The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform
Alex Kogan - One of the best experts on this subject based on the ideXlab platform.
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Euro-Par - TWA -- Ticket Locks Augmented with a Waiting Array
Lecture Notes in Computer Science, 2019Co-Authors: Dave Dice, Alex KoganAbstract:The classic ticket lock is simple and compact, consisting of ticket and grant fields. Arriving threads atomically fetch-and-increment ticket to obtain an assigned ticket value, and then wait for grant to become equal to that value, at which point the thread holds the lock. The corresponding Unlock Operation simply increments grant. This simple design has short code paths and fast handover (transfer of ownership) under light contention, but may suffer degraded scalability under high contention when multiple threads busy wait on the grant field – so-called global spinning.
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TWA - Ticket Locks Augmented with a Waiting Array
arXiv: Operating Systems, 2018Co-Authors: Dave Dice, Alex KoganAbstract:The classic ticket lock consists of ticket and grant fields. Arriving threads atomically fetch-and-increment ticket and then wait for grant to become equal to the value returned by the fetch-and-increment primitive, at which point the thread holds the lock. The corresponding Unlock Operation simply increments grant. This simple design has short code paths and fast handover (transfer of ownership) under light contention, but may suffer degraded scalability under high contention when multiple threads busy wait on the grant field -- so-called global spinning. We propose a variation on ticket locks where long-term waiting threads wait on locations in a waiting array instead of busy waiting on the grant field. The single waiting array is shared among all locks. Short-term waiting is accomplished in the usual manner on the grant field. The resulting algorithm, TWA, improves on ticket locks by limiting the number of threads spinning on the grant field at any given time, reducing the number of remote caches requiring invalidation from the store that releases the lock. In turn, this accelerates handover, and since the lock is held throughout the handover Operation, scalability improves. Under light or no contention, TWA yields performance comparable to the classic ticket lock, avoiding the complexity and extra accesses incurred by MCS locks in the handover path, but providing performance above or beyond that of MCS at high contention.
Dave Dice - One of the best experts on this subject based on the ideXlab platform.
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Euro-Par - TWA -- Ticket Locks Augmented with a Waiting Array
Lecture Notes in Computer Science, 2019Co-Authors: Dave Dice, Alex KoganAbstract:The classic ticket lock is simple and compact, consisting of ticket and grant fields. Arriving threads atomically fetch-and-increment ticket to obtain an assigned ticket value, and then wait for grant to become equal to that value, at which point the thread holds the lock. The corresponding Unlock Operation simply increments grant. This simple design has short code paths and fast handover (transfer of ownership) under light contention, but may suffer degraded scalability under high contention when multiple threads busy wait on the grant field – so-called global spinning.
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TWA - Ticket Locks Augmented with a Waiting Array
arXiv: Operating Systems, 2018Co-Authors: Dave Dice, Alex KoganAbstract:The classic ticket lock consists of ticket and grant fields. Arriving threads atomically fetch-and-increment ticket and then wait for grant to become equal to the value returned by the fetch-and-increment primitive, at which point the thread holds the lock. The corresponding Unlock Operation simply increments grant. This simple design has short code paths and fast handover (transfer of ownership) under light contention, but may suffer degraded scalability under high contention when multiple threads busy wait on the grant field -- so-called global spinning. We propose a variation on ticket locks where long-term waiting threads wait on locations in a waiting array instead of busy waiting on the grant field. The single waiting array is shared among all locks. Short-term waiting is accomplished in the usual manner on the grant field. The resulting algorithm, TWA, improves on ticket locks by limiting the number of threads spinning on the grant field at any given time, reducing the number of remote caches requiring invalidation from the store that releases the lock. In turn, this accelerates handover, and since the lock is held throughout the handover Operation, scalability improves. Under light or no contention, TWA yields performance comparable to the classic ticket lock, avoiding the complexity and extra accesses incurred by MCS locks in the handover path, but providing performance above or beyond that of MCS at high contention.
Taeseok Jin - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the Effectiveness of NFC-based Anti-Theft Security System for Motorbike
International Journal of Security and Its Applications, 2016Co-Authors: Taeseok JinAbstract:This paper proposes a method for the immobilization of motorbike brakes in conjunction with near-field communication (NFC) technology in order to meet the increasing demand for security and convenience of motorbike drivers. The immobilizer proposed in this paper improves previous detachable immobilizers based on mechanical locks in order to provide a fundamental solution to theft prevention. By adopting NFC, the system offers user authentication and personalization services in a secure manner. The author presents the principle of Operation of the proposed method, and configuration of the immobilization device based on secure authentication. In this paper, a solenoid valve design is proposed to remotely perform lock/Unlock Operation with the aid of the motorbike immobilizer and information security system. The author presents the NFC secure authentication method for Unlocking the immobilizer upon identifying the mobile terminal of the user, the method of automatic or manual control of the brake fluid pressure of a stopped motorbike, and the experimental mechanical prototyping results.
Alain Thorel - One of the best experts on this subject based on the ideXlab platform.
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Multi-layer thin film electrolytes for application in High Temperature Ceramic Electrochemical Devices
2018Co-Authors: Rémi Costa, Feng Han, Robert Semerad, Anthony Chesnaud, Mohamed Sennour, Alain ThorelAbstract:Reducing thickness of the electrolyte is a key route to reduce ohmic losses in high temperature electrochemical devices and Unlock Operation at lower temperature. However the production of such a film through conventional ceramic process often requires a sintering step at high temperature – typically above 1200°C – not necessarily compatible with the shrinking behavior and the chemical properties of the supporting materials. This particularly holds true for metal supported cells when pre-manufactured substrates are used. Here we report about a multi-layer electrolyte architecture and its low temperature manufacturing route specifically design for metal supported cells. This consists in interlayers of porous yttria stabilized zirconia (YSZ) directly coated onto the functional electrode and fired at mild temperature – typically below 900°C – followed by a gas tight YSZ and Gadolinium doped Ceria (GDC) double layer deposited by electron beam physical vapor Deposition (EB-PVD). The architecture was implemented into metal supported cells with a size up to 90 mm x 100 mm. Cells were tested in Fuel Cell or Electrolysis Operation for more than 1500 hours and 2000 hours respectively. The evolution of the interfaces was monitored by Electrochemical Impedance Spectroscopy, and the microstructure of the thin films was investigated by Scanning Electron Microscopy and Transmission Electron Microscopy. Most Actual status of development will be given and prospects and challenges will be discussed.
Rémi Costa - One of the best experts on this subject based on the ideXlab platform.
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Multi-layer thin film electrolytes for application in High Temperature Ceramic Electrochemical Devices
2018Co-Authors: Rémi Costa, Feng Han, Robert Semerad, Anthony Chesnaud, Mohamed Sennour, Alain ThorelAbstract:Reducing thickness of the electrolyte is a key route to reduce ohmic losses in high temperature electrochemical devices and Unlock Operation at lower temperature. However the production of such a film through conventional ceramic process often requires a sintering step at high temperature – typically above 1200°C – not necessarily compatible with the shrinking behavior and the chemical properties of the supporting materials. This particularly holds true for metal supported cells when pre-manufactured substrates are used. Here we report about a multi-layer electrolyte architecture and its low temperature manufacturing route specifically design for metal supported cells. This consists in interlayers of porous yttria stabilized zirconia (YSZ) directly coated onto the functional electrode and fired at mild temperature – typically below 900°C – followed by a gas tight YSZ and Gadolinium doped Ceria (GDC) double layer deposited by electron beam physical vapor Deposition (EB-PVD). The architecture was implemented into metal supported cells with a size up to 90 mm x 100 mm. Cells were tested in Fuel Cell or Electrolysis Operation for more than 1500 hours and 2000 hours respectively. The evolution of the interfaces was monitored by Electrochemical Impedance Spectroscopy, and the microstructure of the thin films was investigated by Scanning Electron Microscopy and Transmission Electron Microscopy. Most Actual status of development will be given and prospects and challenges will be discussed.
