56 research outputs found

    Sound from Gramophone Record Groove Surface Orientation

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    ABSTRACT Preserving historic recording on gramophone records is an important task because the traditional record play back system damages/wears out records eventually. We present an optical flow based method to reproduce the sound signal from gramophone records using 3D robust scene reconstruction of the surface orientation of the walls of the grooves. The imaging setup was modified to overcome a shallow depth of field by using a thin glass plate to obtain additional in-focus parts of the image at a second focal length. The sound signal was recovered from the surface orientation and processed further using the industry standard RIAA filter. The overall algorithm has been tested and found to be working correctly using both undamaged and damaged SP records. The algorithm is a "proof of concept" in that it shows sound can be recovered from time-varying 3D orientation of groove walls

    Preliminary Study of Prospective ECG-Gated 320-Detector CT Coronary Angiography in Patients with Ventricular Premature Beats

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    BACKGROUND: To study the applicability of prospective ECG-gated 320-detector CT coronary angiography (CTCA) in patients with ventricular premature beats (VPB), and determine the scanning mode that best maximizes image quality and reduces radiation dose. METHODS: 110 patients were divided into a VPB group (60 cases) and a control group (50 cases) using CTCA. All the patients then underwent coronary angiography (CAG) within one month. CAG served as a reference standard through which the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CTCA in diagnosing significant coronary artery stenosis (luminal stenosis ≥50%) could be analyzed. The two radiologists with more than 3 years' experience in cardiac CT each finished the image analysis after consultation. A personalized scanning mode was adopted to compare image quality and radiation dose between the two groups. METHODOLOGY/PRINCIPAL FINDINGS: At the coronary artery segment level, sensitivity, specificity, PPV, and NPV in the premature beat group were 92.55%, 98.21%, 88.51%, and 98.72% respectively. In the control group these values were found to be 95.79%, 98.42%, 90.11%, and 99.28% respectively. Between the two groups, specificity, sensitivity PPV, NPV was no significant difference. The two groups had no significant difference in image quality score (P>0.05). Heart rate (77.20±12.07 bpm) and radiation dose (14.62±1.37 mSv) in the premature beat group were higher than heart rate (58.72±4.73 bpm) and radiation dose (3.08±2.35 mSv) in the control group. In theVPB group, the radiation dose (34.55±7.12 mSv) for S-field scanning was significantly higher than the radiation dose (15.10±1.12 mSv) for M-field scanning. CONCLUSIONS/SIGNIFICANCE: With prospective ECG-gated scanning for VPB, the diagnostic accuracy of coronary artery stenosis is very high. Scanning field adjustment can reduce radiation dose while maintaining good image quality. For patients with slow heart rates and good rhythm, there was no statistically significant difference in image quality

    Rapid Assembly of Multiple-Exon cDNA Directly from Genomic DNA

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    Backgrouud. Polymerase chain reaction (PCR) is extensively applied in gene cloning. But due to the existence of introns, low copy number of particular genes and high complexity of the eukaryotic genome, it is usually impossible to amplify and clone a gene as a full-length sequence directly from the genome by ordinary PCR based techniques. Cloning of cDNA instead of genomic DNA involves multiple steps: harvest of tissues that express the gene of interest, RNA isolation, cDNA synthesis (reverse transcription), and PCR amplification. To simplify the cloning procedures and avoid the problems caused by ubiquitously distributed durable RNases, we have developed a novel strategy allowing the cloning of any cDNA or open reading frame (ORF) with wild type sequence in any spliced form from a single genomic DNA preparation. Methodology. Our Genomic DNA Splicing technique contains the following steps: first, all exons of the gene are amplified from a genomic DNA preparation, using software-optimized, highly efficient primers residing in flanking introns. Next, the tissue-specific exon sequences are assembled into one full-length sequence by overlapping PCR with deliberately designed primers located at the splicing sites. Finally, software-optimized outmost primers are exploited for efficient amplification of the assembled full-length products. Conclusions. The Genomic DNA Splicing protocol avoids RNA preparation and reverse transcription steps, and the entire assembly process can be finished within hours, Since genamic DNA is more stable than RNA, it may be a more practical cloning strategy for many genes, especially the ones that are very large and difficult to generate a full length cDNA using oligo-dT primed reverse transcription. With this technique, we successfully doned the full-length wild type coding sequence of human polymeric immunoglobulin receptor, which is 2295 bp in length and composed of 10 exons. © 2007 An et al.published_or_final_versio

    Reproduction of Sound Signal from Gramophone Records using 3D Scene Reconstruction

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    Preserving invaluable historic recordings has drawn some interest because the traditional record playback system wears out the record gradually. This paper presents a non-contact method to reproduce sound signal from gramophone records using 3D scene reconstruction of the micro-grooves cast on a record surface. Because of the unique shape of the microgroove, a planar assumption was made during scene reconstruction and recovered surface orientation was used to reproduce the sound signal. A robust estimation method was developed to reduce noise effects. Results from synthetic data were shown to test the technique

    Rice impact in Henan irrigation districts along the lower Yellow River reaches

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    In Yellow River Conservancy Commission. Proceedings, 1st International Yellow River Forum on River Basin Management - Volume II. Zhengzhou, China: The Yellow River Conservancy Publishing Hous
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