• Journal of Korea Water Resources Association
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• v.45 no.6
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• pp.517-529
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• 2012

Climate change can impact hydrologic processes of a watershed system. The integrated modeling systems need to be built to predict and analyze the possible impacts of climate change on water environment for the optimal water resource operation and management. In this study, Namgang Dam watershed in the Nakdong River basin was selected as a study area. To evaluate the vulnerability of Namgang Dam watershed caused by climate change, the change in hydrologic runoff were predicted using the watershed model, SWAT. The RCM scenario was analyzed and downscaled using the artificial neural network and the dynamic quantile mapping. The results of this study will be utilized for suggesting an effective counterplan for climate change, and finally to propose the optimal water resource management method.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.2
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• pp.149-156
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• 2005

In this paper, the VR(Virtual Reality) simulation system is developed to analyze driver's perceptive response on the ASV(Advanced Safety Vehicle). The ASV is the vehicle of next generation equipped with various warning systems. For the purpose, the VR simulation system consists of VR database, vehicle dynamic model, graphic/sound system, and driving system. The VR database which generates 3D graphic and sound information is organized for the driving reality. Mathematical models of vehicle dynamic analysis are constructed to represent the dynamic behavior of a vehicle. The driving system and the graphic/sound system provide a driver with the operation of a vehicle and the feedback of a driving situation. Also, the real-time simulation algorithm synchronizes the vehicle dynamic model with the VR database. To check the validity of the developed system, a simple scenario is applied to investigate driver's perceptive response time and vehicle acceleration on an emergency situation. It is confirmed that the proposed system is useful and helpful to design the FVCWS(Forward Vehicle Collision Warning System).

• Journal of Wetlands Research
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• v.22 no.4
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• pp.321-327
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• 2020

Recently The amount of wastewater and linked wastewater is being increased every year due to industrial development, population growth, and improvement in living standards. Linked wastewater shows the feature-low flow rate and high concentration. Therefore, it has been shown that it has a great impact on the operation of the sewage treatment plant and costs a lot for treating linked wastewater. In this study, a scenario with low increase of water quality when the total amount of the inflow of linked wastewater was entered into individual reactors is obtained. According to the result of modeling, The effluent water quality get the least increment once the water was introduced into the influent and anoxic tank. We generated the various scenarios Based on these results. scenarios are varying according to inflow from linked waste water's distribution ration. As a result of modeling through various scenarios, it was found that the increment of TN and TP were at the least when the inflow of linked water was distributed with ratio between sewage (80%) and oxygen-free tank (20%).

• Journal of the Korea Society for Simulation
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• v.20 no.2
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• pp.11-17
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• 2011

The purpose of this study is 3 dimensional modeling of lower part of drilling system in offshore rig and simulation of drilling process. Recently, shipbuilding companies have been focusing on offshore rigs due to their high added-value and the reduced demand of new shipbuilding. In most cases, however, the basic design, installation and management of offshore rig are carried out by foreign companies. Therefore, it is difficult to obtain the knowledge and information of drilling system. In this study drilling devices, BOP(Blowout Preventor) and cementing job and mud circulation related components are included as the main components of offshore rig. The structure and function of them were analyzed from a viewpoint of object-oriented technique. On the basis of this analysis they were modeled in the 3 dimensional structure with 3D software tool such as CATIA and 3DVIA Composer. The drilling process was simulated according to the scenario of drilling operation. This simulation system can be effectively used for an educational tool for students and engineers in ocean plant industries.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.3
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• pp.83-94
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• 2017

There is a two lane ECTS(Electronic Toll Collection System) that users can pass with 80kph high speed in SeoBusan Tall Gate. This system to be combined two hi-pass lanes for removing meddle-island have been operated successfully. But, the appearance of two Lane ETCS makes toll gate more complicated, so it is very important how to arrange effectively various tolling lanes. This study was trying to evaluate lane configuration for minimizing speed and speed deviation among all kinds of lanes including two Lane ETCS in seoul toll gate. That is, we selected all scenarios to be happened actually, and evaluated them using micro traffic simulation model (VISSIM). The results of this study showed that each alternative had a very different speed and speed deviation by lane each other, so we will be able to achieve effective operation and configuration of lanes in toll gate using scenario methodology.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.1
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• pp.43-50
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• 2016

NAND flash based storage devices adopts multi-channel and multi-way architecture to improve performance using parallel operation of multiple NAND devices. However, multiple NAND devices consume higher current and peak power overlap problem influences on the system stability and data reliability. In this paper, current waveform is measured for erase, program and read operations, peak current and model is defined by profiling method, and estimated probability of peak current overlap among NAND devices. Also, system level TLM simulator is developed to analyze peak overlap phenomenon depending on various simulation scenario. In order to remove peak overlapping, token-ring based simple power management method is applied in the simulation experiments. The optimal peak overlap ratio is proposed to minimize performance degradation based on relationship between peak current overlapping and system performance.

• Journal of the Korean Institute of Navigation
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• v.22 no.2
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• pp.13-22
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• 1998

Shipbome Automatic Identification System (AIS) will be an important manne equipment used for identification, surveillance and communication in the 21st century, which is currently being researched in developed countries. A technical scheme of AlS is proposed in this paper. The main component of the AlS is a broadcast transponder, and the core technology is a VHF radio data link with high capacity, named STDMA (Self-organized Time Division Multiple Access). The ships installed the AlS, which will automatically and periodically broadcast their positions and identities in the marine VHF channels, can be displayed on a screen of an ECDIS on board or in VTS centers. The AlS is able to support not only broadcast service but also point-to-point communication service. This paper presents the configuration, operation principle and functionality of the AlS as well as the scenario of STDMA. In addition, the standardization work of AlS in IMO is introduced in this pauer, too.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.1 s.24
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• pp.39-45
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• 2006

Based on the previous studies on alcohol effects on human behaviour and performance in transportation system such as air-plane and car driving, the alcohol exposure before and on watch of a ship has a great influence on subsequent behaviour. In this paper, to examine the drinking status of officers on board multiple choice questionnaires are circularized under instruction and surveyed for 118 officers. According to the results of the questionnaire survey on alcohol dependency (Alcoholism) that was invented by WHO, over 27 % of those surveyed represented alcohol abuse symptoms. In addition to that, the existing state and awareness for on-board-drinking was summarized to make a scenario of drink-operation with a ship handling simulator to investigate the effect of alcohol (0.08 g% blood alcohol concentrations) on ship operational performance. A main effect for alcohol was found indicating that ship operational performance was comparatively impaired by this alcohol relative to performance in the non-alcohol condition The results of this research can be applied to minimize marine accidents as basic data.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.64.1-64.1
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• 2011

MIRIS (Multipurpose Infra-Red Imaging System), is a small infrared space telescope which is being developed by KASI, as the main payload of Science and Technology Satellite 3 (STSAT-3). Two wideband filters (I and H) of the MIRIS enables us to study the cosmic infrared background by detecting the absolute background brightness. The narrow band filter for Paschen ${\alpha}$ emission line observation will be employed to survey the Galactic plane for the study of warm ionized medium and interstellar turbulence. The opto-mechanical design of the MIRIS is optimized to operate around 200K for the telescope, and the cryogenic temperature around 90K for the sensor in the orbit, by using passive and active cooling technique, respectively. The engineering and qualification model of the MIRIS has been fabricated and successfully passed various environmental tests, including thermal, vacuum, vibration and shock tests. The flight model was also assembled and is in the process of system optimization to be launched in 2012 by a Russian rocket. The mission operation scenario and the data reduction software is now being developed. After the successful mission of FIMS (the main payload of STSAT-1), MIRIS is the second Korean space telescope, and will be an important step towards the future of Korean space astronomy.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.211-216
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• 2006

Within the frame of the MERCOSUR (South Common Market), one of the most important goals to achieve by its member states is a better cost effective international cargo transportation system. For this purpose the project of developing a commercial waterway linking the east region of Uruguay with the south of Brazil has been under study for a number of years now. Because of the high costs involved on the development of such waterway, the project has been indefinitely delayed. It is our intention to show an alternative way to reduce the present obstacles by using a budget oriented approach in order to determine the vessel best suited to use on the proposed waterway. So far, every study related to the project has been focused on the amount of work needed to modify the environment in order to accommodate the hardware already available in the region. The conclusions show that the cost of opening and maintaining the required navigation channel is high enough to discourage investment; the added responsibility to take care of any environmental damage incurred during the building and/or operation of the waterway makes searching for a less costly and hazardous option an interesting challenge. The proposed terminal on the Cebollat? River would be located at the heart of the Uruguayan rice growing region. Uruguay exports 90% of its rice production, being Brazil its biggest buyer. Wood chips and clinker are the other types of cargo considered to use the proposed waterway in route to either Brazil or to overseas destinations through the deep water port of Rio Grande. Through the analysis of local data by a Geographical Information System, international regulations regarding inland waterways and shallow draught vessel characteristics, we seek to propose a cost efficient alternative to apply on this particular scenario.