• Title/Summary/Keyword: Cell Block

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Statistically Controlled Opportunistic Resource Block Sharing for Femto Cell Networks

  • Shin, Dae Kyu;Choi, Wan;Yu, Takki
    • Journal of Communications and Networks
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    • v.15 no.5
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    • pp.469-475
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    • 2013
  • In this paper, we propose an efficient interference management technique which controls the number of resource blocks (or subcarriers) shared with other cells based on statistical interference levels among cells. The proposed technique tries to maximize average throughput of a femto cell user under a constraint on non-real time control of a femto cell network while guaranteeing a target throughput value of a macro cell user. In our proposed scheme, femto cells opportunistically use resource blocks allocated to other cells if the required average user throughput is not attained with the primarily allocated resource blocks. The proposed method is similar to the underlay approach in cognitive radio systems, but resource block sharing among cells is statistically controlled. For the statistical control, a femto cell sever constructs a table storing average mutual interference among cells and periodically updates the table. This statistical approach fully satisfies the constraint of non-real time control for femto cell networks. Our simulation results show that the proposed scheme achieves higher average femto user throughput than conventional frequency reuse schemes for time varying number of users.

A Study on the S-block Structure in Hexagonal Ferrites (육방정 페라이트의 S-block 구조에 대한 연구)

  • 신형섭;이종협;권순주
    • Journal of the Korean Ceramic Society
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    • v.31 no.1
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    • pp.62-68
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    • 1994
  • It is compared the structures of the S-block in the Ba-Co-Zn Y-type hexagonal ferrites (Ba2Co2-xZnxFe12O22, x=0~2) and the Co-Zn spinel ferrites (Co1-xZnxFe2O4, x=0~1) expressed by a hexagonal axis system (space group R3m). The structures have been refined with a Rietveld analysis of the powder X-ray diffraction pattern with high precision (Rwp<0.13, RI<0.03). The overal dimension of the S-block is slightly different from the 1/3 of a hexagonal spinel unit cell as follow: 1.6~2.0% longer c-axis, 1.3~1.6% shorter a-axis and about 1% smaller volume. Upto Zn:Co=1:1 in the Ba-Co-Zn Y-type hexagonal ferrites, the zinc substitute primarily the tetrahedral sites in the S-block. Beyond that the zinc seems to go into the T-block as well.

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Nonparametric Procedures for Comparing Ordered Treatment Effects with a Control in a Randomized Block Design

  • Lim, Dong-Hoon
    • Journal of the Korean Statistical Society
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    • v.26 no.1
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    • pp.89-100
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    • 1997
  • In this paper we are concerned with comparing ordered treatment effects with a control in a randomized block design with multiple observations per cell. Two nonparametric procedures for detecting which treatment are better than the control are proposed and compared. An example is given and the results of a Monte Carlo power study are discussed.

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Synthesis and characterization of polymer electrolyte membrane for fuel cell including sulfonated bis (4-fluorophenyl) phenylphosphine oxide (술폰화된 비스(4-플루오로페닐) 페닐포스핀옥사이드를 포함한 연료전지용 고분자 전해질막의 합성과 특성분석)

  • Yoo, Eun Sil;Nahm, Kee Suk;Yoo, Dong Jin
    • Journal of Energy Engineering
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    • v.25 no.4
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    • pp.176-183
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    • 2016
  • This study relates to a polymer electrolyte membrane for improved performance fuel cell, were researched with respect to properties required for driving a fuel cell. The bis(4-fluorophenyl)phenyl phosphine oxide was sulfonated using fuming sulfuric acid. Synthetic hydrophilic oligomer and the hydrophobic oligomer and the block copolymers were prepared via aromatic nucleophilic substitution polycondensation. A block copolymer structure and degree of sulfonation was analyzed by $^1H$-NMR and gel permeation chromatography(GPC) analysis. Thermal stability was confirmed by thermogravimetric analysis(TGA), block copolymer was stable at high temperature(>$200^{\circ}C$), The ion conductivity was measured in order to demonstrate the performance of fuel cell. Synthesis membrane was the increase of temperature was improved conductivity up to 58 mS/cm due to the influence of the developed ion clusters. The phase separation of the polymer was observed to make AFM analysis.

The Transmit System for Connection System of Super High Speed Optical Fiber Subscriber (초고속 광 가입자 접속장치용 송신장치 설계)

  • Song, Hong-Jong
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.10 no.1
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    • pp.14-26
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    • 2011
  • In this paper, we've studied Optical Fiber Subscribe Transmit system. After receiving the ATM cell passing through the FIFO of the Asynchronous Transfer Method from the ATM Layer images to the VC4 signal payload passing through scrambling of the cell payload, HEC computation of the cell and inserting the Idle/Unassigned cell. At this time formed VC4 signal passing through the generating and inserting POH overhead at the same time indicating the start point of the cell by the H4 byte on the VC4 POH. This ATM cell transmits 155Mbps speed changing the optical signal after outputting the frame format at the STM-1 signal generation block through the AUG bus after generating J1 of the VC4 start point at the AU4 pointer generation block.

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ATM Cell Security Techniques Using OFB Mode on AES Block Cipher (AES 블록 암호에 OFB 모드를 적용한 ATM 셀 보안 기법)

  • Im, Sung-Yeal
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.31 no.6
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    • pp.1237-1246
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    • 2021
  • This paper is about Asynchronous Transfer Mode (ATM) cell security in which an Output Feedback (OFB) mode is applied to an AES block ciphers. ATM cells are divided into user data cells and maintenance cells, and each cell is 53 octets in size and consists of a header of 5 octets and a payload of 48 octets. In order to encrypt/decrypt ATM cells, the boundaries of cells must be detected, which is possible using the Header Error Control (HEC) field in the header. After detecting the boundary of the cell, the type of payload is detected using a payload type (PT) code to encrypt only the user cell. In this paper, a security method for ATM cells that satisfies the requirements of ISO 9160 is presented.

Development of Worm-like Polymeric Drug Carriers with Multiple Ligands for Targeting Heterogeneous Breast Cancer Cells

  • Lee, A-Hyeong;Oh, Kyung-Taek;Baik, Hye-Jung;Lee, Bo-Reum;Oh, Young-Taik;Lee, Don-Haeng;Lee, Eun-Seong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.8
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    • pp.2265-2271
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    • 2010
  • In this study, wormorm-like polymeric micelles were construted from poly(L-lactic acid)-b-poly(ethyelen glycol) (PLLA-b-PEG) block copolymers via worm-like (or cylindrical) self- assembly that consisted of a relatively long PLLA block ($M_n$ 7K Daltons) at the core and a relatively short PEG block ($M_n$ 2K Daltons) as the shell. Several cancer-targeting moieties (such as folate, cobalamin, and cyclic arginine-glycine-aspartic (RGD) peptide) were chemically coupled with the succinylated or maleimided PEG block of PLLA-b-PEG to act as a cancer cell-specific targeting ligand for breast cancer. The worm-like micelles with muplite cancer cell-specific ligands proved to be successful in recognizing different breast cancer cells at once. This has the potential to aid in cancer-specific drug delivery and to be used as an effective treatment for breast cancer.

Block loss analysis of queuing stragegy with 2-level overload control (과부하 제어를 위한 2-단계 Queuing 전략의 블록 손실에 대한 분석)

  • Kwag, Min-Kon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.6
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    • pp.1554-1561
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    • 1998
  • When the superposition of realtime traffic and non-realtime traffic is applied to the ATM network, the successive cell loss(block loss) is more influential on the quality of service (QoS) of two traffic streams than the single loss in case of bursty traffic. Block loss can be identified as an important performance measure because of delay-oriented policy for realtime traffic. In this paper, we consider the system with the two-level overload control reducing of the recurrence of shut-down periods and develop a recursive algorithm to obtain both block loss and cell loss probabilities of both traffic. We can see that it gives the more precise and diverse investigations on performance analysis of queuing strategy.

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Effects of Stellate Ganglion Block for the Treatment of Bronchial Asthmatic Patients -3 cases report- (기관지 천식 환자의 치료에 성상신경절 차단 효과 -3예 보고-)

  • Suh, Jae-Hyun
    • The Korean Journal of Pain
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    • v.8 no.2
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    • pp.331-335
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    • 1995
  • Asthma is a disease of the airways that is characterized by increased responsiveness of the tracheobronchial tree to a multiplicity of stimuli. A number of causes have been postulated for the increased airway reactivity of asthma is conservative as beta-adrenergic agonist, methylxanthines, glucocorticoids, anticholinergics and mast cell stabilizing agent. Stellate ganglion block for the treatment of bronchial asthma has its controversies. Stellate ganglion block was performed for the treatment of 3 patients with bronchial asthma. After stellate ganglion blocks, dyspnea, coughing and wheezing was markedly reduced. Lung function test improved with 1 st case. Two asthma cases were able to discontinue medication for asthma. No severe aggrevation of bronchial symptoms were noted after stellate ganglion blocks. It suggested that stellate ganglion block can be safely performed on bronchial asthmatic patients.

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