• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.5
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• pp.111-117
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• 2019

Shear experiments were carried out to evaluate shear performance of SFRC deep beams with end-anchorage of SD600 high strength headed reinforcing tensile bars. The experimental variables include the end-anchorage methods of tensile bars (headed bar, straight bar), the end-anchorage lengths, and the presence of shear reinforcement. Specimens with a shear span ratio of 1 showed a pattern of the shear compression failure with the slope cracks progressed after the initial bending crack occurred. Specimens with end-anchorage of headed bars (H-specimens) showed a larger shear strengths of 5.6% to 22.4% compared to straight bars (NH-specimens). For H-specimens, bearing stress reached 0.9 to 17.2% of the total stress of tensile bars up to 75% of the maximum load, and reached 22.4% to 46%. This shows that the anchorage strength due to the bearing stress of headed bars has a significant effect on shear strength. The experimental shear strength was 2.68 to 4.65 times the theoretical shear strength by the practical method, and the practical method was evaluated as the safety side.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.686-693
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• 2018

Various types of re-bar splicing methods have been developed and applied to reinforced concrete (RC) structures in the field. According to previous studies, the coupler splice is relatively superior to the lap splice in terms of cost efficiency when the diameter or strength of the re-bar is larger or higher. This study was performed to develop a filler type mechanical splice for a high-strength re-bar (SD600) in reinforced concrete structures. The deformed re-bars were inserted into a circular steel tube coupler and high-strength epoxy filler was then injected into the coupler. The splice system was completed by hardened filler in a coupler. The epoxy filler was used as the manufactured production epoxy to conduct experiments of filler type mechanical splice specimens, and to observe the failure loads and failure aspects of the specimens. For this goal, the experiment of one-way tensile test was conducted for the epoxy filler type mechanical splices specimens according to the compressive strength of epoxy, length of coupler, and diameter of re-bar. The shape of failure of the re-bar coupler splice showed that the re-bars were pulled between the lugs of the re-bars as a result of the shear fracture of the hardened epoxy. The actual failure load of the experiment specimen was approximately 2 times higher than the expected failure load of the epoxy filler, which greatly improves the failure load of the hardening epoxy filler due to the restraint of the steel coupler.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.2061-2068
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• 2015

Background: Tumors are largely unable to metabolize ketone bodies for energy due to various deficiencies in one or both of the key mitochondrial enzymes, which may provide a rationale for therapeutic strategies that inhibit tumor growth by administration of a ketogenic diet with average protein but low in carbohydrates and high in fat. Materials and Methods: Thirty-six male BALB/C nude mice were injected subcutaneously with tumor cells of the colon cancer cell line HCT116. The animals were then randomly split into three feeding groups and fed either a ketogenic diet rich in omega-3 fatty acids and MCT (MKD group; n=12) or lard only (LKD group; n=12) or a standard diet (SD group; n=12) ad libitum. Experiments were ended upon attainment of the target tumor volume of $600mm^3$ to $700mm^3$. The three diets were compared for tumor growth and survival time (interval between tumor cell injection and attainment of target tumor volume). Results: The tumor growth in the MKD and LKD groups was significantly delayed compared to that in the SD group. Conclusions: Application of an unrestricted ketogenic diet delayed tumor growth in a mouse xenograft model. Further studies are needed to address the mechanism of this diet intervention and the impact on other tumor-relevant parameters such as invasion and metastasis.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.2
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• pp.13-21
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• 2000

Au-black for the application of the long wavelength infrared absorber has been prepared by evaporating Au under nitrogen gas-filled low vacuum condition. Characteristics of the deposited Au-black were carefully investigated through structural analysis, infrared absorbance measurement, and patterning of the layer, all of which are dependent on the deposition condition. High density of micro-cavity that trapped infrared were obtained, and infrared absorbance in the wavelength range from 3 $\mu\textrm{g}$ to 14 $\mu\textrm{g}$ was found to be about 90% when the Au-black layer was produced under the deposition condition of mass Per area of about 600 $\mu\textrm{g}$/cm$^{2}$ and chamber pressure of above 1 Torr. Photoresist lift-off process could be performed to pattern the Au-black, of which mass per area was below 900 $\mu\textrm{g}$/cm/ sup 2/. In view of absorbance, heat capacity, and pattern formation, the deposition condition of chamber pressure of about 1 Tow and mass per area of about 600$\mu\textrm{g}$/cm$^{2}$ was most adequate for preparing the Au-black as an infrared absorber.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.9 s.351
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• pp.10-16
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• 2006

This paper presents a fast switching CMOS frequency synthesizer with a new coarse tuning scheme for PHS applications. The proposed coarse tuning method selects the optimal tuning capacitances of the LC-VCO to optimize the phase noise and the lock-time. The measured lock-time is about $20{\mu}s$ and the phase noise is -121dBc/Hz at 600kHz offset. This chip is fabricated with $0.25{\mu}m$ CMOS technology, and the die area is $0.7mm{\times}2.1mm$. The power consumption is 54mW at 2.7V supply voltage.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.2
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• pp.63-71
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• 2002

This paper suggests a 8-bit RISC microcontroller, which has a 4-stage pipeline architecture. Many low-power design techniques that have been proposed by previous works are adopted into it. The proposed microcontroller consumes only 600㎼ per MIPS for 0.6 ${\mu}{\textrm}{m}$ CMOS process and even lower power of 70㎼ per MIPS for 0.25${\mu}{\textrm}{m}$ process. The RTL level design of this microcontroller is carried out using VHDL. The functional verification is thoroughly done at the gate level using 0.6${\mu}{\textrm}{m}$/0.25${\mu}{\textrm}{m}$ CMOS IDEC standard cell library. This microcontroller contains 7000 NAND gates on a 0.36$\textrm{mm}^2$ die using 0.25${\mu}{\textrm}{m}$ process. Finally the comparison of power consumption with other conventional microcontrollers is provided.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.7
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• pp.37-43
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• 2010

As the speed of A/V streaming, the transmission-speed requirement of serial link is continuously increasing. Consequently, commercial standards, which are released previously, are increasing transmission speed in their newly-updated versions. The flexibility between previous and updated versions is very important requirement, therefore, the transceiver which can operates at more than one data rate is important market demand. This paper demonstrates 4-channel 3.2/ 6.4 Gbps transmitter, which is capable of selecting 1, 1.5, 2, and 3 times of pre-emphasis and 200, 300, 400, and 600 mVdiff,p2p of output swing. The prototype chip was fabricated using $0.13{\mu}m$ CMOS process. Its performances are verified on PCB using COB packaging.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.6 s.336
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• pp.59-66
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• 2005

CMOS LC VCO for tri-bind wireless LAN applications was designed in 1.8V 0.18$\mu$m CMOS process. PMOS transistors were chosen for VCO core to reduce flicker noise. The possible operation was verified for 5.8GHz band (5.725$\~$5.825GHz), 5.2GHz band (5.150$\~$5.325GHz), and 2.4GHz band (2.412$\~$2.484GHz) using the switchable L-C resonators. To linearize its frequency-voltage gain (Kvco), optimized multiple MOS varactor biasing technique was used for capacitance linearization and PLL stability improvement. VCO core consumed 2mA current and $570{\mu}m{\times}600{\mu}m$ die area. The phase noise was lower than -110dBc/Hz at 1MHz offset for tri-band frequencies.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.7
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• pp.61-67
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• 2009

This paper reports an Integer-N phase locked loop (PLL) frequency synthesizer which was implemented in a 250nm standard digital CMOS process for a UHF RFID wireless communication system. The main blocks of PLL have been designed including voltage controlled oscillator, phase frequency detector, and charge pump. The LC VCO has been used for a better noise property and low-power design. The source and drain juntions of PMOS transistors are used as the varactor diodes. The ADF4111 of Analog Device has been used for the external pre-scaler and N-divider to divide VCO frequency and a third order RC filter is designed for the loop filter. The measured results show that the RF output power is -13dBm with 50$\Omega$ load, the phase noise is -91.33dBc/Hz at 100KHz offset frequency, and the maximum lock-in time is less than 600us from 930MHz to 970MHz.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.209-212
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• 1986

$\alpha$-Amylase gene of Bacillus amyloliquetaciens was cloned on plasmid YEp13, S. cerevisiae-E. coli shuttle vector. Hybrid plasmid pTG17, carrying $\alpha$-amylase gene of B. amyloliquefaciens, was transformed to E. coli and the expression of it in yeast was investigated. This plasmid was unstable in E. coli and produced two minor plasmids, pTG17-1 and PTG17-2, which resulted from the segregation of it. Transformant of S. cerevisiae MC16 with pTG17-1 plasmid was not appeared on SD medium because of the Leu2 gene defection. S. cerevisiae could be transformed by the hybrid plasmid, and $\alpha$-amylase activity of the yeast transformant was detected by somogyi-Nelson method and agar diffusion method.