• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.1
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• pp.67-73
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• 2012

Coastal erosion and its impact on human activities as well as the economic damage and environmental conservation of coastal area is one of major concern in the national policies. In this study, we conducted physical investigations to evaluate effects of erosion in the Geojin beach, which is located nearby the Geojin Port, for a detecting of shoreline change and beach cross-sectional area. The results showed that significant coastal erosion of the Geojin beach has occurred by the complex resources of natural factor, such as rising sea level, storm surges, high wave, and man-made construction. Especially, due to the sand supplement from Jasan river, the section which is nearby the estuary of Jasan river is maintained as a stable beach, whereas beach erosion of the other site in GW04 section has been increased indeed. Therefore, we suggest that it is need to continuous monitoring using DGPS and various surveying techniques to prevent beach erosion onto the GW04 section.

• Korean Journal of Biological Psychiatry
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• v.22 no.1
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• pp.14-19
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• 2015

Objectives The purpose of this study is to find the cephalometric variables which are significantly correlated with the apnea-hypopnea index (AHI) in suspected Korean obstructive sleep apnea (OSA) patients. Methods We examined lateral cephalogram and attended-full night laboratory polysomnography of the 40 participants who complained of OSA symptoms. The correlation analysis was conducted to find the cephalometric variables which are significantly correlated with the AHI. Results The correlation analysis showed that the higher AHI was associated with the longer distance between hyoid and mandibular plane (p = 0.023), the longer distance between C3 and hyoid (p = 0.014), the longer tongue length (p = 0.003), the larger inferior tongue area (p = 0.008), the larger anterior displacement of the hyoid bone (p = 0.024), the longer distance between posterior nasal spine and the tip of the soft palate (p = 0.021), and the larger cross-sectional area of soft palate (p = 0.001) of cephalogram in erect position. The higher AHI was correlated with the longer distance between hyoid and mandibular plane (p = 0.008), the longer tongue length (p = 0.037), the larger inferior tongue area (p = 0.013), the thicker uvula (p = 0.004), the longer distance between retrognathion and hyoid (p = 0.025), and larger cross-sectional area of soft palate (p = 0.001) of cephalogram in supine position. Conclusions The present preliminary results showed the candidate measurements of cephalogram which are significantly correlated with the AHI in suspected OSA.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.173-179
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• 2019

DICOM(Digital Imaging and Communications in Medicine) imaging plays a significant role in the diagnosis and treatment of the human body, and design modeling is a technology of planning shapes in three dimensions according to the purpose. In this study, we converge these two technologies to observe the relationships of the cross-section, volume, and surface area to the morphological changes of the external ear canal. The experiment applied medical imaging technologies to acquire sections of the human body to create and divide centerlines using 3D shapes extracted from 19 external ear canals by applying stereolithography and 3-matic program. The results showed that the cross-sectional structure of the external ear canal had various shapes, such as oval (38.5%), semicircular (28.2%), mixed (17.9%), square (10.2%), and wrinkled (5.1%). In addition, the cross-sectional area of each phase increased as the length of the external ear canal increased, and the volume and surface area decreased towards the direction of the eardrum. However, the surface area reduction rate was relatively low. This indicates that the structure becomes irregular towards the direction of the eardrum.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.2
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• pp.86-91
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• 2012

A conductor has been produced according to IEC standard and low voltage electrical facility has been installed according to IEC 60364. So we must comply with international standard for design, construction and inspection. But because of many related and varied standards, it is difficult to apply to design and inspect for electrical equipment. We researched the necessity of design guide which is detailed and systematization from survey. For detailed design guide, we suggest calculation method of protective conductor cross-sectional area at TN-S system according to BS 7671 regulation and KS C IEC 60364 standard.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.4
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• pp.41-47
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• 2000

In this study, the purpose finds out the best welding conditions for bonding of electric wire by ultrasonic welding. The material was plastic-insulating low-voltage-cabels for automobiles. The experiment varied the values of welding time and welding pressure and fixed the values of amplitude and energy. With the facts, the best condition for ultrasonic welding to achieve bonding exactly is gained according to the size of the cross-sectional area of the cable, and the adhesive intensity is greatly influenced by the variables of welding time and welding pressure. Also when the welding time and welding time and welding pressure increase as the cross-sectional areas of the cable increase the welding result in gained exactly.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.449-450
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• 2009

In this study, the characteristics of initial shear strength of hollow sectional columns were investigated by experiments with parameters of the aspect ratios, void ratios, web area ratios and load patterns. The test results were analyzed with comparison of the values expected by the empirical equations. The empirical equation was newly proposed on the basis of mechanical characteristics and test results, and its validity was evaluated.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.175-176
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• 2010

Current Bridge Specification for Highway Bridges adopts a simplified method to determine sectional forces of abutment wing by diving its area into four sections. This simplified method was developed when numerical analysis was not mature and computer resources were expensive. It has been criticized that the simplified method produces conservative results. This study evaluates the problem of current design practice to improve the design guideline for abutment wing.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.527-532
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• 1997

Design strength of structural members could be determined by applying a strength reduction factor to nominal strength. At the beginning point of the transition region for the strength reduction factor, P=0.1$\sigma$$_{ck}A_g$, only sectional area and concrete strength are adopted as the variables of P=0.1$\sigma$$_{ck}A_g$. Therefore, P=0.1$\sigma$$_{ck}A_g$ is the empirically adopted which does not consider steel ratio, steel yielding stress, and steel arrangement. So, this research was perpormed the computer program for the analysis of axial force-moment-curvature relationship of reinforced concrete columns by sectional behaviour nonlinear analysis using a concrete compressive stress-strain curve, in order to investigate the ductility of reinforced concrete columns. As a result, ductility indicies of axial force, P=0.1$\sigma$$_{ck}A_g$, represented the lack of consistency of the indicies value for the various sections.

• Bulletin of the Society of Naval Architects of Korea
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• v.17 no.1
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• pp.11-18
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• 1980

In the conventional ship's structures, the stiffeners with asymmetric sections have been widely used, in spite of the disadvantage on the point of strength, compared to those with symmetric sections. So far, the stiffened plating was usually analyzed not considering the geometric unsymmetry characteristics of the section, including only the cross sectional area and moment of inertia. In this paper, the stiffened plating is devided into the strips having a thin-walled open cross section by using the concept of the effective width. The geometric characteristics of the sections are also included. The governing equations are derived, which can be applied to the arbitrary cross section beams, and the symmetric and the asymmetric section beams which have the same cross sectional areas are analyzed by using the finite element method. From that result, we obtain the allowable load of the two sections, and compared them.

• Korean Journal of Materials Research
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• v.3 no.2
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• pp.193-196
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• 1993

A procedure for preparing cross-sectional specimens for transmission electron microscopy(TEM)by focused ion beam(FIB)milling of specific regions of semiconductor devices is outlined. This technique enables TEM specimens to be pripared at precisely preselected area. In-situ #W thin film deposition on the top surface of desired site is complementally used to secure the TEM specimens to be less wedge shaped, which is main shortcoming of previous FIB-assisted TEM sample preparation technique. This technique is quite useful for the TEM sample priparation for fault finding and the characterization of fabrication process associated with submicron contact technologies.