• Science of Emotion and Sensibility
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• v.20 no.1
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• pp.41-48
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• 2017

This study was conducted to develop wearable products with visual and auditory feedback aimed at promoting exercise interest in children. Here we determined the theoretical characteristics of cognitive and motor function development during childhood, empirical characteristics of children's motor functions, and factors that encourage exercise using natural observation and in-depth interview research methods. The questionnaire assessed children's motor ability, intensively trained body parts in sports programs, types of training or classes that improve the motor ability of each muscle group, significantly considered aspects of children's sports programs, and factors that promote children's interest in exercise. Our results suggest that the development of sport programs comprising varied exercise options that enhance body and limb movements are needed for balanced growth. Furthermore, it is very important to provide motivation for regular exercise and appropriate feedback, such as praise and encouragement, to maintain interest in exercise. This study identifies the standards for developing products that peak children's interest in exercise and the basis for a physically and mentally healthy society.

• Journal of information and communication convergence engineering
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• v.8 no.4
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• pp.349-354
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• 2010

Moving pixel displacement detection algorithm using correlation functions for making panorama image on the continuous images is presented in this paper. The input images get from a CMOS image sensor (CIS). The camera is maintained by constant brightness and uniform sensing area in test input pattern. For simple navigation and capture image has to 70% overlapped region. A correlation rate in two image data is evaluated by using reference image with first captures, and compare image with next captures. The displacement of the two images are expressed to second order function of x, y and solved with finding the coefficient in second order function. That results in the change in the peak correlation displacement from the reference to the compare image, is moving to pixel length. The navigating error is reduced by varying the path because the error is shown in the difference of the positioning vector between the true pixel position and the navigated pixel position. The algorithm performance is evaluated to be different from the error vector to vary the navigating path grid.

• Ocean Systems Engineering
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• v.2 no.3
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• pp.189-203
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• 2012

New experiments focusing on the evolution characteristics of nonlinear wave trains were conducted in a large wave flume. A series of wave trains with added sidebands, varying initial steepness, perturbed amplitudes and frequencies, were physically generated in a long wave flume. The experimental results show that the increasing wave steepness, increases the speed of sidebands growth. To study the frequency and phase modulation, the Morlet wavelet transform is adopted to extract the instantaneous frequency of wave trains and the phase functions of each wave component. From the instantaneous frequency, there are local frequency downshifts, even an effective frequency downshift was not observed. The frequency modulation increases with an increase in amplitude modulation, and abrupt changes of instantaneous frequencies occur at the peak modulation. The wrapped phase functions show that in the early stage of the modulation, the phase of the upper sideband first diverges from that of the carrier waves. However, at the later stage, the discrepancy phase from the carrier wave transformed to the lower sideband. The phase deviations appear in the front of the envelope's peaks. Furthermore, the evolution of the instantaneous frequency exhibits an approximate recurrence-type for the experiment with large imposed sidebands, even when the corresponding recurrence is not observed in the Fourier spectrum.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.478-488
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• 2014

Torque pulsation mechanism and highly nonlinear magnetic characterization of switched reluctance motors(SRM) lead to unfavorable torque ripple and limit the variety of applications in industry. In this paper, a modification method proposed for torque ripple minimization of SRM based on conventional torque sharing functions(TSF) to improve maximum speed of torque ripple-free operation considering converter limitations. Due to increasing phase inductance in outgoing phase during the commutation region, reference current tracking can be deteriorated especially when the speed increased. Moreover, phase torque production in incoming phase may not be reached to the reference value near the turn-on angle in which the incremental inductance would be dramatically decreased. Torque error for outgoing phase can cause increasing the resultant motor torque while it would be negative for incoming phase and yields reducing the motor torque. In this paper, a modification method is proposed in which phase torque tracking error for each phase under the commutation added to the other phase so that the resultant torque remained in constant level. This yields to extend constant torque region and reduce peak phase current when the speed increased. Simulation and experimental results for four phase 4 KW, 8/6 SRM validate the effectiveness of the proposed scheme.

• Smart Structures and Systems
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• v.18 no.3
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• pp.425-448
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• 2016

In this paper, a new Pigeon Colony Algorithm (PCA) based on the features of a pigeon colony flying is proposed for solving global numerical optimization problems. The algorithm mainly consists of the take-off process, flying process and homing process, in which the take-off process is employed to homogenize the initial values and look for the direction of the optimal solution; the flying process is designed to search for the local and global optimum and improve the global worst solution; and the homing process aims to avoid having the algorithm fall into a local optimum. The impact of parameters on the PCA solution quality is investigated in detail. There are low-dimensional functions, high-dimensional functions and systems of nonlinear equations that are used to test the global optimization ability of the PCA. Finally, comparative experiments between the PCA, standard genetic algorithm and particle swarm optimization were performed. The results showed that PCA has the best global convergence, smallest cycle indexes, and strongest stability when solving high-dimensional, multi-peak and complicated problems.

• Journal of Medicine and Life Science
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• v.15 no.2
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• pp.62-66
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• 2018

A-type $K^+$ ($I_A$) channels are transiently activated in the suprathreshold membrane potential and then rapidly inactivated. These channels play roles to control the neuronal excitability in pyramidal neurons in hippocampi. We here electrophysiologically tested if regulatory functions of $I_A$ channels might be targeted by acute activation of glutamatergic synaptic transmission in cultured hippocampal neurons(DIV 6~8). The application of high KCl in recording solutions(10 mM, 2 min) to increase presynaptic glutamate release, significantly reduced the peak of somatic $I_A$ without changes of gating kinetics. This indicates that neuronal excitation induced by the enhancement of synaptic transmission may process with distinctive signaling cascades to affect voltage-dependent ion channels in hippocampal neurons. Therefore, it is possible that short-lasting enhancement of synaptic transmission is functionally restricted in local synapses without effects on intracellular signaling cascades affecting a whole neuron, efficiently and rapidly enhancing synaptic functions in hippocampal network.

• Geomechanics and Engineering
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• v.34 no.4
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• pp.341-380
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• 2023

This study evaluates the seismic fragilities in fill slopes in South Korea through parametric finite element analyses that have been barely investigated thus far. We consider three slope geometries for a slope of height 10 m and three slope angles, and two soil types, namely frictional and frictionless, associated with two soil states, loose and dense for frictional soils and soft and stiff for frictionless soils. The input ground motions accounting for four site conditions in South Korea are obtained from one-dimensional site response analyses. By comparing the numerical modeling of slopes using PLAXIS^2D against the previous studies, we compiled suites of the maximum permanent slope displacement (D_max) against two ground motion parameters, namely, peak ground acceleration (PGA) and Arias Intensity (I_A). A probabilistic seismic demand model is adopted to compute the probabilities of exceeding three limit states (minor, moderate, and extensive). We propose multiple seismic fragility curves as functions of a single ground motion parameter and numerous seismic fragility surfaces as functions of two ground motion parameters. The results show that soil type, slope angle, and input ground motion influence these probabilities, and are expected to help regional authorities and engineers assess the seismic fragility of fill slopes in the road systems in South Korea.

• Journal of the Korean GEO-environmental Society
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• v.15 no.11
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• pp.67-75
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• 2014

In this study, the staged seismic performance evaluations were conducted to the 91 high speed railway tunnels in use for checking whether to comply with the recent design criteria or not. In addition, the seismic fragility functions of the tunnels were developed to allow the probabilistic risk assessment. The results of the staged seismic performance evaluations which consist of a preliminary assessment and a detailed assessment, show that the tunnels comply with the recent design criteria. With reference to the results of previous studies, a form of the proposed seismic fragility functions was set as a log-normal distribution by PGA, and the parameters of the functions were determined by using the probability of damage for the design PGA level. The seismic fragility functions were developed for each types (Cut & Cover, NATM) of tunnels. The seismic fragility functions from this study and the existing research results (FEMA, 2004) were compared to evaluate the seismic performance level of the tunnels, as a result the tunnels of this study were relatively superior to the ASSM tunnels on the seismic performance.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.1
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• pp.36-40
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• 2020

Objectives: The aim of this study was to evaluate pulmonary function in patients with mandibular fractures and to determine the pattern of pulmonary functions in these patients. Materials and Methods: This was a cross-sectional study of pulmonary functions in Nigerian non-smoking patients with isolated mandibular fractures managed at our health institution from December 2015 to June 2017. Forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), peak expiratory flow rate (PEFR), and ratio of FEV₁ to FVC (FEV₁/FVC) were measured for all participants using a portable spirometer just before treatment. The pulmonary indices were compared with the predicted reference values for Nigerians to determine the respiratory pattern. Results: Forty participants consisting of six females (15.0%) and thirty-four males (85.0%) with a female to male ratio of 1:5.7 were included in this study. The mean patient age was 34.5±13.1 years (range, 17-63 years). The mean FVC, FEV₁, FEV₁/FVC, and PEFR were 3.8±1.2 L, 3.0±1.0 L, 74.3%±13.8%, and 5.2±2.2 L/s, respectively. Comparison of data with predicted values revealed that 17 subjects (42.5%) had normal pulmonary function pattern while 23 subjects (57.5%) had features suggestive of obstructive and restrictive pulmonary function patterns. Conclusion: Isolated mandibular fractures presented with abnormal pulmonary function pattern.

• Journal of Radiation Protection and Research
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• v.21 no.4
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• pp.285-296
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• 1996

The energy spectra in the air and water of several ${\gamma}-ray$ sources such as Cr-51, Cs-137, Mn-54, Zn-65 have been investigated using the NaI(T1) scintillation detector. General response functions, which can curve fit the measured spectra, have been constructed. We have found that the constructed response functions can successfully represent the measured spectra in the water as well as in the air, It is possible, by comparing the relevant parameters of the response functions, to quantitatively characterize the changing features of the measured spectra as obtained with varying the water depth. Of the response function parameters, those which affect the shape of the full-energy Peak have most notably changed. Besides, those parameters which affect the shapes of the flat continuum, the Compton continuum and edge have also shown slight changes with varying the water depth.