• Korean Journal of Materials Research
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• v.13 no.1
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• pp.31-35
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• 2003

The intensity is measured as functions of both distance from filament to substrate and $CH_3$OH/($CH_3$OH＋$H_2$O) ratio by OES(Optical Emission Spectroscopy) to investigate the effects of activation species such as $H_{\alpha}$, $H_{\beta}$, H$\Upsilon\;C_3$, CH on diamond film growth.$ H_{\alpha}$ increases as $CH_3$OH composition decreases, while CH increases as $CH_3$OH composition increases. The intensity of $H_{\alpha}$ decreases as the distance increases and that of CH increases as the distance increases. The intensities of other activation species of $H_{\beta}$, H$\Upsilon\;C_3$, do not vary as a function of measured position distance. It varies randomly. It means that various parameters for depositing diamond thin film can be explained by the intensity(density) change of activation species, as a function of the distance of the filament.

• Molecules and Cells
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• v.20 no.2
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• pp.183-188
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• 2005

INI1/hSNF5/BAF47 is a core component of the hSWI/ SNF ATP-dependent chromatin remodeling complex, and it has been implicated in regulating gene expression, cell division and tumorigenesis. We investigated whether INI1/hSNF5/BAF47 functions in activation of the colony stimulating factor 1 (CSF1) promoter in HeLa cells. Overexpression of INI1/hSNF5/BAF47 promoted CSF1 transcription, and siRNA targeting INI1/hSNF5/ BAF47 (siINI1) strongly inhibited the activity of the CSF1 promoter. We demonstrated that all conserved domains of INI1/hSNF5/BAF47 are needed for CSF1 transcription. ChIP experiment showed that INI1/ hSNF5/BAF47 is recruited to the region of the CSF1 promoter. Taken together, these results indicate that INI1/hSNF5/BAF47 is involved in activation of the CSF1 promoter.

• Natural Product Sciences
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• v.25 no.2
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• pp.165-171
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• 2019

Although the functions of a standardized extract of Gingko biloba leaves (EGb $761^{(R)}$) has been reported with regard to neurobiological properties, no attention has been paid to the impact of EGb $761^{(R)}$ on the neuronal regulation of energy homeostasis. To evaluate the hypothesis that EGb $761^{(R)}$ affect the secretion of peptide tyrosine tyrosine (PYY) and the activation of free fatty acid receptor 4 (FFA4), which are involved in the neuronal circuitries that control energy homeostasis by inducing the transfer of information about the influx of energy to the brain, we examined whether EGb $761^{(R)}$ can stimulate PYY secretion in the enteroendocrine NCI-H716 cells and if EGb $761^{(R)}$ can activate FFA4 in FFA4-expressing cells. In NCI-H716 cells, EGb $761^{(R)}$ stimulated PYY secretion and the EGb $761^{(R)}$-induced PYY secretion was involved in the increase in intracellular $Ca^{2+}$ concentration and the activation of FFA4. Furthermore, in FFA4-expressing cells, EGb $761^{(R)}$ activated FFA4. These results suggest that EGb $761^{(R)}$ may affect the control of energy homeostasis via the regulation of PYY secretion and FFA4 activation.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.2
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• pp.56-64
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• 1998

Multi-layered perceptrons that are a nonlinear neural network model, have been widely used for various applications mainly thanks to good function approximation capability for nonlinear fuctions. However, for digital hardware implementation of the multi-layere perceptrons, the quantization scheme using "look-up tables (LUTs)" is commonly employed to handle nonlinear signmoid activation functions in the neworks, and thus requires large amount of storage to prevent unacceptable quantization errors. This paper is concerned with a new effective methodology for digital hardware implementation of multi-layered perceptrons, and proposes a "piecewise affine approximation" method in which input domain is divided into (small number of) sub-intervals and nonlinear sigmoid function is linearly approximated within each sub-interval. Using the proposed method, we develop an expression and an error backpropagation type learning algorithm for a multi-layered perceptron, and compare the performance with the quantization method through Monte Carlo simulations on XOR problems. Simulation results show that, in terms of learning convergece, the proposed method with a small number of sub-intervals significantly outperforms the quantization method with a very large storage requirement. We expect from these results that the proposed method can be utilized in digital system implementation to significantly reduce the storage requirement, quantization error, and learning time of the quantization method.quantization method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.101-106
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• 2006

The geoidal undulations are needed for determining the orthometric heights from the Global Positioning System GPS-derived ellipsoidal heights. There are several methods for geoidal undulation determination. The paper presents a method employing a simple architecture Two Layer Multiquadric-Biharmonic Artificial Neural Network (TLMB-ANN) to approximate an area of 4200 square kilometres quasigeoid surface with GPS-levelling data. Hardy’s Multiquadric-Biharmonic functions is used as the hidden layer neurons’ activation function and Levenberg-Marquardt algorithm is used to train the artificial neural network. In numerical examples five surfaces were compared: the gravimetric geometry hybrid quasigeoid, Support Vector Machine (SVM) model, Hybrid Fuzzy Neural Network (HFNN) model, Traditional Three Layer Artificial Neural Network (ANN) with tanh activation function and TLMB-ANN surface approximation. The effectiveness of TLMB-ANN surface approximation depends on the number of control points. If the number of well-distributed control points is sufficiently large, the results are similar with those obtained by gravity and geometry hybrid method. Importantly, TLMB-ANN surface approximation model possesses good extrapolation performance with high precision.

• YAKHAK HOEJI
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• v.50 no.4
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• pp.244-253
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• 2006

Effects of chrysene on immune functions were studied in female BALB/c mice. When mice were treated po with chrysene for 7 consecutive days, the antibody response was suppressed dose-dependently. Chrysene induced the enzyme activities of CYP LA and 2B time- and dose-dependently. In ex vivo lymphocyte proliferation, chrysene inhibited splenocyte proliferation by LPS and Con A. Moreover, the numbers of $CD4^+IL-2^+$ cells were reduced by chrysene. In conclusion, chrysene-induced immunotoxicity might be mediated, at least in part, via IL-2 production, and caused by mechanisms associated with metabolic activation.

• Journal of Medicine and Life Science
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• v.15 no.2
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• pp.62-66
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• 2018

A-type $K^+$ ($I_A$) channels are transiently activated in the suprathreshold membrane potential and then rapidly inactivated. These channels play roles to control the neuronal excitability in pyramidal neurons in hippocampi. We here electrophysiologically tested if regulatory functions of $I_A$ channels might be targeted by acute activation of glutamatergic synaptic transmission in cultured hippocampal neurons(DIV 6~8). The application of high KCl in recording solutions(10 mM, 2 min) to increase presynaptic glutamate release, significantly reduced the peak of somatic $I_A$ without changes of gating kinetics. This indicates that neuronal excitation induced by the enhancement of synaptic transmission may process with distinctive signaling cascades to affect voltage-dependent ion channels in hippocampal neurons. Therefore, it is possible that short-lasting enhancement of synaptic transmission is functionally restricted in local synapses without effects on intracellular signaling cascades affecting a whole neuron, efficiently and rapidly enhancing synaptic functions in hippocampal network.

• Atmosphere
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• v.31 no.1
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• pp.73-83
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• 2021

Numerical weather prediction (NWP) models play an essential role in predicting weather factors, but using them is challenging due to various factors. To overcome the difficulties of NWP models, deep learning models have been deployed in weather forecasting by several recent studies. This study adapts long short-term memory (LSTM), which demonstrates remarkable performance in time-series prediction. The combination of LSTM model input of meteorological features and activation functions have a significant impact on the performance therefore, the results from 5 combinations of input features and 4 activation functions are analyzed in 9 Automated Surface Observing System (ASOS) stations corresponding to cities/islands/mountains. The optimized LSTM model produces better performance within eight forecast hours than Local Data Assimilation and Prediction System (LDAPS) operated by Korean meteorological administration. Therefore, this study illustrates that this LSTM model can be usefully applied to very short-term weather forecasting, and further studies about CNN-LSTM model with 2-D spatial convolution neural network (CNN) coupled in LSTM are required for improvement.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.1
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• pp.64-71
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• 2023

In the recent defence industries, it is required to develop the small and low cost embedded systems for guided missiles. According to the characteristics of guided missiles, the mission is conducted with multiple phases, which include a squib activation phase. By considering the unexpected squib activation, the squib system should be disabled after the launch of a guided missile. Therefore, the squib system needs to include the functions of the safe ignition and status check. This paper presents the squib ignition and status check circuits design for the compact embedded systems in guided missiles. Validation results show that for the functions of the squib ignition and status check, the presented circuits design performs well. The designed circuits also were implemented with various electronic devices and validated by the ground and flight tests.

• IMMUNE NETWORK
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• v.24 no.1
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• pp.11.1-11.18
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• 2024

IL-15 belongs to the common gamma chain cytokine family and has pleiotropic immunological functions. IL-15 is a homeostatic cytokine essential for the development and maintenance of NK cells and memory CD8⁺ T cells. In addition, IL-15 plays a critical role in the activation, effector functions, tissue residency, and senescence of CD8⁺ T cells. IL-15 also activates virtual memory T cells, mucosal-associated invariant T cells and γδ T cells. Recently, IL-15 has been highlighted as a major trigger of TCR-independent activation of T cells. This mechanism is involved in T cell-mediated immunopathogenesis in diverse diseases, including viral infections and chronic inflammatory diseases. Deeper understanding of IL-15-mediated T-cell responses and their underlying mechanisms could optimize therapeutic strategies to ameliorate host injury by T cell-mediated immunopathogenesis. This review highlights recent advancements in comprehending the role of IL-15 in relation to T cell responses and immunopathogenesis under various host conditions.