• Journal of Integrative Natural Science
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• 제11권4호
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• pp.167-183
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• 2018

Electroencephalogram (EEG) recording provides a new way to support human-machine communication. It gives us an opportunity to analyze the neuro-dynamics of human cognition. Machine learning is a powerful for the EEG classification. In addition, machine learning can compensate for high variability of EEG when analyzing data in real time. However, the optimal EEG electrode location must be prioritized in order to extract the most relevant features from brain wave data. In this paper, we propose an intelligent system model for the extraction of EEG data by training the optimal electrode location of EEG in a specific problem. The proposed system is basically a fuzzy system and uses a neural network structurally. The fuzzy clustering method is used to determine the optimal number of fuzzy rules using the features extracted from the EEG data. The parameters and weight values found in the process of determining the number of rules determined here must be tuned for optimization in the learning process. Genetic algorithms are used to obtain optimized parameters. We present useful results by using optimal rule numbers and non - symmetric membership function using EEG data for four movements with the right arm through various experiments.

• Journal of the Institute of Convergence Signal Processing
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• 제4권2호
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• pp.18-24
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• 2003

One of the most important subjects in the implementation of real time speech recognizer is to design both reliable VAD(Voice Activity Detection) and suitable speech feature vector. But, because it is difficult to calculate reliable VAD in the environment having surrounding noise, designed suitable speech feature vector may not be obtained. Solving this problem, in this paper, we implement not only short time power spectrum which is generally used but also two additive parameters, the comparison measure of spectrum density having robust property in noise and linear discriminant function using linear regression, then perform VAD by using the combination of each parameter having apt weight in other magnitudes of surrounding noise and confirm that proposed parameters show a robust characteristic in circumstances having surrounding noise by using DTW(Dynamic Time Waning) in recognition experiment.

• Journal of the Computational Structural Engineering Institute of Korea
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• 제13권4호
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• pp.417-425
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• 2000

This paper describes the application of discretized continuum-type optimality criteria(DCOC) and the development of optimum design program for the reinforced concrete continuous beams with rectangular cross-section. The cost of construction as objective function which includes the costs of concrete, reinforcing steel and formwork is minimized. The design constraints include limits on the maximum deflection, flexural and shear strengths, in addition to ductility requirements, and upper and lower bounds on design variables as stipulated by the design Code. Based on Kuhn-Tucker necessary conditions, the optimality criteria are explicitly derived in terms of the design variables-effective depth, and steel ratio. The self-weight of the beam is included in the equilibrium equation of the real system. An iterative procedure and computer program for updating the design variables are developed. Two numerical examples of reinforced concrete continuous beams are presented to show the applicability and efficiency of the DCOC-based technique.

• Membrane Journal
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• 제14권4호
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• pp.298-303
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• 2004

PTMSP/PDMS-PEI composite membrane was prepared by solution casting method. To investigate the characteristics of this membrane, the analytical methods such as FT-IR, $^1$H-NMR, DSC, TGA, GPC, and SEM have been utilized. The number-average((equation omitted)) and weight-average((equation omitted)) molecular weight of PTMSP/PDMS copolymer were 501,516 and 675,560 respectively. The separation of the gas mixture($H_2$/$N_2$) through the composite membrane was studied as a function of pressure. The separation factor($\alpha$, $\beta$, (equation omitted)) of the composite membrane used in this work increased as the pressure of permeation cell increased. The real separation factor($\alpha$), head separation factor($\beta$), and tail separation factor ((equation omitted)) of PTMSP/PDMS-PEI composite membrane were 21.50, 49.14 and 1.84 respectively at $\Delta$P 345.55 kPa and $25^{\circ}C$.

• Journal of the Korean GEO-environmental Society
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• 제11권4호
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• pp.19-24
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• 2010

Generally, slope behavior is analyzed by 2-dimensional creep model. Creep behavior shows the deformation variation as time goes by without stress increment. Convention 2-dimensional creep analysis does not have the term of stress variation, it means creep analysis could not figure out the relationship of shear strength variation according to the stress variation and displacement. The slope weight and shear strength is directly related and interlocked to the safety variation and displacement of slope, therefore, this phenomenon could be treated and analyzed as combining the hysteresis and creep, the iteration of this process will result in the slope safety. Furthermore, the combined analysis will be the slope analysis considering shear stress, displacement and shear strength with time variation. In real case, because the variation of shear stress and strength happen at the same time, they should be changed into safety factor which is function of them. This paper shows the 3-dimensional variation of unit weight of soil with hybrid analysis considering creep and hysteresis on the seepage and drainage of rainfall, futhermore variations of shear stress and strength which make the safety factor change.

• Membrane Journal
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• 제13권4호
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• pp.291-299
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• 2003

Polymer membranes such as poly(1-trimethylsilyl-1-propyne)-polyetherimide (PTMSP-PEI) and poly(dimethylsiloxane)- polyetherimide (PDMS-PEI) composite membrane were prepared by solution casting method. To investigate the characteristics of these membranes, the analytical methods such as FT-IR, $^1H-NMR,$ DSC, TGA, GPC, and SEM have been utilized. The number-average (equation omitted) and weight-average (equation omitted) molecular weight of PTMSP were 477,920 and 673,329 respectively. The glass transition temperature ($T_g$) of PTMSP was $224^{\circ}C.$ The separation of the gas mixture ($H_2/N_2$) through the composite membranes were studied as a function of pressure. The separation factor (${\alpha}, {\beta},$ quation omitted) of the composite membranes used in this work increased as the pressure of permeation cell increased. The real separation factor (${\alpha}$), head separation factor (${\beta}$), and tail separation factor (equation omitted) of PTMSP-PEI composite membrane were 2.28, 1.17, and 1.96 respectively at ${\Delta}P$ 30psi and $25^{\circ}C.$ (${\alpha}, {\beta}$ and equation omitted of PDMS-PEI composite membrane were 3.70, 1.53, and 2.42 respectively at ${\Delta}P$ 30psi and $25^{\circ}C$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2008년도 지능정보 및 응용 학술대회
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• pp.73-76
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• 2008

We present a area-based method for stereo matching using varying weights. A central problem in a area-based stereo matching is different result from selecting a window size. Most of the previous window-based methods iteratively update windows. However, the iterative methods very sensitive the initial disparity estimation and are computationally expensive. To resolve this problem, we proposed a new function to assign weights to pixels using features. To begin with, we extract features in a given stereo images based on edge. We adjust the weights of the pixels in a given window based on correlation of the stereo images. Then, we match pixels in a given window between the reference and target images of a stereo pair. The proposed method is compared to existing matching strategies using both synthetic and real images. The experimental results show the improved accuracy of the proposed method.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제52권1호
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• pp.81-86
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• 2019

The common hallmark of several neurodegenerative disorders, including Alzheimer's disease (AD), is the presence of chronic neuroinflammation, which contributes to the loss of neuronal structure and function. This study investigated the effects of an ethanolic extract of Sargassum serratifolium (SSE) in a lipopolysaccharides (LPS)-induced murine neuroinflammation model. Mice were administered SSE (100 mg/kg body weight) or vehicle for 5 days by oral gavage, and then treated with LPS or saline by intraperitoneal injection. Thereafter, the brain tissues were collected, and the expression of pro-inflammatory cytokines was analyzed by quantitative real-time RT-PCR. There was a marked increase in the spleen weight index in the LPS-treated groups, which indicated the induction of acute systemic inflammation. Based on significant increases in the levels of IL-1 and IL-6 expression, the induction of neuroinflammation was also evident in the cortex and hippocampus of the LPS-treated groups. The overall expression of IL-1 and IL-6 was decreased slightly by SSE administration, compared with the LPS group, and a marked change in IL-1 was observed in the cortex of the SSE-treated (SSE/LPS) group. These results suggest that SSE has potential as an anti-neuroinflammatory nutraceutical.

• Korean Journal of Optics and Photonics
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• 제14권4호
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• pp.443-448
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• 2003

A study on optimum design of the lightweight mirror of a satellite camera is presented. An optical surface deformation of the lightweight mirror, which is a principal component of the camera system, is an important factor affecting the optical performance of the whole camera system. In this study, optimum design of the lightweight mirror is presented. Total weight of the mirror to reduce the optical surface deformation and the launching cost is used as an objective function. Peak-to-valley value and natural frequency of the mirror are given as constraints to the optimization problem. The sensitivities of the objective function and constraint are calculated by a finite difference method. The optimization procedure is carried out by the commercial optimizer, DOT. As a verification of the optimum design of the mirror, two design examples are treated. In the real application example, the lightweight mirror with 600mm effective diameter is treated. The optimized results with various design variables, which are obtained by considering thickness limitations, are analyzed.

• Journal of KIISE
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• 제42권2호
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• pp.190-202
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• 2015

Much research has been conducted on location-based intelligent personal assistants that can understand a user's intention by learning the user's route model and then inferring the user's destinations and routes using data of GPS and other sensors in a smartphone. The intelligence of the location-based personal assistant is contingent on the accuracy and efficiency of the real-time predictions of the user's intended destinations and routes by processing movement information based on uncertain sensor data. We propose a robust particle filter based on Dynamic Bayesian Network model to infer the user's routes. The proposed robust particle filter includes a particle generator to supplement the incorrect and incomplete sensor information, an efficient switching function and an weight function to reduce the computation complexity as well as a resampler to enhance the accuracy of the particles. The proposed method improves the accuracy and efficiency of determining a user's routes and destinations.