• Proceedings of the Korean Reliability Society Conference
• /
• 2000.04a
• /
• pp.177-183
• /
• 2000

As monitoring, testing, and measuring techniques develop, predictive control of components and complete systems have become more practical and affordable. In this paper we develop a statistics-based approach assuming nonlinear degradation paths and time-dependent standard deviation. This approach can be extended to provide reliability estimates and limit value determination in the censoring case fur predictive maintenance policy.

• Proceedings of the KSR Conference
• /
• 2002.10a
• /
• pp.574-579
• /
• 2002

This paper proposes the method to develop information system for maintenance of urban transit. We have to develop the standard information system, but have difficult to get user's requirement. To solve this problem, we propose the method, web-based, component-based, and prototype-based development method. Proposed method may provide a procedure to develop information system that have hard to get user's requirement.

• Tuberculosis and Respiratory Diseases
• /
• v.81 no.2
• /
• pp.148-155
• /
• 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.

• Journal of Digital Contents Society
• /
• v.11 no.4
• /
• pp.537-543
• /
• 2010

According to software growth, also software maintenance has been continuously improving. In addition, the existing concept of correct maintenance demands operational management and improvement of service. However, we have various limitation matters to reflect the requirements of service base for maintenance accomplishment. Therefore, we need the study of the service based process for solving such a problem. In this paper, we propose a Service based Software Maintenance Process. Proposed process based on ISO12207 standard for software development and maintenance and compares it with the service based representative standards. In a related works, we study activity of $SM^{MM}$, ITSCMM, ITIL and find out activities to be concerned with and compare it with activity of ISO 12207 and distinguish the maintenance process activity of the service base from maintenance activities. And then, we propose a service management stage. It define four activities and eight artifacts. Finally, we validate the result by comparing the proposed process with a general service operational process.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.142-143
• /
• 2017

An analysis of the current water leak status of understand structure (underground parking lots, staircases, plumbing systems, water reservoirs, etc.) of multi-family housing in South Korea shows that water leaks are found from cracks in all areas of the underground structure caused by the degradation environment (water pressure by underground water, humidity, temperature, earth pressure, soil behaviour and vibration, etc.), which result in various problems, including mold, malodour, debonding of finishing materials, exfoliation, breakout, water leaks in electrical boxes, efflorescence, sedimentation of calcium hydroxide, decoloration, rusting, damages and pollution among others. Therefore, this study aims to analyse the current status of water leaks in underground structure and use the results as the basic data for developing a standard guideline for water leaks and maintenance by parts of the underground structure of multi-family housing.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.11a
• /
• pp.221-222
• /
• 2017

An analysis of the current water leak status of understand structure (underground parking lots, staircases, plumbing systems, water reservoirs, etc.) of multi-family housing in South Korea shows that water leaks are found from cracks in all areas of the underground structure caused by the degradation environment (water pressure by underground water, humidity, temperature, earth pressure, soil behaviour and vibration, etc.), which result in various problems, including mold, malodour, debonding of finishing materials, exfoliation, breakout, water leaks in electrical boxes, efflorescence, sedimentation of calcium hydroxide, decoloration, rusting, damages and pollution among others. Therefore, this study aims to analyse the current status of water leaks in underground structure and use the results as the basic data for developing a standard guideline for water leaks and maintenance by parts of the underground structure of multi-family housing.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.1108-1113
• /
• 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.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.935-941
• /
• 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.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.1221-1226
• /
• 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.

• Journal of Korean Society on Water Environment
• /
• v.22 no.5
• /
• pp.905-912
• /
• 2006

In this paper, simulation methods of the system dynamics model developed by Das et al. (1997) for activated-sludge wastewater treatment plants are illustrated in an attempt to determine the operating rules and the policies related to capacity expansion of an activated-sludge wastewater treatment plant. For existing conditions, the analyses were performed by varying activated-sludge return rate to observe changes in effluent water quality and treatment efficiency. The effluent water quality is also analyzed for various average daily inflow conditions and activated-sludge return rates. As a result, without expanding the aeration tank, maximum average daily inflow that can satisfy the effluent water quality standard of BOD $0.02kg/m^3$ was determined as $2,840m^3/hr$, subject to 100% of activated-sludge return rate while other factors remain constant. When the activated-sludge return rate is less than 100%, expansion of the aeration tank is necessary and minimum sizes of the aeration tank to satisfy the effluent water quality standard were determined for various activated-sludge return rates. In addition, the total operating and maintenance as well as unit treatment cost regression equations for activated-sludge wastewater treatment plants are suggested by using the cost data that are obtained from Water and Wastewater Division, Ministry of Environment. The regression analyses showed that the economies of scale phenomena exist in the operating and maintenance costs of activated-sludge wastewater treatment plants.