A study of possible-worlds semantics of relevance-sensitive belief revision

2020 ◽  
Vol 30 (5) ◽  
pp. 1125-1142
Author(s):  
Theofanis Aravanis ◽  
Pavlos Peppas ◽  
Mary-Anne Williams
Keyword(s):  
Belief Revision ◽  
Possible Worlds ◽  
Strong Version ◽  
Possible Worlds Semantics ◽  
Significant Drop ◽  
Natural Connection ◽  
Global And Local ◽  
Shed Light

Abstract Parikh’s relevance-sensitive axiom (P) for belief revision is open to two different interpretations, i.e. the weak and the strong version of (P), both of which are plausible depending on the context. Given that strong (P) has not received the attention it deserves, in this article, an extended examination of it is conducted. In particular, we point out interesting properties of the semantic characterization of the strong version of (P), as well as a vital feature of it that, potentially, results in a significant drop on the resources required for an implementation of a belief-revision system. Lastly, we shed light on the natural connection between global and local revision functions, via their corresponding semantic characterization, hence, a means for constructing global revision functions from local ones, and vice versa, is provided.

Metaphysics of knowledge

2018 ◽  
Author(s):  
Jesper Kallestrup
Keyword(s):  
Modal Logic ◽  
Possible Worlds ◽  
Modal Epistemology ◽  
Physical Realization ◽  
Possible Worlds Semantics ◽  
Justified Belief ◽  
Essential Nature ◽  
The World ◽  
Structure Of Knowledge ◽  
Shed Light

Epistemology has traditionally been concerned with the scope, sources and structure of knowledge and other epistemic statuses such as justified belief. Metaphysics of knowledge seeks to answer metaphysical questions about knowledge and its place in the world as they arise in such epistemological pursuits. More generally, metaphysics of epistemology can be understood to include metaphysical questions about a broader range of epistemic statuses. In either case, answers to such questions may help solve distinctive problems in epistemology or neighbouring fields, or they may be of independent theoretical importance. Since modal logic, possible worlds semantics and related formal frameworks are frequently brought to bear in traditional metaphysics, for example Williamson 2013, metaphysical inquiries about knowledge may also utilize such modal tools. But metaphysics of knowledge is distinct from both modal epistemology, which concerns the necessary links between belief and truth that supposedly constitute knowledge, and epistemology of modality, which concerns knowledge of modalities – that is, of what is necessary, possible, contingent and so on. Metaphysics of knowledge sits at the intersection of epistemology and metaphysics, whereas modal epistemology is an externalist branch of epistemology, and epistemology of modality is a sub-discipline within philosophy of modality. Both modal epistemology and epistemology of modality may of course shed light on metaphysical aspects of knowledge, for example, if it turns out knowledge is essentially a modally sensitive or safe belief. However, the intended scope of metaphysics of knowledge is much broader, encompassing not just the essential nature of knowledge, but also its metaphysical ground and its physical realization.

The Failure of Conceptual Analysis

2018 ◽  
Author(s):  
Jennifer McKitrick
Keyword(s):  
Conceptual Analysis ◽  
Possible Worlds ◽  
Causal Power ◽  
Possible Worlds Semantics ◽  
Conditional Statements ◽  
Reductive Analysis

Dispositions are often regarded with suspicion. Consequently, some philosophers try to semantically reduce disposition ascriptions to sentences containing only non-dispositional vocabulary. Typically, reductionists attempt to analyze disposition ascriptions in terms of conditional statements. These conditional statements, like other modal claims, are often interpreted in terms of possible worlds semantics. However, conditional analyses are subject to a number of problems and counterexamples, including random coincidences, void satisfaction, masks, antidotes, mimics, altering, and finks. Some analyses fail to reduce disposition ascriptions to non-modal vocabulary. If reductive analysis of disposition ascriptions fails, then perhaps there can be metaphysical reduction of dispositions without semantic reduction. However, the reductionist still owes us an account of what makes disposition ascriptions true. But to posit a causal power for every unreduced dispositional predicate is an overreaction to the failure of conceptual analysis.

scholarly journals Ni Oxidation State and Ligand Saturation Impact on the Capability of Octaazamacrocyclic Complexes to Bind and Reduce CO2

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4139
Author(s):  
Barbora Vénosová ◽  
Ingrid Jelemenská ◽  
Jozef Kožíšek ◽  
Peter Rapta ◽  
Michal Zalibera ◽  
...  
Keyword(s):  
Quantum Theory ◽  
Oxidation State ◽  
Central Atom ◽  
Population Analysis ◽  
Mulliken Population Analysis ◽  
Mulliken Population ◽  
Theoretical Methods ◽  
Ni Oxidation ◽  
Shed Light

Two 15-membered octaazamacrocyclic nickel(II) complexes are investigated by theoretical methods to shed light on their affinity forwards binding and reducing CO2. In the first complex 1[NiIIL]0, the octaazamacrocyclic ligand is grossly unsaturated (π-conjugated), while in the second 1[NiIILH]2+ one, the macrocycle is saturated with hydrogens. One and two-electron reductions are described using Mulliken population analysis, quantum theory of atoms in molecules, localized orbitals, and domain averaged fermi holes, including the characterization of the Ni-CCO2 bond and the oxidation state of the central Ni atom. It was found that in the [NiLH] complex, the central atom is reduced to Ni0 and/or NiI and is thus able to bind CO2 via a single σ bond. In addition, the two-electron reduced 3[NiL]2− species also shows an affinity forwards CO2.

3-D Characterization of Global and Local Microstructural Effects on Spall Damage in Shock Loaded FCC Metals: Experimental and Modeling

2013 ◽  
Author(s):  
A. Brown ◽  
K. Krishnan ◽  
L. Wayne ◽  
P. Peralta ◽  
S. N. Luo ◽  
...  
Keyword(s):  
Weak Link ◽  
Heat Treatments ◽  
Taylor Factor ◽  
Weak Links ◽  
Spall Damage ◽  
Heat Treated ◽  
Microstructural Effects ◽  
Global And Local ◽  
Low Pressures

Global and local microstructural weak links for spall damage were investigated using 3-D characterization in polycrystalline (PC) and multicrystalline (MC) copper samples, respectively. All samples were shocked via flyer-target plate experiments using a laser drive at low pressures (2–6 GPa). The flyer plates measured approximately 500 μm thick and 8 mm in diameter and the target plates measured approximately 1000 μm thick and 10 mm in diameter. Electron Backscattering Diffraction (EBSD) and optical microscopy were used to determine to presence of voids and relate them to the surrounding microstructure. Statistics on the strength of grain boundaries (GBs) was conducted by analyzing PC samples and collecting the misorientation across GBs with damage present, and it was found that a misorientation range of 25–50° is favorable for damage. Statistics were also taken of copper PC samples that had undergone different heat treatments and it was found that although the 25–50° range is less dominant, it is still favorable for damage nucleation. Removal of initial plastic strain via heat treatments and an increase in Σ3 CSL boundaries, indicative of strong annealing twins, also led to an increased amount of transgranular damage. 3-D X-ray tomography data were used to investigate the shape of the voids present in untreated, as received and heat treated samples. It was found that the as received sample contained a higher amount of “disk”, or, “sheet-like” voids indicative of intergranular damage, whereas the heat treated samples had a higher fraction of spherical shaped voids, indicative of transgranular damage. MC samples were used to study microstructural weak links for spall damage because the overall grain size is much larger than the average void size, making it possible to determine which GBs nucleated damage. Simulations and experimental analysis of damage sites with large volumes indicate that high Taylor factor mismatches with respect to the crystallographic grain GB normal is the primary cause for the nucleation of damage at a GB interface and a low Taylor factor along the shock direction in either grain drives void growth perpendicular to the GB. Cases where experimental results show damage and simulation results show no damage are attributed to the presence of an intrinsic microstructural weak link, such as an incoherent twin boundary.

scholarly journals Electrophysiological characterization of a diverse group of sugar transporters from Trichoderma reesei

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sami Havukainen ◽  
Jonai Pujol-Giménez ◽  
Mari Valkonen ◽  
Ann Westerholm-Parvinen ◽  
Matthias A. Hediger ◽  
...  
Keyword(s):  
Trichoderma Reesei ◽  
Scientific Literature ◽  
Large Body ◽  
Comprehensive Analysis ◽  
Transport Function ◽  
Sugar Transporters ◽  
New Knowledge ◽  
Electrophysiological Characterization ◽  
Shed Light

AbstractTrichoderma reesei is an ascomycete fungus known for its capability to secrete high amounts of extracellular cellulose- and hemicellulose-degrading enzymes. These enzymes are utilized in the production of second-generation biofuels and T. reesei is a well-established host for their production. Although this species has gained considerable interest in the scientific literature, the sugar transportome of T. reesei remains poorly characterized. Better understanding of the proteins involved in the transport of different sugars could be utilized for engineering better enzyme production strains. In this study we aimed to shed light on this matter by characterizing multiple T. reesei transporters capable of transporting various types of sugars. We used phylogenetics to select transporters for expression in Xenopus laevis oocytes to screen for transport activities. Of the 18 tested transporters, 8 were found to be functional in oocytes. 10 transporters in total were investigated in oocytes and in yeast, and for 3 of them no transport function had been described in literature. This comprehensive analysis provides a large body of new knowledge about T. reesei sugar transporters, and further establishes X. laevis oocytes as a valuable tool for studying fungal sugar transporters.

scholarly journals Insights into Mycobacterium leprae Proteomics and Biomarkers—An Overview

Proteomes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 7
Author(s):  
Sakshi Gautam ◽  
Devesh Sharma ◽  
Anjana Goel ◽  
Shripad A. Patil ◽  
Deepa Bisht
Keyword(s):  
Early Diagnosis ◽  
Causative Agent ◽  
Mycobacterium Leprae ◽  
Pivotal Role ◽  
New Biomarkers ◽  
Shed Light

Although leprosy is curable, the identification of biomarkers for the early diagnosis of leprosy would play a pivotal role in reducing transmission and the overall prevalence of the disease. Leprosy-specific biomarkers for diagnosis, particularly for the paucibacillary disease, are not well defined. Therefore, the identification of new biomarkers for leprosy is one of the prime themes of leprosy research. Studying Mycobacterium leprae, the causative agent of leprosy, at the proteomic level may facilitate the identification, quantification, and characterization of proteins that could be potential diagnostics or targets for drugs and can help in better understanding the pathogenesis. This review aims to shed light on the knowledge gained to understand leprosy or its pathogen employing proteomics and its role in diagnosis.

scholarly journals Nanotechnology in Roman Opaque Red Glass from the 2nd Century AD. Archaeometric Investigation in Red Sectilia from the Decoration of the Lucius Verus Villa in Rome

Heritage ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 2597-2611 ◽  
Author(s):  
Mario Bandiera ◽  
Patrice Lehuédé ◽  
Marco Verità ◽  
Luis Alves ◽  
Isabelle Biron ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Chemical Characterization ◽  
Second Step ◽  
Colorimetric Analysis ◽  
Historical Sources ◽  
Pixe Analysis ◽  
X Ray ◽  
Colorimetric Measurements ◽  
Shed Light

This work aims to characterise the chemical composition of Roman opaque red glass sectilia dated to the 2nd century A.D and to shed light on Roman glassmaking production of different shades of red, from red to reddish-brown. Due to the lack of technical historical sources for this period many questions about technological aspects still remain. In this project a multi-disciplinary approach is in progress to investigate the red glass sectilia with several red hues from the Imperial Villa of Lucius Verus (161–169 A.D.) in Rome. First, colorimetric measurements were taken to identify the various red hues. The second step was chemical characterization of the samples and the identification of crystalline colouring phases. Particle Induced X-Ray Emission (PIXE) analysis was used to investigate the chemical composition of these glass samples, while the crystalline phases were identified by Raman Spectroscopy and Scanning Electrons Microscope with Energy Dispersive X-ray Spectrometry (SEM-EDS). Using SEM-EDS nanoparticles were detected as a colouring agent, the chemical composition and the morphology of which has been studied in depth. This information has been compared with the colorimetric analysis to establish any correlation with the different colour hues.

Investigations into the Precessing Vortex Core Phenomenon in Cyclone Dust Separators

1994 ◽  
Vol 208 (2) ◽  
pp. 147-154 ◽  
Author(s):  
P Yazdabadi ◽  
A J Griffiths ◽  
N Syred
Keyword(s):  
Vortex Core ◽  
Reynolds Numbers ◽  
Frequency Parameter ◽  
Experimental Investigations ◽  
Swirl Number ◽  
Significant Drop ◽  
Precessing Vortex Core ◽  
Dust Separator ◽  
The Relationship

Experimental investigations have been carried out to examine the effect of downstream pipework configurations on the precessing vortex core (PVC) generated within the exhaust region of a cyclone dust separator. Characterization of the PVC using a non-dimensionalized frequency parameter (NDFP) was used to determine the relationship between Reynolds number and geometrical swirl number of the cyclone. The results show that the NDFP tends towards an asymptotic value for Reynolds numbers of about 50 000 and high swirl numbers (> 3.043). This value is reached earlier with lower swirl numbers. It was concluded that any exhaust pipework configuration produced a significant drop in the PVC frequency, and certain configurations either delayed or promoted the development of the PVC.

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