• 대한기계학회논문집B
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• 제27권9호
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• pp.1248-1255
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• 2003

Pressure coefficient in a rotating discharge hole was measured to gain insight into the influence of rotation on the discharge characteristics of rotating discharge holes. Pressures inside the hole were measured by a telemetry system that had been developed by the authors. The telemetry system is characterized by the diversity of applicable sensor type. In the present study, the telemetry system was modified to measure static pressure using piezoresistive pressure sensors. The pressure sensor is affected by centrifugal force and change of orientation relative to the gravity. The orientation of sensor installation for minimum rotating effect and zero gravity effect was found out from the test. Pressure coefficients in a rotating discharge hole were measured in longitudinal direction as well as circumferential direction at various rotating speeds and three different pressure ratios. From the results, the behaviors of pressure coefficient that cannot be observed by a non-rotating setup were presented. It was also shown that the discharge characteristics of rotating discharge hole is much more influenced by the Rotation number irrespective of pressure ratio.

• E2M - 전기 전자와 첨단 소재
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• 제8권1호
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• pp.102-113
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• 1995

일반적으로 단결정 실리콘은 거의 모든 전자소자의 재료로서 널리 사용되고 있으며 제조공정기술 또한 상당한 수준에 도달하고 있다. 최근에는 실리콘 자체의 우수한 압저항효과, 기계적 특성 그리고 반도체 제조공정을 이용한 미세가공기술인 마이크로머시닝을 이용하는 반도체 압력센서에 대한 연구가 활발히 진행되고 있다. 기계식 압력센서에 비해서 전기적 변화를 이용하는 반도체 압력센서에서는 소형, 저가격, 고신뢰성, 고감도, 다기능, 고분해, 고성능 및 집적화 등의 우수한 특성을 지니고 있다. 본고에서는 이러한 특성을 가지는 반도체 압력센서중 특히, 압저항형과 용량형 압력센서의 구조와 원리, 그리고 연구.개발동향 및 향후 전망에 관해서 기술하였다.

• 대한기계학회논문집B
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• 제27권7호
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• pp.948-955
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• 2003

Pressure coefficient in rotating discharge hole was measured to gain insight into the influence of rotation to the discharge characteristics of rotating discharge hole. Pressure measurements were done by the telemetry system that had been developed by the authors. The telemetry system measures static pressure using piezoresistive pressure sensors. Pressure coefficients in rotating discharge hole were measured in longitudinal direction and circumferential direction with various rotating speed and 3 pressure ratios. From the results, the pressure coefficient, and therefore the discharge coefficient, is known to decrease with the increase of Ro number owing to the increase of flow approaching angle to the discharge hole inlet. However, there exists critical Ro number where the decrease rate of discharge coefficient with the increase of Ro number changes abruptly; flow separation occurs from the discharge hole exit at this critical Ro number. Critical Ro number increases with the increase of length-to-diameter ratio, but the increase is small where the length-to-diameter ratio is higher than 3. The decrease rate of discharge coefficient with the increase of Ro number depends on the pressure recovery at the discharge hole, and the rate is different from each length-to-diameter ratio; it has tendency that the short discharge hole shows higher decrease rate of discharge coefficient.

• 동의생리병리학회지
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• 제19권6호
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• pp.1673-1675
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• 2005

The pulse diagnosis is an important and universal method in Oriental medicine. Nevertheless, because of characteristic that depends on subjective sense of Oriental medicine doctor (OMD), it is not recognized by objective basis. The Korean Institute of Oriental Medicine(KIOM) and Daeyo Medi. Co. Ltd. developed the 3-D Mac using arrey piezoresistive sensors and multi-axial robot. 133 healthy subjects participated in this study, 75 males and 58 females, between 20 and 70 years of age. All subjects were relaxed in a supine position on a comfortable chair for twenty minutes before the measurement was taken. The measured position is the radial artery of subject's left wrist and the position is called Chon, Kwan and Chuck in Oriental medicine. To detect floating and sinking pulse, we established coefficient of floating and sinking(CFS). CFS means relative position of maximum pulse pressure in PH curve. The lower CFS value means that the pulse has floating tendency. There was significant diffence between CFS and diagnosis of floating-sinking pulse by OMD(p=0.020). CFS value of over 40's group was significantly larger than those of 20's and 30's(p=0.000). There was no significant difference between male and female(p=0.061).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
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• pp.134-138
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• 2000

The physical, electrical and piezoresitive characteristics of CrN(chromiun nitride) thin-films on silicon substrates have been investigated for use as strain gauges. The thin-film depositions have been carried out by DC reactive magnetron sputtering in an argon-nitrogen atmosphere(Ar-(5~25 %)$N_2$). The deposited CrN thin-films with thickness of $3500{\AA}$nd annealing conditions($300^{\circ}C$, 48 hr) in Ar-10 % $N_2$ deposition atmosphere have been selected as the ideal piezoresistive material for the strain gauges. Under optimum conditions, the CrN thin-films for the strain gauges is obtained a high electrical resistivity, $\rho=1147.65\;{\mu}{\Omega}cm$, a low temperature coefficient of resistance, TCR=-186 ppm/$^{\circ}C$ and a high temporal stability with a good longitudinal gauge factor, GF=11.17.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.135-141
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• 2000

The physical, electrical and piezoresitive characteristics of CrN(chromiun nitride) thin-films on silicon substrates have been investigated for use as strain gauges. The thin-film depositions have been carried out by OC reactive magnetron sputtering in an argon-nitrogen atmosphere(Ar-(5~25 %)$N_2$). The deposited CrN thin-films with thickness of $3500{\AA}$ and annealing conditions($300^{\circ}C$, 48 hr) in Ar-10 % $N_2$ deposition atmosphere have been selected as the ideal piezoresistive material for the strain gauges. Under optimum conditions, the CrN thin-films for the strain gauges is obtained a high electrical resistivity, $\rho=1147.65\;{\mu}{\Omega}cm$, a low temperature coefficient of resistance, TCR=-186 ppm/$^{\circ}C$ and a high temporal stability with a good longitudinal gauge factor, GF=11.17.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.342-344
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• 1995

Using piezoresistive effects of single-crystal and poly-crystalline silicon, pressure sensors of the same pattern were fabricated for comparison of temperature characteristics. Optimum size and aspect ratio of rectangular sensor diaphragm were calculated by FEM. For polsilicon pressure sensor, polysilicon resistors of Wheatstone bridge were deposited by LPCVD to be used in a wide' temperature range. Polysilicon pressure sensors showed more stable temperature characteristics than single-crysta1 silicon in the range of $-20\sim125[^{\circ}C]$. To get low TCO (Temperature Coefficient of Offset), below $\pm$3 [${\mu}V/V/^{\circ}C$], it is needed for each TCR of piezoresistors to have a deviation within $\pm25[ppm/^{\circ}C]$ less than $\pm500[ppm/^{\circ}C]$ of resistors for polysilicon pressure sensor can result in low TCS(Temperature Coefficient of Sensitivity) of -0.1[%FS/$^{\circ}C$].

• 대한전자공학회논문지
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• 제27권4호
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• pp.563-570
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• 1990

A silicon pressure sensor made of a full bridge of diffused resistors was designed and fabricated using semiconductor integrated circuit process. Thin diaphragms with 30\ulcorner thickness were obtained using anisotropic wet chemical etching technique. Our device showed strong temperature dependence. Compensation networks are used to compensate for the temperature dependence of the pressure sensor. The bridge supply voltage having positive temperature coefficient by compensation networks was utilized against the negative temperature coefficient of bridge output voltage. The sensitivity fluctuation of pressure sensor before temperature compensation was -1700 ppm/\ulcorner, while it reduced to -710ppm\ulcorner with temperature compensation. Our result shows that the we could develop accurate and reliable pressure sensor over a wide temperature range(-20\ulcorner~50\ulcorner).

• 사상체질의학회지
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• 제18권1호
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• pp.118-131
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• 2006

1. Objective Pulse diagnosis is generally applied to Traditional Oriental Medicine but not to Sasang Constitution diagnosis. Recently new pulse analyzer using array piezoresistive sensor and multi-channel robot arm developed. It reflects Oriental Medical Doctors' diagnostic processes, and its reproducibility test was done at Korea Institute of Oriental Medicine. We performed this study to set parameters diagnosing Sasang Constitution. 2. Methods One hundred thirty three subjects participated in this study. They are healty and approved this study. Before being tested with pulse analyzer, they had interview with Sasang Constitution Specialist to diagnose their Sasang Constitution. We established some useful parameters from parameters of pulse analyzer according to the Original Texts of Oriental Medicine and clinical experiences to analyze with clinical data of this study. 3. Results (I) There is a significant difference in pre-dicrotic notch time among all parameters of pulse analyzer in Sasang Constitution groups(P=0.047). (2) There is a significant difference in maximum pulse pressure in 33 to 48 year Sasang Constitution groups(P=0.010). (3) There is a significant difference in frequency width in 17 to 32 year Sasang Constitution groups(P=0.002). (4) There is a significant difference in CFS value in groups which OMD diagnoses; Floating & Sinking pulse(P=0.020). (5) There is a significant difference in pulse rate in groups which OMD diagnoses; Rapid & Slow pulse(P=0.000). (6) There is a significant difference in maximum pulse pressure in groups which OMD diagnoses; Deficient & Solid pulse(P=0.000). 4. Conclusions Analyzing parameters in each Sasang Constitution group, we found it shows significant difference in maximum pulse pressure and corresponding tendency in coefficient of floating & sinking pulse with theories of Sasang Consti-tutional Medicine. As we accumulate more clinical data, we will establish algorithm to diagnose Sasang Constitution using a pulse analyzer.

• 센서학회지
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• 제5권6호
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• pp.25-34
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• 1996

본 논문에서는 압저항형 압력센서를 위한 신호처리회로를 설계하였다. 신호처리회로는 압저항형 압력센서를 구동하기 위한 기준전압 회로와 미소한 센서 신호의 증폭을 위한 인스트루먼트 증폭기로 구성이 되어있다. 신호처리회로는 단일 폴리 이중 메탈(single poly double metal) $1.5\;{\mu}m$ BiCMOS 공정 파라미터를 이용하여 HSPICE로 시뮬레이션 하였다. 시뮬레이션 결과, 밴드갭 기준전압회로의 온도 계수는 $0\;{\sim}\;70^{\circ}C$의 범위에서 $21\;ppm/^{\circ}C$였고 PSRR은 80 dB였다. BiCMOS 증폭기의 이득, 옵셋, CMRR, CMR, PSRR, 특성은 CMOS나 바이폴라보다 우수하였고 전력소비 및 잡음전압 특성은 CMOS가 우수하였다. 설계한 신호처리 회로는 옵셋이 적고 입력 임피던스가 높으며 CMRR 특성이 우수하기 때문에 센서 및 계측용 신호처리회로로서 사용하기에 적합하다.