• 한국멀티미디어학회논문지
• /
• 제18권11호
• /
• pp.1391-1399
• /
• 2015

In recent times, studies sentiment analysis are being actively conducted by implementing natural language processing technologies for analyzing subjective data such as opinions and attitudes of users expressed on the Web, blogs, and social networking services (SNSs). Conventionally, to classify the sentiments in texts, most studies determine positive/negative/neutral sentiments by assigning polarity values for sentiment vocabulary using sentiment lexicons. However, in this study, sentiments are classified based on Thayer's model, which is psychologically defined, unlike the polarity classification used in opinion mining. In this paper, as a method for classifying the sentiments, sentiment categories are proposed by extracting sentiment keywords for major sentiments by using hashtags, which are essential elements of Instagram. By applying sentiment categories to user posts, sentiments can be determined through the similarity measurement between the sentiment adjective candidates and the sentiment keywords. The test results of the proposed method show that the average accuracy rate for all the sentiment categories was 90.7%, which indicates good performance. If a sentiment classification system with a large capacity is prepared using the proposed method, then it is expected that sentiment analysis in various fields will be possible, such as for determining social phenomena through SNS.

• 한국멀티미디어학회논문지
• /
• 제21권6호
• /
• pp.649-658
• /
• 2018

In this paper, we propose a mechanical contact inner tap inspection system that can inspect the defect of the inner tap immediately after inner tap is processed within the machining center. The inspection module has the collet chuck structure, so it can mounted on the main spindle of the machining center during inspection. It was developed with a focus on inspection for tap having 20 mm depth which is primarily fabricated in automotive parts and has a double sided PCB-type control system including sensing function based on Zigbee module, micom and IR sensor for wireless transmission of measured data with low power operation, and also a battery for supplying electric power. The current consumption is 46.8mA in the inspection operation mode and 0.0268mA in the power saving mode for 3.7V of the applied power source, so that 30,000 times or more inspection can be performed with assumed 5 seconds inspection time for one tap. Experiments in test jig system and actual machining center confirm that the proposed inner tap inspection system can be applied to the batch process of simultaneous inspection after tapping in the machining center.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.2126-2131
• /
• 2005

Interactions of a humanoid with a human are important, when the humanoid is requested to provide people with human-friendly services in unknown or uncertain environment. Such interactions may require more complicated and human-like behaviors from the humanoid. In this work the arm motions of a human are discussed as the early stage of human motion imitation by a humanoid. A motion capture system is used to obtain human-friendly arm motions as references. However the captured motions may not be applied directly to the humanoid, since the differences in geometric or dynamics aspects as length, mass, degrees of freedom, and kinematics and dynamics capabilities exist between the humanoid and the human. To overcome this difficulty a method to adapt captured motions to a humanoid is developed. The geometric difference in the arm length is resolved by scaling the arm length of the humanoid with a constant. Using the scaled geometry of the humanoid the imitation of actor's arm motions is achieved by solving an inverse kinematics problem formulated using optimization. The errors between the captured trajectories of actor arms and the approximated trajectories of humanoid arms are minimized. Such dynamics capabilities of the joint motors as limits of joint position, velocity and acceleration are also imposed on the optimization problem. Two motions of one hand waiving and performing a statement in sign language are imitated by a humanoid through dynamics simulation.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제8권3호
• /
• pp.243-251
• /
• 2016

Autonomous Underwater Vehicles (AUVs) generally work in complex marine environments. Any fault in AUVs may cause significant losses. Thus, system reliability and automatic fault diagnosis are important. To address the actuator failure of AUVs, a fault diagnosis method based on the Gaussian particle filter is proposed in this study. Six free-space motion equation mathematical models are established in accordance with the actuator configuration of AUVs. The value of the control (moment) loss parameter is adopted on the basis of these models to represent underwater vehicle malfunction, and an actuator failure model is established. An improved Gaussian particle filtering algorithm is proposed and is used to estimate the AUV failure model and motion state. Bayes algorithm is employed to perform robot fault detection. The sliding window method is adopted for fault magnitude estimation. The feasibility and validity of the proposed method are verified through simulation experiments and experimental data.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
• /
• pp.281-284
• /
• 2006

After building a ship in a shipyard, there are so many repeated inspection of welding seam defects and painting status before delivering to the ship's owner. An inspection on the bottom part of a ship in commercial service should be done in every two years for the purpose of safety and for the prevention of ship speed deterioration. conventional welding seam inspection systems are rely on the visual inspection by human or the ultrasonic inspection for the selective part of a ship. This paper suggests a remote controlled inspection system for the examination of large ships or steel structures. The proposed system moves in contact with the ship under inspection and have a CCD camera to provide visual-guidance information to a remotely located human worker. Additionally this system utilizes a weld line tracking algorithm for an optimal position control. We verified the effectiveness of the inspection system by experimental data.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2010년도 추계학술대회
• /
• pp.271-273
• /
• 2010

태양광발전시스템에서 PV모듈이나 어레이의 성능특성 및 성능추정이 요구되고 있다. 태양광 발전 모듈은 장기간 사용 시 환경 요인 등으로 효율이 나빠지며 어레이의 특정 모듈 효율저하는 전체 발전 전력의 감소를 초래하므로 실시간 감시가 필요하다. 이 논문은 태양광 발전 모듈의 발전 전력을 실시간으로 측정하기 위한 것이다. 모듈의 출력을 실시간으로 측정하기 위해 전압, 전류 측정 회로를 제작하고 온도, 일조량 측정 장치를 제작하여 RS485 통신으로 연결하였다. Visual Studio - Basic .Net(2005)과 NI사의 Measurement Studio를 이용하여 실시간 모니터링 프로그램을 제작하였고, 모듈들 사이의 상대적인 발전 출력을 비교하여 효율 저하가 의심되는 모듈을 실시간으로 탐색하였다. 20개 모듈의 직병렬로 구성된 1kW 태양광 발전체에 적용하여 시험한 결과 2개의 모듈에서 성능 저하가 의심되는 결과가 확인되었다.

• 한국산업융합학회 논문집
• /
• 제22권1호
• /
• pp.39-45
• /
• 2019

We propose an active color model based method for tracking motions of multiple human using a networked multiple-camera system in IoT space as a human-robot coexistent system. An IoT space is a space where many intelligent devices, such as computers and sensors(color CCD cameras for example), are distributed. Human beings can be a part of IoT space as well. One of the main goals of IoT space is to assist humans and to do different services for them. In order to be capable of doing that, IoT space must be able to do different human related tasks. One of them is to identify and track multiple objects seamlessly. In the environment where many camera modules are distributed on network, it is important to identify object in order to track it, because different cameras may be needed as object moves throughout the space and IoT space should determine the appropriate one. This paper describes appearance based unknown object tracking with the distributed vision system in IoT space. First, we discuss how object color information is obtained and how the color appearance based model is constructed from this data. Then, we discuss the global color model based on the local color information. The process of learning within global model and the experimental results are also presented.

• Advances in nano research
• /
• 제14권6호
• /
• pp.591-602
• /
• 2023

In the present study, capability of nanobiotics in repairing tendon injuries commonly occur in Taekwondo sport is investigated and some approaches are proposed. In this regard, a brief review on the types and application of nanobiotics is presented. Their capabilities and limitation are discussed. Next, different type of tendon injuries in Taekwondo athletes are discussed along with their treatment approaches. Based on the presented data, a nano-scale feasible robot model carrying nanobiotics is proposed for repairing tendons. Finite element simulations is also conducted to show the effectiveness of the repairing process using nanorobots equipped with nanobiotics. This repairing procedure is a combination of mechanical and chemical treatments. The results indicated that using nanobiotics on nanorobots arms in the repair of tendon injuries has many benefits. First, drug delivery is directly injected to the target section. Second, Due to the nanorobots small sizes more acute treatment is possible. Finally, since the control of the nanorobots are assisted with computers, the possibility of human error reduces significantly. The proposed method of the present study could be utilized by other scientists and technological industry in developing final nanorobots with nanobiotics carrying capacity.

• 한국산학기술학회논문지
• /
• 제13권9호
• /
• pp.3876-3881
• /
• 2012

일반적으로 마스터/슬레이브 원격제어 시스템에서 작업자는 원격에서 슬레이브를 제어하기 위하여 카메라 영상 같은 시각 정보를 이용하는 경우가 많은데, 많은 데이터 양으로 인하여 원격지의 영상 정보에 지연이 발생할 수 있고 카메라 위치에 따라 영상 정보가 제한되거나 불완전하여 제어가 어려운 경우가 생길 수 있다. 카메라 영상을 이용한 원격제어 시스템의 이러한 문제점을 해결하기 위하여 본 논문에서는 영상 정보 대신에 3차원 재구성 그래픽 모델을 이용한 원격제어 시스템을 제안한다. 제안된 원격제어시스템은 로봇 제어 모듈, 힘반향 조이스틱을 이용한 마스터 모듈, 그래픽유저인터페이스모듈로 이루어져 있는데, 여기서 그래픽유저인터페이스모듈은 원격지에서 전달된 적은 양의 센싱 데이터를 이용하여 3차원으로 재구성된 그래픽 모델을 작업자에게 제공해 준다. 제안된 원격제어 시스템은 펙인홀(peg-in-hole) 조립 작업을 이용하여 그 효과가 검증되었다.

• 한국지능시스템학회논문지
• /
• 제15권6호
• /
• pp.720-729
• /
• 2005

본 논문에서는 미지의 비선형 시스템을 제어하기 위해 웨이블릿 신경 회로망을 이용한 간접 적응 제어기를 설계한다. 제안 된 간접 적응 제어기는 웨이블릿 신경 회로망을 이용한 동정 모델과 제어기로 구성된다. 여기서 동정 모델과 제어기에 사용되는 웨이블릿 신경 회로망은 시간과 주파수에 대한 정보를 동시에 포함하는 웨이블릿의 특성을 가지고 있기 때문에 다층구조 신경회로망과 방사 기저 함수 신경회로망에 보다 더 빠른 수렴특성을 보인다. 웨이블릿 신경 회로망의 학습방법은 경사 하강법, 유전알고리듬, DNA 기법등 여러 가지가 있으나, 본 논문에서는 확장 칼만 필터를 기반으로 한 학습 방법을 제안한다. 확장 칼만 필터 학습 방법은 계산이 복잡하기는 하지만 학습되어 갱신되는 파라미터의 이전 데이터 정보를 이용하는 특성 때문에 매우 빠른 수렴 특성을 보인다. 본 논문에서는 Buffing 시스템과 1축 머니퓰레이터에 대한 컴퓨터 모치실험을 통해 제안한 확장 칼만 필터 학습 방법을 이용한 간접 적응 제어기가 일반적인 경사 하강법을 이용한 경우보다 우수함을 보인다.