고립단어의 선형 예측 계수들 상호간의 상관도를 이용한 화자인식에 관한 연구

오예환,김중규 成均館大學校 科學技術硏究所 1995 論文集 Vol.46 No.2

We propose a statistical algorithm which is applicable for speaker recognition and identification. The decision logic is formulated by computing the correlation coefficient between two speakers based on the LPC Log Spectrum and the LPC based Cepstral Spectrum of the speech signals. We tested the algorithm with Korean word "Sung Kyun Kwan" spoken by 11 male speakers, which is sampled at 16KHz rate and quantized to 16 bits. The test result showed very high recognition rates(94.5% for the case of LPC Log Spectrum and 98.2% for LPC based Cepstral Spectrum), whereas the conventional DTW algorithm based on the pitch contours of the speech signal had a relatively low recognition rate(89%). In addition to the recognition rate, the correlation method outperformed the DTW method in processing time as well, i.e. it requires much less computation load than DTW. Thus the proposed algorithm seems to have a strong potential to be applied to the areas where very high recognition rates as well as real time processing are required such as a security control system.

단결정 Si(111) 위에 형성된 Ti-실리사이드에 대한 RBS 및 XRD 분석

이중환,권오준,최치규,박동수,김건호,이상환,이의완,곽호원 濟州大學校 基礎科學硏究所 1991 基礎科學硏究 Vol.4 No.1

초고진공 상태에서 p형 Si(111)기판에 Ti을 증착한 후 고진공에서 열처리하여 Ti-실리사이드를 형성시켰으며, Ti-실리사이드의 상전이 및 형성운동학은 2 MeV⁴He? 이온 후방산란과 x-선 회절방법으로 규명하였다. 형성된 TiSi₂는 결정학적으로 C49(ZrSi₂)와 C54 구조의 두 종류로 확인되었다. C49 TiSi₂상은 열처리온도가 700℃이하의 저온에서 형성되었고, 700℃ 이상의 고온에서는 C54 TiSi₂상으로 나타났다. 본 연구에서 확인된 C54 TiSi₂전이온도(??)는 700℃ 였고, TiSi₂형성온도 영역내에서 TiSi₂ 층두께(χ)와 열처리시간(t)의 관계는 저온(700℃ 이하)일 경우 ??이고, 고온(750℃ 이상)에서는 χ=ct+d 의 관계식이 만족됨을 알 수 있었다. 이것은 700℃ 이하에서 TiSi₂ 형성기구가 Si 확산에 의해 제어되며, 750℃ 이상에서는 핵형성 제어에 의하여 계면반응하는 것으로 나타났다. Titanium silicides were prepared by depositing titanium film on p-type Si(111) followed by annealing in ultra high vacuum. The growth kinetics of Ti-silicide has been studied by using ion backscattering spectrometry and x-ray diffractometry. Two crystallographic structures of Ti-silicide were identified the (ZrSi₂)structure and C54. The C49 TiSi₂ phase was formed at low annealing temperature(<700℃),and it transformed to the C54 phase over 700℃. The relation between the thickness of TiSi₂ layer(χ) and the annealing time(t) was ?? when annealing temperature was under 700℃ and χ=ct+d when that was over 750℃. The former implied that the formation of TiSi₂ was controlled by diffusion and the latter by nucleation of at the Ti/Si(111) interface.

이중혈류유발 심폐소생술이 심정지를 유발한 개의 단기 생존율에 미치는 영향

황성오,조준휘,강구현,김성환,문중범,이강현,이승환,윤정한,최경훈,홍은석 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background and Objectives: We previously reported that, compared with standard cardiopulmonary resuscitation(S-CPR), better hemodynamic effects could be achieved by simultaneous sterno-thoracic cardiopulmonary resuscitation(SST-CPR) in which we compressed the sternum and constricted the thorax circumferentially during the systolic period by using a device. This study was designed to assess whether SST-CPR, compared with S-CPR, improve the survival rate of dogs with cardiac arrest. Subjects and methods: Twenty-five mongrel dogs(19∼31㎏) were enrolled in this study. After four minutes of ventricular fibrillation induced by an AC current, animals were randomized to resuscitate with either S-CPR(n=13) or SST-CPR(n=12). Epinephrine(1 ㎎) was injected into the right atrium every three minutes after the beginning of CPR. Defibrillation was attempted after 6 minutes of CPR. Standard advanced cardiac life support was started if defibrillation was not successful. Results: SST-CPR resulted in significantly(p<0.001) higher systolic arterial pressure(91±47 vs 47±24 ㎜ Hg), diastolic pressure(43±24 vs 17±10 ㎜ Hg), coronary perfusion pressure(35±25 vs 13±9㎜ Hg), and end tidal CO2 tension(9±4 vs 3±2 ㎜ Hg). Two of 13 animals(15 %) resuscitated with S-CPR and six of 12 animals(50%) resuscitated with SST-CPR survived until 12 hours after cardiac arrest(p<0.05). Donclusion: SST-CPR, compared with S-CPR, improves the short-term survival rate in canine cardiac arrest.

打擊速度 및 溫度變化가 豫크랙을 가진 衝擊試驗片의 動的破壞靭性에 미치는 影響

兪在煥,李敬奉,金重吉,李致雨,吳世旭 慶南大學校 附設 工業技術硏究所 1989 硏究論文集 Vol.7 No.-

計裝化衝擊試驗에서 打擊速度와 溫度의 變化가 豫크랙을 揷入한 衝擊試驗片의 動的破壞靭性에 미치는 影響을 考察한 結果 다음을 알 수 있었다. 豫크랙을 揷入한 試驗片이 V-노치 試驗片에 比하여 實驗値의 分散度가 적으며 0℃以下의 溫度領域에서 動的破壞靭性의 有效性이 있었다. 또한 打擊速度와 實驗溫度의 影響은 溫度가 速度보다 훨씬 上廻하는 傾向이었다. The effect of various impact velocity and temperature on dynamic fracture toughness is tested with precracked Charpy specimen, and conclude following results. Precracked specimen has less dispersion of test results than V-notched specimen, unstable crack initiation load didn't agreed to maximum load at room temperature but at 0℃ below, thus, the availability of dynamic fracture toughness is relatively high. Comparing V-notched specimen, the precracked Charpy specimen represented lower shelf of temperature different. But, at this time, the absorbed energy is estimated equivalently. With the decrease of temperature, the reduction of fracture toughness was obvious, but the effect of impact velocity didn't appear.

절단된 안면신경의 일차문합술

강진성,한기환,송중원,오재훈 大韓成形外科學會 1991 Archives of Plastic Surgery Vol.18 No.4

Because the facial nerve innervates the muscles of facial expression, injury to this nerve may cause social, psychological, and functional disability. For this reason, a transected facial nerve must be restored appropriately by any one of a variety of approaches. The choice of anastomosis should be based upon the cause, location of transection and the length of time since paralysis was first noted. Although there are numerous methods of anastomosis, none will result in complete recovery. And thus, the method must be carefully selected and tailored to suit each patient. During the 20 months between July 1988 and February 1990. We have been operated (immediate end to were epineurial repair) in 20 patients. 15 of 20 aged 23 to 60. There were 13 males and 2 females. The nerve injury was unilateral in all cases. One of 15 received a nerve graft harvested from the greater auricular nerve. 12 of 15 Stensen's duct injuries were associated with served zygomatic branch and/or buccal branch. So an end to end anastomosis of the duct was performed simultaneously with anastomosis of the nerve. Failure to repair the duct resulted in a salivary fistula in two cases. To show the success of the procedure, EMG(electromyogram) and NCV(nerve conduction velocity) were done at least 6 months following surgery. The findings have been considered good to excellent and the reinnervated muscles have showed symmetric movements in all cases.

폐좌상시 폐단락률과 PEEP치료의 효과

김영식,황성오,최경훈,안무업,오중환,임경수,윤정환,강성준 大韓應急醫學會 1992 대한응급의학회지 Vol.3 No.1

To evaluate the physiologic extent of pulmonary contusion and effect of PEEP therapy for pulmonary contusion, we studied 16 patients received PEEP therapy with pulmonary contusion from nonpenetrating chest trauma. Hemodynamic parameters including pulmonary vascular resistance index and intrapulmonary shunt fraction were calculated from standard measurement, and arterial oxygen tension was measured. Pulmonary vascular resistance index and intrapulmonary shunt fraction were increased in patient group. Arterial oxygen tension was decreased with increase of the intrapulmonary shunt fraction(R=0.75). Arter minimal PEEP therap(5-10 ㎝H₂O), pulmonary vascular resistance index was remained unchanged and intrapulmonary shunt fraction was decreased without significant changes of pulmonary hemodynamics. Increment of arterial tension was increased with decrease of intrapulmonary shunt fraction(R=0.43). Decreased stroke volume index suggested of cardiac injury such as cardiac contusion in patient group. These results of our study suggested that increased intrapulmonary shunt fraction caused arterial hypoxia in pulmonary contusion and arterial oxygen tension was increased as a result of reduced intrapulmonary shunt by PEEP therapy.

삭골(Bone shaving)한 골의 재생에 골막이 미치는 영향

강진성,권건영,송중원,오석희,한기환 大韓成形外科學會 1989 Archives of Plastic Surgery Vol.16 No.5

Many orientals have a more prominent malar eminence and mandibular angle than westerners so their faces often look rough and unattracive. In recent years more people want to have a more attractive and beautiful face due to economic prosperity and westernization. Therefore people receiving bone shavings or osteotomies for cosmetic purposes are increasing. The effects of the periosteum on lay bone grafts were investigated but the effect of the periosteum after bone shaving or osteotomy is little known. The authors investigated the effect of the periosteum on the regeneration of bone in membranous and endochondral bone of rabbits. Bony defects each measuring about 5.0×5.0×1.5mm were made on the left and right sides of the parietal bones of 15 rabbits and femurs of 15 other rabbits respectively. The periosteum was preserved on the left and removed on the right. The following results were obtained: 1) The average thickness of the regenerated bones in groups 2 δ4 were thinner than those in groups 1 δ 3 at 4, 8 and 12 weeks postoperatively but the differences of thickness were statistically significant at onl 4weeks postoperatively(P<0.05). 2) The histological findings in groups 2 δ 4 showed lesser regeneration of the shaved bone than those in groups 1 δ 3 at 4, 8 and 12weeks postoperatively. 3) There was no significant increase in the thickness of the regenerated bone after 8 weeks postoperatively in all groups. 4) At 12 weeks postoperatively, the thickness of the regenerated bone in all groups was over 70% of the thickness of the resected bone. In summary, the authors found that it is important to perform overcorrection and resect the periosteum simultaneously in bone shaving to prevent the unwanted regeneration.

기능성 소화불량증환자에서 Winstal® 투여에 관한 임상경험

이창형,김영탁,금민수,권중구,안병철,윤영미,권영오,김성국,최용환,정준모 慶北大學校 醫科大學 1994 慶北醫大誌 Vol.35 No.3

목적 : 기능성 소화불량증은 소화, 흡수등 장관의 기능적인 이상과 관련되어 있을 것으로 생각되며 복합소화효소제(Winstal®)를 투여하여 그 임상효과를 평가하고자 본 연구를 실시하였다. 대상 및 방법 : 1994년 3월 부터 6월까지 경북대학교병원 내과를 방문한 기능성 소화불량증을 호소하는 환자 20명을 대상으로 Winstal®을 1회 1정씩, 1일 3회 식후 30분내에 경구로 2주간 투여하였다. 결과 : 소화불량증의 증상은 복부불쾌감, 복부팽만감, 식욕부진 및 오심, 복부동통, 공기연하증, 고창 및 구토순이었으며, 증상의 개선은 복부불쾌감이 76.4%(13/17)로 가장 높았으며, 그 다음으로 복부팽만감 및 공기연하증이 66.5%(10/15, 6/9)이었고, 오심 61.5%(8/13), 식욕부진 53.8%(7/13), 복부동통 41.6%(5/12), 고창 37.5%(3/8)이었다. 각 환자별 종합적인 증상의 개선도는 현저한 개선이 2예(10%), 중등도 개선이 3예(15%), 약간개선이 11예(55%), 불변이 4예(20%)이었으며 종합적인 유효율은 80%(16/20)이었다. 부작용은 한 예에서도 관찰되지 않았다. 결론 : 본 제제는 기능성 소화불량증 환자의 증상개선에 추천할 만한 유효한 약제로 생각된다. Dyspepsia is a common symptom in gastroenterologic practice and trigger for numerous consultations with physician. The treatment of chronic functional dyspesia is unsatisfactory. This study was performed to evaluate the efficacy of the digestive compound (Winstal®) on 20 functional dyspepsia patients. On open trial, all patients were given 6 tablets daily for 2 weeks and we evaluated the efficacy of this preparation according to the degree of the improvement. The improvement of symptoms was 76.4%(13/17) in abdominal discomfort, 66.5%(10/15, 6/9) in abdominal distension and aerophagia, 61.5%(8/13) in nausea, 53.8%(7/13) in abdominal pain, and 37.5% (5/12) in flatulence, respectively. Overall effectiveness of subjective symptoms was 80% (16/20) and there were no untoward effects of the preparations during this study. As a result, We think that this preparation is an effective one to relieve symptoms of functional dyspepsia.

The Impact of International Migration on Unemployment Rates in Urban America

Joong-Hwan Oh,Sung-Chul Lee,Byung-Soo Kim 서울대학교 국제학연구소 2011 Journal of International and Area Studies Vol.18 No.1

This study examines the influence of international migration on unemployment rates in urban America. For this purpose, this study first applies competition and discrimination and assimilation views in examining whether the size and composition of immigrant populations in American metropolitan areas affect urban unemployment rates. Based on local human capital and labor market views, this study also explores whether urban unemployment rates are affected by local human capital(education) and urban labor markets (employment distributions by class of workers), both of which vary with the size and compositions of local immigrant populations. Using a sample of the 301 Primary Metropolitan Statistical Areas /Metropolitan Statistical Areas (PMSAs/MSAs) in 1990 and 2000, this study employs regression models to test four hypotheses. First, the result supports to some degree competition and discrimination and assimilation views. The empirical findings show that more concentration of international migrants in urban areas, including recent immigrant cohorts, tends to increase urban unemployment rates. Second, the models of local human capital also support that growing college graduates play a role in reducing urban unemployment rates after controlling for the volume of immigrant population. However, there are conflicting impacts of local labor market (employment conditions) on urban unemployment rates.

Development and Experimental Evaluation of Respiratory Assist Device by Use of Right Thoracic Negative Pressure Ventilation

Joong Hwan Oh,Sang Hun Lee,Hyun Kyo Lim,Young Hee Lee,Sung Hoon Kim Korean Society of Critical Care Medicine 2005 Acute and Critical Care Vol.20 No.2

BACKGROUND: A diaphragm pacing with electrical stimulation is a new respiratory assist device which has advantages over mechanical ventilation. Unilateral phrenic nerve stimulation makes uneven distribution of intrathoracic negative pressure and most likely relates to paradoxical motion of the diaphragm. Our purpose is to investigate a respiratory effect of right phrenic nerve pacing after thoracotomy compared with bilateral pacing. METHODS: Five dogs were examined under the general anesthesia. Right 5th intercostal space was opened. Two pacing leads were placed around the phrenic nerve and connected to the stimulator. Chest wall was closed after chest tube insertion. Ventilator was off without self respiration. Swan-Ganz catheter was introduced to the pulmonary artery, cardiac output, central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP). Arterial blood gases (PO2 & PCO2), end-tidal PCO2 (PETCO2) and tidal volume were measured with nerve stimulation. Left phrenic nerve was managed as the same manner. RESULTS: Right phrenic nerve pacing resulted in a tidal volume of 186+/-5 ml, PETCO2 of 55.0+/-2.3 mmHg, Arterial PO2 of 115+/-12 mmHg, PCO2 of 59+/-4 mmHg, Cardiac output of 2.3+/-0.5 L/min, CVP of 12.0+/-2.3 mmHg, PCWP of 14.2+/-2.5 mmHg. Bilateral phrenic nerve pacing resulted in a tidal volume of 418+/-3 ml, PETCO2 of 47.0+/-2.7 mmHg, PO2 of 289+/-10 mmHg, PCO2 of 42+/-3 mmHg, Cardiac output of 3.1+/-0.4 L/min, CVP of 10.2+/-2.5 mmHg, PCWP of 14.5+/-2.7 mmHg. Right phrenic nerve pacing showed significantly lower tidal volume, PO2 and higher PETCO2 and arterial blood PCO2 (p