishment of practical bond strength criteria. METHODS: This study aimed to estimate the bond stresses at the interface of BCO using the three dimensional finite element analysis. RESULTS: As a result of this study, major failure mode and maximum bond stress are evaluated through the analysis of normal tensile stress and horizontal shear stress for various traffic and environmental load conditions. CONCLUSIONS: It was known that normal tensile stresses are dominated by environmental loading, and, horizontal shear stresses are dominated by traffic loading. In addition, bond failure occurred by both of normal tensile stresses and horizontal shear stresses; however, normal tensile stresses are predominated over horizontal shear stresses.

• 한국산학기술학회논문지
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• 제18권12호
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• pp.80-87
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• 2017

과거 미국은 낙후된 도심 지역을 되살리기 위한 도시재생의 도구로 대규모 도시개발사업을 진행하여왔고, 이를 통해 현재의 공공주도적 사업형태를 개발하였다. 특히 2008년의 경제위기이후 세계적으로 대규모 도시개발사업이 정체되거나 중단되었으나, 본 연구의 분석대상 사업인 미국 뉴욕시의 허드슨 야드 개발은 그 구조적 특성 및 합리적 협상과정을 통해 경제위기로 인한 어려움을 극복하고 현재 순조롭게 진행되고 있다. 그러나 이와 유사하게 경제상황에 좌우되는 국내 대부분의 개발은 민간주도로 이루어지고 있는 개발현실에서 노출되는 문제점을 반복하고 있으며, 그 대표적인 실패 사례가 용산국제 업무지구 개발이다. 이에 본 연구는 과거 용산국제업무지구 개발의 실패에서 노출된 주요 미비점을 중심으로 허드슨 야드 개발에서 나타나는 사업의 구조적 특성 및 협상과정상의 특성을 분석함으로, 위기를 극복할 수 있게 한 개발 사업의 구조적 유연성과 합리적 협상내용으로 부터 국내 참조가능한 시사점을 도출하고자 한다. 이를 통해 국내 대규모 도시개발의 계획시, 본 연구에서 도출된 다양하고 상이한 구조적 특징과 위기대처 방안의 시사점을 통하여 보다 합리적이고 위기상황에 유연한 개발로 계획함에 일조하고자 한다.

• Pediatric Infection and Vaccine
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• 제8권1호
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• pp.107-113
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• 2001

저자들은 발열과 복통을 주소로 입원한 환아에서 연속적으로 요통 및 둔부 동통을 보여 실시한 자기 공명촬영상 요추 부위의 척추 경막외 농양을 진단하고 수술하였기에 문헌 고찰과 함께 보고하는 바이다.

• 한국항공우주학회지
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• 제48권4호
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• pp.295-301
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• 2020

심우주를 항행하고 있는 우주선에 이상이 발생했을 때 지상-우주선 간 비상 통신 채널은 우주선의 상태를 파악하고 문제를 수정하기 위해 필수적이다. 복구 명령은 보통 길고 복잡한 명령들로 구성되어 있기 때문에 번들 라우팅에 기반한 지연 허용 네트워크 기술의 도움이 필요하다. 우주 패킷 프로토콜을 근간으로 구축된 심우주 우주선 통신 시스템은 지연 허용 네트워크에 의한 통신 서비스를 이용할 수 없기 때문에 우주 데이터 시스템 자문 위원회 커뮤니티에서는 first-hop last-hop 개념의 구체화 및 실용화를 시작하고 있다. 본 논문에서는 달 주변 환경에서 first-hop last-hop의 개념을 적용하였으며, 이는 향후 지연 허용 네트워크 및 우주 패킷 프로토콜 간 중계 개념을 구체화하고 실용화하는데 기여할 것으로 예상한다.

• 대한지리학회지
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• 제37권3호
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• pp.203-221
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• 2002

본 연구의 목적은 사이버스페이스의 공간성을 분석하고 사이버스페이스의 공간적 차별화 현상을 지도화 하려는 것이다. 사이버스페이스의 공간성을 분석하게 위해 선정한 도메인수, 인터넷 기간망, 인터넷 이용자 수의 세 지표간에는 서로 높은 상관성을 띄고 있었다. 사이버스페이스는 공간적으로 매우 차별화 된 분포패턴을 보이고 있으며, 특히 서울의 수위성이 두드러지게 나타나고 있다. 인터넷은 특정 지역들을 선택적으로 연결시키는 동시에 나머지 지역들은 통과하여 접근성을 떨어뜨리면서, 지역간 정보격차를 유발시키고 있었다. 본 연구결과를 통해 디지털 사회가 진전되면서 대두되고 있는 '거리의 소멸 '또는 '지리학의 종말'이라는 주장과는 다르게 사이버스페이스에서도 지리공간은 여전히 중요한 역할을 담당하고 있음을 알 수 있다.

• Computers and Concrete
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• 제24권6호
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• pp.541-553
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• 2019

Alkali-silica reaction (ASR) in concrete can induce degradation in its mechanical properties, leading to compromised serviceability and even loss in load capacity of concrete structures. Compared to other properties, ASR often affects the modulus of elasticity more significantly. Several empirical models have thus been established to estimate elastic modulus reduction based on the ASR expansion only for condition assessment and capacity evaluation of the distressed structures. However, it has been observed from experimental studies in the literature that for any given level of ASR expansion, there are significant variations on the measured modulus of elasticity. In fact, many other factors, such as cement content, reactive aggregate type, exposure condition, additional alkali and concrete strength, have been commonly known in contribution to changes of concrete elastic modulus due to ASR. In this study, an artificial intelligent model using artificial neural network (ANN) is proposed for the first time to provide an innovative approach for evaluation of the elastic modulus of ASR-affected concrete, which is able to take into account contribution of several influence factors. By intelligently fusing multiple information, the proposed ANN model can provide an accurate estimation of the modulus of elasticity, which shows a significant improvement from empirical based models used in current practice. The results also indicate that expansion due to ASR is not the only factor contributing to the stiffness change, and various factors have to be included during the evaluation.