• Title/Summary/Keyword: buffering

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Global Carbon Budget and Ocean Buffering against Rising Atmospheric CO2 Concentration

  • Kwon, O-Yul
    • Journal of Environmental Science International
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    • v.11 no.8
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    • pp.773-781
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    • 2002
  • The natural carbon cycle has been perturbed since the mid-19th century by anthropogenic CO$_2$emissions from fossil fuel combustion and deforestation due to population growth and industrialization. The current study simulated the global carbon cycle for the past 42 years using an eight-box carbon cycle model. The results showed that since the terrestrial biospheric carbon sink was roughly offset by the deforestation source, the fossil fuel emission source was partitioned between the atmospheric and oceanic sinks. However, the partitioning ratio between the atmosphere and the ocean exhibited a change, that is, the carbon accumulation rate was faster in the atmosphere than in the ocean, due to a decrease in the so-called ocean buffering capacity. It was found that the ocean buffering capacity to take up excess CO$_2$decreased by 50% in terms of the buffer factor over the past 42 years. Accordingly, these results indicate that if the current CO$_2$emission trend continues, the future rate of increase in the atmospheric CO$_2$concentration will accelerate.

A New Flash-aware Buffering Scheme Supporting Virtual Page Flushing

  • Lim, Seong-Chae
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.3
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    • pp.161-170
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    • 2022
  • Recently, NAND-type flash memory has been regarded to be new promising storage media for large-scale database systems. For flash memory to be employed for that purpose, we need to reduce its expensive update cost caused by the inablity of in-place updates. To remedy such a drawback in flash memory, we propose a new flash-aware buffering scheme that enables virtual flushing of dirty pages. To this end, we slightly alter the tradional algorithms used for the logging scheme and buffer management scheme. By using the mechanism of virtual flushing, our proposed buffering scheme can efficiently prevent the frequenct occureces of page updates in flash storage. Besides the advantage of reduced page updates, the proposed viurtual flushing mechanism works favorably for shorneing a recocery time in the presense of failure. This is because it can reduce the time for redo actions during a recovry process. Owing to those two benefits, we can say that our scheme couble be very profitable when it is incorporated into cutting-edge flash-based database systems.

Design of Smart OTT Platform based on the Analysis of Adaptive Buffering (적응 버퍼링 성능분석 기반의 스마트 OTT 플랫폼 설계☆)

  • Kim, Inki;Kang, Mingoo
    • Journal of Internet Computing and Services
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    • v.17 no.4
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    • pp.19-26
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    • 2016
  • In this paper, the dynamic buffering based smart OTT platform was proposed, and analyzed for adaptive bit-rate video delivery with the optimization of HLS (HTTP Live Streaming). This platform consists of the software platform between sever and client which detects the bandwidth capacity, and adjusts the quality of the streaming for multiple bit-rates resolutions. In order to apply adaptive buffering, two buffers are added to the basic HLS player, and each buffer is responsible for constantly buffering a previous and the next channels relative to the current channel. This adaptive transmitting with smart OTT platform is superior to delivering a static video file at a single buffering, because the video stream of adaptive double buffers can be switched streaming according to client's available network speed. As a result, this proposed smart OTT can be cooperated to the application of HLS server with segmented H.265 MPEG-2 TS video & m3u8 files with its information based on the optimized transmission channel state of live and VOD, and applied to PLC transmission, too.

Enhanced Methods of Path Finding Based on An Abstract Graph with Extension of Search Space (탐색 영역 확장 기법들을 활용한 추상 그래프 기반의 탐색 알고리즘 성능 개선)

  • Cho, Dae-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.1
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    • pp.157-162
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    • 2011
  • In this paper, we propose enhanced methods of path finding based on an abstract graph with extension of search space to improve the quality of path. The proposed methods that are called simple buffering method, velocity constrained method and distance constrained method are to extract buffering-cells for using search space with valid-cells. The simple buffering method is to extract adjacent cells of valid-cells as buffering-cells. velocity constrained method and distance constrained method are based on simple buffering method, these eliminate buffering-cells through each of threshold. In experiment, proposed methods can improve the quality of path. The proposed methods are applicable to develop various kinds of telematics application, such as path finding and logistics.

Effect of Simulated Acid Rain on Germination, Growth, Acid Buffering Capacity and Nutrient Leaching in Impatiens balsamina L. and Tagetes patula L. (산성비가 봉선화(Impatiens balsamina L.) 및 만수국(Tagetes patula L.)의 발아, 생장, 완충능력 및 양료용탈에 미치는 영향)

  • 김학윤;이인중;신동현;김길웅;조문수
    • Journal of Life Science
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    • v.10 no.6
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    • pp.598-604
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    • 2000
  • This study was conducted to investigate the effect of simulated acid rain (SAR) on germination, growth, acid buffering capacity and nutrient leaching in Impatiens balsamina L. and Tagetes patula L.. In both species, germination was not inhibited at pH 4.0, but the germination rate decreased at the lower pH of 3.0, showing higher rate in Inpatiens balsamina L. than Tagetes patula L.. As the pH decreases, the growth of radicle was markedly decreased than that of hypocotyl in both species. The plant height, root length, leaf area, total dry weight, relative growth rate and net assimilation rate were inhibited by SAR. The acid buffering capacity in the leaves were increased at pH 4.0, on the other hand, it was shown a tendency to decrease at pH 2.0 in both species. As the pH levels decreased from 5.6 to 2.0, the nutrient leaching from leaves was significantly increased in both species. Based on the results, there are a great difference in the responses to SAR between the two species. In general, Tagetes patula L. represented a higher tolerance to SAR than Impatiens balsamina L.. These results suggested that interspecific variation in the acid buffering capacity and nutrient leaching from leaves may be responsible for the interspecific susceptibility to SAR.

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The FB mechanism for TCP traffic over UBR connections in the subnet ATM model (서브네트 ATM 모델에서의 UBR 연결 TCP 트래픽 전송을 위한 FB 기법)

  • 김우준;이병기
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.6
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    • pp.1610-1618
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    • 1998
  • In this paper, we present the FB(Fair Buffering) mechanism for the efficient support of TCP traffic over UBR connections in the subnet ATM model. We show that both throughput and fairness may be improved with the FB mechanism. The FB mechanism is founded on the observation that the performance of TCP over UBR connections is optimal when the buffer space is allocated in proportion to the connection's bandwidth-delay product. We compare through simulation the performance of the existing drop-tail, EB(Equal Buffering) and the proposed FB buffer management schemes, with and without RR(Roung-Robin) scheduling, and demonstrate that the proposed FB mechanism is most effective when used in conjunction with the RR scheduling scheme.

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Proposal and Performance Comparison for a Packet Loss Reduction Scheme of DMM (DMM의 패킷 손실 감소 방안 제안 및 성능 비교)

  • Ha, Sang-Hyuk;Min, Sang-Won
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.6
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    • pp.89-94
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    • 2012
  • In this paper, we considered the performances of PMIPv6 and DMM in the viewpoints of traffic load change and packet delivery latency time, where a new buffering in the previous MAAR is proposed to reduce packet loss during handover. To show the superiority of the DMM and to validate the operation of the buffering scheme, we accomplished its simulation under the typical handover. Our performance comparison results show that the DMM is better than the performance of traffic load change and packet delivery latency time of PMIPv6. We can see that the proposed buffering scheme is better than the existing one in terms of packet loss.

Introduction of a Buffering Layer for the Interfacial Stability of LSGM-Based SOFCs (LSGM계 고체산화물 연료전지의 계면안정성을 위한 완층층의 도입)

  • Kim, Kwang-Nyeon;Moon, Jooho;Son, Ji-Won;Kim, Joosun;Lee, Hae-Weon;Lee, Jong-Ho;Kim, Byung-Kook
    • Journal of the Korean Ceramic Society
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    • v.42 no.9 s.280
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    • pp.637-644
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    • 2005
  • In order to find a proper buffering material which can prohibit an unwanted interfacial reaction between anode and electrolyte of LSGM-based SOFC, we examined a gadolinium doped ceria and scandium doped zirconia as a candidate. For this examination, we investigated the microstructural and phase stability of the interface under different buffering layer conditions. According to the investigation, ceria based material induced a serious La diffusion out of the LSGM electrolyte resulted in the formation of very resistive $LaSrGa_3O_7$ phase at the interface. On the other hand zirconia based material was directly reacted with LSGM electrolyte and thus produced very resistive reaction products such as $La_2Zr_2O_7,\;Sr_2ZrO_4,\;LaSrGaO_4\;and\;LaSrGa_3O_7$. From this study we found that an improper buffering material induced the higher internal cell resistance rather than an interfacial stability.

The Buffering Effect of Family Cohesion in the Relationship between Depression and Suicidal Risk (우울감과 자살위험간의 관계에서 가족결속도의 완충효과)

  • Kim, Yun-Jeong;Kang, Hyun-Jung
    • The Journal of the Korea Contents Association
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    • v.14 no.3
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    • pp.241-249
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    • 2014
  • The aim of this paper is to examine the buffering effect of family cohesion in the relationship between depression and suicidal risk among adolescents, adults, and the elderly. To achieve the research aim, surveys were conducted in 10 cities across the country for 399 adolescents, 473 adults, and 370 elderly from May to August 2010. Major findings of the data analysis are as follows. First, while, in the relationship between depression and suicidal risk, the elderly were the highest, followed by adolescents and adults in descending order, in family cohesion, adults were the highest, followed by the elderly and adolescents. Second, the analysis of the buffering effect of family cohesion in the relationship between depression and suicidal risk showed that it was significant only for adolescents and adults, which means that for those two groups family cohesion alleviates the effects of depression on suicidal risk, demonstrating the necessity of strengthening family cohesion to reduce suicides among the two groups of people. But, for the elderly for whom family relationship is more important than any other age group, the buffering effect of family cohesion in the relationship between depression and suicidal risk was not proved. The interpretation of this phenomenon is given in the part of the paper where the characteristics of the suicide of the old age group is discussed.

Improving the Availability of Scalable on-demand Streams by Dynamic Buffering on P2P Networks

  • Lin, Chow-Sing
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.4 no.4
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    • pp.491-508
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    • 2010
  • In peer-to-peer (P2P) on-demand streaming networks, the alleviation of server load depends on reciprocal stream sharing among peers. In general, on-demand video services enable clients to watch videos from beginning to end. As long as clients are able to buffer the initial part of the video they are watching, on-demand service can provide access to the video to the next clients who request to watch it. Therefore, the key challenge is how to keep the initial part of a video in a peer's buffer for as long as possible, and thus maximize the availability of a video for stream relay. In addition, to address the issues of delivering data on lossy network and providing scalable quality of services for clients, the adoption of multiple description coding (MDC) has been proven as a feasible resolution by much research work. In this paper, we propose a novel caching scheme for P2P on-demand streaming, called Dynamic Buffering. The proposed Dynamic Buffering relies on the feature of MDC to gradually reduce the number of cached descriptions held in a client's buffers, once the buffer is full. Preserving as many initial parts of descriptions in the buffer as possible, instead of losing them all at one time, effectively extends peers’ service time. In addition, this study proposes a description distribution balancing scheme to further improve the use of resources. Simulation experiments show that Dynamic Buffering can make efficient use of cache space, reduce server bandwidth consumption, and increase the number of peers being served.