• Title/Summary/Keyword: Condition-base maintenance

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A Study on the Improvement through Analysis with Present Condition of Progress Management for Construction Project (공사 진척관리 현황분석을 통한 진척관리 개선방안에 관한 연구)

  • Park, Won-Ho;Sim, Jae-Kwang;Yun, Seok-Heon
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.3
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    • pp.137-144
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    • 2010
  • As mega-sized and complex building construction projects are on the rise, the importance of project scheduling and control is being highlighted. Project scheduling and control techniques are not yet widely used in Korea, but interest in these has progressively been increasing. Until now, most research projects have mainly focused on scheduling issues, but project progress management is of equal importance. In this research, the current state of project progress management in Korea is analyzed, and ways for improvement are suggested. We begin by analyzing previous research and practical studies in this field, and then survey experts about the current state of project progress management. This study suggests the Building Information Modeling (BIM)base project progress management method for quantitative and qualitative project progress analysis. Currently, BIM is applied to design, construction and maintenance for construction projects. BIM can also contribute to improving accuracy and understanding of the current project situation.

GE 7FA+e DLN-2.6 Gas Turbine Combustor : Part II Design of Lab Scale Dump Combustor (GE 7FA+e DLN-2.6 가스터빈 연소기 연구 : Part II 모형 덤프 연소기 설계)

  • Oh, Jeong-Seog;Kim, Min-Ki;Heo, Pil-Won;Lee, Jang-Soo;Yoon, Young-Bin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.12 no.5
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    • pp.51-59
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    • 2008
  • DLN-2.6 combustion tuning was carried out for the maintenance of GE 7FA+e gas turbine at Seo-Incheon combined cycle power plant. DLN-2.6 combustion system has the higher level of yellow plume and combustion vibration problem in the initial operating mode than that of the base mode($100{\sim}160MW$). The objectives of this study are to investigate the causes of yellow plume and combustion vibration problems at the starting mode and to suggest the best operating condition for the reliable working of the real combustors. By the analysis of tuning data, we could conclude that a yellow plume is caused by the rich mixture(${\phi}{\sim}1$) in a PM 1 nozzle at mode 3($20{\sim}30MW$). In addition, the combustion vibration($120{\sim}140Hz$) might be related to the cold flow characteristics of PM 3 nozzles at mode 6B($40{\sim}45MW$).

Dynamic Peak Load Calculation for Friendly Environment Energy Supply and Demand Plan at the Newport Area in Busan (부산 신항만지역 환경친화적 에너지 수급을 위한 동적 열부하계산)

  • Yee, Jurng-Jae;Lee, Sun-Ae;Cho, Yong-Soo;Doe, Geun-Young
    • Journal of Navigation and Port Research
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    • v.28 no.3
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    • pp.269-276
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    • 2004
  • The reclaimed land has peculiar characteristic of nature environment unlike midtown or inland and also, in comparison with inland, has bad weather condition, such as low temperature, strong wind, excessive sunshine, and moisture involved in a salt. Therefore the case of developing water front needs understanding characteristic of weather environment mused by reclamation in detail and proper development and organized maintenance. If development which doesn't investigate topographic and climate characteristic sufficiently is drove ahead, a rise of expense for energy and maintenance is going to be mused by deteriorating weather environmental, occurring a flaw of facility and calculating inaccurate capacity of facility. We looked into the weather state and drew up the standard weather data of the newport area in Busan which is reclaiming and developing now. In this research at the base qf the standard weather data, we calculate the dynamic peak loads for commerce, business and residence and then we utilize the results of the load calculation as basic information to determine facility capacity in the rear city of the newport area.

Dynamic Behaviour of Masonry inFilled Reinforced Concrete Frames with Non-Seismic Details (진동대실험을 통한 비내진상세를 가지는 RC 골조의 조적채움벽 유무에 따른 동적 거동 평가)

  • Baek, Eun-Rim;Kim, Kyung-Min;Cheon, Ju-Hyun;Oh, Sang-Hoon;Lee, Sang-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.3
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    • pp.121-129
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    • 2017
  • In this paper, the shake table test for the masonry infilled reinforced concrete frame with non-seismic details was carried out in order to evaluate its dynamic behaviour and damage under seismic condition. The tested specimens were the RC frame and the masonry infilled RC frame and the dynamic characteristics, such as a resonant period, acceleration response, displacement response and base shear force response, were compared between them. As a result of the shake table test, RC frame specimen had flexural cracks at the top and bottom of the column and shear cracks at the joints. In the case of masonry infilled RC frame, the damage of the frame was relatively minor but the sliding cracks and diagonal shear cracks on the masonry wall were severe at the final excitation. The resonant period of infilled RC frame specimen was shorter than that of the RC frame specimen because the masonry infill contributed to increase the stiffness. The maximum displacement response of the infilled RC frame specimen was decreased by about 20% than the RC frame specimen. It was analyzed that the masonry infill wall applied in this study contributed to increase the lateral strength of the RC frame with non - seismic detail by about 2.2 times and the stiffness by about 1.6 times.

The Phenological Responses of Leaf of Deciduous Woody Species to Base Temperature Maintenance (수목 최저 생육온도 이상으로 유지된 조건에서의 한반도 주요 수목 잎의 식물계절학적 반응)

  • Hong, Yongsik;Lee, Seungyeon;Lee, Sooin;Lee, Eungpill;Kim, Euijoo;Park, Jaehoon;Jeong, Heonmo;You, Younghan
    • Korean Journal of Ecology and Environment
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    • v.51 no.4
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    • pp.259-267
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    • 2018
  • This study was conducted to confirm phenological response of main deciduous woody species in Korea according to elevated temperature. Based on seeds collected from the same place, 39 woody species were cultivated in field (control) and in greenhouse (treatment) that was maintained above base temperature ($4.8^{\circ}C$). And then, we observed phenotype change of leaves focused on phenological response and explained relation with their current distribution area. As a result, initiation period of leaves unfolding was 1st~3rd, May in control. It was 13, December~7, January in treatment. Period of leaves yellowing was 11~26, October in control. It was 30, October~13, November in treatment. Consequently, initiation period of leaves unfolding was faster by 119~140 days and period of leaves yellowing was slower by 3~32 days since elevated temperature. Period of leaves growth increased in treatment by 148 days than control. Quercus mongolica and Quercus serrata that cultivated in treatment was changed as evergreen trees which have grown up continuely during one year. Also, initiation period of leaves unfolding of Sorbus alnifolia in treatment was faster than in control. However, difference of the period between control and treatment was smallest. Because period of yellowing leaves was moved ahead. Phenological response of leaves according to elevated temperature had no relation of type of their current distribution area. This is the result of acclimation due to elevated temperature during the winter and suggests that the phenotype of leaves of 39 deciduous woody species is more sensitive to the current growth condition than to the past growth condition.

A Study on Variations of the Low Cycle Fatigue Life of a High Pressure Turbine Nozzle Caused by Inlet Temperature Profiles and Installation Conditions (고압터빈 노즐에서 입구온도분포와 장착조건에 따른 저주기 피로 수명 영향에 대한 연구)

  • Huh, Jae Sung;Kang, Young Seok;Rhee, Dong Ho;Seo, Do Young
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.11
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    • pp.1145-1151
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    • 2015
  • High pressure components of a gas turbine engine must operate for a long life under severe conditions in order to maximize the performance and minimize the maintenance cost. Enhanced cooling design, thermal barrier coating techniques, and nickel-base superalloys have been applied for overcoming them and furthermore, material modeling, finite element analysis, statistical techniques, and etc. in design stage have been utilized widely. This article aims to evaluate the effects on the low cycle fatigue life of the high pressure turbine nozzle caused by different turbine inlet temperature profiles and installation conditions and to investigate the most favorable operating condition to the turbine nozzle. To achieve it, the structural analysis, which utilized the results of conjugate heat transfer analysis as loading boundary conditions, was performed and its results were the input for the assessment of low cycle fatigue life at several critical zones.

Estimate of the Bearing Capacity on Subbase and Subgrade with Dynamic Plate Bearing Test (동평판재하시험을 이용한 도로하부 재료의 지지력 평가)

  • Youn, Ilro;Oh, Sewook
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.8
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    • pp.53-60
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    • 2013
  • The compaction control method of national road substructure is using field density test to determine the relative compaction and plate bearing test to check the load bearing capacity. However, these two tests digitize a construction site manager's judgment based on his experience, so mechanical basis is weak. Resilient modulus method, which is recently being used to resolve such problem, is evaluated as a rational design method of pavement structure that can rationally reflect the stress-strain state of pavement materials that is caused by the condition of load repetition of vehicle load. However, the method of measuring the resilient modulus is difficult and lengthy, and it has many problems. To replace it, light falling weight test is recently being proposed as a simple test method. Therefore, this research uses dynamic plate loading test, which quickly and simply measures the elastic modulus of the subgrade and sub-base construction and site of maintenance, to judge the possibility of compaction control of the stratum under the road, and it proposes relation formula by analyzing the result of static load test.

ICT-based Living in the Contact Type Service Model for Self-life Support of the Elderly Living Alone (독거노인 자가생활지원을 위한 ICT기반의 생활밀착형 서비스 모델 개발)

  • Kim, Mi-Yun;Seo, Dong-Jo;Byun, Jong-Bong;Kang, Jong-Kwan
    • Journal of Digital Convergence
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    • v.13 no.4
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    • pp.25-38
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    • 2015
  • In case of current South Korea, the rapid graying is in the progress. Because of it, the increase of elders who live alone causes variety of social, economic and national problems. Especially in the modern city, the health care, safety and maintenance of pleasant and joyful life of elders who live alone are being a big social issue. Even though practical services have been tried at the whole of government approach, the detailed alternatives are insufficient to improve the daily life support and service to approach the information. This research suggests the "ELA Service Model" which actively improves the easy access to information and corresponds to condition and circumstance of elders for providing the ICT-base Elderly Living alone care service. It is a step self-life support service based on fundamental desire of elders which resolves the problem and contributes to establish the active and balanced policy to the elderly.

Amber Information Design for Supporting Safe-Driving Under Local Road in Small-scale Area (국지지역에서의 안전운전 지원을 위한 경보정보 설계)

  • Moon, Hak-Yong;Ryu, Seung-Ki
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.5
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    • pp.38-48
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    • 2010
  • Adverse weather (e.g. strong winds, snow and ice) will probably appear as a more serious and frequent threat to road traffic than in clear climate. Another consequence of climate change with a natural disastrous on road traffic is respond to traffic accident more the large and high-rise bridge zone, tunnel zone, inclined plane zone and de-icing zone than any other zone, which in turn calls for continuous adaption of monitoring procedures. Accident mitigating measures against this accident category may consist of intense winter maintenance, the use of road weather information systems for data collection and early warnings, road surveillance and traffic control. While hazard from reduced road friction due to snow and ice may be eliminated by snow removal and de-icing measures, the effect of strong winds on road traffic are not easily avoided. The purpose of the study described here, was to design of amber information the relationship between traffic safety, weather, user information on road weather and driving conditions in local-scale Geographic. The most applications are the optimization of the amber information definition, improvements to road surveillance, road weather monitoring and improved accuracy of user information delivery. Also, statistics on wind gust, surface condition, vehicle category and other relevant parameters for wind induced accidents provide basis for traffic control, early warning policies and driver education for improved road safety at bad weather-exposed locations.

Urban Forestry's Scientic System and it's Application to Urban Openspace (都市林學(Urban Forestry)의 學問的 體系와 都市綠地空間에 對한 適用 硏究)

  • Cho, Young-Hwan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.18 no.3 s.39
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    • pp.171-190
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    • 1990
  • It is the purpose of this study to address how to manage the urban vegitation using the concept of Urban Forestry which is relatively new to Korea. When we consider the Urban Forestry as a science, We should understand it interdisciplinary subject which includes Forestry, Horticulture, Urban Planning, Landscape Design, Landuse Planning, Business and Humanities. It may say that people and tree are the fundermental components of Urban Forestry. So there are two ways of Urban Forestry Applications-How people care for trees and How trees care for People-. For the application, this study places the focus on the monetary valuation, tree inventory system and traditional forestry application to urban forest management. Pubic Relation, Communication, Ordinances and Budget are also mentioned as a part of Urban Forestry Policy. Monetary valuation of trees and forests is very important for the proper cognition of their real value. So that, they may be equated and weighed against conflicting uses which would cause to be removed or severely mutilated. A tree inventory system which is the essential part of urban tree management can provide the pertinent information about the present condition of urban tree resource. It may aid in reducing the subjectivity of tree management decisions and stimulate them to be made rapidly and can help reduce potential municipal liability by identifying serious problems in time for corrective maintenance practices to be applied for the maximize community benefits and minimimize public nuisances or hazards. Managers can derive the information from the inventory and use it for the various management plan. When we see the structure of tree inventory system as one of the data base management system, Computer is the best equipment for the efficient management plan. Public relation and communication is also important factors to care the people for urban vegetation management. Volunteer management system is a good example for the public relation and communication. Those skills are need to develop for using the priceless, valuable human resources. Budget holds the key to the execution of Urban Forestry. Good inventory can provide for efficient budgeting stratiges through it's scientific analysis for the way of maximum benefits and minimum costs. Forest can be play a vital role for the aesthetic improvement and recreation in the city. This study suggests that the traditional sivicultural application not only improve the quality of scenic beauty and recreation but also the products of timber. So it is more needed to study for strong and scientific application to urban forest management.

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