• Membrane Journal
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• v.21 no.1
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• pp.13-21
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• 2011

This study investigated the fouling behavior of $Al_2O_3$ colloids on polyethylene microfiltration membrane. To examine the effect of operation variation on fouling, operating pressure was increased from 0.49 to 1.96 bar along with time elapses and then was reduced to 0.49 bar reversely. A hysteresis behavior was observed in the membrane permeate flux over pressure, revealing different fluxes at the same pressure according to the pressure control type, increasing and decreasing. Permeate resistance and its rate of increase was higher in the decreasing pressure cycle than in the increasing pressure cycle. At the initial period of filtration, fouling mechanism for the both cycles was governed by the cake filtration. The degree of fouling was higher in the decreasing pressure cycle compared with in the increasing pressure cycle.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.755-760
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• 2008

The aim of this study was to produce resistant starch preparations from acid-modified com starches prepared at various hydrolysis levels (0.5-4.0 hr). Effect of autoclaving cycles on resistant starch (RS) formation was investigated. Molecular weight distribution, pasting and functional properties of acid-modified com starches were determined. For RS formation native and acid-modified starch samples were gelatinized and autoclaved (1 or 2 cycles). While native and acid-modified starches did not contain any RS, the levels increased to 9.0-13.5% as a result of storage at $95^{\circ}C$ after first autoclaving cycle. Second autoclaving cycle together with storage at $95^{\circ}C$ brought final RS contents of the samples incubated at 4 and $95^{\circ}C$ after the first cycle to comparable level. As acid modification level increased, the amount of high molecular weight fractions decreased, resulting in significant decreases in viscosities (p<0.05). The samples produced in this study had low emulsion stability and capacity values.

• Journal of Information Processing Systems
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• v.19 no.5
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• pp.663-672
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• 2023

Most vehicle detection methods have poor vehicle feature extraction performance at night, and their robustness is reduced; hence, this study proposes a night vehicle detection method based on style transfer image enhancement. First, a style transfer model is constructed using cycle generative adversarial networks (cycleGANs). The daytime data in the BDD100K dataset were converted into nighttime data to form a style dataset. The dataset was then divided using its labels. Finally, based on a YOLOv5s network, a nighttime vehicle image is detected for the reliable recognition of vehicle information in a complex environment. The experimental results of the proposed method based on the BDD100K dataset show that the transferred night vehicle images are clear and meet the requirements. The precision, recall, mAP@.5, and mAP@.5:.95 reached 0.696, 0.292, 0.761, and 0.454, respectively.

• Journal of Embryo Transfer
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• v.31 no.4
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• pp.323-333
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• 2016

Pro-inflammatory cytokines, interleukin-$1{\beta}$(IL1B), IL6, and tumor necrosis factor-alpha (TNF), are known to play important roles in regulating the endometrial function in the uterus during the estrous cycle and pregnancy in several species. However, the expression and function of these cytokines and their receptors in the uterine endometrium during the estrous cycle have not been studied in pigs. Thus, this study determined the expression and regulation of IL1B, IL6, TNF and their respective receptors, IL1R1, IL1RAP, IL6R, GP130, TNFRSF1A, and TNFRSF1B during the estrous cycle in pigs. To analyze levels of each gene expression in the uterine endometrium we obtained from endometrial tissues on Days 0, 3, 6, 9, 12, 15, and 18 of the estrous cycle. Real-time RT-PCR analysis showed that levels of IL1B, IL1RAP, IL6R, GP130, TNF, TNFRSF1A, and TNFRSF1B mRNAs were highest on Day 15 or 18 of the estrous cycle, which corresponds to the proestrus period. Levels of IL1R1 were highest on Day 0, while levels of IL6 were biphasic with high levels on Day 6 and Day 15. The abundance of IL1B, IL6, IL6R, and TNF mRNAs was decreased by progesterone, while levels of GP130 were increased by progesterone in endometrial tissue explants. These results showed that expression of pro-inflammatory cytokines and their receptors changed stage-specifically during the estrous cycle and regulated by progesterone in the uterine endometrium in pigs, suggesting that these pro-inflammatory cytokines may be involved in the regulation endometrial function during the estrous cycle in pigs.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.2
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• pp.113-119
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• 2017

In this paper, we have shown the performance analysis results of the LoRa low power wide area network under duty cycle local regulation in Korean RFID/USN frequency band. Especially, we analyzed uplink throughput and data transmission time of a single LoRa end device. From the analysis results, duty cycle regulation, in which a data transmission should be ended within 0.4 second, limits the performance of LoRa network. Therefore, it is necessary to revise Korea's duty cycle regulation referencing EU regulation in order to assess LoRa network in Korea.

• Proceedings of the Microbiological Society of Korea Conference
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• 1998.04a
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• pp.49.1-49.1
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• 1998

• Transactions of the Korean Society of Mechanical Engineers
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• v.6 no.2
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• pp.101-106
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• 1982

This study was undertaken to determine tensile properties and low-cycle fatigue behavior of 0.6%C high carbon steel used of structural purposes at temperatures up to 500.deg.C. In the low-cycle fatigue test the upper limit was decided by elongation(i.e. the total strain range), while the lower limit was defined by the load (i.e. zero load). The following results were obtained. Both, the ultimate tensile strength and low-cycle fatigue resistance attain the maximum values near 250.deg.C. Above this temperature the values decrease rapidly as the temperature increases. The low-cycle fatigue resistance decreases whenever there is an increase of the total strain range. Because the hardness of cycle fatigued specimen correlates cyclic hardening and cyclic softening, therefore the hardness of cycle fatigued specimen is smaller than that of the nonfatigued specimen at room temperature and 500.deg.C but much larger than the hardness of the nonfatigued specimen near 250.deg.C.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.1013-1019
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• 2011

In this paper, simulation works for a multi-stage cascade refrigeration cycle using propane, ethylene and methane as refrigerants have been performed for the liquefaction of natural gas using Peng-Robinson equation of state built-in PRO/II with PROVISION release 8.3. The natural gas feed compositions were supplied from Korea Gas Corporation and the flow rate was assumed to be 5.0 million tons per annual. Supply temperature for propane refrigerant was fixed as $-40^{\circ}C$, that for ethylene refrigerant as $-95^{\circ}C$, and that for methane refrigerant as $-155^{\circ}C$. For the multi-stage refrigeration cycle, three-stage refrigeration was assumed for propane refrigeration cycle, two-stage refrigeration for ethylene refrigeration cycle and three-stage refrigeration for methane refrigeration cycle. Natural gas was finally cooled and liquefied to $-162^{\circ}C$ by Joule-Thomson expansion. Conclusively, 91.71% by mole of the natural gas liquefaction ratio was obtained through a cascade refrigeration cycle and Joule-Thomson expansion and 0.433 kW of compression power was consumed for the liquefaction of 1.0 kg/hr of natural gas.

• Molecules and Cells
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• v.24 no.3
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• pp.424-430
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• 2007

The biological effects of low-dose radiation have been investigated and debated for more than a century, but its cellular effects and regulatory mechanisms remain poorly understood. This study shows the human cellular responses to low-dose radiation in CCD-18 Lu cells, which are derived from normal human lung fibroblasts. We examined a colony-forming assay for cell survival by ionizing radiation. Live cell counting and cell cycle analysis were measured for cell proliferation and cell cycle progression following low-dose irradiation. We examined Raf and Akt phosphorylation to determine the proliferation mechanism resulting from low-dose radiation. We also observed that p53 and p21 were related to cell cycle response. We found that 0.05 Gy of ionizing radiation enhanced cell proliferation and did not change the progression of the cell cycle. In addition, 0.05 Gy of ionizing radiation transiently activated Raf and Akt, but did not change phospho-p53, p53 and p21 in CCD-18 Lu cells. However, 2 Gy of ionizing radiation induced cell cycle arrest, phosphorylation of p53, and expression of p53 and p21. The phosphorylation of Raf and Akt proteins induced by 0.05 Gy of ionizing radiation was abolished by pre-treatment with an EGFR inhibitor, AG1478, or a PI3k inhibitor, LY294002. Cell proliferation stimulated by 0.05 Gy of ionizing radiation was blocked by the suppression of Raf and Akt phosphorylation with these inhibitors. These results suggest that 0.05 Gy of ionizing radiation stimulates cell proliferation through the transient activation of Raf and Akt in CCD-18 Lu cells.

• Journal of Korea Water Resources Association
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• v.45 no.2
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• pp.203-215
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• 2012

The objective of this study is to develop a catchment hydrologic cycle assessment model which can assess the impact of urban development and designing water cycle improvement facilities. Developed model might contribute to minimize the damage caused by urban development and to establish sustainableurban environments. The existing conceptual lumped models have a potential limitation in their capacity to simulate the hydrologic impacts of land use changes and assess diverse urban design. The distributed physics-based models under active study are data demanding; and much time is required to gather and check input data; and the cost of setting up a simulation and computational demand are required. The Catchment Hydrologic Cycle Assessment Tool (hereinafter the CAT) is a water cycle analysis model based on physical parameters and it has a link-node model structure. The CAT model can assess the characteristics of the short/long-term changes in water cycles before and after urbanization in the catchment. It supports the effective design of water cycle improvement facilities by supplementing the strengths and weaknesses of existing conceptual parameter-based lumped hydrologic models and physical parameter-based distributed hydrologic models. the model was applied to Seolma-cheon catchment, also calibrated and validated using 6 years (2002~2007) hourly streamflow data in Jeonjeokbigyo station, and the Nash-Sutcliffe model efficiencies were 0.75 (2002~2004) and 0.89 (2005~2007).