• Journal of Construction Engineering and Project Management
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• v.7 no.4
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• pp.13-19
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• 2017

This study is based on the use and performance of bamboo reinforcements in construction of low-cost structures. This study investigated the physical and mechanical properties of bamboo reinforcements. Bamboo reinforced concrete beam specimens were tested with different reinforcement ratios and observed the load capacity, deflection and failure patterns. It was observed that, flexural strength of bamboo reinforced column is sufficient higher than plain cement concrete and comparable to steel reinforced concrete beams. Bamboo reinforced concrete columns with different reinforcement ratio also tested and observed the ultimate compressive strength and failure pattern. It found, all columns failed in a similar pattern due to crushing of concrete. According to cost analysis, bamboo reinforced beams and columns with moderate reinforcement ratio showed the best strength-cost ratio among plain cement concrete and steel reinforced concrete.

• Journal of the Korean Wood Science and Technology
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• v.25 no.3
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• pp.96-104
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• 1997

The objective of this research project was to develop the wooden footpath block to reuse of wood waste. Some physical and mechanical properties of the wooden block such as water absorption, thickness swelling, modulus of rupture, internal bond, density profile and impact resistance were studied. Water absorption and thickness swelling of the wooden block were greatly reduced when the wooden block was pressed inside the forming device than by conventional hot pressing. Also, Modulus of rupture and internal bond of the wooden block were increased greatly when the pressing was completed inside the forming device. The density profile of the wooden block was improved up to 93.5%, minimum to average density ratio. The wooden block manufactured in this study have excellent physical and mechanical prperties in comparison with existing wood based materials. So, these wooden blocks are applicable to footpth block or other exterior members.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.36.3-37
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• 2020

Recent observation of the neutron star merger event, GW170817, through both gravitational wave (GW) and electromagnetic wave (EM) observations opened a new way of exploring the universe, namely, multi-messenger astronomy (MMA). One of the keys to the success of MMA is a rapid identification of EM counterpart. We will introduce GW follow-up observation project in Korea for hunting GW EM counterpart rapidly and its strategy for prioritization of GW source host galaxy candidates. Our method relies on recent simulation results regarding plausible properties of GW source host galaxies and the low latency localization map from LIGO/Virgo. We will show a test result for both binary neutron star merger events using previous event and describe observing strategy with our facilities for GW events during the ongoing LIGO/Virgo O3 run. Finally, we report the results of optical/NIR follow-up observation of GW190425, the first neutron.

• Smart Structures and Systems
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• v.11 no.5
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• pp.453-476
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• 2013

DuraMote is a remote sensing system developed for the "NIST TIP project: next generation SCADA for prevention and mitigation of water system infrastructure disaster". It is designed for supervisory control and data acquisition (SCADA) of ruptures in water pipes. Micro-electro mechanical (MEMS) accelerometers, which record the vibration of the pipe wall, are used detect the ruptures. However, the performance of Duramote cannot be verified directly on a water distribution system because it lacks an acceptable recordable level of ambient vibration. Instead, a long-span cable-stayed bridge is an ideal test-bed to validate the accuracy, the reliability, and the robustness of DuraMote because the bridge has an acceptable level of ambient vibration. The acceleration data recorded on the bridge were used to identify the modal properties of the structure and to verify the performance of DuraMote. During the test period, the bridge was subjected to heavy rain, wind, and a typhoon but the system demonstrates its robustness and durability.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.220-223
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• 2001

This study was carried out to developed that appraisement model of Potential Productivity Index (PPI). PPI model was used Farmland Productivity Index(FPI) and Labor Productivity Index(LPI) by GIS, and PPI model applied to farm land consolidation region which has been completed recently. FPI was determined by overlapping Poly Grid of the soil properties at the analyzed project region. LPI was estimated by addition productive wages ratio of total direct productive cost. Addition productive wages was determined by GIS Network analysis of working distance between farm house to paddy and each paddy. PPI variation of each the analyzed paddy of Masu and Weoncheon region was $0.967{\sim}0.712,\;0.986{\sim}0.780$ respectively, and could be showed relative largely PPI value. PPI will provide basic element for large scaling and gathering of farm land and a substitute lot of farm land consolidation, and will be maximize productivity of paddy.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.9
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• pp.442-445
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• 2006

In order to realize the commercial application of HTSC materials, it is necessary to develop the fabrication process of high Tc oxide superconductor materials with desired shape and for practical application and high critical current density as well as good mechanical strength which can withstand high lorenz force generated at high magnetic field. Much studies have been concentrated to develop the fabrication technique for high critical current density but still there are a lot of gap which should be overcome for large scale application of HTSC materials at liquid nitrogen temperature. Recently some new fabrication techniques have been developed for YBaCuO bulk superconductor with high mechanical strength and critical current density. In this project, the establishment of fabrication condition and additive effects of second elements were examined so as to improve the related properties to the practical use of YBaCuO superconductor, and we reported the production of the YBaCuO high Tc superconductor by the pyrolysis method.

• Advances in concrete construction
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• v.9 no.4
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• pp.397-406
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• 2020

The present article deals with post-buckling of geometrically imperfect concrete plates reinforced by graphene oxide powder (GOP) based on general higher order plate model. GOP distributions are considered as uniform and linear models. Utilizing a shear deformable plate model having five field components, it is feasible to verify transverse shear impacts with no inclusion of correction factor. The nonlinear governing equations have been solved via an analytical trend for deriving post-buckling load-deflection relations of the GOP-reinforced plate. Derived findings demonstrate the significance of GOP distributions, geometric imperfectness, foundation factors, material compositions and geometrical factors on post-buckling properties of reinforced concrete plates.

• Genomics & Informatics
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• v.16 no.3
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• pp.65-70
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• 2018

The non-coding DNA in eukaryotic genomes encodes a language which programs chromatin accessibility, transcription factor binding, and various other activities. The objective of this short report was to determine the impact of primary DNA sequence on the epigenomic landscape across 200-base pair genomic units by integrating nine publicly available ChromHMM Browser Extensible Data files of the Encyclopedia of DNA Elements (ENCODE) project. The nucleotide frequency profiles of nine chromatin annotations with the units of 200 bp were analyzed and integrative Markov chains were built to detect the Markov properties of the DNA sequences in some of the active chromatin states of different ChromHMM regions. Our aim was to identify the possible relationship between DNA sequences and the newly built chromatin states based on the integrated ChromHMM datasets of different cells and tissue types.

• Advances in concrete construction
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• v.5 no.1
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• pp.1-15
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• 2017

This research project aimed at evaluating experimentally the effect of natural perlite powder as an alternative supplementary cementing material (SCM) on the performance of fiber reinforced self-consolidating repair mortars (FR-SCRMs). For this purpose, four FR-SCRMs mixes incorporating 0%, 10%, 20%, and 30% of natural perlite powder as cement replacements were prepared. The evaluation was based on fresh (slump flow, flow time, and unit weight), hardened (air-dry unit weight, compressive and flexural strengths, dynamic modulus of elasticity), and durability (water absorption test) performances. The results reveal that structural repair mortars confronting the performance requirements of class R4 materials (European Standard EN 1504-3) could be designed using 10%, 20%, and 30% of perlite powder as cement substitutions. Bonding results between repair mortars containing perlite powder and old concrete substrate investigated by the slant shear test showed good interlocking justifying the effectiveness of these produced mortars.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.45.2-45.2
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• 2015

It is obvious that there are plentiful of dust particles in the interplanetary spaces of the Solar System (IDPs), based on micrometeor craters, zodiacal light and direct measurements on the spacecraft. Because of photon drag and planetary perturbations, these particles are continuously falling to the Sun or planets, therefore continuous source of the IDPs are required. We studied the fractional contribution of each type of solar system objects to the IDPs complex through the optical properties of the potential dust sources and the zodiacal light. We found that more than 90% of the IDPs are originated from cometary nuclei. This result is discussed through the comparison with the dynamic simulation, micrometeors mineralogy and near-infrared spectrum of the zodiacal light. In addition, we introduce our new project on the numerical simulation for the dust particles ejected from the cometary nuclei, to verify the conclusion of dominant cometary contribution and its detailed consequences.