• Journal of the Korean Society for Heat Treatment
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• v.17 no.3
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• pp.165-172
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• 2004

Compared with the hydroforming technology for steel, the hydroforming technology for aluminum has not been actively investigated. Recently, the hydroforming of high strength aluminum tubes has attracted great interest because of its good strength to weight ratio. In this study, front side member (FSM) is fabricated with the hydroforming of aluminum tube and the mechanical properties and dimensional accuracy of the hydroformed FSM is investigated. For hydroforming process, extruded aluminum tubes with ribs to improve the structural rigidity are used. To ensure the mechanical properties, the aluminum tubes are T6 heat-treated before hydroforming.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.2
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• pp.124-131
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• 1993

Recently. with the rapid development in large sea water systems. there occurs much interest in the study of erosion-corrosion. In this study. the mild steel(SB41) was tested by using of a erosion-corrosion test apparatus with fountain-jet and was investigated under the environments of liquid, air-liquid 2 phase flow and solid particle-liquid 2 phase flow. Main results obtained are as follows : 1. The weight loss by corrosion-erosion in air-liquid 2 phase flow are more increased than that in only liquid solution. 2. Effect of air-liquid 2 phase flow on corrosion-erosion sensitivity becomes more sensitive in natural seawater than that in distilled water. 3. The corrosion potential by corrosion-erosion in air-liquid and solid particle-liquid 2 phase flow becomes noble than that of only liquid solution.

• Journal of Korean Neurosurgical Society
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• v.43 no.2
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• pp.69-78
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• 2008

Recently, due to the evolution of technology, the field of neurosurgery is receiving spotlight. In particular endovascular neurosurgery has gained a great interest along with the advancement of the modern neurosurgery. The most remarkable advances were made in embolization of the cerebral aneurysms, arteriovenous malformations and intracranial stenosis during the past 10 years. These advances will further change the role of neurosurgeons in treating cerebrovascular disease. Because interventional neuroradiologists have performed most of procedures in the past, neurosurgeons have been deprived of chances to learn endovascular procedure. This article discusses the development of technological aspect of endovascular neurosurgery in chronological order. By understanding the history and current status of the endovascular surgery, the future of neurosurgery will be promising.

• Journal of Surface Science and Engineering
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• v.47 no.5
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• pp.244-251
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• 2014

In recent years, self-healing coatings have been the subject of increasing interest. The ability of such coatings to self-repair local damage caused by external factors is a major factor contributing to their attractiveness. Metals are extensively used in modern society in a range of applications from infrastructure to aircraft to consumer products. The protection of metals, primarily from corrosion has been an active area of materials science for many years. The aim of this review is the demonstration for recent progress achieved in the development of carrier-based self-healing coatings for the protection of metals. This review mainly covers the reports published after 2010. Two main types of carriers for corrosion inhibitors or healing agents-polymer capsules and porous composite inorganic nanoparticles-are described.

• International Journal of Contents
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• v.12 no.2
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• pp.31-36
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• 2016

The purpose of this research is to realize interactive art based on user's motions information using real time internet search terms. For this purpose, real-time search terms and related news information were extracted from three domestic and foreign portal sites, and the extracted information was used to generate content for interaction with the user. For interaction between the generated content and the user, a motion-based interactive technology that optimizes the intentions and experiences of the user was developed. A motion-based interactive system can be used to develop an immersive interface that induces user interest.

• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.74-75
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• 2010

As global warming due to burning fossil fuels and natural resource depletion issues have emerged, the development of renewable energy sources such as photovoltaics (PV) has been brought to recent interest. Amongst the vast efforts to harvest and convert solar energy into electricity, the module integrated converters (MIC) has become a worthy topic of research for grid-connected photovoltaic systems. Due to the required high-boosting qualities, only a restricted amount of DC/DC converter topologies can be applied to MICs. This paper investigates the possibility of a tapped-inductor boost converter as a candidate for PV MICs. A dual-inductor interleaving scheme operating slightly above the boundary of the two conduction modes (BCM) is suggested for reduction of input current ripple and minimization of component stress. A digital controller is used for implementation, assuring maximum power tracking and transfer while providing sufficient computational space for other grid connectivity applications, etc. For verification, a 200W converter is designed and simulated via computer software including component losses. High efficiency over a wide power range proves the feasibility of the proposed PV MIC system.

• Korean Journal of Remote Sensing
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• v.24 no.5
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• pp.517-524
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• 2008

In order to classify an satellite imagery into geospatial features of interest, the supervised classification needs to be trained to distinguish these features through training sampling. However, even though an imagery is classified, different results of classification could be generated according to operator's experience and expertise in training process. Users who practically exploit an classification result to their applications need the research accomplishment for the consistent result as well as the accuracy improvement. The experiment includes the classification results for training process used VITD polygons as a prior probability and training parameter, instead of manual sampling. As results, classification accuracy using VITD polygons as prior probabilities shows the highest results in several methods. The training using unsupervised classification with VITD have produced similar classification results as manual training and/or with prior probability.

• Korean Journal of Remote Sensing
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• v.16 no.4
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• pp.355-365
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• 2000

The interferometric correlation, or coherence, is calculated to measure the variance of the interferometric phase and amplitude within the neighbourhood of any location within the image at a result of SAR (Synthetic Aperture Radar) interferometric process which utilizes the phase information of the images. The coherence contains additional information that is useful for detecting point targets which change their location in an area of interest (AOI). In this research, a RGB colour composite image was generated with a intensity image (master image), a intensity change image as a difference between master image and slave image, and a coherence image generated as a part of SAR interferometric processing. We developed a technique performing detection of a point target movement using SAR interferometry and applied it to suitable tandem pair images of ERS-1 and ERS-2 as test data. The possibility of change detection of a point target in the AOI could be identified with the technique proposed in this research.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.70-71
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• 2019

Interest in indoor air quality is increasing day by day due to various reasons such as industrial development. Because redmud, an industrial subsidiary, contains titanium dioxide, this study evaluated self-consolidation performance with Slump Flow Test, J-Ring Test, and L-Box Test by mixing redmud in a mixture of ultra-high performance concrete, and sought the optimal combination with high flowability. In addition, the UHPC mixing experiment with photocatalyst was conducted, and the photocatalyst was replaced by the weight ratio of cement and the redmud by the weight ratio of fine aggregate and mixed with the concrete mixture.

• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.3
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• pp.185-196
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• 2015

Titanium (Ti) based alloys are widely used in biomedical implants due to their low density, excellent corrosion resistance and good biocompatibilities. In recent years, growing interest in sever plastic deformation (SPD) has stimulated research and development on the techniques to attain refining of the grain size to the submicrometer or even nanometer level. The mechanical and wear properties determining the application of Ti in medicine may be improved via SPD. High pressure torsion (HPT) technique is one of the approaches available for improving the mechanical and wear properties of biomedical Ti materials. Accordingly, this article is designed to examine most recent state of the art scientific works related to the developments in mechanical properties and wear resistance of biomedical Ti materials processed by HPT. A comprehensive review in this area is systematically presented.