• Title/Summary/Keyword: Maintenance Model

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An Empirical Study on Evaluation of Performance Shaping Factors on AHP (AHP 기법을 이용한 수행영향인자 평가에 관한 연구)

  • Jung, Kyung-Hee;Byun, Seong-Nam;Kim, Jung-Ho;Heo, Eun-Mee;Park, Hong-Joon
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.1
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    • pp.99-108
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    • 2011
  • Almost all companies have paid much attention to the safety management ranging from maintenance to operation even at the stage of designing in order to prevent accidents, but fatal accidents continue to increase throughout the world. In particular, it is essential to systematically prevent such fatal accidents as fire, explosion or leakage of toxic gas at factories in order to not only protect the workers and neighbors but also prevent economic losses and environmental pollution. Though it is well known that accident probability is very low in NPP(Nuclear Power Plants), the reason why many researches are still being performed about the accidents is the results may be so severe. HRA is the main process to make preparation for possibility of human error in designing of the NPP. But those techniques have some problems and limitation as follows; the evaluation sensitivity of those techniques are out of date. And the evaluation of human error is not coupled with the design process. Additionally, the scope of the human error which has to be included in reliability assessment should be expanded. This work focuses on the coincidence of human error and mechanical failure for some important performance shaping factors to propose a method for improving safety effectively of the process industries. In order to apply in these purposes into the thesis, I found 63 critical Performance Shaping Factors of the eight dimensions throughout studies that I executed earlier. In this study, various analysis of opinion of specialists(Personal Factors, Training, Knowledge or Experience, Procedures and Documentation, Information, Communications, HMI, Workplace Design, Quality of Environment, Team Factors) and the guideline for construction of PSF were accomplished. The selected method was AHP which simplifies objective conclusions by maintaining consistency. This research focused on the implementation process of PSF to evaluate the process of PSF at each phase. As a result, we propose an evaluation model of PSF as a tool to find critical problem at each phase and improve on how to resolve the problems found at each phase. This evaluation model makes it possible to extraction of PSF succesfully by presenting the basis of assessment which will be used by enterprises to minimize the trial and error of construction process of PSF.

Optimization for Inspecdtion Planning of Ship Structures Considering Corrosion Effects (부식효과를 고려한 선체구조 검사계획안의 최적화)

  • Sung-Chan Kim;Jang-Ho Yoon;Yukio Fujimoto
    • Journal of the Society of Naval Architects of Korea
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    • v.36 no.4
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    • pp.137-146
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    • 1999
  • Inspection becomes to be important in the safety of structure and economical viewpoint, because structural damage accompanies lots of economical cost and social problems. Especially ship structure is composed of a lot of members and it is impossible to inspect all members continuously. The purpose of this paper is to get optimal inspection plan containing inspection time and method. Crack is one of major modes on the structural failure and can lead to collapse of structure. In this paper, the deteriorating process, which contains inspection to detect the crack before the propagation to large crack, is idealized as Markov chain model. Genetic algorithm is also used to accomplish the optimization of inspection plan. Especially, the probabilistic characteristics of cracks are changed, because ship is operating in corrosive environments and the scantling of structural members is reduced due to corrosion. Non-stationary Markov chain model is used to represent the process of corrosion in structural members. In this paper, the characteristics of indivisual inspection plan are compared by numerical examples for the change of corrosion rate, the cost due to scheduled system down and target failure probability. From the numerical example, it can be seen that the improvement of fatigue life for the members with short fatigue life is the most effective way in order to reduce total maintenance cost.

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Acceleration of DNCB-induced Early-apoptosis via Activation of Corticotropin Releasing Factor in the Hair Root of NC/Nga Mice (DNCB로 유도된 NC/Nga 아토피피부염마우스에서 부신피질자극호르몬방출인자 활성에 따른 모발세포의 초기세포사멸 연구)

  • Park, Gunhyuk;Jang, Eunyoung;Kim, Seongbae;Han, Eunyoung;Kim, Yong-ung
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.43 no.4
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    • pp.281-287
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    • 2017
  • Stress in skin plays a significant role in both the direct/indirect regulation of cellular processes occurring in hair, which in turn affect the hair cycle. However, experimental data regarding the effects of stress-related corticotropin releasing factor (CRF) released by stress on the apoptotic process involved in hair is limited. Therefore, we investigated the acceleration of early-stage apoptosis induced by atopy-related stress using a 2,4-dinitrochlorobenzene NC/Nga mice model. Expression of CRF, its related proteins, annexin V, and mitochondrial dysfunction were measured by immunohistochemical analyses. Atopic stress strongly stimulated stress hormones response, such as CRF and adrenocorticotropic hormone, in outer epithelial sheath of the hair. Moreover, its stress induced mitochondrial damage and early-stage apoptosis of cells in hair root. These findings suggest that hair damage due to apoptosis in atopy model is accelerated in a high CRF environment. Importantly, the effect of stress-related CRF on apoptosis processes involved in atopy dermatitis-related hair loss, suggests that the CRF-regulating development or maintenance materials may provide effective therapeutic strategies for hair health.

Modelling Analysis of Climate and Soil Depth Effects on Pine Tree Dieback in Korea Using BIOME-BGC (BIOME-BGC 모형을 이용한 국내 소나무 고사의 기후 및 토심 영향 분석)

  • Kang, Sinkyu;Lim, Jong-Hwan;Kim, Eun-Sook;Cho, Nanghyun
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.4
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    • pp.242-252
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    • 2016
  • A process-based ecosystem model, BIOME-BGC, was applied to simulate seasonal and inter-annual dynamics of carbon and water processes for potential evergreen needleleaf forest (ENF) biome in Korea. Two simulation sites, Milyang and Unljin, were selected to reflect warm-and-dry and cool-and-wet climate regimes, where massive diebacks of pines including Pinus densiflora, P. koraiensis and P thunbergii, were observed in 2009 and 2014, respectively. Standard Precipitation Index (SPI) showed periodic drought occurrence at every 5 years or so for both sites. Since mid-2000s, droughts occurred with hotter climate condition. Among many model variables, Cpool (i.e., a temporary carbon pool reserving photosynthetic compounds before allocations for new tissue production) was identified as a useful proxy variable of tree carbon starvation caused by reduction of gross primary production (GPP) and/or increase of maintenance respiration (Rm). Temporal Cpool variation agreed well with timings of pine tree diebacks for both sites. Though water stress was important, winter- and spring-time warmer temperature also played critical roles in reduction of Cpool, especially for the cool-and-wet Uljin. Shallow soil depth intensified the drought effect, which was, however, marginal for soil depth shallower than 0.5 m. Our modeling analysis implicates seasonal drought and warmer climate can intensify vulnerability of ENF dieback in Korea, especially for shallower soils, in which multi-year continued stress is of concern more than short-term episodic stress.

Study on the police's protection·support of victims-declaring the Victims Protection years (피해자보호원년을 선언한 경찰의 범죄피해자 보호·지원에 관한 연구)

  • Gong, Jung-Sik
    • Korean Security Journal
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    • no.45
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    • pp.7-35
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    • 2015
  • South Korea's socioeconomic status is high enough to support services for the protection of crime victims. Until now, the Ministry of Justice was the only institution to protect and support the victims, but recently the national police is included. This is considered preferable, since the police is the one to contact the victims first- they can provide immediate support after the incident. Several limits in current laws and crime protection system exist. Therefore, given the importance of protecting victims, model of public-private joint forms should be considered. In premise of establishing a new relationship between the public-private joint system of justice and the maintenance, the range of police's involvement with crime supports will be determined. In the case of developed countries, the police and private organizations maintain close cooperation, appearing as substantial care and support for crime victims. Therefore this study reviews the problems in crime victim protection, assistance from the police stage, and suggest the improvements as follows. The first is to redefine the role of the police who first contacted in the crime victims protection support, the second is to establish a permanent cooperation framework, such as victims specialized police, victims protection agency, the third is to develop services for victim protection available from the police stage, and the fourth, opening Victim Support Center functioning as a temporary accommodation or safety zone for the personal protection of victims. The fifth is to regularize solution conference for victims' protection, and the sixth is to divide of roles in state organization government in charge of victim's protection and local government responsible for victim's support.

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Deriving Topics for Safety of Folk Villages Following Scope and Content of ICT-Based DPD

  • Oh, Yong-Sun
    • International Journal of Contents
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    • v.12 no.2
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    • pp.12-23
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    • 2016
  • This paper presents a novel concept of Disaster Prevention Design (DPD) and its derived subjects and topics for the safety of folk villages in both Korea and Japan. Nowadays, design concepts are focused on 'human-oriented nature' as a whole and this tendency fits to be appropriate for disaster prevention against real dangers of a future society, which is expected to have far more complicated features. On the other hand, convergences have performed with other areas in the field of Information Communication Technology (ICT) so that we can easily find examples like 'the strategy of ICT-based convergence' of the Korean Government in 2014. Modern content designs including UI (user interface) and USN (ubiquitous sensor network) have been developed as one of the representative areas of ICT & UD (universal design) convergences. These days this novel concept of convergence is overcoming the existing limitations of the conventional design concept focused on product and/or service. First of all, from that point our deduced topic or subject would naturally be a monitoring system design of constructional structures in folk villages for safety. We offer an integrated model of maintenance and a management-monitoring scheme. Another important point of view in the research is a safety sign or sign system installed in folk villages or traditional towns and their standardization. We would draw up and submit a plan that aims to upgrade signs and sign systems applied to folk villages in Korea and Japan. According to our investigations, floods in Korea and earthquakes in Japan are the most harmful disasters of folk villages. Therefore, focusing on floods in the area of traditional towns in Korea would be natural. We present a water-level expectation model using deep learning simulation. We also apply this method to the area of 'Andong Hahoe' village which has been registered with the World Cultural Heritage of UNESCO. Folk village sites include 'Asan Oeam', 'Andong Hahoe' and 'Chonju Hanok' villages in Korea and 'Beppu Onsen' village in Japan. Traditional Streets and Markets and Safe Schools and Parks are also chosen as nearby test-beds for DPD based on ICT. Our final goal of the research is to propose and realize an integrated disaster prevention and/or safety system based on big data for both Korea and Japan.

Study on the Plan for Reduction of Credit Risk of Medium-size Construction Companies Preparing for Restructuring (구조조정에 대비한 중견건설사 신용리스크 저감방안에 관한 연구)

  • Lee, YunHong
    • Korean Journal of Construction Engineering and Management
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    • v.21 no.5
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    • pp.64-73
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    • 2020
  • The government announced a plan for fund support to the enterprises with high possibility of recovery and early restructuring for the enterprises with low recovery by objectifying credit assessment system. Such announcement of government could be extended to restructuring risk of middle standing enterprises with low financial soundness by establishing the basis to prepare prompt restructuring by reinforcing the basis for restructuring through capital market. This research analyzed financial soundness based on the financial evaluation of bank by selecting 10 middle standing construction companies which focused on housing business in 2019, based on such analysis result, it was confirmed that there was a high possibility of restructuring risk. This research determined that there would be a decrease in growth rate of construction industry on the whole in 2020 due to fall of economic growth rate and reinforced real estate regulation, accordingly, there's a big possibility for middle standing construction companies with paid-in capital ratio due to its low possibility of maintenance of stable credit rating. This research established KCSI assessment model by utilizing the material of a reliable research institute in order for middle standing construction companies to evade restructuring risk, and indicated risk ratio differentiated per each item through a working-level expert survey. Such research result could suggest credit risk reduction method to middle standing construction company management staffs, and prepare a basis to evade restructuring risk.

A Study on the Service Quality Evaluation in Electronic Customs Clearance Making Use of Kano-IGA Integrated Approach (Kano-IGA 통합접근법을 이용한 전자통관 서비스 품질의 평가에 관한 연구)

  • Song, Sun-Yok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.10
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    • pp.54-61
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    • 2019
  • This paper reports a comparative review of the service quality attributes of Electronic Customs Clearance (UNI-PASS) by applying the Kano model, Timko's BW coefficients, and IGA model, as reported by Tontini et al. in terms of a service quality evaluation of electronic customs clearance as the comprehensive national customs administration information system. In addition, this study examined which quality attributes should be focused on to improve the service quality and enhance customer satisfaction using the electronic customs clearance service. The Kano, Timko, and IGA models were classified into the four common quality attributes: attractive quality, one-dimensional quality, must-be quality, and indifferent quality. Because the integrated approach was used, one-dimensional quality was included in the area for critical improvement, while the must-be quality was included in the area for intensive maintenance. In addition, the indifferent quality was included in the area of carefree, while the attractive quality was included in the area of competitive advantage.

A Study on Condition Analysis of Revised Project Level of Gravity Port facility using Big Data (빅데이터 분석을 통한 중력식 항만시설 수정프로젝트 레벨의 상태변화 특성 분석)

  • Na, Yong Hyoun;Park, Mi Yeon;Jang, Shinwoo
    • Journal of the Society of Disaster Information
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    • v.17 no.2
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    • pp.254-265
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    • 2021
  • Purpose: Inspection and diagnosis on the performance and safety through domestic port facilities have been conducted for over 20 years. However, the long-term development strategies and directions for facility renewal and performance improvement using the diagnosis history and results are not working in realistically. In particular, in the case of port structures with a long service life, there are many problems in terms of safety and functionality due to increasing of the large-sized ships, of port use frequency, and the effects of natural disasters due to climate change. Method: In this study, the maintenance history data of the gravity type quay in element level were collected, defined as big data, and a predictive approximation model was derived to estimate the pattern of deterioration and aging of the facility of project level based on the data. In particular, we compared and proposed models suitable for the use of big data by examining the validity of the state-based deterioration pattern and deterioration approximation model generated through machine learning algorithms of GP and SGP techniques. Result: As a result of reviewing the suitability of the proposed technique, it was considered that the RMSE and R2 in GP technique were 0.9854 and 0.0721, and the SGP technique was 0.7246 and 0.2518. Conclusion: This research through machine learning techniques is expected to play an important role in decision-making on investment in port facilities in the future if port facility data collection is continuously performed in the future.

Analysis of Water Quality Variation by Lowering of Water Level in Gangjeong-Goryong Weirin Nakdong River (낙동강 강정고령보 수위저하 운영에 따른 수질 변동특성 분석)

  • Park, Dae-Yeon;Park, Hyung-Seok;Kim, Sung-Jin;Chung, Se-Woong
    • Journal of Environmental Impact Assessment
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    • v.28 no.3
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    • pp.245-262
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    • 2019
  • The objectives of this study were to construct a three-dimensional water quality model (EFDC) for the river reach between Chilgok Weir and Gangjeong-Goryong Weir (GGW) located in Nakdong River, and evaluate the effect of hydraulic changes, such as water level and flow velocity, on the control of water quality and algae biomass. After calibration, the model accurately simulated the temporal changes of the upper and lower water temperatures that collected every 10 minutes, and appropriately reproduced changes in organic matter, nitrogen, phosphorus, and cyanobacteria. However, the simulated values were overestimated for the diatoms and green algae cell density, possibly due to the uncertainties of the parameters associated with algae metabolism and the lack of zooplankton predation function in the simulations. As a result of scenario simulation of running the water level of GGW from EL. 19.44 m to EL. 14.90 m (4.54 m drop), Chl-a and algae cell density decreased significantly.In particular,the cyanobacteria on the surface layer, which causes algal bloom, declined by 56.1% in the low water level scenario compared to the existing management level. The results of this study are in agreement with the previous studies that maintenance of critical flow velocity is effective for controlling cyanobacteria, and imply that hydraulic control such as decrease of water level and residence time in GGW is an alternative to limit the overgrowth of algae.