Object tracking using SIFT features and mean shift

A scale invariant feature transform (SIFT) based mean shift algorithm is presented for object tracking in real scenarios. SIFT features are used to correspond the region of interests across frames. Meanwhile, mean shift is applied to conduct similarity search via color histograms. The probability distributions from these two measurements are evaluated in an expectation–maximization scheme so as to achieve maximum likelihood estimation of similar regions. This mutual support mechanism can lead to consistent tracking performance if one of the two measurements becomes unstable. Experimental work demonstrates that the proposed mean shift/SIFT strategy improves the tracking performance of the classical mean shift and SIFT tracking algorithms in complicated real scenarios.

Spectrally efficient cooperative diversity protocol for uplink wireless transmission

A spectrally efficient cooperative protocol for uplink wireless transmission in a centralised communication system is proposed, where each of the N users play the relaying and source roles simultaneously by using superposition (SP) modulation. The probability density function of the mutual information between SP-modulated transmitted and received signals of the cooperative uplink channels is derived. Using the high-signal-to-noise ratio (SNR) approximation of this density function, the outage probability formula of the system as well as its easily computable tight upper and lower bounds are obtained and these formulas are evaluated numerically. Numerical results show that the proposed strategy can achieve around 3 dB performance gain over comparable schemes. Furthermore, the multiplexing and diversity tradeoff formula is derived to illustrate the optimal performance of the proposed protocol, which also confirms that the SP relaying transmission does not cause any loss of data rate. Moreover, performance characterisation in terms of ergodic and outage capacities are studied and numerical results show that the proposed scheme can achieve significantly larger outage capacity than direct transmission, which is similar to other cooperative schemes. The superiority of the proposed strategy is demonstrated by the fact that it can maintain almost the same ergodic capacity as the direct transmission, whereas the ergodic capacity of other cooperative schemes would be much worse.

COMMUNICATION AND GREEK ENVIRONMENTAL ORGANISATIONS: MEANS OF COMMUNICATION AND INFLUENCING FACTORS

A basic operational objective of any environmental organisation is to raise awareness among the public on issues of environmental protection, through the dissemination of knowledge and experience to local communities, so that the conservation and ecologically sound management of natural resources can acquire a local dimension. This can be achieved either through interventions directed at the State, mainly in relation to its legislative function, or by encouraging citizens to change or improve their attitude regarding environmental matters. In order to ensure a successful outcome and the efficient functioning of any organisation, a feeling of mutual trust and understanding should exist between the latter and its various audiences, i.e. the State and society. A basic ingredient of this balance between the organisation, the broader public and the State is effective communication and activity planning. As a way of contributing to the exploration of this process, this paper describes the means of communication used by Greek environmental organisations, and presents, through a non-linear model, the differentiation amongst them, in conjunction with aspects of the profile of those running each organisation and other indicators, such as the years in operation and the membership figures in each sampled organisation. The paper concludes by arguing that the diversification of communication means is related to the head person's years as a member of the organisation and the extent of its total membership. Another important finding is that the more the involvement in activities within the organisation, the less differentiation we observe amongst the employed means of communication.

New peace, new teachers: student teachers’ perspectives on diversity and community relations in Northern Ireland

This paper reflects upon student teachers’ conceptions of inter-community relations and the preparation they receive to address issues of diversity and mutual understanding. The study in Northern Ireland is set against a backdrop of political, social and educational change, where a shared, peaceful future appears possible. Student teachers at a Catholic institution and a predominantly Protestant institution indicated a willingness to engage with issues concerning diversity and inter-community relations, despite having a limited knowledge of the concepts. However they also demonstrated clear views about the relevance and value of the preparation they received. The findings are evaluated using multicultural theory.

Imaging the future: theatre and change within the child protection system

The use of social pedagogy as a paradigm for critically appraising developments within child and family social work has been largely neglected. This paper outlines the work of Augusto Boal and his adoption of social pedagogy as a method for empowering oppres-sed social groups in Brazil. It is argued that Boal’s approach can be adapted by using action research techniques to analyse and effect change in situations where child care professionals face daily contradictions in their attempts to both protect children and support families. To demonstrate its relevance to child care practice, a description is provided of how the approach was used with two groups of social work students – one undertaking qualifying training, the other post-qualifying training. The results of this application suggest a new theoretical framework for practice which aims to establish communicative consensus around the needs of children and a mutual appreciation of roles and responsibilities.

Effects of Constraint Errors on Parallel Manipulators with Decoupled Motion

From perspective of structure synthesis, certain special geometric constraints, such as joint axes intersecting at one point or perpendicular to each other, are necessary in realizing the end-effector motion of kinematically decoupled parallel manipulators (PMs) along individual motion axes. These requirements are difficult to achieve in the actual system due to assembly errors and manufacturing tolerances. Those errors that violate the geometric constraint requirements are termed “constraint errors”. The constraint errors usually are more troublesome than other manipulator errors because the decoupled motion characteristics of the manipulator may no longer exist and the decoupled kinematic models will be rendered useless due to these constraint errors. Therefore, identification and prevention of these constraint errors in initial design and manufacturing stage are of great significance. In this article, three basic types of constraint errors are identified, and an approach to evaluate the effects of constraint errors on decoupling characteristics of PMs is proposed. This approach is illustrated by a 6-DOF PM with decoupled translation and rotation. The results show that the proposed evaluation method is effective to guide design and assembly.

Teachers’ understandings of reconciliation and inclusion in four troubled societies.

In this article, the authors examine how teachers in four troubled societies – Israel, Cyprus, Northern Ireland and South Africa – understand and implement reconciliation in light of the increasing diversity of these societies. The authors particularly pay attention to a dialogical encounter between reconciliation and inclusion, as they look for ways to contemplate how each might be of mutual benefit in educational theory and practice. In the first part of the article, the authors give an overview of current thinking on reconciliation and its role in education, and suggest that the notion of inclusiveness can enrich it. The context of the research is then provided by looking briefly at the socio-political and educational settings in which the study was conducted, followed by a discussion of the research methodology. The findings from the study are then presented with the main themes identified as arising across the four research locations. These themes concern understandings of reconciliation and inclusion, student diversity, teachers’ challenges, helping students deal with conflict, and teachers’ development. Finally, whilst acknowledging the exploratory nature of these findings, the authors discuss what policy makers, school leaders and teachers might change about policies and practices for reconciliation education in the four settings studied and, by implication, other comparable settings.

An acanthocephalan parasite mediates intraguild predation between invasive and native freshwater amphipods (Crustacea)

1. The balance of predation between closely related invasive and native species can be an important determinant of the success or failure of biological invasions. In Irish freshwaters, the introduced amphipod Gammarus pulex has replaced the native G. duebeni celticus, possibly through differential mutual intraguild predation (IGP). Theoretically, parasitism could mediate such predation and hence the invasion outcome. However, this idea remains poorly studied.

Assessment of fighting ability in animal contests

Selection should favour accurate information gathering regarding the likely costs and benefits of continued conflict. Here we consider how variation in the abilities of contestants to assess resource-holding potential (RHP) influences fights. This has been examined in various game theory models. However, discriminating between assessment strategies has proven difficult and has resulted in confusion. To add clarity, we group existing models into three main types that differ in the information about RHP that contestants are presumed to gather: (1) pure self-assessment, (2) cumulative assessment and (3) mutual assessment. Within this framework we outline methods advocated to discriminate successfully between the three main assessment models. We discuss support for each model, before highlighting a number of conflicting and inconclusive studies, leading us to consider alternative approaches to investigate assessment. Furthermore, we examine support for newly emerging concepts such as 'varying degrees of assessment', 'switching assessment' strategies and the possibility of contestants adopting different assessment strategies within a fight involving distinctive roles. We suggest future studies will benefit by judicious use of a battery of techniques to determine how animals settle contests. Finally, we highlight difficulties with current game theory models, and raise concerns regarding the use of certain behavioural criteria to accept or reject a model, particularly since this may conflict with evidence for a given assessment strategy. Furthermore, the failure of existing models to account for newly emerging concepts points to limitations of their use and leads us to challenge game theoreticians to develop upon them. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Information gathering and decision making about resource value in animal contests

Contestants are predicted to adjust the cost of a fight in line with the perceived value of the resource and this provides a way of determining whether the resource has been assessed. An assessment of resource value is predicted to alter an animal's motivational state and we note different methods of measuring that state. We provide a categorical framework in which the degree of resource assessment may be evaluated and also note limitations of various approaches. We place studies in six categories: (1) cases of no assessment, (2) cases of internal state such as hunger influencing apparent value, (3) cases of the contestants differing in assessment ability, (4) cases of mutual and equal assessment of value, (5) cases where opponents differ in resource value and (6) cases of particularly complex assessment abilities that involve a comparison of the value of two resources. We examine the extent to which these studies support game theory predictions and suggest future areas of research. (C) 2008 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Large body size for winning and large swords for winning quickly in swordtail males, Xiphophorus helleri

Contestants can either assess their own resource-holding potential relative to their opponent (mutual assessment) or rely solely on the assessment of their own fighting ability (self-assessment). To discriminate between these possibilities, we staged dyadic territorial contests between 'size-matched' male swordtails. These contests consist of a combination of ritualized displays and direct fighting. Although size differences were small, winners were larger than losers and smaller fish tended to be winners only when the size difference was negligible. Body size, however, did not influence contest duration and there was no increase in contest duration with mean body size; thus, there is no support for self-assessment in these animals. We also examined the effects of the sword, which comprises a sexually selected extension used in female choice that reduces swimming efficiency but increases acceleration. The length of the sword (adjusted for body size) did not differ between winners and losers; however, losers conceded earlier if the opponent had a large sword for its body size but this decision was independent of the loser's own sword length. Losers thus assessed the swords of winners, which precludes self-assessment; however, because winners appeared not to assess the swords of losers, this does not fully support the idea of mutual assessment. (c) 2008 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Interactions between invasive and native crustaceans: differential functional responses of intraguild predators towards juvenile hetero-specifics

Intraguild predation (IGP) between invasive and native species can lead to species exclusions or co-existence, dependent on the direction and strength of the interaction. Recently, derivation of 'functional responses' has been identified as a means of comparing the community impacts of invasive and native species. Here, we employ a novel use of this functional response methodology to evaluate any IGP asymmetries between the invasive Ponto-Caspian amphipod Echinogammarus ischnus and the North American native Gammarus fasciatus. The direction and magnitude of intraguild predation of adult males on hetero-specific adult females has previously been shown to reverse across a water conductivity gradient. This partially explains field patterns, but does not predict the co-existence of the two species observed in many habitats and locations. Here, we compared intraguild predation by both species on each other's juveniles in high- and low- conductivity water. G. fasciatus has a higher type II functional response towards E. ischnus juveniles compared to the reciprocal interaction. Conductivity did not influence the predation rate on juveniles of either E. ischnus or G. fasciatus. Thus, the male/female IGP advantage to the native G. fasciatus in low conductivity water is compounded by a juvenile IGP asymmetry, which also counteracts the male/female IGP advantage to E. ischnus in high conductivity waters, helping to explain field patterns of exclusion and co-existence. Thus, complex asymmetries in mutual IGP associated with inherent species differences, environmental modulation, and life-history effects can help us understand and predict the population and community level outcomes of species invasions.

Ionic liquid S-alkylthiouronium salts

The prepn. and characterization of a series of ionic liqs. based on S-alkylthiouronium cations prepd. from thiourea, 1,3-dimethylthiourea, 1,3-diethylthiourea and 1,3-tetramethylthiourea coupled with bis{(trifluoromethane)sulfonyl}imide, bromide, methylsulfate or ethylsulfate anions are reported. All are liqs. at room temp. or solids with m.ps. close to room temp., except for the bromide salts, which have m.ps. below 92 °C. Systematic variation in the N- and S-alkyl substituents demonstrates how the phys. properties of these ionic liqs. can be readily controlled. The mutual miscibility limits of representative examples with octane, dodecane and toluene have been detd. as a function of temp., and the extn. of dibenzothiophene from dodecane as a model for desulfurisation of diesel has been investigated.

Integrating Human Rights? Socio-Economic Rights and Budget Analysis

This article explores an opportunity for mutual learning between the fields of human rights law and economic analysis. Specifically it considers how economic techniques might be used to appraise public expenditure in line with international obligations arising from the International Covenant on Economic, Social and Cultural Rights 1966 (ICESCR). Our argument is that such tools do have the potential to contribute to this aim, but that embedding them within government budget processes through “human rights mainstreaming” may prove problematic in practice. We therefore suggest, as part of a broader strategy which includes judicial enforcement, that mainstreaming initiatives and budget analysis can be useful as complementary tools for the full realisation of all human rights.

Interfacial tensions of imidazolium-based ionic liquids with water and n-alkanes

The interfacial tension of the liquid-liquid phase boundary of several 1,3-dialkyl imidazolium based ionic liquids, namely, 1,3-dimethylimidazolium bis{(trifluoromethyl)sulfonyl}imide [C(1)mim][NTf2], 1-ethyl-3-methylimidazoliurn bis{(trifluoromethyl)sulfonyl}imide [C(2)mim][NTf2], 1-butyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide [C(4)mim][NTf2], 1-hexyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide [C(6)mim][NTf2], 1-octyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide [C(8)mim][NTf2], 1-butyl-3-methylimidazolium trifluoromethylsulfonate [C(4)mim][CF3SO3], and 1-butyl-3-methylimidazolium trifluoroacetate [C(4)mim][CF3COO] with water and with the n-alkanes, n-hexane, n-octane and n-decane, has been measured using the pendant drop method as a function of temperature from 293 to 323 K. The experimental interfacial tension data were correlated using the ionic liquid parachor estimation method and a mutual solubility model. The influence of the cation and anion of ionic liquids and also of alkyl chain length of n-alkanes on interfacial tension is discussed. It has also been demonstrated that the interfacial tension data estimated by the correlation methods are in good agreement with the experimental data. (C) 2010 Elsevier B.V. All rights reserved.