• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.05a
• /
• pp.250-251
• /
• 2019

Lots of infrastructures have been newly constructed through the rapid economic growth of 1970's. Since the infrastructures has mostly deteriorated and this circumstance makes the need for maintenance and rehabilitation(M&R) of infrastructures to obtain the convenience and safety of users even more essential. Although markets for M&R project become larger, the construction standards for cost estimation of M&R work are insufficient. Thus, the purpose of this study is to examine the present state of standards for cost estimation of M&R works using case studies. Finally, this work could be utilized as the basis for the development of national standard for estimation of M&R work.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.1269-1274
• /
• 2011

To cut down the maintenance expenses at branch lines, the foreign developed countries have developed the low-cost signalling on low-density lines. These examples are FFB(FunkFahrBetrieb) Radio based train operation by German railways(Deutsche Bahn AG), ERTMS REGIONAL by Europe and LOCOPROL system using a GPS. Also, Korea is developing Information and Communication Technology based low-cost signalling on low-density lines. The characteristics of this system are directly controled switch and crossing by driver. For the purpose of this paper, we reviewed the business process for switch and crossing control. Specially, we compared and analysed both methods whether the driver takes control over the operation procedures of switch or the control message is carried by the command of the controller. And by utilizing the instrument of UML, I planned the switch according to the control authority and the operation procedures needed for the control of crossing.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.5
• /
• pp.791-798
• /
• 2020

The share of advanced technology in modern weapon systems are gradually increasing, and life cycle of components are shortened due to the rapid speed of technological development. On the other hand, the weapon systems have a characteristic that takes a long time in the requirement stage of weapon to the operation and maintenance stage. Due to inevitably, obsolescence of the main components for parts occurs in the acquisition phase. The obsolescence parts could cause delays in mass production schedules, and further adversely affects operational availability due to poor supply of repair parts during in the maintenance phase. However, business managers are obliged to maximize the performance while minimizing the cost of the total life cycle of the design, production, and operation stages. It is necessary to establish and implement an appropriate components and parts of life cycle management plan. In this research, we analyzed the effectiveness of parts obsolescence management through cost avoidance and total life cycle cost that can be reduced through proper parts obsolescence management.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.9
• /
• pp.82-91
• /
• 2020

Recently, the research and development of weapon systems have expanded from ILS centered on acquisition costs to LCS, including operating maintenance costs. Regulations define the provision and formula of operating maintenance costs, but this does not consider the characteristics of the design and operation/maintenance of real weapon systems based on engineering calculations. Therefore, this study suggests a simulation design method to complement these areas and produce more accurate operating maintenance costs. The research procedures are as follows. First, the provision and formula of operating maintenance costs were defined to make the simulation results applicable. Second, a simulation model was developed by reviewing design considerations so that the simulation results reflect reality more accurately. The design considerations include the PBS of weapon systems, operation schedules, specifications for operation/maintenance/warehouse facilities, and basic cost information (personnel expense and spare part/equipment cost). This study is expected to be effective in calculating the operating maintenance costs more easily and accurately.

• Journal of Korean Institute of Industrial Engineers
• /
• v.30 no.4
• /
• pp.261-266
• /
• 2004

In this paper, the software reliability growth model which incorporates the periodic maintenance after the release is proposed. Using the proposed model, the debugging and periodic maintenance cost subject to the required level of the software reliability are investigated. An optimal software release time is derived for a fixed interval of periodic maintenance. To validate the proposed model, release times obtained in this study are compared with examples. The proposed investigation is expected to be served as one of factors in determining the release time of the software where periodic maintenance is considered.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.28 no.3
• /
• pp.103-109
• /
• 2016

The purpose of this study is to perform comparative economic evaluation for the systems of ground source heat pump (GSHP) and district heating and cooling (DHC) by focusing on the analysis of operation case of GSHP. The adapted research object is a public office building located in Seoul. The capacity of ground source pump is about 3,900 kW. Ground heat exchanger is closed loop type. The analysis period for life cycle cost is 30 years. Economic evaluation is assessed from the viewpoints of the following four parts: initial cost, energy cost, maintenance and replacement cost, and environment cost. The total life cycle cost of GSHP is approximately 8,447 million won. The cost of the DHC System is approximately 3,793 million won. The cost of the DHC is approximately 46% lower than GSHP system under the condition of current rate for GSHP and DHC.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.921-926
• /
• 2006

The present study has been conducted economic analysis through actual operation of EHP and GHP which are installed at the same building of an university Cost items, such as initial cost, annual energy cost and maintenance cost of each system are considered to analyze LCC and economical efficiency is compared. The initial cost is considered on the basis of actual costs, and annual energy cost is converted into the cost after measuring electricity and gas consumption a day. LCC applied present value method is used to assess economical efficiency of both them. Variables used to LCC analysis are electricity cost escalation rate, natural gas cost escalation rate, interest rate, and service lives and when each of them are 4%, 2%, 8%, and 20 years, results of analysis short that EHP(148,257,306 won) is 8.05%(12,981,990 won) more profitable than GHP(161,239,295 won).

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.43 no.3
• /
• pp.41-52
• /
• 2020

This paper investigates the stress-reducing preventive maintenance model through numerical experiments. The preventive maintenance model is used to analyze the relationship between related conditions and variables to gain insight into the efficient operation of the system when performing preventive maintenance in real-world situations. Various preventive maintenance models have been developed over the past decades and their complexity has increased in recent years. Increasing complexity is essential to reflect reality, but recent models can only be interpreted through numerical experiments. The stress-reducing preventive maintenance is a newly introduced preventive maintenance concept and can only be interpreted numerically due to its complexity, and has received little attention because the concept is unfamiliar. Therefore, for information purposes, this paper investigates the characteristics of the stress-reducing preventive maintenance and the relationship between parameters and variables through numerical experiments. In particular, this paper is focusing on the economic feasibility of stress-reducing preventive maintenance by observing changes in the optimal preventive maintenance period in response to changes in environmental stress and the improvement factor. As a result, when either the environmental stress or the improve effect of stress-reducing preventive maintenance is low, it is not necessary to carry out the stress-reducing preventive maintenance at excessive cost. In addition, it was found that the age reduction model is more economical than the failure rate reduction model.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.5
• /
• pp.1559-1569
• /
• 2014

The purpose of this study is to estimate the degree of cost inefficiency for the urban railway lines of a metropolitan city operated by public institutions in Korea and identify the causes of this inefficiency. To this end, we assume that the urban railway lines produce the output of train-km by putting three production factors of labor, electric power and maintenance and set the variable cost function model with the translog function to make a stochastic cost frontier analysis. Based on estimated result, we conclude that the cost savings for 6 years of all lines are about 6,672 hundred million won and top five lines with high inefficiency are Busan Line1, Daegu Line1, Daejeon Line1, Gwangju Line1, and Daegu Line2. The causes of inefficiency are attributable to labor and maintenance factors. The results of this study can be useful in case of finding the priorities of measures and specific plans for reducing labor and maintenance costs in the urban railway operation.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2006.11a
• /
• pp.111-116
• /
• 2006

The objective of this research is to develop an assesment system for BTL Project. A new method for the prediction of construction and maintenance cost in the educational facilities has been considered and under development by the authors. This paper explains the current BTL assesment method used by most local district office of education and lists its potential problems. Main conceptual modules in the new Assesment System are shown in this paper. Also, viable results of each module are discussed in this paper.