4,016 research outputs found

    An Optimization Based Empirical Mode Decomposition Scheme for Images

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    Bidimensional empirical mode decompositions (BEMD) have been developed to decompose any bivariate function or image additively into multiscale components, so-called intrinsic mode functions (IMFs), which are approximately orthogonal to each other with respect to the 2\ell_2 inner product. In this paper, a novel optimization problem is designed to achieve this decomposition which takes into account important features desired of the BEMD. Specifically, we propose a data-adapted iterative method which we call Opt-BEMD which minimizes in each iteration a smoothness functional subject to inequality constraints involving the strictly local extrema of the image. In this way, the method constructs a sparse data-adapted basis for the input function as well as an envelope in a mathematically stringent sense. Moreover, we propose an ensemble version of Opt-BEMD to strengthen its performance when applied to noise-contaminated images or images with only few extrema

    A unique polar representation of the hyperanalytic signal

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    The hyperanalytic signal is the straight forward generalization of the classical analytic signal. It is defined by a complexification of two canonical complex signals, which can be considered as an inverse operation of the Cayley-Dickson form of the quaternion. Inspired by the polar form of an analytic signal where the real instantaneous envelope and phase can be determined, this paper presents a novel method to generate a polar representation of the hyperanalytic signal, in which the continuously complex envelope and phase can be uniquely defined. Comparing to other existing methods, the proposed polar representation does not have sign ambiguity between the envelope and the phase, which makes the definition of the instantaneous complex frequency possible.Comment: 2014 IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP

    A different view on the vector-valued empirical mode decomposition (VEMD)

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    The empirical mode decomposition (EMD) has achieved its reputation by providing a multi-scale time-frequency representation of nonlinear and/or nonstationary signals. To extend this method to vector-valued signals (VvS) in multidimensional (multi-D) space, a multivariate EMD (MEMD) has been designed recently, which employs an ensemble projection to extract local extremum locations (LELs) of the given VvS with respect to different projection directions. This idea successfully overcomes the problems of locally defining extrema of VvS. Different from the MEMD, where vector-valued envelopes (VvEs) are interpolated based on LELs extracted from the 1-D projected signal, the vector-valued EMD (VEMD) proposed in this paper employs a novel back projection method to interpolate the VvEs from 1-D envelopes in the projected space. Considering typical 4-D coordinates (3-D location and time), we show by numerical simulations that the VEMD outperforms state-of-art methods.Comment: 7th International Congress on Image and Signal Processing (CISP

    Would Adopting the US Dollar Have Led to Improved Inflation, Output and Trade Balances for New Zealand in the 1990s?

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    Deterministic simulations with the Reserve Bank of New Zealand's core FPS model show how New Zealand's broad macroeconomic environment might have evolved over the 1990s, if a US nominal yield curve and US TWI exchange rate movements under a common currency arrangement had been experienced. Relatively looser monetary conditions would have prevailed, and led to modest short-run output gains, greater excess demand pressures, noticeably higher CPI inflation rates over the whole of the 1990s, and less favourable trade balance outcomes, especially for the late 1990s. These macroeconomic outcomes are overall less favourable than those obtained from simulating the equivalent Australian monetary conditions.Common currency; monetary policy; deterministic simulation; New Zealand; Australia; United States

    WOULD ADOPTING THE US DOLLAR HAVE LED TO IMPROVED INFLATION, OUTPUT AND TRADE BALANCES FOR NEW ZEALAND IN THE 1990s?

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    Deterministic simulations with the Reserve Bank of New Zealand’s core FPS model show how New Zealand’s broad macroeconomic environment might have evolved over the 1990s, if a US nominal yield curve and US TWI exchange rate movements under a common currency arrangement had been experienced.Relatively looser monetary conditions would have prevailed, and led to modest short-run output gains, greater excess demand pressures, noticeably higher CPI inflation rates over the whole of the 1990s, and less favourable trade balance outcomes, especially for the late 1990s.These macroeconomic outcomes are overall less favourable than those obtained from simulating the equivalent Australian monetary conditions.Common currency; monetary policy; deterministic simulation; New Zealand; Australia; United States.

    Monetary policy rules in practice: Evidence from New Zealand

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    We use the ten years of experience in inflation-targeting in New Zealand since 1989 to test whether monetary policy appears to conform to the simple rules that have been recommended for it in the literature. Of the inflation targeting central banks, the Reserve Bank of New Zealand has both the longest experience and probably the most clearly defined target and policy framework for achieving it. We show that while a Taylor rule with the standard parameters used in the US does indeed describe New Zealand monetary policy quite well, the Reserve Bank has focused rather more strongly on price stability, as required by its Policy Target Agreements. However, while the conduct of New Zealand monetary policy as set out in the Monetary Policy Statements is firmly based on targeting the inflation rate in the future we find, using the Bank’s own forecasts, that nevertheless targeting inflation close to the present appears to be a better description of policy. Furthermore, restricting the policy choice to the information available to the Reserve Bank at the actual time of policy settings and ignoring subsequent revisions to published statistics does not result in a much improved explanation of its actions. We find a clear ‘smoothing’ element to the Bank’s policy rather than immediate response to every small fluctuation. We show further that some of the variables that enter the policy rule have slightly asymmetric cycles. From symmetric and asymmetric cointegration tests on the long-run relationship between interest rates, the output gap, and inflation we show that there is insufficient evidence to suggest that monetary policy has been asymmetric in treating upside inflationary pressures differently from those towards deflation.monetary policy; Taylor rule; inflation targeting; New Zealand

    Penggunaan Internet yang Sehat dan Aman Di Kalangan Masyarakat dan Pelajar

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    Internet merupakan hal yang paling sering digunakan oleh masyarakat tiap harinya. Pengguna internet dominan berasal dari kelompok remaja atau pelajar. Sering kali ditemukan oknum yang menyalahgunakan internet sehingga perlu adanya pengedukasian akan cara berinternet sehat dan aman. Internet Sehat dan Aman (INSAN) adalah suatu program dari pemerintah Indonesia yang dirancangkan oleh Kementrian Komunikasi dan Informatika Indonesia (Kemkominfo) dengan tujuan mensosialisasikan penggunaan internet secara sehat dan aman melalui pembelajaran etika berinternet secara sehat dengan melibatkan seluruh komponen masyarakat. Melalui kegiatan Pancasila Social Experiment Project (PASEPRO) yang merupakan tugas proyek mata kuliah Pancasila dalam bentuk pengabdian masyarakat yang memiliki tujuan untuk mengembangkan pendidikan karakter dengan pendekatan partisipatif dan kolaboratif, penulis mengadakan sosialisasi. Kegiatan PASEPRO dilaksanakan dengan tujuan mengedukasi pelajar akan pentingnya berinternet sehat dan aman dan dapat menggunakan  internet secara bijak.. Metode pelaksanaan kegiatan yang digunakan adalah metode penyuluhan atau sosialisasi dan menggunakan teknik analisis data kualitatif untuk menganalisis data yang diperoleh. Melalui pelaksanaan proyek ini akan menghasilkan kalangan pelajar yang dapat memaksimalkan dampak positif penggunaan internet dan meminimalkan dampak negatif berinternet sehingga terciptanya kalangan masyarakat yang cerdas dan produktif kedepannya

    Conservation Genetics of Threatened Gopher Tortoises, \u3ci\u3eGopherus polyphemus\u3c/i\u3e: An Assessment of Genetic Variation and Parentage in Two Populations in South Mississippi

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    Despite the protection of gopher tortoises, Gopherus polyphemus, in the western portion of their range for over twenty years, populations of the De Soto National Forest (DNF) in southern Mississippi experience low recruitment and lower hatching success than populations in the eastern portion of the range, and the causes of this are unknown. Previous work has shown that Mississippi populations of the DNF have lower levels of genetic diversity than eastern populations, which prompted the suggestion that reduced levels of genetic variation may play a part in low hatching success. Small populations can become more susceptible to the effects of inbreeding which can have negative effects on fitness of offspring. Using a microsatellite-based approach, I assessed genetic variation at two sites in south Mississippi that have different levels of recruitment to test for a correlation between genetic variation and survivorship. T44 at Camp Shelby is a low recruitment site, and Hillsdale is a high recruitment site. I found evidence of a heterozygosity fitness correlation among tortoises belonging to different age classes in the Hillsdale population. Multilocus genotypic data was also used to perform parentage assessments to characterize the mating systems and movements of both populations. Both populations demonstrated unequal reproductive success among adult tortoises, and spatial analyses revealed strong colony fidelity within populations even across several years
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