Iterative Refinement on FPGAs

Author(s):  
Jun Kyu Lee ◽  
Gregory D. Peterson
Keyword(s):  
Author(s):  
Alejandro Pardo ◽  
Humam Alwassel ◽  
Fabian Caba Heilbron ◽  
Ali Thabet ◽  
Bernard Ghanem

1994 ◽  
Vol 3 (2) ◽  
pp. 111-129 ◽  
Author(s):  
William Bricken ◽  
Geoffrey Coco

The Virtual Environment Operating Shell (veos) was developed at University of Washington's Human Interface Technology Laboratory as software infrastructure for the lab's research in virtual environments. veos was designed from scratch to provide a comprehensive and unified management facility to support generation of, interaction with, and maintenance of virtual environments. VEOS emphasizes rapid prototyping, heterogeneous distributed computing, and portability. We discuss the design, philosophy and implementation of veos in depth. Within the Kernel, the shared database transformations are pattern-directed, communications are asynchronous, and the programmer's interface is LISP. An entity-based metaphor extends object-oriented programming to systems-oriented programming. Entities provide first-class environments and biological programming constructs such as perceive, react, and persist. The organization, structure, and programming of entities are discussed in detail. The article concludes with a description of the applications that have contributed to the iterative refinement of the VEOS software.


Geophysics ◽  
2010 ◽  
Vol 75 (1) ◽  
pp. E9-E29 ◽  
Author(s):  
Alberto Mendoza ◽  
Carlos Torres-Verdín ◽  
Bill Preeg

As a result of its high numerical accuracy and versatility to include complex tool configurations and arbitrary spatial distributions of material properties, the Monte Carlo method is the foremost numerical technique used to simulate borehole nuclear measurements. Although recent advances in computer technology have considerably reduced the computer time required by Monte Carlo simulations of borehole nuclear measurements, the efficiency of the method is still not sufficient for estimation of layer-by-layer properties or combined quantitative interpretation with other borehole measurements. We develop and successfully test a new linear iterative refinement method to simulate nuclear borehole measurements accurately and rapidly. The approximation stems from Monte Carlo-derived geometric response factors, referred to as flux sensitivity functions (FSFs), for specific density and neutron-tool configurations. Our procedure first invokes the integral representation of Boltzmann’s transport equation to describe the detector response from the flux of particles emitted by the radioactive source. Subsequently, we use theMonte Carlo N-particle (MCNP) code to calculate the associated detector response function and the particle flux included in the integral form of Boltzmann’s equation. The linear iterative refinement method accounts for variations of the response functions attributable to local perturbations when numerically simulating neutron and density porosity logs. We quantify variations in the FSFs of neutron and density measurements from borehole environmental effects and spatial variations of formation properties. Simulations performed with the new approximations yield errors in the simulated value of density of less than [Formula: see text] with respect to Monte Carlo-simulated logs. Moreover, for the case of radial geometric factor of density, we observe a maximum shift of [Formula: see text] at 90% of the total sensitivity as a result of realistic variations of formation density. For radial variation of neutron properties (migration length), the maximum change in the radial length of investigation is [Formula: see text]. Neutron porosity values simulated with the new approximation differ by less than 10% from Monte Carlo simulations. The approximations enable the simulation of borehole nuclear measurements in seconds of CPU time compared to several hours with MCNP.


2018 ◽  
Vol 23 (suppl_1) ◽  
pp. e6-e7
Author(s):  
Rebecca Wang ◽  
Ronik Kanani ◽  
Niraj Mistry ◽  
Yara El Bardisi ◽  
Joana Dos Santos

Abstract BACKGROUND Bowel and bladder dysfunction (BBD) is a common yet underdiagnosed paediatric condition that describes a constellation of lower urinary tract symptoms (LUTS) associated with constipation and/or encopresis. Many children with BBD have co-morbid neuropsychiatric symptoms (e.g., inattention, anxiety) and psychosocial stressors. Thus, clinical assessment of behavioural symptoms and social risk factors in this population is essential. However, there is no standardized approach for a comprehensive assessment of BBD. OBJECTIVES We aim to develop and evaluate physician and parent perceptions with 1) a standardized BBD history and physical intake form for physicians, and 2) a parent-reported intake form. DESIGN/METHODS From June to Oct 2017, a quality improvement study was conducted in the BBD network, an existing paediatric collaborative initiative consisting of 7 community sites with support of the paediatric urology division in a tertiary hospital. Based on literature review and expert opinions, a standardized intake form was developed for BBD assessment with targeted questions for LUTS, constipation, behavioural, dietary, and psychosocial history, along with a physical exam checklist for neurological red flags. Further, a shorter parent-reported intake questionnaire was developed to clarify patterns of dysfunctional voiding symptoms, dietary recall and stool history. Both forms underwent usability testing and iterative refinement. Prior to clinic, families of children referred for BBD were mailed an intake package for completion. During the clinic, physicians were asked to use the standardized intake form for new referrals. Afterwards, both physicians and parents were given anonymous surveys to evaluate their perceptions of the intake process. RESULTS A total of 8 physicians and 20 parents responded, with 60% of patients being between ages 4–10 and 55% male. Physicians found the standardized intake form to be a useful guide that reminded them to ask about specific urinary symptoms (88% of the time), constipation (75%), and psychosocial history (76%). The majority of physicians (75%) agreed they would use the intake form again and recommended its implementation. Further, parents responded positively by agreeing that the intake package was easy to complete (65%), felt included in care decisions (95%), and had questions answered appropriately (100%). CONCLUSION In assessment of BBD, a standardized intake form can help guide physicians to efficiently gather a comprehensive history, rule out red flags, and screen for psychosocial risk factors. With refinements, it can potentially help create a common clinical experience and empower more community paediatricians to manage BBD in the future.


Author(s):  
Hartwig Anzt ◽  
Goran Flegar ◽  
Vedran Novaković ◽  
Enrique S. Quintana-Ortí ◽  
Andrés E. Tomás

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