Number Of Bytes Research Articles

Performance Analysis of HSTCP for Optimizing Data Transfer rate in Mobile Ad-hoc Networks

the era of communication congestion is the majorproblemwhich degrades the performance. In Ad hoc networks due to infrastructure less character there is no guaranteed bandwidth and node mobility. The traditional TCP variants were good for wired environment, whereas in Ad-hoc networks there are lots of other factors to be considered. The congestion window is one of the factors that determine the number of bytes that can be outstanding at any time. The congestion window indicates the maximum amount of data that can be sent out on a connection without being acknowledged. HSTCP is the very important protocol that will be used only when congestion window increases abruptly. To improve the retransmission time and to avoid congestion in completely dynamic conditions where node mobility is completely random is the main concern of our research work. KeywordsHSTCP, Congestion, MANETs

English

A In spite of wide usage of controller area network (CAN) in the embedded networked control system, nondeterministic response time have restricted the wider use of CAN in safety-critical real time systems, since the CAN uses Non Return to Zero (NRZ) coding and includes a bit-stuffing mechanism, which causes the CAN frame length to become a complex function of the data contents. To minimize CAN response-time jitter and make the transmission time fixed value according to the number of bytes in the data field, many techniques have been suggested as XOR masking , Software Bit Stuffing (SBS), inversion bit stuffing mechanism (IBSM) and Eight-to-Eleven Modulation (EEM), in this paper a novel alternative method known as Third Bit Complement (TCB) is used for “bit stuffing” to prevent hard-ware bit stuffing in the data field part completely, the new technique was compared with previous available techniques showing that six data bytes can be inserted in the data part compared with five bytes in SBS and EEM techniques.

QMMMW: A wrapper for QM/MM simulations with Quantum ESPRESSO and LAMMPS

We present QMMMW, a new program aimed at performing Quantum Mechanics/Molecular Mechanics (QM/MM) molecular dynamics. The package operates as a wrapper that patches PWscf code included in the Quantum ESPRESSO distribution and LAMMPS Molecular Dynamics Simulator. It is designed with a paradigm based on three guidelines: (i) minimal amount of modifications on the parent codes, (ii) flexibility and computational efficiency of the communication layer and (iii) accuracy of the Hamiltonian describing the interaction between the QM and MM subsystems. These three features are seldom present simultaneously in other implementations of QMMM. The QMMMW project is hosted by qe-forge at (http://qe-forge.org/gf/project/qmmmw/). Program summaryProgram title: QMMMWCatalogue identifier: AEWS_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEWS_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: GNU General Public License, version 3No. of lines in distributed program, including test data, etc.: 7544822No. of bytes in distributed program, including test data, etc.: 121657035Distribution format: tar.gzProgramming language: Python, C and Fortran95.Computer: All Linux based workstations and parallel supercomputers.Operating system: GNU/Linux.Classification: 3, 7.7, 16.1, 23.Nature of problem: Calculation of the hybrid quantum mechanics/molecular mechanics of molecular systems.Solution method:With the current patches QMMMW allows the performance of QM/MM simulations with mechanical coupling (i.e. classical point charge based, QM and the MM system interacts electrostatically only at the classical level.) and electrostatic coupling according to the scheme proposed by Laio, VandeVondele and Rothlisberger, J. Chem. Phys. 116, 6941 (2002).Restrictions:Only coded for orthorhombic cell. The interactions coupling QM and MM degrees of freedom cannot be bonded. The QM region can only be modeled with PWscf.Unusual features:Minimal amount of modifications to the parent codes. Flexibility and computational efficiency of the communication layer. Accuracy of the Hamiltonian describing the interaction between the QM and MM subsystems.Additional comments:Relevant versions of Quantum ESPRESSO and LAMMPS are included in the distribution file and in the number of lines and number of bytes shown.!!!!! The distribution file for this program is over 121 Mbytes and therefore is not delivered directly when download or Email is requested. Instead a html file giving details of how the program can be obtained is sent. !!!!!Running time:From a few minutes for small molecules on serial machines up to many hours on multiple processors for complex nanosystems with hundreds of atoms.

IJARCCE - Computer and Communication Engineering

In Cloud computing involves deploying groups of remote servers and software networks that allow centralized data storage and online access to computer services or resources. Clouds can be classified as public, private or hybrid. Cloud service providers offer both highly available storage and massively parallel computing resources at relatively low costs. As cloud computing becomes prevalent, an increasing amount of data is being stored in the cloud and shared by users with specified privileges, which define the access rights of the stored data. One critical challenge of cloud storage services is the management of the ever-increasing volume of data. Datadeduplication is a specialized data compression technique for eliminating duplicate copies of repeating data. This technique is used to improve storage utilization and can also be applied to network data transfers to reduce the number of bytes that must be sent and save bandwidth. To protect the confidentiality of sensitive data while supporting deduplication, the convergent encryption technique is used to encrypt the data before outsourcing. It encrypts/decrypts a data copy with a convergent key, which is obtained by computing the cryptographic hash value of the content of the data copy. Convergent encryption allows the cloud to perform deduplication on the ciphertexts and the proof of ownership prevents the unauthorized user to access the file. To enhance the system in security OAuth is used. OAuth (Open Authorization) is an open protocol for token-based authentication and authorization on the Internet used in hybrid cloud to enhance the security. OAuth enables the system to ensure that the user is an authenticated person or not. Only such authenticated user got the token for uploading and downloading in pubic cloud.

Development and research of adaptive data compression methods based on linear fibonacci form

A fundamentally new data compression approach, which is based on the optimizing properties of Fibonacci numbers lies in the fact that the figures are considered as positive whole numbers and presented by a linear Fibonacci form, was investigated. Formation features of the numerical data source model were examined. The effect of the length of data blocks of the compressed file on the compression ratio was studied. Changing the number of bytes in the block provides the formation of different data source models. Ability to change the data source model allows to choose a model that provides the greatest compression ratio for a given encoding rule. Analysis of the results has shown that the effect of the data block length on the compression ratio is different for different file types. For some types, the greatest compression ratio is achieved when the block length is 100 bytes, and the ratio decreases with the increased length. For other file types, the effect of the data block length has a wave pattern (the ratio repeatedly increases and decreases with the increased length), and for certain types of files, the dependence of the transformed data on the data source model used is negligible. Low compression ratios and no compression for certain file types are caused by the fact that the data modeling used does not ensure the formation of numbers that are compactly presented by the linear Fibonacci form. To eliminate this shortcoming, two adaptive data compression methods, based on the linear Fibonacci form, which involve using a set of numerical data source models were proposed and investigated. These models are based on the maximum value of the numerical equivalents of the ASCII codes of bytes that make up the block. Adaptation enhances the compression ratio compared to non-adaptive compression method based on the linear Fibonacci form.

A hierarchical approach to reducing communication in parallel graph algorithms

Large-scale graph computing has become critical due to the ever-increasing size of data. However, distributed graph computations are limited in their scalability and performance due to the heavy communication inherent in such computations. This is exacerbated in scale-free networks, such as social and web graphs, which contain hub vertices that have large degrees and therefore send a large number of messages over the network. Furthermore, many graph algorithms and computations send the same data to each of the neighbors of a vertex. Our proposed approach recognizes this, and reduces communication performed by the algorithm without change to user-code, through a hierarchical machine model imposed upon the input graph. The hierarchical model takes advantage of locale information of the neighboring vertices to reduce communication, both in message volume and total number of bytes sent. It is also able to better exploit the machine hierarchy to further reduce the communication costs, by aggregating traffic between different levels of the machine hierarchy. Results of an implementation in the STAPL GL shows improved scalability and performance over the traditional level-synchronous approach, with 2.5×-8× improvement for a variety of graph algorithms at 12,000+ cores.

Desempeño de redes inalámbricas y redes industriales inalámbricas en procesos de control en tiempo real bajo ambientes industriales

El uso creciente de las redes Ethernet en el piso de la pirámide de automatización ha hecho que muchas compañías desarrollen dispositivos para operar bajo los requerimientos característicos de este nivel, en la actualidad denominada red Industrial Ethernet, a nivel industrial se encuentra en el mercado variedad de sensores y actuadores que incorporan esta tecnología, muchos de estos equipos se venden a muy alto costo, por eso en este artículo se evaluó el desempeño de dos redes inalámbricas, una con dispositivos del Ethernet convencional, y otra con dispositivos de industrial Ethernet variando cuatro parámetros que son: distancia, número de bytes, relación señal a ruido y la tasa de error de paquetes, midiendo los retardos y comparando con métricas estadísticas los resultados, para ello se usaron graficas Box Plot. Al final, se concluye que bajo los parámetros y condiciones evaluados, las redes inalámbricas pueden servir como sistema de comunicación en aplicaciones de control con retardos permisibles de hasta 50 ms, además, los resultados demuestran un mejor desempeño de las redes industrial Ethernet con respecto a las convencionales, con diferencias en los RTT de milisegundos, por lo tanto, se recomienda establecer qué riesgo representa para el proceso a controlar estos retardos y así determinar si los equipos convencional aplican, ya que bajo ciertas características como condiciones de humedad y temperatura pueden operar adecuadamente durante un tiempo considerable y a un menor costo que los dispositivos de Industrial Ethernet.

Network coding is the 5G Key Enabling Technology: effects and strategies to manage heterogeneous packet lengths

ABSTRACTThe exponential growth of the mobile devices market, not only smartphones but also tablets, laptops or wearables, poses a serious challenge for 5G communications. Random linear network coding is a promising solution for present and future networks as it has been shown to provide increased throughput, security and robustness for the transmission of data through the network. Most of the analysis and the demonstrators have focused on the study of data packets with the same size (number of bytes). This constitutes a best‐case scenario as coded packets will incur little overhead to handle such packets. However, packet lengths are quite heterogeneous in real networks, which can cause a high overhead or, alternatively, a high delay in the transmission of data packets. As we show, this can have a severe effect on a variety of applications. This paper proposes a series of mechanisms to manage heterogeneous packet lengths and analyses the induced overhead of those mechanisms using real packet length distributions provided by the Center for Applied Internet Data Analysis (CAIDA) and own measurements using video content. Our results show that an appropriate packetisation of the data packets can reduce the overhead from over 100 per cent (zero‐padding packets) to below 5 per cent for CAIDA packet distributions and that the right choice of parameters can reduce the overhead to less than 10 per cent in the case of video data. Copyright © 2014 John Wiley & Sons, Ltd.

Analysis and Simulation of Binary Search Algorithm

Some drawbacks of existing binary search algorithm has been improved to reduce the number of paging through improved reader in this paper to reduce the number of bytes for each tag and reader communication transmission, thereby reducing the improved algorithm of recognition time. At the same time, an improved binary anti-collision algorithm, and by Matlab simulation results show the advantages of the improved algorithm compared to other improved binary search algorithm.

A time for reliability

When a new technology reaches the market, we typically focus on the want or need that it can fulfill. As the technology becomes a commodity and its market matures, reliability often become a key differentiating factor between competing products. We posit that as broadband capacities continue to improve and users migrate to over-the-Internet services, such as on-demand video and voice-over-IP services, we will see this common pattern emerge for broadband services. In this poster, we present the first study of reliability in broadband networks. Using data collected from residential gateways (via FCC/SamKnows), we study the availability and reliability of fixed-line broadband services across the US. Using natural experiments, we look at the impact of increased network downtime on user network demand. We use traditional metrics (e.g. failure rate, MTBF, MTTR) to quantify broadband services, as well as each ISP's configured DNS. Since the impact of a network outage will depend on when it occurred (e.g. time of day), we compare ISP services by the annual average number of bytes lost, based on typical user demand during periods of network downtime.

Histogram Equilization on Wavelet based Compression Techniques

This paper analyzes the effect of histogram equalization on the wavelet based compression techniques. Image compression is reducing the size of an image using one of the encoding techniques. Encoding helps in saving disk space by representing the same data in lesser number of bytes. Histogram is a graphical representation of intensity distribution of an image. It expresses the number of pixel values for each intensity value of an image. Histogram Equalization is a method used to improve the contrast of an image to stretch out the full range of an intensity .Comparison among algorithms has been made with respect to PSNR (Peak signal to noise ratio), MSE (Mean square error), MAE (Mean Absolute Error), L2RAT, Compression ratio.

Discount Counting for Fast Flow Statistics on Flow Size and Flow Volume

A complete flow statistics report should include both flow size (the number of packets in a flow) counting and flow volume (the number of bytes in a flow) counting. Although previous studies have contributed a lot to the flow size counting problem, it is still a great challenge to well support the flow volume statistics due to the demanding requirements on both memory size and memory bandwidth in monitoring device. In this paper, we propose a DIScount COunting (DISCO) method, which is designed for both flow size and flow bytes counting. For each incoming packet of length $l$ , DISCO increases the corresponding counter assigned to the flow with an increment that is less than $l$ . With an elaborate design on the counter update rule and the inverse estimation, DISCO saves memory consumption while providing an accurate unbiased estimator. The method is evaluated thoroughly under theoretical analysis and simulations with synthetic and real traces. The results demonstrate that DISCO is more accurate than related work given the same counter sizes. DISCO is also implemented on the network processor Intel IXP2850 for a performance test. Using only one microengine (ME) in IXP2850, the throughput can reach up to 11.1 Gb/s under a traditional traffic pattern. The throughput increases to 39 Gb/s when employing four MEs.

Analyzing Security and Performance Issue in Web Data Mining Technology

Since as the internet and web application emerges security is the most challenging issue which we are facing, leads possibility of being easily damaged. Currently we based application structure is designed only by considering little security but avoid Performance issue. After the detailed study of web services architecture it is analyzed that it is not suitable in counter-tracing the WS attack, an adaptive intrusion detection and prevention (ID/IP) framework to protect The WS against attacks related to WSDL/JSON/SQL is thus introduced. Through Explanation by examples, the framework Verified that by making use of agents that act as Sensors, data mining techniques such as clustering, association and sequential rule coupled with fuzzy logic to further analyze and identify anomalies, is able to exhibit the adaptive nature of capturing anomalies and avoiding false alarm. Also the log files which contain User Name, IP Address, Visiting Path, Time Stamp, Page last visited , number of Bytes Transferred, Result Status, URL which can effectively supervise the network attack. In this paper we will discuss elaborately about several security problem and performance issue related to web application and their possible solutions.

Modeling and Simulation Study of Space Data Link Protocol

This research paper describes the design and implementation of the Consultative Committee for Space Data Systems (CCSDS) standards REF _Ref401069962 \r \h \* MERGEFORMAT [1] for Space Data Link Layer Protocol (SDLP). The primer focus is the telecommand (TC) part of the standard. The implementation of the standard was in the form of DLL functions using C++ programming language. The second objective of this paper was to use the DLL functions with OMNeT++ simulating environment to create a simulator in order to analyze the mean end-to-end Packet Delay, maximum achievable application layer throughput for a given fixed link capacity and normalized protocol overhead, defined as the total number of bytes transmitted on the link in a given period of time (e.g. per second) divided by the number of bytes of application data received at the application layer model data sink. In addition, the DLL was also integrated with Ground Support Equipment Operating System (GSEOS), a software system for space instruments and small spacecrafts especially suited for low budget missions. The SDLP is designed for rapid test system design and high flexibility for changing telemetry and command requirements. GSEOS can be seamlessly moved from EM/FM development (bench testing) to flight operations. It features the Python programming language as a configuration/scripting tool and can easily be extended to accommodate custom hardware interfaces. This paper also shows the results of the simulations and its analysis.

Performance of BCH codes with (1 + x ) s error detection

The performance is investigated of a combined error correction and detection decoder for BCH codes for which the generator polynomial g ( x ) has been augmented by a (1 + x ) s term in order to make the informations bits an integral number of bytes. An ARQ retransmission scheme on an additive white Gaussian noise channel is assumed and a comparison with an FEC-only BCH code is given in terms of probability of error against E b / N 0 . It is shown for a BCH (127, 106, 7) code that at high E b / N 0 the performance improvement is of three orders of magnitude at the cost of a small rate degradation. Goppa codes, whose length is an integral number of bytes, have also been investigated, producing similar results.

MRAM 기반 SSD 파일 시스템의 에너지 효율적 서브페이징

The advent of the state-of-the-art technologies such as cloud computing and big data processing stimulates the provision of various new IT services, which implies that more servers are required to support them. However, the need for more servers will lead to more energy consumption and the efficient use of energy in the computing environment will become more important. The next generation nonvolatile RAM has many desirable features such as byte addressability, low access latency, high density and low energy consumption. There are many approaches to adopt them especially in the area of the file system involving storage devices, but their focus lies on the improvement of system performance, not on energy reduction. This paper suggests a novel approach for energy reduction in which the MRAM-based SSD is utilized as a storage device instead of the hard disk and a downsized page is adopted instead of the 4KB page that is the size of a page in the ordinary file system. The simulation results show that energy efficiency of a new approach is very effective in case of accessing the small number of bytes and is improved up to 128 times better than that of NAND Flash memory.

Reporting Available Demand Response

Demand response is increasingly important in many power systems but Transmission System Operators (TSO) require confirmation that the response is available if it is to be used effectively. Demand response may be used to minimise the amount of spinning reserve obtained from partially loaded generators. The ability of the proposed smart metering communication system in the U.K. to report the available demand response from domestic appliances was examined. This communication system expects to send all data traffic at an average rate of about 190 Mbytes per minute through a central Data Communication Company (DCC) to any actor operating in the power system. It is unlikely that this communication system will, in addition, support reporting demand response in near real-time. Using load profiles of fridges, cooking appliances and washers and dryers, the load profiles of 40 000 houses were constructed. These load profiles were used to calculate the average number of load changes in a typical house, a 11/0.4 kV transformer and a high voltage substation. Using these average numbers of load changes and the number of transformers and substations in the U.K. power system, the number of messages sent by all smart meters in the U.K. was calculated. It is shown that the wide area network proposed for the U.K. need to send an additional 162 Mbytes per minute to report demand response in near real-time. Then, a hierarchically arranged communication system that follows the hierarchy of electrical network was examined. It was assumed that aggregating units are installed at distribution transformers and substations. It is shown that by aggregating and sending only measurement changes, the number of bytes sent through the U.K. smart metering communication system per minute could be reduced from 162 M to 30 k. This has important implications as the U.K. is now finalizing the specifications for smart metering communications for about 27 million smart electricity meters that will be installed in the period 2014-2020.

Statistical Analysis of Compression Methods for Storing Binary Image for Low-Memory Systems

The paper is focused on the statistical comparison of the selected compression methods which are used for compression of the binary images. The aim is to asses, which of presented compression method for low-memory system requires less number of bytes of memory. For assessment of the success rates of the input image to binary image the correlation functions are used. Correlation function is one of the methods of OCR algorithm used for the digitization of printed symbols. Using of compression methods is necessary for systems based on low-power micro-controllers. The data stream saving is very important for such systems with limited memory as well as the time required for decoding the compressed data. The success rate of the selected compression algorithms is evaluated using the basic characteristics of the exploratory analysis. The searched samples represent the amount of bytes needed to compress the test images, representing alphanumeric characters.

Summarizing numeric spatial data streams by trend cluster discovery

Advances in pervasive computing and sensor technologies have paved the way for the explosive living ubiquity of geo-physical data streams. The management of the massive and unbounded streams of sensor data produced poses several challenges, including the real-time application of summarization techniques, which should allow the storage and query of this amount of georeferenced and timestamped data in a server with limited memory. In order to face this issue, we have designed a summarization technique, called SUMATRA, which segments the stream into windows, computes summaries window-by-window and stores these summaries in a database. Trend clusters are discovered as summaries of each window. They are clusters of georeferenced data which vary according to a similar trend along the window time horizon. Several compression techniques are also investigated to derive a compact, but accurate representation of these trends for storage in the database. A learning strategy to automatically choose the best trend compression technique is designed. Finally, an in-network modality for tree-based trend cluster discovery is investigated in order to achieve an efficacious aggregation schema which drastically reduces the number of bytes transmitted across the network and maintains a longer network lifespan. This schema is mapped onto the routing structure of a tree-based WSN topology. Experiments performed with several data streams of real sensor networks assess the summarization capability, the accuracy and the efficiency of the proposed summarization schema.

Improved recovery and reconstruction of DEFLATEd files

This paper presents a method for recovering data from files compressed with the DEFLATE algorithm where short segments in the middle of the file have been corrupted, yielding a mix of literal bytes, bytes aligned with literals across the corrupted segment, and co-indexed unknown bytes. An improved reconstruction algorithm based on long byte n-grams increases the proportion of reconstructed bytes by an average of 8.9% absolute across the 21 languages of the Europarl corpus compared to previously-published work, and the proportion of unknown bytes correctly reconstructed by an average of 20.9% absolute, while running in one-twelfth the time on average. Combined with the new recovery method, corrupted segments of 128–4096 bytes in the compressed bit-stream result in reconstructed output which differs from the original file by an average of less than twice the number of bytes represented by the corrupted segment. Both new algorithms are implemented in the trainable open-source ZipRec 1.0 utility program.