Some Properties of the Broyden Restricted Class of Updates with Oblique Projections

2013 ◽  
pp. 169-182
Author(s):  
Andrzej Stachurski
Keyword(s):  
Restricted Class ◽  
Oblique Projections

Oblique projections for the geographer

Cartography ◽  
1979 ◽  
Vol 11 (2) ◽  
pp. 92-95
Author(s):  
G. Halsey
Keyword(s):  
Oblique Projections

scholarly journals On the existence of nonterminating queries for a restricted class of PROLOG-clauses

1989 ◽  
Vol 41 (2) ◽  
pp. 237-248 ◽  
Author(s):  
Danny de Schreye ◽  
Maurice Bruynooghe ◽  
Kristof Verschaetse
Keyword(s):  
Restricted Class

Radiological features of degenerative-dystrophic changes in the spine

1986 ◽  
Vol 67 (1) ◽  
pp. 61-64
Author(s):  
I. I. Kamalov
Keyword(s):  
Radiological Examination ◽  
Radiological Features ◽  
Oblique Projections ◽  
Radiological Examinations

The aim of this study was to examine in detail the radiological signs of degenerative-dystrophic lesions of the spine.A comprehensive clinical and radiological examination was performed in 147 patients (97 male and 50 female) aged 18 to 60 years. Radiological examinations were started with observation and sighting spondylograms. Depending on the further research tasks and indications, spinal images, oblique projections, direct magnification, as well as functional spondylography with load and tomography were performed.

CHALLENGES IN CLINICAL PRACTICE OF CR MAMMOGRAPHY IN TANZANIA

2018 ◽  
Vol 184 (1) ◽  
pp. 109-115
Author(s):  
Jofrey Jackson ◽  
Wilbroad E Muhogora ◽  
Ismael N Makundi
Keyword(s):  
Clinical Practice ◽  
Staff Training ◽  
Beam Quality ◽  
Improve Patient Care ◽  
Operational Conditions ◽  
Inappropriate Use ◽  
Regulatory Guidance ◽  
Mean Glandular Dose ◽  
Oblique Projections ◽  
Improve Patient

Abstract The aim of this study was to evaluate the clinical practice of CR mammography in Tanzania. The equipment performance and operational conditions were studied; and mean glandular dose (DG) estimated to 75 women undergoing diagnosis at three mammography facilities. All mammograms during this study were reported to be useful for the intended diagnosis. The median DG for craniocaudal and mediolateral oblique projections ranged from 1.27 ± 0.18 mGy to 1.9 ± 0.27 mGy and from 1.3 ± 0.18 mGy to 1.9 ± 0.27 mGy, respectively, and were below the national regulatory guidance of 2.5 mGy. Despite this positive result, unavoidable inappropriate use of beam quality and tube loading settings which could have been through appropriate staff training and performing routine quality control were not uncommon. This work provides an insight of current operational conditions of CR in Tanzania and what strategy should be employed to this service to improve patient care in the country.

Instrumentalism

2015 ◽  
Author(s):  
P. Kyle Stanford
Keyword(s):  
Newtonian Mechanics ◽  
Scientific Theories ◽  
Restricted Class ◽  
Scientific Realist ◽  
Scientific Domain ◽  
The World

This chapter seeks to explore and develop the proposal that even our best scientific theories are not (as the scientific realist would have it) accurate descriptions of how things stand in otherwise inaccessible domains of nature but are instead simply powerful conceptual tools or instruments for engaging practically with the world around us. It describes a number of persistent challenges facing any attempt to apply the American Pragmatists’ global conception of all ideas, beliefs, theories, and cognitions quite generally as such tools or instruments to only a restricted class or category of such entities (such as our best scientific theories) instead. It then seeks to overcome these challenges by regarding scientific instrumentalism as simply applying the scientific realist’s own attitude toward a theory like Newtonian mechanics to even the most empirically successful and instrumentally powerful theory we have in any given scientific domain.

scholarly journals Fast GCM – ice sheet model coupling software OBLIMAP 2.0, including on-line embeddable mapping routines

2016 ◽  
Author(s):  
Thomas Reerink ◽  
Roderik van de Wal
Keyword(s):  
General Circulation ◽  
Ice Sheet ◽  
Circulation Model ◽  
Adaptive Grids ◽  
Performance Gain ◽  
Ice Caps ◽  
Oblique Projections ◽  
On Line ◽  
Grid Nodes ◽  
Reverse Mapping

Abstract. This paper accompanies the second OBLIMAP open source release. The package is developed to map climate fields between a general circulation model (GCM) and an ice sheet model (ISM) in both directions by using optimal aligned oblique projections, which minimize distortions. Both grids may be irregularly spaced and the ratio of the grids is allowed to differ largely. The stand-alone version of OBLIMAP is a powerful tool to map various differently gridded datasets on one uniform ISM grid with an optimal centered projection. This is demonstrated by relevant applicatons concerning the major ice caps. As this applies also for the reverse mapping direction, it can be used as an off-line coupler. Besides, OBLIMAP 2.0 is an embeddable GCM–ISM coupler, suited for high frequent on-line coupled experiments. A new fast scan method is presented as an alternative for the former time consuming grid search strategy, realising a performance gain of several orders of magnitude and enabling the mapping of high resolution datasets with a much larger number of grid nodes. Further a highly flexible masked mapping option is added. The limitations of the fast scan method with respect to unstructured and adaptive grids are discussed together with several proposed parallel implementations in order to achieve another performance gain.

scholarly journals Deterministic, Strategyproof, and Fair Cake Cutting

2017 ◽  
Author(s):  
Vijay Menon ◽  
Kate Larson
Keyword(s):  
Mechanism Design ◽  
Impossibility Result ◽  
Restricted Class ◽  
Piecewise Constant ◽  
Incentive Compatible ◽  
Negative Results ◽  
Cake Cutting ◽  
Design Perspective ◽  
A Minor ◽  
Cutting Problem

We study the classic cake cutting problem from a mechanism design perspective, in particular focusing on deterministic mechanisms that are strategyproof and fair. We begin by looking at mechanisms that are non-wasteful and primarily show that for even the restricted class of piecewise constant valuations there exists no direct-revelation mechanism that is strategyproof and even approximately proportional. Subsequently, we remove the non-wasteful constraint and show another impossibility result stating that there is no strategyproof and approximately proportional direct-revelation mechanism that outputs contiguous allocations, again, for even the restricted class of piecewise constant valuations. In addition to the above results, we also present some negative results when considering an approximate notion of strategyproofness, show a connection between direct-revelation mechanisms and mechanisms in the Robertson-Webb model when agents have piecewise constant valuations, and finally also present a (minor) modification to the well-known Even-Paz algorithm that has better incentive-compatible properties for the cases when there are two or three agents.

scholarly journals Representation Dependence in Probabilistic Inference

2004 ◽  
Vol 21 ◽  
pp. 319-356 ◽  
Author(s):  
J. Y. Halpern ◽  
D. Koller
Keyword(s):  
Maximum Entropy ◽  
Deductive Reasoning ◽  
Probabilistic Inference ◽  
Irrelevant Information ◽  
Restricted Class ◽  
Inference Procedure ◽  
Reasoning Systems ◽  
Restricted Representation ◽  
Default Assumption ◽  
Principle Of Maximum

Non-deductive reasoning systems are often representation dependent: representing the same situation in two different ways may cause such a system to return two different answers. Some have viewed this as a significant problem. For example, the principle of maximum entropyhas been subjected to much criticism due to its representation dependence. There has, however, been almost no work investigating representation dependence. In this paper, we formalize this notion and show that it is not a problem specific to maximum entropy. In fact, we show that any representation-independent probabilistic inference procedure that ignores irrelevant information is essentially entailment, in a precise sense. Moreover, we show that representation independence is incompatible with even a weak default assumption of independence. We then show that invariance under a restricted class of representation changes can form a reasonable compromise between representation independence and other desiderata, and provide a construction of a family of inference procedures that provides such restricted representation independence, using relative entropy.

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