448 research outputs found
Hydrogen Ion Reaction of Native Inidana Fern Soils
A number of studies of soil acidity in relation to plant groups and plant distribution have been made in recent years, but none of these have been carried on with the ferns of Indiana soils. The present study was made in the hope of extending such information to a wider range of soil conditions
Process of designing robust, dependable, safe and secure software for medical devices: Point of care testing device as a case study
This article has been made available through the Brunel Open Access Publishing Fund.Copyright © 2013 Sivanesan Tulasidas et al. This paper presents a holistic methodology for the design of medical device software, which encompasses of a new way of eliciting requirements, system design process, security design guideline, cloud architecture design, combinatorial testing process and agile project management. The paper uses point of care diagnostics as a case study where the software and hardware must be robust, reliable to provide accurate diagnosis of diseases. As software and software intensive systems are becoming increasingly complex, the impact of failures can lead to significant property damage, or damage to the environment. Within the medical diagnostic device software domain such failures can result in misdiagnosis leading to clinical complications and in some cases death. Software faults can arise due to the interaction among the software, the hardware, third party software and the operating environment. Unanticipated environmental changes and latent coding errors lead to operation faults despite of the fact that usually a significant effort has been expended in the design, verification and validation of the software system. It is becoming increasingly more apparent that one needs to adopt different approaches, which will guarantee that a complex software system meets all safety, security, and reliability requirements, in addition to complying with standards such as IEC 62304. There are many initiatives taken to develop safety and security critical systems, at different development phases and in different contexts, ranging from infrastructure design to device design. Different approaches are implemented to design error free software for safety critical systems. By adopting the strategies and processes presented in this paper one can overcome the challenges in developing error free software for medical devices (or safety critical systems).Brunel Open Access Publishing Fund
Mastering the Master Space
Supersymmetric gauge theories have an important but perhaps under-appreciated
notion of a master space, which controls the full moduli space. For
world-volume theories of D-branes probing a Calabi-Yau singularity X the
situation is particularly illustrative. In the case of one physical brane, the
master space F is the space of F-terms and a particular quotient thereof is X
itself. We study various properties of F which encode such physical quantities
as Higgsing, BPS spectra, hidden global symmetries, etc. Using the plethystic
program we also discuss what happens at higher number N of branes. This letter
is a summary and some extensions of the key points of a longer companion paper
arXiv:0801.1585.Comment: 10 pages, 1 Figur
Debugging knowledge-based applications with a generic toolkit.
Knowledge refinement tools assist in the debugging and maintenance of knowledge based systems (KBSs) by attempting to identify and correct faults in the knowledge that account for incorrect problem-solving. Most refinement systems target a single shell and are able to refine only KBSs implemented in this shell. Our KRUSTWorks toolkit is unusual in that it provides refinement facilities that can be applied to a number of different shells, and is designed to be extensible to new shells. The paper outlines the components of the KRUSTWorks toolkit and how it is applied to faulty KBSs. It describes its application to two real aerospace KBSs implemented in CLIPS and POWER-MODEL to demonstrate its flexibility of application
On Dimer Models and Closed String Theories
We study some aspects of the recently discovered connection between dimer
models and D-brane gauge theories. We argue that dimer models are also
naturally related to closed string theories on non compact orbifolds of \BC^2
and \BC^3, via their twisted sector R charges, and show that perfect
matchings in dimer models correspond to twisted sector states in the closed
string theory. We also use this formalism to study the combinatorics of some
unstable orbifolds of \BC^2.Comment: 1 + 25 pages, LaTeX, 11 epsf figure
HIV provider and patient perspectives on the Development of a Health Department “Data to Care” Program: a qualitative study
Abstract Background U.S. health departments have not historically used HIV surveillance data for disease control interventions with individuals, but advances in HIV treatment and surveillance are changing public health practice. Many U.S. health departments are in the early stages of implementing “Data to Care” programs to assists persons living with HIV (PLWH) with engaging in care, based on information collected for HIV surveillance. Stakeholder engagement is a critical first step for development of these programs. In Seattle-King County, Washington, the health department conducted interviews with HIV medical care providers and PLWH to inform its Data to Care program. This paper describes the key themes of these interviews and traces the evolution of the resulting program. Methods Disease intervention specialists conducted individual, semi-structured qualitative interviews with 20 PLWH randomly selected from HIV surveillance who had HIV RNA levels >10,000 copies/mL in 2009–2010. A physician investigator conducted key informant interviews with 15 HIV medical care providers. Investigators analyzed de-identified interview transcripts, developed a codebook of themes, independently coded the interviews, and identified codes used most frequently as well as illustrative quotes for these key themes. We also trace the evolution of the program from 2010 to 2015. Results PLWH generally accepted the idea of the health department helping PLWH engage in care, and described how hearing about the treatment experiences of HIV seropositive peers would assist them with engagement in care. Although many physicians were supportive of the Data to Care concept, others expressed concern about potential health department intrusion on patient privacy and the patient-physician relationship. Providers emphasized the need for the health department to coordinate with existing efforts to improve patient engagement. As a result of the interviews, the Data to Care program in Seattle-King County was designed to incorporate an HIV-positive peer component and to ensure coordination with HIV care providers in the process of relinking patients to care. Conclusions Health departments can build support for Data to Care efforts by gathering input of key stakeholders, such as HIV medical and social service providers, and coordinating with clinic-based efforts to re-engage patients in care
MartiTracks: A Geometrical Approach for Identifying Geographical Patterns of Distribution
Panbiogeography represents an evolutionary approach to biogeography, using rational cost-efficient methods to reduce initial complexity to locality data, and depict general distribution patterns. However, few quantitative, and automated panbiogeographic methods exist. In this study, we propose a new algorithm, within a quantitative, geometrical framework, to perform panbiogeographical analyses as an alternative to more traditional methods. The algorithm first calculates a minimum spanning tree, an individual track for each species in a panbiogeographic context. Then the spatial congruence among segments of the minimum spanning trees is calculated using five congruence parameters, producing a general distribution pattern. In addition, the algorithm removes the ambiguity, and subjectivity often present in a manual panbiogeographic analysis. Results from two empirical examples using 61 species of the genus Bomarea (2340 records), and 1031 genera of both plants and animals (100118 records) distributed across the Northern Andes, demonstrated that a geometrical approach to panbiogeography is a feasible quantitative method to determine general distribution patterns for taxa, reducing complexity, and the time needed for managing large data sets
Applying genetic algorithms to multi-objective land use planning.
This paper explores the application of multi-objective genetic algorithms (mGAs) to rural land-use planning, a spatial allocation problem. Two mGAs are proposed. Both share an underlying structure of: fitness assignment using Pareto-dominance ranking, niche induction and an individual replacement strategy. They are differentiated by their representations: a fixed-length genotype composed of genes that map directly to a land parcel's use, and a variable-length, order-dependent representation making allocations indirectly via a greedy algorithm. The latter representation requires additional breeding operators to be defined and post-processing of the genotype structure, to identify and remove duplicate genotypes. The two mGAs are compared on a real land-use planning problem, and the strengths and weaknesses of the underlying framework - and of each representation - are identified
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