• Proceedings of the KSR Conference
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• 2008.11b
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• pp.864-869
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• 2008

Magnetic Levitated(Maglev) Vehicle, which utilizes electromagnetic forces between dual-pole electromagnets and a steel rail, generally runs on guideway structures. A prototype of an Urban Maglev Vehicle has been developed and tested in Korea, This study was conducted as a cooperation research subject of the 3-1 subject, performance improvement of maglev track structures, of the Center for Urban Maglev Program, statred in 2006. As the Maglev load is distributed rather than concentrated, a field test was conducted on Simple Span PSC-BOX Girder Bridge(L=25.0m) of the Expo-Maglev test track in Daejeon to examine the dynamic effect of the Maglev load on the bridge. Numerical analyses were also performed up to the maximum passing speed of 110 km/h by 10 km/h increments of Maglev Vehicle using Finite Element model of bridge, and girder deflections, accelerations and Dynamic Amplification Factor (DAF) are analysed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.353-362
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• 1993

Behaviors of effulent are observed and discussed with reference to the tide and freshwater discharge in the estuary of Suyoung Bay. The esturine front is located at $0.5{\sim}1.3km$ seaward from of the Suyoung Bridge at the spring tide, and $0.8{\sim}1.0km$ at the neap tide. After the heavy precipitations, the front moved seaward and was located at $1.3{\sim}2.5km$ southeast of the Suyoung Bridge. Internal Froude numbers in the estuarine salinity front are estimated approximately to be 1 both at the spring and neap tide. Entrainment coefficient decreases down stream to the estuarine front, and then increases seaward from the estuarine front due to the tidal mixing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2702-2707
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• 2010

The load distribution factor (LDF) values of new composite I-beam panel bridges that were subjected to dead load were investigated using three-dimensional finite element analyses with the computer program ABAQUS(2007). This study considered some design parameters such as the slab thickness, the steel-plate thickness, and the span length for design of new composite bridges. The distribution values that were obtained from these analyses were compared with those from the AASHTO Standard, AASHTO LRFD, and the equations presented by Tarhini and Frederick, and Back and Shin. For the simple application of the design, bridge engineers can use the LDF of 0.67 for the exterior girder and of 0.340 for the interior girder.

• Journal of IKEEE
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• v.12 no.3
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• pp.167-171
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• 2008

A bridge resistance deviation-to-frequency (BRD-to-F) converter is presented for interfacing resistive sensor bridges. It consists of a linear operational transconductance amplifier (LOTA), a current-controlled oscillator (CCO). The prototype converter was simulated using commercially available discrete components. The result shows that the converter has a conversion sensitivity amounting to 16.90 kHz/${\Omega}$ and a linearity error less than ${\pm}$0.03 %.

• Journal of Korean Society on Water Environment
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• v.24 no.3
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• pp.378-382
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• 2008

During the dry periods, many types of pollutants are being accumulated on the paved surface by vehicle activities and the accumulated various pollutants are inflowing into the near watershed areas for the rainfall periods. Particularly, bridges are the centralized region to be the surface runoff of the stromwater due to the high ratio of the impermeable area. Also, the metals, toxic chemicals and sediments originated from bridges could be strongly influenced to the watershed areas during the runoff. Therefore, the present study is achieved to provide washoff characteristics and correlation from the bridge during rainfall periods. The result shows that the EMC ranges for 95% confidence intervals in a bridge land use are 10.12~128.09 mg/L for TSS, 6.07~21.15 mg/L for BOD, 2.10~6.70 mg/L for TN and 0.06~0.85 mg/L for TP.

• KIEAE Journal
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• v.17 no.3
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• pp.15-21
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• 2017

Purpose: "Building energy design standard" is used to limit the thermal transmittance of building in Korea. However, it only covers the insulation standard for each appropriate elements of a building, not the thermal performance of Junction thermal bridge of windows and doors installed in wall. Therefore in this study, we have evaluated the thermal performance of Junction thermal bridge depending on installation method and position of windows and provide it as design data. Method: We analyzed heat transfer of 4-Track sliding window and tilt & turn triple glazed window that are placed in the first class category on window energy efficiency rating using Window 7.4 and Therm 7.4. Result : First, linear thermal transmittance of 4-Track sliding window differs by 2.2 times or more depending of installation method and location. It is higher than the linear thermal transmittance, 0.01W/mK, proposed by Passivhaus. Second, linear thermal transmittance of Tilt & turn triple glazed window differs by 7.7 times or more depending of installation method and location. The average linear thermal transmittance was less than 0.01W /mK when windows were installed on the internal wall insulation by the fixed hardware attachment method. Third, the thermal losses of a window caused by a junction thermal bridge are inversely proportional to the window area and converge gradually as the area increased.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.3
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• pp.335-344
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• 2011

In this paper, the results of computational analysis for the stability and F.S.(Factor of Safety) of Bailey Panel Bridge have been presented by FEM(Finite Element Method). The computational analysis was conducted by using LUSAS V14.0 that is a program applicated in the field of Civil Engineering. 6-free beam elements and 3-free truss elements were considered and F.S. against Yield Stress of main sections(considered self-weight and Live-Load) was investigated through the linear-elastic analysis method. The results showed that currently used sections of bailey bridge satisfied for the standard F.S. unit and could be operated in drill of troops and battle fields.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.2
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• pp.212-224
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• 1994

The purpose of this study was to evaluate and compare film thickness of five kinds of resin luting cements [Comspan, Panavia Ex, Maryland bridge adhesive, All-bond C & B cementation kit, and Super-bond C & B]. Zinc-phosphate cement and glass-ionomer cement were used as the control group. In order to measure the film thickness the methods used were in broad compliance with ADA Specification No. 8, a tapered-die system that simulates clinical conditions more closely, and the connected tapered-die system that simulates bridge conditions. The inorganic filler size of resin cements was also examined with scanning electron micrographs. The results were obtained as follows ; 1. The film thickness of resin cements was increased in the order of Comspan, Panavia Ex, Super-bond C & B, Maryland bridge adhesive, and All-bond C & B cementation kit. Maryland bridge adhesive and All-bond C & B cementation kit showed significantly higher film thickness than the control group(p<0.01). 2. For all resin cements, there was a significant difference of film thickness between the ADA method and the tapered-die system. Generally, the tapered-die system demonstrated lower film thickness than the ADA method(p<0.01). 3. There was no significant difference in film thickness between the tapered-die system and the tapered-die bridge system in all resin cements(p<0.01). 4. The scanning electron microscope showed that the cement with larger filler had a tendency to be higher in film thickness.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.3
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• pp.18-24
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• 2011

This paper presents that the yield strength of the pressure sensor with a double boss diaphragm structure can be improved as the grooves are formed at the corner of the diaphragm bridge. Generally the boss structure is widely used for the low-pressure sensor, of which the sensitivity is not enough in case of the small diaphragm size limited by a chip size constraint. The double boss structure pressure sensor exhibits a great sensitivity, but suffers from the low yield strength problem due to the high stress occurred at the corner of the diaphragm bridge to be limited in the operating range. ANSYS simulation is performed by changing the length of the groove from 0.5${\mu}m$ to 10${\mu}m$ at the corner of the diaphragm bridge of the double boss structure pressure sensor. The maximum stress is analyzed at the corner of the diaphragm bridge, the edge of the diaphragm bridge, and the position of the piezoresistive sensor. Consequently, in case the length of the groove from the edge of the diaphragm is 6${\mu}m$ or greater, the stress occurred in the corner of the bridge is less than the stress acting on a piezoresistive element.

• Journal of Sensor Science and Technology
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• v.4 no.1
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• pp.9-14
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• 1995

To fabricate low field magnetic sensors using magnetoresistance(MR) effects, we deposited thin layers of $600{\AA}$ in thickness of Ni-Co(0.7Ni-0.3Co) alloy on slide glasses. In the layers we ordered 4 arms of the fullbridge sensors in the shape of grid structure to be inclined at an angle of $45^{\circ}$ to main axis and made the areal rate increase to 67%. While the response characteristics of the fabricated sensors had good linearity in the magnetic field of ${\pm}0.5mT$ ranges, the white noise was 0.2 nV and the voltage sensitivity was 7.6 $nV/{\mu}T$.