• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.177-178
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• 2018

Unlike the projects that the government has implemented recently to develop new cities under the New Deal project, Saeddeul Village projects to improve the environment of the city are gaining attention. The problem has been found to be that many of the buildings in Saeddeul Village are still not earthquake-proof by using drones to review the state of the town. It also revealed that after two years of earthquakes, Pilotis structures are the most vulnerable to earthquakes. However, it is suitable for small spaces in the city because it provides parking spaces as well as residential spaces. Accordingly, the focus should be on repair and reinforcement rather than reconstruction. In this study, a concrete-based seismic design and construction method is developed in the columns of the existing pylotis structure.

• Journal of Digital Convergence
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• v.9 no.4
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• pp.77-89
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• 2011

The purpose of this study is to find out a more effective and functional way to apply management innovation, by analyzing the relationship between the innovation and leadership of a public enterprise CEO. To fulfill the purpose, a structured survey was executed with twenty one public enterprises those who have had management innovation before January, 2010. The proof of the research shows the leadership of public enterprises gives a big impact on each work group, operation structure innovation, and also individual innovation. Accordance with these conclusions, in order to create effective management innovation, the leadership of CEO should be very revolutionary rather than being conservative.

• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1125-1134
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• 2017

In this paper, we present a new multilevel in space and energy diffusion (MSED) method for solving multigroup diffusion eigenvalue problems. The MSED method can be described as a PI scheme with three additional features: (1) a grey (one-group) diffusion equation used to efficiently converge the fission source and eigenvalue, (2) a space-dependent Wielandt shift technique used to reduce the number of PIs required, and (3) a multigrid-in-space linear solver for the linear solves required by each PI step. In MSED, the convergence of the solution of the multigroup diffusion eigenvalue problem is accelerated by performing work on lower-order equations with only one group and/or coarser spatial grids. Results from several Fourier analyses and a one-dimensional test code are provided to verify the efficiency of the MSED method and to justify the incorporation of the grey diffusion equation and the multigrid linear solver. These results highlight the potential efficiency of the MSED method as a solver for multidimensional multigroup diffusion eigenvalue problems, and they serve as a proof of principle for future work. Our ultimate goal is to implement the MSED method as an efficient solver for the two-dimensional/three-dimensional coarse mesh finite difference diffusion system in the Michigan parallel characteristics transport code. The work in this paper represents a necessary step towards that goal.

• Earthquakes and Structures
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• v.7 no.3
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• pp.333-347
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• 2014

Multi-scale model can take both computational efficiency and accuracy into consideration when it is used to conduct elasto-plastic seismic response analysis for complex steel bridges. This paper proposed a method based on pushover analysis of member sharing the same section pattern to verify the accuracy of multi-scale model. A deck-through type steel arch bridge with a span length of 200m was employed for seismic response analysis using multi-scale model and fiber model respectively, the validity and necessity of elasto-plastic seismic analysis for steel bridge by multi-scale model was then verified. The results show that the convergence of load-displacement curves obtained from pushover analysis for members having the same section pattern can be used as a proof of the accuracy of multi-scale model. It is noted that the computational precision of multi-scale model can be guaranteed when length of shell element segment is 1.40 times longer than the width of section where was in compression status. Fiber model can only be used for the predictions of the global deformations and the approximate positions of plastic areas on steel structures. However, it cannot give exact prediction on the distribution of plastic areas and the degree of the plasticity.

• Progress in Medical Physics
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• v.26 no.4
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• pp.215-222
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• 2015

In this work, we performed a proof-of-concept experiment for phase-contrast x-ray imaging (PCXI) based on a single antiscatter grid and a polychromatic x-ray source. We established a table-top setup which consists of a focused-linear grid having a strip density of 200 lines/inch, a microfocus x-ray tube having a focal-spot size of about $5{\mu}m$, and a CMOS-type flat-panel detector having a pixel size of $48{\mu}m$. By using our prototype PCXI system and the Fourier demodulation technique, we successfully obtained attenuation, scattering, and differential phase-contrast images of improved visibility from the raw images of several selected samples at x-ray tube conditions of $90kV_p$ and 0.1 mAs. Further, fusion image (e.g., the attenuation+the scattering) may have an advantage in displaying details of the sample's structures that are not clearly visible in the conventional attenuation image. Our experimental results indicate that single-grid-based approach seems a useful method for PCXI with great simplicity and minimal requirements on the setup alignment.

• Journal of Digital Convergence
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• v.19 no.4
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• pp.151-157
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• 2021

Recently, IoT technology has been applied to various cloud environments, requiring accurate verification of various information generated by IoT devices. However, due to the convergence of IoT technologies and 5G technologies, accurate analysis is required as IoT information processing is rapidly processed. This paper proposes a blockchain-based multi-IoT verification model for overlay cloud environments. The proposed model multi-processes IoT information by further classifying IoT information two layers (layer and layer) into bits' blockchain to minimize the bottleneck of overlay networks while ensuring the integrity of information sent and received from embedded IoT devices within local IoT groups. Furthermore, the proposed model allows the layer to contain the weight information, allowing IoT information to be easily processed by the server. In particular, transmission and reception information between IoT devices facilitates server access by distributing IoT information from bits into blockchain to minimize bottlenecks in overlay networks and then weighting IoT information.

• Korean Journal of Radiology
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• v.24 no.7
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• pp.647-659
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• 2023

Objective: The study was conducted to investigate the effect of correct occlusion of the left atrial appendage (LAA) on intracardiac blood flow and thrombus formation in patients with atrial fibrillation (AF) using four-dimensional (4D) flow magnetic resonance imaging (MRI) and three-dimensional (3D)-printed phantoms. Materials and Methods: Three life-sized 3D-printed left atrium (LA) phantoms, including a pre-occlusion (i.e., before the occlusion procedure) model and correctly and incorrectly occluded post-procedural models, were constructed based on cardiac computed tomography images from an 86-year-old male with long-standing persistent AF. A custom-made closed-loop flow circuit was set up, and pulsatile simulated pulmonary venous flow was delivered by a pump. 4D flow MRI was performed using a 3T scanner, and the images were analyzed using MATLAB-based software (R2020b; Mathworks). Flow metrics associated with blood stasis and thrombogenicity, such as the volume of stasis defined by the velocity threshold ($\left|\vec{V}\right|$ < 3 cm/s), surface-and-time-averaged wall shear stress (WSS), and endothelial cell activation potential (ECAP), were analyzed and compared among the three LA phantom models. Results: Different spatial distributions, orientations, and magnitudes of LA flow were directly visualized within the three LA phantoms using 4D flow MRI. The time-averaged volume and its ratio to the corresponding entire volume of LA flow stasis were consistently reduced in the correctly occluded model (70.82 mL and 39.0%, respectively), followed by the incorrectly occluded (73.17 mL and 39.0%, respectively) and pre-occlusion (79.11 mL and 39.7%, respectively) models. The surfaceand-time-averaged WSS and ECAP were also lowest in the correctly occluded model (0.048 Pa and 4.004 Pa^-1, respectively), followed by the incorrectly occluded (0.059 Pa and 4.792 Pa^-1, respectively) and pre-occlusion (0.072 Pa and 5.861 Pa^-1, respectively) models. Conclusion: These findings suggest that a correctly occluded LAA leads to the greatest reduction in LA flow stasis and thrombogenicity, presenting a tentative procedural goal to maximize clinical benefits in patients with AF.

• The Journal of the Korea Contents Association
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• v.17 no.3
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• pp.643-653
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• 2017

The purpose of this study is to analyze the influence of Trans Media Brand Experience on Brand Image, Brand Preference, and Purchase Intent. Trans Media experience refers the act of enjoying contents by crossing a number of different media. With the advance of digital convergence, brand experience communication has become more diverse. This study focuses on one particular Trans Media case, Bacchus Self-Scanner by using Smart PLS to analyze 119 participants on a structural equation model. The result shows that 1) brand experience has a positive impact(+) on brand image and purchase intent, 2) brand image has a positive impact(+) on Brand Preference and Purchase Intent, and 3) Brand Preference has a positive impact(+) on Purchase Intent. As the result shows, the empirical proof that Brand Experience affects not only the indirect-effect of Brand Image and Brand Preference but also Purchase Intent as the direct-effect, and that Brand Image can affect Brand Preference and Purchase Intent, will serve as strategic implications for Brand Experience and Brand Image.

• Journal of KIISE
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• v.43 no.6
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• pp.613-620
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• 2016

This paper presents a MOHA(Many-Task Computing on Hadoop) framework which aims to effectively apply the Many-Task Computing(MTC) technologies originally developed for high-performance processing of many tasks, to the existing Big Data processing platform Hadoop. We present basic concepts, motivation, preliminary results of PoC based on distributed message queue, and future research directions of MOHA. MTC applications may have relatively low I/O requirements per task. However, a very large number of tasks should be efficiently processed with potentially heavy inter-communications based on files. Therefore, MTC applications can show another pattern of data-intensive workloads compared to existing Hadoop applications, typically based on relatively large data block sizes. Through an effective convergence of MTC and Big Data technologies, we can introduce a new MOHA framework which can support the large-scale scientific applications along with the Hadoop ecosystem, which is evolving into a multi-application platform.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.431-437
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• 2014

The purpose of this study was to perform an actual proof analysis on the structural effects of recognition of radiation risks on management and benefits. Data was collected using self-administered questionnaires targeting students having majors related to radiation from 1 April to 31 May in 2013 of one four-year-course university located in Chungbuk, Korea. As a result of the analysis, it turned out that as recognition of radiation risks is higher, recognition of radiation management is higher, which has a significant effect on benefits. It was indicated that although recognition of radiation risks does not directly influence radiation benefits, positive recognition on radiation benefits could increase through the parameter, radiation management. In order to improve smooth use of radiation and increase benefits, education that emphasizes the need of proper radiation management should be performed.