Showing papers by "Macquarie University published in 1994"

Accelerated image reconstruction using ordered subsets of projection data

Abstract: The authors define ordered subset processing for standard algorithms (such as expectation maximization, EM) for image restoration from projections. Ordered subsets methods group projection data into an ordered sequence of subsets (or blocks). An iteration of ordered subsets EM is defined as a single pass through all the subsets, in each subset using the current estimate to initialize application of EM with that data subset. This approach is similar in concept to block-Kaczmarz methods introduced by Eggermont et al. (1981) for iterative reconstruction. Simultaneous iterative reconstruction (SIRT) and multiplicative algebraic reconstruction (MART) techniques are well known special cases. Ordered subsets EM (OS-EM) provides a restoration imposing a natural positivity condition and with close links to the EM algorithm. OS-EM is applicable in both single photon (SPECT) and positron emission tomography (PET). In simulation studies in SPECT, the OS-EM algorithm provides an order-of-magnitude acceleration over EM, with restoration quality maintained. >

Consumer Perception of Product Quality and the Country-of-Origin Effect1:

Abstract: Consumer attitudes to local and foreign products and the likely “country-of-origin” effect in “Buy Local” and “Made In …” campaigns are surveyed. First, the importance of country of origin in relat...

Reliability of the DSM-III-R Childhood Anxiety Disorders Using Structured Interview: Interrater and Parent-Child Agreement

Abstract: Objective The aim of the study was to examine the interrater and parent-child agreement for the major child anxiety disorders. Method One hundred sixty-one children and their parents underwent a semistructured interview (Anxiety Disorders Interview Schedule for Children). To increase external validity, clinicians did not receive specific, extensive training in diagnosing anxiety disorders apart from their standard qualifications. The design of the study allowed for calculation of agreement between raters based on information obtained from the parents alone, from the child alone, or through combined information from both the parents and child, and for calculation of agreement between information obtained from the parents and information obtained from the child. Results Levels of interrater agreement either as principal or additional diagnoses were moderate to strong for all of the major childhood anxiety disorders (K values .59 to .82). In contrast, parent-child agreement was poor for most diagnostic categories (K values .11 to .44). Conclusions The data indicate that, despite the fact that parents and their children do not demonstrate strong agreement, the DSM-III-R childhood anxiety disorders can be reliably diagnosed by pairs of general clinicians using structured interviews.

Adaptive signal processing algorithms: stability and performance

Abstract: PART I. 1. Introduction. 2. Offline Analysis. 3. Iterative Minimization. 4. Algorithm Construction. 5. Algorithm Analysis: Gaussian White Noise Setting. 6. Algorithm Analysis: Deterministic Global Theory. PART II. 7. Deterministic Averaging: Single Time Scale. 8. Deterministic Averaging: Mixed Time Scale. PART III. 9. Stochastic Averaging: Single Time Scale. 10. Stochastic Averaging: Mixed Time Scale. APPENDICES. A. Matrix Analysis Review. B. Stochastic Signals and Systems Review. C. Deterministic Signals and Systems Review. D. Mathematical Analysis Review. E. Probability Review. Bibliography. Index.

An open-systems approach to video on demand

Abstract: Open systems will enable video servers and set-tops to provide different services in a variety of environments Hewlett-Packard is interested in applying the principles of open systems to video on demand (VOD) In particular, the company is developing a technology base that will allow their servers and set-tops to operate in a variety of environments and enable the provision of a variety of services The impact that the different VOD system elements have on the video server and set-top are examined from a communications standpoint Opportunities for open or standard interfaces are identified and recommendations are made on what these should be where possible >

The Catalytic Hydrogenolysis of Esters to Alcohols

Abstract: The hydrogenolysis of esters to alcohols is a reaction between esters and hydrogen which selectively splits a C-0 bond adjacent to a carbonyl group (1). A well-known large-scale industrial process based on this reaction the production of fatty alcohols from natural fatty acid esters-has been operated commercially for more than 50 years. Several processes which include the hydrogenolysis of an ester have been proposed for the manufacture of basic chemicals such as methanol and ethanol. Furthermore, there has been continuous interest over the past two decades in replacing the existing, energy-intensive processes for the production of ethylene glycol and 1,4-butanedioI by more cost-effective routes involving ester hydrogenolysis. While particular aspects of the literature on hydrogenolysis of esters have been reviewed already [1–3], the objective of the present work is to give a more general summary with special emphasis on the present or possible industrial applications of ester hydrogenolysis.

Virtual Geography: Living with Global Media Events

Abstract: The paper is composed of speculations upon four scenes from weird global media events: August 23, 1990 Saddam Hussein and the hostages; November 12, 1989 East Berlin wall; May 20, 1989 Tienanmen Square; October 19, 1987 New York Stock Exchange crash.

Assessment instrument for panic disorder that includes fear of sensation‐producing activities: The albany panic and phobia questionnaire

Abstract: A set of items was developed to assess fear of activities which produce physical sensations (e.g., exercise) based on clinical observations that individuals with panic disorder fear such activities in addition to agoraphobic situations. Factor analysis of a 32-item pool based on responses from 438 subjects confirmed three distinct factors which were labelled: agoraphobia, social phobia, and in-teroceptive fears. Evidence was obtained to support the internal consistency, test-retest reliability, and construct validity of all three factors. Importantly, the interoceptive factor demonstrated a slightly different pattern of relationships with other constructs to the agoraphobic factor, even though the two were highly related. The present questionnaire will help to expand current assessments of panic disorder for both clinical work and research. Anxiety 1:114–122 (1994/1995). © 1995 Wiley-Liss, Inc.

The Influence of Culture on Organizational Design and Planning and Control in Australia and the United States Compared with Singapore and Hong Kong

Abstract: This study draws on the national cultural dimensions of power distance, individualism, and Confucian dynamism to predict and explain differences in philosophies for, and approaches to organizational design and management planning and control systems in Australia and the US, representing Anglo-American nations, and Singapore and Hong Kong, representing the ‘five dragons' of East Asia. Data were gathered by survey questionnaires mailed to senior accounting and finance executives in 800 organizations. The results were largely as predicted and, in general, provide support for the importance of national culture in influencing organizational design and management planning and control systems. In particular, the cultural values of Anglo-American society relative to East Asian society are associated with a greater emphasis on decentralization and responsibility centres in organizational design, and a greater emphasis on quantitative and analytical techniques in planning and control. By contrast, the cultural values of East Asian society are associated with a greater emphasis on long-term planning and on group centred decision-making. The results are important to managers in global organizations who need to understand the cultural bases of observed differences in organizational and management planning and control practices in Anglo-American and East Asian nations.

An Overview of Temporal and Modal Logic Programming

Abstract: This paper presents an overview of the development of the field of temporal and modal logic programming. We review temporal and modal logic programming languages under three headings: (1) languages based on interval logic, (2) languages based on temporal logic, and (3) languages based on (multi)modal logics. The overview includes most of the major results developed, and points out some of the similarities, and the differences, between languages and systems based on diverse temporal and modal logics. The paper concludes with a brief summary and discussion.

On the stability of slowly time-varying linear systems

Abstract: New conditions are given in both deterministic and stochastic settings for the stability of the system x=A(t)x when A(t) is slowly varying. Roughly speaking, the eigenvalues of A(t) are allowed to “wander” into the right half-plane as long as “on average” they are strictly in the left half-plane.

The selection and design of marine protected areas: Australia as a case study

Abstract: Recently there has been increased interest in the use of Marine Protected Areas (MPAs) as tools for the conservation of marine habitats and species. This has resulted in the declaration of many MPAs around the world. Despite this activity there have been few tests of hypotheses about the design criteria for selection and management of these areas, resulting in a haphazard and ad hoc selection of protected areas, with conflicting and inconsistent terminology and objectives. The application of appropriately tested scientific information to the design of MPAs will increase the likelihood of success in the future. To 1st January 1992, 267 MPAs had been declared in Australia, covering a total area of ca 400 019 km2. The history of their declaration has been sporadic and uneven. Conflicts over State and Federal legislation and, within states, conflicts over jurisdiction among agencies caused by overlapping responsibilities, have at times slowed the declaration of MPAs. In this paper, the history of MPAs in Australia is used as a case study to discuss the problems, both biological and administrative, of declaring MPAs.

Rapid screening of the antimicrobial activity of extracts and natural products

Abstract: A spectrophotometric method has been developed for the rapid measurement of the antimicrobial activity of natural products, including crude extracts or pure materials. The assay depends on the measurement of non-specific esterase activity using fluorescein diacetate (FDA) hydrolysis in broth cultures of microbes after they have been treated with test compounds. The assay is accurate, reproducible and economical in both time and materials. The speed and economy of the method make it suitable for the rapid screening of many samples and the bioassay directed purification of antimicrobial substances. The assay can also be used with a wide variety of micro-organisms since most micro-organisms are FDA positive. Applications are described in the fields of marine natural products chemistry and essential oils research.

Neoproterozoic-early Cambrian geology and palaeontology of Iberia

Abstract: Neoproterozoic-early Cambrian successions in Iberia are reexamined. A gradual transition across the Neoproterozoic-Cambrian boundary is present in Central Iberia, whereas in the Cantabrian region and the Iberian Chains Lower Cambrian arenaceous successions rest with profound angular unconformity on Neoproterozoic turbidites. In Central Iberia, the Neoproterozoic sedimentary succession is referred to the informal Domo Extremeno group, representing mostly basinal facies, and the overlying Rio Huso group consisting of slope deposits and proximal turbidites that grade into shallower marine deposits. The latter is inferred to represent distal slope to outer platform depositional conditions and contains widespread carbonate olistostromic units. The position of the Precambrian-Cambrian boundary is within the Pusa shale of the Rio Huso group and can be correlated at the regional level by the occurrence of trace fossils, acritarchs, and in particular the abundant shelly metazoan Cloudina. The succession also yielded megascopic carbonaceous fossils, such as vendotaenids and Beltanelioides? sp. ind., and Sabellidites. Contrary to former interpretations assuming transport of older platform carbonates from the Ibor region into ‘younger’ olistostromic beds of the Rio Huso group, we interpret sedimentary and fossil evidence to suggest that shallower platform deposits of the informal Ibor group were penecontemporaneously incorporated in the olistostromic lower part of the Rio Huso group. Hence, the olistostromes are not believed to mark a major erosive unconformity. Based on the ichnofossil record and recent U-Pb age determinations, we argue that a proposed disconformity between Lower and Upper ‘Alcudian’ strata is neither regional nor does it mark a significant hiatus. Neoproterozoic-early Cambrian deposition in Central Iberia can be accommodated in a model that implies a generalized stretching of the crust during an extensional event which closely followed the Cadomian phase of the Pan-African Orogeny and which eventually could have included transcurrent components. An extensional phase with transcurrent components during the deposition of the Ibor and lower Rio Huso groups is regarded as a probable cause of widespread ponding resulting in the juxtaposition of platform and basinal successions, eventually leading to anoxic conditions in Pusa shale deposition times. A possible cause for repeated collapse events developing olistostromes and intra-sequential folding could be sought in this tectonic context.

Application of flow cytometric methods for the routine detection of Cryptosporidium and Giardia in water

Abstract: Cryptosporidium and Giardia are common causes of waterborne disease. The currently used methods of detecting these organisms in water rely on filtration capture, immunofluorescence labelling, and epifluorescence microscopy. These methods are inefficient, labour intensive, and require a highly skilled microscopist. We describe an alternative technique using flocculation concentration, followed by flow cytometry with fluorescence activated cell sorting. Environmental samples were analysed, and protozoan-like particles were sorted and collected before confirmation with epifluorescence microscopy. The technique was found to be significantly more sensitive and considerably faster than the conventional methods. © 1994 Wiley-Liss, Inc.

A self-consistent model for the discharge kinetics in a high-repetition-rate copper-vapor laser

Abstract: A self-consistent computer model has been developed to simulate the discharge kinetics and lasing characteristics of a copper-vapor laser (CVL) for typical operating conditions. Using a detailed rate-equation analysis, the model calculates the spatio-temporal evolution of the population densities of 11 atomic and ionic copper levels, four neon levels, and includes 70 collisional and radiative processes, in addition to radial particle transport. The long-term evolution of the plasma is taken into account by integrating the set of coupled rate equations describing the discharge and electrical circuit through multiple excitation-afterglow cycles. A time-dependent two-electron group model, based on a bi-Maxwellian electron energy distribution function, has been used to evaluate the energy partitioning between the copper vapor and the neon-buffer gas. The behavior of the plasma in the cooler end regions of the discharge tube near the electrodes, where the plasma kinetics are dominated by the buffer gas, has also been modeled. Results from the model have been compared to experimental data for a narrow-bore (/spl phi/=1.8 cm) CVL operating under optimum conditions. Close agreement is obtained between the results from the model and experimental data when comparing electrical I-V characteristics of the discharge tube and circuit, and spatio-temporal evolution of the population densities of the laser levels and other excited Cu I and Ne I states, and lasing characteristics. During the period of lasing action, the populations of the laser levels are perturbed by 10-20 percent due to stimulated emission. >

Assessing Benefits to Both Participants in a Lycaenid-Ant Association

Abstract: We examined interactions between the ant Iridomyrmex nitidiceps and the lycaenid butterfly Paralucia aurifera in southeastern Australia, and present data supporting the hypothesis that both participants benefit from their association. In the field, lycaenids persisted only on those host plants that ants subsequently colonized. In the laboratory, lycaenid larvae reared with ants were 31-76% heavier, developed 37% faster, and commonly completed one or two fewer instars than larvae reared without ants. Ant tending also resulted in 20% heavier pupae, 69% shorter pupal duration, and 5% larger adults as mea- sured by forewing length; adults were not significantly different as measured by body length. We hypothesize that these positive effects occurred largely because ant-tended lycaenid larvae spent more time feeding than did untended larvae. Field data documented that ants colonized host plants only after lycaenid larvae were present, indicating that ants actively maintained the association. In laboratory experiments, 40% more ant workers survived when lycaenid larvae were present than when they were absent, although ant mass was not significantly affected. We hypothesize that the survivorship effects occurred because ants consumed the lycaenid's nectary gland secretions, which contained considerable amounts of glucose and amino acids. Our results show that lycaenids can benefit from ants in ways other than, or in addition to, protection from natural enemies and that they incur minimal developmental costs from associating with ants.

Assessing the Sensitivity of a Land-Surface Scheme to the Parameter Values Using a Single Column Model

Abstract: The sensitivity of a land-surface scheme (the Biosphere Atmosphere Transfer Scheme, BATS) to its parameter values was investigated using a single column model. Identifying which parameters were important in controlling the turbulent energy fluxes, temperature, soil moisture, and runoff was dependent upon many factors. In the simulation of a nonmoisture-stressed tropical forest, results were dependent on a combination of reservoir terms (soil depth, root distribution), flux efficiency terms (roughness length, stomatal resistance), and available energy (albedo). If moisture became limited, the reservoir terms increased in importance because the total fluxes predicted depended on moisture availability and not on the rate of transfer between the surface and the atmosphere. The sensitivity shown by BATS depended on which vegetation type was being simulated, which variable was used to determine sensitivity, the magnitude and sign of the parameter change, the climate regime (precipitation amount and fre...

IMHP: a mobile host protocol for the Internet

Abstract: This paper describes a protocol that allows transparent routing of IP packets to mobile hosts in the Internet, while using only the mobile host's home IP address. The protocol, called IMHP (Internet Mobile Host Protocol), requires no changes in stationary hosts that communicate with mobile hosts, and requires no changes in mobile hosts above the IP level. IMHP quickly converges to optimal routing following the movement of a mobile host, while preserving the current level of security in the Internet. Detailed examples of operation are presented.

Characterization of O-linked glycosylation motifs in the glycopeptide domain of bovine κ-casein

Abstract: kappa-Casein is the major glycoprotein in bovine milk. It has a proteinase-sensitive (chymosin) site which cleaves the glycoprotein into two segments: N-terminal para-kappa-casein domain and the C-terminal kappa-casein macroglycopeptide domain which is highly heterogeneous in oligosaccharide content. We have identified six sites of O-glycosylation on the macroglycopeptide by solid-phase Edman degradation: Thr121, Thr131, Thr133, Thr136 (A variant only), Thr142 and Thr165. No Ser residues are glycosylated. The glycosylation status of 15 of 17 potential O-glycosylation sites in the B variant was accurately predicted using the four peptide motifis previously proposed for the glycosylation of human glycophorin A (Pisano, A., Redmond, J.W., Williams, K.L. and Gooley, A.A., Glycobiology, 3, 429-435, 1993), provided one additional assumption is made concerning an inhibitory role for a nearby Ile.

Atomic soliton in a traveling wave laser beam.

Abstract: A vector quantum field theory is employed to study the propagation of an ultracold atomic wave packet in a traveling wave laser beam with a Gaussian intensity profile. The collective dipole-dipole correlation induced by photon exchanges between atoms produces a ``Kerr-type'' nonlinearity of atomic waves. We show that such an atomic nonlinearity could result in an atomic soliton under appropriate conditions.

When a ROWS is a ROSE: Phonological effects in written word comprehension

Abstract: When skilled readers make speeded categorization judgements about printed words, errors occur to homophones of real category exemplars. In Experiments 1 and 2, for example, subjects incorrectly accepted both the word STEAL (as a member of the category A METAL) and the nonword JEAP (as A VEHICLE) significantly more often than incorrect non-homophonic items matched in orthographic similarity to real exemplars. Experiment 3 demonstrated equivalent error rates for homophone targets differing from real exemplars by various types of single-letter change, but reduced error rates, especially for non-word homophones, when subjects were instructed to accept only correctly spelled instances. Experiments 4 and 5 established that the magnitude of the homophone effect is predicted by the degree of orthographic similarity between homophonic mates but not by spelling-sound regularity of the presented homophone. The results suggest that automatic phonological activation plays a major role in the comprehension of written w...

Facilitation of the N1 peak of the auditory ERP at short stimulus intervals.

Abstract: EVENT-RELATED potentials (ERP) were recorded to 1 kHz tones presented at random stimulus onset asynchronies (SOA) between 100 and 1000 ms. The Adjar correction procedure was employed to overcome waveform distortion resulting from previous response overlap. The results showed dramatic enhancements of

Roman Pompeii: Space and Society

Abstract: 1. Ancient and Modern Town Planning 2. Public Building and Urban Identity 3. Local Identity: Neighbours and Neighbourhoods 4. Production and Consumption 5. Deviant Behaviour 6. Street Activity and Public Interaction 7. The Production of Space 8. Property Ownership and Urban Land Value 9. The Temporal Logic of Space 10. Urbanism and the Production of Adults 11. Urbanism in Roman Italy