Fuzzy Rate Control Research Articles

FJND-based fuzzy rate control of scalable video for streaming applications

A fuzzy rate controller with buffer constraint in combination with a perceptual quality controller is proposed for streaming applications of the AVC/H.264 scalable (SVC) video. The bit rate of each video layer is controlled separately by the fuzzy controller that adjusts the quantization parameter (QP) on a group of pictures (GOP) basis. The QPs of pictures are computed from the GOP QP by the well-known QP cascading technique. While the fuzzy controller provides the buffering constraint for each video layer, the quality controller tries to improve the perceptual quality of the compressed video based on the foveated just-noticeable distortion (FJND) model. The quality controller regulates the QP of each macroblock around the picture QP based on the visibility threshold of the FJND model. In these applications, the initial buffering allows slight variations of the bit rate leading to produce a variable bit rate (VBR) video bit stream with consistent quality. Experimental results show that the proposed algorithm effectively adapts to the buffer size, while strictly prevents buffer overflow and underflow. In addition, incorporating the perceptual quality controller into the fuzzy rate controller achieves higher perceptual quality at the same bit rate.

Fuzzy logic-based scalable video rate control algorithm for high-delay applications of scalable high-efficiency video coding

The second version of the high-efficiency video coding standard introduced a scalable extension, which is called scalable high-efficiency video coding. It is necessary to design appropriate rate controllers for this extension based on the specific application requirements. According to delay and buffering constraints, rate control algorithms are divided into constant bit rate and variable bit rate (VBR) algorithms. Our focus is on high-delay applications like streaming and broadcast for which VBR controllers are suitable. Our proposed VBR controller utilizes a fuzzy logic-based algorithm to control long-term average bit rate while preventing buffer overflow or underflow. Targeting perceptual quality, the proposed algorithm has been implemented at the group of pictures level to minimize unnecessary fluctuations of quantization parameter and consequently minimizing video quality fluctuations. Experimental results show a high performance in terms of rate control and quality of the compressed video for the proposed algorithm.

Correction to: A fuzzy rate controller for variable bit rate video using foveated just-noticeable distortion model

In the original publication, the affiliations of the two authors were incorrectly written as “University of Sistan and Bluchestan” when it should be “University of Sistan and Baluchestan.” The correct affiliations are presented in this erratum.

Congestion-Aware Routing and Fuzzy-based Rate Controller for Wireless Sensor Networks

In this paper, congestion-aware routing and fuzzy- based rate controller for wireless sensor networks (WSNs) is proposed. The proposed method tries to make a distinc- tion between locally generated data and transit data by using apriority-basedmechanismwhichprovidesanovelqueueing model. Furthermore, a novel congestion-aware routing us- ing greedy approach is proposed. The proposed congestion- aware routing tries tofind more aordable routes. Moreover, a fuzzy rate controller is utilized for rate controlling which uses two criteria as its inputs, including congestion score and buer occupancy. These two parameters are based on total packet input rate, packet forwarding rate at MAC layer, number of packets in the queue buer, and total buer size at each node. As soon as the congestion is detected, the notifi- cation signal is sent to the ospring nodes. As a result, they are able to adjust their data transmission rate. Simulation results clearly show that the implementation of the proposed method using a greedy approach and fuzzy logic has done significant reduction in terms of packet loss rate, end-to-end delay and average energy consumption.

A GOP-level fuzzy rate control algorithm for high-delay applications of HEVC

The high -efficiency video coding (HEVC) standard was introduced for high-resolution video contents suitable for many high-delay applications. The bit rate of compressed video is controlled in almost all digital video applications according to the practical constraints such as available channel bandwidth and allowed delay or buffering constraint. In high-delay video applications such as video broadcasting and video streaming applications, variable-bit-rate videos can provide a higher visual quality than constant-bit-rate videos. In this paper, a rate control algorithm (RCA) for high-delay applications of the HEVC standard with buffering constraint is proposed. A fuzzy controller and a virtual buffer are used in the proposed RCA. The fuzzy controller is designed to minimize the fluctuations of quantization parameter (QP) while the buffering constraint is obeyed. It computes a base QP for each group of pictures (GOP) to prevent unnecessary fluctuations of QP at GOP level and thereafter provide a higher visual quality. Experimental results show that not only the bit rate and but also buffering constraints are fully maintained but also the objective quality of compressed video is well preserved. Moreover, the proposed RCA provides smooth QP and peak signal-to-noise ratio close to constant QP case for encoded videos that means high subjective quality.

A fuzzy rate controller for variable bit rate video using foveated just-noticeable distortion model

In this paper, a rate control algorithm for variable bit rate video applications with buffer constraint is proposed. The proposed algorithm utilizes a fuzzy rate controller and a perceptual quality...

Vibrational motion control for foamed polystyrene machining robot and extraction of radius of curvature for fuzzy feed rate control

There are two serious requirements to machining systems used in manufacturing industries. They are machining quality and efficiency. In this paper, a vibrational motion control is proposed for an endmill attached to the tip of a machining robot to suppress the occurrence of undesirable cusp marks. In addition, the calculation of radius of curvature along discrete CL data is introduced for a fuzzy feed rate controller which can regulate the tangent velocity. The radius of curvature is effective information as a fuzzy input. The effectiveness of the proposed methods is validated through experiments.

Machining robot for foamed polystyrene materials using fuzzy feed rate controller

Generally, cast metal is produced by using a sand mould. A foamed polystyrene mould is used as not only the master mould for making the corresponding sand mould but also the lost–foam pattern for full mould casting, i.e., lost–foam casting. Recently, the development of a flexible machining robot for foamed polystyrene materials is expected in the cast metal industries because of the high cost and inefficiency of conventional large sized CNC machine tools. In this paper, a machining robot based on an industrial robot is developed for foamed polystyrene materials by applying the already developed robotic CAM system. A compact and lightweight high performance tool is also considered and attached to the arm tip. The feed rate of an end mill is skilfully regulated by a fuzzy reasoning method. The design of the machining robot using the robotic CAM system and fuzzy feed rate controller is presented to efficiently produce foamed polystyrene moulds.

Intelligent Data Rate Control in Cognitive Mobile Heterogeneous Networks

An adaptive rate controller (ARC) based on an adaptive neural fuzzy inference system (ANFIS) is designed to autonomously adjust the data rate of a mobile heterogeneous network to adapt to the changing traffic load and the user speed for multimedia call services. The effect of user speed on the handoff rate is considered. Through simulations, it has been demonstrated that the ANFIS-ARC is able to maintain new call blocking probability and handoff failure probability of the mobile heterogeneous network below a prescribed low level over different user speeds and new call origination rates while optimizing the average throughput. It has also been shown that the mobile cognitive wireless network with the proposed CS-ANFIS-ARC protocol can support more traffic load than neural fuzzy call-admission and rate controller (NFCRC) protocol.

DESIGN AND PERFORMANCE EVALUATION OF A FUZZY-BASED TRAFFIC CONDITIONER FOR MOBILE AD HOC NETWORKS

A mobile ad hoc network is a collection of mobile hosts forming a temporary network on the fly, without using any fixed infrastructure. Characteristics of mobile ad hoc networks such as lack of central coordination, mobility of hosts, dynamically varying network topology, and limited availability of resources make QoS provisioning very challenging in such networks. In this paper, we introduce a fuzzy QoS traffic conditioner for mobile ad hoc networks. The proposed traffic conditioner consists of fuzzy admission control (FAC), fuzzy traffic rate controller (FTRC), and fuzzy scheduler (FS). The proposed FAC monitors the delay and available bandwidth and decides whether to accept or reject the request. The FTRC uses the additive increase multiplicative decrease (AIMD) rate control algorithm as a base, in which a node increments its transmission rate when the observed delay is below the predefined threshold, with an increment rate of c Kbps and decreases its transmission rate by r% when the delay passes the threshold. FTRC accepts the packet delay and the "delay-threshold d" as inputs and calculates c and r by using a set of fuzzy rules. The third part of the proposed traffic conditioner is FS, which is based on the traditional weighted round robin (WRR) mechanism. FS monitors the packet drop and delay of each queue and adjusts the queue weights by using a fuzzy inference engine.

Semi-Fuzzy Rate Controller for Variable Bit Rate Video

A novel semi-fuzzy (SF) rate control algorithm (RCA) for variable bit rate (VBR) video applications is proposed. The proposed RCA is optimized to provide high quality compressed video bit streams in a wide operating range from constant quality to nearly constant bit rate. Thanks to a low degree of computational complexity, it is suitable for real-time applications of VBR video. The proposed RCA operates under given buffer size, delay and quality constraints. It provides a VBR video bit stream by controlling the quantization parameter (QP) on a picture basis. The QP is mainly controlled by a fuzzy rate controller and a deterministic quality controller, which are optimized such that they minimize the variation of quality to provide encoded video with high and stable visual quality. The proposed RCA has been implemented in an H.264/AVC video codec and the experimental results show that it provides a high-level average quality for encoded video while strictly obeying the buffering delay and quality constraints.