The behavior of real exchange rates: the case of Japan

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

Low-complexity face-assisted video coding

[[abstract]]This paper presents a novel face-assisted video coding scheme to enhance the visual quality of the face regions in video telephony applications. A skin-color based face detection and tracking scheme is proposed to locate the face regions in real-time. After classifying the macroblocks into the face and non-face regions, we present a dynamic distortion weighting adjustment (DDWA) scheme to drop the static non-face macroblocks, and the saved bits are used to compensate the face region by adjusting the distortion weighting of the face macroblocks. The quality of face regions will thus be enhanced. Moreover, the computation originally required for the skipped macroblocks can also be saved. The experimental results show that the proposed method can significantly improve the PSNR and the subjective quality of face regions, while the degradation introduced on the non-face areas is relatively insensitive to human perception. The proposed algorithm is fully compatible with the H.263 standard, and the low complexity feature makes it well suited to implement for real-time applications[[fileno]]2030144030041[[department]]電機工程學

Dynamic region of interest transcoding for multipoint video conferencing

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

Contrasting acrylate versus methacrylate crosslinking reactions and the impact of temperature

Divinyl monomers containing multiple vinyl groups are commonly used in polymerization reactions to introduce crosslinked networks. The reactivity of the second vinyl group in a crosslinker monomer decreases once it becomes incorporated in a polymer chain. This Reduced Reactivity Parameter (Ψ) depends on the monomer-crosslinker pair. To date, our group has developed this concept exclusively from methacrylate-based copolymerization systems1,2. Acrylate co-monomers introduce another level of complexity from a competing mechanism toward gel content and macromolecular network development; long chain branching from chain transfer to polymer. The later form networks via α-hydrogen abstraction, which is a prominent reaction with acrylates. Moreover, the differences in reactivity ratio between acrylates and methacrylates add another layer of heterogeneity through the polymerization which also impacts the kinetics and ultimate network structure. In this work, we compare the network formation reaction and the Ψ-parameters for 1,4 butanediol dimethacrylate (BDDMA, containing methacrylate groups) with its acrylate-based counterpart (BDDA, containing acrylate groups) in copolymerization reactions with either n-butyl methacrylate (nBMA) or n-butyl acrylate (nBA). The Ψ-parameter for all systems is estimated by comparing the experimental results with Monte Carlo simulations of the polymerization reactions. The goal of the work is to decouple the contributions of pendent-vinyl based crosslinking and long-chain branching (α-hydrogen abstraction) from the resulting kinetic profile that the Ψ parameter is determined from. Moreover, we contrast the balance of contributions from propagation, chain transfer, reactivity ratios, and utility of the pendent vinyl groups for crosslinking between reactions at either 60 or 70 °C. Even this seemingly small shift in temperature has a marked impact on the kinetics and resulting network for the different pairs of (meth)acrylate comonomers. Tripathi, A.K.; Neenan, M.L.; Sundberg, D.C.; Tsavalas, J.G., Influence of n-Alkyl Ester Groups on Efficiency of Crosslinking for Methacrylate Monomers Copolymerized with EGDMA: Experiments and Monte Carlo Simulations of Reaction Kinetics and Sol-Gel Structure , Polymer (2016), 96, 130–145, DOI:10.1016/j.polymer.2016.04.017 Tripathi, A.K.; Tsavalas, J.G.; Sundberg, D.C., “Monte Carlo Simulations of Free Radical Polymerizations with Divinyl Crosslinker: Pre- and Post-Gel Simulations of Reaction Kinetics and Molecular Structure , Macromolecules (2015) 48, 184−197, DOI: 10.1021/ma502085

Automatic inspection system for dimensional measurements of the saw blade milling cutter

The demand for measuring equipments of automatic optical inspection has grown rapidly, because of its benefits of promoted efficiency and higher precision. Instead of manual projection measurements, measurement performance and efficiency can be obviously enhanced by the image measurement system. In this investigation, digital image processing and geometrical measurement principles have been integrated to develop a dynamic measurement system for the dimensional measurements of a saw blade milling cutter. The repeatability of the measurement system has been analyzed and its accuracy has been verified by using commercial 3D image measurement system. The analysis results show that the dimensional precision of 25μm and the angular precision of 0.21° can be realized by the self-developed measurement system. Between the results of the developed system and reference standard system, there are 25μm deviation in dimensional measurement and 0.26° in angular measurement. That measuring performances can meet the industrial requirement and the higher measurement efficiency can be achieved.Peer Reviewe

Gender Determination using Fingerprint Features

Several previous studies have investigated the gender difference of the fingerprint features. However, regarding to the statistical significance of such differences, inconsistent results have been obtained. To resolve this problem and to develop a method for gender determination, this work proposes and tests three fingertip features for gender determination. Fingerprints were obtained from 115 normal healthy adults comprised of 57 male and 58 female volunteers. All persons were born in Taiwan and were of Han nationality. The age range was18-35 years. The features of this study are ridge count, ridge density, and finger size, all three of which can easily be determined by counting and calculation. Experimental results show that the tested ridge density features alone are not very effective for gender determination. However, the proposed ridge count and finger size features of left little fingers are useful, achieving a classification accuracy of 75% (P-valu