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Recent studies have concentrated on environmental and economic impacts of ships. In this regard, fuel and C O 2 emission is considered as one of the important factors for such impacts. In particular, the sailing speed of the vessels affects the fuel consumption and therefore the emission directly. In this study, we consider a speed optimization problem in inland waterway, which is characterized by stochastic waiting times at the lock caused by uncertainty in lock processing time estimations of other vessels. The objective is to minimize fuel consumption of an approaching ship, such that it traverses the river segment in a set deadline. We introduce a mathematical model for this problem and evaluate the effectiveness and attractiveness of two solution approaches: an optimal solution and a simple heuristic. This creates intuitive guidelines for skippers based on information provision to select an appropriate speed decision approach to minimize the total expected fuel consumption and C O 2 emission of inland waterway transportation.

Piezo-stepping actuator is one device that produces large displacement while some voltage is applied to it or vice-versa by micro-meter accuracy and nanometer resolution. The displacement in stepper actuators happens with steps. A linear stepping movement of the base of the actuator is proposed in this paper. A linear stepping motion of the piezo actuators is achieved with four sets of push–pull actuators and four sets of lock release actuators. The designed stepper actuator produces linear displacements. The design and control of the stepper actuators are explained in the paper. A trapezoidal signal is being generated from the triangular wave moreover this is implemented as the input for the smooth functioning of a stepping actuator. Control operation of push–pull and lock-release actuators was performed and for various input displacements the experimental displacements of actuators were achieved and the results were plotted. Control operation of Push-pull and lock release assembly was conducted for varying input displacement and corresponding experimental displacement is measured and also the results were plotted. The actuator assembly was proficient in driving the linear guideways.

The particular structure and configuration of the Venice lagoon represents a paramount case study concerning coastal flooding which affects natural, historical/cultural properties, together with industrial, commercial, economical and port activities. In order to defend Venice (and other sites) within the lagoon from severe floods, the Italian Government promoted the construction of a complex hydraulic/maritime system, including a movable storm surge barrier named Experimental Electromechanical Module (MoSE), to be activated when specific water levels occur. When the MoSE barriers are raised, the only access to the lagoon for commercial and cruise ships is represented by the Malamocco lock gate, provided that suitable safety conditions (involving the significant wave height) are satisfied. In addition, the Italian Government has recently established that, in the near future, large ships will always have to enter/exit the lagoon only through the Malamocco entrance. In turn, the navigation within the Venice lagoon is (will be) controlled by the combined MoSE-Malamocco system, ruled by both univariate and bivariate paradigms/guidelines. As a novelty, in the present work, for the first time, the statistics of significant wave heights and water levels in the Venice lagoon (both univariate and bivariate ones) are investigated: in particular, these variables turn out to be dependent, and their joint occurrence (statistically modeled via Copulas) can determine the stop of ship navigation, yielding significant economic losses. Here, univariate and bivariate Return Periods and Failure Probabilities are used to thoroughly model the statistical behavior of significant wave heights and water levels, in order to provide useful quantitative indications for the management of the tricky hydraulic, maritime and economical system of the Venice lagoon.

Locks are important components of a waterway system. To improve the efficiency of inland waterway transport, it is important to ensure ships passing locks without having to spend unnecessary waiting times at lock entrances. Meanwhile, with the trends towards digitalized and smart waterways, it is also worth investigating how the information availability could contribute to optimizing lock operations and ship arrivals on inland waterways. Therefore, this paper proposes an optimization method to schedule ships’ arrivals and their placements in locks on inland waterways, based on a mixed-integer programming model, and solves the optimization problem with large neighborhood search based heuristics. The optimization objective is threefold: first, optimizing the arrival sequence of ships at the locks; second, maximize the utilization of each lockage operation; and third, reducing the overall time that each ship spends from entering the waterway area till leaving the last lock on the waterway. Simulations are carried out to evaluate the performance of the proposed method.

The emergence of an internal control system to guide operations along the Rideau Canal beginning in 1832 is examined through analysis of a book of directives (the Order Book) maintained by the lockmaster at the Isthmus lockstation. The Orders guided the work of the lockmaster and established general controls and control activities. Orders for adequate documents and records, physical control over assets and records, and proper authorization of activities were common. Orders are seen as efforts by British Royal Engineers, who were geographically removed from the oversight of the Rideau Canal Office, to discipline civilian lockmasters and to encourage lockmasters to govern themselves. Comparing the Order Book to Orders and Regulations in place in 1831 for the Royal Engineers also highlights similarities between expectations of Royal Engineers and those established for the civilian workforce under their direction, indicating a transfer of accounting technologies from the Royal Engineers to the civilian workforce.

A series of lock-release experiments are carried out to investigate the hydrodynamics of weakly and strongly stratified two-layer gravity currents (GC) on a flat bottom. A particle image velocimetr...

In this article, we propose Failure-atomic Byte-addressable R-tree (FBR-tree) that leverages the byte-addressability, persistence, and high performance of persistent memory while guaranteeing the crash consistency. We carefully control the order of store and cacheline flush instructions and prevent any single store instruction from making an FBR-tree inconsistent and unrecoverable. We also develop a non-blocking lock-free range query algorithm for FBR-tree. Since FBR-tree allows read transactions to detect and ignore any transient inconsistent states, multiple read transactions can concurrently access tree nodes without using shared locks while other write transactions are making changes to them. Our performance study shows that FBR-tree successfully reduces the legacy logging overhead and the lock-free range query algorithm shows up to 2.6x higher query processing throughput than the shared lock-based crabbing concurrency protocol.

The results of studies to determine the main indicators of the head filling system of a lock chamber with cylindrical culverts under Tainter gates are presented along with design solutions for improving the operation of the filling system.

During the tunnel construction in soft ground, the insufficient bearing capacity of tunnel foundation usually causes a series of settlement problems. Tunnel feet-lock pipe (TFP) has been widely used to take the vertical load acting at the foundation of a tunnel foot. However, the detailed bearing performance of TFP is still not clear, and there is a lack of quantitative research. In this paper, a simple analytical approach is adopted to evaluate the performance of the TFP, and the main parameters affecting the supporting performance of the TFP are analyzed. The results show that the ϕ42–ϕ140 TFP with the angle of 10° can take 3.8%–40.4% of vertical load. TFP has an effective length of 1.7 m–2.8 m, which is related to the relative stiffness between the TFP and the stratum. With the increase of the installation angle, the TFP shares more vertical load. This trend is more obvious when the angle of the TFP is greater than 20°. If the proportion coefficient of the subgrade reaction coefficient is doubled, the vertical load shared by the TFP can be increased by 34%–38%. For every 10 cm increase in overbreak behind the steel rib, the vertical load shared by TFP is reduced by 16%.

NOVA, a state-of-the-art non-volatile memory (NVM) file system, has limited performance due to its coarse-grained per-file lock when multiple threads perform I/Os to a shared file in a manycore environment. For instance, a writer lock blocks other threads attempting to access the same file, although they access different regions of a file. When multiple threads reading the same file share a cache line containing a reader counter, performance can be significantly degraded due to cache consistency protocol as we increase the number of readers. This paper proposes a fine-grained segment-based range lock ( SRL ) that divides a file into multiple segments and manages a lock variable dynamically for each segment. Consequently, write operations can be parallelized without blocking unless there is a conflict in accessing the same range in a file. Moreover, SRL maintains a reader counter per segment that allows multiple reader threads to perform read operations without causing a performance bottleneck. We evaluated an SRL -based NOVA on an Intel Optane DC persistent memory (PM) manycore server. The benchmarking results showed that the average write throughput of the SRL -based NOVA is $3\times $ higher than the original NOVA, and the average read throughput scales linearly, while the original NOVA does not scale.

In India, very first infection due to Covid-19 was reported by end of January 2020 and, the same has been increased with the span of time. In order to fight the increasing risk among the citizens of nation, the complete lock-down was declared on March 25, 2020 for initially 21 days and thereafter it has been subsequently increased up to its present 4th phase, which would be remain continue until May 31, 2020. First two phases of lock-down were imposed without any relaxation, however, there were gradual relaxation implemented in third and fourth lock-down phases. Air pollution depends on emission of the pollutants from vehicles and industries, as well as dust from construction activities. Due to lock-down, operations concerning these activities were completely shut down. The effect of lock-down on PM2.5, PM10, NO2, SO2, CO and AQI level was studied and comparison of PM2.5, PM10, NO2, SO2, CO and AQI during lock-down with same dates of previous year was also considered.

The aim of this paper is to compare the inland river transport on the Danube and the Rhine according to different aspects. Different historical and economic development of countries in the western, central and eastern Europe led to differences related to dimensions of vessels, canals and lock chambers. The development of ports on the Rhine and the Danube is also slightly connected to the historical and economic development. Comparison of inland navigation on the Danube and the Rhine and activities in ports are the fundamental of the future development of cooperation between different parts of Europe. Thanks to comparisons like this one it is possible to create new frameworks of the future development of inland waterways in Europe. In the future, better connections between river systems will certainly have a positive effect on the development of transport and economic conditions of countries along these rivers.

A Screw Jack is used to lift a heavy load. This jack is modified and made in such a way that it can be fitted to the frame of the vehicle. Hence when the jack operates, the car can be lifted up. The jack operation is made possible with the buttons fitted to the dashboard of the vehicle. In case of puncture or any other service, there is no need for external jack. The system is user-friendly such as in case of the power window. The rocker switch is used to enable the reverse operation of the jack too. The jack is operated by an electric motor powered by the car battery. The Rocker switches are placed inside a lock protected box, in order to prevent any accidents. The rocker switch can be accessed only when it is needed.

A Hyperledger Fabric is a popular permissioned blockchain platform and has great commercial application prospects. However, the limited transaction throughput of Hyperledger Fabric hampers its performance, especially when transactions with concurrency conflicts are initiated. In this paper, we focus on transactions with concurrency conflicts and propose solutions to optimize the performance of Hyperledger Fabric. Firstly, we propose a novel method LMLS to improve the Write-Write Conflict. This method introduces a lock mechanism in the transaction flow to enable some conflicting transactions to be marked at the beginning of the transaction process. And indexes are added to conflicting transactions to optimize the storage of the ledger. Secondly, we propose a cache-based method to improve the Read-Write Conflict. The cache is used to speed up reading data, and a cache log is added to Hyperledger Fabric to ensure the data consistency. Extensive experiments demonstrate that the proposed novel methods can significantly increase transaction throughput in the case of concurrency conflicts, and maintain high efficiency in transactions without concurrency conflicts.

This paper investigates the hypothesis that power relations in the current, fossil fuel-based capitalist system allow the natural gas industry to appropriate the notion of a hydrogen energy utopia ...

In the Qing dynasty (1644–1911 CE), the town of Yuekou, in Hubei Province, was an important and renowned lock production center. Yuekou locks produced there won high acclaim for their use of quality materials. Transported via water routes, they were marketed in other provinces in China and other Southeast Asian countries. Even today, Yuekou locks are the favorites of antique collectors. After the introduction of the Western-style pin tumbler lock in the 1950s, the popularity of traditional Chinese locks began to decline, and they disappeared from the market. Receiving no attention from people, they were forgotten. From 2009 to 2016, the research team visited Yuekou eight times to conduct field research and interview surviving locksmiths and their descendants, achieving significant results. There are six main types of Yuekou locks, including combination locks, regular locks, pull-back locks, maze locks, multi-stage locks, and hidden-keyhole locks. The crafting of Yuekou locks is conducted in four stages: material preparation, molding, shaping, and assembling. The entire process is operated manually. This work introduces the historical development of Yuekou locks, summarizes the verbatim interviews, explores the production of Yuekou locks, and analyzes the types and structures of Yuekou locks.

The coronavirus pandemic has caused a global reduction in economic activity and although this is major cause for concern, the slowing down of human activity during lockdown period appears to have had a positive impact on the environment. Due to less human activities, manmade pollution has gone to almost zero level in this period in many parts of the world. In India, many attempts have been made for making Ganga river clean during the last many years. That Ganga river has become clean in a three week lock-down. In the month of April, residents of Jalandhar city in Punjab, got a surprise when they witnessed Dhauladhar Mountain range situated at a distance of about 200 Km in Himachal Pradesh (H.P.) for the first time in a decade. Similarly the Pir Panjal range which extends from H.P. to Jammu and Kashmir was a blur to the locals, recently the view is completely clear.

The waterway freight volume through the Three Gorges ship lock (TGL) has increased significantly since it started operation in 2003 and exceeded the designed capacity of 100 million tons in 2011, 19 years earlier than expected. This made the TGL a bottleneck for the Yangtze River waterway transport development. Based on the historical freight volumes and types through the TGL, a combination of qualitative and quantitative analyses are conducted here to identify the key factors affecting freight demand. A genetic algorithm and backpropagation (GA–BP) forecasting model (optimized backpropagation neural network model using a genetic algorithm) was developed to estimate freight demand at the TGL over the period 2020–2040. We predict that freight demand will continue to increase, reaching 260.2 million tons in the basic scenario by 2040 (or 224.7 million tons in the conservative scenario and 276.7 million tons in the optimistic scenario). However, the growth rate will gradually decline. The freight composition will tend to be more stable and homogeneous, with over 64% of the freight related to investment and construction. From the perspective of freight volume evolution, the necessity of the Three Gorges New Locks Project is justified and necessary.

The e-commerce business process net (EBPN) is a novel formal model for describing an e-commerce system and its interactive parts, such as shoppers, merchants, and the third-party payment platforms. Vulnerability analysis has a great impact on the trustworthiness of EBPN, which is an issue stemming from data inconsistency problems. Data inconsistency problems affect the consistency of the EBPN transaction analysis. The underlying causes of inconsistent data are closely related to concurrent operations, such as control flow and data flow. However, most of the existing detection methods have difficulties characterizing the vulnerabilities and interactions of control and data flows. In this paper, we propose a new method based on the dynamic data slice (DDS) that considers both transaction consistency and data state consistency. First, by analyzing control flow characteristics of EBPN, we obtain the dynamic slice. This dynamic slice is based on all paths of the EBPN reachability graph. Second, we perform the data inconsistency analysis by considering both transaction consistency and data-state consistency. Based on these, we construct a DDS to characterize the behavioral logic and the data-dependence information. The DDS acquires the dynamic data firing sequence. Based on that sequence and a given data marking, we can construct the DDSs for several types of EBPNs. Constructing the DDS can be completed in polynomial time. The DDS is designed to characterize the behavioral logic and data-dependence information. Based on these, we design a method to judge the data constraints. This method satisfies the EBPN need for transaction consistency by considering both the control and data states. In addition, according to the data-dependence information, we can lock the vulnerable regions caused by abnormal trading data in the system. Finally, we give a method to compute the vulnerability level.

The Nile navigable Damietta branch extends between Cairo and Damietta open seaport on the Mediterranean. For safe navigation throughout the branch, a 2.30 m minimum flow depth (MFD) is required. A recovery project to improve the branch navigation was started in 1999 and completed in 2005. The project was to implement a 40 m wide navigable waterway. About 6.50 million m3 of bed materials had been removed from bottlenecks at $ 18.20 million cost. In 2003, the construction of a new lock of 150.0 m length, 17.0 m width and (1.50) m bed level was completed on Zefta Barrages (ZB) east side to meet the navigation requirements. The barrages are located at Km 119.625 downstream (D/S) El-Roda Gauge in Cairo. However, the resulting water stage (WS) D/S (ZB) during low discharges was insufficient to provide the MFD. Field studies were conducted to reveal the reasons. They found the branch flow carrying capacity had increased due to excessive dredging which caused a decline in WSs D/S (ZB). Analyzing the hydrologic and topographic conditions, two solution concepts were reached; either to raise the WS by 0.70 m or to lower the bed level of the diversion channel located D/S the new lock by 1.0 m. Therefore, this study aims to introduce solutions to overcome the problem. The solutions are to use a D/S rubber weir for raising the WS or construct a new lock within the D/S diversion channel for lowering the bed level or build new barrages with a new lock.

The decision to build a new waterway (strait) in the Polish part of the Vistula Spit was made in 2017. The new connection between the Gulf of Gdańsk and the Vistula Lagoon is planned as an artificial navigable channel with a lock and a small port. During storm surges and wind tides in the gulf or in the lagoon, sluicing will be required for vessels to tackle the Vistula Spit. This procedure does not require significant water flow through the channel in normal conditions. However, in the case of a lock failure or in the case of controlled opening of the gate to increase water exchange in the lagoon or to reduce flood risk in the Vistula Lagoon, high flow rates may occur in the navigable channel and in the neighboring port basin. In order to inves-tigate the hydraulic conditions in such extraordinary situations, numerical modeling of the hydrodynamics during water damming in the gulf or in the lagoon is performed. To analyze the hydrodynamics of the artificial connection between the sea and the lagoon during periods of high water stages, mathematical modeling is required. This paper presents the shallow water equations (SWE) model adapted to simulate the flow through the port basin and the navigable channel. The calcula-tions allowed the relation between the water head and the capacity of the navigable channel to be found, as well as to analyze circulations which may occur in the port basin.

In a cross-flow moving bed, the gas-solid cross-flow pattern facilitates the high gas process capacity for a relatively low pressure drop, while the appearance of the abnormal phenomena of cavity, pinning and air lock reduces the bed operating flexibility. A new structural optimization of a gas-solid baffle is proposed. Relevant equations for evaluating these three phenomena are theoretically derived or summarized in the original bed and the bed with a gas-solid baffle. Based on experimental and theoretical data, with the proposed structural optimization, the cavity and pinning are weakened in rectangular and radial beds and the air lock can be easily controlled by increasing the height and diameter of the feed tube. The preferred location of the gas-solid baffle is the middle position (x/L = 0.5) of the rectangular bed and/or the position (r-r1)/(r2-r1)

The popularity of Non-Uniform Memory Access (NUMA) architectures has led to numerous locality-preserving hierarchical lock designs, such as HCLH, HMCS, and cohort locks. Locality-preserving locks trade fairness for higher throughput. Hence, some instances of acquisitions can incur long latencies, which can be intolerable for certain applications. Few locks allow a waiting thread to abort on a timeout. State-of-the-art abortable locks are not fully locality aware, introduce high overheads, and are unsuitable for frequent aborts. Enhancing locality-aware locks with lightweight timeout capability is critical for their adoption. In this article, we describe the design and implementation of the HMCS-T lock, a Hierarchical MCS (HMCS) lock variant that admits timeout. HMCS-T maintains the locality benefits of HMCS while ensuring aborts are lightweight. HMCS-T offers the progress guarantee missing in most abortable queuing locks. The resulting locking algorithm is complex and stateful. Proving the correctness of a complex, stateful synchronization algorithm is challenging. We prove the correctness of HMCS-T by first decomposing the problem via a novel technique that uses non-deterministic finite acceptors (NFAs). The decomposed problems become small enough to be mechanically model checked without a state-space explosion. Then, we generalize the correctness proof of any arbitrary lock configuration using a construction argument.

This final task report aims to design and Meng-implementasikan a series that serves to security and follow technology installed on the security of the door and controlling the existing doors of the door such as the Module key of the RF Remote Arduino that is for opening and closing doors. And discussing about RF Remote which is used to detect a frequency that will be output and input for the Arduino microcontroller. To control the Arduino microcontroller used the C and Arduino programming languages by using the Arduino software. The way this tool works is when people want to be quick and concise in opening and closing its doors. The door that has been on the security of the RF Remote will not be in the process, if the RF Remote button does not press on the password that has been known on the microcontroller, if the existing door lock RF Remot will turn on the opening and closing doors. In the door there is also a sound mark when in the Sensor Switch does not get a hard enough clearance or emphasis, if the microcontroller does not GET the ID for 5 seconds and automatically instantly Sounds The buzzer or sound of the alarm tone if the door is forced to open or close. The RF Remote Module receives a frequency signal and is connected to the Solenoid door lock, and is processed by the Arduino and then to through the relay to connect the line current on the door lock Solenoid and Servo Motor

In this paper, the current limiting and the interrupting operations of the flux-lock type superconducting fault current limiting interrupter (SFCLI) using the mechanical switch (MS), which could be driven without additional driving power source, were analyzed. The operational principle of the suggested SFCLI is the same as one, except that the MS performs the fault current interrupting operation, driven by the electromagnetic repulsion force generated within the driving coil without the additional driving power source. Furthermore, the interrupting operation of the MS directly, after the current limiting operation of this SFCLI, can contribute to the improvement of the previous SFCL's performance. To verify the operational characteristics of the suggested SFCLI, the MS with the fixed plate (FP) and the moving plate (MP), which were located just above open round bobbin wound by the driving coil, was designed and manufactured. The short-circuit tests of the SFCLI using MS were carried out. Through the analysis on the results of the short-circuit tests, the current limiting and interrupting operations of the flux-lock type SFCLI using the MS could be confirmed to be effectively performed without the additional driving power source.

The upstream lock gate at The Dalles Lock and Dam on the Columbia River is a radial, or Tainter, gate. Tainter gates operate by being raised and lowered through a circular path by means of hoisting cables. The continued operability of the gate is of extreme economic importance to the Columbia River basin region, as the gates facilitate the transportation of billions of dollars in goods annually. One of the critical issues during operation of the gate is uneven, or skewed, hoisting of the gate, which causes twisting in the gate leading to the potential for unaccounted stresses. This study focuses on the operational behavior of the Tainter gate at The Dalles and detection of uneven hoisting during gate operation. The initial goal of this study was to develop an automated method to detect uneven hoisting of the gate utilizing strain gage data from a continuous monitoring system. However, disagreement between the incoming data compared to the expected behavior of the gate led to concerns about the Tainter gate. Three explanations for the disagreement seemed possible: the model of the gate was flawed, the sensors were unreliable, or the gate was actually already hoisting unevenly. To provide a definitive diagnosis of the issues seen in the data, a short-term monitoring program was devised using vibration measurements of the hoisting cables of the gate. Then, a frequency domain method was employed to estimate the force in the cables, which provides an indication of the unevenness of the gate hoisting. Results indicate that, indeed, the Tainter gate at The Dalles regularly hoists unevenly and that the installed sensor system is sensitive to the presence of uneven hoisting.

As more emerging applications are moving to GPUs, thread-level synchronization has become a requirement. However, GPUs only provide warp-level and thread-block-level rather than thread-level synchronization. Moreover, it is highly possible to cause live-locks by using CPU synchronization mechanisms to implement thread-level synchronization for GPUs. In this article, we first propose a software-based thread-level synchronization mechanism called lock stealing for GPUs to avoid live-locks. We then describe how to implement our lock stealing algorithm in mutual exclusive locks and readers-writer locks with high performance. Finally, by putting it all together, we develop a thread-level locking library (TLLL) for commercial GPUs. To evaluate TLLL and show its general applicability, we use it to implement six widely used programs. We compare TLLL against the state-of-the-art ad-hoc GPU synchronization, GPU software transactional memory (STM), and CPU hardware transactional memory (HTM), respectively. The results show that, compared with the ad-hoc GPU synchronization for Delaunay mesh refinement (DMR), TLLL improves the performance by 22 percent on average on a GTX970 GPU, and shows up to 11 percent of performance improvement on a Volta V100 GPU. Moreover, it significantly reduces the required memory size. Such low memory consumption enables DMR to successfully run on the GTX970 GPU with the 10-million mesh size, and the V100 GPU with the 40-million mesh size, with which the ad-hoc synchronization can not run successfully. In addition, TLLL outperforms the GPU STM by 65 percent, and the CPU HTM (running on a Xeon E5-2620 v4 CPU with 16 hardware threads) by 43 percent on average.

This article explains that the Modern period marked by the collapse of the power of the church and the rise of science authority. At the next phase, the new image of man becomes inevitable. After modernist philosophers called on people to go away from the church, science in turn lock and catch the man, then he is traped in factories and industries. Substantive dimensions in man is eliminated, so that his presence in the world is subordinated by the industrial machines. Human in modern world is not more than a "the screw of industry.

The past decade has seen the development of many shared-memory graph processing frameworks intended to reduce the effort of developing high-performance parallel applications. However, many of these frameworks, based on Vertex-centric or Edge-centric paradigms suffer from several issues, such as poor cache utilization, irregular memory accesses, heavy use of synchronization primitives, or theoretical inefficiency, that deteriorate over-all performance and scalability. Recently, we proposed a cache and memory-efficient partition-centric paradigm for computing PageRank [26]. In this article, we generalize this approach to develop a novel Graph Processing Over Parts (GPOP) framework that is cache efficient, scalable, and work efficient. GPOP induces locality in memory accesses by increasing granularity of execution to vertex subsets called “parts,” thereby dramatically improving the cache performance of a variety of graph algorithms. It achieves high scalability by enabling completely lock and atomic free computation. GPOP’s built-in analytical performance model enables it to use a hybrid of source and part-centric communication modes in a way that ensures work efficiency each iteration, while simultaneously boosting high bandwidth sequential memory accesses. Finally, the GPOP framework is designed with programmability in mind. It completely abstracts away underlying parallelism and programming model details from the user and provides an easy to program set of APIs with the ability to selectively continue the active vertex set across iterations. Such functionality is useful for many graph algorithms but not intrinsically supported by the current frameworks. We extensively evaluate the performance of GPOP for a variety of graph algorithms, using several large datasets. We observe that GPOP incurs up to 9×, 6.8×, and 5.5× less L2 cache misses compared to Ligra, GraphMat, and Galois, respectively. In terms of execution time, GPOP is up to 19×, 9.3×, and 3.6× faster than Ligra, GraphMat, and Galois, respectively.

Inland waterways ports are key elements of an efficient multimodal freight transportation system. Data on the capacity and throughput of inland waterway ports by commodity support effective long-term freight planning and travel demand modeling. More specifically, such data can be used to estimate multimodal commodity-based freight fluidity performance measures and to support location selection for freight transload facilities. State-of-the-practice means of obtaining commodity flows data, such as shipper/carrier surveys and vessel and vehicle movements, are limited in their ability to provide monthly or seasonal statistics on individual port operations; rather, they provide annualized statistics for river segments which may contain multiple ports. These limitations are addressed herein by developing a multicommodity assignment model to quantify commodity throughput at inland waterways ports. The model fuses waterborne lock performance monitoring system data, which provides the commodity dimension, and anonymous truck Global Positioning System (GPS) data, which allows for spatial disaggregation. A goal-programming approach minimizes the deviation between known and estimated truck flows at each port. The methodology was applied to the Arkansas River, a 308-mile navigable waterway served by 14 locks and 43 freight ports. Overall, 84% of ports showed less than 20% difference between observed and predicted truck flows. The model is applicable to any inland waterways system with aggregated commodity flow data and truck GPS coverage and fills a critical data gap by describing commodity throughput at inland waterway ports using publicly available data.

Grass Carp Ctenopharyngodon idella have been intentionally stocked for aquatic vegetation control across the Midwestern United States for several decades. During the 1970s, escapement of Grass Carp into the Missouri River facilitated their naturalization into much of the Mississippi River basin, including the Upper Mississippi River. Lock and Dam 19 (LD19) in Keokuk, Iowa, is a high-head dam that represents a focal point for naturalized Grass Carp management where populations may differ between upstream and downstream pools as result of limited upstream migration, but potential differences between populations have yet to be evaluated to the best of our knowledge. The objective of this study was to compare the relative abundance, size structure, condition, growth, and recruitment variability of Grass Carp collected upstream and downstream of LD19. We sampled Grass Carp monthly (April–October) during 2014 and 2015 from four locations in the Des Moines River (downstream of LD19) and five locations throughout the Skunk, Iowa, and Cedar rivers (upstream of LD19) using boat electrofishing and trammel net sets. We captured 29 Grass Carp upstream of LD19 compared with 179 individuals captured downstream. Trammel nets only captured Grass Carp downstream of LD19; trammel net catch per unit effort upstream of LD19 was low and ranged from 0.0 to 8.0 fish/net lift (mean ± SE = 0.39 ± 0.13). Electrofishing catch per unit effort ranged from 0.0 to 22.7 fish/h (1.49 ± 0.30) and was higher downstream (2.42 ± 0.30) of LD19 than upstream (0.57 ± 0.07). Grass Carp downstream of LD19 tended to be smaller, younger, of lower body condition, had higher mortality rates, and were slower growing compared with those collected upstream and to populations documented in other systems. Understanding and monitoring adult Grass Carp population characteristics upstream and downstream of LD19 is necessary to determine how they may change in response to ongoing harvest efforts for invasive carps in these river reaches.

As the number of cores equipped in a system grows, the impact of the spinlock waiting inside the operating system (OS) kernel on the performance and energy efficiency of a system worsens. In particular, it deteriorates the effectiveness of simultaneous multithreading (SMT). Because spinlocks are indispensable in OS kernels, it is necessary to suppress the spin wait overhead in the many-core systems. To address this issue, we propose the catnap spinlock that exploits the ACPI-C state, which is named as the catnap state and is induced by the MONITOR / MWAIT instruction pair. The catnap state releases the processor resources while deceiving the kernel that the thread is iterating a busy-waiting loop. Because entering and exiting from the C-state require considerable time, we applied the catnap loop only to the non-head waiters not to delay the lock handover operation. Furthermore, we selectively applied the catnap spinlock to the lock instances for sufficiently long critical sections based on the observation made in profiling runs. The proposed scheme was implemented in the Linux kernel and evaluated in a many-core processor system with a few workloads from the PARSEC and Re-aim benchmark suites. Our evaluation showed that the proposed scheme improved the performance by up to 33.59% and reduced energy consumption by 39.11%.

Recent years have witnessed a boom in blockchain systems written in Rust to utilize its efficiency and safety. Unfortunately, deadlock bugs have become one of the ubiquitous banes to these systems due to the heavy use of locks for parallelism and the misunderstanding of the lock mechanism in Rust. This paper analyzed the common lock-related pitfalls in blockchain systems written in Rust and proposed Stuck-me-not, the first MIR-based static deadlock detector, for the most common deadlock type: double-lock. We have discovered 29 previously unknown double-lock bugs in 11 popular blockchain-related projects. We believe our work can greatly improve the concurrency security of the current blockchain ecosystem.

The scope of this work is to try to quantify the reduction of emissions due to COVID-19; an analysis covering the entire port of Naples will be presented. The explosion of the global pandemic from SARS-CoV-2 led to the adoption of local and global countermeasures aimed at containing contagions. The transportation sector, and in particular the passenger moving sector, was deeply affected; this almost total block of movements between regions and countries if, on the one hand, seriously slowed the economy, on the other, it drastically reduced the emissions on a global and local scale. In this work, the case study of the cruise ships berthed at the Maritime Station (Stazione Marittima) in the port of Naples is examined. The traffic of cruise ships during the lockdown and in the immediately following months was analysed and compared first with respect to the calendars scheduled for the same period and then with respect to the same months of 2019. The reduction in number of cruise ships and passengers were analysed and compared to the previous trends. The vessels collected, for 2019 and 2020 (both those that arrived and those that suffered the effects of the movement block) were subsequently characterized in terms of power and speed. Finally, an estimate of the emissions of NOX, SOX, CO2 produced and saved was carried out. The 2020 results will be compared with the hypothetical emissions that would have occurred in the absence of the lockdown and with those of the same period of the previous year.

Record-and-replay systems are useful tools for debugging non-deterministic parallel programs by first recording an execution and then replaying that execution to produce the same access pattern. Existing record-and-replay systems generally target thread-based execution models, and record the behaviors and interleavings of individual threads. Dynamic multithreaded languages and libraries, such as the Cilk family, OpenMP, TBB, and the like, do not have a notion of threads. Instead, these languages provide a processor-oblivious model of programming, where programs expose task parallelism using high-level constructs such as spawn/sync without regard to the number of threads/cores available to run the program. Thread-based record-and-replay would violate the processor-oblivious nature of these programs, as they incorporate the number of threads into the recorded information, constraining the replayed execution to the same number of threads. In this article, we present a processor-oblivious record-and-replay scheme for dynamic multithreaded languages where record and replay can use different number of processors and both are scheduled using work stealing. We provide theoretical guarantees for our record and replay scheme—namely that record is optimal for programs with one lock and replay is near-optimal for all cases. In addition, we implemented this scheme in the Cilk Plus runtime system and our evaluation indicates that processor-obliviousness does not cause substantial overheads.

The design of the formwork support for a certain section of the Beijing subway project was carried out in this paper. And the disk lock formwork support was used in the engineering.It was analyzed on the the design of the formwork support for the roof with the thickness of 1.5m of the interval engineering. The manual calculation and the sap2000 finite element analysis were also used in the paper.The effect of the diagonal brace and its number were analyzed in addition to the design of the formwork support. It was showed that the axial force of the standing tube tends to be uneven with the increase of the number of slant bars in the framework. And the axial force of the standing tube connected to diagonal brace is larger than that of the framework without brace significantly. So it will be dangerous to the framework without considering the effect of it by the manual calculation.

West Java field operated 60 electric submersible pumps (ESPs) as a lifting method with 2.850 BOPD production contribution. These ESP wells produce from a mature structure. At one point, 48% of ESP operation were shut down due to ESP non-optimum operation. The challenges in ESP operations in the asset are high gas-liquid ratio (GLR), impurities, sand and scale buildup, and well integrity where high GLR was deemed as the major problem that deteriorated the ESP's performance. Conventional ESPs gas separator were installed in the field, but the gas-handling device could not handle more than 45% free gas while some wells have more than 50% free gas. Three wells in particular were assessed, Well A, Well B, and Well C, which have 585, 1196, and 1690 average GLR respectively. These wells had problem with reduced pump efficiency and very low run life due to frequent ESP trips which were caused by the gas lock problem. A solution to maintaining oil production was by changing the production zone to zone that producing less gas and by installing more advanced gas-handling device. However, the probability of experiencing high gas production from new zones can't be ruled out therefore other mitigation plan had to be found. Gas lock protection control is an algorithm that manipulates ESP real-time rotational speed to prevent gas interference inside pump. The algorithm was introduced as a mitigation measure and commissioned in July 2020 at Well A where it directly optimized production by 16%. To prove the robustness of the gas lock prevention control, the project was then extended to Well B and Well C which began to implement gas lock prevention control in August 2020 to handle the increase of their gas production. Thanks to this gas lock prevention control, the wells have been able to maintain production without spending either time or money to change production zone or to change the ESP completion. Going forward, gas lock protection control will be set as an option on ESP devices. Thus, unplanned gas interference effects may be reduced in other wells that being produced by ESP thereby helping to maintain production at an optimum level.

The present paper presents a view of water spilled over hydropower plants as an energy loss. In the current climate conditions, flood events are becoming more frequent due to human impact on the environment, water spills are also more frequent, which means more and more energy is lost. How much water is spilled and, consequently, how much energy is lost is shown in the present article on the chain of power plants on the Sava River in the five years from 2015 to 2019. An analytical assessment of the current situation in the lock was carried out, which showed that the available water through the locks could be used efficiently. The paper presents a case study of one overflow event lasting 48 h. The calculated theoretical losses of energy (of spilled water) and possible technical implementation for capturing losses are given. The proposed technical implementation is based on established technology, so we could expect that the approach is feasible. The results show that the estimated spilled water energy potential reaches about 40% of the actual spilled water or energy lost.

Inland waterways play a key role within the freight transportation system by connecting productive heartland areas to international gateways, while keeping costs competitive. Quantifying commodity flow is important because it affects cost-based supply chain decision-making. However, data on commodity movements to inform investment and planning decisions is elusive. Publicly available commodity data on U.S. inland waterways is limited in its spatial aggregation to the location of locks, which is insufficient to identify inter-port commodity flows. Automatic Identification System (AIS) data has the potential to disaggregate freight-flows to the port and river segment levels but it does not identify the commodity carried. This paper characterizes and quantifies vessel trips by port of origin-destination, timestamp, commodity carried, and path (mapped to an inland waterway network), allowing for disaggregated commodity flow analysis, previously unavailable in the public domain in the U.S. This is accomplished through a multi-commodity assignment model which conflates AIS vessel movement data with commodity-specific port throughput. A stochastic approach is introduced to handle uncertainty in cargo-to-vessel ratios. Validation using data from the Arkansas River show agreement between model predictions and aggregated commodity volumes with differences lower than 1.82% by commodity and lock. Ubiquitous AIS data permit the transferability of the proposed work.

Kernel synchronization primitives are of paramount importance to achieving good performance and scalability for applications. However, they are usually invisible and out of the reach of application developers. Instead, kernel developers and synchronization experts make all the decisions regarding kernel lock design. In this paper, we propose contextual concurrency control (C3), a new paradigm that enables userspace applications to tune concurrency control in the kernel. C3 allows developers to change the behavior and parameters of kernel locks, to switch between different lock implementations and to dynamically profile one or multiple locks for a specific scenario of interest. To showcase this idea, we designed and implemented Concord, a framework that allows a privileged userspace process to modify kernel locks on the fly without re-compiling the existing code base. We performed a preliminary evaluation on two locks showing that Concord allows userspace tuning of kernel locks without incurring significant overhead.

Transactional memory is a prominent synchronization mechanism for shared memory multiprocessors. Access to critical sections of programs is accomplished with atomic transactions of memory accesses. The transactions are inherently deadlock-free and alleviate drawbacks of classic lock-based synchronization (i.e. deadlocks). Transactional memory has been implemented in modern CPUs and programming languages. In this talk, we consider the distributed shared memory setting where processor nodes are connected through a communication network. We consider the data flow model in which the transactions access shared memory objects that move from node to node through paths in the network. We study transaction execution scheduling problems which determine the movements of the shared objects so that transactions execute when their requested objects are fetched. We present scheduling algorithms with efficient execution time and communication cost. First, we observe that there are hard problem instances where the execution time and communication cost cannot be minimized simultaneously. We then provide efficient schedules for the execution time in specialized graphs that are useful in practical scenarios such as: Clique, Line, Grid, Cluster, Hypercube, Butterfly, and Star. In most of these cases, when individual transactions request k objects, we obtain solutions that approximate the execution time within an O(k) factor from optimal, yielding near-optimal solutions for constant k. The communication cost is also low since the objects follow near-optimal paths in the network. We discuss how to adapt the offline performance analysis to the online (dynamic) execution setting where transactions are generated continuously over time.

A vacant unit, once used by a Portuguese Deli, was converted to a bar/music room in Toronto. The unit was divided into two spaces along its north-south axis. The western portion was designed as a music room that would provide a performance space from a solo artist to a Jazz combo to a small rock band. The eastern part was designed as a regular bar/dining area. The plan also called for a microbrewery unit at the back of the unit. The bar music can be loud, while the music room can be pianissimo to forte depending on the type of performance. The acoustical design aspects are critical for the music room. In addition, the acoustical separation between the two spaces is equally important. The music room/bar is currently in use. The design results are compared to actual field measurements. The results showed that the music venue performed satisfactorily. The acoustical separation between the music venue and the bar/restaurant was better than expected other than an installation deficiency of the south side sound lock doors. The background sound along the northern portion was NC-35 or less. However, the southern portion’s background sound exceeded NC-35 due to the hissing of the return air grille. The acoustical design and the performance results of the music venue-bar/restaurant are presented in this paper.

Hydro-floating ship lifts are a milestone in the field of high dam navigation. In order to ensure the running safety of a hydro-floating ship lift, the effective integration of a numerical simulation method and cloud model theory was carried out to deal with the hydrodynamic risks presented by water surface deviations from the shafts in the filling–emptying system such as a lock. In this study, the average values of water surface deviation from the shafts were 0.2, 0.22 and 0.24 m, through numerical simulation on a similar hydro-floating ship lift at the lifting heights of 80, 100 and 120 m, respectively. An increase in the lifting height causes the water surface deviation from the shafts to increase, and the hydrodynamic risk is greatly increased in the equal inertial pipeline filling–emptying system. In addition, the water surface deviations from the shafts of the equal inertial pipeline and longitudinal culvert filling–emptying system like a lock were compared. The longitudinal culvert was better at optimizing running safety in the filling–emptying system and dealing with the uncertainty of water surface deviation from the shafts. The results show that the numerical simulation method and cloud model theory can effectively control the risk of water surface deviation from the shafts and can be used to aid in decision-making for risk prevention in relation to hydro-floating ship lifts.

In HPC systems, the increasing need for a higher level of concurrency has led to packing more cores within a single chip. However, since multiple processes share memory space, the frequent access to resources in critical sections where only atomic operation has to be executed can result in poor performance. In this paper, we focus on reducing lock contention on the memory management system of an HPC manycore architecture. One of the critical sections causing severe lock contention in the I/O path is in the page management system, which uses multiple Least Recently Used (LRU) lists with a single lock instance. To solve this problem, we propose a Finer-LRU scheme, which optimizes the page reclamation process by splitting LRU lists into multiple sub-lists, each having its own lock instance. Our evaluation result shows that the Finer-LRU scheme can improve sequential write throughput by 57.03% and reduce latency by 98.94% compared to the baseline Linux kernel version 5.2.8 in the Intel Knights Landing (KNL) architecture.

Hardware transactional memory is a new parallel programming paradigm supported by current commercial multiprocessors. This paradigm provides optimistic concurrency and overcomes some of the problems associated with classical lock-based synchronization, such as deadlock and serialization. Certain algorithms of computational geometry are found to be good candidates for parallelization with this paradigm. However, hardware transactional approaches to these algorithms lead to poor performance as the resulting transactions are too large for the underlying hardware to deal with. Large transactions overflow hardware resources serializing the execution. In this paper, we propose using privatizing transactions to parallelize two computational geometry algorithms: Lee’s algorithm, which solves the shortest-route problem, and Ruppert’s algorithm for Delaunay/Voronoi mesh refinement. Privatizing transactions are based on commercial hardware transactional memory extensions, and their goal is to reduce transaction footprint by means of a non-transactional private execution section. This results in effective smaller transactions. Our implementation is able to further reduce the transaction size as we propose a reduced validation set for privatizing transactions. Programming complexity of these implementations is discussed. Results show that our privatizing transaction implementations indeed enhance performance comparing with existing hardware transactional memory versions. Experiments with Intel’s transactional memory extensions yield speedups ranging from 2 × to 3.5 × with four threads.

Storage systems in general and databases in particular usually balance between write durability and performance. It is not uncommon that write durability often relies on transaction systems that also offer a relaxed model of durability for performance. As hardware vendors provision more cores and faster storage devices, attaining fast data durability for concurrent file writes is demanding to high-performance storage systems in large-scale cluster systems. We approach the challenge by proposing a system that uses a small amount of fast persistent memory for buffering concurrent file writes while preserving data durability. The main technical issue in designing a durable file buffer is allowing concurrent file writes to store data in a shared and limited space of persistent memory without incurring lock or resource contention. This article addresses such issue and presents AutoBahn, a durable file buffer that expedites file I/O operations. To prove practicality and effectiveness, we implemented a prototype of AutoBahn in Linux-4.8.7 and ran several key-value systems—Redis, RocksDB, and WiredTiger—on AutoBahn. Evaluation results on a multicore server demonstrate that all the key-value systems achieved performance levels almost matching the non-durable counterpart. AutoBahn is a useful method that can efficiently deal with concurrent file I/O streams on multicores and fast storage devices.

Because in-house debugging and test are difficult to discover all potential data races in multicore programs, it is necessary and significant to tolerate the potential data races in the production-run phase to secure the correct execution. However, the existing tolerating methods are limited to some kinds of data races. This paper proposes a new data-race tolerating approach, which can detect and adjust the data races whether it is in the protection of critical section or lack of protection to improve the correctness of multicore programs. It uses sliding windows to accommodate the memory instructions in critical section or recent memory instructions lack of protection and detects the potential data races which are more likely to cause errors. Then, by delaying the critical reversion points, data races are adjusted to reduce the probability of software failure. To implement the tolerating approach, the current multicore processor need not change its original cache coherence protocol and just adds very little hardware. Simulation results show that it brings low hardware, low bandwidth overhead, and negligible slowdown.

The purpose of the article is introduction to the scientific turnover of a unique find discovered on the archaeological site of the Isker hillfort – an iron mortise lock. The relevance of the study is conditioned by the fact that mortise locks, as a rule, are poorly preserved and, in general, were not as widespread as padlocks, and in rare publications there is no detailed description of the remaining parts. The lock from Isker is distinguished by good preservation, which made it possible to examine in detail the mechanism of locking device and to make its detailed reconstruction. On the basis of considered analogies, it was concluded that the lock, in its design features, is similar to the locks popular in Eastern Europe and Siberia in the 15th – 18th centuries, differing from the latter by a special latch device. The difference in the latch device led to conclusion that the locks were made by local blacksmiths. Multiple findings of parts of interior locks in Isker show that in everyday life citizens used trunks fitted with locks of two different design schemes. This made it possible to supplement the existing classification by emphasizing two variants of locks, which were previously considered within the framework of a single type of interior all-metal locks.