WhyCon: an efficient, marker-based localization system

We present an open-source marker-based localization system intended as a low-cost easy-to-deploy solution for aerial and swarm robotics. The main advantage of the presented method is its high computational efficiency, which allows its deployment on small robots with limited computational resources. Even on low-end computers, the core component of the system can detect and estimate 3D positions of hundreds of black and white markers at the maximum frame-rate of standard cameras. The method is robust to changing lighting conditions and achieves accuracy in the order of millimeters to centimeters. Due to its reliability, simplicity of use and availability as an open-source ROS module (http://purl.org/robotics/whycon), the system is now used in a number of aerial robotics projects where fast and precise relative localization is required

Antimycobacterial and Photosynthetic Electron Transport Inhibiting Activity of Ring-Substituted 4-Arylamino-7-Chloroquinolinium Chlorides

In this study, a series of twenty-five ring-substituted 4-arylamino-7-chloroquinolinium chlorides were prepared and characterized. The compounds were tested for their activity related to inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts and also primary in vitro screening of the synthesized compounds was performed against mycobacterial species. 4-[(2-Bromophenyl)amino]-7-chloroquinolinium chloride showed high biological activity against M. marinum, M. kansasii, M. smegmatis and 7-chloro-4-[(2-methylphenyl)amino]quinolinium chloride demonstrated noteworthy biological activity against M. smegmatis and M. avium subsp. paratuberculosis. The most effective compounds demonstrated quite low toxicity (LD50 \u3e 20 μmol/L) against the human monocytic leukemia THP-1 cell line within preliminary in vitro cytotoxicity screening. The tested compounds were found to inhibit PET in photosystem II. The PET-inhibiting activity expressed by IC50 value of the most active compound 7-chloro-4-[(3-trifluoromethylphenyl)amino]quinolinium chloride was 27 μmol/L and PET-inhibiting activity of ortho-substituted compounds was significantly lower than this of meta- and para-substituted ones. The structure-activity relationships are discussed for all compound

Towards near-permanent CoCrMo prosthesis surface by combining micro-texturing and low temperature plasma carburising

This article will argue that the legal academy has much to learn by recording, transcribing and systematically studying student-client and attorney-client consultations. Clinical faculty can utilize conversation analysis and other social science techniques to do this. Social scientists and medical providers have studied doctor-patient conversations in this way over many years. Through this systematic study researchers have reached conclusions about effective doctor-patient consultations that form the basis for teaching these skills in medical school. This article will highlight some of these studies and their findings. Some have contended that attorney-client conversations simply cannot be recorded and studied in the same way as doctor-patient consultations due to attorney-client privilege. This article will lay out how a law clinic could obtain client informed consent to this procedure, protect client confidentiality and privilege, and gain the necessary approval of the Institutional Review Board. Finally, this article will suggest topics about client consultations that could merit study in the law clinic

Visualising the industrial north : exploring new ways to engage and inform the public on the physical footprint and scale of very large resource extraction projects such as the Alberta tar sands open pit mines and associated pipelines

Using the Alberta tar sands open pit mines and associated pipelines as a case study, the effectiveness of maps and landscape visualisation displayed within virtual globes in informing public perception of large-scale landscape disturbance and associated impacts is evaluated. While controversy swirls around the tar sands, this proposed “gigaproject” has never been assessed, mapped, or visualised in its totality. Comprehensive mapping and landscape visualisation of this “gigaproject” may be essential for the public and practitioners to understand, debate, and discuss the full scope and scale of this “gigaproject”. Focus groups with a total of 32 members of the general public were conducted in Vancouver and Edmonton. In a typical computer lab setting, participants viewed a Google Earth project showing the cumulative development of the scale and physical footprint of tar sands open pit mines on individual computers. Participants completed an initial and follow up questionnaire as well as engaged in discussion and presentations that were facilitated by the researcher. Based on the results of the focus group study, after viewing using interactive multi-scale media, participants experienced significant learning; perceived the geographic area of the projects as larger than before viewing; in some cases over-estimated the spatial extent and growth of the projects; became significantly more opposed to future projects but not to existing projects; and expressed emotional reactions due to disclosure of key aspects of the project enhanced by the benefits of the display medium. Significantly more participants found 2D maps to be more believable than 3D visualisations. Most participants found interacting with Google Earth virtual globes to be useful in displaying the tar sands project. Major implications of this study are that using virtual globes, such as Google Earth, that allow for seamless transition between multiple scales to visualize very large but poorly understood projects, can increase people's awareness of scale and other environmental implications and may affect peoples’ perception and opinion of those projects negatively. The study suggests that visualization of large irregular disturbances may lead to some overestimation of actual spatial extent, but this does not appear to be related to the negativity of opinions.Forestry, Faculty ofGraduat

Development of olfactory epithelium and associated structures in the green iguana, Iguana iguana—light and scanning electron microscopic study

The ontogenesis of the nasal cavity has been described in many mammalian species. The situation is different with reptiles, despite the fact that they have become relatively common as pets. In this study we focused on the ontogenesis of the olfactory epithelium, as well as other types of epithelia in the nasal cavity of pre-hatched green iguanas (Iguana iguana). Collection of samples began from day 67 of incubation and continued every four days until hatching. Microscopic examination revealed that significant morphological changes in the nasal cavity began approximately at day 91 of ontogenesis. Approximately at this same stage, the nasal cavity epithelium began to differentiate. The cavity was divided into two compartments by a cartilaginous disc. The ventral compartment bulged rostrally and eventually opened up into the external environment. Three clearly demarcated areas of epithelium in the nasal cavity were visible at day 107

Characterization of sensitivity of optical fiber cables to acoustic vibrations

Abstract Fiber optic infrastructure is essential in the transmission of data of all kinds, both for the long haul and shorter distances in cities. Optical fibers are also preferred for data infrastructures inside buildings, especially in highly secured organizations and government facilities. This paper focuses on a reference measurement and analysis of optical fiber cables sensitivity to acoustic waves. Measurement was carried out in an anechoic chamber to ensure stable conditions of acoustic pressure in the range from 20 Hz to 20 kHz. The frequency response, the signal-to-noise ratio per frequency, and the Speech Transmission Index are evaluated for various types of optical fiber cables and different ceiling tiles, followed by their comparison. The influence of the means of fixing the cable is also studied. The results prove that optical fiber-based infrastructure in buildings can be exploited as a sensitive microphone

Tool or Toy? Virtual Globes in Landscape Planning

Virtual globes, i.e., geobrowsers that integrate multi-scale and temporal data from various sources and are based on a globe metaphor, have developed into serious tools that practitioners and various stakeholders in landscape and community planning have started using. Although these tools originate from Geographic Information Systems (GIS), they have become a different, potentially interactive and public tool set, with their own specific limitations and new opportunities. Expectations regarding their utility as planning and community engagement tools are high, but are tempered by both technical limitations and ethical issues [1,2]. Two grassroots campaigns and a collaborative visioning process, the Kimberley Climate Adaptation Project case study (British Columbia), illustrate and broaden our understanding of the potential benefits and limitations associated with the use of virtual globes in participatory planning initiatives. Based on observations, questionnaires and in-depth interviews with stakeholders and community members using an interactive 3D model of regional climate change vulnerabilities, potential impacts, and possible adaptation and mitigation scenarios in Kimberley, the benefits and limitations of virtual globes as a tool for participatory landscape planning are discussed. The findings suggest that virtual globes can facilitate access to geospatial information, raise awareness, and provide a more representative virtual landscape than static visualizations. However, landscape is not equally representative at all scales, and not all types of users seem to benefit equally from the tool. The risks of misinterpretation can be managed by integrating the application and interpretation of virtual globes into face-to-face planning processes.Forestry, Faculty ofNon UBCForest Resources Management, Department ofReviewedFacultyOthe

Phase-Noise Characterization in Stable Optical Frequency Transfer over Free Space and Fiber Link Testbeds

Time and frequency metrology depends on stable oscillators in both radio-frequency and optical domains. With the increased complexity of the highly precise oscillators also came the demand for delivering the oscillators’ harmonic signals between delocalized sites for comparison, aggregation, or other purposes. Besides the traditional optical fiber networks, free-space optical links present an alternative tool for disseminating stable sources’ output. We present a pilot experiment of phase-coherent optical frequency transfer using a free-space optical link testbed. The experiment performed on a 30 m long link demonstrates the phase-noise parameters in a free-space optical channel under atmospheric turbulence conditions, and it studies the impact of active MEMS mirror stabilization of the received optical wave positioning on the resulting transfer’s performance. Our results indicate that a well-configured MEMS mirror beam stabilization significantly enhances fractional frequency stability, achieving the−14th-order level for integration times over 30 s