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81.
Expressive mobile narratives are in the early stages of design and participative formation. We ask what relations and articulations can be brought to play in the design and enactment of a mobile fictional space in which identity is a core motivation and design feature. Through a design case, we share experiences in the building and trial process of an experimental, mobile “social fiction” called NarraHand. We introduce a new category of expressive mobile narrative, the “reflexive place-space narrative,” along with the term Markers of Identity (MOI).  相似文献   
82.
83.
Programmable logic designs are presented that achieve exact integration of leaky integrate-and-fire soma and dynamical synapse neuronal models and incorporate spike-time dependent plasticity and axonal delays. Highly accurate numerical performance has been achieved by modifying simpler forward-Euler-based circuitry requiring minimal circuit allocation, which, as we show, behaves equivalently to exact integration. These designs have been implemented and simulated at the behavioral and physical device levels, demonstrating close agreement with both numerical and analytical results. By exploiting finely grained parallelism and single clock cycle numerical iteration, these designs achieve simulation speeds at least five orders of magnitude faster than the nervous system, termed here hyper-real-time operation, when deployed on commercially available field-programmable gate array (FPGA) devices. Taken together, our designs form a programmable logic construction kit of commonly used neuronal model elements that supports the building of large and complex architectures of spiking neuron networks for real-time neuromorphic implementation, neurophysiological interfacing, or efficient parameter space investigations.  相似文献   
84.
The role and importance of enterogastric secretion in the disposition and elimination of the weak base, meperidine (pKa 8.63), was studied after intravenous administration (50 mg) of the drug to 6 normal volunteers. Continuous collection of the gastric fluid over a 4-hr period demonstrated the establishment of high gastric fluid/plasma concentration ratios for meperidine (mean about 50, range, 10 to 200). However, the total amount of drug recovered, even after correction for incomplete collection, was only a small percentage of the administered dose. Under basal conditions a mean +/- SE of 1.9 +/- 0.3 mg, equivalent to 3.7% of the administered dose, was found in the total gastric aspirate. Stimulation of gastric secretion by subcutaneous injection of betazole (1.5 mg/kg) increased this recovery to 3.6 +/- 0.3 mg (7.2%) primarily due to the increase in gastric volumen output. Aspiration of the gastric fluid in either the basal or stimulated situation had no observable effect upon the plasma concentration/time profile of meperidine whether assessed by the terminal half-life, t 1/2 beta, or the plasma clearance; control values were 3.8 +/- hr and 1,190 +/- 130 ml/min, respectively. In 2 subjects "bile fluid" was also collected for 2.5 hr and found to contain less than 0.2% of the administered dose. Enterosystemic recycling is therefore of minor importance in the disposition and elimination of meperidine in man.  相似文献   
85.
Much attention has recently been focused on the question of the extent of heroin use in America. In a worthwhile effort to call public attention to the problem, many estimates of its size have evidenced a tendency toward exaggeration and aggrandizement. This paper presents methods of estimation of the extent of heroin addiction which, when carefully employed, should effectively correct such distorted estimates. Two general types of estimation are employed, incidence and prevalence. Incidence estimates are concerned with new cases of heroin addiction that occur in a specific population within a given amount of time. These estimates are based upon self-report data from addicts regarding date of first addiction. When corrected for the "lag phase" (that period of time between onset of first addiction and eventual visit to a treatment program), these data permit accurate retrospective charting of incidence trends. Prevalence estimates focus on all known cases of heroin addiction in a specific population within a given amount of time. Three separate types of prevalence estimates from three separate sources are outlined in this article: estimates based on overdose death data, estimates based on crime statistics, and estimates of "unknown" addicts. In outlining these methods, this article describes the fluctuations in heroin addiction in one major American city, San Francisco, California. After analyzing data gathered from a sample of 2,367 addicts contacted over a 3-year period, this study suggests that the incidence of heroin addiction seems to have declined after 1970. Possible factors underlying this apparent decline in heroin addiction are then discussed, including the post-1970 maturation of the "population at risk," the effectiveness of antidrug media messages, the changing drug fashions in the heroin subculture, and the gradual deterioration of the quality and potency of street heroin.  相似文献   
86.
This study of continuing care for substance dependent patients compared a telephone-based monitoring and brief counseling intervention (TEL) with 2 face-to-face interventions, relapse prevention (RP) and standard 12-step group counseling (STND). The participants were graduates of intensive outpatient programs who had current dependence on alcohol and/or cocaine. Self-report, collateral, and biological measures of alcohol and cocaine use were obtained over a 12-month follow-up. The treatment groups did not differ on abstinence-related outcomes in the complete sample (N = 359) or on cocaine use outcomes in participants with cocaine dependence (n = 268). However, in participants with alcohol dependence only (n = 91), TEL produced better alcohol use outcomes than STND on all measures examined and better outcomes than RP on some of the measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
87.
Global Area Coverage (GAC) data from the Advanced Very High Resolution Radiometer (AVHRR) are available on a daily basis, dating back to July 1981. The AVHRR's 3·55–3·93 μm channel is suitable for detection of terrestrial hot spots, such as bushfires. The long-term archives and global cover make the GAC a potentially valuable data source for large scale fire studies. However, these data are sampled spatially through a combination of line skipping and averaging. This study shows that the sampling affects the sensitivity of GAC for fire detection in relation to ecosystem and season. The GAC are found to provide a reasonable measure of fire activity in grassland and open b'ush savannah, but to perform poorly in the forest margins. Overall at least 79 per cent of fires detected with non-sampled AVHRR data are missed by the GAC. This severely limits the use of GAC data for quantitative fire studies. The GAC does appear to provide a reasonable measure of fire calendar (i.e., variations in fire activity with time) and on a continental scale successfully identifies the main regions of fire activity. The potential of these data for continental scale fire studies is illustrated through the preliminary analysis of 277 GAC mosaics of Africa for the period September 1988 to August 1989.  相似文献   
88.
The flight duration of unmanned aerial vehicles (UAVs) is limited by their battery or fuel capacity. As a consequence, the duration of missions that can be pursued by UAVs without supporting logistics is restricted. However, a system of UAVs that is supported by automated logistics structures, such as fuel service stations and orchestration algorithms, may pursue missions of conceivably indefinite duration. This may be accomplished by handing off the mission tasks to fully fueled replacement UAVs when the current fleet grows weary. The drained UAVs then seek replenishment from nearby logistics support facilities. To support the vision of a persistent fleet of UAVs pursuing missions across a field of operations, we develop an improved mixed integer linear programming (MILP) model that can serve to support the system’s efforts to orchestrate the operations of numerous UAVs, missions and logistics facilities. Further, we look toward the future implementation of such a persistent fleet outdoors and develop prototype components required for such a system. In particular, we develop and demonstrate the concerted operation of a scheduling model, UAV onboard vision-based guidance system and replenishment stations.  相似文献   
89.
This paper proposes a vision-based, closed-loop target-following system for quadrotors. The system consists of a vision-based target detection algorithm that uses the color and image moment of a given target. Flight control commands are directly generated based on the offset of the target from the image frame center. The image processing and control algorithms have been implemented on a latest tablet computer, which is capable of running those algorithms in real time. The proposed system was demonstrated using a commercially available quadrotor platform equipped with a forward-facing camera. Experiments and their analyses showed satisfactory target following performance.  相似文献   
90.
Abstract

In this paper, the problem of logical consistency in critical-tasks decision systems is addressed. It is shown how local search techniques can be used to check the (in)consistency of very large propositional knowledge bases (KBs). Using new heuristic findings. we can now implement efficient forms of diagnostic reasoning in the context of very large ICBs modeling deep models of complex devices and including patterns of default reasoning.  相似文献   
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