In this paper, the performance of quasi-synchronous direct-sequence CDMA communication systems based on diierent sets of orthogonal codes is investigated. We search for sets of sequences that minimize the probability of bit detection error, given that there is imperfect synchronization among the signals. Orthogonal sequences based on the Sylvester-type Hadamard matrices (Walsh functions) are sh...

Raman measurements in the 1.5-20 cm(-1) energy range were performed on single crystals of Sr14-xCaxCu24O41. A quasielastic scattering peak (QEP) which softens with cooling is observed only in the polarization parallel to the ladder direction for samples with x=0, 8, and 12. The QEP is a Raman fingerprint of pinned collective density wave excitations screened by uncondensed carriers in the ladde...

In the service business, event correlation systems are used to predict and avoid system failures. Strategically, this may contribute to higher system availability and better service activity planning. Companies that want to benefit from this competitive advantage often meet two fundamental problems: the complexity of service monitoring increases with the number of correlation patterns. At the s...

In this paper, we present an indoor optical wireless model to evaluate the impact of direct and reflected light on the bit error rate (BER) performance of an indoor optical wireless CDMA system. In this model, we divided each wall into small reflecting surfaces and took into account multiple surfaces. Based on this model, the optical received power with and without considering the reflected lig...

In spread spectrum systems, pseudo-random (PN) sequences are used to spread the data bits. There are various type of PN sequences are available with good correlation properties, most of which are generated by Linear Feedback Shift Register (LFSR). In this paper we describe the generation pseudo chaotic sequences (PCS) and conventional PN sequences and its correlation properties. Here, pseudo-ch...

5.1.1.1. Sensor Design There are misperceptions in the power industry that the measurement technologies for suspended flow have reached a mature state. Despite the considerable effort in recent years there is still a great deal to be done to advance the technologies. There are presently no systems that can provide absolute measurement of coal mass flow rate and particle sizing distribution. Ins...

The mechanisms which lead to shear failure of longitudinally reinforced concrete beams are complex and often misunderstood. In this paper, a combination of a special closed loop test technique and machine vision are applied to tests on two reinforced concrete beams failing in shear: one made of normal strength concrete and the second of high strength concrete. To control the progression of the ...

This paper is concerned on the new type of the sensing elements for a particle volume of flow rate measurements based on cross correlation flowmeters. The new type of sensing elements exploit the fact that the solid particles being carried by a flowing air and impacting a properly formed obstacle generate an acoustic surface wave (acoustic emission AE). The acoustic signal is indicated by the a...

The analysis of the BER performance for synchronous all-optical code-division multiple-access (CDMA) local area networks (LANs) with modified prime codes is presented. The mean and variance of periodic cross-correlation values of modified prime codes are derived analytically. The effects of shot noise, thermal noise, interference and the architecture of optical receivers are included in the eva...