2016 International Conference on Emerging eLearning Technologies and Applications (ICETA)
With population over 7.4 billion, communication barrier becomes a serious problem. To reduce such... more With population over 7.4 billion, communication barrier becomes a serious problem. To reduce such barriers, one of potential solutions can be lifelong learning of foreign languages. Authors of this study focus on process of learning foreign languages with an effective transformation to learning through smartphones. As a result, an e-learning Android application is presented, taking advantages of popular and successful “Callan” learning method.
When representing the geometry of voxelized three-dimensional scenes (especially if they have bee... more When representing the geometry of voxelized three-dimensional scenes (especially if they have been voxelized to high resolutions) in a naive—uncompressed—form, one may end up using vast amounts of data. These can easily attack the available memory capacity of the graphics card, the operating memory or even secondary storage of computer. A viable solution to this problem is to use domain-specific hierarchical data structures, based on octant trees or directed acyclic graphs, which, among other advantages, provide a compact binary representation that can thus be considered to be their compressed encoding. These data structures include—inter alia—sparse voxel octrees, sparse voxel directed acyclic graphs and symmetry-aware sparse voxel directed acyclic graphs. The paper deals with the proposal of a new domain-specific hierarchical data structure: the clustered sparse voxel octrees. It is designed to represent the geometry of voxelized three-dimensional scenes and can be constructed usi...
2017 IEEE 15th International Symposium on Applied Machine Intelligence and Informatics (SAMI)
The Network Intrusion Detection Systems (NIDS) are either signature based or anomaly based. In th... more The Network Intrusion Detection Systems (NIDS) are either signature based or anomaly based. In this paper presented NIDS system belongs to anomaly based Neural Network Intrusion Detection System (NNIDS). The proposed NNIDS is able to successfully recognize learned malicious activities in a network environment. It was tested for the SYN flood attack, UDP flood attack, nMap scanning attack, and also for non-malicious communication.
2021 IEEE 19th World Symposium on Applied Machine Intelligence and Informatics (SAMI), 2021
The paper deals with the problematics of the dense volume datasets representation, in which voxel... more The paper deals with the problematics of the dense volume datasets representation, in which voxels are formed as multi-bit scalar values, and is oriented to the use of hierarchical data structures, not only as the medium for encoding and storing of volume datasets, but also for their lossless compression. The main contribution of the paper is in the design of the hierarchical data structure, that allows carving out of subtrees, that are homogenously filled not only by the symbol 0 or symbol 1, but any binary representation of voxel value from defined set of values. Designed data structure provides the possibility of fixed-length and also variable-length (Huffman) encoding of voxel values in leaf node level of the data structure and also in the non-leaf nodes. Results of tests, performed on medical volume datasets that were obtained by various non-invasive imaging techniques, including Computed Tomography and Magnetic Resonance Imaging, along with conclusions that were made, based on the test results, take place in the second part of the paper.
Abstract: This paper introduces basic parallelism in fuzzy databases and its queries. Article des... more Abstract: This paper introduces basic parallelism in fuzzy databases and its queries. Article describes basic characteristics of fuzzy databases and their properties, compares fuzzy logic with boolean one in connection with fuzzy databases. Deal with data clasification and form of storage fuzzy data in database systems. Paper describes fuzzy queries and parallelism in queries from view of today’s systems and their connection to SQL language and its extension fuzzy SQL. Discuss about pipeline parallelism of query operators and its benefits.
This paper deals with the issues of volume dataset representation as an important part of data st... more This paper deals with the issues of volume dataset representation as an important part of data storage and processing in many fields including science, research and development, medicine or industry. Due to the significant amount of data included in volume datasets, operations performed on them are often, time-and space-consuming. One of those operationsloading data from secondary storage into the operating memory of computer or memory of graphics cardcan be time-consuming and lead to a bad user experience and significantly delay the subsequent processes. Therefore, the main contribution hereof is the design and introduction of an algorithm to generate volume dataset segmentation metadata. It allows (with a small data overhead, as a trade-off) to prepare metadata about splitting the particular volume dataset into segments with different priority levels. Subsequently, it is possible to reorganize the volume dataset according to the priority of the data segments, in descending order. The algorithm proposed herein allows to start the visualization of the volume dataset in its final quality (resembling visualization of the complete volume dataset, although only a part of the data was loaded from the secondary storage), within a fraction of the total load time of the volume dataset. The remaining data are continually read in the background during data visualization, without affecting volume data visualization quality. The first section herein, contains an introduction to the proposed algorithms. Results of tests, performed with different parameter setups on non-invasive medical imaging volume datasets, obtained by computed tomography and magnetic resonance imaging, are included in the second part of the paper. Conclusions, drawn from test results, are summarized in the last part of the paper.
This paper deals with the Encrypted Key Exchange (EKE) authentication method, which offers an opp... more This paper deals with the Encrypted Key Exchange (EKE) authentication method, which offers an opportunity to log on to a server and to authenticate the user itself without using a certificate or any direct transmission of the password. This makes the method an interesting alternative solution, where at the end of the authentication process generated is a key that can be further used for the needs of symmetric encryption. In the paper, an implementation of a client-server application that uses EKE authentication method is described. This application after a successful login process enables the user to transfer files in encrypted form, while the encryption key is generated at the end of the authentication process.
The goal of this paper is to present designed architecture of intrusion detection system based on... more The goal of this paper is to present designed architecture of intrusion detection system based on events planning and intrusion signature. The article describes problematic of the variation of intrusions and intrusion detection systems. The core of the proposed architecture is intrusion signature matching through petri nets that clasify system behaviour and determine potential intrusion of monitored computer system. The result is a new method of intrusions signature detection.
This paper examines the issues of domain-specific hierarchical data structures, based on directed... more This paper examines the issues of domain-specific hierarchical data structures, based on directed acyclic graphs, dedicated to the representation of the geometry of threedimensional scenes. In this paper, the authors introduce two versions (out-of-core and semi-out-of-core) of an algorithm to transform hierarchical data structurespointerless sparse voxel directed acyclic graphs, into sparse voxel directed acyclic graphs. Pointerless sparse voxel directed acyclic graphs are not suitable for immediate traversing, due to the absence of pointers to the child nodes; however, they are suitable for archiving and streaming, as they have a more compact binary-level representation. Sparse voxel directed acyclic graphs, on the other hand, allow quick traversing during visualization or other forms of processing, since their nodes include pointers to child nodes. The disadvantage of this, is that the binary-level representation, requires more operating memory or secondary storage space. Both hierarchical data structuressparse voxel directed acyclic graphs and pointerless sparse voxel directed acyclic graphsand both versions of the proposed conversion algorithm are described in the first part of the paper. Results of tests, performed on various modelspreviously surface polygonal models, stored in the Wavefront Technologies geometry definition file format (OBJ)now voxelized to the respective resolutions, are summarized in the second part of the paper. The binary-level representation lengths of both data structures, along with the time consumption of both versions of the proposed conversion algorithms, are detailed in the last part of the paper.
Boolean function minimization is an area important not only in the development and optimization o... more Boolean function minimization is an area important not only in the development and optimization of digital logic, but also in other research and development areas, such as, the optimization of control systems, simplifying program logic, artificial intelligence, etc. The aim of this paper is to present a hardware accelerated first step of the systematic minimization of single-output Boolean functionsthe generation of a set of prime implicants for both the disjunctive normal form (DNF) and the conjunctive normal form (CNF), having defined the OFF and ON sets andalternativelyalso the DC ("don't care") set. The proposed hardware accelerator is designed as combinational logic, described in VHDL. Its advantages include an extremely short prime-implicant-generation time in the order of ns and/or tens of nsin case of Boolean functions with small amount of input variablesand the possibility to generate the valid-prime-implicant set of Boolean functions having a defined number of input variables at a constant time, regardless of the cardinality of the ON or, eventually, the DC sets. However, these advantages come with a large spatial complexitythe number of utilized implementation elementsof the respective combinational module, generating the prime-implicant set. The authors verified the proposed design using Field Programmable Gate Array (FPGA) technology, implementing the hardware using a Xilinx Kintex-7 KC-705 Evaluation Kit development board.
Nowadays, when computers and computer systems are almost omnipresent and are part of most househo... more Nowadays, when computers and computer systems are almost omnipresent and are part of most households and most people have access to them, they are more vulnerable than ever. Today, protection and security of computer networks and systems using passive protection does not suffice anymore. One has to anticipate attacks and be a step ahead of the attackers. To achieve this type of security, one has to employ active protection techniques, such as digital baitshoneypots. The primary goal of using honeypots is to divert the interest of potential attackers from other really important targets within a particular computer network. The secondary goal is to acquire information about the attackers' activities and methods. Subsequently, these data are thoroughly analysed. By analysing the attacks, security improvement measures aimed at the particular network and/or computer system may be proposed in order to prevent threats. The goal of this paper is to contribute to computer security by proposing a clustered, high-interactionhoneypot-based security system.
Cognitive radio (CR) is the underlying platform for the application of dynamic spectrum access (D... more Cognitive radio (CR) is the underlying platform for the application of dynamic spectrum access (DSA) networks. Although the auction theory and spectrum trading mechanisms have been discussed in the CR related works, their joint techno-economic impact on the efficiency of distributed CR networks has not been researched yet. In this paper we assume heterogeneous primary channels with network availability statistics unknown to each secondary user (SU) terminal. In order to detect the idle primary user (PU) network channels, the SU terminals trigger regularly the spectrum sensing mechanism and make the cooperative decision regarding the channel status at the fusion center. The imperfections of the spectrum mechanism create the possibility of the channel collision, resulting in the existence of the risk (in terms of user collision) in the network. The spectrum trading within SU network is governed by the application of the sealed-bid first-price auction, which takes into account the channel valuation as well as the statistical probability of the risk existence. In order to maximize the long-term payoff, the SU terminals take an advantage of the reinforcement comparison strategy. The results demonstrate that in the investigated model, total revenue and total payoff of the SU operator (auctioneer) and SU terminals (bidders) are characterized by the existence of the global optimum, thus there exists the optimal sensing time guaranteeing the optimum economic factors for both SU operator and SU terminals.
Paper deals with the data driven computation control paradigm, which is alternative to the mainst... more Paper deals with the data driven computation control paradigm, which is alternative to the mainstream control flow model of program execution control. In the second part of the paper we are introducing computer architecture that is proposed at the Department of Computers and Informatics, Faculty of Electrical Engineering and Informatics, Technical University of Košice, according to the data driven computation control model with use of tile computing principles. In the final part of the paper, subgraph colouring technique that is unique characteristic of proposed computer architecture is described.
V článku uvedená architektúra je založená na výpočtovom modeli „data flow“, v ktorom riadenie výp... more V článku uvedená architektúra je založená na výpočtovom modeli „data flow“, v ktorom riadenie výpočtu je založené na spracovaní toku dát. Základným prvkom DF architektúry je koordinačný procesor (CP), ktorý je zodpovedný za riadenie a organizáciu vykonávania inštrukcií. Štruktúrna organizácia CP je navrhnutá ako dynamický multifunkčný systém. Pri vykonávaní operácií môže CP prechádzať rôznymi stavmi, v dôsledku čoho táto jednotka predstavuje dynamický prúdový systém. Prechod a poradie prechodu medzi jednotlivými stavmi CP je podmienený typom spracovaného operátora pri interpretovaní prúdu operandov. Z možných typov operátorov, článok uvádza mikroprogramové riadenie pre jednovstupové operátory.
One of the main goals of an operating system is the efficient usage of system resources and their... more One of the main goals of an operating system is the efficient usage of system resources and their management. Modern systems offer complex mechanisms for the management of these resources. Their system-wide use may be separated into multiple layersfrom the lowest (the operating system kernel) to the highest (various virtualization techniques). Somewhere in the middle are the applications consuming these system resources. An example of such an application is the Apache web server. It implements some of the resource management mechanisms at application level. However, the system contains elements, the management of which is not possible at application level or its implementation has a significant overhead and may negatively affect the performance and secure usage of the server. The aim of the study is to create a more efficient resource management mechanism at the level of the Apache web server. The proposed architecture allows the treatment of possible security threats, such as DoS attacks, makes the use of system resources more efficient, thusindirectlyit also addresses the environmental impacts of data centers. The reason for selecting the Apache web server as the referential implementation of the resource usage improvement are its market share and its open source nature, which renders making amendments to the server simple.
Due to the expansion of high-speed Internet access, the need for secure and reliable networks has... more Due to the expansion of high-speed Internet access, the need for secure and reliable networks has become more critical. Since attacks are becoming more sophisticated and networks are becoming larger there is a need for an efficient intrusion detection systems (IDSs) that can distinguish between legitimate and illegitimate traffic and be able to signal attacks in real time, before serious damages are produced. Although there are some existing mechanisms for intrusion detection, there is need to improve the performance. Data mining techniques and machine learning are a new approach for intrusion detection. In this work naive Bayes classifier and decision trees with C4.5 and CART algorithms for detecting abnormal traffic patterns in the KDD Cup 1999 data are used. The IDS system is supposed to distinguish normal traffic from intrusions and to classify the intrusions into five classes: Normal, DoS, probe, R2L and U2R. Research shows that decision trees gives better overall performance than the naive Bayes classifier.
2012 IEEE 16th International Conference on Intelligent Engineering Systems (INES), 2012
ABSTRACT This paper deals with recent results of a supporting mechanism for efficient evaluation ... more ABSTRACT This paper deals with recent results of a supporting mechanism for efficient evaluation of network traffic parameters. Most of the network monitoring tools store the measured data in a database for the later analysis. With the growth of the data in the database, processing of queries is becoming more and more time consuming. This fact results in an excessive response time of the database, which subsequently brings an adverse impact on the monitoring tool. While most of the monitoring tools make evaluations on the basis of outdated data from a database, the vast majority of them have to deal with this problem. In this contribution a new approach of efficient network traffic data evaluation through a database will be introduced, while the main attention will be dedicated to the implementation details.
2012 IEEE 10th International Symposium on Applied Machine Intelligence and Informatics (SAMI), 2012
ABSTRACT This paper deals with the solution of database related problems which can occur during n... more ABSTRACT This paper deals with the solution of database related problems which can occur during network traffic monitoring. During data evaluation through a database excessive response time can be noticed. While the time necessary to obtain the data from the database has a significant effect on the result of the monitoring, it is important to keep its value as low as possible. Practically, the vast majority of the monitoring tools have to deal with the problems related to the database's excessive response time, so their solution is really justified. In this paper an alternative method of network monitoring, the BasicMeter tool will be introduced by which the exact problems and their solution will be illustrated.
2016 International Conference on Emerging eLearning Technologies and Applications (ICETA)
With population over 7.4 billion, communication barrier becomes a serious problem. To reduce such... more With population over 7.4 billion, communication barrier becomes a serious problem. To reduce such barriers, one of potential solutions can be lifelong learning of foreign languages. Authors of this study focus on process of learning foreign languages with an effective transformation to learning through smartphones. As a result, an e-learning Android application is presented, taking advantages of popular and successful “Callan” learning method.
When representing the geometry of voxelized three-dimensional scenes (especially if they have bee... more When representing the geometry of voxelized three-dimensional scenes (especially if they have been voxelized to high resolutions) in a naive—uncompressed—form, one may end up using vast amounts of data. These can easily attack the available memory capacity of the graphics card, the operating memory or even secondary storage of computer. A viable solution to this problem is to use domain-specific hierarchical data structures, based on octant trees or directed acyclic graphs, which, among other advantages, provide a compact binary representation that can thus be considered to be their compressed encoding. These data structures include—inter alia—sparse voxel octrees, sparse voxel directed acyclic graphs and symmetry-aware sparse voxel directed acyclic graphs. The paper deals with the proposal of a new domain-specific hierarchical data structure: the clustered sparse voxel octrees. It is designed to represent the geometry of voxelized three-dimensional scenes and can be constructed usi...
2017 IEEE 15th International Symposium on Applied Machine Intelligence and Informatics (SAMI)
The Network Intrusion Detection Systems (NIDS) are either signature based or anomaly based. In th... more The Network Intrusion Detection Systems (NIDS) are either signature based or anomaly based. In this paper presented NIDS system belongs to anomaly based Neural Network Intrusion Detection System (NNIDS). The proposed NNIDS is able to successfully recognize learned malicious activities in a network environment. It was tested for the SYN flood attack, UDP flood attack, nMap scanning attack, and also for non-malicious communication.
2021 IEEE 19th World Symposium on Applied Machine Intelligence and Informatics (SAMI), 2021
The paper deals with the problematics of the dense volume datasets representation, in which voxel... more The paper deals with the problematics of the dense volume datasets representation, in which voxels are formed as multi-bit scalar values, and is oriented to the use of hierarchical data structures, not only as the medium for encoding and storing of volume datasets, but also for their lossless compression. The main contribution of the paper is in the design of the hierarchical data structure, that allows carving out of subtrees, that are homogenously filled not only by the symbol 0 or symbol 1, but any binary representation of voxel value from defined set of values. Designed data structure provides the possibility of fixed-length and also variable-length (Huffman) encoding of voxel values in leaf node level of the data structure and also in the non-leaf nodes. Results of tests, performed on medical volume datasets that were obtained by various non-invasive imaging techniques, including Computed Tomography and Magnetic Resonance Imaging, along with conclusions that were made, based on the test results, take place in the second part of the paper.
Abstract: This paper introduces basic parallelism in fuzzy databases and its queries. Article des... more Abstract: This paper introduces basic parallelism in fuzzy databases and its queries. Article describes basic characteristics of fuzzy databases and their properties, compares fuzzy logic with boolean one in connection with fuzzy databases. Deal with data clasification and form of storage fuzzy data in database systems. Paper describes fuzzy queries and parallelism in queries from view of today’s systems and their connection to SQL language and its extension fuzzy SQL. Discuss about pipeline parallelism of query operators and its benefits.
This paper deals with the issues of volume dataset representation as an important part of data st... more This paper deals with the issues of volume dataset representation as an important part of data storage and processing in many fields including science, research and development, medicine or industry. Due to the significant amount of data included in volume datasets, operations performed on them are often, time-and space-consuming. One of those operationsloading data from secondary storage into the operating memory of computer or memory of graphics cardcan be time-consuming and lead to a bad user experience and significantly delay the subsequent processes. Therefore, the main contribution hereof is the design and introduction of an algorithm to generate volume dataset segmentation metadata. It allows (with a small data overhead, as a trade-off) to prepare metadata about splitting the particular volume dataset into segments with different priority levels. Subsequently, it is possible to reorganize the volume dataset according to the priority of the data segments, in descending order. The algorithm proposed herein allows to start the visualization of the volume dataset in its final quality (resembling visualization of the complete volume dataset, although only a part of the data was loaded from the secondary storage), within a fraction of the total load time of the volume dataset. The remaining data are continually read in the background during data visualization, without affecting volume data visualization quality. The first section herein, contains an introduction to the proposed algorithms. Results of tests, performed with different parameter setups on non-invasive medical imaging volume datasets, obtained by computed tomography and magnetic resonance imaging, are included in the second part of the paper. Conclusions, drawn from test results, are summarized in the last part of the paper.
This paper deals with the Encrypted Key Exchange (EKE) authentication method, which offers an opp... more This paper deals with the Encrypted Key Exchange (EKE) authentication method, which offers an opportunity to log on to a server and to authenticate the user itself without using a certificate or any direct transmission of the password. This makes the method an interesting alternative solution, where at the end of the authentication process generated is a key that can be further used for the needs of symmetric encryption. In the paper, an implementation of a client-server application that uses EKE authentication method is described. This application after a successful login process enables the user to transfer files in encrypted form, while the encryption key is generated at the end of the authentication process.
The goal of this paper is to present designed architecture of intrusion detection system based on... more The goal of this paper is to present designed architecture of intrusion detection system based on events planning and intrusion signature. The article describes problematic of the variation of intrusions and intrusion detection systems. The core of the proposed architecture is intrusion signature matching through petri nets that clasify system behaviour and determine potential intrusion of monitored computer system. The result is a new method of intrusions signature detection.
This paper examines the issues of domain-specific hierarchical data structures, based on directed... more This paper examines the issues of domain-specific hierarchical data structures, based on directed acyclic graphs, dedicated to the representation of the geometry of threedimensional scenes. In this paper, the authors introduce two versions (out-of-core and semi-out-of-core) of an algorithm to transform hierarchical data structurespointerless sparse voxel directed acyclic graphs, into sparse voxel directed acyclic graphs. Pointerless sparse voxel directed acyclic graphs are not suitable for immediate traversing, due to the absence of pointers to the child nodes; however, they are suitable for archiving and streaming, as they have a more compact binary-level representation. Sparse voxel directed acyclic graphs, on the other hand, allow quick traversing during visualization or other forms of processing, since their nodes include pointers to child nodes. The disadvantage of this, is that the binary-level representation, requires more operating memory or secondary storage space. Both hierarchical data structuressparse voxel directed acyclic graphs and pointerless sparse voxel directed acyclic graphsand both versions of the proposed conversion algorithm are described in the first part of the paper. Results of tests, performed on various modelspreviously surface polygonal models, stored in the Wavefront Technologies geometry definition file format (OBJ)now voxelized to the respective resolutions, are summarized in the second part of the paper. The binary-level representation lengths of both data structures, along with the time consumption of both versions of the proposed conversion algorithms, are detailed in the last part of the paper.
Boolean function minimization is an area important not only in the development and optimization o... more Boolean function minimization is an area important not only in the development and optimization of digital logic, but also in other research and development areas, such as, the optimization of control systems, simplifying program logic, artificial intelligence, etc. The aim of this paper is to present a hardware accelerated first step of the systematic minimization of single-output Boolean functionsthe generation of a set of prime implicants for both the disjunctive normal form (DNF) and the conjunctive normal form (CNF), having defined the OFF and ON sets andalternativelyalso the DC ("don't care") set. The proposed hardware accelerator is designed as combinational logic, described in VHDL. Its advantages include an extremely short prime-implicant-generation time in the order of ns and/or tens of nsin case of Boolean functions with small amount of input variablesand the possibility to generate the valid-prime-implicant set of Boolean functions having a defined number of input variables at a constant time, regardless of the cardinality of the ON or, eventually, the DC sets. However, these advantages come with a large spatial complexitythe number of utilized implementation elementsof the respective combinational module, generating the prime-implicant set. The authors verified the proposed design using Field Programmable Gate Array (FPGA) technology, implementing the hardware using a Xilinx Kintex-7 KC-705 Evaluation Kit development board.
Nowadays, when computers and computer systems are almost omnipresent and are part of most househo... more Nowadays, when computers and computer systems are almost omnipresent and are part of most households and most people have access to them, they are more vulnerable than ever. Today, protection and security of computer networks and systems using passive protection does not suffice anymore. One has to anticipate attacks and be a step ahead of the attackers. To achieve this type of security, one has to employ active protection techniques, such as digital baitshoneypots. The primary goal of using honeypots is to divert the interest of potential attackers from other really important targets within a particular computer network. The secondary goal is to acquire information about the attackers' activities and methods. Subsequently, these data are thoroughly analysed. By analysing the attacks, security improvement measures aimed at the particular network and/or computer system may be proposed in order to prevent threats. The goal of this paper is to contribute to computer security by proposing a clustered, high-interactionhoneypot-based security system.
Cognitive radio (CR) is the underlying platform for the application of dynamic spectrum access (D... more Cognitive radio (CR) is the underlying platform for the application of dynamic spectrum access (DSA) networks. Although the auction theory and spectrum trading mechanisms have been discussed in the CR related works, their joint techno-economic impact on the efficiency of distributed CR networks has not been researched yet. In this paper we assume heterogeneous primary channels with network availability statistics unknown to each secondary user (SU) terminal. In order to detect the idle primary user (PU) network channels, the SU terminals trigger regularly the spectrum sensing mechanism and make the cooperative decision regarding the channel status at the fusion center. The imperfections of the spectrum mechanism create the possibility of the channel collision, resulting in the existence of the risk (in terms of user collision) in the network. The spectrum trading within SU network is governed by the application of the sealed-bid first-price auction, which takes into account the channel valuation as well as the statistical probability of the risk existence. In order to maximize the long-term payoff, the SU terminals take an advantage of the reinforcement comparison strategy. The results demonstrate that in the investigated model, total revenue and total payoff of the SU operator (auctioneer) and SU terminals (bidders) are characterized by the existence of the global optimum, thus there exists the optimal sensing time guaranteeing the optimum economic factors for both SU operator and SU terminals.
Paper deals with the data driven computation control paradigm, which is alternative to the mainst... more Paper deals with the data driven computation control paradigm, which is alternative to the mainstream control flow model of program execution control. In the second part of the paper we are introducing computer architecture that is proposed at the Department of Computers and Informatics, Faculty of Electrical Engineering and Informatics, Technical University of Košice, according to the data driven computation control model with use of tile computing principles. In the final part of the paper, subgraph colouring technique that is unique characteristic of proposed computer architecture is described.
V článku uvedená architektúra je založená na výpočtovom modeli „data flow“, v ktorom riadenie výp... more V článku uvedená architektúra je založená na výpočtovom modeli „data flow“, v ktorom riadenie výpočtu je založené na spracovaní toku dát. Základným prvkom DF architektúry je koordinačný procesor (CP), ktorý je zodpovedný za riadenie a organizáciu vykonávania inštrukcií. Štruktúrna organizácia CP je navrhnutá ako dynamický multifunkčný systém. Pri vykonávaní operácií môže CP prechádzať rôznymi stavmi, v dôsledku čoho táto jednotka predstavuje dynamický prúdový systém. Prechod a poradie prechodu medzi jednotlivými stavmi CP je podmienený typom spracovaného operátora pri interpretovaní prúdu operandov. Z možných typov operátorov, článok uvádza mikroprogramové riadenie pre jednovstupové operátory.
One of the main goals of an operating system is the efficient usage of system resources and their... more One of the main goals of an operating system is the efficient usage of system resources and their management. Modern systems offer complex mechanisms for the management of these resources. Their system-wide use may be separated into multiple layersfrom the lowest (the operating system kernel) to the highest (various virtualization techniques). Somewhere in the middle are the applications consuming these system resources. An example of such an application is the Apache web server. It implements some of the resource management mechanisms at application level. However, the system contains elements, the management of which is not possible at application level or its implementation has a significant overhead and may negatively affect the performance and secure usage of the server. The aim of the study is to create a more efficient resource management mechanism at the level of the Apache web server. The proposed architecture allows the treatment of possible security threats, such as DoS attacks, makes the use of system resources more efficient, thusindirectlyit also addresses the environmental impacts of data centers. The reason for selecting the Apache web server as the referential implementation of the resource usage improvement are its market share and its open source nature, which renders making amendments to the server simple.
Due to the expansion of high-speed Internet access, the need for secure and reliable networks has... more Due to the expansion of high-speed Internet access, the need for secure and reliable networks has become more critical. Since attacks are becoming more sophisticated and networks are becoming larger there is a need for an efficient intrusion detection systems (IDSs) that can distinguish between legitimate and illegitimate traffic and be able to signal attacks in real time, before serious damages are produced. Although there are some existing mechanisms for intrusion detection, there is need to improve the performance. Data mining techniques and machine learning are a new approach for intrusion detection. In this work naive Bayes classifier and decision trees with C4.5 and CART algorithms for detecting abnormal traffic patterns in the KDD Cup 1999 data are used. The IDS system is supposed to distinguish normal traffic from intrusions and to classify the intrusions into five classes: Normal, DoS, probe, R2L and U2R. Research shows that decision trees gives better overall performance than the naive Bayes classifier.
2012 IEEE 16th International Conference on Intelligent Engineering Systems (INES), 2012
ABSTRACT This paper deals with recent results of a supporting mechanism for efficient evaluation ... more ABSTRACT This paper deals with recent results of a supporting mechanism for efficient evaluation of network traffic parameters. Most of the network monitoring tools store the measured data in a database for the later analysis. With the growth of the data in the database, processing of queries is becoming more and more time consuming. This fact results in an excessive response time of the database, which subsequently brings an adverse impact on the monitoring tool. While most of the monitoring tools make evaluations on the basis of outdated data from a database, the vast majority of them have to deal with this problem. In this contribution a new approach of efficient network traffic data evaluation through a database will be introduced, while the main attention will be dedicated to the implementation details.
2012 IEEE 10th International Symposium on Applied Machine Intelligence and Informatics (SAMI), 2012
ABSTRACT This paper deals with the solution of database related problems which can occur during n... more ABSTRACT This paper deals with the solution of database related problems which can occur during network traffic monitoring. During data evaluation through a database excessive response time can be noticed. While the time necessary to obtain the data from the database has a significant effect on the result of the monitoring, it is important to keep its value as low as possible. Practically, the vast majority of the monitoring tools have to deal with the problems related to the database's excessive response time, so their solution is really justified. In this paper an alternative method of network monitoring, the BasicMeter tool will be introduced by which the exact problems and their solution will be illustrated.
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