• 한국신뢰성학회지:신뢰성응용연구
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• 제15권4호
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• pp.256-261
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• 2015

The aim of this paper is to present some issues to be discussed in relation to failure rate of a system that has identical parallel units. It is assumed that Time-to-Failure of each unit has the same exponential distribution and all units are repairable with a periodic maintenance of time interval T. Effective failure rate is widely recommended for nonrepairable systems as the reciprocal of MTTF but it should not be applied for repairable systems if delayed maintenance is used. And equivalent failure rate of an imaginary system is taken into consideration, the reliability value of which is the same as that of the redundant system when time interval T is given. With a numerical example, failure rate, effective failure rate, and equivalent failure rate of the redundant system are analyzed comparatively.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.117-120
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• 2007

The main purpose of this paper is to introduce the early traffic opening-capable continuous multi-layer asphalt pavement maintenance method using electric arc furnace slag aggregate and emulsified asphalt to the actual construction sites. As well known, the previous surface treatment method of emulsified asphalt mixture have various shortcomings such as long work-time, traffic congestions, plastic deformation and poor evenness. Thus, the proposed method has enabled tile early traffic opening by utilizing the optimized emulsified asphalt after consideration of the climate and road conditions in Korea. The application of the electric furnace slag with $6\;{\sim}\;18\;mm$ thickness is helpful to become a environment-friendly construction method. And also, it has been improved enough to accommodate night-time works of mechanized construction activities for wearing course and control course.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.245-253
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• 2004

There has been recent demand for extending the life of age-degraded structures and equipment by such techniques as diagnosis, maintenance, safety assessment, and estimating residual life on iron-making plants and hydraulic, thermal, and nuclear power plants. These techniques take into account comprehensive scenarios that may cause malfunction and structural damage and allow an assessment of risk based on the likely scenarios. In particular the safety assessment and residual life estimation of age-degraded ships and equipment facilities require consideration of various factors such as mechanical and thermal stresses, corrosion, hardness, load variation due to changes of operating condition, crack generation and strength reduction of material by fatigue. In this study, a detail thermal stress analysis, one of useful techniques of safety assessment and maintenance, is performed on a blast furnace by using general FEM code (MSC/NASTRAN).

• 한국구조물진단유지관리공학회 논문집
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• 제7권2호
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• pp.209-218
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• 2003

The analytical studies included nonlinear finite element analysis of split-tee connection details subjected to axial load and lateral load. A three-dimensional model of the connections between CFT columns and H-beams has been developed. Both initial geometrical imperfections and residual stresses are taken into consideration. A geometrically nonlinear load-displacement analysis of the structure containing the imperfection is then performed, using the Riks method. Analytical results are compared with existing experimental results. Extensive parametric analyses are carried out to investigate the relation of the connections between CFT columns and H-beam to various parameters such as the axial load, column width-thickness ratio, and split-tee thickness.

• 한국구조물진단유지관리공학회 논문집
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• 제4권3호
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• pp.169-176
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• 2000

In the strengthening of the existed reinforced concrete(RC) structures, it is required that the more rational strengthening method and the amounts of strengthening materials would be decided under the consideration of the present state of RC structures. Therefore, this study examined the strengthening effects of concrete cylinders strengthened with carbon fiber sheet(CFS). In this studying we modeled the reduction of internal forces and the initial strains of concrete cylinders as the load history over the elastic limit. From the results, it revealed that the strengthening of two layer CFS was more effective on the concrete cylinders under the action of load history such as cyclic and cracking load.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 추계 학술논문 발표대회
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• pp.133-136
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• 2005

While reconstruction has been criticized since 1990 for its tendency of resource over-usage and negative impact on the surrounding environments, remodeling has begun drawing attention as its new alternative. Through examining the recent legal and systematic conditions such as Construction Law, Common Housing Administration Ordinance, and Housing Law, etc. this research analyzes problems on the current legal systems on remodeling, and it aims to suggest systematic and policy-driven schemes which could revitalize remodeling on its software and hardware sides. Careful consideration in regards to remodeling should be given from the initial design stage and throughout the maintenance stages of construction to achieve lengthy durability of buildings, and realization of long-term maintenance costs should also be pursued during this process. This will set in place the practice of remodeling in longer than 50-years intervals since the construction rather than the current 20 or 30 years.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1024-1028
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• 2009

Government imposed a duty to perform feasibility investigation on huge development projects which cost are higher than 50 million dollars on May 1999. This is to prevent waste of money occur from lack of review on huge public projects and raise the efficiency of government budget. Although maintenance and managing analysis method for public infrastructures are developed and proposed by other institutions as Korea Infrastructure Safety & Technology Corporation but it is not well applied on the aspect of the railway fixed time and costumer costs. Therefore a good point of quantitative and qualitative reference which fits railway character is need and following guidelines from the phase of feasibility study are need to prevent governments budget waste.

• 한국구조물진단유지관리공학회 논문집
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• 제2권3호
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• pp.176-187
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• 1998

The Dismantlement and Construction of the buildings have the characteristic of floating change with repetition within a Time Schedule which has fixed resources, that is, Manpower, Materials and Equipments, and involve many disaster factors in performing each processes. But as these factors are variable, a work supervisor should be able to understand data analysed distinctive factors of each activities systematically, organizationally, and scientifically, and diagrammatic information media so that he can control any complex and situation beyond forecast. Thus this study is intended to be a barometer of weighing if the existing process schedule has taken security into consideration by making the characteristics of organization and action of Work package per process in a building field with more factors like these into a network system and is intended to minimize construction disasters by systematizing this into a Transformational Network.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2004년도 추계학술발표대회 논문집
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• pp.165-166
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• 2004

Apartment, which have become the major housing style in Korea, have contributed to the development of housing culture as well as achieved a growth in volume. However, the demands and characteristics of residents have not been reflected in the apartment, because it has been developed only for a growth in volume. In this society, housing unit was the first consideration rather than common space. Therefore, a required resident-centered common space is the domestic housing market's necessity. Under this circumstance, this study investigated previous studies on interior design guidelines for common space were analyzed using Murtha and Lee's user benefit criteria which emphasizes humanity. In-depth content analysis was employed in this study. The result showed that four categories of the model were related toward more user-centered residential environment-behavioral facilitation, physiological maintenance, perceptual maintenance, and social facilitation.

• 대한안전경영과학회지
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• 제13권1호
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• pp.75-80
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• 2011

This paper reviewed the relationship between superior leadership and job stress responses, and the moderating effect of age in maintenance area of air force. Based on the responses from 450 air force maintenance persons, the results of multiple regression analysis showed that transactional leadership has negative relationship with physiological stress response, charisma has negative relationship with psychological stress, and individual consideration has negative relationship with behavioral stress. In moderating effects, age has negative effect on the relationship between transactional leadership and physiological stress response, and age has positive effect on the relationship between charisma and psychological stress response.