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Patent
University of Electronic Science, Technology of China and Institute Of Electronic And Information Engineering In Dongguan | Date: 2016-12-07

A bidirectional Metal-Oxide-Semiconductor (MOS) device, including a P-type substrate, and an active region. The active region includes a drift region, a first MOS structure and a second MOS structure; the first MOS structure includes a first P-type body region, a first P+ contact region, a first N+ source region, a first metal electrode, and a first gate structure; the second MOS structure includes a second P-type body region, a second P+ contact region, a second N+ source region, a second metal electrode, and a second gate structure; and the drift region includes a dielectric slot, a first N-type layer, a second N-type layer, and an N-type region. The active region is disposed on the upper surface of the P-type substrate. The first MOS structure and the second MOS structure are symmetrically disposed on two ends of the upper layer of the drift region.


Sun G.,Key Laboratory of Optical Fiber Sensing and Communications Ministry of Education | Sun G.,Institute of Electronic and Information Engineering in Dongguan | Bu S.,Key Laboratory of Optical Fiber Sensing and Communications Ministry of Education | Anand V.,New York University | And 2 more authors.
IoTBD 2016 - Proceedings of the International Conference on Internet of Things and Big Data | Year: 2016

Cloud computing has become a cost-effective paradigm for deploying online service applications in large data centers in recent years. Virtualization technology enables flexible and efficient management of physical resources in cloud data centers and improves the resource utilization. A request for resources to a data center can be abstracted as a virtual data center (VDC) request. Due to the use of a large number of resources and at various locations, reliability is an important issue that should be addressed in large and multiple data centers. However, most research focuses on the problem of reliable VDC embedding in a single data center. In this paper, we study the problem of reliable VDC embedding across multiple data centers, such that the total bandwidth consumption in the inter-data center backbone network is minimized, while satisfying the reliability requirement of each VDC request. We model the problem by using mixed integer linear programming (MILP) and propose a heuristic algorithm to address this NP-hard problem efficiently. Simulation results show that the proposed algorithm performs better in terms of lowering physical resource consumption and VDC request blocking ratio compared with existing solution. Copyright © 2016 by SCITEPRESS - Science and Technology Publications, Lda. All rights reserved.


Liao D.,University of Electronic Science and Technology of China | Liao D.,Institute of Electronic and Information Engineering in Dongguan | Sun G.,University of Electronic Science and Technology of China | Sun G.,Institute of Electronic and Information Engineering in Dongguan | And 2 more authors.
KSII Transactions on Internet and Information Systems | Year: 2014

Network virtualization technology plays a key role in cloud computing, which serves as an effective approach for provisioning a flexible and highly adaptable shared substrate network to satisfy the demands of various applications or services. Recently, the problem of mapping a virtual network (VN) onto a substrate network has been addressed by various algorithms. However, these algorithms are typically efficient for unicast service-oriented virtual networks, and generally not applicable to multicast service-oriented virtual networks (MVNs). Furthermore, the survivable MVN mapping (SMVNM) problem that considers the survivability of MVN has not been studied and is also the focus of this work. In this research, we discuss SMVNM problem under regional failures in the substrate network and propose an efficient algorithm for solving this problem. We first propose a framework and formulate the SMVNM problem with the objective of minimizing mapping cost by using mixed integer linear programming. Then we design an efficient heuristic to solve this problem and introduce several optimizations to achieve the better mapping solutions. We validate and evaluate our framework and algorithms by conducting extensive simulations on different realistic networks under various scenarios, and by comparing with existing approaches. Our simulation experiments and results show that our approach outperforms existing solutions. © 2014 KSII.


Zhou H.P.,University of Electronic Science and Technology of China | Zhou H.P.,Nanyang Technological University | Xu S.,Nanyang Technological University | Zhao Z.,University of Electronic Science and Technology of China | And 2 more authors.
Journal of Alloys and Compounds | Year: 2014

Al-doped ZnO (AZO) thin films deposited by means of RF magnetron sputtering were processed in a low frequency inductively coupled plasma of H2, aiming at heterojunction (HJ) solar cell applications. A variety of characterization results show that the hydrogen plasma processing exerts a significant influence on the microstructures, electrical and optical properties of the AZO films. The incorporation of hydrogen under the optimum treatment simultaneously promoted the transmittance and conductivity due to the hydrogen associated passivation effect on the native defects and the formation of shallow donors in the films, respectively. A p-type c-Si based HJ solar cell with a front AZO contact was also treated in as-generated non-equilibrium hydrogen plasma and the photovoltaic performance of the solar cell was prominently improved. The underlying mechanism was discussed in terms of the beneficial impacts of high-density hydrogen plasma on the properties of AZO itself and the hetero-interfaces involved in the HJ structure (interface defect and energy band configuration). © 2014 Elsevier B.V. All rights reserved.


Sun G.,University of Electronic Science and Technology of China | Liao D.,University of Electronic Science and Technology of China | Liao D.,Institute of Electronic and Information Engineering in Dongguan | Anand V.,New York University | And 2 more authors.
Future Generation Computer Systems | Year: 2016

Datacenter virtualization technologies have attracted a lot of attention to enable various cloud computing services and to facilitate virtual machine (VM) migration. VM migration can help service providers to achieve the goals of saving energy, enhancing resource efficiency and quality of service (QoS). In order to ensure the QoS, the migration time and the downtime of VM should be considered while implementing the VM migration. Most researches focus on the issue of single VM migration by using the post-copy migration strategy or pre-copy migration strategy. However, there is few research that focuses on the problem of live migration for multiple VMs. Therefore, in this paper, we first propose an improved serial migration strategy and introduce the post-copy migration scheme into it. We then propose the m mixed migration strategy that is based on the improved serial migration strategy and the parallel migration strategy. Furthermore, we develop queuing models (i.e., the M/M/C/C and the M/M/C queuing models) to quantify performance metrics, such as the blocking ratio and average waiting time of each migration request. We evaluate the performance of the proposed migration strategy by conducting mathematical analysis, the numerical results show that our proposed strategy outperforms the existing approach. © 2015 Elsevier B.V.


Yang X.L.,University of Electronic Science and Technology of China | Liao D.,University of Electronic Science and Technology of China | Liao D.,Institute of Electronic and Information Engineering in Dongguan | Sun G.,University of Electronic Science and Technology of China | And 3 more authors.
Advanced Materials Research | Year: 2014

Compared with traditional GPCR, there are three differences in the new GPCR-D: 1) GPCR-D is a topology and position based routing protocol. 2) It can detect dynamically the network density and establish the local areas with high node density, where vehicles' speed is limited and topology changes slowly. Therefore, we adopt shortest path algorithm aimed at delivering packets speedily. While outside the local areas, topology changes rapidly, so greedy forwarding is used to avoid restoring and maintaining links frequently. Thus GPCR-D makes full use of their respective advantages. 3) The repair strategy of GPCR-D selects the neighbor whose direction is closest to destination in the neighbor table as the next forwarding hop. The simulation shows that GPCR-D works more effectively than GPCR in terms of average delivery success rate and end-to-end time delay. © (2014) Trans Tech Publications, Switzerland.


Liao D.,University of Electronic Science and Technology of China | Liao D.,Institute of Electronic and Information Engineering in Dongguan | Sun G.,University of Electronic Science and Technology of China | Sun G.,Institute of Electronic and Information Engineering in Dongguan | And 2 more authors.
Optical Switching and Networking | Year: 2014

Network virtualization technology plays an important role in cloud-based data centers that serve as an effective method for provisioning a flexible and highly adaptable shared substrate network to satisfy the demands of various applications. Although there has been some work on efficient mapping of unicast service oriented virtual networks there has been very limited work on addressing the problem of efficient mapping of multicast oriented virtual networks. Furthermore, how to guarantee survivability of multicast service oriented virtual network request has not been studied. In this work, we investigate the survivable multicast service oriented virtual network mapping (SMVNM) problem and propose an efficient algorithm for solving this problem. We first formulate the SMVNM problem with the objective of minimizing mapping cost by using mixed integer linear programming. We then design an efficient algorithm to solve this problem since it is NP-hard. We validate and evaluate our framework and algorithms by conducting extensive simulations on different realistic networks under various scenarios, and by comparing with existing approaches. The simulation results show that our approach outperforms existing solutions. © 2014 Elsevier B.V.


Liao D.,University of Electronic Science and Technology of China | Liao D.,Institute of Electronic and Information Engineering in Dongguan | Huang X.,University of Electronic Science and Technology of China | Anand V.,New York University | And 2 more authors.
2016 IEEE International Conference on Communications, ICC 2016 | Year: 2016

Location-Based Service (LBS) is one of the fundamental and central functionalities of mobile social networks. Since users usually have to report their locations to the LBS providers while using services, the protection of user's location privacy poses a critical challenge. Although many existing approaches can preserve user's location privacy effectively, most of them must include and use the user's real location. In this paper, we first propose an efficient k-anonymity based Dummy Location and divided Circular Area (k-DLCA) approach to protect the user's location privacy. Different from existing studies, the k-DLCA algorithm adopts a greedy strategy to select dummy locations and considers the semantic location information of the location. Moreover, the user's real location may not be contained in the chosen dummy locations. We then show that k-DLCA algorithm can resist the attacks from adversaries, and has a low probability of exposing the user's real location. We conduct extensive simulations to evaluate the efficiency of the proposed scheme. The simulation results demonstrate that our proposed scheme is promising. © 2016 IEEE.


Zeng S.,University of Electronic Science and Technology of China | Li L.,University of Electronic Science and Technology of China | Liao D.,Institute of Electronic and Information Engineering in Dongguan
Applied Mathematics and Information Sciences | Year: 2013

In this paper, we develop a fluid model that seeks to expose the fundamental characteristics and mathematical theory of peerto- peer streaming system with transcoding. We find out and prove that, to provide peers receiving data above some flow rate, there is a lower bound of server upload bandwidth in this kind of system. We give a flow rate allocation algorithm to achieve the minimal server upload bandwidth in the proof. We compare this lower bound with the minimal demand of server upload bandwidth of no transcoding system. And, we prove that, the demand of server upload bandwidth in transcoding peer-to-peer streaming system using the proposed algorithm is the necessary (not sufficient) condition for the no transcoding one. At last, we give the simulations experiment to show the difference of server load in transcoding and no transcoding systems. © 2013 NSP Natural Sciences Publishing Cor.


Patent
University of Electronic Science, Technology of China and Institute Of Electronic And Information Engineering In Dongguan | Date: 2016-07-13

A bidirectional IGBT device, including a cellular structure including: two MOS structures, a substrate drift layer, two highly doped buried layers operating for carrier storage or field stop, two metal electrodes, and isolating dielectrics. Each MOS structure includes: a body region, a heavily doped source region, a body contact region, and a gate structure. Each gate structure includes: a gate dielectric and a gate conductive material. The two MOS structures are symmetrically disposed on the top surface and the back surface of the substrate drift layer. The heavily doped source region and the body contact region are disposed in the body region and independent from each other, and both surfaces of the heavily doped source region and the body contact region are connected to each of the two metal electrodes. The gate dielectric separates the gate conductive material from a channel region of each of the MOS structures.

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