자동차 잡음 및 오디오 출력신호가 존재하는 자동차 실내 환경에서의 강인한 음성인식

박철호,배재철,배건성,Park, Chul-Ho,Bae, Jae-Chul,Bae, Keun-Sung 대한음성학회 2007 말소리 Vol.62 No.-

In this paper, we carried out recognition experiments for noisy speech having various levels of car noise and output of an audio system using the speech interface. The speech interface consists of three parts: pre-processing, acoustic echo canceller, post-processing. First, a high pass filter is employed as a pre-processing part to remove some engine noises. Then, an echo canceller implemented by using an FIR-type filter with an NLMS adaptive algorithm is used to remove the music or speech coming from the audio system in a car. As a last part, the MMSE-STSA based speech enhancement method is applied to the out of the echo canceller to remove the residual noise further. For recognition experiments, we generated test signals by adding music to the car noisy speech from Aurora 2 database. The HTK-based continuous HMM system is constructed for a recognition system. Experimental results show that the proposed speech interface is very promising for robust speech recognition in a noisy car environment.

단순 임계치와 은닉마르코프 모델을 혼합한 영상 기반 낙상 알고리즘

박철호,유윤섭,Park, Culho,Yu, Yun Seop 한국정보통신학회 2014 한국정보통신학회논문지 Vol.18 No.9

영상 정보를 이용한 자동 낙상 감지 알고리즘을 제안한다. 자동으로 낙상을 감지하기 위한 낙상 특징 파라미터를 추출하기 위해서 영상정보를 광류 방식에 적용하여 움직임 값들을 추출하고 이 움직임 값들에 대한 전체적인 변화의 정도와 기울기, 중심점을 주성분 분석 방법으로 계산한다. 계산된 고유값과 고유 벡터를 사용하여 6가지 낙상 특징 파라미터를 정의한다. 이 낙상특징파라미터가 미리 정해둔 임계값을 초과하는 경우를 낙상으로 판단하는 단순 임계치 방법과 낙상특징파라미터를 은닉 마르코프 모델(Hidden Markov Model; HMM)에 적용시켜 낙상을 판단하는 방법과 단순임계치와 은닉 마르코프 모델을 결합한 낙상 감지 방법을 제안하고 그 결과를 비교 및 분석한다. 단순 임계치와 은닉 마르코프 모델을 결합한 방법은 단순임계치 방법으로 낙상 가능한 행동들을 결정하고 이 결정된 낙상 행동들만을 은닉 마르코프 모델을 적용하여 낙상을 감지한다. 이 방법은 계산량을 줄이면서 감지 정확도를 유지하는 결과를 보인다. Automatic fall-detection algorithms using video-data are proposed. Six types of fall-feature parameters are defined applying the optical flows extracted from differential images to principal component analysis(PCA). One fall-detection algorithm is the simple threshold method that a fall is detected when a fall-feature parameter is over a threshold, another is to use the HMM, and the other is to combine the simple threshold and HMM. Comparing the performances of three types of fall-detection algorithm, the algorithm combining the simple threshold and HMM requires less computational resources than HMM and exhibits a higher accuracy than the simple threshold method.

R.F. Magnetron Sputtering으로 다양한 Interlayer 층위에 형성시킨 PZT 박막의 미세구조와 강유전 특성

박철호,최덕영,손영국,Park, Chul-Ho,Choi, Duck-Young,Son, Young-Guk 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.8

R. F. magnetron sputtering법을 이용하여 Pt/Ti/$SiO_2$/Si 기판 위에 $Pb_{1.1}Zr_{0.53}Ti_{0.47}O_3$ target을 사용하여 박막을 제조하였다. Interlayer(PbO, $TiO_2$, PbO/$TiO_2$)층을 삽입함으로써 박막의 결정성을 향상시켰고, 박막의 기판온도도 상당히 낮출 수 있었다. 순수한 PZT에 비하여 interlayer를 삽입한 PZT는 높은 유전상수과 낮은 유전손실 및 높은 누설전류를 가지는 우수한 전기적 특성을 나타내었다. 이러한 PZT 박막과 interlayer 층은 증착온도에서 서로 반응하여 하나의 고용체를 이루지 않고, 각각 독립적인 층으로 존재함을 XPS 분석을 통해 확인하였다. 여러 interlayer중 특히 PbO/$TiO_2$는 우수한 유전특성(${\varepsilon}_r$=414.94, tan${\delta}$=0.0241, Pr=22${\mu}C/cm^2$)을 나타내었고 가장 효과적인 seed로써의 역할을 하였다. The PZT thin films werre deposited on Pt/Ti/$SiO_2$/Si substrate by R. F. magnetron sputtering with $Pb_{1.1}Zr_{0.53}Ti_{0.47}O_3$ target. When interlayers(PbO, $TiO_2$, PbO/$TiO_2$) were inserted between PZT and Pt, the crystallization of the PZT thin films was considerably improved and the processing temperature was lowered. Compared to the pure PZT thin films, dielectric constant, dielectric loss and polarization properties of PZT thin films with interlayers were considerably improved. From XPS depth profile analysis, it was confirmed that PZT thin films and interlayers existed independently. In particular, PZT thin films deposited on interlayer(PbO/$TiO_2$) showed the best dielectric property (${\varepsilon}_r$=414.94, tan${\delta}$=0.0241, Pr=22${\mu}C/cm^2$).

PbO 완충층을 이용한 Pt/Pb_1.1Zr_0.53Ti_0.47O₃/PbO/Si (MFIS)의 미세구조와 전기적 특성

박철호,송경환,손영국,Park, Chul-Ho,Song, Kyoung-Hwan,Son, Young-Guk 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.2

PbO 완충층의 역할을 확인하기 위해, r.f. magnetron sputtering법을 이용하여 p-type (100) Si 기판 위에 $Pt/Pb_{1.1}Zr_{0.53}Ti_{0.47}O_{3}$와 PbO target으로 Pt/PZT/PbO/Si의 MFIS 구조를 제조하였다. MFIS 구조에 완충층으로 PbO를 삽입함으로써 PZT 박막의 결정성이 크게 향상되었고, 박막의 공정온도도 상당히 낮출 수 있었다. 그리고 XPS depth profile 분석 결과, PbO 증착시 기판온도가 PbO와 Si의 계면에서 Pb의 확산에 미치는 영향을 확인하였다. PbO 완충층을 삽입한 MFIS는 높은 메모리 윈도우와 낮은 누설전류 밀도를 가지는 추수한 전기적 특성을 나타내었다. 특히, 기판온도 $300^{\circ}C$에서 증착된 PbO를 삽입한 Pt/PZT(200nm, $400^{\circ}C)PbO(80nm)/Si$는 9V의 인가전압에서 2.OV의 가장 높은 메모리 윈도우 값을 나타내었다. To study the role of PbO as the buffer layer, Pt/PZT/PbO/Si with the MFIS structure was deposited on the p-type (100) Si substrate by the r.f. magnetron sputtering with $Pb_{1.1}Zr_{0.53}Ti_{0.47}O_3$ and PbO targets. When PbO buffer layer was inserted between the PZT thin film and the Si substrate, the crystallization of the PZT thin films was considerably improved and the processing temperature was lowered. From the result of an X-ray Photoelectron Spectroscopy (XPS) depth profile result, we could confirm that the substrate temperature for the layer of PbO affects the chemical states of the interface between the PbO buffer layer and the Si substrate, which results in the inter-diffusion of Pb. The MFIS with the PbO buffer layer show the improved electric properties including the high memory window and low leakage current density. In particular, the maximum value of the memory window is 2.0V under the applied voltage of 9V for the Pt/PZT(200 nm, $400^{\circ}C)/PbO(80 nm)/Si$ structures with the PbO buffer layer deposited at the substrate temperature of $300^{\circ}C$.

대동맥 축착증 수술치험 2례

박철호,우종수,조광현,Park, Cheol-Ho,U, Jong-Su,Jo, Gwang-Hyeon 대한흉부심장혈관외과학회 1988 Journal of Chest Surgery (J Chest Surg) Vol.21 No.3

Coarctation of the aorta is classically a congenital narrowing of the upper descending thorac aorta adjacent to the site of attachment of the ductus arteriosus which is sufficiently severe that there is a pressure gradient across the area. Recently we have experienced two cases of coarctation of the aorta and successfully performed resection of the sites of coarctation and end to end anastomosis of the aorta. The first case was a juxtaductal type of coarctation of the aorta with PDA and the pathology of the lesion was a diaphragm with central narrow opening. And the resection length was about 0.5cm and aortic clamping time was 20 minutes. The second case was also juxtaductal type coarctation of the aorta with mild tubular hypoplasia of aortic isthmus, left SVC and the pathology was also a diaphragm with central narrow opening. And the resection length was about 0.5cm and aortic clamping time was 29 minutes. Both postoperative course was uneventful and the patients were discharged two weeks after operation.

피부괴사로 노출된 인공 심박동기 치험 1

박철호,우종수,조광현,Park, Cheol-Ho,U, Jong-Su,Jo, Gwang-Hyeon 대한흉부심장혈관외과학회 1987 Journal of Chest Surgery (J Chest Surg) Vol.20 No.1

Exposure of the cardiac pacemaker is still a difficult problem associated with high morbidity. Grossly infected pacemaker systems had been required removal and insertion of a new system. It would highly desirable to develop a new method that could salvage an exposed well functioning unit because cardiac pacemaker is very expensive. We have experienced one patient with exposed well functioning cardiac pacemaker, which was relocated to contralateral subpectoral pocket and healed without complication. This relocation of the pacemaker to subpectoral pocket is less simple, expensive and should be considered as an alternative to complete replacement of unit.

기관협착증 치험 3례

박철호,우종수,조광현,Park, Cheol-Ho,U, Jong-Su,Jo, Gwang-Hyeon 대한흉부심장혈관외과학회 1988 Journal of Chest Surgery (J Chest Surg) Vol.21 No.2

Increasing success in the management of patients with severe respiratory failure by mechanical respirators has produced iatrogenic tracheal stenosis. And the surgical management of these lesions have provided a major field for tracheal reconstructive surgery. Recently we have experienced three cases of postintubation tracheal stenosis between December, 1985 and October, 1987 and successfully performed circumferential resection and end to end anastomosis of the trachea. The lesion of the first case which was located in the subcricoid level was resected about 2cm length with cervical incision. And the lesion of the second case located at the cuff site was also resected about 2.5cm length with cervical and median sternotomy incision. Also the lesion of the third case located at the stoma site was resected about 1.8cm length with cervical incision. The postoperative courses were uneventful but there was extubation difficulty in the third case because of stupor mentality and problem of secretion excretion. So we have observed the postoperative course after T-tube insertion.

돈육선물 왜 필요한가!

박철호,Park, Cheol-Ho 축산물품질평가원 2008 KAPE누리 Vol.144 No.-

가끔 우리는 생각지도 못한 일이 생겨 돼지가격이 곤두박질치는 것을 본다. 지난 2002년 5월 경기 충북 일대에서 발생한 구제역이 바로 그런 경우인데, 양돈기업들은 그때 전 재산이나 다름없는 수만 마리의 돼지들을 땅속에 묻어야 했다. 돼지 가격을 흔드는 것은 구제역, 돼지콜레라 뿐만이 아니다. 돼지 가격이 좋을 때 갑자기 사육 두수가 늘어나면 언제 또 돼지 값이 폭락할 지 알 수가 없다. 지난 10년간의 돼지 가격은 거의 매년 폭락과 폭등을 반복하고 있다. 가격이 좋을 때에는 괜찮겠지만 문제는 가격이 폭락할 때이다. 가격이 좋아서 큰돈을 버는 것도 좋지만 거의 해마다 반복되는 가격 폭락을 피하고 돼지를 제값에 팔 수 있다면 얼마나 좋을까? 여기에 '선물거래'가 해답이 될 수 있다.

젖소에서 $PGF_2{\alpha}$ 투여에 의한 발정 유도 후 수태율과 다른 인자와의 관계

박철호,임원호,서국현,오기석,손창호,Park, Chul-Ho,Lim, Won-Ho,Suh, Guk-Hyun,Oh, Ki-Seok,Son, Chang-Ho 한국수정란이식학회 2010 한국동물생명공학회지 Vol.25 No.3

The purpose of this study was to determine the relationship between conception rate and other parameters (body condition score; BCS, progesterone concentrations and follicle size) before estrus induction with $PGF_2{\alpha}$. The conception rate in cows with (2.75, 2.75 to 3.25 and 3.25), BCS regardless of AI (artificial insemination) time was 47.5, 67.5% and 48.5% at $PGF_2{\alpha}$ injection, respectively. The conception rate regardless of BCS was 59.0% in cows inseminated based on detected estrus, and 46.2% in cows inseminated at 72 to 80 hours (timed artificial insemination, TAI) after $PGF_2{\alpha}$ injection. The conception rate regardless of AI time was 43.0% in cows with low progesterone concentrations (less than 1.0 ng/ml), and 67.5% in cows with high progesterone concentrations (more than 1.0 ng/ml) at $PGF_2{\alpha}$ injection. The conception rate regardless of progesterone concentrations was 59.9% in cows inseminated based on detected estrus, and 48.1% in cows of TAI after $PGF_2{\alpha}$ injection. The conception rate regardless of AI time was 36.0% in cows with small dominant follicles (less than 5 mm), 56.0% in cows between 5 mm to 10 mm of follicle size, and 65.5% in cows with large dominant follicles (more than 10 mm) at $PGF_2{\alpha}$ injection, respectively. The conception rate regardless of follicle size was 57.3% in cows inseminated based on detected estrus, and 47.6% in cows of TAI after $PGF_2{\alpha}$ injection. These results indicated that if the cows with BCS 2.75 to 3.25, active corpus luteum, and/or large dominant follicle (more than 10 mm) are used for estrus induction, the conception rate will be greater.

국방획득체계를 위한 시스템엔지니어링 지침 및 발전 전략에 대한 연구

박철호,박종선,김호성,김병철,Park, Chul Ho,Park, Jong Sun,Kim, Ho Sung,Kim, Byong Chol 한국시스템엔지니어링학회 2009 시스템엔지니어링학술지 Vol.5 No.2

A newly established provision to enforce the systems engineering was added in the regulation for arms acquisition management in January 2009, and a systems engineering guidelines for defence acquisition is being developed. In this paper we conduct a comparative study of the defence acquisition system in the United States and the Republic of Korea, and propose a improving plan about the domestic defence acquisition system.