275 research outputs found
BIRP: Software for interactive search and retrieval of image engineering data
Better Image Retrieval Programs (BIRP), a set of programs to interactively sort through and to display a database, such as engineering data for images acquired by spacecraft is described. An overview of the philosophy of BIRP design, the structure of BIRP data files, and examples that illustrate the capabilities of the software are provided
Maritime Safety - Stakeholders in Information Exchange Process
This paper presents the methodology and research results on identification of potential users of the ESABALT system, which is targeted towards improving the situational awareness in the Baltic Sea region. We describe the technique of analysing the stakeholders involved in maritime sector processes, especially in maritime transport processes, while also taking into account their different classification criteria. The resulting list of stakeholders is used to identify system users and their classification into user profiles groups. This study will form the basis for the identification of user requirements of the ESABALT system
Analysis and Identification of Requirements for a System to Enhance Situational Awareness at Sea
This paper presents the research results of identifying and analyzing key requirements for the ESABALT system based on pre-defined user profile groups. These requirements have been identified through multiple sources, which include an electronic survey of potential users of the system, interviews with specialists in navigation, law and computer science, analysis of state-of-the-art in maritime safety procedures, and study of past R&D projects in this field. Finally, these requirements are classified into user level, domain level and system level requirements for easy interpretation while designing the system architecture and its function-al specifications. The presented system specification is discussed
Weyl points and exceptional rings with polaritons in bulk semiconductors
Weyl points are the simplest topologically-protected degeneracy in a
three-dimensional dispersion relation. The realization of Weyl semimetals in
photonic crystals has allowed these singularities and their consequences to be
explored with electromagnetic waves. However, it is difficult to achieve
nonlinearities in such systems. One promising approach is to use the
strong-coupling of photons and excitons, because the resulting polaritons
interact through their exciton component. Yet topological polaritons have only
been realized in two dimensions. Here, we predict that the dispersion relation
for polaritons in three dimensions, in a bulk semiconductor with an applied
magnetic field, contains Weyl points and Weyl line nodes. We show that
absorption converts these Weyl points to Weyl exceptional rings. We conclude
that bulk semiconductors are a promising system in which to investigate
topological photonics in three dimensions, and the effects of dissipation,
gain, and nonlinearity.Comment: 11 pages, 7 figures. v2: Improved figures, additional references and
discussions. v3: Additional figur
PowerAqua: fishing the semantic web
The Semantic Web (SW) offers an opportunity to develop novel, sophisticated forms of question answering (QA). Specifically, the availability of distributed semantic markup on a large scale opens the way to QA systems which can make use of such semantic information to provide precise, formally derived answers to questions. At the same time the distributed, heterogeneous, large-scale nature of the semantic information introduces significant challenges. In this paper we describe the design of a QA system, PowerAqua, designed to exploit semantic markup on the web to provide answers to questions posed in natural language. PowerAqua does not assume that the user has any prior information about the semantic resources. The system takes as input a natural language query, translates it into a set of logical queries, which are then answered by consulting and aggregating information derived from multiple heterogeneous semantic sources
The effects of scale on the costs of targeted HIV prevention interventions among female and male sex workers, men who have sex with men and transgenders in India
BACKGROUND: The India AIDS Initiative (Avahan) project is involved in rapid scale-up of HIV-prevention interventions in high-risk populations. This study examines the cost variation of 107 non-governmental organisations (NGOs) implementing targeted interventions, over the start up (defined as period from project inception until services to the key population commenced) and first 2 years of intervention. METHODS: The Avahan interventions for female and male sex workers and their clients, in 62 districts of four southern states were costed for the financial years 2004/2005 and 2005/2006 using standard costing techniques. Data sources include financial and economic costs from the lead implementing partners (LPs) and subcontracted local implementing NGOs retrospectively and prospectively collected from a provider perspective. Ingredients and step-down allocation processes were used. Outcomes were measured using routinely collected project data. The average costs were estimated and a regression analysis carried out to explore causes of cost variation. Costs were calculated in US76 per person registered with the project. Sixty-one per cent of the cost variation could be explained by scale (positive association), number of NGOs per district (negative), number of LPs in the state (negative) and project maturity (positive) (p<0.0001). CONCLUSIONS: During rapid scale-up in the initial phase of the Avahan programme, a significant reduction in average costs was observed. As full scale-up had not yet been achieved, the average cost at scale is yet to be realised and the extent of the impact of scale on costs yet to be captured. Scale effects are important to quantify for planning resource requirements of large-scale interventions. The average cost after 2 years is within the range of global scale-up costs estimates and other studies in India
ESABALT - Improvement of Situational Awareness in the Baltic with the Use of Crowdsourcing
This paper presents the key assumptions and preliminary research on an integrated system called ESABALT, for enhancing maritime safety, which incorporates the latest technological advances in positioning, e-Navigation, Earth observation systems and multi-channel cooperative communications. The most novel part of the ESABALT concept, however, is a focus on user-driven crowdsourcing techniques for information gathering and integration. The system will consist of a situational awareness solution for real-time maritime traffic monitoring via utilizing various positioning technologies; an observation system of the marine environment relevant to transportation and accidents including assessing the sea ice, oil spread, waves, wind etc.; and a methodology for context-aware maritime communication with cooperative, multi-channel capabilities. The paper presents the intelligent, novel, user-driven solution and associated services developed in ESABALT for enhancing the maritime safety in the whole Baltic area
The Historical Context of the Gender Gap in Mathematics
This chapter is based on the talk that I gave in August 2018 at the ICM in Rio de Janeiro at the panel on "The Gender Gap in Mathematical and Natural Sciences from a Historical Perspective". It provides some examples of the challenges and prejudices faced by women mathematicians during last two hundred and fifty years. I make no claim for completeness but hope that the examples will help to shed light on some of the problems many women mathematicians still face today
- …