Time filter

Source Type

Yang X.-K.,National Digital Switching System Engineering Technical Researching Center | Qu D.,National Digital Switching System Engineering Technical Researching Center | Zhang W.-L.,National Digital Switching System Engineering Technical Researching Center | Zhang W.-Q.,Tsinghua University
2016 IEEE Workshop on Spoken Language Technology, SLT 2016 - Proceedings | Year: 2016

The National Digital Switching System Engineering and Technological R&D Center (NDSC) speech-to-text transcription system for the 2016 multi-genre broadcast challenge is described. Various acoustic models based on deep neural network (DNN), such as hybrid DNN, long short term memory recurrent neural network (LSTM RNN), and time delay neural network (TDNN), are trained. The system also makes use of recurrent neural network language models (RNNLMs) for re-scoring and minimum Bayes risk (MBR) combination. The WER on test dataset of the speech-to-text task is 18.2%. Furthermore, to simulate real applications where manual segmentations were not available an automatic segmentation system based on long-term information is proposed. WERs based on the automatically generated segments were slightly worse than that based on the manual segmentations. © 2016 IEEE.

Yao J.,Shanghai JiaoTong University | Costanzo G.T.,Technical University of Denmark | Zhu G.,Ecole Polytechnique de Montréal | Wen B.,National Digital Switching System Engineering Technical Researching Center
IEEE Transactions on Industrial Electronics | Year: 2015

This paper presents a control scheme for thermal management in smart buildings based on predictive power admission control. This approach combines model predictive control with budget-schedulability analysis in order to reduce peak power consumption as well as ensure thermal comfort. First, the power budget with a given thermal comfort constraint is optimized through budget-schedulability analysis which amounts to solving a constrained linear programming problem. Second, the effective peak power demand is reduced by means of the optimal scheduling and cooperative operation of multiple thermal appliances. The performance of the proposed control scheme is assessed by simulation based on the thermal dynamics of a real eight-room office building located at Danish Technical University. © 1982-2012 IEEE.

Hu C.,Xi'an Jiaotong University | Wu C.,Zhejiang University | Xiong W.,Zhejiang University | Wang B.,National Digital Switching System Engineering Technical Researching Center | And 2 more authors.
IEEE Communications Magazine | Year: 2011

A great deal of research has contributed to the energy efficiency of battery-operated devices in the area of wireless communications, but recently, the energy consumption of the underlying network infrastructure has started to attract more attention as people have become aware of the significant fraction of energy consumed by the Internet of all the energy we consume. We argue that the architecture of routers in constructing the Internet can be improved so as to fully utilize chances to save energy related to transmission equipment. A green reconfigurable router is thus presented for this purpose. © 2011 IEEE.

Shanghai RedNeurons Co. and National Digital Switching System Engineering Technical Researching Center | Date: 2016-02-08

The present invention discloses a software/hardware device with uncertain service function and structural characterization and a method for scheduling the same. The device comprises a policy generator, a scheduler and a plurality of heterogeneous functional equivalents with equivalent functions, wherein, the policy generator is configured for providing a scheduling policy for the heterogeneous functional equivalents to the scheduler; the scheduler is configured for receiving an external service request, determining heterogeneous functional equivalents that provide a service to the external service request according to the scheduling policy given by the policy generator, assigning the service request to the determined heterogeneous functional equivalents, and outputting a service response which has an uncertain relation with uncertain structural characterization according to a feedback and the scheduling policy given by the policy generator. Therefore, the service response provided to the service request has an uncertain correspondence relation with feedback results of the heterogeneous functional equivalents of the device, so that the effectiveness of detection or attack on an unknown loophole, trapdoor of the device is greatly lowered, and the protective ability of the software/hardware device is enhanced.

Wang W.-Y.,National Digital Switching System Engineering Technical Researching Center | Zhu Y.-J.,National Digital Switching System Engineering Technical Researching Center
IEEE Photonics Journal | Year: 2016

In this paper, a multiple light-emitting diode (LED) collaborated signal design based on amplitude-phase superposition (MLC-APS) for multi-input single-output visible light communication (VLC) systems is proposed. By using the additive unique factorization technique, all the LED chips can be viewed as transmitting in parallel to increase the rate of VLC systems. In the MLC-APS system, each LED adopts on-off-keying (OOK) modulation, and therefore, the influences of peak-to-average power ratio and clipping are reduced significantly. Simulation results show its significant error performance gains over the direct-current-biased optical orthogonal frequency division multiplexing (OFDM) system. © 2016 IEEE.

Lan J.-L.,National Digital Switching System Engineering Technical Researching Center | Cheng D.-N.,National Digital Switching System Engineering Technical Researching Center | Hu Y.-X.,National Digital Switching System Engineering Technical Researching Center
Tongxin Xuebao/Journal on Communications | Year: 2014

Based on the thinking of network reconfiguration, the reconfigurable information communication basal network architecture was proposed, and then the network atomic capacity theory, polymorphic addressing and routing mechanism, network reconfiguration mechanism and the secure manageability and controllability mechanism were put forward respectively. The architecture would provide a resolution for current and future applications with different quality of services, flexible and expansible function, universal inter-connection, heterogeneous convergence, manageability and controllability, which also supports the compatible evolution with current internet and is feasible to be implemented on a large scale.

Wang Z.-M.,National Digital Switching System Engineering Technical Researching Center | Wang B.-Q.,National Digital Switching System Engineering Technical Researching Center
Dianzi Yu Xinxi Xuebao/Journal of Electronics and Information Technology | Year: 2013

The substrate link failures have made a great impact on the reliability of Reconfigurable Service Carrying Networks (RSCNs) over Reconfigurable Flexible Network (RFNet). In this paper, the reliability problem of delay-sensitive RSCNs is solved based on a path backup strategy, and a two-stage approach is presented to further reduce the backup resource cost. In the topology preprocessing stage, according to whether the path split is supported by RSCNs, the Splittable Minimum Backup Topology Generation (S-MBT-Gen) and Minimum Backup Spanning Tree Generation (MBST-Gen) algorithms are respectively proposed to reduce the total bandwidth constraints of backup topology. In the topology mapping stage, a Reconfigurable service carrying Network Mapping algorithm with coordinated Primary and Backup Topology (RNM-PBT) is proposed to make the best of the substrate network resource. The simulation experiments show that our proposed algorithms can reduce the average resource cost and execution time cost, while improving the request accepted ratio of RSCNs.

Luo W.,National Digital Switching System Engineering Technical Researching Center
IEEE Wireless Communications and Networking Conference, WCNC | Year: 2013

The unstable characteristic of ill-conditioned system is used to guarantee wireless security in this paper. The use of ill-conditioned theory to protect wireless transmissions is proposed as a way to secure wireless networks at physical layer. Firstly, the problem of randomized transmission is converted to that of solving ill-conditioned equation to guarantee wireless transmissions with inherent low-probability-of interception (LPI). Secondly, a conditional ill-conditioned optimization function is constructed. The function of legitimate node is stable because of its matched channel. But the function of eavesdropper is randomized because that she has not the legitimate conditions, which relate to the wireless medium contains domain-specific information. In this context, we propose a security scheme for wireless security in time-variant channels. In this scheme, the variable part of channels is converted to additional conditions, which can be solved by optimizing parameters. In contrast to conventional physical-layer security techniques, the scheme exploits the redundancy of ill-conditioned problem's solutions instead of array redundancy for deliberate signal randomization, which effectively randomizes the eavesdropper's received signals but not the authorized receiver's signals. Extensive simulations and analysis results show that our proposed scheme is useful for securing wireless transmissions. © 2013 IEEE.

Yang T.C.,National Digital Switching System Engineering Technical Researching Center | Jin L.,National Digital Switching System Engineering Technical Researching Center
Science China Information Sciences | Year: 2011

This paper proposes an algorithm, called circle fitting algorithm, for locating targets by using maneuverable single station in non-line-of-sight environment. This algorithm estimates the position and scattering distance of all scatters based on the circular motion character. The pseudo-target trajectory is calculated from observation results from different observation positions. With scatters regarded as virtual observation stations, the problem of single station location can be converted into a problem of multi-station location. Finally, the traditional multi-station location algorithm is used to estimate target position. Simulation results prove that the proposed method is effective. © Science China Press and Springer-Verlag Berlin Heidelberg 2010.

Li Q.-L.,National Digital Switching System Engineering Technical Researching Center
Proceedings - IEEE Military Communications Conference MILCOM | Year: 2012

Security capacity improvement is always the implementation goal of physical layer security, which can be achieved by deliberate randomization based on differentia and uniqueness of wireless channels through signal processing method. An information-guided randomization secure transmission scheme is proposed combined with a spatial modulation system in which information can be carried by receiving antennas index but actually by channel differentia. Randomization is generated along with channel modulation procedure realized by corresponding preprocessing to transmitting signals. We provide three approaches for designing preprocessing weights under different constraint conditions. The former two can only be used when the number of receiving antennas is less than transmitting and have a tradeoff with varying degrees between receiving performance and security. The third one then relaxes the limits via generalized spatial modulation and can be used for arbitrary antennas configuration but with a receiving performance compromise. Lastly, results of performance analysis and numerical evaluation show that the proposed secure scheme is effective to prohibit the eavesdropper from intercepting information. © 2012 IEEE.

Loading National Digital Switching System Engineering Technical Researching Center collaborators
Loading National Digital Switching System Engineering Technical Researching Center collaborators