• 로봇학회논문지
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• 제5권1호
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• pp.55-63
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• 2010

This paper describes performance improvement of GPS/DR Integration system using area decision algorithm and vehicle movement information. In GPS signal blockage area, i.e., tunnel and underground parking area, DR sensor errors are accumulated and navigation solution is gradually diverged. We use the car movement information according to moving area to correct the DR sensor error. Also, vehicle movement is decided as stop, straight line, turn and movement changing region through DR sensor data analysis. The car experiment is performed to verify the supposed method. The results show that supposed method provides small position and heading error than previous method.

• 제어로봇시스템학회논문지
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• 제17권10호
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• pp.1014-1020
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• 2011

This presents a motion and force estimation system of human fingers by using an Electromyography (EMG) sensor module and a data glove system to be proposed in this paper. Both EMG sensor module and data glove system are developed in such a way to minimize the number of hardware filters in acquiring the signals as well as to reduce their sizes for the wearable. Since the onset of EMG precedes the onset of actual finger movement by dozens to hundreds milliseconds, we show that it is possible to predict the pattern of finger movement before actual movement by using the suggested system. Also, we are to suggest how to estimate the grasping force of hand based on the relationship between RMS taken EMG signal and the applied load. Finally we show the effectiveness of the suggested estimation system through several experiments.

• 풍력에너지저널
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• 제10권3호
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• pp.5-11
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• 2019

This paper suggests and compares two algorithms, a moving average filter method and a method developed by the National Renewable Energy Laboratory (NREL), to verify the yaw control algorithm characteristic to reduce yaw error for a wind turbine. A characteristic change for yaw movement in accordance with control parameter change that consists of each control method has been verified. Also, yaw simulations were performed using nacelle wind data measured from two areas with different turbulence intensities and the yaw movement data in each area was compared. These two algorithms and real data were compared by calculating mean absolute error (MSE) and the number of yawing (NY). As a result of the analysis, the MSE values were not significantly different between the two algorithms, but the algorithm proposed by the NREL was found to reduce yaw movement by up to 50 percent more than the moving average filter method.

• 한국소음진동공학회논문집
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• 제25권12호
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• pp.901-906
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• 2015

It is difficult to measure aircraft noise at many points, because the noise measurement is need to long time, 24 hours and consecutive 7 days, which results in high costs. As an alternative, movement measuring points are set to measure aircraft noise for less than 24 hours, and so it is needed to overcome the limitation of shorter measuring time. Thus, this study measured military aircraft noise on movement measuring points and conducted a comparative analysis on the data according to each measuring time. The data of measuring noise for 24 hours and less than 24 hours were compared to suggest appropriate measuring time on the movement measuring points. As a result of comparing data of measuring noise, an error was within 3 dB in case of measuring time of 3 hours, and an error was within 1 dB in case of 6 hours of measurement.

• 한국운동역학회지
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• 제30권2호
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• pp.165-172
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• 2020

Objective: The purpose of this study was to provide quantitative and objective data of throwing movement in baseball catcher through biomechanical analysis. Method: Eight high school baseball catchers (age: 17.3±0.7 yrs, height: 175.3±4.5 cm, weight: 82.5±9.0 kg, Career: 7.4±2.1 yrs) participated and 3-dimentional motion capture system and electromyography (EMG) were used in this study. Results: The maximum center of mass position displacement was observed in forward direction. The linear velocity magnitude of the upper extremity segments were showed as "wrist>elbow>shoulder" which is indicative of kinematic chain. For kinetic EMG data, we also observed the greater muscle activation in the left brachioradial and erector spine muscles muscle that during throwing movement. Conclusion: We expect that biomechanical data from this study will provide important training implications to baseball coaches and trainers in order to effectively train their baseball catchers.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.627-628
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• 2022

디지털 무역은 관련 산업 및 거래의 종류가 다양하고 범위도 넓어서 국제적으로 통용되는 명문화된 정의는 없으나, 일반적으로 기존 상품 중심의 전자상거래를 포함, '인터넷과 ICT 등 디지털 기술을 이용한 국가간 교역 활동(상품+서비스+Data) 전반'을 의미한다. 최근에는 4차 산업혁명으로 인한 IT 등 기술의 발전으로 디지털 무역에 혁신적인 변화가 발생하고 있고, 미국, EU, 일본 등 선진국들은 데이터 이동 자유화 등 디지털 무역 이슈를 디지털무역협정의 협상안건에 포함시키고 있다. 국경 간 데이터 이동 자유화에 대한 쟁점은 디지털 무역 활성화를 위해 데이터 이동의 자유가 필요하나, 정보 보안과 사생활 침해의 위험성도 증가한다는 것이다. 선진국들의 방향을 살펴보면, 미국은 규제 최소화, 유럽은 역내 단일시장화는 찬성하나 소극적 대외 개방, 중국은 규제를 통한 독자적 시장육성 입장을 치하고 있다. 따라서 국경간 데이터 이동 제한조치 강화 조치는 최근 국가별로 정책이 시행되고 있거나 조만간 국제적 합의가 예정되어 있는 이슈로 우리나라도 이에 대한 긴밀한 대응이 필요하다.

• 한국전문물리치료학회지
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• 제27권2호
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• pp.140-148
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• 2020

Background: Scapular winging (SW) could be caused by tightness or weakness of the periscapular muscles. Although data mining techniques are useful in classifying or predicting risk of musculoskeletal disorder, predictive models for risk of musculoskeletal disorder using the results of clinical test or quantitative data are scarce. Objects: This study aimed to (1) investigate the difference between young women with and without SW, (2) establish a predictive model for presence of SW, and (3) determine the cutoff value of each variable for predicting the risk of SW using the decision tree method. Methods: Fifty young female subjects participated in this study. To classify the presence of SW as the outcome variable, scapular protractor strength, elbow flexor strength, shoulder internal rotation, and whether the scapula is in the dominant or nondominant side were determined. Results: The classification tree selected scapular protractor strength, shoulder internal rotation range of motion, and whether the scapula is in the dominant or nondominant side as predictor variables. The classification tree model correctly classified 78.79% (p = 0.02) of the training data set. The accuracy obtained by the classification tree on the test data set was 82.35% (p = 0.04). Conclusion: The classification tree showed acceptable accuracy (82.35%) and high specificity (95.65%) but low sensitivity (54.55%). Based on the predictive model in this study, we suggested that 20% of body weight in scapular protractor strength is a meaningful cutoff value for presence of SW.

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

• 대한기계학회논문집B
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• 제25권12호
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• pp.1802-1812
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• 2001

The purpose of this study is to analyze numerically the movement of particles included in turbulent fluid flow characteristics of metallic surfaces. To describe fluid flew, the incompressible Navier-Stokes equation discretized by the finite volume method were solved on the non-orthogonal coordinates with non-staggered variable arrangement, and the k-$\xi$ turbulence model was adapted. After fluid flow was calculated, particle movement was predicted from the Lagrangian approaches. Non-essential complexities were avoided by assuming that the particles had spherical shapes and the Stoke's drag formula only consisted of external farces acting upon them. In order to validate the numerical calculations, the results were compared with the experimental data reported in literature and agreed well with them. The drag force coefficient equation showed better agreement with the experimental data in the prediction of particle movement than the correction factor equation. Impact velocity and impact angle increased as inlet turbulence intensity decreased, relative jet height was lower. or the Reynolds number was larger.

• 한국산학기술학회논문지
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• 제13권5호
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• pp.2390-2395
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• 2012

지진의 영향으로 인한 지각변동 모니터링은 지구물리 및 측지학 분야에서 중요한 연구대상이다. 본 연구에서는 지난 3월 11일 오후 2시 46분 경 발생한 일본 지진에 따른 지각변동 영향을 분석하기 위해 일본지역의 9개 IGS 상시관측소를 대상으로 지진 발생 전 후의 자료를 정밀절대측위로 처리하고, 상시관측소의 위치 해석을 통해 지진으로 인한 일본지역의 지각변동을 분석하였다. 지각변동 모니터링 결과, 일본지역의 지진 변위량과 지진 전 후 지각 변동의 변화를 정량적으로 제시할 수 있었다. 지진 전 후 일본지역의 지각변동이 기존과 다른 양상을 나타내고 있음을 볼 때, GPS 관측자료 해석을 통한 지속적인 지각변동 모니터링이 필요할 것이다.