Journal articles: 'Blocking synchronization'

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Nazaruk, Vladislav, and Pavel Rusakov. "Blocking and Non-Blocking Process Synchronization: Analysis of Implementation." Scientific Journal of Riga Technical University. Computer Sciences 44, no. 1 (January 1, 2011): 145–50. http://dx.doi.org/10.2478/v10143-011-0033-2.

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Blocking and Non-Blocking Process Synchronization: Analysis of Implementation —In computer programs with multiple processes, inter-process communication is of high importance. One of its main aspects is process synchronization, which can be divided into two classes: blocking and non-blocking. Blocking synchronization is simpler and mostly used; however, non-blocking synchronization allows avoiding some negative effects. In this paper, there is discussed the logic of widespread process synchronization mechanisms and is analyzed the support of these mechanisms in different platforms.

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Yang, Mao Lin, Hang Lei, Yong Liao, and Lin Hui Hu. "Synchronization Analysis for Hard Real-Time Multicore Systems." Applied Mechanics and Materials 241-244 (December 2012): 2246–52. http://dx.doi.org/10.4028/www.scientific.net/amm.241-244.2246.

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Multicore processors are increasingly used in real-time embedded systems. Better utilization of hard real-time systems requires accurate scheduling and synchronization analysis. In this paper, we characterize the major synchronization penalties arising from partitioned fixed priority scheduling for hard real-time tasks on multicore platform, including transitive remote preemption, multiple remote blocking, and multiple priority inversions. Subsequently, we propose a new response time analysis by improving the approach to bound task blocking time. The key idea of this approach is to classify the total blocking time into (i) direct blocking, including local and remote blocking, and transitive remote preemption; and (ii) multiple local interference which is incurred by multiple priority inversion. Simulation results indicate that the proposed approach produces less pessimistic results in task blocking time, and better schedulability performance.

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Wang, Shu-Ying, Jian-Feng Zhao, Xian-Feng Li, and Li-Tao Zhang. "Image Blocking Encryption Algorithm Based on Laser Chaos Synchronization." Journal of Electrical and Computer Engineering 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/4138654.

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In view of the digital image transmission security, based on laser chaos synchronization and Arnold cat map, a novel image encryption scheme is proposed. Based on pixel values of plain image a parameter is generated to influence the secret key. Sequences of the drive system and response system are pretreated by the same method and make image blocking encryption scheme for plain image. Finally, pixels position are scrambled by general Arnold transformation. In decryption process, the chaotic synchronization accuracy is fully considered and the relationship between the effect of synchronization and decryption is analyzed, which has characteristics of high precision, higher efficiency, simplicity, flexibility, and better controllability. The experimental results show that the encryption algorithm image has high security and good antijamming performance.

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Kim, Changhui, Euteum Choi, Mingyun Han, Seongjin Lee, and Jaeho Kim. "Performance Analysis of RCU-Style Non-Blocking Synchronization Mechanisms on a Manycore-Based Operating System." Applied Sciences 12, no. 7 (March 29, 2022): 3458. http://dx.doi.org/10.3390/app12073458.

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There have been recent advances in multi-core machines with tens and hundreds of cores, and there is an increasing emphasis on the software structure. Many different synchronization mechanism techniques have been developed to improve the performance and the scalability of manycore systems. As the non-blocking algorithms are promising in overcoming performance limits in traditional lock-based blocking synchronization mechanisms, we are observing an increased usage ratio and a number of non-blocking synchronization algorithms. For example, the usage ratio of RCU increased sharply in recent years. Since RCU exhibits low write performance and is difficult to use, the research community introduced RLU and MV-RLU synchronization algorithms to address the issues. RLU and MV-RLU, which are called RCU-style synchronization mechanisms, are promising in terms of providing easy-to-use APIs (Application Programming Interfaces) and better performance in manycore machines. To expand the applicability of RCU-style mechanisms, we need to measure the performance and analyze their measurements in various environments. To meet the goal, we evaluate them at the user and kernel level in sv6 variant, which is a research operating system on a manycore system. In order to enable RCU-style synchronization algorithms in sv6 variant, we implemented and modified some of the libraries and memory allocators in sv6 variant. We use micro-benchmarks that exploit a linked list and hash table to measure the performance while experimenting with parameters of the benchmarks and types of data structures. In most of the experiments, we observed that MV-RLU is scalable. MV-RLU exhibits about thirteen times better throughput than RCU in the case of running 70 threads. In addition, we compare the operation procedures and APIs of each RCU-style synchronization algorithm to analyze the pros and cons of the algorithms.

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Kumar, Ajitesh, and Sanjai Kumar Gupta. "Synchronization-Aware Task Allocation Techniques for Preemption Control to Reduce Blocking Time in Multiprocessor Real-Time System." International Journal of Embedded and Real-Time Communication Systems 11, no. 4 (October 2020): 60–79. http://dx.doi.org/10.4018/ijertcs.2020100104.

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Multiprocessor real-time systems receive a great deal of attention. For better utilization of multiprocessors in a real-time context, an optimal approach for scheduling, allocation, and synchronization is required. In this research, a novel heuristic synchronization-aware scheduling has been proposed to reduce the blocking delays in a critical section and also bound to minimize multiple priority inversion. The key idea of this technique is to assign the task set in the same processor that accesses a common shared resource and also access them for the longest period of time; thereby, the global sharing of resource transforms into local sharing. From simulation results, it was concluded that the duration of blocking overheads should be minimized up to 25% to 30% and context switching between processors also reduced up to 10% to 15%. On the basis of result analysis, schedulability, minimization of context switching, and reduced blocking time indicate that the proposed method outperforms the existing methods and does not affect the task completion time.

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Greenwald, Michael, and David Cheriton. "The synergy between non-blocking synchronization and operating system structure." ACM SIGOPS Operating Systems Review 30, SI (October 28, 1996): 123–36. http://dx.doi.org/10.1145/248155.238767.

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Yang, Maolin, Jian-Jia Chen, and Wen-Hung Huang. "A misconception in blocking time analyses under multiprocessor synchronization protocols." Real-Time Systems 53, no. 2 (December 7, 2016): 187–95. http://dx.doi.org/10.1007/s11241-016-9261-4.

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Aziez, Sameir A., Nawar Al-Hemeary, Ahmed Hameed Reja, Tamás Zsedrovits, and György Cserey. "Using KNN Algorithm Predictor for Data Synchronization of Ultra-Tight GNSS/INS Integration." Electronics 10, no. 13 (June 23, 2021): 1513. http://dx.doi.org/10.3390/electronics10131513.

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The INS system’s update rate is faster than that of the GNSS receiver. Additionally, GNSS receiver data may suffer from blocking for a few seconds for different reasons, affecting architecture integrations between GNSS and INS. This paper proposes a novel GNSS data prediction method using the k nearest neighbor (KNN) predictor algorithm to treat data synchronization between the INS sensors and GNSS receiver and overcome those GNSS receiver’s blocking, which may occur for a few seconds. The experimental work was conducted on a flying drone over a minor Hungarian (Mátyásföld, 47.4992 N, 19.1977 E) model airfield. The GNSS data are predicted by four different scenarios: the first is no blocking of data, and the other three have blocking periods of 1, 4, and 8 s, respectively. Ultra-tight architecture integration is used to perform the GNSS/INS integration to deal with the INS sensors’ inaccuracy and their divergence throughout the operation. The results show that using the GNSS/INS integration system yields better positioning data (in three axes (X, Y, and Z)) than using a stand-alone INS system or GNSS without a predictor.

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9

Lee, Eunji. "A Low Latency Non-blocking Skip List with Retrial-Free Synchronization." Journal of Computing Science and Engineering 13, no. 4 (December 31, 2019): 141–50. http://dx.doi.org/10.5626/jcse.2019.13.4.141.

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Ruiz, Alejandro Perez, Mario Aldea Rivas, and Michael Gonzalez Harbour. "Non-Blocking Synchronization Between Real-Time and Non-Real-Time Applications." IEEE Access 8 (2020): 147618–34. http://dx.doi.org/10.1109/access.2020.3015385.

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Moir, Mark. "Laziness pays! Using lazy synchronization mechanisms to improve non-blocking constructions." Distributed Computing 14, no. 4 (December 1, 2001): 193–204. http://dx.doi.org/10.1007/s004460100063.

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Tsigas, Philippas, and Yi Zhang. "Evaluating the performance of non-blocking synchronization on shared-memory multiprocessors." ACM SIGMETRICS Performance Evaluation Review 29, no. 1 (June 2001): 320–21. http://dx.doi.org/10.1145/384268.378810.

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13

Maruf, Abdullah Al, and Sandip Roy. "Observability-blocking control using sparser and regional feedback for network synchronization processes." Automatica 146 (December 2022): 110586. http://dx.doi.org/10.1016/j.automatica.2022.110586.

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14

Ahn, Jin Ho. "Scalable Checkpointing-Based Rollback Recovery Protocol for Geographically Distributed Systems." Applied Mechanics and Materials 263-266 (December 2012): 1492–96. http://dx.doi.org/10.4028/www.scientific.net/amm.263-266.1492.

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Two opposite approaches were proposed to address some scalability problem resulting from coordinated checkpointing's synchronization during failure-free operation: minimizing the number of checkpointing participants and having the checkpointing process non-blocking. However, these previous approaches, oblivious to the underlying network, may not fundamentally provide any breakthrough for ensuring high scalability required in very large-scale P2P-based systems. This paper proposes a non-blocking coordinated checkpointing protocol to significantly reduce checkpointing synchronization overhead by structuring the peer-to-peer network into a set of groups according to a particular criterion. In this protocol, among processes in a group, one is designated as representative with the following special roles, intra-group and inter-group checkpointing coordination. Intra-group checkpointing coordination addresses the checkpointing procedure among processes within a group. On the other hand, inter-group checkpointing coordination is performed only among representatives. Thanks to this beneficial feature, the proposed protocol may considerably reduce the number of checkpointing control messages routed on core networks compared with the existing ones.

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Travetskyy, M. O., A. Y. Krajewski, and Y. V. Musienko. "Профілактика ембріональної смертності у корів." Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies 19, no. 77 (March 7, 2017): 200–203. http://dx.doi.org/10.15421/nvlvet7743.

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The article analyzes the scientific data and own research on study and formulation the preventive efficacy of ketoprofen during embryonic mortality in cows for estrus synchronization, depending on the duration of the period after birth. It is known that in cows at spontaneous recovery of sexual cyclicity after calving for its next synchronization form smaller corpus luteum, although their fertilization is higher than in animals without sexual cyclical recovery after giving birth to synchronize estrus. The application for cows with small yellow bodies of NSAIDs inhibit the production of prostaglandin F2α by uterine lining through blocking Cyclogenesis of type II. Stimulation and sexual cyclical synchronization was performed using surfagon and estrofan and at the 10th day cows were inseminated. Animals of the experimental subgroups at the 11th day after insemination were injected in therapeutic dose NSAIDs ainil. The prophylactic use of ainil towards embryonic mortality after insemination of cows for previous estrus synchronization promotes animal insemination by average of 7.3%. Such effect of NSAIDs on cows fertilization depending on the period after calving can point to the prevention of fetal death in animals with restored sex cycles after calving regardless the cause of the formation of the corpus luteum at spontaneous manifestation of the sexual cycle or estrus synchronization.

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Karasik, O. N., and A. A. Prihozhy. "ADVANCED SCHEDULER FOR COOPERATIVE EXECUTION OF THREADS ON MULTI-CORE SYSTEM." «System analysis and applied information science», no. 1 (May 4, 2017): 4–11. http://dx.doi.org/10.21122/2309-4923-2017-1-4-11.

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Three architectures of the cooperative thread scheduler in a multithreaded application that is executed on a multi-core system are considered. Architecture A0 is based on the synchronization and scheduling facilities, which are provided by the operating system. Architecture A1 introduces a new synchronization primitive and a single queue of the blocked threads in the scheduler, which reduces the interaction activity between the threads and operating system, and significantly speed up the processes of blocking and unblocking the threads. Architecture A2 replaces the single queue of blocked threads with dedicated queues, one for each of the synchronizing primitives, extends the number of internal states of the primitive, reduces the inter- dependence of the scheduling threads, and further significantly speeds up the processes of blocking and unblocking the threads. All scheduler architectures are implemented on Windows operating systems and based on the User Mode Scheduling. Important experimental results are obtained for multithreaded applications that implement two blocked parallel algorithms of solving the linear algebraic equation systems by the Gaussian elimination. The algorithms differ in the way of the data distribution among threads and by the thread synchronization models. The number of threads varied from 32 to 7936. Architecture A1 shows the acceleration of up to 8.65% and the architecture A2 shows the acceleration of up to 11.98% compared to A0 architecture for the blocked parallel algorithms computing the triangular form and performing the back substitution. On the back substitution stage of the algorithms, architecture A1 gives the acceleration of up to 125%, and architecture A2 gives the acceleration of up to 413% compared to architecture A0. The experiments clearly show that the proposed architectures, A1 and A2 outperform A0 depending on the number of thread blocking and unblocking operations, which happen during the execution of multi-threaded applications. The conducted computational experiments demonstrate the improvement of parameters of multithreaded applications on a heterogeneous multi-core system due the proposed advanced versions of the thread scheduler.

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17

Sannita, W. G., L. Lopez, and L. Narici. "Muscarinic blocking and synchronization of cortical narrow-band oscillatory responses to luminance stimuli." Biological Psychiatry 42, no. 1 (July 1997): 165S—166S. http://dx.doi.org/10.1016/s0006-3223(97)87566-x.

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Magoulès, Frédéric, and Guillaume Gbikpi-Benissan. "JACK2: An MPI-based communication library with non-blocking synchronization for asynchronous iterations." Advances in Engineering Software 119 (May 2018): 116–33. http://dx.doi.org/10.1016/j.advengsoft.2018.01.009.

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19

Sagan, Jaroslaw. "Inter-thread communication efficiency." Annales Universitatis Mariae Curie-Sklodowska, sectio AI – Informatica 15, no. 1 (January 1, 2015): 12. http://dx.doi.org/10.17951/ai.2015.15.1.12-15.

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In this paper I compare inter-thread communication methods: blocking queue and LMAX Disruptor without synchronization according to a number of threads (CPU cores) and consumer rate. The research is carried out using a multiprocessor machine with Non Uniformed Memory and Oracle Java Runtime Environment. I determine if processing on many multi-core CPUs with NUMA is faster than on single multi-core CPU or vice versa.

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Wang, Qingyun, Xia Shi, and Guanrong Chen. "Delay-induced synchronization transition in small-world Hodgkin-Huxley neuronal networks with channel blocking." Discrete & Continuous Dynamical Systems - B 16, no. 2 (2011): 607–21. http://dx.doi.org/10.3934/dcdsb.2011.16.607.

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21

Chen, Mu-Yen, Da-Ren Chen, and Shu-Ming Hsieh. "A Blocking-Aware Scheduling for Real-Time Task Synchronization Using a Leakage-Controlled Method." International Journal of Distributed Sensor Networks 10, no. 2 (January 2014): 428230. http://dx.doi.org/10.1155/2014/428230.

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22

WITTMANN, MARKUS, GEORG HAGER, JAN TREIBIG, and GERHARD WELLEIN. "LEVERAGING SHARED CACHES FOR PARALLEL TEMPORAL BLOCKING OF STENCIL CODES ON MULTICORE PROCESSORS AND CLUSTERS." Parallel Processing Letters 20, no. 04 (December 2010): 359–76. http://dx.doi.org/10.1142/s0129626410000296.

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Bandwidth-starved multicore chips have become ubiquitous. It is well known that the performance of stencil codes can be improved by temporal blocking, lessening the pressure on the memory interface. We introduce a new pipelined approach that makes explicit use of shared caches in multicore environments and minimizes synchronization and boundary overhead. Benchmark results are presented for three current x86-based microprocessors, showing clearly that our optimization works best on designs with high-speed shared caches and low memory bandwidth per core. We furthermore demonstrate that simple bandwidth-based performance models are inaccurate for this kind of algorithm and employ a more elaborate, synthetic modeling procedure. Finally we show that temporal blocking can be employed successfully in a hybrid shared/distributed-memory environment, albeit with limited benefit at strong scaling.

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GUPTA, SUNIL KUMAR, R. K. CHAUHAN, and PARVEEN KUMAR. "A MINIMUM-PROCESS COORDINATED CHECKPOINTING PROTOCOL FOR MOBILE COMPUTING SYSTEMS." International Journal of Foundations of Computer Science 19, no. 04 (August 2008): 1015–38. http://dx.doi.org/10.1142/s0129054108006108.

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Checkpoint is a designated place in a program at which normal process is interrupted specifically to preserve the status information necessary to allow resumption of processing at a later time. A checkpoint algorithm for mobile distributed systems needs to handle many new issues like: mobility, low bandwidth of wireless channels, lack of stable storage on mobile nodes, disconnections, limited battery power and high failure rate of mobile nodes. These issues make traditional checkpointing techniques unsuitable for such environments. Minimum-process coordinated checkpointing is an attractive approach to introduce fault tolerance in mobile distributed systems transparently. This approach is domino-free, requires at most two checkpoints of a process on stable storage, and forces only a minimum number of processes to checkpoint. But, it requires extra synchronization messages, blocking of the underlying computation or taking some useless checkpoints. In this paper, we design a minimum-process checkpointing algorithm for mobile distributed systems, where no useless checkpoint is taken. We reduce the blocking of processes by allowing the processes to do their normal computations, send messages and receive selective messages during their blocking period.

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Fu, Gang, Jian Hua Lin, and Qian He. "Research on Data Parallel Synchronous Transmission Technology Based Virtual Radio." Applied Mechanics and Materials 644-650 (September 2014): 1414–17. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.1414.

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Analyzing the parallel synchronous transmission data based on the proposed use of time-multiplexing transmission mode dynamic solve the transmission delay is large, the traditional structure of the software causing the radio frame data are transmitted in parallel low-speed data blocking phenomenon; and problems caused by data transmission and processing delay for virtual radio monitoring system uses asynchronous mode uncertainty, proposed time synchronization method based on the data frame structure to a more generalized approach to achieve a measure of sync.

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Fatourou, Panagiota, Yiannis Nikolakopoulos, and Marina Papatriantafilou. "Linearizable Wait-Free Iteration Operations in Shared Double-Ended Queues." Parallel Processing Letters 27, no. 02 (June 2017): 1750001. http://dx.doi.org/10.1142/s0129626417500013.

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Shared data object implementations that allow non-blocking concurrent operations are useful for in-memory data-processing, especially when they support consistent bulk operations like iterations. We propose an algorithmic implementation for concurrent iterators on shared double-ended queues (deques), building on and complementing a known lock-free deque implementation by M. Michael. The proposed construction is linearizable and wait-free. Moreover, it is read-only, so it does not execute expensive synchronization primitives and it does not interfere with update operations.

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Sannita, Walter G., L. Lopez, and L. Narici. "SYNCHRONIZATION OF NARROW-BAND CORTICAL OSCILLATORY RESPONSE TO FLASH STIMULATION AND MUSCARINIC BLOCKING IN HUMANS." Journal of Clinical Neurophysiology 14, no. 4 (July 1997): 348. http://dx.doi.org/10.1097/00004691-199707000-00017.

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27

Bellanger, Gilbert. "Blocking Hydrogen Diffusion in Palladium Cathode i—Analyzed by Electrochemistry; ii—Analyzed by Chaos." Hydrogen 3, no. 1 (March 17, 2022): 123–60. http://dx.doi.org/10.3390/hydrogen3010010.

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Electrochemical chaos is caused when, during diffusion, hydrogen and, at worst, tritium is trapped in palladium after the formation of adsorbates. The mechanism leads to cracking corrosion, as seen by scanning electron microscopy. The instabilities were apprehended from voltammetry and electrochemical impedance spectroscopy in the active potential where the cathodic hydrogen is charged from two models of transients. Tests performed using an electrochemical chaos analyzer simplify the expertise of the palladium cathode in focusing on the blocking diffusion of hydrogen. A complex electrical circuit of chaos is considered for adsorption and the blocking diffusion. Depending on the active potential, distinct behavior such as the transformation of transients and limited diffusion can occur. Phase-space spectra are obtained, and synchronization has been developed to clarify the chaos leading to the cracking of palladium. By applying these different analytical tests for the restricted diffusion, it is possible to interpret the processes from the power spectra, autocorrelation function, or the divergence coefficient in the region of active potentials. Analyzers can detect flaws in this hydrogen diffusion process and suggest corrective measures.

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HUANG, LONG, JUN MA, JUN TANG, and FAN LI. "TRANSITION OF ORDERED WAVES IN NEURONAL NETWORK INDUCED BY DIFFUSIVE POISONING OF ION CHANNELS." Journal of Biological Systems 21, no. 01 (January 31, 2013): 1350002. http://dx.doi.org/10.1142/s0218339013500022.

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Normal physiological activities are often affected by some drugs, and some ion channels are blocked due to the katogene of drugs. This paper investigates the propagation of ordered waves in neuronal networks induced by diffusive poisoning, where the process is measured by increasing the number of neurons in the poisoned area of the networks. A coefficient of poisoning K is defined to measure the time units from one poisoned site to the adjacent site, a smaller K means that more neurons are poisoned in a certain period (a higher poisoning speed). A statistical factor of synchronization R in the two-dimensional array is defined to detect the transition of spiral waves induced by ion channel blocking. It is confirmed that the evolution of the spiral waves depends on the coefficient of poisoning K and number of poisoned neurons. Furthermore, breakup of the spirals is observed when weak channel noise is considered. Finally, the formation of the spiral wave induced by blocking the target wave with line defects is briefly discussed.

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Xu, Ying, Wuyin Jin, and Jun Ma. "Emergence and robustness of target waves in a neuronal network." International Journal of Modern Physics B 29, no. 23 (September 17, 2015): 1550164. http://dx.doi.org/10.1142/s0217979215501647.

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Target waves in excitable media such as neuronal network can regulate the spatial distribution and orderliness as a continuous pacemaker. Three different schemes are used to develop stable target wave in the network, and the potential mechanism for emergence of target waves in the excitable media is investigated. For example, a local pacing driven by external periodical forcing can generate stable target wave in the excitable media, furthermore, heterogeneity and local feedback under self-feedback coupling are also effective to generate continuous target wave as well. To discern the difference of these target waves, a statistical synchronization factor is defined by using mean field theory and artificial defects are introduced into the network to block the target wave, thus the robustness of these target waves could be detected. However, these target waves developed from the above mentioned schemes show different robustness to the blocking from artificial defects. A regular network of Hindmarsh–Rose neurons is designed in a two-dimensional square array, target waves are induced by using three different ways, and then some artificial defects, which are associated with anatomical defects, are set in the network to detect the effect of defects blocking on the travelling waves. It confirms that the robustness of target waves to defects blocking depends on the intrinsic properties (ways to generate target wave) of target waves.

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Wang, Qing-Yun, and Yan-Hong Zheng. "Effects of information transmission delay and channel blocking on synchronization in scale-free Hodgkin-Huxley neuronal networks." Acta Mechanica Sinica 27, no. 6 (September 27, 2011): 1052–58. http://dx.doi.org/10.1007/s10409-011-0497-x.

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Ragozina, Polina Ilyinichna, and Valery Nikolayevich Ignatyev. "Detection of erroneous usage of synchronization monitor in С# via static analysis." Proceedings of the Institute for System Programming of the RAS 34, no. 4 (2022): 63–78. http://dx.doi.org/10.15514/ispras-2022-34(4)-5.

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The paper describes static analysis algorithms aimed at finding three types of errors related to the concept of a synchronizing monitor: redefinition of a variable of mutually exclusive locking inside a critical section; use of an incorrect variable type when entering the monitor; blocking involving an object that has methods that use a reference to an instance (this) to lock. Developed algorithms rely on symbolic execution technology and involve interprocedural analysis via summary of functions, which ensures scalability, field-, context-, and flow-sensivity. Proposed methods were implemented in the infrastructure of a static analyzer in the form of three separate detectors. Testing on the set of open source projects revealed 23 errors and the true positive ratio of 88.5% was obtained, while the time consumption only made up from 0.1 to 0.7% of the total analysis time. The errors that these detectors were designed to find are difficult to detect by testing or dynamic analysis because of their multithreading nature. At the same time, it is necessary to find them: just one such defect can lead to incorrectness of the program and even make it vulnerable to intruders.

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Kang, Rui, Chen Yu Huang, and Kai Yang. "Time-Space Diagram Analysis of Urged Acceleration CA Model." Advanced Materials Research 779-780 (September 2013): 1203–6. http://dx.doi.org/10.4028/www.scientific.net/amr.779-780.1203.

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Based on the SDNS cellular automaton (CA) traffic model, an improved single lane traffic CA model with considering the urged acceleration and safe deceleration was proposed. The model not only simulated the interaction between vehicles, but also reproduced nonlinear phenomena which tallies with real traffic such as the synchronism flow and the metastable state. The time-space diagram of new model shows a gray synchronous band zone rather than that black blocking band zone. The range of synchronization is smaller when ps is bigger, urging has less function, congestion area is wider. Comparing with SDNS model, with the proposed model in this paper, when emerging congestion, the combined action of urging and safe deceleration enabled system self-adjustment so that efficiently mitigated congestion.

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Thual, Sulian, Andrew Majda, and Nan Chen. "Seasonal Synchronization of a Simple Stochastic Dynamical Model Capturing El Niño Diversity." Journal of Climate 30, no. 24 (December 2017): 10047–66. http://dx.doi.org/10.1175/jcli-d-17-0174.1.

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Recently, a simple stochastic dynamical model was developed that automatically captures the diversity and intermittency of El Niño–Southern Oscillation (ENSO) in nature, where state-dependent stochastic wind bursts and nonlinear advection of sea surface temperature (SST) are coupled to simple ocean–atmosphere processes that are otherwise deterministic, linear, and stable. In the present article, it is further shown that the model can reproduce qualitatively the ENSO synchronization (or phase locking) to the seasonal cycle in nature. This goal is achieved by incorporating a cloud radiative feedback that is derived naturally from the model’s atmosphere dynamics with no ad hoc assumptions and accounts in simple fashion for the marked seasonal variations of convective activity and cloud cover in the eastern Pacific. In particular, the weak convective response to SSTs in boreal fall favors the eastern Pacific warming that triggers El Niño events while the increased convective activity and cloud cover during the following spring contributes to the shutdown of those events by blocking incoming shortwave solar radiations. In addition to simulating the ENSO diversity with realistic non-Gaussian statistics in different Niño regions, the eastern Pacific moderate and super El Niño and the central Pacific El Niño and La Niña show a realistic chronology with a tendency to peak in boreal winter as well as decreased predictability in spring consistent with the persistence barrier in nature. The incorporation of other possible seasonal feedbacks in the model is also documented for completeness.

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Akbudak, Kadir, Hatem Ltaief, Vincent Etienne, Rached Abdelkhalak, Thierry Tonellot, and David Keyes. "Asynchronous computations for solving the acoustic wave propagation equation." International Journal of High Performance Computing Applications 34, no. 4 (May 19, 2020): 377–93. http://dx.doi.org/10.1177/1094342020923027.

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The aim of this study is to design and implement an asynchronous computational scheme for solving the acoustic wave propagation equation with absorbing boundary conditions (ABCs) in the context of seismic imaging applications. While the convolutional perfectly matched layer (CPML) is typically used for ABCs in the oil and gas industry, its formulation further stresses memory accesses and decreases the arithmetic intensity at the physical domain boundaries. The challenges with CPML are twofold: (1) the strong, inherent data dependencies imposed on the explicit time-stepping scheme render asynchronous time integration cumbersome and (2) the idle time is further exacerbated by the load imbalance introduced among processing units. In fact, the CPML formulation of the ABCs requires expensive synchronization points, which may hinder the parallel performance of the overall asynchronous time integration. In particular, when deployed in conjunction with the multicore-optimized wavefront diamond temporal blocking (MWD-TB) approach for the inner domain points, it results in a major performance slow down. To relax CPML’s synchrony and mitigate the resulting load imbalance, we embed CPML’s calculation into MWD-TB’s inner loop and carry on the time integration with fine-grained computations in an asynchronous, holistic way. This comes at the price of storing transient results to alleviate dependencies from critical data hazards while maintaining the numerical accuracy of the original scheme. Performance and scalability results on various x86 architectures demonstrate the superiority of MWD-TB with CPML support against the standard spatial blocking on various grid sizes. To our knowledge, this is the first practical study that highlights the consolidation of CPML ABCs with asynchronous temporal blocking stencil computations.

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Zou, Min, Pan Fang, Yongjun Hou, Guodong Chai, and Jinsong Chen. "Self-synchronization theory of tri-motor excitation with double-frequency in far resonance system." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 234, no. 16 (March 22, 2020): 3166–84. http://dx.doi.org/10.1177/0954406220913584.

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With the rapid development of petroleum exploitation industry, vibrating screen actuated with a single frequency is unsuitable to separate cuttings from drilling fluid, since it usually results in screen blocking. Hence, for solving the above-mentioned problem, tri-motor excitation with double-frequency in far resonance system is introduced. This paper aims to explore the self-synchronization mechanism of the proposed system. First, dynamic equation is established according to physical model of the system. Then, displacement response of the system in steady state is obtained with dynamic formulas. Subsequently, synchronous condition among the three exciters is determined by small parameters method, and criterion of synchronous stability among the three exciters is derived by Poincare-Lyapunov method. Finally, in light of the differential motion equation, Runge-Kutta principle is assigned to validate the reliability of self-synchronous theory and the stability of the double-frequency system. The results indicate that electromagnetic torques of low-frequency motors are dynamically antisymmetric in synchronous operation, and synchronous ability of the system is determined by the mass ratio among the rotors. In addition, stable phase difference among the rotors is significantly influenced by the structural parameters of the system. And this study will be helpful for the improvement of separation technology.

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Yang, Shinhyung, Seongho Jeong, Byunguk Min, Yeonsoo Kim, Bernd Burgstaller, and Johann Blieberger. "Design-space evaluation for non-blocking synchronization in Ada: lock elision of protected objects, concurrent objects, and low-level atomics." Journal of Systems Architecture 110 (November 2020): 101764. http://dx.doi.org/10.1016/j.sysarc.2020.101764.

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Hassnen, Mohamed Lotfy, and Mahmoud Mohammad. "Timing synchronization for Individual training for blocking skill accord to the values of the physical characteristic curve of volleyball players." International Journal of Sports Science and Arts 010, no. 010 (June 1, 2019): 100–137. http://dx.doi.org/10.21608/eijssa.2019.72928.

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Kubiak, Ireneusz. "Digital processing methods of images and signals in electromagnetic infiltration process." Image Processing & Communications 18, no. 1 (March 1, 2013): 5–14. http://dx.doi.org/10.2478/v10248-012-0070-7.

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Abstract The article contains information about the capabilities of electromagnetic infiltration process in case of occurrence of strong interfering signals. As a methods supporting infiltration process used method of digital processing of signals and images in the form of histogram transformations, global and local thresholding of signal amplitudes and logical filters. The material presented in the article shows that risk can arise if the uncontrolled use of the computer. Risks that could decide our safety and security of our data. obtained images. Manipulation of histograms, threshold amplitudes of the emission signal correlated with the classified signals or logical filters highlight the weakness of the security used at the source. The presence of strong interfering signals such as vertical and horizontal synchronization signals blocking measurement receivers, do not prevent the reproduction of classified information. Opportunities of the electromagnetic infiltration in situations of weak compromising emissions occurs are presented in the article.

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Chapman, C. Andrew, and Jean-Claude Lacaille. "Intrinsic Theta-Frequency Membrane Potential Oscillations in Hippocampal CA1 Interneurons of Stratum Lacunosum-Moleculare." Journal of Neurophysiology 81, no. 3 (March 1, 1999): 1296–307. http://dx.doi.org/10.1152/jn.1999.81.3.1296.

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Intrinsic theta-frequency membrane potential oscillations in hippocampal CA1 interneurons of stratum lacunosum-moleculare. The ionic conductances underlying membrane potential oscillations of hippocampal CA1 interneurons located near the border between stratum lacunosum-moleculare and stratum radiatum (LM) were investigated using whole cell current-clamp recordings in rat hippocampal slices. At 22°C, when LM cells were depolarized near spike threshold by current injection, 91% of cells displayed 2–5 Hz oscillations in membrane potential, which caused rhythmic firing. At 32°C, mean oscillation frequency increased to 7.1 Hz. Oscillations were voltage dependent and were eliminated by hyperpolarizing cells 6–10 mV below spike threshold. Blockade of ionotropic glutamate and GABA synaptic transmission did not affect oscillations, indicating that they were not synaptically driven. Oscillations were eliminated by tetrodotoxin, suggesting that Na+ currents generate the depolarizing phase of oscillations. Oscillations were not affected by blocking Ca2+ currents with Cd2+ or Ca2+-free ACSF or by blocking the hyperpolarization-activated current ( I h) with Cs+. Both Ba2+ and a low concentration of 4-aminopyridine (4-AP) reduced oscillations but TEA did not. Theta-frequency oscillations were much less common in interneurons located in stratum oriens. Intrinsic membrane potential oscillations in LM cells of the CA1 region thus involve an interplay between inward Na+ currents and outward K+ currents sensitive to Ba2+ and 4-AP. These oscillations may participate in rhythmic inhibition and synchronization of pyramidal neurons during theta activity in vivo.

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Nazari, Siroos, Aghileh Heydari, Mahboobeh Tavakoli, and Javad Khaligh. "A New Three-Oscillator Model for the Heart System in the Case of Time Delay and Designing Appropriate Controller for Its Synchronization." ISRN Applied Mathematics 2014 (June 5, 2014): 1–8. http://dx.doi.org/10.1155/2014/168247.

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If the SA and AV oscillators are not synchronized, it may arise some kinds of blocking arrhythmias in the system of heart. In this paper, in order to examine the heart system more precisely, we apply the three-oscillator model of the heart system, and to prevent arrhythmias, perform the following steps. Firstly, we add a voltage with rang a1 and ω frequency to SA node. Then, we use delay time factor in oscillators and finally the appropriate control is designed. In this paper, we have explained how simulating and curing these arrhythmias are possible by designing a three-oscillator system for heart in the state of delay and without delay and by applying an appropriate control. In the end, we present the simulation results.

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Medina-Ceja, Laura, Juan C. Salazar-Sánchez, Jorge Ortega-Ibarra, and Alberto Morales-Villagrán. "Connexins-Based Hemichannels/Channels and Their Relationship with Inflammation, Seizures and Epilepsy." International Journal of Molecular Sciences 20, no. 23 (November 27, 2019): 5976. http://dx.doi.org/10.3390/ijms20235976.

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Connexins (Cxs) are a family of 21 protein isoforms, eleven of which are expressed in the central nervous system, and they are found in neurons and glia. Cxs form hemichannels (connexons) and channels (gap junctions/electric synapses) that permit functional and metabolic coupling between neurons and astrocytes. Altered Cx expression and function is involved in inflammation and neurological diseases. Cxs-based hemichannels and channels have a relevance to seizures and epilepsy in two ways: First, this pathological condition increases the opening probability of hemichannels in glial cells to enable gliotransmitter release, sustaining the inflammatory process and exacerbating seizure generation and epileptogenesis, and second, the opening of channels favors excitability and synchronization through coupled neurons. These biological events highlight the global pathological mechanism of epilepsy, and the therapeutic potential of Cxs-based hemichannels and channels. Therefore, this review describes the role of Cxs in neuroinflammation and epilepsy and examines how the blocking of channels and hemichannels may be therapeutic targets of anti-convulsive and anti-epileptic treatments.

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Michaelson, David, Wasif Abidi, Daniele Guardavaccaro, Mo Zhou, Ian Ahearn, Michele Pagano, and Mark R. Philips. "Rac1 accumulates in the nucleus during the G2 phase of the cell cycle and promotes cell division." Journal of Cell Biology 181, no. 3 (April 28, 2008): 485–96. http://dx.doi.org/10.1083/jcb.200801047.

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Rac1 regulates a wide variety of cellular processes. The polybasic region of the Rac1 C terminus functions both as a plasma membrane–targeting motif and a nuclear localization sequence (NLS). We show that a triproline N-terminal to the polybasic region contributes to the NLS, which is cryptic in the sense that it is strongly inhibited by geranylgeranylation of the adjacent cysteine. Subcellular fractionation demonstrated endogenous Rac1 in the nucleus and Triton X-114 partition revealed that this pool is prenylated. Cell cycle–blocking agents, synchronization of cells stably expressing low levels of GFP-Rac1, and time-lapse microscopy of asynchronous cells revealed Rac1 accumulation in the nucleus in late G2 and exclusion in early G1. Although constitutively active Rac1 restricted to the cytoplasm inhibited cell division, activated Rac1 expressed constitutively in the nucleus increased the mitotic rate. These results show that Rac1 cycles in and out of the nucleus during the cell cycle and thereby plays a role in promoting cell division.

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Stefanescu, Roxana A., and Susan E. Shore. "Muscarinic acetylcholine receptors control baseline activity and Hebbian stimulus timing-dependent plasticity in fusiform cells of the dorsal cochlear nucleus." Journal of Neurophysiology 117, no. 3 (March 1, 2017): 1229–38. http://dx.doi.org/10.1152/jn.00270.2016.

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Cholinergic modulation contributes to adaptive sensory processing by controlling spontaneous and stimulus-evoked neural activity and long-term synaptic plasticity. In the dorsal cochlear nucleus (DCN), in vitro activation of muscarinic acetylcholine receptors (mAChRs) alters the spontaneous activity of DCN neurons and interacts with N-methyl-d-aspartate (NMDA) and endocannabinoid receptors to modulate the plasticity of parallel fiber synapses onto fusiform cells by converting Hebbian long-term potentiation to anti-Hebbian long-term depression. Because noise exposure and tinnitus are known to increase spontaneous activity in fusiform cells as well as alter stimulus timing-dependent plasticity (StTDP), it is important to understand the contribution of mAChRs to in vivo spontaneous activity and plasticity in fusiform cells. In the present study, we blocked mAChRs actions by infusing atropine, a mAChR antagonist, into the DCN fusiform cell layer in normal hearing guinea pigs. Atropine delivery leads to decreased spontaneous firing rates and increased synchronization of fusiform cell spiking activity. Consistent with StTDP alterations observed in tinnitus animals, atropine infusion induced a dominant pattern of inversion of StTDP mean population learning rule from a Hebbian to an anti-Hebbian profile. Units preserving their initial Hebbian learning rules shifted toward more excitatory changes in StTDP, whereas units with initial suppressive learning rules transitioned toward a Hebbian profile. Together, these results implicate muscarinic cholinergic modulation as a factor in controlling in vivo fusiform cell baseline activity and plasticity, suggesting a central role in the maladaptive plasticity associated with tinnitus pathology. NEW & NOTEWORTHY This study is the first to use a novel method of atropine infusion directly into the fusiform cell layer of the dorsal cochlear nucleus coupled with simultaneous recordings of neural activity to clarify the contribution of muscarinic acetylcholine receptors (mAChRs) to in vivo fusiform cell baseline activity and auditory-somatosensory plasticity. We have determined that blocking the mAChRs increases the synchronization of spiking activity across the fusiform cell population and induces a dominant pattern of inversion in their stimulus timing-dependent plasticity. These modifications are consistent with similar changes established in previous tinnitus studies, suggesting that mAChRs might have a critical contribution in mediating the maladaptive alterations associated with tinnitus pathology. Blocking mAChRs also resulted in decreased fusiform cell spontaneous firing rates, which is in contrast with their tinnitus hyperactivity, suggesting that changes in the interactions between the cholinergic and GABAergic systems might also be an underlying factor in tinnitus pathology.

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Rizkilina, Tri Multy, and Nur Rohman Rosyid. "Packet Filtering Automation System Design Based on Data Synchronization on IP Profile Database Using Python." Journal of Internet and Software Engineering 3, no. 1 (November 30, 2022): 12–19. http://dx.doi.org/10.22146/jise.v3i1.3978.

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Data traffic on a dense network is a threat to cybercrime and a high vulnerability for technology companies so that the challenges to prevent it will be more diverse. Adding a strengthening of the boundary wall or firewall and sorting data through packet filtering plus writing firewall rules to prevent malware and attacks from outside at the network device level is an alternative to protect the traffic you have. When heavy traffic makes data exchange uncontrollable, this research will create an automation design so that the sorting of incoming data packets through selection based on the specified rules runs in real-time so that the prevention of crime that enters the network is more swiftly handled. The system is running successfully by connecting the MQTT Collector as a subscriber that uses the python programming language to retrieve profiling data from the IP Profile database. The system was tested on a mikrotik router RB951Ui-2HnD which then the blocking track record will be stored in the Dynamic Firewall Data database in MongoDB. Also added a tool for controlling data in storage in the form of a program release. The results of the test show that data with an average base score above 20 is blocked and then stored in the block list in checking the collection in the database every 30 seconds. In addition, the data in the database will be checked every day within 30 days which will then be released and recorded in the release log in MongoDB.

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Hannachi, A. "On the Origin of Planetary-Scale Extratropical Winter Circulation Regimes." Journal of the Atmospheric Sciences 67, no. 5 (May 1, 2010): 1382–401. http://dx.doi.org/10.1175/2009jas3296.1.

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Abstract Sectorial and planetary-scale winter circulation regimes are studied and the relationship between them is investigated in order to find how much the simultaneous occurrence of sectorial regimes contributes to the occurrence of hemispheric regimes. The strategy is based on the multivariate Gaussian mixture model. The number of components in the model is estimated using two approaches. The first one is based on arguments from order statistics of the mixture proportions and the second uses a more severe test based on reproducibility. The procedure is applied next to the 500-hPa height field over the North Pacific, the North Atlantic, and the Northern Hemisphere using the empirical orthogonal function state space. Two highly significant regimes are found in each case, namely, the Pacific–North America (pattern) (±PNA)–North Atlantic Oscillation (±NAO) for the hemisphere—±PNA for the Pacific sector and ±NAO for the Atlantic sector. The sectorial regimes reflect mainly blocking and no-blocking flows. The results are tested further by applying a spatial clustering algorithm and are found to be consistent, particularly along the regime axes in the system state space. The relationship between hemispheric and sectorial circulation regimes is investigated. The data in each sector are first classified and then the times of simultaneous occurrence of sectorial regimes are identified. A new hemispheric dataset is then obtained by discarding maps corresponding to those co-occurrence times, and a new regime analysis is conducted. The results show that the hemispheric regime behavior has significantly decreased, suggesting that synchronization between sectorial circulation regimes could play an important role in the occurrence of planetary circulation regimes. The interannual variability of regime events is also discussed.

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Murugappan, Suresh Kanna, Li Xie, Heung Yan Wong, Zafar Iqbal, Zhuogui Lei, Aruna Surendran Ramkrishnan, and Ying Li. "Suppression of Pain in the Late Phase of Chronic Trigeminal Neuropathic Pain Failed to Rescue the Decision-Making Deficits in Rats." International Journal of Molecular Sciences 22, no. 15 (July 22, 2021): 7846. http://dx.doi.org/10.3390/ijms22157846.

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Trigeminal neuropathic pain (TNP) led to vital cognitive functional deficits such as impaired decision-making abilities in a rat gambling task. Chronic TNP caused hypomyelination in the anterior cingulate cortex (ACC) associated with decreased synchronization between ACC spikes and basal lateral amygdala (BLA) theta oscillations. The aim of this study was to investigate the effect of pain suppression on cognitive impairment in the early or late phases of TNP. Blocking afferent signals with a tetrodotoxin (TTX)-ELVAX implanted immediately following nerve lesion suppressed the allodynia and rescued decision-making deficits. In contrast, the TTX used at a later phase could not suppress the allodynia nor rescue decision-making deficits. Intra-ACC administration of riluzole reduced the ACC neural sensitization but failed to restore ACC-BLA spike-field phase synchrony during the late stages of chronic neuropathic pain. Riluzole suppressed allodynia but failed to rescue the decision-making deficits during the late phase of TNP, suggesting that early pain relief is important for recovering from pain-related cognitive impairments. The functional disturbances in ACC neural circuitry may be relevant causes for the deficits in decision making in the chronic TNP state.

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Tatas, Konstantinos, Costas Kyriacou, Paraskevas Evripidou, Pedro Trancoso, and Stephan Wong. "Rapid Prototyping of the Data-Driven Chip-Multiprocessor (D2-CMP) using FPGAs." Parallel Processing Letters 18, no. 02 (June 2008): 291–306. http://dx.doi.org/10.1142/s0129626408003399.

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This paper presents the FPGA implementation of the prototype for the Data-Driven Chip-Multiprocessor (D2-CMP). In particular, we study the implementation of a Thread Synchronization Unit (TSU) on FPGA, a hardware unit that enables thread execution using dataflow-like scheduling policy on a chip multiprocessor. Threads are scheduled for execution based on data availability, i.e., a thread is scheduled for execution only if its input data is available. This model of execution is called the non-blocking Data-Driven Multithreading (DDM) model of execution. The DDM model has been evaluated using an execution driven simulator. To validate the simulation results, a 2-node DDM chip multiprocessor has been implemented on a Xilinx Virtex-II Pro FPGA with two PowerPC processors hardwired on the FPGA. Measurements on the hardware prototype show that the TSU can be implemented with a moderate hardware budget. The 2-node multiprocessor has been implemented with less than half of the reconfigurable hardware available on the Xilinx Virtex-II Pro FPGA (45% slices), which corresponds to an ASIC equivalent gate count of 1.9 million gates. Measurements on the prototype showed that the delays incurred by the operation of the TSU can be tolerated.

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Lin, Zhipeng, Wenjing Yang, Houcun Zhou, Xinhai Xu, Liaoyuan Sun, Yongjun Zhang, and Yuhua Tang. "Communication Optimization for Multiphase Flow Solver in the Library of OpenFOAM." Water 10, no. 10 (October 16, 2018): 1461. http://dx.doi.org/10.3390/w10101461.

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Multiphase flow solvers are widely-used applications in OpenFOAM, whose scalability suffers from the costly communication overhead. Therefore, we establish communication-optimized multiphase flow solvers in OpenFOAM. In this paper, we first deliver a scalability bottleneck test on the typical multiphase flow case damBreak and reveal that the Message Passing Interface (MPI) communication in a Multidimensional Universal Limiter for Explicit Solution (MULES) and a Preconditioned Conjugate Gradient (PCG) algorithm is the short slab of multiphase flow solvers. Furthermore, an analysis of the communication behavior is carried out. We find that the redundant communication in MULES and the global synchronization in PCG are the performance limiting factors. Based on the analysis, we propose our communication optimization algorithm. For MULES, we remove the redundant communication and obtain optMULES. For PCG, we import several intermediate variables and rearrange PCG to reduce the global communication. We also overlap the computation of matrix-vector multiply and vector update with the non-blocking computation. The resulting algorithms are respectively referred to as OFPiPePCG and OFRePiPePCG. Extensive experiments show that our proposed method could dramatically increase the parallel scalability and solving speed of multiphase flow solvers in OpenFOAM approximately without the loss of accuracy.

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Tong, Jinjin, Dongdong Sun, Chao Yang, Yingxue Wang, Sichao Sun, Qing Li, Jun Bao, and Yun Liu. "Serum starvation and thymidine double blocking achieved efficient cell cycle synchronization and altered the expression of p27, p53, bcl-2 in canine breast cancer cells." Research in Veterinary Science 105 (April 2016): 10–14. http://dx.doi.org/10.1016/j.rvsc.2016.01.008.

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Kano, Toshiyuki, Yuji Inaba, Margherita D'Antuono, Giuseppe Biagini, Maxime Levésque, and Massimo Avoli. "Blockade of in vitro ictogenesis by low-frequency stimulation coincides with increased epileptiform response latency." Journal of Neurophysiology 114, no. 1 (July 2015): 21–28. http://dx.doi.org/10.1152/jn.00248.2015.

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Low-frequency stimulation, delivered through transcranial magnetic or deep-brain electrical procedures, reduces seizures in patients with pharmacoresistant epilepsy. A similar control of ictallike discharges is exerted by low-frequency electrical stimulation in rodent brain slices maintained in vitro during convulsant treatment. By employing field and “sharp” intracellular recordings, we analyzed here the effects of stimuli delivered at 0.1 or 1 Hz in the lateral nucleus of the amygdala on ictallike epileptiform discharges induced by the K+ channel blocker 4-aminopyridine in the perirhinal cortex, in a rat brain slice preparation. We found that 1) ictal events were nominally abolished when the stimulus rate was brought from 0.1 to 1 Hz; 2) this effect was associated with an increased latency of the epileptiform responses recorded in perirhinal cortex following each stimulus; and 3) both changes recovered to control values following arrest of the 1-Hz stimulation protocol. The control of ictal activity by 1-Hz stimulation and the concomitant latency increase were significantly reduced by GABAB receptor antagonism. We propose that this frequency-dependent increase in latency represents a short-lasting, GABAB receptor-dependent adaptive mechanism that contributes to decrease epileptiform synchronization, thus blocking seizures in epileptic patients and animal models.

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Journal articles on the topic 'Blocking synchronization'

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