10,548 research outputs found

    Discrete denoising of heterogenous two-dimensional data

    Full text link
    We consider discrete denoising of two-dimensional data with characteristics that may be varying abruptly between regions. Using a quadtree decomposition technique and space-filling curves, we extend the recently developed S-DUDE (Shifting Discrete Universal DEnoiser), which was tailored to one-dimensional data, to the two-dimensional case. Our scheme competes with a genie that has access, in addition to the noisy data, also to the underlying noiseless data, and can employ mm different two-dimensional sliding window denoisers along mm distinct regions obtained by a quadtree decomposition with mm leaves, in a way that minimizes the overall loss. We show that, regardless of what the underlying noiseless data may be, the two-dimensional S-DUDE performs essentially as well as this genie, provided that the number of distinct regions satisfies m=o(n)m=o(n), where nn is the total size of the data. The resulting algorithm complexity is still linear in both nn and mm, as in the one-dimensional case. Our experimental results show that the two-dimensional S-DUDE can be effective when the characteristics of the underlying clean image vary across different regions in the data.Comment: 16 pages, submitted to IEEE Transactions on Information Theor

    Electrogenic transport and K(+) ion channel expression by the human endolymphatic sac epithelium.

    Get PDF
    The endolymphatic sac (ES) is a cystic organ that is a part of the inner ear and is connected to the cochlea and vestibule. The ES is thought to be involved in inner ear ion homeostasis and fluid volume regulation for the maintenance of hearing and balance function. Many ion channels, transporters, and exchangers have been identified in the ES luminal epithelium, mainly in animal studies, but there has been no functional study investigating ion transport using human ES tissue. We designed the first functional experiments on electrogenic transport in human ES and investigated the contribution of K(+) channels in the electrogenic transport, which has been rarely identified, even in animal studies, using electrophysiological/pharmacological and molecular biological methods. As a result, we identified functional and molecular evidence for the essential participation of K(+) channels in the electrogenic transport of human ES epithelium. The identified K(+) channels involved in the electrogenic transport were KCNN2, KCNJ14, KCNK2, and KCNK6, and the K(+) transports via those channels are thought to play an important role in the maintenance of the unique ionic milieu of the inner ear fluid

    The Three Strikes Policy in Korean Copyright Act 2009: Safe or Out?

    Get PDF
    Korea has grown to be one of the Internet powers in a short period. Because of insufficient copyright protection, Korea recently revised the Korean Copyright Act to reinforce protection of copyright and promote sound distribution of copyrighted works. The new law allows the Minister of Culture, Sports and Tourism to issue orders and the Korea Copyright Commission to issue recommendations. Orders and recommendations are distinguished by the subject of the issuance and the legal force. Orders and recommendations enable online service providers to delete or stop transmission of illegal reproductions, give warning notices to infringers, or suspend the account of repetitive infringers. The “three strikes” policy is controversial and has raised several constitutional concerns. First, the suspension of the repeat infringer’s account may be an unconstitutional violation of the infringer’s freedom of speech. Second, an executive agency’s decision to issue a correction order could be an unconstitutional violation of the separation of powers. The final concern is that the policy violates the principles of due process. This Article examines the “three strikes” policy, the constitutional concerns regarding the policy, and possible policy revisions for more effective copyright protection
    • …
    corecore