• 대한의용생체공학회:의공학회지
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• 제21권5호
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• pp.477-485
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• 2000

본 논문에서는 신경신호기록을 위한 반도체 미세전극용 전치증폭기의 잡음특성을 설계하기 위한 체계적인 방법을 제시한다. 세포외기록(extracellular recording)에 의하여 측정된 신경신호와 전형적인 CMOS소자의 저주파 잡음특성을 함계 고려하여 전체 신호대잡음비를 계산하였다. 2단 CMOS 차동증폭기에 대한 해석과 함께 신호대잡음비에 중요한 영향을 끼치는 요소들에 대하여 설명하였다. 출력잡음전력에 대한 해석적인식을 유도하였으며 이로부터 회로설계자가 조절할 수 있는 주파수응답과 소자 파라미터들을 결정하였다. 입력소자의 크기와 트랜스컨덕턴스의 비가 최적영역으로부터 약간 벗어날 경우에 신호대잡음비가 크게 저하됨을 보였다. 이와 함께 만족스런 잡음특성을 위한 증폭이의 설계 변수 값들도 제시하였다.

• 한국ITS학회 논문지
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• 제9권3호
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• pp.73-84
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• 2010

본 연구에서는 고속도로에서 GPS(Global Positioning System)수신기를 장착한 프로브차량을 이용하여 수집한 속도자료를 이용하여 사고 위험구간을 추출하는 방법론을 제시하였다. 위험구간 추출을 사고발생 유 무를 판단하는 분류문제(Classification)로 정형화하고 베이지안 신경망을 적용하였다. 개별차량의 속도자료를 이용하여 다양한 잠재적 독립변수를 설정하고 이항 로지스틱 회귀분석을 이용하여 통계적으로 유의미한 변수만을 추출하여 베이지안 신경망의 입력자료로 사용하였다. 제안된 방법론의 성능 평가를 위해 사고 발생 경험이 있는 위험구간을 정확히 추출하는 분류정확도를 효과척도로 활용하였다. 본 연구에서 제안한 방법론의 타당성을 60%의 분류정확도를 통해 확인할 수 있었다. 고속도로 신설노선의 교통안전성을 평가하고 사고예방을 위한 대응책 개발 및 적용에 본 연구의 결과가 효과적으로 활용될 것으로 기대된다.

• Journal of Genetic Medicine
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• 제1권1호
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• pp.45-50
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• 1997

Neuroblastoma, a pediatric malignant neoplasm of neural crest origin, has a wide range of clinical virulence. The mechanisms contributing to the development of neuroblastomas are largely unclear, but non-random chromosomal changes identified over the past years suggest the involvement of genetic alterations. Amplification of the human N-myc proto-oncogene is frequently seen either in extrachromosomal double minutes or in homogeneously staining regions (HSRs) of aggressively growing neuroblastomas. N-myc maps to chromosome 2 band 24, but HSR have never been observed at this band, suggesting transposition of N-myc during amplification. We have constructed and analyzed the region-specific painting probe for HSR in neuroblastoma IMR-32 to determine the derivative chromosomes. Microdissection was performed on HSR using an inverted microscope with the help of microglass needles and an micromanipulator. We pretreated the microdissected fragments with Topoisomerase I which catalyzes the relaxation of supercolled DNA, and performed two initial rounds of DNA synthesis with T7 DNA polymerase followed by conventional PCR to enable the reliable preparation of Fluorescent in situ hybridization probe from a single microdissected chromosome. With this method, it was possible to construct the region-specific painting probe for HSR. The probe hybridized specifically to the HSRs of IMR-32, and to 2p24, 2p13 of normal chromosome. Our results suggest there was coamplification of N-myc together with DNA of the chromosome 2p24 and 2p13. Moreover, the fluorescent signals for the amplified chromosomal regions in IMR-32 cells were also easily recognized at a Thus this painting probe can be applied to detect the similar amplification of N-myc in neuroblastoma tissue, and the probe pool for HSR may be used to identify the cancer-relevant genes.

• 한국공작기계학회논문집
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• 제10권4호
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• pp.70-75
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• 2001

In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. This paper models of the thermal errors for error analysis and develops on-the-machine measurement system by which the volumetric error are measured and compensated. The thermal error is modeled by means of angularity errors of a column and thermal drift error of the spindel unit which are measured by the touch probe unit with a star type styluses, a designed spherical ball arti-fact, and five gap sensors. In order to analyze the thermal characteristics under several operating conditions, experiments performed with the touch probe unit and five gap sensors on the vertical and horizontal machining centers.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1704-1709
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• 2000

This paper proposes a spherical probe allowing acoustic intensity measurements in three dimensions to be made, which creates a diffracted field that is well-defined, thanks to analytic solution of diffraction phenomena. Six microphones are distributed on the surface of the sphere along three rectangular axes. Its measurement technique is not based on finite difference approximation, as is the case for the ID probe but on the analytic solution of diffraction phenomena. In fact, the success of sound source identification depends on the inverse models used to estimate inverse diffraction phenomena, which has non-linear properties. In this paper, we introduce the concept of nonlinear inverse diffraction modeling using a neural network and the idea of 3 dimensional sound source identification with several tests.

• 한국공작기계학회논문집
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• 제10권6호
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• pp.95-101
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• 2001

This work is concerned with construction of the intelligence stress predictor far compression strength evaluation using neural network-ultrasonic waves. The contact pressure in jointed plates was measured by using ultrasonic technique. Neural network is used to evaluate and predict contact pressure from the results of the calibration curves. The organized neural system was leaned with the accuracy of 99%, as a result of learning the ultrasonic echo ratio to the contact pressure measurement between SM45C and STS410 materials. And it could be evaluated and predicted with the accuracy of 90% in the evaluation of ultrasonic echo ratio difference in the same surface roughness and contact pressure, and 85% in the prediction of virtual ultrasonic echo ratio. Thus the proposed stress predictor is very useful for the evaluation and prediction of the contact pressure between SM45C and STS410 materials.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.216-216
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• 1996

The purpose of the present study was to determine whether in vivo noradrenergic neural activity in the locus coeruleus is related to the development of hypertension. Two groups of animals were prepared, 1) young spontaneously hypertensive rats (SHR) and 2) age-matched normotensive wistar kyoto rats (WKY). At il weeks of age, the release of norepinephrine (NE) and 3,4-dihydroxyphenylglycol (DOPEG) from locus coeruleus of young SHR and WKY as an index of neural activity were determined by in vivo microdialysis along with blood pressure (BP) at three conditions : 1) normal; 2) elevated BP by systemic injection of phenylephrine and 3) alpha-1 adrenoceptor stimulated by perfusion of phenylephrine into the locus coeruleus through microdialysis probe. Basal releases of NE and DOPEG from the iocus coeruleus were 0.415+/-0.089pg/20min, 1.311+/-0.293 pg/20min in SHR and 0.204+/-0.078 pg/20min, 1.492+/-0.365 pg/20min in WKY respectively. Basal release of NE from the locus coeruleus of SHR was significantly greater than that of WKY. Phenylephrine systemic injection caused elevation of BP in both SHR and WKY in a dose related manner. Following phenyephrine injection, the releases of NE and DOPEG from the locus coeruleus of SHR were significantly decreased, whereas there were no significant changes in the releases of NE and DOPEG In young WKY. Alpha-1 adrenoceptor stimulation in the locus coeruleus by perfused phenylephrine through microdialysis probe caused pressor responses in both SHR and WKY, but the magnitude of pressor response in SHR was larger compared with that in WKY. The result from the present study suggests that noradrenergic neural activity in locus coeruleus may contribute as one of triggering factors for the expression of hypertension in young SHR.

• 전자공학회논문지
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• 제50권4호
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• pp.229-235
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• 2013

본 논문은 최근 활발하게 연구되고 있는 뇌-기계 접속을 위한 완전 삽입형 마이크로 시스템의 구현에 있어서 중요한 이슈들을 고찰한다. 현재까지의 과학 기술적 연구는 신경 신호 증폭기, 무선 신호 전송 등 주로 고성능 저전력 전자기기 및 시스템을 구현하는데 집중되어 왔으나, 마이크로 시스템의 실제적인 응용은 전자 기기의 특성뿐만 아니라 밀봉 구조의 디자인에서 뇌의 생리 해부학적 특성에 이르기까지 여러 가지 요인에 의해 영향을 받게 된다. 본 논문은 특히 뇌 삽입형 마이크로 시스템의 실질적인 구현에 결정적인 영향을 주는 시스템 발열의 영향, 신경 프로브의 감지 부피, 무선 데이터 전송 및 전력 전달, 그리고 뇌의 생리 해부학적인 고려 요인에 대해 논의한다.

• 한국생산제조학회지
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• 제6권1호
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• pp.27-33
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• 1997

A neural network approach has been developed to determine the depth of a surface breaking crack in a steel plate from ultrasonic backscattering data. The network is trained by the use of feedforward three-layered network together with a back-scattering algorithm for error correction. The signal used for crack insonification is a mode converted 70$^{\circ}$transverse wave. A numerical analysis of back scattered field is carried out based on elastic wave theory, by the use of the boundary element method. The numerical data are calibrated by comparison with experimental data. The numerical analysis provides synthetic data for the training of the network. The training data have been calculated for cracks with specified increments of the crack depth. The performance of the network has been tested on other synthetic data and experimental data which are different from the training data.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1445-1446
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• 2007

In this paper, we have studied for analysis of the partial discharge(PD) signal in power transmission line. The PD signal has estimated as detected signal accumulation of a PRPDA method by using Labview, and analyzed with neural-fuzzy algorithm. With practical PD logic implementation of theoretical detected system and hardware implementation, the device for Hipotronics Company's 22.9kV or 154kV setup have generated and then have applied with 18kV,20kV with 1:1 time probe. It's also used the LDPE 0.27mmt (scratch error 0.05mmt) to sample for making PD. Our new class of PD detected algorithm have also compared with previous PRPDA or Neural Fuzzy algorithm, which has diagnose more conveniently by adding numerical values.