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Liu Y.,Tsinghua National Laboratory for Information Sciences and Technology | Liu Y.,Dalian Airforce Communication NCO Academy | Zhong X.,Tsinghua National Laboratory for Information Sciences and Technology | Wang J.,Tsinghua National Laboratory for Information Sciences and Technology
2016 23rd International Conference on Telecommunications, ICT 2016 | Year: 2016

In the multiuser cooperative communication, a core problem is how to efficiently find an appropriate cooperative relay node with lower power consumption and minimal payment when the number of relay nodes is large. This is referred to as optimal relay selection problem, which characterize the desired tradeoff between the probing cost for establishing cooperative transmission and the reward via the cooperative diversity. In this paper, we establish optimal strategies for the homogenous relay node and heterogenous relay node by using optimal stopping theory with a finite horizon. Furthermore, for the homogenous and heterogenous case, the optimal strategies exhibit a pure SNR threshold structure and reward threshold structure, respectively. Therefore, they are simple to be implemented. Theoretical analysis and numerical results indicate that the proposed optimal relay selection strategies can reduce the number of probing candidate relays and improve the transmission rate with lower energy consumption and minimal payment. © 2016 IEEE.

Liu D.-D.,Heilongjiang University | Wei C.-Y.,Heilongjiang University | Li D.-W.,China Coal Technology and Engineering Co. | Li D.-W.,State Key Laboratory of Methane Disaster Monitoring & Emergency Technology | Teng Y.-L.,Dalian Airforce Communication NCO Academy
Meitan Xuebao/Journal of the China Coal Society | Year: 2016

The traditional light scattering measuring device could be polluted easily by dust. This study simulates the gas-solid two phase flow using Fluent software, and thus designs a more rational structure based on the influencing factors which are found from the analysis of particle trajectories. The numerical simulation experimental data shows that the low-velocity vortex is due to scouring the measurement structure by gas for a long time, and becoming polluted. A new structure is designed, which cannot be polluted easily. The experimental results show that this new design makes gas pass the channel speedily and form a turbulent vortex, so dust cannot be detained in the measuring device. This can ensure the veracity and timeliness of the measuring device. © 2016, Editorial Office of Journal of China Coal Society. All right reserved.

Liu Y.,LIAONING Technical University | Zhang X.,Jilin University | Liu D.,Dalian Ocean University | Zhiqiang H.,Dalian airforce communication NCO academy
Advanced Materials Research | Year: 2013

The TDOA localization algorithm for wireless sensor networks can help us measure thetime differences of an unknown node to more anchor nodes, which establish nonlinear equation ofthe differential distance between unknown node and anchor node. Newton iteration is the crucialmethod for nonlinear equation numerical solutions, so using the Newton iterative method can betterachieve nonlinear optimization in TDOA location. The simulation results indicate that the algorithmcan meet the requirement of localization and possesses the preferable localization precision. © (2013) Trans Tech Publications, Switzerland.

Yin X.,PLA Air Force Aviation University | Liu Y.,PLA Air Force Aviation University | Fang Y.,Dalian Airforce Communication NCO Academy
Proceedings - 2014 IEEE Workshop on Advanced Research and Technology in Industry Applications, WARTIA 2014 | Year: 2014

Problem of intranet security is almost birth with network interconnection, especially when the demand for network interconnection is booming throughout the world. The traditional technology can't guarantee the access terminals to its safe and reliable. In view of this, this paper introduces the trustworthiness evaluation technology in trusted computing. The collection and management model is established to deal with the evidences. Through analysing access terminals' own environment and behavior this paper puts forward a model of trust evaluation of tree type, and focuses on the analysis of decision attributes in the model. The model uses multi dimension attributes to determine the trusted access. Finally, the assessment model is analyzed and validated through a simulation experiment, and the results show that the evaluation model is feasible and effectiveness. © 2014 IEEE.

Zheng J.-J.,Dalian Airforce Communication NCO Academy | Lin J.-L.,Xihua University | Zhu W.-L.,University of Electronic Science and Technology of China
Dianzi Keji Daxue Xuebao/Journal of the University of Electronic Science and Technology of China | Year: 2011

Time domain synchronous-orthogonal frequency-division multiplexing (TDS-OFDM) system makes used of PN sequence as guard interval, which is used as channel estimation. Because PN serial correlation is not ideal δ function, extra error has been inducted. A channel equalization method suitable for OFDM system is propose in the paper. Cepstral technique is employed in the method to attain the channel equalization. The simulation results indicate that this method has perfect equalization effect.

Hao X.N.,Dalian Airforce Communication NCO Academy | Wang X.M.,Dalian University of Technology | Deng L.Q.,Dalian Airforce Communication NCO Academy
Advanced Materials Research | Year: 2014

In view of practical applications, it is a high priority to optimize the efficiency of methods for secure multi-party computations. A classic problem is described as following: there are two secrets, α and β, shared among n players using Shamir (t+1,n)-threshold secret sharing scheme, and how to make their product αβshared among n players using the same way. The protocol of Gennaro, Rabin and Rabin (1998) is a well known and efficient protocol for this purpose. It requires one round of communication and O(n2k log2 n+nk2)bit-operations per player, where k is the bit size of the computing field and n is the number of players. In a previous paper(2007), the author presented a modification of this protocol, which reduced its complexity to O(n2k+nk2). In 2009, Peter Lory reduced its complexity to O(n2k). A new protocol is presented in our paper, which reduces this complexity further to O(nklog2k). It is better than Gennaro protocol unconditionally. And as to Peter Lory protocol, the reduction is profitable in situation where log2k is smaller than n. © (2014) Trans Tech Publications, Switzerland.

Xie J.-P.,Lanzhou University | Xie J.-P.,Dalian Airforce Communication NCO Academy | Lv W.-L.,Lanzhou University | Yang T.,Lanzhou University | And 2 more authors.
Faguang Xuebao/Chinese Journal of Luminescence | Year: 2012

Organic field-effect transistors (OFETs) based on copper phthalocyanine were fabricated and their current-voltage characteristics were measured in dark/under illumination. The results showed that OFETs with Au as source/drain electrodes exhibited a photo-current/dark-current ratio of 0.4 and a photoresponsivity of 2.55 mA/W under illumination by a laser diode with a wavelength of 655 nm and power density of 100 mW/cm 2; however, OFETs with Al as source/drain electrodes exhibited a photo-current/dark-current ratio up to 10 4 and a much lower photoresponsivity of 0.39 mA/W under the same conditions. The tremendous increase of photo-current/dark-current ratio is ascribed to the decrease of dark-current caused by Schottky contacts between Al source/drain electrodes and CuPc.

Yu Y.,Dalian Airforce Communication NCO Academy | Yuan H.,Dalian Airforce Communication NCO Academy | Fan F.,Dalian Airforce Communication NCO Academy
Advanced Materials Research | Year: 2012

How to allocate the numbers of transmitted bits to the sub carriers in OFDM system is studied in this article. Among all the bit loading algorithms, three classic bit loading algorithms are investigated, the Greedy algorithm is mostly analyzed, the performance of the three algorithms are also analyzed by simulation and some improved methods are proposed. © (2012) Trans Tech Publications, Switzerland.

Cui L.,Dalian Airforce Communication NCO Academy | Kang Y.,Dalian Airforce Communication NCO Academy | Huang W.,Dalian Airforce Communication NCO Academy | Wang H.,Dalian Airforce Communication NCO Academy | Zhang Y.Q.,Dalian Airforce Communication NCO Academy
WIT Transactions on Information and Communication Technologies | Year: 2014

The FP-growth algorithm compact all frequent patterns in a tree based on divideand- conquer approach so that the mining algorithm in main memory cannot realize in larger database. This paper brings an improved FP-tree construction algorithm, which diminishes breadth of FP-tree to reduce occupation space by using dynamic node insert technique to construct the FP-tree and improves the efficiency of mining algorithm by increasing the length of shared prefix. Because mining completely frequent patterns set in intensive data is very difficult, so a new algorithm for mining maximal frequent patterns based on the improved FPtree- IFPmax is proposed, which uses the rank of nodes to prejudge, labels already exist nodes according to the nature of maximal frequent patterns, and effectively avoids redundant traversal and improves the time efficiency of the maximal frequent pattern mining algorithms. The results of experiments based on different standard data sets show the effectiveness of the algorithm. © 2014 WIT Press.

Xia M.,Dalian Airforce Communication NCO Academy | He F.,Dalian Airforce Communication NCO Academy | Jiang W.,Dalian Airforce Communication NCO Academy
Advanced Materials Research | Year: 2012

Atmosphere laser communication, as a very good wireless communication method, has been studied by so many people theoretically and experimentally since the invention of laser. In the atmosphere laser communication system the effect of different weather conditions to the transmission was different, there was no theoretical formula of the effect of rainfall to laser communication and only the empirical formula could be achieved by plenty of observations. Since the parameters of empirical formula from different literatures were different, in this article rainfall attenuation was simulated according to the empirical formula under different parameters and the results differed. It was proved that the conditions to the empirical formula could not be incarnated in the formula itself, large numbers of tests were needed to make sure that the parameters were confirmed. In this article rain attenuation under normal weather conditions was presented with some familiar parameters. © (2012) Trans Tech Publications, Switzerland.

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