• 전기학회논문지
• /
• 제64권8호
• /
• pp.1193-1201
• /
• 2015

This paper presents a study of circulating current of modular multi-level converter (MMC) based a high voltage direct current (HVDC) system under unbalanced grid conditions. Due to the connection of a dependent DC source in each phase, the MMC system inherently generates the power ripple of double-line-frequency components in the AC-side and as a result, the additional sinusoidal current named circulating current flows through the each arm. Reliability improvement of HVDC system under an unbalanced grid condition is one of the important criteria. Generally, the modeling of the circulating current is based on the power relation between DC-side and AC-side. However, the method is not perfectly matched in the MMC system due to the difference of the structural characteristic. In this paper, improved modeling method of circulating current is proposed, which is based on the inner arm power. The proposed method is verified by several simulations to have good agreement of the circulating current components.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
• /
• pp.121-125
• /
• 2006

A new GPS receiver correlator for the deeply-coupled GPS/INS integration system is proposed in order to the computation time problem of the Kalman filter. The proposed correlator consists of two early, prompt and late arm pairs. One pair is for detecting data bit transition boundary and another is for the correlator value calculation between input and replica signal. By detecting the data bit transition boundary, the measurement calculation time can be made longer than data bit period. As a result of this, the computational time problem of the integrated Kalman filter can be resolved. The validity of the proposed method is given through computer simulations.

• 국제물리치료학회지
• /
• 제2권1호
• /
• pp.244-250
• /
• 2011

The purpose of this study is to investigate whether there are differences in physique characteristics between the excellent domestic player groups in each sport player's, to prevent epidemiologic damage of musculoskeletal system and to provide fundamental data to improve performances for players. This study has performed for total 60 student players from Y University in Yongin, Gyeonggi-do, consists of 20 Kendo players, 20 Judo players and 20 Taekwondo players. We measured the length and circumference of arm, leg, body using Martin anthropometer to collect the data for 3 groups. There was significant difference in lower left arm length between player groups(p<.01), and Kendo players' right side femoral were longer than other 2 groups for leg length measurement(p<.01). Judo players' circumference for right/left stretched arm/bent upper arm were thicker than other 2 groups(p<.01). Taekwondo players' chest circumference were smaller than other 2 groups(p<.01), and Taekwondo players' right/left femoral circumference were thinner than other 2 groups(p<.05). From this study, it was found that there are physique characteristics differences between the Kendo, Judo and Taekwondo player groups. This indicates that repeated exercise for each sport player causes physique change, and it may cause epidemiologic damage of musculoskeletal system. It is recommended to perform balancing exercise prior to main exercise.

• 대한약침학회지
• /
• 제19권3호
• /
• pp.197-206
• /
• 2016

Introduction: This study aims to investigate the effects of acupuncture stimulation on the radial artery's pressure pulse wave, along with various hemodynamic parameters, and to explore the possible underlying mechanism of pulse diagnosis in healthy participants in their twenties. Methods and analysis: This study is a prospective, single-arm, exploratory clinical study. A total of 25 healthy participants, without regard to gender, in their twenties will be recruited by physicians. Written informed consent will be obtained from all participants. The participants will receive acupuncture once at ST36 on both sides. The radial arterial pulse waves will be measured on the left arm of the subjects by using an applicable pulse tonometric device (KIOM-PAS). On the right arm (appearing twice), electrocardiogram (ECG), photoplethysmogram (PPG), respiration and cardiac output (CO) signals, will be measured using a physiological data acquisition system (Biopac module), while the velocity of blood flow, and the diameter and the depth of the blood vessel will be measured using an ultrasonogram machine on the right arm (appearing twice). All measurements will be conducted before, during, and after acupuncture. The primary outcome will be the spectral energy at high frequencies above 10 Hz ($SE_{10-30Hz}$) calculated from the KIOM-PAS device signal. Secondary outcomes will be various variables obtained from the KIOM-PAS device, ECG, PPG, impedance cardiography modules, and an ultrasonogram machine. Discussion: The results of this trial will provide information regarding the physiological and the hemodynamic mechanisms underlying acupuncture stimulation and clinical evidence for the influence of acupuncture on the pressure pulse wave in the radial artery. Ethics and dissemination: This study was approved by the Institutional Review Board (IRB) of Kyung Hee University's Oriental Medical Center, Seoul, Korea (KOMCIRB-150818-HR-030). The study findings will be published in peer-reviewed journals and presented at national and international conferences. Trial registration number: This trial was registered with the Clinical Research Information Service (CRIS) at the Korea National Institute of Health (NIH), Republic of Korea (KCT0001663), which is a registry in the World Health Organization's (WHO's) Registry Network.

• 대한음성학회:학술대회논문집
• /
• 대한음성학회 2007년도 한국음성과학회 공동학술대회 발표논문집
• /
• pp.217-220
• /
• 2007

This study outlines a small-sized dialog style ETRI Korean TTS system which applies a HMM based speech synthesis techniques. In order to build the VoiceFont, dialog-style 500 sentences were used in training HMM. And the context information about phonemes, syllables, words, phrases and sentence were extracted fully automatically to build context-dependent HMM. In training the acoustic model, acoustic features such as Mel-cepstrums, logF0 and its delta, delta-delta were used. The size of the VoiceFont which was built through the training is 0.93Mb. The developed HMM-based TTS system were installed on the ARM720T processor which operates 60MHz clocks/second. To reduce computation time, the MLSA inverse filtering module is implemented with Assembly language. The speed of the fully implemented system is the 1.73 times faster than real time.

• The Korean Journal of Pain
• /
• 제26권2호
• /
• pp.191-194
• /
• 2013

Pseudoaneurysm of the abdominal wall is a possible but very rare clinical entity. It is a known complication of surgery, trauma, or arterial puncture, but it is rarely spontaneous. Even though it can usually present with a wide range of local symptoms, it can cause referred pain via spinal cord, which is cross-excited with afferent sympathetic nervous system. We report a case of right arm pain which was referred from a small abdominal pseudoaneurysm like a referred pain from gall bladder. This rare entity should be considered in the differential for pain management in case that the pain does not resolve with medication or interventional pain management.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2005년도 생물공학의 동향(XVII)
• /
• pp.755-756
• /
• 2005

• 제어로봇시스템학회논문지
• /
• 제4권6호
• /
• pp.713-721
• /
• 1998

In this paper a new modeling and an optimal pole-placement control for the suspension system of Macpherson type are investigated. The rotational motion of the unsprung mass is emphasized in the new modeling. The two generalized coordinates selected in the new model are the vortical displacement of sprung mass and the angular displacement of control arm. Both variables are measured from their static equilibrium points. It is shown that the conventional model is a special case of the new model since the transfer function of the new model coincides with that of the conventional one if the lower support point of the shock absorber is located at the mass center of the unsprung mass. It is also shown that the resonance frequencies of the new model agree better with experimental results. Therefore, the new model is more general in the sense that it Provides an extra degree of freedom in determining the plant model for control system design. An optimal pole-placement control which combines LQ control and pole-placement technique is applied to the new model. Simulations are provided.

• 한국멀티미디어학회논문지
• /
• 제19권1호
• /
• pp.68-79
• /
• 2016

Electromyographic (EMG) signals have been widely used as motion commands of prosthetic arms. Although EMG signals contain meaningful information including the movement intentions of human body, it is difficult to predict the subject's motion by analyzing EMG signals in real-time due to the difficulties in extracting motion information from the signals including a lot of noises inherently. In this paper, four Ag/AgCl electrodes are placed on the surface of the subject's major muscles which are in charge of four upper arm movements (wrist flexion, wrist extension, ulnar deviation, finger flexion) to measure EMG signals corresponding to the movements. The measured signals are sampled using DAQ module and clustered sequentially. The Fuzzy C-Means (FCMs) method calculates the center values of the clustered data group. The fuzzy system designed to detect the upper arm movement intention utilizing the center values as input signals shows about 90% success in classifying the movement intentions.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2018년도 추계학술대회
• /
• pp.538-539
• /
• 2018

본 논문에서는 오픈 소스 컴퓨터 비전 라이브러리 중 하나인 OpenCV를 사용하여 차선 인식 기능을 구현한 내용을 정리하였다. ARM 프로세서 기반인 Raspberry Pi 3 보드에 Linux 운영체제인 Rasbian(r18.03.13)을 탑재하였고, 영상처리를 수행하기 위해 Raspberry Pi Camera를 사용하였다. 차선인식을 구현하기 위해서 OpenCV 라이브러리에 구현된 Canny Edge Detection, Hough Transform 알고리즘을 사용하였고, 소실점(Vanishing Point)의 흔들림을 방지하고 원하는 직선만을 검출하도록 RANSAC 알고리즘을 사용하였다. 또한, 검출된 차선에 따라 자동차가 주행하도록 DC모터와 Servo모터를 제어하였다.