18 research outputs found
Criminal networks and spatial density
The authors work in this area [2,6,7], in collaboration with West Midlands Police (WMP), is with the high volume crime of Burglary from Dwelling Houses (BDH). The presented work involves the brokerage metric from social network analysis combined with a geographical component (not present in other approaches) to add to the interpretation of the network and its key players. Our work builds upon several years of experimentation using forensic psychology guided exploratory techniques from artificial intelligence, statistics and spatial statistics
The criminal patterns of retail offending gangs: Some lessons from the integration of social network and geographical analyses
No abstract availabl
āPins in Mapsā: Visualisation of crime data, as a basis for a predictive model
No abstract availabl
The Cretaceous volcanic-plutonic province of the central Queensland (Australia) coastāa rift related ācalc-alkalineā province
Silicic and minor intermediate and mafic pyroclastics, lavas, and dykes occupy a NW-trending zone through the Whitsunday, Cumberland and Northumberland Island groups, and locally areas on the adjacent mainland, over a distance of more than 300 km along the central Queensland coast. K-Ar and Rb-Sr data indicate an age range of 95ā132 Ma, with the main activity approximately between 105ā120 Ma; there is, however, evidence for easterly increasing ages. Comagmatic granites, some clearly intrusive into the volcanics, occur together with two localised areas of Triassic potassic granites (229 Ma), that form the immediate basement. The volcanics are dominantly rhyolitic to dacitic lithic ignimbrites, with intercalated surge and bedded tuffs, accretionary lapilli tuffs, and lag deposits. Associated rock types include isolated rhyolitic and dacitic domes, and volumetrically minor andesite and rare basalt flows. The sequence is cut by abundant dykes, especially in the northern region and adjacent mainland, ranging from dolerite through andesite, dacite and rhyolite. Dyke orientations show maxima between NW-NNE. Isotope data, similarities in petrography and mineralogy, and alteration patterns all suggest dyke intrusion to be broadly contemporaneous with volcanism. The thickness of the volcanics is unconstrained, although in the Whitsunday area, minimum thicknesses of >1 km are inferred. Eruptive centres are believed to occur throughout the region, and include at least two areas of caldera-style collapse. The sequences are thus considered as predominantly intracaldera. The phenocryst mineralogy is similar to modern āorogenicā volcanics. Phases include plagioclase, augite, hypersthene (uralitised), magnetite, ilmenite, with less common hornblende, and even rarer quartz, sanidine, and biotite. Fe-enriched compositions only develop in some high-silica rhyolites. The granites range from quartz diorite to granite s.s., and some contain spectacular concentrations of partially disaggregated dioritic inclusions. Chemically, the suite ranges continuously from basalt to high-silica rhyolite, with calc-alkali to high-K affinities, and geochemical signatures similar to modern subduction-related magmas. Only the high-silica rhyolites and granites exhibit evidence of extensive fractional crystallisation (e.g. pronounced Eu anomalies). Variation within the suite can only satisfactorily be modelled in terms of two component mixing, with superimposed crystal fractionation. Nd and Sr isotope compositions are relatively coherent, with ĪµNd + 2Ā·2 to +7Ā·3, and ISr (calculated at 110 and 115 Ma) 0Ā·7031-0Ā·7044. These are relatively primitive, and imply mantle and/or newly accreted crustal magma sources. The two end-members proposed are within-plate tholeiitic melt, and ?low-silica rhyolitic melts generated by partial fusion of Permian (to ?Carboniferous) arc and arc basement. The arc-like geochemistry is thus considered to be source inherited. The tectonic setting for Cretaceous volcanism is correlated with updoming and basin rifting during the early stages of continental breakup, culminating in the opening of the Tasman Basin. Cretaceous volcanism is also recognised in the Maryborough Basin (S Queensland), the Lord Howe Rise, and New Caledonia, indicating the regional extent of volcanism associated with the complex breakup of the eastern Australasian continent margin
Matching and predicting crimes
Our central aim is the development of decision support systems based on appropriate technology for such purposes as profiling single and series of crimes or offenders, and matching and predicting crimes.
This paper presents research in this area for the high-volume crime of Burglary Dwelling House, with examples taken from the authorsā own work a United Kingdom police force.
Discussion and experimentation include exploratory techniques from spatial statistics and forensic psychology. The crime matching techniques used are case-based reasoning, logic programming and ontologies, and naĆÆve Bayes augmented with spatio-temporal features. The crime prediction techniques are survival analysis and Bayesian networks
An overview of the geochemical and isotopic characteristics of the eastern australian cainozoic volcanic provinces
A broad zone of intra-plate volcanism occurs for some 3000 km along eastern Australia. Mafic lavas dominate, and include the following types (with frequency % occurrence, based on 1757 analyses): Leucitites (21), melilitites, nephelinites, and analcimites (5-4), basanites (12-7), alkali basalts (7-0), ne- hawaiites and hawaiites (44-4), transitional basalts and Ol-tholeiites (17-4), and Q-tholeiites (11-0). These lavas are erupted through a wide variety of crustal-tectonic environments, from Proterozoic to Mesozoic. Marked differences in chemistry exist between the lavas erupted from central volcano provinces (in which most āevolvedā lava types occur) and lava-field provinces, the former exhibiting greater isotopic variability and evidence for more extensive crystal fractionation (AFC). More evolved lava types include mugearites, benmoreites, icelandites, peralkaline and non-peralkaline trachytes and phonolites, comendites, low-silica and high-silica rhyolites. Marked regional differences exist with respect to distribution of various lava types; northern Queensland and Tasmania, for example, apparently have very few strongly evolved lavas, the latter region also containing a disproportionately high percentage of nephelinites. Trace element geochemistry of the mafic lavas is very variable, but typically continental; the lavas are enriched in incompatible elements, but enrichment varies greatly, being extreme in the leucitites, melilitites, and nephelinites, and slight (relative to MORB) in certain Q-tholeiites. It is shown that the patterns of the more extreme incompatible element enrichments are consistent with recent work on extraction of small melt fractions. Nevertheless, marked source inhomogeneities are indicated by the data, believed to be lithospheric; arc-modified lithosphere is suggested as a source for at least some lava field tholeiites. It is clear, however, that the majority of lavas have been modified by some degree of low-medium pressure crystal fractionation processes (olivine Ā±augite Ā± plagioclase Ā± Fe-Ti oxides). The critical role of fractional crystallization is even more apparent in the chemistry of the intermediate and silicic lavas, which exhibit dual patterns of progressive and ultimately extreme element enrichment (e.g., Pb, Th) and depletion (e.g., Mg, V, Ni, Cr, Sr, Ba, Eu). These patterns are readily modelled by Rayleigh fractionation, but require elevated K values, appropriate to silicic magmas; continually varying Ks are also indicated by some data sets. The mafic lavas exhibit a wide, but continuous variation of isotopic compositions, there being marked regional differences, but with the leucitite exception, no particular compositional ranges characterize particular compositional types. Correlations are observed between Sr, Nd, and to a less extent Pb isotopic compositions with, for example, Bh/Th, Ba/Nb, and mg-ratios. Much of the observed geochemical-isotope data, excepting the most undersaturated lavas, can be modelled in terms of AFC processes, utilizing upper and lower crustal models. The isotopic data of the alkaline Tasmanian lavas are distinctive and are interpreted as asthenospheric; these compositions, and those of rare magnesian alkaline lavas from elsewhere in the region, suggest a mixed mantle source containing a component approaching the āSt. Helena-typeā. The leucitites have a marked DUPAL isotopic signature, and it is noted that these occur above an interpreted Proterozoic rift system, suggesting a lithospheric source. Isotopic and geochemical data for the trachytes and low-silica rhyolites are consistent with AFC processes, with variable assimilation, modelled in terms of upper crustal components. The high-silica rhyolites are isotopically distinctive, and are interpreted as local upper crustal melts, but modified by subsequent crystal-liquid fractionation
Criminal networks
Workshop on Data Mining, Information Extraction, and Evidentiary Reasoning for Law Enforcement and Counter-Terroris