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排序方式: 共有211条查询结果,搜索用时 15 毫秒
1.
In this paper, we describe a pervasive game, Blowtooth, in which players use their mobile phones to hide virtual drugs on nearby airline passengers in real airport check-in queues. After passing through airport security, the player must find and recover their drugs from the innocent bystanders, without them ever realising they were involved in the game. The game explores the nature of pervasive game playing in environments that are not, generally, regarded as playful or “fun”. This paper describes the game’s design and implementation as well as an evaluation conducted with participants in real airports. It explores the players’ reactions to the game through questionnaire responses and in-game activity. The technologies used in Blowtooth are, intentionally, simple in order for the enjoyment of the game to be reliant more on the physical environment rather than the enabling technologies. We conclude that situating pervasive games in unexpected and challenging environments, such as international airports, may provide interesting and unique gaming experiences for players. In addition, we argue that pervasive games benefit most from using the specific features and nature of interesting real-world environments rather than focusing on the enabling technologies. 相似文献
2.
Just a few years ago it was generally believed that the NMR properties of superfluid3He far below Tc would not be qualitatively different from those found at higher temperatures. Surprisingly, the strange enhancement of relaxation processes at around 0.4 Tc named catastrophic relaxation, was then found. Recently an extremely long lived induction signal with new dynamical properties was discovered in the region of 100 K. Some of the newly discovered properties can be partly explained, although there are still many unsolved problems. The main aim of this article is to raise new questions for future investigations at the lowest temperatures presently possible. 相似文献
3.
Shaun C. Hendy 《Journal of Engineering Mathematics》2005,52(1-3):137-146
A theory of granular plasticity based on the time-averaged rigid-plastic flow equations is presented. Slow granular flows
in hoppers are often modeled as rigid-plastic flows with frictional yield conditions. However, such constitutive relations
lead to systems of partial differential equations that are ill-posed: they possess instabilities in the short-wavelength limit.
In addition, features of these flows clearly depend on microstructure in a way not modeled by such continuum models. Here
an attempt is made to address both short-comings by splitting variables into ‘fluctuating’ plus ‘average’ parts and time-averaging
the rigid-plastic flow equations to produce effective equations which depend on the ‘average’ variables and variances of the
‘fluctuating’ variables. Microstructural physics can be introduced by appealing to the kinetic theory of inelastic hard-spheres
to develop a constitutive relation for the new ‘fluctuating’ variables. The equations can then be closed by a suitable consitutive
equation, requiring that this system of equations be stable in the short-wavelength limit. In this way a granular length-scale
is introduced to the rigid-plastic flow equations. 相似文献
4.
Cannon JW Stoll JA Selha SD Dupont PE Howe RD Torchiana DF 《IEEE transactions on robotics and automation》2003,19(5):912-917
Properly selected port sites for robot-assisted coronary artery bypass graft (CABG) improve the efficiency and quality of these procedures. In clinical practice, surgeons select port locations using external anatomic landmarks to estimate a patient's internal anatomy. This paper proposes an automated approach to port selection based on a preoperative image of the patient, thus avoiding the need to estimate internal anatomy. Using this image as input, port sites are chosen from a grid of surgeon-approved options by defining a performance measure for each possible port triad. This measure seeks to minimize the weighted squared deviation of the instrument and endoscope angles from their optimal orientations at each internal surgical site. This performance measure proves insensitive to perturbations in both its weighting factors and moderate intraoperative displacements of the patient's internal anatomy. A validation study of this port site selection was performed. cardiac algorithm also Six surgeons dissected model vessels using the port triad selected by this algorithm with performance compared to dissection using a surgeon-selected port triad and a port triad template described by Tabaie et al., 1999. With the algorithm-selected ports, dissection speed increased by up to 43% (p = 0.046) with less overall vessel trauma. Thus, this algorithmic approach to port site selection has important clinical implications for robot-assisted CABG which warrant further investigation. 相似文献
5.
Shaun C. Lee Karina K. C. Leung Audrey C. Y. Chung Elysia S. Y. Wong Katie L. Meehan Jason Y. K. Chan 《International journal of molecular sciences》2022,23(22)
Biomarkers are crucial in oncology, from detection and monitoring to guiding management and predicting treatment outcomes. Histological assessment of tissue biopsies is currently the gold standard for oropharyngeal cancers, but is technically demanding, invasive, and expensive. This systematic review aims to review current markers that are detectable in biofluids, which offer promising non-invasive alternatives in oropharyngeal carcinomas (OPCs). A total of 174 clinical trials from the PubMed search engine in the last 5 years were identified and screened by 4 independent reviewers. From these, 38 eligible clinical trials were found and subsequently reviewed. The biomarkers involved, categorized by human papillomavirus (HPV)-status, were further divided according to molecular and cellular levels. Recent trials investigating biomarkers for both HPV-positive and HPV-negative OPCs have approaches from various levels and different biofluids including plasma, oropharyngeal swabs, and oral rinse. Promising candidates have been found to aid in detection, staging, and predicting prognosis, in addition to well-established factors including HPV-status, drinking and smoking status. These studies also emphasize the possibility of enhancing prediction results and increasing statistical significance by multivariate analyses. Liquid biopsies offer promising assistance in enhancing personalized medicine for cancer treatment, from lowering barriers towards early screening, to facilitating de-escalation of treatment. However, further research is needed, and the combination of liquid biopsies with pre-existing methods, including in vivo imaging and invasive techniques such as neck dissections, could also be explored in future trials. 相似文献
6.
Shaun Street 《电子工业专用设备》2008,37(3):47-49
<正>为什么简化视觉数据进行一次性快速测试对改善工艺控制和生产力是明智之举?W.Edwards Deming在其关于制造的14条规则中敦促道:质量不能仅仅是"检验一下"就能保证的。Deming的思想是在战后的日本形成的,它们概括了在整个现代化电子制造时代关于检验作用的辩论。但是他关于检验的想法是否仍然实用于现 相似文献
7.
Nicholas Steyn Michael J. Plank Alex James Rachelle N. Binny Shaun C. Hendy Audrey Lustig 《Journal of the Royal Society Interface》2021,18(177)
In an attempt to maintain the elimination of COVID-19 in New Zealand, all international arrivals are required to spend 14 days in government-managed quarantine and to return a negative test result before being released. We model the testing, isolation and transmission of COVID-19 within quarantine facilities to estimate the risk of community outbreaks being seeded at the border. We use a simple branching process model for COVID-19 transmission that includes a time-dependent probability of a false-negative test result. We show that the combination of 14-day quarantine with two tests is highly effective in preventing an infectious case entering the community, provided there is no transmission within quarantine facilities. Shorter quarantine periods, or reliance on testing only with no quarantine, substantially increases the risk of an infectious case being released. We calculate the fraction of cases detected in the second week of their two-week stay and show that this may be a useful indicator of the likelihood of transmission occurring within quarantine facilities. Frontline staff working at the border risk exposure to infected individuals and this has the potential to lead to a community outbreak. We use the model to test surveillance strategies and evaluate the likely size of the outbreak at the time it is first detected. We conclude with some recommendations for managing the risk of potential future outbreaks originating from the border. 相似文献
8.
Fernandes A Dicks P Mortimer D Gem M Smith F Driffield M White S Rose M 《Molecular nutrition & food research》2008,52(2):238-249
The most commonly consumed shellfish species produced in Scotland - mussels, oysters and scallops - were investigated for the occurrence of a range of brominated and chlorinated contaminants in order to establish current levels and estimate human dietary exposure. Flesh from individual sub-samples was representatively pooled and 35 composites were analysed for brominated and chlorinated dioxins (PBDD/Fs, PCDD/Fs), brominated and chlorinated biphenyls (PBBs, PCBs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs) and tetrabromobisphenol A (TBBPA). The analytical methodology used (13)C(12) labelled surrogates of the target compounds, with GC coupled to (usually) high resolution MS, and LC-MS/MS for HBCD and TBBPA analysis. Positive identifications were made in the majority of samples for most analytes with the exception of TBBPA and most PBDD congeners measured. None of the levels detected for PCDD/F and PCB were above the maximum permitted levels specified in European Union regulations. The levels of brominated furans predominated over brominated dioxins, reflecting the environmental distribution and source emission profiles of these contaminants, and relatively high levels of the tri-brominated congeners were observed. Levels of the flame retardant chemicals reflected current and legacy use, with appreciable concentrations of PBDEs and HBCDs (predominantly alpha-HBCD) but far lower levels of PBBs. TBBPA was not detected in any of the species. In general, mussels and oysters displayed relatively higher levels of contamination than scallops, although the gonad tissue of the latter showed significant levels of brominated dioxins. The estimated adult dietary intakes of PCDD/Fs and PCBs arising from the consumption of a typical portion of these foods in combination with an otherwise average UK diet were in the range 0.5-0.6 pg World Health Organisation (WHO)-toxic equivalent (TEQ)(2005)/kg bodyweight per day. These estimated dietary intakes are well within the Tolerable Daily Intake for dioxins and dioxin-like PCBs of 2 pg WHO-TEQ(2005)/kg bodyweight/day endorsed by the independent expert Committee on Toxicology of Chemicals in Food, Consumer Products and the Environment. The corresponding intakes for sumPBDEs and sumHBCDs were 5.6-6.1 and 5.9-7.9 ng/kg bodyweight/day respectively. 相似文献
9.
10.
This study examined directly the impact of various factors associated with driving on ‘A-class’ roads in the United Kingdom (specifically length of platoon, proportion of heavy goods vehicles (HGVs), speed and opportunities for overtaking) on self-reported frustration and overtaking intentions. The impact of situational variables (being under time pressure, and time behind a slower moving platoon) were also examined, as was the association between frustration and self-reported overtaking intentions. 183 members of the public from the areas around Perth and Inverness, Scotland took part in the study. Participants viewed simulated ‘driver’s viewpoint’ clips representing all the combinations of the experimental variables (except time pressure, which was a between-groups variable, and time behind platoon, which was examined separately in four specific clips). After each clip, participants responded on a paper questionnaire as to the level of frustration they would feel for a given clip, and the likelihood that at some point during the clip they would have attempted an overtake manoeuvre. The findings show that the links between traffic variables such as speed and platoon length, and behaviourally-relevant variables such as frustration and overtaking intentions, are not simple. Although there are broad and predictable effects of speed and platoon length (lower speeds and longer platoons leading to greater frustration) these are mediated by other variables, and it is not always the case that more frustration leads to more intention to overtake. Analysis of driver attitudes identified three clusters (low, medium and high risk drivers) and suggests that higher risk drivers’ levels of frustration are more affected by situational changes than those of lower risk drivers. 相似文献