• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.2
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• pp.267-272
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• 2017

Piceatannol (PIC) is a natural hydroxylated analog of resveratrol (RSV), which is a polyphenol known to extend lifespan by stimulating sirtuins. The aim of this study was to investigate the effects of PIC and RSV on the toll-like receptor 4 (TLR4)-nuclear factor kappa B ($NF-{\kappa}B$) pathway in mouse hepatocytes and an obese/diabetic KK/HlJ mouse model. AML12 mouse hepatocytes in the absence or presence of palmitic acids (PA) were treated with PIC ($50{\mu}M$) or RSV ($50{\mu}M$). Male KK/HlJ mice at 20 weeks of age were divided into three subgroups as follows: 1) obese and diabetic control (KK), 2) KK_PIC, and 3) KK_RSV. PIC and RSV were administered orally at a dose of 10 mg/kg/d for 4 weeks. Four weeks of PIC and RSV treatment did not affect body weight or food intake in KK mice. Serum fasting blood glucose was significantly reduced in KK_PIC, and 2 h oral glucose tolerance test area under the curve was significantly reduced by PIC and RSV treatment in KK mice. PIC tended to improve homeostasis model assessment of the insulin resistance index (HOMA-IR) and HOMA beta-cells in diabetic KK mice. TLR4 and $NF-{\kappa}B$ were down-regulated by PIC and RSV treatments in hepatocytes in the absence or presence of PA. Insulin receptor, AMP-activated protein kinase, peroxisome proliferator-activated receptor gamma, nucleotide oligomerization domain-like receptor family pyrin domain-containing 3, interleukin-1, and $NF-{\kappa}B$ were altered in PIC-treated livers. Collectively, PIC and RSV inhibited the $TLR4-NF-{\kappa}B$ pathway, and PIC seems to be more effective than RSV in the regulation of analyzed targets, which are involved in insulin signaling and inflammation in vivo.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.7
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• pp.911-918
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• 1997

The turbulent viscous wake flows behind a single airfoil, two-dimensional stationary blade row and three-dimensional rotating blade row were calculated, and the numerical results were compared with experimental ones. The numerical technique was based on the SIMPLE algorithm using three turbulent closure models, standard k-.epsilon. model(WFM), low Reynolds number k-.epsilon. model(LRN) and Reynolds stress model (RSM). In the case of a single airfoil, WFM, LRN and RSM presented fairly good velocity distributions in the wake compared with experimental data. In the case of the stationary blade row, LRN and RSM presented better results than WFM for wake velocity distribution, and especially LRN showed best results among these three turbulent models. In the case of the rotating blade row, WFM and LRN showed fairly good agreement with experimental data of the three-dimensional velocity component distributions in the range from hub to mid span region. LRN was also superior to WFM in accuracy of prediction for the wake velocity distribution as same with the cases of a airfoil and the stationary blade row.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.245-249
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• 2013

In this paper, we propose two rate control algorithms for multi-view extension of HEVC with two rate control algorithms adopted in HEVC and analyze the multi-view rate control performance. The proposed multi-view rate controls are designed on HEVC-based multi-view video coding (MV-HEVC) platform with consideration of high-level syntax, inter-view prediction, etc. not only for the base view but also for the extended views using the rate control algorithms based on URQ (Unified Rate-Quantization) and R-lambda model adopted in HEVC. The proposed multi-view rate controls also contain view-wise target bit allocation for providing the compatibility to the base view. By allocating the target bitrates for each view, the proposed multi-view rate control based on URQ model achieved about 1.83% of average bitrate accuracy and 1.73dB of average PSNR degradation. In addition, about 2.97% of average bitrate accuracy and 0.31dB of average PSNR degradation are achieved with the proposed multi-view rate control based on R-lambda model.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.1
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• pp.101-108
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• 2016

The RCS characteristics of stealth modified three-surface aircraft are analyzed in this paper. Prototype A is built with CATIA software and the three-dimensional digital models of modified stealth three-surface B and C are also designed based on carrier-based aircraft Su-33; the numerical simulation of RCS characteristics of three-surface aircraft is conducted with RCSAnsys software based on physical optics method and the method of equivalent currents; The following results are obtained by comparative analysis and mathematical statistics: (1) by the use of physical optics method and equivalent electromagnetic current method, the scattering intensity for each part of the model and RCS characteristic of the aircraft can be analyzed efficiently and accurately; (2) compared with model A, the mean RCS value of model B is reduced to 14.1% in forward direction and 48.1% in lateral direction; (3) compared with model A, the mean RCS value of model C decreases to 11.4% in forward direction and 21.6% in lateral direction. The results are expected to provide theoretical basis and technical support to the conceptual design of aircraft and stealth technology research.

• Environmental Engineering Research
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• v.22 no.4
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• pp.417-425
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• 2017

Indonesia is known as the largest oil palm producer in the world. However, along with the production, it generates wastes and pollution that caused the environmental problem in surrounding areas. Previous researchers reported that the high palm oil mill effluent (POME) concentration inhibited microalgae growth. However, the inhibition factor was not clearly explained by using kinetic model. This study presents kinetic models of Botryococcus braunii (B. braunii) cultivated on POME wastewater under different turbidity condition. Results showed that the growth model of Zwietering was closely suitable with experimental results. It was found that B. braunii was able to consume organic carbon from the POME wastewater on the logarithmic model. A modified kinetic model of Monod Haldane described the influence of turbidity and chemical oxygen demand on the cultivation. Turbidity of POME medium inhibited the growth rate at KI 3.578 and KII 179.472 NTU, respectively. The Lipid (39.9%), and carbohydrate (41.03%) were found in the biomass that could be utilized as biofuel source.

• Journal of IKEEE
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• v.13 no.3
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• pp.39-46
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• 2009

Wireless sensor networks consist of small, autonomous devices with wireless networking capabilities. In order to further increase the applicability in real world applications, minimizing energy consumption is one of the most critical issues. Therefore, accurate energy model is required for the evaluation of wireless sensor networks. In this paper we analyze the power consumption for wireless sensor networks. To develop the power consumption model, we have measured the power characteristics of commercial Kmote node based on TelosB platforms running TinyOS. Based on our model, the estimated lifetime of a battery powered sensor node can use about 6.9 months for application of human detection using PIR sensors. This result indicates that sensor nodes can be used in a monitoring system for elderly living alone.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.2 s.257
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• pp.141-150
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• 2007

This paper presents a lumped model to predict crosstalk characteristics of thermally driven inkjet print heads. Using the lumped R-C model, heating characteristics of the head are predicted to be in agreement with IR temperature measurements. The inter-channel crosstalk is simulated using the lumped R-L network. The values of viscous flow resistance, R and flow inertance, L of connecting channels are adjusted to accord with the 3-D numerical simulation results of three adjacent jets. The crosstalk behaviors of a back shooter head as well as a top shooter head have been investigated. Predictions of the proposed lumped model on the meniscus oscillations are consistent with numerical simulation results. Comparison of the lumped model with experimental results identifies that abnormal two-drop ejection phenomena are related to the increased meniscus oscillations because of the more severe crosstalk effects at higher printing speeds. The degree of crosstalk has been quantified using cross-correlations between neighboring channels and a critical channel dimension for acceptable crosstalk has been proposed and validated with the numerical simulations. Our model can be used as a design tool for a better design of thermal inkjet print heads to minimize crosstalk effects.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.3
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• pp.219-229
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• 1996

Path loss prediction method, one of the most essential parts in measuring the service area in mobile telecommunication, has been developed for many years. But, wave propagation depends on many kinds of environmental factors such as frequency, distance, the heights of transmitting and receiving antenna and the terrain status(buildings in large city, hilly terrain, mountain). These are the main reasons that the propagation models developed in foreign environments can not fit into Korean propagation condition. In this paper, therefore, we performed the measurement in Korean terrain environment in pager frequency band after deviding the terrain characteristics into six types. With this measured data, we derived several curves that follows the long-term wave progagation behavior and developed the wave propagftion prediction model which calculates the field strength at any point in the service area. The proposed model estimates the field strength in two categories, LOS(line-of-sight), or non LOS. We applied this model using the digital terrain data base and compared with the measured data. The result shows that the errors were between 3~9dB, which turned out to be practical.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.2
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• pp.457-463
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• 2009

This study aimed to evaluate the anti-asthmatic effects of Seonpye-tang (SPT) using OVA-induced asthmatic mice model. Scavenging activity of SPT on DPPH free radical and SOD-like activity of SPT were measured at final concentration 62.5, 125, 250, 500 (${\mu}g/m{\ell}$), RBL-2H3 cells were treated with DNP IgE for 24hr, and treated with SPT (1, 10, 100 ${\mu}g/m{\ell}$) for 1hr, followed by treatment with DNP-HSA for 1hr at $37^{\circ}C$. The level of IL-4 and TNF-${\alpha}$ were measured by ELISA. Asthmatic mice model was conducted by repeated challenge of OVA using C57BL/6 mice. Each group was treated with distilled water, SPT (400 mg/kg and 200 mg/kg) extract or cyclosporin A (10 mg/kg) for the later 8 weeks. Immune cells subpopulation, eotaxin, IL-5 and TNF-${\alpha}$ in BALF were analyzed. SPT dose-dependently increased Scavenging activity on DPPH free radical and SOD-like activity. SPT significantly ameliorated the increase of total cells number and eosinophil including of immune cell subpopulation of $CD3^+/CD69^+$, $CCR3^+$, $B220^+/CD22^+$, $B220^+/CD45^+$ and $B220^+/IgE^+$ cells in BALF comparing to control group. Eotaxin and IL-5 level in BALF were significantly decreased by SPT. These results strongly suggest that SPT would be a effective candidate for herbal-originated anti-asthmatic drug. However, this drug should be further studied for characterization of the accurate action and underlying mechanisms using variant disease model in the future.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.6
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• pp.529-539
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• 2008

Background and Purpose : Oral squamous cell carcinoma (OSCC) is one of the most aggressive tumors of the head and neck area. OSCC is known to preferentially metastasize via lymphatic system, and resulting cervical lymph node metastasis is the most reliable of treatment failure. But the biological mechanism of the regional nodal metastasis is not clear. So, we determined metastasis-related factors in orthotopic nude mouse models of OSCC. Experimental Design : Two cell lines-KB and YD-10B cells, established from human oral mucosal squamous cell carcinoma, were xenografted into the tissue space of athymic murine mouth floor. The mice were followed for tumor development and growth, the murine tumors were examined histopathologically for local invasion or regional or distant metastasis. Finally, we performed immunohistochemical assays with antiepithelial growth factor (EGF), EGF receptor (EGFR), phosphorylated EGFR (pEGFR), and anti-vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR)-2, phosphorylated VEGFR-2/3 (pVEGFR-2/3) antibodies. We also determined the microvessel density. Results : Transplantation of human OSCC tumor cells into the mouth floor successfully resulted in the formation of orthotopic tumors. KB cell line showed significantly higher tumor proliferation and higher nodal metastatic potential than YD-10B cell line. Furthermore, immunohistochemical staining demonstrated higher expression of EGFR/pEGFR, VEGF, and pVEGFR-2/3 as well as higher microvessel density in KB murine tumors than in YD-10B murine tumors. Conclusion : An orthotopic model of OSCC in athymic mice was established which copies the cervical lymph nodal metastasis of human OSCC. Our mouth floor model should facillitate the understanding of the molecular pathogenesis of cervical nodal metastasis of OSCC.