• Title/Summary/Keyword: multi-cell environment

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Constructing Landscape as an Operational Multi-Environmental Control Utility and Green Infrastructure - Landscape Design for National Marine Biology Resource Institute - (작동하는 복합환경조절장치 및 녹색기반시설로서 조경 - 국립해양생물자원관 옥외공간 설계 -)

  • Sung, Jongsang
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.2
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    • pp.41-56
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    • 2012
  • Landscape space can and should play as a multi-functional agent : healing contaminated soil, reducing natural hazards, supporting living things, making comfortable environment for human, and appealing to human aesthetics, etc. This article aims to show the possibility and role of landscape space as such agent. In landscape design for National Marine Biology Resource Institute, distributed rain water treatment system and rain gardens are introduced to replace a mono-functioning large detention pond which was suggested by disaster impact assesment. Phytoremediation and vegetation filtering system with muti-cell wetlands are also adapted to heal the contaminated soil. This kind of landscape as a 'living machine' which can play as an operational control utility of multi-environment and thus can be combined effectively into green infrastructure is important for post-industrial city, especially in an era of climate change.

Optimal Selection of Reference Vector in Sub-space Interference Alignment for Cell Capacity Maximization (부분공간 간섭 정렬에서 셀 용량 최대화를 위한 최적 레퍼런스 벡터 설정 기법)

  • Han, Dong-Keol;Hui, Bing;Chang, Kyung-Hi;Koo, Bon-Tae
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.5A
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    • pp.485-494
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    • 2011
  • In this paper, novel sub-space interference alignment algorithms are proposed to boost the capacity in multi-cell environment. In the case of conventional sub-space alignment, arbitrary reference vectors have been adopted as transmitting vectors at the transmitter side, and the inter-cell interference among users are eliminated by using orthogonal vectors of the chosen reference vectors at the receiver side. However, in this case, sum-rate varies using different reference vectors even though the channel values keep constant, and vice versa. Therefore, the relationship between reference vectors and channel values are analyzed in this paper, and novel interference alignment algorithms are proposed to increase multi-cell capacity. Reference vectors with similar magnitude are adopted in the proposed algorithm. Simulation results show that the proposed algorithms provide about 50 % higher sum-rate than conventional algorithm.

Resource Allocation Scheme for D2D Communications in Multi-Cell Environments (다중 셀 환경에서 단말 간 직접 통신을 위한 자원 할당 방식)

  • Oh, Sung-Min;Lee, Changhee;Yun, Miyoung;Shin, Jaesheung;Park, Ae-Soon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.10
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    • pp.601-609
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    • 2014
  • This paper proposes a resource allocation scheme suitable for D2D communications in multi-cell environment. In order to solve the inter-cell interference, the proposed scheme allocates the pre-assigned resource group and shares the information with neighbor cells. This paper also proposes a power control scheme for D2D communication to enhance the cell throughput. By the simulation results, the average SINR of the cellular uplink and D2D communication link are mostly higher than 10 dB when the proposed scheme is applied. On the other hand, with the inter-cell non-coordinated resource allocation scheme, the average SINR of the D2D communication link are decreased by 0 dB. In addition, the proposed scheme can enhance the cell throughput up to 8 % compared with the inter-cell non-coordinated resource allocation scheme.

Energy Efficient Cell Management by Flow Scheduling in Ultra Dense Networks

  • Sun, Guolin;Addo, Prince Clement;Wang, Guohui;Liu, Guisong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.9
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    • pp.4108-4122
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    • 2016
  • To address challenges of an unprecedented growth in mobile data traffic, the ultra-dense network deployment is a cost efficient solution to off-load the traffic over other small cells. However, the real traffic is often much lower than the peak-hour traffic and certain small cells are superfluous, which will not only introduce extra energy consumption, but also impose extra interference onto the radio environment. In this paper, an elastic energy efficient cell management scheme is proposed based on flow scheduling among multi-layer ultra-dense cells by a SDN controller. A significant power saving was achieved by a cell-level energy manager. The scheme is elastic for energy saving, adaptive to the dynamic traffic distribution in the office or campus environment. In the end, the performance is evaluated and demonstrated. The results show substantial improvements over the conventional method in terms of the number of active BSs, the handover times, and the switches of BSs.

Emerging role of RUNX3 in the regulation of tumor microenvironment

  • Manandhar, Sarala;Lee, You Mie
    • BMB Reports
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    • v.51 no.4
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    • pp.174-181
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    • 2018
  • A number of genes have been therapeutically targeted to relieve cancer, but cancer relapse is still a growing issue. The concept that the surrounding tumor environment is critical for the progression of cancer may foster an answer to the issue of cancer malignancy. Runt domain transcription factors (RUNX1, 2, and 3) are evolutionarily conserved and have been intensively studied for their roles in normal development and pathological conditions. During tumor growth, a hypoxic microenvironment and infiltration of the tumor by immune cells are common phenomena. In this review, we briefly introduce the consequences of hypoxia and immune cell infiltration into the tumor microenvironment with a focus on RUNX3 as a critical regulator. Furthermore, based on our current knowledge of the functional role of RUNX3 in hypoxia and immune cell maintenance, a probable therapeutic intervention is suggested for the effective management of tumor growth and malignancy.

An Efficient frame size Decision and Resource Allocation Method for Multiuser OFDM/TDD System in Multicell Environment (멀티셀 기반의 다중 사용자 OFDM-TDD 시스템에서 효과적인 프레임 크기 결정과 자원 할당 기법)

  • Keum Seung-Won;Kim Jung-Gon;Shin Kil-Ho;Kim Hyung-Myung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.8A
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    • pp.760-768
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    • 2006
  • In this paper, an novel resource allocation scheme is proposed for adaptive multiuser OFDM-TDD systems in multiuser, multicell and frequency-selective time-varying channels. The optimal frame size and mode switching level of each user is determined by maximizing the spectrum efficiency. In multi-cell environment, the allocation scheme must consider the cochannel interference of other cells. The measured SINR is changed in one frame size because the interference is changed. The frame size is determined to consider both the optimal frame size and cochannel user's frame size of other cells. we propose the efficient resource allocation scheme which is satisfied the target BER.

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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Performance Evaluation of the Physical Layer of the DSRC Operating in 5.8 GHz Frequency Band

  • Lee, Byung-Seub;Yim, Choon-Sik;Ahn, Dong-Hyun;Oh, Deock-Gil
    • ETRI Journal
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    • v.23 no.3
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    • pp.121-128
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    • 2001
  • In this paper, the theoretical as well as experimental results of BER characteristics of three different modulation schemes, ASK, FSK and BPSK, in a multi-path Rician channel are addressed. These BER characteristics are analyzed as a function of $E_b/N_o$ and the power ratio of the line of sight (LOS) component to the Rayleigh scattered component. The theoretical as well as computer simulation results shows the ASK is the most suitable modulation scheme for the dedicated short range communication (DSRC) in terms of implemental cost and system complexity. The decision feedback equalizer is proved to be very effective in canceling the multi-path interference in the DSRC channel environment. The simulation result of the equalized ASK, reveals the performance enhancement achievable with decision feedback (DFE) equalizer for the first generation DSRC system. The multi-ray DSRC channel model is also provided to predict the received carrier power and fluctuation, which are quite dependent on the surroundings of a cell.

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Design of QCA Content-Addressable Memory Cell for Quantum Computer Environment (양자컴퓨터 환경에서의 QCA 기반 내용주소화 메모리 셀 설계)

  • Park, Chae-Seong;Jeon, Jun-Cheol
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.2
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    • pp.521-527
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    • 2020
  • Quantum-dot cellular automata (QCA) is a technology that attracts attention as a next-generation digital circuit design technology, and several digital circuits have been proposed in the QCA environment. Content-addressable memory (CAM) is a storage device that conducts a search based on information stored therein and provides fast speed in a special process such as network switching. Existing CAM cell circuits proposed in the QCA environment have a disadvantage in that a required area and energy dissipation are large. The CAM cell is composed of a memory unit that stores information and a match unit that determines whether or not the search is successful, and this study proposes an improved QCA CAM cell by designing the memory unit in a multi-layer structure. The proposed circuit uses simulation to verify the operation and compares and analyzes with the existing circuit.

A Design of Initial Cell Searcher for 3GPP LTE Downlink System (3GPP LTE 하향링크 시스템을 위한 초기 셀 탐색기 설계)

  • Shin, Kyung-Chan;Im, Se-Bin;Ok, Kwang-Man;Choi, Hyung-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.7A
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    • pp.733-742
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    • 2008
  • In 3GPP LTE downlink system, initial cell search is essential for mobile station to connect to base station. In order to obtain information of the base station, the mobile station detects frame timing, frequency offset, and cell identification using primary synchronization channel(PSC) and secondary synchronization channel(SSC), which are defined in downlink OFDMA specification. In this paper, we analyze various detection algorithms in practical environment of inter-cell-interference, frequency offset, and multi-path fading channel and propose the optimal algorithm. Simulation results show that partial correlation method (for PSC acquisition) and interference cancellation method (for SSC detection) are the most superior algorithms among the applicable algorithms. Employ these two algorithms for receiver design, initial cell search is performed with 99% probability within 70ms in the channel environment considered.