200 research outputs found

    User Recognition Based on Human Body Impulse Response: A Feasibility Study

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    Human recognition technologies for security systems require high reliability and easy accessibility in the advent of the internet of things (IoT). While several biometric approaches have been studied for user recognition, there are demands for more convenient techniques suitable for the IoT devices. Recently, electrical frequency responses of the human body have been unveiled as one of promising biometric signals, but the pilot studies are inconclusive about the characteristics of human body as a transmission medium for electric signals. This paper provides a multi-domain analysis of human body impulse responses (HBIR) measured at the receiver when customized impulse signals are passed through the human body. We analyzed the impulse responses in the time, frequency, and wavelet domains and extracted representative feature vectors using a proposed accumulated difference metric in each domain. The classification performance was tested using the k-nearest neighbors (KNN) algorithm and the support vector machine (SVM) algorithm on 10-day data acquired from five subjects. The average classification accuracies of the simple classifier KNN for the time, frequency, and wavelet features reached 92.99%, 77.01%, and 94.55%, respectively. In addition, the kernel-based SVM slightly improved the accuracies of three features by 0.58%, 2.34%, and 0.42%, respectively. The result shows potential of the proposed approach for user recognition based on HBIR

    A Generalization of Self-Improving Algorithms

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    Ailon et al. [SICOMP'11] proposed self-improving algorithms for sorting and Delaunay triangulation (DT) when the input instances x1,,xnx_1,\cdots,x_n follow some unknown \emph{product distribution}. That is, xix_i comes from a fixed unknown distribution Di\mathsf{D}_i, and the xix_i's are drawn independently. After spending O(n1+ε)O(n^{1+\varepsilon}) time in a learning phase, the subsequent expected running time is O((n+H)/ε)O((n+ H)/\varepsilon), where H{HS,HDT}H \in \{H_\mathrm{S},H_\mathrm{DT}\}, and HSH_\mathrm{S} and HDTH_\mathrm{DT} are the entropies of the distributions of the sorting and DT output, respectively. In this paper, we allow dependence among the xix_i's under the \emph{group product distribution}. There is a hidden partition of [1,n][1,n] into groups; the xix_i's in the kk-th group are fixed unknown functions of the same hidden variable uku_k; and the uku_k's are drawn from an unknown product distribution. We describe self-improving algorithms for sorting and DT under this model when the functions that map uku_k to xix_i's are well-behaved. After an O(poly(n))O(\mathrm{poly}(n))-time training phase, we achieve O(n+HS)O(n + H_\mathrm{S}) and O(nα(n)+HDT)O(n\alpha(n) + H_\mathrm{DT}) expected running times for sorting and DT, respectively, where α()\alpha(\cdot) is the inverse Ackermann function

    New Record of Sillago sinica (Pisces: Sillaginidae) in Korean Waters, and Re-identification of Sillago parvisquamis Previously Reported from Korea as S. sinica

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    A single specimen of the genus Sillago, collected from Gwangyang, Korea, in May 2009, is characterized by XI first dorsal fin spines, 3 or 4 rows of melanophore pattern along the second dorsal fin membrane, and a darkish posterior margin of the caudal fin. Our specimen was identified as Sillago sinica reported as a new species; this identification is confirmed by mitochondrial DNA cytochrome oxidase subunit I sequences, which show that our specimen corresponds to S. sinica (d=0.000) and differs from the congeneric species Sillago parvisquamis (d=0.170). Comparisons of Korean specimens previously reported as S. parvisquamis with specimens of S. sinica show that the S. parvisquamis specimens are actually S. sinica. We propose the new Korean name “buk-bang-jeom-bo-ri-myeol” for S. sinica

    Chronic Epstein-Barr virus infection causing both benign and malignant lymphoproliferative disorders

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    The Epstein-Barr virus (EBV) is oncogenic and can transform B cells from a benign to a malignant phenotype. EBV infection is also associated with lymphoid interstitial pneumonia (LIP). Here, we report the case of a 14-year-old boy who was diagnosed with a latent EBV infection and underlying LIP, without any associated immunodeficiency. He had been EBV-seropositive for 8 years. The first clinical presentations were chronic respiratory symptoms and recurrent pneumonia. The symptoms worsened in the following 2 years. The results of in situ hybridization were positive for EBV, which led to a diagnosis of LIP. The diagnosis was confirmed by the results of a thoracoscopic lung biopsy. The EBV titer of the bronchoalveolar lavage specimens obtained after acyclovir treatment was found to be fluctuating. The patient had latent EBV infection for 8 years, until presented at the hospital with intermittent abdominal pain and distension. Physical examination and pelvic computed tomography revealed a large mesenteric mass. A biopsy of the excised mass led to a diagnosis of Burkitt's lymphoma (BL). The patient received combination chemotherapy for 4 months, consisting of vincristine, methotrexate, cyclophosphamide, doxorubicin, and prednisolone. He is now tumor-free, with the LIP under control, and is being followed-up at the outpatient clinic. This is the first report of a Korean case of chronic latent EBV infection that developed into LIP and BL in a nonimmunocompromised child

    Outer membrane protein a of Salmonella enterica serovar Typhimurium activates dendritic cells and enhances Th1 polarization

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    <p>Abstract</p> <p>Background</p> <p>Typhoid, which is caused by <it>Salmonella enterica </it>serovar Typhimurium, remains a major health concern worldwide. Multidrug-resistant strains of <it>Salmonella </it>have emerged which exhibit increased survivability and virulence, thus leading to increased morbidity. However, little is known about the protective immune response against this microorganism. The outer membrane protein (Omp)A of bacteria plays an important role in pathogenesis.</p> <p>Results</p> <p>We purified OmpA from <it>S. enterica </it>serovar Typhimurium (OmpA-sal) and characterized the role of OmpA-sal in promoting adaptive and innate immune responses. OmpA-sal functionally activated bone marrow-derived dendritic cells by augmenting expression of CD80, CD86, and major histocompatibility complex classes I and II. Interestingly, OmpA-sal induced production of interferon-γ from T cells in mixed lymphocyte reactions, thus indicating Th1-polarizing capacity. The expression of surface markers and cytokine production in dendritic cells was mediated by the TLR4 signaling pathway in a TLR4 Knock-out system.</p> <p>Conclusions</p> <p>Our findings suggest that OmpA-sal modulates the adaptive immune responses to <it>S. enterica </it>serovar Typhimurium by activating dendritic cells and driving Th1 polarization, which are important properties to consider in the development of effective <it>S. enterica </it>serovar Typhimurium vaccines and immunotherapy adjuvant.</p

    Cutis Verticis Gyrata and Alopecia Areata: A Synchronous Coincidence?

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    Cutis verticis gyrata (CVG) is a descriptive term for a scalp condition that is convoluted folds and deep furrows that resemble the surface of the cerebral cortex. It is categorized by the underlying etiology, as primary essential, primary non-essential and secondary. Alopecia areata (AA) is a common, organ specific autoimmune disease, and most AA cases are sporadic. There is clearly a strong genetic component. There is no established relationship between CVG and AA. We report one case which was affected with essential primary CVG and alopecia areata, and suggest a possibility of genetic association between CVG and AA, possibly both being related to mutations in the fibroblast growth factor receptor 2 (FGFR2)

    Could a Growth Spurt Cause Linear Focal Elastosis Like Striae Distensae?

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    Linear focal elastosis (LFE) is characterized by several asymptomatic, yellow, palpable, irregularly indurated, striae-like lines extending horizontally across the middle and lower back. A focal increase in elastic fibers is a hallmark of the disease as seen from biopsy specimens. The pathogenesis of LFE is unclear, as is the association between LFE and striae distensae (SD). However, the prevailing opinion is that LFE represents an excessive regenerative process of elastic fibers and is analogous to keloidal repair of SD. Although the timing of onset of LFE and SD was not synchronous in our patient, the triggering factor was the same, which was the growth spurt. This case is supporting the putative association between LFE and SD
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