• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.915-916
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• 2014

With the upcoming era of internet of things, the study of sensor network has been paid attention. Raspberry pi is a tiny versatile computer system which is able to act as a sensor node in hadoop cluster network. In this paper, we deployed 5 Raspberry pi's to construct an experimental testbed of hadoop sensor network with 5-node map-reduce hadoop software framework. We compared and analyzed the network architecture in terms of efficiency, resource management, and throughput using various parameters. We used a learning machine with support vector machine as test workload. In our experiments, Raspberry pi fulfilled the role of distributed computing sensor node in the sensor network.

• The Journal of Engineering Geology
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• v.20 no.3
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• pp.339-348
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• 2010

As part of preparing for future earthquakes near three LNG receiving terminals located in coastal regions of Korea, acceleration monitoring systems were installed at four free field sites and on a pile foundation beneath a storage tank in a receiving terminal. Several equipments and accessories were devised to successfully install and operate the monitoring system at LNG receiving terminals. Synthetic earthquake-alarming software systems designed for decisionmaking, based on peak ground acceleration computed using the measured data, were developed for rapid response during earthquakes, not only in each local terminal area but also in the central control division. In addition, a framework software linking nationwide data on peak ground accelerations was included in the integrated earthquake alarming system in the central division, for various future applications. The earthquake alarming systems developed in this research for LNG receiving terminals, based on acceleration monitoring, represent a useful framework for industrial facilities located in coastal regions, where geotechnical conditions may show marked spatial variations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.283-290
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• 2020

In this study, a floater was developed for a frame-type solar power plant. The floater supports the frame and the solar panels. A finite element analysis was performed to design its shape and thickness, and the floater was manufactured by a rotational molding method using linear low-density polyethylene. It was found that the floater did not cause collapse and it maintained its stiffness even at 4 times the maximum load of 322.7 kgf. To perform a long-term compression test, a weight-type load application device that uses gravity was designed and manufactured. The amount of compressive deformation was measured for 7 days, and a long-term deformation equation was obtained. Even under small loads, continuous deformation was observed. However, the 10-year deformation amount for a constant load of 100 kgf was predicted to be small at about 4.64 mm. As a result, it was found that the developed floater could be used in a solar power plant on a body of water.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.367-378
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• 2023

With the recent development of computer-aided design-computer-aided manufacturing technology and 3D printing technology, and the introduction of various digital techniques, the accuracy and efficiency of top-down definitive prosthetic restoration are increasing. In this clinical case, stable occlusion support was obtained through the placement of a total of 9 maxillary and mandibular posterior implants in patient with anterior-posterior crossed occlusion. The edentulous area of the maxillary anterior teeth, which showed a tendency of high resorption of the residual alveolar bone, was restored with a Kennedy Class IV implant assisted removable partial denture to restore soft tissue esthetics. Computed tomography guided surgery was used to place implants in the planned position, double scan technique was used to reflect the stabilized occlusion in the interim restoration stage to the definitive prostheses, and metal 3D printing was used to manufacture the coping and framework. This clinical case reports that efficient and predictable top-down full mouth rehabilitation was achieved using various digital technologies and techniques.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.2
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• pp.77-92
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• 2021

For the construction of a large underground space with a complex plant installed, it is necessary to analyze the stability considering the ground conditions and various load conditions. In this paper, finite element analysis was performed to analyze the support load that can be used in the design of a large underground space for high-density arrangement of complex plant. An analysis of underground continuous wall (D-wall) was performed considering the load and horizontal earth pressure in the large underground space. In addition, foundation ground analysis was carried out according to the load condition of the complex plant. In order to shorten the construction period, increase the space layout utilization, and secure the stability of the plant structure when installing the complex plant underground, the pipe rack module structure analysis was conducted. This study proposes a design and construction method for the optimal arrangement of underground complex plants using the analysis results.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.6
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• pp.287-292
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• 2021

Load and resistance factor design is an efficient design approach that provides a system of consistent design solutions. This study aims to determine the load and resistance factors needed for the design of breakwater foundations within a probabilistic framework. In the study, four typical types of Korean breakwaters, namely, rubble mound breakwaters, vertical composite caisson breakwaters, perforated caisson breakwaters, and horizontal composite breakwaters, are investigated. The bearing capacity of breakwater foundations under wave loading conditions is thoroughly examined. Two levels of the target reliability index (RI) of 2.5 and 3.0 are selected to implement the load and resistance factors calibration using Monte Carlo simulations with 100,000 cycles. The normalized resistance factors are found to be lower for the higher target RI as expected. Their ranges are from 0.668 to 0.687 for the target RI of 2.5 and from 0.576 to 0.634 for the target RI of 3.0.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.6
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• pp.675-683
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• 2011

When impacts by falling objects are applied to the structures, vertical resisting member(column or column group) results in progressive collapse. By knowing clearly load-deformation relationship of a structural frame, to prevent progressive collapse by absorbing potential energy of falling objects though column groups are lost by the impact of falling object accidently. If residual strength in vertical direction exceeds vertical load, which the sum of the weight of falling objects and usual supportive vertical load as the result of absorbing released location energy, it does not result in progressive collapse. On the other hand, in case when weight of falling objects is included in usual supportive vertical load. In this paper, 1-story 4-spans model is analyzed by non-linear FEM and to examine the level of deterioration, limit analysis of 1-story 4-spans plane frame was carried out.

• The Journal of Society for e-Business Studies
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• v.20 no.1
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• pp.153-166
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• 2015

The main purpose of this study is to develop and empirically validate the research model that examines the relationship between technostress and employees' continuance commitment at their jobs. In addition, the moderating effects of involvement facilitation and technical support provision were examined as enhancing factors on the relationship among the proposed constructs. The data from 179 employees at various organizations were analyzed to test proposed hypotheses. Results show that all proposed hypotheses were supported. This study contributes to IS community in terms of theoretically research framework as well as understanding of technostress at a workplace.

• The Journal of the Convergence on Culture Technology
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• v.3 no.4
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• pp.101-106
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• 2017

This paper investigates how news media frame news editorials to deliver their subjective ideological stance through news discourse related with two candidates in 2016 U.S presidential election. For this purpose, 13 editorials were chosen and analyzed which appeared on the New York Time for the period from Sept. 1 to Sept. 30, almost two months prior to the election, giving special attention to the headlines of those editorials and the expressive linguistic forms in the selected two articles, based on the two theoretical frameworks-van Dijk' (1996)'s ideological square and Martin and White (2005)'s Appraisal Theory. The results are as follows: (1) editorials clearly supported Hillary Clinton; (2) following the appraisal theory, the category of 'feeling' was applied in expressing the preference for Hillary, whereas the strategy of judgment for Trump, where the strategy of 'emphasis' from the ideological framework were used for both candidates.

• Journal of Korea Technology Innovation Society
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• v.18 no.1
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• pp.176-203
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• 2015

While the importance of adopting cloud computing service has been emerged, comparatively little research has been conducted on examining factors of an individual user's intention to switch toward cloud computing service. Hereafter, this study presents and empirically tests users' intention to switch to cloud computing. Our model posits that the characteristics of cloud computing such as effectiveness, economics, accessability, switching cost, security concern, and satisfaction toward existing IT service to cloud service affect perceived value, which in turn, influences intention to switch. An experimental study using student subjects provided empirical validation for our proposed model. Survey data from 204 respondents was used to test the model using partial least square analysis. As the result of the analysis, five hypotheses out of seven hypotheses were supported. According to our results, among the characteristics of cloud computing, effectiveness, economics, switching cost, and security concern were found to have significant impact on users' intention to switch that mediated by perceived value. Based on our research findings, we hope that this research will stimulate researchers' interest in the emerging area of cloud computing adoption.