• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권5호
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• pp.286-292
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• 2004

In this study, an integrated microelectrode array was fabricated on glass slide using microfabrication technology. Probe DNAs consisting of mercaptohexyl moiety at their 5-end were spotted on the gold electrode using micropipette or DNA arrayer utilizing the affinity between gold and sulfur. Cyclic voltammetry in 5mM ferricyanide/ferrocyanide solution at 100 ㎷/s confirmed the immobilization of probe DNA on the gold electrodes. When several DNAs were detected electrochemically, there was a difference between target DNA and control DNA in the anodic peak current values. It was derived from specific binding of Hoechst 33258 to the double stranded DNA due to hybridization of target DNA. It suggested that this DNA chip could recognize the sequence specific genes. It suggested that multichannel electrochemical DNA microarray is useful to develop a portable device for clinical gene diagnostic System.

• ETRI Journal
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• 제42권6호
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• pp.943-950
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• 2020

We propose 8.2-GHz band radar RFICs for an 8 × 8 phased-array frequency-modulated continuous-wave receiver developed using 65-nm CMOS technology. This receiver panel is constructed using a multichip solution comprising fabricated 2 × 2 low-noise amplifier phase-shifter (LNA-PS) chips and a 4ch RX front-end chip. The LNA-PS chip has a novel phase-shifter circuit for low-voltage operation, novel active single-to-differential/differential-to-single circuits, and a current-mode combiner to utilize a small area. The LNA-PS chip shows a power gain range of 5 dB to 20 dB per channel with gain control and a single-channel NF of 6.4 dB at maximum gain. The measured result of the chip shows 6-bit phase states with a 0.35° RMS phase error. The input P1 dB of the chip is approximately -27.5 dBm at high gain and is enough to cover the highest input power from the TX-to-RX leakage in the radar system. The gain range of the 4ch RX front-end chip is 9 dB to 30 dB per channel. The LNA-PS chip consumes 82 mA, and the 4ch RX front-end chip consumes 97 mA from a 1.2 V supply voltage. The chip sizes of the 2 × 2 LNA-PS and the 4ch RX front end are 2.39 mm × 1.3 mm and 2.42 mm × 1.62 mm, respectively.

• Journal of Welding and Joining
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• 제31권3호
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• pp.84-88
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• 2013

These days embedded technology may be the most significant development in the electronics industry. The study focused on the development of active device embedding using flexible printed circuit in view of process and materials. The authors fabricated 30um thickness Si chip without any crack, chipping defects with a dicing before grinding process. In order to embed chips into flexible PCB, the chip pads on a chip are connected to bonding pad on flexible PCB using an ACF film. After packaging, all sample were tested by the O/S test and carried out the reliability test. All samples passed environmental reliability test. In the future, this technology will be applied to the wearable electronics and flexible display in the variety of electronics product.

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권2호
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• pp.83-87
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• 2004

Phase noise performance and current consumption of Radio Frequency (RF) Voltage-Controlled Oscillator (VCO) are largely dependent on the Quality (Q) factor of inductor-capacitor (LC) tank. Because the Q-factor of LC tank is determined by on-chip spiral inductor, we designed, analyzed, and modeled on-chip differential inductor to enhance differential Q-factor, reduce current consumption and save silicon area. The simulated inductance is 3.3 nH and Q-factor is 15 at 2 GHz. Self-resonance frequency is as high as 13 GHz. To verify its use to RF applications, we designed 2 GHz differential LC VCO. The measurement result of phase noise is -112 dBc/Hz at an offset frequency of 100 kHz from a 2GHz carrier frequency. Tuning range is about 500 MHz (25%), and current consumption varies from 5mA to 8.4 mA using bias control technique. Implemented in $0.35-{\mu}m$ SiGe BiCMOS technology, the VCO occupies $400\;um{\times}800\;um$ of silicon area.

• Applied Biological Chemistry
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• 제35권6호
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• pp.437-442
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• 1992

우리나라에서 널리 보급되어 재배되고 있는 감자 품종인 수미(秀美, Superior) 및 남작(男爵, Irish Cobbler) 두 품종을 원료로 potato chip을 제조할 때 품질에 직접적으로 영향을 미치는 Maillard 반응의 중요한 요인으로 작용하는 환원당의 함량을 감소시키기 위하여 화학적 저해제로 알려진 $CaCl_2$와 NaCl을 사용하여 감자를 전처리한 후 환원당 함량을 분석하고 potato chip을 제조하여 색상을 비교한 결과 NaCl로 침지 처리한 경우에는 환원당의 감소가 $15{\sim}30%$에 불과하고 chip의 색상도 좋지 못하였다. 그러나 NaCl 침지 가열처리의 경우에는 환원당의 감소가 평균 40%였으며, 특히 두 품종 모두 0.08% NaCl 용액으로 5분 및 7분간 처리한 것이 좋은 효과를 나타내었다. $CaCl_2$ 용액에 침지처리한 것은 NaCl 용액으로 처리한 것보다 효과는 있었으나 색상이 고르지 못하고 부분적으로 갈색화되었다. $CaCl_2$용액에 침지 가열처리한 것이 가장 좋은 결과를 나타내어 환원당의 감소가 약 50% 정도였으며 그 중에서도 0.05% 및 0.07% $CaCl_2$ 용액에 5분 및 7분간 처리한 것이 환원당의 감소는 물론 chip의 색상도 가장 좋았다. 침지시 상온에서 처리하는 것보다는 $72{\sim}82^{\circ}$ 에서 NaCl 용액 보다는 $CaCl_2$ 용액으로 blanching하는 것이 가장 효과적이었다.

• International Journal of Precision Engineering and Manufacturing
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• 제6권3호
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• pp.24-28
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• 2005

Stress state of chip formation zone is one of the main problems in metal cutting mechanics. In two-dimensional case this process is usually considered as consistent shears of work material along one of several shear surfaces, separating chip from workpiece. These shear planes are assumed to be trajectories of maximum shear stress forming corresponding slip-line field. This paper suggests a new approach to the constriction of slip-line field, which implies uniform compression in chip formation zone. Based on the given model it has been found that imaginary shear line in orthogonal cutting is close to the trajectory of maximum normal stress and the problem about its determination has been considered as well. It has been shown that there is a second central slip-line field inside chip, which corresponds well to experimental data about stress distribution on tool rake face and tool-chip contact length. The suggested model would be useful in understanding mechanistic problems in machining.

• 센서학회지
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• 제25권2호
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• pp.143-147
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• 2016

Characteristics of the conventional gold (Au) surface plasmon resonance (SPR) chip, bi-metallic(Au/silver (Ag)) SPR chip, and tri-metallic(Au/Ag/Au) SPR chip were investigated and compared in the intensity measurement mode for the enhancement of SPR image sensor reactivity. Reflectance curves of the Au, bi- and tri-metallic SPR chips were acquired in phosphate-buffered saline (PBS) solution and were compared. The line width of the reflectance curve of the bi-metallic chip was the narrowest among the three different types of the chips. Also, the tangential slope of the bi-metallic chip was steeper than those of the other chips. Various concentrations of bovine serum albumin (BSA) were utilized in the SPR experiment. As a result, among the above three chips reflectance variation value of the bi-metallic chip was the largest.

• Bulletin of the Korean Chemical Society
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• 제26권3호
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• pp.379-383
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• 2005

This research aims to develop DNA chip array without an indicator. We fabricated microelectrode array by photolithography technology. Several DNA probes were immobilized on an electrode. Then, indicator-free target DNA was hybridized by an electrical force and measured electrochemically. Cyclic-voltammograms (CVs) showed a difference between DNA probe and mismatched DNA in an anodic peak. Immobilization of probe DNA and hybridization of target DNA could be confirmed by fluorescent. This indicator-free DNA chip microarray resulted in the sequence-specific detection of the target DNA quantitatively ranging from $10^{-18}\;M\;to\;10^{-5}$ M in the buffer solution. This indicator-free DNA chip resulted in a sequence-specific detection of the target DNA.

• 센서학회지
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• 제18권2호
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• pp.160-167
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• 2009

In this study, secondary antibody-containing quartz crystal microbalance(QCM) sensor chip was prepared and utilized for the detection of human and bovine haptoglobin. Anti-goat immunoglobulin G antibody, which is a secondary antibody capable of capturing primary antibodies raised in goat, was immobilized through the reaction between hydrazide and aldehyde group prepared on the QCM surface and antibody respectively. The resulting sensor chip showed higher stability in the repeated surface regeneration with acidic dissociation solution as well as requiring lower amount of primary antibody when compared to the protein G sensor chip. The secondary antibody sensor chip was applied for the estimation of bovine and human haptoglobin.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2000년도 학술대회논문집
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• pp.219-224
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• 2000

This paper presents a ripple reduction of BLDC motor using TMS320F240. A fault of permanent magnet(PM) BLDC motor possible to miniaturization and high-output is to be difficult to reduce speed-ripple at low speed region. An existing solution is to be use of PWM waveform by PI control with computing control angle of 60$^{\circ}$. The new family of DSP controllers provides a single chip solution by integrating on-chip not only a high computational power but also, all the peripherals necessary for electric motor control. This paper gives an advanced solution of the SVPWM technique for the purpose of reducing control angel rather than 60$^{\circ}$. This technique gives an excellent speed ripple characteristic.