• 전자공학회논문지B
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• 제31B권2호
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• pp.80-87
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• 1994

Fetal monitoring is a routine procedure to obtain a record of physiologic functions during pregnancy and labor. It is required to determine fetal heart frequency accurately. There are various types of fetal heart rate(FHR) determination and the most frequently applied method is transabdominal Doppler ultrasound. However, in the case of weak or noise corrupted Doppler ultrasound signals, conventional peak detections and the autocorrelation function method have many difficulties to determine FHR precisely. Also the autocorrelation function is effected by threshold level and window size. To solve these problems, the high resolution pitch determination algorinthm is introduced to detect FHR from Doppler ultrasound signals. This scheme digitally processes Doppler ultrasound signal for digital rectification, envelope detection, decimation and correlation calculation of two interconnected segments and then FHR is determined by its maximal value. Even in the case of a greatly smeared noise signal, this algorithm is able to search FHR more accurately than autocorrelation function by means of compensating FHR with a constant correlation threshold. This algorithm is simulated by 386-MATLAB on PC 486/DX and verified that it is superior to the autocorrelation function method.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 춘계학술대회
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• pp.96-99
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• 1994

Despite the simplicity of processing, a conventional autocorrelation function(ACF) method for the precise determination of fetal heart rate (FHR) has many problems. In case of weak or noise corrupted Doppler ultrasound signal. the ACF method is very sensitive to the threshold level and data window length. It is very troublesome to extract FHR when there is a data loss. To overcome these problems, the high resolution pitch detection algorithm was adopted to estimate the FHR. This method is more accurate, robust and reliable than the ACF method. With a lot of calculation, however, it is impossible to process real time FHR estimation. This paper is presented a new FHR estimation algorithm for real time processing.

• Communications for Statistical Applications and Methods
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• 제13권1호
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• pp.73-88
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• 2006

In this paper, we construct data-base for fetal heart rate (FHR) data and develop the FHR Monitering system to diagnose fetus, HYFM-III. For diagnostic system, a few statistical decision making mechanism are adopted, such as approximate entropy, neural networks, and logistic discrimination. Since FHR data is very chaotic, we mostly adopt nonlinear statistical methods. On the basis of this system, we expect to develop expert system for early detection of abnormal fetus.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1993년도 춘계학술대회
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• pp.81-85
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• 1993

Despite the simplicity of processing, conventional autocorrelation function (ACF) method for the precise determination of fetal heart rate (FHR) has many problems. In the case of weak or noise corrupted Doppler ultrasound singnals, the ACF method is very sensitive to the threshold level and data window length. It is real troublesome to extract FHR when there is a data loss. To overcome these problems, the high resolution pitch detection algorithm is adapted to estimate the FHR. The FHR is determined from the correlation of two interconnected segments by its maximum correlation value. FHR is compensated with a constant correlation threshold in a greatly smeared noise signal. This method yields more accurate, robust and reliable than the ACF method.

• 대한의용생체공학회:의공학회지
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• 제16권2호
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• pp.175-182
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• 1995

태아 심음을 측정하기 위한 기존의 자기상관 함수 법은 처리과정이 간편한 반면에 많은 문제점을 가지고 있다. 초음파 도플러 신호가 열악할 경우 고전적인 자기상관 함수 법은 문턱 값의 선정과 창 함수 크기에 매우 민감하다. 특히 데이터 손실이 생길 때 정확한 태아 심박동 수를 찾기가 어렵다. 이들 문제점들을 보완하기 위하여 초음파 도플러 신호로부터 정확한 태아 심박동 수를 찾는 고해상 피치검출 알고리듬이 제안되었다. 이 알고리듬은 자기상관 함수법 보다 정확하고, 잡음에 강하며, 높은 신뢰성을 갖으나 계산량이 많아 실시간 처리가 어렵다. 본 논문에서는 실시간 처리에 적합한 새로운 태아 심음 추출 알고리듬을 제안하고, 제안된 알고리듬을 적용한 실시간 태아 심음 감시시스템에 관하여 연구하였다.

• 한국산학기술학회논문지
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• 제11권12호
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• pp.4954-4961
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• 2010

본 배경 : 병원들과 병상 수들의 과잉공급과 의료시장 개방으로 인해 병원들 사이의 경쟁이 매우 심화되고 있다. 더 많은 환자 유치를 위해 환자들이 선호하는 특화서비스에 대해 조사하게 되었다. 방법 : 환자만족도를 조사하기 위해 약 20개 항목의 설문지를 개발하여 병원들 방문한 외래 환자 297명과 입원환자 302명을 조사하였으며 Excel과 SPSS를 이용하여 기술통계와 회귀분석을 하였다. 결과 : 환자의 충성도와 특화된 병원서비스의 관련성이 지인에게 이 병원 이용을 추천하겠다와 관련이 있으며 1) FHR사용과 지속적인 치료 및 관리를 위한 도우미는 외래환자와 PHR사용에서 양의 관련성을 가지고 있었고 FHR은 외래환자에서 양의 관련성을 갖고 있었다. 2) 병원의 재방문 : PHR사용자와 환자치료 도우미의 요구가 있었으며 TV사용료 지불은 부정적 관련성을 가지고 있었다. 결론 : FHR, PHR과 환자치료 도우미들은 환자의 충성도를 증가시키는데 매우 중요한 요인들이었다.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권4호
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• pp.167-174
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• 2002

This study describes a fetal heart rate(FHR) estimation algorithm using phonogram. Using a phonogram amplifier, various fetal heart sounds are collected in a university hospital. The FHR estimation algorithms consists of a lowpass filter, decimation, envelop detection, pitch detection, and post-processing. The post-processing is the FHR decision procedure using all informations of fetal heart rates. Using the algorithm and other parameters of fetal heart sound, a fetal monitoring software was developed. This can display the original signals, the FFT spectra, FHR and its trajectory. Even though the fetal phonogram amplifier detects the fetal heart sounds well, the sound quality is not so good as the ultrasonography. In case of very week fetal heart sound, autocorrelation of it showed clear periodicity. But two main peaks in one period is an obstacle in pitch detection and peaks are not so vivid. The proposed FHR estimation algorithm showed very accurate and stable results. Since the developed software displays multiple parameters in real time and has convenient functions, it will be useful for the phonogram-style fetal monitoring device.

• 인터넷정보학회논문지
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• 제8권4호
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• pp.17-29
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• 2007

본 논문에서는 RNG 기반의 스캐터넷 토폴로지 구성, 자기 치유 및 라우팅 경로의 최적화를 위한 알고리즘(RNG-FHR)을 제시하고, ns-2와 블루투스 확장인 blueware 시뮬레이터를 이용하여 알고리즘의 성능을 분석하였다. 소규모 분산망 환경에서 스캐터넷 구성, 노드의 링크 설정 및 자기 치유 관점에서 분석한 결과, 초기에는 이웃노드 발견을 위한 메시지 교환량이 증가하여 지연이 점차 증가하지만 시간이 지남에 따라 이웃노드 발견과 충분한 로컬 정보 교환에 따라 지연이 다소 줄어듦을 알 수 있다. 결국 블루투스 망을 RNG 기반으로 확장하여 소규모의 분산망에 적용하는 경우 소량의 메시지 교환과로컬 정보 교환으로 인해망 구성, 자기 치유 및 라우팅 경로의 최적화가 가능하여 성능과 구현측면에서 충분히 실현 가능함을 알 수 있다.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.817-825
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• 2022

A recent benchmarking effort, under the auspices of the Organization for Economic Cooperation and Development (OECD) Nuclear Energy Agency (NEA), has been made to evaluate the current state of modeling and simulation tools available to model fluoride salt-cooled high temperature reactors (FHRs). The FHR benchmarking effort considered in this work consists of several cases evaluating the neutronic parameters of a 2D prismatic FHR fuel assembly model using the participants' choice of simulation tools. Benchmark participants blindly submitted results for comparison with overall good agreement, except for some which significantly differed on cases utilizing a molybdenum-bearing control rod. Participants utilizing more recently updated explicit isotopic cross sections had consistent results, whereas those using elemental molybdenum cross sections observed reactivity differences on the order of thousands of pcm relative to their peers. Through a series of supporting tests, the authors attribute the differences as being nuclear data driven from using older legacy elemental molybdenum cross sections. Quantitative analysis is conducted on the control rod to identify spectral, reaction rate, and cross section phenomena responsible for the observed differences. Results confirm the observed differences are attributable to the use of elemental cross sections which overestimate the reaction rates in strong resonance channels.

• Journal of Welding and Joining
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• 제20권4호
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• pp.538-543
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• 2002

M/S TB(Mash Seam Tailored Blank) is a production method for blanks by welding together blanks of different material, thickness and coating, and is an attractive method for manufacturing car body because it makes parts lighter and can save the cost and time to manufacture. However, there have not been quantified criteria to evaluate the quality of TB weld. This study introduced FHR (failure height ratio) in order to assess formability or/and weldability of the M/S welds and the applicability of FHR was confirmed by actual auto body forming and FLD tests. Furthermore, a new parameter, HN(heat number) based on the heat input of "$Q=I^2Rt$" was proposed and assessed. It was found that the concept of HN could be utilized to evaluate the soundness of M/S welds without any destructive tests.ive tests.