A matrix-free algorithm for multiple wavelength fluorescence tomography

In the recent years, there has been an increase in applications of non-contact diffusion optical tomography. Especially when the objective is the recovery of fluorescence targets. The non-contact acquisition systems with the use of a CCD-camera produce much denser sampled boundary data sets than fibre-based systems. When model-based reconstruction methods are used, that rely on the inversion of a derivative operator, the large number of measurements poses a challenge since the explicit formulation and storage of the Jacobian matrix could be in general not feasible. This problem is aggravated further in applications, where measurements at multiple wavelengths are used. We present a matrix-free model-based reconstruction method, that addresses the problems of large data sets and reduces the computational cost and memory requirements for the reconstruction. The idea behind the matrix-free method is that information about the Jacobian matrix could be available through matrix times vector products so that the creation and storage of big matrices can be avoided. We tested the method for multiple wavelength fluorescence tomography with simulated and experimental data from phantom experiments, and we found substantial benefits in computational times and memory requirements. (C) 2009 Optical Society of Americ

Working with Memory in the Archaeology of Modern Conflict

The aim of this article is to situate archaeological approaches to modern conflicts within a framework of conflict memory and commemoration. A critical appreciation of historical archaeology as a commemorative practice requires a firm grounding in memory theory, specifically the formation and contestation of memory narratives. This article offers a detailed analysis of the relevant theories and demonstrates their applicability in the contested archaeology of the Nazi era in Berlin. On the basis of this critique I argue that archaeological work on contested sites offers a unique and powerful forum for socially engaged interdisciplinary research

Concepts and their Use for Modelling Objects and References in Programming Languages

In the paper a new programming construct, called concept, is introduced. Concept is pair of two classes: a reference class and an object class. Instances of the reference classes are passed-by-value and are intended to represent objects. Instances of the object class are passed-by-reference. An approach to programming where concepts are used instead of classes is called concept-oriented programming (CoP). In CoP objects are represented and accessed indirectly by means of references. The structure of concepts describes a hierarchical space with a virtual address system. The paper describes this new approach to programming including such mechanisms as reference resolution, complex references, method interception, dual methods, life-cycle management inheritance and polymorphism.Comment: 43 pages. Related papers: http://conceptoriented.com

Noise thresholds for optical cluster-state quantum computation

In this paper we do a detailed numerical investigation of the fault-tolerant threshold for optical cluster-state quantum computation. Our noise model allows both photon loss and depolarizing noise, as a general proxy for all types of local noise other than photon loss noise. We obtain a threshold region of allowed pairs of values for the two types of noise. Roughly speaking, our results show that scalable optical quantum computing is possible for photon loss probabilities less than 0.003, and for depolarization probabilities less than 0.0001. Our fault-tolerant protocol involves a number of innovations, including a method for syndrome extraction known as telecorrection, whereby repeated syndrome measurements are guaranteed to agree. This paper is an extended version of [Dawson et al., Phys. Rev. Lett. 96, 020501].Comment: 28 pages. Corrections made to Table I

The Impact of User Interface Design on Idea Integration in Electronic Brainstorming: An Attention-Based View

This paper introduces an attention-based view of idea integration that underscores the importance of IS user interface design. The assumption is that presenting ideas via user interface plays a key role in enabling and motivating idea integration in electronic brainstorming (EBS), and thus advances productivity. Building upon Cognitive Network Model of Creativity and ability-motivation framework, our attention-based theory focuses on two major attributes of user interface: visibility and prioritization. While visibility enables idea integration via directing attention to a limited set of ideas, prioritization enhances the motivation for idea integration by providing individuals with a relevant and legitimate proxy for value of the shared ideas. The theory developed in this paper is distinct from previous research on EBS in at least two ways: (1) this theory exclusively focuses on idea integration as the desired outcome and studies it in the context of IS user interface; and (2) rather than debating whether or not EBS universally outperforms verbal brainstorming, the proposed theory revisits the links between user interface and idea integration as an attention-intensive process that contributes to EBS productivity. Idea integration by individuals within a group is an essential process for organizational creativity and thus for establishing knowledge-based capabilities. Lack of such integration significantly reduces the value of idea sharing, which has been a predominant focus of the EBS literature in the past. The current theory posits that the ability of electronic brain-storming to outperform nominal or verbal brainstorming depends on its ability to leverage information system (IS) artifact capabilities for enhancing idea integration to create a key pattern of productivity. The developed theory provides a foundation for new approaches to EBS research and design, which use visibility and prioritization, and also identify new user interface features for fostering idea integration. By emphasizing idea integration, designers and managers are provided with practical, cognition-based criteria for choosing interface features, which can improve EBS productivity. This theory also has implications for both the practice and research of knowledge management, especially for the attention-based view of the organization.

A Study on an Assessment Framework for the Novelty of Ideas Generated by Analogical Thinking

AbstractAlthough there have been many educational programs focusing on the creation of new ideas, the assessment of novelty is still a controversial issue. As an ideation tool, analogical thinking enables conceptual change, which is seen as a crucial aspect of creativity. In this regard, the use of analogy can be an important instrument to facilitate novel idea generation. Analogies are generated by superficial or structural similarities from the memory. For creating a new idea by analogy, this study regards novelty as the domain-changing influenced by structural consistency with the source ideas. Consequently, we designed an assessment framework based on the latent semantic analysis of the domains and the consistency of the underlying mechanism between the source and the new ideas. Data was collected from the 14 subjects who participated in the workshop for this study. The workshop consists of three tasks: 1) Pre-task: All subjects were asked to read the 25 cases of the collective intelligence services, which is a business model creating value from large and loosely organized groups of people working together electronically e.g. Amazon.com, Google Japanese input; 2) Categorization task: Subjects were asked to categorize each case based on the underlying mechanism of the business through group discussion; 3) Generation task: Subjects were asked to create a new service idea individually using analogical thinking. As a result, 12 ideas were created, 6 of which were assessed as novel according to our assessment framework. Among the remaining 6 ideas, 4 were assessed as having high superficial similarity in terms of the idea domain, and 2 as having neither superficial nor structural similarity with the source ideas. Although our findings suggest that the proposed assessment framework for novelty evaluation is unable to provide a ‘one-size fits-all method’, it does enable us to overcome some of the limitations of current evaluation methods which depend on subjective judgements for rating

Cinematic Narratives of Product Interaction Experiences: Methods for Cross-Media Fertilisation of the Design Process

This paper outlines the initial phases of a practice-based PhD research project; it outlines methods that will be used to analyse the role of objects within cinematic narratives and how these narrative roles could be translated into methods for designing products to enrich the experience of using the products. The starting point for this project is the hypothesis that any interaction between a user and an object will be remembered and interpreted in a user's mind as a form of narrative. This project therefore tries to harness narrative structures and devices from other media to inform the design of products that can specifically cater to these narrative qualities inherent in the way we experience products. This paper outlines methods for opening up the dialogue about these cross-media narrative comparisons, to assist in generating design work which focuses on the narrative qualities of product experience