Artur Sierszeń

Reduction of Reference Set for Network Data Analyzing Using the Bubble Algorithm

Data in modern networks should be analysed in real time. This is necessary to maintain security and enable management. The real problem is the size of analysed data and its classification. One of several solutions to these problems may be reduction the reference network data set. Most algorithms for the condensation of the reference set involve a lot of computation when processing a very large set which contains several dozens of objects. That was the basis for our attempt to develop a completely new classifier which would maintain the quality of classification on the levels obtained with the primary reference set as well as allow to accelerate computations considerably. The proposed solution consists in covering the primary reference set with disjoint hyperspheres; however, these hyperspheres may contain objects from one class only. Classification is completed when it has been determined that the classified point belongs to one of the mentioned spheres. If an object does not belong to any hypersphere, it is counted among the objects of the same class, to which the objects from the nearest hypersphere belong (the distance to the centre of the sphere minus the radius). As was shown in our tests, this algorithm was very effective with very large data sets.

Self-configuration Networks

The observation of the network behavior and the quantitative description of the network condition is one of the most important activities for network administrators and analysts. Networks are dynamically changing over time, while their structure stays fixed traffic or device load can rapidly change causing networking failures, inaccessibilities or delays due to nodes overload. The article is focused on the active monitoring and configuration of network nodes using the general common standards. The work concerns a design of a decision system based on predefined actions invoking network reconfiguration when observed parameters exceed acceptable limits. The general concept of the self-configuration networks system is presented; the architecture, requirements and basic activities are widely discussed.

QoE-Oriented Fairness Control for DASH Systems Based on the Hierarchical Structure of SVC Streams

Nowadays, multimedia content is the basis of most popular network services. At the same time, adaptive video streaming is becoming more widely used method for delivering such content to end users. The main purpose of the mechanisms of adaptation is to maximize the usage of network resources while ensuring the best quality of transmitted video. The implementation of adaptation, however, has a serious drawback of not considering the mutual influence of simultaneous transmission of multiple video streams. In this article, we propose a method of the QoE-oriented fairness control for DASH systems which uses a new utility function. This function based on a hierarchical structure of a SVC video stream. The properties of this solution were evaluated in a test environment that uses SDN principles. Functional features of the proposed control method were compared with standard algorithm of the adaptation used by DASH supported devices.

Gradation of Video Quality in Dash Services Using the H.264/SVC Coding

Abstract The share of video streaming services in the global network traffic is increasing every year. For this reason the problem of optimal use of the available bandwidth, while ensuring an acceptable level of quality of the transmitted video is becoming an important issue. A combination of two techniques, DASH streaming and H.264/AVC video coding can be an important step towards solving this problem. The article presents the discussion the choice of the proper gradation of SVC encoding parameters inside representation of video content in DASH systems. We propose the Temporal Preservation (T-P) method of selection of the SVC stream structure to optimize the grading changes of video quality. This method allows for the implementation of DASH adaptation to changes in available bandwidth on the transmission link, which minimizes the impact of this process on the quality of the received video. According to results of conducted tests, the T-P method offers a better final video quality in DASH systems than similar solutions based on a standard adaptation method. The comparison with the DASH system that uses H.264/AVC encoding also showed superiority of the T-P method, especially in situations of high network congestion

Software Defined Home Network for Distribution of the SVC Video Based on the DASH Principles

With the spread of Dynamic Adaptive Streaming over HTTP (DASH) systems, appeared the problem related to the resources management in end-users’ networks. The article proposes a new solution for the distribution of Scalable Video Coding (SVC) video streams in home networks. It relies on a Software Defined Network (SDN) controller, which based on the parameters of transmitted SVC video and the usage status of network resources allows for dynamic traffic shaping. At the same time, it was assumed that the proposed solution is compatible with Server and Network Assisted DASH (SAND) standard and its implementation is possible without the use of additional, dedicated hardware. The article presents the analysis of influence of proposed SDN on the improvement of the SVC video quality received by DASH clients in a typical home network. Test results confirm the superiority of the proposed system over the conventional solutions.

Sensor Fusion Enhancement for Mobile Positioning Systems

Recently, a great amount of mobile devices are equipped with various sensors such as accelerometers, GPS receivers, gyroscopes, microphones and cameras. Moreover, all these devices use embedded Bluetooth and wireless network cards for mobile communication. One of the most significant development of recent years is GPS. This system has become the standard for navigation for many people all over the world. A huge variety of applications employ GPS from car positioning to mobile phone navigation for emergency purposes. In spite of the fact that this system is commonly used in everyday’s actions it has some limitations. GPS is unable to determine the position inside the buildings, because of the loss of signal from satellites. Recently, due to existence of ubiquities mobile devices the curiosity in location based services has considerably increased. The application of Bluetooth and wireless network was employed for portable positioning systems. However, those systems considerably increase the accuracy for indoor localization, still the outcome is not satisfactory. Thus, the combination of a variety of signals measured by mobile equipments could provide an enhancement for mobile system used in positioning.

System of Distance Measurement and Localization of Wireless Devices Communicating Based on Bluetooth Technologies

Personal wireless networks are very popular nowadays. Wireless networks administrators have access to a great deal of information about users. They may use selected information in order to try to locate a devices who is active in a network. A mechanism has been implemented which enables the user to locate devices communicating based on bluetooth technologies, using coordinates or references to characteristic points.

Evaluation of Reliability of a Decision-Making Process Based on Pattern Recognition

In recent years, all kinds of assistance to decision-making processes have become of great importance. In many areas of life, technology, and science, computation machines, i.e. computers, assist people in making decisions; in some particular cases, computers are even able to make these decisions themselves. There are, admittedly, many situations, i.e. in flight control, airport traffic, or biomedical data analysis, where even decisions made by the most efficient algorithm (or the most efficient machine) must be confirmed by a man. Nevertheless, in many disciplines, such as finance, psychology, medicine, or biology, mechanisms assisting the decision-making process facilitate work significantly. One of the key issues is the reliability of made decisions. However, this issue is often passed over due to great increase in the amount of data processed by those systems, what forces the designers to focus on the systems’ efficiency.