27385183
Standard Deviation and Intra Prediction Mode Based Adaptive Spatial Error Concealment (SEC) in H.264/AVC
Transmission of compressed video over error prone channels may result in packet losses or errors, which can significantly degrade the image quality. Therefore an error concealment scheme is applied at the video receiver side to mask the damaged video. Considering there are 3 types of MBs (Macro Blocks) in natural video frame, i.e., Textural MB, Edged MB, and Smooth MB, this paper proposes an adaptive spatial error concealment which can choose 3 different methods for these 3 different MBs. For criteria of choosing appropriate method, 2 factors are taken into consideration. Firstly, standard deviation of our proposed edge statistical model is exploited. Secondly, some new features of latest video compression standard H.264/AVC, i.e., intra prediction mode is also considered for criterion formulation. Compared with previous works, which are only based on deterministic measurement, proposed method achieves the best image recovery. Subjective and objective image quality evaluations in experiments confirmed this.
28547446
Low-Complex Equalization for Single Carrier Systems Employing Cyclic Prefix over Time-Variant Channels
A simplified equalization method based on the band structure of the frequency domain channel matrix is proposed for the single carrier systems employing cyclic prefix (SC-CP) over time-varying wireless channels. Using both theoretical analysis and computer simulation, it is shown that the complexity of this method is proportional to the number of symbols in one SC-CP block and is less than that of traditional block equalization methods. We also show that they have similar performance.
37102468
Variable Block Size Motion Vector Retrieval Schemes for H.264 Inter Frame Error Concealment
With the ubiquitous application of Internet and wireless networks, H.264 video communication becomes more and more common. However, due to the high-efficiently predictive coding and the variable length entropy coding, it is more sensitive to transmission errors. The current error concealment (EC) scheme, which utilizes the spatial and temporal correlations to conceal the corrupted region, produces unsatisfied boundary artifacts. In this paper, first we propose variable block size error concealment (VBSEC) scheme inspired by variable block size motion estimation (VBSME) in H.264. This scheme provides four EC modes and four sub-block partitions. The whole corrupted macro-block (MB) will be divided into variable block size adaptively according to the actual motion. More precise motion vectors (MV) will be predicted for each sub-block. Then MV refinement (MVR) scheme is proposed to refine the MV of the heterogeneous sub-block by utilizing three step search (TSS) algorithm adaptively. Both VBSEC and MVR are based on our directional spatio-temporal boundary matching algorithm (DSTBMA). By utilizing these schemes, we can reconstruct the corrupted MB in the inter frame more accurately. The experimental results show that our proposed scheme can obtain better objective and subjective EC quality, respectively compared with the boundary matching algorithm (BMA) adopted in the JM11.0 reference software, spatio-temporal boundary matching algorithm (STBMA) and other comparable EC methods.
45070598
An Adaptive Spatial Error Concealment for H.264/AVC Video Stream
A drill guide for positioning on a surface of a bone includes a projection for penetrating the bone, an abutment for engaging the surface of the bone to ensure penetration of the bone by the projection to a predetermined depth, less than the length of the projection, and a pair of guide passages having central longitudinal axes, respectively, converging at a predetermined point in the bone when the projection penetrates the bone to the predetermined depth. A kit for fixating soft tissue to bone includes a drill guide, a drill bit, a suture and a suture passer. The drill bit is insertable in a pair of guide passages of the drill guide to cut first and second passages converging in the bone to define a continuous tunnel. The suture passer has a portion for being introduced in the tunnel to engage the suture externally of the bone such that the suture is drawn through the tunnel when the suture passer is withdrawn therefrom. A method of fixating soft tissue to bone includes the steps of penetrating a bone with a projection of a drill guide, engaging the bone with an abutment of the drill guide to ensure penetration of the bone by the projection to a predetermined depth, introducing a drill bit through a pair of guide passages of the drill guide and into the bone to form first and second passages converging in the bone to define a continuous tunnel, introducing a suture passer into the tunnel such that a suture engaging member of the suture passer protrudes externally of the bone, engaging a suture with the suture engaging member, withdrawing the suture passer from the tunnel to draw the suture through the tunnel and using the suture to fixate soft tissue to the bone.
7144886
Khatri-Rao Unitary Space-Time Modulation
Based on the Khatri-Rao matrix product, we propose a novel unitary space-time modulation design called KR-USTM in this paper. Different from existing USTM schemes, such as the systematic approach and space-time frequency-shift keying (ST-FSK), KR-USTM does not require any computer search and can be applied to any number of transmit antennas. Moreover, the special structure of KR-USTM also makes it a high-rate scheme and achieve full antenna diversity as well as lower decoding complexity. Simulation results show that the proposed KR-USTM constellation achieves error performance comparable to existing USTM designs at low rates, while it outperforms them at high rates.
32712174
Hailstone Detection Based on Image Mining
Hailstone is one of the main meteorological disasters and it is very difficult to be forecasted effectively. A novel method of automatic recognition hail cloud is proposed base on association rules in this paper. Firstly, the method preprocesses the original reflectivity image. Then the color features and texture features are extracted from the radar echo image. Lastly, the association rules, which are used to distinguish hailstorm from rainstorm and super refract, are constructed, namely hail echo ensemble forecast model based on image mining is constructed. The results show that hail echo ensemble forecast model based on image mining has higher accuracy compared with the PUP products.
6795883
Error-tolerance memory microarchitecture via dynamic multithreading redundancy
Presented in this paper is an error-tolerance multithreaded register file microarchitecture that employs dynamic multithreading redundancy for error control. The proposed technique is based on the observation that concurrent threads may not access a register entry simultaneously. The non-overlapped register access patterns create hardware redundancy dynamically that can be exploited for error control. This significantly improves access time during error recovery. Simulation results of a generic simultaneous multithreading processor on the SPEC CPU2000 benchmark programs demonstrate 13.8% to 50.7% reduction in register read access overheads subject to 2% hardware overheads. The proposed error-tolerance memory microarchitecture features good scalability for future microprocessor generations, where soft errors are expected to get worse with semiconductor process scaling.
34620301
Video Local Pattern based Image Matching for Visual Mapping
Image matching plays an important role in visual mapping, a critical task of vision based mobile robot navigation. Based on the observation that the visual content in these video sequences generally changes in a slow and continuous mode, a concept of "video local pattern" is proposed to model each video frame, which is defined as a set of frames that are visually-similar and temporally-adjacent to that frame. Instead of manually labelling, a tracking based method is developed to automatically detect the local pattern for each frame. A model is then estimated from a local pattern, and the matching of images is performed by comparing these models. Experimental results demonstrated its improvement over that comparing individual frames
27554160
Supporting Partial Component Matching
In this paper we define a formal framework for describing components and gaps or holes (where components can be plugged in) This is based on the theory of interface automata The main focus is to define a component partially satisfying the requirements of a hole A partial plug-in of a hole will result in other holes The definition of a partial plug-in does not result in a unique set of holes, i.e., the resulting holes can have different properties We define an software engineering process which uses the formal framework to complete the component selection and insertion process The process is defined in terms of the possible interactions between a component vendor and a customer seeking a component.
14258683
A framework for checking behavioral compatibility for component selection
Component selection and composition are the main issues in component-based development (CBD). Existing approaches suffer from the problem that the components retrieved usually do not exactly fit with other components in the system being developed. While formal methods can be used to describe and check semantic characteristics to better match components, there are practical limitations which restrict their adoption. In this paper, we propose a framework to support a semantic description and selection of components. Towards this we first introduce a Simple Component Interface Language (SCIL). SCIL files can be translated to a variety of models including those that have a formal basis. We report our experience with two specific tools, viz., Reactive Modules and Alloy with a view to using tools based on formal methods but without exposing the details of the tools