• Journal of the Korean Geotechnical Society
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• v.40 no.4
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• pp.179-188
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• 2024

Nondestructive pile integrity tests are used to confirm the construction of drilled shafts as the foundation of many facilities. However, the safety of the foundation is determined only by the presence or absence of defects, and the location and scale of defects are not considered. In this study, we propose an analysis model for the lateral bearing capacity and section force connected building information modeling (BIM) by extracting the cross-sectional characteristics of the defect in piles and reviewing the safety of piles with defects. Defects at the top of piles had more effect on the change in the deflection of the pile head. Moreover, the decrease in the axial force-bending moment interaction diagram due to cross-sectional reduction increased the risk of destruction of the piles more than the change in the bending moments due to defects. The proposed method can help review the comprehensive safety of piles.

• Clinical and Experimental Vaccine Research
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• v.11 no.2
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• pp.141-148
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• 2022

Purpose: Human papillomavirus (HPV) genotype and age distribution of HPV infection were crucial for the national vaccination and screening program planning. However, there was a limited study providing these data in the normal cervix population. This study aimed to explore the HPV genotypes profile of women with clinically normal cervix based on Visual Inspection of Acetic Acid (VIA) test. Materials and Methods: A 7-year cross-sectional study was conducted from 2012 to 2018 in private and public health care centers in Jakarta. Subjects were recruited consecutively. Data were collected by anamnesis, VIA, and HPV DNA test using the polymerase chain reaction (PCR; SPF10-DEIA-LiPA25) method. HPV genotyping procedures include DNA extraction, PCR (SPF10-DEIA-LiPA25) using the HPV XpressMatrix kit (PT KalGen DNA, East Jakarta, Indonesia), and hybridization. The IBM SPSS ver. 20.0 (IBM Corp., Armonk, NY, USA) were used to analyze the data. Results: A total of 1,397 subjects were collected. Positive HPV-DNA tests were found in 52 subjects (3.7%); 67% were single and 33% were multiple HPV infections. HPV 52 was the most frequently detected HPV genotype, followed by HPV 39, 16, 18 74, 44, 31, 54, and 66, respectively. The highest HPV infections in this population were in the 31-40 and 41-50 years old group. Conclusion: This study suggested beneficial screening for women aged 31-50 years old. Instead of "original" nonavalent (HPV 16, 18, 6, 11, 31, 33, 45, 52, 58), the different "nonavalent" formula for HPV vaccines protecting against HPV 16, 18, 6, 11, 31, 39, 44, 52, 74 might be useful for Indonesian population. However, further multicenter studies with a huge sample size are still needed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.1
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• pp.9-26
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• 1997

Stokes drift(SD) and Lagrangian discharge(LD) are important factors for analysis of flushing time, tidal exchange, solute transport and pollutant dispersion. The factors should be calculated using the approached method to flow phenomena. The aim of this paper re-examines the previous procedures for computing the SD and LD, and is to propose the new method approached to stratified flow field in the cross-section of coastal region, e.g. Masan Bay. The intensity of velocity near the bottom boundary layer(BBL) depends on the sea-bed irregularity in the coastal estuaries. So we calculated the depth mean velocity(DMV) considering that of BBL omitted in Kjerfve's calculation method. It revealed that BBL effect resulting in application of the bay acts largely on DMV in half more among 1l stations. The new expression of SD and LD per unit width in the cross-section using the developed DMV and proposed decomposition procedure of current were derived as follow : $$Q=u_0+\frac{1}{2}H_1{U_1cos(\varphi_h-\varphi_u)+U_3cos(\varphi_h-\varphi{ud})} LD ED SD$(Q_{skim}+Q_{sk2}) The third term, $Q_{sk2}$, on the right-hand of the equation is showed newly and arise from vertical oscillatory shear. According to the results applied in 3 cross-sections including 11 stations of the bay, the volume difference between proposed and previous SD was founded to be almost 2 times more at some stations. But their mean transport volumes over all stations are 18% less than the previous SD. Among two terms of SD, the flux of second term, $Q_{skim}$, is larger than third term, $Q_{sk2}$, in the main channel of cross-section, so that $Q_{skim}$ has a strong dependence on the tidal pumping, whereas third term is larger than second in the marginal channel. It means that $Q_{sk2}$ has trapping or shear effect more than tidal pumping phenomena. Maximum range of the fluctuation in LD is 40% as compared with the previous equations, but mean range of it is showed 11% at all stations, namely, small change. It mean that two components of SD interact as compensating flow. Therefore, the computation of SD and LD depend on decomposition procedure of velocity component in obtaining the volume transport of temporal and spacial flow through channels. The calculation of SD and LD proposed here can separate the shear effect from the previous SD component, so can be applied to non-uniform flow condition of cross-section, namely, baroclinic flow field.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3056-3061
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• 2007

The technology of AC solenoid valves is now considered as a core technology in the fields of the production line of semi-conductor chips and the micro fluid chips for medical applications. And AC solenoid valves, which operate by compressed air, are characterized by high speed response, great repeatability and that the pressure on the cross sectional area of poppet is kept constant regardless of the fluctuation of the pressure exerted on the ports. In this study, AC solenoid valves that posses the high-speed responsibility and the high rate of flow have designed and analyzed through the law of equivalent magnetic circuit and Finite Element Method (FEM) respectively. In case of poppet, Flow field characteristic was analyzed by the variation of poppet and it was able to display flow field by changing the location of the poppet. Also, we verified possibility of the design through the static and dynamic pressure and the 3D distribution curve of the force by working the front poppet.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.1870-1875
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• 2007

The microchannel heat sink is promising heat dissipation method for high heat flux source. Contrary to conventional circular channel, MEMS based microchannel had rectangular or trapezoidal cross-sectional shape. In our study, we conducted three dimensional conjugate heat transfer calculation for rectangular shape microchannel. First, we simulated that channel was completely drained with known heating power. As a result we obtained calibration line, which indicates heat loss was function of temperature. Second, we simulated single phase heat transfer with various mass flux, 100-400 $kg/m^2s$. In conclusion, the single phase test verified that the present heat loss evaluation method is applicable to micro scale heat transfer devices. Heat fluxes from each side wall shows difference due to non-uniform heating. However those ratios were correlated with supplied total heat. Finally, we proposed effective area correction factor to evaluate appropriate heat flux.

• Journal of Aerospace System Engineering
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• v.1 no.3
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• pp.26-31
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• 2007

This paper addresses a method for structural optimum design of composite rotor blade. The basic model of a composite helicopter main rotor blade is designed and its parameters determining the structural/dynamic properties are studied. Through the investigation of flap/lag/torsional stiffness, the structural properties of the model are analyzed. In this study, helicopter rotor blades are analyzed by using VABS. The computer program VABS (Variational Asymptotic Beam Section Analysis) uses the variational asymptotic method to split a three-dimensional nonlinear elasticity problem into a two dimensional cross-sectional analysis and a one-dimensional nonlinear beam problem. This is accomplished by taking advantage of certain small parameters inherent to beam-like structures. In addition, the rotational stability of the blade is estimated by the frequency diagram from FE analysis(MSC.Patran/Nastran) to understand its vibrational property. From the result, design parameters to determine and optimize the properties of the model are presented.

• Journal of the Korean Society of Industry Convergence
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• v.8 no.4
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• pp.205-212
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• 2005

This paper presents the application of system identification approaches for the load carrying capacity evaluation of composite PCI girder bridges based on the result of field test. For these problems, the moment of inertia of cross-sectional area and the natural frequency of bridge were used as structural parameters, the SAP2000 program for the structural analysis and the SLP method for the minimum error. As a result, it is found that the proposed algorithm for this study appears applicable to real structures with reasonable complexity. It is shown that the introduction of approximate quadratic equations is more realistic and timesaving than the common methods.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.415-428
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• 1994

The purpose of this research is to establish the load-shortening relationship for undamaged members and damaged members with pin-ended support. An analytical method based on the numerical integration was proposed to obtain the ascending and descending branch of load-deformation behavior. The analysis was performed by using the momentthrust-curvature relationship including the effect of cross-sectional distortion. A parametric study regarding the the influence of damages on the ultimate strength of tubular members was also performed. Several experiments for the corroded, fabricated tubular members with dent were performed and the results were compared with the proposed method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.6
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• pp.53-58
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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. 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 application method and review items at calculations for voltage drop calculations on low voltage feeder by IEC 60364, BS 7671 standard and Consumer's Electrical Installation Guide.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.247-250
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• 1998

Ferroelectric PZT(10/90)PZT(90/10) heterolayered thin films were fabricated by spin-coating method on the Pt/Ti/SiO$^2$/Si substrate alternately using PZT(10/90) and PZT(90/10) metal alkoxide solutions. The coating and heating procedure was repeated six times to form PZT heterolayered films. The surface, cross-sectional microstructures and thickness of the films were observed using scanning electron microscope(SEM). The relative dielectric constant and dielectric loss of the 5-coated PZT heterolayered films were 1331 and 4.8% respectively.