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Several Experimental Results (several + experimental_result)

Distribution by Scientific Domains

Information Science and Computing	50%

Selected Abstracts

A Theoretical Insight into the Mechanism of the Silver-Catalysed Transsiliranation Reaction

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 7 2010
José Antonio Mayoral
Abstract DFT calculations on a silver-catalysed transsiliranation reaction (silylene transfer from a silirane to an alkene) have shown the key role of a silylenesilver ion in the catalyticcycle. Although the corresponding triflate-bound species has previously been detected by NMR and IR spectroscopy, no significant silylene-transfer activity is predicted for such a nonionised structure. Several experimental results can be explained by this new reaction mechanism. [source]

Kernel approach to possibilistic C -means clustering

INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 3 2009
Frank Chung-Hoon Rhee
Kernel approaches can improve the performance of conventional clustering or classification algorithms for complex distributed data. This is achieved by using a kernel function, which is defined as the inner product of two values obtained by a transformation function. In doing so, this allows algorithms to operate in a higher dimensional space (i.e., more degrees of freedom for data to be meaningfully partitioned) without having to compute the transformation. As a result, the fuzzy kernel C -means (FKCM) algorithm, which uses a distance measure between patterns and cluster prototypes based on a kernel function, can obtain more desirable clustering results than fuzzy C -means (FCM) for not only spherical data but also nonspherical data. However, it can still be sensitive to noise as in the FCM algorithm. In this paper, to improve the drawback of FKCM, we propose a kernel possibilistic C -means (KPCM) algorithm that applies the kernel approach to the possibilistic C -means (PCM) algorithm. The method includes a variance updating method for Gaussian kernels for each clustering iteration. Several experimental results show that the proposed algorithm can outperform other algorithms for general data with additive noise. © 2009 Wiley Periodicals, Inc. [source]

Multiresolution Random Accessible Mesh Compression

COMPUTER GRAPHICS FORUM, Issue 3 2006
Junho Kim
This paper presents a novel approach for mesh compression, which we call multiresolution random accessible mesh compression. In contrast to previous mesh compression techniques, the approach enables us to progressively decompress an arbitrary portion of a mesh without decoding other non-interesting parts. This simultaneous support of random accessibility and progressiveness is accomplished by adapting selective refinement of a multiresolution mesh to the mesh compression domain. We present a theoretical analysis of our connectivity coding scheme and provide several experimental results. The performance of our coder is about 11 bits for connectivity and 21 bits for geometry with 12-bit quantization, which can be considered reasonably good under the constraint that no fixed neighborhood information can be used for coding to support decompression in a random order. Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling [source]

Adalimumab in severe and acute sciatica: A multicenter, randomized, double-blind, placebo-controlled trial,

ARTHRITIS & RHEUMATISM, Issue 8 2010
Stéphane Genevay
Objective Based on several experimental results and on a preliminary study, a trial was undertaken to assess the efficacy of adalimumab, a tumor necrosis factor , inhibitor, in patients with radicular pain due to lumbar disc herniation. Methods A multicenter, double-blind, randomized controlled trial was conducted between May 2005 and December 2007 in Switzerland. Patients with acute (duration of <12 weeks) and severe (Oswestry Disability Index score of >50) radicular leg pain and imaging-confirmed lumbar disc herniation were randomized to receive as adjuvant therapy either 2 subcutaneous injections of adalimumab (40 mg) at 7-day intervals or matching placebo. The primary outcome was the score for leg pain, based on a visual analog scale (0,100 mm), which was recorded every day for 10 days and at 6 weeks and 6 months. Results Of the 265 patients screened, 61 were enrolled; 31 patients were assigned to receive adalimumab, and 4 patients in the placebo group were lost to followup. Over time, the course of leg pain was more favorable in the adalimumab group than in the placebo group (P = 0.002). However, the effect size was relatively small, and at the last followup visit the difference was 13.8 (95% confidence interval ,11.5, 39.0). Compared with patients in the placebo group, approximately twice as many patients in the adalimumab group fulfilled the criteria for "responders" and for "low residual disease impact" (P < 0.05), and fewer surgical discectomies were performed (6 versus 13 in the placebo group; P = 0.04). Conclusion The addition of a short course of adalimumab to the treatment regimen of patients experiencing acute and severe sciatica resulted in a small decrease in leg pain and in significantly fewer surgical procedures. [source]