FFTPL: An Analytic Placement Algorithm Using Fast Fourier Transform for Density Equalization

We propose a flat nonlinear placement algorithm FFTPL using fast Fourier transform for density equalization. The placement instance is modeled as an electrostatic system with the analogy of density cost to the potential energy. A well-defined Poisson's equation is proposed for gradient and cost computation. Our placer outperforms state-of-the-art placers with better solution quality and efficiency

Attenuation of Guided Wave Propagation by the Insulation Pipe

Pipeline systems are widely used in gas, refinery, chemical and petro-chemical industries, which usually carry high pressure, high temperature or even highly corrosive fluids. Cracks and corrosion are often found at the outer or inner surface of pipeline and can lead to a serious thinning of wall thickness. Leaks or sudden failures of pipes can cause injuries, fatalities and environmental damage. Ultrasonic nondestructive techniques are available for the detection of wall loss associated with defects in the pipe. Unfortunately, a high proportion in pipelines of these industrial are insulated, so that even external corrosion cannot readily be detected by the conventional ultrasonic testing (single position measurement) without the removal of the insulation, which in most case is time-consuming and cost expensive. Especially in typically industrial plants, there are hundreds of kilometers of pipelines can be in operation. Making inspection of full pipelines is virtually impossible in industrial plants. There is therefore a quick reliable method for the detection of corrosion under insulation (CUI). This technique, called guided wave, employs a pulseecho system applied at a single location of a pipe where only a small section of insulation need to be removed, using waves propagation along the pipe wall. The changes in the response signal indicate the presence of an impedance change in the pipe. The shape and axial location of defects and features in the pipe are also determined by reflected signals and their arrival times. Propagation distance of many tens of meters can readily be obtained in steel pipes [1-6]. Since these guided waves are cylindrical Lamb waves along the pipe, no lateral spreading can occur and the propagation is essentially one-dimensional. In a uniform pipe, their amplitude with propagation distance is therefore only reduced by the material attenuation of the steel [7]

The Design and Analysis of Passive Pitch Control for Horizontal Axis Wind Turbine

AbstractThe purpose of this thesis is to design and analysis of passive pitch control. Design a mechanics to control different revolution of blade's pitch angle. The use of small wind turbines gradually popularization, but how to overcome the low wind speed start-up and the operation under high wind speed, that is the difficult problems encountered by designers. In order to extend the use and the safe of wind speed, this design is required. This paper is focus on the mechanism design of the passive pitch control for the small horizontal axis wind turbine (HAWT). When the wind speed is fast, the rotation speed is also faster and faster. The system uses centrifugal force to make Pulley disk driven the pitch angle of the blade. It can achieve the effect of passive pitch control. The mechanism is our laboratory's patent. Through the experiments in wind tunnel, it can be observed the variation of the performance curve when the pitch rotation. This system not only successfully operates under high wind speed but also has better performance at low wind speed

Genotoxicity Assessment of Multispecies Probiotics Using Reverse Mutation, Mammalian Chromosomal Aberration, and Rodent Micronucleus Tests

Genotoxicity assessment is carried out on freeze dried powder of cultured probiotics containing Lactobacillus rhamnosus LCR177, Bifidobacterium adolescentis BA286, and Pediococcus acidilactici PA318. Ames tests, in vitro mammalian chromosome aberration assay, and micronucleus tests in mouse peripheral blood are performed. For 5 strains of Salmonella Typhimurium, the Ames tests show no increased reverse mutation upon exposure to the test substance. In CHO cells, the frequency of chromosome aberration does not increase in responding to the treatment of probiotics. Likewise, the frequency of micronucleated reticulocytes in probiotics-fed mice is indistinguishable from that in the negative control group. Taken together, the toxicity assessment studies suggest that the multispecies probiotic mixture does not have mutagenic effects on various organisms

Precise Latency Calculation for Audio-Video Synchronization

Synchronization between the audio and video tracks in recording equipment is usually achieved using an audio-first approach. In this approach, the timestamp of a target video frame is compared to the timestamp of the sound emitted during that frame, timestamps being counted in units of video frames. Videos have a relatively low sampling rate, e.g., a 60 frame-per-sec video has frames separated by 16.67 milliseconds. Thus, the measurement of audio-video asynchrony is imprecise. This disclosure describes video-first techniques for audio-video synchronization. A target video frame is captured, and its timestamp is mapped to the audio track. The audio track has millisecond-level time resolution due to high audio-sampling rates. Using the audio track, the timestamp of the sound (pulse) emitted during the target video frame is determined to millisecond accuracy. Timestamps of the target video frame and of the audio pulse are differenced to obtain a high-precision estimate of audio-video asynchrony

Decreased Risk of Osteoporosis Incident in Subjects Receiving Chinese Herbal Medicine for Sjögren Syndrome Treatment: A Retrospective Cohort Study with a Nested Case-Control Analysis

Sjögren syndrome (SS) is a long-lasting inflammatory autoimmune disease that may cause diverse manifestations, particularly osteoporosis. Though usage of Chinese herbal medicine (CHM) can safely manage autoimmune disease and treatment-related symptoms, the relation between CHM use and osteoporosis risk in SS persons is not yet recognized. With that in mind, this population-level nested case-control study aimed to compare the risk of osteoporosis with and without CHM use. Potential subjects aged 20–70 years, diagnosed with SS between 2001 and 2010, were retrieved from a national health claims database. Those diagnosed with osteoporosis after SS were identified and randomly matched to those without osteoporosis. We capitalize on the conditional logistic regression to estimate osteoporosis risk following CHM use. A total of 1240 osteoporosis cases were detected and randomly matched to 1240 controls at a ratio of 1:1. Those receiving conventional care plus CHM had a substantially lower chance of osteoporosis than those without CHM. Prolonged use of CHM, especially for one year or more, markedly dwindled sequent osteoporosis risk by 71%. Integrating CHM into standard care may favor the improvement of bone function, but further well-designed randomized controlled trials to investigate the possible mechanism are needed

Bioactive Eunicellin-Based Diterpenoids from the Soft Coral Cladiella krempfi

Four new eunicellin-based diterpenoids, krempfielins A–D (1–4), along with two known compounds (5 and 6) have been isolated from a soft coral Cladiella krempfi. The structures of the new metabolites were elucidated by extensive spectroscopic analysis and by comparison with spectroscopic data of related known compounds. Compounds 5 and 6 were shown to exhibit cytotoxicity against a limited panel of cancer cell lines. Furthermore, compounds 2, 3, 5 and 6 were shown to exert significant in vitro anti-inflammatory activity against LPS-stimulated RAW264.7 macrophage cells