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As more and more Cloud systems are designed and deployed in business and science engineering areas, how to evaluate and monitor the system’s runtime performance is becoming an important issue. However, few efforts are taken to address such an issue because the resources in Cloud systems often owned by different institutes. In this paper, we present an integrated performance evaluation framework, which is aiming to provide cloud users an easy-to-use toolkit to evaluate their system’s runtime performance, or compare the performance under different resource management policies. The design and implementation of our framework is highly extensible and re-useable in most existing cloud systems. Currently, the prototype of our implementation is examined by a series of experiments, and the results indicate that its configurable feature is very useful when users are conducting performance comparing under different contexts.

Ubiquitous networks allow the co-existence of different wireless technologies (3GPP and non-3GPP) such as GSM (Global System for Mobile Communication), Wireless Fidelity (Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications System (UMTS) and Long Term Evolution (LTE). One of the challenging issues in Next Generation Wireless Systems (NGWS) is seamless Vertical Handover (VHO) during Mobile User (MU) mobility between these technologies therefore, the telecommunication operators will be required to develop a strategy for interoperability of these different types of existing networks to get the best connection anywhere anytime. In this survey, we overview two mechanisms which were proposed independently by IEEE and 3GPP, namely; Media Independent Handover (MIH) and Access Network Discovery and Selection Function (ANDSF), respectively that enable seamless VHO between the different types of technologies (3GPP and non-3GPP). We survey the VHO approaches proposed in the literature and classify them into three main categories based on these mechanisms for which we present their objectives, issues and evaluate their complexity of implementation. Finally, a conclusion about who will lead RATs through VHO is given.

Simple theoretical closed algebraic expressions are derived with Hermite-Gauss trial function. These obtained expressions for the normalized propagation constant, the cut-off frequency and the field width of the slab and rectangular optical waveguides. They are shown to have reasonably good precision over a wide range of normalized frequency and modes. These closed expressions are obtained for the conventional variational method and the modified variational technique including either Maractili's method or effective index method. The derived expressions are available for the semi-infinite waveguide. Moreover, results with Hermite Gauss optical field is more confinement than cosusoidal optical field. Also in this work, we present a proposed technique to give a simple and accurate analysis of the rectangular waveguide. The proposed technique based on mixed both the first and the third methods above. The driven equations and the proposed technique show very good accuracy with respect to the finite element method, finite difference method and vectorial boundary element method.

In this work, we develop on average relationship between the Per-Antenna Signal to Interference plus Noise Ratio (PA-SINR) and the Per-Antenna Signal to Leakage plus Noise Ratio (PA-SLNR) performance metrics. Simulation results confirm the equivalence between the two metrics which opens up the door to use PA-SLNR instead of PA-SINR to construct simple Multi-user Multiple Input Multiple Output (MU-MIMO) precoding algorithm.

When RFID systems become pervasive in our life, tag search becomes crucial. However, the problem of RFID search has not been widely addressed in the literature. RFID search protocol which is used to find specific tags has many applications such as inventory management, supply chain management. In this paper, we propose a set of secure and private Hash-based RFID search protocols that can meet all known major attacks in RFID systems, and especially it can protect the privacy of mobile reader users.

An ultra-wideband (UWB) antenna with a narrow frequency notch is presented. The antenna has been fabricated on a FR4 substrate and occupies an area of only 25 × 25 mm2. Starting from a Circular planar patch exhibiting a VSWR smaller than 2.5 in the 3.5−10 GHz band, a frequency notch at 5.65 GHz is introduced by two open slots above the coplanar waveguide feeding. The measured return loss shows a good agreement with the simulation results and proves that this kind of antenna is suitable for reducing the detrimental interference effects of WLAN, operating around 5.5 GHz, on UWB radio link for indoor communication.

The specific methods of the maximum average mutual information quantization are analyzed and deduced. With this method to quantify the initial message, the variable messages and check messages are converted into integers. Then the min-sum decoding algorithm based on integer arithmetic is implemented. Simulation results demonstrate that the decoding performance of min-sum algorithm based on integer with 7-bit maximum average mutual information quantization is almost the same as that of min-sum algorithm based on integer with 8-bit uniform quantization. Meanwhile, all the variables in the algorithm are fixed-length integers, so it is convenient for hardware implementation. Although the decoding performance is slightly worse than that of the sum-product decoding algorithm, the decoding time is greatly reduced. So it is very convenient for future generation communication.

Clustering problem is one of the significant issues for wireless sensor networks concerned with energy consumption and large-scale deployment. Several energy-efficient clustering algorithms have been proposed to improve the energy utilization efficiency and prolong the network lifetime. In this paper, we propose a new clustering scheme after a comprehensive analysis on existing protocols. In our algorithm, named WPCA (Weighted Probabilistic Clustering Algorithm), every node independently decides whether to be a cluster head according to a weighted probability, which is related to the ratio between node’s residual energy and average remaining energy. The nodes with more residual energy are assigned larger weight value to further increase the chances to be elected as cluster heads. In addition, the rotation procedure of cluster heads in previous algorithms is totally abandoned. Simulation results show that WPCA achieves longer lifetime than previous probabilistic-based clustering algorithms and gets a very close approximation compared with a deterministic clustering method.

Emerging demands for high data rate services and high spectral efficiency are the key driving forces for the continued technology evolution in wireless communications. MIMO technology has attracted attention in wireless communications, because it offers significant increases in data throughput and link range without additional bandwidth or transmit power. It achieves this by higher spectral efficiency (more bits per second per hertz of bandwidth) and link reliability or diversity (reduced fading). Orthogonal space-time block codes (STBC’s) have received considerable attention in recent open-loop multiple-input-multiple-output (MIMO) wireless communication because they allow low decoding complexity and guarantee full diversity. Trellis-Coded Modulation (TCM) is a kind of channel coding with improving the coding gain. Therefore, concatenation of STBC and TCM is a combined channel coding to achieve both diversity gain and coding gain advantages. This paper presents a detailed study of space-time block coding (STBC) schemes including orthogonal STBC for 3×4 antennas and high-coding rate STBC. In this paper the performance of OSTBC along with TCM is evaluated using QPSK.

Most CDNs pay more attention to CSP (Content Service Provider) to gain more profit from faster access rate and lower server load. However they ignore that the CDNs pay the ISPs (Internet Service Provider) for using the underlying networks based on the traffic volume generated by CDN servers. ISPs expect to save their operational cost from inter-ISP traffic and improve the QoS (Quality of Service) as well. In this paper, we propose novel decentralized content delivery architecture, ISP Manage Content Delivery Network (IMCDN). For more effectively improving the performance of IMCDN, we propose a cooperative dynamic caching strategy based on the dleft Record Counters Bloom Filter (dl-RCBF). We use the dl-RCBF to improve the remote hit rate and adopt optimistic synchronization to restrict the broadcast traffic. The experiments show that our dynamic caching strategy outperforms state-of-the-art models in hit rate for multiple cache sizes and inter-ISP traffic reduction.

As concerns about energy efficiency and conservation grow, smart grid and intelligent transportation systems that consist of a large number of sensors, actuators and controllers have positioned as a crucial infrastructure. In such systems, machine-to-machine (M2M) communications between components make it possible the full automatic control of the systems. M2M communications is different from existing systems in the sense that it involves an enormous number of machine-type-communication (MTC) devices. Also traffic patterns and as well as QoS requirements vary widely depending on applications. LTE-Advanced of 3GPP provides a list of supportive functions to facilitate the M2M communications. To this end, a massive admission control scheme for the M2M communications was proposed. However, it is neither scalable nor adaptive particularly when the transmission interval of a device is relatively longer than its delay constraint. As a result, the call blocking probability under such scenario is much higher than normal cases. In this paper, we propose a method that is free from such limitation. Furthermore it can decrease the computational overhead under the condition that the transmission interval and the delay meet certain conditions. Through a set of simulations, we show the improvement in the call blocking probability when using the proposed method. We also provide the theoretical proofs that the proposed method can satisfy the delay constraint.

In the newly released 802.11aa-2012 protocol, intra access category prioritization (IACP) and drop eligibility indicator (DEI) enable stream classification service (SCS) with graceful degradation for robust audio and video streaming. IACP introduces the need for scheduling between the primary and alternative AC queues (AC_VI and AAC_VI) for differentiating real-time and non-real-time video streams. This paper proposes a novel cross-layer design for the scheduler between AC_VI and AAC_VI, which combines a real-time video importance scheme in the Application layer and a priority weighting and dropping algorithm (PWD) in the MAC layer, where priority weighting is applied only to AC_VI and priority dropping to both AC_VI and AAC_VI. The results show that the proposed design outperforms the conventional ones, including IACP-RR, ICAP-WRR, and SCS-WRR, with substantial performance gains for both real-time and non-real-time video streams via AC_VI and AAC_VI. Such a win-win game, not possibly achieved by the conventional designs, shows the true power of PWD.

The lower limbs of motion body contain rich identification of individuals in the process of walking. A gait recognition method based on ankle joint motion trajectory and bending angle is proposed. First it obtains lower limb joint points according to each part of the body and height proportion. It obtains the position coordinates of the toe by using skeleton algorithm. According to the position relationship between joint points and toe, we can extract bending angle information. The feature vector is made up of the relative velocity of ankle joint motion trajectory and the bending angle. Support vector machine (SVM) Classifier and the Nearest Neighbor (NN) Classifier are used for the gait classification. In addition, the most methods are tested experiment performance under 0 degree viewing angle. We use 45 degree viewing angle which has a larger view in our experiment. CASIA_A database is used to evaluate the performance of the proposed method. The experimental results demonstrate that the approach has an encouraging recognition performance.

In this paper, we present a dynamic spectrum access strategy to reduce the average overall system time of secondary users (SUs) in multi-channel cognitive radio networks. Before transmitting a packet, SU senses the spectrum environment. If there are free channels in the system, SU randomly selects one for transmitting. If all the channels are busy, we consider a probability-based spectrum selection scheme in which the access channel is chosen based on the predetermined probabilities for saving the sensing power and reducing the overall system time of SU. When the transmission of SU is preempted by the primary user (PU), SU will stay on the operating channel and retransmit the whole data after PU leaves the channel. SU may undergo multiple interruptions before finishing a successful transmission. The interruptions and retransmissions inevitably increase the overall system time of SU. We propose an analytical model by applying the preemptive repeat identical priority M/G/1 queueing theory. Based on the model, we obtain the overall system time expression of SU packets under different spectrum environment and find the optimal distribution vector for the probability-based spectrum access scheme to minimize the average overall system time for SU.

For distributed optical fiber pipeline pre-warning system, the sampling rate used is very high and thus huge data will be generated, which makes it difficult to transfer and store. Compressive sensing is a new compressed sampling method in the field of signal processing which compresses and samples the signal simultaneously. In this paper, an adaptive compressive sensing method is presented for compression and reconstruction of distributed optical fiber pipeline data. First, partial reconstruction based detection method is used to detect whether a hazardous event happened, then different compression ratios are taken for different classes of signal thereby increasing the compression ratio. In signal reconstruction phase, a sparsity determination algorithm is used to determine the sparsity of different segment of the signal, and then wavelet tree combined with CoSamp algorithm is adopted to reconstruct the signal. The adaptive compression algorithm improves the compression ratio and the sparsity determination in reconstruction phase can determine the sparsity of each segment when the signal varies without prior knowledge of the sparsity of the signal. Experimental results show that, the proposed algorithm can obtain higher reconstruction accuracy at a relatively high compression ratio. Furthermore, location simulation shows that the reconstructed signal by the proposed method is effective for danger signal positioning.

The present study raises the concept of network technical anonymity, and designs its corresponding evaluation indicators and model, in order to provide the basis and methods for the evaluation of how anonymous a behavioral agent is on the net. Network technical anonymity is defined as the difficulty in tracking the real identity of a network agent. Five indicators have been designed as follows: name, valid address, alias and behaviors on the net and social attributions. Besides, based on AHP and the fuzzy theory, we have worked out the relative weights of the evaluation indicators and an evaluation model. With this model, we made evaluation of the network technical anonymity of several network applications that are commonly used now in China. The evaluation indicators and model can be applied to the evaluation of how anonymous a network user is in various kinds of network applications, and serve as references for management and design of web services.

A novel connection admission control (CAC) scheme based on bandwidth throughput evaluation algorithm is studied in multi-priority multimedia network. In the new scheme, bandwidth throughput evaluation algorithm is introduced to obtain the delay threshold of different priority traffic. Through bandwidth throughput evaluation algorithm, the delay threshold result of different traffic class is derived. The admission of different priority traffic was controlled by the delay threshold so as to guarantee network quality of service. Numerical results show that not only the service of high priority traffic or the service of low priority traffic is guaranteed in the new scheme, but also the network utilization is promoted.

In this paper, a parameters self-learning PID controller algorithm based on modified BP neural network is proposed to eliminate the influence of time delay on the stability and maneuverability of tele-operation manipulators. This control algorithm adjusts the three parameters of PID controller on line through BP neural network. Conjugate gradient method is used for real-time adjustment of weighted coefficient of BP neural network so as to adjust the output parameter of PID controller. The model of three-joint manipulator with three degrees of freedom (3-DOF) was established. The simulation results show that force tracking performance of master and slave manipulators is good, the maximum error is 0.15. The position tracking performance of slave manipulator is stable, the amplitude decay can be ignored, the maximum error is 3.9 and time delay is 0.3s. This control algorithm has fine self-learning capability and robustness. It had better time delay control effect and could improve the operability of internet-based tele-operation manipulators.

A new algorithm named Differential Evolution Algorithm for Community Detection (DEACD) was proposed in the paper. DEACD used DE as its search engine and used the network modularity as the fitness function to search for an optimal community partition of a network. In this algorithm, there is a modified binomial crossover mechanism to transmit some important information about the community structure in evolution effectively. In addition, a biased process and clean-up operation were employed in DEACD to improve the quality of the community partitions detected in evolution. Experimental results showed that DEACD has very competitive performance compared with other state-of-the-art community detection algorithms. In the process of evolution, the colony evolution was conducted under DE scheme, the network modularity was used to evaluate the fitness of individuals in the colony. The performance of DECD was analyzed by computer generated network and real-world network examples. The algorithm was implemented using matlab Genetic Algorithm Optimization Toolbox (GAOT), and the parametric analysis was performed in the experiment.

The TD-SCDMA is a Chinese 3G mobile phone standard, which has proven technological maturity and commercial viability. In this paper, a patent map is generated by Patent Information Analyze System(PIAS) of Chinese State Intellectual Property Office, and which are researched that the characteristics of the patent application behavior of standard developers in China. The research shows that patent applications of their own technology by standard developers provide technological basis for the establishment of standards. The leading enterprises of technical standard proposals are the core in the correlation relationship of standard developers and play key roles in the standards establishment. The patents of standard developers are the foundation in the early stage, and also decide in the standards future evolution.

Location-based Services (LBS) have brought the potential threats of mobile users’ sensitive personal information. Privacy-aware in LBS is including location privacy and query privacy. Unfortunately, existing privacy protection algorithms rarely pay attention to both of them. This paper proposes a novel privacy protection method which combines K-anonymity and L-diversity to protect both location privacy and query privacy. Two effective query-privacy-aware methods are introduced into the cloaking algorithm. One is the history sharing scheme which confuses history queries within tolerance time. Another is the batch query scheme which confuses real queries presented by the peers. Our technique is suitable for P2P mobile networks, which can effectively eliminate the bottleneck of system brought by the anonymizer. In addition, we develop an imprecise location scheme to prevent the inference attack of few malicious peers. The experiments show that the proposed algorithms are effective to protect users’ location privacy and query privacy in the mobile P2P system.

The addressing principle of distributed optical fiber Bragg grating (FBG) sensor based on frequency modulation continuous wave (FMCW) multiplexing technology was studied, and the theoretical analysis of FBG multiplex distance were carried out; In order to analyze the impact on the spectrum signal, the effect of grating position information, scanning time and scanning frequency range on the spectrum signals were analyzed by simulation. When the FBG multiplex distance is integer or non-integer multiple of system minimum resolution distance, for the FMCW multiplexing scheme was simulated. The grating distance, the scan time and the scanning frequency range significantly affect the signal strength and the signal-to-noise ratio. Finally, the related experimental system was established and the results are consistent with the theory.

Delay Tolerant Networks (DTNs) are a class of emerging networks where disconnections may occur frequently due to propagation phenomena, node mobility, and power outages. Delay is inevitable in DTNs, thus, making better use of buffer space to maximize the packet delivery rate is more important than concentrating on how to decrease the delay. In this paper, we improve the buffer scheme of Epidemic Routing, which is a well-known routing protocol in DTNs. Epidemic Routing utilizes the FIFO buffer management scheme to manage the queuing. However, Epidemic Routing is still very sensitive to the buffer size. Epidemic Routing, furthermore, can only achieve good performance with respect to infinite buffer size due to that a node may have enough space to store lots of messages in its buffer and carry them along for long periods of times until appropriate forwarding opportunities arise. Once there is not enough buffer size, then the performance of Epidemic Routing will fall down hastily. We propose a new buffer scheme in Epidemic Routing, named Location and Direction Aware Drop Scheme (LDDS). LDDS utilizes the location and moving direction information of nodes to determine the drop sequence. A node can get the location and moving direction information of other nodes by receiving beacon packets periodically from anchor nodes and referring to received signal strength indicator (RSSI) for the beacon. In particular, LDDS is able to guarantee the high packet delivery ratio under small buffer size.

This paper shows the range improvement achieved using Multiple-Input Multiple-Output (MIMO) in line with jointly encoding the data over subcarriers or across OFDM symbols for Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) ultra wideband (UWB) System. The framework adopted can be for any coding scheme such as Space-Time-Frequency Codes (STFC), Space Time or Space Frequency code. Theoretical derivations are provided based on Saleh-Valenzuela fading model which characterize the random clustering property of UWB channels. The range and pairwise error probability(PEP) improvement obtained from the diversity gain regardless of any type of coding scheme using MIMO-OFDM system through increasing the number of jointly encoded subcarriers, jointly encoded OFDM symbols, or the number of Antennas is investigated and compared with that of conventional Multiband OFDM UWB system. The relation between coding gain and channel model parameters of UWB channels is also discussed.