Convergence Settings Research Articles

Cybercriminal Networks, Social Ties and Online Forums: Social Ties Versus Digital Ties within Phishing and Malware Networks

Online forums serve as offender convergence settings for cybercriminals, but it is unknown whether all cybercriminal networks use forums. Important questions are how cybercriminals meet, how cybercriminal networks develop and what this means for the criminal capabilities of these networks. To gain insight into these questions, we analysed 18 criminal investigations into phishing and malware networks and developed four models of growth. Social ties still play an important role in the origin and growth of the majority of networks. Forums, however, also play a significant role in a number of networks, for example, to find suitable co-offenders or to get into contact with enablers. Criminals with access to forums are able to increase criminal capabilities of their network relatively quickly.

Early Paleozoic and Early Mesozoic intraplate tectonic and magmatic events in the Cathaysia Block, South China

The geodynamic framework of the South China Craton in the Early Paleozoic and Early Mesozoic has been modeled as developing through either oceanic convergence or intracontinental settings. On the basis of an integrated structural, geochemical, zircon U-Pb and Hf isotopic, and mica 40Ar/39Ar geochronologic study we establish that an intracontinental setting is currently the best fit for the available data. Our results suggest that widespread tectonomagmatic activity involving granite emplacement and mylonitic deformation occurred during two distinct stages: ~435–415 Ma and ~230–210 Ma. The coeval nature of emplacement of the plutons and their ductile deformation is corroborated by the subparallel orientation of the mylonitic foliation along the pluton margins, gneissose foliation in the middle part of pluton, the magmatic foliation within the plutons, and the schistosity in the surrounding metamorphosed country rocks. The 435–415 Ma granitoids exhibit peraluminous, high-K characteristics, and zircons show negative eHf(t) values (average −6.2, n = 66), and Paleoproterozoic two-stage model ages of circa 2.21–1.64 Ga (average 1.84 Ga). The data suggest that the Early Paleozoic plutons were derived from the partial melting of the Paleoproterozoic basement of the Cathaysia Block. The 230–210 Ma granites are potassic and have zircons with eHf(t) values of −2.8–−8.7 (average −5.4, n = 62), corresponding to TDM2 ages ranging from 2.0 to 1.44 Ga (average 1.64 Ga), suggesting that the Early Mesozoic partial melts in Cathaysia were also derived from basement. The geochemical distinction between the two phases of granites traces continental crustal evolution with time, with the Early Mesozoic crust enriched in potassium, silicon, and aluminum, but deficient in calcium, relative to the Paleozoic crust. Kinematical investigations provide evidence for an early-stage ductile deformation with a doubly vergent thrusting pattern dated at 433 ± 1 to 428 ± 1 Ma (40Ar/39Ar furnace step-heating pseudoplateau ages obtained on muscovite and biotite from mylonite and deformed granite) and a late-stage strike-slip movement with sinistral sense of ductile shearing at 232 ± 1 to 234 ± 1 Ma (40Ar/39Ar furnace step-heating pseudoplateau ages) along an E-W direction. The geological, geochemical, and isotopic signatures likely reflect far-field effects in response to continental assembly events at these times.

Subjective Evaluation of Focus Pulling for the S3D Video

In this paper, we have designed two experiments to investigate the visual comfort of focus pulling for S3D video with different shooting configurations. The variables mainly includes:1) convergence setting ;2) the distance between camera and subjects;3) pulling direction of focus. Evaluation results showed that different convergence settings would affect the visual comfort during focus pulling obviously. With the increasing of convergence distance, the subjects would appear from inside to outside of the screen, and the visual comfort value of focus shifting would decrease. Our research can provide data analysis for improving the visual comfort and shooting technology of S3D videos.

Anticipating industry convergence: semantic analyses vs IPC co-classification analyses of patents

Purpose – The convergence of industries exposes the involved firms to various challenges. In such a setting, a firm's response time becomes key to its future success. Hence, different approaches to anticipating convergence have been developed in the recent past. So far, especially IPC co-classification patent analyses have been successfully applied in different industry settings to anticipate convergence on a broader industry/technology level. Here, the aim is to develop a concept to anticipate convergence even in small samples, simultaneously providing more detailed information on its origin and direction. Design/methodology/approach – The authors assigned 326 US-patents on phytosterols to four different technological fields and measured the semantic similarity of the patents from the different technological fields. Finally, they compared these results to those of an IPC co-classification analysis of the same patent sample. Findings – An increasing semantic similarity of food and pharmaceutical patents and personal care and pharmaceutical patents over time could be regarded as an indicator of convergence. The IPC co-classification analyses proved to be unsuitable for finding evidence for convergence here. Originality/value – Semantic analyses provide the opportunity to analyze convergence processes in greater detail, even if only limited data are available. However, IPC co-classification analyses are still relevant in analyzing large amounts of data. The appropriateness of the semantic similarity approach requires verification, e.g. by applying it to other convergence settings.

Accelerated barrier optimization compressed sensing (ABOCS) reconstruction for cone-beam CT: phantom studies.

Recent advances in compressed sensing (CS) enable accurate CT image reconstruction from highly undersampled and noisy projection measurements, due to the sparsifiable feature of most CT images using total variation (TV). These novel reconstruction methods have demonstrated advantages in clinical applications where radiation dose reduction is critical, such as onboard cone-beam CT (CBCT) imaging in radiation therapy. The image reconstruction using CS is formulated as either a constrained problem to minimize the TV objective within a small and fixed data fidelity error, or an unconstrained problem to minimize the data fidelity error with TV regularization. However, the conventional solutions to the above two formulations are either computationally inefficient or involved with inconsistent regularization parameter tuning, which significantly limit the clinical use of CS-based iterative reconstruction. In this paper, we propose an optimization algorithm for CS reconstruction which overcomes the above two drawbacks. The data fidelity tolerance of CS reconstruction can be well estimated based on the measured data, as most of the projection errors are from Poisson noise after effective data correction for scatter and beam-hardening effects. We therefore adopt the TV optimization framework with a data fidelity constraint. To accelerate the convergence, we first convert such a constrained optimization using a logarithmic barrier method into a form similar to that of the conventional TV regularization based reconstruction but with an automatically adjusted penalty weight. The problem is then solved efficiently by gradient projection with an adaptive Barzilai-Borwein step-size selection scheme. The proposed algorithm is referred to as accelerated barrier optimization for CS (ABOCS), and evaluated using both digital and physical phantom studies. ABOCS directly estimates the data fidelity tolerance from the raw projection data. Therefore, as demonstrated in both digital Shepp-Logan and physical head phantom studies, consistent reconstruction performances are achieved using the same algorithm parameters on scans with different noise levels and∕or on different objects. On the contrary, the penalty weight in a TV regularization based method needs to be fine-tuned in a large range (up to seven times) to maintain the reconstructed image quality. The improvement of ABOCS on computational efficiency is demonstrated in the comparisons with adaptive-steepest-descent-projection-onto-convex-sets (ASD-POCS), an existing CS reconstruction algorithm also using constrained optimization. ASD-POCS alternatively minimizes the TV objective using adaptive steepest descent (ASD) and the data fidelity error using projection onto convex sets (POCS). For similar image qualities of the Shepp-Logan phantom, ABOCS requires less computation time than ASD-POCS in MATLAB by more than one order of magnitude. We propose ABOCS for CBCT reconstruction. As compared to other published CS-based algorithms, our method has attractive features of fast convergence and consistent parameter settings for different datasets. These advantages have been demonstrated on phantom studies.

TU-A-213CD-10: Accelerated Barrier Optimization Compressed Sensing (ABOCS) Reconstruction for Cone-Beam CT

Purpose: Compressed sensing (CS) enables accurate CTimage reconstruction from low‐dose measurements, due to the sparsifiable feature of most CTimages using total variation (TV). The CS‐based reconstruction is formulated as either a constrained problem to minimize the TV objective within a small and fixed data fidelity error, or an unconstrained problem to minimize the data fidelity error with TV regularization. However, the conventional solutions to the above two formulations are either computationally inefficient or involved with inconsistent regularization parameter tuning. In this work, we propose an optimization algorithm for cone‐beam CT(CBCT) CS reconstruction which overcomes the above two drawbacks. Methods: The data fidelity tolerance of CS reconstruction is well estimated using the measured data, as most of the projection errors are from Poissonnoise. We therefore adopt the TV optimization framework with data fidelity as constraints. To accelerate the convergence, we first convert such a constrained optimization using a logarithmic barrier method into a similar form to the conventional TV‐regularization reconstruction but with an automatically adjusted penalty weight. The problem is then solved efficiently by gradient projection. The proposed algorithm is referred to as Accelerated Log‐barrier Optimization for CS (ABOCS). Results: As demonstrated on Shepp‐Logan phantom, ABOCS achieves consistent reconstruction performances using the same parameters on scans with different datasets, while the TV‐regularization method needs a large‐scale tuning on the penalty weight. ABOCS also requires less computation time than ASD‐POCS in Matlab by >10 times. ABOCS is further accelerated on GPU to reconstruct a head patient volume of 512×512×200 voxels in <10 minutes using 25% projections, and the image quality is comparable to that of the full‐view FDK reconstruction.Conclusions: We propose ABOCS for CBCTreconstruction. As compared to other published CS‐based algorithms, our method has attractive features of fast convergence and consistent parameter settings for different datasets. NIH under the grant number 1R21EB012700‐01A1

Cybercrime and virtual offender convergence settings

Felson coined the term ‘offender convergence settings’ to describe certain physical locations, e.g. local tough bars, in which (potential) offenders meet each other. Here they relax with friends and acquaintances, meet new people, exchange information, sell stolen material or plan new criminal acts. The perpetrators of cybercrime also make use of such locations, albeit digitally in so-called virtual forums. From a law enforcement point of view, both types of settings should be suppressed. However, a physical location is easier closed down than a virtual one. This is because the virtual forum is often situated in countries that will not cooperate with requests to take down servers. This could be considered as an advantage for the offender. But virtual forums also have specific disadvantages. Every contact and discussion is digitally preserved for those who know where to look. A law enforcement agency was able to take such a look in one particular forum. This revealed over 150,000 postings by 1,846 members. More importantly, these postings disclosed crime scripts as criminals themselves see it. It turns out that hacking accounts and stealing money is not their biggest problem. What is a risk, however, is not leaving traces when wiring the money into other accounts. This article tries to translate such insights in policy recommendations.

Subduction geodynamics in Archean and formation of diamond-bearing lithospheric keels and early continental crust of cratons

The diamond-bearing mantle keels underlying Archean cratons are a unique phenomenon of Early Precambrian geology. The common stable assemblage of the Archean TTG early continental crust and underlying subcontinental lithospheric mantle clearly shows their coupled tectogenesis, which was not repeated in younger geological epochs. One of the least studied aspects of this phenomenon is concerned with the eclogitic xenoliths carried up by kimberlite pipes together with mantle-derived nodules. The eclogitic xenoliths reveal evidence for their subduction-related origin, but the Archean crustal counterparts of such xenoliths remained unknown for a long time, and the question of their crustal source and relationships to the formation of early continental crust remained open. The Archean crustal eclogites recently found in the Belomorian Belt of the Baltic Shield are compared in this paper with eclogitic xenoliths from kimberlites in the context of the formation of both Archean subcontinental lithospheric mantle (SCLM) and early continental crust. The crustal eclogites from the Belomorian Belt are identical in mineral and chemical compositions to the eclogite nodules (group B), including their diamond-bearing varieties. The eclogite protoliths are comparable in composition with the primary melts of the Meso- and Neoarchean oceanic crust, which was formed at a potential temperature of the upper mantle which exceeded its present-day temperature by 150–250 K. The reconstructed pathways of the Archean oceanic crust plunging in the upper mantle suggest that the Archean mantle was hotter than in the modern convergence settings. The proposed geodynamic model assumes coupled formation of the Archean diamond-bearing SCLM and growth of early continental crust as a phenomenon related to the specific geodynamics of that time controlled by a higher terrestrial heat flow.

Exhumation of deep orogenic crust

Exhumation of deeply buried material at plate convergence settings brings up fragments of oceanic crust and continental margin, and even larger segments of continental crust that equilibrated at high or ultrahigh pressure (mantle depths). Subduction channels are capable of cycling sizable crustal blocks from downward to upward trajectories, depending on the viscosity and buoyancy of material at the subduction interface and the geometric evolution of the channel. In collision zones, the exhumation of deeply buried continental crust also relies on the nature of the coupling between the subducted and overlying plates (if there is partial melting of subducted crust, hydration of mantle wedge, etc.), as well as the evolution of boundary conditions (e.g., switch to extension or transtension, break-off of mantle slab). Exhumation in mature collisional orogens is dominated by erosion of the thrust wedge at the front of the overthickened continental plateau. For the case of the Himalaya, debate exists on the nature and path of material that has fed the orogenic front and constructed the Greater Himalayan Sequence, particularly in the Miocene. The work by [Grujic et al. (2011)][1] adds significantly to this debate and documents mid-Miocene exhumation of rocks that were at the base of the south Tibetan crust in mid-Miocene time. Within only a few million years, these young eclogites were heated to granulite facies and rapidly exhumed along with their partially molten crustal host. This discovery offers new insight on the relative role of thrusting versus crustal flow in the construction of orogenic wedges; links mantle heat input, crustal melting, and crustal flow with the dynamics of the orogenic front; and provides renewed knowledge of lithospheric evolution in collisional orogens. [1]: #ref-25

Magnetic Facilities

Facilities that draw youth from different communities are prone to become offender convergence settings and intercity crime generators. Applying network analysis to self-nominated hangouts of 5,082 delinquent youth residing in Southern California revealed specific facilities acting as regional convergence settings. A small number of magnetic locations (measured by popularity and breadth of appeal) enable the congregation and interaction of youth that would otherwise not be exposed to each other. As predicted, the sociocirculatory structure of place networks remains relatively constant over time. In-degree and betweenness centrality statistics offer a viable analytic strategy to identify facilities operating as stable regional convergence locations. Crime prevention programs invoking effective place management through ordinances may offer a way to publicly govern these private facilities.

The Impact of Co-Offending

Co-offending (committing crime in the company of others) has a major impact on the arithmetic of crime rates and the burdens on the justice system. This paper studies co-offending by single year of age using data that comprise 750,000 negative police contacts (those charged, chargeable and suspected in criminal offenses) in a largely metropolitan dataset from British Columbia, Canada, 2002-06. We find that shifts in co-offending rates within teenage years are extremely rapid and highly sensitive to sample age ranges, such that a single co-offending rate for all teenagers is misleading. Co-offending opens a range of policy options and issues concerning the presence of youth hangouts and offender convergence settings that can assist the search for suitable co-offenders.

Structural control on late Miocene to Quaternary volcanism in the NE Honshu arc, Japan

Volcanological and structural field data are used to define the tectonic control on the N–S volcanic arc of NE Honshu (Japan) since late Miocene. During late Miocene‐Pliocene, bimodal products were mainly erupted from along‐arc and NE–SW‐aligned and elongated calderas. The deformation pattern mostly consisted of N–S dextral faults and subordinate NE–SW extensional structures produced by NE–SW compression. This pattern, because of the indentation of the Kuril sliver, is similar to that of oblique convergence settings. Magma rose and extruded along NE–SW areas of localized extension created by the dextral faults. These extensional areas were uncoupled with regard to those, ∼E–W trending, inferred to have focused the rise of melts from the subducting slab in the mantle. During Quaternary, a larger amount of andesite was mainly erupted from along‐arc and ∼E–W‐aligned and elongated stratovolcanoes. The deformation pattern mostly consisted of N–S thrust faults and subordinate ∼E–W extensional structures, produced by ∼E–W compression, resulting from orthogonal convergence due to the variation in the absolute motion of the Pacific Plate. The ∼E–W extensional structures are the shallowest expression of ∼E–W‐trending hot mantle fingers, suggesting mantle‐crust coupling for the rise of magma. Such a coupling ensures (1) higher extrusion and (2) mixing between a deeper mafic and a shallower felsic magma, generating the andesites. The significantly larger volumes (Ma−1 200 km−1 of length of the arc) of magma erupted during Quaternary show that pure convergence conditions do not necessarily hinder the rise and extrusion of magma.

Vertical Scaling With the Rasch Model Utilizing Default and Tight Convergence Settings With WINSTEPS and BILOG–MG

This study compared vertical scaling results for the Rasch model from BILOG–MG and WINSTEPS. The item and ability parameters for the simulated vocabulary tests were scaled across 11 grades; kindergarten through 10th. Data were based on real data and were simulated under normal and skewed distribution assumptions. WINSTEPS and BILOG–MG were each executed with default and tightened convergence settings. The results were compared in terms of differences and correlations between estimated item and ability parameters. Under default convergence settings, BILOG–MG appeared to capture the individual and mean estimates more accurately. However, once convergence settings were tightened, the programs generated similar results and reproduced the simulated parameter estimates more accurately than when default convergence settings were used.