Transforming floundering into success

We show how logic programs with "delays" can be transformed to programs without delays in a way which preserves information concerning floundering (also known as deadlock). This allows a declarative (model-theoretic), bottom-up or goal independent approach to be used for analysis and debugging of properties related to floundering. We rely on some previously introduced restrictions on delay primitives and a key observation which allows properties such as groundness to be analysed by approximating the (ground) success set. This paper is to appear in Theory and Practice of Logic Programming (TPLP). Keywords: Floundering, delays, coroutining, program analysis, abstract interpretation, program transformation, declarative debuggingComment: Number of pages: 24 Number of figures: 9 Number of tables: non

Logic Programming and the INTERNET

Editorial for Theory and Practice of Logic Programming's special issue on 'Logic Programming and the INTERNET'

An analysis of New South Wales electronic vote counting

We re-examine the 2012 local government elections in New South Wales, Australia. The count was conducted electronically using a randomised form of the Single Transferable Vote (STV). It was already well known that randomness does make a difference to outcomes in some seats. We describe how the process could be amended to include a demonstration that the randomness was chosen fairly. Second, and more significantly, we found an error in the official counting software, which caused a mistake in the count in the council of Griffith, where candidate Rina Mercuri narrowly missed out on a seat. We believe the software error incorrectly decreased Mercuri's winning probability to about 10%---according to our count she should have won with 91% probability. The NSW Electoral Commission (NSWEC) corrected their code when we pointed out the error, and made their own announcement. We have since investigated the 2016 local government election (held after correcting the error above) and found two new errors. We notified the NSWEC about these errors a few days after they posted the results

Perceiving time differences when you should not: applying the El Greco fallacy to hypnotic time distortions

The way we experience and estimate time – subjective time – does not systematically correspond to objective time (the physical duration of an event). Many factors can influence subjective time and lead to mental dilation or compression of objective time. The emotional valence of stimuli or the level of attention or expectancy are known to modulate subjective time although objective time is constant. Hypnosis too is known to alter people’s perception of time. However, it is not known whether hypnotic time distortions are intrinsic perceptual effects, based for example on the changing rate of an internal clock, or rather the result of a response to demand characteristics. Here we distinguished the theories using the logic of the El Greco fallacy. When participants initially had to compare the duration of two successive events —with the same duration — while in “trance”, they responded that the second event was on average longer than the first event. As both events were estimated in “trance”, if hypnosis impacted an internal clock, they should have been affected to the same extent. Conversely, when only the first event was in “trance”, there was no difference in perceived duration. The findings conform to an El Greco fallacy effect and challenge theories of hypnotic time distortion arguing that “trance” itself changes subjective time

Individually tailored client-focused reports for ubiquitous devices : an experimental analysis

We describe results of a test of a method for tailoring communications based on the recipient&rsquo;s preferred information processing style and dominant motivational attitude. Results indicate that the greater the match between the style of the report and the individual&rsquo;s attributes, the more informed the reader feels about the subject of the report. This research has been conducted as part of a study into methods to design patient-centred medical using diabetic patients as an exemplar of chronic disease. The long term aim is to use reports personalised to the recipient to better inform patients about their disease and strengthen their motivation to follow the treatment plan.<br /

Size-Change Termination, Monotonicity Constraints and Ranking Functions

Size-Change Termination (SCT) is a method of proving program termination based on the impossibility of infinite descent. To this end we may use a program abstraction in which transitions are described by monotonicity constraints over (abstract) variables. When only constraints of the form x>y' and x>=y' are allowed, we have size-change graphs. Both theory and practice are now more evolved in this restricted framework then in the general framework of monotonicity constraints. This paper shows that it is possible to extend and adapt some theory from the domain of size-change graphs to the general case, thus complementing previous work on monotonicity constraints. In particular, we present precise decision procedures for termination; and we provide a procedure to construct explicit global ranking functions from monotonicity constraints in singly-exponential time, which is better than what has been published so far even for size-change graphs.Comment: revised version of September 2

Cancellous bone and theropod dinosaur locomotion. Part I—an examination of cancellous bone architecture in the hindlimb bones of theropods

This paper is the first of a three-part series that investigates the architecture of cancellous (‘spongy’) bone in the main hindlimb bones of theropod dinosaurs, and uses cancellous bone architectural patterns to infer locomotor biomechanics in extinct non-avian species. Cancellous bone is widely known to be highly sensitive to its mechanical environment, and has previously been used to infer locomotor biomechanics in extinct tetrapod vertebrates, especially primates. Despite great promise, cancellous bone architecture has remained little utilized for investigating locomotion in many other extinct vertebrate groups, such as dinosaurs. Documentation and quantification of architectural patterns across a whole bone, and across multiple bones, can provide much information on cancellous bone architectural patterns and variation across species. Additionally, this also lends itself to analysis of the musculoskeletal biomechanical factors involved in a direct, mechanistic fashion. On this premise, computed tomographic and image analysis techniques were used to describe and analyse the three-dimensional architecture of cancellous bone in the main hindlimb bones of theropod dinosaurs for the first time. A comprehensive survey across many extant and extinct species is produced, identifying several patterns of similarity and contrast between groups. For instance, more stemward non-avian theropods (e.g. ceratosaurs and tyrannosaurids) exhibit cancellous bone architectures more comparable to that present in humans, whereas species more closely related to birds (e.g. paravians) exhibit architectural patterns bearing greater similarity to those of extant birds. Many of the observed patterns may be linked to particular aspects of locomotor biomechanics, such as the degree of hip or knee flexion during stance and gait. A further important observation is the abundance of markedly oblique trabeculae in the diaphyses of the femur and tibia of birds, which in large species produces spiralling patterns along the endosteal surface. Not only do these observations provide new insight into theropod anatomy and behaviour, they also provide the foundation for mechanistic testing of locomotor hypotheses via musculoskeletal biomechanical modelling

Reassessing the post-Last Glacial Maximum retreat history from the Southwest Ross Sea

Constraining the timing of the retreat of the Last Glacial Maximum (LGM) Antarctic Ice Sheet in the Ross Sea provides insights into the processes controlling marine-based ice sheet retreat. The over-deepened Ross Sea continental shelf is an ideal configuration for marine ice-sheet instability, and this region was thought to be one of the largest Antarctic contributors to post-LGM sea level rise. However, the chronology and pattern of retreat of the LGM ice sheet in the Ross Sea is largely constrained by coastal records along the Transantarctic Mountain front in the Western Ross Sea. Although these offer more reliable dating techniques than marine sediment cores, they may be influenced by local glaciers derived from East Antarctic outlet glaciers. Consequently, these coastal records may be ambiguous in the broader context of retreat in the central regions of the Ross Sea. However, previous studies have inferred that records in this region retreated in a north to south pattern, and was fed by ice sourced from the central Ross Sea – with the implication that broader ice sheet retreat in the central Ross Sea occurred as late as the mid Holocene. We present two lines of evidence that counter this established interpretation of the pattern of retreat in the Ross Sea: 1) a sedimentary facies succession and foraminifera-based radiocarbon chronology from within the Ross Sea embayment that indicates glacial retreat and open marine conditions to the east of Ross Island was already in place before 8.6 cal ka BP, at least 1 kyr earlier than indicated by terrestrial records in McMurdo Sound; and 2) a new multibeam swath bathymetry data that identifies well-preserved glacial features indicating thick (>700m) marine-based ice derived from the East Antarctic Ice Sheet (EAIS) coastal outlet glaciers dominated the ice sheet input into the southwestern Ross Sea during the last phases of glaciation – and thus may have acted independent of any ice in the central Ross Sea embayment. Comparing these data to new modelling experiments, we hypothesize that marine-based ice sheet retreat was triggered by oceanic forcings along most of the Pacific Ocean coastline of Antarctica, but continued early Holocene retreat into the inner shelf region of the Ross Sea occurred primarily as a consequence of marine ice sheet instability. Keywords: Ross Sea, deglaciation, Last Glacial Maximum, Holocen