• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.5
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• pp.543-553
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• 2023

This study was conducted to propose a simple method to evaluate the load-carrying capacity of RC slab bridges, which have been most frequently constructed in Korea. A number of RC slab bridges have been considerably deteriorated associate with the long service year. However, since these bridges are not included in the 1st and 2nd class infrastructures due to their short span length, they have been relatively neglected compared to other bridge types in terms of safety management. In the previous theoretical study, a process (draft) was proposed for evaluating the damage of RC slab bridges using the relationship between the displacement response ratio and the stiffness reduction rate derived by the measured displacement and natural frequency. In this paper, to verify the validity of the proposed damage evaluation process (draft), the results to the actual bridges were compared with the safety grade and the Matsui's deterioration index. In addition, to enhance the practical applicability of the existing process (draft), an improved method approximately evaluating the load-carrying capacity using only the measured natural frequency was presented. If an error of 10% of the load-carrying capacity is allowed, it is judged that the proposed damage evaluation process can be appropriately used not only for evaluating the safety of RC slab bridges, but also for determining priorities for their maintenance.

• Journal of Korean Society of Transportation
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• v.17 no.3
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• pp.31-46
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• 1999

In the middle of motorization, the traffic problems become serious social problems in Korea. The walking environment is not only a topic which restores the community spirit of a city or society but also a lever which renovates the future space of the city environment-friendly. Thus, the Purpose of this study is to suggest the new criteria of walkway level of service adopting the concepts of safety. convenience, comfort, environment, security, and continuity in addition to present pedestrian flow rate, and to provide basic data for walkway plan in Korea. In order to analyze the adequacy of the present walkway level of service criteria, the walkways of which service levels were A, C, E according to USHCM were selected as study walkways, and an interview surrey was conducted to compare the three service levels with those that pedestrians evaluate actually. Also, another interview survey was conducted to analyze the service conditions and satisfaction level at the walkways of high service levels(A and B). For the establishment of more reasonable walkway level of service criteria. the survey of pedestrian\`s consciousness for walkway service was conducted. Based on the survey results, the new criteria for the evaluation of walkway service were selected and the six levels of service for each criterion was analyzed: so the comprehensive criteria of walkway level of service were suggested.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.708-708
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• 2012

국내에는 농업용수 공급을 목적으로 축조된 저수지가 2008년 통계연보기준에 따르면 17,649개소가 있으며, 이 중 3,326개소는 한국농어촌공사에서 관리하고, 나머지 14,323개소는 지자체에서 관리하고 있는 것으로 파악되고 있다. 유효저수량으로 보면 공사관리가 24억4천7백만$m^3$, 지자체관리가 3억2천3백만$m^3$으로 각각 88.3%와 11.7%를 관리하고 있는 셈이다. 경상북도와 같은 산이 많은 지방은 지자체관리가 전체 대비 34.5%인 4,943개소이지만 유효저수량으로 보면 전체 27억7천만$m^3$ 중 8천4백만$m^3$ 3%수준, 지자체관리 대비 26.1%수준의 저수지가 있는 셈이다. 저수지의 축조년도를 지자체관리 저수지의 58%인 8,352개소의 저수지가 1948년 이전에 축조된 일명 '밀가루 댐'으로 불리는 저수지가 대부분이다. 축조된 지 60년 이상 된 시설물은 공용내구연한이 경과한 시설로서 노후손상부위를 복구해야 함은 물론 이상기후에 따른 강우사상의 변화로 설계빈도를 달리하여 재해대비 보강이 필요한 시설이다. 2002년 8월 제15호 태풍 루사나 2003년 9월 제14호 태풍 매미 등에 의해 저수지의 피해가 발생하는 빈도가 점차 늘어가고 있다. 따라서 지자체관리 저수지의 안전관리방안의 마련을 통한 재해대비보강 및 기능강화가 시급한 실정이다. 따라서 본 연구에서는 시 군 관리 농업용 저수지에 대하여 저수지 준공년도별 설계빈도에 대한 등급 구분 및 홍수배제 능력 등 수리 수문학적 안정성 기준을 설정하여 검토한 결과 1960년대 이전에 축조된 저수지의 경우 50%이상의 저수지에서 안정성에 문제가 생긴 것으로 파악되며, 1970년대에는 38%, 1980년대에는 34%, 1990년대에는 24%로 검토되었다. 이와 같이 안정성에 문제가 있는 저수지는 주기적인 모니터링과 보강이 필요하다고 사료된다.

• Journal of Society of Preventive Korean Medicine
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• v.17 no.3
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• pp.19-30
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• 2013

This study was aimed to develop a new formula for herbal medicine-safety classification in terms of evidence-based medicine. Recently, human equivalent dose(HED)-based therapeutic index was developed for herbal medicine-safety classification by transforming $LD_{50}$ to HED. However, the use of the $ED_{50}$ and $LD_{50}$ to derive the therapeutic index may be misleading as to safety, depending on the slope of the dose-response curves for therapeutic and lethal effects. To overcome this deficiency, HED-based MOS(Margin of Safety)was developed and suggested in this study. The HED-based MOS developed by using $LD_1$, changing to ALD(approximate lethal dose), and $ED_{99}$. The HED-based MOS seems to be more useful and safer than HED-based therapeutic index since its values for several herbal medicines are basically two times less than the values from HED-based therapeutic index. Thus, HED-based MOS can be a good example of Evidence-based approach for herbal medicine-safety classification.

• Journal of the Korea Society of Computer and Information
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• v.9 no.4 s.32
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• pp.173-178
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• 2004

A network of Asynchronous Transfer Mode (ATM) will be required to carry the traffics(CVR, VBR, UBR. ABR) generated by a wide range of services ATM services the Quality-of-Service (QoS) management of traffice sources and bandwidth. Besides efficiency and throughput, the security services are achieved in the traffic sent in ATM network. In this paper, the scheduler evaluate and the packets sent in ATM security group. The scheduler transmits the safty packet, drop the unsafty packet and evaluate mark packet as the requirement of the delay. In this paper, we propose the scheduling algorithm of mark packet which evaluates the packet. The suggested model performance of the firewall switch is estimate simulation in terms of the delay by computer.

• International Journal of Highway Engineering
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• v.9 no.3
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• pp.91-100
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• 2007

The most important thing for driver's safety on the road is equipment of crash cushion as a vehicle protection safety facility. But development of crash cushion is defective because there's no rational and reality way of design. And also without an alternative plan, it rely on crash test hereby it suffers a great economic loss and wastes time. This study that uses data of cash test proves the suitability of single degree of freedom which considers the safety of passengers about three-dimensional complicated Crash Analysis. As the study analyzes the conduct of crash cushion, it want to develop the effective method of design on Single Degree of Freedom Crash Cushion. And it presents the way of crash cushion design through making a crash analysis model with single degree of freedom. To verify the validness of the crash cushion plan, with single degree of freedom plan, we make the level CC2 crash cushion and execute the crash test. A performance test brings satisfied result and a plan of single degree of freedom crash cushion is proven as an one of the way to be a good system which can design crash cushion.

• Journal of the Korean Geotechnical Society
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• v.35 no.4
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• pp.5-14
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• 2019

The typical four conditions related to internal erosion were set from the results of the regular dam safety inspection for 17,500 dams, and a questionnaire survey was conducted for dam safety experts to quantify these four typical current dam conditions with scores between 0 and 10, respectively. In addition, we proposed 'possible score range' for each condition to minimize the decision limits for dam managers to quantify dam conditions while helping to quantify various dam conditions except 4 representative conditions. A case study based on 'quantified score' and 'possible score range' for each condition showed that this method consistently reflects the dangerousness of the dam and provides a reasonable probability of failure. This helps to overcome limitations of dam rating determination by weighted average, and it will help to evaluate dangerous dams as dangerous dams.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.1
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• pp.17-24
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• 2016

At present, summer cloudburst and local torrential rainfalls have increased in this country, because of climatic change. Therefore, studies on prevention of soil loss have been actively proceeded, and Korea Forest Service has offered landslide hazard map. Landslide hazard map divides risks into 5 classes, by giving weight with 9 kinds of elements. In August 25 2014, soil loss occurred in the whole Oryun Tunnel, Geumjeong-gu, Busan, because of local torrential heavy rain. As a result of comparing with landslide hazard map, the area where soil loss occurred in reality is a safety zone on hazard map. Rainfall, soil map, geological map, forest type map, gradient, drainage network, watershed, basin shape, and efflux of the whole Oryun Tunnel where soil loss occurred were analyzed. As a result of an analysis, it is judged that soil, forest type, much efflux and peak discharge, degree of water network and basin shape of a place where landslide occurred are causes of soil loss. It is judged that efflux, peak discharge, and basin shape by the localized rainfall that is not considered in landslide hazard map of them are the biggest causes of soil loss. It is judged that efflux, peak discharge, degree of water network and basin shape by the rainfall are important through a study on a causual analysis on soil loss in the whole Oryun Tunnel where is one of occurrence area where a lot of propertywere lost by the record local torrential rainfalls. A localized torrential downpour should be prepared by considering these elements on judgement of a landslide hazard area.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.1038-1041
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• 2007

어플리케이션 또는 네트워크 레벨의 외곽 방어에 의한 보안 기능의 한계로 인하여 운영체제 내부 보안에 대한 필요성이 증대되고 있다. 그에 따라 시스템상에서의 또는 시스템에 의한 행동을 제어하기 위한 차세대 보안솔루션으로 보안 운영체제가 부각되고 있다. 이에 본 논문에서는 안전한 운영체제 구축을 위한 보안 요구 사항의 기준이 될 수 있는 다중등급 보안에 의한 윈도우 서버 보안 강화 기술을 소개하고 본 논문에서 설계하고 구현한 보안 커널의 기능을 중심으로 기술한다. 또한 기존의 전형적인 보안레이블을 확장하여 추가적으로 제어할 수 있도록 수정된 보안 모델을 제시한다.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2001.10a
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• pp.83-90
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• 2001

절개면의 안정도 평가와 더불어 낙석으로 인한 안전사고를 방지하기 위한 적절한 투자와 대책 마련은 도로의 신설과 유지 차원에서 실시되어야 한다. 절개면의 안정도를 정량적으로 파악하여 위험등급을 분류하는 것은 현실적으로 많은 어려움이 뒤따른다. 이는 절개면 안정도 평가시 조사인자의 선정에서 전문기술자의 주관적인 판단 차이로 인하여 발생되는 경우가 적지 않다. 본 연구에서는 절개면의 안정도 평가법 개발을 위하여 절개면의 조사인자를 설정하고 설정된 인자를 5점 척도법을 이용한 퍼지 이론으로 안정도를 평가하는 기법을 개발하였다. 또한, 정량화 값만으로 평가된 절개면 안정도에 따른 대책공법의 설정은 현장성과 적용성에서 문제가 발생할 가능성이 많다. 본 연구에서는 현장의 여건을 최대한으로 고려하여 도로 관리자뿐만 아니라 지반 전문가가 대책공법을 선정할 수 있는 기법을 개발하였다. 개발된 평가법과 시스템은 효율적인 정보관리화가 이루어지도록 전산시스템화 되어 있으며 도로절개면 유지관리시스템에 병합하여 운영하도록 되어 있다.