• Title/Summary/Keyword: Channels

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Role of Stretch-Activated Channels in Stretch-Induced Changes of Electrical Activity in Rat Atrial Myocytes

  • Youm, Jae-Boum;Jo, Su-Hyun;Leem, Chae-Hun;Ho, Won-Kyung;Earm, Yung E.
    • The Korean Journal of Physiology and Pharmacology
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    • v.8 no.1
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    • pp.33-41
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    • 2004
  • We developed a cardiac cell model to explain the phenomenon of mechano-electric feedback (MEF), based on the experimental data with rat atrial myocytes. It incorporated the activity of ion channels, pumps, exchangers, and changes of intracellular ion concentration. Changes in membrane excitability and $Ca^{2+}$ transients could then be calculated. In the model, the major ion channels responsible for the stretch-induced changes in electrical activity were the stretch-activated channels (SACs). The relationship between the extent of stretch and activation of SACs was formulated based on the experimental findings. Then, the effects of mechanical stretch on the electrical activity were reproduced. The shape of the action potential (AP) was significantly changed by stretch in the model simulation. The duration was decreased at initial fast phase of repolarization (AP duration at 20% repolarization level from 3.7 to 2.5 ms) and increased at late slow phase of repolarization (AP duration at 90% repolarization level from 62 to 178 ms). The resting potential was depolarized from -75 to -61 mV. This mathematical model of SACs may quantitatively predict changes in cardiomyocytes by mechanical stretch.

Study On the Six Channels Demonstration Answering the Question in Treatise on Exogenous Febrile Disease (${\ll}$상한론(傷寒論)${\gg}$의 육경변증(六經辨證) 설문에 관한 연구)

  • Park, Min-Kwan;Kim, Min-Yong;Park, Young-Jae
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.9 no.2
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    • pp.83-93
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    • 2005
  • It is well known that Treatise on Exogenous Febrile Disease is one of the oldest and most authoritative books in Oriental Medicine, suggesting the concept of Exogenous Febrile and Six channels as a theoretical basis of clinical experience and prescription. But, since Thang Thongjing had written the book, the numberous medical practitioners and theorists asserted their various and different views on the concept of Exogenous Febrile and its Six channels. 3UM-3YANG of Treatise on Exogenous Febrile Disease is basically the thing of specialization UM-YANG, eventually UM-YANG are two functional characteristics in human body. It is specialized to 3UM-3YANG by spatial and time criteria Therefore, it is important to apprehend the concept correctly that was written on Treatise on Exogenous Febrile Disease. I'd like to look into a bodily state by answering the question that is easy to access and based on Six Channels.

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Flow Condensation Inside Mini-Channels (II) -Experimental Study of the Circular and Rectangular Channels- (작은 유로 내에서의 흐름응축 열전달 (II) -원형 및 사각유로에서의 실험적 연구-)

  • Shin, Jeong-Seob;Kim, Moo-Hwan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.11
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    • pp.1432-1439
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    • 2004
  • By using unique experimental techniques and careful construction of the experimental apparatus, the characteristics of the local heat transfer were investigated using the condensing R134a two-phase flow, in horizontal single mini-channels. The circular channels (D$_{h}$=0.493, 0.691, and 1.067 mm) and rectangular channels (Aspect Ratio=1.0, D$_{h}$=0.494, 0.658, and 0.972 mm) were tested and compared. Tests were performed for a mass flux of 100, 200, 400, and 600 kg/$m^2$s, a heat flux of 5 to 20 ㎾/$m^2$, and a saturation temperature of 4$0^{\circ}C$. In this study, effect of heat flux, mass flux, vapor qualities, hydraulic diameter, and channel geometry on flow condensation are investigated and the experimental local condensation heat transfer coefficients are shown. The experimental data of condensation Nusselt number are compared with existing correlations.ons.

Implementation of Covert Channel Using Mutex Shared Resources in Virtual Machine (가상머신 내 mutex 공유 자원을 이용한 은닉 채널 구현)

  • Ko, Ki-Wan;Choi, Hyoung-Kee
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.29 no.5
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    • pp.961-971
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    • 2019
  • Isolation between virtual machines in a cloud computing environment is an important security factor. The violation of isolation between virtual machines leads to interferences of shared resources and the implementation of covert channels. In this paper, the structure of Hyper-V hypervisor is analyzed to implement covert channels between virtual machines. Hyper-V uses a mutex technique for mutual exclusion between virtual machines. It indicates that isolation of virtual machines is violated and covert channels can be implemented due to mutex. We implemented several covert channels by designing a method for searching mutex resources applicable to Hyper-V with complex architectures. The mutex-based covert channel is not hardware dependent. If the covert channel is detected or defended, the defensive technique can be avoided by using the other covert channel among several covert channels.

The PRISMA Statement: The Characteristics of Fashion Distribution Channels in Virtual Reality

  • Jae-Min LEE
    • Journal of Distribution Science
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    • v.21 no.10
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    • pp.85-95
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    • 2023
  • Purpose: Virtual reality's impact on fashion distribution extends beyond singular transactions, facilitating the emergence of novel collaborations. As investigating the characteristics of fashion distribution channels in virtual reality, this study explores how the fashion industry can utilize virtual reality distribution channels to their maximum capacity while minimizing potential disadvantages. Research design, data, and methodology: The approach used to gather previous studies for this study adheres to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology. This method is widely acknowledged and recommended for its systematic and transparent approach to selecting relevant literature. This kind of literature search plays a vital role in a systematic evaluation as it informs the results. Results: The finding indicates consistently a total of eight kinds of characteristics of fashion distribution channels in virtual reality. The result means that the attributes of fashion distribution channels in virtual reality are causing significant changes in the fashion industry, revolutionizing the consumer experience, and redefining the parameters of creativity and collaboration. Conclusions: In sum, the global reach and accessibility of modern technology enhance the capacity of fashion companies to expand their market presence. This facilitates their participation in intercultural interactions and allows them to serve a wide range of customers.

Selection of Three (E)UV Channels for Solar Satellite Missions by Deep Learning

  • Lim, Daye;Moon, Yong-Jae;Park, Eunsu;Lee, Jin-Yi
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.1
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    • pp.42.2-43
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    • 2021
  • We address a question of what are three main channels that can best translate other channels in ultraviolet (UV) and extreme UV (EUV) observations. For this, we compare the image translations among the nine channels of the Atmospheric Imaging Assembly on the Solar Dynamics Observatory using a deep learning model based on conditional generative adversarial networks. In this study, we develop 170 deep learning models: 72 models for single-channel input, 56 models for double-channel input, and 42 models for triple-channel input. All models have a single-channel output. Then we evaluate the model results by pixel-to-pixel correlation coefficients (CCs) within the solar disk. Major results from this study are as follows. First, the model with 131 Å shows the best performance (average CC = 0.84) among single-channel models. Second, the model with 131 and 1600 Å shows the best translation (average CC = 0.95) among double-channel models. Third, among the triple-channel models with the highest average CC (0.97), the model with 131, 1600, and 304 Å is suggested in that the minimum CC (0.96) is the highest. Interestingly they are representative coronal, photospheric, and chromospheric lines, respectively. Our results may be used as a secondary perspective in addition to primary scientific purposes in selecting a few channels of an UV/EUV imaging instrument for future solar satellite missions.

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Factors influencing mulberry fruit farmers' choice of sales channels and farm revenue

  • Seungjee Hong;Jaehong Park
    • Korean Journal of Agricultural Science
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    • v.51 no.3
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    • pp.351-359
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    • 2024
  • Under the global economic system, farmers are developing various sales channels in addition to traditional sales channels due to continuous changes in the market environment and consumer behavior. As a result, many farmers have started direct marketing, and the government is implementing policies to support direct transactions to secure farm income. The purpose of this study is to identify factors affecting the selection of sales channels such as wholesale, farmsite sales, and store sales of mulberry fruit farmers using a multinomial logit model, and to present basic data for a difference in revenues by sales channel. As a result of analyzing the factors influencing the selection of sales channels of mulberry fruit farmers, it was found that the number of family members, the presence of successors, and the size of the mulberry fields have more impact than demographic characteristics such as the age and farming experience of farm owners. In addition, as a result of comparing the revenues of mulberry fruit farms by sales channel, it was found that farms with store sales as their main sales channel earned statistically significantly more revenues than farms with farm sales as their main sales channel. Based on these results, there were some suggestions for selection of sales channel for mulberry fruit farms.

Independent Production Routines and Environmental Changes In 'Comprehensive Programming Television Channels' in Korea Focusing on Interviews with Independent Producers, Broadcast Writers and Individuals Involved with the TV Channels (종합편성채널의 독립제작 환경과 관행에 관한 연구 독립PD, 작가 및 종합편성채널 관계자 심층인터뷰를 중심으로)

  • Choi, Sun Young;Han, Hee Jeong
    • Korean journal of communication and information
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    • v.73
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    • pp.56-91
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    • 2015
  • This study examined changes in the independent production environment in the perspectives from flexible specialization of labor and media routines since January 2011, when comprehensive programming television channels (JTBC, MBN, Channel A, TV Chosun) emerged in Korea. In-depth interviews were conducted with thirteen individuals, including producers from independent production companies, broadcast writers, and individuals involved with these TV channels. The interview results indicated that a flexible specialization production system had been established by the comprehensive programming channels. This means that they were heavily dependent on independent producers, except in relations to their own news programs. Moreover, it was identified that the production of diverse programs could be difficult due to absurd contract practices such as those related to TV ratings and performance systems. Second, these channels have implemented some positive changes such as the payment of higher production costs and an incentive system, compared to terrestrial TV stations. However, the incentive system also helps to aggravate internal competition in the channel and also instigate contract competitions among independent companies, which can eventually result in the channels for holding exclusive rights to certain content and, hence, unfair business practices. Third, as a result of the newspaper and broadcast cross-owenership system of the comprehensive programming channels, hierarchical independent production practices can be established under the influence of newspaper proprietors and executives or managers who have previously worked for newspapers. Lastly, as a result of interviews with independent producers and individuals involved with the TV channels concerning the awareness of comprehensive programming channels, it could not be ascertained whether it is difficult to produce programs dealing with diverse items and genres, because programming autonomy has been distorted by capital or the advertisement market. In this circumstance, it is not surprising that some comprehensive programming channels mentioned that they prioritize profit and performance in programming. In conclusion, it is absolutely imperative that complementary and legal measures be implemented institutionally in order to redress the existing systematic dysfunctional routines in the independent productions of the comprehensive programming TV channels in Korea.

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Block Error Performance of Transmission in Slow Nakagami Fading Channels with Diversity

  • Kim, Young-Nam;Kang, Heau-Jo;Chung, Myung-Rae
    • Journal of information and communication convergence engineering
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    • v.1 no.3
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    • pp.119-122
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    • 2003
  • In this paper presents equations which describe an average weighted spectrum of errors and average block error probabilities for noncoherent frequency shift keying (NCFSK) used in D-branch maximal ratio combining (MRC) diversity in independent very slow nonselective Nakagami fading channels. The average is formed over the instantaneous receiver signal to noise ratio (SNR) after combining. the analysis is limited to additive Gaussian noise.

Transient Receptor Potential Ion Channels and Animal Sensation: Lessons from Drosophila Functional Research

  • Kim, Chang-Soo
    • BMB Reports
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    • v.37 no.1
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    • pp.114-121
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    • 2004
  • Ion channels of the transient receptor potential (TRP) superfamily are non-selective cationic channels with six transmembrane domains. The TRP channel made its first debut as a light-gated $Ca^{2+}$ channel in Drosophila. Recently, research on animal sensation in Drosophila disclosed other members of the TRP family that are required for touch sensation and hearing as well as the sensation of painful stimuli.