Wyniki wyszukiwania dla: reliability analysis
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Dependable Integration of Medical Image Recognition Components
PublikacjaComputer driven medical image recognition may support medical doctors in the diagnosis process, but requires high dependability considering potential consequences of incorrect results. The paper presentsa system that improves dependability of medical image recognition by integration of results from redundant components. The components implement alternative recognition algorithms of diseases in thefield of gastrointestinal endoscopy....
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Low-Cost Surrogate Modeling of Miniaturized Microwave Components Using Nested Kriging
PublikacjaIn the paper, a recently reported nested kriging methodology is employed for modeling of miniaturized microwave components. The approach is based on identifying the parameter space region that contains high-quality designs, and, subsequently, rendering the surrogate in this subset. The results obtained for a miniaturized unequal-power-split rat-race coupler and a compact three-section impedance transformer demonstrate reliability...
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Procedure based functional safety and information security management of industrial automation and control systems on example of the oil port installations
PublikacjaThe approach addresses selected technical and organization aspects of risk mitigation in the oil port installations with regard to functional safety and security requirements specified in standards IEC 61508, IEC 61511 and IEC 62443. The procedure for functional safety management includes the hazard identification, risk analysis and assessment, specification of overall safety requirements and definition of...
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Functional safety with cybersecurity for the control and protection systems on example of the oil port infrastructure
PublikacjaSafety and cybersecurity aspects consist of two different group of functional requirements for the industrial control and protection systems in the oil port installation. It is the main reason why the analyses of safety and cybersecurity shouldn’t be integrated directly. These article presented some important issues of the functional safety analysis with regard to cybersecurity aspects in the oil seaport infrastructure. The proposed...
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An Enhanced Reduced Basis Method for Wideband Finite Element Method Simulations
PublikacjaIn this paper, we present a novel strategy for selecting expansion points in the reduced basis method. A single computation of the error estimator is used to select a few expansion points in the multi-parameter space simultaneously. The number of selected points is determined adaptively, based on the accuracy of the current reduced model. The reliability and efficiency of this proposed approach are illustrated by numerical tests...
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Improvement of subsoil and railway substructure by explosive means.
PublikacjaQuick and effective method of subsoil and railway substructure improvement by using explosive means (registered trade name: microblasting) allowes design and construct railways on lowered bearing soils (i.e. wetlands, marshlands, industrial by-products, municipal wastes, degraded antropogenic embankments). It is usefull and recommendable technology to construct new railways, modernization or maintenance and repairing of old ones...
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Harmony Search to Self-Configuration of Fault-Tolerant Grids for Big Data
PublikacjaIn this paper, harmony search algorithms have been proposed to self-configuration of fault-tolerant grids for big data processing. Some tasks related to big data processing have been considered. Moreover, two criteria have been applied to evaluate quality of grids. The first criterion is a probability that all tasks meet their deadlines and the second one is grid reliability. Furthermore, some intelligent agents based on harmony...
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Methods of navigation in the mobile application supporting movement of the blind
PublikacjaThis paper presents conclusions from the last development phase of the “Voice Maps” project. Authors specify newly found available options for navigation in affordable system for the blind with all their related aspects. System uses dedicated geographical data, built-in smartphone GPS receivers and DGPS external device in order to assist blind users in their everyday travelling. Authors also discuss new methods to improve positioning...
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Fast Design Closure of Compact Microwave Components by Means of Feature-Based Metamodels
PublikacjaPrecise tuning of geometry parameters is an important consideration in the design of modern microwave passive components. It is mandatory due to limitations of theoretical design methods unable to quantify certain phenomena that are important for the operation and performance of the devices (e.g., strong cross-coupling effects in miniaturized layouts). Consequently, the initial designs obtained using analytical or equivalent network...
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Quantitative Assessment of Operation of Ship Main Diesel Engine
PublikacjaOperation of ship propulsion system is associated with realization of definite operational goals. If to elements of the system the operational reliability strategy could be applied, the situation would be very simple as existing conditions would unambiguously determine application of means being on hand. However decision to reject application of the strategy (even if hypothetical) becomes obvious with a view of necessity of ensuring...
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Integrated approach for functional safety and cyber security management in maritime critical infrastructures
PublikacjaThe work is devoted important issues of the management in maritime critical infrastructure of functional safety analysis, in particular the safety integrity level (SIL) verification of safety functions to be implemented within the distributed control and protection systems with regard to cyber security aspects. A method based on quantitative and qualitative information is proposed for the SIL (IEC 61508, 61511) verification with...
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Problems in designing and operating the functional safety solutions of higher integriity levels
PublikacjaThe aim of this article is to identify and discuss some problems that have been encountered in designing and operating the functional safety solutions of higher safety integrity levels (SIL 3 and SIL 4) in the light of analyses outlined in a new version of the international standard IEC 61508:2010. Examples of such solutions are the electric / electronic / programmable electronic systems (E/E/PESs) and the safety instrumented systems...
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PROBLEMS OF EXPERIMENTAL DETERMINATION OF COEFFICIENTS OF THE WEAR OF SHIP PIPING SYSTEMS
PublikacjaThe article presents series of considerations relating to experimental evaluation of the reliability of ship piping systems. The aim of this study is to attempt to answer the following questions: What should be the tested element? How to choose the diameter of the tested item? What should be the result of measurements and calculations? How to measure? How to choose the duration of the test? How to choose the sample size and elaborate...
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On Configurability of Distributed Volunteer-Based Computing in the Comcute System
PublikacjaThe chapter proposes additional solutions that can be implemented within the Comcute system to increase its configurability. This refers to configuration of the reliability level in the W and S server layers, static or on-the-fly data partitioning and integration, configuration of the system for processing in the data streaming fashion, extending the system for selection of a project that the client wants to contribute to, ease...
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Simulation of Parallel Applications on Large-scale Distributed Systems
PublikacjaThis chapter has a form of a review article in the field of simulating High-Performance Computing systems. We justify the need for a new versatile simulator considering heterogeneity, energy efficiency and reliability of HPC systems. We sketch the problems that need to be solved by such simulator and rationalize using discrete-event simulation for this purpose. Based on a review of existing discrete-event HPC simulation solutions...
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Study of the Performance of DSSS UAC System Depending on the System Bandwidth and the Spreading Sequence
PublikacjaA signal transmitted in an Underwater Acoustic Communication (UAC) system operating in a shallow-water channel suffers from strong time dispersion due to multipath propagation. This causes the Inter-Symbol Interference (ISI) observed in the received signal, which significantly limits the communication system’s reliability and transmission rate. In such propagation conditions, the Direct-Sequence Spread Spectrum (DSSS) method is...
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Construction of a simulation model of goods delivery in international road transportation taking into account the functioning efficiency of logistics supply chain
PublikacjaThe object of this study is the process of goods delivery in international road transport using various types of logistics chains. The problem being solved is due to the need to develop recommendations for exporters of goods to reformat or design new supply chains during wartime. The expediency of organizing foreign trade operations by the cargo owners' own forces or with the involvement of enterprises providing logistics consulting...
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Distribution Transformer with Multi-Zone Voltage Regulation for Smart Grid System Application
PublikacjaThe article presents four concepts of the multi-zone voltage regulation (MZVR) system. It is a combination of a distribution transformer with an on-load tap-changer, for step voltage regulation, and a power electronic converter, dimensioned for a fraction of MZVR power, realizing continuous voltage regulation, supplemented by a special switch, the so-called bypass. This allows voltage regulation at high resolution, wide range and...
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The Impact of Micro-Sources on Voltage Distortions in a Power Grid
PublikacjaThe increase in the number of photovoltaic (PV) systems integrated with low voltage (LV) grids has led to a great need to analyse the impact of these systems on the quality of electricity and the reliability of its supply. This paper presents and compares the energy quality requirements imposed by various countries on photovoltaic plants. Then, based on real object tests and simulation in DIgSILENT PowerFactory, the impact has...
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Investigation of RTS Noise in Reverse Polarized Silicon Carbide Schottky Diodes
PublikacjaOne of the method of electronic device quality and reliability evaluation is observation of its inherent noise. The RTS phenomena usually indicates the presence of large defects in the structure of the material of the device, therefore it can be treated as an indicator of technology quality. In the paper authors present results of RTS investigations in reverse polarized Silicon Carbide Schottky diodes. Devices being studied are...
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Transmission Quality Measurements in DAB+ Broadcast System
PublikacjaIn the age of digital media, delivering broadcast content to customers at an acceptable level of quality is one of the most challenging tasks. The most important factor is the efficient use of available resources, including bandwidth. An appropriate way of managing the digital multiplex is essential for both the economic and technical issues. In this paper we describe transmission quality measurements in the DAB+ broadcast system....
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Multiple-Input Multiple-Output Technique for Underwater Acoustic Communication System
PublikacjaThe performance of an underwater acoustic communication (UAC) system is limited due to tough propagation conditions in the UAC channel. Multiple-Input Multiple-Output (MIMO) technique can improve the reliability of the data transmission system, increase its speed, increase its range, and reduce the energy consumption. The paper presents an implementation method of MIMO technique in the form of coding the Space-Time Block Code and...
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Procedure based proactive functional safety management for the risk mitigation of hazardous events in the oil port installations including insurance aspects
PublikacjaThis article addresses selected technical and organization aspects of risk mitigation in the oil port installations with regard to functional safety requirements specified in standards IEC 61508 and IEC 61511. The procedure for functional safety management includes the hazard identification, risk analysis and assessment, specification of overall safety requirements and definition of safety functions. Based on risk assessment results...
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Towards a process based management system for oil port infrastructure in context of insurance
PublikacjaThis article addresses selected methodological aspects of a process based management system based on analysis of hazards and threats and risk evaluation for an oil port infrastructure in context of insurance. The oil port terminal is regarded as important system of the critical infrastructure that require careful system oriented approach to deal with integrated aspects of environmental, safety and security management to reduce...
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Validation of dynamic electrochemical impedance spectrograms using autocorrelation function
PublikacjaValidation of impedance data is essential for checking the reliability of experimental data. Kramers – Kronig transformation is used to verify data obtained from classical Electrochemical Impedance Spectroscopy (EIS) measurements. Data obtained from Dynamic Electrochemical Impedance Spectroscopy (DEIS) could be validated in the same way, but in this case, there is no information about internal consistency between every single spectrum...
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Underwater acoustic communication system using broadband signal with hyperbolically modulated frequency
PublikacjaThe implementation of reliable acoustic underwater communication in shallow waters is a scientific and engineering challenge, mainly due to the permanent occurrence of the multipath phenomenon. The article presents the concept of a transmission system using a broadband signal with hyperbolically modulated frequency (HFM) to transmit data symbols and synchronize data frames. The simulation tests were carried out in channels with...
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Low-energy positron scattering from gas-phase uracil
PublikacjaQuantum scattering calculations are presented for the interaction of low energy positrons with the uracil molecule, an important component of biological systems. The rotational elastic and inelastic cross sections and vibrational inelastic cross sections are reported and compared with existing experiments, indicating a general trend of the cross sections different from the experimental findings and in line with what should be expected...
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Improved-Efficacy Optimization of Compact Microwave Passives by Means of Frequency-Related Regularization
PublikacjaElectromagnetic (EM)-driven optimization is an important part of microwave design, especially for miniaturized components where the cross-coupling effects in tightly arranged layouts make traditional (e.g., equivalent network) representations grossly inaccurate. Efficient parameter tuning requires reasonably good initial designs, which are difficult to be rendered for newly developed structures or when re-design for different operating...
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Secured wired BPL voice transmission system
PublikacjaDesigning a secured voice transmission system is not a trivial task. Wired media, thanks to their reliability and resistance to mechanical damage, seem an ideal solution. The BPL (Broadband over Power Line) cable is resistant to electricity stoppage and partial damage of phase conductors, ensuring continuity of transmission in case of an emergency. It seems an appropriate tool for delivering critical data, mostly clear and understandable...
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Application of wireless communication to small WECS with induction generator
PublikacjaWind energy conversion systems (WECS) seem to be self-evident elements of the future smart grids. Among many generator types the squirrel cage induction generator (SCIG) characterizes robustness and low cost. A full-scale power converter can perform smooth grid connection over wide speed range of multiple-stage geared SCIG. Increasing number of sensors can improve the WECS control and diagnostics but increasing number of thin wires...
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Safety-based approach in multifunctional building design
PublikacjaABSTRACT: The modern trend in design of the public buildings is to create multifunctional environments in one building, hosting a variety of functions. Multifunctional buildings entertain large number of visitors. The complexity and vulnerability of this type of public space are the main reasons to use within their design process the performance based approach including the recognition of hazards. Safety and reliability approach...
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LLA : A New Anypath Routing Scheme Providing Long Path Lifetime in VANETs
PublikacjaVehicular ad-hoc networks (VANETs) are a promising solution to improve the road traffic safety, reduce the environmental pollution, or simply provide the on-board infotainment services. However, these actions are often not possible due to high mobility of vehicles causing frequent failures of VANET links. In this paper, we focus on anypath routing to improve the reliability of multihop VANET communications. In particular, the paper...
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A Concept of Modeling and Optimization of Applications in Large Scale Systems
PublikacjaThe chapter presents the idea that includes modeling and subsequent optimization of application execution on large scale parallel and distributed systems. The model considers performance, reliability and power consumption. It should allow easy modeling of various classes of applications while reflecting key parameters of both the applications and two classes of target systems: clusters and volunteer based systems. The chapter presents...
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Smart heating system for home extending utilization of renewable energy sources
PublikacjaIn the paper a modern approach to smart home heating is presented. Proposed solution utilizes at least two low-polluting energy source technologies. The main idea is to connect well known ecological energy sources in a way that they can support each other and minimize risks of failure when using single system or even both of them but managed in separate way. Considered energy technologies, used separatelly, have disadvan-tages,...
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Wake-Up Receiver for Underwater Acoustic Communication Using in Shallow Water
PublikacjaA data frame transmitted over the underwater acoustic channel usually begins with a preamble. Therefore, underwater communication systems have a dedicated receiver that constantly listens to the preamble signals. A receiver that is to work effectively in shallow waters must have solutions that effectively reduce the impact of the permanently occurring multipath propagation. The article presents a solution based on complementary...
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Automatic road traffic safety management system in urban areas
PublikacjaTraffic incidents and accidents contribute to decreasing levels of transport system reliability and safety. Traffic management and emergency systems on the road, using, among others, automatic detection, video surveillance, communication technologies and institutional solutions improve the organization of the work of various departments involved in traffic and safety management. Automation of incident management helps to reduce...
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Problems of Active Dynamic Thermography Measurement Standardization in Medicine
PublikacjaReliability of thermographic diagnostics in medicine is an important practical problem. In the field of static thermography, a great deal of effort has been made to define the conditions for thermographic measurements, which is now the golden standard for such research. In recent years, there are more and more reports on dynamic tests with external stimulation, such as Active Dynamic Thermography, Thermographic Signal Reconstruction...
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Harmony Search for Self-configuration of Fault–Tolerant and Intelligent Grids
PublikacjaIn this paper, harmony search algorithms have been proposed to self-configuration of fault-tolerant grids for big data processing. Self-configuration of computer grids lies in the fact that new computer nodes are automatically configured by software agents and then integrated into the grid. A base node works due to several configuration parameters that define some aspects of data communications and energy power consumption. We...
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Risk criteria for sea-going ships arising from the operation of the main engines' crankshaft - conecting rod - piston systems
PublikacjaIn the article the risk criterion for sea-going ships arising from the operation of the main engines' crankshaft - connecting rod - piston systems is proposed. These criterion is based on the procedures recommended in the Formal Safety Assessment method developed under the auspices of International Maritime Organization (IMO). First of all the collective risk criterion for ship has been proposed. In the next step, the share of...
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Prototype of a low-cost luxmeter with wide measuring range designed for railway stations dynamic lighting systems
PublikacjaThe paper presents the development of a low-cost luxmeter designed for usage in automatic applications for continual (long-term) measurement of illuminance. The measured information is used to adjust the level of lighting systems of artificial lighting on railways (platforms, marshalling yard, tracks etc.). The reason of this measuring device is a requirement for massive deployment of dimmable lighting systems for railways, in...
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Reliable Document-Centric Processing in Loosely Coupled Email-Based Systems
PublikacjaEmail is a simple way to exchange digital documents of any kind. The Mobile INteractive Document architecture (MIND) enables self-coordination and self-steering of document agent systems based on commonly available email services. In this paper, a mechanism for providing integrity and reliability of such an email based agent system is proposed to cope with message soft or hard bounces, user interrupts, and other unexpected events....
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Zarządzanie bezpieczeństwem w złożonych obiektach i instalacjach krytycznych
PublikacjaW rozdziale scharakteryzowano wybrane metody wspomagające zarządzanie bezpieczeństwem w systemach technicznych, w tym metodę RCM (reliability-centered maintenance) polegającą na proaktywnej obsłudze, której celem jest nie dopuszczać lub przynajmniej ograniczać skutki potencjalnych uszkodzeń oraz metodę RBM (risk-based maintanance) i procedurę RIMAP (risk-based inspection and maintanance procedures) stosowaną w zarządzaniu bezpieczeństwem...
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Integrating heterogeneous systems with high-dependability requirements by means of web services
PublikacjaWeb services are commonly used on boundaries of heterogeneous components in Service Oriented Architecture (SOA) as they provide a universal communication channel not bound to any particular programming language or run-time platform. This paper describes how web services can be used to integrate heterogeneous systems which serve purposes requiring high dependability, reliability and availability. Examples of such systems include...
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Size Reduction of Microwave Couplers by EM-Driven Optimization
PublikacjaThis work addresses simulation-driven design optimization of compact microwave couplers that explicitly aims at circuit footprint area reduction. The penalty function approach allows us to minimize the area of the circuit while ensuring a proper power division between the output ports and providing a sufficient bandwidth with respect to return loss and isolation around the operating frequency. Computational cost of the optimization...
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Wireless Networks as an Infrastructure for Mission-Critical Business Applications
PublikacjaDespite the dynamic growth of wireless network systems, their pres-ence in business-support infrastructure has been limited. In the article we provide an overview of generic corporate network architecture and examine usefulness of available wireless network solutions in such systems. Following this overview we analyze new wireless network architecture which currently undergoes standardization process - wireless mesh. It can result...
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Multilevel inverter neutral-point voltage sensor diagnostic based on the Extended Kalman Filter
PublikacjaA new algorithm for neutral point voltage imbalance estimation in DC link of the three-level (3L) neutral point clamped (NPC) voltage source inverter (VSI) is proposed. Application of the proposed algorithm does not require any additional sensors. The unbalanced voltage calculation is based on the information derived from the inverter output measured currents and from the knowledge of the load model parameters. In order to estimate...
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A Measurement-Based Approach for Speed Control of Induction Machines
PublikacjaThis paper presents an approach to design a measurement-based controller for induction machines. The proposed control approach is motivated by the fact that developing an appropriate mechanical model of such induction machines is a challenging task. Since our proposed control methodology is only on the basis of measured data, the controller design does not require any information about the model of the mechanical part. The control...
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HYDROSTATIC THRUST BEARING WITH REDUCED POWER LOSSES
PublikacjaIn many cases in rotating machinery, axial load is carried by tilting pad thrust bearings which have been developed since the beginning of 20th century. For high reliability and simplicity, most commonly the bearings are bath lubricated. In the times of sustainable development, however, minimization of friction losses becomes an important criterion for machinery assessment, and a strategic goal of their development. Performed calculations,...
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Efficient Calibration of Cost-Efficient Particulate Matter Sensors Using Machine Learning and Time-Series Alignment
PublikacjaAtmospheric particulate matter (PM) poses a significant threat to human health, infiltrating the lungs and brain and leading to severe issues such as heart and lung diseases, cancer, and premature death. The main sources of PM pollution are vehicular and industrial emissions, construction and agricultural activities, and natural phenomena such as wildfires. Research underscores the absence of a safe threshold for particulate exposure,...
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DUABI - Business Intelligence Architecture for Dual Perspective Analytics
PublikacjaA significant expansion of Big Data and NoSQL databases made it necessary to develop new architectures for Business Intelligence systems based on data organized in a non-relational way. There are many novel solutions combining Big Data technologies with Data Warehousing. However, the proposed solutions are often not sufficient enough to meet the increasing business demands, such as low data latency while still maintaining high...