• Title/Summary/Keyword: long-term cost

Search Result 998, Processing Time 0.035 seconds

Limitations and improvement of the in situ measurements of ground thermal conductivity in Korea (국내 지중열전도도 측정 방법의 한계 및 개선 방향)

  • Shim, Byoung Ohan
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2011.05a
    • /
    • pp.195.2-195.2
    • /
    • 2011
  • The borehole heat exchanger of Geothermal Heat Pump (GHP) system should be sustainable and cost effective for long term operation. To guaranty the performance of the system thermal Response Tests (TRTs) with simple recommended procedures have been applied in many countries. Korea government developed a standard TRT procedure in order to control the quality on GHP projects. In the TRT procedure interpretation method has a rule that data set has to be interpreted by the line source model(LSM). The LSM employes some assumptions that surrounding medium is homogeneous and the line source is infinite and constant heat flux, however real ground condition is unisotropic and heterogeneous, and showing regional or local ground water flows in many cases. We need to develope improved evaluation models to estimate accurate ground thermal conductivity with respect to geological and influence of ground water because current TRT standard test procedure has limitations to be applied for every locations and system. This study surveyed the uncertainty of the thermal parameters from the interpretation method considering different evaluation period. The interpretation of 208 TRT data sets represents limitations of LSM application that some obtained ground thermal conductivities are statistically unstable and convergence time of ground thermal conductivity over test period shows trends responding the length of test period. This evaluation study will be helpful to provide some effective procedure for the thermal parameter estimation and to complement current TRT standard procedure.

  • PDF

The Affections of System Stability on Replacing the Synchronous Condenser in Jeju Island (제주 동기조상기 교체에 따른 계통안정성 영향 연구)

  • Chang, Byung-Hoon;Yoon, Jong-Su;Han, Jeong-Yeol;Shim, Jeong-Woon;Kang, Sang-Gyun;Lee, Byong-Joon
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.56 no.10
    • /
    • pp.1715-1720
    • /
    • 2007
  • The CSC-based HVDC system links the Jeju system to the mainland system. Because CSC-based HVDC is installed in Jeju, the reactive power is needed to transfer active power through the HVDC. In order to supply reactive power, switched capacitors and synchronous condensers are installed in Jeju system. The deterioration of established synchronous condensers, however, causes a reactive power supply capability decline and high maintenance cost. It brings about the instability of Jeju system and the incremental of maintenance and repair costs. In the future the installation of wind generators and additional HVDC system would aggravate the stability of Jeju system. Therefore, it needs to consider a countermeasure against above problems. In this paper, Analysis of several contingencies of Jeju system was peformed, and some contingencies caused voltage-reactive power problem was known. CPF method was introduced in order to make countermeasures to replace the synchronous condensers and to solve the voltage-reactive power problem. The location and capacity of reactive power sources were also decided. It could guarantee medium and long term stability of Jeju system.

A Study on Risk Transference Processes of Natural Hazard - Focus on the human adjustment according socio-economic structure - (자연재해의 위험성 전이 과정에 대한 연구 - 사회.경제적 구조에 따른 인간의 적응양식을 중심으로 -)

  • Park, Eui-Joon
    • Journal of the Korean association of regional geographers
    • /
    • v.8 no.2
    • /
    • pp.247-255
    • /
    • 2002
  • In recent decades, the characteristics of natural hazard has been changed and the global cost of natural disasters has increased substantially. There are several trends in society and nature that suggest this pattern may continue, with more frequent mega-disasters occurring in the future. In particular, risk perception that is at odds with the "real" risk underlies the process of risk transference increases long-term vulnerability. Therefore investigating the correct risk transference and adjustments according to regional socio-economic structure can mitigate and reduce environmental, so called man-made hazard.

  • PDF

Effects of Youth Unemployment Bonus (청년고용촉진장려금 효과 분석)

  • Lee, Chul-In
    • Journal of Labour Economics
    • /
    • v.39 no.4
    • /
    • pp.1-29
    • /
    • 2016
  • This study examines the effects of the "youth unemployment bonus" program implemented in 2004. We view this program through the lenz of search-matching models and apply a quasi-experimental approach to an administrative unemployment insurance database of Korea. This episode is particularly useful because the program aims at long-term unemployed youths and the size of public assistance is large enough to subsidize employers for a year with a monthly subsidy of about $600. The main effects are found to be as follows: (i) the search period gets shortened by 18 days, (ii) the subsequent wage has increased by about three percents, and (iii) a conservative benefit-cost analysis reveals the validity of this program. We interpret these results in the context of general equilibrium models.

  • PDF

An Area of Accounting Related to the Management Planning (경영계획(經營計劃)에 관련(關聯)되는 회계(會計)의 영역(領域))

  • Park, Dae-Kyu
    • Korean Business Review
    • /
    • v.4
    • /
    • pp.25-50
    • /
    • 1991
  • A management planning is an index to accomplish the goal of business enterprise and a managing guide of the top manager. It is a top manager's authority with he gives directions at the beginning of the budget year and has something to do with a responsible accounting. If we correlate this management planning with an area of accounting, we can subdivide it into followings; production and marketing schedule, demand-supply program of raw material, demand-supply program of the personnel and lobor cost program, facility investment program, balance fund program, profit and loss, and financial position program. I think, in the field of accounting for the sake of the management planning, there are motivation accounting, responsible accounting, divisional system accounting, evaluating accounting and so on. A management planning should be accomplishe and as it is accomplished, a business is going to be grown up and developed. Especially, it must be set up on the ground of the long-term strategies. When the accomplishment through the management planning, which is a social responibility that all the business enterprise are seeking after, is attained, it makes the development of business possible and we cannot dent that it is closely connected with the national economic development.

  • PDF

Experiences of Implementing TPM in Swedish Industries

  • Liselott Lycke;Akersten, Per-Anders
    • International Journal of Reliability and Applications
    • /
    • v.1 no.1
    • /
    • pp.1-14
    • /
    • 2000
  • The global marketplace is highly competitive and organisations, who want to survive long-term, have to continuously improve, change and adapt in response to market demands. These improvements should focus on cost cutting, increasing productivity levels and quality and guaranteeing deliveries in order to satisfy customers. Total Productive Maintenance (TPM) is one method, which can be used to achieve these goals. TPM is a change management approach that involves employees from both production and maintenance departments. The purpose is to eliminate major production losses by introducing a program of continuous and systematic improvements to production equipment. TPM should be developed and expanded to embrace the whole organisation and all employees should be involved in the process as members of improvement teams. This paper gives a short description of the development of TPM and the TPM implementation process. Findings are reported from a case study in which one of the authors had the possibility of following and guiding a company through their TPM implementation. The implementation process takes several years and the research has focused on the initial three years. The study demonstrates that driving forces, obstacles and difficulties often are dependent on the organisation, its managers and the individual employees.

  • PDF

A Study on the Change and the Hint of Public Reverse Mortgage System in Japan (일본 공적역모기지의 변화와 시사점)

  • Yoo Seon-Jong
    • Journal of the Korean housing association
    • /
    • v.16 no.5
    • /
    • pp.49-56
    • /
    • 2005
  • This study will focus on status and structure of Japanese public reverse mortgage that has been changed since 1980. Especially, on newly introduced long-term supporting system for living fund after 2003. Private housing construction companies studied preceding cases of real estate products with reverse mortgage theory and also induced learning point from the change of Japanese public reverse mortgage market. From this on the purpose of this study is suggesting a better plan for successful reverse mortgage introduction in Korea. The data and articles of Japanese reverse mortgage are used for this study, also reverse mortgage related data are collected from web-site and research reports from the inside and outside of the country. From the total postal survey in September, 2004, the system contents after Year 2003 are described here. As described above, reverse mortgage is a way to support public social pension system and expected to play an important role as an assisting method for stable housing and supporting living cost to the aged. Eventually, it is necessary to find a way for introducing a public reverse mortgage as a welfare system for low income people.

A Study of Risk Analysis on Apartment Reconstruction Projects (공동주택 재건축사업의 리스크 분석에 관한 연구)

  • Lee Lo-Na;Woo Kwang-Min;Lee Hak-Ki
    • Proceedings of the Korean Institute Of Construction Engineering and Management
    • /
    • 2004.11a
    • /
    • pp.232-235
    • /
    • 2004
  • The apartment reconstruction project is making some problems, such as delay of lack specialty, conflict between project owners and cost increasing etc. The enforcement process of project are very complicated, the term of project is long and too many project owners are participating. For this reasons. it is always in the face of uncertainty. To promote the reconstructing project successfully. we need to make risk management process to get rid of uncertain factors which occur in forwarding the reconstructing project This study has for its objects. First, suggest the best way of risk analysis to manage risk factors systematically and efficiently recognized in The Apartment reconstruction protect. Second, furnish basic data to build the risk managing system of The apartment reconstructing project.

  • PDF

The Trend and forecast of Civil Aircraft market (세계 민간 항공기 시장 동향과 전망)

  • Chang, Tae-Jin
    • Current Industrial and Technological Trends in Aerospace
    • /
    • v.8 no.1
    • /
    • pp.12-22
    • /
    • 2010
  • The great recession which caused by financial crisis made steep rise of oil price and the serious problems of the aircraft industry. High oil price increases operating cost and the recession decreases air traffic. After a period of high book order and delivery from global economic recovery, the aircraft order fell down suddenly. Also the Aircraft price and lease rate deceased and the MRO market is reduced, too. But, the air cargo and passenger increase again since late of 2009. So, it is difficult to predict the market movement, most of the forecasters agreed that the air traffic and aircraft demand will grow gradually in long term with the growth of emerging markets like China, India and Africa. And more efficient, safe and clean aircraft is needed and will need in the market.

  • PDF

The Role of FDG PET in Malignant Lymphoma (악성 림프종에서 FDG PET의 역할)

  • Yun, Mi-Jin
    • The Korean Journal of Nuclear Medicine
    • /
    • v.36 no.1
    • /
    • pp.53-63
    • /
    • 2002
  • FDG PET is a functional imaging modality whose ability to detect lesions is directly based on a change of the glycolytic metabolism of targeted tissues, may be advantageous over other techniques. Combined with excellent image qualify, high spatial resolution, and whole body imaging capability, it has become popular as a new approach in the evaluation of patients with various malignancies. Initial staging of nodal and extranodal lymphoma using FDG PET has been proven to be at least equal or superior to conventional imaging modalities. For the assessment of treatment responsiveness, FDG PET has a major impact on the management of patients in differentiating residual lymphoma from treatment related benign changes. Residual FDG uptake after the completion of chemotherapy is a good predictor of early relapse. However, it seems that the absence of FDG uptake in tumor mass may not exclude minimal residual disease causing later relapse. In the early evaluation of treatment response only after a few cycles of chemotherapy, FDG PET may have a promising role in identifying non-responders who could benefit from a different treatment strategy. At present, FDG PET appears to be the cost-effective, diagnostic modality of choice in the management of lymphoma patients. The role of FDG PET based-systems in terms of affecting long-term prognosis and survival benefit should be further elucidated in future prospective studios.