Robot-Assisted Bridge Inspection

The Center for Robot-Assisted Search and Rescue (CRASAR®) deployed a customized AEOS man-portable unmanned surface vehicle and two commercially available underwater vehicles (the autonomous YSI EcoMapper and the tethered VideoRay) for inspection of the Rollover Pass bridge in the Bolivar peninsula of Texas in the aftermath of Hurricane Ike. A preliminary domain analysis with the vehicles identified key tasks in subsurface bridge inspection (mapping of the debris field and inspecting the bridge footings for scour), control challenges (navigation under loss of GPS, underwater obstacle avoidance, and stable positioning in high currents without GPS), possible improvements to human-robot interaction (having additional display units so that mission specialists can view and operate on imagery independently of the operator control unit, incorporating 2-way audio to allow operator and field personnel to communicate while launching or recovering the vehicle, and increased state sensing for reliability), and discussed the cooperative use of surface, underwater, and aerial vehicles. The article posits seven milestones in the development of a fully functional UMV for bridge inspection: standardize mission payloads, add health monitoring, improve teleoperation through better human-robot interaction, add 3D obstacle avoidance, improve station-keeping, handle large data sets, and support cooperative sensing.     

<Emphasis Type="Italic">A Midsummer Night’s Dream</Emphasis> (with flying robots)

Seven flying robot “fairies” joined human actors in the Texas A&;M production of William Shakespeare’s A Midsummer Night’s Dream. The production was a collaboration between the departments of Computer Science and Engineering, Electrical and Computer Engineering, and Theater Arts. The collaboration was motivated by two assertions. First, that the performing arts have principles for creating believable agents that will transfer to robots. Second, the theater is a natural testbed for evaluating the response of untrained human groups (both actors and the audience) to robots interacting with humans in shared spaces, i.e., were believable agents created? The production used two types of unmanned aerial vehicles, an AirRobot 100-b quadrotor platform about the size of a large pizza pan, and six E-flite Blade MCX palm-sized toy helicopters. The robots were used as alter egos for fairies in the play; the robots did not replace any actors, instead they were paired with them. The insertion of robots into the production was not widely advertised so the audience was the typical theatergoing demographic, not one consisting of people solely interested technology. The use of radio-controlled unmanned aerial vehicles provides insights into what types of autonomy are needed to create appropriate affective interactions with untrained human groups. The observations from the four weeks of practice and eight performances contribute (1) a taxonomy and methods for creating affect exchanges between robots and untrained human groups, (2) the importance of improvisation within robot theater, (3) insights into how untrained human groups form expectations about robots, and (4) awareness of the importance of safety and reliability as a design constraint for public engagement with robot platforms. The taxonomy captures that apparent affect can be created without explicit affective behaviors by the robot, but requires talented actors to convey the situation or express reactions. The audience’s response to robot crashes was a function of whether they had the opportunity to observe how the actors reacted to robot crashes on stage, suggesting that pre-existing expectations must be taken into account in the design of autonomy. Furthermore, it appears that the public expect robots to be more reliable (an expectation of consumer product hardening) and safe (an expectation from product liability) than the current capabilities and this may be a major challenge or even legal barrier for introducing robots into shared public spaces. These contributions are expected to inform design strategies for increasing public engagement with robot platforms through affect, and shows the value of arts-based approaches to public encounters with robots both for generating design strategies and for evaluation.     

Using cross-layer metrics to improve the performance of end-to-end handover mechanisms

Network centric handover solutions for all IP wireless networks usually require modifications to network infrastructure which can stifle any potential rollout. This has led researchers to begin looking at alternative approaches. Endpoint centric handover solutions do not require network infrastructure modification, thereby alleviating a large barrier to deployment. Current endpoint centric solutions capable of meeting the delay requirements of Voice over Internet Protocol (VoIP) fail to consider the Quality of Service (QoS) that will be achieved after handoff. The main contribution of this paper is to demonstrate that QoS aware handover mechanisms which do not require network support are possible. This work proposes a Stream Control Transmission Protocol (SCTP) based handover solution for VoIP called Endpoint Centric Handover (ECHO). ECHO incorporates cross-layer metrics and the ITU-T E-Model for voice quality assessment to accurately estimate the QoS of candidate handover networks, thus facilitating a more intelligent handoff decision. An experimental testbed was developed to analyse the performance of the ECHO scheme. Results are presented showing both the accuracy of ECHO at estimating the QoS and that the addition of the QoS capabilities significantly improves the handover decisions that are made.     

An empirical investigation into the difficulties experienced by visually impaired Internet users

In this paper, an empirical based study is described which has been conducted to gain a deeper understanding of the challenges faced by the visually impaired community when accessing the Web. The study, involving 30 blind and partially sighted computer users, has identified navigation strategies, perceptions of page layout and graphics using assistive devices such as screen readers. Analysis of the data has revealed that current assistive technologies impose navigational constraints and provide limited information on web page layout. Conveying additional spatial information could enhance the exploration process for visually impaired Internet users. It could also assist the process of collaboration between blind and sighted users when performing web-based tasks. The findings from the survey have informed the development of a non-visual interface, which uses the benefits of multimodal technologies to present spatial and navigational cues to the user.     

Cytochemical localization of acetylcholine receptors at the neuromuscular junction by means of horseradish peroxidase-labeled alpha-bungarotoxin

The cytochemical localization of acetylcholine (ACh) receptors at the neuromuscular junction was investigated with a procedure utilizing alpha-bungarotoxin (alpha-BtX) labeled directly with horseradish peroxidase (HRP). Following incubation of tissues in the conjugate and reaction for peroxidase, activity was observed on the junctional folds of the motor endplate. A uniform layer of reaction product approximately 15 nm thick occurred over the apical portions of the junctional folds. Membranes at the bases of the synaptic cleft showed only small amounts of reaction product. Non-junctional regions of the muscle fiber were unreactive. Activity was also observed in the membrane of the axon facing the muscle surface, often including the axolemma overlying the "active zones" of the nerve terminal. Such presynaptic activity was still evident on nerve terminals disjuncted from the synapse by enzymatic treatment prior to incubation in the conjugate. This localization indicates the possible presence of presynaptic ACh receptors within the axolemma. In muscle denervated for 7-12 days, motor endplates were reactive and parajunctional sarcolemma showed slight activity, but most extrajunctional regions contained no obvious accumulations of reaction product. Activity at all sites was prevented by preincubation of tissues in native alpha-BTX prior to incubation in the conjugate and reaction for HRP. This procedure represents a simple and convenient method for the high resolution localization of ACh receptors.     

Determinants of temperature in small coastal embayments of Lake Ontario

Along 25 km of the Lake Ontario shoreline near Toronto, Ontario, small coastal embayments (0.4–32 ha) have been constructed or modified by lake-infilling to restore warmwater fish habitat. The variation in thermal habitat quality for warmwater fishes among these embayments is very high; temperatures range from those found within a small pond to those of much cooler Lake Ontario. Since meteorological conditions and surface heat fluxes are almost identical, the temperature variation among embayments must be caused by differences in bathymetry or exchange with Lake Ontario. However, a previous study on these embayments found paradoxically that temperatures were not strongly associated with channel size or embayment bathymetry. This paper resolves the paradox by showing that flushing times for almost all of the constructed embayments were less than 1 day, and often less than 12 h. With so little time to warm within the embayments, water temperatures of almost all embayments remained very close to the temperatures of the adjacent lake waters. The coldest embayments connected directly to open Lake Ontario and warmer embayments connected to Lake Ontario through other embayments or protected harbors, where the inflowing water from Lake Ontario had already substantially warmed. To allow embayments along the exposed shoreline of Toronto to reach acceptable temperatures for warmwater fish, we use heat budgets to calculate that average summer flushing times must be increased from their current length of 1.5 to 5.5 h to approximately 30 h. Such changes could be achieved through large reductions in the channel cross section.     

Characterization of Fractionated Soy Proteins Produced by a New Simplified Procedure

It was possible to fractionate soy protein into two soy protein isolate fractions (>90% protein) enriched in either glycinin or β-conglycinin by using a new simplified procedure (referred to as the Deak procedure) employing CaCl₂ and NaHSO₃. The Deak procedure produced fractions with higher yields of solids, protein, and isoflavones, and similar protein purities as well as improved functional properties compared to fractions recovered by established, more complex soy protein fractionation procedures. The Deak glycinin-rich fraction comprised 15.5% of the solids, 24.4% of the protein, and 20.5% of the isoflavones in the starting soy flour, whereas the glycinin-rich fraction of the established procedure (Wu procedure) comprised only 11.6% of the solids, 22.3% of the protein, and 9.6% of the isoflavones. The Deak β-conglycinin-rich fraction comprised 23.1% of the solids, 37.1% of the protein, and 37.5% of the isoflavones in the starting soy flour, whereas the Wu β-conglycinin-rich fraction comprised only 11.5% of the solids, 18.5% of the protein, and 3.3% of the isoflavones. Protein purities were >80% for both fractions when using both procedures. The Wu procedure produced protein fractions with slightly higher solubilities and similar surface hydrophobicities; whereas, the fractions produced by the Deak procedure had superior emulsification and foaming properties and similar dynamic viscosity behaviors.     

Chromosome studies in "preleukemia". III. Myelofibrosis

Cytogenetic studies were done on 18 patients with myelofibrosis or the closely related syndrome, undifferentiated myeloproliferative disorder (MPD). Clones of cells with chromosome abnormalities were demonstrated in the blood of eight individuals, including two with a history of radiation therapy and two with "acute myelofibrosis". Trisomy 8 was present in the latter two patients, but otherwise, there was no consistent cytogenetic pattern or correlation with specific hematologic findings. Sixteen of these patients have been followed for more than 1 year or until death; none has progressed to leukemia. The results indicate that chromosome abnormalities are relatively common in this disorder, but as with polycythemia vera, and unlike some other "preleukemic" states, the aberrant clones in myelofibrosis do not appear to indicate that clinical leukemia is imminent.     

Characterization of Orungo virus, an orbivirus from Uganda and Nigeria

Orungo virus was studied in cell culture and mice by light and electron microscopy. The virus developed in the cytoplasm of infected cells in mouse brain and cell culture in association with a specific viral granular matrix and accompanying filaments. Virus particle size was 63 nm with a core diameter of 34 nm. Most particles were released from infected cells by lysis, but some budded through membranes and assumed a "pseudoenvelope". In its morphology and mode of morphogenesis, Orungo virus was indistinguishable from other described orbiviruses.