• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.65-69
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• 2012

An oxygen rich preburner was tested and the responses from the pressure sensors were studied with FFT analysis. Since the limited capability of the static sensor, less than 250 Hz frequency domain was investigated and compared to the results of the dynamic sensors. As a result, 60 Hz harmonics were presented dominant in the combustion pressure and oxygen inlet pressure. While similar harmonics were shown with the dynamic sensor, it indicated that harmonics less than 60 Hz were very minor and the high frequency is more important.

• Computers and Concrete
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• v.8 no.4
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• pp.465-472
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• 2011

This paper investigates bond behavior of structural lightweight concrete (SLWC) and ordinary concrete (OC) comparatively using bending test called Standard Belgium Hinged Beam Test (SBHBT). For this purpose the experiments were carried out as three series on 36 beam specimens (12 specimens of SLWC and OC with $20{\phi}$ development length, 12 specimens of SLWC with $25{\phi}$ development length). For each series bond behavior of steel rebars with 8, 10, 12, 14 mm diameters were tested. The results indicate that bond strength of SLWC is considerable lower than OC and $20{\phi}$ development length is insufficient for steel rebars with 12 mm and 14 mm diameters. Therefore development length of SLWC was extended to $25{\phi}$, even if 8 and 10 mm steel rebars provided acceptable bond strength. In this way, bond strength between SLWC and 8 and 10 mm steel rebars was developed. In addition, adequate bond behavior was achieved for 12 mm rebar but the beam in which 14 mm rebar used exceeded their bearing capacity by shear forces before yield stress. This result shows that SBHBT is more convenient for small sized steel rebars.

• Structural Engineering and Mechanics
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• v.47 no.1
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• pp.75-98
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• 2013

This study focuses on shear strengthening performance of simply supported reinforced concrete (RC) T-beams bonded by glass fibre reinforced polymer (GFRP) strips in different configuration, orientations and transverse steel reinforcement in different spacing. Eighteen RC T-beams of 2.5 m span are tested. Nine beams are used as control beam. The stirrups are provided in three different spacing such as without stirrups and with stirrups at a spacing of 200 mm and 300 mm. Another nine beams are used as strengthened beams. GFRP strips are bonded in shear zone in U-shape and side shape with two types of orientation of the strip at $45^{\circ}$ and $90^{\circ}$ to the longitudinal axis of the beam for each type of stirrup spacing. The experimental result indicates that the beam strengthened with GFRP strips at $45^{\circ}$ orientation to the longitudinal axis of the beam are much more effective than $90^{\circ}$ orientation. Also as transverse steel increases, the effectiveness of the GFRP strips decreases.

• Journal of the Korean Solar Energy Society
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• v.30 no.2
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• pp.10-15
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• 2010

The experimental study was conducted to optimize the system dissipating properly heat from the in-situ solar panel installed on the roof. For this purpose, six 12-Watt panels, which were consisted of the different design conditions such as containing phase change material(PCM), changing the array of the aluminum fin and honeycomb at the back of the panel, were tested. PCM, which had $44^{\circ}C$ melting point, was chosen in this study. In order to enhance absorbing and expelling heatin PCM, profiled aluminum fin was placed either inward oroutward from the panel. Furthermore, Aluminum honeycomb is imbedded in the back container to find if it would improve the thermal conductivity of PCM. During the experiment, there were ranged to $26^{\circ}C\sim32^{\circ}C$ for outdoor temperature and $700W/m^2\sim1000W/m^2$ for irradiance. As a result, the solar panel, combined with honeycomb and outward fins with PCM instead of placing the fins inward, is showing the best performance in terms of controling panel temperature and its efficiency.

• YAKHAK HOEJI
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• v.48 no.5
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• pp.297-302
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• 2004

The purpose of the present study was to evaluate the bioequivalence of two cimetidine tablets, Tagamet (Yuhan Pharm. Co., Ltd.) and Nex (Bi-nex Pharm. Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The cimetidine release from the two cimetidine tablets in vitro was tested using KP Apparatus I method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solutions and water). The dissolution profiles of two cimetidine tablets were very similar at all dissolution media. Twenty four healthy male volunteers were divided into two groups with a randomized $2{\times}2$ cross-over study. After four tablets (800 mg cimetidine) were orally administrated, blood was taken and the concentrations of cimetidine in serum were determined using HPLC with UV detector. The pharmacokinetic parameters such as $AUC_{t}$, $C_{max}$ and $T_{max}$ were determined. The result showed that the differences in $AUC_{t}$, and $C_{max}$ between two cimetidine tablets based on the Tagamet were -6.82% and -12.98%, respectively. There were no sequence effects between two tablets in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) (e.g., log(0.90)log(0.97) and log(0.82)log(0.93) for $AUC_{t}$ and $C_{max}$, respectively), indicating that Thrumetin tablet was bioequivalent to Tagamet tablet.

• Journal of the Korea Society of Computer and Information
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• v.6 no.3
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• pp.131-136
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• 2001

Men's dress shoe was made from Steer-finished leather manufactured by this study. Men's dress shoe applied by the cementing method in KS G 3116 and used by the chloroprene adhesive has been evaluated. For the qualify test of adhesive for Oxford using chloroprene adhesive, duration for environmental exposure was tested. Also, the quality test result of chloroprene adhesive, which had been applied to men's dress shoe as well as ladies' dress shoe, was better than expected. In case of adhesion-strength measurement. the KS G 3116 method of peel strength at the end of toe was found to be resonable compared to our measurement method through toe to heel seat on feather edge.

• Journal of the Korea Society of Computer and Information
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• v.7 no.3
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• pp.115-121
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• 2002

This paper discussed to design system to overcome time, place and service limitation in the case of extracting traffic on active service in the ATM network. There are several specification in this system : for a remote control function, a real-time traffic extraction from ATM link on service without affect in-service, and an O&M(Operating and Maintenance) cost down effect. This paper include the requirement, module structure, operating characteristics and command for the developing function. This product installed at the KT's telephone office. And we have tested the stability, reliability and functionality. As the result, it was verified that this system commercially is abel to use without especial problem. Hereafter, we are improving module structure for the cost down.

• Journal of the Korea Society of Computer and Information
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• v.23 no.1
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• pp.33-39
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• 2018

In this paper, We studied the possibility of SoC(System On Chip) design using infrared image processing IP(Intellectual Property). And, we studied NUC(Non Uniformity Correction), BPR(Bad Pixel Recovery), and CEM(Contrast Enhancement) processing, the infrared image processing algorithm implemented by IP. We showed the logic and timing diagram implemented through the hardware block designed based on each algorithm. Each algorithm was coded as RTL(Register Transfer Level) using Verilog HDL(Hardware Description Language), ALTERA QUARTUS synthesis, and programed in FPGA(Field Programmable Gated Array). In addition, we have verified that the image data is processed at each algorithm without any problems by integrating the infrared image processing algorithm. Particularly, using the directly manufactured electronic board, Processor, SRAM, and FLASH are interconnected and tested and the verification result is presented so that the SoC type can be realized later. The infrared image processing IP proposed and verified in this study is expected to be of high value in the future SoC semiconductor fabrication. In addition, we have laid the basis for future application in the camera SoC industry.

• Food Science and Preservation
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• v.1 no.1
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• pp.1-7
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• 1994

To investigate the effect of several bactericides and fungicides against fruit & vegetable decay grapefruit seed extract(GFSE) was tested in a dilution solution. GFSE was shown to be effective against decay and rind breakdown and to extend the shelf-life of fruits and vegetables during storage and tiansport. Antimicrobial efficiency of GFSE on a wide spectra of gram + & - bacteria, moulds and yeasts was demonstrated by the measurement of minimal inhibitory concentrations performed (Bacteria 10-500ppm, Fungi:250-1,000ppm, Yeasts:100-250ppm). GFSE was separated and extracted into water-soluble fraction, water-insoluble and non-dialyzed fraction to isolate the antimicrobial substances. The water-soluble fraction showed the most active antimicrobial effect. The antimicrobial substances were isolated by gas chromatography. As the result of the isolation using GC, Peak-D was found to be the antimicrobial compound in GFSE. The identification of the most antimicrobial substance was carried out by using GC-MS.

• Computers and Concrete
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• v.21 no.6
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• pp.727-739
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• 2018

Crack is the most common typical feature of concrete deterioration, so routine monitoring and health assessment become essential for identifying failures and to set up an appropriate rehabilitation strategy in order to extend the service life of concrete structures. At present, image segmentation algorithms have been applied to crack analysis based on inspection images of concrete structures. The results of crack segmentation offering crack information, including length, width, and area is helpful to assist inspectors in surface inspection of concrete structures. This study proposed an algorithm of image segmentation enhancement, named morphological segmentation based on edge detection-II (MSED-II), to concrete crack segmentation. Several concrete pavement and building surfaces were imaged as the study materials. In addition, morphological operations followed by cross-curvature evaluation (CCE), an image segmentation technique of linear patterns, were also tested to evaluate their performance in concrete crack segmentation. The result indicates that MSED-II compared to CCE can lead to better quality of concrete crack segmentation. The least area, length, and width measurement errors of the concrete cracks are 5.68%, 0.23%, and 0.00%, respectively, that proves MSED-II effective for automatic measurement of concrete cracks.