• Journal of Environmental Policy
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• v.4 no.2
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• pp.57-82
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• 2005

In this study, we propose methods for. the efficient management and integrity of groundwater in response to a diminishing supply. As an alternative water resource for the future. we investigated and comparatively analyzed the quality standards of groundwater in the US (New York, Wisconsin and Texas), Austria, Netherlands, Canada, Japan and United Kingdom. These developed countries heavily depend on groundwater, more than 70%, for drinking water and apply those drinking water standards to groundwater quality. However, there exists few differences in the quality standards of groundwater among the countries, because each country possesses its own individual environment and management. In Korea, surface water pollution is getting serious and its water resources are diminishing. Therefore we propose several new quality criteria that many countries regulate at these days for their efficient management of groundwater. There is a need to divide BTEX criterion into Benzene, Toluene, Ethylbenzene and Xylene, individually. In. addition, it is needed to establish BTEX criteria into agricultural water and industrial water use standards as well as daily life use standards. Also, regulations for some PAHs, showing carcinogenicity, are required. Due to rapid industrialization various hazardous chemicals were utilized and their uses are increasing each year. Therefore, there is a strong need to introduce n~w standards and tighter regulations of the levels. At the same time, the criterion of nitrogenous compounds need' to be regulated individually in order to prevent the damage incurred by the compounds. Several developed countries have established standards for radon, previously caused environmental accidents in Korea. Therefore, we propose the necessity of groundwater quality standards for radon in this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.614-627
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• 2018

Urban railway lines have been constructed adjacent to residential buildings and urban areas. The expansion of transportation networks and reconstruction of residential buildings in highly populated urban areas require deep excavations in areas adjacent to urban railways. Mobilized soil stresses and changes in the groundwater level induced by deep excavations results in track irregularities in urban railways. In this study, a three-dimensional finite difference model using the commercial program FLAC3D was adopted to estimate the horizontal displacements of earth retaining structures, settlements of backfill, the stability of track irregularity and underground box structure based on the criteria of each railway organization and its relationships. In deep excavations, a change in groundwater level induces relatively very small differences for track gauge irregularities, whereas relatively large differences for longitudinal irregularities of 72.5%, twist irregularities of 83.3%, cross level irregularities of 61.9%, and alignments of 43.3% were found to be the maximum differences when the horizontal displacement of earth retaining wall and settlement of backfill were 65.1% and 21.4%, respectively, because the groundwater level (GWL) on the ground surface-mobilized tensile strength of the underground box structure exceeds the allowable value. Therefore, three-dimensional numerical analysis was performed in this study. Overall, real-time monitoring should be carried out to prevent railway accidents in advance when a deep excavation adjacent to urban railway structures is constructed.

• Journal of the Korean Institute of Navigation
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• v.19 no.2
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• pp.77-97
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• 1995

The protection of the marine environment is one of the main international legal problems in recent years. In parallel with the industrial development, a great quantity of chemical materials were used and in consequence, mass transportation of oil and other dangerous materials was required on the one hand, and discharge of industrial wasters drew also the attention on the other hand. Furthermore, oil tankers accidents, mass use of nuclear materials, sea-bed exploration and exploitation stimulated further deep human concern on the marine environment. The expansion of international concern to new and more dangerous sources of marine pollution regarded more strict and legal control on the Oil Tanker(DWT 95, 000tons, Cb=0.805) model. Calculation results are compared to the international, especially regional level. In particular, this study is concerned with the preservation of the Northeast Asian Seas surrounded by Japan, the Russian Far East, South Korea, North Korea, China and Taiwan. These adjacent countries must intensify cooperation regarding the prevention, reduction and control of the contamination of the sea. And this cooperation between the States concerned should, as much as possible, be aimed at maximizing the effectiveness of measures to prevent or abate transboundary environmental pollution. To achieve this purpose, States concerned should be imposed upon duties such as duty to assess the environmental impact, duty to inform, duty to consult and duty to assist on the basis of general principle of international law, international customary law and other various resolutions of international bodies. Depending on the nature and extent of actual or potential transboundary pollution with the use of a natural resource or the environment in general the establishment of some form of institutionalized cooperation between the States concerned may become useful or indispensable. The functions of this Organization are, inter alia, to keep the implementation of the Convention and the protocals under continuous observation, to make recommendations on regional or sub-regional rules and standards to be elaborated and on measures to be taken by the Contracting Parties, to be notified of any grave and imminent danger from pollution or threat of pollution by the Contracting Parties and to promote in close cooperation with appropriate governmental bodies additional measures to protect the marine environment of the Northeast Asian Seas, and so on. Above mentioned countries, first of all, are located within the Northeast Asian Seas geographically and, therefore, take responsibilities of preserving the clean sea against marine interferences regardless of any difference of the social, political and economic systems. They must be followed under the UNCLOS and other marine conventions. Under the present circumstances, Northeast Asian Seas will become dead seas in case that there is no instant and prompt action against pollution. Hence we have an absolute obligation to promote the development of the mandatory international environmental law, which in turn can faciliate more effective implementation of the regional cooperation by the neighbouring states within this area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.628-637
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• 2017

The automobile industry has developed Advanced Driver Assistance Systems (ADASs) to prevent traffic accidents and reduce the burden for drivers. One example is the Lane Keeping Assistance System (LKAS), which was developed for automotive vehicle systems for safety and better driving. The main system of the LKAS supports the driver while maintaining the vehicle within a lane. LKAS uses a radar sensor and camera sensor to collect information about the vehicle's position in the lane and send commands to the actuator to influence the lateral movement of the vehicle if necessary. Recently, vehicles equipped with LKAS have become commercially available. Test procedures for international LKAS evaluation are being discussed and developed by international committees, such as the International Organization for Standardization and United Nations Economic Commission for Europe. In Korea, an evaluation of LKASs for car safety is being planned by the Korean New Car Assessment Program. Therefore, test procedures should be developed for LKASs that are suitable for the domestic road environment while accommodating international standards. We developed a test scenario for LKASs and propose a formula for obtaining the target relative distance. To validate the methods, a series of experiments were conducted using commercially available vehicles equipped with LKAS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.330-336
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• 2020

An anti-collision system between equipment is essential on a drill floor where multiple moving machines are operated simultaneously. This is to prevent accidents by halting the machines when required, by inspecting possibility of a collision based on the relative position data sent by the equipment. In this paper, we propose a framework for an Anti-Collision System (ACS) by considering expandability of the number of machines and computational speed, to promote development of drilling machines and corresponding ACS software. Each drilling equipment is represented as an object in the software with its own message format, and the message is constructed with serialization/deserialization to manage any additional equipment or data. The data handling process receives the current status of machines from the drilling control network, and relays a collision related message (including bypass signal) back to the machines. A commercial visualization software shows the bounding boxes moving with the equipment and indicates probable collision. It has been determined that the proposed system maintains total execution time below 5ms to process data from the network and relay the information hence, the system has no effect on the machine control systems having 100ms control cycle.

• Tunnel and Underground Space
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• v.29 no.6
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• pp.407-424
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• 2019

To prevent possible accidents by surface subsidence, backfilling operation is known to be one of the most effective methods for ensuring the long-term ground stability because it can eliminate fundamentally the origin of underground mine opening collapse. Also, for effective backfilling of underground mine opening, it is necessary to keep monitoring of backfilled mine opening for analyzing several factors such as filling effect with change of backfill material and characteristics of backfill material. Therefore, in this study, a monitoring system which consists of measuring device and software program has developed to examine the performance of backfilling operation and verify to field applicability to underground mine. Sensors for measuring device have been selected through study of recent research papers and mock-up test has been performed to verify the system compliance. Also, monitoring result of the mock-up test compared to case studies in some countries. From monitoring result fo the mock-up test compared to case studies in some countries, consequently, it was concluded that the developed real-time monitoring system had ensured filed applicability in the underground mine.

• Journal of Korean Society of Transportation
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• v.27 no.6
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• pp.97-106
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• 2009

The purpose of this study is to analyze factors for resolving problems of Jejusi Residential Parking Permit Program and to draw up a plan by examining Jejusi case. This program was started by way of showing an example in October, 2005, and then has been put in practice in the heart of Jejusi since October, 2007. Jejusi government introduced this system to prevent all kinds of accidents by the indiscreet parking near the residental street and to guarantee the rights to live comfortably by encouraging a pleasant parking environment. As the result of the survey which is about residents' participation from the process of decision-making, the answers such as "Should Participate" and "Surely should participate" are at the high rate of 87.5 percent. A matter of the utmost importance is that this system should be reformed to make the visitors pay parking if they want to park near there. Almost 36 percent of the respondents have a negative opinion, and this is because they consider their visitors. Especially the important factors from the Logistic Regression Analysis are that the government should exercise stricter control over illegal parking, that the system should be improved for the visitors to pay parking, and that the government should support the declining sales of the shops near shopping streets. The suggestions are as follows. First, the government should enforce on reducing the illegal parking. Second, they should secure the parking lots for visitors. Third, they should minimize the impact on the declining sales of the shops near shopping streets.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.629-634
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• 2017

In the case of the UHP (Ultra high performance) tire that the demand has increased rapidly, compared with the commonly used tire, severe deformation has been observed because of the low aspect ratio. When repeated deformations are applied to the sidewall rubber, accumulated fatigue damage may cause fatigue failure. Thus, the evaluation of the durability of the tire sidewall rubber has become a very important issue to prevent accidents that occur while the vehicle is running. However, the research and design criteria for the durability performance of the tire sidewall rubber hardly exist. In this study, we suggest a lifetime prediction formula using strain energy density obtained by performing tensile tests and fatigue tests on two different kinds of the tire sidewall compounds. Additionally, the applicability of our findings for low fuel consumption tires was reviewed by converting the fatigue life of the sidewall rubber into the expected mileage of the tire.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.29-37
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• 2013

PURPOSES : This study aims to review the possibility of developing a road snow-melting system that can prevent slip accidents by maintaining a constant temperature of the winter roads and enhance performance of structures, including improvement of compressive strength by mixing carbon nanotube (hereafter referred to as CNT) with cement paste, the basic material. METHODS : To achieve the above purpose, an experiment was conducted by mixing power-type CNT and wrap-type CNT up to cement paste formulation by weight of 0.0wt%~4.1wt% in accordance with "KS L ISO 679(of cement strength test method)", and compressive strength was measured at 28 days of curing. In addition, the volume resistivity of the specimen was measured to test thermal and electrical characteristics, and the rate of temperature changes in specimen surface by power consumption was measured by passing electricity through the cross-sections of the specimen. Meanwhile, the criteria for checking the performance as a road snow-melting system was determined as volume resistivity of $100{\Omega}{\cdot}cm$ or less. RESULTS : A comparative analysis between specimen with 0wt% CNT content in plain status and specimen containing various types of CNTs was carried out. From its results, it was found that compressive strength increased approximately 19%, showing the highest rate when 0.2wt% of wrap-type CNT was contained, but volume resistivity of $100{\Omega}{\cdot}cm$ or less appeared only in specimens containing more than 0.2wt% CNT. In addition, it was observed that the surface temperature increased by $4.62^{\circ}C$ per minute on average in specimens containing 3.2wt% CNT. CONCLUSIONS : In this study, CNT was examined as an underlying material for a road snow-melting system, and the possibility of developing the road now-melting system was reviewed by conducting various experiments using CNT-Cement composites. From the experimental results, the specimens were found to have a superior performance when compared to the existing road snow-melting systems that place the heat transfer medium such as copper on the road. However, satisfactory strength performance were not obtained from the specimen containing CNT(2.0% or more) that functions as a heating element, which leads to the need for reviewing methods to increase the strength by using plasticizer or admixture.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.4
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• pp.345-352
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• 2020

To preserve and restore tidal flats and prevent safety accidents, it is necessary to construct tidal flat topographic information including the exact location and shape of tidal creeks. In the tidal flats where the field surveying is difficult to apply, airborne LiDAR surveying can provide accurate terrain data for a wide area. On the other hand, we can economically obtain relatively high-resolution data from UAV (Unmanned Aerial Vehicle) surveying. In this study, we proposed the methodology to generate high-resolution topographic information of tidal flats effectively by integrating airborne LiDAR and UAV point clouds. For the purpose, automatic ICP (Iterative Closest Points) registration between two different datasets was conducted and tidal creeks were extracted by applying CSF (Cloth Simulation Filtering) algorithm. Then, we integrated high-density UAV data for tidal creeks and airborne LiDAR data for flat grounds. DEM (Digital Elevation Model) and tidal flat area and depth were generated from the integrated data to construct high-resolution topographic information for large-scale tidal flat map creation. As a result, UAV data was registered without GCP (Ground Control Point), and integrated data including detailed topographic information of tidal creeks with a relatively small data size was generated.