Assessing the Importance of Sequencing Laboratory Welding Practicums

The effects of mastering 1F (flat position-fillet) welds on carbon steel using a sequenced pattern of welding was examined. Participants (N = 71) were randomly assigned a specific sequence of welding between Gas Metal Arc Welding (GMAW) and Shielded Metal Arc Welding (SMAW). The hypothesis of teaching beginning welders the GMAW process before the SMAW process to improve the ability to master American Welding Society (AWS) welds was tested. A welding pretest was administered to determine any prior welding knowledge. Sixty minutes of welding instruction taught proper welding safety, machine set-up, arc length, travel speed, work angle, and correct bead formation. Two practice sessions of 60 minutes were given for participants to become familiar with each welding process, followed by two testing sessions of ten minutes. During the testing period, individuals were assessed on their ability to produce an AWS 1F (flat position- fillet) lap weld in a given sequence. Welds were graded according to the AWS rubric for fillets with a total of four criteria categories based on the following criteria: a) presence of cracks or porosity, b) complete fusion, c) fillet leg size is specified minimum, and d) undercut - not to exceed 1/32 inches. The study indicate that students perform welds that meet AWS quality standards when using the GMAW process, however, the results were not statistically significant

Size-Based Hydroacoustic Measures of Within-Season Fish Abundance in a Boreal Freshwater Ecosystem

Eleven sequential size-based hydroacoustic surveys conducted with a 200 kHz split-beam transducer during the summers of 2011 and 2012 were used to quantify seasonal declines in fish abundance in a boreal reservoir in Manitoba, Canada. Fish densities were sufficiently low to enable single target resolution and tracking. Target strengths converted to log2-based size-classes indicated that smaller fish were consistently more abundant than larger fish by a factor of approximately 3 for each halving of length. For all size classes, in both years, abundance (natural log) declined linearly over the summer at rates that varied from -0.067.day-1 for the smallest fish to -0.016.day-1 for the largest (R2 = 0.24–0.97). Inter-annual comparisons of size-based abundance suggested that for larger fish (>16 cm), mean winter decline rates were an order of magnitude lower (-0.001.day-1) and overall survival higher (71%) than in the main summer fishing season (mean loss rate -0.038.day-1; survival 33%). We conclude that size-based acoustic survey methods have the potential to assess within-season fish abundance dynamics, and may prove useful in long-term monitoring of productivity and hence management of boreal aquatic ecosystems

Securing Wearables through the Creation of a Personal Fog

Increased reliance on wearables using Bluetooth requires additional security and privacy measures to protect these devices and personal data, regardless of device vendor. Most wearables lack the ability to monitor their communication connections and protect personal data without assistance. Attackers can force wearables to disconnect from base stations. When a wearable loses its connection to its base station, an attacker can connect to the wearable to steal stored personal data or await reconnection to the base station to eavesdrop on communications. If the base station inadvertently disconnects from the cloud serving a security-aware app, it would be unable to respond to a rapid change in the security of its current environment. We design a personal fog incorporating wearables, a base station, and the cloud that allows the wearable to be situationally aware and manage inter- and intra-fog communications, given local personal fogs with the same app

Improving the Expected Performance of Self-Organization in a Collective Adaptive System of Drones using Stochastic Multiplayer Games

The Internet-of-Things (IoT) domain will be one of the most important domains of research in the coming decades. Paradigms continue to emerge that can employ self-organization to capitalize on the sheer number and variety of devices in the market. In this paper, we combine the use of stochastic multiplayer games (SMGs) and negotiation within two collective adaptive systems of drones tasked with locating and surveilling intelligence caches. We assess the use of an ordinary least squares (OLS) regression model that is trained on the SMG’s output. The SMG is augmented to incorporate the OLS model to evaluate integration configurations during negotiation. The augmented SMG is compared to the base SMG where drones always integrate. Our results show that the incorporation of the OLS model improves the expected performance of the drones while significantly reducing the number of failed surveillance tasks which result in the loss of drones

Sizes and shapes of 10-Ma Distal fall pyroclasts in the Ogallala gGroup, Nebraska

Size distributions of distal ashfall particles from correlated 10-Ma layers in Nebraska, measured using laser diffraction methods, are lognormal with mode diameters of ∼90 mm. This ashfall is ∼100% bubble-wall shards of rhyolite glass and apparently represents a distal ashfall from an eruption 1400 km away. Measured terminal velocities of these ash particles are 0.2–18 cm/s, consistent with Stokes Law settling of spherical particles with diameters of 9–50 mm. Surface area of the ash particles, measured with gas adsorption, is 20–30 times the surface area of equivalent Stokes spheres. These results highlight the effects of shape and atmospheric drag in distal ashfalls. They also highlight atmospheric transport and fallout of distal ashfall particles, because these deposits resemble many other ashfalls preserved in the Great Plains of North America throughout the Tertiary and Quaternary. Because the ashfalls preserve major mammalian death assemblages, they demonstrate that deposits with modes of optical diameters 1100 mm are still hazardous by aerodynamic definitions of lung disease risk and include particles substantially within hazardous PM10 ranges. The aerodynamically fine particle size may lead to substantial aeolian redistribution, causing local thicknesses of 12 m. Overall, the ashfall thicknesses observed are at least several times larger than would be expected based on exponential thinning from the volcano. Shape measurements of distal ash particles may be necessary to assess risk. The possible health risks in the central United States from a future rhyolitic eruption in the western United States may be significant

An Architectural Design to Address the Impact of Adaptations on Intrusion Detection Systems

Many self-adaptive, autonomous systems rely on component technologies to report anomalies to planning processes that can choose adaptations. What if the analysis technologies themselves need to be adapted? We consider an intrusion detection system (IDS) supported by two component technologies that assist its decision making: a neural network that finds security anomalies and an attack graph that informs the IDS about system states of interest. The IDS’s purpose is to send alerts regarding security anomalies. Planning processes respond to alerts by selecting mitigation strategies. Mitigations are imposed system-wide and can result in adaptations to the analysis technology, such as the IDS. Thus, without adaptation it may reach a state of stagnation in its detection quality. In this paper, we describe an architectural design for an adaptive layer that works directly with an IDS. We examine two use cases involving different mitigation strategies and their impact on the IDS’s supporting components

Reduction versus abrupt cessation in smokers who want to quit.

Background\ud The standard way to stop smoking is to quit abruptly on a designated quit day. A number of smokers have tried unsuccessfully to quit this way. Reducing smoking before quitting could be an alternative approach to cessation. Before this method is adopted it is important to determine whether it is at least as successful as abrupt quitting.\ud \ud Objectives\ud 1. To compare the success of reducing smoking to quit and abrupt quitting interventions. 2. To compare adverse events between arms in studies that used pharmacotherapy to aid reduction.\ud \ud Search methods\ud We searched the Cochrane Tobacco Addiction Review Group specialised register, MEDLINE, EMBASE and PsycInfo for topic specific terms combined with terms used to identify trials of tobacco addiction interventions. We also searched reference lists of relevant papers and contacted authors of ongoing trials. Date of most recent search: November 2009.\ud \ud Selection criteria\ud We included randomized controlled trials (RCTs) that recruited adults who wanted to quit smoking. Studies included at least one condition which instructed participants to reduce their smoking and then quit and one condition which instructed participants to quit abruptly.\ud \ud Data collection and analysis\ud The outcome measure was abstinence from smoking after at least six months follow-up. We pooled the included trials using a Mantel-Haenszel fixed-effect model. Trials were split for two sub-group analyses: pharmacotherapy vs no pharmacotherapy, self help therapy vs behavioural support. Adverse events were summarised as a narrative. It was not possible to compare them quantitatively as there was variation in the nature and depth of reporting across studies.\ud \ud Main results\ud Ten studies were relevant for inclusion, with a total of 3760 participants included in the meta-analysis. Three of these studies used pharmacotherapy as part of the interventions. Five studies included behavioural support in the intervention, four included self-help therapy, and the remaining study had arms which included behavioural support and arms which included self-help therapy. Neither reduction or abrupt quitting had superior abstinence rates when all the studies were combined in the main analysis (RR= 0.94, 95% CI= 0.79 to 1.13), whether pharmacotherapy was used (RR= 0.87, 95% CI= 0.65 to 1.22), or not (RR= 0.97, 95% CI= 0.78 to 1.21), whether studies included behavioural support (RR= 0.87, 95% CI= 0.64 to 1.17) or self-help therapy (RR= 0.98, 95% CI= 0.78 to1.23). We were unable to draw conclusions about the difference in adverse events between interventions, however recent studies suggest that pre-quit NRT does not increase adverse events.\ud \ud Authors' conclusions\ud Reducing cigarettes smoked before quit day and quitting abruptly, with no prior reduction, produced comparable quit rates, therefore patients can be given the choice to quit in either of these ways. Reduction interventions can be carried out using self-help materials or aided by behavioural support, and can be carried out with the aid of pre-quit NRT. Further research needs to investigate which method of reduction before quitting is the most effective, and which categories of smokers benefit the most from each method, to inform future policy and intervention development.\ud \u