Nowadays, analyzing human facial image has gained an ever-increasing importance due to its various applications. Image segmentation is required as a very important and fundamental operation for significant analysis and interpretation of images. Among the segmentation methods, image thresholding technique is one of the most well-known methods due to its simplicity, robustness, and high precision...

Sadao Yaegashi (八 重 樫 定 夫) From the Department of Physiology, Iwate Medical College, Morioka; Director: Prof. T. MitA (Received for publication, September 30, 1957) If the threshold voltages of alternating currents passing through the head, as determined with flickering phosphenes as an index of excitation, are plotted as a function of frequencies, there is found a distinct minimum at a frequen...

We analyze the optimum threshold value used in determining the modulation and coding scheme (MCS) level of retransmission packets in HARQ schemes. In HARQ schemes, although the first packet is erroneous, it has a considerable energy that can enhance the system performance such as packet error rate (PER) and throughput. Using the existing energy of the first transmission packet, we can save the ...

Image compression is dissimilar than compressing other unprocessed binary data. Obviously, general purpose compression techniques deliberated for raw binary data can be used to compress images, but the result is not the finest one, because of the variations in statistical property of image. Statistical properties of image must be completely exploit by encoders to obtained efficient image compre...

QUEST [Watson and Pelli, Perception and Psychophysics, 13, 113-120 (1983)] is an efficient method of measuring thresholds which is based on three steps: (1) Specification of prior knowledge and assumptions, including an initial probability density function (p.d.f.) of threshold (i.e. relative probability of different thresholds in the population). (2) A method for choosing the stimulus intensit...

Evolutionary systems may often be accurately modelled by Markov processes. However the state space invariably turns out to be vast and multi-dimensional, thus limiting the application of Markov theory to broad abstraction rather than specific problems. One notable exception is the analysis of error thresholds in finite populations by (Nowak & Schuster 1989), where a (seemingly unjustifiable) ap...

The risk involved in basing a nematode management decision on predicted crop loss is related to the uncertainty in the crop damage function and error in measuring nematode population density. The sampling intensity necessary to measure a nematode population with specified precision varies with population density. Since the density is unknown prior to sampling, optimum sampling intensity for a m...

This paper investigates the detection performance of an improved energy detector for a secondary user with spatially correlated multiple antennas. In an improved energy detector, an arbitrary positive power operation p replaces the squaring operation in a conventional energy detector, and the optimum value of p that gives the best detection performance may be different from 2. Firstly, for a gi...

Abstract In OFDM-CDMA down link, frequency equalization is necessary at the receiver to restore orthgonality among different users. But the noise enhancement due to orthgonality restoration degrades transmission performance. In this paper, pilot-aided frequency equalization with threshold detection (TD) is presented that can effectively suppress the noise enhancement. There is an optimal thresh...

An input and output queueing ATM switch model with a backpressure (BP) mode and a queue loss (QL) mode to decrease the system delay and the cell loss probability under nonuniform traffic is proposed. In the proposed model, the QL mode is adopted if the size of the backpressure exceeds the threshold. We consider a synchronous system with Bernoulli arrivals under hot-spot traffic that consists of...