Ji Shen

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In this paper, we propose a new image quality assessment method based on a hybrid of curvelet, wavelet, and cosine transforms called hybrid no-reference (HNR) model. From the properties of natural scene statistics, the peak coordinates of the transformed coefficient histogram of filtered natural images occupy well-defined clusters in peak coordinate space,(More)
In order to support real-time video, audio and data communication among heterogeneous third generation (3G) handsets, 3G phones/terminals are required to support 3G-324M, the multimedia transmission protocol stack for 3G communication. This paper discusses some efficient approaches and experiences in the implementation of 3G-324M protocol stack.(More)
Increasing evidence has emerged for non-random spatial distributions of microbes, but knowledge of the processes that cause variation in microbial assemblage among ecosystems is lacking. For instance, some studies showed that deterministic processes such as habitat specialization are important, while other studies hold that bacterial communities are(More)
Next-generation network (NGN) is a new concept and becoming more and more important for future telecommunication networks. This paper illustrates five function layers of NGN architecture and discusses some end-to-end QoS (quality of service) issues for NGN (called NGNQoS). The five function layers are: (1) Application Layer that supports SIP protocol; (2)(More)
3G-324M is a multimedia transmission protocol designed for 3G communication environment. Meanwhile H.245 standard is a control protocol in 3G-324M and gives specific descriptions about terminal information messages in H.245 control channel as well as the procedures using them. The message syntax is defined using an external data representation standard(More)
The modern Indian summer monsoon (ISM) is characterized by exceptionally strong interhemispheric transport, indicating the importance of both Northern and Southern Hemisphere processes driving monsoon variability. Here, we present a high-resolution continental record from southwestern China that demonstrates the importance of interhemispheric forcing in(More)
It is widely accepted that biodiversity is lower in more extreme environments. In this study, we sought to determine whether this trend, well documented for macroorganisms, also holds at the microbial level for bacteria. We used denaturing gradient gel electrophoresis (DGGE) with phylum-specific primers to quantify the taxon richness (i.e., the DGGE band(More)
We analyze a nonlinear pricing model with limited information. Each buyer can purchase a large variety, <i>d</i>, of goods. His preference for each good is represented by a scalar and his preference over <i>d</i> goods is represented by a <i>d</i>-dimensional vector. The type space of each buyer is given by a compact subset of <i>R<sup>d</sup></i>+ with a(More)
We analyze the canonical nonlinear pricing model with limited information. A seller offers a menu with a finite number of choices to a continuum of buyers with a continuum of possible valuations. By revealing an underlying connection to quantization theory, we derive the optimal finite menu for the socially efficient and the revenue-maximizing mechanism. In(More)