Xie H.,Beijing University of Posts and Telecommunications |
Liang D.,Beijing University of Posts and Telecommunications |
Zhang Z.,Beijing University of Posts and Telecommunications |
Jin H.,Beijing University of Posts and Telecommunications |
And 2 more authors.
IEEE International Conference on Data Mining Workshops, ICDMW | Year: 2017
kNN (k nearest neighbors) is widely adopted because of its simplicity. However, its shortcomings can not be neglected, especially its time complexity. Consequently a great amount of approaches emerged in large numbers in decades to cope with this issue with a tradeoff in performance of the classification. In this paper, a novel improved kNN algorithm is proposed with a better performance than traditional kNN when its time complexity is meanwhile reduced. In the proposed algorithm, a pre-classification which cost little time is to be conducted before proposed kNN algorithm. Then the training set can be divided into several parts according to the classification probability with some thresholds. After that the parts with probability nearer to 1 or 0 are selected to be training sets. The accuracy rate and the area under the ROC curve (the receiver operating characteristic curve) of the proposed algorithm is calculated and compared with basic kNN algorithm in the experiments. The experiment results show that not only the pre-classification based kNN algorithm greatly reduced the time cost, but it also performs better than the original kNN algorithm in accuracy and AUC (the area under the ROC curve). © 2016 IEEE.
Yan H.,Beijing University of Technology |
Zhang Y.,China Mobile Communications Group |
Pang Z.,ABB |
Xu L.D.,CAS Institute of Computing Technology |
And 3 more authors.
IEEE Transactions on Industrial Informatics | Year: 2014
Industrial wireless sensor network (IWSN) is a key enabling technology for the Internet-of-things (IoT). IWSN acts as one of the fundamental elements of the IoT infrastructure to bridge the physical sensors and actuators in field and backbone systems in the Internet. For deterministic performances, all mainstream IWSN standards utilize the slotted media access control (MAC) where the communication is allocated based on the superframe that comprises a number of slots in either contention-based access or contention-free access modes. In this paper, the planning of the superframe structure of the slotted MAC is investigated by two means: 1) a mathematical model of the MAC access latency based on the queue theory; and 2) an easy-to-use software tool based on packet-level simulation. The mathematical model gives an overall estimation of the average MAC access latency of the whole network. The software tool gives the exact latency of each packet and then can derive the optimal superframe structure of the network. The two means are validated correspondingly. With the methods proposed in this paper, IWSN designers can minimize the MAC access latency while satisfying the requirements at different generating rates of packet, number of nodes in the network, and packet buffer length of each node. © 2012 IEEE.
Qiang G.,Nanjing Southeast University |
Lei C.,China Mobile Communications Group
Conference Proceedings of the International Symposium on Signals, Systems and Electronics | Year: 2010
Due to the dynamic characteristics of the available spectrum for secondary users inherent in cognitive radio network, to avoid interference among secondary users, available radio resources should be allocated coordinately among them, thus control channel is needed. In multi-hop cognitive radio networks, a control channel common to all secondary users is not available, and control channel has to be selected in a distributed fashion. The control channel selection problem in multi-hop cognitive radio network is investigated in this paper. A distributed algorithm is proposed with the goal to minimize the number of control channel in the whole network. The control channel selection scheme for each node is obtained. Simulation results show that with the increase of total available channels, the required number of control channel decreases. © 2010 IEEE.
Jiang Y.,Nanjing Southeast University |
Liu Q.,China Mobile Communications Group |
Zheng F.,University of Reading |
Gao X.,Nanjing Southeast University |
You X.,Nanjing Southeast University
IEEE Transactions on Vehicular Technology | Year: 2016
In this paper, joint resource allocation and power control for energy-efficient device-to-device (D2D) communications underlaying cellular networks are investigated. The resource and power are optimized for maximization of the energy efficiency (EE) of D2D communications. Exploiting the properties of fractional programming, we transform the original nonconvex optimization problem in fractional form into an equivalent optimization problem in subtractive form. Then, an efficient iterative resource allocation and power control scheme is proposed. In each iteration, part of the constraints of the EE optimization problem are removed by exploiting the penalty function approach. We further propose a novel two-layer approach, which allows finding the optimum at each iteration by decoupling the EE optimization problem of joint resource allocation and power control into two separate steps. In the first layer, the optimal power values are obtained by solving a series of maximization problems through root finding, with or without considering the loss of cellular users' rates. In the second layer, the formulated optimization problem belongs to a classical resource-allocation problem with single allocation format, which admits a network flow formulation so that it can be solved to optimality. Simulation results demonstrate the remarkable improvements in terms of EE by using the proposed iterative resource allocation and power control scheme. © 2015 IEEE.
Yu Y.,Jilin University |
Gao K.,China Mobile Communications Group
Wireless Personal Communications | Year: 2015
This paper proposes a new interleaving rule, with which a new IBF (IBF, intertwined bridge function) is generated. Not only does the new intertwined bridge function have a zero correlation zone, but also its cross-correlation performance is ideal. An ultra-wideband system is introduced, which uses the intertwined bridge functions as the spreading code. The sequence of interleaved bridge function with zero autocorrelation bridge area and zero cross-correlation zones can better reduce multiple access interference and multipath interference. It is shown by the simulation results that the ultra-wideband systems using the interleaved bridge function as the spreading sequence have better error rate performance. © 2015 Springer Science+Business Media New York
Zhang Y.,Northeast Petroleum University |
Bi H.,Key Laboratory of Network System and Network Culture |
Zhu B.,Petrochina |
Dong B.,China Mobile Communications Group
Advances in Information Sciences and Service Sciences | Year: 2012
Digital Watermarking technology is employed today mainly to protect the copyright and economic interests of the digital media owners. Independent component analysis (ICA) is an effective method of blind signal separation by calculating higher-order statistical information of data, and then estimating the source signal from the observation signal. In this paper, based on the similarity between the mixing/separation model in ICA and the embedding/extraction process in watermarking, we present the improved algorithm where direct inverse is proposed. As the ICA embedding, we introduce the mixing matrix to obtain the watermarked image and the key image, accomplishing the watermark embedding, however, unlike the ICA extraction, we exploits inverse matrix calculation in replacement of the ICA algorithm to solve the uncertainty issue in ICA. The simulation results show that the improved algorithm not only eliminates the sequence uncertainty, but also obtains better robustness while maintaining its visual invisibility.
Zhu H.-J.,Qiqihar University |
Li D.F.,China Mobile Communications Group
Advanced Materials Research | Year: 2014
The group customer line service has become one of the key businesses for communication operators, and the line PTN technology development currency, the PTN technology application, and the development trend are researched. According to the PTN technology and client group line error correction algorithm, the multi granularity hash correction algorithm is used for data video aware, and when the PTN data is changed fast, the fuzzy block effect happened. The customer line service performance is bad. An improved group customer line correction algorithm is proposed based on PTN technology. The hidden Markov model is used for packet loss rate prediction, and the multiple steps are selected in random, and the data stream iteration algorithm is designed. The tamper detection algorithm is obtained. PTN technology group customer line correction is realized. Simulation results show that the new method can reduce error transmission rate of the PTN group customer line, the customer loss and delay of the data transmission can be controlled, and the peak signal to noise ratio is improved, the error correction performance is better, and it can be effectively applied to communications operator service. © (2014) Trans Tech Publications, Switzerland.
An Q.,Huawei |
Gao J.,China Mobile Communications Group
INTELEC, International Telecommunications Energy Conference (Proceedings) | Year: 2014
In the field such as telecommunications, UPS, finance, electric power and so on, the VRLA batteries are usually used in a series connection, but when there exists a faulty or several faulty batteries, the performance/life of the battery bank will deteriorate seriously to endanger the safety of power supply. After inspecting and analyzing the problem occurred of the battery backup time shortage in the actual site, we found that almost all the problems are due to the faulty battery existance in spite of the other batteries being still healthy. In this paper the author has studied some indicators commonly used to describe the uniformity of the VRLA battery, but found that these indicators only concern the initial state of the battery when they start to use rather than the internal factors to affect the uniformity of the VRLA battery really. When the battery is put into operation, due to the complexity and the diversity of the environment battery working, the same initial state of the VRLA battery cannot make sure the same performance/life throughout the lifespan. We can use the fishbone diagram method, which is a comprehensive analysis of various factors affecting the uniformity of the VRLA battery, from six aspects, 5M1E, namely Man, Machine, Material, Method, Measurement and Environment, to find out the key influencing factors and improve them. Furthermore, by means of the wireless distributed online real-time monitoring technology, we can monitor, even remote monitor the state of the VRLA battery, detect the faulty battery accurately, then replace it promptly to ensure the safety of power supply for the network. © 2014 IEEE.
Xiaofei Z.,Huawei |
Zhen W.,China Mobile Communications Group |
INTELEC, International Telecommunications Energy Conference (Proceedings) | Year: 2016
Modular UPSs have more than ten years of history, and have been widely used in large data centers thanks to their features of high availability, high scalability, easy maintenance, high efficiency, and many other advantages. The reliability of a modular UPS primarily depends on the system architecture design which should be simple and decoupled to avoid single points of failure. Key parts such as power modules, control modules, the system communication bus, power supply, and fans must be redundant. The UPS system reliability also depends on the system fault detection and isolation mechanisms, which ensure that a faulty unit is promptly detected and automatically isolated from the system so that remaining operational units can continue supplying power safely. Lastly, real-time detection and health condition evaluation of vulnerable devices ensure long term reliable operation of the power supply system. Leveraging its powerful and professional test verification platform, Huawei verifies and optimizes its modular UPS products through 21 special reliability tests, ensuring strong UPS adaptability to power grids, various environments, and loads. © 2015 IEEE.
Gao J.,China Mobile Communications Group |
Yu L.,China Mobile Communications Group
INTELEC, International Telecommunications Energy Conference (Proceedings) | Year: 2010
Traditionally, 2V cells have been the most widely batteries used in the base stations in the China Mobile network, and have provided very good performance over the years. As technology has advanced, and space or "footprint" has become more and more valuable in large urban installations, 12V front terminal batteries (that require far less space), are becoming more and more attractive. This paper will introduce how 12V front terminal VRLA batteries are being applied in base stations as power supply back up within the China Mobile Network. There is concern whether the present 12V front terminal VRLA batteries will be able to legitimately replace the 2V VRLA batteries, with consistent performance, in most installations. What challenge will the telecom operator face when using 12V front terminal batteries? China Mobile investigated this question and attempted to find out the detailed technical characteristics of the 12V front terminal VRAL batteries, the advantages, as well as the relevant challenge widely deploying these batteries in China Mobile's network. Compiling field and lab data, China Mobile has been able to fully evaluate 12V batteries in the most appropriate sites, with the least possible risk, and to their best advantage. © 2010 IEEE.