205,110 research outputs found

    Investigation of a Rotating Shaft with a Novel Integrated Wireless Accelerometer

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    Rotating shafts are the most critical components of rotating machines such as motors, pumps, engines and turbines. Due to their heavy workloads, defects are more likely to develop during operation. There are many techniques used to monitor shaft defects by analysing the vibration of the shaft as well as the instantaneous angular speed (IAS) of the shaft. The signals are measured either using non-contact techniques such as laser-based measurement or indirect measurement such as the vibration on bearing housings. The advancement in low cost and low power Micro Electro Mechanical Systems (MEMS) make it possible to develop an integrated wireless sensor mounted on rotating shafts directly. This can make the fault diagnosis of rotating shafts more effective as it is likely to capture more details of shaft dynamics. This paper presents a novel integrated wireless accelerometer mounted directly on a rotating shaft and demonstrates that it can effectively monitor different degree of misalignments occurring commonly in a shaft system

    A multiple-instance scoring method to predict tissue-specific cis-regulatory motifs and regions

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    Transcription is the central process of gene regulation. In higher eukaryotes, the transcription of a gene is usually regulated by multiple cis-regulatory regions (CRRs). In different tissues, different transcription factors bind to their cis-regulatory motifs in these CRRs to drive tissue-specific expression patterns of their target genes. By combining the genome-wide gene expression data with the genomic sequence data, we proposed multiple-instance scoring (MIS) method to predict the tissue-specific motifs and the corresponding CRRs. The method is mainly based on the assumption that only a subset of CRRs of the expressed gene should function in the studied tissue. By testing on the simulated datasets and the fly muscle dataset, MIS can identify true motifs when noise is high and shows higher specificity for predicting the tissue-specific functions of CRRs

    Prospects and Strategies of Gaming Ventures in China

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    This paper analyzes the prospects of gaming ventures in China and discusses the strategies for Western investors. A strong demand for gambling, changing government attitudes, increased wealth and leisure, and a fairly established foundation of tourism have created a favorable climate for gaming ventures in China. The major risks are political instability, policy inconsistency, and inflation. To develop gaming projects in China, Western gaming investors need to choose the right regions and build casinos different from those in Las Vegas. At the current stage, active involvement with a small amount of capital is recommended

    Computations of Mather Minimal Log Discrepancies

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    We compute the Mather minimal log discrepancy via jet schemes and arc spaces for toric varieties and very general hypersurfaces

    Zero-error communication over adder MAC

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    Adder MAC is a simple noiseless multiple-access channel (MAC), where if users send messages X1,…,Xh∈{0,1}nX_1,\ldots,X_h\in \{0,1\}^n, then the receiver receives Y=X1+⋯+XhY = X_1+\cdots+X_h with addition over Z\mathbb{Z}. Communication over the noiseless adder MAC has been studied for more than fifty years. There are two models of particular interest: uniquely decodable code tuples, and BhB_h-codes. In spite of the similarities between these two models, lower bounds and upper bounds of the optimal sum rate of uniquely decodable code tuple asymptotically match as number of users goes to infinity, while there is a gap of factor two between lower bounds and upper bounds of the optimal rate of BhB_h-codes. The best currently known BhB_h-codes for h≥3h\ge 3 are constructed using random coding. In this work, we study variants of the random coding method and related problems, in hope of achieving BhB_h-codes with better rate. Our contribution include the following. (1) We prove that changing the underlying distribution used in random coding cannot improve the rate. (2) We determine the rate of a list-decoding version of BhB_h-codes achieved by the random coding method. (3) We study several related problems about R\'{e}nyi entropy.Comment: An updated version of author's master thesi
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