The Experts below are selected from a list of 34164 Experts worldwide ranked by ideXlab platform
Hyunseung Choo - One of the best experts on this subject based on the ideXlab platform.
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WCNC - Efficient Algorithm for Reducing Delay Variation on Delay-Bounded Multicast Trees in Heterogeneous Networks
2008 IEEE Wireless Communications and Networking Conference, 2008Co-Authors: Soobeen Ahn, Moonseong Kim, Hyunseung ChooAbstract:This paper investigates the construction of a multicast tree satisfying Quality of Service (QoS) real-time group communication in a heterogeneous network comprising multiple Mobile Ad-hoc NETworks (MANETs) attached to the backbone Internet. The main objective of our work is to optimize the Delay- and Delay Variation Bounded Multicast Tree (DVBMT) problem, which has been proved to be NP-complete. This problem has to satisfy the minimum Delay Variation and the end-to-end Delay within an upper bound. The well-known algorithms solved this problem are the DVMA, the DDVCA, the Cheng's algorithm, and so on. In this paper, we propose an algorithm that outperforms other algorithms in terms of the multicast Delay Variation in the realistic network environment. The enhancement increases to approximately 3.7%~ 32.9% in terms of that. The time complexity of the proposed algorithm is O(mn2), which is comparable to that of DDVCA.
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On efficient core selection for reducing multicast Delay Variation under Delay constraints
IEICE Transactions on Communications, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Hyung-jin Lim, Hyunseung ChooAbstract:With the proliferation of multimedia group applications, the construction of multicast trees satisfying the Quality of Service (QoS) requirements is becoming a problem of the prime importance. An essential factor of these real-time application is to optimize the Delay- and Delay Variation-Bounded Multicast Tree (DVBMT) problem. This problem is to satisfy the minimum Delay Variation and the end-to-end Delay within an upper bound. The DVBMT problem is known as NP-complete problem. The representative algorithms for the problem are DVMA, DDVCA, and so on. In this paper, we show that the proposed algorithm outperforms any other algorithm. The efficiency of our algorithm is verified through the performance evaluation and the enhancement is up to about 13.5% in terms of the multicast Delay Variation. The time complexity of our algorithm is O(mn 2 ) which is comparable to well known DDVCA.
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An Efficient Multicast Tree with Delay and Delay Variation Constraints
Lecture Notes in Computer Science, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Jong S. Yang, Hyunseung ChooAbstract:With the rapid evolution of real time multimedia applications like audio/video conferencing, interactive distributed games and real time remote control system, a certain Quality of Service (QoS) needs to be guaranteed in underlying networks. Multicast routing algorithms should support the required QoS. There are two important QoS parameters, bounded Delay and Delay Variation, that need to be guaranteed in order to support the real time multimedia applications. Here we solve Delay and Delay Variation Bounded Multicast Tree (DVBMT) problem which has been proved to NP-complete. In this paper, we propose an efficient algorithm for DVBMT. The performance enhancement is up to about 21.7% in terms of Delay Variation as compared to the well-known algorithm, KBC [9].
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On multicasting steiner trees for Delay and Delay Variation constraints
Lecture Notes in Computer Science, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Hyunseung ChooAbstract:The objective of multicasting is to find a tree that has a minimum total cost, which called the Steiner tree. Multicast routing algorithms should support the required QoS. There are two important Quality of Service (QoS) parameters that need to be guaranteed in order to support the real time and multimedia applications. Firstly, we consider the Delay parameter where, the data sent from source need to reach destinations within a certain time limit (Delay bound). Secondly, in addition to the Delay constraint, we add the Delay Variation constraint. The Delay Variation constraint is a bound on the Delay difference between any two destinations. Our research subject is Delay and Delay Variation Bounded Steiner Tree (DVBST) problem. The problem has been proved to NP-complete. In this paper, we propose efficient algorithm for DVBST. Simulations demonstrate that our algorithm is better in terms of tree cost as compared to the existing algorithms.
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ICCSA (3) - An efficient multicast tree with Delay and Delay Variation constraints
Computational Science and Its Applications - ICCSA 2006, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Jong S. Yang, Hyunseung ChooAbstract:With the rapid evolution of real time multimedia applications like audio/video conferencing, interactive distributed games and real time remote control system, a certain Quality of Service (QoS) needs to be guaranteed in underlying networks. Multicast routing algorithms should support the required QoS. There are two important QoS parameters, bounded Delay and Delay Variation, that need to be guaranteed in order to support the real time multimedia applications. Here we solve Delay and Delay Variation Bounded Multicast Tree (DVBMT) problem which has been proved to NP-complete. In this paper, we propose an efficient algorithm for DVBMT. The performance enhancement is up to about 21.7% in terms of Delay Variation as compared to the well-known algorithm, KBC [9].
Moonseong Kim - One of the best experts on this subject based on the ideXlab platform.
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ESC: Estimation of selecting core for reducing multicast Delay Variation under Delay constraints
International Journal of Communication Systems, 2010Co-Authors: Moonseong Kim, Matt W. Mutka, Hye-young KimAbstract:With the spread of multimedia group applications, the construction of multicast trees satisfying the Quality of Service (QoS) requirements becomes a problem of prime importance. A principal factor of these real-time applications is to optimize the Delay- and Delay Variation-bounded multicast tree (DVBMT) problem. This problem is to satisfy the minimum Delay Variation and the end-to-end Delay within an upper bound. The DVBMT problem is known as an NP-complete problem. The representative algorithms are the DVMA, the DDVCA, and the ECS algorithm. In this paper, we show that the proposed ESC algorithm outperforms the DDVCA and the ECS algorithm. The efficiency of our algorithm is verified through performance evaluation and the enhancement is up to about 19.6% in terms of normalized surcharge for multicast Delay Variation. The time complexity of our algorithm is O(mn2), which is comparable to the well-known DDVCA. Copyright © 2010 John Wiley & Sons, Ltd.
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WCNC - Efficient Algorithm for Reducing Delay Variation on Delay-Bounded Multicast Trees in Heterogeneous Networks
2008 IEEE Wireless Communications and Networking Conference, 2008Co-Authors: Soobeen Ahn, Moonseong Kim, Hyunseung ChooAbstract:This paper investigates the construction of a multicast tree satisfying Quality of Service (QoS) real-time group communication in a heterogeneous network comprising multiple Mobile Ad-hoc NETworks (MANETs) attached to the backbone Internet. The main objective of our work is to optimize the Delay- and Delay Variation Bounded Multicast Tree (DVBMT) problem, which has been proved to be NP-complete. This problem has to satisfy the minimum Delay Variation and the end-to-end Delay within an upper bound. The well-known algorithms solved this problem are the DVMA, the DDVCA, the Cheng's algorithm, and so on. In this paper, we propose an algorithm that outperforms other algorithms in terms of the multicast Delay Variation in the realistic network environment. The enhancement increases to approximately 3.7%~ 32.9% in terms of that. The time complexity of the proposed algorithm is O(mn2), which is comparable to that of DDVCA.
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On efficient core selection for reducing multicast Delay Variation under Delay constraints
IEICE Transactions on Communications, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Hyung-jin Lim, Hyunseung ChooAbstract:With the proliferation of multimedia group applications, the construction of multicast trees satisfying the Quality of Service (QoS) requirements is becoming a problem of the prime importance. An essential factor of these real-time application is to optimize the Delay- and Delay Variation-Bounded Multicast Tree (DVBMT) problem. This problem is to satisfy the minimum Delay Variation and the end-to-end Delay within an upper bound. The DVBMT problem is known as NP-complete problem. The representative algorithms for the problem are DVMA, DDVCA, and so on. In this paper, we show that the proposed algorithm outperforms any other algorithm. The efficiency of our algorithm is verified through the performance evaluation and the enhancement is up to about 13.5% in terms of the multicast Delay Variation. The time complexity of our algorithm is O(mn 2 ) which is comparable to well known DDVCA.
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An Efficient Multicast Tree with Delay and Delay Variation Constraints
Lecture Notes in Computer Science, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Jong S. Yang, Hyunseung ChooAbstract:With the rapid evolution of real time multimedia applications like audio/video conferencing, interactive distributed games and real time remote control system, a certain Quality of Service (QoS) needs to be guaranteed in underlying networks. Multicast routing algorithms should support the required QoS. There are two important QoS parameters, bounded Delay and Delay Variation, that need to be guaranteed in order to support the real time multimedia applications. Here we solve Delay and Delay Variation Bounded Multicast Tree (DVBMT) problem which has been proved to NP-complete. In this paper, we propose an efficient algorithm for DVBMT. The performance enhancement is up to about 21.7% in terms of Delay Variation as compared to the well-known algorithm, KBC [9].
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On multicasting steiner trees for Delay and Delay Variation constraints
Lecture Notes in Computer Science, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Hyunseung ChooAbstract:The objective of multicasting is to find a tree that has a minimum total cost, which called the Steiner tree. Multicast routing algorithms should support the required QoS. There are two important Quality of Service (QoS) parameters that need to be guaranteed in order to support the real time and multimedia applications. Firstly, we consider the Delay parameter where, the data sent from source need to reach destinations within a certain time limit (Delay bound). Secondly, in addition to the Delay constraint, we add the Delay Variation constraint. The Delay Variation constraint is a bound on the Delay difference between any two destinations. Our research subject is Delay and Delay Variation Bounded Steiner Tree (DVBST) problem. The problem has been proved to NP-complete. In this paper, we propose efficient algorithm for DVBST. Simulations demonstrate that our algorithm is better in terms of tree cost as compared to the existing algorithms.
Young-cheol Bang - One of the best experts on this subject based on the ideXlab platform.
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On efficient core selection for reducing multicast Delay Variation under Delay constraints
IEICE Transactions on Communications, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Hyung-jin Lim, Hyunseung ChooAbstract:With the proliferation of multimedia group applications, the construction of multicast trees satisfying the Quality of Service (QoS) requirements is becoming a problem of the prime importance. An essential factor of these real-time application is to optimize the Delay- and Delay Variation-Bounded Multicast Tree (DVBMT) problem. This problem is to satisfy the minimum Delay Variation and the end-to-end Delay within an upper bound. The DVBMT problem is known as NP-complete problem. The representative algorithms for the problem are DVMA, DDVCA, and so on. In this paper, we show that the proposed algorithm outperforms any other algorithm. The efficiency of our algorithm is verified through the performance evaluation and the enhancement is up to about 13.5% in terms of the multicast Delay Variation. The time complexity of our algorithm is O(mn 2 ) which is comparable to well known DDVCA.
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An Efficient Multicast Tree with Delay and Delay Variation Constraints
Lecture Notes in Computer Science, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Jong S. Yang, Hyunseung ChooAbstract:With the rapid evolution of real time multimedia applications like audio/video conferencing, interactive distributed games and real time remote control system, a certain Quality of Service (QoS) needs to be guaranteed in underlying networks. Multicast routing algorithms should support the required QoS. There are two important QoS parameters, bounded Delay and Delay Variation, that need to be guaranteed in order to support the real time multimedia applications. Here we solve Delay and Delay Variation Bounded Multicast Tree (DVBMT) problem which has been proved to NP-complete. In this paper, we propose an efficient algorithm for DVBMT. The performance enhancement is up to about 21.7% in terms of Delay Variation as compared to the well-known algorithm, KBC [9].
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On multicasting steiner trees for Delay and Delay Variation constraints
Lecture Notes in Computer Science, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Hyunseung ChooAbstract:The objective of multicasting is to find a tree that has a minimum total cost, which called the Steiner tree. Multicast routing algorithms should support the required QoS. There are two important Quality of Service (QoS) parameters that need to be guaranteed in order to support the real time and multimedia applications. Firstly, we consider the Delay parameter where, the data sent from source need to reach destinations within a certain time limit (Delay bound). Secondly, in addition to the Delay constraint, we add the Delay Variation constraint. The Delay Variation constraint is a bound on the Delay difference between any two destinations. Our research subject is Delay and Delay Variation Bounded Steiner Tree (DVBST) problem. The problem has been proved to NP-complete. In this paper, we propose efficient algorithm for DVBST. Simulations demonstrate that our algorithm is better in terms of tree cost as compared to the existing algorithms.
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ICCSA (3) - An efficient multicast tree with Delay and Delay Variation constraints
Computational Science and Its Applications - ICCSA 2006, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Jong S. Yang, Hyunseung ChooAbstract:With the rapid evolution of real time multimedia applications like audio/video conferencing, interactive distributed games and real time remote control system, a certain Quality of Service (QoS) needs to be guaranteed in underlying networks. Multicast routing algorithms should support the required QoS. There are two important QoS parameters, bounded Delay and Delay Variation, that need to be guaranteed in order to support the real time multimedia applications. Here we solve Delay and Delay Variation Bounded Multicast Tree (DVBMT) problem which has been proved to NP-complete. In this paper, we propose an efficient algorithm for DVBMT. The performance enhancement is up to about 21.7% in terms of Delay Variation as compared to the well-known algorithm, KBC [9].
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HPCC - On multicasting steiner trees for Delay and Delay Variation constraints
High Performance Computing and Communications, 2006Co-Authors: Moonseong Kim, Young-cheol Bang, Hyunseung ChooAbstract:The objective of multicasting is to find a tree that has a minimum total cost, which called the Steiner tree. Multicast routing algorithms should support the required QoS. There are two important Quality of Service (QoS) parameters that need to be guaranteed in order to support the real time and multimedia applications. Firstly, we consider the Delay parameter where, the data sent from source need to reach destinations within a certain time limit (Delay bound). Secondly, in addition to the Delay constraint, we add the Delay Variation constraint. The Delay Variation constraint is a bound on the Delay difference between any two destinations. Our research subject is Delay and Delay Variation Bounded Steiner Tree (DVBST) problem. The problem has been proved to NP-complete. In this paper, we propose efficient algorithm for DVBST. Simulations demonstrate that our algorithm is better in terms of tree cost as compared to the existing algorithms.
Reza Mahmoudi - One of the best experts on this subject based on the ideXlab platform.
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a 10 50ghz true time Delay phase shifter with max 3 9 Delay Variation
Radio Frequency Integrated Circuits Symposium, 2014Co-Authors: Q Qian, Domine M W Leenaerts, Reza MahmoudiAbstract:A fully integrated passive True Time Delay (TTD) phase shifter with 32ps continuous changing Delay time has been realized in a 0.25μm SiGe:C BiCMOS technology. A new TTD architecture is proposed based on broadband matching technique, resulting in less than 4% Delay Variation over a very large, 10-50GHz frequency span, meanwhile maintaining an input return loss better than 10dB. The measured input 1dB compression point and input IP3 are +15.5dBm and +24.7dBm at 30GHz, respectively. The phase shifter core occupies less than 0.22mm 2 .
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a 12ps true time Delay phase shifter with 6 6 Delay Variation at 20 40ghz
Radio Frequency Integrated Circuits Symposium, 2013Co-Authors: Domine M W Leenaerts, Reza MahmoudiAbstract:A fully integrated 2-channel Ka-band True Time Delay (TTD) phase shifter with 12ps continuous changing Delay time has been realized in a 0.25μm SiGe:C BiCMOS technology. A Delay Variation cancellation technique is proposed, resulting in less than 0.8ps Delay Variation over a 20-40GHz frequency span, meanwhile maintaining a constant input impedance. In the high (low) power mode, the measured input 1dB compression point and input IP3 are +9.7dBm (+3.6dBm) and +18dBm (+13dBm) at 30GHz with an averaged power consumption per channel of 145mW (33mW) for the same TTD performance. The size of the core phase shifter is less than 0.1mm2.
Frank E Van Vliet - One of the best experts on this subject based on the ideXlab platform.
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compact cascadable gm c all pass true time Delay cell with reduced Delay Variation over frequency
IEEE Journal of Solid-state Circuits, 2015Co-Authors: Seyed Kasra Garakoui, Eric A M Klumperink, Bram Nauta, Frank E Van VlietAbstract:At low-GHz frequencies, analog time-Delay cells realized by LC Delay lines or transmission lines are unpractical in CMOS, due to their large size. As an alternative, Delays can be approximated by all-pass filters exploiting transconductors and capacitors (g m -C filters). This paper presents an easily cascadable compact g m -C all-pass filter cell for 1-2.5 GHz. Compared to previous g m -RC and g m -C filter cells, it achieves at least 5x larger frequency range for the same relative Delay Variation, while keeping gain Variation within 1 dB. This paper derives design equations for the transfer function and several non-idealities. Circuit techniques to improve phase linearity and reduce Delay Variation over frequency, are also proposed. A 160 nm CMOS chip with maximum Delay of 550 ps is demonstrated with monotonous Delay steps of 13 ps (41 steps) and an RMS Delay Variation error of less than 10 ps over more than an octave in frequency (1-2.5 GHz). The Delay per area is at least 50x more than for earlier chips. The all-pass cells are used to realize a four element timed-array receiver IC. Measurement results of the beam pattern demonstrate the wideband operation capability of the g m -RC time Delay cell and timed-array IC-architecture.