• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.5
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• pp.121-132
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• 2009

The agency which is responsible for work related to the restoration of vegetation on the quarry in Hong Kong is the Geotechnical Engineering Office of Civil Engineering and Development Department (CEDD). CEDD's environmental management system was certified as ISO 14001 : 2004 in 2006 and diverse instructions and technical documents about the restoration of the quarry were published and used for the performance of work and the implementation of the project. The restoration of the quarry is being carried out to respond to short-term and long-term goals. The general instructions for the restoration of vegetation says that a plant, when selected, should be self-sustainable with minimum maintenance required, have a high growth and survival rate, be tall enough to cover the rock slope faces, and preferably produce colourful flowers. These instructions prescribe the vegetation introduction technology, planting seasons, structural material of the vegetation works, maintenance and management, tree nursery operation, means of water supply, etc. This report introduced the outline of work on restoring vegetation carried out at Anderson Road, Shek O, Lam Tei, Turret Hill, Lamma, all large-sized quarries. In addition, it additzed Anderson Road's master plan. It is hoped that the Hong Kong examples so introduced are referred to in terms of institutional and technical considerations related to the nation's project for restoring quarries.

• Journal of the Korea Institute of Building Construction
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• v.7 no.1 s.23
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• pp.99-106
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• 2007

Water leakage could be caused deterioration of environmental conditions, user condition, reduction of life span and long term safety in underground concrete structure. Many materials and construction method to repair on these problems have been developed, however, it is not proper to successful repair or raise problem of increasing repair cost However, there are many limitations as practical appraisal methods due to different view of reliability for test methods. Because, it was not enough that the technical objectivity could be lack and also application of environmental condition is inadequate. In this paper, we suggest varied test methods divided to appraisal for property of matter, construction, manufacturing, specification and maintenance, friendly environmental condition. It could be more practical as a objective standard considering various angles. In summery, it should be subdivided and differentiated to accomplish proper application and to select proper materials and construction method for repair even if the synthetical condition is very complicated.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.5
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• pp.511-518
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• 2016

The dynamic positioning system (DPS) maintains an offshore vessel's position and heading under various environmental conditions by using its own thrust. DPS is regarded as one of the most important systems in offshore vessels. So, efficient operation and maintenance of the DPS are important issues. To monitor the DPS, it is necessary to define an appropriate key performance indicator (KPI) that can express the condition of the DPS from the perspective of operational efficiency and maintenance. In this study, a new KPI for the DPS is proposed considering the efficiency of the machinery and controller, the energy efficiency, and the environmental conditions in which the DPS is operated. The KPI is defined as a function of control deviation, energy consumption, and environmental load. A normalization factor is used to normalize the effect of environmental load on the KPI. The KPI value is calculated from DPS simulation and model test data. The possibility of applying the KPI to monitoring of DPS condition is discussed by comparing the values. The result indicates the feasibility of the new KPI.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.04a
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• pp.393-398
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• 2008

The environment is the important resource to use as well as to conserve for the development. Since 1990s, it has accentuated the importance of the environment and tried to conserve the environment in many areas. Among many area, the building industry has played a role to destruct the environment for providing the living decent space and brought the environmental affect. Therefore, the building industry should endeavor to mitigate the environmental affect. In building life cycle, it consumes the energy and natural resources. But it is difficult to evaluate the environmental affect during the whole building life. It is impossible to calculate the environmental affect without the much time and effort. Therefore. it requires the easy and handing program to calculate the affect to environment in each building life cycle. Until now, many program for assessing the affect to the environment have been developed and limitedly used because of the assessment scope and contents. In this paper, it aimed at developing the assessment program of LCA, focused on the energy consumption and carbon-dioxide emission compared with the domestic and foreign concerned programs. The developed program is divided into 3 areas; construction, maintenance, demolition.

• Smart Structures and Systems
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• v.12 no.2
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• pp.209-233
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• 2013

With an annual growth rate of about 30%, wind energy systems, such as wind turbines, represent one of the fastest growing renewable energy technologies. Continuous structural health monitoring of wind turbines can help improving structural reliability and facilitating optimal decisions with respect to maintenance and operation at minimum associated life-cycle costs. This paper presents an integrated monitoring system that is designed to support structural assessment and life-cycle management of wind turbines. The monitoring system systematically integrates a wide variety of hardware and software modules, including sensors and computer systems for automated data acquisition, data analysis and data archival, a multiagent-based system for self-diagnosis of sensor malfunctions, a model updating and damage detection framework for structural assessment, and a management module for monitoring the structural condition and the operational efficiency of the wind turbine. The monitoring system has been installed on a 500 kW wind turbine located in Germany. Since its initial deployment in 2009, the system automatically collects and processes structural, environmental, and operational wind turbine data. The results demonstrate the potential of the proposed approach not only to ensure continuous safety of the structures, but also to enable cost-efficient maintenance and operation of wind turbines.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.1
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• pp.41-51
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• 2015

Gosan Yoon, Sundo's Gumswae-dong Garden Heritage has been designated as a National Historical Site 432 including Hyunsan old fortress wall. The site requires maintenance planning. For the plan, it also requires the consideration of Gosan's written documents describing the garden heritage and the site survey with on-site inspections for authentic maintenance approaches. It should be based on the thorough comprehension of historical remains. The site is a traditional ancient garden, so its approaches should be different with a historic structure and building. For the planning, the study conducts the interview of residents and experts, literature review, the investigation of historical materials, site survey, and the analysis of aerial photography. The results are following:5) Firstly, the paper suggests three types of an excavation area selection: core, recommend and investigation. Secondly, of 22 landscapes named by Gosan, it has the plan of guidance facilities, vegetation maintenance, safety facilities, landscape maintenance as view points, pathway maintenance, deck, and halting place. Thirdly, it also suggests pathway plan for authentic garden promenade according to the literature of Gumswaedong-Gi, an old map and aerial photography(1967, 1976, 1990), and interviews with residents. Fourthly, it suggests vegetation refurbishment at the site to check erection time and to require a preservation plan. In a case of no historic remains part, it also has a plan of amenities for visitors and wetlands for biodiversity of ecology and landscape. Finally, although it requires excavation and more historical evidences for the Hyunsan fortress wall, it suggests a maintenance plan of Pyeonchuksseong and Hyeopchuksseong partially.

• International Journal of Reliability and Applications
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• v.5 no.4
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• pp.115-128
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• 2004

Reliability of a power supply timber pole depends on complex combination of age, environmental factors involved in deterioration process ans inspection and maintenance actions influencing reliability and safety. In this paper soil and human factors are identified, models have been developed and analyzed for optimal maintenence decisions related to electrical power supply timber poles.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.715-722
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• 2016

Most of the domestic railroad tracks are ballast track and repetitive maintenance is required in this track. Therefore, it is necessary to optimize maintenance process for maintenance cost reduction and more effective maintenance. For this, it is important to develop a reasonable settlement progressive model of ballast layer. However, the behavior of ballast is different to that of soils, since ballast is composed of large coarse gravel. Thus, in this study, we carried out numerical analysis by using the discrete element method (PFC 2D) for better understanding of ballast settlement and development of reasonable settlement progressive model. And, we evaluated the settlement of ballast according to particles shape, porosity and loading conditions.

• Journal of Korean Society on Water Environment
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• v.28 no.2
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• pp.202-212
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• 2012

Due to the deterioration of water supply network and the deficiency of raw water, the water utility of local governments have performed various projects to improve their revenue water ratio. However, it is very difficult to estimate the cost for maintaining the revenue water ratio at higher level after completing the project, because local governments have different conditions affecting the operating and maintenance cost of water supply network. The purpose of this study is to present a procedure to estimate the operating and maintenance cost required to maintain the target revenue water ratio of the water supply network. For this purpose, we estimated the cost used only for operation and maintenance of water supply network of 164 local governments with the aid of K-Mean Clustering Analysis and the data from 40 representative local governments. Then, the regression analysis was performed to find relationship between revenue water ratio and the operating and maintenance cost with two different data sets generated by two classification methods; the first method classifies the local governments by means of k-means clustering, and the other classifies the local governments according to the index standardized by the operating and maintenance cost per unit length of water mains per revenue water ratio. The results shows that the method based on the index standardized by the cost and revenue water ratio of each government produces more reliable results for finding regression equations between revenue water ratio and the operating and maintenance cost only for water supply network. The estimated regression equations for each group can be used to estimate the cost required to keep the target revenue water ratio of the local government.

• International Journal of Highway Engineering
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• v.15 no.5
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• pp.91-99
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• 2013

PURPOSES : This study aims at proposing the methodology for benefit evaluations in pavement maintenance methods and timings using KoPMS(Korean Pavement Management System) software which was developed for efficient pavement management. METHODS : This study classified pavement sections into 4 clusters considering AADT(Annual Average Daily Traffic) and ESAL(Equivalent Single-Axle Load) using cluster analysis and used the deterioration models in each cluster. Increased user costs due to pavement deterioration as time goes by and agent costs for maintenance were estimated. Based on deterioration model and KoPMS software, Methodology for benefit evaluation was proposed in pavement maintenance methods and with/without implementation using real pavement section data. RESULTS : This study verified that considering agent costs only would be constrained to decide pavement maintenance methods and timings, and ascertained that decision making with agent and user costs would be effective. In addition, this study revealed that pavement maintenance methods and timings can be affected by AADT and ESAL and frequent pavement maintenances can be more efficient for benefits in pavement sections with more AADT and ESAL. Also this study found that user costs would be more affected to decision making than agent costs. Moreover, Delay of conducting pavement maintenance caused increased vehicle operating costs and environmental costs because of poor conditions of pavements. CONCLUSIONS : This study proposed LCCA and benefit estimation methodology of pavement with considering agent and user costs. The results of this study can be used for baseline data of efficient pavement asset management.