• Title/Summary/Keyword: Cell Coordination

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Downlink Transmit Power Allocation in Soft Fractional Frequency Reuse Systems

  • Kim, Dong-Hee;Ahn, Jae-Young;Kim, Ho-Joon
    • ETRI Journal
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    • v.33 no.1
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    • pp.1-5
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    • 2011
  • Downlink transmit power allocation schemes are proposed for soft fractional frequency reuse (FFR) in loose and tightly coordinated systems. The transmit powers are allocated so that the loss of spectral efficiency from the soft FFR is minimized, and the required cell edge user throughput is guaranteed. The effect of the soft FFR on spectral efficiency is evaluated depending on the power allocation schemes and the number of subbands. Results show that the loss of spectral efficiency from the soft FFR can be reduced by configuring an appropriate number of subbands in the loosely coordinated systems. In tightly coordinated systems, results show that the loss of spectral efficiency can be minimized regardless of the number of subbands due to its fast coordination.

An Inter-cell Interference Coordination Scheme for a Downlink OFDMA Relay Networks with Multicells (다중 셀 하향 링크 OFDMA 중계 네트워크를 위한 셀간 간섭 조정 기법)

  • Eun, Junho;Lee, Jae Hong
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2011.07a
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    • pp.250-253
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    • 2011
  • 차세대 무선통신에서는 높은 데이터 전송률을 필요로 하여 높은 밀도의 주파수 재사용을 요구하게 된다. 따라서 셀 간 간섭을 효율적으로 줄이는 방법을 필요로 하게 된다. 기존의 정적인 간섭 조정 기법들은 셀 가장자리 성능을 향상시키기 위해서 네트워크 전체의 성능을 희생한다는 단점이 존재한다. 한편, 높은 전송률을 필요로 하며, 동시에, 높은 신뢰도의 통신을 위해서 중계단말기를 사용한 OFDMA 중계 네트워크에 대한 관심이 높아지고 있다. 따라서, 본 논문에서는 다중 셀 환경의 OFDMA 중계 네트워크에서의 셀 간 간섭을 적응적으로 조정하는 기법을 제안한다. 제안된 기법에서는 셀 간 간섭을 줄여서 셀 가장자리 성능을 향상시킴과 동시에 네트워크 전체 성능 또한 향상시키는 것을 목적으로 한다. 모의실험을 통해, 제안된 알고리즘이 정적 셀 간 간섭조정 기법들 보다 셀 가장자리 성능과 네트워크 전체 성능이 우수함을 확인한다.

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Cooperative Interference Mitigation Using Fractional Frequency Reuse and Intercell Spatial Demultiplexing

  • Chang, Jae-Won;Heo, Jun;Sung, Won-Jin
    • Journal of Communications and Networks
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    • v.10 no.2
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    • pp.127-136
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    • 2008
  • For mobile wireless systems with full frequency reuse, co-channel interference near the cell coverage boundaries has a significant impact on the signal reception performance. This paper addresses an approach to efficiently mitigate the effect of downlink co-channel interference when multi-antenna terminals are used in cellular environments, by proposing a signal detection strategy combined with a system-level coordination for dynamic frequency reuse. We demonstrate the utilization of multi-antennas to perform spatial demultiplexing of both the desired signal and interfering signals from adjacent cells results in significant improvement of spectral efficiency compared to the maximal ratio combining (MRC) performance, especially when an appropriate frequency reuse based on the traffic loading condition is coordinated among cells. Both analytic expressions for the capacity and experimental results using the adaptive modulation and coding (AMC) are used to confirm the performance gain. The robustness of the proposed scheme against varying operational conditions such as the channel estimation error and shadowing effects are also verified by simulation results.

Multi-factors Bidding method for Job Dispatching in Hybrid Shop Floor Control System

  • Lee, Seok--Hee;Park, Kyung-Hyun;Bae, Chang-Hyun
    • International Journal of Precision Engineering and Manufacturing
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    • v.1 no.2
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    • pp.124-131
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    • 2000
  • A shop floor can be considered as and importand level to develop a Computer Integrated Manufacturing system (CIMs). The shop foor is a dynamic environment where unexpected events contrinuously occur, and impose changes to planned activities. The shop floor should adopt an appropriate control system that is responsible for scheduling coordination and moving the manufacturing material and information flow. In this paper, the architecture of the hybrid control model identifies three levels; i.e., the shop floor controller (SFC), the cell controller(CC) and the equipment controller (EC). The methodology for developing these controller is employ an object-oriented approach for static models and IDEF0 for function models for dispatching a job. SFC and CC are coordinated by employing a multi-factors bidding and an adapted Analytic Hierarchy Process(AHP) prove applicability of the suggested method. Test experiment has been conducted by with the shopfloor, consisting of six manufacturing cells.

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The Low Temperature Laser Treatment of Sealing Glass Substrate for ECL (ECL용 유리기판의 레이저 저온 실링처리)

  • Choi, Hye-Su;Park, Cha-Soo;Gwak, Dong-Joo;Sung, Youl-Moon
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1134-1135
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    • 2015
  • In this paper, we reported fabrication of sealing the glass substrate using laser treatment at low temperature for electrochemical luminescence (ECL) cell. The laser treatment at temperature is using laser diode. The glass substrate sealing by laser treatment tested at 1-5 W, 1-5 mm/s for builted and tested. The sealing laser treatment method will allow associate coordination between the two glass substrate was enclosed. The effect of laser treatment to sealing the glass substrate was found to have cracks and air gap at best thickness of about $845-780{\mu}m$ for condition 5 W, 1-5 mm/s. The surface of sealing was roughness which was not influent to electrodes So, it is more effective viscosity between two glasses substrate.

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Jab1 as a Mediator of Nuclear Export and Cytoplasmic Degradation of p53

  • Lee, Eun-Woo;Oh, Wonkyung;Song, Jaewhan
    • Molecules and Cells
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    • v.22 no.2
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    • pp.133-140
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    • 2006
  • Jun activation domain-binding protein 1 (Jab1) is involved in various cellular mechanisms including development in Drosophila and mouse, cell cycle control and signal transduction pathways. Recent studies also determined that Jab1 functions as a nuclear exporter and inducer of cytoplasmic degradation for several proteins including p53, p27, capsid of West Nile virus, and Smad4/7 proteins. In particular, p53 is shown to bind to and to be exported into the cytoplasm by Jab1, which helps to maintain low levels of p53 under normal conditions. This review was undertaken in an effort to understand the biological significance of the homeostasis of p53 as maintained in the presence of Jab1. Based on our observations, we have provided potential mechanistic hypotheses for the nuclear export of p53 in coordination with Jab1 and the role of other factors in these processes.

Coordination of Basic and Development Researches on Vitamins

  • Mitsuda, Hisateru
    • Korean Journal of Food Science and Technology
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    • v.3 no.3
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    • pp.193-210
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    • 1971
  • Reviewed biosynthetic pathways in green leaves of thiamine, riboflavin and folate as disclosed by the authors, and the regulatory systems operating on their biosynthesis and biodegradation as revealed since a potent inhibitory activity of ATP was found for the phosphatase reactions in 1965. Physiological roles of ascorbic acid in plant were evidenced by its higher content in green and flower leaves; the content in persimmon leaves for example was found ten or more times of that in citrus fruits. A close relationship existing between basic and development researches was illustrated by examples chosen from the author's researches. Examples cited were as follows; basic researches on vitamins were extended to the creation of thiamine enriched rice, to the growth promotion of rice plant by foliar application of thiamine, and to the use of ascorbic acid to prevent the appearance of beer cloudness; histological and biochemical studies on protein bodies in rice endosperm turned out amino acid enriched rice; techniques acquired in the studies on catalase were successfully employed for the utilization of single cell protein (MIPRON) for human food; conception of hybernation was led up to under-water or under-ground storage of cereal grains.

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Investigation of Glass Substrate Sealing for ECL Application using Laser Welding Technology (레이저 웰딩 기술을 이용한 ECL용 유리 기판 접합에 대한 고찰)

  • Sung, Youl-Moon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.12
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    • pp.28-32
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    • 2015
  • In this work, we reported fabrication of sealing the glass substrate using laser treatment at low temperature for electrochemical luminescence (ECL) cell. The laser treatment at temperature is using laser diode. The glass substrate sealing by laser treatment tested at 3-10W, 2-5 mm/s for build and tested. The sealing laser treatment method will allow associate coordination between the two glass substrate was enclosed. The effect of laser treatment to sealing the glass substrate was found to have cracks and air gap at best thickness of about 550-600 im for condition 3 W, 3 mm/s. The surface of sealing was roughness which was not influent to electrodes It can reduce the cracks, crevices and air gaps as well, improves the performance viscosity in butter bus bar electrodes. Therefore, it is more effective viscosity between two FTO glasses substrate.

Diversity of contractile properties in skeletal muscle fibers (골격근 섬유의 수축성 특성의 다양성)

  • Kim, Sik-hyun
    • PNF and Movement
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    • v.2 no.1
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    • pp.35-47
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    • 2004
  • Purpose : The purpose of this article was to review the literature on contractile properties of skeletal muscle with reference to its molecular and functional diversity. Method : This review outlines scientific findings regarding different contractile properties in skeletal muscle fibers, and discusses their involvement in functional diversity. Result & Conclusions: Muscle fibers possess distinct mechanical and energetic properties. Myosis, one of the primary contractile muscle proteins, displays structural, functional variability and plays the role of the molecular motor of muscle contraction. Muscle satellite cells are normally mitotically quiescent, but initiate proliferation and give rise to daughter myogenic precursor cells as required for the postnatal growth and regeneration of adult muscle. Passive extensibility is an important component of total muscle function because it allows for the maximal length of skeletal muscles. Proprioceptive neuromuscular facilitation(PNF) stretching can help to restore or improve flexibility and coordination, thereby improving overall muscle function.

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Effects of Overexpression of C5 Protein on rnpB Gene Expression in Escherichia coli

  • Kim, Yool;Lee, Young-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.30 no.4
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    • pp.791-793
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    • 2009
  • Escherichia coli RNase P is composed of a large RNA subunit (M1 RNA) and a small protein subunit (C5 protein). Since both subunits are assembled in a 1:1 ratio, expression of M1 RNA and C5 protein should be coordinately regulated for RNase P to be efficiently synthesized in the cell. However, it is not known yet how the coordination occurs. In this study, we investigated how overexpression of C5 protein affects expression of the rnpB gene encoding M1 RNA, using a lysogenic strain, which carries an rnpB-lacZ transcription fusion. Primer extension analysis of rnpB-lacZ fusion transcripts showed that the overexpression of C5 protein increased the amount of the fusion transcripts, suggesting that rnpB expression increases with the increase of intracellular level of C5 protein.