• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.115-115
• /
• 2000

A gait pattern classification method using electromyography(EMG) signal is presented. The gait pattern with four stages such as stance, heel-off, swing and heel-strike is analyzed and classified using feature parameters such as zero-crossing, integral absolute value and variance of the EMG signal. The EMG signal from Tibialis Anterior and Gastrocnemius muscles was obtained using the surface electrodes, and low-pass filtered at 10kHz. The filtered analog signal was sampled at every 0.5msec and converted to digital signal with 12-bit resolution. The obtained data is analyzed and classified in terms of feature parameters. Analysis results are given to show that the gait patterns classified by the proposed method are feasible.

• Journal of Biomedical Engineering Research
• /
• v.11 no.1
• /
• pp.163-170
• /
• 1990

In this paper, fast Fourier transform and fast Walsh transform algorithm are studied for ECG data compression. ECG data-12 bit samples digitized at 480 samples-are segmented into QRS complexes and 50 intervals by di%ital derivative filter, which used for detection of QS width and difrerenre compressed in Fourler or welsh domain. And also the existing techniques for data compression-TP, MTP, CORTES, AZTEC, MCORTES, which have not been evaluated with a common measurement of goodness, were processed to get absolute terms of values in the same condition.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.54 no.4
• /
• pp.251-258
• /
• 2005

Automatic document classification may differ significantly according to the characteristics of documents that are subject to classification, as well as classifier's performance. This research identifies e-mail document's characteristics to apply a three-step preprocessing algorithm that can minimize e-mail document's atypical characteristics. In the first 5go, uncertain based sampling algorithm that used Mean Absolute Deviation(MAD), is used to address the question of selection learning document for the rule generation at the time of classification. In the subsequent stage, Weighted vlaue assigning method by attribute is applied to increase the discriminating capability of the terms that appear on the title on the e-mail document characteristic level. in the third and last stage, accuracy level during classification by each category is increased by using Naive Bayesian Presumptive Algorithm's Dynamic Threshold. And, we implemented an E-Mail Recommendtion System using a three-step preprocessing algorithm the enable users for direct and optimal classification with the recommendation of the applicable category when a mail arrives.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.14 no.7
• /
• pp.607-616
• /
• 2002

This study has been conducted to evaluate the applicability of the control method in the dehumidification-integrated radiant floor cooling system in terms of stability of the room air temperature and the control variables through experiments. To do this, the relationship between the control variables in preventing floor surface condensation is first analyzed and the control method is predetermined through simulations. The results are as follows. First, it is necessary to determine the operation status of the dehumidification system according to the relationship between floor surface temperature and dew point temperature in the conditioned space. Second, outdoor reset with indoor temperature feedback control is better than on/off bang-bang control with respect to temperature stability in controlling the room air temperature and the possibility of energy savings. Finally, the humidity sensor can be located with the current thermostat in that there are small differences in absolute humidity in vertical distribution.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.52 no.8
• /
• pp.500-505
• /
• 2003

In this paper, the method to register multiple sets of skull CT images to absolute coordinate system is proposed. Contrary to correspondence paired mapping of previous techniques, four anatomical landmark points, three coplanar points and one non-coplanar point, compose three principal axes simple and unique for efficient registration by means of rigid body transformation. Throughout the numerical simulation with added random noises, the error performances in terms of different rotation and rounding-off of landmark points, and incorrect localization of anatomical landmark and target points are quantitatively analyzed to generalize the proposed technique. Experiments using real skull CT images demonstrate the feasibility for an efficient use in clinical practice.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.9B
• /
• pp.1596-1603
• /
• 2000

In this paper an image coding scheme using the correlation of neighboring VQ indices in wavelet domain is proposed. The codewords in each sub-codebook are reordered in ascending order according to their energy in order to inmcrease the dependency of the indices. And the relative dresses of the reordered indices are transmitted to a receiver instead of to absolute addresses. LBG algorithm is used for obtaining a multiresolution codebool and PNN using k-d tress used for generating its initial values. Our experimental results show that the proposed coding scheme outperforms JPEG and an ordinary wavelet-VQ method at low-bit rates in terms of PSNR.

• The Korean Journal of Applied Statistics
• /
• v.6 no.2
• /
• pp.247-252
• /
• 1993

Consider minimizing the sum of absolute deviations for multiple regression models. If a regression line is assumed to pass a given point, then we can find that the $L_1$ regression coefficient can be defined in terms of the weighted medians of the slopes from each data point to the given point. Therefore, $L_1$ method could be regarded to find the optimal point which regression line passes over.

• Bulletin of the Korean Chemical Society
• /
• v.4 no.3
• /
• pp.128-132
• /
• 1983

The self-diffusion experiment of water was performed across two series of tactic poly(2-hydroxyethyl methacrylate), P(HEMA) membranes prepared by crosslinking with various amount of hexamethylene diisocyanate (HMDIC). The tagging material was tritium hydroxide (THO) and the efflux of THO was counted on a Liquid Scintillation Counter. The transport data of THO show that the permeability decreases as the amount of HMDIC increased from 2.5 to 10 mole % and the self-diffusions coefficient shows a parallel trend with it. The diffusivity data was discussed in terms of the change of water structural orderliness within membranes. Using the relation between viscosities and diffusivities derived from Eyring's absolute rate theory, the corresponding viscosities of water within two series of tactic P(HEMA) membranes were obtained. From this, it is seen that the viscosity of water within tactic P(HEMA) membranes may have the same values with those of supercooling water whose temperature ranges from -28 to -$36^{\circ}C.$.

• Computers and Concrete
• /
• v.24 no.1
• /
• pp.7-17
• /
• 2019

The complex phenomenon of the bond formation in geopolymer is not well understood and therefore, difficult to model. This paper present applied statistical models for evaluating the compressive strength of geopolymer. The applied statistical models studied are divided into three different categories - linear regression [least absolute shrinkage and selection operator (LASSO) and elastic net], tree regression [decision and bagging tree] and kernel methods (support vector regression (SVR), kernel ridge regression (KRR), Gaussian process regression (GPR), relevance vector machine (RVM)]. The performance of the methods is compared in terms of error indices, computational effort, convergence and residuals. Based on the present study, kernel based methods (GPR and KRR) are recommended for evaluating compressive strength of Geopolymer concrete.

• Nuclear Engineering and Technology
• /
• v.51 no.1
• /
• pp.95-103
• /
• 2019

Vapor explosions can be classified in terms of modes of contact between the hot molten fuel and the coolant, since different contact modes may affect fuel-coolant mixing and subsequent vapor explosion energetics. It is generally accepted that most vapor explosion phenomena fall into three different modes of contact; fuel pouring into coolant, coolant injection into fuel and stratified fuel-coolant layers. In this study, we review previous stratified steam explosion experiments as well as recent experiments performed at the KTH in Sweden. While experiments with prototypic reactor materials are minimal, we do note that generally the energetics is limited for the stratified mode of contact. When the fuel mass involved in a steam explosion in a stratified geometry is compared to a pool geometry based on geometrical aspects, one can conclude that there is a very limited set of conditions (when melt jet diameter is small) under which a steam explosion is more energetic in a stratified geometry. However, under these limited conditions the absolute energetic explosion output would still be small because the total fuel mass involved would be limited.