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Zhang Y.J.,BUPT | Yang L.J.,BUPT
Applied Mechanics and Materials | Year: 2014

In traditional Bayesian classification data mining methods, there may be defects such as predictions unreliable because the selected predictors are little or not related with the target factor. this paper analyzes the correlation between predictors and the target factor using correlation coefficient based on Bayesian classification model and combines with Hadoop distributed file system and parallel programming models to explore an improved algorithm. The experiments show that this method not only makes the prediction more reliable but also saves resources and improves the efficiency of the algorithm greatly. In addition, it is suitable for massive data processing. © 2014 Trans Tech Publications, Switzerland.

Xu P.,State Key Laboratory of Networking and Switching Technology | Huang H.,BUPT | Wen J.,BUPT
Journal of Convergence Information Technology | Year: 2012

Traditional telecommunication network provides a variety of multimedia services based on IP. While IP Multimedia Subsystem (IMS) is gaining more and more interests from the industry, a set of problems have to be faced such as centralized control, low efficiency and poor scalability of core equipment, especially compared with the IT environment using cloud computing. One of the more important reasons which IMS could not adopt those IT technologies is IMS highly relies on Session Initiation Protocol (SIP) and SIP is a session based protocol which is not compatible with transaction based IT environment. In this paper, Cloud SIP System (CSS) is brought forward to decompose SIP sessions into transactions. The introduction of CSS could facilitate the migration of IMS from the traditional dedicated infrastructure into the shared infrastructure to promote both the use ratio of the infrastructure and the scalability of the system.

Shuang K.,BUPT | Tai X.,BUPT | Su S.,BUPT
Journal of Convergence Information Technology | Year: 2012

Traditional telecommunication network provides MMTel service in centralized manner which leads to some inherent drawbacks, such as high cost to extend capacities of serving nodes and single point of failure. Meanwhile some similar MMTel service now popular on the Internet performs not well because of complex environment on the Internet, and lack of mature security and management scheme. The paper presents a novel way to solve these problems by applying distributed technology in traditional telecommunication network to provide a cost-efficient, scalable, reliable and controllable MMTel service. Leveraging P2P technology, we organize the serving node in the core network to form an overlay under the application layer. In the overlay, user data resource are stored in the serving node, some P2P algorithms are used to discover and locate resources on the overlay, which means two clients can find each other for communication not by traditional centralized manner, but a distributed way without single point of failure, also the serving node can join in or leave from the overlay anytime without disturbing current service. Therefore all the characters lead to high quality services for clients, and low cost for network operators.

Liu D.,BUPT | Wang W.,BUPT | Guo W.,BUPT
IEEE Communications Letters | Year: 2013

Financial and environmental considerations provide new trends in wireless communication network known as green communication. The main object of green communication is to save energy consumption of the communication system as much as possible with users' quality of service (QoS) guaranteed. In this paper, cooperative spectrum sharing is investigated as a means of energy saving. We present an optimal power and time allocation to minimize the overall energy consumption under service quality constraints in cooperative spectrum sharing network. The proposed technique can achieve energy saving while offering SUs' communication opportunities. Numerical results demonstrate the validity of the proposed technique. © 1997-2012 IEEE.

Wang D.,BUPT | Wang X.,BUPT | Gu B.,Waseda University
IEICE Transactions on Communications | Year: 2014

In this paper, a multicast concept for Device-to-Device (D2D) communication underlaying a cellular infrastructure is investigated. To increase the overall capacity and improve resource utilization, a novel interference coordination scheme is proposed. The proposed scheme includes three steps. First, in order to mitigate the interference from D2D multicast transmission to cellular networks (CNs), a dynamic power control scheme is proposed that can determine the upper bound of D2D transmitter power based on the location of Base Station (BS) and areas of adjacent cells from the coverage area of D2D multicast group. Next, an interference limited area control scheme that reduces the interference from CNs to each D2D multicast receiver is proposed. The proposed scheme does not allow cellular equipment (CUE) located in the interference limited area to reuse the same resources as the D2D multicast group. Then two resource block(RB) allocation rules are proposed to select the appropriate RBs from a candidate RB set for D2D multicast group. From the simulation results, it is confirmed that the proposed schemes improve the performance of the hybrid system compared to the conventional ways. © 2014 The Institute of Electronics, Information and Communication Engineers.

Peng M.,Key Laboratory of Universal Wireless Communication | Wang W.,BUPT | Chen H.-H.,National Cheng Kung University
IEEE Vehicular Technology Magazine | Year: 2010

This article focuses on the evolutional strategies (which can be divided into four phases) from the current commercial time division-synchronous code division multiple access (TD-SCDMA) to the future International Mobile Telecommunications (IMT)-Advanced systems. The first evolutional phase is to develop an N-frequency technology to improve capacity and ease network planning of the current TD-SCDMA system. Single- and multicarrier high-speed packet access (HSPA) is specified in the second phase for providing high-rate packet services. Long-term evolution (LTE) technology is introduced in the third phase to provide a similar performance of mobile worldwide interoperability for microwave access (WiMAX). Finally, the fourth phase is to implement time division duplex (TDD)-based IMT-Advanced system, which is one of the alternative standards beyond third-generation (3G) systems. The advanced technologies to enhance spectral efficiency are the critical issues emphasized in all the four phases. The challenges and open issues in the different evolutional phases are identified in this article as well. © 2006 IEEE.

Yao G.,Tsinghua University | Bi J.,Tsinghua University | Guo L.,BUPT
Proceedings - International Conference on Network Protocols, ICNP | Year: 2013

In this paper, a potential threat to reliability of Software Defined Networking (SDN) is disclosed: the cascading failures of controllers. Current SDN designs have widely utilized multiple controllers and the load of a failed controller can be redistributed to the other controllers. However, simply utilizing multiple controllers cannot protect SDN networks from a single point of failure: the load of the controllers which carry the load of the failed controller can exceed the capacity of them, and then cascading failures of controllers will happen. In this article, at first we propose a model for such failures and present simulation results based on the model. Strategies for initial load balance and load redistribution after failure are designed to prevent such failures. The simulation result shows the strategies can significantly increase the resistance of SDN networks to cascading failures. © 2013 IEEE.

Chen L.,Beijing University of Posts and Telecommunications | Chen W.,BUPT | Wang B.,BUPT | Zhang X.,BUPT | And 2 more authors.
IEEE Communications Magazine | Year: 2011

System-level simulation has been widely used to evaluate the comprehensive performance of different mobile cellular systems. System-level simulation methodologies for different systems have been discussed by different organizations and institutions. However, the framework for a unified simulation methodology and platform has not been established. In this article, we propose a general unified simulation methodology for different cellular systems. Both the design of the simulation structure and the establishment of the simulation platform are studied. Meanwhile, the unified modeling and the realization of various modules related to the system-level simulation are presented. The proposed unified simulation methodology and the general simulation platform can be used to evaluate the performance of multiple mobile communication systems fairly. Finally, the overall performance of LTE and Mobile WiMAX systems is evaluated through the proposed framework. The key simulation results for both Full Buffer and VoIP traffics are presented and discussed. It is shown that the LTE system exhibits better performance than Mobile WiMAX. © 2010 IEEE.

Lee Y.-C.,Hanyang University | Hong J.,Hanyang University | Kim S.-W.,Hanyang University | Gao S.,BUPT | Hwang J.-Y.,AskStory
HT 2015 - Proceedings of the 26th ACM Conference on Hypertext and Social Media | Year: 2015

AskStory is a company providing an e-recruitment service where job seekers find a variety of job openings. This paper discusses an approach to recommending job openings attractive to job seekers.

A significant portion of the Chinese characters is phonogram, whose phonetic part can be used for overall sound inference. Phonetic degree is an inherent problem in the inference because low phonetic degree implies little phonetic dependence between the phonogram and its phonetic components. Solving the phonetic degree problem requires association each phonogram with the acoustic features. This paper introduces acoustic feature-based clustering, a classifying model that divides the common phonogram by defining new similarity of the sounds. This allows phonetic degree to be evaluated more reasonable. We demonstrate the clustering outperformed the traditional empirical estimation by having more accurate and real expressiveness. Acoustic feature-based clustering output 48.6% as phonetic degree, less than the empirical claim which is around 75%. As a clustering classifier, our model is competitive with a much clearer boundary on the phonogram dataset. © (2012) Trans Tech Publications, Switzerland.

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