Nyquist Frequency in Sequentially Sampled Data

This paper studies the sequential sampling scheme as a solution to the problem of aliasing, where the sampling interval is restricted to a minimum allowable value. Sequential sampling is analyzed and it is proved that when the sampling ratio is an integral number, the associated spectral estimates give a Nyquist frequency . This sampling scheme can, therefore, be employed to yield a required cut- off frequency.Nyquist Freqency; cut-off frequency; Sequential Sampling; Spectral Density Function

Dependent Nonparametric Bayesian Group Dictionary Learning for online reconstruction of Dynamic MR images

In this paper, we introduce a dictionary learning based approach applied to the problem of real-time reconstruction of MR image sequences that are highly undersampled in k-space. Unlike traditional dictionary learning, our method integrates both global and patch-wise (local) sparsity information and incorporates some priori information into the reconstruction process. Moreover, we use a Dependent Hierarchical Beta-process as the prior for the group-based dictionary learning, which adaptively infers the dictionary size and the sparsity of each patch; and also ensures that similar patches are manifested in terms of similar dictionary atoms. An efficient numerical algorithm based on the alternating direction method of multipliers (ADMM) is also presented. Through extensive experimental results we show that our proposed method achieves superior reconstruction quality, compared to the other state-of-the- art DL-based methods

On the Economic Value and Price-Responsiveness of Ramp-Constrained Storage

The primary concerns of this paper are twofold: to understand the economic value of storage in the presence of ramp constraints and exogenous electricity prices, and to understand the implications of the associated optimal storage management policy on qualitative and quantitative characteristics of storage response to real-time prices. We present an analytic characterization of the optimal policy, along with the associated finite-horizon time-averaged value of storage. We also derive an analytical upperbound on the infinite-horizon time-averaged value of storage. This bound is valid for any achievable realization of prices when the support of the distribution is fixed, and highlights the dependence of the value of storage on ramp constraints and storage capacity. While the value of storage is a non-decreasing function of price volatility, due to the finite ramp rate, the value of storage saturates quickly as the capacity increases, regardless of volatility. To study the implications of the optimal policy, we first present computational experiments that suggest that optimal utilization of storage can, in expectation, induce a considerable amount of price elasticity near the average price, but little or no elasticity far from it. We then present a computational framework for understanding the behavior of storage as a function of price and the amount of stored energy, and for characterization of the buy/sell phase transition region in the price-state plane. Finally, we study the impact of market-based operation of storage on the required reserves, and show that the reserves may need to be expanded to accommodate market-based storage

The relationship between women entrepreneurship and gender equality

The degree at which entrepreneurship affects the economy depends on numerous factors, including the quality, gender composition, and type of entrepreneurial activity. Gender equality and female entrepreneurship are key factors in economic development. In order to study the relationship between gender equality and the rate of female entrepreneurship, this paper investigates how gender-related economic development and women entrepreneurial activity are related. We characterize the relationship between gender-related development indices (introduced by the United Nations) and different stages of women entrepreneurial activity (created by Global Entrepreneurship Monitor, GEM) through a correlation analysis. Our results suggest that female entrepreneurial activity is not significantly correlated with gender equality

Effects Of Road Geometry And Roadside Trees On Urban Road Thermal Performance In Penang

Penyelidikan ini merupakan kajian tentang kesan sifat fizikal jalan dan pokok bersebelahan jalan terhadap perilaku termal jalan di Pulau Pinang Malaysia; iaitu di kawasan tropika dengan keamatan radiasi solar yang tinggi. This research investigates the effects of the physical road characteristics and roadside tree features on the road thermal performance in Penang, Malaysia; located in tropical region where there is high solar radiation intensity