2,283 research outputs found

    The behavior of real exchange rates: the case of Japan

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    The study examines the convergence rate of mean reversion by contrasting the estimated half-life of real exchange rate (RER). We employ an extensive monthly consumer price index (CPI)-based product price’s panel for Japan (the U.S. as the num´eraire). We find that the disaggregated RERs are persistent due to the cross-sectional dependence problems. By controlling common correlated effects, the estimated half-life for all goods may fall to as low as 2.54 years, below the consensus view of 3 to 5 years summarized by Rogoff (1996). After correcting the small-sample bias, the estimated half-life of deviations from purchasing power parity (PPP) increase by 1.03 year. Our findings also support that the half-life of mean reversion of RER is about 3.55 years for traded goods, about 0.11 year lower than non-traded goods. We also show that traded goods and non-traded goods perform distinct distributions of persistence

    On the Miura and Backlund transformations associated with the supersymmetric Gelfand-Dickey bracket

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    The supersymmetric version of the Miura and B\"acklund transformations associated with the supersymmetric Gelfand-Dickey bracket are investigated from the point of view of the Kupershmidt-Wilson theorem.Comment: 8 pages, Revtex, version to appear on Mod. Phys. Lett.

    Are there contagion effects in the REIT market? The case of Brexit

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    On June 23, 2016 the Brexit event that tremendously surprised and shocked investors around the world was considered the largest black swan with a political earthquake in 2016, and even spread to the international financial market and real estate market. This study uses the heteroscedasticity biases based on correlation coefficients by Forbes and Rigobon and the GJR-GARCH model to examine the contagion effects of the Brexit event on global REITs markets. The data are collected at the daily interval covering the time period from June 23, 2015 to December 30, 2016. Evidence reveals that no REITs markets suffered from Brexit, suggesting no transmission of Brexit across REITs markets, even the neighbouring markets, is found

    Supply Chain Efficiency Analysis: A Theoretical Approach

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    We divide the supply chain into a central control system (CCS) case and a decentralized control system (DCS) case, and compare the supply chain efficiency with both the CCS case and the DCS case.  We find that the supply chain efficiency of a capital-intensive industry is better under the CCS case than under the DCS case.  Under the CCS case, the maximized supply chain efficiency can be reached by choosing either the lowest price that the upstream firm is willing to receive or the highest price that the downstream firm is willing to pay for intermediate goods

    Dynamic region of interest transcoding for multipoint video conferencing

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    This paper presents a region of interest transcoding scheme for multipoint video conferencing to enhance the visual quality. In a multipoint videoconference, usually there are only one or two active conferees at one time which are the regions of interest to the other conferees involved. We propose a Dynamic Sub-Window Skipping (DSWS) scheme to firstly identify the active participants from the multiple incoming encoded video streams by calculating the motion activity of each sub-window, and secondly reduce the frame-rates of the motion inactive participants by skipping these less-important subwindows. The bits saved by the skipping operation are reallocated to the active sub-windows to enhance the regions of interest. We also propose a low-complexity scheme to compose and trace the unavailable motion vectors with a good accuracy in the dropped inactive sub-windows after performing the DSWS. Simulation results show that the proposed methods not only significantly improve the visual quality on the active subwindows without introducing serious visual quality degradation in the inactive ones, but also reduce the computational complexity and avoid whole-frame skipping. Moreover, the proposed algorithm is fully compatible with the H.263 video coding standard. 1

    Power Allocation and Time-Domain Artificial Noise Design for Wiretap OFDM with Discrete Inputs

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    Optimal power allocation for orthogonal frequency division multiplexing (OFDM) wiretap channels with Gaussian channel inputs has already been studied in some previous works from an information theoretical viewpoint. However, these results are not sufficient for practical system design. One reason is that discrete channel inputs, such as quadrature amplitude modulation (QAM) signals, instead of Gaussian channel inputs, are deployed in current practical wireless systems to maintain moderate peak transmission power and receiver complexity. In this paper, we investigate the power allocation and artificial noise design for OFDM wiretap channels with discrete channel inputs. We first prove that the secrecy rate function for discrete channel inputs is nonconcave with respect to the transmission power. To resolve the corresponding nonconvex secrecy rate maximization problem, we develop a low-complexity power allocation algorithm, which yields a duality gap diminishing in the order of O(1/\sqrt{N}), where N is the number of subcarriers of OFDM. We then show that independent frequency-domain artificial noise cannot improve the secrecy rate of single-antenna wiretap channels. Towards this end, we propose a novel time-domain artificial noise design which exploits temporal degrees of freedom provided by the cyclic prefix of OFDM systems {to jam the eavesdropper and boost the secrecy rate even with a single antenna at the transmitter}. Numerical results are provided to illustrate the performance of the proposed design schemes.Comment: 12 pages, 7 figures, accepted by IEEE Transactions on Wireless Communications, Jan. 201

    Realtime object extraction and tracking with an active camera using image mosaics

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    [[abstract]]Moving object extraction plays a key role in applications such as object-based videoconference, surveillance, and so on. The dimculties of moving object segmentation lie in the fact that physical objects are normally not homogeneous with to low-level features and it's usually tough to segment them accnrately and efficiently. Object segmentation based on prestored background information has proved to be effective and efficient in several applications such as videophone, video conferencing, and surveillance, etc. The previous works, however, were mainly concentrated on object segmentation with a static camera and in a stationary background. In this paper, we propose a robust and fast segmentation algorithm and a reliable tracking strategy without knowing the shape of the object in advance. The proposed system can real-time extract the foreground from the background and track the moving object with an active (pan-tilt) camera such that the moving object always stays around the center of images.[[fileno]]2030144030033[[department]]電機工程學

    Pneumocystis jiroveci Pneumonia in Patients with Non-Hodgkin's Lymphoma Receiving Chemotherapy Containing Rituximab

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    AbstractRituximab enhances treatment efficacy of B-lineage lymphoma by targeting CD20+ B-cells. Such target therapies may compromise the immune system and render patients susceptible to opportunistic infections. We report 2 cases of lymphoma complicated with Pneumocystis jiroveci (previously known as P. carinii) pneumonia (PCP) while being treated with rituximab-containing chemotherapy regimens. In both cases, PCP developed during the neutropenic period. With timely diagnosis and proper management, both were treated successfully. We searched the literature and found that such opportunistic infection occurred only infrequently in lymphoma patients, and it has not been reported in the large-scale clinical trials of rituximab. Such cases demonstrate the importance of taking PCP into diagnostic consideration in lymphoma patients receiving similar therapies

    The morphology of diaphragmatic defects in hepatic hydrothorax: Thoracoscopic finding

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    BackgroundUntil now, the pathophysiology of hepatic hydrothorax has been moot. We discuss (on the basis of gross videothoracoscopy findings in 11 cases and the literature) the pathogenesis and clinical presentation of this complex condition.MethodsWe prospectively studied 11 patients (age, 31–73 years; 6 men and 5 women) with refractory hepatic hydrothorax (Child-Pugh class B-C) who underwent thoracoscopic repair of diaphragmatic defects. The diaphragmatic defects were examined intraoperatively.ResultsThe diaphragmatic defects stemming from hepatic hydrothorax were classified into 4 morphologic types: type I, no obvious defect (1 patient); type II, blebs lying on the diaphragm (4 patients); type III, broken defects (fenestrations) in the diaphragm (8 patients); and type IV, multiple gaps in the diaphragm (1 patient). The type of diaphragmatic defect did not correlate with the volume occupied by the pleural effusion in the preoperative chest radiograms.ConclusionsThe finding of this study allowed hepatic hydrothorax pathophysiology to be directly visualized, and further studies concerning the treatment of hepatic hydrothorax might be based on these mechanisms
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