Being as Activity

2019 ◽  
pp. 123-192
Author(s):  
Francisco J. Gonzalez
Keyword(s):  
Current Context

In a lengthy and important article, M. F. Burnyeat has argued that the passage found at Metaphysics 1048b18-36, in which Aristotle distinguishes sharply between kinēsis and energeia, though written by Aristotle, does not belong in its current context in Book Theta. The present paper aims to show that the philological, philosophical, and historical arguments adduced in favor of this thesis do not stand up to scrutiny. More positively, the paper aims to establish the indispensable role the passage plays within Book Theta in making the connection between energeia and being a telos, as well as the indispensable role it plays within the Metaphysics as a whole, by developing a conception of being as a complete activity that makes possible the characterization of the highest being as an unmoved mover.

scholarly journals The generalized perpetual American exchange-option problem

2008 ◽  
Vol 40 (1) ◽  
pp. 163-182 ◽  
Author(s):  
Shek-Keung Tony Wong
Keyword(s):  
Optimal Stopping ◽  
First Passage Time ◽  
Passage Time ◽  
Optimal Stopping Problem ◽  
Full Generality ◽  
Investment Timing ◽  
Current Context ◽  
Geometric Brownian Motions ◽  
Underlying Processes

This paper revisits a general optimal stopping problem that often appears as a special case in some finance applications. The problem is essentially of the same form as the investment-timing problem of McDonald and Siegel (1986) in which the underlying processes are two correlated geometric Brownian motions (GBMs) with drifts less than the discount rate. By contrast, we attempt to analyze the underlying optimal stopping problem to its full generality without imposing any restriction on the drifts of the GBMs. By extending the first passage time approach of Xia and Zhou (2007) to the current context, we manage to obtain a complete and explicit characterization of the solution to the problem on all possible drift domains. Our analysis leads to a new and interesting observation that the underlying optimal stopping problem admits a two-sided optimal continuation region on some certain parameter domains.

Toward a Characterization of Adaptive Systems

2012 ◽  
Vol 54 (6) ◽  
pp. 1008-1024 ◽  
Author(s):  
Karen M. Feigh ◽  
Michael C. Dorneich ◽  
Caroline C. Hayes
Keyword(s):  
Adaptive Systems ◽  
Future Research ◽  
Cognitive State ◽  
Research Issues ◽  
Systems Research ◽  
Recent Developments ◽  
Current Context ◽  
Physiological Sensors ◽  
Trigger Mechanisms

Objective: This article presents a systematic framework characterizing adaptive systems. Background: Adaptive systems are those that can appropriately modify their behavior to fit the current context. This concept is appealing because it offers the possibility of creating computer assistants that behave like good human assistants who can provide what is needed without being asked. However, the majority of adaptive systems have been experimental rather than practical because of the technical challenges in accurately perceiving and interpreting users’ current cognitive state; integrating cognitive state, environment, and task information; and using it to predict users’ current needs. The authors anticipate that recent developments in neurological and physiological sensors to identify users’ cognitive state will increase interest in adaptive systems research and practice over the next few years. Method: To inform future efforts in adaptive sys-tems, this work provides an organizing framework for characterizing adaptive systems, identifying consider-ations and implications, and suggesting future research issues. Results: A two-part framework is presented that (a) categorizes ways in which adaptive systems can modify their behavior and (b) characterizes trigger mechanisms through which adaptive systems can sense the current situation and decide how to adapt. Conclusion: The framework provided in this article provides a tool for organizing and informing past, present, and future research and development efforts in adaptive systems.

scholarly journals Characterization of Visitors’ Perception of Landscape Heterogeneity in Urban Green Spaces

Urban Science ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 86
Author(s):  
Alice Meyer-GrandBastien ◽  
Françoise Burel ◽  
Emmanuelle Hellier ◽  
Benjamin Bergerot
Keyword(s):  
Management Practices ◽  
Landscape Heterogeneity ◽  
Positive Impact ◽  
Well Being ◽  
Green Spaces ◽  
Urban Green ◽  
Urban Green Spaces ◽  
Planning And Management ◽  
Current Context

In the current context of global urbanization, interdisciplinary research is needed to identify planning and management practices in urban green spaces (UGS) that would enhance both biodiversity and visitors’ well-being. The perception of landscape heterogeneity, a core ecological concept, has been demonstrated to have a positive impact on visitors’ psychological restoration. In order to apply these findings within UGS to planning and management practices, we need to characterize visitors’ perception of landscape heterogeneity. We gathered data on 390 visitors’ perception of landscape heterogeneity. Our results highlighted that visitors perceive landscape heterogeneity through the mixing of different heights of three vegetation strata and flower areas. Planning and management practices should enhance this landscape aspect within UGS to simultaneously promote biodiversity and visitors’ psychological well-being.

The generalized perpetual American exchange-option problem

2008 ◽  
Vol 40 (01) ◽  
pp. 163-182 ◽  
Author(s):  
Shek-Keung Tony Wong
Keyword(s):  
Optimal Stopping ◽  
First Passage Time ◽  
Passage Time ◽  
Optimal Stopping Problem ◽  
Full Generality ◽  
Investment Timing ◽  
Current Context ◽  
Geometric Brownian Motions ◽  
Underlying Processes

This paper revisits a general optimal stopping problem that often appears as a special case in some finance applications. The problem is essentially of the same form as the investment-timing problem of McDonald and Siegel (1986) in which the underlying processes are two correlated geometric Brownian motions (GBMs) with drifts less than the discount rate. By contrast, we attempt to analyze the underlying optimal stopping problem to its full generality without imposing any restriction on the drifts of the GBMs. By extending the first passage time approach of Xia and Zhou (2007) to the current context, we manage to obtain a complete and explicit characterization of the solution to the problem on all possible drift domains. Our analysis leads to a new and interesting observation that the underlying optimal stopping problem admits a two-sided optimal continuation region on some certain parameter domains.

A Computational Methodology to Support Reimbursement Requests Analysis Concerning Electrical Damages

2015 ◽  
Vol 16 (6) ◽  
pp. 569-577
Author(s):  
Afonso Bernardino Almeida Junior ◽  
Isaque Nogueira Gondim ◽  
Paulo Henrique Oliveira Rezende ◽  
José Carlos Oliveira
Keyword(s):  
Software Process ◽  
Decision Making Process ◽  
Actual Case ◽  
Software Analysis ◽  
Important Challenge ◽  
Current Context ◽  
Computational Methodology ◽  
Consumer Representation

Abstract In light of the growing number of reimbursement requests processed from consumers for electrical damage to equipment, supposedly caused through the manifestation of anomalies on the power grid, there comes the need for reliable means for providing a decision on the issues highlighted herein. Through the recognition that in the current context, the procedures used are based on reviews, information and records of occurrences in the field, there has been significant inadequacy and fragility in the issuing of conclusive advice or opinions. In particular, the search for mechanisms grounded in classical principles and accepted in electrical engineering presents itself as an important challenge on which to base the decision making process in full awareness of its incumbent science and technology. Therefore, with the aim of meeting these assumptions, the study in question excels in its presentation of the principles that guided the software analysis, which intend above all else to correlate cause and effect. The elaborated strategy involves modelling stages as well as studies aimed at: distribution supply reproduction; characterization of the distribution network to the complainant consumer; representation of the diverse electro-electronic appliances and lastly, a proposal for correlating the disturbances impacting on equipment with their dielectric and thermal supportability requirements. For the purpose of illustrating the software process, an actual case study coupled with a loss and claim scenario is presented.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

Characterization of Coherent, Ordered Precipitates in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 144-145
Author(s):  
B. H. Kear ◽  
J. M. Oblak
Keyword(s):  
Stable Phase ◽  
Nickel Base Superalloy ◽  
Alloy 718 ◽  
Commercial Alloy ◽  
Precipitate Morphology ◽  
Continuous Precipitation ◽  
Nickel Base ◽  
Base Superalloy ◽  
Strengthening Precipitate

A nickel-base superalloy is essentially a Ni/Cr solid solution hardened by additions of Al (Ti, Nb, etc.) to precipitate a coherent, ordered phase. In most commercial alloy systems, e.g. B-1900, IN-100 and Mar-M200, the stable precipitate is Ni3 (Al,Ti) γ′, with an LI2structure. In A lloy 901 the normal precipitate is metastable Nis Ti3 γ′ ; the stable phase is a hexagonal Do2 4 structure. In Alloy 718 the strengthening precipitate is metastable γ″, which has a body-centered tetragonal D022 structure.Precipitate MorphologyIn most systems the ordered γ′ phase forms by a continuous precipitation re-action, which gives rise to a uniform intragranular dispersion of precipitate particles. For zero γ/γ′ misfit, the γ′ precipitates assume a spheroidal.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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