• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.19 no.1
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• pp.25-29
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• 1989

The author has evaluated the panoramic image clarity of the midfacial anatomic structures in dry skull according to the skull position. The radiopaque markers were attached to the anatomic structures: infraorbial rim, upper and lower borders of zygomatic arch, pterygomaxillary fissure, lateral pterygoid plate, pyriform aperture of nasal cavity, lateral wall of maxilla, orbital floor, infraorbital foramen, and nasal floor. Position of the skull were divided into four groups. standard, 25mm forward, chin-down, chin-up position. The results were as follows: 1. The pyriform aperture of nasal cavity, lateral wall of the maxilla, orbital floor, infraorbital foramen and nasal floor did net cast any discernible image. 2. Nearly all images of midfacial structures were blurred in the chin-up position. 3. The forward position provided good visualization of the maxillary sinus. 4. The chin-down position provided good visualization of the zygomatic arch, pterygomaxillary fissue, and lateral pterygoid plate.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.809-815
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• 2007

The floor structure of railway vehicles consists of plywood, rubber, and wood keystone plate which affects on the comfort of passengers. Its structural characteristics has been investigated experimentally and numerically for samples of beam and plate structure, and the real floor structure in this paper. The material properties of etch part measured directly by experiments. The deformation and stress distribution of the sample beams for 6 different joints were sought experimentally and calculated using a commercial software. The numerical calculation shows that the effect of friction and clearance between joints is crucial. The DMU/EMU plates were also experimented and compared for different loading conditions. The structural characteristics of the whole floor structure were calculated numerically. The results show that the method of joint between plywoods is an important factor to decide the strength of the floor structure of railway vehicles.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.2
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• pp.66-71
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• 2008

The data of the deformation and the stress according to time are studied at upper model of press and lower model of the blanking plate applied by press with the width, length and height of 0.4 m and 0.6 m respectively. The press is pushing downward on the plate fixed at the lower floor. These data are compared and investigated through this study. By using these results, there is the maximum deformation at 4 corners in the lower plate model of aluminium alloy fixed at lower floor. This deformation incase of elapsed time of 0.6 second becomes 4 times as much as in case of elapsed time of 0.2 second. The quantity of deformation at the lower plate model becomes more than at the upper press model to the extent of 10%. At the lower plate model of aluminium alloy, there is the maximum Von-Mises equivalent stress at 4 corners and both sides of middle area on the lower plate model of aluminium alloy. This stress in case of elapsed time of 0.6 second becomes 6 times as much as in case of elapsed time of 0.2 second. The Von-Mises equivalent stress of lower plate model becomes 2 times as much as that of upper press mode.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.751-755
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• 2003

In this paper, floor impact noise reduction in a steel structure is studied. A mock-up is built by using 6t steel plate, and two identical cabins are made where 25t panel is used to construct wall and ceiling inside the steel structure. Various floating floor systems are tested for which normalized impact noise is measured according to ISO 140-7. In addition, floor SBN(Structure-borne Noise) and floor damping are measured to study the effect of floating floor. structure. It is shown that VL(Visco-elastic Layer) is more effective when hard plates are added above the VL.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.4 no.2
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• pp.115-118
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• 1975

The constriction thermal resistance due to the floor supports in the Ondol floor heating system was investigated. The resistance has significant influence on the uniformity of floor surface temperature and heat flux through the floor. The heat flux decreased as much as $30\%$ for the geometry of the same channel and support areas.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.5
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• pp.41-47
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• 2004

In this paper, floor impact noise reduction in cruise ship cabin is studied. A mock-up is built by using 6t steel plate, and two identical cabins are made where 25t panel is used to construct wall and ceiling inside the steel structure. Various floating floor systems are tested for which normalized impact noise is measured according to ISO 140-7. In addition, floor SBN (Structure-borne Noise) and floor damping are measured to study the effect of floating floor structure. It is shown that VL(Visco-elastic Layer) is more effective when hard plates are added above the VL.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.7 s.94
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• pp.1864-1873
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• 1993

A biomechanical approach was carried out to analyze foot-floor reaction forces acting on five male subjects performing a walking task. The task analyzed was walking over an obstacle with the right bare foot. The foot-floor reaction data were measured from a force plate, and then processed using a software developed. The source program was coded in the C language for easier on-line data acquisition and graphic displays. High repeatability was found in the reaction data acquired from three trials by each subject. For obstacle height from 0 to 25 cm, the maximum in reaction force reached up to 1.048 BW in the vertical, 0.174 BW in the anterior-posterior, and 0.054 BW in the medio-lateral components, respectively. A quantity was defined by the difference between two vertical reaction values, and this quantity was found to be proportional to the obstacle height. It was also shown that the whole body motion could be predicted the measured foot-floor reaction data.

• Journal of Korean Society of Steel Construction
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• v.16 no.2 s.69
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• pp.235-245
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• 2004

The advantages of composite construction are now well understood in terms of structural economy, good performance in service, and ease of construction. However, these conventional composite construction systems have some problems in application to steel framed buildings due to their large depth. So, in this study we executed an experimental test with the "Slim Floor"system which could reduce the overall depth of composite beam. Slim Floor system is a method of steel frame multi-story building construction in which the structural depth of each floor is minimized by incorporating the steel floor beams within the depth of the concrete floor slab. Presented herein is an experimental study that focuses on the flexural behaviour of the partially connected slim floor system with asymmetric steel beams encased in composite concrete slabs. Eight full-scale specimens were constructed and tested in this study with different steel beam height, slab width, with or without shear connection and concrete topping thickness. Observations from experiments indicated that the degree of shear connection without additional shear connection was $0.53{\sim}0.95$ times that of the full shear connection due to inherent mechnical and chemical bond stress.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.524-525
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• 2009

Heavy-weight impact noise(HN) is the most irritating noise in Korean apartment houses. It has been proclaimed standard floor system of 210mm thick slab with isolation material in the wall type structure. But this regulation is applied only new construction field and is not considered remodeling field. In general, the LN can be reduced by using isolation material but HN is known as relating with stiffness, strength & boundary condition of slab. Therefore it is difficulty in improving the HN on remodeling field. In this study, We conducted the reinforcement of concrete slab using C.F.S.(carbon fiber sheet), steel plate and steel beam after on-dol with isolation material on the remodeling field. As the test results, It appeared using C.F.S was no improved but using steel plate & steel beam were a little improved on HN.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.377-380
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• 2005

Damping materials encompass a broad range of materials, including, but not limits to, pressure sensitive adhesives, epoxies, rubbers, foams, thermoplastics, enamels and mastics. Their common characteristic is that their modulus is represented by a complex quantity, possessing both a stored and dissipative energy component. Loss factor of damping material analyzed more than 2 times than rubber to 1.5 $\sim$ 2.3, could know that Damping layer has excellent attenuation performance in side of vibration reduction. Measurements of vibration using accelerometers by adhesion of Damping layer, square Plate by Separation of Damping layer is less binding of Damping layer, analyzed low loss factor and Natural Frequency by free Vibration of Square Plate.