• Journal of the Korea institute for structural maintenance and inspection
• /
• v.23 no.7
• /
• pp.87-94
• /
• 2019

Recently, the advance of accurate dynamic displacement measurement devices, such as GPS, computer vision, and optic laser sensor, has enhanced the structural monitoring technology. In this study, the dynamic displacement data was used to verify the applicability of the structural physical parameter estimation method through subspace system identification. The subspace system identification theory for estimating state-space model from measured data and physics-based interpretation for deriving the physical parameter of the estimated system are presented. Three-degree-freedom steel structures were fabricated for the experimental verification of the theory in this study. Laser displacement sensor and accelerometer were used to measure the displacement data of each floor and the acceleration data of the shaking table. Discrete state-space model generated from measured data was verified for precision. The discrete state-space model generated from the measured data extracted the floor stiffness of the building after accuracy verification. In addition, based on the story stiffness extracted from the state space model, five column stiffening and damage samples were set up to extract the change rate of story stiffness for each sample. As a result, in case of reinforcement and damage under the same condition, the stiffness change showed a high matching rate.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.12 no.4
• /
• pp.651-658
• /
• 2001

A novel multi-section power divider configuration is proposed to obtain wide-band frequency performance up to microwave frequency region. Design procedures for the proposed microwave broadband power divider are composed of a planar multi-section three-ports hybrid and a waveguide transformer design procedures. The multi-section power divider is based on design theory of the optimum quarter-wave transformer. Furthermore, in order to obtain the broadband isolation performance between the two adjacent output ports, the odd mode equivalent circuit should be matched by using the lossy element such as resistor. The derived design formula for calculating these odd mode matching elements is based on the singly terminated filter design theory. The waveguide transformer section is designed to suppress the propagation of the higher order modes such as waveguide modes due to employing the metallic electric wall. Thus, each section of the designed waveguide transformer should be operated with evanescent mode over the whole design frequency band of the proposed microwave broadband power divider. This paper presents several simulations and experimental results of multi-section power divider to show validity of the proposed microwave broadband power divider configuration. Simulation and experiment show excellent performance of multi section power divider.

• Physical Therapy Korea
• /
• v.24 no.3
• /
• pp.47-56
• /
• 2017

Background: Given the potential benefits of wellness programs promoting physical activity of the community-dwelling frail elderly, it is recommended that comprehensive wellness programs combined with the component of physical activity. This may improve overall health and potentially lower the health care cost of the frail elderly. In general, the frail elderly residing in community or those after being discharged from hospitals are often committed to enhancing the status of participation in physical activity. Objects: The purposes of this study were to identify specific shortcomings of current wellness programs as part of continuum of community rehabilitation services and to propose alternatives for the care of the community-dwelling frail elderly. Through this study, geriatric health care professionals may be able to implement assessments and programs to successfully promote an effective continuum of care for the frail elderly. Methods: Article reviews were summarized and evaluated. Results: A model elaborating the relationship between components of successful wellness program and participation in physical activities for the community-dwelling frail elderly are recommended. First, periodic monitoring the levels of physical activity by the use of online measurement system should be considered. Second, individualized adaptive technologies for selecting optimal physical activities for the elderly may be better fit to individuals' current status of physical activity. Conclusion: The current status of physical activity in community-dwelling frail elderly can be monitored by online assessment systems. Through the innovative measurement system, elderly may assess his/her physical activity status overtime, select optimal physical activities matching the status, and create the elderly's own adaptive wellness programs that match to the status while residing in his/her community.

• Nuclear Engineering and Technology
• /
• v.49 no.7
• /
• pp.1555-1562
• /
• 2017

A loose part monitoring system is used to identify unexpected loose parts in a nuclear reactor vessel or steam generator. It is still necessary for the mass estimation of loose parts, one function of a loose part monitoring system, to develop a new method due to the high estimation error of conventional methods such as Hertz's impact theory and the frequency ratio method. The purpose of this study is to propose a mass estimation method using a Markov decision process and compare its performance with a method using an artificial neural network model proposed in a previous study. First, how to extract feature vectors using discrete cosine transform was explained. Second, Markov chains were designed with codebooks obtained from the feature vector. A 1/8-scaled mockup of the reactor vessel for OPR1000 was employed, and all used signals were obtained by impacting its surface with several solid spherical masses. Next, the performance of mass estimation by the proposed Markov model was compared with that of the artificial neural network model. Finally, it was investigated that the proposed Markov model had matching error below 20% in mass estimation. That was a similar performance to the method using an artificial neural network model and considerably improved in comparison with the conventional methods.

• Interdisciplinary Bio Central
• /
• v.6 no.4
• /
• pp.2.1-2.7
• /
• 2014

Sexual dimorphism in intelligence suggests that this phenotype is a sexually selected trait. This view is supported by an overrepresentation (compared to the autosomal genome) of genes affecting cognition on the X chromosome. The aim of this study is to test the hypothesis that sexual selection can explain sex and country-level differences in performance on tests of fluid intelligence. Nationally representative samples from N = 44 countries were obtained from the Programme for International Student Assessment (PISA) Creative Problem Solving (CPS), which evaluates the core of intelligence, that is novel problem solving ability. Sexual selection has the double effect of increasing the prevalence of a favored phenotype and reducing genetic variation in sexually selected traits. Matching these predictions from evolutionary theory, the average country fluid intelligence is positively correlated to sexual dimorphism after partialling out per capita GDP and the latter in turn is inversely correlated to variance in intelligence scores within populations. Males have a higher variance than females but there is a negative correlation between male-female difference in variance and sexual dimorphism in intelligence, suggesting that selection reduces variance more in the selected sex. Average country male height is negatively correlated to sexual dimorphism in intelligence, a fact that supports the notion of a trade-off between physical and intellectual competition in the context of access to females. The results of this study, if replicated, imply that genome-wide association studies of cognition may benefit from a focus on sex chromosomes, which so far have been neglected. Another implication of this study is that intelligence has continued to evolve after different human populations migrated out of Africa and possibly up to the 19th century, as suggested by the substantial variability in sex differences even between neighbouring countries.

• Journal of KIISE:Computer Systems and Theory
• /
• v.29 no.1
• /
• pp.16-21
• /
• 2002

Repetitive strings have been studied in such diverse fields as molecular biology data compression etc. Some important regularities that have been studied are perods, covers seeds and squares. A natural extension of the repetition problems is to allow errors. Among the four notions above aproximate squares and approximate periodes have been studied. In this paper, we introduce the notion of approximate covers which is an approximate version of covers. Given two strings P(｜P｜=m) and T(｜T｜=n) we propose and algorithm with finds the minimum distance t such that P is a t-approximate cover of T. The algorithm take O(m,n) time for the edit distance and $O(mn^2)$ time of finding a string which is an approximate cover of T is minimum distance is NP-complete.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.2 no.2
• /
• pp.19-24
• /
• 1991

This paper propose a new taegeuk shaped directional couper and verify the possibility of high power division rate in those directional coupler through the experiments. We took the taegeuk shaped structure in those proposed directional coupler to utilize a $3\lambda/4$ section of hybrid ring directional coupler actively, and calculated the branch admittances, which satisfied the condition of perfect matching and isolation in the center frequency, by even odd mode analyzing methodes. On the result, we knew that it can be realized a much higher power division rate than reported result in same circuit area within the producible resistance limit in the microstrip line, made the taegeuk shaped directional couplers with 0, 8, 16 dB power split ratio in the 10 GHz frequency using CGP - 502 plate, and confirmed the validity of theory through the experiments.

• Applied Microscopy
• /
• v.40 no.1
• /
• pp.21-28
• /
• 2010

In a simulation study of atomic resolution transmission electron microscope images of single layer and bilayer graphene, it is demonstrated that the conventional Bloch wave formulations can be used when high-order Laue zone reflections are properly taken into account in the theory. The simulated images for bilayer graphene show 3-fold rotational lattice symmetry rather than the 6-fold one under certain conditions. This result can be understood as revealed the 3-fold rotational lattice symmetry of bilayer graphene in three dimensions along [0001]. For single layer graphene the observed phase images showing 3-fold rotational lattice symmetry were particularly noted. This phenomenon has been explained by an assumption of the re-configuration of electron density on the surface of graphene. And the matching images have been obtained as simulated with up to the second order Laue zone reflections only, reflecting the re-configuration of electrons on the surface.

• The Korean Journal of Food And Nutrition
• /
• v.25 no.4
• /
• pp.999-1007
• /
• 2012

This study is to implement a model of CPC-mentoring program based on the mentoring theory and research environment analysis as well as to present the operation case of teaching and learning in colleges. Major research results should use the practical research methods utilizing the statistical program in order to verify the effectiveness of the program of CPC-mentoring program by comparing the before with the after of running the CPC-mentoring program of the research objects, comparison group (61 people) and experiment group (33 people). After running the CPC-mentoring program, whether there was a certification's acquisition or not of the comparison group and the experiment group, a statistically significant difference between the comparison group 34.3% (21) and the experiment group 72.7% (24), (p<0.05) was shown. The goal of the students participating in the CPC-mentoring program was to help one another in order to obtain certification. moreover, by engaging in mutually developing human relationship activities thru various methods, such as adaptation of college life, development of sociality, graduation, etc., good cooperative relationships with one another as well as further development of the relationship was formed. CPC-mentoring program is neither doing only people that want nor being effective for people only that want. A successful matching will naturally lead to all success since mentoring is human relationships is the misunderstanding. The role of a mentoring coordinator(professor) for the operation of a successful CPC-mentoring program and for the application method of detailed CPC-mentoring program was set. In addition, by considering the connectivity with the counseling guidance (shared and individual guidance) of students, which is the characterization direction of technical department of the college, it is expected to make a positive contribution if utilized in a multilateral manner.

• Journal of Computing Science and Engineering
• /
• v.7 no.2
• /
• pp.99-111
• /
• 2013

Approximating a divergence between two probability distributions from their samples is a fundamental challenge in statistics, information theory, and machine learning. A divergence approximator can be used for various purposes, such as two-sample homogeneity testing, change-point detection, and class-balance estimation. Furthermore, an approximator of a divergence between the joint distribution and the product of marginals can be used for independence testing, which has a wide range of applications, including feature selection and extraction, clustering, object matching, independent component analysis, and causal direction estimation. In this paper, we review recent advances in divergence approximation. Our emphasis is that directly approximating the divergence without estimating probability distributions is more sensible than a naive two-step approach of first estimating probability distributions and then approximating the divergence. Furthermore, despite the overwhelming popularity of the Kullback-Leibler divergence as a divergence measure, we argue that alternatives such as the Pearson divergence, the relative Pearson divergence, and the $L^2$-distance are more useful in practice because of their computationally efficient approximability, high numerical stability, and superior robustness against outliers.