• Molecules and Cells
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• v.41 no.7
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• pp.613-621
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• 2018

The capacity of differentiation of human pluripotent stem cells (hPSCs), which include both embryonic stem cells and induced pluripotent stem cells, into cardiomyocytes (CMs) in vitro provides an unlimited resource for human CMs for a wide range of applications such as cell based cardiac repair, cardiac drug toxicology screening, and human cardiac disease modeling. However, their applicability is significantly limited by immature phenotypes. It has been well known that currently available CMs derived from hPSCs (hPSC-CMs) represent immature embryonic or fetal stage CMs and are functionally and structurally different from mature human CMs. To overcome this critical issue, several new approaches aiming to generate more mature hPSC-CMs have been developed. This review describes recent approaches to generate more mature hPSC-CMs including their scientific principles, advantages, and limitations.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.149-153
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• 2005

The optical fiber micro-cellular system requires the high linearity that determines the quality and capacity of system. Hence, there is a need for improving the linearity in mobile communication system. In order to compensate dispersion-induced signal distortion, we fabricated the optical feedforward transmitter. The compared 3rd-IMD was enhanced by 38 dB for two-tone case and the Adjacent Channel Power Ratio was enhanced by 20 dB for W-CDMA 1 carrier and by 16 dB for W-CDMA 3 carriers. Also, the induced noise level was reduced.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.4
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• pp.961-971
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• 1996

The effect of inband TDMA narrow band jammers to DS-CDMA system performance and the suppression techniques are investigated using Monte Carlo simulations. TIA stantard North American Digital Cellular wea used as jammer. Levinson Dubin and conventional recursive least square algorithm were emphasized since these techniques can be implemented with a few DSPs for CDMA application. Two filter structures, i.e., complex suppression filter and real suppression filter in each inphase and quadrature channels, are investigated and their performances are compared. Complex suppression filter with Levinson Durbin algorithm of 20msec updata rate is the most promising with respect to implementation and performance poit of view. Implementation feasibility is discussed and the channel capacity lost by suppression is computed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2664-2673
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• 1997

The signal fading distortion has effect on the capacity of cellular mobile communication systems. The short term fading is solved by signal processing techniques depending on the radio communication methods, but another distortion compensation techniques are necessary to combat long term fading. in this paper, we have simulated the call processing in DS-CDMA system using distributed antennas to overcome the long term fading. From the simulation results, we have conformed that the blocking probability of a new call andthe forced probability of handoff-request-call have decreased by increasing the number of distributed antennas.

• Journal of Korean Physical Therapy Science
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• v.1 no.2
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• pp.333-343
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• 1994

This study was performed to assess the efficacy of electrical stimulation for healing of wound in injured tissue, and to provide a baseline for electrical stimulation in the treatment. Although the specific mechanism by electrical stimulation which may promote injured tissue to heal is not known, generally many hypothesis exist such as bactericidal effect, enhanced circulation, stimulation of cellular biosynthesis and replication, and attraction of connective tissues and inflammatory cells The results of this study are as follows : 1. The healing of skin wound was facilitated by electrical stimulation 2. The capacity of collagen synthesis was significantly accelerated by electrical stimulation 3. The application of electrical stimulation to injured tissue may be helpful in augmenting the rate of wound contracture

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.4
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• pp.336-344
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• 2000

The soft handoffs between two adjacent MSC's should be employed to support the calls requesting handoffs to an MSC while minimizing the undesirable ping pong phenomenon of back-and-forth handoffs between two adjacent cells in conventional hard handoffs. In this paper, the soft handoff scheme between two MSC's is considered using the trunk between the packet routers for the two MSC's. The trunk network is proposed to support the inter-MSC soft handoff scheme in the service area with many MSC's. The probability that a soft handoff to an adjacent MSC will be blocked due to the shortage of the trunk capacity is derived.

• Molecules and Cells
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• v.39 no.1
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• pp.20-25
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• 2016

Photosynthesis is a highly robust process allowing for rapid adjustment to changing environmental conditions. The efficient acclimation depends on balanced redox metabolism and control of reactive oxygen species release which triggers signaling cascades and potentially detrimental oxidation reactions. Thiol peroxidases of the peroxiredoxin and glutathione peroxidase type, and ascorbate peroxidases are the main peroxide detoxifying enzymes of the chloroplast. They use different electron donors and are linked to distinct redox networks. In addition, the peroxiredoxins serve functions in redox regulation and retrograde signaling. The complexity of plastid peroxidases is discussed in context of suborganellar localization, substrate preference, metabolic coupling, protein abundance, activity regulation, interactions, signaling functions, and the conditional requirement for high antioxidant capacity. Thus the review provides an opinion on the advantage of linking detoxification of peroxides to different enzymatic systems and implementing mechanisms for their inactivation to enforce signal propagation within and from the chloroplast.

• Molecules and Cells
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• v.43 no.9
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• pp.774-783
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• 2020

The lung has a vital function in gas exchange between the blood and the external atmosphere. It also has a critical role in the immune defense against external pathogens and environmental factors. While the lung is classified as a relatively quiescent organ with little homeostatic turnover, it shows robust regenerative capacity in response to injury, mediated by the resident stem/progenitor cells. During regeneration, regionally distinct epithelial cell populations with specific functions are generated from several different types of stem/progenitor cells localized within four histologically distinguished regions: trachea, bronchi, bronchioles, and alveoli. WNT signaling is one of the key signaling pathways involved in regulating many types of stem/progenitor cells in various organs. In addition to its developmental role in the embryonic and fetal lung, WNT signaling is critical for lung homeostasis and regeneration. In this minireview, we summarize and discuss recent advances in the understanding of the role of WNT signaling in lung regeneration with an emphasis on stem/progenitor cells.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5203-5217
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• 2018

In order to increase the capacity and improve the spectrum efficiency of wireless communication systems, this paper proposes a rate-based two-sided many-to-one matching game algorithm for energy-harvesting small cells with non-orthogonal multiple access (NOMA) in heterogeneous cellular networks (HCN). First, we use a heuristic clustering based channel allocation algorithm to assign channels to small cells and manage the interference. Then, aiming at addressing the user access problem, this issue is modeled as a many-to-one matching game with the rate as its utility. Finally, considering externality in the matching game, we propose an algorithm that involves swap-matchings to find the optimal matching and to prove its stability. Simulation results show that this algorithm outperforms the comparing algorithm in efficiency and rate, in addition to improving the spectrum efficiency.

• Journal of Integrative Natural Science
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• v.14 no.2
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• pp.50-56
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• 2021

Due to the recent increase in the mobile streaming market, mobile traffic is increasing exponentially. IMT-2020, named as the next generation mobile communication standard by ITU, is called the 5th generation mobile communication (5G), and is a technology that satisfies the data traffic capacity, low latency, high energy efficiency, and economic efficiency compared to the existing LTE (Long Term Evolution) system. 5G implements this technology by utilizing a high frequency band, but there is a problem of path loss due to the use of a high frequency band, which is greatly affected by system performance. In this paper, small cell technology was presented as a solution to the high frequency utilization of 5G mobile communication system, and furthermore, the system performance was improved by applying machine learning technology to macro communication and small cell communication method decision. It was found that the system performance was improved due to the technical application and the application of machine learning techniques.