The Experts below are selected from a list of 33507 Experts worldwide ranked by ideXlab platform
S K Changchien - One of the best experts on this subject based on the ideXlab platform.
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interleaved four phase buck based current source with center tapped energy Recovery Scheme for electrical discharge machining
IEEE Transactions on Power Electronics, 2009Co-Authors: S K ChangchienAbstract:This paper presents the interleaved four-phase buck-based current source in continuous conduction mode with proposed isolated energy-Recovery Scheme for electrical discharge machining (EDM). EDM requires a pulse current with high slew rate in the output current of the current source. The interleaving technique allows the output slew rate of the buck-based current source to be improved due to the existence of the paralleled inductors at the start of discharge. The proposed isolated energy-Recovery Scheme provides a major path for the inductor to release its stored energy, thus avoiding high voltage stress in the output terminal when the gap reverts to the high-impedance state. The energy stored in the inductor is recycled to the input capacitor and can be reused for machining. The experimental results validate that the output current slew rate is high and that the energy is recovered when the gap is in the high-impedance state.
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interleaved four phase buck based current source with center tapped energy Recovery Scheme for electrical discharge machining
Applied Power Electronics Conference, 2008Co-Authors: S K ChangchienAbstract:This paper proposes a center-tapped energy-Recovery Scheme used in the interleaved four-phase buck-based current source in continuous conduction mode (CCM) for electrical discharge machining (EDM). A pulse machining current with high slew rate is required for the EDM. Using the interleaving technique, the output current slew rate of the buck-based current source can be improved because of the paralleled inductors at the start of discharge. The proposed center-tapped energy-Recovery Scheme provides a major path for the inductor to release its stored energy to avoid high voltage stress in the output terminal when the gap is in the high-impedance state. The energy stored in the inductor is recovered to the input capacitor, and can be reused for machining. The experimental results are provided as the verification of the high output current slew rate and the energy Recovery when the gap is in high-impedance state.
Weixiao Meng - One of the best experts on this subject based on the ideXlab platform.
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Packet Loss Recovery Scheme with Uniquely-Decodable Codes for Streaming Multimedia over P2P Networks
IEEE Journal on Selected Areas in Communications, 2013Co-Authors: Qi-yue Yu, Weixiao MengAbstract:This paper presents an effective packet loss Recovery Scheme for Internet Protocol (IP) based peer-to-pear (P2P) networks that deliver multimedia streaming contents. The proposed Scheme consists of two key components, a packet forward error correction (FEC) Scheme and a uniquely decodable coding (UDC) Scheme. The FEC Scheme is devised to recover network packet loss over the transport layer to improve link transmission reliability at the user-ends of the P2P networks. The UDC Scheme is employed to allow multiple sources to transmit data streams simultaneously in such a way that the combined data streams can be separated uniquely without ambiguity at the user-ends. This simultaneous multiple sources data transmission increases the throughput at the user-ends. Theoretical analysis and computer simulations show that the proposed Scheme can achieve the commonly acceptable of 10^{-6} end-to-end packet loss rate for input packet loss rate of up to 10%with a reasonably small bandwidth expansion factor, while maintains a high throughput at the user-ends.
T. Pollet - One of the best experts on this subject based on the ideXlab platform.
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An early-late timing Recovery Scheme for filter-bank-based multicarrier transmission
IEEE Transactions on Communications, 2000Co-Authors: J. Louveaux, L. Vandendorpe, L. Cuvelier, T. PolletAbstract:This paper is devoted to the design and the steady-state performance analysis of a data-aided or decision-directed timing Recovery Scheme for filter bank-based multicarrier transmission with equalization. The symbol synchronizer is obtained from a Mueller and Muller approach extended to multiband transmission. A simple synchronizer is first proposed which can be derived from an approximate likelihood function. Then, possible improvements are discussed. Timing jitter variances are computed and discussed for high bit-rate transmission over copper wires.
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An early-late timing Recovery Scheme for filter-bank-based multicarrier transmission
IEEE Transactions on Communications, 2000Co-Authors: J. Louveaux, L. Vandendorpe, L. Cuvelier, T. PolletAbstract:This paper examines a decision-directed timing Recovery Scheme for filter-bank-based multicarrier transmission. The symbol synchronizer is obtained from a maximum-likelihood approach and uses the digital equalization filters. The algorithm is first derived, the performances of the Scheme (timing offset and timing jitter) are then computed, and computational results are provided for high bit-rate transmission over copper wires. Finally, different improvements are discussed
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ICC - An early-late timing Recovery Scheme for filter-bank based multicarrier transmission
1999 IEEE International Conference on Communications (Cat. No. 99CH36311), 1Co-Authors: J. Louveaux, L. Vandendorpe, L. Cuvelier, T. PolletAbstract:This paper is devoted to a decision-directed timing Recovery Scheme for filter bank based multicarrier transmission. The symbol synchronizer is obtained from a maximum-likelihood approach and uses the equalizer outputs. The algorithm is first derived and computational results for the resulting timing error are provided for high bit rate transmission over copper wires. Finally, different improvements are discussed.
Qi-yue Yu - One of the best experts on this subject based on the ideXlab platform.
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Packet Loss Recovery Scheme with Uniquely-Decodable Codes for Streaming Multimedia over P2P Networks
IEEE Journal on Selected Areas in Communications, 2013Co-Authors: Qi-yue Yu, Weixiao MengAbstract:This paper presents an effective packet loss Recovery Scheme for Internet Protocol (IP) based peer-to-pear (P2P) networks that deliver multimedia streaming contents. The proposed Scheme consists of two key components, a packet forward error correction (FEC) Scheme and a uniquely decodable coding (UDC) Scheme. The FEC Scheme is devised to recover network packet loss over the transport layer to improve link transmission reliability at the user-ends of the P2P networks. The UDC Scheme is employed to allow multiple sources to transmit data streams simultaneously in such a way that the combined data streams can be separated uniquely without ambiguity at the user-ends. This simultaneous multiple sources data transmission increases the throughput at the user-ends. Theoretical analysis and computer simulations show that the proposed Scheme can achieve the commonly acceptable of 10^{-6} end-to-end packet loss rate for input packet loss rate of up to 10%with a reasonably small bandwidth expansion factor, while maintains a high throughput at the user-ends.
Tae-sun Chung - One of the best experts on this subject based on the ideXlab platform.
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A Crash Recovery Scheme for a Hybrid Mapping FTL in NAND Flash Storage Devices
Electronics, 2021Co-Authors: Jong Hyeok Park, Tae-sun Chung, Dong-joo Park, Sang-won LeeAbstract:An FTL (flash translation layer), which most flash storage devices are equipped with, needs to guarantee the consistency of modified metadata from a sudden power failure. This crash Recovery Scheme significantly affects the writing performance of a flash storage device during its normal operation, as well as its reliability and Recovery performance; therefore, it is desirable to make the crash Recovery Scheme efficient. Despite the practical importance of a crash Recovery Scheme in an FTL, few works exist that deal with the crash Recovery issue in FTL in a comprehensive manner. This study proposed a novel crash Recovery Scheme called FastCheck for a hybrid mapping FTL called Fully Associative Sector Translation (FAST). FastCheck can efficiently secure the newly generated address-mapping information using periodic checkpoints, and at the same time, leverages the characteristics of an FAST FTL, where the log blocks in a log area are used in a round-robin way. Thus, it provides two major advantages over the existing FTL Recovery Schemes: one is having a low logging overhead during normal operations in the FTL and the other to have a fast Recovery time in an environment where the log provisioning rate is relatively high, e.g., over 20%, and the flash memory capacity is very large, e.g., 32 GB or 64 GB.
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Implementation of Power off Recovery Scheme for Block Mapping FTL
Lecture Notes in Electrical Engineering, 2015Co-Authors: Ji-hwan Chung, Tae-sun ChungAbstract:Flash memory is widely used in portable devices and storage system. But flash memory has its own characteristics compared to traditional hard disk. This feature is erase-before-write and different unit of read/write and erase. For these reasons, flash memory has FTL (Flash Translation Layer) system software. Up to now many FTL algorithms have been suggested, but power off Recovery Scheme has not been considered. In this paper, we suggest a power off Recovery Scheme for block-mapping FTL. And this Recovery Scheme can be applied to many FTL algorithms.
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PORCE: An efficient power off Recovery Scheme for flash memory
Journal of Systems Architecture, 2008Co-Authors: Tae-sun Chung, Myungho Lee, Yeonseung Ryu, Kangsun LeeAbstract:Flash memory is now replacing hard disk in many embedded applications including cellular phones, digital cameras, car navigation systems, and so on. However, because flash memory has its own characteristics such as ''erase-before-write'' and wear-leveling, a software layer called FTL (flash translation layer) should be provided. However, most FTL algorithms did not include the power off Recovery module though it is very important in portable devices. In this paper, we suggest an efficient power off Recovery Scheme for flash memory called PORCE (Power Off Recovery Scheme for flash memory). PORCE is tightly coupled to FTL operations and minimizes performance degradation during normal operations by storing Recovery information as small as possible. Additionally, PORCE provides cost-based reclamation protocols which include the wear-leveling module. Our empirical study shows that PORCE is an efficient Recovery protocol.
