• 한국IT서비스학회지
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• 제8권2호
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• pp.43-70
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• 2009

As software development and maintenance cost increase quickly, information systems managers are more concerned about how to effectively manage software cost. To estimate the software development cost, most public institutes of Korea use the software cost estimation standard established by the government. Unfortunately, the accuracy of the estimation derived from the standard has not been satisfactory in spite of repetitive modifications made to improve it. One of the major reasons for the inaccuracy is that the standard has too small a number of cost adjustment factors to reflect the various characteristics of a software development project. To remedy this problem, we propose new cost adjustment factors which can be incorporated into the standard and are important to enhance the estimation accuracy, based on the analysis of several well-known software estimation models. Furthermore, by applying the proposed model to real world software projects, we show that the proposed model can produce more accurate estimates than the current standard.

• 전기학회논문지
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• 제67권2호
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• pp.331-336
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• 2018

In this paper, the life cycle cost of the auxiliary power unit in the conventional 8200 series electric locomotive is evaluated and an effective life cycle cost reduction method is sought. For this, a life cycle cost evaluation model was proposed using IEC 60300-3-3 standard. As a result of analysis, material cost which accounted for a large percentage of preventive maintenance cost, accounted for 64% of total cost, and breakdown maintenance cost was as high as 27%. Except for the cost of preventive maintenance, the breakdown maintenance cost ratio was the highest. In order to reduce the LCC of the auxiliary power unit(APU) of the 8200 series in the future, it is necessary to reduce the material cost in case of development and to secure the high reliability according to the parts manufacturing so as to minimize the maintenance cost.

• 한국기계가공학회지
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• 제20권4호
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• pp.119-126
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• 2021

During the development of a weapon system, the concept of maintainability is used for quantitatively predicting and analyzing the maintenance time. However, owing to the complexity of a weapon system, the standard maintenance time predicted during the system's development differs significantly from the measured time during the operation of the equipment after the system's development. According to the analysis presented in this paper, the maintenance time can be predicted by considering the system's complexity on the basis of the military specifications, and the procedure can be Part B of Procedure II and Method B of Procedure V. The maintenance work elements affected by the system complexity were identified by the analytic hierarchy process technique, and the system-complexity-reflecting weights of the maintenance work elements were calculated by the Delphi method, which involves expert surveys. Based on MIL-HDBK-470A and MIL-HDBK-472, it is going to present a Korean-style maintainability prediction method that reflects system complexity of weapons systems.

• 한국건축시공학회지
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• 제7권2호통권24호
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• pp.67-76
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• 2007

The purpose of this study is to propose the efficient improvement in the lawsuit to request the guarantee against defect. This study points out several problems about related act and subordinate statue and judgement by analyzing the character of contract in apartment house, related laws and regulations, appraisals and judicial decisions. This study deduces the necessity of the establishment of the specification and the breakdown cost for repair and maintenance work to provide the standard for the detached judgement.

• 한국관개배수논문집
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• 제17권2호
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• pp.28-34
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• 2010

This study re-exams hydrologic stability on spillway outlet capacity of agricultural reservoirs using hydrologic data with current rainfall condition instead of project hydrologic data applied at design on Backgok reservoir located in Chungbuk province. It is concluded that Backgok reservoir is not hydrologically stable and therefore structural measures including the extension of spillway and non structural measures should be taken. Continuous basic plan for river maintenance including additional bank reinforcement to bottom river shall be carried out. Due to high peak flood with more than 290% compared to 200 year frequency probability flood which was design standard of the past in view of the results of calculating PMF according to revised design standard for reservoirs, there could a problem for securing rationality in case of applying PMF with design flood. Therefore, hydrological stability, construction, and maintenance cost shall be synthetically studied and reasonal application shall be made if the decision is made on applying PMF with design flood.

• 한국구조물진단유지관리공학회 논문집
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• 제1권2호
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• pp.151-156
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• 1997

An experimental study was performed on the pull-out behavior of 90-deg standard hooks from exterior beam-column connections. The effects of the number of hooked bars of joint area were investigated. Under the pull-out action of hooked bars, the damage and cracking of joint area tends to be more extensive as the number of hooks pulling out from a joint increases. The pull-out strength and post-peak ductility of hooked bar are adversely influenced by the increase in number of hooks pulling out from an exterior joint. Current hooked bar anchorage design guidelines may be improved by considering the effect of the number of hooked bars on anchorage conditions at exterior joints.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 추계 학술논문 발표대회
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• pp.51-54
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• 2005

The concrete structure hasn't perfect waterproofing performance but if it doesn't have a joint part that could isolate a permeability. Concrete structure(communication tunnel and underground structure) has an expansion joint and construction joint. There are a lot of joint type after construction or expansion, shrinkage, vibration, over load, performance of decline etc.. they offer a water of way by variety change. In this reason, It carries in effect a waterproofing work for the concrete structure of waterproofing. but the structure has a behavior that cause a problem by waterproofing layer of damage, heaving phenomenon, temperature of shrinkage. In this study, we will estimate a field of application for Sealer of injection type for leakage maintenance of construction standard on the waterproofing performance.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.184-190
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• 2009

Recently, the concern for the reliability of railway is increasing, also the study about reliability is being processed at a good pace. However, in case of an existing railway operating it is true that the railway system is being operated without a clear RAM standard. There is not a clear RAM standard about product menual of a city railroad, and there are only basic provisions concerning traction motor which can be called a main equipment. In this paper, we calculated the availability and reliability of subway having MKBSF, MKBF, MTBF, MTTR analyzing accumulated maintenance data about a main equipment of a VVVF direct subway being operated in line #4. By watching the reliability grade of a VVVF subway being operated and manufactured within the country and being applied with the development of a city railway reflected by RAM menual when the new subway is manufactured, and with the basic data of RCM, we'd like to grope the methods which can be improved by operation stability of a city railway.

• 한국구조물진단유지관리공학회 논문집
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• 제4권1호
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• pp.139-145
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• 2000

In this experimental program specimens. designed by the test variables, such as percentage of steel fiber incorporated, were constructed and tested to evaluate the flexural performance of reinforced steel fiber concrete beams. Based on the test results reported in this study, the following conclusions are made. Comparing with the load-displacement relationship of standard specimen, specimen over 0.5% of steel fiber incorporated, could be improved significantly flexural performance, such as capacity, ductility, and crack pattern. As increasing in quantity of steel fiber incorporated(0.5%~2.0%), the flexural strength of each specimen was shown the enhancement of 13%~40% in comparision with the standard specimen BSS.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1008-1012
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• 1987

This paper describes the general approach to ISDN operation & maintenance. First we focused on the CCITT SG XVIII activities on the ISDN. As a general principles for operating and maintaining an ISDN they propose TMN(Telecommunication Management Network) concept which specifies several OM function modules and standard interfaces. Based on the concept we studied proper methodology to set up an efficient OM structure under the ISDN environments.