A systematic algorithm development for image processing feature extraction in automatic visual inspection : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in the Department of Production Technology, Massey University

Image processing techniques applied to modern quality control are described together with the development of feature extraction algorithms for automatic visual inspection. A real-time image processing hardware system already available in the Department of Production Technology is described and has been tested systematically for establishing an optimal threshold function. This systematic testing has been concerned with edge strength and system noise information. With the a priori information of system signal and noise, non-linear threshold functions have been established for real time edge detection. The performance of adaptive thresholding is described and the usefulness of this nonlinear approach is demonstrated from results using machined test samples. Examination and comparisons of thresholding techniques applied to several edge detection operators are presented. It is concluded that, the Roberts' operator with a non-linear thresholding function has the advantages of being simple, fast, accurate and cost effective in automatic visual inspection

Resurvey of order and chaos in spinning compact binaries

This paper is mainly devoted to applying the invariant, fast, Lyapunov indicator to clarify some doubt regarding the apparently conflicting results of chaos in spinning compact binaries at the second-order post-Newtonian approximation of general relativity from previous literatures. It is shown with a number of examples that no single physical parameter or initial condition can be described as responsible for causing chaos, but a complicated combination of all parameters and initial conditions is responsible. In other words, a universal rule for the dependence of chaos on each parameter or initial condition cannot be found in general. Chaos does not depend only on the mass ratio, and the maximal spins do not necessarily bring the strongest effect of chaos. Additionally, chaos does not always become drastic when the initial spin vectors are nearly perpendicular to the orbital plane, and the alignment of spins cannot trigger chaos by itself.Comment: 16 pages, 7 figure

Design of Fixed-Point Processing Based LDPC Codes Using EXIT Charts

Logarithmic representation of the variables processed by iterative decoding algorithms of Low-Density Parity-Check (LDPC) codes are attractive, since the resultant reduced dynamic range of its Logarithmic Likelihood Ratios (LLRs) allows a Fixed Point (FP) operand-representation to be used. This FP representation has a lower computational complexity than a floating point representation, allowing the decoder's hardware to have a low energy consumption, which depends on the Operand-Width (OW) of the LLRs. However, if the OW is too low, then an inevitable performance degradation will be introduced. Therefore it is desirable to determine the minimum OW that does not impose a significant performance degradation. Previous efforts have advocated different OWs based on results obtained using time-consuming Bit Error Ratio (BER) simulations. However, these simulations are extremely time consuming, owing to the requirement of considering a range of channel Signal-to-Noise Ratios (SNRs). Therefore, in this paper, we propose the employment of EXtrinsic Information Transfer (EXIT) charts to overcome this drawback. Furthermore, EXIT charts analysis has the additional benefit of offering insights into the specific causes of the performance degradations encountered. Finally, a FP scheme having an overall OW = 6 is proposed for the implementation of the Min-Sum Algorithm (MSA)

Diffusion Models for Double-ended Queues with Renewal Arrival Processes

We study a double-ended queue where buyers and sellers arrive to conduct trades. When there is a pair of buyer and seller in the system, they immediately transact a trade and leave. Thus there cannot be non-zero number of buyers and sellers simultaneously in the system. We assume that sellers and buyers arrive at the system according to independent renewal processes, and they would leave the system after independent exponential patience times. We establish fluid and diffusion approximations for the queue length process under a suitable asymptotic regime. The fluid limit is the solution of an ordinary differential equation, and the diffusion limit is a time-inhomogeneous asymmetric Ornstein-Uhlenbeck process (O-U process). A heavy traffic analysis is also developed, and the diffusion limit in the stronger heavy traffic regime is a time-homogeneous asymmetric O-U process. The limiting distributions of both diffusion limits are obtained. We also show the interchange of the heavy traffic and steady state limits

Impact of Interupted Education on Earnings: The Educational Cost of the Chinese Cultural revolution

Impact of school interruptions on earnings through lower subsequent educational attainment and lower quality of education is investigated using the Chinese Cultural Revolution as a natural experiment. During the Cultural Revolution, most schools in China stopped normal operation for 3 to 4 years, universities stopped normal student recruitment for an even longer period. Such large scale school interruptions reduced the opportunity of the cohort to obtain university degrees. We find that individuals who did not obtain a university degree becasue of the Cultural revolution on average lost 46 per cent of their potential earnings. In addition most of the cohort experienced missed or interrupted schooling, at a given level of education and we show that this reduced earnings of degree holders of the Cultural Revolution cohort by 7.3 per cent on average. The findings in this paper also indicate that the quality of schooling affected earnings of individuals in a non-linear way, that is, only missed schooling at junior and senior high level reduced subsequent earnings and it only reduced earnings of those with degrees.

The role of Guanxi on Chinese leadership innovation:the pilot study on the electric motor sector

This research aims to examine the existence and nature of complex business-social relationships in the Chinese context (Guanxi) and evaluate how these relationships influence the behaviors of managers in State-owned Chinese engineering firms. Research on Guanxi is comprehensive though little work investigates internal influences and how internal relationships may mirror or replicate external Guanxi. This study uses a snowball sample of 66 senior managers across the key functional disciplines in typical large Chinese firms and explores how often strategic level problems in the firm are solved through relationships outside, inside or between the companies. Do Guanxi networks penetrate the organization itself and are there relationships that are unique to internal networks? The research finds that problem solving at strategic levels are often through internal and external networks, rather than internal management structures, but also that different problems complexities typically demonstrate unique problem-solving networks. The research identifies three different forms that these relationships take: Internal, inter-firm and hybrid relationship modes. Implications for this work suggest problem solving in Chinese firms is enhanced through cooperation and mutual respect, and likely to be inhibited by traditional Western approaches to management

Self-assembled island formation in heteroepitaxial growth

We investigate island formation during heteroepitaxial growth using an atomistic model that incorporates deposition, activated diffusion and stress relaxation. For high misfit the system naturally evolves into a state characterized by a narrow island size distribution. The simulations indicate the existence of a strain assisted kinetic mechanism responsible for the self-assembling process, involving enhanced detachment of atoms from the edge of large islands and biased adatom diffusion.Comment: ReVTeX, 10 pages, 3 ps figure