• 한국정보통신학회논문지
• /
• 제10권1호
• /
• pp.23-28
• /
• 2006

피치 주기는 음성 인식, 화자 식별, 음성 분석 및 합성 등과 같은 음성 신호 처리 분야에 있어서 중요한 요소이며, 이러한 피치 주기 검출에 관련된 다양한 알고리즘이 지금까지 연구되고 있다. 피치 검출에 사용되는 알고리즘의 하나인 AMDF(average magnitude difference function)는 각 계곡점의 거리를 피치 주기로 계산한다. 이때, 피치 주기 검출을 위한 계곡점 선정에 있어서 알고리즘이 복잡해지는 문제점이 발생한다. 따라서 본 논문에서는 AMDF의 회전변환을 이용하여 전체 최소 계곡점을 음성 신호의 피치 주기로 검출하는 간단한 알고리즘을 제안하였으며, 시뮬레이션을 통해 기존의 방법들과 비교하였다.

• 천문학회지
• /
• 제37권5호
• /
• pp.527-531
• /
• 2004

It is argued that the key task in understanding magnetic fields in the cosmos is to comprehend the origin of their order or coherence over large length scales in galaxies. Obtaining magnetic fields can be done in stars, whose lifetime is usually $10^{10}$ rotations, while galactic disks have approximately 20 to 50 rotations in their lifetime since the last major merger, which established the present day gaseous disk. Disorder in the galactic magnetic fields is injected on the disk time scale of about 30 million years, about a tenth of the rotation period, so after one half rotation already it should become completely disordered. Therefore whatever mechanism Nature is using, it must compete with such a short time scale, to keep order in its house. This is the focal quest.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
• /
• pp.630-634
• /
• 2003

This paper proposes a Carrier-Rotation PWM technique that is new solution for the voltage unbalancing problem of flying capacitors in the Flying Capacitor Multi-level Inverter (FCMI).The proposed PWM technique equalizes the utilization of phase leg voltage redundancies corresponding to the charging and the discharging state of flying capacitors during one switching period of all the switches. it also has the same switch utilization and the reduced harmonics of output voltage. Hence, it is more suitable for the FCMI compared with the conventional solutions. Experimental results on the laboratory prototype flying capacitor 3-level inverter confirm the validity of the proposed PWM technique.

• 천문학회지
• /
• 제45권2호
• /
• pp.49-57
• /
• 2012

In this study, I calculate the past and future dynamical states of the Earth-Moon system by using modified Lambeck's formulae. I find that the ocean tidal effect must have been smaller in the past compared to its present amount. Even though the Moon is already in the spin-orbit synchronous rotational state, my calculation suggest that it will not be in geostationary rotational state in the next billion years or so. This is due to the associated Earth's obliquity increase and slow retardation of Earth's spin and lunar orbital angular velocities. I also attempt to calculate the precessional period of the Earth in the future. To avoid uncertainties in the time scale, the future state is described by using the Earth-Moon distance ratio as independent parameter. Effects due to solar tidal dissipation are included in all calculations.

• Korean Journal of Acupuncture
• /
• 제17권1호
• /
• pp.47-65
• /
• 2000

The meridian, the meridian point and the Acupuncture-Bu-Xie(鍼灸補瀉) of oriental medicine are very important in the Department of Acupuncture and Moxibustion. Until now it has been confused at the practical use, and it showed up many transformation to the ages and many scholars. And then, I made a study of effects on the thermal changes of Sangyang($LI_1$,商陽), Igan($LI_2$,二間), Samgan($LI_3$,三間), Hapkok($LI_4$,合谷), Yanggye($LI_5$,陽谿), Kokchi($LI_{11}$,曲池), Yonghyang($LI_{20}$,迎香) following acupuncture on the Hapkok with the Rotated Acupuncture-Bu-Xie(捻轉補瀉) stimulation. This study researched into clinical statistics for 140 men who are in good health, and they are studying oriental medicine at Woosuk university in Korea. This study was covered a period of 3 months form June, 1999 to August, 1999. The objective was divided into seven groups, those are the control group(CON, N=20), the acupuncture stimulation group with non-rotation on Hapkok of left hand(A-I, N=20), the acupuncture stimulation group with non-rotation on non-meridian point(NA) of left hand(A-II, N=20), the acupuncture stimulation group with Bu-rotation(捻轉補法) on Hapkok of left hand(B-I, N=20), the acupuncture stimulation group with Bu-rotation on non-meridian point(NA) of left hand(B-II, N=20), the acupuncture stimulation group with Xie-rotation(捻轉瀉法) on Hapkok of left hand(C-I, N=20), and the acupuncture stimulation group with Xie-rotation on non-meridian point of left hand(C-II, N=20). The first, I took a picture for 140 men with the Digital infrared thermal image(D.I.T.I.). After 10 minutes, I took a second picture for each group following experimental methods, those were followed acupuncture on the Hapkok and the non-meridian point with the retentive and Rotated Acupuncture-Bu-Xie stimulation. The results are summarized as follows : 1. The thermal changes of the area which is a meridian point in the Large Intestine Meridian of the acupuncture stimulation group on Hapkok different from the control groups with significantly change. 2.The thermal changes of the area which is a meridian point in the Large Intestine Meridian of acupuncture stimulation groups on non-meridian point was not significantly different from the control group. 3. The thermal changes of the area which is a meridian point in the Large Intestine Meridian of the acupuncture stimulation group with Bu-rotation on Hapkok different from the control group with significant increase. 4. The thermal changes of the area which is a meridian point in the Large Intestine Meridian of acupuncture stimulation group with Bu-rotation on non-meridian point was not significantly different from the control group. 5. The thermal changes of the area which is a meridian point in the Large Intestine Meridian of the acupuncture stimulation group with Xie-rotation on Hapkok different from the control group with significant decrease and increase following the decreasing or increasing temperature class, and the increasing temperature class of the acupuncture stimulation group with Xie-rotation on Hapkok significantly different from the acupuncture stimulation group with Bu-rotation on Hapkok. 6. The thermal changes of the area which is a meridian point in the Large Intestine Meridian of acupuncture stimulation group with Xie-rotation on non-meridian point was not significantly different from the control group. As a conclusion, I could think that the acupuncture stimulation with Bu-rotation or Xie-rotation on Hapkok affected the thermal change of the area which is a meridian point in the Large Intestine Meridian. And then I could relate these results with the existence of the meridian and meridian point, and with the Rotated Acupuncture-Bu-Xie theory of oriental medicine.

• 천문학회지
• /
• 제50권3호
• /
• pp.41-49
• /
• 2017

We conduct BVRI and R band photometric observations of asteroid (5247) Krylov from January 2016 to April 2016 for 51 nights using the Korea Microlensing Telescope Network (KMTNet). The color indices of (5247) Krylov at the light curve maxima are determined as $B-V=0.841{\pm}0.035$, $V-R=0.418{\pm}0.031$, and $V-I=0.871{\pm}0.031$ where the phase angle is $14.1^{\circ}$. They are acquired after the standardization of BVRI instrumental measurements using the ensemble normalization technique. Based on the color indices, (5247) Krylov is classified as a S-type asteroid. Double periods, that is, a primary period $P_1=82.188{\pm}0.013h$ and a secondary period $P_2=67.13{\pm}0.20h$ are identified from period searches of its R band light curve. The light curve phases with $P_1$ and this indicate that it is a typical Non-Principal Axis (NPA) asteroid. We discuss the possible causes of its NPA rotation.

• Clinics in Shoulder and Elbow
• /
• 제17권3호
• /
• pp.120-126
• /
• 2014

Background: To compare the treatment of the proximal humerus fracture using a Polarus nail or Philos plate, we aimed to analyze the functional recovery and the factors affecting the selection between the two types of surgery. Methods: The study included 107 patients with proximal humerus fracture who underwent surgery at our institution. Of these patients, 67 underwent surgery with Polarus nails (G1) and 40 with Philos plates (G2). In G1, the cases of two- and three-part fractures were 60 and 7 cases, in G2, the cases of two-, three-, and four-part fractures were 28, 10, and 2 cases, respectively. The average age was 61 years old, and the average follow-up period was 32.5 months. We compared radiological results, the functional recovery retrospectively. Results: The radiological union time was 6.8 weeks and 8.7 weeks on average in G1 and G2 (p < 0.05). At the one-year follow-up period, these were visual analogue scale (VAS) 1.355, forward flexion (FF) 130.968, external rotation (ER) 50.161, internal rotation (IR) L2 in G1, and VAS 0.781, FF 135.806 ER 51.25, IR L1 in G2, respectively, showing no significant differences between the two groups (p > 0.05). Similar observations were made at the final follow-up. In terms of functional recovery, no significant differences were seen at the one-year or at the final follow-up period (p > 0.05). Conclusions: For the surgical treatment of proximal humeral fracture, the selection of the type of surgery is affected by the fracture pattern. However, both methods give satisfactory outcomes and do not show significant differences in the functional outcome after the surgery.

• Clinics in Shoulder and Elbow
• /
• 제9권1호
• /
• pp.105-110
• /
• 2006

Purpose: This study reports the clinical results of the arthroscopic Bankart repair in traumatic anterior instability of the shoulder with bio-knotless anchor. Materials and Methods: 21 cases of 21 patients (20 male and 1 female) were included in this study. The average age was 24.8 years old and the period from the first injury to operation was average 37.2 months. All cases had Bankart lesion and 12 cases had Hill-Sachs' lesion. The SLAP lesion was associated in 6 cases. Preoperative Rowe score was average 29.1. Arthroscopic Bankart repair with bio-knotless anchor were performed in all cases; 3 anchors at 3, 4, 5 O'clock position of the glenoid were used in 11 cases and 2 anchors at 4, 5 O'clock position were used in 10 cases. All the associated SLAP lesions were repaired arthroscopically with bio-knotless anchor. Thermal capsular shrinkage at the anterior and inferior shoulder capsule after the Bankart repair was performed in 3 cases. The average follow up period was 20.2 months. Results: The Rowe score improved to 92.8, excellent in 17 cases and good in 4 cases, at last follow up period and 20 cases had full range of motion of the shoulder. 1 case had mild limited range of motion of the shoulder (150 degrees in flexion, 60 degrees in external rotation and T12 level in internal rotation) without any problem in normal activity. The arthroscopic revision surgery of the shoulder was performed in 1 case because of multiple traumatic injuries of the shoulder with pain postoperatively. Conclusion: Arthroscopic Bankart repair with bio-knotless anchor in traumatic anterior shoulder instability is one of the good methods because of the good clinical results.

• Clinics in Shoulder and Elbow
• /
• 제17권1호
• /
• pp.18-24
• /
• 2014

Background: To evaluate the efficacy of the subclavian portal approach for the arthroscopic repair of isolated subscapularis tendon tear. Methods: We used the subclavian portal to carry out arthroscopic repair of the isolated subscapularis tendon tear. The surgery was carried out in 18 cases (average age of 53) from May 2006 to December 2009 with a mean follow-up period of 35 months. Of these cases, 13 patients had the tear in their dominant arms, 16 were male, and 12 were from traumatic ruptures with on average 7.6 months of symptom period to operation. Additional surgery, acromioplasty and subacromial debridement, were carried out on 4 cases each during the subscapularis repair. The integrity of cuff status was assessed by ultrasonographic examination at 6 months and at 1 year after operation. Results: The initial average range of motion in forward flexion, external rotation, and internal rotation were $160^{\circ}$, $50^{\circ}$ and L4, respectively. At the 1 year follow-up period, these improved to $160^{\circ}$, $52^{\circ}$ and T12, respectively. The initial average functional scores were assessed by KSS, ASES, UCLA, and Constant scoring systems, which were 67, 60, 26, and 65, respectively. These scores improved progressively with time. At 3 months after operation, the scores were 74, 67, 27, and 74; at 6 months, 83, 77, 31, and 75; at 1 year, 88, 86, 32, and 79; and at the final follow-up of 35 months, 84, 92, 34, and 84. Conclusions: In the repair of isolated subscapularis tendon tear, the subclavian portal approach provided a good angle for anchor insertion and sufficient space to manage the upper portion of the tendon tear. In turn, these provisions resulted in satisfactory clinical results.

• 한국인터넷방송통신학회논문지
• /
• 제15권6호
• /
• pp.291-296
• /
• 2015

주행 중인 차량의 타이어와 노면 사이에서 발생하는 랜덤성 초음파신호의 주기성을 검출하여 타이어의 손상을 분별하는 방법에 대하여 연구하였다. 잡음으로부터 타이어손상에 의한 유효한 펄스를 검출하기 위해 적응 임계치를 설정하는 방법을 제안하였고, 이를 위한 전처리로서 신호의 랜덤성을 감소시키는 저역통과필터를 사용하였다. 자동차의 속도에 따라 검출된 펄스의 시간간격을 밀도함수화하고 피크점의 시간을 측정하여 타이어 손상물질을 검출하는 방법을 제안하였다. 손상물질이 한 개이고, 주행속도가 50km/h, 80km/h, 100km/h 일 때, 시간밀도함수의 제 1 피크시간 측정결과는 각각 169.8ms, 97.9ms, 81.8ms로 주행속도에 따라 계산한 타이어 회전주기의 오차범위내로 측정되었으며, 한개 이상의 손상물질의 경우에는 각 피크시간의 합이 타이어 회전주기의 오차범위내로 측정되는 결과를 얻을 수 있었다.