Breaking the theft-chain-cycle: Property marking as a defensive tool

Any viable method of protecting property, dissuading the theft of property or ensuring the swift recovery of stolen property could be considered essential to general society. A number of crime preventive measures have been used in an attempt to achieve this objective. One such measure is property marking, employing various techniques to make property more readily identifiable. The study assesses technology to investigate effectiveness, both for dissuasion and for tracing once stolen. Mechanism for the disposal of stolen property forms an important part of this study, commencing with the mapping of the theft‐supply‐chain. Using a mixed methods approach, the research project has set out to identify if security technology could be used to break what is termed the ‘theft‐chain‐cycle’, whereby articles are stolen, stolen to order or for barter. The theft‐supply‐chain is not a single linear model; rather property passes through a number of formal and informal chains prior to reaching its “new” illegal owner. A significant factor is the ease of disposal linked to ease of detection using property marking to aid conviction. Based upon the findings, potential strategies and changes in legislation that better direct limited resources can be developed to assist in curbing the growing level of burglaries

Breaking the Theft-Chain-Cycle: Property Marking as a Defensive Tool

Any viable method of protecting property, dissuading the theft of property or ensuring the swift recovery of stolen property could be considered essential to general society. A number of crime preventive measures have been used in an attempt to achieve this objective. One such measure is property marking, employing various techniques to make property more readily identifiable. The study assesses technology to investigate effectiveness, both for dissuasion and for tracing once stolen. Mechanism for the disposal of stolen property forms an important part of this study, commencing with the mapping of the theft‐supply‐chain. Using a mixed methods approach, the research project has set out to identify if security technology could be used to break what is termed the ‘theft‐chain‐cycle’, whereby articles are stolen, stolen to order or for barter. The theft‐supply‐chain is not a single linear model; rather property passes through a number of formal and informal chains prior to reaching its “new” illegal owner. A significant factor is the ease of disposal linked to ease of detection using property marking to aid conviction. Based upon the findings, potential strategies and changes in legislation that better direct limited resources can be developed to assist in curbing the growing level of burglaries

Training and Generalization of Complex Auditory-Visual Conditional Discriminations in Individuals With Autism: New Procedures Using Dynamic Stimuli

Individuals with autism and other developmental disabilities often have difficulty learning auditory-visual conditional discriminations that are important for early communication and generalization may be restricted. Programs for teaching these individuals often involve the fading (gradual change) of stimuli in small steps across trials. Failure to establish desired discriminations occurs when the fading does not direct attention to the relevant critical aspects of the stimuli. The research described here illustrates new attention-shaping procedures for teaching complex auditory-visual discriminations and assessing generalization. The major purpose was to begin evaluation of the dual-modality transfer procedures with abstract stimulus sets that would rule out pre-experimental learning as an explanation of cross-modal (i.e., visual-to-auditory) transfer of stimulus control. In one procedure, auditory samples (pairs of same and different tones) were added to visual stimuli (pairs of same and different forms that participants matched already) presented as samples and comparisons. Across-trial contrast fading then gradually ‘vanished’ the visual samples, in order to establish conditional control of comparison selections by the pairs of same and different tones. Generalization then was assessed using new frequencies of the tones. Another procedure introduced a novel dynamic fading method. The visual cues that already controlled responding were erased actively within trials (like apparent movement) and cumulatively across trials. After fading, conditional control was demonstrated by the auditory samples only. Generalization was tested using tones with frequencies different from the training stimuli. Presented at the 38th Annual Convention of the Association for Behavior Analysis International

Reduction of blade-vortex interaction noise using higher harmonic pitch control

An acoustics test using an aeroelastically scaled rotor was conducted to examine the effectiveness of higher harmonic blade pitch control for the reduction of impulsive blade-vortex interaction (BVI) noise. A four-bladed, 110 in. diameter, articulated rotor model was tested in a heavy gas (Freon-12) medium in Langley's Transonic Dynamics Tunnel. Noise and vibration measurements were made for a range of matched flight conditions, where prescribed (open-loop) higher harmonic pitch was superimposed on the normal (baseline) collective and cyclic trim pitch. For the inflow-microphone noise measurements, advantage was taken of the reverberance in the hard walled tunnel by using a sound power determination approach. Initial findings from on-line data processing for three of the test microphones are reported for a 4/rev (4P) collective pitch control for a range of input amplitudes and phases. By comparing these results to corresponding baseline (no control) conditions, significant noise reductions (4 to 5 dB) were found for low-speed descent conditions, where helicopter BVI noise is most intense. For other rotor flight conditions, the overall noise was found to increase. All cases show increased vibration levels

Permeation of CO₂ and N₂ through glassy poly(dimethyl phenylene) oxide under steady- and presteady-state conditions

Glassy polymers are often used for gas separations because of their high selectivity. Although the dual‐mode permeation model correctly fits their sorption and permeation isotherms, its physical interpretation is disputed, and it does not describe permeation far from steady state, a condition expected when separations involve intermittent renewable energy sources. To develop a more comprehensive permeation model, we combine experiment, molecular dynamics, and multiscale reaction–diffusion modeling to characterize the time‐dependent permeation of N₂ and CO₂ through a glassy poly(dimethyl phenylene oxide) membrane, a model system. Simulations of experimental time‐dependent permeation data for both gases in the presteady‐state and steady‐state regimes show that both single‐ and dual‐mode reaction–diffusion models reproduce the experimental observations, and that sorbed gas concentrations lag the external pressure rise. The results point to environment‐sensitive diffusion coefficients as a vital characteristic of transport in glassy polymers

Inferring late-Holocene climate in the Ecuadorian Andes using a chironomid-based temperature inference model

Presented here is the first chironomid calibration data set for tropical South America. Surface sediments were collected from 59 lakes across Bolivia (15 lakes), Peru (32 lakes), and Ecuador (12 lakes) between 2004 and 2013 over an altitudinal gradient from 150 m above sea level (a.s.l) to 4655 m a.s.l, between 0–17◦ S and 64–78◦ W. The study sites cover a mean annual temperature (MAT) gradient of 25 ◦ C. In total, 55 chironomid taxa were identified in the 59 calibration data set lakes. When used as a single explanatory variable, MAT explains 12.9% of the variance (λ1/λ2 =1.431). Two inference models were developed using weighted averaging (WA) and Bayesian methods. The best performing model using conventional statistical methods was a WA (inverse) model (R2jack= 0.890; RMSEPjack= 2.404 ◦C, RMSEP – root mean jack squared error of prediction; mean biasjack = −0.017 ◦C; max biasjack = 4.665 ◦C). The Bayesian method produced a model with R2jack = 0.909, RMSEPjack = 2.373 ◦C, mean jack biasjack = 0.598 ◦C, and max biasjack = 3.158 ◦C. Both models were used to infer past temperatures from a ca. 3000-year record from the tropical Andes of Ecuador, Laguna Pindo. Inferred temperatures fluctuated around modern-day conditions but showed significant departures at certain intervals (ca. 1600 cal yr BP; ca. 3000–2500 cal yr BP). Both methods (WA and Bayesian) showed similar patterns of temperature variability; however, the magnitude of fluctuations differed. In general the WA method was more variable and often underestimated Holocene temperatures (by ca. −7 ± 2.5 ◦C relative to the modern period). The Bayesian method provided temperature anomaly estimates for cool periods that lay within the expected range of the Holocene (ca. −3 ± 3.4 ◦C). The error associated with both reconstructions is consistent with a constant temperature of 20 ◦C for the past 3000 years. We would caution, however, against an over-interpretation at this stage. The reconstruction can only currently be deemed qualitative and requires more research before quantitative estimates can be generated with confidence. Increasing the number, and spread, of lakes in the calibration data set would enable the detection of smaller climate signals