The BG News November 15, 2005

The BGSU campus student newspaper November 15, 2005. Volume 96 - Issue 59https://scholarworks.bgsu.edu/bg-news/8516/thumbnail.jp

Nylon Tension PID Control During Raw Tire Assembly

The purpose of this study is to evaluate several control methods to see which one has the best control of nylon tension during raw tire assembly. After nylon application step of the tire building process, the shape of the tire will undergo inflation that causes the nylon layers to expand and produces tension gradient. To overcome such a problem, the process needs to preapply a nylon trip with a gradient of tension so the tension can be balanced after the inflation step. The study evaluated several PID controllers and gathered data to see which controller results in the best nylon tension gradient. The study also discusses the cost and simplicity of implementation as well as its overall performance

Performance evaluation of communication systems with transmit diversity

Transmit diversity is a key technique to combat fading with multiple transmit antennae for next-generation wireless communication systems. Space-time block code (STBC) is a main component of this technique. This dissertation consists of four parts: the first three discuss performance evaluation of STBCs in various circumstances, the fourth outlines a novel differential scheme with full transmit diversity. In the first part, closed-form expressions for the bit error rate (BER) are derived for STBC based on Alamouti\u27s scheme and utilizing M-ary phase shift keying (MPSK) modulation. The analysis is carried out for a slow, flat Rayleigh fading channel with coherent detection and with non-coherent differential encoding/decoding. The BER expression for coherent detection is exact. But for differential detection it is an approximation appropriate for a high signal-to-noise ratio. Numerical results are provided for analysis and simulations for BPSK and QPSK modulations. A signal-to-noise ratio loss of approximately 3 dB always occurs with conventional differential detection for STBC compared to coherent detection. In the second part of this dissertation, a multiple-symbol differential detection (MSDD) technique is proposed for MPSK STBCs, which greatly reduces this performance loss by extending the observation interval for decoding. The technique uses maximum likelihood block sequence detection instead of traditional block-by-block detection and is carried out on the slow, flat Rayleigh fading channel. A generalized decision metric for an observation interval of N blocks is derived. It is shown that for a moderate number of blocks, MSDD provides more than 1.0 dB performance improvement corresponding to conventional differential detection. In addition, a closed-form pairwise error probability for differential BPSI( STBC is derived for an observation interval of N blocks, and an approximate BER is obtained to evaluate the performance. In the third part, the BER performance of STBC over a spatio-temporal correlated channel with coherent and noncoherent detection is illustrated, where a general space-time correlation model is utilized. The simulation results demonstrate that spatial correlation negatively effects the performance of the STBC scheme with differential detection but temporal correlation positively impacts it. However, with coherent detection, spatial correlation still has negative effect on the performance but temporal correlation has no impact on it. In the final part of this dissertation, a differential detection scheme for DS/CDMA MIMO link is presented. The transmission provides for full transmit and receive diversity gain using a simple detection scheme, which is a natural extension of differential detection combined with an orthogonal transmit diversity (OTD) approach. A capacity analysis for this scheme is illustrated

Leadership styles, school effective, needs of 'mien' (face) behaviour: the interactions in Hong Kong private schools

National cultures vary and the variations challenge the conventional wisdom of the Western management theory and practice in other cultural contexts. Specifically, the national characteristic of 'face(mien) behaviour' is immensely important at all levels in Chinese interpersonal communications. The notion of 'mien' permeates every aspect of interpersonal relationships in Chinese culture because of the culture’s overarching concern with relationships. This study examines the nature of 'mien' behaviour, explores how 'mien' functions in the Hong Kong educational context, and how leadership styles of secondary school principals interact with 'mien' as perceived by their teaching staff and how, eventually, these interactions influence the effectiveness of the schools. Whenever Chinese behaviour is discussed, the social philosophy of Confucianism is relevant. The Confucian ethical system regulating social behaviour has three principle ideas: ren(), yi() and li(); benevolence, righteousness or justice, and propriety or courtesy. This study also examines how these three principles nurture 'mien' and considers whether any alternate style of leadership in Hong Kong context can be formulated

3-D defect profile reconstruction from magnetic flux leakage signatures using wavelet basis function neural networks

The most popular technique for inspecting natural gas pipelines involves the use of magnetic flux leakage (MFL) methods. The measured MFL signal is interpreted to obtain information concerning the structural integrity of the pipe. Defect characterization involves the task of calculating the shape and size of defects based on the information contained in the signal. An accurate estimate of the defect profile allows assessment of the safe operating pressure of the pipe. Artificial neural networks (ANNs) have been employed for characterizing defects in the past. However, conventional neural networks such as radial basis function neural networks are not always suitable for the following reasons: (1) It is difficult to quantify and measure the confidence level associated with the profile estimates. (2) They do not provide adequate control over output accuracy and network complexity trade-off. (3) Optimal center selection schemes typically use an optimization technique such as least-mean-square (LMS) algorithm---a tedious and computationally intensive procedure. These disadvantages can be overcome by employing a wavelet basis function (WBF) neural network. Such networks allow multiple scales of approximation. For the specific application on hand, Gaussian radial basis functions and Mexican hat wavelet frames are used as scaling functions and wavelets respectively. The proposed basis function centers are calculated using a dyadic expansion scheme and the k-means clustering algorithm;The validity of the proposed approach is demonstrated by predicting defect profiles from simulation data as well as experimental magnetic flux leakage signals. The results demonstrate that wavelet basis function neural networks can successfully map MFL signatures to three-dimensional defect profiles. The center selection scheme requires minimal effort compared to conventional methods. Also, the accuracy of the output can be controlled by varying the number of network resolutions. It is also shown that the use of a priori information such as estimates of the geometric parameters of the defect helps improve characterization results

Market supervision by Hong Kong regulators on disclosure of interests and insider dealing.

by Hui Lok Yee Connie.Thesis (M.B.A.)--Chinese University of Hong Kong, 1999.Includes bibliographical references (leaves 92-95).ABSTRACT --- p.ivACKNOWLEDGEMENT --- p.vTABLE OF CONTENTS --- p.viChapterChapter I. --- INTRODUCTION --- p.1Objectives of Securities Regulations --- p.3Regulatory Framework of the Hong Kong Securities Market --- p.5Objectives of This Study --- p.6Methodology --- p.7Chapter II. --- DISCLOSURE OF INTERESTS --- p.8Development of Securities (Disclosure of Interests) Ordinance in HK --- p.8Disclosure of Interests in Shares --- p.9Commentary --- p.17Recommendations --- p.23Chapter III. --- INSIDER DEALING --- p.29Development of Securities (Insider Dealing) Ordinance in HK --- p.29Overview of the Supervision of Insider Dealing Activitiesin Hong Kong and Singapore --- p.30Circumstances of Insider Dealing --- p.32Consequences of Insider Dealing --- p.36Case Studies --- p.39Commentary --- p.51Recommendations --- p.55Chapter IV. --- CONCLUSION --- p.60APPENDICE --- p.63Appendix 1 --- p.64Appendix 2 --- p.68Appendix 3 --- p.72Appendix 4 --- p.76Appendix 5 --- p.77Appendix 6 --- p.85Appendix 7 --- p.90Appendix 8 --- p.91Appendix 9 --- p.92BIBLIOGRAPHY --- p.9

PIRANHA: an engine for a methodology of detecting covert communication via image-based steganography

In current cutting-edge steganalysis research, model-building and machine learning has been utilized to detect steganography. However, these models are computationally and cognitively cumbersome, and are specifically and exactly targeted to attack one and only one type of steganography. The model built and utilized in this thesis has shown capability in detecting a class or family of steganography, while also demonstrating that it is viable to construct a minimalist model for steganalysis. The notion of detecting steganographic primitives or families is one that has not been discussed in literature, and would serve well as a first-pass steganographic detection methodology. The model built here serves this end well, and it must be kept in mind that the model presented is posited to work as a front-end broad-pass filter for some of the more computationally advanced and directed stganalytic algorithms currently in use. This thesis attempts to convey a view of steganography and steganalysis in a manner more utilitarian and immediately useful to everyday scenarios. This is vastly different from a good many publications that treat the topic as one relegated only to cloak-and-dagger information passing. The subsequent view of steganography as primarily a communications tool useable by petty information brokers and the like directs the text and helps ensure that the notion of steganography as a digital dead-drop box is abandoned in favor of a more grounded approach. As such, the model presented underperforms specialized models that have been presented in current literature, but also makes use of a large image sample space (747 images) as well as images that are contextually diverse and representative of those seen in wide use. In future applications by either law-enforcement or corporate officials, it is hoped that the model presented in this thesis can aid in rapid and targeted responses without causing undue strain upon an eventual human operator. As such, a design constraint that was utilized for this research favored a False Negative as opposed to a False Positive - this methodology helps to ensure that, in the event of an alert, it is worthwhile to apply a more directed attack against the flagged image