27479532
Subspace-Based Blind Detection of Space-Time Coding
Space-time coding (STC) schemes for communication systems employing multiple transmit and receive antennas have received considerable interest recently. On space-time coding, some algorithms with perfect channel state information (CSI) have been proposed. In certain fast varying situation, however, it may be difficult to estimate the channel accurately and it is natural to study the blind detection algorithm without CSI. In this paper, based on subspace, a new blind detection algorithm without CSI is proposed. Using singular value decomposition (SVD) on output signal, noise subspace and signal subspace, which keep orthogonal to each other, are obtained. By searching the intersection of the signal subspace and the limited symbol vector set, symbol detection is achieved. The simulations illustrate that the proposed algorithm significantly improves system performance by receiving more output signals relative to transmit symbols. Furthermore, the presented algorithm is robust to the fading channel that changes between two successive blocks.
27148951
Diffusion filtering in image processing based on wavelet transform
The nonlinear diffusion filtering in image processing bases on the heat diffusion equations. Its key is the control of diffusion amount. In the previous models, the diffusivity depends on the gradients of images. So it is easily affected by noises. This paper first gives a new multiscale computational technique for diffusivity. Then we proposed a class of nonlinear wavelet diffusion (NWD) models that are used to restore images. The NWD model has strong ability to resist noise. But it, like the previous models, requires higher computational effort. Thus, by simplifying the NWD, we establish linear wavelet diffusion (LWD) models that consist of advection and diffusion. Since there exists the advection, the LWD filter is anisotropic, and hence can well preserve edges although the diffusion at edges is isotropic. The advantage is that the LWD model is easy to be analyzed and has lesser computational load. Finally, a variety of numerical experiments compared with the previous model are shown.
41632859
A Novel Frequency Offset Estimator over Frequency Selective Fading Channels by Using Correlative Coding
A new data-aided carrier frequency offset (CFO) estimation technique is presented for correlative coded OFDM systems in the presence of strong multipath. Different from traditional data-aided estimation techniques, the technique estimates CFO by detecting amplitude of pilots rather than their phase shift and removes effects on CFO estimation due to intercarrier interference by an iterative compensation method. A theoretical analysis of its performance has been derived and simulation results comparing the new technique with a traditional data-aided estimation technique are presented.
36390607
Wavelet-based diffusion approaches for signal denoising
The efficiency of nonlinear diffusion filters is related to diffusivity. In the previous models, diffusivity depended on the derivatives of a signal, and hence it is easily affected by noise. This paper considers the nonlinear wavelet-based diffusion (NWD) methods for signal denoising in which the diffusivity is expressed by the wavelet transforms of received signal at several scales. Due to the multiresolution of wavelet transform, the proposed diffusivity with wavelet transforms efficiently reduces the influence of noise on the estimate of diffusion amount and improves nonlinear diffusion filters. Some numerical experimental results compared with the previous models are shown.
22450367
Networking Business Model In Regional Medical Service- Case of Chikamori Medical Group in Kochi, Japan
Japan's Health Care System has experienced a number of changes over the last half a century. And the most heated aspect of current health policy debate focuses on the potential radical reform of the medical care system. In addition, the regional medical service organizations are in front of a more severe challenge because of the rapidly aging population and decreasing young population. Consequently, hospitals and other NHS organizations in local areas have been required to introduce reforms in their management structure for their survival This paper reports in depth on a case study of a private Japanese hospital, the Chikamori medical group, to introduce a key competence-based management model and differentiation marketing strategy. As one of the regional medical care support hospitals, Chikamori plays an active and important role in the regional medical care network. The case implies the effective business model based on positioning in the network architecture, which is significant not only for medical service field but also for other regional industries. The mutual correlations among financial strategy, human resource design, managing policy and collaboration manner with regional doctors are discussed in the paper.
4963124
Blind equalization Using ν- support vector regressor for constant modulus signals
The support vector machine has been recently developed for blind equalization of constant modulus signals. In this paper we propose to use a v-support vector regressor (nu-SVR) for blindly equalizing multipath channels because of the high generalization ability of the SVR for short burst sequences. A weighted least square procedure is presented for solving the blind nu-SVR equalizer. The performance of the proposed algorithm is analyzed by means of computer simulations.
1518844
Discovering panoramas in web videos
While methods for stitching panoramas have been successful given proper source images, providing these source images still remains a burden. In this paper, we present a method to discover panoramic source images within widely available web videos. The challenge comes from the fact that many of these videos are not recorded intentionally for stitching panoramas. Our method aims to find segments within a video that work as panorama sources. Specifically, we determine a video segment to be a valid panorama source according to the following three criteria. First, its camera motion should cover a wide field-of-view of the scene. Second, its frames should be "mosaicable", which states that the inter-frame motion should observe the underlying conditions for stitching a panorama. Third, its frames should have good image quality. Based on these criteria, we formulate discovering panoramas in a video as an optimization problem that aims to find an optimal set of video segments as panorama sources. After discovering these panorama sources, we synthesize regular scene panoramas using them. When significant dynamics is detected in the sources, we fuse the dynamics into the scene panoramas to make activity synopses to convey the dynamics. Our experiment of querying panoramas from YouTube confirms the feasibility of using web videos as panorama sources and demonstrates the effectiveness of our method.
22925595
A Novel Chase Based Multiuser Detector for MIMO-CDMA Systems
This paper proposes a new chase based multiuser detection scheme for MIMO-CDMA systems. The proposed approach provides performance gain by concentrating on improving the detection accuracy of the weakest symbol. Compared to the layered space-time multiuser detector (LAST-MUD), the proposed scheme can achieve substantial performance improvement, especially, when the number of transmit antennas is equal to the number of receive antennas. The comparison between our scheme and another chase based scheme, the B-Chase detector, which was originally proposed for improving the performance of the vertical Bell Laboratories layered space-time (V-BLAST) system, is also presented. The problem existing in the B-Chase detector is the criterion for selecting the weakest symbol. In our scheme, a more reasonable selection criterion is proposed. We show that the proposed scheme has less complexity than the B-Chase detector but with the tendency of achieving better performance at high SNR.
8017889
An architecture of wireless Web and dialogue system convergence for multimodal service interaction over converged networks
This paper presents the software architecture for a new paradigm of wireless Web and dialogue system convergence and its corresponding approach to deliver multimodal multimedia enterprise communication services in the wireless environment. It uses an event-triggered service delivery method that separates service interaction and wireless web-based service delivery. A customized content presentation approach is adopted to transform the content of the service into a format suitable for presentation on the target devices. The system also contains a service delivery monitoring and backup mechanism, which is capable of sending the service content using other communication channels according to the user's preference and the channel conditions. A prototype system was implemented based on the proposed approach, which demonstrates the performance advantage of our method in the enterprise service application.
14931435
Automatic image retargeting with fisheye-view warping
Image retargeting is the problem of adapting images for display on devices different than originally intended. This paper presents a method for adapting large images, such as those taken with a digital camera, for a small display, such as a cellular telephone. The method uses a non-linear fisheye-view warp that emphasizes parts of an image while shrinking others. Like previous methods, fisheye-view warping uses image information, such as low-level salience and high-level object recognition to find important regions of the source image. However, unlike prior approaches, a non-linear image warping function emphasizes the important aspects of the image while retaining the surrounding context. The method has advantages in preserving information content, alerting the viewer to missing information and providing robustness.
6780116
Joint MMSE Vector Precoding Based on GMD Method for MIMO Systems
We propose a geometric mean decomposition (GMD) based vector precoding (VP) for multiple input multiple output (MIMO) systems. Minimum mean square error (MMSE) criterion is used for the joint VP design. The application of GMD method eliminates the imbalance among subchannel gains and obtains a better perturbation vector than the conventional method. We then exploit the extended channel matrix for further performance improvement. Simulation results show the proposed schemes significantly outperform the existing VP schemes.