• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1C
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• pp.65-76
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• 2010

Recent earthquake events revealed that severe seismic damages were concentrated mostly at sites composed of soil sediments rather than firm rock. This indicates that the site effects inducing the amplification of earthquake ground motion are associated mainly with the spatial distribution and dynamic properties of the soils overlying bedrock. In this study, an integrated GIS-based information system for geotechnical data was constructed to establish a regional counterplan against ground motions at a representative metropolitan area, Seoul, in Korea. To implement the GIS-based geotechnical information system for the Seoul area, existing geotechnical investigation data were collected in and around the study area and additionally a walkover site survey was carried out to acquire surface geo-knowledge data. For practical application of the geotechnical information system used to estimate the site effects at the area of interest, seismic zoning maps of geotechnical earthquake engineering parameters, such as the depth to bedrock and the site period, were created and presented as regional synthetic strategy for earthquake-induced hazards prediction. In addition, seismic zonation of site classification was also performed to determine the site amplification coefficients for seismic design at any site and administrative sub-unit in the Seoul area. Based on the case study on seismic zonations for Seoul, it was verified that the GIS-based geotechnical information system was very useful for the regional prediction of seismic hazards and also the decision support for seismic hazard mitigation particularly at the metropolitan area.

• International Journal of Contents
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• v.3 no.1
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• pp.14-18
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• 2007

General replacement policy includes document-based LRU or LFU technique and other various replacement policies are used to replace the documents within cache effectively. But, these replacement policies function only with regard to the time and frequency of document request, not considering the popularity of each web site. In this paper, we present the document replacement policies with regard to the popularity of each web site, which are suitable for modern network environments to enhance the hit-ratio and efficiently manage the contents of cache by effectively replacing documents on intermittent requests by new ones.

• Journal of the speleological society of Korea
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• no.5
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• pp.5-14
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• 1997

This research is to survey the possibility of developing Yoryang coral cave as the local tour site uitable for local self-government era of Kangwon province, with relation to the tour development of Odaesan and Tebagsesan. This cave is only coral one founded in Asia and has very high speleological, and academic values. The people in the mining village can live a safe and rich life by getting two more jobs through developing the tour site in Yoryang coral cave round. The tour train running between Kangnung and Wonju makes coral cave as the local tour site, the beneficial condition of developing Yoryang.

• Journal of the Korean Solar Energy Society
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• v.33 no.2
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• pp.101-107
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• 2013

It is evident that in the wind energy business as an economic activity there is a close relationship between the wind speed and the revenues. The wind turbine test facility for wind turbine accreditation is intended to be used by the industry for testing of both main components and systems. This paper suggest the wind test site for certification of prototype wind turbine with international regulations. The test site has an environmental permit for wind turbines with a maximum hub height of 120m and a rotor diameter up to 120m, and can accommodate prototypes with installed electrical powers up to 5MW each. A wind turbine manufacturer can lease the location for a period of type certification. And also researchers are the development of new methods for measuring the influence, performance and durability of the components, a mathematical and numerical modelling of component responses by using the site.

• Environmental Engineering Research
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• v.19 no.3
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• pp.269-274
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• 2014

On-site sanitation systems are typically installed to treat grey and toilet wastewaters in areas without sewer and centralized treatment systems. It is well known that, due to inappropriate design and operation, treatment performance of these systems in developing countries is not satisfactory in the removal of pathogens and organic matters. This research aimed to investigate the hydraulic conditions occurring in some on-site sanitation systems and the effects of hydraulic retention times (HRTs) on the system performance. The experiments were conducted with a laboratory-scale septic tank (40L in size) and an actual septic tank (600L in size), to test the hydraulic conditions by using tracer study with HRTs varying at 12, 24 and 48 hr. The experimental results showed the dispersion numbers to be in the range of 0.017-0.320 and the short-circuit ratios in the range of 0.014-0.031, indicating the reactors having a high level of sort-circuiting and approaching complete-mix conditions. The removal efficiency of $BOD_5$ was found to be 67% and the $k_{30}$ values for $BOD_5$ was $2.04day^{-1}$. A modified complete-mix model based on the relationship between $BOD_5$ removal efficiencies and HRTs was developed and validated with actual-scale septic tank data having a correlation coefficient ($R^2$) of 0.90. Therefore, to better protect our environment and minimizing health risks, new generation toilets should be developed that could minimize short-circuiting and improving treatment performance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1C
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• pp.63-74
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• 2008

Site response analyses were performed based on equivalent linear technique using the local geologic and dynamic site characteristics, which include soil profiles, shear wave velocity profiles and depth to bedrock for 125 sites collected in Korean Peninsula. From the results of site response analyses, 2-parameters site classification system based on the combination of mean shear wave velocity of soil and depth to bedrock was newly recommended for regions of shallow bedrock depth in Korea. First, as the borders of bedrock depth (H) for site classification were determined as 10m and 20m, the soil sites were divided into 3 classes as $H_1$, $H_2$ and $H_3$ sites. And then, the 3 site classes were subdivided into 7 classes based on the mean shear wave velocity of soil ($V_{s,soil}$). The feasibility of new site classification system was verified and the representative site coefficients ($F_a$ and $F_v$) and design response spectrum were suggested by analyzing uniform trend and dispersion of site coefficients for each site class. The suggested site coefficients and the regression curves present the nonlinear characteristics of soils according to the change of rock outcrop acceleration with uniform trend effectively. From the comparison between the mean values of response spectrum which was acquired from the site response analysis and the suggested design response spectrum, there was a little difference in some of site classes and it was verified to adjust the integration interval to make it more suitable for the site condition in Korea.

• Journal of Engineering Education Research
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• v.15 no.6
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• pp.71-79
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• 2012

In this paper, we present, based on a systematic job analysis, the definition, flowchart and description of Ship Building & Ocean Engineering Technician's job in Ship Building & Ocean Engineering Industry for developing an Ship Building & Ocean Engineering education and training program in the context of Korea situation. In addition, it is suggested that the courses be directed toward job site-centered reform through conducting job analysis with experts in the environmental industry. serving new courses demanded by industries in practice and providing training programs for industries.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.42-53
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• 2015

Construction industry has the form of industry progressed through mutual cooperation among participants in various fields. Accordingly, it may be referred to as an aggregate of information where various pieces of information are generated and managed according to each construction phase. Most of the information on the construction project is issued in the form of a document. And document management of the site is critical to successful execution of the project. Therefore, in the construction site to use IT technology for efficient information management. But, most of the information on the construction site is managed by the non-structured document. and Information management in the construction site is difficult to lack of information management systems. In this study, proposed construction information database structure and breakdown structure to the information management of the construction site through the BIM technology. Therefore, previous studies were reviewed about the document management and information link management. and Space breakdown structure and information breakdown structure was proposed to structure the information of the construction site and Database for information storage is designed. And, BIM-based construction information database was examined through the application scenario.

• Environmental Engineering Research
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• v.15 no.3
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• pp.167-172
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• 2010

The effects of low impact development (LID) techniques, such as green roofs and porous pavements, on the runoff and pollutant load from an apartment complex were simulated using the Site Evaluation Tool (SET). The study site was the Olympic Village, a preexisting apartment complex in Seoul, South Korea, which has a high percentage of impervious surfaces (approximately 72% of the total area). Using the SET, the effects of replacing parking lots, sidewalks and driveways (37.5% of the total area) having porous pavements and rooftops (14.5% of the total area) with green roofs were simulated. The simulation results indicated that LID techniques reduced the surface runoff, and peak flow and pollutant load, and increased the evapotranspiration and soil infiltration of precipitation. Per unit area, the green roofs were better than the porous pavements at reducing the surface runoff and pollutant loads, while the porous pavements were better than green roofs at enhancing the infiltration to soil. This study showed that LID methods can be useful for urban stormwater management and that the SET is a useful tool for evaluating the effects of LID on urban hydrology and pollutant loads from various land covers.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.2
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• pp.109-116
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• 2017

In this paper, we propose an Internet of Things (IoT) platform for ocean observation buoys. The proposed system consists of various sensor modules, a gateway, and a remote monitoring site. In order to integrate sensor modules with various communications interfaces, we propose a controller area network (CAN)-based sensor data packet and a protocol for the gateway. The proposed scheme supports the registration and management of sensor modules so as to make it easier for the buoy system to manage various sensor modules. Also, in order to extend communication coverage between ocean observation buoys and the monitoring site, we implement a multi-hop relay network based on a mesh network that can provide greater communication coverage than conventional buoy systems. In addition, we verify the operation of the implemented multi-hop relay network by measuring the received signal strength indication between buoy nodes and by observing the collected data from the deployed buoy systems via our monitoring site.