As the worldwide aviation fleet continues to age, methods for accurately predicting the presence of structural flaws, such as hidden corrosion and disbonds, that compromise air worthiness become increasingly necessary. Ultrasonic guided waves, Lamb waves, allow large sections of aircraft structures to be rapidly inspected. However, extracting quantitative information from Lamb wave data has always involved highly trained personnel with a detailed knowledge of mechanical waveguide physics. In addition, human inspection process tends to be highly subjective, slow and prone to errors. The only practical alternative to traditional inspection routine is a software expert system capable of interpreting data with minimum error and maximum speed and reliability. Such a system would use the laws of guided wave propagation and material parameters to help signal processing algorithms automatically extract information from digitized waveforms. This work discusses several practical approaches to building such an expert system.;The next step in the inspection process is data interpretation, and imaging is the most natural way to represent two-dimensional structures. Unlike conventional ultrasonic C-scan imaging that requires access to the whole inspected area, tomographic algorithms work with data collected over the perimeter of the sample. Combined with the ability of Lamb waves to travel over large distances, tomography becomes the method of choice for solving NDE problems. This work explores different tomographic reconstruction techniques to graphically represent the Lamb wave data in quantitative maps that can be easily interpreted by technicians. Because the velocity of Lamb waves depends on the thickness, the traveltimes of the fundamental modes can be converted into a thickness map of the inspected region. Lamb waves cannot penetrate through holes and other strongly scattering defects and the assumption of straight wave paths, essential for many tomographic algorithms, fails. Diffraction tomography is a way to incorporate scattering effects into tomographic algorithms in order to improve image quality and resolution. This work describes the iterative reconstruction procedure developed for the Lamb Wave tomography and allowing for ray bending correction for imaging of moderately scattering objects.

Widespread support for capital account liberalization in emerging markets has recently shifted to skepticism and even support for capital controls in certain circumstances. This sea-change in attitudes has been bolstered by the inconclusive macroeconomic evidence on the benefits of capital account liberalization. There are several compelling reasons why it is difficult to measure the aggregate impact of capital controls in very different countries. Instead, a new and more promising approach is more detailed microeconomic studies of how capital controls have generated specific distortions in individual countries. Several recent papers have used this approach and examined very different aspects of capital controls - from their impact on crony capitalism in Malaysia and on financing constraints in Chile, to their impact on US multinational behavior and the efficiency of stock market pricing. Each of these diverse studies finds a consistent result: capital controls have significant economic costs and lead to a misallocation of resources. This new microeconomic evidence suggests that capital controls are not just "sand", but rather "mud in the wheels" of market discipline

The increasing interest and focus on unconventional reservoirs is a result of the industry's direction toward exploring alternative energy sources. It is due to the fact that conventional reservoirs are being depleted at a fast pace. Shale gas reservoirs are a very favorable type of energy sources due to their low cost and long-lasting gas supply. In general, according to Ausubel (1996), natural gas serves as a transition stage to move from the current oil-based energy sources to future more stable and environment-friendly ones. By looking through production history in the U.S Historical Production Database, HPDI (2009), we learn that the Barnett Shale reservoir in Newark East Field has been producing since the early 90's and contributing a fraction of the U.S daily gas production. Zhao et al. (2007) estimated the Barnett Shale to be producing 1.97 Bcf/day of gas in 2007. It is considered the most productive unconventional gas shale reservoir in Texas. By 2004 and in terms of annual gas production volume, Pollastro (2007) considered the Barnett Shale as the second largest unconventional gas reservoir in the United States. Many studies have been conducted to understand better the production controls in Barnett Shale. However, this giant shale gas reservoir is still ambiguous. Some parts of this puzzle are still missing. It is not fully clear what makes the Barnett well produce high or low amounts of gas. Barnett operating companies are still trying to answer these questions. This study adds to the Barnett chain of studies. It tests the effects of the following on Barnett gas production in the core area (Denton, Wise, and Tarrant counties): * Barnett gross thickness, including the Forestburg formation that divides Barnett Shale. * Perforation footage. * Perforated zones of Barnett Shale. Instead of testing these parameters on each well production decline curve individually, this study uses a new technique to simplify this process. Decline Map Analysis (DMA) is introduced to measure the effects of these parameters on all production decline curves at the same time. Through this study, Barnett gross thickness and perforation footage are found not to have any definite effects on Barnett gas production. However, zone 3 (Top of Lower Barnett) and zone 1 (Bottom of Lower Barnett) are found to contribute to cumulative production. Zone 2 (Middle of Lower Barnett) and zone 4 (Upper Barnett), on the other hand, did not show any correlation or influence on production through their thicknesses.

The inside is controlled to want to reach enterprise's goal , improve business efficiency , strengthening enterprise's physique , promoting the mechanism with indispensable competitiveness of enterprises, Taiwan is going through August of 1995, staff's practicing fraud case at the basic level of maximum amount in a Taiwanese financial history --After country's ticket case causes great losses of country's ticket , ' the inside is controlled ' relevant topic boiling reporting , making a self-criticism without restraint. Several things of shaking compatriots will recur again in 2003 , will include: Incident of steal and sell customer's stock , the financial card of the bank happen in the same year and is stolen by side recording , national treasurying etc. that famous in October to speak to the staff of law office of law, the relevant newspapers and magazines mention the question that ' the inside is controlled ' again, this topic causes everybody's concern once again too. This research case company, in order to set up the reason law lawyer's office of remarkable reputation for many years in the bar , only because the inside controls and causes the fraud case of breaking into the staff to defalcate improperly. This research audits the criterion communique No. 99 with U.S.A. ' check the financial statemant to the doing in the test amount that is deceived ' Three risk factors that the composition pointed out in (Conskderations of Fraud in a Financial Statement Audit ) practices fraud: Inducement and pressure (incentive/pressure), five major key elements of the attitude and rationalized (attitude/rationalization ) , and the chance (opportunity ) and composition that the inside control, control the environment , risk and assess , control the activity , information and communicate and supervise etc. to analyse the production reason of the incident and disappearance of controlling the system of inside that this case practice fraud. The result shows , an office lacks the system to restrain, totally places the control of different potential risks of the office on people's moral character , must examine the system in proper and management way again in fact.

This study examines how reliance on the client’s internal audit function (IAF) affects auditors’ ability to persuade management to accept material weakness assessments of detected internal control deficiencies. I further investigate whether auditors’ ability to persuade management to accept material weakness assessments depends on the subjectivity the control deficiency assessment to varied interpretations (ambiguity). I apply group affiliation and persuasion theories to hypothesize that management will have higher group identification with the IAF than with the auditors. I predict that management’s group affiliation will lead them to be more accepting of auditors’ internal control assessments when the auditors rely on the client’s IAF than when auditors do not. Further, I hypothesize that the greater the ambiguity in the internal control deficiency assessment, the more persuaded management will be to accept the auditors’ control assessment in situations where the auditors rely on the IAF than when the auditors do not. I conduct an experiment using a 2 X 2 between-subjects design in which I manipulate auditors’ reliance on the client’s IAF during tests of the client’s internal controls (rely or not rely) and the level of ambiguity in the internal control deficiency assessment (less ambiguous or more ambiguous) in a SOX 404 Internal Controls Over Financial Reporting (ICFR) audit setting. The study’s findings provide evidence that relying on the client’s IAF can improve auditors’ likelihood of persuading the client when control assessments are more open to varied interpretations. This study sheds light on a previously ignored benefit of using the client’s IAF – as a persuasion tactic. Thus, my research contributes to two literature streams: factors influencing auditor-client negotiations and the effects of using the IAF on audit engagements. These results provide both practical and theoretical insights to academics, practitioners and auditing standard setters.

Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems are a major component of worldwide energy consumption, and frequently consist of complex networks of interconnected components. The ubiquitous nature of these systems suggests that improvements in their energy efficiency characteristics can have significant impact on global energy consumption. The complexity of the systems, however, means that decentralized control schemes will not always suffice to balance competing goals of energy efficiency and occupant comfort and safety. This dissertation proposes control solutions for three facets of this problem. The first is a cascaded control architecture for actuators, such as electronic expansion valves, that provides excellent disturbance rejection and setpoint tracking characteristics, as well as partial nonlinearity compensation without a compensation model. The second solution is a hierarchical control architecture for multiple-evaporator vapor compression systems that uses model predictive control (MPC) at both the supervisory and component levels. The controllers leverage the characteristics of MPC to balance energy efficiency with occupant comfort. Since the local controllers are decentralized, the architecture retains a degree of modularity—changing one component does not require changing all controllers. The final contribution is a new distributed optimization algorithm that is rooted in distributed MPC and is especially motivated by HVAC&R systems. This algorithm allows local level optimizers to iterate to a centralized solution. The optimizers have no knowledge of any plant other than the plant they are associated with, and only need to communicate with their immediate neighbors. The efficacy of the algorithm is displayed with two sets of examples. One example is simulation based, wherein a building is modeled in the EnergyPlus software suite. The other is an experimental example. In this example, the algorithm is applied to a multiple evaporator vapor compression system. In both cases the design method is discussed, and the ability of the algorithm to reduce energy consumption when properly applied is demonstrated.

Trichogramma pretiosum Riley is a generalist egg parasitoid that is mass released in biological control programmes to control various insect pests on different plant species. The parasitism rates achieved by T. pretiosum vary across host species and across plant species, which suggests that the species of host and its host plant could both influence the host searching performance of this parasitoid. A comparative behavioural study across the eggs of two moth species, Helicoverpa armigera Hübner and Spodoptera litura Fabricius, was conducted because these two host eggs have different characteristics. Helicoverpa armigera eggs are laid singly, whereas S. litura eggs are laid in clusters and are covered with fine scales from the moth abdomen. I tested how these and other differences in host species affect the behaviour of T. pretiosum females towards their host species. The ovipositional responses of T. pretiosum females, from different natal hosts and of different ages since emergence, to eggs of H. armigera and S. litura were studied in choice and no choice tests. Helicoverpa armigera eggs were consistently preferred over S. litura eggs, regardless of the natal host and adult age. When only S. litura eggs were available as hosts, they were parasitized at statistically similar rates to H. armigera eggs. The adult lifespan and lifetime fecundity of T. pretiosum were variable but were significantly affected by natal host species and/or host species to which they were exposed. The ovigeny index (OI) was significantly lower in the parasitoids exposed to H. armigera eggs than in those exposed to S. litura eggs, regardless of the natal host, indicating that H. armigera eggs sustain the adult parasitoids better, through host feeding, than S. litura eggs. Trichogramma females, like other egg parasitoids, use chemical cues that originate not only from their host plants and host eggs, but also from the adult insects that deposit the hosts. These last include the scales left by the ovipositing moths. These host-associated cues are used by parasitoids over long and short distances to find their hosts. Olfactometer tests demonstrated that the odours from moth scales and host plants attracted T. pretiosum females significantly, and thus function as long range cues. By contrast, the odour from host eggs did not attract them in this way. The strength of attraction was similar across the scales from H. armigera and S. litura moths. The female parasitoids responded most strongly to odours from tomato and cabbage, whereas odour from corn was not such a strong attractant. A non-host plant tested did not attract the parasitoids at all. The odours of moth scales from both H. armigera and S. litura were more attractive to T. pretiosum females than was the odour of the host plants tested. When parasitoids have followed these long range cues to the nearby vicinity of their hosts, they respond to short range cues to localise the hosts. Moth scales did not attract female parasitoids over a short distance, but they did arrest their movement so that they remained longer in the area with scales. Trichogramma pretiosum females took significantly more time to localise S. litura eggs than it took for them to locate H. armigera eggs. Time to locate hosts did not increase significantly when the eggs had been washed with hexane, which suggests that cues other than chemicals are associated with the eggs and play a more significant role in host finding over short distances. On their emergence, parasitoids are confronted by several options, including mating, searching for hosts, and seeking food. Season influenced the daily pattern of T. pretiosum emergence, with cooler winter temperatures extending emergence over two days. In summer they emerged earlier in the day and all parasitoids in the tests emerged during the first day. Parasitoids left their emergence sites by walking before their wings expanded fully. Adults of T. pretiosum visit flowers, presumably for nectar. Olfactometer tests showed that both males and females of T. pretiosum were attracted to the odor of alyssum flowers. The attraction to flower odour was significant for males when they had had no access to nutrients for 24h, but was less significant when they had just emerged. On the contrary, the attraction to food was more significant in newly emerged females. For 1 day starved females, cues associated with host plants (tomato leaves) and food (alyssum flowers) were equally important. Nutritional sources influenced the adult lifespan and reproductive performance of the parasitoids. Honey was the best source of nutrition for adults of T. pretiosum, resulting in the longest lifespan and the highest reproductive output, followed by alyssum flowers, tomato leaves and water. The results are discussed in relation to (i) understanding the entire mechanism of host searching behaviour of egg parasitoids, (ii) interpreting the behavioural interaction between generalist parasitoids and their different host insects and plants, and (iii) the better use of egg parasitoids in biological control. Throughout the discussion suggestions are made for further research.

Our understanding of the neural control of breathing-swallowing coordination (BSC) is largely unclear. Although brainstem control is undoubtedly predominant, this research investigated the hypothesis that the cortex becomes increasingly influential in BSC between birth and adulthood. The main paradigm used to test this primary hypothesis was a comparison of BSC in conditions along a continuum of volitional through non-volitional swallowing on the basis of a decreasing level of cortical activation along this continuum. Voluntarily-initiated swallows during wakefulness were at one end of the continuum and reflexively-initiated swallows during sleep were at the other extreme. Non-volitional wakeful swallows were considered between these two conditions. The BSC of ten infants between birth and 1 year of age and twenty adults between the ages of 20 and 75 years was recorded using non-invasive time-locked recording methods. In order to apply the 'continuum-of-volition' paradigm to swallowing conditions in infants, BSC was monitored during nutritive (breast- or bottle-feeding), non-nutritive wake, and sleep swallows. Infants were monitored longitudinally to determine whether maturation of the cortex and corticobulbar tracts during the first year of life influenced the patterns of BSC. In adults, BSC was monitored during three non-nutritive conditions: volitional, spontaneous wake, and sleep conditions. Post-swallow expiration was found to be predominant in all conditions for all participants at all ages. In addition, the infant results revealed that nutritive BSC matured during the first year of life and differed to non-nutritive wakeful BSC, particularly in the first 2 months of life. Non-nutritive wakeful and sleep BSC did not differ from one another. In summary, the infant results support increasing cortical input into volitional nutritive BSC, an early impact of feeding on BSC, and no difference between BSC when asleep and non-volitional non-nutritive swallows when awake. The results obtained from adults revealed that irrespective of the level of arousal, volitional BSC is different to non-volitional BSC. These results imply that cortical influence on BSC is limited to conditions in which swallowing is voluntarily initiated. The combined interpretation of infant and adult results suggest that cortical influence over BSC, although increasing with maturation, is limited to the volitional swallowing conditions of feeding in infants and during non-nutritive but volitional swallows in adults. From this, it can be deduced that the most likely cortical sites involved in BSC are those involved in the voluntary initiation or planning of swallowing. Infant and adult swallowing apnoea duration (SAD) was also compared across all of the above conditions. SAD was influenced by feeding throughout the first year of life but was not influenced by level of arousal at any stage in the first year or in adulthood. Also, SAD did not change with age in any swallowing condition during infancy. However, comparison of non-nutritive wake SAD across the lifespan revealed that SAD of newborns and young adults is shorter than that of elderly adults, with no difference between consecutive age-groups: newborns, one-year-olds, and young adults. These results suggest SAD is largely mature at birth and impervious to descending suprabulbar influence. Finally, the effects of volitional swallowing and level of arousal on peak submental surface electromyography (SEMG) was investigated in adults. Like BSC, submental muscle activity was influenced only by volitional swallowing, being longer for volitional than non-volitional swallows without being influenced by level of arousal. Since peak submental SEMG activity represents a measure of relative hyolaryngeal excursion, these results suggest that the cortex has some degree of influence over this particular feature of pharyngeal-stage swallowing.

Thesis (M.Eng.Sc.)--University of Adelaide, Dept. of Electrical Engineering, 1978.

Thesis (M.Com.)(Agricultural Economics)--University of Pretoria, 2004. / Includes summary. Includes bibliographical references (leaves 100-107).