• The Journal of the Korean bone and joint tumor society
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• v.10 no.1
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• pp.45-49
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• 2004

Chondroblastoma is a benign chondroid-forming tumor usually originating in the epiphysis. The base of metatarsal bone contains neither an epiphysis nor a secondary ossification center and so is the rare site of chondroblastoma. Here, we present a case of chondroblastoma of the base of fifth metatarsal bone in 34-year-old man. Histologically, the osteoclast-like giant cells were abundant enough to simulate a giant cell tumor. And the chondroid intercellular matrix was intermixed but scanty. However, the background mononuclear cells showed irregular and indented nuclei with longitudinal clefts and positive immunoreactivity for S-100 protein, as the evidence of chondroblasts.

• Journal of the Korea Computer Graphics Society
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• v.23 no.1
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• pp.39-48
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• 2017

We present penetration depth (PD) computation algorithms using explicit Minkowski sum construction ($PD_e$) and implicit Minkowski sum construction ($PD_i$). Minkowski sum construction is the most time consuming part in fast PD computation. In order to address this issue, we find a candidate solution using a centroid difference and motion coherence. Then, $PD_e$ constructs or updates partial Minkowski sum around the candidate solution. In contrast, $PD_i$ constructs only a tangent plane to the Minkowski sums iteratively. In practice, our algorithms can compute PD for complicated models consisting of thousands of triangles in a few milli-seconds. We also discuss the benefits of using different construction of Minkowski sums in the context of PD.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.6
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• pp.899-905
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• 2013

In this paper, we focus on how to calibrate multi-cameras easily and how to efficiently detect quad-copters with small-numbered particles. Each particle is a six dimensional vector that is composed of 3D position and 3D orientation of a quad-copter in the space. Due to curse of dimensionality, that leads to explosive computational costs with a large amount of high-dimensioned particles. To detect efficiently, we need to put more particles in very promising spaces and few particles in other spaces. Though computational cost is lowered by minimizing particles, in order to track a quad-copter with multiple cameras in real-time, multiple images from the cameras should be synchronized and analyzed. Therefore, lots of the computations still need to be done. Because of this, GPGPU(General-Purpose computing on Graphics Processing Units) is implemented for parallel computing. This method has been successfully tested and gives accurate results in practical situations.

• Journal of Advanced Navigation Technology
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• v.19 no.6
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• pp.601-606
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• 2015

Recently wireless data services have widely spread on various multimedia devices such as smart phones and tablets. Existing wired data services have been replaced by wireless data services using mobile devices. Especially domestic mobile devices supporting both Wireless-Fidelity (Wi-Fi) and long term evolution (LTE) services have increased steadily. While Wi-Fi network is provided free of charge, LTE network is offered to pay for. Therefore, mobile devices provide smart network switch to support both preferred Wi-Fi and LTE networks. However, such handover and roaming between Wi-Fi and LTE networks can cause data connection stop in spite of charged data services. This paper has proposed the method to overcome data connection stop for guaranteeing seamless data service during handover and roaming procedures between networks.

• Journal of Labour Economics
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• v.37 no.3
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• pp.45-73
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• 2014

This study analyzes the effect of labor unions in Korean manufacturing industry on wage variance of men from 1988 to 2012. The results are as follows. Firstly, the wage variance within establishments is higher than that between establishments, and the wage variance between establishments in the non-union sector has increased significantly compared to that in the union sector since 2000. There is strong evidence that the latter is due to the solidarity wage policy of unions which has strengthened since the early 2000s. Secondly, the influence of labor unions on the wage structure within the union sector has gotten stronger recently despite the general drop in the labor union membership. Thirdly, since the mid-1990s labor unions have contributed to reducing the overall wage variance. It implies that decline in the unionization rate over the years in Korea is likely to have contributed to increasing wage inequality.

• Journal of Korean Library and Information Science Society
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• v.46 no.3
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• pp.119-140
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• 2015

The domestic and foreign standards of school libraries suggest that school library should be run to give useful and pleasant experiences to students. This study applies Csikszentmihalyi's 'flow theory' to analyze the relationships between students' flow experience and their satisfaction about school libraries use. The variables selected in this study are students' satisfaction, flow experience, library skill, challenge of library use, types of library use and students' learning styles. The research model is designed by using these 6 variables in this study. The data are collected from 293 students and analyzed by structural equation modeling. The results of this study are as follows: The entire casual relationships show that library skills influence in types of library use, types of library use affect students' learning styles and students' learning styles influence in satisfaction through flow. To improve students' satisfaction about school library use, this study proposes effective ways related to teacher librarians' role performances to expand students' flow experience and increase their library skills.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.7
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• pp.1701-1707
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• 2010

This study is intended for implementing the system environment that can help integrate and retrieve various types of data in real-time by providing semantic interoperability among distributed heterogeneous information systems. The semantic interoperability is made possible by providing a TMDR(Topicmaps Metadata Registry), a set of ontologies. TMDR, which has been made by combining MDR(MetaData Registry) and TopicMaps and storing them in the database, is able to generate distributed query and provide efficient knowledge. MDR is a metadata management technique for distributed data management. TopicMaps is an ontology representation technique that takes into consideration the hierarchy and association for accessing knowledge data. We have created TMDR, a kind of ontology, that is fit for any system and able to detect and resolve semantic conflicts on the level of data and schema. With this system we propose a query-processing technique to integrate and access heterogeneous information sources. Unlike existing retrieval methods this makes possible efficient retrieval and reasoning by providing association focusing on subjects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.180-194
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• 2015

On roads vehicles are the bossy, while pedestrians are the frangible. The current paper has a purpose for contributing to pedestrian's safety. First, it studies the association between demographic parameters and TPB(Theory of Planned Behavior)'s variables(pedestrian's attitude toward crossing behavior in roads, personal norm, etc.) and his/her crossing intention, perceived risk while crossing, and the experience of past traffic accidents. Its sample comes from a specific population(college students). Further, the present study endeavors to explain the portion of human cognitive failure/error, impulsiveness, time perspective, and probabilistic/math-logical judgment ability in pedestrian's riky crossings on roads. Research results found that TPB variables and such a few human characteristics have some significant association with the risky crossing intention on the road. Considering the human psychological portion in pedestrian accidents would help us prevent the accidents and reduce unhappiness of the accidents and, further, economic loss and insurance expenditure related with the accidents.

• Journal of Music and Human Behavior
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• v.7 no.1
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• pp.61-77
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• 2010

As a means to support maternal transition, a home-based music intervention was employed to facilitate mothers' singing to their infants. Four mothers were recruited as volunteers for this study their typically developing infants ranged in age from 2 months to 11 months. Interviews were conducted after the completion of the intervention. An educational music intervention was used to introduce the benefits of mothers' singing to their infants and to encourage four mothers to perform regular singing to their infants for the two-week period. In the interview, mothers provided valuable information regarding their personal experiences, thoughts, abilities to carry out the daily singing, and additional support needs in singing. All mothers demonstrated positive experiences and needs for future intervention development. Overall, the results showed that music-involved educational intervention is beneficial for mothers to support their maternal transition. The need emerged for future studies to develop music-involved educational intervention to support maternal transition.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.363-374
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• 2010

Supply chain (SC) strategies will influence corporate performance and customer satisfaction. However, few empirical research has investigated the impact of the gap between prescriptive and current strategy on customer satisfaction. Based on the profile analysis with data from 31 products, the results of this study show the significant relationship between customer satisfaction and the fit between SC context and speculation-postponement strategies. The results imply that different SC strategies should be applied in accordance with product attributes and supply environments.