• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1069-1074
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• 2017

Reduction of breakdown voltage is serious short channel effect (SCE) by shrink of channel length. The deviation of breakdown voltage for doping concentration is investigated with structural parameters of sub-10 nm double gate (DG) MOSFET in this paper. To analyze this, thermionic and tunneling current are derived from analytical potential distribution, and breakdown voltage is defined as drain voltage when the sum of two currents is $10{\mu}A$. As a result, breakdown voltage increases with increase of doping concentration. Breakdown voltage decreases by reduction of channel length. In order to solve this problem, it is found that silicon and oxide thicknesses should be kept very small. In particular, as contributions of tunneling current increases, breakdown voltage increases.

• Journal of Advanced Navigation Technology
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• v.15 no.3
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• pp.386-391
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• 2011

CRU (contiguous resource unit) composed of adjacent OFDMA subcarriers is popularly adopted for recently developed cellular communication standards, e.g. IEEE 802.16e/m. If multiple CRUs having different SNR are assigned to a mobile station, and multiple packet streams are independently transmitted by using H-ARQ transmission, an achievable data rate can be varied according to the channel allocation method of re-transmission packets and new transmission packets. In this paper, the optimum channel allocation method for the above stated problem, and several sub-optimum channel allocation methods to reduce the computational complexity of the optimum allocation method are proposed. According to the simulation results, a sub-optimum allocation method assigning a CRU having good SNR to new transmission packet shows marginal performance loss compared with optimum method, however, the computational complexity can be significantly reduced.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2707-2712
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• 2009

5-$HT_{3}$ receptor;5-$HT_{3A}$ receptor channel activity;Novel 5-$HT_{3}$ receptor channel current blockers;Chlorophenyl substituted piperazinylethylaminomethylpyrazoles; The 5-$HT_{3A}$ receptors are one of ligand-gated ion channels and are known to be involved in visceral pain, anxiety, or anticancer agent-induced nausea and vomiting. In present study, we designed novel skeletons based on the developed 5-$HT_{3}$ receptor antagonists and evaluated their effects on 5-$HT_{3A}$ receptor channel currents ($I_{5-HT}$) of a series of pyrazole derivatives having N-chlorophenylpiperazine functionality (6-9). We found that most of N-p-chlorophenyl substituted piperazinyl-pyrazole derivatives (7b, 7c, 7e and 7h) exhibited the high potency for the inhibition of $I_{5-HT}$, whereas the compound without chloride (6) or with m-chlorophenyl group (a serious of 8 and 9) showed the low potency. These result indicate that p-chlorophenyl group is might play an important role for increasing the inhibitory potency on $I_{5-HT}$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.4
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• pp.287-295
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• 1986

In this paper, a SBC(sub-band-coding) is proposed to code a speech signal for a digital mobile radio and a robustness of speech quality of the SBC over the Rayleigh fading channel is investigated via a computer simulation. First the Rayleigh fading channel and 16-ary DPSK receiver models are presentes and verified its validitties by comparing with theoretical values. Three different measures: SNR, LPC distance measure and subjective listening test, were used to evaluate the effects due to the Rayleigh fading channel errors. From the results of computer simulation at BER=$10_{-3}$, $10_{-2}$, 5$ imes$$10_{-2}$, it was found that the speech remained quite intelligible at BER=$10_{-2}$and the link is still usuable even at BER=5$ imes$$10_{-2}$ Thus it was concluded that the SBC can be applicable to the digital mobile radio on the Rayleigh fading channel error in the range of $10_{-4}$~$10_{-2}$ without emplowing any error correction codes.

• Development and Reproduction
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• v.24 no.4
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• pp.297-306
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• 2020

Repetitive changes in the intracellular calcium concentration ([Ca²⁺]i) triggers egg activation, including cortical granule exocytosis, resumption of second meiosis, block to polyspermy, and initiating embryonic development. [Ca²⁺]i oscillations that continue for several hours, are required for the early events of egg activation and possibly connected to further development to the blastocyst stage. The sources of Ca²⁺ ion elevation during [Ca²⁺]i oscillations are Ca²⁺ release from endoplasmic reticulum through inositol 1,4,5 tri-phosphate receptor and Ca²⁺ ion influx through Ca²⁺ channel on the plasma membrane. Ca²⁺ channels have been characterized into voltage-dependent Ca²⁺ channels (VDCCs), ligand-gated Ca²⁺ channel, and leak-channel. VDCCs expressed on muscle cell or neuron is specified into L, T, N, P, Q, and R type VDCs by their activation threshold or their sensitivity to peptide toxins isolated from cone snails and spiders. The present study was aimed to investigate the localization pattern of N and P/Q type voltage-dependent calcium channels in mouse eggs and the role in fertilization. [Ca²⁺]i oscillation was observed in a Ca²⁺ contained medium with sperm factor or adenophostin A injection but disappeared in Ca²⁺ free medium. Ca²⁺ influx was decreased by Lat A. N-VDCC specific inhibitor, ω-Conotoxin CVIIA induced abnormal [Ca²⁺]i oscillation profiles in SrCl₂ treatment. N or P/Q type VDC were distributed on the plasma membrane in cortical cluster form, not in the cytoplasm. Ca²⁺ influx is essential for [Ca²⁺]i oscillation during mammalian fertilization. This Ca²⁺ influx might be controlled through the N or P/Q type VDCCs. Abnormal VDCCs expression of eggs could be tested in fertilization failure or low fertilization eggs in subfertility women.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.5
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• pp.397-404
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• 2022

Fesoterodine, an antimuscarinic drug, is widely used to treat overactive bladder syndrome. However, there is little information about its effects on vascular K⁺ channels. In this study, voltage-dependent K⁺ (Kv) channel inhibition by fesoterodine was investigated using the patch-clamp technique in rabbit coronary artery. In whole-cell patches, the addition of fesoterodine to the bath inhibited the Kv currents in a concentration-dependent manner, with an IC₅₀ value of 3.19 ± 0.91 μM and a Hill coefficient of 0.56 ± 0.03. Although the drug did not alter the voltage-dependence of steady-state activation, it shifted the steady-state inactivation curve to a more negative potential, suggesting that fesoterodine affects the voltage-sensor of the Kv channel. Inhibition by fesoterodine was significantly enhanced by repetitive train pulses (1 or 2 Hz). Furthermore, it significantly increased the recovery time constant from inactivation, suggesting that the Kv channel inhibition by fesoterodine is use (state)-dependent. Its inhibitory effect disappeared by pretreatment with a Kv 1.5 inhibitor. However, pretreatment with Kv2.1 or Kv7 inhibitors did not affect the inhibitory effects on Kv channels. Based on these results, we conclude that fesoterodine inhibits vascular Kv channels (mainly the Kv1.5 subtype) in a concentration- and use (state)-dependent manner, independent of muscarinic receptor antagonism.

• International Journal of Computer Science & Network Security
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• v.23 no.7
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• pp.1-8
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• 2023

An Orthogonal Frequency Division Multiplexing (OFDM) based wireless communication system has drawn wide attention for its high transmission rate and high spectrum efficiency in not only radio but also Underwater Acoustic (UWA) applications. Because of the narrow sub-carrier spacing of OFDM, orthogonality between sub-carriers is easily affected by Doppler effect caused by the movement of transmitter or receiver. Previously, Doppler compensation signal processing algorithm for Desired propagation path was proposed. However, other Doppler shifts caused by delayed Undesired signal arriving from different directions cannot be perfectly compensated. Then Receiver Bit Error Rate (BER) is degraded by Inter-Carrier-Interference (ICI) caused in the case of Multi-path Doppler channel. To mitigate the ICI effect, a modified Delay and Doppler Profiler (mDDP), which estimates not only attenuation, relative delay and Doppler shift but also sampling clock shift of each multi-path component, is proposed. Based on the outputs of mDDP, an ICI canceling multi-tap equalizer is also proposed. Computer simulated performances of one-tap equalizer with the conventional Time domain linear interpolated Channel Transfer Function (CTF) estimator, multi-tap equalizer based on mDDP are compared. According to the simulation results, BER improvement has been observed. Especially, in the condition of 16QAM modulation, transmitting vessel speed of 6m/s, two-path multipath channel with direct path and ocean surface reflection path; more than one order of magnitude BER reduction has been observed at CNR=30dB.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.9
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• pp.2882-2903
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• 2022

Image super-resolution (SR) processing is of great value in the fields of digital image processing, intelligent security, film and television production and so on. This paper proposed a densely connected deep learning network based on cascade architecture, which can be used to solve the problem of super-resolution in the field of image quality enhancement. We proposed a more efficient residual scaling dense block (RSDB) and the multi-channel cascade architecture to realize more efficient feature reuse. Also we proposed a hybrid loss function based on L₁ error and L_∞ error to achieve better L_∞ error performance. The experimental results show that the overall performance of the network is effectively improved on cascade architecture and residual scaling. Compared with the residual dense net (RDN), the PSNR / SSIM of the new method is improved by 2.24% / 1.44% respectively, and the L_∞ performance is improved by 3.64%. It shows that the cascade connection and residual scaling method can effectively realize feature reuse, improving the residual convergence speed and learning efficiency of our network. The L_∞ performance is improved by 11.09% with only a minimal loses of 1.14% / 0.60% on PSNR / SSIM performance after adopting the new loss function. That is to say, the L_∞ performance can be improved greatly on the new loss function with a minor loss of PSNR / SSIM performance, which is of great value in L_∞ error sensitive tasks.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.2
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• pp.159-165
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• 2016

Recently, active efforts are being made for future Si CMOS technology by various researches on emerging devices and materials. Capability of low power consumption becomes increasingly important criterion for advanced logic devices in extending the Si CMOS. In this work, a junctionless field-effect transistor (JLFET) with ultra-thin poly-Si (UTP) channel is designed aiming the sub-10-nm technology for low-power (LP) applications. A comparative study by device simulations has been performed for the devices with crystalline and polycrystalline Si channels, respectively, in order to demonstrate that the difference in their performances becomes smaller and eventually disappears as the 10-nm regime is reached. The UTP JLFET would be one of the strongest candidates for advanced logic technology, with various virtues of high-speed operation, low power consumption, and low-thermal-budget process integration.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.2
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• pp.288-307
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• 2013

This paper formulates resource allocation for decode-and-forward (DF) relay assisted multi-cell orthogonal frequency division multiple (OFDM) networks as an optimization problem taking into account of inter-cell interference and users fairness. To maximize the transmit rate of system we propose a joint interference coordination, subcarrier and power allocation algorithm. To reduce the complexity, this semi-distributed algorithm divides the primal optimization into three sub-optimization problems, which transforms the mixed binary nonlinear programming problem (BNLP) into standard convex optimization problems. The first layer optimization problem is used to get the optimal subcarrier distribution index. The second is to solve the problem that how to allocate power optimally in a certain subcarrier distribution order. Based on the concept of equivalent channel gain (ECG) we transform the max-min function into standard closed expression. Subsequently, with the aid of dual decomposition, water-filling theorem and iterative power allocation algorithm the optimal solution of the original problem can be got with acceptable complexity. The third sub-problem considers dynamic co-channel interference caused by adjacent cells and redistributes resources to achieve the goal of maximizing system throughput. Finally, simulation results are provided to corroborate the proposed algorithm.