• 한국정보기술학회논문지
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• 제16권11호
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• pp.61-68
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• 2018

도플러 레이더에 응용할 목적으로 전압제어 발진기와 주파수 혼합기가 합쳐진 10.525GHz 자체발진 혼합기 반도체 IC 칩을 실리콘 CMOS 기술을 이용하여 설계하였다. 자체발진 혼합기에 포함된 p-코어 형태의 VCO는 송신신호에 포함된 잡음을 최소화한다. 이 잡음 최소화는 센싱 가능 거리를 늘여서 움직임 감지센서의 도달거리와 도달감도에 유리한 방향으로 작용한다. 위상잡음에 대한 시뮬레이션 결과 P-코어로 설계된 VCO는 1MHz 오프셋에서 -106.008dBc/Hz, 25MHz 오프셋에서 -140.735dBc/Hz의 잡음특성을 가짐으로써 N-코어 및 NP-코어로 설계된 VCO에 비하여 우수한 잡음 특성을 보였다. 본 연구에 의한 p-코어로 설계된 VCO를 이용하여 자체 발진 혼합기를 구현한다면 도달거리와 도달감도가 우수한 움직임 감지센서를 제작할 수 있을 것이다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 춘계종합학술대회 A
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• pp.997-999
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• 2008

본 연구에서는 항만오염의 주원인의 하나인 오염물질을 검출할 수 있는 센서 개발을 위하여 Viologen 유도체를 사용하였다. 자기조립법을 이용하여 Viologen 유도체를 수정진동자의 금 전극에 수식하였으며, 순환전압전류법을 이용하며 산화 환원 반응 특성과 피크전류의 변화를 관찰하였다. 그리고 벤젠, 인산염, 계면활성제 등의 오염물질에 대한 선택적 특성을 검토하였다.

• 한국산업정보학회논문지
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• 제19권4호
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• pp.33-39
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• 2014

본 논문에서는 나노미티 기술에서 HCI와 BTI와 같은 노화 현상에 의해 야기되는 MOSFET 디지털 회로의 실패를 정확히 예측을 위한 플립플롭 기반의 온-칩 노화 센싱 회로를 제안한다. 제안된 센싱 회로는 순차회로의 가드밴드 (guardband) 위반에 대한 경고를 나타내는 타이밍 윈도우를 이용해서 노화에 의한 회로의 동작 실패 전에 경고 비트를 발생한다. 발생된 비트는 고신뢰의 시스템 설계를 위한 적응형 셀프-튜닝 방법에서 제어 신호로 사용될 것이다. 노화 센싱 회로는 0.11um CMOS 기술을 사용해서 구현되었고, 파워-게이팅 구조를 가지는 $4{\times}4$ 곱셈기에 의해서 평가되었다.

• 한국염색가공학회지
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• 제30권2호
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• pp.63-69
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• 2018

In this study, we report on successful attempt towards the synthesis of sulfur self-doped $g-C_3N_4$ by directly heating thiourea in air. The synthesized materials were characterized using UV-vis spectral technique, FT-IR, XRD and TEM analysis. Further, the obtained material shows an excellent detection of carcinogenic TNP(Tri nitro phenol) in the presence of 10-fold excess of various other common interferences. The strong inner filter effect and molecular interactions(electrostatic, ${\pi}-{\pi}$, and hydrogen bonding interactions) between TNP and the $S-g-C_3N_4$ Nano sheets led to the fluorescence quenching of the $S-g-C_3N_4$ Nano sheets with an excellent selectivity and sensitivity towards TNP compared to that of other nitro aromatics under optimal conditions and the detection limit calculated was found to be 6.324 nM for TNP. The synthesized nanocomposite provides a promising platform for the development of sensors with improved reproducibility and stability for ultra-sensitive and selective sensing of TNP.

• 한국정보전자통신기술학회논문지
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• 제10권5호
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• pp.396-401
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• 2017

본 논문은 블루투스와 다른 장치를 연결하였을 때 블루투스와의 간섭 현상에 대한 해결 방안을 제시한다. 랜덤 주파수 도약 기법은 무선랜 간섭을 고려하지 않고 블루투스 전체 채널을 이용하여 도약 패턴을 생성하는 기법이다. 제안된 적응적 주파수 도약 기법은 블루투스의 주기적인 캐리어 센싱을 통해 무선랜 간섭을 고려하여 블루투스 채널의 도약 패턴을 생성하는 기법이다. 모의실험을 통해 무선랜 간섭이 혼잡한 상황에서도 블루투스 캐리어 센싱 간격이 줄어들수록 적응적 주파수 도약 기법을 사용하면 패킷 오류율이 감소되는 것을 확인하였다. 특히 주파수 도약 기법은 적응적 주파수 도약 기법 대비 평균 패킷 오류율은 약 13%의 성능 향상이 있었다.

• 한국항해학회지
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• 제10권1호
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• pp.81-100
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• 1986

Self-contained portable remote-indicating magnetic compass was designed and tested. Its sensing part consists of main scale disk of rotary encoder with photo-etched 180, oopaque slits and three pairs of light sources and detectors seperated by a transparent index scale, so that any angular deflection of main scale disk against the bowl may be detected optically. The outputs from the sensing part are transformed into digital ship's course indication by electronics unit which consists of operational amplifier, phase discriminator, up-down counter and counting starter circuit. The results from testign the above compass with turntable at variable rate of turn are as following : 1) The main scale disk deflection against the bowl can be detected without any disturbing influence to the freedom of its north-seeking function. 2) The digital indication resolution is found to be $\circ \pm$1 degree. 3) Misrepresenting indication can be avoided by ensuring dimension uniformity and arrangement accuracy of slits on main and index scale disks and by centering pivot in the encoder disk. 4) Indication resolution should be improved by modifying the signal processing and by doubling the number of slits on compass card. 5) Further study should be made on developing non-conductive compass liquid, analogue repeater driving system and more compact processing element.

• 한국전기전자재료학회논문지
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• 제31권6호
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• pp.427-432
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• 2018

High-capacity secondary batteries can cause explosion hazards owing to microcurrent variations or current surges that occur in short circuits. Consequently, complete safety cannot be achieved with general protection that is limited to a mere current fuse. Hence, in the case of secondary batteries, it is necessary for the protector to limit the inrush current in a short circuit, and to detect the current during microcurrent variations. To serve this purpose, a fuse can be employed for the secondary battery protection circuit with current detection. This study aims at designing a protection device that can stably operate in the hazardous circumstances associated with high-capacity secondary batteries. To achieve the said objective, a detecting fuse was designed from an alloy of low melting point elements for securing stability in abnormal current states. Experimental results show that the operating I-T and V-T characteristic constraints can be satisfied by employing the proposed current detecting self-contained low melting point fuse, and through the resistance of the heating resistor. These results thus verify that the proposed protection device can prevent the hazards of short circuit current surges and microcurrent variations of secondary batteries.

• 한국전기전자재료학회논문지
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• 제31권1호
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• pp.29-33
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• 2018

Using a vanadium dioxide ($VO_2$) source, highly pure and amorphous vanadium oxide (VO) thin films were deposited using an e-beam evaporator at room temperature and high vacuum (<$10^{-7}$ Torr). Then, by controlling the post-annealing conditions such as $N_2:O_2$ pressure ratio and annealing time, we could easily synthesize a homogeneous $VO_2$ thin film and also mixed-phase VO thin films, including $VO_2$, $V_2O_5$, $V_3O_7$, $V_5O_9$, and $V_6O_{13}$. The crystallinity and phase of these were characterized by X-ray diffraction, and the surface morphology by FE-SEM. Moreover, the electrical properties and ethanol sensing measurements of the VO thin films were analyzed as a function of temperature. In general, mixed-phases as a self-doping effect have enhanced electrical properties, with a high carrier density and an enhanced response to ethanol. In summary, we developed an easy, scalable, and reproducible fabrication process for VO thin films that is a promising candidate for many potential electrical and optical applications.

• 센서학회지
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• 제15권3호
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• pp.192-198
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• 2006

In this study, the light addressable potentiometric sensors (LAPS) with $Si_{3}N_{4}/SiO_{2}/Si$, and $Ta_{2}O_{5}/SiO_{2}/Si$ structures were fabricated. The penicillinsae was immobilized on the devices to hydrolyze the penicillin using self-assembled monolayer (SAM) method. Then response characteristics according to the penicillin concentrations were measured and compared. The measuring system was simplified by using LabVIEW. The pH response characteristics of fabricated devices are 56 mV/pH ($Si_{3}N_{4}$ sensing membrane) and 61 mV/pH ($Ta_{2}O_{5}$ sensing membrane). The sensitivity of sensor by enzyme reaction result of the enzyme reaction were 60 mV/decade and 74 mV/decade for $Si_{3}N_{4}/SiO_{2}/Si$ and $Ta_{2}O_{5}/SiO_{2}/Si$ structure, respectively, in the range of $0.1\;mM{\sim}10\;mM $of the penicillin concentration.

• 전자공학회논문지C
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• 제34C권11호
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• pp.1-11
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• 1997

The transient current components of the dRAM are analyzed and the sensing current, data path operation current and DC leakage current are revealed to be the major curretn components. It is expected that the supply voltage of less than 1.5V with low VT MOS witll be used in multi-giga bit dRAM. A low voltage dual VT self-timed CMOS logic in which the subthreshold leakage current path is blocked by a large high-VT MOS is proposed. An active signal at each node of the nature speeds up the signal propagation and enables the synchronous DRAM to adopt a fast pipelining scheme. The sensing current can be reduced by adopting 8 bit prefetch scheme with 1.2V VDD. Although the total cycle time for the sequential 8 bit read is the same as that of the 3.3V conventional DRAM, the sensing current is loered to 0.7mA or less than 2.3% of the current of 3.3V conventional DRAM. 4 stage pipeline scheme is used to rduce the power consumption in the 4 giga bit DRAM data path of which length and RC delay amount to 3 cm and 23.3ns, respectively. A simple wave pipeline scheme is used in the data path where 4 sequential data pulses of 5 ns width are concurrently transferred. With the reduction of the supply voltage from 3.3V to 1.2V, the operation current is lowered from 22mA to 2.5mA while the operation speed is enhanced more than 4 times with 6 ns cycle time.