• Nuclear Engineering and Technology
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• v.50 no.1
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• pp.182-189
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• 2018

A neutron generation system was developed to induce fissile fission in a lead slowing down spectrometer (LSDS) system. The source neutron is one of the key factors for LSDS system work. The LSDS was developed to quantify the isotopic contents of fissile materials in spent nuclear fuel and recycled fuel. The source neutron is produced at a multilayered target by the (e,${\gamma}$)(${\gamma}$,n) reaction and slowed down at the lead medium. Activation analysis of the target materials is necessary to estimate the lifetime, durability, and safety of the target system. The CINDER90 code was used for the activation analysis, and it can involve three-dimensional geometry, position dependent neutron flux, and multigroup cross-section libraries. Several sensitivity calculations for a metal target with different geometries, materials, and coolants were done to achieve a high neutron generation rate and a low activation characteristic. Based on the results of the activation analysis, tantalum was chosen as a target material due to its better activation characteristics, and helium gas was suggested as a coolant. In addition, activation in a lead medium was performed. After a distance of 55 cm from the lead surface to the neutron incidence, the neutron intensity dramatically decreased; this result indicates very low activation.

• Korean Journal of Child Studies
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• v.28 no.4
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• pp.113-126
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• 2007

This study explored mediating effects of the maternal emotional expressiveness between maternal behavioral inhibition/behavioral activation system and children's emotional intelligence. subjects were 138 4- to 5-year-old preschoolers (92 boys, 46 girls) and their mothers. The maternal behavioral inhibition/behavioral activation system was measured by BIS/BAS(Behavioral Inhibition System/Behavioral Activation System, Carver & White, 1994), maternal emotional expressiveness was measured by the Self-Expressiveness in the Family Questionnaire (Halberstadt, 1995), and children's emotional intelligence was measured by the Emotional Intelligence Questionnaire (Lee, 1998). Data were analyzed by descriptive statistics and multiple regression analysis. Results were that maternal positive expressiveness mediated the effects of maternal BIS on children's self-understanding and maternal negative expressiveness mediated the effects of maternal BAS on children's self-regulation.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.3
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• pp.361-368
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• 2011

Purpose : The aims of this study was to identify the activation of the mirror neuron system during action observation in people with stroke and the difference between left hemisphere and right hemisphere and to provide possibility of the use of action observation as a clinical method for improving motor function after stroke. Methods : Seventeen participants were asked to observe 3 different stimulation conditions for 80 seconds. A 30 second rest period was given between stimulations. Electroencephalogram(EEG) signals from electrodes on the participant's scalp were recorded during action observation. The activation of the mirror neuron system(MNS) between the picture observation condition and action observation condition was compared with a paired t-test. An independent t-test was used to compare difference between C3 and C4 on the activation of the mirror neuron system in the action observation condition. Results : Result of paired t-test showed a significantly decreased log ratio in the activation of the mirror neuron system in the action observation condition compared to the picture observation condition. Result of the independent t-test indicated no significant differences in the activation of the mirror neuron system in the right and left hemisphere. Conclusion : The mirror neuron system showed greater activation in the action observation condition than in the picture observation condition and activation in the both hemisphere during action observation. We conclude that these findings suggest that this may possibly be an efficient clinical intervention method for improving motor function.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.10
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• pp.955-961
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• 2006

The global ultrasonic system for the self-localization of a mobile robot consists of several ultrasonic transmitters fixed at some reference positions in the global coordinates of robot environment. By activating the ultrasonic transmitters, the mobile robot is able to get the distance to the ultrasonic transmitters and compute its own position in the global coordinate. Due to the limitation on the ultrasonic signal strength and beam width as well as the environmental obstacles however, the ultrasonic signals from some generator may not be transmitted to the robot. Thus, instead of activating the all ultrasonic transmitters, it is necessary to select some ultrasonic generators to activate based on the current robot position. In this paper, we propose a selective activation algorithm for self-localization with the global ultrasonic system. The selective activation algorithm gets the meaningful ultrasonic data at every sampling instants, which results in the faster and more accurate response of the self-localization than the conventional sequential activation. Through the self-localization and path following control, we verify the effectiveness of the proposed selective activation algorithm.

• Journal of the Korea Society for Simulation
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• v.13 no.4
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• pp.1-16
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• 2004

The modelling and simulation of the activation process for the heart system is meaningful to understand special excitatory and conductive system in the heart and to study cardiac functions because the heart activation conducts through this system. This thesis proposes two dimensional cellular automaton(CA) model for the activation process of the myocardium and conducted simulation by means of discrete time and discrete event algorithm. In the model, cells are classified into anatomically similar characteristic parts of the heart and each of cells has a set of cells with preassigned properties. Each cell in this model has state variables to represent the state of the cell and has some state transition rules to change values of state variables executed by state transition function. The state transition rule is simple as follows. First, the myocardium cell at rest stay in passive state. Second, if any one of neighborhood cell in the myocardium cell is active state then the state is change from passive to active state. Third, if cell's state is an active then automatically go to the refractory state after activation phase. Four, if cell's state is refractory then automatically go to the passive state after refractory phase. These state transition is processed repeatedly in all cells through the termination of simulation.

• PNF and Movement
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• v.9 no.4
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• pp.33-40
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• 2011

Purpose : The aims of this study was to identify changes mu rhythm according to familiarity with a stimulus in people with stroke. Methods : Seventeen right-handed participants were asked to observe 2 different stimulus; a non-familiarity stimulus condition (NFSC), and a familiarity stimulus condition (FSC). Electroencephalogram (EEG) signals from electrodes on the participant's scalp were recorded during action observation. The activation of the mirror neuron system was compaired between FSC and NFSC by a paired t-test. An independent t-test was used to compare the difference between right and left hemispheres for the activation of the mirror neuron system during action observation of performing a task with the right hand. Results : The result of paired t-test showed no significantly difference between NFSC and FSC in the activation of the mirror neuron system. The Result of independent t-test also showed no significantly difference in the activation of mirror neuron system between the right and left hemispheres. Conclusion : The familiarity with a stimulus had no signigicant effect on the activation of the mirror neuron system according to the familiarity and in either the right or left hemispheres in people with chronic stroke.

• BMB Reports
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• v.49 no.10
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• pp.529-535
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• 2016

The NLRP3 inflammasome is activated by a variety of external or host-derived stimuli and its activation initiates an inflammatory response through caspase-1 activation, resulting in inflammatory cytokine IL-1β maturation and secretion. The NLRP3 inflammasome activation is a kind of innate immune response, most likely mediated by myeloid cells acting as a host defense mechanism. However, if this activation is not properly regulated, excessive inflammation induced by overactivated NLRP3 inflammasome can be detrimental to the host, causing tissue damage and organ dysfunction, eventually causing several diseases. Previous studies have suggested that mitochondrial damage may be a cause of NLRP3 inflammasome activation and autophagy, which is a conserved self-degradation process that negatively regulates NLRP3 inflammasome activation. Recently, mitochondria-selective autophagy, termed mitophagy, has emerged as a central player for maintaining mitochondrial homeostasis through the elimination of damaged mitochondria, leading to the prevention of hyperinflammation triggered by NLRP3 inflammasome activation. In this review, we will first focus on the molecular mechanisms of NLRP3 inflammasome activation and NLRP3 inflammasome-related diseases. We will then discuss autophagy, especially mitophagy, as a negative regulator of NLPP3 inflammasome activation by examining recent advances in research.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.450-452
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• 2004

Every movement, perception and thought we perform is associated with distinct neural activation patterns. Neurons in the brain communicate with each other by sending electrical impulses that produce currents. These currents give rise to electrical fields that can be measured outside the head. It shows some variation on the electroencephalographic signals. In recent devices, the EEG signals measured from head surface are a sum of all the momentary brain activation. With these EEG signals, it is difficult to distinguish the patterns correlated with a certain event from the signals. However, the system must discriminate some patterns with some events especially for any kind of device as a brain control interface system. In this experiment, the sensory-motor cortex of humans has been extensively studied. Activation related to several movements on both sides of the sensory-motor cortices in imaginary. The activation patterns during imagination of several movements resemble the activation patterns during preparation of movements. The result represents the system based on the optimal filters discriminated at least 60% of mental imageries.

• Proceedings of the Safety Management and Science Conference
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• 2006.11a
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• pp.367-372
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• 2006

Since 1990's, many enterprises have constructed Integration Information System. Especially, they want to become an advanced company use ERP package. Already, ERP system come to high level which is stabilized and support independent business process of many industry sectors. Therefore, important success factors for ERP project are change management and organization activation. Although most companies had previous good plans, but those are not satisfied. Because of failed to change management and discontinued next activity for promotion. This paper studied success factors of project team and plan for organization activation. Also, it proposed next study subject about investigate the role of the member of task force team as a factor that makes the ERP system a success. The results of this study can be used for a successful construction of the ERP system as a solution about internal problems of Project team.

• Journal of the Korea Safety Management & Science
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• v.8 no.5
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• pp.231-242
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• 2006

Since 1990's, many enterprises have constructed Integration Information System. Especially, they want to become an advanced company use ERP package. Already, ERP system come to high level which is stabilized and support independent business process of many industry sectors. Therefore, important success factors for ERP project are change management and organization activation. Although most companies had previous good plans, but those are not satisfied. Because of failed to change management and discontinued next activity for promotion. This paper studied success factors of project team and plan for organization activation. Also, it proposed next study subject about investigate the role of the member of task force team as a factor that makes the ERP system a success. The results of this study can be used for a successful construction of the ERP system as a solution about Internal problems of Project team.