하악 제3대구치가 하악 우각부 골절에 미치는 영향

조성필,이재훈,김철환,Cho, Sung-Pil,Lee, Jae-Hoon,Kim, Chul-Hwan 대한악안면성형재건외과학회 2006 Maxillofacial Plastic Reconstructive Surgery Vol.28 No.1

Mandibular fractures have higher incidence rate compared to facial bone fractures because of relatively prominent form. Specially, mandibular angle fractures were known as common fracture site because of morphological anatomic structure. The mandibular third molar appears to be the most frequent impacted tooth. The mandibular third molar have influence on mandibular angle fractures according to it's eruption state. Also, the mandibular angle fracture including the third molar may influence on post operative infection whether the third molar is in impacted or extracted state when reduction of fracture site is operated. The presence or absence and degree of impaction of the mandibular third molar were assessed for each patient and were related to the occurrence of the mandibular angle fracture. The extraction or non extraction of the mandibular third molar were related to the occurrence of the post operative infection in the reduction of mandibular angle fractures. In the presence of mandibular third molar, the possibility of mandibular angle fractures were relatively common. When viewing the mandibular third molar at occlusal plane, the possibility of mandibular angle fractures were high in the class C group. The possibility of mandibular angle fractures were high in the mesial angulation and partial impaction. There was a statistically significant difference(P<0.05). In complete erupted mandibular third molar, the possibility of post operative infection occurs quite often, but there was no statistical significant difference(P>0.05). In the extracted or non extracted of mandibular third molar, the post operative infection showed no statistical significant difference(P>0.05). With the results mentioned above, mandibular third molar was significantly more susceptible to mandibular angle fracture. In the reduction of mandibular angle fracture, it was recommended that mandibular third molar should be extracted especially in case of pericoronitis, periodontitis and other infections.

하악 제3대구치가 하악 우각부 골절에 미치는 영향

조성필,이재훈,김철환,Cho, Sung-Pil,Lee, Jae-Hoon,Kim, Chul-Hwan 대한악안면성형재건외과학회 2006 Maxillofacial Plastic Reconstructive Surgery Vol.28 No.2

Mandibular fractures have higher incidence rate compared to facial bone fractures because of relatively prominent form. Specially, mandibular angle fractures were known as common fracture site because of morphological anatomic structure. The mandibular third molar appears to be the most frequent impacted tooth. The mandibular third molar have influence on mandibular angle fractures according to it's eruption state. Also, the mandibular angle fracture including the third molar may influence on post operative infection whether the third molar is in impacted or extracted state when reduction of fracture site is operated. The presence or absence and degree of impaction of the mandibular third molar were assessed for each patient and were related to the occurrence of the mandibular angle fracture. The extraction or non extraction of the mandibular third molar were related to the occurrence of the post operative infection in the reduction of mandibular angle fractures. In the presence of mandibular third molar, the possibility of mandibular angle fractures were relatively common. When viewing the mandibular third molar at occlusal plane, the possibility of mandibular angle fractures were high in the class C group. The possibility of mandibular angle fractures were high in the mesial angulation and partial impaction. There was a statistically significant difference(P<0.05). In complete erupted mandibular third molar, the possibility of post operative infection occurs quite often, but there was no statistical significant difference(P>0.05). In the extracted or non extracted of mandibular third molar, the post operative infection showed no statistical significant difference(P>0.05). With the results mentioned above, mandibular third molar was significantly more susceptible to mandibular angle fracture. In the reduction of mandibular angle fracture, it was recommended that mandibular third molar should be extracted especially in case of pericoronitis, periodontitis and other infections.

Penicillium diversum 으로부터 두 chitin synthase 유전자 절편의 분리

조성필,이상근,이동훈,배경숙,박희문,맹필재 ( Seong Pil Cho,Sang Keun Lee,Dong Hun Lee,Kyung Sook Bae,Hee Moon Park,Pil Jae Maeng ) 한국균학회 1997 韓國菌學會誌 Vol.25 No.3

최소 제곱 가속 기반의 적응 디지털 필터를 이용한 두피 뇌전도에서의 심전도 잡음 추정 및 제거

趙盛必(Sung Pil Cho),宋美惠(Mi Hye Song),朴鎬東(Ho Dong Park),李景中(Kyoung Joung Lee) 대한전기학회 2007 전기학회논문지 Vol.56 No.7

A new method for detecting and eliminating the Electrocardiogram(ECG) artifact from the scalp Electroencephalogram (EEG) is proposed. Based on the single channel EEG, the proposed method consists of 4 procedures: emphasizing the R-wave of ECG artifact from EEG using the least squares acceleration(LSA) filter, detecting the R-wave from the LSA filtered EEG using the phase space method and R-R interval, generating the delayed impulse synchronized to the Rr-wave and elimination of the ECG artifacts based on the adaptive digital filter using the impulse and raw EEG. The performance of the proposed method was evaluated in the two separating parts of R-wave detection and, ECG estimation and elimination from EEG. In the R-wave detection, the proposed method showed the mean error rate of 6.285(%). In the ECG estimation and elimination using simulated and/or real EEG recordings, we found that the ECG artifacts were successfully estimated and eliminated in comparison with the conventional multi-channel techniques, in which independent component analysis and ensemble average method are used. From this we can conclude that the proposed method is useful for the detecting and eliminating the ECG artifact from single channel EEG and simple for ambulatory/portable EEG monitoring system.

수변전설비의 표준화에 관한 연구 : 지하철 역사전기설비를 중심으로

조성필(CHO SUNG-PIL),강차녕(KANG CHA-NYEONG),김학련(KIM HAK-LYUN) 한국철도학회 2006 한국철도학회 학술발표대회논문집 Vol.- No.-

In our modern society, such electric facilities as lighting, elevators, water supplies, drainages, waste water treatments and landscape lighting are being more enlarged, diversified and technology-intensive owing to outstanding technological development, while they require reliable and safe electricity. On the other hand, as more electric energy is consumed with more complicated systems operated, any accident from a personal electric system is likely to have wider spreading effects. In particular, the electric receivers and transformers installed for such public facilities as subway stations require highest safety, reliability and economy, but such requirements tend to be less considered than such financial requirements as budget conditions, much less their safety and reliability. In such a circumstance, this study was aimed at suggesting some standards for safe, reliable and economic subway electric systems in terms of their scale, location and uses. Specifically, this study put forwards the ways to optimize and standardize the electric systems including receivers and transformers for subway stations in order to make them safer, more reliable and economic.

단일 채널 뇌전도를 이용한 호흡성 수면 장애 환자의 각성 검출

趙盛必(Sung-Pil Cho),崔浩善(Ho-Seon Choi),李景中(Kyoung-Joung Lee) 대한전기학회 2006 전기학회논문지 D Vol.55 No.5

Frequent arousals during sleep degrade the quality of sleep and result in sleep fragmentation. Visual inspection of physiological signals to detect the arousal events is cumbersome and time-consuming work. The purpose of this study is to develop an automatic algorithm to detect the arousal events. The proposed method is based on time-frequency analysis and the support vector machine classifier using single channel electroencephalogram (EEG). To extract features, first we computed 6 indices to find out the informations of a subject's sleep states. Next powers of each of 4 frequency bands were computed using spectrogram of arousal region. And finally we computed variations of power of EEG frequency to detect arousals. The performance has been assessed using polysomnographic (PSG) recordings of twenty patients with sleep apnea, snoring and excessive daytime sleepiness (EDS). We could obtain sensitivity of 79.65%, specificity of 89.52% for the data sets. We have shown that proposed method was effective for detecting the arousal events.

심박변화율을 이용한 폐쇄성 수면무호흡 검출

최호선,조성필,Choi Ho-Seon,Cho Sung-Pil 대한전자공학회 2005 電子工學會論文誌-SC (System and control) Vol.42 No.3

폐쇄성 수면무호흡은 수면장애를 나타내는 대표적인 증상으로 주간의 과도한 졸음과 피로, 고혈압, 부정맥 등을 유발할 뿐만 아니라 심한 경우 수면 중 심장마비, 돌연사 등의 결과를 초래할 수 있으므로 그의 발생 여부 및 빈도를 검출하는 것은 매우 중요하다. 이를 위해 사용되고 있는 수면다원검사는 여러 가지 생체신호를 함께 측정하므로 불편하고 비용이 많이 드는 단점이 있다. 이러한 단점을 보완하기 위해 적은 수의 생체신호를 사용한 폐쇄성 수면무호흡 검출에 관한 연구가 필요하다. 본 논문에서는 폐쇄성 수면무호흡을 검출하기 위한 최소한의 생체신호로서 심전도 신호를 이용하였다. PhysioNet에서 제공하는 수면무호흡 환자의 심전도 데이터로부터 1분간의 R-R 간격의 평균과 표준편차 그리고 R-R 간격과 S점 크기의 power spectrum 등을 계산하였고, 이를 신경망에 적용함으로써 폐쇄성 수면무호흡 검출 알고리즘을 개발하였다. 개발된 알고리즘에 심전도 신호를 적용하여 검출 성능을 평가한 결과, 평균 $89.66\%$의 sensitivity와 $95.25\%$의 specificity를 얻었으며 이를 통해 본 연구에서 제안한 검출파라미터들의 유용성을 확인하였다. Obstructive Sleep Apnea (OSA) is a representative symptom of sleep disorder caused by the obstruction of upper airway. Because OSA causes not only excessive daytime sleepiness and fatigue, hypertension and arrhythmia but also cardiac arrest and sudden death during sleep in the severe case, it is very important to detect the occurrence and the frequency of OSA. OSA is usually diagnosed through the laboratory-based Polysomnography (PSG) which is uncomfortable and expensive. Therefore researches to improve the disadvantages of PSG are needed and studies for the detection of OSA using only one or two parameters are being made as alternatives to PSG. In this paper, we developed an algorithm for the detection of OSA based on Heart Rate Variability (HRV). The proposed method is applied to the ECG data sets provided from PhysioNet which consist of learning set and training set. We extracted features for the detection of OSA such as average and standard deviation of 1 minute R-R interval, power spectrum of R-R interval and S-peak amplitude from data sets. These features are applied to the input of neural network. As a result, we obtained sensitivity of $89.66\%$ and specificity of $95.25\%$. It shows that the features suggested in this study are useful to detect OSA.

도플러 레이더와 에어 매트리스를 이용한 무구속 방식의 신생아 감시 장치 설계

양성수,조성필,박호동,이경중,Yang, Seong-Soo,Cho, Sung-Pil,Park, Ho-Dong,Lee, Kyoung-Joung 대한의용생체공학회 2014 의공학회지 Vol.35 No.6

Continuous monitoring of heart rates and respiratory rates for newborns or infants is very important since the abnormal breathing and heart problems can threaten the life of newborns or infants. A noncontact baby monitoring system based on a Doppler radar and an air mattress was designed. The Doppler radar was used to acquire respiratory signals and the air mattress was employed to obtain heart rates. The performance of the designed system was evaluated using a commercialized infant simulator ($Simbaby^{TM}$) and a respiration belt transducer was used to measure respiration rates as a reference. Results for respiratory rates revealed that the correlation coefficients between I-and Q-channel and the respiration belt were 0.84 and 0.91 and the mean ${\pm}$ standard deviations of errors between them were $1.66{\pm}1.92$ (bpm) and $0.88{\pm}1.65$ (bpm). Heart rates showed that the correlation coefficient between air mattress and set value of the simulator was 0.73 and the mean ${\pm}$ standard deviation of errors between them was $1.09{\pm}3.45$ (bpm). These results indicate that the designed system holds the potential as an effective monitoring tool for continuous monitoring heart rates and respiratory rates of newborns or infants.

고효율 DC/DC 컨버터용 전류분할과 시분할 스위치 비교 연구

고성훈,조성필,이수원,이성룡,Ko, Sung-Hun,Cho, Sung-Pil,Lee, Su-Won,Lee, Seong-Ryong 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.1

This paper presents a comparative analysis of the parallel operation of different switches in a DC/DC converter. In high power applications, multi-switch PWM power conditioners may be preferred despite a higher component count, due to the absence of low frequency filters, reduced switching losses and fault tolerance. The paper demonstrates how current sharing (CSH) and time sharing (TSH) lead to the reduction of switching stress in the parallel operation of switches in any converter. The solutions proposed in this study can be applied on different scales to other power conditioners for DC/DC converter systems. Discussions of the concepts, hypotheses and computer simulations are verified by 1 kW experimental results.

천연망간광석을 이용한 선택적 촉매환원반응에서 수분에 의한 영향 및 조촉매에 의한 반응 특성 연구

최상현 ( Sang Hyun Choi ),이도경 ( Do Kyung Lee ),조성필 ( Sung Pil Cho ),이준엽 ( Jun Yub Lee ),홍성호 ( Sung Ho Hong ),홍성창 ( Sung Chang Hong ) 한국환경분석학회 2006 환경분석과 독성보건 Vol.9 No.1