La noción de lugar en la física aristotélica

El análisis filosófico de la noción de lugar en el tratado de la física de aristóteles revela una riqueza de nudos conceptuales que permite situar el importante papel de esta noción en la ontología natural aristotélica, además de nutrir debates posterioreThe philosophical analysis of the place notion in aristotle's physics reveals a wealth of implications that allows us to fix the important role this notion has in aristotelian natural ontology, apart from feeding further debates in philosophy of science

Knowledge sharing and competitiveness of professional service firms: A case study

The problem addressed in this study is that little action is taken to create the social aspects and social value of knowledge-sharing culture within organizations. There is a need for increased understanding of the behavioral side of knowledge management. The purpose of this study was to focus on knowledge sharing from a behavioral perspective. Knowledge management is defined as the accumulation, protection, and leverage of knowledge. This research study investigated the relationship between knowledge sharing and competitiveness and approached the field of knowledge management from the organizational, cultural, and behavioral perspectives. The research questions examined how knowledge workers described the parameters and conditions of knowledge sharing, as well as the relationship between knowledge sharing and competitiveness of professional service firms. The overall research design employed three focus groups and individual interviews of a selected professional service firm. Similarity and commonalities of data from interviews were color coded and labeled. Field notes, handouts, and a qualitative research computer program were used to triangulate data. Results of the study generated and established five specific categories. The categories of spiritual essence of business, believability and openness, and ethical responsibility present the mind and spiritual connection to enhance the value of knowledge sharing as a factor for competitiveness. In addition, the categories of whole brain learning and connectivity are context for creating a learning organization. The implications for social change include a clearer understanding of knowledge sharing which can increase organizational competitiveness. The effect of the added competitiveness of professional service firms can result in enhancing economic and social value of their key stakeholders

Optimal VDC service provisioning in optically interconnected disaggregated data centers

©2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Virtual data center (VDC) is a key service in modern data center (DC) infrastructures. However, the rigid architecture of traditional servers inside DCs may lead to blocking situations when deploying VDC instances. To overcome this problem, the disaggregated DC paradigm is introduced. In this letter, we present an integer linear programming (ILP) formulation to optimally allocate VDC requests on top of an optically interconnected disaggregated DC infrastructure, aiming to quantify the benefits that such an architecture can bring when compared with traditional server-centric DCs. Moreover, a lightweight simulated annealing-based heuristic is provided for the scenarios where the ILP scalability is challenged. The obtained numerical results reveal the substantial benefits yielded by the resource disaggregation paradigm.Peer ReviewedPostprint (author's final draft

End-to-end 5G service deployment and orchestration in optical networks with QoE guarantees

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe upcoming 5G deployments will impose stringent requirements. Optical networks control and resource orchestration is set to potentially turn into software-defined approaches in order to address such requirements. As a result, there rises a need for an architectural scheme capable of supporting the different types of services defined for 5G verticals.We present in this paper an architecture enabling end-to-end (E2E) provisioning and monitoring of such 5G services over optical network segments. In particular, the scenario considers the coordination of various optical enabled network segments by a higher level E2E Orchestrator, which provides of network slice deployment and is able to guarantee agreed levels of Quality of Experience (QoE). Moreover, we discuss an example of 5G service provisioning using the proposed architecture to demonstrate its behaviour in front of different network events.Peer ReviewedPostprint (author's final draft

Detection and characterization of environmentally persistent free radicals (EPFRs) in soils and sediments from superfund sites

Environmentally persistent free radicals (EPFRs) from combustion-generated PM have been demonstrated to form via reactions of molecular precursors with redox-active transition metals at 150-500C thermal reactions in a few seconds reaction times. While ambient temperatures are much lower, soils/sediments contain similar transition metals, and reaction times of contaminants in soils/sediments are years, rather than seconds. This questions whether EPFRs could be formed at ambient temperatures in soils/sediments from Superfund sites that are contaminated with hazardous materials. Superfund soils contaminated with PCP from Georgia and Montana, and sediments contaminated with PAHs from Washington. Using EPR spectroscopy, EPFR concentrations and structural assignments were determined. Contaminated soils/sediments were ~30x, ~12x, ~2x higher than the background at the Georgia, Montana, and Washington sites, respectively. Conventional humic substances extraction procedures revealed ~90% of the EPFRs originated from clays/minerals/humins fraction. Similarity of EPR signals in the Georgia and Montana PCP contaminated soils were observed (g = 2.00300 and ΔHp-p = 6.0 G), whereas, signals in the Washington sediments were similar to other PAH contaminated soils (g = 2.00270 and ΔHp-p = 9.0G). Several methods of analyses (Total Carbon Content, GC-MS, ICP-AES, Vapor and gas/liquid phase dosing) confirm pentachlorophenoxyl EPFR. Chemisorption and electron transfer from PCP or PAHs to transition metals and other electron sinks in soil are indicated for EPFRs formation. Low temperature thermal treatment of PCP contaminated soil in an open type heating system indicated the formation of a more oxygen-centered structure of the pentachlorophenoxyl radical or new, similar radicals. Both type of heating system, open and closed, demonstrated an EPFR concentrations that peaked at ~10 x 10E+18 spins/g of soil at ~75-100C, with lifetimes of 2 – 24 days at room temperature in ambient air indicating persistency in the environment. Discovery of EPFRs formed in PCP contaminated soils indicates that EPFRs are not only confined to combustion-generated particles. Studies on EPFR similar to pentachlorophenoxyl cause cardiopulmonary dysfunctions via induction of oxidative stress. The existence of potentially toxic EPFRs questions the long held belief that sorption of an organic pollutant to a soil matrix is a method of mitigating its environmental impact

Comparison of four different programs for the analysis of hemispherical photographs using parameters of canopy structure and solar radiation transmittance

There have been many studies involving the use of hemispherical photographs to indirectly estimate canopy structures and forest light environments. A variety of commercial and free software packages are available for the analysis of hemispherical photographs. The costs of investment might represent an advantage of the free programmes over the commercial, but as yet little has been documented about the differences in their outputs and in the technical applications from a user (ecologist and forester) perspective. The objective of the study was to compare the canopy structure variables (canopy openness and effective plant area index) and solar radiation transmission estimates (direct, diffuse and global solar radiation transmittances) from digital hemispherical photographs taken under two forest canopy conditions (gap and closed canopy) in three different broadleaf forest regions (Chile, Germany, Venezuela) and calculated using four different programmes. The hemispherical photographs were analysed using one commercial (HemiView) and three free programmes (Gap Light Analyzer, hemIMAGE and Winphot). The results obtained revealed that all of the programmes computed similar estimates of both canopy structures and below-canopy solar radiation. Only the results relating to the effective plant area index with an ellipsoidal leaf angle distribution made with HemiView and Winphot deviated significantly. Other user aspects are also discussed, such as costs, image formats, computer system requirements, etc.In vielen Studien werden Hemisphärenphotos genutzt um indirekt die Kronenstruktur und die Belichtungsverhältnisse zu schätzen. Verschiedene kommerzielle und kostenfreie Softwarepakete sind zu Analyse von Hemisphärenphotos verfügbar. Es gibt bisher keine umfassende Vergleichsstudie zu Ergebnissen oder technischer Handhabung aus Sicht der Nutzer dieser Programme (Ökologen und Forstwissenschaftler). Das Ziel dieser Studie war der Vergleich der Schätzungen von Kronenstrukturvariablen (Kronenöffnung und effektiver Pflanzenflächenindex) Solartransmission (direkte, diffuse und Global-Strahlung) aus digitalen Hemisphärenphotos berechnet mit vier verschiedenen Programmen (kostenpflichtig: Hemi- View und frei: Gap Light Analyzer, hemIMAGE and Winphot). Die verwendeten Photos stammen aus drei verschiedenen Laubwaldregionen (Chile, Deutschland und Venezuela) und repräsentieren jeweils Verhältnisse unter geschlossenem Kronendach und in Lücken. Die ermittelten Schätzungen für die verschiedenen Strukturvariablen und Einstrahlungsverhältnisse zeigten eine sehr hohe Übereinstimmung. Einzig der effektive Pflanzenflächenindex basierend auf ellipsoider Blattwinkelverteilung unterschied sich signifikant zwischen den Programmen. Weitere für Nutzer interessante Aspekte wie Kosten, Bildformate, Systemvoraussetzungen und mehr wurden verglichen und diskutiert

Simulation-based inference using surjective sequential neural likelihood estimation

We present Surjective Sequential Neural Likelihood (SSNL) estimation, a novel method for simulation-based inference in models where the evaluation of the likelihood function is not tractable and only a simulator that can generate synthetic data is available. SSNL fits a dimensionality-reducing surjective normalizing flow model and uses it as a surrogate likelihood function which allows for conventional Bayesian inference using either Markov chain Monte Carlo methods or variational inference. By embedding the data in a low-dimensional space, SSNL solves several issues previous likelihood-based methods had when applied to high-dimensional data sets that, for instance, contain non-informative data dimensions or lie along a lower-dimensional manifold. We evaluate SSNL on a wide variety of experiments and show that it generally outperforms contemporary methods used in simulation-based inference, for instance, on a challenging real-world example from astrophysics which models the magnetic field strength of the sun using a solar dynamo model

Human Automotive Interaction: Affect Recognition for Motor Trend Magazine\u27s Best Driver Car of the Year

Observation analysis of vehicle operators has the potential to address the growing trend of motor vehicle accidents. Methods are needed to automatically detect heavy cognitive load and distraction to warn drivers in poor psychophysiological state. Existing methods to monitor a driver have included prediction from steering behavior, smart phone warning systems, gaze detection, and electroencephalogram. We build upon these approaches by detecting cues that indicate inattention and stress from video. The system is tested and developed on data from Motor Trend Magazine\u27s Best Driver Car of the Year 2014 and 2015. It was found that face detection and facial feature encoding posed the most difficult challenges to automatic facial emotion recognition in practice. The chapter focuses on two important parts of the facial emotion recognition pipeline: (1) face detection and (2) facial appearance features. We propose a face detector that unifies state‐of‐the‐art approaches and provides quality control for face detection results, called reference‐based face detection. We also propose a novel method for facial feature extraction that compactly encodes the spatiotemporal behavior of the face and removes background texture, called local anisotropic‐inhibited binary patterns in three orthogonal planes. Real‐world results show promise for the automatic observation of driver inattention and stress