• Structural Engineering and Mechanics
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• v.58 no.3
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• pp.515-532
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• 2016

The elastoplastic response of functionally graded material (FGM) beams resting on a nonlinear elastic foundation to an eccentric axial load is investigated by using the finite element method. The FGM is assumed to be formed from ceramic and metal phases with their volume fraction vary in the thickness direction by a power-law function. A bilinear elastoplastic behavior is assumed for the metallic phase, and the effective elastoplastic properties of the FGM are evaluated by Tamura-Tomota-Ozawa (TTO) model. Based on the classical beam theory, a nonlinear finite beam element taking the shift in the neutral axis position into account is formulated and employed in the investigation. An incremental-iterative procedure in combination with the arc-length control method is employed in computing the equilibrium paths of the beams. The validation of the formulated element is confirmed by comparing the equilibrium paths obtained by using the present element and the one available in the literature. The numerical results show that the elastoplastic post-buckling of the FGM beams is unstable, and the post-buckling strength is higher for the beams associated with a higher ceramic content. Different from homogeneous beams, yielding in the FGM beam occurs in the layer near the ceramic layer before in the layer near metal surface. A parametric study is carried out to highlight the effect of the material distribution, foundation support and eccentric ratio on the elastoplastic response of the beams.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4595-4600
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• 2014

A geoid has great meaning as a vertical reference plane, and at this point when GPS measurement is vitalized, it is an important factor that makes level measurements with GPS possible. This study carried out GPS and leveling of newly created complex control points targeting Daejeon. The geoid for the precise area was built by calculating the plane location, elevation and the geoid of each reference point using GPS/Leveling. In addition, this study evaluated the potential of GPS leveling throughout the site calibration. The geoid for the precise area intervals of approximately 1.5km throughout the study was determined. The results highlight the possibility of leveling by estimating direct leveling performance and mean altitude deviation by less than 2cm. Based on the results, if a geoid model for the precise and wide area can be developed throughout ongoing research, survey tasks that require elevation can be streamlined and the efficiency maximized.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.8
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• pp.2895-2912
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• 2014

Content-based image retrieval has been the most important technique for managing huge amount of images. The fundamental yet highly challenging problem in this field is how to measure the content-level similarity based on the low-level image features. The primary difficulties lie in the great variance within images, e.g. background, illumination, viewpoint and pose. Intuitively, an ideal similarity measure should be able to adapt the data distribution, discover and highlight the content-level information, and be robust to those variances. Motivated by these observations, we in this paper propose a probabilistic similarity learning approach. We first model the distribution of low-level image features and derive the free energy kernel (FEK), i.e., similarity measure, based on the distribution. Then, we propose a learning approach for the derived kernel, under the criterion that the kernel outputs high similarity for those images sharing the same class labels and output low similarity for those without the same label. The advantages of the proposed approach, in comparison with previous approaches, are threefold. (1) With the ability inherited from probabilistic models, the similarity measure can well adapt to data distribution. (2) Benefitting from the content-level hidden variables within the probabilistic models, the similarity measure is able to capture content-level cues. (3) It fully exploits class label in the supervised learning procedure. The proposed approach is extensively evaluated on two well-known databases. It achieves highly competitive performance on most experiments, which validates its advantages.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.555-560
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• 2014

In Korea, quantitative growth rate of artificial reef construction is supposed to reach the peak point therefore, new approach is needed to the point of artificial reefs business. Functional reefs like shellfish reefs, recreational reefs, seaweed reefs as well as fish reefs are beneficial alternatives. This study conducted hydraulic testing to assess the stability of new types of artificial reefs (ARs) constructed to promote the growth of shellfish and seaweed. The results of this study revealed that some dimensionless design parameters affected the stability of new types of artificial reef under various wave and water depth conditions in the fixed bed condition. The findings also highlight the importance of hydraulic experiments in solving problems that have emerged in the design and construction of artificial reefs.

• Computers and Concrete
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• v.19 no.6
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• pp.725-736
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• 2017

This paper presents the two-, three-, and four-lane transverse reduction factor based on FEA method, probability theory, and the recently actual traffic flow data. A total of 72 composite girder bridges with various spans, number of lanes, loading mode, and bridge type are analyzed with time-varying static load FEA method by ANSYS, and the probability models of vehicle load effects at arbitrary-time point are developed. Based on these probability models, in accordance to the principle of the same exceeding probability, the multi-lane transverse reduction factor of these composite girder bridges and the relationship between the multi-lane transverse reduction factor and the span of bridge are determined. Finally, the multi-lane transverse reduction factor obtained is compared with those from AASHTO LRFD, BS5400, JTG D60 or Eurocode. The results show that the vehicle load effect at arbitrary-time point follows lognormal distribution. The two-, three-, and four-lane transverse reduction factors calculated by using FEA method and probability respectively range between 0.781 and 1.027, 0.616 and 0.795, 0.468 and 0.645. Furthermore, a correlation between the FEA and AASHTO LRFD, BS5400, JTG D60 or Eurocode transverse reduction factors is made for composite girder bridges. For the two-, three-, and four-lane bridge cases, the Eurocode code underestimated the FEA transverse reduction factors by 27%, 25% and 13%, respectively. This underestimation is more pronounced in short-span bridges. The AASHTO LRFD, BS5400 and JTG D60 codes overestimated the FEA transverse reduction factors. The FEA results highlight the importance of considering span length in determining the multi-lane transverse reduction factors when designing two-lane or more composite girder bridges. This paper will assist bridge engineers in quantifying the adjustment factors used in analyzing and designing multi-lane composite girder bridges.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4478-4488
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• 2015

This paper aims to develop and validate a situational judgement test to diagnose the Competencey of public ethics for undergraduates. A criterion group composing of high performers was formed. Critical incidents and responses were developed from interviews with members of the criterion group. Also an expert committee was composed of six university members who have professional knowledge and experience on Competencey based selection or education. This committee reviewed all the items developed and selected some of them for the final test. Item validity and reliability were examined through the final test that 519 college students took. The result of the confirmatory as well as exploratory factor analysis showed that the Competencey of public ethics consisted of 2 sub-elements which were work ethics and democratic citizenship. The correlation between results of the test and the HEXACO model was statistically significant. Overall, the findings of the study highlight that a situational judgement test can be developed and utilized to diagnose Competencey levels of public ethics for undergraduates.

• Journal of Broadcast Engineering
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• v.7 no.2
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• pp.96-106
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• 2002

We introduce a novel scheme to characterize and index events in TV golf programs using MPEG-7 descriptors. Our goal is to identify and localize the golf events of interest to facilitate highlight-based video indexing and summarization. In particular, we analyze multiple (low-level) visual features using domain-specific model to create a perceptual relation for semantically meaningful(high-level) event identification. Furthermore, we summarize a TV golf program with TV-Anytime segmentation metadata, a standard form of an XML-based metadata description, in which the golf events are represented by temporally localized segments and segment groups of highlights. Experimental results show that our proposed technique provides reasonable performance for identifying a variety of golf events.

• Korean Journal of Pharmacognosy
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• v.42 no.4
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• pp.366-370
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• 2011

Bee venom (BV) has been used as a treatment for a wide variety of ailments such as inflammatory diseases in korean traditional medicine. Despite its well documented anti-inflammatory property, it has not been fully demonstrated regarding the influence of BV against Propionibactierium acnes (P. acnes), which promotes follicular inflammation (inflammatory acne). This study evaluated the anti-inflammatory property of BV against P. acnes in vivo. To induce inflammation in vivo using P. acnes, $1{\times}10^7$ CFU of living P. acnes were intradermally injected into the ear of mice. BV (1, 10, 100 ${\mu}g$) in vaseline was applied epicutaneously on the ear resulting in P. acnes-induced ear swelling and inflammation. Epicutaneous administration of BV with P. acnes decreased the number of infiltrated inflammatory cells and inflammatory cytokines in the ear, thereby relieving P. acnes-induced ear swelling and granulomatous inflammation, especially at the dose of 1 ${\mu}g$ of BV. In this report, we demonstrated the therapeutic effects of BV on P. acnes-induced inflammation in vivo using the mouse model. These data highlight the potential of using BV as an alternative treatment to the antibiotic therapy of acne vulgaris.

• Proceedings of the Korean Society for Quality Management Conference
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• 2007.04a
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• pp.59-63
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• 2007

Customers have the various needs and personalities and try to get them. The behaviour of buying products, one of the highlight things, is the most general phenomenon of filling up their desires, and even these types are eventually personalized. Also there are various criteria for selecting it and also those are to be determined by the customers' own personalities. Mostly customers show the more attractive behaviours for those products which are more attractive to them, and for carefully buying them they use various paths. The criteria to buy the products are the mostly generalized things such as price, design, size, weight, trend, and so on, and it can be affected by the specifics of the products. But it is not definitely unimportant to consider the personality. Customers have the unusual personality for the product which is more attractive to them, and then for the unattractive, they only show the unclear criteria or specifics. The existing studies are focused on the product itself, and then they just show the results related to the specifics of the products, but it could be considered a case that the customers could think some products classified into the highly involvement products would be the lower involvement ones. Upon this, for same products if the customers show some differences of information(relating to the degree of involvement), I am going to figure it out by using AHP that what the criteria to buy is. In this study, with the computer products which are considered as the highly involvement products, I will select two groups showing the differences of awareness of the products, and then figure out the selecting criteria.

• The Korean Journal of Applied Statistics
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• v.24 no.6
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• pp.1033-1043
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• 2011

In this paper, we use a nested family of models of Generalized Autoregressive Conditional Heteroscedasticity(GARCH) to verify asymmetric conditional heteroscedasticity in the KOSPI and Won-Dollar exchange rate. This study starts from an investigation of whether time series data have asymmetric features not explained by standard GARCH models. First, we use kernel density plot to show the non-normality and asymmetry in data as well as to capture asymmetric conditional heteroscedasticity. Later, we use three representative asymmetric heteroscedastic models, EGARCH(Exponential Garch), GJR-GARCH(Glosten, Jagannathan and Runkle), APARCH(Asymmetric Power Arch) that are improved from standard GARCH models to give a better explanation of asymmetry. Thereby we highlight the fact that volatility tends to respond asymmetrically according to positive and/or negative values of past changes referred to as the leverage effect. Furthermore, it is verified that how the direction of asymmetry is different depending on characteristics of time series data. For the KOSPI and Korean won-US dollar exchange rate, asymmetric heteroscedastic model analysis successfully reveal the leverage effect. We obtained predictive values of conditional volatility and its prediction standard errors by using moving block bootstrap.