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We experimentally observe periodical soliton bunches in a microfiber-based graphene saturable absorber mode-locked fiber laser. The optomechanical effect and dispersive wave are responsible for the inter- and intra-soliton-bunch interaction in the laser, respectively.
New ADCP(Acoustic Doppler current profiler) can estimate surface wave based on current measurement. Now existing background correction algorithm only considers current amplitude, TRDI ADCP commercial software WAVESMON suggest if current amplitude is greater than 0.75m/s, wave estimation should be corrected for background current. The research shows that when background exists, background current amplitude,...
False data injection attack can bypass the bad data defense process in the power systems and affect the results of state estimation, so that the system security is in danger because of the wrong states obtained in the dispatch center. The traditional false data injection attack is based on the DC power flow model and has many limitations. In this paper, a global attack model and local attack model...
We have designed, implemented and evaluated the novel single array acoustic localization system SAILoc. The SAILoc system can interact with the commercial-off-the-shelf (COTS) smart phone and it is easier to deploy than multiple sensors' system. We also propose a robust time delay estimation (TDE) algorithm which is based on frequency domain (FD-TDE) and has an advantage over generalized cross-correlation...
This paper presents a new discriminative learning framework to associate the relationship between the objects and the words in an image and perform template matching scheme for complex association patterns. The problem is first formulated as a bipartite graph matching problem. Thereafter, structural support vector machine (SVM) is employed to obtain the optimal compatibility function to encode the...
Multiuser MIMO (MU-MIMO) plays an important role in Wireless Local Area Networks (WLAN), due to its ability of enabling concurrent transmissions between multiple users and Access Points. However, a larger amount of erroneous packets often occur in the MU-MIMO streams, resulting in massive retransmissions and severe transmission lags. Based on our empirical observations, we found that the incorrect...
Microphone array for high-quality audio recording has been realized by dedicated devices. But lack of portability and high cost prevent such system being widely adopted. Today's commercial-off-the-shelf (COTS) smartphones are relatively more convenient for audio recording. However, in order to estimate the target's direction of arrival (DOA), several asynchronous receivers (smartphones) must be precisely...
We find and study the phenomenon of single-mode excitation in a microring resonators dye laser. A submicron thickness silica ring embedded in a simplified hollow-core microstructured optical fiber (SHMOF) is used as a microring resonator. We discuss the factors that influence the single-mode excitation and analyze the principle.
In the compound-Gaussian background, for the problem that a fusion-based detector was not fully adaptive when using the sample covariance matrix (SCM) estimation, this paper replaces SCM with the normalized sample covariance matrix (NSCM) to estimate the clutter covariance matrix and a new empirical formula of the adjustable parameter of the adaptive NSCM-based detector is derived. At last, the CFAR...
Today's internet has witnessed a fast growth of mobile video streaming. Different from traditional PC/laptop-based video streaming, mobile video streaming relies on the usage of mobile devices and wireless networks, allowing people to receive video content on the move. The change has challenged traditional video content delivery, which uses centralized infrastructure (e.g., CDN) inside the network...
With the advances in wireless communication and the growing popularity of mobile devices, it has become rather normal to watch videos using mobile devices such as mobile phones and tablets. In order to improve user engagement in mobile video sessions, it is important for content providers and CDN operators to understand the correlations between video quality and Quality of Experience (QoE) of mobile...
This paper presents a new closed-form solution for 3D source localization using the hybrid measurements of angles of arrival and gain ratios of arrival. Under the small Gaussian noise condition, we linearize the hybrid measurement equations to obtain a weighted least-squares solution and then the mean-square error matrix of the proposed method is derived. Theoretical analysis and simulations show...
In recent years, Dynamic Adaptive Streaming over HTTP (DASH) has gained momentum as an effective solution for delivering videos on the Internet. This trend is further driven by the deployment of existing HTTP cache infrastructures in DASH systems to reduce the traffic load as well as to serve clients better. However, deploying conventional cache servers in DASH systems still suffers from low cache...
Electric vehicle (EV) driving range directly reflects EVs' performance, safety, reliability and economy. EV has gained wide attention in recent years. However, most of researches are carried out under ideal conditions and the existing methods have numerous drawbacks. This paper presents a novel prediction method based on a least squares support vector machine (LSSVM) model with parameters γ and σ2...
Recent years have witnessed a new content delivery paradigm named crowdsourced CDN, in which devices deployed at edge network can prefetch contents and provide content delivery service. Crowdsourced CDN offers high-quality experience to end-users by reducing their content access latency and alleviates the load of network backbone by making use of network and storage resources at millions of edge devices...
Driven by the exponentially increasing amount of mobile video traffic, caching videos closer to the end users has become an appealing solution to reduce the traffic through the backbone network while improving users' perceived quality-of-experience (e.g., better video quality and reduced service delay). This research interest has been gaining lots of momentums due to the emergence of smart Access...
Recent years have witnessed an explosion of gamecasting applications in the market, in which game players (or gamers in short) broadcast their game scenes in real-time. Such pioneer applications as YouTube Gaming, Twitch, and Mobcrush have attracted a massive number of online broadcasters, and each of them can attract hundreds or thousands of fellow viewers. The growing number however has created...
Today's WiFi networks deliver a large fraction of traffic. However, the performance and quality of WiFi networks are still far from satisfactory. Among many popular quality metrics (throughput, latency), the probability of successfully connecting to WiFi APs and the time cost of the WiFi connection set-up process are the two of the most critical metrics that affect WiFi users' experience. To understand...
With rapid development and popularity, smartphones have been of importance in our daily life. Despite of its convenience in communication and computing, smartphones also lead potential security threats to users. Existing methods on smartphones for protecting user's privacy mainly depend on password or fingerprint based authentication. Most smartphone passwords are very simple and easy to guess or...
The fabrication and test of a new type of electrostatic vertical comb drive scanning micromirror is presented in this paper. Conventional vertical comb-drive actuators need two structural layers, one for the rotor fingers and a second for the stator fingers. In our work, we fabricated the rotor and stator fingers using one mask lithography step and designed a new assembly method to achieve the vertical...
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