MMSE-STSA 기반의 음성개선 기법에서 잡음 및 신호 전력 추정에 사용되는 파라미터 값의 변화에 따른 잡음음성의 인식성능 분석

박철호,배건성,Park Chul-Ho,Bae Keun-Sung 대한음성학회 2006 말소리 Vol.57 No.-

The MMSE-STSA based speech enhancement algorithm is widely used as a preprocessing for noise robust speech recognition. It weighs the gain of each spectral bin of the noisy speech using the estimate of noise and signal power spectrum. In this paper, we investigate the influence of parameters used to estimate the speech signal and noise power in MMSE-STSA upon the recognition performance of noisy speech. For experiments, we use the Aurora2 DB which contains noisy speech with subway, babble, car, and exhibition noises. The HTK-based continuous HMM system is constructed for recognition experiments. Experimental results are presented and discussed with our findings.

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${\mu}C/cm^2$).

고령자 낙상에 의한 응급 상황의 4족 로봇 기반 알리미 시스템 설계 및 구현

박철호,임동하,김남호,유윤섭,Park, ChulHo,Lim, DongHa,Kim, Nam Ho,Yu, YunSeop 한국정보통신학회 2013 한국정보통신학회논문지 Vol.17 No.4

In this paper, we introduce a quadruped robot-based alarm system for monitoring the emergency situation due to falling in the elderly. Quadruped robot includes the FPGA Board(Field Programmable Gate Array) applying a red-color tracking algorithm. To detect a falling of the elderly, a sensor node is worn on chest and accelerations and angular velocities measured by the sensor node are transferred to quadruped robot, and then the emergency signal is transmitted to manager if a fall is detected. Manager controls the robot and then he judges the situation by monitoring the real-time images transmitted from the robot. If emergency situation is decided by the manager, he calls 119. When the fall detection system using only sensor nodes is used, sensitivity of 100% and specificity of 98.98% were measured. Using the combination of the fall detection system and portable camera (robot), the emergency situation was detected to 100 %. 본 논문에서는 노인의 낙상에 의한 위급상항을 모니터링 하기 위한 4족 로봇 및 모니터링 시스템을 소개한다. 4족 로봇은 FPGA Board(Field Programmable Gate Array)를 이용한 특정 색을 판별하는 영상처리에 기반하여 자율 이동한다. 노인의 낙상을 감지하기 위해 가슴에 센서노드를 착용하고, 낙상에 의한 응급 상황 시에 4족 로봇이 낙상신호를 관리자에게 전송한다. 관리자는 전송된 영상을 기반으로 4족 로봇을 제어 및 상황판단을 하고, 위급상황이면 119에 신고를 한다. 센서노드만을 사용한 낙상 감지 시스템에서 98.33% 낙상의 Sensitivity와 일상행동 94.375% Specificity가 측정 되었다. 100% 낙상 감지를 못했던 점을 낙상 감지 시스템과 이동형 카메라(로봇)의 결합 알고리즘을 제안 및 실험을 통해 100% 검증 하였다.

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.

한우에서 $PGF_{2{\alpha}}$ 투여에 의한 발정유도 후 난소 구조물 및 호르몬의 변화와 수태율

박철호,류재선,유대중,박인철,김종택,서국현,오기석,손창호,Park, Chul-Ho,Ryu, Jae-Sun,Yu, Dae-Jung,Park, In-Chul,Kim, Jong-Taek,Suh, Guk-Hyun,Oh, Ki-Seok,Son, Chang-Ho 한국수정란이식학회 2012 한국동물생명공학회지 Vol.27 No.3

This study was carried out to develop the useful inducing method of estrus for Korean native cows. Under the condition of estrus induction by administering $PGF_{2{\alpha}}$ for the cows in which corpus luteum (CL) in ovaries was detected by ultrasonography, ovarian responses and the changes of progesterone ($P_4$) concentration against $PGF_{2{\alpha}}$ compared with conception rate were observed in cows and heifers. In inducing estrus administering $PGF_{2{\alpha}}$. to the cows which has corpus luteum in ovaries, ovarian reponses, the changes of progesterone concentration, and conception rate were identified and compared. The results attained from the studies were as follows. Significant decreases of CL in size over time after $PGF_{2{\alpha}}$ administration were detected in both cow and heifer groups (p<0.001), but not different between groups in the CL regression rate (p>0.05). In addition, the percentage changes relative to the plasma $P_4$ concentration on day 1 after $PGF_{2{\alpha}}$ treatment were decreased to below 1ng/ml. The growth rate of follicle was observed as 31% on day 1 and 42% on day 2 in cows, and 34% on day 1 and 97% on day 2 in heifers, resulting that growth of heifers are faster than that of cows (p<0.05). The conception rate after $PGF_{2{\alpha}}$ treatment were 60.5% and 64.2% in cows and heifers, respectively. It also indicated that the conception rate after estrus observation with $PGF_{2{\alpha}}$ injection was as high as 66.6% while that with timed-artificial insemination (TAI) regardless of the estrus observation was 56%, which means the pregnancy rate of artificial insemination after estrus observation was higher than that of TAI (p<0.05). In the result of all above, there were significant decreases in CL size and the plasma $P_4$ concentration by days but rapid growth in follicles, which has no differences in cows and heifers. The conception rate was commonly high after estrus observation and more than 50% under TAI.

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.

한우에서 $PGF_{2{\alpha}}$ 투여 후 난포 크기 및 발달 과정에 따른 발정 증상의 발현

박철호,류재선,유대중,박인철,김종택,서국현,오기석,손창호,Park, Chul-Ho,Ryu, Jae-Sun,Yu, Dae-Jung,Park, In-Chul,Kim, Jong-Taek,Suh, Guk-Hyun,Oh, Ki-Seok,Son, Chang-Ho 한국수정란이식학회 2012 한국동물생명공학회지 Vol.27 No.3

This study was operated to establish induction using ultrasonography by estimating the relation of follicle size and estrus manifestation. Clinical estrus symptoms were observed 97.4% in cows and 87.5% in heifers when overall 55 cows were induced to estrus in a single dose of $PGF_{2{\alpha}}$ after verifying CL through ultrasonography, which means estrus hours among those 52 cows showing the clinical estrus symptoms were estimated 2.39 days on cows and for 2.37 days on heifers which showed no differences (p>0.05). The estrus manifestation hours according to the follicle size in cows didn't have any significance each other (p>0.05), though estrus hours was 54 hours (the shortest) with follicle size bigger than 10 mm and were made up within 69 hours. The estrus manifestation hours according to the follicle size in heifers didn't have any significance each other (p>0.05) and took around 42 hours (the shortest) with follicle size of 5mm (the smallest) and were made up within 66 hours. Follicles after $PGF_{2{\alpha}}$ injection were ovulated and assigned to many phases as follows; Group 1 (growing phase) - continuously growing into ovulation, Group 2 (growing and static phase) - delaying in growth after the growth of follicles, Group 3 (static and growing phase) - growing after growth delay, Group 4 (regressing and new growing phase) - the follicle is closed and a new follicle grows. In addition, the process of follicle development and estrus hours had no significance each other (p>0.05), though estrus manifestation hours in Group 1 and 2 was relatively short, and in Group 3 and 4 for a relatively long time. In the result of all above, the estrus manifestation hours after $PGF_{2{\alpha}}$ injection has no differences accoring to the follicle size in cows and heifers. Therefore, High pregnancy rate is obtained when practicing artificial insemination within 3 days in estrus or TAI in 72 to 80 hours after adminitrating $PGF_{2{\alpha}}$.

시스템엔지니어링 전산지원환경 구축 절차에 관한 연구

박철호,유정근,Park, Cheol Ho,Yoo, Jung Kun 한국시스템엔지니어링학회 2010 시스템엔지니어링학술지 Vol.6 No.2

국내에 다양한 시스템 엔지니어링 전산지원도구(Computer Aided tools for Systems Engineering)가 도입되고 도구의 기능이 향상됨에 따라 시스템 엔지니어링 전산지원환경을 구축하는 사례가 늘어나고 있다. 전산지원환경을 구축하기 위해서는 기존의 국내외 시스템 엔지니어링 표준 및 지침에서 언급되지 않은 구체적인 업무에 대한 고려가 요구되기 때문에, 많은 노력과 시간이 소요된다. 시스템 엔지니어링 본 연구에서는 국내 연구소 및 기업의 시스템 엔지니어링 전산지원환경을 구축하는 과정에서 습득된 문제점과 경험적 교훈(lessons learned)을 정리하였다.

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.

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.