• The Journal of Korean Physical Therapy
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• 제33권1호
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• pp.47-52
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• 2021

Purpose: Biofeedback using various ways has helped correct the sitting posture. This study compared the multifidus muscle activity, pelvic and 2nd sacrum tilting angle during typing in nonspecific lower back pain (NCLBP) subjects with and without visual biofeedback. Methods: Thirty subjects with NCLBP were enrolled in this study. An electromyography device was used to measure the multifidus muscle activity. An electromagnetic tracking motion device was used to measure the pelvic and 2nd sacrum tilting angle. The multifidus muscle activity, pelvic, and 2nd sacrum tilting angle were measured before and after typing for 30 minutes in the sitting position. An independent t-test was used to compare the changing values for 30 minutes between the group with and without visual biofeedback. Results: The changing values of the multifidus muscle activity, pelvic, and 2nd sacrum tilting angle were significantly smaller in the group with visual biofeedback than the group without visual biofeedback (p<0.05). Conclusions: In subjects with NCLBP, the visual biofeedback can be recommended to maintain the multifidus muscle activity, pelvic, and 2nd sacrum tilting angle during typing for 30 minutes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권2호
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• pp.826-840
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• 2020

Vertigo is one of the most common complaints encountered by physicians and the patients are steadily increasing. These patients are exposed to the risk of secondary accidents such as falls due to vertigo. There are two ways to improve this symptom: medication and rehabilitation. Although temporary symptomatic improvement may be expected in patients treated with medication, vertigo may recur and medication can delay central compensation. In contrast vestibular rehabilitation exploits central mechanisms of neuroplasticity to increase postural stability and enhance visual-vestibular interactions in situations that generate conflicting sensory information. However, vestibular rehabilitation may be compromised by incorrect performance of exercises, and there is a need for active effort and interest from the patient during rehabilitation. To solve these problems, we decided to apply FOVE HMD for eye-tracking and Unity3D to create virtual reality. The proposed eye-tracking based algorithm calculates the concentration of users with eye tracking data and calculates the motion width of the patient with nystagmus, thus the severity of the patient according to the score can be determined. According to our experimental test against healty group and patients group, this result showed the meaningful data to use define the contents result.

• 대한의용생체공학회:의공학회지
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• 제31권6호
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• pp.427-433
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• 2010

Although tracking methods are efficient and popular for vessel segmentation, they require a seed to initiate an instance of tracking. In this paper, a new method to detect new seeds for tracking of arterial segments from CT angiography (CTA) and to construct a vascular structure is proposed. The proposed algorithm is based on shape analysis of connected components in a volume of interest around a vessel segment which was already extracted by tracking. The eigenvalues of the covariance matrix are used as the shape features for detection. The experimental results on actual clinical data showed that the results totally revealed the arterial tree not hindered by bone or veins. In visual comparison to a method which combines registration and subtraction of both pre-contrast and post-contrast CT volumes, the proposed method produced comparable results to the reference method and were confirmed of its feasibility for clinical use of reducing the cost and burden of patients.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.805-825
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• 2017

Correlation Filter-based Trackers (CFTs) gained popularity recently for their effectiveness and efficiency. To deal with the size changes of the target which may degenerate the tracking performance, scale estimation has been introduced in existing CFTs. However, the variations of the aspect ratio were usually neglected, which also influence the size of the target. In this paper, Size Aware Correlation Filter Trackers (SACFTs) are proposed to deal with this problem. The SACFTs not only determine the translation and scale variations, but also take the aspect ratio changes into consideration, thus a better estimation of the size of the target can be realized, which improves the overall tracking performance. And competing results can be achieved compared with state-of-the-art methods according to the experiments conducted on two large scale datasets.

• 한국레이저가공학회지
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• 제12권1호
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• pp.19-24
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• 2009

Because of its fast and precise welding performance, laser welding is becoming a new excellent welding method. However, the precise focusing and robust seam tracking are required to apply laser welding to the practical fields. In order to laser weld a type of T joint like a circular pipe on a square pipe, which could be met in the three dimensional structure such as an aluminum space frame, a visual sensor system was developed for automation of focusing and seam tracking. The developed sensor system consists of a digital CCD camera, a structured laser, and a vision processor. It is moved and positioned by a 2-axis motorized stage, which is attached to a 6 axis robot manipulator with a laser welding head. After stripe-type structured laser illuminates a target surface, images are captured through the digital CCD camera. From the image, seam error and defocusing error are calculated using image processing algorithms which includes efficient techniques handling continuously changed image patterns. These errors are corrected by the stage off-line during welding or teaching. Laser welding of a circular pipe on a square pipe was successful with the vision tracking system by reducing the path positioning and de focusing errors due to the robot teaching or a geometrical variation of specimens and jig holding.

• 제어로봇시스템학회논문지
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• 제19권12호
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• pp.1067-1071
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• 2013

A 3D visual sensing method using a laser structured beam is presented for robotic tracking applications in a simple and reliable manner. A cylindrical shaped laser structured beam is proposed to measure the pose and position of the target surface. When the proposed laser beam intersects on the surface along the target trajectory, an elliptic pattern is generated. Its ellipse parameters can be induced mathematically by the geometrical relationship of the sensor coordinate and target coordinate. The depth and orientation of the target surface are directly determined by the ellipse parameters. In particular, two discontinuous points on the ellipse pattern, induced by seam trajectory, indicate mathematically the 3D direction for robotic tracking. To investigate the performance of this method, experiments with a 6 axis robot system are conducted on two different types of seam trajectories. The results show that this method is very suitable for robot seam tracking applications due to its excellence in accuracy and efficiency.

• 대한인간공학회지
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• 제26권2호
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• pp.103-112
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• 2007

This study was designed to validate Spreading Activation Theory (SAT) for an evaluation methodology for menu structure through Eye-Tracking approach. When a visual search is on the way, more eye fixations and time are necessary to visually process complex and vague area. From the aspect of recognition, well-designed menu structures were hypothesized to have fewer numbers of fixations and shorter duration because well-designed menu structures reflecting the users' mental model would be well matched with the product's menu structure, resulting in reducing the number of fixations and duration time. The results show that the shorter reaction times for SAT had significantly fewer numbers of fixation and shorter duration time as the hypothesis for this study stated. In conclusion, SAT was proved to be an effective evaluation methodology for menu structure with the eye tracking equipment. In addition, using SAT instead of the real performance experiment would be useful for designing user-centered systems and convenient information structures because SAT was proven to be the theoretical background for design and evaluation of menu structures.

• 한국멀티미디어학회논문지
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• 제25권2호
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• pp.145-156
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• 2022

Nowadays, the complexity of object tracking models among hardware applications has become a more in-demand duty to complete in various indeterminable environment tracking situations with multifunctional algorithm skills. In this paper, we propose a virtual city environment using AirSim (Aerial Informatics and Robotics Simulation - AirSim, CityEnvironment) and use the DQN (Deep Q-Learning) model of deep reinforcement learning model in the virtual environment. The proposed object tracking DQN network observes the environment using a deep reinforcement learning model that receives continuous images taken by a virtual environment simulation system as input to control the operation of a virtual drone. The deep reinforcement learning model is pre-trained using various existing continuous image sets. Since the existing various continuous image sets are image data of real environments and objects, it is implemented in 3D to track virtual environments and moving objects in them.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.275-276
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• 2021

In the construction industry, many of the inspection activities have been conducted by experts' eyes. The inspection performance of this kind of method is highly influenced by experience and knowledge of the expert. The experts who have fluent experience may show better inspection performance than the novice. The problem is the deficiency of experts in the near future due to the acceleration of retirement of the aging expert. Eye-tracking technology can be a solution to effectively educate the novice through transferring the knowledge of an expert and to advance the inspection activities using experts' eyes. This study, as an initial step to suggest the solution, (1) figured out the state of the art of eye-tracking technology, (2) reviewed the previous research to improve the inspection in construction using experts' eye, (3) explored the potential of the application area of eye-tracking technology, and (4) established the framework to develop the advanced inspection method in two application area which are construction site safety management and infrastructure performance measurement.

• 대한지구과학교육학회지
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• 제16권2호
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• pp.261-275
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• 2023

이 연구의 목적은 탄소중립에 대한 중등 과학 예비 교사의 개념 이해의 수준을 분석하고, 시각화 자료에 나타나는 시선 패턴을 파악하는 것이다. 이 연구의 대상은 중등 과학 예비교사 20명이며, 연구참여자들의 탄소중립에 대한 개념 이해 수준을 구분하고 이에 따른 시선운동의 차이를 분석하였다. 연구 결과는 다음과 같다. 첫째, '2050 탄소중립' 개념을 적용하여 2100년까지의 탄소 배출량과 제거량을 예측하는 모델링 활동을 수행한 결과 연구참여자의 50%가 탄소 배출량이 계속 증가할 것이라는 패턴 매칭을 생각하는 오개념을 갖고 있었다. 또한 연구참여자의 25%는 순 이산화탄소의 배출량과 누적 농도의 인과 관계를 제대로 이해하지 못했다. 둘째, 탄소중립 관련 시각자료에 대한 연구참여자들의 시선운동은 글 영역에 제시된 정보에 크게 영향을 받으며, 그래프의 경우 주로 데이터 영역에 관심이 집중되었다. 그리고 시각적 데이터를 동일한 기능과 범주에 배열했을 때 연구 참가자들은 개념을 설명하는 자료나 왼쪽에 배치된 시각적 데이터에 가장 많은 관심을 보였다. 이는 특정 위치나 순서에 선호가 있음을 의미한다. 개념 이해도가 낮고 요소 간의 인과관계를 제대로 파악하지 못한 연구참여자들은 집중력과 전반적인 시선흐름이 크게 떨어지는 것으로 나타났다. 이러한 결과는 자연재해 및 기후변화를 포함한 탄소중립의 개념적 이해가 시각화 자료에 대한 관심과 참여에 영향이 있음을 나타낸다.