• Title/Summary/Keyword: buffer

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An Asymmetric Buffer Management Policy for SSD (SSD를 위한 비대칭 버퍼 관리 기법)

  • Jung, Ho-Young;Kang, Soo-Yong;Cha, Jae-Hyuk
    • Journal of Digital Contents Society
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    • v.12 no.2
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    • pp.141-150
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    • 2011
  • Recently the Solid State Drive (SSD) is widely used for storage system of various mobile devices. In this case, existing buffer replacement algorithms based on the hard disk do not consider characteristics of flash memory, so it caused performance degradation of the system. This paper proposes a novel buffer replacement policy called ABM (Asymmetric Buffer Management) policy. ABM policy separates read and write buffer space and applies different replacement unit and replacement algorithm for each buffer. In addition, write buffer delay scheme and dynamic size adaptation algorithm is applied for better performance. ABM outperforms other replacement policies, especially ABM-LRU-CLC shows 32% better performance than normal LRU policy.

Properties of IZTO Thin Films on Glass with Different Thickness of SiO2 Buffer Layer

  • Park, Jong-Chan;Kang, Seong-Jun;Yoon, Yung-Sup
    • Journal of the Korean Ceramic Society
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    • v.52 no.4
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    • pp.290-293
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    • 2015
  • The properties of the IZTO thin films on the glass were studied with a variation of the $SiO_2$ buffer layer thickness. $SiO_2$ buffer layers were deposited by plasma-enhanced chemical vapor deposition (PECVD) on the glass, and the In-Zn-Tin-Oxide (IZTO) thin films were deposited on the buffer layer by RF magnetron sputtering. All the IZTO thin films with the $SiO_2$ buffer layer are shown to be amorphous. Optimum $SiO_2$ buffer layer thickness was obtained through analyzing the structural, morphological, electrical, and optical properties of the IZTO thin films. As a result, the IZTO surface roughness is 0.273 nm with a sheet resistance of $25.32{\Omega}/sq$ and the average transmittance is 82.51% in the visible region, at a $SiO_2$ buffer layer thickness of 40 nm. The result indicates that the uniformity of surface and the properties of the IZTO thin film on the glass were improved by employing the $SiO_2$ buffer layer and the IZTO thin film can be applied well to the transparent conductive oxide for display devices.

A Novel Hydrogen-reduced P-type Amorphous Silicon Oxide Buffer Layer for Highly Efficient Amorphous Silicon Thin Film Solar Cells (고효율 실리콘 박막태양전지를 위한 신규 수소저감형 비정질실리콘 산화막 버퍼층 개발)

  • Kang, Dong-Won
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.10
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    • pp.1702-1705
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    • 2016
  • We propose a novel hydrogen-reduced p-type amorphous silicon oxide buffer layer between $TiO_2$ antireflection layer and p-type silicon window layer of silicon thin film solar cells. This new buffer layer can protect underlying the $TiO_2$ by suppressing hydrogen plasma, which could be made by excluding $H_2$ gas introduction during plasma deposition. Amorphous silicon oxide thin film solar cells with employing the new buffer layer exhibited better conversion efficiency (8.10 %) compared with the standard cell (7.88 %) without the buffer layer. This new buffer layer can be processed in the same p-chamber with in-situ mode before depositing main p-type amorphous silicon oxide window layer. Comparing with state-of-the-art buffer layer of AZO/p-nc-SiOx:H, our new buffer layer can be processed with cost-effective, much simple process based on similar device performances.

Effect of ZnO buffer layer on the property of ZnO thin film on $Al_{2}O_{3}$ substrate (사파이어 기판 위에 증착된 ZnO 박막 특성에 대한 ZnO 버퍼층의 영향)

  • Kim, Jae-Won;Kang, Jeong-Seok;Kang, Hong-Seong;Lee, Sang-Yeol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.04a
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    • pp.140-142
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    • 2003
  • ZnO thin films are demanded for device applications, so ZnO buffer layer was used to improve for good properties of ZnO thin film. In this study, the structural, electrical and optical properties of ZnO thin films deposited with various buffer thickness was investigated by X-ray diffraction (XRD), Hall measurements, Photoluminescence(PL). ZnO buffer layer and ZnO thin films on sapphire($Al_{2}O_{3}$) substrate have been deposited $200^{\circ}C$ and $400^{\circ}C$ respectively by pulsed laser deposition. It is observed the variety of lattice constant of ZnO thin film by (101) peak position shift with various buffer thickness. It is founded that ZnO thin film with buffer thickness of 20 nm was larger resistivity of 200 factor and UV/visible of 2.5 factor than that of ZnO thin films without buffer layer. ZnO thin films with buffer thickness of 20 nm have shown the most properties.

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Effect of Green Buffer Zone in Reducing Gaseous Air Pollutants in the Shiwha Industrial Area (시화공단 완충녹지대의 대기오염물질 저감 효과 분석)

  • Song Young-Bae
    • Journal of the Korean Institute of Landscape Architecture
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    • v.33 no.6 s.113
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    • pp.90-97
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    • 2006
  • The effects of a green buffer zone to protect a residential area from air pollution from industrial facilities and traffic was examined by analyzing the case of a green buffer zone in the Shiwha industrial complex. The green buffer zone is 175 m wide. The intent was to assess the dispersion patterns of atmospheric air pollutants and the reduction in concentration around the green buffer zone. To measure atmospheric sulfur dioxide$(SO_2)$ and nitrogen dioxide$(NO_2)$ concentration, badge-type passive samplers were used and set up at 76 locations in order to measure the concentration of air pollutants with respect to the spatial dispersion. The weighted mean values of $SO_2\;and\;NO_2$ concentration were $3\~57 ppb\;and\;18\~62 ppb$ and the differences among the green buffer zone, the industrial area and the residential areas were $0.7\~1.1 ppb$. Mean values of atmospheric concentrations of $NO_2$ were similar in industrial and, residential areas and the green buffer zone. Results of the study show that the effect of the green buffer zone on reducing the dispersion of air pollutants was very low. This study also recommends that micro-climate, i.e., wind direction should be considered as a factor for planning and design of green buffer zones.

Timer-based Buffer Management for Reliable Multicast (신뢰적 멀티캐스트를 위한 타이머 기반 버퍼 관리)

  • 안상현;김영민;권영호
    • Journal of KIISE:Information Networking
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    • v.30 no.4
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    • pp.513-519
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    • 2003
  • In order to deliver multicast traffic efficiently, multicast routing and reliable transmission mechanisms are required. The reliable delivery implies that lost packets must be retransmitted, which in turn requires that transmitted packets be stored in a retransmission buffer. Therefore how to manage a retransmission buffer is important and, in this paper, we try to solve the problem of how many packets should be maintained in the buffer. Our proposed scheme, the timer-based buffer management (TBM), maintains only necessary amount of buffer based on the timer value calculated from the NAKs between the replier and receivers on a multicast tree and can adjust to the dynamic network conditions. By performing simulations, we show that TBM manages the buffer efficiently regardless of the error situation, network size, and so on.

Analysis of Total Nitrogen Reduction Efficiency with Established Riparian Buffer System using SWAT-REMM Model in Bonggok Watershed (SWAT-REMM 모형을 이용한 봉곡천 유역의 수변림 조성에 따른 총 질소 저감 효율 분석)

  • Ryu, Jichul;Kang, Hyunwoo;Kim, Nam Won;Jang, Won Seok;Lee, Ji Won;Moon, Jong-pil;Lee, Kyu-seung;Lim, Kyoung Jae
    • Journal of Korean Society on Water Environment
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    • v.26 no.6
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    • pp.910-918
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    • 2010
  • In recent years, riparian buffer system has been known as one of the effective best management practices. However, establishment of riparian buffer system in aspect of plant species and its position in the riparian buffer zone has not been investigated due to lack of efficient evaluation method for the analysis of water quality improvement with established riparian buffer system. To solve this problem, the SWAT-REMM prototype was developed by the researchers in Canada. But, SWAT-REMM model can not consider the $NO_3-N$ load into riparian buffer system through subsurface flow. Thus to solved this problem, Fortran code of SWAT-REMM model was modified. This modified SWAT-REMM system was applied to the Bonggok watershed. Three riparian buffer scenarios, 15 m, 10 m, 5 m width for tree and grass, were made to evaluate the effects of riparian buffer system on water quality improvement. Reduction efficiency of T-N by riparian buffer system of 15 m wide was the greatest (6 ~ 37%, depending on subwatershed characteristics) among 3 scenarios. It indicates that the reduction efficiency of T-N load has increasing-tendency, as buffer width increasing. The results obtained from the analysis showed that wide buffer zones are found to be more effective in reducing non-point pollutant than narrow buffer zones in the riparian buffer zone system. Hence, the SWAT-REMM model could be efficiently used for evaluation and design the most effective riparian buffer systems to reduce pollutant loads to the watershed although many limitations still exist in SWAT-REMM model.

A Real-Time Multiple Circular Buffer Model for Streaming MPEG-4 Media (MPEG-4 미디어 스트리밍에 적합한 실시간형 다중원형버퍼 모델)

  • 신용경;김상욱
    • Journal of KIISE:Computing Practices and Letters
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    • v.9 no.1
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    • pp.13-24
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    • 2003
  • MPEG-4 is a standard for multimedia applications and provides a set of technologies to satisfy the needs of authors, service providers and end users alike. In this paper, we suggest a Real-time Multiple Circular Buffer (M4RM Buffer) model, which is suitable for streaming these MPEG-4 contents efficiently. M4RM buffer generates each structure of the buffer, which matches well with each object composing an MPEG-4 content, according to the transferred information, and manipulates multiple read/write operations only by its reference. It divides the decoder buffer and the composition buffer, which are described in the standard, by the unit of frame allocated to minimize the range of access. This buffer unit of a frame is allocated according to the object description. Also, it processes the objects synchronization within the buffer and provides APIs for an efficient buffer management to process the real-time user events. Based on the performance evaluation, we show that M4RM buffer model decreases the waiting time in a buffer frame, and so allows the real-time streaming of an MPEG-4 content using the smaller size of the memory block than IM1-2D and Window Media Player.

Electrochemical Preparation of Indidum Sulfide Thin Film as a Buffer Layer of CIGS Solar Cell (CIGS 태양전지 버퍼층으로의 활용을 위한 인듐설파이드의 전기화학적 합성)

  • Kim, Hyeon-Jin;Kim, Kyu-Won
    • Journal of the Korean Electrochemical Society
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    • v.14 no.4
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    • pp.225-230
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    • 2011
  • CIGS solar cells are kind of thin film solar cells, which are studied several years. CdS buffer layer that makes heterojunction between window layer and absorbing layer was one of issue in the CIGS solar cell study. New types of buffer layer consisted of indium sulfide are being studied these days owing to high price and environmental harmful of CdS. In this study, we demonstrated electrochemical synthesis of indium sulfide film as a buffer layer, which is cheaper and faster than other methods. A uniform indium sulfide film was obtained by applying two different alternating potentials. The band gap of the film was optimized by controlling temperature during the electrochemical synthesis. Using x-ray photoelectron spectroscopy and diffraction method we confirmed that ${\beta}$-indium sulfide was formed on ITO electrode surface.

Den of I/O Controller for Future Communication Platform (차세대 통신 플랫폼을 위한 입출력 컨트롤러 설계)

  • Hyun Eugin;Seong Kwang-Su
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.42 no.4 s.304
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    • pp.59-68
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    • 2005
  • In this paper, we design a PCI Express controller for future communication system The controller supports the full functionality of Transaction Layer and Data Link Layer of PCI Express. The designed controller has the proposed transmitter buffer architecture to obey Replay mechanism. This scheme merges the transmitting buffer and the replay buffer. The proposed buffer has the higher data transfer efficiency than the conventional buffer architecture because it can dynamically adjust size of a replay buffer space. We also design transmitter of Transmitter Transaction Layer to effectively support the proposed buffer, The receiver device of PCI Express must possess the buffer for three types of transaction to support Flow Control. And it must report the amount of the buffer space regularly to the Port at the opposite end of the link. We propose the simple receiver buffer scheme using only one buffer to easily support Flow Control. And the designed controller is verified under proposed test bench