음성 신호로부터 주기, 비주기 성분의 반복적 계산법에 의한 분리 실험

조철우,리타오,Jo Cheol-Woo,Lee Tao 대한음성학회 2003 말소리 Vol.48 No.-

source of speech signal is actually composed of combination of periodic and aperiodic components, although it is often modeled to either one of those. In the paper an experiment which can separate periodic and aperiodic components from speech source. Linear predictive residual signal was used as a approximated vocal source the original speech to obtain the estimated aperiodic part. Iterative extrapolation method was used to compute the aperiodic part.

풍선도자관의 Ho-166-DTPA 흡수선량

조철우,박찬희,윤석남,강해준,김미화,장지선,박경배 한국의학물리학회 2002 의학물리 Vol.13 No.2

관상동맥 성형술 시행시 재협착률을 줄이기 위하여 풍선도자에 Ho-166을 주입하였을 때 혈관 주위에 전달되는 방사선의 흡수선량을 여러 가지 풍선 직경에 따라 평가하였다. 액체 상태의 Ho-166은 한국원자력연구소에서 중성자핵반응인(n, ${\gamma}$)반응으로 얻었다. 혈관 내벽의 흡수선량을 구하기 위하여 GafChromic film과 개조한 마이크로 메터를 이용하여 거리에 따른 홉수선량을 구하였다. 풍선내의 방사능 농도와 조사시간을 고려하여 흡수선량율의 단위를 Gy/min/GBq/ml 로 구하였다. 이는 단위체적당의 방사능 즉 방사능농도(GBq/ml)에 따른 분당 흡수선량 즉 흡수선량률(Gy/min)이다. 직경이 2.5, 3.0, 3.5, 4.0 mm인 풍선도자의 풍선의 표면에서의 흡수선량율은 각각 0.86, 1.01, 1.11, 1.24 Gy/min/GBq/ml 로 측정 되었다. 풍선표면에서부터 거리에 따라 급격히 감소하는 흡수선량을 정확하게 측정 할 수 있는 방법을 제시하였다. 또한 진공펌프를 이용하여 풍선내의 공기방울을 제거하여 균일한 흡수선량이 되도록 하였다. The purpose of this study was to evaluate the absorbed dose to the coronary artery segment from various sized balloon angio catheters. The liquid form of Ho-166 was produced at the KAERI by (n, ${\gamma}$ ) reaction. We used GafChromic film for the estimation of the absorbed dose by beta particles. The exposed films were read using a videodensitometer. Several film exposures were made with varying irradiation times and activities. A modified micrometer was used for the measurement of the absorbed dose distribution near the balloon surface. Four balloons of coronary catheters evaluated were 30 m long and 2.5, 3.0, 3.5 and 4.0 mm in diameter. All doses are plotted in units of Gy/min/GBq/ml as a function of radial distance in mm from the surface of balloon. The absorbed dose rate was 0.86, 1.01, 1.11 and 1.24 Gy/min/GBq/ml at a balloon surface for various balloon diameter 2.5, 3.0, 3.5 and 4.0 mm respectively. Using a vacuum pump, the air in the balloon was evacuated prior to instillation of the Ho-166 source. By removing air bubbles in the balloon, the absorbed dose distribution was more uniform.

PHONETIC TEXT GENERATOR을 위한 제안 - 한국어 음소법칙의 규칙화를 중심으로 - ( Some Considerations For Phonetic Text Generator )

조철우,이우선,이태원,이용주 대한전자공학회 1986 대한전자공학회 학술대회 Vol.1986 No.1

Ho-166-CHICO 치료 후 평면 영상을 이용한 방사선 흡수선량의 계산

조철우,박찬희,원재환,왕희정,김영미,박경배,이병기 한국의학물리학회 1998 의학물리 Vol.9 No.3

방사성 동위원소의 치료에 베타 방출 선원이 많이 이용되고 있다. 베타 방출 핵종 들은 투과력이 약해 방사선 도달거리 (range)가 짧아 병소내에 직접 주입하여 선택적으로 병소만을 조사하여 치료 의 효과를 얻을 수 있고 주변 정상 조직의 방사선 피폭을 줄일 수 있다. 최근 한국 원자력연구소의 원자로인 하나로를 이용하여 베타 입자 방출체인 Ho-l66 용액을 만들어 여기에 키토산 화합물을 표지 하였다. Ho-l66 은 고 에너지 베타 방출체라는 점과 일부 감마선이 방출됨으로써 감마카메라로 쉽게 영상을 얻을 수 있다는 장점이 있다. 본 연구에서는 감마카메라로 얻은 평면 영상을 이용하여 Ho-l66으로 치료한 부위와 그 주변의 정상 장기들의 방사선 홉수선량을 구하였다. 감마카메라는 Siemens 의 2중 head를 가진 Multispect2 시스템이 이용되었고, 콜리메이터는 medium energy, 최대 에너지는 80 keV, 창은 20%로 5분간 영상을 획득하였다. Ho-166 에 대한 투과인자 (transmission factor)는 환자 있을 때와 없을 때의 영상으로 관심영역의 ROIs 의 비로 구하였다 .3일간의 평면 영상으로 유효반감기를 구하여 Marinelli 공식과 MIRD 공식으로 베타입자에 대한 방사선 흡수선량을 구하였다. 감마선에 의한 흡수선량은 매우 적으므로 무시하였다. Transmission factor는 환자에 따라 다르지만 1110 MBq(30 mCi)을 주입하여 치료에 임한 간암 환자의 경우 간은 4.6, 비장은 4.65, 폐는 3.34, 뼈는 5.65 의 값을 보였다. 방사선 홉수선량은 tumor 에는 179.7, 정상간에는 16.3, 비장은 18.5, 폐에는 7.0, 뼈에는 9.0 Gy 가 각각 계산되었다. 이를 tumor dose 에 100%로 normalization 시킬 경우 정상간, 비장, 폐, 뼈에 각각 9.1, 10.3, 3.9, 5.0%로 분포되었음을 알았다. 본 연구를 통하여 tumor dose 뿐만이 아니고 주변 주요 위험장기 (critical organ) 에 대한 방사선 흡수선량을 전ㆍ후면 평면영상으로 얻을 수 있음을 보여 줌으로써 평면영상법을 이용한 dosimetry 의 가능성을 보았다. 또한 주변 주요 위험 장기의 한계선량에 맞는 주입할 양을 결정하는데 기초 자료가 될 수 있음을 보여준다. Ho-l66 was produced by neutron reaction in a reactor at the Korea Atomic Energy Institute (Taejon, Korea). Ho-l66 emits a high energy beta particles with a maximum energy of 1.85 MeV and small proportion of gamma rays (80 keV). Therefore, the radiation absorbed dose estimation could be based on the in-vivo quantification of the activity in tumors from the gamma camera images. Approximately 1 mCi of Ho-l66 in solution was mixed into the flood phantom and planar scintigraphic images were acquired with and without patient interposed between the phantom and scintillation camera. Transmission factor over an area of interest was calculated from the ratio of counts in selected regions of the two images described above. A dual-head gamma camera(Multispect2, Siemens, Hoffman Estates, IL, USA) equipped with medium energy collimators was utilized for imaging(80 keV${\pm}$10%). Fifty-nine year old female patient with hepatoma was enrolled into the therapeutic protocol after the informed consent obtained. Thirty millicuries(110MBq) of Ho-166-CHICO was injected into the right hepatic arterial branch supplying hepatoma. When the injection was completed, anterior and posterior scintigraphic views of the chest and pelvic regions were obtained for 3 successive days. Regions of interest (ROIs) were drawn over the organs in both the anterior and posterior views. The activity in those ROIs was estimated from geometric mean, calibration factor and transmission factors. Absorbed dose was calculated using the Marinelli formula and Medical Internal Radiation Dose (MIRD) schema. Tumor dose of the patient treated with 1110 MBq(30 mCi) Ho-l66 was calculated to be 179.7 Gy. Dose distribution to normal liver, spleen, lung and bone was 9.1, 10.3, 3.9, 5.0 % of the tumor dose respectively. In conclusion, tumor dose and absorbed dose to surrounding structures were calculated by daily external imaging after the Ho-l66 therapy for hepatoma. In order to limit the thresholding dose to each surrounding organ, absorbed dose calculation provides useful information.

제43차 대한핵의학회 추계학술대회 : 포스터 ; 낭성 종양치료를 위한 Ho-166의 흡수선량분포

조철우,윤석남,윤준기,이명훈,안영실,박경배,양인규,김학균 대한핵의학회 2004 핵의학 분자영상 Vol.38 No.5

패키지(Package) 보험(상)

조철우,Jo, Cheol-U 한국화재보험협회 2000 防災와 保險 Vol.85 No.-

한국어 시청각 음성데이타베이스의 수집

조철우 國立 昌原大學校 精報通信硏究所 1999 精報通信論文集 Vol.3 No.-

Recently interests about audio-visual speech activities are growing. The knowledge of audio-visual speech can be used for speech recognition to improve the recognition rate and also can be used for speech synthesis to add the visual images for enhanced message transfer. There are many researchers carried on about audio-visual speech area. But the way of measuring visual speech activity varies according to the research groups. Some of the method use expensive tracking device. Some of the method use simple markers to trace the movement of articulatory organs. The main aim of this experiments is to collect some audio-visual materials which can be used for later experiments to estimate and model the actions of human articulatory organs such as mouth, jaw etc. In this collection process we collect audio-visual data from the seven directions separately. Twelve makers are used to trace the movements.

과도한 잡음성분이 포함된 장애음성의 분류

조철우,리타오 國立 昌原大學校 產業技術硏究院 2004 産技硏論文集 Vol.18 No.-

In this paper we tried to classify the pathological voice signal with severe noise component based on two different parameters, the spectral slope and the ratio of energies in the harmonic and noise components (HNR). The spectral slope is obtained by using a curve fitting method and the HNR is computed in cepstrum quefrency domain. Speech data from normal peoples and patients are collected, diagnosed and divided into three different classes (normal, relatively less noisy and severely noisy data). The mean values and the standard deviations of the spectral slope and the HNR are computed and compared with in the three kinds of data to characterize and classify the severely noisy pathological voice signals from others.

실시간 포만트 합성기를 이용한 음성합성 실험시스템 구성에 관하여

조철우 國立 昌原大學校 産業技術硏究所 1989 産技硏論文集 Vol.3 No.-

This paper describes the implementation of the experimental system for the speech synthesis using the real-time formant speech synthesizer. Following the design of the real-time formant synthesizer, experimental synthesis system is constructed. This system is thought to be useful for the extraction of the phonetie parameters from the recursive synthesis procedures.

정서정보의 변화에 따른 피치와 지속시간의 변화

조철우 國立 昌原大學校 産業技術硏究所 1997 産技硏論文集 Vol.11 No.-

In this paper, the pitch and durations of speech materials which includes emotional contents are measured using CECIL, speech analysis tool. Speech materials are collected from actors and other subjects. Analysis is mainly focused on pitch variation and durations of utterances. In addition to actor's speech, speeches from autobiographical recall method are also analysed. Each measurements are tabled and graphed to examine general characteristics of emotional speech. This experiment can provide invaluable background materials for analysing informations contained to the emotional speech.