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Investigation of three-pulse photon echo in thick crystal using finite-difference time-domain method

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Chinese Physics B 2017年第4期26卷 190-197页

作者：马秀荣徐林常世元张双根 department of computer and communication eng.neering Tianjin University of TechnologyTianjin 300384China eng.neering Research Center of communication Devices and Technology Ministry of EducationTianjin Key Laboratory of Film Electronic and Communication DevicesTianjin 300384China 不详

This paper investigates the phenomenon of three-pulse photon echo in thick rare-earth ions doped crystal whose thickness is far larger than 0.002 cm which is adopted in previous *** influence of thickness on the three-pulse photon echo＇s amplitude and efficiency is analyzed with the Maxwell-Bloch equations solved by finite-difference timedomain *** demonstrate that the amplitude of three-pulse echo will increase with the increasing of thickness and the optimum thickness to generate three-pulse photon echo is 0.3 cm for Tm^（3＋）：YAG when the attenuation of the input pulse is taken into ***,we find the expression 0.09 exp（α＇L）,which is previously employed to describe the relationship between echo＇s efficiency and thickness,should be modified as 1.3 · 0.09 exp（2.4 ·α＇L） with the propagation of echo considered.

关键词： three-pulse photon echo Maxwell-Bloch equations finite-difference time-domain method

Secure and efficient k-nearest neighbor query for location-based services in outsourced environments

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Science China(information Sciences) 2018年第3期61卷 231-233页

作者： Haiqin WU Liangmin WANG Tao JIANG department of computer Science and communication eng.neering Jiangsu University School of Cyber eng.neering Xidian University

Dear editor,Recently,due to the proliferation of location-aware mobile devices,k nearest neighbor query(k NN)has become increasing popular in location-based services,especially in outsourced environments where data owners(DO)outsource their private points-of-interests(POIs)to the location service provider(LSP)and allow authorized clients to query k POIs nearest to his ***,the

关键词： DII Secure and efficient k-nearest neighbor query for location-based services in outsourced environments

Cloud Based Software Computing as a Service in Hybrid Evolution Algorithm with Feedback Assistance

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Journal of Electronic Science and Technology 2016年第4期14卷 362-369页

作者： Ming-Shen Jian Jun-Hong Shen Kuan-Wei Lee Yi-Chen Jhou Chien-Tang Mai department of computer Science and information eng.neering National Formosa University Yunlin County department of information communication Asia University Taichung

This paper develops cloud based software computing as a service （SCaaS） in the hybrid evolution algorithm with feedback assistance to solve the data optimal NP-complete problems such as travel salesman problems and job shop scheduling problems. Suitable steps, methods, or procedures of the genetic algorithm can be adopted from various evolution procedures or methods of the genetic algorithms based on the fitness evaluation results and survival ratio of different crossover methods in the current generation. The proposed system can dynamically emphasize the corresponding methods or procedures for the better performance in optimal solution searching. In addition, according to the proposed XML format, system users can upload only the coding of chromosomes without implementing the genetic algorithm program. Furthermore, by using the feedback assistance, the convergence time of the optimal solution can be enhanced.

关键词： Cloud computing evolution algorithm,job shop scheduling problem traveling salesman problem.

Out of sight, out of mind: a distance-aware forgetting strategy for adaptive random testing

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Science China(information Sciences) 2017年第9期60卷 78-98页

作者： Cheng.ing MAO Tsong Yueh CHEN Fei-Ching KUO School of Software and communication eng.neering Jiangxi University of Finance and Economics department of computer Science and Software eng.neering Swinburne University of Technology

Adaptive random testing(ART) achieves better failure-detection effectiveness than random testing by increasing the diversity of test cases. However, the intention of ensuring even spread of test cases inevitably causes an overhead problem. Although two basic forgetting strategies(i.e. random forgetting and consecutive retention) were proposed to reduce the computation cost of ART, they only considered the temporal distribution of test cases. In the paper, we presented a distance-aware forgetting strategy for the fixed size candidate set version of ART(DF-FSCS), in which the spatial distribution of test cases is taken into consideration. For a given candidate, the test cases out of its "sight" are ignored to reduce the distance computation cost. At the same time, the dynamic adjustment for partitioning and the second-round forgetting are adopted to ensure the linear complexity of DF-FSCS algorithm. Both simulation analysis and empirical study are employed to investigate the efficiency and effectiveness of DF-FSCS. The experimental results show that DF-FSCS significantly outperforms the classical ART algorithm FSCS-ART in efficiency, and has comparable failure-detection effectiveness. Compared with two basic forgetting methods, DF-FSCS is better in both efficiency and effectiveness. In contrast with a typical linear-time ART algorithm RBCVT-Fast, our algorithm requires less computational overhead and exhibits the similar failure-detection capability. In addition, DF-FSCS has more reliable performance than RBCVT-Fast in detecting failures for the programs with high-dimensional input domain.

关键词： adaptive random testing software testing test cases computational overhead diversity

Multi-domain Lightweight Asymmetric Group Key Agreement

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Chinese Journal of Electronics 2018年第5期27卷 1085-1091页

作者： ZHeng.Jiamin TAN Yu'an ZHANG Xiaosong ZHANG Qikun ZHANG Quanxin ZHANG Changyou School of computer Science and Technology Beijing Institute of Technology department of computer Science and Technology Tangshan University Institute of computer and communication eng.neering Zhengzhou University of Light Industry Institute of Software Chinese Academy of Science

The terminals in mobile cloud computing have themselves the special characteristics, such as mobile flexibility, distributed in different domains, resourceconstraint and easily to be captured et al. The terminals in mobile cloud computing participated the collaborative computing, information exchange and sharing secrets may come from different domains, different networks or different clouds. For this complex network environment the paper proposes a Multi-domain lightweight Asymmetric group key agreement(ML-AGKA). It adopts the bilinear mapping and blind key technology to achieve an asymmetric group key agreement protocol among mobile terminals distributed in different domains, proposes a computation and communication migration technologies to ensure that the mobile terminals are lightweight computing and communication consumption. The protocol can also achieve anonymity and authentication. The protocol is proven secure under the Computational Diffe-Hellman(CDH) problem assumption and the performance analysis shows that the proposed protocol is highly efficient.

关键词： Asymmetric group key agreement(AGKA) Lightweight computing Bilinear mapping Multi-domain

Automatic tuning of sparse matrix-vector multiplication on multicore clusters

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Science China(information Sciences) 2015年第9期58卷 17-30页

作者： LI ShiGang HU ChangJun ZHANG JunChao ZHANG YunQuan State Key Laboratory of computer Architecture Institute of Computing Technology Chinese Academy of Sciences School of computer and communication eng.neering University of Science and Technology Beijing department of computer Science University of Illinois at Urbana-Champaign

To have good performance and scalability, parallel applications should be sophisticatedly optimized to exploit intra-node parallelism and reduce inter-node communication on multicore clusters. This paper investigates the automatic tuning of the sparse matrix-vector(Sp MV) multiplication kernel implemented in a partitioned global address space language, which supports a hybrid thread- and process-based communication layer for multicore systems. One-sided communication is used for inter-node data exchange, while intra-node communication uses a mix of process shared memory and multithreading. We develop performance models to facilitate selecting the best configuration of threads and processes hybridization as well as the best communication pattern for Sp MV. As a result, our tuned Sp MV in the hybrid runtime environment consumes less memory and reduces inter-node communication volume, without damaging the data locality. Experiments are conducted on 12 real sparse matrices. On 16-node Xeon and 8-node Opteron clusters, our tuned Sp MV kernel gets on average 1.4X and 1.5X improvement in performance over the well-optimized process-based message-passing implementation, respectively.

关键词： Sp MV PGAS hybridization model-driven multicore clusters

Multi-feature Multimodal Biometric Recognition Based on Quaternion Locality Preserving Projection

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Chinese Journal of Electronics 2019年第4期28卷 789-796页

作者： WANG Zhifang ZHEN Jiaqi LI Yanchao LI Guoqiang HAN Qi department of Electronic eng.neering Heilongjiang University department of information Security and communication Technology Norwegian University of Science and Technology department of computer Science and Technology Harbin Institute of Technology

This paper proposed Quaternion locality preserving projection(QLPP) for multi-feature multimodal biometric recognition. Multi-features fill the real part or the three imaginary parts of quaternion to constitute the quaternion fusion features. In quaternion division ring, QLPP extracts the local information and finds essential manifold structure of the quaternion fusion features. Deferent from Quaternion principal component analysis(QPCA) and Quaternion fisher discriminant analysis(QFDA), QLPP takes advantage of the optimal linear approximations to find the nonlinear manifold structures. Two experiments are designed: one fuses four features from two biometric modalities, and the other fuses three features from three biometric *** experimental results show the proposed algorithm achieves much better performance than the unimodal biometric algorithms, the traditional feature level fusion methods(weighted sum rule and series rule) and two quaternion representation methods(QPCA and QFDA).

关键词： Multimodal biometrics Quaternion Feature fusion Quaternion locality preserving projection(QLPP)

Mobile Internet Big Data Platform in China Unicom

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Tsinghua Science and Technology 2014年第1期19卷 95-101页

作者： Wenliang Huang Zhen Chen Wenyu Dong Hang Li Bin Cao Junwei Cao China Unicom Groups No. 21 Financial Street Xicheng.District Research Institute of information Technology (RIIT) and Tsinghua National Lab for information Science and Technology (TNList) Tsinghua University department of computer Science and Technology Tsinghua University department of computer Science and Technology PLA Univ. of info. & eng.

China Unicorn, the largest WCDMA 3G operator in China, meets the requirements of the historical Mobile Internet Explosion, or the surging of Mobile Internet Traffic from mobile terminals. According to the internal statistics of China Unicom, mobile user traffic has increased rapidly with a Compound Annual Growth Rate （CAGR） of 135%. Currently China Unicorn monthly stores more than 2 trillion records, data volume is over 525 TB, and the highest data volume has reached a peak of 5 PB. Since October 2009, China Unicom has been developing a home-brewed big data storage and analysis platform based on the open source Hadoop Distributed File System （HDFS） as it has a long-term strategy to make full use of this Big Data. All Mobile Internet Traffic is well served using this big data platform. Currently, the writing speed has reached 1 390 000 records per second, and the record retrieval time in the table that contains trillions of records is less than 100 ms. To take advantage of this opportunity to be a Big Data Operator, China Unicom has developed new functions and has multiple innovations to solve space and time constraint challeng.s presented in data processing. In this paper, we will introduce our big data platform in detail. Based on this big data platform, China Unicom is building an industry ecosystem based on Mobile Internet Big Data, and considers that a telecom operator centric ecosystem can be formed that is critical to reach prosperity in the modern communications business.

关键词： big data platform China Unicorn 3G wireless network Hadoop Distributed File System (HDFS) mobilenternet network forensic data warehouse HBase

Clustering-based adaptive low-power subframe configuration with load-aware offsetting in dense heterogeneous networks

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Digital communications and Networks 2022年第5期8卷 843-852页

作者： Dinkisa A.Bulti Jyri Hämäläinen Beneyam B.Haile Yihenew Wondie School of Electrical and computer eng.neering Addis Ababa Institute of Technology(AAiT)Ethiopia department of communication and Networking Aalto UniversityFinland

Heterogeneous Networks(HetNets)and cell densification represent promising solutions for the surging data traffic demand in wireless *** dense HetNets,user traffic is steered toward the Low-Power Node(LPN)when possible to enhance the user throughput and system capacity by increasing the area spectral ***,because of the transmit power differences in different tiers of HetNets and irregular service demand,a load imbalance typically exists among different serving *** offload more traffic to LPNs and coordinate the Inter-Cell Interference(ICI),Third-Generation Partnership Project(3GPP)has facilitated the development of the Cell Range Expansion(CRE),enhanced Inter-Cell Interference Coordination(eICIC)and Further enhanced ICIC(FeICIC).In this paper,we develop a cell clustering-based load-aware offsetting and an adaptive Low-Power Subframe(LPS)*** solution allows the separation of User Association(UA)functions at the User Equipment(UE)and network server such that users can make a simple cell-selection decision similar to that in the maximum Received Signal Streng.h(max-RSS)based UA scheme,where the network server computes the load-aware offsetting and required LPS periods based on the load conditions of the *** proposed solution is evaluated using system-level simulations wherein the results correspond to performance changes in different service *** show that our method effectively solves the offloading and interference coordination problems in dense HetNets.

关键词： Heterogeneous networks(HetNets) 5G LTE-AUser association Interference coordination Load balancing Cell range expansion Almost blank subframe Further enhanced ICIC Low-power subframe