• Journal of Korean Society of Water and Wastewater
• /
• v.29 no.2
• /
• pp.271-281
• /
• 2015

• Journal of the Earthquake Engineering Society of Korea
• /
• v.18 no.6
• /
• pp.271-278
• /
• 2014

Seismic intensity deduced from instrumental data has been evaluated using the empirical relationship between intensity and peak ground acceleration (PGA) during an earthquake. The Japan Meteorological Agency (JMA) developed a seismic intensity meter, which can estimate the real-time seismic intensity from seismic motions observed at a local site to evaluate the damage during the earthquake more correctly. This paper proposes a practical application of the JMA intensity to dams during the 2013 earthquake in Yeongcheon, Korea. In the present paper, seismic intensity was estimated from the relationships between accelerations observed at Yeongcheon Dam. Estimated seismic intensities were in the range of 0 to 3, which was verified from the displacements of dams and the variation of the ground water level observed at Yeongcheon dam during the earthquake. The JMA intensity, which is determined by considering the frequency, duration of cyclic loading, etc., was 0 (zero) and there was no damage to Yeoncheon dam during the earthquake.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2005.05a
• /
• pp.51-56
• /
• 2005

It does not find for solution by limitation of technological mechanism of existent of leakage maintenance material. So, it is paid for huge expense because continuous repeat maintenance work is consisting. Furthermore, it is indicated by big problem in construction work that is constructed by field experience that thing by definite and systematic theory is not with proper performance test and analysis up to now. Therefore, wish to measure physical performance change by various environment condition maintenance of structure and performance construction work aspect in that apply to water leakage maintenance material using of acrylic resin system water expansion, leakage maintenance material in this research, and present suitable form of construction work under these environment. also, wish to ready diversified remedy by oversea market opening.

• Journal of Korea Water Resources Association
• /
• v.43 no.7
• /
• pp.609-623
• /
• 2010

In this paper the feedback loop mechanisms that are inherent in the management of water supply systems were identified based on the system dynamics modeling methodology. As a result, a system dynamics (SD) computer simulation model that can be used to aid efficient management of water supply systems was developed. The developed SD model can be used to predict operating conditions of water supply systems including the effects of pipe maintenance on the entire system. The developed model is consisted of water supply, pipe maintenance and water supply business finance model. The operation and maintenance data from a study water supply system were used to verify the model and to predict the past and future operating conditions of the system. The policy leverage that greatly affects the operating condition was evaluated by the sensitivity analyses for the operational indices due to changes in the exogenous variables. It was found that while the pipe maintenance related exogenous variables had great effects on the leakage and conditions of pipes, they did not have great effects on the major operational indices such as revenue water ratio. It is considered that the social costs due to leaks and pipe breaks and the corresponding mechanism of propagation of the costs must be modeled to better evaluate the effects of pipe maintenance on the operational conditions of water supply systems.

• Journal of Korean Society of Rural Planning
• /
• v.12 no.1 s.30
• /
• pp.11-21
• /
• 2006

The purpose of this study is to verify the result of the previous studies and to clarify the types and activation factors of maintenance activities of the naturally favorable water space through the participation of residents in rural areas, through a further survey of the area proposed as a program in the existing study review and previous study related to the participation of residents. The survey was conducted through the survey of 1,242 households and 1,335 persons intended for Japanese rural areas. The study result is summarized as follows. The types of the maintenance activities in the areas intended for the survey have been classified into 'rural type' and 'combination type' through the analysis results by the references like the comparison analysis, job percentage and main utilization purpose of facilities for each type of maintenance and operation activities. In case of the 'rural type' area, residents were doing maintenance activities centered on the group activities rather than personal maintenance activities. Also, the activities of maintenance & operation group members were more active than non-members, and the water-friendly utilization to the facilities was not directly affecting the maintenance activities of residents. In case of the 'combinational type' area, there was no common characteristic according to each area, and the participation percentage in the maintenance activities was low compared with the 'rural type' area. According to the analysis result based on the participation degree of personal maintenance activities, the repair of facilities as a naturally favorable water space, implementation of projects reflecting the opinions of residents, educational programs conducted in order to motivate the participation of residents, etc. have been analyzed as the factors affecting the activation of maintenance activities of residents. Through the above results, for continuous maintenance activities to be made with residents as a main body in the future, it is necessary to support maintenance groups on an administrative level and procure experts for the production and operation of programs that can increase the participation percentage of residents.

• Proceedings of the KIEE Conference
• /
• 2007.11b
• /
• pp.63-65
• /
• 2007

Recently with increase consumption of electric power, the scale of the electric system becomes bigger and complex. Then, it is increasing the hardship in the operation of electric system and the continuance of stability. Especially, as the differences between demand and supply in electric power keeping low frequency oscillating attenuation from electric power have been very important in the continuance part of stability. The more control time of electricity system is getting faster with digitalization the more stability of electricity system is getting worse. As solutions of these problems, by establishing Power System Stabilizing Controller putting PSS output signal and putting damping to vibration of the rotor at generators's AVR in area where is oscillated, We are willing to contribute the electricity system by holding in generator output vibration.

• Journal of Wetlands Research
• /
• v.15 no.3
• /
• pp.317-328
• /
• 2013

The aim of this study is to compare the effects of the maintenance water supply methods on the ecological restoration of 5 urban streams such as Mugeo cheon, Yaksa cheon, Yeocheon cheon, Myeongjeong cheon and Cheokgwa cheon in Ulsan metropolitan city. Water quality of the streams have been innovatively improved and the ecosystems have gradually been restored by supplying maintenance water constantly. However, we found that if the maintenance water was in a state of higher salinity or low quality, even enough supply was not helpful and even harmful for ecological restoration. We confirmed that the most important things to create or maintain from the urban stream to the ecological stream are that facilities like a walkway construction should be installed at least, supplying appropriate maintenance water, and a connection with the main stream.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.424-425
• /
• 2008

This paper presents application of RCM(Reliability Centered Maintenance) in waterworks system. The reliability-based probability model for predicting the failure probability is established and FTA(Fault Tree Analysis) is proposed to considering RCM. To calculate failure probability, Weibull distribution is usually used due to age related reliability. FTA is an engineering analysis which is using logic symbols. The real historical data of CMMS(Computerized Maintenance Management System) make full use of case study for waterworks system. Consequently, the RCM would be likely to permit utilities to reduce overall costs in maintenance and improve the total benefit.

• Journal of Korean Society of Water and Wastewater
• /
• v.28 no.6
• /
• pp.669-679
• /
• 2014

3D-based BIM(Building Information Modeling) technologies can be utilized effectively as a means of systematic management of facility information for safety assurance and effective maintenance of waterworks facilities. In this study, BIM models of water treatment facilities that can be used as basic data for BIM-based maintenance of waterworks facilities were developed. Information exchange and generality of the developed BIM models were evaluated by conducting interoperability analysis of IFC(Industry Foundation Classes) conversion models. In addition, the application of COBie(Construction Operations Building information exchange) was recommended as an effective countermeasure to deal with technical limitation regarding exchange and utilization of facilities-related information through current IFC models. The results of this study can contribute to the development of BIM-based maintenance system for waterworks facilities.

• Journal of Environmental Impact Assessment
• /
• v.28 no.3
• /
• pp.263-274
• /
• 2019

The purpose of this study is to examine a monitoring method, management zones, and maintenance strategies for water friendly facilities in urban streams after the completion of ecological restoration projects. Maintenance monitoring items are composed of 'use space& facilities', 'trails& bike roads', 'access', and 'boards'. The evaluation standards of water friendly facilities are 'maintenance conditions', 'safety', and 'usage level' which are rated as 'good', 'moderate', and 'poor'. Through a field survey and evaluation of 15 stream sections in Jeonjucheon,the management levels of each water friendly facility are determined as 'priority maintenance', 'general maintenance', 'maintain/remove', and 'remove'. Based on the evaluation results, management zones and maintenance strategies are proposed for each stream section. As a results, the stream sections of J2, J3, J4, and J9 which have 5 to 9 facilities with 'priority maintenance' are determined as 'intensive management zone'. The stream sections of J5, J6, J7, J8, J11, and J14 which have 1 to 3 facilities with 'priority maintenance' are determined as 'regular management zone'. The stream sections of J1, J10, J12, J13, and J15 which have no facilities with 'priority maintenance' are determined as 'minimum management zone'. The process of monitoring & evaluation system and determining management zones can be applied to establish a systematic maintenance plan for water friendly facilities by participation of governance in the future.