The Experts below are selected from a list of 63 Experts worldwide ranked by ideXlab platform
Francesco Mainardi - One of the best experts on this subject based on the ideXlab platform.
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On the fractional Poisson process and the discretized stable subordinator, preprint
2016Co-Authors: Rudolf Gorenflo, Francesco MainardiAbstract:Paper dedicated to Professor A.M.Mathai on the occasion of his 75-th anniversary We consider the renewal counting number process N = N(t) as a forward march over the non-negative integers with independent identically distributed waiting times. We embed the values of the counting numbers N in a ”pseudo-spatial” non-negative half-line x ≥ 0 and observe that for physical time likewise we have t ≥ 0. Thus we apply the Laplace transform with respect to both variables x and t. Applying then a modification of the Montroll-Weiss-Cox formalism of continuous time random walk we obtain the essential characteristics of a renewal process in the transform domain and, if we are lucky, also in the physical domain. The process t = t(N) of accumulation of waiting times is inverse to the counting number process, in honour of the Danish mathematician and Telecommunication Engineer A.K. Erlang we call it the Erlang process. It yields the probability of exactly n renewal events in the interval (0, t]. We apply our Laplace-Laplace formalism to the fractional Poisson process whose waiting times are of Mittag-Leffler type and to a renewal process whose waiting tmes are of Wright type. The process of Mittag-Leffler type includes as a limiting case the classical Poisson process, the process of Wright type represents the discretized stable subordinator and a re-scaled version of it was used in our method of parametric subordination of time-space fractional diffusion processes. Properly rescaling the counting number process N(t) and the Erlang process t(N) yields as diffusion limits the inverse stable and the stable subordinator, respectively
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on the fractional poisson process and the discretized stable subordinator
Axioms, 2015Co-Authors: Rudolf Gorenflo, Francesco MainardiAbstract:We consider the renewal counting number process N = N(t) as a forward march over the non-negative integers with independent identically distributed waiting times. We embed the values of the counting numbers N in a “pseudo-spatial” non-negative half-line x ≥ 0 and observe that for physical time likewise we have t ≥ 0. Thus we apply the Laplace transform with respect to both variables x and t. Applying then a modification of the Montroll-Weiss-Cox formalism of continuous time random walk we obtain the essential characteristics of a renewal process in the transform domain and, if we are lucky, also in the physical domain. The process t = t(N) of accumulation of waiting times is inverse to the counting number process, in honour of the Danish mathematician and Telecommunication Engineer A.K. Erlang we call it the Erlang process. It yields the probability of exactly n renewal events in the interval (0; t]. We apply our Laplace-Laplace formalism to the fractional Poisson process whose waiting times are of Mittag-Leffler type and to a renewal process whose waiting times are of Wright type. The process of Mittag-Leffler type includes as a limiting case the classical Poisson process, the process of Wright type represents the discretized stable subordinator and a re-scaled version of it was used in our method of parametric subordination of time-space fractional diffusion processes. Properly rescaling the counting number process N(t) and the Erlang process t(N) yields as diffusion limits the inverse stable and the stable subordinator, respectively.
Michele Vadursi - One of the best experts on this subject based on the ideXlab platform.
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Design and implementation of a reconfigurable test-bed for real-time security measurements in VoIP systems
Measurement, 2013Co-Authors: Leopoldo Angrisani, Mauro Di Lelio, Pasquale Morabito, Rosario Schiano Lo Moriello, Michele VadursiAbstract:Abstract Voice over Internet Protocol (VoIP) systems have to face a great number of security threats, which are basically connected to the underlying Internet Protocol (IP) infrastructure. Along with relevant economic losses and malfunction for the VoIP system itself, external attacks exploiting a security hole could also bring to a major security failure for the interconnected Public-Switched Telephone Network (PSTN), usually regarded as a reliable and secure domain. This is the reason why before connecting a private VoIP network to the carrier infrastructure, a great number of tests have to be carried out, to verify the security robustness of the VoIP network to common attacks. Security tools that are commonly used to address potential threats in VoIP networks are: the insertion of firewalls, the separation of data and voice networks and the adoption of access control lists. The introduction of such elements in the network can lead to unpredictable modifications on the performance of the network and, consequently, of the VoIP service. The paper presents the design and implementation of a reconfigurable test-bed for real-time measurements on VoIP systems, which provides the Telecommunication Engineer with means to plan the necessary changes in order to reach a higher level of security. In its basic version, the test-bed permits to take into account the right balance between security tools and the required Quality of Service (QoS)/Quality of Experience (QoE) for real time operations. An interesting feature of the enhanced version is the possibility of evaluating QoS and QoE in the presence of firewalls and different security configurations, and assessing the effect of the joint variation of QoS parameters on QoE results.
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M&N - Security in VoIP systems: towards the design and implementation of a reconfigurable test bed for real-time measurements
2011 IEEE International Workshop on Measurements and Networking Proceedings (M&N), 2011Co-Authors: Leopoldo Angrisani, Mauro Di Lelio, Pasquale Morabito, Rosario Schiano Lo Moriello, Michele VadursiAbstract:VoIP systems have to face far tougher security threats than their underlying IP infrastructure. In fact, a security hole in a VoIP infrastructure could bring to a major security failure for the interconnected PSTN network(s), usually regarded as a reliable and secure domain. This is the reason why before connecting a private VoIP network to the carrier infrastructure, a great number of tests have to be carried out, to verify the security robustness of the VoIP network to common attacks. The paper presents the design and implementation of a reconfigurable test bed for real time measurements on VoIP systems, which provides the Telecommunication Engineer with means to plan the necessary changes in the network/VoIP platform, eventually reaching a higher level of security. At the same time, the test bed permits to take into account the right balance between security instruments and the required QoS/QoE for real time operations.
Rudolf Gorenflo - One of the best experts on this subject based on the ideXlab platform.
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On the fractional Poisson process and the discretized stable subordinator, preprint
2016Co-Authors: Rudolf Gorenflo, Francesco MainardiAbstract:Paper dedicated to Professor A.M.Mathai on the occasion of his 75-th anniversary We consider the renewal counting number process N = N(t) as a forward march over the non-negative integers with independent identically distributed waiting times. We embed the values of the counting numbers N in a ”pseudo-spatial” non-negative half-line x ≥ 0 and observe that for physical time likewise we have t ≥ 0. Thus we apply the Laplace transform with respect to both variables x and t. Applying then a modification of the Montroll-Weiss-Cox formalism of continuous time random walk we obtain the essential characteristics of a renewal process in the transform domain and, if we are lucky, also in the physical domain. The process t = t(N) of accumulation of waiting times is inverse to the counting number process, in honour of the Danish mathematician and Telecommunication Engineer A.K. Erlang we call it the Erlang process. It yields the probability of exactly n renewal events in the interval (0, t]. We apply our Laplace-Laplace formalism to the fractional Poisson process whose waiting times are of Mittag-Leffler type and to a renewal process whose waiting tmes are of Wright type. The process of Mittag-Leffler type includes as a limiting case the classical Poisson process, the process of Wright type represents the discretized stable subordinator and a re-scaled version of it was used in our method of parametric subordination of time-space fractional diffusion processes. Properly rescaling the counting number process N(t) and the Erlang process t(N) yields as diffusion limits the inverse stable and the stable subordinator, respectively
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on the fractional poisson process and the discretized stable subordinator
Axioms, 2015Co-Authors: Rudolf Gorenflo, Francesco MainardiAbstract:We consider the renewal counting number process N = N(t) as a forward march over the non-negative integers with independent identically distributed waiting times. We embed the values of the counting numbers N in a “pseudo-spatial” non-negative half-line x ≥ 0 and observe that for physical time likewise we have t ≥ 0. Thus we apply the Laplace transform with respect to both variables x and t. Applying then a modification of the Montroll-Weiss-Cox formalism of continuous time random walk we obtain the essential characteristics of a renewal process in the transform domain and, if we are lucky, also in the physical domain. The process t = t(N) of accumulation of waiting times is inverse to the counting number process, in honour of the Danish mathematician and Telecommunication Engineer A.K. Erlang we call it the Erlang process. It yields the probability of exactly n renewal events in the interval (0; t]. We apply our Laplace-Laplace formalism to the fractional Poisson process whose waiting times are of Mittag-Leffler type and to a renewal process whose waiting times are of Wright type. The process of Mittag-Leffler type includes as a limiting case the classical Poisson process, the process of Wright type represents the discretized stable subordinator and a re-scaled version of it was used in our method of parametric subordination of time-space fractional diffusion processes. Properly rescaling the counting number process N(t) and the Erlang process t(N) yields as diffusion limits the inverse stable and the stable subordinator, respectively.
Fairuz Abdullah - One of the best experts on this subject based on the ideXlab platform.
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OPTISYSTEM: AN ALTERNATIVE TO OPTOELECTRONICS AND FIBER OPTICS TEACHING E-LABORATORY Nor Iza binti Mohd Rawi †
2014Co-Authors: Zaini Jamaludin, Fairuz AbdullahAbstract:This paper introduces the OptiSystem software as an alternative to support the Optoelectronics and Fiber Optics laboratory in Universiti Tenaga Nasional (UNITEN). In recent years, communication Engineering has been focusing on wireless technology and optical communication to achieve seamless and high-speed connectivity. Hence, this paper presents the advantages and effects of implementing e-learning in this elective subject to complement the learning process in order to produce a high quality Telecommunication Engineer in the field of Optical Communication.
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Optisystem: An Alternative to Optoelectronics and Fiber Optics Teaching E-Laboratory
International journal of Asian social science, 2014Co-Authors: N. I. M. Rawi, Zaini Jamaludin, Fairuz AbdullahAbstract:This paper introduces the OptiSystem software as an alternative to support the Optoelectronics and Fiber Optics laboratory in Universiti Tenaga Nasional (UNITEN). In recent years, communication Engineering has been focusing on wireless technology and optical communication to achieve seamless and high-speed connectivity. Hence, this paper presents the advantages and effects of implementing e-learning in this elective subject to complement the learning process in order to produce a high quality Telecommunication Engineer in the field of Optical Communication.
Leopoldo Angrisani - One of the best experts on this subject based on the ideXlab platform.
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Design and implementation of a reconfigurable test-bed for real-time security measurements in VoIP systems
Measurement, 2013Co-Authors: Leopoldo Angrisani, Mauro Di Lelio, Pasquale Morabito, Rosario Schiano Lo Moriello, Michele VadursiAbstract:Abstract Voice over Internet Protocol (VoIP) systems have to face a great number of security threats, which are basically connected to the underlying Internet Protocol (IP) infrastructure. Along with relevant economic losses and malfunction for the VoIP system itself, external attacks exploiting a security hole could also bring to a major security failure for the interconnected Public-Switched Telephone Network (PSTN), usually regarded as a reliable and secure domain. This is the reason why before connecting a private VoIP network to the carrier infrastructure, a great number of tests have to be carried out, to verify the security robustness of the VoIP network to common attacks. Security tools that are commonly used to address potential threats in VoIP networks are: the insertion of firewalls, the separation of data and voice networks and the adoption of access control lists. The introduction of such elements in the network can lead to unpredictable modifications on the performance of the network and, consequently, of the VoIP service. The paper presents the design and implementation of a reconfigurable test-bed for real-time measurements on VoIP systems, which provides the Telecommunication Engineer with means to plan the necessary changes in order to reach a higher level of security. In its basic version, the test-bed permits to take into account the right balance between security tools and the required Quality of Service (QoS)/Quality of Experience (QoE) for real time operations. An interesting feature of the enhanced version is the possibility of evaluating QoS and QoE in the presence of firewalls and different security configurations, and assessing the effect of the joint variation of QoS parameters on QoE results.
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M&N - Security in VoIP systems: towards the design and implementation of a reconfigurable test bed for real-time measurements
2011 IEEE International Workshop on Measurements and Networking Proceedings (M&N), 2011Co-Authors: Leopoldo Angrisani, Mauro Di Lelio, Pasquale Morabito, Rosario Schiano Lo Moriello, Michele VadursiAbstract:VoIP systems have to face far tougher security threats than their underlying IP infrastructure. In fact, a security hole in a VoIP infrastructure could bring to a major security failure for the interconnected PSTN network(s), usually regarded as a reliable and secure domain. This is the reason why before connecting a private VoIP network to the carrier infrastructure, a great number of tests have to be carried out, to verify the security robustness of the VoIP network to common attacks. The paper presents the design and implementation of a reconfigurable test bed for real time measurements on VoIP systems, which provides the Telecommunication Engineer with means to plan the necessary changes in the network/VoIP platform, eventually reaching a higher level of security. At the same time, the test bed permits to take into account the right balance between security instruments and the required QoS/QoE for real time operations.
