• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.6
• /
• pp.596-604
• /
• 2005

This paper presents the work on evaluating the LCC (Life-Cycle Cost) of a heat pump system as unutilized energy system. The river water as an unutilized energy source was used for the heat source of heat pump system. LCC analysis is a concrete method for evaluating the economical efficiency of energy facilities of building. The present case study shows an example of adequate use of the LCC analysis on a heat pump system and conventional gas boiler and refrigerator for building heat supply. A life cycle of 20 years was used to calculated net present value of energy cost. Over a 20 year life cycle, the energy cost could be reduced by 612 million won if a heat pump system were used instead of a conventional boiler and an absorption refrigerator.

• Journal of Aerospace System Engineering
• /
• v.4 no.2
• /
• pp.16-20
• /
• 2010

In General, the hydraulic system of T-50 Advanced Trainer is applied to flight control system, wheel & Brake system and fuel system for aircraft operation. The hydraulic system is operation with pressure of 3000psi. and many mechanical parts which is operated by hydraulic system has been stressed in incomplete environment same as heat and friction. for example, Oil leakage had occurred in the shutoff valve of FFP used in a certain period of time. After study, The crack progressed by fatigue due to the irregular hydraulic pressure and vibration has been identified as the reason of oil leakage. This paper presents life cycle extension plans of FFP shutoff valve by configuration improvements of shutoff valve and FFP hydraulic motor.

• Journal of Information Technology Services
• /
• v.5 no.2
• /
• pp.39-58
• /
• 2006

The e-business strategies ultimately pursue creating the maximal value for customers through the competitive advantages and business opportunities newly created on the basis of information technologies. For the realization of e-business strategies, the successful implementation and operation of e-business system must be the crucial activities in and out of an organization. Therefore, in physical world, there were lots of interests that what kind of key factors can lead the success of e-business system. Moreover, in the field of academia also, there have been many research results for investigating and finding out the key success factors for e-business system. However, the perceptual level of the significance of key success factors that organization members perceive can be changed over each phase of system life cycle such phases as introduction, growth, maturity, and decline. This study investigated that there might be significant differences in the perceptual level regarding importance of success factors among phases of system life cycle.

• Korean Journal of Construction Engineering and Management
• /
• v.5 no.2 s.18
• /
• pp.55-63
• /
• 2004

A building structures was used the facility management phase through $planing\cdotdesign\cdotconstruction$. phase. building's length of life was shorter than its physical length of life, because of the lack of law and institution, the lack of related agencies' preparation and owner's preparation. Also, considering the construction life-cycle, the facility phase accounted for $70\%$ of whole official lift, therefore, it needed to be opposed to systemic facility management. Current facility management system practically managed the defect of facility and almost never communicated between the other phase. In the side of policy, domestic law, institution, and policy related to building structure focused built-up market. and then the management of existing facilities was not consolidated efficiently. The purpose of this study was to suggest the direction of facility management construction for managing, utilizing, and operating public facilities, moreover, to study the direction of current facility management system improvement corresponding to total computer integrated construction system under government agencies.

• Journal of the Society of Naval Architects of Korea
• /
• v.42 no.6 s.144
• /
• pp.673-678
• /
• 2005

IMO adopted ' International Convention for The Control and Management of Ships' Ballast Water and Sediments ' on February 13th 2004. According to this convention, a ballast water treatment system should be installed in all ships obligatorily up to a standard date. When the system is installed, economic propriety should be considered. The economic propriety analysis examines the profit of a relevant project which can be presented by a equation, (Profit) = (income) - (expense) - (tax). However, the ballast water system is not for the profit during the life cycle but for the satisfaction of the regulation. Therefore, the expense should be minimum against the profit. This study presents the LCC(Life-Cycle Cost) analysis for economic evaluation of several ballast water system of foreign products.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.5
• /
• pp.1189-1202
• /
• 1999

As compared with VOD data, NOD article data has the following characteristics: it is created at any time, has a short life cycle, is selected as not one article but several articles by a user, and has high access locality in time. Because of these intrinsic features, user access patterns of NOD article data are different from those of VOD. Thus, building NOD system using the existing techniques of VOD system leads to poor performance. In this paper, we analysis the log file of a currently running electronic newspaper, show that the popularity distribution of NOD articles is different from Zipf distribution of VOD data, and suggest a new popularity model of NOD article data MS-Zipf(Multi-Selection Zipf) distribution and its approximate solution. Also we present a life cycle model of NOD article data, which shows changes of popularity over time. Using this life cycle model, we develop LLBF (Largest Life-cycle Based Frequency) prefetching algorithm and analysis he performance by simulation. The developed LLBF algorithm supports the similar level in hit-ratio to the other prefetching algorithms such as LRU(Least Recently Used) etc, while decreasing the number of data replacement in article prefetching and reducing the overhead of the prefetching in system performance. Using the accurate user access patterns of NOD article data, we could analysis correctly the performance of NOD server system and develop the efficient policies in the implementation of NOD server system.

• Korean Chemical Engineering Research
• /
• v.53 no.2
• /
• pp.164-173
• /
• 2015

This study aims to design energy supply systems from various energy sources for transportation sectors and comparatively analyze the life cycle cost of different scenario-based systems. For components of the proposed energy supply system, we consider a typical oil refinery, byproduct hydrogen system, renewable energy source (RES)-based electric generation system and existing electricity grid. We also include three types of vehicles in transportation sector such as internal combustion engine vehicle (ICEV), electric vehicle (EV), fuel cell vehicle (FCV). We then develop various energy supply scenarios which consist of such components and evaluate the economic performance of different systems from the viewpoint of life cycle cost. Finally we illustrate the applicability of the proposed framework by conducting the design problem of energy supply systems of Jeju, Korea. As the results of life cycle cost analysis, EV fueled by electricity from grid is the most economically feasible. In addition, we identify key parameters to contribute the total life cycle cost such as fuel cost, vehicle cost, infra cost and maintenance cost using sensitivity analysis.

• Journal of the Society of Naval Architects of Korea
• /
• v.41 no.2
• /
• pp.121-127
• /
• 2004

The objective of this study is to design the technical information system for naval engineering (named TISNE). As the basic concept of the system, CALS (Continuous Acquisition and Life-cycle Support) and KMS(Knowledge Management System) were considered for the management and sharing of standardized digital information throughout the life-cycle of naval ship. To define the system components and their functionalities, the processes of naval ship design and construction were reviewed. Also web-based system prototype and the graphical user interlaces were designed and implemented.

• Journal of Sport and Applied Science
• /
• v.3 no.1
• /
• pp.1-14
• /
• 2019

Numerous types of sporting events have been hosted in Korea during the last decades. Sport events produce various types of data, and there is a clear necessity of storing and utilizing this information. From this background, the purpose of this study is to draw complex sports categories from international sport events life cycles in order to categorize standards of knowledges management system. This study utilized qualitative methods: expert groups discussion for overall life cycle steps and in-depth interviews for detail life cycle steps. The results show that there are several life cycle steps: bidding, preparation, operation, evaluation, post management steps. To be more specific, for the bidding step, there are check, plan, implementing detail phase; and the preparation step is based on event preparation Basis Build, event preparation implementation, test and supplementation phases. For the operation step, event operation system switch, event operation during the period, finish operation phases are deducted. Evaluation and post management step do not have detail phases. Efforts to store and utilize knowledge can be one of the starting points to make the operation of sport events efficiently.

• Journal of the Korean housing association
• /
• v.15 no.1
• /
• pp.33-40
• /
• 2004

Considering the present development situation of rental apartment since 1982, the supply of rental housing for low-income dwellers has contributed a amount of quantities, but has been deficient qualities in housing policy. To propose the device of remodeling for low-income dwellers in deteriorated apartment, this study investigated the energy consumption of central heating system and the characteristics of maintenance cost in permanent rental apartment. The results of evaluation of alternative heating systems by Life Cycle Costing in permanent rental apartment were as follows; From Life Cycle 15∼20 years by Present Worth Method, the economic heating system of remodeling is central heating system (heat source: B-C oil), unit heating system(natural gas), central heating system(natural gas) in order.