• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.245-250
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• 2019

Milli-scale crawling robots have been widely studied due to their maneuverability in confined spaces. For successful crawling, the crawling robots basically required to fulfill alternating gait with elliptical foot trajectory. The alternating gait with elliptical foot trajectory normally generates both forward and upward motion. The upward motion makes the aerial phase and during the aerial phase, the forward motion enables the crawling robots to proceed. This simultaneous forward and upward motion finally results in fast crawling speed. In this paper, we propose a novel alternating mechanism to make a crab-inspired eight-legged crawling robot. The key design strategy is an alternating mechanism based on double four-bar linkages. Crab-like robots normally employs gear-chain drive to make the opposite phase between neighboring legs. To use the gear-chain drive to this milli-scale robot system, however, is not easy because of heavy weight and mechanism complexity. To solve the issue, the double-four bar linkages has been invented to generate the oaring motion for transmitting the equal motion in the opposite phase. Thanks to the proposed mechanism, the robot crawls just like the real crab with the crawling speed of 0.57 m/s.

• Korean Journal of Artificial Intelligence
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• v.11 no.4
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• pp.15-20
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• 2023

Machine learning is comprised of supervised learning, unsupervised learning and reinforcement learning as the type of data and processing mechanism. In this paper, as input and output are unclear and it is difficult to apply the concrete modeling mathematically, reinforcement learning method are applied for crawling robot in this paper. Especially, Q-Learning is the most effective learning technique in model free reinforcement learning. This paper presents a method to implement a crawling robot that is operated by finding the most optimal crawling method through trial and error in a dynamic environment using a Q-learning algorithm. The goal is to perform reinforcement learning to find the optimal two motor angle for the best performance, and finally to maintain the most mature and stable motion about EV3 Crawling robot. In this paper, for the production of the crawling robot, it was produced using Lego Mindstorms with two motors, an ultrasonic sensor, a brick and switches, and EV3 Classroom SW are used for this implementation. By repeating 3 times learning, total 60 data are acquired, and two motor angles vs. crawling distance graph are plotted for the more understanding. Applying the Q-learning reinforcement learning algorithm, it was confirmed that the crawling robot found the optimal motor angle and operated with trained learning, and learn to know the direction for the future research.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.453-463
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• 2015

Objective : The purpose of this study was to investigate the effects of the Probody Massage Program on the physical characteristics, gross motor function and ROM (Range Of Motion) of children with cerebral palsy. Method : The subjects of this study were two children who have been diagnosed with first grade cerebral palsy that utilized T development support center located in B Metropolitan city for 8 weeks, twice a week, to carry out the Probody Massage Program for 30 minutes. Physiological reactions (height, weight, BMI, blood pressure (an index of inflammation), pulse rate) and large operating functions (sitting, crawling and the joints' range of motion as an angle of the shoulders' upper limb articulation) were measured pretest, after 4 weeks, and after 8 weeks. Results : The Probody Massage Program showed positive changes in physical characteristics (blood pressure, sitting, and crawling), gross motor function (upper limb shoulder movement), joint range of motion, height, body weight, metabolic activation and blood circulation of children with cerebral palsy. Conclusion : We believe making a practical impact on the growth and development, functional recovery of daily life, and improvement of quality of life of children with cerebral palsy by utilizing Probody Massage Program improves blood pressure (an index of inflammation), pulse, sitting, crawling, and the joints' range of motion as an angle of the shoulder joints' upper limb movement of children with cerebral palsy.

• Journal of the Korean Society of Visualization
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• v.12 no.2
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• pp.18-22
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• 2014

Caenorhabditis elegans (C. elegans) is an undulatory nematode which exhibits two distinct locomotion types of swimming and crawling. Although in its natural habitat C. elegans lives in a non-Newtonian fluidic environment, our current understanding has been limited to the behavior of C. elegans in a simple Newtonian fluid. Here, we present some experimental results on the penetrating behavior of C. elegans at the interface from liquid to solid environment. Once C. elegans, which otherwise swims freely in a liquid, makes a contact to the solid gel boundary, it begins to penetrate vertically to the surface by changing its stroke motion characterized by a stiffer body shape and a slow stroke frequency. The particle image velocimetry (PIV) analysis reveals the flow streamlines produced by the stroke of worm. For the worm that crawls on a solid surface, we utilize a technique of traction force microscopy (TFM) to find that the crawling nematode forms localized force islands along the body where makes direct contacts to the gel surface.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.2
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• pp.125-130
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• 2012

The nematode Caenorhabditis elegans is a widely used model organism in biological research. Thanks to the availability of well-established knowledge about its neural connectivity, a wide range of studies have been attempted to uncover the relationship between behaviors and the responsible neurons. In our research, the adaptive behavior of C. elegans in solid environments with different surface rigidities is investigated, where the worm adapts to different mechanical stiffnesses by modulating its crawling waveform. The amplitude and wavelength of the crawling waveform decrease as the environment becomes more rigid. Interestingly, the mechanosensation-defective mutant shows different responses to the surface rigidity compared to those of the wild-type worm. To explain the adaptation process in mechanically different environments, we suggest a plausible neural circuit model.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.463-464
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• 2019

본 논문은 기계학습을 기반으로 아두이노와 시리얼통신을 통한 사용자의 동작인식을 이용해 보다 간단하게 인터넷상의 원하는 동영상을 찾을 수 있는 검색시스템을 제작하고자 하였다. 이 검색시스템은 Python을 기반으로 SVM(Support Vector Machine)을 이용한 패턴 분류를 사용하였으며 이를 통해 사용자의 동작을 입력받아 문자를 예측 할 수 있다. 사용자는 이 검색시스템을 사용하기 위하여 우선 문자에 대한 사용자의 동작입력을 통해 학습 데이터 셋을 만들어야 하며 그것을 SVM을 이용하여 학습 모델과 식별자를 만들고, 만들어진 분류기를 통하여 동작인식을 바탕으로 문자의 결과를 예측 할 수 있다. 최종적으로 사용자의 동작인식을 거쳐 만들어진 문자열을 이용해 인터넷 동영상 사이트인 Youtube를 통해 웹 크롤링하여 문자열과 관련 있는 동영상을 찾아준다.

• Journal of Animal Science and Technology
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• v.55 no.6
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• pp.559-565
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• 2013

This study examined the effect of therapeutic horseback riding in children with spastic cerebral palsy. Participants were placed in a therapeutic riding (TR) group (n=7) or physical therapy (PT) group (n=7). This study was then conducted for 30 minutes, twice a week, for 8 weeks. The gross motor function measure (GMFM), range of motion (ROM), and spasticity test (ST) were analyzed pre-test (TR0 and PT0), mid-test (TR1 and PT1), and post-test (TR2 and PT2). We used the SPSS 12.0 statistical software for data analysis. We observed significant changes in GMFM Dimension C (crawling and kneeling), D (standing), and E (walking, running, and jumping) between TR2 and TR0 (P < 0.05). In the control group, GMFM Dimension B (sitting) and E showed significant changes between PT2 compared to PT0 (P < 0.05). In future studies we will consider using a therapeutic riding program for the treatment of children with disorders.

• Journal of Broadcast Engineering
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• v.1 no.1
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• pp.44-54
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• 1996

In this paper, we propose a new 3-D deinterlacing algorithm based on wide sparse vector correlations and a vertical edge based motion detection algorithm. which is an extension of the deinterlacing algorithm proposed in [10. llJ by the authors. The prooised algorithm is developed mainly for the format conversion problem encountered in current HDTV system, but can also be aplicable to the double scan conversion problesm frequently encountered in ths NTSC systems. By exploiting the edge oriented spatial interpolation based on the wide vector correlations, visually annoying artifiacts caused by interlacing such as a serrate line. line crawling, a line flicker, and a large area flicker can be remarkably reduced since the use of the wide vectors increases the range of the edge orientations that can be detected, and by exploiting sparse vectors correlations the HjW complexity for realizing the algorithm in applications cam be significantly simplified. Simulations are provided indicating thet the proposed algorithm results in a high performance comparable to the performance of the deinterlacing algorithm. based on the wide vector correlations.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.149-154
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• 2002

A simplified 3D dynamic model of tracked vehicle crawling on cohesive soft soil is investigated. The vehicle is assumed as rigid body with 6-dof. Cohesive soft soil is modeled through relations: pressure to sinkage, shear displacement to shear stress, and shear to dynamic sinkage. Equations of motion of vehicle are derived with respect to the body-fixed coordinates. In order to investigate 3D transient dynamics of tracked vehicle, Newmark's method is employed based on incremental-iterative algorithm. 3D dynamic simulations are conducted for a tracked vehicle model and steering performance is investigated.