A Box-Counting Method with Adaptable Box Height for Measuring the Fractal Feature of Images

Most of the existing box-counting methods for measuring fractal features are only applicable to square images or images with each dimension equal to the power of 2 and require that the box at the top of the box stack of each image block is of the same height as that of other boxes in the same stack, which gives rise to inaccurate estimation of fractal dimension. In this paper, we propose a more accurate box-counting method for images of arbitrary size, which allows the height of the box at the top of each grid block to be adaptable to the maximum and minimum gray-scales of that block so as to circumvent the common limitations of existing box-counting methods

Energy Harvesting Noncoherent Cooperative Communications

This paper investigates simultaneous wireless information and power transfer (SWIPT) in energy harvesting (EH) relay systems. Unlike existing SWIPT schemes requiring the channel state information (CSI) for coherent information delivery, we propose a noncoherent SWIPT framework for decode-and-forward (DF) relay systems bypassing the need for CSI and consequently saving energy in the network. The proposed SWIPT framework embraces power-splitting noncoherent DF (PS-NcDF) and time-switching noncoherent DF (TS-NcDF) in a unified form, and supports arbitrary M-ary noncoherent frequency-shift keying (FSK) and differential phase-shift keying (DPSK). Exact (noncoherent) maximum-likelihood detectors (MLDs) for PS-NcDF and TS-NcDF are developed in a unified form, which involves integral evaluations yet serves as the optimum performance benchmark for noncoherent SWIPT. To reduce the computational cost of the exact MLDs, we also propose closed-form approximate MLDs achieving near-optimum performance, thus serving as a practical solution for noncoherent SWIPT. Numerical results demonstrate a performance tradeoff between the first and second hops through the adjustment of time switching or power splitting parameters, whose optimal values minimizing the symbol-error rate (SER) are strictly between 0 and 1. We demonstrate that M-FSK results in a significant energy saving over M-DPSK for M >= 8; thus M-FSK may be more suitable for EH relay systems

A Study on the Growth and Formation of Single Person Households and Their Housing Decisions in Taiwan

The number of single person households has dramatically increased in Taiwan in the past several decades as it has elsewhere in the world, but this phenomenon has been largely neglected in the literature. This research explores the factors that affect the formation of single person households and their housing decisions. Taiwan¡¦s population census data for 1980, 1990 and 2000 are used. Some interesting trends can be found. First of all, people who are married or cohabiting have exhibited an increasing tendency to live alone census by census. This shows the increasing need in a modern society for the husband and wife to live separately due to employment or other reasons. Secondly, unmarried and widowed elderly persons have had an increasing probability of living alone over the decades. Thirdly, the number of female single person households has been increasing rapidly, and there is a higher probability that they are homeowners and also occupying a larger living space than their male counterparts. To sum up, the results of this study show that the demand for housing among single person households will continue to increase as their numbers increase. Their demand for homeownership and living space are also increasing.Single person household formation; Tenure choice; Living space; Binary probit model; Sample selection model