Time-gated transillumination and reflection by biological tissues and tissuelike phantoms: simulation versus experiment

A numerical method is presented to solve exactly the time-dependent diffusion equation that describes light transport in turbid media. The simulation takes into account spatial variations of the scattering and absorption factors of the medium and the objects as well as random fluctuations of these quantities. The technique is employed to explore the possibility of locating millimeter-sized objects immersed in turbid media from time-gated measurements of the transmitted or reflected (near-infrared) light. The simulation results for tissue-like phantoms are compared with experimental transillumination data, and excellent agreement is found. Simulations of time-gated reflection experiments indicate that it may be possible to detect objects of 1-mm radius.

Sequential Deliberation for Social Choice

In large scale collective decision making, social choice is a normative study of how one ought to design a protocol for reaching consensus. However, in instances where the underlying decision space is too large or complex for ordinal voting, standard voting methods of social choice may be impractical. How then can we design a mechanism - preferably decentralized, simple, scalable, and not requiring any special knowledge of the decision space - to reach consensus? We propose sequential deliberation as a natural solution to this problem. In this iterative method, successive pairs of agents bargain over the decision space using the previous decision as a disagreement alternative. We describe the general method and analyze the quality of its outcome when the space of preferences define a median graph. We show that sequential deliberation finds a 1.208- approximation to the optimal social cost on such graphs, coming very close to this value with only a small constant number of agents sampled from the population. We also show lower bounds on simpler classes of mechanisms to justify our design choices. We further show that sequential deliberation is ex-post Pareto efficient and has truthful reporting as an equilibrium of the induced extensive form game. We finally show that for general metric spaces, the second moment of of the distribution of social cost of the outcomes produced by sequential deliberation is also bounded

Ambient-aware continuous care through semantic context dissemination

Background: The ultimate ambient-intelligent care room contains numerous sensors and devices to monitor the patient, sense and adjust the environment and support the staff. This sensor-based approach results in a large amount of data, which can be processed by current and future applications, e. g., task management and alerting systems. Today, nurses are responsible for coordinating all these applications and supplied information, which reduces the added value and slows down the adoption rate. The aim of the presented research is the design of a pervasive and scalable framework that is able to optimize continuous care processes by intelligently reasoning on the large amount of heterogeneous care data. Methods: The developed Ontology-based Care Platform (OCarePlatform) consists of modular components that perform a specific reasoning task. Consequently, they can easily be replicated and distributed. Complex reasoning is achieved by combining the results of different components. To ensure that the components only receive information, which is of interest to them at that time, they are able to dynamically generate and register filter rules with a Semantic Communication Bus (SCB). This SCB semantically filters all the heterogeneous care data according to the registered rules by using a continuous care ontology. The SCB can be distributed and a cache can be employed to ensure scalability. Results: A prototype implementation is presented consisting of a new-generation nurse call system supported by a localization and a home automation component. The amount of data that is filtered and the performance of the SCB are evaluated by testing the prototype in a living lab. The delay introduced by processing the filter rules is negligible when 10 or fewer rules are registered. Conclusions: The OCarePlatform allows disseminating relevant care data for the different applications and additionally supports composing complex applications from a set of smaller independent components. This way, the platform significantly reduces the amount of information that needs to be processed by the nurses. The delay resulting from processing the filter rules is linear in the amount of rules. Distributed deployment of the SCB and using a cache allows further improvement of these performance results

Evaluating Metaphor Reification in Tangible Interfaces

International audienceMetaphors are a powerful conceptual device to reason about human actions. As such, they have been heavily used in designing and describing human computer interaction. Since they can address scripted text, verbal expression, imaging, sound, and gestures, they can also be considered in the design and analysis of multimodal interfaces. In this paper we discuss the description and evaluation of the relations between metaphors and their implementation in human computer interaction with a focus on tangible user interfaces (TUIs), a form of multimodal interface. The objective of this paper is to define how metaphors appear in a tangible context in order to support their evaluation. Relying on matching entities and operations between the domain of interaction and the domain of the digital application, we propose a conceptual framework based on three components: a structured representation of the mappings holding between the metaphor source, the metaphor target, the interface and the digital system; a conceptual model for describing metaphorical TUIs; three relevant properties, coherence, coverage and compliance, which define at what extent the implementation of a metaphorical tangible interface matches the metaphor. The conceptual framework is then validated and applied on a tangible prototype in an educational application

The Values of Tangible User Interfaces: How to discover, assess and evaluate them?

Since the introduction of Tangible User Interfaces, in the beginning of the 90s, a generation grew up interacting with computers. At the same time the context of computing changed dramatically: from a device used almost exclusively by specialists, it evolved to a general device that plays a dominant role in our societies. But where does this leave TUI? In many respects, the idea of tangibility plays a marginal role in Human Computer Interaction. It makes sense to re-evaluate the intrinsic values of TUI design. This paper proposes to research the appropriate metrics to do so

TangiWheel: A widget for manipulating collections on tabletop displays supporting hybrid Input modality

In this paper we present TangiWheel, a collection manipulation widget for tabletop displays. Our implementation is flexible, allowing either multi-touch or interaction, or even a hybrid scheme to better suit user choice and convenience. Different TangiWheel aspects and features are compared with other existing widgets for collection manipulation. The study reveals that TangiWheel is the first proposal to support a hybrid input modality with large resemblance levels between touch and tangible interaction styles. Several experiments were conducted to evaluate the techniques used in each input scheme for a better understanding of tangible surface interfaces in complex tasks performed by a single user (e.g., involving a typical master-slave exploration pattern). The results show that tangibles perform significantly better than fingers, despite dealing with a greater number of interactions, in situations that require a large number of acquisitions and basic manipulation tasks such as establishing location and orientation. However, when users have to perform multiple exploration and selection operations that do not require previous basic manipulation tasks, for instance when collections are fixed in the interface layout, touch input is significantly better in terms of required time and number of actions. Finally, when a more elastic collection layout or more complex additional insertion or displacement operations are needed, the hybrid and tangible approaches clearly outperform finger-based interactions.. ©2012 Springer Science+Business Media, LLC & Science Press, ChinaThe work is supported by the Ministry of Education of Spain under Grant No. TSI2010-20488. Alejandro Catala is supported by an FPU fellowship for pre-doctoral research staff training granted by the Ministry of Education of Spain with reference AP2006-00181.Catalá Bolós, A.; García Sanjuan, F.; Jaén Martínez, FJ.; Mocholi Agües, JA. (2012). TangiWheel: A widget for manipulating collections on tabletop displays supporting hybrid Input modality. Journal of Computer Science and Technology. 27(4):811-829. doi:10.1007/s11390-012-1266-4S811829274Jordà S, Geiger G, Alonso M, Kaltenbrunner M. The reacTable: Exploring the synergy between live music performance and tabletop tangible interfaces. In Proc. TEI 2007, Baton Rouge, LA, USA, Feb. 15-17, 2007, pp.139–146.Vandoren P, van Laerhoven T, Claesen L, Taelman J, Raymaekers C, van Reeth F. IntuPaint: Bridging the gap between physical and digital painting. In Proc. TABLETOP2008, Amterdam, the Netherlands, Oct. 1-3, 2008, pp.65–72.Schöning J, Hecht B, Raubal M, Krüger A, Marsh M, Rohs M. Improving interaction with virtual globes through spatial thinking: Helping users ask “why?”. In Proc. IUI 2008, Canary Islans, Spain, Jan. 13-16, 2008, pp.129–138.Fitzmaurice GW, BuxtonW. An empirical evaluation of graspable user interfaces: Towards specialized, space-multiplexed input. In Proc. CHI 1997, Atlanta, USA, March 22-27, 1997, pp.43–50.Tuddenham P, Kirk D, Izadi S. Graspables revisited: Multitouch vs. tangible input for tabletop displays in acquisition and manipulation tasks. In Proc. CHI 2010, Atlanta, USA, April 10-15, 2010, pp.2223–2232.Lucchi A, Jermann P, Zufferey G, Dillenbourg P. An empirical evaluation of touch and tangible interfaces for tabletop displays. In Proc. TEI 2010, Cambridge, USA, Jan. 25-27, 2010, pp.177–184.Fitzmaurice G W, Ishii H, Buxton W. Bricks: Laying the foundations for graspable user interfaces. In Proc. CHI 1995, Denver, USA, May 7-11, 1995, pp.442–449.Ishii H, Ullmer B. Tangible bits: Towards seamless interfaces between people, bits and atoms. In Proc. CHI 1997, Atlanta, USA, March 22-27, 1997, pp.234–241.Ullmer B, Ishii H, Glas D. mediaBlocks: Physical containers, transports, and controls for online media. In Proc. SIGGRAPH1998, Orlando, USA, July 19-24, 1998, pp.379–386.Shen C, Hancock M S, Forlines C, Vernier F D. CoR2Ds: Context-rooted rotatable draggables for tabletop interaction. In Proc. CHI 2005, Portland, USA, April 2-7, 2005, pp.1781–1784.Lepinski G J, Grossman T, Fitzmaurice G. The design and evaluation of multitouch marking menus. In Proc. CHI 2010, Atlanta, USA, April 10-15, 2010, pp.2233–2242.Accot J, Zhai S. Beyond Fitts’ law: Models for trajectorybased HCI tasks. In Proc. CHI 1997, Atlanta, USA, March 22-27, 1997, pp.295–302.Song H, Kim B, Lee B, Seo J. A comparative evaluation on tree visualization methods for hierarchical structures with large fan-outs. In Proc. CHI 2010, Atlanta, USA, April 10-15, 2010, pp.223–232.Bailly G, Lecolinet E, Nigay L. Wave menus: Improving the novice mode of hierarchical marking menus. In Proc. INTERACT2007, Río de Janeiro, Brazil, Sept. 10-14, 2007, pp.475–488.Zhao S, Agrawala M, Hinckley K. Zone and polygon menus: Using relative position to increase the breadth of multi-stroke marking menus. In Proc. CHI 2006, Montreal, Canada, April 24-27, 2006, pp.1077–1086.Patten J, Recht B, Ishii H. Interaction techniques for musical performance with tabletop tangible interfaces. In Proc. ACE2006, Hollywood, USA, Jun. 14-16, 2006, Article No.27.Weiss M, Wagner J, Jansen Y, Jennings R, Khoshabeh R, Hollan J D, Borchers J. SLAP widgets: Bridging the gap between virtual and physical controls on tabletops. In Proc. CHI 2009, Boston, USA, April 4-9, 2009, pp.481–490.Hancock M, Hilliges O, Collins C, Baur D, Carpendale S. Exploring tangible and direct touch interfaces for manipulating 2D and 3D information on a digital table. In Proc. ITS 2009, Banff, Canada, Nov. 23-25, pp.77–84.Hilliges O, Baur D, Butz A. Photohelix: Browsing, sorting and sharing digital photo collections. In Proc. Horizontal Interactive Human-Computer Systems (TABLETOP2007), Newport, Rhode Island, USA, Oct. 10-12, 2007, pp.87–94.Hesselmann T, Flöring S, Schmidt M. Stacked half-Pie menus: Navigating nested menus on interactive tabletops. In Proc. ITS 2009, Banff, Canada, Nov. 23-25, 2009, pp.173–180.Gallardo D, Jordà S. Tangible jukebox: Back to palpable music. In Proc. TEI 2010, Boston, USA, Jan. 25-27, 2010, pp.199–202.Fishkin K. A taxonomy for and analysis of tangible interfaces. Personal and Ubiquitous Computing, 2004, 8(5): 347–358.Catala A, Jaen J, Martinez-Villaronga A A, Mocholi J A. AGORAS: Exploring creative learning on tangible user interfaces. In Proc. COMPSAC 2011, Munich, Germany, July 18-22, 2011, pp.326–335.Catala A, Garcia-Sanjuan F, Azorin J, Jaen J, Mocholi J A. Exploring direct communication and manipulation on interactive surfaces to foster novelty in a creative learning environment. IJCSRA, 2012, 2(1): 15–24.Catala A, Jaen J, van Dijk B, Jord`a S. Exploring tabletops as an effective tool to foster creativity traits. In Proc. TEI 2012, Kingston, Canada, Feb. 19-22, 2012, pp.143–150.Hopkins D. Directional selection is easy as pie menus. In: The Usenix Association Newsletter, 1987, 12(5): 103.Microsoft Surface User Experience Guidelines. http://msdn.microsoft.com/en-us/library/ff318692.aspx , May 2011.Maydak M, Stromer R, Mackay H A, Stoddard L T. Stimulus classes in matching to sample and sequence production: The emergence of numeric relations. Research in Developmental Disabilities, 1995, 16(3): 179–204

Rethinking ‘Advanced Search’: A New Approach to Complex Query Formulation

Knowledge workers such as patent agents, recruiters and media monitoring professionals undertake work tasks where search forms a core part of their duties. In these instances, the search task often involves the formulation of complex queries expressed as Boolean strings. However, creating effective Boolean queries remains an ongoing challenge, often compromised by errors and inefficiencies. In this demo paper, we present a new approach to query formulation in which concepts are expressed on a two-dimensional canvas and relationships are articulated using direct manipulation. This has the potential to eliminate many sources of error, makes the query semantics more transparent, and offers new opportunities for query refinement and optimisatio

Pre-Sleep Low Glycemic Modified Starch Does Not Improve Next Morning Running Performance in Endurance Athletes

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