• Title/Summary/Keyword: Open Channel

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Performance Analysis of the Satellite High Speed link applying the Encryption (암호화를 적용한 위성 고속링크의 성능 분석)

  • Hwang, Lan-Mi;Jeong, Won-Ho;Yeo, Bong-Gu;Kim, Seoung-Woo;Kim, Ki-Hong;Park, Sang-Hyun;Yang, Sang-Woon;Lim, Jeong-Seok;Kim, Kyung-Seok
    • Journal of Satellite, Information and Communications
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    • v.10 no.4
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    • pp.39-45
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    • 2015
  • Satellite communication is high-speed large-capacity transmission in such a manner as to communicate with satellites in the chamber, and there is a wide area communication, but is not the security of the information. To compensate for this, AES encryption was applied to the CTR and CBC mode. Also, Blockage channel using a Markov chain to determine the impact caused by obstacles such as trees or buildings between the transmitter and the receiver was composed of Urban and Open Environment. The results of analyzing the performance of satellite communications over a high-speed link-based simulation, If applying encryption, performance of security is complementary but performance of the BER was aggravated and In the Open Environment fewer obstacles confirmed the BER performance is improved than the Urban Environment many obstacles.

Antidepressant drug paroxetine blocks the open pore of Kv3.1 potassium channel

  • Lee, Hyang Mi;Chai, Ok Hee;Hahn, Sang June;Choi, Bok Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.1
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    • pp.71-80
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    • 2018
  • In patients with epilepsy, depression is a common comorbidity but difficult to be treated because many antidepressants cause pro-convulsive effects. Thus, it is important to identify the risk of seizures associated with antidepressants. To determine whether paroxetine, a very potent selective serotonin reuptake inhibitor (SSRI), interacts with ion channels that modulate neuronal excitability, we examined the effects of paroxetine on Kv3.1 potassium channels, which contribute to high-frequency firing of interneurons, using the whole-cell patch-clamp technique. Kv3.1 channels were cloned from rat neurons and expressed in Chinese hamster ovary cells. Paroxetine reversibly reduced the amplitude of Kv3.1 current, with an $IC_{50}$ value of $9.43{\mu}M$ and a Hill coefficient of 1.43, and also accelerated the decay of Kv3.1 current. The paroxetine-induced inhibition of Kv3.1 channels was voltage-dependent even when the channels were fully open. The binding ($k_{+1}$) and unbinding ($k_{-1}$) rate constants for the paroxetine effect were $4.5{\mu}M^{-1}s^{-1}$ and $35.8s^{-1}$, respectively, yielding a calculated $K_D$ value of $7.9{\mu}M$. The analyses of Kv3.1 tail current indicated that paroxetine did not affect ion selectivity and slowed its deactivation time course, resulting in a tail crossover phenomenon. Paroxetine inhibited Kv3.1 channels in a use-dependent manner. Taken together, these results suggest that paroxetine blocks the open state of Kv3.1 channels. Given the role of Kv3.1 in fast spiking of interneurons, our data imply that the blockade of Kv3.1 by paroxetine might elevate epileptic activity of neural networks by interfering with repetitive firing of inhibitory neurons.

Efficient Radio Resource Measurement System in IEEE 802.11 Networks (IEEE 802.11 네트워크에서 효율적인 라디오 자원 측정 시스템 연구)

  • Yang, Seung-Chur;Lee, Sung-Ho;Kim, Jong-Deok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.11
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    • pp.2437-2445
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    • 2012
  • This paper presents the efficient measurement method of radio resource by analyzing various medium occupied elements. The medium occupied time consists of 802.11 frames, wireless interference, and protocol waiting time from a wireless node on a current channel. And it is used to performance metric. Existing research is only measured partial occupied elements, and is lack of validation of measurement unit and scalability on various IEEE 802.11 radio. This paper presents the measurement method of classified occupied elements. To achieve this, we modified 802.11n based OpenHAL device driver to collect the register information of wireless chipset, and to analyze receiving frames in an virtual monitor mode. We conclude accurate medium occupied time measurement system from various validation methods.