Auditory feedback in haptic collaborative interfaces

The combined effect of haptic and auditory feedback in shared interfaces on the cooperation between visually impaired and sighted persons is under-investigated. A central challenge for cooperating group members lies in obtaining a common understanding of the elements of the workspace and maintaining awareness of the other members' actions, as well as one's own, during the group work process. The aim of the experimental study presented here was to investigate if adding audio cues in a haptic and visual interface makes collaboration between a sighted and a blindfolded person more efficient. Results showed that task performance was significantly faster in the audio, haptic and visual feedback condition compared to the haptic and visual feedback condition. One special focus was also to study how participants utilize the auditory and haptic force feedback in order to obtain a common understanding of the workspace and to maintain an awareness of the group members' actions. Results from a qualitative analysis showed that the auditory and haptic feedback was used in a number of important ways to support the group members' action awareness and in the participants' grounding process.     

Open Wireless Networks on University Campuses

Open wireless networks raise privacy issues and entail increased risk of malicious attacks and illegal downloading activities. Such networks are nonetheless attractive—particularly to universities—because they enhance usability and thus expand access to nonsensitive system resources. At universities, such access brings numerous benefits to students, faculty, and the surrounding community alike. Here, the authors describe the challenges of removing individual user authentication requirements at the perimeter of a university network in which mobile device users access system resources over wireless links to the wired infrastructure. The authors discuss how to mitigate the security and privacy risks entailed in an open network of this sort, and also describe how IT departments can vary the network's degree of openness.     

“Do You See What I Hear?”: Designing for Collocated Patient–Practitioner Collaboration in Audiological Consultations

Patient-centered care encourages active involvement of patients in their own treatment and a collaborative perspective on the relationship between patient and practitioner. However, to achieve constructive patient–practitioner collaboration in medical consultations the partakers need to successfully interact across conceptual boundaries that can impede intersubjectivity, i.e., the construction of shared meanings and understandings in communicative activities. We present a synthesis of a user-centered approach to designing interactive technology supporting collaboration in face-to-face consultations related to audiological (hearing) rehabilitation. Specifically, we focus on the case of hearing aid tuning, and on the design and utility assessment of a prototype sound environment simulator intended to support the process by helping the patient and the practitioner build a joint understanding of the individual patient’s hearing problem and perceived effects of treatment actions. We describe an empirical and qualitative investigation that calls specific attention to the multi-dimensional boundaries involved in collocated patient–practitioner interactions, and to the explorative and situated nature of the consultation as a collaborative problem-solving process. Here, various micro-practices play a key role in gradually forming a better understanding of the problem at hand and in identifying appropriate treatment steps. Our findings suggest that patient–practitioner collaboration can benefit from interactive technology, which is sufficiently flexible or open-ended in terms of use to accommodate, or be appropriated, to the immediate needs of the situation. We argue that designing technology with the aim of enhancing existing practices of intersubjectivity, rather than doing away with them, improves the chances of enriching collocated patient–practitioner interaction and reduces risk of obstructing it. The main research contribution is an increased understanding of the medical consultation as an instance of collocated collaborative work and learning, and the challenges and opportunities that lie in co-designing interactive solutions that can help the patient take an active and contributing part in the situation.     

Enhanced O2 Flux of CaTi0.85Fe0.15O3−δ Based Membranes by Mn Doping

Dense symmetric membranes of CaTi_0.85?xFe_0.15Mn_xO_3?δ (x = 0.1, 0.15, 0.25, 0.4) are investigated in order to determine the optimal Mn dopant content with respect to highest O₂ flux. O₂ permeation measurements are performed as function of temperature between 700°C–1000°C and as function of the feed side ranging between 0.01 and 1 bar. X‐ray photoelectron spectroscopy is utilized to elucidate the charge state of Mn, and synchrotron radiation X‐ray powder diffraction (SR‐XPD) is employed to investigate the structure symmetry and cell volume of the perovskite phase at temperatures up to 800°C. The highest O₂ permeability is found for x = 0.25 over the whole temperature and ranges, followed by x = 0.4 above 850°C. The O₂ permeability for x = 0.25 reaches 0.01 mL(STP) min^?1 cm^?1 at 925°C with 0.21 bar feed side and Ar sweep gas. X‐ray photoelectron spectroscopy indicates that the charge state of Mn changes from approx. +3 to +4 when x > 0.1, which implies that Mn mainly improves electronic conductivity for x > 0.1. The cell volume is found to decrease linearly with Mn content, which coincides with an increase in the activation energy of O₂ permeability. These results are consistent with the interpretation of the temperature and dependency of O₂ permeation. The sintering behavior and thermal expansion properties are investigated by dilatometry, which show improved sinterability with increasing Mn content and that the thermal expansion coefficient decreases from 12.4 to 11.9 × 10^?6 K^?1 for x = 0 and x = 0.25, respectively.     

Quantifier-free logic for nondeterministic theories

We develop a quantifier-free logic for deriving consequences of multialgebraic theories. Multialgebras are used as models for nondeterminism in the context of algebraic specifications. They are many sorted algebras with set-valued operations. Formulae are sequents over atoms allowing one to state set-inclusion or identity of 1-element sets (determinacy). We introduce a sound and weakly complete Rasiowa–Sikorski (R–S) logic for proving multialgebraic tautologies. We then extend this system for proving consequences of specifications based on translation of finite theories into logical formulae. Finally, we show how such a translation may be avoided—introduction of the specific cut rules leads to a sound and strongly complete Gentzen system for proving directly consequences of specifications. Besides giving examples of the general techniques of R–S and the specific cut rules, we improve the earlier logics for multialgebras by providing means to handle empty carriers (as well as empty result-sets) without the use of quantifiers, and to derive consequences of theories without translation into another format and without using general cut.     

Using prior knowledge in SVD-based parameter estimation for magnetic resonance spectroscopy--the ATP example

We introduce the knowledge-based singular value decomposition (KNOB-SVD) method for exploiting prior knowledge in magnetic resonance (MR) spectroscopy based on the SVD of the data matrix. More specifically, we assume that the MR data are well modeled by the superposition of a given number of exponentially damped sinusoidal components and that the dampings alphakappa, frequencies omegakappa, and complex amplitudes rhokappa of some components satisfy the following relations: alphakappa = alpha (alpha = unknown), omegakappa = omega + (kappa- 1)delta (omega = unknown, delta = known), and rhokappa = Ckapparho (rho = unknown, ckappa = known real constants). The adenosine triphosphate (ATP) complex, which has one triple peak and two double peaks whose dampings, frequencies, and amplitudes may in some cases be known to satisfy the above type of relations, is used as a vehicle for describing our SVD-based method throughout the paper. By means of numerical examples, we show that our method provides more accurate parameter estimates than a commonly used general-purpose SVD-based method and a previously suggested prior knowledge-based SVD method.     

The influence of electrochemical potential on wear

Electrochemical potentials between ?1.4 and +1.2 V (saturated calomel electrode) applied to Ni(200) in the nominally inert electrolyte 1 M NaClO₄ resulted in an observed order of magnitude variation in the wear rate of the nickel under fretting and sliding conditions. The pin-on-disc experiments were carried out with a fused Al₂O₃ pin loaded at 9.8 and 19.6 MPa sliding on discs at 10 m min^?1, and fretting wear was simulated by a high frequency (10⁵–10⁷cm^?2s^?1) low amplitude impact of a vibrating Al₂O₃ pin on the disc. These results suggest that it is possible to control wear in ionically conducting fluids through the application of appropriate electrochemical potentials.