Problem Of Data Synchronization Research Articles

Optimal Design of Data Acquisition System for Fault Diagnosis of Hydraulic Machinery

Abstract Fault diagnosis of hydraulic machinery has high requirements on the synchronization of monitoring data and the anti-interference of monitoring equipment. The performance and data quality of the existing operation monitoring equipment of the unit cannot meet the requirements. At the same time, due to the variety of sensors and the different wiring methods of different types of sensors, the preparation work such as wiring of data acquisition equipment in the test is complicated. This paper analyzes the application requirements of fault diagnosis data and the problems existing in the conventional data collection process. A data collection solution specified for diagnosis of hydraulic machinery, which better solves the problem of data synchronization, is designed. The new designed system has high sampling accuracy and anti-interference characteristics, as well as the advantages of strong capability and simple equipment deployment. The proposed system has been applied in multiple power stations, pumping stations and pump test platforms. The relevant functions have been effectively verified.

Pilot protection method of half-wavelength AC transmission lines based on random matrix theory

The fault characteristics of ultra-high voltage (UHV) half-wavelength (HWL) transmission lines exhibit significant differences from those of conventional transmission lines, which renders the conventional relay protection method unsuitable for ensuring the protection of HWL. To solve this problem, a pilot protection method of HWTL based on random matrix theory was proposed. Voltage and current fault components obtained at the protection installation on both sides of the line were used as the input of the random matrix to form the singular value equivalent matrix, and the eigenvalues of the random matrix at both ends were calculated. The faults inside and outside the area were determined according to the distribution of the eigenvalues in the circular plane area. The protection scheme avoids the data synchronization problem at both ends of the line. Real time digital simulation system (RTDS) simulation revealed that the proposed protection method can protect the full length of the line, is suitable for various fault types and fault conditions, and exhibits excellent resistance to transition resistance.

TVSR‐OR: Tile‐based 360‐degree video streaming over real time streaming protocol with optimized read

AbstractAmong video application use cases and scenarios, 360‐degree video applications gradually become significant. The state‐of‐the‐art solution for 360‐degree video streaming is field of view (FOV) transmission, whose quality of experience highly depends on system processing speed and network latency. The extant 360‐degree video FOV transmission profiles transmit multiple video tile streams to the client over either Hypertext Transfer Protocol (HTTP) or Real Time Streaming Protocol (RTSP). The client needs to merge all different tile streams after receiving them, which may cause a data synchronization problem of waiting for each tile to sync in the presents of packet losses. Therefore, we propose a system to select and merge tile streams on the Content Delivery Network (CDN) server and transmit the merged stream to the client. During the streaming service, the client can send a viewport switch request through RTSP signaling, and the server will subsequently deliver the merged video stream of the new viewport to the client after receiving the request. Also, to reduce disk overhead from parallel reads, we optimize the system with a file prefetch strategy to reduce unorganized, random, and parallel reads into serialized reads of large data trunks. We evaluate its performance through user request simulation experiments. Compared with the extant transmission solution, our system provides slightly lower video transmission latency, lower central processing unit (CPU) usage, and better disk performance under heavy service load.

The Implementation of the Family Hope Program (PKH) During the Pandemic in Batu City

The purpose of the study was to find out that the Family Hope Program was carried out according to its purpose, namely eradicating poverty during a pandemic. The problem is focused on the implementation of the Family Hope Program (PKH) during the pandemic which has an impact on increasing poverty rates. To approach the problem. The research uses the theory of Merilee S. Grindle to build a network that allows public policy goals to be realized as a result of government activities. The research was carried out qualitatively with a descriptive approach to solving problems. The results showed that the Family Hope Program during the pandemic increased, but did not reach all affected families due to data synchronization problems. This finding indicates that the implementation of the Family Hope Program run by the Batu City Social Service is not going well.

Digital Twin Empowered Heterogeneous Network Selection in Vehicular Networks With Knowledge Transfer

Digital twin (DT) has emerged as a promising technology to create digital replicas of physical vehicles to facilitate driving in Internet of Vehicles (IoV). However, due to the uneven distribution of vehicles in the networks and the dynamics of heterogeneous wireless links, how to optimize the connection along the vehicle's trip between the vehicle and its DT to achieve the lowest cost ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i.e.</i> , delay and energy consumption) is a fundamental challenge. In this paper, we investigate the joint network selection and power level allocation problem in the data synchronization issue between vehicles and DTs in the heterogeneous access networks. In order to better use the information shared by DT to facilitate the data synchronization process, we propose a learning-based heterogeneous network selection scheme in DT empowered IoV. First, we consider the data divided into blocks and model the data synchronization problem as a Markov Decision Process (MDP) to minimize the long-term cost in terms of the delay and energy consumption. Based on the information obtained from the digital twin communications, we develop an actor-critic learning approach to solve the MDP problem with the block-level state method, and obtain the optimal network selection strategy for the vehicles. In addition, we explore the capability of digital twins by applying transfer learning. The vehicles are divided into two types, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i.e.</i> , learner vehicles and expert vehicles, so that the knowledge can be transferred from the expert vehicles to the learner vehicles to effectively improve the learning efficiency and decrease the data synchronization latency. Extensive experiments demonstrate that our scheme can effectively find the optimal network selection policy and achieve the fast convergence and better performance compared with existing related approaches.

Research on Multiterminal Current Differential Protection Criterion With High Sensitivity and Synchronization Error Tolerance Capability

As the most suitable main protection for multiterminal transmission lines represented by T-connections, current differential protection exhibits great performance due to its high reliability and sensitivity. However, considering multiple substations geographically, there are more severe problems of data synchronization for multiterminal current differential protection than for double-terminal types based on a typical channel. To solve the aforementioned problems, the operating characteristics of multiterminal line differential protection under different synchronization errors on the ρ plane are first analyzed. Based on the influence of synchronization errors on the magnitude and phase of the protection operating value, a design method for the restraint current of multiterminal current differential protection is proposed. To achieve the sensitivity of a high resistance internal fault, as well as the tolerance capability of the data phase-shift error, double restraint coefficients are introduced to optimize the shape and area of the restraint region. Subsequently, the setting method is inferred, which can be used as a reference for an engineering application and the promotion of multiterminal line differential protection. Finally, the simulation results indicate that the proposed method can significantly improve the criterion security for the case of additional data synchronization errors while maintaining the sensitivity of the internal fault.

ЗАСТОСУВАННЯ МЕТОДУ БЕЗГРАДІЕНТНОЇ ОПТИМІЗАЦІЇ ПРИ СИНХРОНІЗАЦІЇ ДАНИХ МОНІТОРИНГУ РОБОЧОГО ПРОЦЕСУ ДВИГУНІВ ВНУТРІШНЬОГО ЗГОРЯННЯ

The possibility of using the gradientless n-parametric minimization of Powell'64 in the tasks of monitoring the workflow of ship diesel engines is considered. Monitoring the workflow of ship diesel engines includes the problem of cyclical analysis of indicator diagrams in the working cylinders. The problem of data synchronization should be solved - the transfer of pressure charts from the time function to an angle of crankshaft rotation function. It is shown that the hardware detection of the crankshaft rotation phases applying pick-up sensors configured in statics will have errors when the engine is under load. The synchronization task should be solved with the help of an algorithm by analyzing the indicator diagram in real time. Examples of the search for a global minimum of the Rosenbrock test function are given. Applying the Powell'64 method, least square method functionals are minimized in problems of synchronization and modeling of compression-expansion curves in the working cylinder. Cases of data synchronization calculation for low-speed two-stroke and mid-envelope four-stroke marine diesel engines are shown. Taking into account the assumptions made in practice, it was shown that at the point of maximum pressure growth rate on the compression curve, the cylinder volume above the piston can be calculated applying the known geometric dimensions of the cylinder and the P and dP/dφ values obtained from the indicator diagram. The next step is to calculate the first approximation of the position of the top dead center of the piston, and the application of the digital filters is necessary. Finally, the synchronization problem is solved on the basis of the equation dP/dφ = 0, compiled for the section from the start of compression to the start of combustion in the cylinder. The selection of boundary conditions for modeling is shown. The advantage of applying the Powell'64 method is its high efficiency for quadratic functionals. Unlike gradient methods, the Powell'64 method does not require the calculation of derivatives and is universal to minimize complex nonlinear functionals of a general form. The original author's algorithm for data synchronization by analyzing indicator diagrams, which applies the Powell'64 method, is used in the latest versions of the D4.0HT marine diesel engine monitoring systems

3-D Markerless Tracking of Human Gait by Geometric Trilateration of Multiple Kinects

In this paper, we develop an integrated markerless gait tracking system with three Kinect v2 sensors. A geometric principle-based trilateration method is proposed for optimizing the accuracy of the measured gait data. To tackle the data synchronization problem among the Kinect clients and the server, a synchronization mechanism based on NTP (Network Time Protocol) is designed for synchronizing the server and Kinect clients' clocks. Furthermore, a time schedule is designed for timing each Kinect client's data transmission. In the experiment, participants are asked to perform a 60 s walk while the proposed tracking system obtains the participant's gait data. Six joints (including left hip, right hip, left knee, right knee, left ankle and right ankle) of the participants are tracked where the obtained gait data are described as 6000 {movements} of joint positions (1000 {movements} for each joint). The results show that the trilateration tracking result by the three Kinect sensors has a much higher accuracy compared with the accuracy measured by a single Kinect sensor. Within a randomly sampled time period (67.726 s in the experiment), 98.37% of the frames generated by the gait tracking system have timing errors less than 1 ms, which is much better than the default NTP service embedded in the Windows 8.1 operating system. The accuracy of the proposed system is quantitatively evaluated and verified by a comparison with a commercial medical system (Delsys Trigno Smart Sensor System).

Method for Heterogeneous Identification Peer-to-peer Resolution Technology of IoT Based on Block Chain

In IoT-related technologies, because of the lack of a unified standard, there are various identity types and coexist of many resolution services which cannot interconnect with each other, prone to single-point failure, single point of control and so on, cannot make full use of IoT resources, limiting the rapid development of the IoT. In order to solve the above problems, many scholars put forward solutions of decomposing the single resolution service into multi-root, and design new identity resolution to solve the heterogeneous identification. However, these solutions ignored the fundamental problem of data synchronization between nodes due to architecture change. This paper explores a peer-to-peer resolution service architecture based on block chain, makes full use of its consensus mechanism and trust feature to ensure the consistency of Common Mapping Table, and design the heterogeneous identity peer-to-peer resolution service. At last, through the experimental data of consistency conflicting indicators, the peer-to-peer resolution service based on block chain can effectively solve the problem of data consistency in distributed architecture, guarantee the correctness of data.

Data Synchronization Model for Heterogeneous Mobile Databases and Server-side Database

Mobile devices, because they can be used to access corporate information anytime anywhere, have recently received considerable attention, and several research efforts have been tailored towards addressing data synchronization problems. However, the solutions are either vendor specific or homogeneous in nature. This paper proposed Heterogeneous Mobile Database Synchronization Model (HMDSM) to enable all mobile databases (regardless of their individual differences) and participate in any data synchronization process. To accomplish this, an experimental approach (exploratory and confirmatory) was employed. Also existing models and algorithms are classified, protracted and applied. All database peculiar information, such as trigger, timestamp and meta-data are eliminated. A listener is added to listen to any operation performed from either side. To prove its performance, the proposed model underwent rigorous experimentation and testing. X2 test was used to analyze the data generated from the experiment. Results show the feasibility of having an approach which can handle database synchronization between heterogeneous mobile databases and the server. The proposed model does not only prove its generic nature to all mobile databases but also reduces the use of mobile resources; thus suitable for mobile devices with low computing power to proficiently process large amount of data. © 2015 The Science and Information (SAI) Organization Limited.

Probabilistic Models and Algorithms for Data Synchronization/Broadcast Via Network Coding

We investigate the problem of data synchronization in which a sender has a set of packets to be distributed to all the receivers via a broadcast channel. Initially, each receiver has some fraction of the packets. At each time slot, the sender might broadcast a packet to all the receivers. The goal is to find a broadcast scheme that minimizes the number of time slots until all the receivers successfully obtain all the packets. We propose two probabilistic models on how the initial fractions of packets at receivers are distributed. These models arise naturally in many large-scale systems, such as peer-to-peer networks, data centers, and distributed storage systems. Based on these models, we establish probabilistic bounds and asymptotic results on the minimum number of time slots to successfully transmit all the packets to all the receivers. Next, we propose and analyze a number of random network coding algorithms for finding the approximately optimal solution. Theoretical analysis and simulations are provided to verify the probabilistic bounds and the proposed algorithms.

Research on Synchronization Model Based on Parallel Compression

In recent years, with the rapid development of mobile communication technology, intelligent mobile terminal tendency is increasingly popular. People are stepping into the era of mobile networks. Information systems created for enterprise or individual gradually rely on mobile networks and mobile devices. Because the mobile network is often interrupted, data synchronization working on the mobile network is very difficult. We put forward a model of the data synchronization in mobile network. JSON and data compression with parallel processing are introduced into the model. Thus, the model has high efficiency. It was applied to a company's Warehouse Management System and solved the problem of data synchronization preferably.

Ulteo OVD as a cloud-based learning environment

Recently, there has been a rapid informatization of the learning process. Information and communication network services, such as Web 2.0 services, distance learning courses, communication on specific scientific topics in chat rooms and forums, webinars, and video conferences are actively used.The development of technology has led to the fact that one user has several devices PC classroom, PC home, laptop, netbook, smartphone. Mobile learning requires access to learning materials from the home network, the institution's local network, the library, Internet cafes, and other locations. This leads to data synchronization problems and many local copies of files on different devices.

A New File Updating Discovery Algorithm Supporting Semantic Synchronization

Updates discovery is the key problem of data synchronization; it has been used to generate updates operations. The traditional algorithms ignore the modify semanteme, cause the updates operations increased. A new file updating discovery algorithm that supports semantic synchronization is proposed in this paper. The algorithm takes advantage of semantic info, which preserved in file system journal, to accurately recognize users originally modify intents. We take the NTFS file system as an example to realize and test the new algorithm. By comparison, the algorithm effectively reduces synchronization requests. Experiments show that, the algorithm cans timely respond to users’ modification and support massive file changes that occurred in short time. The algorithm is designed based on the basic features of file system journal, and can be applied to other file systems.

Integrating COTS Software into Systems through Instrumentation and Reasoning

Commercial-off-the-shelf (COTS) software tends to be cheap, reliable, and functionally powerful due to its large user base. It has thus become highly desirable to incorporate COTS software into software products (systems) as it can significantly reduce development cost and effort, while maintaining overall software product quality and increasing product acceptance. However, incorporating COTS software into software products introduces new complexities that developers are currently ill equipped to handle. Most significantly, while COTS software frequently contains programmatic interfaces that allow other software components to obtain services from them on a direct call basis, they usually lack the ability to initiate interactions with other components. This often leads to problems of state and/or data inconsistency. This paper presents a framework for integrating COTS software as proactive components within a software system that maintain the consistency of the state and data they share with other components. The framework utilizes a combination of low-level instrumentation and high-level reasoning to expose the relevant internal activities within a COTS component required to initiate the communication needed to maintain consistency with the other components with which it shares state and data. We will illustrate these capabilities through the integration of IBM's Rational Rose into a design suite and demonstrate how our framework solves the complex data synchronization problems that arise from this integration.