• International Journal of Aeronautical and Space Sciences
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• v.14 no.4
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• pp.324-333
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• 2013

The purpose of this paper is to improve the efficiency of multi-objective topology optimization using a genetic algorithm (GA) with bar-system representation. We proposed a new GA using an elite initial population obtained from a Solid Isotropic Material with Penalization (SIMP) using a weighted sum method. SIMP with a weighted sum method is one of the most established methods using sensitivity analysis. Although the implementation of the SIMP method is straightforward and computationally effective, it may be difficult to find a complete Pareto-optimal set in a multi-objective optimization problem. In this study, to build a more convergent and diverse global Pareto-optimal set and reduce the GA computational cost, some individuals, with similar topology to the local optimum solution obtained from the SIMP using the weighted sum method, were introduced for the initial population of the GA. The proposed method was applied to a structural topology optimization example and the results of the proposed method were compared with those of the traditional method using standard random initialization for the initial population of the GA.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.6009-6027
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• 2019

Support vector machine (SVM) classifiers have been widely used for object detection. These methods usually locate the object by finding the region with maximal score in an image. With bag-of-features representation, the SVM score of an image region can be written as the sum of its inside feature-weights. As a result, the searching process can be executed efficiently by using strategies such as branch-and-bound. However, the feature-weight derived by optimizing region classification cannot really reveal the category knowledge of a feature-point, which could cause bad localization. In this paper, we represent a region in an image by a collection of local feature-points and determine the object by the region with the maximum posterior probability of belonging to the object class. Based on the Bayes' theorem and Naive-Bayes assumptions, the posterior probability is reformulated as the sum of feature-scores. The feature-score is manifested in the form of the logarithm of a probability ratio. Instead of estimating the numerator and denominator probabilities separately, we readily employ the density ratio estimation techniques directly, and overcome the above limitation. Experiments on a car dataset and PASCAL VOC 2007 dataset validated the effectiveness of our method compared to the baselines. In addition, the performance can be further improved by taking advantage of the recently developed deep convolutional neural network features.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.4
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• pp.72-82
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• 1990

A simple numerical analysis procedure has been proposed to trace the response of unstiffened offshore tubular members subjected to lateral impacts and eventually to estimate the consequential extent of damage. In the procedure a tubular member is reduced to a spring-mass system having two degrees-of-freedom. one for local denting deformation and the other for that of overall bending. Results of impact tests have been correlated with those of numerical analysis in order to achieve an empirical representation of the strain-rate sensitivity and other dynamic effects upon the spring coefficient for bending deformation. The theoretical estimates of extents of damage correlate reasonably well with those obtained in experiments.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.5
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• pp.688-693
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• 2010

Vision based object recognition in mobile robots has many issues for image analysis problems with neighboring elements in dynamic environments. SURF(Speeded Up Robust Features) is the local feature extraction method of the image and its performance is constant even if disturbances, such as lighting, scale change and rotation, exist. However, it has a difficulty of real-time processing caused by representation of high dimensional vectors. To solve th problem, execution of SURF in GPU(Graphics Processing Unit) is proposed and implemented using CUDA of NVIDIA. Comparisons of recognition rates and processing time for SURF between CPU and GPU by variation of robot velocity and image sizes is experimented.

• Science of Emotion and Sensibility
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• v.20 no.4
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• pp.101-112
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• 2017

We investigated the neural representation of reward probability recognition and its neural connectivity with other regions of the brain. Using functional magnetic resonance imaging (fMRI), we used a simple guessing task with different probabilities of obtaining rewards across trials to assay local and global regions processing reward probability. The results of whole brain analysis demonstrated that lateral prefrontal cortex, inferior parietal lobe, and postcentral gyrus were activated during probability-based decision making. Specifically, the higher the expected value was, the more these regions were activated. Fronto-parietal connectivity, comprising inferior parietal regions and right lateral prefrontal cortex, conjointly engaged during high reward probability recognition compared to low reward condition, regardless of whether the reward information was extrinsically presented. Finally, the result of a regression analysis identified that cortico-subcortical connectivity was strengthened during the high reward anticipation for the subjects with higher cognitive impulsivity. Our findings demonstrate that interregional functional involvement is involved in valuation based on reward probability and that personality trait such as cognitive impulsivity plays a role in modulating the connectivity among different brain regions.

• The Mathematical Education
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• v.51 no.4
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• pp.455-469
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• 2012

Given the importance of mathematical connections in instruction, this paper analyzed the objects and the methods of mathematical connections according to the lesson flow featured in 20 elementary lessons selected as effective instructional methods by local educational offices in Korea. Mathematical connections tended to occur mainly in the introduction, the first activity, and the sum-up period of each lesson. The connection between mathematical concept and procedure was the most popular followed by the connection between concept and real-life context. The most prevalent method of mathematical connections was through communication, specifically the communication between the teacher and students, followed by representation. Overall it seems that the objects and the methods of mathematical connections were diverse and prevalent, but the detailed analysis of such cases showed the lack of meaningful connection. These results urge us to investigate reasons behind these seemingly good features but not-enough connections, and to suggest implications for well-connected mathematics teaching.

• Structural Engineering and Mechanics
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• v.22 no.1
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• pp.71-83
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• 2006

This paper deals with the effects of various moisture environments on the structural behavior of concrete beams. The presented results were obtained within a large experimental program carried out at the Laboratoire Central des Ponts et Chauss$\acute{e}$es (LCPC), with Electricit$\acute{e}$ de France (EDF) as a partner. The aim of this paper is to point out and to quantify the strains resulting from unidirectional moisture conditions: a drying gradient applied during 14 months, followed by the re-wetting of the dried surface during 9 months. The effect of reinforcement on the shrinkage and on the deformation due to water absorption is pointed out. Moreover, a lot of tests on companion cylinders and prisms were carried out to determine the mechanical characteristics of the material and help checking analysis methods. The paper focuses on numerous measurements obtained during the 23 months on one plain concrete beam and one reinforced concrete beam: variation of water content, followed by precise weighing and gammadensitometry, relative humidity measurements, local and global deformations in the three directions and deflection of the beams. Thus, the effects of drying and water absorption on the behavior of concrete structures are documented and analyzed in comparison with existing representation of water diffusion.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.4
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• pp.630-647
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• 2021

As generations Y and Z gain influence, luxury fashion brands are interacting with younger digital consumers through fashion film, seeking to offer them a differentiated brand experience. Using a literature review addressing characteristics of fashion films as a communication medium and luxury fashion brands' heritage in the digital era, this study examines how brands express their heritage through fashion film, categorizing those expressions in terms of implicit meaning. The case study analyzed films from Louis Vuitton, Chanel, Dior, and Burberry uploaded to YouTube between 2018 and 2020. First, to retain their status as luxury, brands emphasize historical legitimacy. Specifically, they highlight their iconic historical image, their succession of creative directors, valuable historic locations, and diversity of consumer's brand experiences. Second, by stressing craftsmanship, integrating contemporary art and local culture, and utilizing a museum aura, they use brand heritage to acquire luxury status. Third, they attempt to mythify the founders by creating the persona of the fashion designer and the artist. The results show that the heritage depicted in fashion films is a key way in which luxury fashion brands resolve the tension between accessibility and exclusivity that they encounter and to get consumers emotionally engaged with brands.

• Structural Engineering and Mechanics
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• v.68 no.5
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• pp.591-601
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• 2018

Non-moment beam-to-column connections, which are usually referred to as simple or shear connections, are typically designed to carry only gravity loads in the form of vertical shears. Although in the analysis of structures these connections are usually assumed to be pinned, they may provide a small amount of rotational stiffness due to the typical connection details. This paper investigates the effects of this small rotational restraint of simple beam-to-column connections on the behavior and seismic response of steel braced non-moment resisting frames. Two types of commonly used simple connections with bolted angles, i.e., the Double Web angle Connection (DWC) and Unstiffened Seat angle Connection (USC) are considered for this purpose. In addition to the pinned condition - as a simplified representation of these connections - more accurate semi-rigid models are established and then applied to some frame models subjected to nonlinear pushover and nonlinear time history analyses. Although the use of bracing elements generally reduces the sensitivity of the global structural response to the behavior of connections, the obtained results indicate considerable effects on the local responses. Namely, our results show that consideration of the real behavior of connections is essential in designing the column elements where the pin-connection assumption significantly underestimates design of outer columns of upper stories.

• Journal of Information Processing Systems
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• v.15 no.4
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• pp.986-1016
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• 2019

Mobile user interface pattern (MUIP) is a kind of structured representation of interaction design knowledge. Several studies have suggested that MUIPs are a proven solution for recurring mobile interface design problems. To facilitate MUIP selection, an effective clustering method is required to discover hidden knowledge of pattern data set. In this paper, we employ the semi-supervised kernel fuzzy c-means clustering (SSKFCM) method to cluster MUIP data. In order to improve the performance of clustering, clustering parameters are optimized by utilizing the global optimization capability of particle swarm optimization (PSO) algorithm. Since the PSO algorithm is easily trapped in local optima, a novel PSO algorithm is presented in this paper. It combines an improved intuitionistic fuzzy entropy measure and a new population search strategy to enhance the population search capability and accelerate the convergence speed. Experimental results show the effectiveness and superiority of the proposed clustering method.