• Korean Journal of Plant Taxonomy
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• v.52 no.4
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• pp.214-218
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• 2022

Eleocharis R. Br. (Cyperaceae) is characterized by unbranched culms, one terminal spikelet, bisexual flowers, and bristly perianths, occurring mainly in circumboreal marshes and wetlands. There are about 250 species worldwide, and 15 taxa in Korea have been recognized. Chromosomes in Cyperaceae are known to be holocentric, missing constricted centromeres during cell division. For the first time, we report the chromosome counts of Eleocharis from Korean populations of E. attenuata f. laeviseta (Nakai) H. Hara (2n = 20); E. parvula (Roem. & Schult.) Link ex Bluff, Nees & Schauer (2n = 10); E. ussuriensis Zinserl. (2n = 16); and E. valleculosa var. setosa Ohwi (2n = 16). The populations exhibit variations in their chromosome sizes from ca.1.7 ㎛ to ca. 6 ㎛, categorized as gradient and bimodal karyotypes. The karyotypes observed are congruent with previous phylogenetic groups proposed. To clarify the traditional and phylogenetic classification of Korean Eleocharis, further taxonomic and chromosomal investigations with additional taxon sampling efforts are required.

• IMMUNE NETWORK
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• v.16 no.4
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• pp.256-260
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• 2016

An association between drug treatment for viral infections and severe cutaneous adverse reactions has been noted. We investigated six patients diagnosed with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) after being prescribed acetaminophen for suspected viral illnesses. Multiplex analysis was performed to measure cytokine levels in sera before and after treatment. IL-2Ra levels significantly decreased during the convalescence phase. Although acetaminophen is relatively safe, the drug can trigger SJS/TEN in patients with suspected viral infections. T-cells and monocytes may be key components of the link between viral infection and acetaminophen-induced SJS/TEN.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.192-198
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• 2024

This paper investigates the application of multi-agent deep reinforcement learning in the fighting game Samurai Shodown using Proximal Policy Optimization (PPO) and Advantage Actor-Critic (A2C) algorithms. Initially, agents are trained separately for 200,000 timesteps using Convolutional Neural Network (CNN) and Multi-Layer Perceptron (MLP) with LSTM networks. PPO demonstrates superior performance early on with stable policy updates, while A2C shows better adaptation and higher rewards over extended training periods, culminating in A2C outperforming PPO after 1,000,000 timesteps. These findings highlight PPO's effectiveness for short-term training and A2C's advantages in long-term learning scenarios, emphasizing the importance of algorithm selection based on training duration and task complexity. The code can be found in this link https://github.com/Lexer04/Samurai-Shodown-with-Reinforcement-Learning-PPO.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.2
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• pp.154-161
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• 2013

This paper presents the signal-to-interference plus noise ratio (SINR) estimation of IEEE 802.16m WirelessMAN-Advanced mobile station with simulation and implementation results. The downlink signal of IEEE 802.16m has two kinds of A-Preambles: the PA-preamble and the SA-preamble. This paper proposes the efficient method of estimating SINR with A-Preambles, by measuring noise power from PA-preamble and measuring interference power and signal power from SA-preamble. The proposed SINR measurement block contains important features such as subcarrier phase rotation elimination and simplified dB transform. The result of this paper is integrated to ETRI's IEEE 802.16m test mobile station, used for decision of adaptive-modulation-and-coding (AMC) and hand-over. It showed good measurement performance in simulation and unified system link test also.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9A
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• pp.767-775
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• 2011

In this paper, we propose a new multi-input multi-output (MIMO) channel modeling method for mobile-to-mobile (M2M) communications based on IEEE 802.16n. To reflect the mobilities at the transmitter and the receiver, we propose a new channel model by invoking the geometrical two-ring scattering model and modifying the conventional IEEE 802.16m fixed-to-mobile (F2M) channel model considering M2M communication environments. Through computer simulations, we analyze the statistical properties of proposed channel model in terms of the time correlation and the spatial correlation. Finally, the performance of the system using the proposed M2M channel model is compared with that using the conventional 802.16m F2M channel model by link level simulations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8643-8648
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• 2015

In this paper presents the design and demonstrate 8 W 3-stage HPA(High Power Amplifier) MMIC(Monolithic Microwave Integrated Circuits) for Ka-band down link satellite communications payload system at 19.5 GHz ~ 22 GHz frequency band. The HPA MMIC consist of 3-stage GaN HEMT(Hight Electron Mobility Transistors). The gate periphery of $1^{st}$ stage, $2^{nd}$ stage and output stage is determined $8{\times}50{\times}2$ um, $8{\times}50{\times}4$ um and $8{\times}50{\times}8$ um, respectively. The fabricated HPA MMIC shows size $3,400{\times}3,200um^2$, small signal gain over 29.6 dB, input matching -8.2 dB, output matching -9.7 dB, output power 39.1 dBm and PAE 25.3 % by using 0.15 um GaN technology at 20 V supply voltage in 19.5~22 GHz frequency band. Therefore, this HPA MMIC is believed to be adaptable Ka-band satellite communication payloads down link system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.197-203
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• 2016

In this paper, the dipole antenna that can control a beam steering were designed for attaching on LEO(Low Earth Orbit) small satellite. The proposed antenna was based on Yagi-Uda antenna. The parasitic element was proposed as a T-shape. Depending on the state of open or short at the end of a vertical element, we can choose a characteristic of the parasitic element with fixing a vertical element length of the parasitic element. Using this characteristic, we designed the director element and reflector element. The proposed antenna was designed to receive UHF 436.5 MHz. Antenna gain was chosen by link budget between one satellite and the other satellite or between the satellite and the ground station. By changing a vertical element length which is the largest variable that chooses an antenna characteristic, we confirmed that ${\lambda}/2$ length transformer has a result that improve 0.5 dB in comparison ${\lambda}/4$ length transformer from maximum gain direction. In production, we made an on/off switch composed of a diode, capacitor, and inductor control an open and short at the end of the parasitic element. As a result, the gain of antenna used in a link between one satellite and the other satellite had average 5.92 dBi. And the gain of antenna used in a link between the satellite and the ground station had average 0.99 dBi.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.5
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• pp.1-9
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• 2000

In this paper, for the reverse link of a imperfect power controlled DS/CDMA cellular system when a mobile radio channel is a Rayleigh distributed multipath fading channel, A extended DS/CDMA blocking probability formula considering both shadowing and multipath fading is derived. Erlang capacity and equivalent channel number considering shadowing are analyzed and compared with those considering both shadowing and multipath fading, respectively. The DS/CDMA blocking probability is calculated based on the analysis method that obtains Erlang capacity and ICF(interference correction factor) using the median value of $E_{b(i)}$/ $I_{0}$ corresponding to each reverse link user Assuming that the blocking probability set 2%, it is observed that the Erlang capacity is 19.97 Erlang at the data rate $R_{b}$=9.6 kbps and 11.67 Erlang at the data rate $R_{b}$=14.4 kbps and then is less 16% and 19% than the Erlang capacity considering shadowing only, respectively. It is also shown that the effect of multipath fading must not be ignored and then exact Erlang capacity and equivalent channel numbers that the DS/CDMA cellular system can support are provided.d.d.d.

• Nutrition Research and Practice
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• v.16 no.6
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• pp.729-744
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• 2022

BACKGROUND/OBJECTIVES: 4-Hydroxy-2-nonenal (HNE) is a biomarker for oxidative stress to induce inflammation. Methionine is an essential sulfur-containing amino acid with antioxidative activity. On the other hand, the evidence on whether and how methionine can depress HNE-derived inflammation is lacking. In particular, the link between the regulation of the nuclear factor-κB (NF-κB) signaling pathway and methionine intake is unclear. This study examined the link between depression from HNE accumulation and the anti-inflammatory function of ⳑ-methionine in rats. MATERIALS/METHODS: Male Wistar rats (3-week-old, weighing 70-80 g) were administered different levels of ⳑ-methionine orally at 215.0, 268.8, 322.5, and 430.0 mg/kg body weight for two weeks. The control group was fed commercial pellets. The hepatic HNE contents and the protein expression and mRNA levels of the inflammatory mediators were measured. The interleukin-10 (IL-10) and glutathione S-transferase (GST) levels were also estimated. RESULTS: Compared to the control group, hepatic HNE levels were reduced significantly in all groups fed ⳑ-methionine, which were attributed to the stimulation of GST by ⳑ-methionine. With decreasing HNE levels, ⳑ-methionine inhibited the activation of NF-κB by up-regulating inhibitory κBα and depressing phosphoinositide 3 kinase/protein kinase B. The mRNA levels of the inflammatory mediators (cyclooxygenase-2, interleukin-1β, interleukin-6, inducible nitric oxide synthase, tumor necrotic factor alpha) were decreased significantly by ⳑ-methionine. In contrast, the protein expression of these inflammatory mediators was effectively down regulated by ⳑ-methionine. The anti-inflammatory action of ⳑ-methionine was also reflected by the up-regulation of IL-10. CONCLUSIONS: This study revealed a link between the inhibition of HNE accumulation and the depression of inflammation in growing rats, which was attributed to ⳑ-methionine availability. The anti-inflammatory mechanism exerted by ⳑ-methionine was to inhibit NF-κB activation and to up-regulate GST.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.509-518
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• 2023

In this paper, we designed a 4Kb poly-fuse OTP IP (Intellectual Property) required for analog circuit trimming and calibration. In order to reduce the BL resistance of the poly-fuse OTP cell, which consists of an NMOS select transistor and a poly-fuse link, the BL stacked metal 2 and metal 3. In order to reduce BL routing resistance, the 4Kb cells are divided into two sub-block cell arrays of 64 rows × 32 rows, with the BL drive circuit located between the two 2Kb sub-block cell arrays, which are split into top and bottom. On the other hand, in this paper, we propose a core circuit for an OTP cell that uses one poly-fuse link to one select transistor. In addition, in the early stages of OTP IP development, we proposed a data sensing circuit that considers the case where the resistance of the unprogrammed poly-fuse can be up to 5kΩ. It also reduces the current flowing through an unprogrammed poly-fuse link in read mode to 138㎂ or less. The poly-fuse OTP cell size designed with DB HiTek 90nm CMOS process is 11.43㎛ × 2.88㎛ (=32.9184㎛2), and the 4Kb poly-fuse OTP IP size is 432.442㎛ × 524.6㎛ (=0.227mm²).