• Geophysics and Geophysical Exploration
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• v.6 no.1
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• pp.40-52
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• 2003

Despite the various opening models of the southwestern part of the East Sea (Japan Sea) between the Korean Peninsula and the Japan Arc, the continental margin of the Korean Peninsula remains unknown in crustal structure. As a result, continental rifting and subsequent seafloor spreading processes to explain the opening of the East Sea have not been adequately addressed. We investigated crustal and sedimentary velocity structures across the Korean margin into the adjacent Ulleung Basin from multichannel seismic reflection and ocean bottom seismometer data. The Ulleung Basin shows crustal velocity structure typical of oceanic although its crustal thickness of about 10 km is greater than normal. The continental margin documents rapid transition from continental to oceanic crust, exhibiting a remarkable decrease in crustal thickness accompanied by shallowing of Moho over a distance of about 50 km. The crustal model of the margin is characterized by a high-velocity (up to 7.4 km/s) lower crustal (HVLC) layer that is thicker than 10 km under the slope base and pinches out seawards. The HVLC layer is interpreted as magmatic underplating emplaced during continental rifting In response to high upper mantle temperature. The acoustic basement of the slope base shows an igneous stratigraphy developed by massive volcanic eruption. These features suggest that the evolution of the Korean margin can be explained by the processes occurring at volcanic rifted margins. Global earthquake tomography supports our interpretation by defining the abnormally hot upper mantle across the Korean margin and in the Ulleung Basin.

• Journal of the Korean Geophysical Society
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• v.10 no.1
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• pp.13-25
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• 2007

We investigated the undulation of Moho depth and the crustal structure of the continental margin in the East Sea along the Korea Peninsula from inversion and modelling using potential data and previous seismic results. Free-air gravity anomalies generally reflect topography effect. Bouguer gravity anomalies increase toward the Ulleung Basin, indicating that Moho depth is shallower under the Ulleung Basin. Positive magnetic anomalies exist along the continental margin and decrease toward the Ulleung Basin. In analytic signal, the small anomaly in the Hupo Bank infers that the Hupo Bank is uplifted by igneous intrusion and the strong anomaly on the continental slope denotes existence of SDR(seaward dipping reflectors), which are in accordance with the location of SDR detected in previous seismic studies. The inversion result of Bouguer gravity anomaly and the 2-dimensional gravity modelling indicate that the undulation of Moho depth shallows from the continental shelf toward the Ulleung Basin. This is in good agreement with the Moho depth calculated by the previous seismic velocity model using ocean bottom seismometer(OBS). The 2-dimensional gravity modelling infers magmatic underplating zone under the lower continental crust on the continental margin of the East Sea, indicating the possible rifiting of the continental margin.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.90-98
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• 2016

High-rise buildings construction project have various risk factors. Major risk factors are negative results such as time delay and increase of costs. Therefore, this study was analyzed risk factors in construction stages of high-rise buildings using by PROMETHEE technique. For this, this research were identified risk factors through experts Focus Group Interview(FGI). And, PROMETHEE was used to setup evaluation standard for analysis of high-rise building construction risks. Next, the standard of evaluation index calculation was composed by using the definition level in PDRI. Preference function and evaluation index were identified through questionnaires. Through these processes, this study has calculated the importance of high-rise building construction risks using by PROMETHEE technique. As a result, high degree risk factors were as following. These are 'Operation plan of material lifting', 'Outrigger & Belt Truss Construction', 'Foundation work plan of high-rise building' and 'Considering a Structure concept of high-rise building'.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.10
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• pp.1109-1116
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• 2014

The wheelchair mechanism for a car that is proposed in this study primarily consists of a transfer mechanism and storage mechanism. The wheelchair transfer mechanism consists of a manipulator installed in the roof of a car, and performs the function of transferring the wheelchair from the driver's seat to the trunk. The wheelchair storage mechanism consists of a lifting hoist installed in the trunk of car, and performs the function of storing the transferred wheelchair in the trunk and safely fastening it in place. This study analyzed and reviewed various manipulators, including a vertical type, Scara type, and telescopic type, with the goal of selecting the best type of manipulator for the wheelchair transfer mechanism. The telescopic type was selected and applied because of its good load support and storage capabilities. In addition, with regard to the wheelchair storage mechanism, a slide hoist type that used a slide rail and lift wire and a rotating link hoist type that used a rotating mechanism consisting of a worm gear and link were analyzed and reviewed. The slide hoist type was selected and applied because it had an advantage in relation to trunk space utilization. This study proposed a wheelchair transfer mechanism for a car to support a conventional wheelchair user's movements, and in order to conform to the structure of a domestic welfare car for the disabled.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.4
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• pp.42-50
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• 2008

The real-time bio-signal monitoring system based on the ZigBee and SIP/RTP has proposed and implemented for telemedicine but that has some problems at the stabilities to transmit bio-signal from the sensors to the other sides. In this paper, we designed and implemented a real-time bio-signal monitoring system that is focused on the reliability and efficiency for transmitting bio-signal at real-time. We designed the system to have enhanced architecture and performance in the ubiquitous sensor network, SIP/RTP real-time transmission and management of the database. The Bluetooth network is combined with ZigBee network to distribute traffic of the ECG and the other bio-signal. The modified and multiplied RTP session is used to ensure real-time transmission of ECG, other bio-signals and speech information on the internet. The modified ECG compression method based on DWLT and MSVQ is used to reduce data rate for storing ECG to the database. Finally we implemented a system that has improved performance for transmitting bio-signal from the sensors to the monitoring console and database. This implemented system makes possible to make various applications to serve U-health care services.