• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.4
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• pp.146-154
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• 2011

Recently, the paradigm of social infrastructure investment has been changed from new construction to maintenance and management. As a consequence, the management and maintenance system of existing highway facilities needed an innovation involving the concept of asset management. This paper discusses the new facility management system suitable to local highway agencies. The new system incorporates asset management concept so that it can analyze the network level facility management solution and it can also improve the budget efficiency for local government. This paper also presents systematic method to integrate various facilities for management system.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.233-239
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• 2008

It is very important to set a reliability target and verify the requirement when procuring the rolling stock in the aspect of safety, availability and LCC. While there are a few different methods to verify the reliability target, it is required that the most appropriate method should be used considering the characteristics of rolling stock itself and the operation environment. Even though recently the quantitative reliability requirements are widely adopted in domestic market, there is no substantial contents in the various standards and guidelines. In this study we investigate the various reliability demonstration test plans and evaluate them for rolling stock application. And three test plans among them were applied to the real operation data.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.2
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• pp.233-244
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• 2002

The purposes of this research are to use the buildings efficiently and long, save energies, make the cozy and comfortable environment of residential and living spaces, rearrange the related acts for easy implementation of remodeling, and activate the government's support programs so as to make remodeling activated in a safe mode. The scope and methodology of this research include the review of existing literatures and data on remodeling, census on apartment residents, influence factors, and the development of methods for activation of building remodeling and strengthening of safety management, like activation measures, licensing and ordering regulation updates, etc regarding the remodeling. Safety inspection and in-depth inspection before and after remodeling should be regulated. The construction materials for remodeling should be light weighted and the construction methods which can minimize the impact and vibration during construction should be selected. The improvement of regulation on the remodeling contractor qualification and order method should be updated. If the remodeling is activated and safety management is reinforced by the suggested measures, solving of lack of house, prevention of abuse of resources, and improvement of residential environment could be accomplished rationally.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.11
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• pp.591-598
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• 2009

The service quality with the various building equipments tends to depend on the individual superintendent's capability and efforts generally and this often lead to poor maintenances and managements of them. N-BMS(Networked Building Management System), proposed in this study, is a new type of building management method, which links principal equipments within many buildings into a communication network and carries out several significant missions such as fault detection, deterioration diagnosis and control the equipments and so on, as well as monitoring which is the main and unique purpose of the conventional BMS. How to construct the N-BMS was considered to keep performance of equipments high and thus to save energy and resource. LCC(Life Cycle Cost) based analysis was also performed in order to verify the effects of some maintenance and management works for the building HVAC systems.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.2
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• pp.71-78
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• 2009

Up until recently, the energy and the economic analysis of a cogeneration system have been implemented by a manual calculation that is based on monthly thermal loads of buildings. In this study, a cogeneration system modeling validation with a detail building energy simulation, eQUEST, for a building energy and cost prediction has been implemented. By analyzing the hourly building electricity and thermal loads, it enables users to decide proper cogeneration system capacity and to estimate more accurate building energy consumption. eQUEST also verified the energy analysis when the heat pump system is integrated with the cogeneration system. The mechanical system configuration benefits from the high efficiency heat pump system while avoiding the building electricity demand increase. Economic analysis such as LCC (Life Cycle Cost) method is carried out to verify economical benefits of the system by applying actual utility rates of KEPCO(Korea Electricity Power COmpany) and KOGAS(KOrea GAS company).

• Journal of the Korean Solar Energy Society
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• v.22 no.4
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• pp.97-106
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• 2002

The purpose of this study is to analyze the life cycle cost of primary cooling system by systematic support cost. Life Cycle Cost(LCC) is the process of making an economic assessment of an item, area, system, or facility by considering all significant costs of ownership over an economic life, expressed in terms of equivalent costs. The essence of life cycle costing is the analysis of equivalent costs of various alternative proposals. In order to select economical primary cooling system in early heat source plan stages, the research investigates cost items and cost characteristics during project process phases such as planning/design, construction, maintenance /management, and demolition/sell phases. The study also analyze the life cycle cost by capacity leading to suggest the most economical primary cooling system by systematic support cost.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.869-877
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• 2016

Necessity has compelled man to improve upon the art of tapping wind energy for power generation; an apt reliever of strain exerted on the non-renewable fossil fuel. The power generation in a Wind Farm (WF) depends on site and wind velocity which varies with time and season which in turn determine wind power modeling. It implies, the development of an accurate wind speed model to predict wind power fluctuations at a particular site is significant. In this paper, Box-Jenkins ARIMA (Auto Regressive Integrated Moving Average) time series model for wind speed is developed for a 99MW wind farm in the southern region of India. Because of the uncertainty in wind power developed, the economic viability and reliability of power generation is significant. Life Cycle Costing (LCC) method is used to determine the economic viability of WF generated power. Reliability models of WF are developed with the help of load curve of the utility grid and Capacity Outage Probability Table (COPT). ARIMA wind speed model is used for developing COPT. The values of annual reliability indices and variations of risk index of the WF with system peak load are calculated. Such reliability models of large WF can be used in generation system planning.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.159-169
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• 2007

In this paper, a PMS(Pavement Management System) is presented for the public agency who wish to execute rational repair by referring to asset management information regarding road pavement. The aim of the paper is to provide the decision makers with the planning information regarding maintenance strategies for efficient road pavement management. We found that life cycle cost can be minimized and repair cost in each year fluctuates when repeating repair at the IRI management level. The validity of PMS application presented in this paper is investigated through case studies for conducted for 22 national highway road sections in Korea.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.2
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• pp.55-61
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• 2011

We propose power-saving real-time scheduling method for mixed task sets which consist of both time-based periodic and event-based aperiodic tasks in the automotive operating system. In this system, we have to pursue maximization of power-saving using the slack time estimation and minimization of response time of aperiodic tasks simultaneously. However, since these two goals conflict each other, one has to make a compromise between them according to the given application domain. In this paper, we find the adjustment factor which gives better response time of aperiodic tasks with slight power consumption increase. The adjustment factor denotes the gravity of response time for aperiodic tasks. We apply the ccEDF scheduling for time-based periodic tasks and then calculate new utilization to be applied to the adjustment factor. In this paper, we suggest the lccEDF algorithm to make a tradeoff between the two goals by systematically adjusting the factor. Simulation results show that our approach is excellent for variety of task sets.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.6
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• pp.459-468
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• 2020

The pole interaction of the line-commutated converter high-voltage direct current (HVDC) is analyzed, and a practical solution that uses a surge arrester is proposed. Jeju HVDC No. 2 is a double-monopole HVDC link that has a rated power capacity of 2 × 200 MW and was commissioned in 2012. During normal operation, Jeju HVDC No. 2 is operated in the bipolar mode to minimize the loss caused by the dedicated metallic return. However, when one pole of the inverter valve is bypassed, a commutation failure can occur in the other pole. This phenomenon is called pole interaction in this work. This pole interaction interrupts the HVDC power transfer for almost 2 s and may affect the stability of the power system. This research proposes the installation of a surge arrester at the inverter neutral, which can be an effective and practical solution for pole interaction. The HVDC system is analyzed, and the residual voltage of the surge arrester is determined. Detailed simulation using PSCAD/EMTDC demonstrates that the proposed method eliminates the pole interaction of the bipolar-operated HVDC.