• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.1
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• pp.27-34
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• 2009

Site amplification should be considered in order to estimate Soil-Structure Interaction (SSI), seismic source and attenuation parameters with a greater degree of reliability. The horizontal to vertical (H/V) ratio technique, originally proposed by Nakamura (1989), has been applied to analyze the surface waves in microtremor records. Recently, its application has been extended to the shear wave energy of strong motion in order to study the site transfer function. The purpose of this paper is to estimate the H/V spectral ratio using the observed data from 9 seismic stations distributed within the Southern Korean Peninsula, from the Odesan earthquake (2007/01/20). The results show that most of the stations have more stable amplification characteristics in a low frequency band than in a high frequency band. However, each seismic station showed its own characteristic resonant frequency and low and high frequency. The resonant frequency at each station should be estimated carefully, because the quality of seismic data is dependent on the resonant frequency. It can be obtained more reliable results of seismic source and attenuation parameters, if seismic ground motions which deconvolved from site transfer function is used. The site amplification data from this study can be used to generally classify the sites within the Southern Korean Peninsula.

• Journal of Korea Entertainment Industry Association
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• v.15 no.7
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• pp.181-192
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• 2021

This study was conducted to investigate the effects of a participatory rehabilitation program on sit-rise and rise-to-walk test performances, and perception and motor skills in adults with medically vulnerable individuals and, adults with developmental disabilities in particular. Seventeen adults with developmental disabilities participated in a participatory rehabilitation program using resistance bands and exercise balls, for 60 minutes once weekly over 13 weeks. Their performances were measured before and immediately after the intervention, and 12 weeks after. The findings were as follows. In the sit-rise test, the number of times rising from sitting posture increased after the intervention versus before, but the difference was not statistically significant. In the rise-to-walk test, the performance showed statistically significant difference over time, and the post-hoc test showed a significant effect after the intervention versus before. There was no significant difference in perception and motor skills. In sum, the participatory rehabilitation program positively influenced dynamic balancing related to functional activities but had no significant effect on perception and motor skills, which is related to motor control and motor learning. It is suggested that to increase the participation in community activities, reduce fall risk, and improve dynamic balancing abilities in adults with developmental disabilities, participatory rehabilitation programs should be utilized to promote the physical wellbeing.

• Journal of the Korea Society of Computer and Information
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• v.19 no.7
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• pp.77-85
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• 2014

Recently, several environment damage caused by malicious or suspicious code is increasing. We study comprehensive response system actively for malware detection. Suspicious code is installed on your PC without your consent, users are unaware of the damage. Also, there are need to technology for realtime processing of Big Data. We must develope advanced technology for malware detection. We must analyze the static, dynamic of executable file for fundamentally malware detection in recently and verified by a reputation for verification. It is need to judgment of similarity for realtime response with big data. In this paper, we proposed realtime detection and verification technology using multiple filter. Our malware study suggests a new direction of realtime malware detection.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.1
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• pp.1-8
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• 1999

Dynamic elastoplastic LPM (lumped parameter mass) analyses are carried out in order to investigate the seismic resistant performance of a typical high-rise shear wall apartment subjected to several earthquakes. Three-dimensional nonlinear pushover analysis is adopted to estimate initial elastic stiffness, yielding strength and post-yielding stiffness of each story for the time history analysis of LPM shear model. For the hysteresis of each story, Clough and bilinear models are used with the input of four recorded earthquake ground motions of EI Centro 1940 NS, Taft 1952 EW, Hachinohe 1968 NS and Kobe 1995 NS, of which the amplitudes are scaled down to have the same maximum ground velocity of 12 kine. The result shows that yieldings take place in most storys of the building, i.e. the earthquake resistant capacity of this high-rise shear wall apartment is not sufficient at the event of earthquake M=5~6.

• Korean Chemical Engineering Research
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• v.45 no.1
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• pp.87-92
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• 2007

Recently, developments of process monitoring system in order to detect and diagnose process abnormalities has got the spotlight in process systems engineering. Normal data obtained from processes provide available information of process characteristics to be used for modeling, monitoring, and control. Since modern chemical and environmental processes have high dimensionality, strong correlation, severe dynamics and nonlinearity, it is not easy to analyze a process through model-based approach. To overcome limitations of model-based approach, lots of system engineers and academic researchers have focused on statistical approach combined with multivariable analysis such as principal component analysis (PCA), partial least squares (PLS), and so on. Several multivariate analysis methods have been modified to apply it to a chemical process with specific characteristics such as dynamics, nonlinearity, and so on.This paper discusses about missing value estimation and sensor fault identification based on process variable reconstruction using dynamic PCA and canonical variate analysis.

• Nuclear Engineering and Technology
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• v.26 no.2
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• pp.212-224
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• 1994

A numerical method has been developed for studying the dynamics of a flexible cylinder in a coaxial cylindrical duct, immersed in inviscid flow. The unsteady inviscid fluid-dynamic force acting on the oscillating cylinder has been estimated more rigorously by means of a spectral collocation method without simplification of governing equations. This numerical approach is applicable to the system haying wider annular gap and/or shorter length of cylinder as compared to existing potential theory. The governing equation of the unsteady flow was obtained from Laplace equation. The equation of cylinder motion coupled with the fluid motion was discretized by Galerkin's method, from which the dynamic behaviour of the system has been evaluated. The effect of the length of the cylinder and the annular gap on the critical flour velocity, where the system loses stability by buckling, was investigated. To validate the numerical method, the potential flow theory developed by Hobson based on thin film approximation has been improved. Typical results of the present numerical theory on the dynamics and stability of the system are compared with those of available existing theory and the present approximate results. Good agreement was found between the results. It was also found that a nondimensional critical flow velocity becomes larger as increasing the annular gap and decreasing the length of cylinder.

• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.415-426
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• 2006

The essential characteristic of ubiquitous is context-awareness, and that means ubiquitous computing can automatically process the data that change according to space and time, without users' intervention. However, in circumstance of context awareness, since location information is able to be collected without users' clear approval, users cannot control their location information completely. These problems can cause privacy issue when users access their location information. Therefore, it is important to construct the location information system, which decides to release the information considering privacy under the condition such as location, users' situation, and people who demand information. Therefore, in order to intercept an outflow information and provide securely location-based information, this paper suggests a new system based CS-RBAC with the existing LBS, which responds sensitively as customer's situation. Moreover, it accommodates a merit of PCP reflecting user's preference constructively. Also, through privacy weight, it makes information not only decide to providing information, but endow 'grade'. By this method, users' data can be protected safely with foundation of 'Role' in context-aware circumstance.

• Korean Journal of Metals and Materials
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• v.46 no.9
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• pp.545-553
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• 2008

Dynamic deformation behavior of ultra-fine-grained pure coppers fabricated by equal channel angular pressing (ECAP) was investigated in this study. Dynamic torsional tests were conducted on four copper specimens using a torsional Kolsky bar, and then the test data were analyzed by their microstructures and tensile properties. The 1-pass ECAP'ed specimen consisted of fine dislocation cell structures elongated along the ECAP direction, which were changed to very fine, equiaxed subgrains of 300~400 nm in size as the pass number increased. The dynamic torsional test results indicated that maximum shear stress increased with increasing ECAP pass number. Adiabatic shear bands were not found at the gage center of the dynamically deformed torsional specimen of the 1- or 4-pass ECAP'ed specimen, while some weak bands were observed in the 8-pass ECAP'ed specimen. These findings suggested that the grain refinement according to the ECAP was very effective in strengthening of pure coppers, and that ECAP'ed coppers could be used without serious reduction in fracture resistance under dynamic torsional loading as adiabatic shear bands were hardly formed.

• PNF and Movement
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• v.21 no.3
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• pp.337-344
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• 2023

Purpose: The purpose of this study was to evaluate changes in the lower extremity kinematics of subjects with dynamic knee valgus after we applied non-elastic tape while they performed overhead squat. Methods: Twenty-five subjects (12 females, 13 males) with dynamic knee valgus participated in this study. Hip and knee joint kinematics and medial knee displacement were measured during overhead squat with and without hip correction taping. Results: Hip joint internal rotation, knee valgus, and medial knee displacement were significantly lower during overhead squat with hip correction taping than without hip correction taping, but there was no significant difference in hip joint flexion and abduction. Conclusion: Hip joint correction using non-elastic taping is recommended to subjects with dynamic knee valgus to improve their lower extremity movement and alignment during overhead squat.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.387-397
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• 2019

The purpose of this study is to analyze the relationship between health related physical fitness, cognitive function, depression and quality of life variables of elderly people in a comprehensive way based on quantitative evaluation. The subjects of this study were 385 people who voluntarily participated in the elderly welfare center in Gyeonggi and Seoul the elderly people. As for the data collection methods, were measured the characteristics, depression and quality of life, cognitive function questionnaires along with measures of lower and upper body strength, dynamic equilibrium and agility, total endurance and grip strength. As a result, the first was a statistically significant correlation between integrated health of the elderly, cognitive function, quality of life and depression. Second, the analysis of cognitive function, elderly integrated health, quality of life, and depression revealed statistical significance among all variables. Third, there was the partial intervention effect of function in the quality of life and depression of the elderly.