Sliding Window Protocol Research Articles

Joint Device Detection, Channel Estimation, and Data Decoding With Collision Resolution for MIMO Massive Unsourced Random Access

In this paper, we investigate a joint device activity detection (DAD), channel estimation (CE), and data decoding (DD) algorithm for multiple-input multiple-output (MIMO) massive unsourced random access (URA). Different from the state-of-the-art slotted transmission scheme, the data in the proposed framework is split into only two parts. A portion of the data is coded by compressed sensing (CS) and the rest is low-density-parity-check (LDPC) coded. In addition to being part of the data, information bits in the CS phase also undertake the task of interleaving pattern design and CE. The principle of interleave-division multiple access (IDMA) is exploited to reduce the interference among devices in the LDPC phase. Based on the belief propagation (BP) algorithm, a low-complexity iterative message passing (MP) algorithm is utilized to decode the data embedded in these two phases separately. Moreover, combined with successive interference cancellation (SIC), the proposed joint DAD-CE-DD algorithm is performed to further improve performance by utilizing the belief of each other. Additionally, based on the energy detection (ED) and sliding window protocol (SWP), we develop a collision resolution protocol to handle the codeword collision, a common issue in the URA system. In addition to the complexity reduction, the proposed algorithm exhibits a substantial performance enhancement compared to the state-of-the-art in terms of efficiency and accuracy.

Geological map feature extraction using object detection techniques - a comparative analysis

Conducting a geological field survey at the initial stage is an important step in geo-oriented projects and construction. Therefore, better and more accurate solutions are only possible with field analysis and proper modeling. The geological modeling process takes a long time, especially depending on the area of interest. It is inefficient to digitize 2D geological maps with traditional software that uses manual user interaction. This paper proposes a state-of-the-art feature detection methodology for detecting geological features on high-resolution maps. With the development of efficient deep learning algorithms and the improvement of hardware systems, the accuracy of detecting specific objects in digital images, such as human facial features, has reached more than 90%. Current object detection models based on convolutional neural networks cannot be directly applied to high-resolution geological maps due to the input image size limitations of conventional object detection solutions, mostly limited by hardware resources. This paper proposes a sliding window method for character detection of geological features. Detection models are trained using transfer learning with You Look Only Once-v3 (YOLO-v3), Single Shot Multi-Box Detector (SSD), Faster-Region-based Convolutional Neural Network (Faster-RCNN), and Single Shot Multi-Box Detector_RetinaNet (SSD_RetinaNet). All models provide competitive success rates with an average precision (AP) of 0.96 on YOLOv3, 0.88 AP on EfficientNet, 0.92 AP on Faster- RCNN, and 0.97 AP on SSD_RetinaNet. YOLOv3 outperformed the best detection over SSD according to F1 recall and score. Since the input size of detection models is limited, a sliding window algorithm is used to separate high-resolution map images. The final detected strike features are provided as a digital dataset that can be used for further manipulations. Thus, Convolutional Neural Network (CNN) based object detection along with a sliding window protocol can be applied to manual map digitization processes to provide instantaneous digitized data with higher accuracy. This automated process can be used to detect small features and digitize other high-resolution drawings.

On the Use of Proof-of-Work in Permissioned Blockchains: Security and Fairness

In permissioned blockchains, a set of identifiable miners validates transactions and creates new blocks. In scholarship, the proposed solution for the consensus protocol is usually inspired by the Byzantine fault tolerance (BFT) based on voting rather than the proof-of-work (PoW). The advantage of PoW with respect to BFT is that it allows the final user to evaluate the cost required to change a confirmed transaction without the need to trust the consortium of miners. In this paper, we analyse the problems that arise from the application of PoW in permissioned blockchains. In standard PoW, it may be easy for colluded miners to temporarily reach 50% of the total hash power (HP). Moreover, since mining rewards are not usually expected in permissioned contexts, the problem of balancing the computational efforts among the miners becomes crucial. We propose a solution based on a sliding window algorithm to address these problems and analyse its effectiveness in terms of fairness and security. Furthermore, we present a quantitative, analytical model in order to assess its capacity to balance the hash power provided by heterogeneous miners. Our study considers the trade-off between the need to trust the entire consortium of miners guaranteed by the global HP invested by the mining process and the need to prevent collusion among malicious miners aimed at reaching 50% of the total HP. As a result, the model can be used to find the optimal parameters for the sliding window protocol.

A Design of Parallel Content-Defined Chunking System Using Non-Hashing Algorithms on FPGA

Content-defined chunking is a common method in many applications such as data deduplication and data synchronization. In recent years, new CDC algorithms using non-hashing methods have been developed, and positive results have been obtained. However, most of the algorithms are developed for single-thread computation on microprocessors. After analyzing some popular CDC algorithms, we observed that the algorithms using the basic sliding window protocol are more feasible to process in parallel. In this work, we proposed a new parallel chunking method that aims for hardware implementation. Additionally, we used the PCI algorithm, which does not include hash functions, to implement a multi-thread chunking system on FPGA devices. By exploiting the strength of the FPGAs, our proposed design achieves not only high computational speed but also great scalability.

Sliding Window Protocol for Internet of Things

Internet of Things (IoT) refers to the concept of connecting non-traditional computers and related sources with the help of the internet. This includes incorporating basic computing and communication technologies for daily use into Physical things. Security and Confidentiality are two major challenges in IoT. In the current security mechanisms available for IoT, the limitations in the memory, energy resources, and CPU of IoT devices compromises the critical security specifications in IoT devices. Also, the centralized architectures for security are not appropriate for IoT because of a Single attack point. It is costly to defend against attacks targeted on centralized infrastructure. Therefore, it is important to decentralize the IoT security architecture to meet the requirements of resource constraints. Blockchain is a decentralized encryption system with a large number of uses. However, because of its high computational complexity and poor scalability, the Traditional Blockchain environment is not suitable for IoT applications. So, we introduce a Sliding window protocol to the traditional blockchain so that it will better suit the applications in the IoT environment. Changing the conventional blockchain and introducing a sliding window to it makes it use previous blocks in proof of work to shape the next hash block. SWBC's results are analyzed on a data stream generated from an IoT testbed (Smart Home) in real-time. The results show that the proposed sliding window protocol improves security and reduces memory overhead and consumes fewer resources for Security.

Loss of Mammographic Tissue Homeostasis in Invasive Lobular and Ductal Breast Carcinomas vs. Benign Lesions.

The 2D wavelet transform modulus maxima (WTMM) method is used to perform a comparison of the spatial fluctuations of mammographic breast tissue from patients with invasive lobular carcinoma, those with invasive ductal carcinoma, and those with benign lesions. We follow a procedure developed and validated in a previous study, in which a sliding window protocol is used to analyze thousands of small subregions in a given mammogram. These subregions are categorized according to their Hurst exponent values (H): fatty tissue (H ≤ 0.45), dense tissue (H ≥ 0.55), and disrupted tissue potentially linked with tumor-associated loss of homeostasis (0.45 < H < 0.55). Following this categorization scheme, we compare the mammographic tissue composition of the breasts. First, we show that cancerous breasts are significantly different than breasts with a benign lesion (p-value ∼ 0.002). Second, the asymmetry between a patient’s cancerous breast and its contralateral counterpart, when compared to the asymmetry from patients with benign lesions, is also statistically significant (p-value ∼ 0.006). And finally, we show that lobular and ductal cancerous breasts show similar levels of disruption and similar levels of asymmetry. This study demonstrates reproducibility of the WTMM sliding-window approach to help detect and characterize tumor-associated breast tissue disruption from standard mammography. It also shows promise to help with the detection lobular lesions that typically go undetected via standard screening mammography at a much higher rate than ductal lesions. Here both types are assessed similarly.

A Quantitative Assessment of Time, Frequency, and Time-frequency Algorithms for Automated Seizure Detection and Monitoring

Epilepsy is a chronic brain disorder impacting more than 65 million people worldwide (1% of the population). Its primary symptoms, seizures, can occur without warning and can be deadly. Each year, over 100,000 patients die from Sudden Unexpected Death in Epilepsy (SUDEP). A reliable seizure warning system can help patients stay safe. This work presents a comprehensive, comparative analysis of three different signal processing algorithms for automated seizure/ictal detection. The methods perform feature extraction and seizure detection on scalp electroencephalogram (EEG) signals. The first optimized mathematical model, Approximate Entropy, performed statistical time domain analysis using a new sliding window protocol. The second algorithm performed seizure-specific spectral energy binning using the Fast Fourier Transform in the frequency domain. The third method applied signal decomposition to extract ictal features by implementing a time-frequency Discrete Wavelet Transform method. Each epileptic seizure detection algorithm was successfully validated using &amp;gt;75 hours of recordings from the Boston Children’s Hospital’s CHB-MIT scalp EEG clinical database. Results indicated that the Discrete Wavelet Transform algorithm performed the best, achieving a seizure detection sensitivity of 92% and a specificity of 98%. The experimental results show that the proposed methods can be effective for accurate automated seizure detection and monitoring in clinical care.

Design and Analysis of Sliding Window ARQ Protocols With Rate Adaptation for Burst Transmission Over FSO Turbulence Channels

This paper studies a cross-layer design of error-control protocols with rate adaptation for a free-space optical (FSO) burst transmission over atmospheric turbulence channels. Specifically, sliding window automatic repeat request (ARQ) protocols are designed so that the window size is determined by the burst duration. This facilitates an effective operation for sliding window protocols with the adaptive rate (AR) transmission over atmospheric turbulence channels. To analyze performance of the design, the time-varying behavior of the atmospheric turbulence channels, modeled by the popular gamma&#x2013;gamma (&#x0393;&#x0393;) distribution, is captured to develop the burst error model. An embedded Markov model, which is formulated in the discrete time defined by the burst duration, is analyzed based on the developed burst error model. Using the queueing analysis, the frame loss rate, average delay, and system throughput are analytically derived. Numerical results quantitatively demonstrate the impact of atmospheric turbulence on the system performance and support the optimal selection of system parameters over turbulence conditions. Monte Carlo simulations are also performed to validate the analytical results, and an excellent agreement between the analytical and simulation results is confirmed.

Application of adaptive strategy for supply chain agent

With the tremendous increase in the globalization of trade the corresponding supply chains supporting the manufacture, distribution and supply of goods has become extremely complex. Intelligent agents can help with the problem of effective management of these complex supply chains. In this paper we introduce the design, implementation and testing of an intelligent agent for handling procurement, customer sales, and scheduling of production in a stylized supply chain environment. The supply chain environment used in this paper is modeled after the trading agent competition that is held annually to choose the best agent for managing a supply chain. Our supply chain agent, which we call SCMaster, uses dynamic inventory control and various reinforcement learning techniques like Q-learning, Softmax, e-greedy, and sliding window protocol to make our agent adapt dynamically to the changing environment created by competing agents. A multi-agent simulation environment is developed in Java to test the efficacy of our agent design. Two competing agents are created modeled after the winners of past trading agent competitions and are tested against our agent in various experimental designs. Results of simulations show that our agent has better performance compared to the other agents.

A comparative analysis of Matrixx and EPID for dosimetric verification of intensity-modulated radiotherapy

Objective To compare the dosimetric verification results of Varian Portal Dosimetry and Matrixx, and to assess the reliability of the clinical application of electronic portal imaging device (EPID) verification. Methods Varian TrueBeam linear accelerator, which was equipped with a 120-leaf multileaf collimator and an amorphous silicon EPID, as well as portal dose prediction software. IBA I′mRT Matrixx ion chamber array was used. EPID algorithm configuration, dose calibration, and testing before use were performed. The sliding-window protocol was used. There were 77 patients with tumors involving the head and neck (mainly nasopharyngeal carcinoma), mediastinum, abdomen, and pelvic cavity were selected. The verification plan of the portal dose was created with a source-detector distance of 100 cm, and the gantry angle was kept the same as the treatment plan. The verification plan was carried out in the TrueBeam machine, and the data were collected at the same time by EPID. Comparison between the measured and calculated dose images was performed, and the evaluation standard was gamma index (3%/3 mm). The paired t-test was used for difference analysis. Results For the 77 patients, the Gamma passing rates of both methods were above 97%. Except for head and neck carcinoma were a significant difference between the results of dosimetric results using EPID and Matrixx in intensity-modulated radiotherapy (P=0.018) other remaining all P> 0.05. Conclusions The dosimetric verification results of EPID are consistent with those of Matrixx. EPID can be used for dosimetric verification, and Matrixx ion chamber array can be used only in case of a low Gamma passing rate. Key words: Dosimetric verification; Portal dosimetry; Matrixx

Parameterized, concurrent session types for asynchronous multi-actor interactions

Session types have been proposed as a means of statically verifying implementations of communication protocols. Although prior work has been successful for some classes of protocols, it does not cope well with parameterized, multi-actor scenarios with inherent asynchrony. For example, the sliding window protocol is not expressible in previously proposed session type notations. This article defines System-A: a novel session type system, as well the associated programming language that together overcome many of the limitations of prior work. With explicit support for asynchrony and concurrency, as well as multiple forms of parameterization, we demonstrate that System-A can be used for the static verification of a large class of asynchronous communication protocols.

Deductive Verification of the Sliding Window Protocol

We consider the well-known Sliding Window Protocol which provides reliable and efficient transmission of data over unreliable channels. A formal proof of correctness for this protocol faces substantial difficulties caused by a high degree of parallelism which creates a significant potential for errors. Here we consider a version of the protocol that is based on selective repeat of frames. The specification of the protocol by a state machine and its safety property are represented in the language of the verification system PVS. Using the PVS system, we give an interactive proof of this property of the Sliding Window Protocol.

Prefetching for mobile web album

AbstractA web album service allows a user to publish photo albums on the web and view albums of other users. Through broadband mobile telecom, users can enjoy watching contents of web albums at any place in real time. User experience on mobile web album is affected by the transmission delay of mobile network, which determines whether the user needs to wait to view the images. We propose a prefetching mechanism that enhances user experience on accessing mobile web albums. A transmission control protocol‐like sliding window protocol (of size N) is exercised, and when the buffer for the sliding window at the user equipment is full, prefetching is suspended. The buffer size N affects the prefetching performance. The larger the N value, the better the user experience. However, a large N value means that many images will be prefetched. If they are not actually viewed by the user, the network resources for transmitting these images are wasted. This paper proposes both analytic and simulation models to select the smallest N (the optimal N value) so that the expected user experience can be achieved. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Deductive verification of the Sliding Window Protocol

We consider the well-known Sliding Window Protocol which provides reliable and efficient transmission of data over unreliable channels. A formal proof of correctness for this protocol faces substantial difficulties, caused by a high degree of parallelism which creates a significant potential for errors. Here we consider a version of the protocol that is based on selective repeat of frames. The specification of the protocol by a state machine and its safety property are represented in the language of the verification system PVS. Using the PVS system, we give an interactive proof of this property of the Sliding Window Protocol.

IMPORTANCE OF SLIDING WINDOW PROTOCOL

The data can get lost, reordered or duplicated due to the presence of routers and buffer space over th e unreliable channel in the conventional networks. The data link layer deals wi th frame formation, flow control, error control, an d addressing and link management. All such functions will be performed on ly by data link protocols. The sliding window proto col will detect and correct error if the received data have enough redundant bi ts or repeat a retransmission of data. The paper sh ows the working of this duplex protocol of data link network.

Parameterized Concurrent Multi-Party Session Types

Session types have been proposed as a means of statically verifying implementations of communication protocols. Although prior work has been successful in verifying some classes of protocols, it does not cope well with parameterized, multi-actor scenarios with inherent asynchrony. For example, the sliding window protocol is inexpressible in previously proposed session type systems. This paper describes System-A, a new typing language which overcomes many of the expressiveness limitations of prior work. System-A explicitly supports asynchrony and parallelism, as well as multiple forms of parameterization. We define System-A and show how it can be used for the static verification of a large class of asynchronous communication protocols.

Causal Message Sequence Charts

Scenario languages based on Message Sequence Charts (MSCs) have been widely studied in the last decade. The high expressive power of MSCs renders many basic problems concerning these languages undecidable. However, several of these problems are decidable for languages that possess a behavioral property called “existentially bounded”. Unfortunately, collections of scenarios outside this class are frequently exhibited by systems such as sliding window protocols. We propose here an extension of MSCs called causal Message Sequence Charts and a natural mechanism for defining languages of causal MSCs called causal HMSCs (CaHMSCs). These languages preserve decidable properties without requiring existential bounds. Further, they can model collections of scenarios generated by sliding window protocols. We establish here the basic theory of CaHMSCs as well as the expressive power and complexity of decision procedures for various subclasses of CaHMSCs. We also illustrate the modeling power of our formalism with the help of a realistic example based on the TCP sliding window feature.

Formal Model and Analysis of Sliding Window Protocol Based on NuSMV

System states space based on Kripke structure can be exhausted by model checking, thus system key property described by temporal logic can be automatically verified. Presently model checking has been widely used in hardware validation and network protocol analysis. Sliding window protocol is a classical receive-send protocol, which is used in TCP/IP protocol group. In this paper, we propose the respective formal model of sliding window protocol under three conditions, as well as Kripke structure semantics of the protocol. The key properties of system such as data integrity, liveliness and information consistency are automatically validated. Finally experiment, table and analysis are given out. The method we proposed to analysis specific bit sliding window protocol can be extended to analysis arbitrary bit sliding window protocol.

Modeling and verification of the SDL-specified communication protocols using high-level Petri nets

To simplify modeling and verification of communication protocols presented in the SDL language, the so-called hierarchical typed timed Petri nets (HTT nets), which are substantial modifications of colored Petri nets, are introduced. A method of translation of the SDL language into HTT nets is described. A program complex SPV (SDL Protocol Verifier), which includes a translator from SDL into HTT nets and means for editing, simulation, visualization, and verification of these net models, is presented. For the verification, a model checking method for properties presented by μ-calculus formulas is used. Experiments on application of the SPV complex for modeling and verifying two ring protocols (RE and ATMR protocols), an optimized version of the sliding window protocol (i-protocol), and a dynamic version of the InRes protocol are described

Formal Validation of the Safety Property of Sack Protocol Using Theorem Proving Technique

This paper demonstrates the formal validation process of safety properties of Selective ACKnowledgment (SACK) protocol. SACK is a complex communication protocol as it is used in various types of distributed computer systems and networks. This acknowledgment mechanism is used with sliding window protocol that allows the receiver to acknowledge packets received out of order, but within the correct sliding window. One of the critical property of SACK is its' safety property. In order to validate this property formally by using the Z/Eves theorem prover, we specify the SACK protocol using Z formal specification language. By using theorem prover tool, it helps to reduce time, energy and mistake than in relatively manual theorem proving which can be tedious and error-prone task.