• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.213-216
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• 2008

CFT(Concrete Filled Steel Tubular) Structure filled steel tubes with a concrete improves the stiffness and strength of the structure by the confinement effect of fillers. CFTA(Concrete Filled and Tied Steel Tubular Arch) girder is a new type structure that applies an arch structure and a pre-stressed structure to CFT Structure to maximize the efficiency of structure and economic. One of conspicuous characteristics of CFTA girder is exposed tendon and that is pointed out as the weak point of this girder. Therefore in this study, safety estimation for the exposed tendon is performed and dynamic analysis is also performed by the collision numerical simulation. For analyzing this model, ABAQUS 6.5-1 was used.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.1 s.24
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• pp.53-59
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• 2006

The prevention of marine accidents has been a major topic in marine society and various policies and countermeasures have been developed, applied to the industries. The coastal VTS and navigational aids are considered a, one of the effective methods to promote marine safety but they need relatively huge amount of budgets to build. Thus prior to establishing these coastal VTS and navigational aids, it should be evaluated the navigational risk level in the coastal waterways from the Environmental Stress. So far as human beings are concerned, there are many types of fuzziness in the evaluation of navigational safety level. In order to reflect these fuzziness on this evaluation, this paper introduces the fuzzy integral suggested by Choquet to represent the fuzziness in the evaluation process. This paper aims to develop the method for this evaluation from the viewpoint of mariner's operational stress using the fuzzy logic and Choquet integral. In this paper, Korean coastal area is divided into 8 sectors and evaluated the priority for the needs of coastal VTS and navigational aids.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.1
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• pp.61-69
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• 2024

An ultra-high strength prestressed prismatic beam of 100 MPa in compressive strength was developed by increasing the water-tightness of concrete by utilizing centrifugal molding processes without adding expensive admixtures. The centrifugal prismatic PSC beam developed as the superstructure of the avalanche tunnel was constructed on a rahmen bridge in a small local river. In this study, the centrifugal prismatic beam was compared and analyzed based on the results of measurements made through static load tests and the results of numerical analysis of the target structure. The common load-carrying capacity and safety of the rahmen bridge were evaluated. The static·dynamic load tests and finite element analysis results of this bridge were similar, and it was confirmed that the behavior of the centrifugal prismatic beam was well simulated. All centrifugally formed square beams that make up the composite rahmen bridge were evaluated to secure sufficient load carrying capacity under the design live load, and structural reliability was proven by ensuring safety.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.696-699
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• 2010

원자력 발전소의 격납건물은 인위적 또는 자연적 재해로부터 방사능의 외부누출을 방지함으로써 공중을 보호하는 역할을 하기 때문에 지속적인 건전성 확인을 통해 안전을 확보하는 것이 필수적이다. 격납건물의 구조적 건전성 확인은 통상 주기적으로 콘크리트에 대한 비파괴강도, 균열 및 중성화, 프리스트레스 텐던의 유효 긴장력 등의 측정을 통해 수행되고 있으나, 이러한 검사는 국부적인 건전도 정보만을 제공할 뿐 격납건물과 같은 대형 구조물 전체의 건전성에 대한 신뢰성 있는 평가 결과를 얻는데 많은 시간과 경비가 소요된다는 단점이 있다. 이러한 단점은 최근 구조물 전체의 상태를 평가하는 방법으로 주목받고 있는 구조건전성모니터링(Structural Health Monitoring, SHM)기법을 이용하여 극복할 수 있다. 본 논문에서는 실제 운전 중인 격납건물을 대상으로 상시진동 측정을 수행하였으며, SHM 기법의 기초자료로 활용될 수 있는 동적특성, 즉 격납건물의 고유진동수와 모드형상을 제시하였다.

• Magazine of the Korea Concrete Institute
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• v.9 no.4
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• pp.155-165
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• 1997

Since the biggest time-dependent prestress loss of reactor containment structure is due to creep of concrete. the creep is one of important structural factors to be considered for the safety maintenance in the containment structure during design. construction and main enance. This paper is about the creep charactoristies of concrete for the reactor containment structure. In this paper, creep test was performed to show the creep characteristics of reactor containment concrete structure made of the type-V cement. Then, in order to evaluate the applicability of creep prediction equations of recently revised Korean Concrete Standard Specification(KSCE-96) and Japanes Concrete Standard Specification. ACI-209. CEB/FIP-90. and HANSEN, creep test results were compared with prediction results obtained from he equations. From the comparisons, it was shown that the equation of th KSCE-96 predicts creep for younger concrete than 1 year, better than the other equations and that all of the equations predicts creep, for older concrete than 1 year, smaller than test. From regression analysis. a creep prediction equation which effectively predicts creep of concrete due to loading after 1year was proposed.

• Journal of Food Hygiene and Safety
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• v.17 no.2
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• pp.106-116
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• 2002

The 70% ethanol extract of Alpinia officinarum and its major flavonoid, galangin showed strong antioxidative effect on the lipid peroxidation of ethyl linolate with Fenton's reagent and free radical scavenging effect to DPPH radical generation. However, they did not reveal any pro-oxidant effect on bleomycin-Fe(III) dependent DNA degradation. They also showed the protective effect against $H_2O$$_2$, KO$_2$ or UV-induced cytotoxicity in mammalian cells. They also showed the suppressive effect of DNA damage induced by $H_2O$$_2$ or KO$_2$ with dose-dependent manner in single cell gel electrophoresis(SCGE) assay. On the other hand, they have an anticlastogenic effect against adriamycin-induced micronucleated reticulocyte in peripheral blood of mice. These results suggest that the mechanism of inhibition by 70% ethanol extract of Alpinia officinarum and galangin against reactive oxygen species (ROS)-induced genotoxicity or cytotoxicity is due, at least partly, to their antioxidative and free radical scavenging properties without pro-oxidant effect. All these results indicate that 70% ethanol extract of Alpinia officinarum and galangin may be useful for protection against ROS-induced cytotoxicity and DNA damage.

• The Journal of Sustainable Design and Educational Environment Research
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• v.9 no.1
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• pp.32-40
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• 2010

The purpose of this study was to evaluate structural safety and economic efficiency of prestressed hybrid beam using T-shape steel member which was developed to build large span educational facilities. Hybrid beam specimens were manufactured with 16.0m long and load was uniformly distributed by 12.0kN steel hexahedrons. In this study, honeycomb beam design process was introduced to T-shape section steel beam design. Vibration condition of specimens were analyzed by Korea Building Code 2009 and AISC Steel Design Guide Series-11. As a result, the prestressed hybrid beam with T-shape steel member has about 10.4% of cost reduction effect.

• Journal of the Korea Safety Management & Science
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• v.15 no.4
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• pp.365-372
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• 2013

This paper reviewed the relationship between perceived organizational justice(distributive justice, procedural justice, interactional justice) and job stress, and the moderating effect of trust(organizational trust and superior trust). Based on the responses from 176 employees, the results of multiple regression analysis appeared as follow; 1) Distributive justice and interactional justice effect negatively on job stress, but procedural justice does not effect on job stress. 2) While organizational trust and superior trust are stronger, interactional justice effect less negatively on job stress. When interactional justice is higher, job stress is lower in high trust level than in low trust level.

• Journal of the Korea Safety Management & Science
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• v.16 no.1
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• pp.45-52
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• 2014

The purpose of this study is to make sure what the stress causes of women's EMTs within the firehouse are, and is to suggest ideas (plans) that are possible to resolve this problem. The reasons are because of difficulties such as not only the overwork at one's tasks, the uncomfortable working environment and circumstances, women's pregnancy, but also shift work or the shift system. It's own ideas about the way to resolve these difficulties are as follows: a separate operation of first-aid department, environmental improvement within a fire house (fire station) via remodeling, activation of substitute man power, alterating women's EMT services into daywork system, mutual encouragement and solicitude among co-workers, reinforcement of the number of the working force to be mobilized, and adoption about the rest year system in employment.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.252-254
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• 2005

음용수 처리공법으로 BPA를 분해하는 TiO$_{2}$광분해과정의 생물학적 안전성을 zebrafish(Danio Rerio, wild type)의 발생과 성장기를 통해 알아보았다. TiO$_{2}$ 광분해는 BPA를 제거하는 효과가 있었으며, TiO$_{2}$ 광분해 환경에서 부화된 자어의 경우 배발생 초기와 성장기, 성체시기에 형태적인 이상을 보이지 않았다. 그러나 항산화효소인 catalase 의 활성도는 발생초기와 부화 1, 5주에는 대조군에 비해 별다른 차이가 나타나지 않았으나 28주의 성체기에는 활성도가 절반 이하로 떨어지는 자체방어계의 이상을 보였다.