Showing papers by "Queensland University of Technology published in 2002"

The Beta Reputation System

Abstract: Reputation systems can be used to foster good behaviour and to encourage adherence to contracts in e-commerce. Several reputation systems have been deployed in practical applications or proposed in the literature. This paper describes a new system called the beta reputation system which is based on using beta probability density functions to combine feedback and derive reputation ratings. The advantage of the beta reputation system is flexibility and simplicity as well as its foundation on the theory of statistics.

YAWL: yet another workflow language

Abstract: Based on a rigorous analysis of existing workflow management systems and workflow languages, a new workflow language is proposed: yet another workflow language (YAWL). To identify the differences between the various languages, we have collected a fairly complete set of workflow patterns. Based on these patterns we have evaluated several workflow products and detected considerable differences in their ability to capture control flows for non-trivial workflow processes. Languages based on Petri nets perform better when it comes to state-based workflow patterns. However, some patterns (e.g. involving multiple instances, complex synchronisations or non-local withdrawals) are not easy to map onto (high-level) Petri nets. This inspired us to develop a new language by taking Petri nets as a starting point and adding mechanisms to allow for a more direct and intuitive support of the workflow patterns identified. This paper motivates the need for such a language, specifies the semantics of the language, and shows that soundness can be verified in a compositional way. Although YAWL is intended as a complete workflow language, the focus of this paper is limited to the control-flow perspective.

Use of the scored Patient-Generated Subjective Global Assessment (PG-SGA) as a nutrition assessment tool in patients with cancer.

Abstract: Objective: To evaluate the use of the scored Patient-Generated Subjective Global Assessment (PG-SGA) as a nutrition assessment tool in patients with cancer. Design: An observational study assessing the nutritional status of patients with cancer. Setting: Oncology ward of a private tertiary Australian hospital. Subjects: Seventy-one cancer patients aged 18–92 y. Intervention: Scored PG-SGA questionnaire, comparison of scored PG-SGA with subjective global assessment (SGA), sensitivity, specificity. Results: Some 24% (17) of 71 patients were well nourished, 59% (42) of patients were moderately or suspected of being malnourished and 17% (12) of patients were severely malnourished according to subjective global assessment (SGA). The PG-SGA score had a sensitivity of 98% and a specificity of 82% at predicting SGA classification. There was a significant difference in the median PG-SGA scores for each of the SGA classifications (P<0.001), with the severely malnourished patients having the highest scores. Re-admission within 30 days of discharge was significantly different between SGA groups (P=0.037). The mortality rate within 30 days of discharge was not significantly different between SGA groups (P=0.305). The median length of stay of well nourished patients (SGA A) was significantly lower than that of the malnourished (SGA B+C) patients (P=0.024). Conclusion: The scored PG-SGA is an easy to use nutrition assessment tool that allows quick identification and prioritisation of malnutrition in hospitalised patients with cancer. Sponsors: The Wesley Research Institute.

Collaborative Climate and Effectiveness of Knowledge Work - an Empirical Study

Abstract: Suggests that collaborative climate is one of the major factors influencing effectiveness of knowledge work. Discusses the concept of collaborative climate and develops a survey instrument to measure it. Presents results based on data from 8,277 respondents in a wide variety of public and private sector organisations. Collaborative climate tends to improve with age, education level and managerial role. It is generally better in private firms, and seems to peak with mid‐size firm level. Employees tend to experience a U‐formed appreciation of the collaborative climate. Theories proposing that people reach a “professional plateau” (an S‐formed curve) have been supported to some degree. Finally, collaborative climate in the private sector is generally better than in the public sector. Uses the data to identify gaps and potentials for improving effectiveness. Further investigates two cases of good and bad practice and identifies strengths and weaknesses.

Infrared and Raman study of interlayer anions CO32–, NO3–, SO42– and ClO4– in Mg/Al-hydrotalcite

Abstract: The difference in the local environment of CO32−, NO3−, SO42−, and ClO4− in Mg/Al-hydrotalcite compared to the free anions was studied by infrared and Raman spectroscopy. In comparison to free CO32− a shift toward lower wavenumbers was observed. A band around 3000–3200 cm−1 has been attributed to the bridging mode H2O-CO32−. The IR spectrum of CO3− hydrotalcite clearly shows the split ν3 band around 1365 and 1400 cm−1 together with weak ν2 and ν4 modes around 870 and 667 cm−1. The ν1 mode is activated and observed as a weak band around 1012 cm−1. The Raman spectrum shows a strong ν1 band at 1053 cm−1 plus weak ν3 and ν4 modes around 1403 and 695 cm−1. The symmetry of the carbonate anions is lowered from D 3 h to C 2 s resulting in activation of the IR inactive ν1 mode around 1050–1060 cm−1. In addition, the ν3 shows a splitting of 30–60 cm−1. Although NO3-hydrotalcite has incorporated some CO32− the IR shows a strong ν3 mode at 1360 cm−1 with a weak band at 827 cm−1, and the ν4 band is observed at 667 cm−1, although it is largely obscured by the hydrotalcite lattice modes. The Raman spectrum shows a strong ν1 mode at 1044 cm−1 with a weaker ν4 band at 712 cm−1. The ν3 mode at 1355 cm−1 is obscured by a broad band due to the presence of CO32−. The symmetry of NO3− did not change when incorporated in hydrotalcite. The IR spectrum of SO4-hydrotalcite shows a strong ν3 at 1126, ν4 at 614 and a weak ν1 mode at 981 cm−1. The Raman spectrum is characterized by a strong ν1 mode at 982 cm−1 plus medium ν2 and ν4 bands at 453 and 611 cm−1; ν3 cannot be identified as a separate band, although a broad band can be seen around 1134 cm−1. The site symmetry of SO42− is lowered from T d to C 2 v . The distortion of ClO4− in the interlayer of hydrotalcite is reflected in the IR spectrum with both ν3 and ν4 bands split around 1096 and 1145 cm−1 and 626 and 635 cm−1, respectively. A weak ν1 band is observed at 935 cm−1. The Raman spectrum shows a strong ν1 mode at 936 cm−1 plus ν2 and ν4 bands at 461 and 626 cm−1, respectively. A ν3 mode cannot be clearly recognized, but a broad band is visible around 1110 cm−1. These data indicative a lowering of symmetry from T d to C s .

Declarative composition and peer-to-peer provisioning of dynamic Web services

Abstract: The development of new services through the integration of existing ones has gained a considerable momentum as a means to create and streamline business-to-business collaborations. Unfortunately, as Web services are often autonomous and heterogeneous entities, connecting and coordinating them in order to build integrated services is a delicate and time-consuming task. In this paper, we describe the design and implementation of a system through which existing Web services can be declaratively composed, and the resulting composite services can be executed following a peer-to-peer paradigm, within a dynamic environment. This system provides tools for specifying composite services through. statecharts, data conversion rules, and provider selection, policies. These specifications are then translated into XML documents that can be interpreted by peer-to-peer inter-connected software components, in order to provision the composite service without requiring a central authority.

What's in a Service?

Abstract: A proper understanding of the general nature, potential and obligations of electronic services may be achieved by examining existing commercial services in detail. The everyday services that surround us, and the ways in which we engage with them, are the result of social and economic interaction that has taken place over a long period of time. If we attempt to provide electronic services, and do not take this history into account, then we will fail. Any attempt to provide automated electronic services that ignores this history will deny consumers the opportunity to negotiate and refine, over a large range of issues, the specific details of the actual service to be provided. To succeed, we require a rich and accurate means of representing services. An essential ingredient of service representation is capturing the non-functional properties of services. These include the methods of charging and payment, the channels by which the service is requested and provided, constraints on temporal and spatial availability, service quality, security, trust and the rights attached to a service. Not only are comprehensive descriptions essential for useful service discovery, they are also integral to service management, enabling service negotiation, composition, and substitution. This paper builds on an understanding of services and their interactions, to outline the non-functional properties of services and their uses.

Compensation of distribution system voltage using DVR

Abstract: A dynamic voltage restorer (DVR) is a power-electronic controller that can protect sensitive loads from disturbances in the supply system. In this paper, it is demonstrated that this device can tightly regulate the voltage at the load terminal against imbalance or harmonic in the source side. The behavior of the device is studied through steady-state analysis, and limits to achievable performance are found. This analysis is extended to the study of transient operation where the generation of the reference voltage of the DVR is discussed. Once the reference signals are generated, they are tracked using a switching band scheme. A suitable structure in which the DVR is realized by voltage-source inverters (VSIs) is also discussed. Particular emphasis to the rating of this device is provided. Extensive simulation results are included to illustrate the operating principles of a DVR.

Socioeconomic differences in food purchasing behaviour and suggested implications for diet-related health promotion.

Abstract: BACKGROUND: The relationship between socioeconomic position (SEP) and diet has been examined mainly on the basis of food and nutrient intake. As a complement to this work, we focused on the socioeconomic patterning of food purchasing, as many educational dietary messages emphasize behaviours such as food choice when shopping. Also, the type of food people buy influences the quality of their nutrient intake. METHODS: A probability sample of households in Brisbane City, Australia (n = 1003, 66.4% response rate). Data were collected using face-to-face interviews. SEP was measured using education, occupation and household income. Food purchasing was examined on the basis of grocery items (including meat and chicken) and fruit and vegetables. RESULTS: Significant associations were found between each socioeconomic indicator and food purchasing. Persons from socioeconomically disadvantaged backgrounds were less likely to purchase grocery foods that were comparatively high in fibre and low in fat, salt and sugar. The least educated, those employed in blue-collar (manual) occupations and residents of low income households purchased fewer types of fruit and vegetables, and less regularly, than their higher status counterparts. CONCLUSIONS: Health promotion efforts aimed at narrowing socioeconomic differences in food purchasing need to be designed and implemented with an understanding of, and a sensitivity to, the barriers to nutritional improvement that difficult life circumstances can impose.

An exploration of sense of community, Part 3: Dimensions and predictors of psychological sense of community in geographical communities

Abstract: Within the discipline of community psychology there remains considerable debate as to the latent structure of psychological sense of community (PSOC). One of the few theoretical discussions is that of McMillan and Chavis (1986), who hypothesized four dimensions: Belonging; Fulfillment of Needs; Influence; and Shared Connections. Discussion has also emerged in the literature regarding the role of identification within PSOC. However few studies have empirically investigated the role of identification in PSOC. The current study explored PSOC in a sample of residents of rural, regional and urban geographical communities (N = 669). In an endeavor to clarify the underlying dimensions of PSOC, a test battery included several measures of PSOC as well as measures of identification with the community. The study also examined the role of demographic factors in predicting PSOC. Results provided support for McMillan and Chavis' (1986) four dimensions of PSOC. Further, a fifth dimension emerged, that of Conscious Identification, suggesting that identification is separate to existing dimensions of PSOC. The demographic factors significantly associated with PSOC were type of region, with rural participants displaying higher PSOC than their urban counterparts; participation in local organizations; having children; and a vision of one’s neighborhood as broader than just a street or block. These results, and the implications for PSOC research, are discussed.

A basic study of some normoxic polymer gel dosimeters

Abstract: Polymer gel dosimeters offer a wide range of potential applications in the three-dimensional verification of complex dose distribution such as in intensity-modulated radiotherapy (IMRT). Until now, however, polymer gel dosimeters have not been widely used in the clinic. One of the reasons is that they are difficult to manufacture. As the polymerization in polymer gels is inhibited by oxygen, all free oxygen has to be removed from the gels. For several years this was achieved by bubbling nitrogen through the gel solutions and by filling the phantoms in a glove box that is perfused with nitrogen. Recently another gel formulation was proposed in which oxygen is bound in a metallo-organic complex thus removing the problem of oxygen inhibition. The proposed gel consists of methacrylic acid, gelatin, ascorbic acid, hydroquinone and copper(II)sulphate and is given the acronym MAGIC gel dosimeter. These gels are fabricated under normal atmospheric conditions and are therefore called 'normoxic' gel dosimeters. In this study, a chemical analysis on the MAGIC gel was performed. The composition of the gel was varied and its radiation response was evaluated. The role of different chemicals and the reaction kinetics are discussed. It was found that ascorbic acid alone was able to bind the oxygen and can thus be used as an anti-oxidant in a polymer gel dosimeter. It was also found that the anti-oxidants N-acetyl-cysteine and tetrakis(hydroxymethyl)phosphonium were effective in scavenging the oxygen. However, the rate of oxygen scavenging is dependent on the anti-oxidant and its concentration with tetrakis(hydroxymethyl)phosphonium being the most reactive anti-oxidants. Potentiometric oxygen measurements in solution provide an easy way to get a first impression on the rate of oxygen scavenging. It is shown that cupper(II)sulphate operates as a catalyst in the oxidation of ascorbic acid. We, therefore, propose some new normoxic gel formulations that have a less complicated chemical formulation than the MAGIC gel.

Socio-economic differences in fruit and vegetable consumption among Australian adolescents and adults

Abstract: Objectives: To determine whether socio-economic groups differ in their fruit and vegetable consumption, and the variety eaten, and whether socio-economic differences are similar for adolescents and adults. The study also examined whether socio-economic groups vary in their reported desire to increase the amount of fruit and vegetables consumed, and the perceived barriers to achieving this. Design, setting and subjects: The 1995 Australian National Nutrition Survey collected fruit and vegetable intake data from adolescents aged 13–17 years (n = 654) and adults 18–64 years (n = 7695) using a 24-hour dietary recall. Gross annual household income was used to measure socio-economic position. Results: Approximately 44% of males and 34% of females did not consume fruit in the 24 hours preceding the survey, and 20% of males and 17% of females did not consume vegetables. Among adolescents and adults, fruit and vegetable consumption was positively related to income. The only exception was vegetable consumption among adolescent males, which did not vary by income Lower-income adults consumed a smaller variety of fruits and vegetables than their higher-income counterparts. Fruit and vegetable variety did not vary by income among adolescents. Lower-income adults expressed less desire to increase their fruit and vegetable consumption, and were more likely to report that price and storage were barriers to doing so. Socio-economic differences in consumption and variety were more apparent for adults than for adolescents. Conclusions: In addition to increasing the consumption of fruits and vegetables among the general population, nutrition interventions, programmes and policy aiming to improve diet should target adolescents and adults from low socio-economic groups. Strategies should address price and storage barriers.

Critical thinking in nursing education: literature review.

Abstract: The need for critical thinking in nursing has been accentuated in response to the rapidly changing health-care environment. Nurses must think critically to provide effective care while coping with the expansion in role associated with the complexities of current health-care systems. This literature review will present a history of inquiry into critical thinking and research to support the conclusion that critical thinking is necessary not only in the clinical practice setting, but also as an integral component of nursing-education programmes to promote the development of nurses' critical-thinking abilities. The aims of this paper are to: (i) review the literature on critical thinking; (ii) examine the dimensions of critical thinking; (iii) investigate the various critical thinking strategies for their appropriateness to enhance critical thinking in nurses; and (iv) examine issues relating to the evaluation of critical-thinking skills in nursing.

Age and Visual Impairment Decrease Driving Performance as Measured on a Closed-Road Circuit

Abstract: In this study the effects of visual impairment and age on driving were investigated and related to visual function. Participants were 139 licensed drivers (young, middle-aged, and older participants with normal vision, and older participants with ocular disease). Driving performance was assessed during the daytime on a closed-road driving circuit. Visual performance was assessed using a vision testing battery. Age and visual impairment had a significant detrimental effect on recognition tasks (detection and recognition of signs and hazards), time to complete driving tasks (overall course time, reversing, and maneuvering), maneuvering ability, divided attention, and an overall driving performance index. All vision measures were significantly affected by group membership. A combination of motion sensitivity, useful field of view (UFOV), Pelli-Robson letter contrast sensitivity, and dynamic acuity could predict 50% of the variance in overall driving scores. These results indicate that older drivers with either normal vision or visual impairment had poorer driving performance compared with younger or middle-aged drivers with normal vision. The inclusion of tests such as motion sensitivity and the UFOV significantly improve the predictive power of vision tests for driving performance. Although such measures may not be practical for widespread screening, their application in selected cases should be considered.

Thermal decomposition of bauxite minerals: infrared emission spectroscopy of gibbsite, boehmite and diaspore

Abstract: Infrared emission spectroscopy has been used to study the dehydroxylation behavior over the temperature range from 200 to 750°C of three major Al-minerals in bauxite: gibbsite (synthetic and natural), boehmite (synthetic and natural) and diaspore. A good agreement is found with the thermal analysis and differential thermal analysis curves of these minerals. Loss in intensity of especially the hydroxyl-stretching modes of gibbsite, boehmite and diaspore as function of temperature correspond well with the observed changes in the TGA/DTA patterns. The DTA pattern of gibbsite clearly indicates the formation of boehmite as an intermediate shown by a endotherm around 500°C. Dehydroxylation of gibbsite is followed by a loss of intensity of the 3620 and 3351 cm−1 OH-stretching bands and the corresponding deformation band around 1024 cm−1. Dehydroxylation starts around 220°C and is complete around 350°C. Similar observations were made for boehmite and diaspore. For boehmite dehydroxylation was observed to commence around 250°C and could be followed by especially the loss in intensity of the bands around 3319 and 3129 cm−1. The DTA pattern of diaspore is more complex with overlapping endotherms around 622 and 650°C. The dehydroxylation can be followed by the decrease in intensity of the OH-stretching bands around 3667, 3215 and 2972 cm−1. Above 550°C only a single band is observed that disappears after heating above 600°C corresponding to the two endotherms around 622 and 650°C in the DTA.

The biomechanics of adiposity--structural and functional limitations of obesity and implications for movement.

Abstract: Obesity is a significant health problem and the incidence of the condition is increasing at an alarming rate worldwide. Despite significant advances in the knowledge and understanding of the multifactorial nature of the condition, many questions regarding the specific consequences of the disease remain unanswered. For example, there is a dearth of information pertaining to the structural and functional limitations imposed by overweight and obesity. A limited number of studies to date have considered plantar pressures under the feet of obese vs. non-obese, the influence of foot structure on performance, gait characteristics of obese children and adults, and relationships between obesity and osteoarthritis. A better appreciation of the implications of increased levels of body weight and/or body fat on movement capabilities of the obese would provide an enhanced opportunity to offer more meaningful support in the prevention, treatment and management of the condition.

Safety Climate and Safety Behaviour

Abstract: This paper provides an overview of a research program examining the antecedents and consequences of safety climate and safety behaviour. A model is presented identifying the linkages between safety climate, safety knowledge, safety motivation, and safety behaviour. Findings from a series of studies are reviewed that support the hypothesized linkages between safety climate and safety behaviour. Longitudinal analyses have examined the role of additional factors, such as general organisational climate, supportive leadership and conscientiousness as sources of stability and change in safety climate and safety behaviour. Further developments of the model, aimed at integrating safety behaviour into broader models of work effectiveness, are also discussed.

Multidimensional Properties of the Lot-R: Effects of Optimism and Pessimism on Career and Well-Being Related Variables in Adolescents:

Abstract: The Life Orientation Test–Revised (LOT-R), measures of career maturity, career decision-making, career goals, and well-being were administered to 504 high school students. Exploratory and confirmatory factor analyses demonstrated bi-dimensionality rather than uni-dimensionality for the LOT-R, with the two factors of optimism and pessimism being largely unrelated. Those with high optimism reported high levels of career planning and exploration, were more confident about their career decisions, and had more career related goals. Those with high pessimism reported low levels of career and decision-making knowledge, were more career indecisive, and reported low levels of school achievement. For well-being, those with high levels of optimism reported high levels of self-esteem and low levels of psychological distress, whereas those with high levels of pessimism reported low levels of self-esteem and more psychological distress.

Critical thinking in nursing education: literature review

Abstract: The need for critical thinking in nursing has been accentuated in response to the rapidly changing health care environment. Nurses must think critically to provide effective care whilst coping with the expansion in role associated with the complexities of current health care systems. This literature review will present a history of inquiry into critical thinking and research to support the conclusion that critical thinking is necessary not only in the clinical practice setting, but also as an integral component of nursing education programs to promote the development of nurses’ critical thinking abilities. The aims of this paper are: (a) to review the literature on critical thinking; (b) to examine the dimensions of critical thinking; (c) to investigate the various critical thinking strategies for their appropriateness to enhance critical thinking in nurses, and; (d) to examine issues relating to evaluation of critical thinking skills in nursing.

“It's OK if we say it, but you can't”: responses to intergroup and intragroup criticism

Abstract: Three experiments were conducted examining group members' responses to criticism from ingroup and outgroup members. In Experiment I a, Australians read scripts of a person making either negative or positive comments about Australia. The speaker was identified as coming from either Australia (ingroup member) or another country (outgroup member). Responses indicated an intergroup sensitivity effect; that is, while ingroup criticisms were tolerated surprisingly well, outgroup criticisms were met with sensitivity and defensiveness. This pattern was replicated using the identity of,university student' (Experiment 1b). Experiment 2 demonstrated that the intergroup sensitivity effect is driven by perceptions that ingroup criticisms are seen to be more legitimate and more constructive than are outgroup criticisms. The results are discussed in terms of their implications for intragroup and intergroup relations. Copyright (C) 2002 John Wiley Sons, Ltd.

Socioeconomic Position Across the Lifecourse and Cognitive Function in Late Middle Age

Abstract: Objectives To examine the influence of childhood and adult socioeconomic position, socioeconomic mobility, and cumulative disadvantage across the lifecourse on cognitive function in late middle age. Methods Cross-sectional population-based study of 486 men age 58 and 64 from eastern Finland. Respondent's socioeconomic position in childhood was measured using parent's education and occupation, and respondent's position in adulthood was indicated by attained education and personal income. Cognitive function was assessed using five neuropsychological tests: Trail Making, Selective Reminding, Verbal Fluency, Visual Reproduction, and the Mini-Mental State Exam. Results Each indicator of socioeconomic position made statistically independent contributions to levels of cognitive function: Respondents from poor childhood backgrounds, and those who attained a limited education and earned a low income, performed worst on each test. Men who occupied a disadvantaged socioeconomic position in childhood and then experienced upward mobility over the lifecourse exhibited better cognitive performance than those with similar socioeconomic origins but limited or no upward mobility. Conversely, men from advantaged childhood backgrounds who later in life experienced downward mobility scored poorer on each cognitive test than their counterparts who remained in the most advantaged groups throughout the lifecourse. There was a strong, graded association between cumulative socioeconomic disadvantage and cognitive function: Men who occupied a low socioeconomic position during both childhood and adulthood scored worse on every test than those who occupied a high position at all points in their lives. Discussion Socioeconomic conditions across all stages of the lifecourse appear to make unique contributions to cognitive function in late middle age. These results also suggest that in terms of cognitive function, origin is not necessarily destiny, as disadvantaged socioeconomic circumstances in childhood may be overcome to some extent by upward mobility later in life.

Expression and Action of the Growth Hormone Releasing Peptide Ghrelin and its Receptor in Prostate Cancer Cell Lines

Abstract: This study has examined the expression of two new facets of the growth hormone axis, the growth hormone secretagogue receptor (GHS-R) and its recently identified putative natural ligand ghrelin, in prostate cancer cells. GHS-R 1a and 1b isoforms and ghrelin mRNA expression were detected by RT-PCR in the ALVA-41, LNCaP, DU145 and PC3 prostate cancer cell lines. A normal prostate cDNA library expressed GHS-R1a, but not the 1b isoform or ghrelin. Immunohistochemical staining for the GHS-R 1a isoform and ghrelin was positive in the four cell lines studied. PC3 cells showed increased cell proliferation in vitro in response to ghrelin to levels 33% above untreated controls, implying a potential tumour-promoting role for ghrelin in this tissue. This study is the first to demonstrate the co-expression of the GHS-R and ghrelin in prostate cancer cells. It is also the first study to provide evidence that a previously unrecognised autocrine/paracrine pathway involving ghrelin, that is capable of stimulating growth, exists in prostate cancer.

Sense of community in science fiction fandom, Part 1: Understanding sense of community in an international community of interest

Abstract: Within the discipline of community psychology there is debate as to the dimensions underlying the construct psychological sense of community (PSOC). One of the few theoretical discussions is that of McMillan and Chavis (1986), who hypothesized four dimensions: Belonging; Fulfillment of Needs; Influence; and Shared Connections. Discussion has also emerged in the literature regarding the role of identification within PSOC. It has been suggested that differences in PSOC may be understood in terms of the degree to which members identify with their community (Fisher & Sonn, 1999). However, few studies have explored the place of identification in PSOC. In addition, while PSOC has been applied to both communities of interest and geographical communities, little research has looked in depth at PSOC within communities of interest. The current study therefore explored PSOC in science fiction fandom, a community of interest with membership from all over the world, by means of a questionnaire distributed at an international science fiction convention (N = 359). In an endeavor to clarify the underlying dimensions of PSOC, the questionnaire included several measures of PSOC, and measures of identification with the community. Results showed that science fiction fandom reported high levels of PSOC. Support emerged for McMillan and Chavis' (1986) four dimensions of PSOC, with the addition of a fifth dimension, that of Conscious Identification. These results, and implications for PSOC research, are discussed.

Exploratory Study of Hong Kong Teacher Education Students' Epistemological Beliefs: Cultural Perspectives and Implications on Beliefs Research

Abstract: This paper reports a study of epistemological beliefs of Hong Kong teacher education students in which such four belief dimensions have been identified. The result is similar to that found by Schommer with North American university students in that the number of dimensions is the same but the nature of the dimensions is different. The paper hypothesizes that these differences can be accounted for in terms of differences in cultural context. In particular, the difference in dimensions concerned with authority–expert knowledge and effort and learning reported in this study might be explained by value differences between Western (North American) and non-Western (Hong Kong Chinese) culture. From a methodological perspective, the interview data also imply difficulties in measuring knowledge beliefs and one finding from the study is that in-depth interviews to complement quantitative data are necessary for trustworthy study of epistemological beliefs.

A new technique for instantaneous frequency rate estimation

Abstract: This letter introduces a two-dimensional bilinear mapping operator referred to as the cubic phase (CP) function. For first-, second-, or third-order polynomial phase signals, the energy of the CP function is concentrated along the frequency rate law of the signal. The function, thus, has an interpretation as a time-frequency rate representation. The peaks of the CP function yield unbiased estimates of the instantaneous (angular) frequency rate (IFR) and, hence, can be used as the basis for an IFR estimation algorithm. The letter defines an IFR estimation algorithm and theoretically analyzes it. The estimation is seen to be asymptotically optimal at the center of the data record for high signal-to-noise ratios. Simulations are provided to verify the theoretical claims.

A new technique for instantaneous frequency rate estimation

Abstract: This letter introduces a two-dimensional bilinear mapping operator referred to as the cubic phase (CP) function. For first-, second-, or third-order polynomial phase signals, the energy of the CP function is concentrated along the frequency rate law of the signal. The function, thus, has an interpretation as a time-frequency rate representation. The peaks of the CP function yield unbiased estimates of the instantaneous (angular) frequency rate (IFR) and, hence, can be used as the basis for an IFR estimation algorithm. The letter defines an IFR estimation algorithm and theoretically analyzes it. The estimation is seen to be asymptotically optimal at the center of the data record for high signal-to-noise ratios. Simulations are provided to verify the theoretical claims.

SELF-SERV: a platform for rapid composition of web services in a peer-to-peer environment

Abstract: The automation of Web services interoperation is gaining a considerable momentum as a paradigm for effective Business-to-Business collaboration [2]. Established enterprises are continuously discovering new opportunities to form alliances with other enterprises, by offering value-added integrated services. However, the technology to compose Web services in appropriate time-frames has not kept pace with the rapid growth and volatility of available opportunities. Indeed, the development of integrated Web services is often ad-hoc and requires a considerable eort of low level programming. This approach is inadequate given the size and the volatility of the Web. Furthermore, the number of services to be integrated may be large, so that approaches where the development of an integrated service requires the understanding of each of the underlying services are inappropriate. In addition, Web services may need to be composed as part of a short term partnership, and disbanded when the partnership is no longer profitable. Hence, the integration of a large number of Web services requires scalable and flexible techniques, such as those based on declarative languages. Also, the execution of an integrated service in existing approaches is usually centralised, whereas the underlying services are distributed and autonomous. This calls for the investigation of distributed execution paradigms (e.g., peer-to-peer models), that do not suffer of the scalability and availability problems of centralised coordination [3]. Motivated by these concerns, we have developed the SELF-SERV platform for rapid composition of Web services [1]. In SELF-SERV, Web services are declaratively composed, and the resulting composite services are executed in a peer-to-peer and dynamic environment. In this paper we overview the design and implementation of the SELF-SERV system.