• Title/Summary/Keyword: adaptive movement

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Neurogenesis in the Adult Brain (성체 뇌 조직의 신경발생)

  • Kim, Sik-Hyun;Kim, Sang-Su
    • PNF and Movement
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    • v.6 no.3
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    • pp.37-51
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    • 2008
  • Purpose : This paper focuses on the emerging concept that adult central nervous system neurogenesis can be regulated by various physical activity, enriched environment, and pathological conditions. Neurogenesis-the production of new neuron-is an ongoing process that persists in the adult brain of mammalian, including humans. Result : The adult brain was thought be limited in its regenerative function. However, this concepts changed, recent evidence of neurogenesis in certain adult brain areas such as SVZ(subventricular zone) and SGZ(subgranular zone) in hippocampus, raised possibility for improved treatment for patient with stroke. Neural plasticity has an adaptive purpose, because an ability of the brain to change in response to peripheral stimulation, physical activity, experience, and injury. Conclusions : The major function of the neurogenesis in adult brain seems to be replacing the neuron that die regularly in discrete adult brain regions. These cells are capable of functionally integrating into neighboring neural cells, and reconnecting to the correct neural networks. This review suggest that various intervention, including physical activity, voluntary movement training, skilled forelimb reaching training, and enriched environment, induced neural cell production in certain adult brain, and associated with functional recovery after stroke.

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The Design of Temporal Bone Type Implantable Microphone for Reduction of the Vibrational Noise due to Masticatory Movement (저작운동으로 인한 진동 잡음 신호의 경감을 위한 측두골 이식형 마이크로폰의 설계)

  • Woo, Seong-Tak;Jung, Eui-Sung;Lim, Hyung-Gyu;Lee, Yun-Jung;Seong, Ki-Woong;Lee, Jyung-Hyun;Cho, Jin-Ho
    • Journal of Sensor Science and Technology
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    • v.21 no.2
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    • pp.144-150
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    • 2012
  • A microphone for fully implantable hearing device was generally implanted under the skin of the temporal bone. So, the implanted microphone's characteristics can be affected by the accompanying noise due to masticatory movement. In this paper, the implantable microphone with 2-channels structure was designed for reduction of the generated noise signal by masticatory movement. And an experimental model for generation of the noise by masticatory movement was developed with considering the characteristics of human temporal bone and skin. Using the model, the speech signal by a speaker and the artificial noise by a vibrator were supplied simultaneously into the experimental model, the electrical signals were measured at the proposed microphone. The collected signals were processed using a general adaptive filter with least mean square(LMS) algorithm. To confirm performance of the proposed methods, the correlation coefficient and the signal to noise ratio(SNR) before and after the signal processing were calculated. Finally, the results were compared each other.

Hard Handover by the Adaptive Time-to-trigger Scheme based on Adaptive Hysteresis considering the Load Difference between Cells in 3GPP LTE System (3GPP LTE 시스템에서 셀 간 부하 차이를 고려하는 적응 히스테리시스 기반의 적응 타임-투-트리거 방법에 의한 하드 핸드오버)

  • Jeong, Un-Ho;Kim, Dong-Hoi
    • Journal of Broadcast Engineering
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    • v.15 no.4
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    • pp.487-497
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    • 2010
  • In this paper, we propose a hard handover scheme which adaptively decides important handover parameters such as hysteresis and time-to-trigger values considering the load difference between the target and serving cells. First of all, the hysteresis value can be automatically adjusted according to the load difference, thus it is used to decide the handover trigger time. As a result, through the adaptive hysteresis scheme, handover drop rate is improved. However, this adaptive hysteresis scheme has a problem that the ping-pong effect, which occurs due to the frequent movement of mobile stations at the cell boundary, is increased. Therefore, to solve this problem, we propose a novel adaptive time-to-trigger scheme with the time-to-trigger which is in inverse proportion to the hysteresis value already established by the adaptive hysteresis scheme which adapts to the changing load difference between the target and serving cells. The simulation results show that the proposed adaptive time-to-trigger scheme based on the adaptive hysteresis is better than existing schemes in terms of handover drop rate and ping-pong generation.

A Study on Robust Moving Target Detection for Background Environment (배경환경에 강인한 이동표적 탐지기법 연구)

  • Kang, Suk-Jong;Kim, Do-Jong;Bae, Hyeon-Deok
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.5
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    • pp.55-63
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    • 2011
  • This paper describes new moving target detection technique combining two algorithms to detect targets and reject clutters in video frame images for surveillance system: One obtains the region of moving target using phase correlation method using $N{\times}M$ sub-block images in frequency domain. The other uses adaptive threshold using learning weight for extracting target candidates in subtracted image. The block region with moving target can be obtained using the characteristics that the highest value of phase correlation depends on the movement of largest image in block. This technique can be used in camera motion environment calculating and compensating camera movement using FFT phase correlation between input video frame images. The experimental results show that the proposed algorithm accurately detects target(s) with a low false alarm rate in variety environment using the receiver operating characteristics (ROC) curve.

The Study on Applying Ankle Joint Load Variable Lower-Knee Prosthesis to Development of Terrain-Adaptive Above-Knee Prosthesis (노면 적응형 대퇴 의족개발을 위한 발목 관절 부하 가변형 하퇴 의족 적용에 대한 연구)

  • Eom, Su-Hong;Na, Sun-Jong;You, Jung-Hwun;Park, Se-Hoon;Lee, Eung-Hyuk
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.883-892
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    • 2019
  • This study is the method which is adapted to control ankle joint movement for resolving the problem of gait imbalance in intervals where gait environments are changed and slope walking, as applying terrain-adaptive technique to intelligent above-knee prosthesis. In this development of above-knee prosthesis, to classify the gait modes is essential. For distinguishing the stance phases and the swing phase depending on roads, a machine learning which combines decision tree and random forest from knee angle data and inertial sensor data, is proposed and adapted. By using this method, the ankle movement state of the prosthesis is controlled. This study verifies whether the problem is resolved through butterfly diagram.

Unsuspected Plasticity of Single Neurons after Connection of the Corticospinal Tract with Peripheral Nerves in Spinal Cord Lesions

  • Brunelli, Giorgio;Wild, Klaus von
    • Journal of Korean Neurosurgical Society
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    • v.46 no.1
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    • pp.1-4
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    • 2009
  • Objective: To report an unsuspected adaptive plasticity of single upper motor neurons and of primary motor cortex found after microsurgical connection of the spinal cord with peripheral nerve via grafts in paraplegics and focussed discussion of the reviewed literature. Methods: The research aimed at making paraplegics walk again, after 20 years of experimental surgery in animals. Amongst other things, animal experiments demonstrated the alteration of the motor endplates receptors from cholinergic to glutamatergic induced by connection with upper motor neurons. The same paradigm was successfully performed in paraplegic humans. The nerve grafts were put into the ventral-lateral spinal tract randomly, with out possibility of choosing the axons coming from different areas of the motor cortex. Results: The patient became able to selectively activate the re-innervated muscles she wanted without concurrent activities of other muscles connected with the same cortical areas. Conclusion: Authors believe that unlike in nerve or tendon transfers, where the whole cortical area corresponding to the transfer changes its function a phenomenon that we call "brain plasticity by areas". in our paradigm due to the direct connection of upper motor neurons with different peripheral nerves and muscles via nerve grafts motor learning occurs based on adaptive neuronal plasticity so that simultaneous contractions of other muscles are prevented. We propose to call it adaptive functional "plasticity by single neurons". We speculate that this phenomenon is due to the simultaneous activation of neurons spread in different cortical areas for a given specific movement, whilst the other neurons of the same areas connected with peripheral nerves of different muscles are not activated at the same time. Why different neurons of the same area fire at different times according to different voluntary demands remains to be discovered. We are committed to solve this enigma hereafter.

Control Method of Adaptive Duty-cycling for Monitoring System in Excavations (굴착현장 모니터링 시스템을 위한 적응적인 듀티사이클링 제어 기법)

  • Kim, Taesik;Min, Hong;Jung, Jinman
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.6
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    • pp.141-146
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    • 2016
  • Geotechnial engineering projects that requires excavation activity can cause massive ground deformation and this can damage adjacent structures. Depending on the engineering characteristics of ground material and the excavation depth, the ground movement is various. To overcome this issue, the ground deformation is monitored by multiple sensors. Typically, an inclinometer is installed behind the support wall. In this paper, we present an adaptive duty-cycling control mechanism using wireless sensors for monitoring ground deformation in excavations. The proposed mechanism dynamically adjusts the sleep time based on the urgency degree of sensed data from inclinometer. Through analytical evaluation of expected latency time, we confirm our adaptive duty-cycling mechanism has lower latency compared with periodic duty-cycling mechanism under variable conditions.

Adaptive Finite Element Mesh Generation Schemes for Dynamic Structural Analyses

  • Yoon, Chong-Yul
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.1
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    • pp.23-28
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    • 2010
  • Reliable dynamic analysis is essential in order to properly maintain structures so that structural hazards may be minimized. The finite element method (FEM) is proven to be an affective approximate method of structural analysis if proper element types and meshes are chosen. When the method is applied to dynamics analyzed in time domain, the meshes may need to be modified at each time step. As many meshes need to be generated, adaptive mesh generation schemes have become an important part in complex time domain dynamic finite element analyses of structures. In this paper, an adaptive mesh generation scheme for dynamic finite element analyses of structures is described. The concept of representative strain value is used for error estimates and the refinements of meshes use combinations of the h-method (node movement) and the r-method (element division). The validity of the scheme is shown through a cantilever beam example under a concentrated load with varying values. The example shows reasonable accuracy and efficient computing time. Furthermore, the study shows the potential for the scheme's effective use in complex structural dynamic problems such as those under seismic or erratic wind loads.

Received Power Optimization applying Adaptive Genetic Algorithm in Visible light communication (가시광통신에서 적응형 유전자 알고리즘을 적용한 수신전력 최적화)

  • Lee, Byung-Jin;Kim, Yong-Won;Kim, Kyung-Seok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.6
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    • pp.147-154
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    • 2013
  • To provide a method for optimizing the variation range of the received power is applied to Adaptive Genetic Algorithm in a LED communication environment. By optimizing the power distribution dynamically for mobile or fixed using a genetic algorithm, to eliminate the need for a system design that is customized to be independent of the movement pattern of the user's adaptability, and environmental properties. It is possible to improve easily the convenience of the user. The room power deviation from any location can be reduced by reducing the energy. the simulation results, the proposed method does not exist obstacles in an empty room with power deviation $10.5{\mu}W$ decreased 10 percent to reduce the deviation of the received power is shown that. In comparison with conventional methods, convergence to the optimal value is improved, the genetic algorithm proposed was confirmed to be efficient in terms of energy savings.

Motion Adaptive Temporal-Spatial Noise Reduction Scheme with Separated Pre- and Post-Spatial Filter (분리된 전처리 및 후처리 광간영역 필터를 가진 움직임 적응적 시공간영역 잡음 제거 기법)

  • Kim, Sung-Deuk;Lim, Kyoung-Won
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.5
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    • pp.40-47
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    • 2009
  • A motion adaptive video noise reduction scheme is proposed by cascading a temporal filter and a spatial filter. After a noise-robust motion detection is performed with a pre-spatial filter, the strength of the motion adaptive temporal filter is controlled by the amount of temporal movement. In order to fully utilize the temporal correlation of video signal, noisy input image is processed first by the temporal filter, therefore, image details of temporally stationary region are quite well preserved while undesired noises are suppressed. In contrast to the pre-spatial filter used for the robust motion detection, the cascaded post-spatial filter removes the remained noises by considering the strength of the temporal filter and the spatial self-similarity search results obtained from the pre-spatial filter.