THE NECESITY FOR AUDITING THE FINANCIAL-ACCOUNTING ACTIVITY

Many financial-accounting information users mistake internal audit and accounting. These confusion has, at is basis, the fact that most internal audit activities regard financial-accounting information and the fact that most internal auditors have a significant background in fields regarding accounting. Although the origins of accounting and audit are not clearly defined they have different application domains. The practice has imposed the abandonment of the entity’s internal audit correlated with the financial-accounting function significance and the growth of its importance by including the internal audit function in the direct subordination of the general managementaudit, system, value for money, performance, financial-accounting information

Clustered Hierarchical Entropy-Scaling Search of Astronomical and Biological Data

Both astronomy and biology are experiencing explosive growth of data, resulting in a “big data” problem that stands in the way of a “big data” opportunity for discovery. One common question asked of such data is that of approximate search (ρ–nearest neighbors search). We present a hierarchical search algorithm for such data sets that takes advantage of particular geometric properties apparent in both astronomical and biological data sets, namely the metric entropy and fractal dimensionality of the data. We present CHESS (Clustered Hierarchical Entropy-Scaling Search), a search tool with virtually no loss in specificity or sensitivity, demonstrating a 13.6 × speedup over linear search on the Sloan Digital Sky Survey’s APOGEE data set and a 68 × speedup on the GreenGenes 16S metagenomic data set, as well as asymptotically fewer distance comparisons on APOGEE when compared to the FALCONN locality-sensitive hashing library. CHESS demonstrates an asymptotic complexity not directly dependent on data set size, and is in practice at least an order of magnitude faster than linear search by performing fewer distance comparisons. Unlike locality-sensitive hashing approaches, CHESS can work with any user-defined distance function. CHESS also allows for implicit data compression, which we demonstrate on the APOGEE data set. We also discuss an extension allowing for efficient k-nearest neighbors search

Adaptive Subcarrier PSK Intensity Modulation in Free Space Optical Systems

We propose an adaptive transmission technique for free space optical (FSO) systems, operating in atmospheric turbulence and employing subcarrier phase shift keying (S-PSK) intensity modulation. Exploiting the constant envelope characteristics of S-PSK, the proposed technique offers efficient utilization of the FSO channel capacity by adapting the modulation order of S-PSK, according to the instantaneous state of turbulence induced fading and a pre-defined bit error rate (BER) requirement. Novel expressions for the spectral efficiency and average BER of the proposed adaptive FSO system are presented and performance investigations under various turbulence conditions and target BER requirements are carried out. Numerical results indicate that significant spectral efficiency gains are offered without increasing the transmitted average optical power or sacrificing BER requirements, in moderate-to-strong turbulence conditions. Furthermore, the proposed variable rate transmission technique is applied to multiple input multiple output (MIMO) FSO systems, providing additional improvement in the achieved spectral efficiency as the number of the transmit and/or receive apertures increases.Comment: Submitted To IEEE Transactions On Communication

Outage performance of cognitive relay networks with wireless information and power transfer

In this paper, we consider underlay cognitive radio (CR) networks with one primary receiver, one cognitive transmitter-receiver pair, and one energy harvesting relay. The transmission power of the secondary source is opportunistically determined by its interference to the primary receiver, and the relay transmission is powered by the energy harvested from the radio-frequency observations at the relay. For the considered CR networks with simultaneous wireless information and power transfer (SWIPT), we derive analytical expressions for the outage probability, as well as their high signal-to-noise ratio (SNR) approximations in closed form. The developed analytical results demonstrate that the use of SWIPT will not cause any loss in diversity gain, but the outage probability achieved by the SWIPT-CR scheme asymptotically decays as log SNR/SNR, whereas a decaying rate of 1/SNR is achieved by a conventional CR network. Computer simulation results are also provided to demonstrate the accuracy of the presented analysis

Accuracy-guaranteed bit-width optimization

Published versio

MODELING AND EXPERIMENTAL VERIFICATION OF TORQUE RIPPLE IN PERMANENT MAGNET DC MOTORS

ABSTRACT In this paper we have developed a simple parametric model based on motor geometries to estimate the torque ripple in permanent-magnet DC (PMDC) motors. Torque ripple is the combined results of many different motor design parameters such as magnetic material properties and geometry as well as rotor slot geometry. As the PMDC motors are being used in more precision applications while being produced at a lower price, the effect of torque ripple is becoming an important issued for precision motion control. The main objective of this study is to identify motor parameters that affect the magnitude of the torque ripples as well as developing a cost effective measuring device for motor vendors. The analytical model focused on the effect of air gap volume on effective magnetic flux and in terms impact the torque generation. The effectiveness of the proposed model was verified by experimental data collected with motors from four large volume motor vendors that meets the same design specification. Sensitivity analysis was also performed to identify the key motor parameters that impacted the magnitude of the torque ripple. INTRODUCTION The use of brushed permanent magnet DC (PMDC) motors in machines that are used in precision application has become more common over the years. The reason for this trend is due to an increase in quality and cost effectiveness through advances in manufacturing processes. These advances have not however eliminated a periodic fluctuation of the output torque of the motor which is dependent on angular position and can be termed torque ripple (TR). This paper will first discuss a model of the motor developed torque T D and TR and then compar

The application of input shaping to a system with varying parameters

The original input shaping technique developed by Singer and Seering is summarized and a different definition for residual vibration is proposed. The new definition gives better insight into the ability of input shaping method to reduce vibration. The extension of input shaping to a system with varying parameters, e.g. natural frequency, is discussed and the effect of these variations is shown to induce vibration. A modified command shaping technique is developed to eliminate this unwanted motion

Combining Beamforming and Orthogonal Space-Time Block Coding

Abstract-Multiple transmit and receive antennas can be used in wireless systems to achieve high data rate communication. Recently, efficient space-time codes have been developed that utilize a large portion of the available capacity. These codes are designed under the assumption that the transmitter has no knowledge about the channel. In this work, on the other hand, we consider the case when the transmitter has partial, but not perfect, knowledge about the channel and how to improve a predetermined code so that this fact is taken into account. A performance criterion is derived for a frequency-nonselective fading channel and then utilized to optimize a linear transformation of the predetermined code. The resulting optimization problem turns out to be convex and can thus be efficiently solved using standard methods. In addition, a particularly efficient solution method is developed for the special case of independently fading channel coefficients. The proposed transmission scheme combines the benefits of conventional beamforming with those given by orthogonal space-time block coding. Simulation results for a narrow-band system with multiple transmit antennas and one or more receive antennas demonstrate significant gains over conventional methods in a scenario with nonperfect channel knowledge

Student politics, teaching politics, black politics: an interview with Ansel Wong

Ansel Wong is the quiet man of British black politics, rarely in the limelight and never seeking political office. And yet his ‘career’ here – from Black Power firebrand to managing a multimillion budget as head of the Greater London Council’s Ethnic Minority Unit in the 1980s – spells out some of the most important developments in black educational and cultural projects. In this interview, he discusses his identification with Pan-Africanism, his involvement in student politics, his role in the establishment of youth projects and supplementary schools in the late 1960s and 1970s, and his involvement in black radical politics in London in the same period, all of which took place against the background of revolutionary ferment in the Third World and the world of ideas, and were not without their own internal class and ethnic conflicts