• Transactions on Electrical and Electronic Materials
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• 제8권5호
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• pp.196-200
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• 2007

In this paper, we propose and discuss the design using a simple method that reduces the fixed pattern noise(FPN) generated on the amorphous Si($\alpha-Si$) bolometer. This method is applicable to an IR image sensor. This method can also minimize the size of the reference resistor in the readout integrated circuit(ROIC) which processes the signal of an IR image sensor. By connecting four bolometer cells in parallel and averaging the resistances of the bolometer cells, the fixed pattern noise generated in the bolometer cell due to process variations is remarkably reduced. Moreover an $\alpha-Si$ bolometer cell, which is made by a MEMS process, has a large resistance value to guarantee an accurate resistance value. This makes the reference resistor be large. In the proposed cell structure, because the bolometer cells connected in parallel have a quarter of the original bolometer's resistance, a reference resistor, which is made by poly-Si in a CMOS process chip, is implemented to be the size of a quarter. We designed a ROIC with the proposed cell structure and implemented the circuit using a 0.35 um CMOS process.

• 한국전자파학회논문지
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• 제18권8호
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• pp.847-853
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• 2007

본 논문에서는 마이크로스트립 사각 개방 루프 공진기와 가변 부성 저항을 이용한 향상된 push-push 전압제어 발진기를 제시하였다. 마이크로스트립 사각 개방 루프 공진기는 큰 결합 계수 값을 갖는데, 이는 Q값을 크게 만들고, 전압 제어 발진기의 위상 잡음을 줄인다. 1.8V의 공급 전압을 사용한 전압 제어 발진기는 $5.744{\sim}5.859GHz$의 주파수 조절 범위에서 $-124.67{\sim}-122.67dBc/Hz\;@\;100 kHz$의 위상 잡음 특성을 갖는다. 이 전압 제어 발진기의 FOM은 같은 주파수 조절 범위에서 $-202.83{\sim}-201dBc/Hz\;@\;100 kHz$의 값을 갖는다. 마이크로 스트립 사각 개방 루프 공진기를 이용한 단일 종단 전압 제어 발진기와 마이크로스트립 공진기를 이용한 push-push 발진기와 비교했을 때 개선된 위상 잡음 특성은 각각 -8.51 dB와 -33.67 dB이다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.153-160
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• 2003

While the interests on the environmental problem during the construction are increasing, the use of low noise-vibration auger-drilled pilling is increasing to solve noise and vibration problem in pilling. Therefore, in Korea, SIP(Soil-Cement Injected Precast Pile) method is mainly used as auger-drilled pilling. However, there is no proper design criteria compatible with the ground condition of Korea, so which is most wanted. To improve and supplement this situation, direct shear tests between SIP pile skin interface and soil were executed on various conditions. Through the analysis of test results, skin resistance characteristics of SIP were investigated thoroughly. Also, the nonlinear unit skin resistance capacity model with SM, SC soil were suggested.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.7-8
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• 2009

In the presence of infrared light, a CMOS Readout IC (ROIC) for a microbolometer typed infrared sensor detects the voltage or current that is caused by the changing in resistance in the bolometer sensor. A serious problem in designing the ROIC is how the value of the bolometer and reference resistors vary because of variations in manufacturing process. Since different pixel have different, resistance values, sensor operations must contend with fixed pattern noise (FPN) problems. In this paper, we propose a novel technique to compensate for the fluctuation in reference resistance by tiling into account the process variation. By using constant current source basing and correlated double sampling, we solved FPN.

• 대한전자공학회논문지SD
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• 제37권2호
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• pp.1-4
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• 2000

공통컬렉터 잡음등가회로 해석에 기초한 베이스저항 추출방법을 제시하였다. 측정은 BiCMOS공정으로 제조되고 폴리에미터 구조를 갖는 소자에 대해서 실행 되었다. 베이스저항 측정은 서로 다른 베이스전류와 구조에 따라 수행되었다. 낮은 베이스전류에서 측정된 실험값은 이론적으로 예측된 값과 매우 잘 일치하는 결과를 얻었다

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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• pp.218-221
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• 2001

In this paper, High Q Inductor using negative resistance circuit and the ceramic inductor was designed and fabricated at 2GHz. It was Improved the inductor of Q=90 using a inductor with Q=30 added to negative resistance circuit at 2GHz. As a result, at the bias condition of 3V and 16mA, the output power and phase noise in the operation frequency 2.01GHz are 5dBm and -115.34dBc/Hz at 100kHz offset from carrier, respectively. Phase noise was improved -10dBc/Hz at 100kHz offset compared to only using ceremic inductor.

• 한국전기전자재료학회논문지
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• 제22권2호
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• pp.119-122
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• 2009

As infrared light radiates, the CMOS Readout IC (ROIC) for the microbolometer typed infrared sensor detects voltage or current which is caused by the variation of resistance in the bolometer sensor. A serious problem we may have in designing the ROIC is the value of bolometer and reference resistors will be changed due to process variation. Since each pixel does not have the same value of resistance, fixed pattern noise problems happen during the sensor operations. In this paper, we propose a novel technique to compensate the fluctuation of reference resistance with taking account of process variation. By using a comparator and a cross coupled latch, we will make the value of reference resistor same as the bolometer's.

• 자동차안전학회지
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• 제7권2호
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• pp.19-24
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• 2015

Ferritic Nitro Carburizing (FNC) cast iron brake discs is known to improve corrosion resistance and brake creep groan noise as well as prevent corrosion-induced pulsation. But, it is necessary to treat honing machining on braking surface to avoid grinding noise during braking.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.196-201
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• 2003

Axial fans are widely used for automotive engine cooling device due to their ability to produce high flow rate to keep engine cool. At the same time, the noise generated by these fans causes one of the most serious problems. Especially, engine cooling fan noise in idle condition of a car is noticeable. Therefore, the high efficient and low-noise fan is seriously needed. When a new fan system is designed, system resistance and non-uniform inflow are the key factors to get the high performance and low noise fan system. In this study, experimental study on the fan and system was carried out and brought a successful result of performance and noise from a designed fan. And through the modification of the fan system, the fan produced more flow rate and became less noisy.

• Journal of Welding and Joining
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• 제17권2호
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• pp.97-103
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• 1999

The dynamic resistance monitoring in primary circuit is one of the important issues. Because in-process and real time quality assurance of resistance spot weld is needed to increase the product reliability. In this study, new dynamic resistance detecting method is proposed as a practical manner of weld quality assurance using instantaneous current and voltage measured at the primary circuit. and also, various patterns of primary dynamic resistance curve are characterized with the macro photograph and the weldability lobe curve. It is found that the primary dynamic resistance patterns are basically similar to those of the secondary, but there is evident advantage such as no extra devices are needed to obtain the quality information and eventually real time feedback control will be possible.