1,663 research outputs found
Experimental radio frequency link for Ka-band communications applications
An experimental radio frequency link has been demonstrated to provide two-way communication between a remote user ground terminal and a ground-based Ka-band transponder. Bit-error-rate performance and radio frequency characteristics of the communication link were investigated
Symmetry groupoids and patterns of synchrony in coupled cell networks
A coupled cell system is a network of dynamical systems, or âcells,â coupled together. Such systems
can be represented schematically by a directed graph whose nodes correspond to cells and whose
edges represent couplings. A symmetry of a coupled cell system is a permutation of the cells that
preserves all internal dynamics and all couplings. Symmetry can lead to patterns of synchronized
cells, rotating waves, multirhythms, and synchronized chaos. We ask whether symmetry is the only
mechanism that can create such states in a coupled cell system and show that it is not.
The key idea is to replace the symmetry group by the symmetry groupoid, which encodes information
about the input sets of cells. (The input set of a cell consists of that cell and all cells
connected to that cell.) The admissible vector fields for a given graphâthe dynamical systems with
the corresponding internal dynamics and couplingsâare precisely those that are equivariant under
the symmetry groupoid. A pattern of synchrony is ârobustâ if it arises for all admissible vector
fields. The first main result shows that robust patterns of synchrony (invariance of âpolydiagonalâ
subspaces under all admissible vector fields) are equivalent to the combinatorial condition that an
equivalence relation on cells is âbalanced.â The second main result shows that admissible vector
fields restricted to polydiagonal subspaces are themselves admissible vector fields for a new coupled
cell network, the âquotient network.â The existence of quotient networks has surprising implications
for synchronous dynamics in coupled cell systems
Investigating the Effectiveness of Strategic Environmental Assessment in Thailand
Strategic environmental assessment (SEA) was introduced in Thailand in 2005, aiming to direct decision making at the strategic level (policy, programme, plan) towards sustainable development (SD). Given reforms to the SEA requirements in 2018, it is timely to evaluate emerging SEA experience in the Thai context to inform future practice. The effectiveness of 14 SEAs was investigated based on a version of a recently published framework which substitutes âlegitimacyâ for normative effectiveness and pluralism, modified through the addition of disaggregated sub-criteria associated with each dimension of effectiveness (procedural, substantive, transactive and legitimacy), to facilitate a richer understanding of the effectiveness of practice. This more detailed effectiveness framework enabled a comprehensive evaluation of practice, and should be transferable to other contexts. The findings suggest that SEA in Thailand currently partially achieves procedural, substantive, and transactive effectiveness. Achieving some elements of substantive effectiveness where practice is currently weak is considered to be particularly challenging, and also determinative in the achievement of legitimacy. Consequently, the majority of SEAs evaluated in this study failed to achieve legitimacy
New Zealand Agribusiness Success: An Approach to exploring the role of strategy, structure and conduct on firm performance
This paper presents a framework to explore agribusiness success in New Zealand. The framework provides the basis for historical analysis. It draws on existing theory based on the structure-conduct-performance paradigm but expanded to take account of firm strategy and the analysis of value chains.Agribusiness, structure, conduct, performance, history, Agribusiness,
High-resolution x-ray diffraction study of the heavy-fermion compound YbBiPt
YbBiPt is a heavy-fermion compound possessing significant short-range
antiferromagnetic correlations below a temperature of K,
fragile antiferromagnetic order below K, a Kondo temperature
of K, and crystalline-electric-field splitting on the
order of K. Whereas the compound has a
face-centered-cubic lattice at ambient temperature, certain experimental data,
particularly those from studies aimed at determining its
crystalline-electric-field scheme, suggest that the lattice distorts at lower
temperature. Here, we present results from high-resolution, high-energy x-ray
diffraction experiments which show that, within our experimental resolution of
\AA, no structural phase transition
occurs between and K. In combination with results from dilatometry
measurements, we further show that the compound's thermal expansion has a
minimum at K and a region of negative thermal expansion for
K. Despite diffraction patterns taken at K which indicate that
the lattice is face-centered cubic and that the Yb resides on a
crystallographic site with cubic point symmetry, we demonstrate that the linear
thermal expansion may be modeled using crystalline-electric-field level schemes
appropriate for Yb residing on a site with either cubic or less than
cubic point symmetry.Comment: 7 pages, 3 figures, submitted to Phys. Rev.
Mating tactics of male feral goats ( Capra hircus ): risks and benefits
Intense competition between males for reproduction has led to the evolution of alternative mating tactics (AMTs). Feral goat males usually use a tactic called tending, in which they defend oestrous females from other males. Males may also use a second mating tactic called coursing, in which they gain access to oestrous females by disturbing a tending pair. Herein, we examine estimated mating success (EMS) and risks of using these tactics. Tending was only used by mature (â„4 years old), higher-ranking males and accounted for 75% of EMS. Coursing was used by males of all ages and dominance ranks, and accounted for 25% of EMS. Using coursing, male kids achieved 8% of EMS. Mature males achieved 92% of EMS. Both age and dominance rank were related to EMS, but age was not important after its relationship with dominance was controlled. Tending bouts were, on average, ca. 30min long, while coursing bouts only averaged ca. 2min. Males were more likely to suffer a butt while coursing than while tending, and formerly tending males were responsible for most butts. Kids that coursed had the highest risk of being butted. In most AMTs, there are reductions in the risks in relation to low fitness benefits. However, we found that the risks of butts during coursing were high, while our evidence suggests that the EMS was probably low. Nevertheless, the existence of an effective AMT in male feral goats may have an important influence on the intensity of sexual selection and the effective population siz
Remote viewing of concealed target pictures under light and dark conditions
Context The belief that performing a nonlocal task in darkness plays a facilitating role in remote viewing and other psi-related phenomena is well established in esoteric and traditional beliefs (Grim, 1983; Hallowell, 1942; Lyon, 2012). However, the role of darkness in RV success is unclear beyond these esoteric explanations. Objective This study explored the differential effect of darkness/light on remote viewing ability alongside the effect of time and their potential interaction. Design From an initial sample of twenty, seven remote viewers contributed a total of nineteen sessions each (nine light/ ten dark) which utilised randomized target selection, free-response descriptions, and ratings by both participants and an independent judge. Results The usable data gave the edge to dark condition performance; the difference was not statistically significant. A statistically significant difference between remote viewer and independent judge raw scores attributed to the target image was identified (t (132) = 4.56, p <.001 (two-tailed) Mdiff = 14.21 [8.05, 20.4]) with a medium effect size (d = .40 [.21, .57]). Exploratory post-hoc analyses concerning the numinosity of target images were conducted, to determine if this characteristic was associated with success. For numinosity ratings of target images, a mean difference of 11.24, 95% CI [.12, 22.3] was shown as significant, with the target images of participant âhitâ sessions containing higher numinosity ratings than unsuccessful âmissâ sessions (t (11.47) = 2.22, p (two-tailed) = .048) with a large effect size (d = 1.02, [.01, 1.99]). Conclusion The findings may have implications for the use of participant judgements in future remote viewing research. Furthermore, because there are several advantages to what parapsychologists refer to as âfree responseâ targets as opposed to âforced choiceâ targets (Honorton, 1975), the findings for target numinosity may have implications for the future selection of target material
Exploring the relationship between context and effectiveness in impact assessment
Impact Assessment (IA) has been adopted worldwide typically to ensure the achievement of its goal(s), which might be one or more of sustainable development, environmental policy integration, and democratic governance. Researchers have developed and applied effectiveness frameworks in order to evaluate whether IA achieves its goal(s). The application of these frameworks often identifies some areas of ineffectiveness, and the frameworks are rarely transferable to other cases either within or across different jurisdictions, which makes national and international comparisons problematic. Context is frequently cited as a reason why ineffectiveness is identified in a case, and yet context is not clearly understood in relation to effectiveness. Our aim in this paper is to unpack the notion of context in order to better understand how IA can achieve its goal(s). Based on literature review and a subsequent conceptualisation of context drawing, for the first time, on Integral Theory, we propose that the notion of context can be understood as a range of mediators, which act either as enablers or barriers to the ability of IA to deliver its goal(s). It is these mediators which lead to very different IA system performance in terms of goals achievement, despite applying similar procedural steps. Our conceptualisation provides a significant contribution as it clarifies the validity of claims about contextual elements in the literature, explains the nature of different elements of context, provides a framework with which they can be meaningfully considered and makes an initial attempt at identifying strategies for ensuring mediators act as enablers rather than barriers. It also potentially serves to help unify literature on the meaning of context for IA effectiveness, effectiveness dimensions, and causation in IA, thus providing clarity over the challenges of goals achievement and the appropriateness of capacity development interventions
'Be candid where we can' : the rational dissent of Joseph Priestley
This essay locates the origins of the religious and political radicalism of Joseph Priestley in his early abandonment of Calvinism: having deprived himself of a powerful, subjective system of explanation, he sought a view of the world that could be justified by entirely objective criteria. He was assisted in this project by the
psychological theory of associationism - which purports to provide an empirical explanation of mental activity - and by the concept of candour: which in the eighteenth century embodied not only frankness
but also a certain generosity of spirit and a willingness to engage in unacrimonious debate.
In the central chapters of this essay, four aspects of his work are examined: his activity as an historian (and to some extent as a scientist, an historian of nature), his theology and preaching, his philosophical writings and his political theory, in each of these areas, his work is marked by concern for objectivity and devotion to
associationism. He saw history as a providential mechanism in which
mental associations played an essential role and he looked to history to provide empirical, objective justification for Christian belief. He found, however, that there were some Christian dogmas - notably
that of Christ's divinity - which could not be so justified, and he abandoned them. He thus came to oppose (even more strongly than
orthodox dissenters) the religious foundations of the British state; he advocated instead a candid free market in ideas (by means of which Godâs providence could operate unhindered).
The final chapter describes how this project came to grief, having written an historical account of the growth of those Christian
doctrines to which he was opposed, Priestley hoped that he could engage in candid conversation with his critics. But he underestimated the alarm which his opinions provoked, especially in the years after the
fall of the Bastille: the debate grew heated, he was publically vilified and, at last, forced into exile
The Impact of Institutional Ownership on Corporate Operating Performance
This paper examines the relationship between institutional investor involvement in and the operating performance of large firms. We confirm a significant relationship between a firmâs operating cash flow returns and both the percent of institutional stock ownership and the number of institutional stockholders. However, the positive relationship between the number of institution al investors holding stock and operating cash flow returns is found only for pressure-insensitive institutional investors (those with no business relationship with the firm). The number of pressure-sensitive institutional investors (those with an existing or potential business relationship with the firm) has no impact on performance. These results suggest that institutional investors that need to protect actual or promote potential business relationships with firms in which they invest are compromised as monitors of the firm, and lend credence to calls for greater independence of board members from firms
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