• 제목/요약/키워드: Maintenance strategy

검색결과 521건 처리시간 0.02초

VVVF 도시철도 차량의 신뢰성 평가 시스템 개발에 관한 연구 (A Study on Development of the Reliability Evaluation System for VVVF Urban Transit)

  • 배철호;김성빈;이호용;장석화;서명원
    • 한국자동차공학회논문집
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    • 제13권5호
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    • pp.7-18
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    • 2005
  • Over the past twenty years, the maintenance system has been developed and its importance has been increased. For the effective maintenance of the urban transit, we have developed the maintenance system based on the concept of RCM(Reliability Centered Maintenance). RCM analysis is a systematic approach to developing a cost-effective maintenance strategy based on the various components's reliability of the system in question. It is performed according to process that includes the following steps; definition of function and functional failures of the systems, construction of RB D(Reliability Block Diagram), performance of FMEA(Failure Modes & Effects Analysis) and calculation of the reliability index. The final process of RCM is to determine appropriate failure maintenance strategies. This paper aims to define the procedure of maintenace based on the concept of RCM for urban transit. The key for a successful maintenance system is an automated scheduling to the maximum extent possible and timely executions. The developed system issues maintenance plan and repair request based on analyzed data and maintenance experience.

Pemetrexed Continuation Maintenance versus Conventional Platinum-Based Doublet Chemotherapy in EGFR-Negative Lung Adenocarcinoma: Retrospective Analysis

  • Paik, Seung Sook;Hwang, In Kyoung;Park, Myung Jae;Lee, Seung Hyeun
    • Tuberculosis and Respiratory Diseases
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    • 제81권2호
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    • pp.148-155
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    • 2018
  • Background: Although targeted therapy and immuno-oncology have shifted the treatment paradigm for lung cancer, platinum-based combination is still the standard of care for advanced non-small cell lung cancer (NSCLC). Pemetrexed continuation maintenance therapy has been approved and increasingly used for patients with nonsquamous NSCLC. However, the efficacy of this strategy has not been proven in patients without driving mutations. The objective of this study was to compare the clinical benefit of pemetrexed continuation maintenance to conventional platinum-based doublet in epidermal growth factor receptor (EGFR)-negative lung adenocarcinoma. Methods: A total of 114 patients with EGFR-negative lung adenocarcinoma who were treated with platinum doublet were retrospectively enrolled. We compared the survival rates between patients received pemetrexed maintenance after four-cycled pemetrexed/cisplatin and those received at least four-cycled platinum doublet without maintenance chemotherapy as a first-line treatment. Results: Forty-one patients received pemetrexed maintenance and 73 received conventional platinum doublet. Median progression-free survival (PFS), which was defined as the time from the day of response evaluation after four cycles of chemotherapy to disease progression or death, was significantly higher in the pemetrexed maintenance group compared to conventional group (5.8 months vs. 2.2 months, p<0.001). Median overall survival showed an increasing trend in the pemetrexed maintenance group (22.3 months vs. 16.1 months, p=0.098). Multivariate analyses showed that pemetrexed maintenance chemotherapy was associated with better PFS (hazard ratio, 0.73; 95% confidence interval, 0.15-0.87). Conclusion: Compared to conventional platinum-based chemotherapy, premetrexed continuation maintenance treatment is associated with better clinical outcome for the patients with EGFR wild-type lung adenocarcinoma.

몬테카를로 시뮬레이션 기반 부유 쓰레기 차단막 유지관리 비용 추정 방안 (Monte Carlo Simulation-Based Cost Estimation for Floating Trash Barrier Maintenance)

  • 김석환;김태건;김홍조
    • 대한토목학회논문집
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    • 제44권2호
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    • pp.231-235
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    • 2024
  • 강물을 통해 유입되는 해양 부유 쓰레기는 환경에 부정적인 영향을 주며, 인간의 건강에도 직접적인 위협이 된다. 부유 쓰레기의 유출을 막기 위한 차단시설물을 설치하고 있지만 이들 시설의 유지보수, 특히 차집 쓰레기 수거 스케줄링 대한 관심은 미비하다. 현재 유지관리는 현장 작업자의 경험에 기반한 순차적 수거 방식을 사용하고 있을 뿐이며, 이를 위한 체계적인 연구는 미비하다. 이에 AI기술인 YOLOv7기반 차집량 분석 모니터링 기술을 이용한 새로운 피드백 기반 수거 비용 추정 프레임워크를 제안한다. 제안하는 수거 방식은 CCTV 등의 원격 센서로부터 측정된 차집 쓰레기 정보량을 토대로 수거를 진행하며, MCS로 예상 금액을 통계적으로 경제적 비교를 하였다. 결과적으로 신규 수거 전략을 이용한 방식은 기존 수거 전략 대비 약 63 %의 비용적 우위를 보였다.

중국 ASP 시장 분석과 한국 기업의 진입 전략에 대한 시사점 (Analysis of Chinese ASP Market and Implications for Korean Firm's Chinese Market Entry Strategy)

  • 김대호;권순동
    • Journal of Information Technology Applications and Management
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    • 제13권1호
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    • pp.95-116
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    • 2006
  • Many SMEs have adopted ASP models which have brought various benefits to SMEs such as decreasing the total cost, using new IT technology, enhancing the maintenance, and implementing the information systems rapidly. Ministry of Information and Communication had implemented the ASP diffusion project for the ASP venders and SMEs between 2001 and 2003. As results of this project, various industries adopted the ASP applications of which the performance was enhanced, and then the competitiveness of the ASP vendors in Korea was increased. The purpose of this study is to make a strategy of the penetration into China market for ASP services which have competitive advantages. This study uses various research methods such as questionnaire survey, visiting SMEs in china and making interviews. This study shows the current status of Chines ASP market, the several cases of using ASP services, and questionnaire analyses(service recognition, service requirement and factors and infrastructure, business environment and supporting organizations etc) of ASP demand. And finally this study proposes several strategic considerations in entering China market and suggests several support policies for supporting Korean ASPs.

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인공 면역계 기반 자율분산로봇 시스템의 협조 전략과 군행동 (Cooperative Strategies and Swarm Behavior in Distributed Autonomous Robotic Systems Based on Artificial Immune System)

  • 심귀보;이동욱;선상준
    • 제어로봇시스템학회논문지
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    • 제6권12호
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    • pp.1079-1085
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    • 2000
  • In this paper, we propose a method of cooperative control (T-cell modeling) and selection of group behavior strategy (B-cell modeling) based on immune system in distributed autonomous robotic system (DARS). An immune system is the living bodys self-protection and self-maintenance system. these features can be applied to decision making of the optimal swarm behavior in a dynamically changing environment. For applying immune system to DARS, a robot is regarded as a B-cell, each environmental condition as an antigen, a behavior strategy as an antibody, and control parameter as a T-cell, respectively. When the environmental condition (antigen) changes, a robot selects an appropriate behavior strategy (antibody). And its behavior strategy is stimulated and suppressed by other robots using communication (immune network). Finally, much stimulated strategy is adopted as a swarm behavior strategy. This control scheme is based on clonal selection and immune network hypothesis, and it is used for decision making of the optimal swarm strategy. Adaptation ability of the robot is enhanced by adding T-cell model as a control parameter in dynamic environments.

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Cooperative Strategies and Swarm Behavior in Distributed Autonomous Robotic Systems based on Artificial Immune System

  • Sim, Kwee-bo;Lee, Dong-wook
    • 한국지능시스템학회논문지
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    • 제11권7호
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    • pp.591-597
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    • 2001
  • In this paper, we propose a method of cooperative control (T-cell modeling) and selection of group behavior strategy (B-cell modeling) based on immune system in distributed autonomous robotic system (DARS). Immune system is living body's self-protection and self-maintenance system. These features can be applied to decision making of optimal swarm behavior in dynamically changing environment. For applying immune system to DARS, a robot is regarded as a B-cell, each environmental condition as an antigen, a behavior strategy as an antibody and control parameter as a T-cell respectively. The executing process of proposed method is as follows. When the environmental condition changes, a robot selects an appropriate behavior strategy. And its behavior strategy is stimulated and suppressed by other robot using communication. Finally much stimulated strategy is adopted as a swarm behavior strategy. This control school is based on clonal selection and idiotopic network hypothesis. And it is used for decision making of optimal swarm strategy. By T-cell modeling, adaptation ability of robot is enhanced in dynamic environments.

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도시철도 토목시설물 유지관리를 위한 데이터베이스 구축방안 연구 (Development of the Database System for Maintenance of Civil Facilities in Urban Transit)

  • 신정렬;김길동;이우동;박서영
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 춘계학술대회 논문집
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    • pp.1108-1113
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    • 2004
  • While the environment of usage of information and technology is getting stable and technology is being developed more deeply due to the globalization, making information, standardization, in order to make a fast response to the new industry strategy and business environment, mutual communication and management of correct and fast information are focused on as fundamental elements of keeping competitive power. Accordingly strategic development of urban transit operation organization, storage of information technology of urban railroad, and buildup of standard information infra are very important, so that computerized information system has been built up standardizing efficient maintenance framework of urban transit facilities. To maintain these facilities efficiently, storing the real-time information by standardizing the maintenance organization and building up computerized information system are very important with management of information history of existing maintenance work. Therefore, for the efficient maintenance of civil facilities among urban transit facilities, standardized facilities classification and definition of management elements, and the plan of designing and building standardized database about civil facilities through standardizing technology resources are described in this paper.

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도시철도 선로시설물 유지관리를 위한 데이터베이스 구축방안 연구 (Development of the Database System for Maintenance of Track System in Urban Transit)

  • 신정렬;이우동;김길동;박서영
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 춘계학술대회 논문집
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    • pp.935-941
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    • 2004
  • While the environment of usage of information and technology is getting stable and technology is being developed more deeply due to the globalization, making information, standardization, in order to make a fast response to the new industry strategy and business environment, mutual communication and management of correct and fast information are focused on as fundamental elements of keeping competitive power. Accordingly strategic development of urban transit operation organization, storage of information technology of urban railroad, and buildup of standard information infra are very important, so that computerized information system has been built up standardizing efficient maintenance framework of urban transit facilities. To maintain these facilities efficiently, storing the real-time information by standardizing the maintenance organization and building up computerized information system are very important with management of information history of existing maintenance work. Therefore, for the efficient maintenance of track system among urban transit facilities, standardized facilities classification and definition of management elements, and the plan of designing and building standardized database about track. system through standardizing technology resources are described in this paper.

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도시철도 역설비 시설물 유지관리를 위한 데이터베이스 구축 방안 연구 (Development of the Database System for Maintenance of Station Facilities in Urban Transit)

  • 이우동;신정렬;이호용;안태기
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 춘계학술대회 논문집
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    • pp.1221-1226
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    • 2004
  • While the environment of usage of information and technology is getting stable and technology is being developed more deeply due to the globalization, making information, standardization, in order to make a fast response to the new industry strategy and business environment, mutual communication and management of correct and fast information are focused on as fundamental elements of keeping competitive power. Accordingly strategic development of urban transit operation organization, storage of information technology of urban railroad, and buildup of standard information infra are very important, so that computerized information system has been built up standardizing efficient maintenance framework of urban transit facilities. To maintain these facilities efficiently, storing the real-time information by standardizing the maintenance organization and building up computerized information system are very important with management of information history of existing maintenance work. Therefore, for the efficient maintenance of station facilities among urban transit facilities, standardized facilities classification and definition of management elements, and the plan of designing and building standardized database about station facilities through standardizing technology resources are described in, this paper.

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체중감량 이후 장기적인 유지를 위한 다양한 행동전략 (Behavioral Strategies for Weight Loss Maintenance)

  • 조영혜
    • 비만대사연구학술지
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    • 제2권1호
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    • pp.6-10
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    • 2023
  • Compensatory changes in energy consumption and neuro-hormonal changes following weight loss make it difficult to maintain the reduced weight and may cause weight regain. Therefore, establishing a long-term weight control plan and strategy starting from the initial weight loss period is necessary. Both the patient and doctor should know that weight loss cannot occur continuously, and that maintaining weight after the weight loss period is the basic course of obesity treatment. No single dietary pattern is effective for weight maintenance, and a variety of dietary control methods - such as calorie restriction and healthy proportions of carbohydrates, proteins, fats, and meal replacements - should be used to target an integrated and healthy dietary habit. An increase in physical activity is needed for weight loss and maintenance; however, rather than recommending an excessive amount of exercise, it is better to set realistic and long-term achievable goals. It is necessary to reset the goal according to the patient's weight maintenance stage and continuously apply behavioral therapies, such as self-monitoring and stress management. In previous studies, since the degree of weight loss and changes in behavioral patterns over the course of one year were important factors in maintaining long-term weight loss, obesity therapists should closely examine patient data and behavioral patterns across a period of one year and actively intervene when needed.