• Resources Recycling
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• v.17 no.1
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• pp.29-37
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• 2008

Recently, domestically and internationally, the occurrences of Waste Glass are on the increase. Most of scrap glass are either reused of recycled. However, glass not recycled is buriedand is causing secondary environmental problem. With 5% mixture of Waste Glass, the average paste viscosity (rheology) decreased by 22.3% and 28-day compressive strength of mortar's flow and aging decreased by 1.5% and 6% respectively. Also, as Waste Glass mixture ratio of un-hardened elf-compacting concrete increased, fluidity increased and compressive strength decreased. In consideration of adequate compressive strength and fluidity that meets the 2nd class JSCE regulations; optimum mixture ratio of Waste Glass can be concluded as 20%.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.3
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• pp.328-338
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• 2021

A study on common modular design based on open standards to reduce the life cycle cost of ground weapon system is underway. Since the ground weapon system includes major mission equipment such as fire control system, it is essential to apply the concept of fault tolerance through automatic reconfiguration and blocking unspecified equipment through connectivity control. However, it is difficult to generalize due to the difference in operating characteristics for each system. In this paper, we propose a plug-and-play framework, which includes plug-and-play architecture and mechanism. The proposed method can be used in common by the application of each component as it is divided into a common service layer. In addition, the proposed connectivity control and autonomous reconfiguration method facilitates reflection of operating characteristics for each system. We constructed a verification environment that can simulate ground weapon systems and components, and verified that the proposed framework works through scenario-based functional tests.

• Molecules and Cells
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• v.44 no.11
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• pp.830-842
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• 2021

When perceiving microbe-associated molecular patterns (MAMPs) or plant-derived damage-associated molecular patterns (DAMPs), plants alter their root growth and development by displaying a reduction in the root length and the formation of root hairs and lateral roots. The exogenous application of a MAMP peptide, flg22, was shown to affect root growth by suppressing meristem activity. In addition to MAMPs, the DAMP peptide PEP1 suppresses root growth while also promoting root hair formation. However, the question of whether and how these elicitor peptides affect the development of the vascular system in the root has not been explored. The cellular receptors of PEP1, PEPR1 and PEPR2 are highly expressed in the root vascular system, while the receptors of flg22 (FLS2) and elf18 (EFR) are not. Consistent with the expression patterns of PEP1 receptors, we found that exogenously applied PEP1 has a strong impact on the division of stele cells, leading to a reduction of these cells. We also observed the alteration in the number and organization of cells that differentiate into xylem vessels. These PEP1-mediated developmental changes appear to be linked to the blockage of symplastic connections triggered by PEP1. PEP1 dramatically disrupts the symplastic movement of free green fluorescence protein (GFP) from phloem sieve elements to neighboring cells in the root meristem, leading to the deposition of a high level of callose between cells. Taken together, our first survey of PEP1-mediated vascular tissue development provides new insights into the PEP1 function as a regulator of cellular reprogramming in the Arabidopsis root vascular system.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.3
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• pp.497-506
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• 2024

In this paper, medium-power wireless power transmission is implemented using the commercial power frequency (60 Hz). Since general magnetic induction wireless power transmission devices use more than several tens of kHz, the commercial power frequency (60 Hz) cannot be used as is. Therefore an AC/DC converter is used to convert the 60 Hz power frequency into DC, and a high-frequency power amplifier is used to convert DC into several tens of kHz. In magnetic induction wireless power transmission, the AC/DC converter and high-frequency power amplifier are removed, and a extremely low frequency wireless power transmission(ELF-WPT) system using commercial frequency consisting of only transmitting resonance tank, transmitting coil, receiving resonance tank, and receiving coil is implemented, and verified through wireless power transmission experiments.

• Journal of Animal Science and Technology
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• v.50 no.5
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• pp.641-648
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• 2008

There has been great success for making transgenic animals using somatic cell nuclear transfer(SCNT) up to this time. However, the success rates of the production of live transgenic animals are still very low. The current research has been carried out for delineation of differentially expressed genes between SCNT and normal placenta in cattle. In the present observations, high expression has been observed for CTSZ, LOC509426 and ELF1 genes in normal placenta. On the other hand, TIMP2, PAG1B, PAG-21, LOC782894, SERPINB6 and mKIAA2025 protein were highly expressed in SCNT placenta. Five genes, which were highly expressed in SCNT placenta, have been further investigated using semi-quantitative real-time PCR. The results were similar to that we observed using ACP. In the future, all genes affecting the SCNT and normal placenta have to be discovered and their networks will be fully investigated. The genes were identified in this study would be great help for identifying differential gene expressions in SCNT placenta.

• Tuberculosis and Respiratory Diseases
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• v.60 no.3
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• pp.297-303
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• 2006

Background : Pulmonary tuberculosis is frequently accompanied with complications such as bronchiectasis, cavities, fibrosis and a deterioration of the lung function. However, there is little information available on the pathogenesis of these complications in pulmonary tuberculosis. Among the many factors involving in tissue remodeling, transforming growth factor-${\beta}1$ ($TGF-{\beta}1$) is a potent stimulus of the extracellular matrix fomation and a mediator of potential relevance for airway wall remodeling. Therefore, this study examined the relationship between the radiological changes and the $TGF-{\beta}1$ level in patients with pulmonary tuberculosis. Methods : Serum and bronchoalveolar lavage fluid (BALF) were collected from total of 35 patients before treating them for active pulmonary tuberculosis, and the $TGF-{\beta}1$ levels were measured using an enzyme-linked immunosorbent assay (ELISA). The BALF levels were recalculated as the epithelial lining fluid (ELF) levels using the albumin method. pulmonary function test (PFT) and high resolution computed tomography (HRCT) were performed before and after treatment. Results : There was a strong correlation between the serum $TGF-{\beta}1$ level and the presence of cavities (r=0.404, p=0.006), even though the BAL $TGF-{\beta}1$ level showed a weak correlation with complications. In addition, there was no correlation between the $TGF-{\beta}1$ levels before treatment and the changes in the PFT and HRCT during treatment. Conclusion : There is a correlation between the serum $TGF-{\beta}1$ level and cavity formation in pulmonary tuberculosis before treatment. However, further study will be needed to confirm this.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.509-517
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• 2014

Objectives: This study was conducted to investigate the patterns of exposure of welders to strong magnetic fields for extended periods of time on the basis of their daily activities as recorded in a logbook. Methods: Male workers whose main job is welding, specifically seven welders occupied with gas tungsten arc welding(GTAW), two performing shielded metal arc welding(SMAW), and ten engaged in gas metal arc welding(GMAW), were measured in terms of the degree to which they were exposed to extremely low frequency(ELF) magnetic fields over 24 hours by using an electromagnetic field meter(EMF meter), as well as based on a daily activity log. Results: The welders were exposed to $1.25{\pm}4.95{\mu}T$ of magnetic field per day on average. For those who spent more than half a day-735.26 minutes, or 51.1% of the day-at work, the figure averages $3.88{\pm}8.85{\mu}T$ with a maximum value of $221.28{\mu}T$. The subject welders spent $338.14{\pm}154.95$ minutes per day at home. During their stays at home, they were exposed to an average of $0.17{\pm}0.06{\mu}T$ with a maximum value of $3.50{\mu}T$. The maximum exposure of $221.28{\mu}T$ occurred when welders performed GMAW. The average exposure reached its highest at $17.71{\pm}6.96{\mu}T$ when conducting SMAW. Magnetic field exposure also depends upon posture: welders who sat while welding were exposed five times more than those who stood during work, and this difference is statistically significant. As for the relationship between distance from the welding power supply and maximum magnetic field exposure, maximum magnetic field exposure decreases as the distance increases. The average magnetic field exposure, in the meantime, showed no significant difference depending on distance. Conclusions: The following were observed through this study: 1) welders, while conducting jobs, are exposed to magnetic fields not only from the welding machine, but also from the surrounding base material due to the current flowing between the welding machine and base material, meaning that they are continuously exposed to a magnetic field; and 2) welders are more exposed to magnetic fields while they sit at a job compared to when they stand up.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.7
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• pp.639-647
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• 2009

In this work, wrapping conductors with thin magnetic materials is proposed as a magnetic shielding method. The 0.1 mm thick metal sheets of mu-metal, grain-oriented electrical steel, and non-oriented electrical steel were produced from commercial alloy sheets through cold rolling and followed high temperature annealing. In case of 3-phase electric currents, mu-metal was the best in shielding performance at a B-field magnitude of about 100 ${\mu}T$, whereas silicon steels were better than mu-metal at a B-magnitude over 500 ${\mu}T$. In addition, wrapping with silicon steel(inner) together with mu-metal(outer) resulted in a shielding factor less than 0.1 even at 500 ${\mu}T$. These results are due to changes in hierarchy of magnetic permeabilities of the materials with increasing magnetic field strength. In case of single-phase electric current, B-magnitude outside the magnetic shell was rather increased compared to the unshielded case. This result is explained by vector composition of B-fields near magnetic shielding materials.

• Korean Journal of Microbiology
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• v.34 no.3
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• pp.101-107
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• 1998

Biological treatment of Arabian light crude oil-contaminated pebble was investigated in laboratory microcosms after supplementation with inorganic nutrients and oil-degrading microorganisms. Glass columns ($10cm{\times}20cm$) were used as microcosms and each microcosm was filled with pebbles of diameter less than 40 mm. After initial oil contamination of 2.4% (w/v), Inipol EAP-22 or slow release fertilizer (SRF) was added as inorganic nutrients and microorganisms were sprayed over pebbles. When $C_{17}$/pristane and $C_{18}$/phytane ratios were used as a marker for oil biodegradation, both ratios for microcosm supplemented with SRF and microorganisms were the lowest (below detectable range) after 92 days. Elimination of oil by abiotic processes, however, were minimal with decrease of $C_{17}$/pristane and $C_{18}$/phytane ratios from 3.55 and 2.41 to 3.06 and 1.50, respectively. The numbers of heterotrophic and oil-degrading microorganisms, and biological activity (dehydrogenase activity) corresponded to the course of biodegradation activities in all microcosms. During the whole experimental period, there was no significant nutrient deficiency only in the microcosm with SRF and microorganisms. It seemed that a continuous supply of inorganic nutrients using SRF was the most important factor for the successful performance of biological treatment in oil-contaminated pebbles.

• Science of Emotion and Sensibility
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• v.13 no.4
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• pp.721-732
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• 2010

As increasing of electrical device usage, social concerns about the possible effects of 60Hz electromagnetic fields (EMF) on human health have increased. The number of people with self-attributed electromagnetic hypersensitivity (EHS) who complain of subjective symptoms such as headache, insomnia etc. also increased. However, we don't know whether the EHS results from psychological factor or real perception to the electromagnetic field. In this study, we simultaneously investigated physiological changes(heart rate, respiration rate, heart rate variability, alpha and beta waves in EEG), subjective symptoms and perception accuracy to assess origins of subjective symptoms according to the EMF exposure. Experiment consists of real and sham sessions and 60Hz 12.5uT magnetic field was on(real) or off(sham) to 15 EHS and 16 nonEHS. As the results, EMF exposure did not have any effects on physiological parameters or subjective symptoms for both groups. There was also no evidence that EHS group perceived the EMFs correctly than the control group. Therefore, the origins of subjective symptoms is not the 60Hz magnetic field but psychological factors.