Research and Implementation of Aurora Protocol NFC System

The aircraft industry, as a whole, has been deeply concerned with improving the aerodynamic efficiency of current and future flight vehicles, particularly in the commercial and military markets. However, of particular interest to the field of aerodynamics is the elusive concept of a workable flow control mechanism. Effective flow control is a concept which if properly applied can increase aerodynamic efficiency. Various concepts and ideas to obtain successful flow control have been studied in an attempt to reap these rewards. Some examples include boundary layer blowing (steady and periodic), suction, and compliant walls for laminar flow control. The overall goal of flow control is to increase performance by increasing lift, reducing drag, and delaying or eliminating leading edge separation. The specific objectives of flow control are to (1) delay or eliminate flow separation, (2) delay boundary layer transition, and (3) and reduce skin friction drag. The purpose of this research is to investigate dynamic roughness as a novel method of flow control technology for external boundary layer flows. As opposed to standard surface roughness, dynamic roughness incorporates small time dependent perturbations to the surface of the airfoil. These surface perturbations are actual humps and/or ridges on the surface of the airfoil that are on the scale of the laminar boundary, and oscillate with an unsteady motion. Research has shown that this can provide a means to modify the instantaneous and mean velocity profile near the wall and favorably control the existing state of the boundary layer. Several flow control parameters were studied including dynamic roughness frequency, amplitude, and geometry. The results of this study have shown, both numerically and experimentally, that dynamic roughness can provide an effective means for eliminating both a short and long laminar separation bubble and possibly prove a viable alternative in effective flow control, hence reaping some of the rewards of an effective flow control system.

Network-on-Chip is an alternative paradigm to improve communication bandwidth compared to bus-based communication, and its performance degrades if there is no effective flow control method., Heterogeneous networks with very slow processing elements (PEs) especially need a flow control mechanism at the transport layer to prevent too much packet injection. In this paper, a credit-based end-to-end flow control (CB-EEFC) is implemented to control the network latency at high traffic loads. Simulation in mesh networks shows improved performance in latency and 0.5% up to 3% saturated throughput decrease with the CB-EEFC method. RTL gate level simulation shows that a network interface using CB-EEFC brings about a 31.4% increase in complexity compared to a network interface without CB-EEFC.

In this study, passive and active flow control methods were used together to manipulate the flow around a circular cylinder. The experiments were conducted in a wind tunnel for the Reynolds number range of 4000 and 10000 based on the diameter of the circular cylinder (D). A splitter plate was used as passive flow control device and its length was chosen to be about 3.75D. Plasma actuators were placed on the circular cylinder at a position of ±90° as an active flow control device. Combining the active and passive flow control methods, a greater reduction of the drag coefficient was achieved compared to that of the cases when using these methods separately. For Reynolds numbers of 5000 and 10000, the hybrid method gives a reduction in drag of 48% and 45%, respectively. The velocity measurements were carried out by using the hot-wire anemometry and velocity profiles were obtained in the wake region. The flow was visualized by using a smoke wire method. The results revealed that the wake region of the circular cylinder with plasma actuator and splitter plate has a narrower width than the plain cylinder and with splitter plate. Also, it can be seen from spectral analysis that the vortex shedding frequency was suppressed significantly by usage of the hybrid flow control method was used.

The problem of flow control for little LEO satellite communication systems is studied. In these systems the satellites functions as a bent pipe transponder for messaging between small terminals (tags) and a control and data acquisition (CDA) Earth station. A novel scheme for averting traffic overflow on the in-bound channel (from tag to CDA), which we call based multiple access (DBMA), is introduced. In DBMA, the CDA specifies a subset of the visibility footprint as a region of eligibility (ROE). Only tags located in the ROE are permitted to transmit. By varying the area and location of the ROE, effective flow control is achieved on the inbound channel. The ROEs are specified in terms of parameters of the Doppler S-curve observed at tags on the outbound channel. The effectiveness and elegance of DBMA protocol are illustrated through computer simulations.

: Acoustic communications provide a viable means for underwater networking. However, extreme propagation delays, limited bandwidth, and half duplex communications, with its inherent use of delay inducing collision avoidance media access and flow control, severely limit the throughput and power of such networks. While full duplex communications eliminate access coordination and enable more effective flow control, they impact transmission time and may lead to wasted channel capacity. The authors hold that, by combining demand assigned multiple access techniques with bandwidth on demand allocations, the cost of full duplex, in terms of latency, can be significantly reduced. This paper makes two contributions. First, it formally evaluates the limitations imposed on delay-constrained networks by adherence to stop-and-wait methods. Second, it demonstrates by simulation the potential to reduce message latency by inverse multiplexing, using the aforementioned techniques, for delay-challenged networks incorporating full duplex communications. These levels of latency improvement, observed through simulation, provide a lower bound for performance in delay challenged networks that employ bandwidth-on-demand and sliding-window techniques under similar traffic load parameters.

We propose a scheme to schedule the transmission of data center traffic to guarantee a transmission rate for long flows without affecting the rapid transmission required by short flows. We call the proposed scheme Deadline-Aware Queue (DAQ). The traffic of a data center can be broadly classified into long and short flows, where the terms long and short refer to the amount of data to be transmitted. In a data center, the long flows require modest transmission rates to keep maintenance, data updates, and functional operation. Short flows require either fast service or be serviced within a tight deadline. Satisfaction of both classes of bandwidth demands is needed. DAQ uses per-class queues at supporting switches, keeps minimum flow state information, and uses a simple but effective flow control. The credit-based flow control, employed between switch and data sources, ensures lossless transmissions. We study the performance of DAQ and compare it to those of other existing schemes. The results show that the proposed scheme improves the achievable throughput for long flows up to 37% and the application throughput for short flows up to 33% when compared to other schemes. DAQ guarantees a minimum throughput for long flows despite the presence of heavy loads of short flows.

The objective of our paper is to demonstrate the use of spectral/hp element technology in unravelling global flow instability mechanisms. Understanding these mechanisms is central to devising flow control approaches based on theoretically-founded physical principles. Global instability theory is concerned with prediction and control of linear and nonlinear disturbances developing in flows that are inhomogeneous in more than one spatial direction. As such, this theory encompasses the classic analysis of Tollmien which is valid for simple geometries of academic interest (e.g. a flat-plate) and therefore broadens the scope of this well-established but simplified methodology to include realistic problems encountered in aeronautical engineering. Compared with a direct numerical simulation approach, global instability theory can be used to explore efficiently far wider parameters ranges and deliver physical information to be used as handle for effective flow control.

This paper presents a new structure of DRAM, using two-transistor cell. The most important advantages of this structure are: a) High speed read, write and refresh operation b) low data access latency c) low power consumption compared to other structures d) each write/refresh operation can be carried out just in one cycle and e) no need to special process and compatible with standard digital process.

For the shortcomings of traditional data communication electronic mode and bus interface, optical fiber communication electronic technology and compact peripheral component interconnect (CPCI) bus interface mode with industry standard are adopted to design a kind of optical fiber communication electronic data transmission mode. The optical fiber communication electronic board based on CPCI bus constitutes a novel optical fiber communication electronic system. In the process of hardware design, the small form-factor pluggable (SFP) transceiver module is used to convert the photoelectric signal and complete the transmission of optical fiber data. Regarding the existence of differential signal in high-speed serial circuit of electronic board, the wiring is reasonably arranged. The hardware test platform of optical fiber communication electronic system is built based on PCI9054 CPCI bus and industrial personal computer (IPC) communication electronics. FPGA with embedded high-speed serial transceiver module is adopted to design the hardware logic function. Binary gray code is used to count. FIFO protocol and Aurora protocol are supported. Protocol IP core is customized to realize the full duplex electronic communication of high-speed data. Considering the loss problem of the system, the grey model GM(1, 1), ARIMA model and Elman neural network are employed as the big data level research scheme, which are combined into the loss prediction model according to a certain proportion. In the experiment, the test of DMA data reading and writing function is designed, and the embedded highspeed transceiver module and optical fiber communication electronic logic function are simulated. The results show that the symbol error rate (SER) is always 0, and the low-pass filtering characteristics of the channel are effectively compensated, which makes the signal quality stabler. Compared with the single big data level research scheme, the combined model has smaller prediction error and higher prediction accuracy.

Phantom: a simple and effective flow control scheme

Modern computing systems are overwhelmingly designed to move data to computation. This design choice goes directly against at least three key trends in computing that cause performance, scalability and energy bottlenecks: (1) data access is a key bottleneck as many important applications are increasingly data-intensive, and memory bandwidth and energy do not scale well, (2) energy consumption is a key limiter in almost all computing platforms, especially server and mobile systems, (3) data movement, especially off-chip to on-chip, is very expensive in terms of bandwidth, energy and latency, much more so than computation. These trends are especially severely-felt in the data-intensive server and energy-constrained mobile systems of today. At the same time, conventional memory technology is facing many technology scaling challenges in terms of reliability, energy, and performance. As a result, memory system architects are open to organizing memory in different ways and making it more intelligent, at the expense of higher cost. The emergence of 3D-stacked memory plus logic, the adoption of error correcting codes inside the latest DRAM chips, proliferation of different main memory standards and chips, specialized for different purposes (e.g., graphics, low-power, high bandwidth, low latency), and the necessity of designing new solutions to serious reliability and security issues, such as the RowHammer phenomenon, are an evidence of this trend. This chapter discusses recent research that aims to practically enable computation close to data, an approach we call processing-in-memory (PIM). PIM places computation mechanisms in or near where the data is stored (i.e., inside the memory chips, in the logic layer of 3D-stacked memory, or in the memory controllers), so that data movement between the computation units and memory is reduced or eliminated. While the general idea of PIM is not new, we discuss motivating trends in applications as well as memory circuits/technology that greatly exacerbate the need for enabling it in modern computing systems. We examine at least two promising new approaches to designing PIM systems to accelerate important data-intensive applications: (1) processing using memory by exploiting analog operational properties of DRAM chips to perform massively-parallel operations in memory, with low-cost changes, (2) processing near memory by exploiting 3D-stacked memory technology design to provide high memory bandwidth and low memory latency to in-memory logic. In both approaches, we describe and tackle relevant cross-layer research, design, and adoption challenges in devices, architecture, systems, and programming models. Our focus is on the development of in-memory processing designs that can be adopted in real computing platforms at low cost. We conclude by discussing work on solving key challenges to the practical adoption of PIM.

PurposeThis study aims to achieve optimum flow separation control for a road vehicle using a reverse flow fan on rear side.Design/methodology/approachA full-length reverse flow fan array (fan’s air speed is 50% of the car’s speed) is attached throughout the width of the vehicle at rear edge corner.FindingsThe reverse flow fan array positioned at rear edge of car pushes the airflow against the car’s rear window. It creates the recirculation region and alters the pressure distribution. This reduces the lift coefficient by 150%, which becomes the downforce and reduces the drag coefficient by 22%. As the car speed increases, fan speed should also be increased for effective flow control.Research limitations/implicationsThis active flow control method for 3D Ahmed car body has been studied computationally at low speed (40 m/s).Practical implicationsThis design increases the downforce, thus gives better cornering speed and stability, and decreases the drag which improves fuel efficiency. It can be used for effective flow control of cars (hatchback/sedan). The findings can be applied to the bluff bodies, road vehicles, UAV and helicopter fuselage for flow separation control.Originality/valueThe fan array is attached on car’s rear side, which blows air against the car’s rear window. It alters the pressure distribution and aerodynamics forces favorably. But the existing high-speed fan used in a sports cars sucks the air from bottom and pushes it rearward, which increases both the traction force and drag.

Secure vehicular communication is important in sustaining secure and effective transportation infrastructures. Advances in the Vehicular Internet of Things (VIoT) technology enable communication among vehicles as well as roadside facilities, offering effective traffic flow and security control. However, the vehicular networks are exposed to increased risks from cyberattacks, particularly from incoming quantum computers with the ability to interpret out-of-date conventional codes. This paper proposes a security solution based on post-quantum cryptography (PQC), which enhances Ascon encryption by adding quantum-proof key exchange. This method ensures secure authentication and protects against replay, sybil, collision, phishing, and man-in-the-middle attacks. A 32-bit Ascon hash coupled with SHA-512 provides data integrity. Investigations on resource-constrained vehicular environments confirm that the new scheme provides better performance, producing 128–512-bit keys in microseconds, much quicker than Kyber and Falcon. It also outperforms Ascon in hash rendering speed, completing a 256 × 256 grayscale image in 0.0782s, compared to 0.822s for standard Ascon, thereby emphasizing its ability to provide secure, immediate communication between vehicles in scenarios sensitive to quantum technologies. These observations show that the suggested approach is strongly secure and computationally efficient, and hence it is suitable for protecting future connected and autonomous vehicles from cyberattacks in the quantum era.

Introduction. Provisioning is the process of setting aside an amount that may be necessary to settle a possible obligation when neither the amount nor the date of the obligation can be estimated with certainty. The objective of accounting and reporting in this area is to establish provisions and to choose the best option for making such provisions. Due to their dynamic nature, liabilities significantly affect the solvency of a business entity, require effective cash flow management and control over the actual status of settlements. The purpose of this article is to study the main aspects of recognising collateral, covering domestic and international accounting and reporting practices. Methods. In the course of the study, the following methods were used: monographic method for studying the literature on the recognition of collateral; method of regulatory support for assessing the established rules and regulations on collateral; analytical method for analytical assessment of the justification of collateral. Results. The creation of collateral is a necessity determined by current legislation and regulations. However, the list of collateral provided in National Accounting Standards 11 is not exhaustive, as an entity should create collateral to reimburse any future expenses (of course, subject to the recognition conditions). Taking into account the specifics of the entities' business, various circumstances may arise that will lead to the emergence and recognition of provisions, which in turn requires careful analysis and justification. Conclusions. Based on the study of the conditions for the formation of collateral in the accounting system and the tasks of accounting and management of enterprises, it is advisable to involve qualified specialists and managers to justify the recognition of collateral. Also, the order on accounting policy should reflect information on the types of payments for which a specific provision is formed. It is recommended to improve the wording of the criteria for recognising collateral in accounting, which will facilitate the convergence of National Accounting Standards 11 and IAS 37.

We experimentally demonstrate a highly spectral efficient optical flow control technique for intra data center networks. A bi-directional system is implemented for generating flow control signal by reusing label wavelength and the transmission link within the same WDM channel. Dynamic operation shows high-quality flow control signal with 265 ns latency including 220 ns propagation delay and 500 mV amplitude with low input power and low bias current. Error free operation with 0.5 dB penalty for 40 Gb/s payload indicates that no distortion has been caused due the transmission of label and flow control signal.