• Title, Summary, Keyword: Bulk Data Transmission

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Study for the Bragg Detuning Effects on the Transmission Holograms and the Reflection Holograms (투과형 홀로그램과 반사형 홀로그램에서의 Bragg detuning 현상에 대한 연구)

  • Kwon, Yun-Young;Kim, Kun-Yul;Park, Joo-Youn
    • Transactions of the Society of Information Storage Systems
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    • v.2 no.3
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    • pp.189-195
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    • 2006
  • Bragg detuning effect if, one of the serious problems if the photopolymer is used for the recording material of holography memories. And the critical reasons of that are known as the bulk refractive index change and shrinkage of recording material. However, the trials for analyzing the effect are mainly on the K-sphere and biased on the transmission hologram. So, we approached Bragg detuning effect numerically and applied the method to the transmission holograms and the reflection holograms all together. We simulated it with MATLAB. As a result, the bulk refractive index change causes+Bragg detuning effect on the transmission holograms and the reflection holograms. But the shrinkage leads to+Bragg detuning effect on the transmission hologram and-Bragg detuning effect on the reflective hologram. Compared to experimental result, the bulk refractive index change(${\fallingdotseq}4{\times}10^{-4}$) and the ratio of shrinkage to the thickness of the material(${\fallingdotseq}1.67{\times}10^{-3}$) could be matched with Bragg detuning effect on the transmission hologram and the reflection hologram.

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A Design and Implementation of Bulk Data Transmission Tool based on UDT (UDT 기반의 대용량 데이터 전송도구 설계 및 구현)

  • Park, Jong-Seon;Kim, Seung-Hae;Hwang, Gun-Joon;Cho, Gi-Hwan
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.2
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    • pp.23-31
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    • 2012
  • With advance of high bandwidth network infrastructure, the requirement is dramatically increasing to cooperate between the users who are far from each other and make use of bulk data. However, as the prominent data transmission protocol, it is well known that TCP suffers some degrees of inefficiency for bulk data transmission when RTT is relatively big. So, some works are on going to suggest a new transmission method to utilize the bandwidth in effective. UDT(UDP-based Data Transfer protocol) is one of these. It is a UDP based application level protocol which can guarantee reliability and stability. much like as TCP. In this paper, we present a design and implementation of UDT based bulk data transmission tool by applying parallel and compressive techniques. The implementation result is examined to measured its performance improvement on a real test-bed, and then compared with existing bulk data transmission tools. Experimental results show that proposed tool is more stable and shows greater performance than that of native UDT. Especially, the performances show 244% improvement in RTT 400ms without losses and 229% in RTT 250ms with 0.005% losses respectively.

Reliable Data Transmission Based on Erasure-resilient Code in Wireless Sensor Networks

  • Lei, Jian-Jun;Kwon, Gu-In
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.4 no.1
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    • pp.62-77
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    • 2010
  • Emerging applications with high data rates will need to transport bulk data reliably in wireless sensor networks. ARQ (Automatic Repeat request) or Forward Error Correction (FEC) code schemes can be used to provide reliable transmission in a sensor network. However, the naive ARQ approach drops the whole frame, even though there is a bit error in the frame and the FEC at the bit level scheme may require a highly complex method to adjust the amount of FEC redundancy. We propose a bulk data transmission scheme based on erasure-resilient code in this paper to overcome these inefficiencies. The sender fragments bulk data into many small blocks, encodes the blocks with LT codes and packages several such blocks into a frame. The receiver only drops the corrupted blocks (compared to the entire frame) and the original data can be reconstructed if sufficient error-free blocks are received. An incidental benefit is that the frame error rate (FER) becomes irrelevant to frame size (error recovery). A frame can therefore be sufficiently large to provide high utilization of the wireless channel bandwidth without sacrificing the effectiveness of error recovery. The scheme has been implemented as a new data link layer in TinyOS, and evaluated through experiments in a testbed of Zigbex motes. Results show single hop transmission throughput can be improved by at least 20% under typical wireless channel conditions. It also reduces the transmission time of a reasonable range of size files by more than 30%, compared to a frame ARQ scheme. The total number of bytes sent by all nodes in the multi-hop communication is reduced by more than 60% compared to the frame ARQ scheme.

PC-based Control System of Serially Connected Multi-channel Speakers (직렬연결 다채널 스피커의 PC 기반 제어 시스템)

  • Lee, Sun-Yong;Kim, Tae-Wan;Byun, Ji-Sung;Song, Moon-Vin;Chung, Yun-Mo
    • The KIPS Transactions:PartA
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    • v.15A no.6
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    • pp.317-324
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    • 2008
  • In this paper, we propose a system which easily controls the existing serially connected multi-channel speakers in a general personal computer by using a USB(Universal Serial Bus) interface. The personal computer as a host of the USB interface analyzes a sound source and sends audio data in a real-time fashion by the use of the isochronous transmission, one of four transmission methods provided by the USB interface. In addition, a channel is assigned by means of the bulk transmission, one of four transmission methods provided by the USB interface. Transmitted data from the USB host are sent to each speaker through compression and packet generation process. Each speaker detects corresponding digital data and regenerates audio signals through DAC(Digital-to-Analog Converter). A user can easily select a sound source file and a channel by the use of a GUI environment in a personal computer.

A Study on the Shape of the Pattern Milled Using FIB (집속이온빔 연마에 의한 패턴의 형태에 관한 연구)

  • Jung, Won-Chae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.11
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    • pp.679-685
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    • 2014
  • For the measurements of surface shape milled using FIB (focused ion beam), the silicon bulk, $Si_3N_4/Si$, and Al/Si samples are used and observed the shapes milled from different sputtering rates, incident angles of $Ga^+$ ions bombardment, beam current, and target material. These conditions also can be influenced the sputtering rate, raster image, and milled shape. The fundamental ion-solid interactions of FIB milling are discussed and explained using TRIM programs (SRIM, TC, and T-dyn). The damaged layers caused by bombarding of $Ga^+$ ions were observed on the surface of target materials. The simulated results were shown a little bit deviation with the experimental data due to relatively small sputtering rate on the sample surface. The simulation results showed about 10.6% tolerance from the measured data at 200 pA. On the other hand, the improved analytical model of damaged layer was matched well with experimental XTEM (cross-sectional transmission electron microscopy) data.

A Performance Improvement Method with Considering of Congestion Prediction and Packet Loss on UDT Environment (UDT 환경에서 혼잡상황 예측 및 패킷손실을 고려한 성능향상 기법)

  • Park, Jong-Seon;Lee, Seung-Ah;Kim, Seung-Hae;Cho, Gi-Hwan
    • The Journal of the Korea Contents Association
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    • v.11 no.2
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    • pp.69-78
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    • 2011
  • Recently, the bandwidth available to an end user has been dramatically increasing with the advancing of network technologies. This high-speed network naturally requires faster and/or stable data transmission techniques. The UDT(UDP based Data Transfer protocol) is a UDP based transport protocol, and shows more efficient throughput than TCP in the long RTT environment, with benefit of rate control for a SYN time. With a NAK event, however, it is difficult to expect an optimum performance due to the increase of fixed sendInterval and the flow control based on the previous RTT. This paper proposes a rate control method on following a NAK, by adjusting the sendInterval according to some degree of RTT period which calculated from a set of experimental results. In addition, it suggests an improved flow control method based on the TCP vegas, in order to predict the network congestion afterward. An experimental results show that the revised flow control method improves UDT's throughput about 20Mbps. With combining the rate control and flow control proposed, the UDT throughput can be improved up to 26Mbps in average.

A Study on the Reliability Evaluation of KEPCO Long-term Transmission System (한전의 장기 송전계통 공급신뢰도 평가에 관한 연구)

  • Chu, Jin-Boo;Moon, Ki-Seung;Sin, Sang-Gyoun;Lee, Ki-Seon
    • Proceedings of the KIEE Conference
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    • pp.67-69
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    • 1993
  • The purpose of the facility investment planning for bulk power system is to appropriately configure the power system network to supply the load, which has the supply capability satisfying the probabilistically changing load on the desired reliability level. In order to achieve this purpose, this paper represents the reliability evaluation of the KEPCO's real system with using the MEXICO model, and builds the data base of the power system operation in order to effectively handle the computer model.

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Characteristic of the femtosecond laser machining in glass (펨토초 레이어 기반 유리 내부가공 특성)

  • Yoo B.H.;Kim Y.M.;Cho S.H.;Chang W.S.;Kim J.G.;Whang K.H.;Lee D.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.239-240
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    • 2006
  • For longer than picosecond pulses, bulk damage inside defect-free dielectrics involves the heating and multiplication of spurious electrons by the incident laser beam and transfer of this energy to the lattice. The situation is quite different for femtosecond pulses which are shorter than the time scale for electron energy transfer to the lattice. Damage caused by these pulses is produced with smaller statistical uncertainty and is controllable on a microscopic scale. These properties can be exploited to produce laser devices such as arrays of damage dots for all optical memories with high data storage density or arrays of parallel grooves to form transmission gratings. In this work, we observed characteristic of the femtosecond laser machining in BK7 and fused silica.

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A SES Alarmed Link Encryption Synchronization Method for High-speed Video Data Encryption (고속 영상데이터 암호화에 적합한 SES Alarmed 링크 암호동기 방식)

  • Kim, HyeongRag;Lee, HoonJae;Kwon, DaeHoon;Pak, UiYoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.12
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    • pp.2891-2898
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    • 2013
  • CCSDS Standard is widely used in international space telecommunication area. In this standard, Encryption is realized using a unique hierarchical encryption protocol and satisfied security requirements of communication channels. For synchronization, encryption sync is attached in the beginning of encrypted data. But exceptional case(timing jittering, abnormal system shutdown, etc.) is occurred, receiving equipment cannot decrypt received data. In this paper, we propose a SES Alarmed link encryption synchronization method for sending warning signal to the transmitter when some problems have been occurred during the transmission and we also suggest optimum conditions for SES Alarm signal through performance analysis.

Mineralogical and Geochemical Characteristics of Soils of Barton Peninsula, King George Island, South Shetland Islands, West Antarctica (서남극 사우스셰틀랜드 킹조지섬 바톤반도 육상 토양의 광물학적, 지화학적 특성)

  • Jung, Jaewoo;Koo, Taehee;Yang, Kiho;Kim, Jinwook
    • Journal of the Mineralogical Society of Korea
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    • v.30 no.1
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    • pp.21-29
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    • 2017
  • Surface soils on Barton Peninsula, King George Island, West Antarctica were investigated to acquire the mineralogical and geochemical data of soil in Antarctica. Multiline of techniques for example, X-ray diffraction (XRD), transmission electron microscopy (TEM)-electron energy loss spectroscopy (EELS), and wet chemistry analysis were performed to measure the composition of clay minerals, Fe-oxidation states, cation exchange capacity, and total cation concentration. Various minerals in sediments such as smectite, illite, chlorite, kaolinite, quartz and plagioclase were identified by XRD. Fe-oxidation states of bulk soils showed 20-40% of Fe(II) which would be ascribed to the reduction of Fe in clays as well as Fe-bearing minerals. Moreover, redox states of Fe in smectite structure was a ~57% of Fe(III) consistent to the values for the bulk soils. The cation exchange capacity of bulk soils ranged from 100 to 300 meq/kg and differences were not significantly measured for the sampling locations. Total cations (Mg, K, Na, Al, Fe) of bulk soils varies, contrast to the heavy metals (Co, Ni, Cu, Zn, Mn). These results suggested that composition of bed rocks influenced the distribution of elements in soil environments and soils containing clay compositions may went through the bio/geochemical alteration.