• Journal of Korea Multimedia Society
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• v.14 no.12
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• pp.1583-1590
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• 2011

A Certificate Revocation List(CRL) should be distributed quickly to all the vehicles for vehicular communications to protect them from malicious users and malfunctioning equipment as well as to increase the overall security and safety of vehicular networks. Thus, a major challenge in vehicular networks is how to efficiently distribute CRLs. This paper proposes a Multimedia Object Transfer(MOT) protocol based on CRL distribution scheme over T-DMB infrastructure. To complete the proposed scheme, a handoff method, CRL encoding rules based on the MOT protocol, and relative comparison are presented. The scheme can broaden breadth of network coverage and can get real-time delivery with enhanced transmission reliability. Even if road side units are sparsely deployed or, even not deployed, vehicles can obtain recent CRLs from T-DMB infrastructure effectively.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.691-699
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• 2015

To evaluate the possibility of charcoal as Green Infrastructure (GI) materials, data such as moisture content, amount of adsorbed water, and amount of evaporation were collected. Some data from previous study were referenced to find out if correlations exist between results in this study and previous study. Only porosity was directly related to moisture content. Two mechanical charcoal had better abilities than traditional charcoal in all three categories. Mechanical black charcoal chips produced by National Forestry Cooperative Federation (NFCFC) adsorbed 333.3% of water in thirty minutes, 297.5% in five minutes, and evaporated around 75% water in four days. This ability is much higher than other five charcoal. Even though results of test showed various degrees and NFCFC was the best as GI materials, data of charcoal were also within acceptable range based on generally accepted characteristics of GI materials.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1100-1105
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• 2022

Denoising, registering, and detecting changes of 3D digital map are generally conducted by skilled technicians, which leads to inefficiency and the intervention of individual judgment. The manual post-processing for analyzing 3D point cloud data of construction sites requires a long time and sufficient resources. This study develops automation technology for analyzing 3D point cloud data for construction sites. Scanned data are automatically denoised, and the denoised data are stored in a specific storage. The stored data set is automatically registrated when the data set to be registrated is prepared. In addition, regions with non-homogeneous densities will be converted into homogeneous data. The change detection function is developed to automatically analyze the degree of terrain change occurred between time series data.

• Journal of Korean Society on Water Environment
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• v.36 no.5
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• pp.405-422
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• 2020

Land use change by urbanization has significantly affected the hydrological process including the runoff characteristics. Due to this situation, it has been becoming more complicated to manage non-point source pollutions caused by rainfall. In order to effectively control non-point sources, it is necessary to identify the reduction efficiency of the various management method based on land use characteristics. Thus, the purpose of this study is to analyze the reduction efficiency of non-point source pollution management practices targeting three different watersheds with the different land use characteristics using the Soil and Water Assessment Tool (SWAT). To do this, the vulnerable subwatersheds to non-point source pollution occurrence within each watershed were selected based on the streamflow and water quality simulation results. Then, considering the land use, low impact development (LID) or best management practices (BMPs) were applied to the selected subwatersheds and the efficiency of each management was analyzed. As a result of analysis of the non-point source pollution reduction efficiency, when LID was applied to urban areas, the average reduction efficiencies of SS, NO₃-N, and TP were 5.92%, 4.62%, and 10.35%, respectively. When BMPs were applied to rural areas, the average reduction efficiencies of SS, TN and TP were 35.45%, 4.37%, and 10.16%, respectively. The results of this study can be used as a reference for determining appropriate management methods for non-point source pollution in urban, rural, and complex watersheds.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.5
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• pp.21-27
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• 2014

Sediment-laden water is problematic in aquatic ecosystem and for hydraulic structures in a watershed, and agriculture area in a watershed is one of source areas of nonpoint source (NPS), since soil surface typically exposures due to agricultural activities. Especially, severe sediment might flow into stream when agricultural area is located near stream like the Imha-dam watershed. Soil erosion is affected by precipitation, therefore there is a need to consider precipitation characteristics in soil erosion and best management practices (BMPs) simulation. The Web-based Spreadsheet Tool for the Estimation of Pollutant Load (STEPL WEB) allows estimating long-term sediment loads and the impact of best management practices to reduce sediment loads. STEPL WEB and predicted precipitation data by MIROC-ESM model was used to estimate sediment loads and its reduction by filter strip and conversion of agricultural area to forest in the future 30 years. The result indicates that approximately 70 % of agricultural area requires filter strip installation or that approximately 50 % of agricultural area needs to be converted to forest, for 41 % of sediment load reduction.

• Journal of the Korean Geosynthetics Society
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• v.19 no.4
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• pp.51-63
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• 2020

In this study, the model test of a reservoir was performed through a dynamic analysis method by using the data obtained from seismometers. Besides, we analyzed the behavior of the seismic acceleration amplification by reservoir height. To test the model, the data measured by the seismometers were applied at the foundation of the reservoir as input data, and the results from the analysis were compared with the data measured at the dam crest. The analysis results manifest that the peak values and the trend of the seismic wave obtained from the numerical analysis are in good agreement with the measured data. Also, the acceleration amplification ratio was proportional to the reservoir height and the magnitude of the earthquake. Through this study, the dynamic analysis method, which is based on the cyclic elastoplastic constitutive equation, can be considered as an appropriate technique to analyse the seismic behavior by the application of the data obtained from the seismometers installed in the reservoir. Also, the applicability of the seismometers can be enhanced through this technique in the future.

• Journal of the Korean Geosynthetics Society
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• v.22 no.1
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• pp.97-107
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• 2023

This study analyzed the causes of frost damage and freezing depth for concrete ballast sites in the Gangwon mountainous area, which has a high freezing index, and considered the equation for freezing depth in concrete roadbeds. Comparing the freezing depth tendencies of concrete roadbeds in the Gangwon mountainous area and Gangwon area, it was found that the freezing depth of concrete roadbeds was higher than that of the Gangwon area when the freezing index was less than 400. However, in sections with a freezing index greater than 400, the freezing depth was higher in the Gangwon area than in the concrete roadbeds. This study proposed an equation for computing the freezing depth in the Gangwon area to provide basic data for establishing preventive measures against frost damage during railway and road construction projects in the Gangwon region.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.2
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• pp.37-46
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• 2009

In this study the infrastructure of PKIMS(ParK Information Management System) was constructed based on SDI(Spatial Data Infrastructure) not only to provide the consistent spatial information of the space called park but also to share the latest information so that administrative officers could make people satisfied for their information request and promote consistent policy for the park management. PKIMS was developed by integrating with SDI for all life cycle of spatial data such as the data generation, use and share so that the efficiency and executive of administrative services could be acquired. Moreover, this construction of successful application system based on SDI would be the very good sample for implementation of NSDI(National Spatial Data Infrastructure).

• Journal of Environmental Science International
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• v.26 no.3
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• pp.281-287
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• 2017

The main task of landscape architecture is to create a higher quality of the environment by utilizing resources or to provide effective stewardship for the preserved environment. These outcomes enhance the correlation between humans and the environment. Landscape architect deals with direct use of market economic goods in private property resources such as capital, land, plant, structure. But it also has indirect use of non-market economic goods in public resources like scenic view from the forest, sea, urbanscape, and refreshing atmosphere. At this point, landscaping products should have a role of public goods, and even these attribute to individuals or certain group. From the results of neo-liberalism regime in modern era such as guarantee of private property, deregulation for free market, and reduction of social welfare, minority has getting less opportunity to enjoy the quality life in ecotop and social welfare. With all future, landscape architecture should have the role of social infrastructure through planning concept that ensures public interests first. The virtuous functions of Green Infrastructure is a proper tool in realizing environmental justice in that it efficiently protects environment, and distributes fair benefits to all people.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.8
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• pp.699-705
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• 2012

In this paper, an infrastructure-based localization method using underwater wireless sensor network (UWSN) is addressed. A localization using the UWSN is necessary to widen the usage of underwater applications, however it is very difficult to establish the UWSN due to the restrictions of water. In this paper, to extend the usage of UWSN at the infrastructure, we propose a sophisticated UWSN localization method using the Received Signal Strength Indicator (RSSI) of the electromagnetic waves. During the electromagnetic waves propagating in underwater, there arises a lot of attenuation according to the distance, while the attenuation shows uniformity according to the distance. Using this characteristics, the localization system in underwater infrastructure is proposed and the experimental results show the effectiveness.