2,110 research outputs found
Application of temporal streamflow descriptors in hydrologic model parameter estimation
This paper presents a parameter estimation approach based on hydrograph descriptors that capture dominant streamflow characteristics at three timescales (monthly, yearly, and record extent). The scheme, entitled hydrograph descriptors multitemporal sensitivity analyses (HYDMUS), yields an ensemble of model simulations generated from a reduced parameter space, based on a set of streamflow descriptors that emphasize the timescale dynamics of streamflow record. In this procedure the posterior distributions of model parameters derived at coarser timescales are used to sample model parameters for the next finer timescale. The procedure was used to estimate the parameters of the Sacramento soil moisture accounting model (SAC-SMA) for the Leaf River, Mississippi. The results indicated that in addition to a significant reduction in the range of parameter uncertainty, HYDMUS improved parameter identifiability for all 13 of the model parameters. The performance of the procedure was compared to four previous calibration studies on the same watershed. Although our application of HYDMUS did not explicitly consider the error at each simulation time step during the calibration process, the model performance was, in some important respects, found to be better than in previous deterministic studies. Copyright 2005 by the American Geophysical Union
Film as museum. Semiotics anf the elastic film image
[Abstract] This presentation explores the relationship and mutual influences integration between the high art (especially paintings) in the popular art territory, in the film «Le Fabuleux destin d'Amélie Poulain». This film is a hybrid phenomenon, allowing for a new kind of intervisual dialogue between the arts, how these fields interact and how they may expand beyond their existing limits? Film has the ability to engulf and ingest other genres and disciplines together. I would borrow Michael Backtin’s term of super-genre. In fact, film is a medium, which seeks to shape its form to different languages, text, and disciplines, constantly changeable, the film as a genre of all genres. The new technology brings new possibilities in film image towards a new kind of a museum. The «new museum» in this sense is not a museum of pictures alone, it is also a museum of objects, shapes, compositions, attitudes, gestures, pictorial fragments, colors, forms, all made existential, real. This collaboration creates a new kind of film closer to the Carnival concept. The focus is on translation, re-vision, interpretation and transformation of the arts into the filmic elastic image, through the use of codes, colors, form, composition, set design, pictorial fragments, camera and other aesthetic elements of film, providing a new semiotic experience. This film manifests the challenge of using masterpieces of the past in the film image, being in constant flux, evolving and change, creating a new kind of a Museum integrating in the multiple visual vision of our time The aim is to show the contribution of this hybrid phenomenon to the field of visual culture and to present new possibilities of expansion for the cinematic dialogue between the disciplines
OT 060420: A Seemingly Optical Transient Recorded by All-Sky Cameras
We report on a ~5th magnitude flash detected for approximately 10 minutes by
two CONCAM all-sky cameras located in Cerro Pachon - Chile and La Palma -
Spain. A third all-sky camera, located in Cerro Paranal - Chile did not detect
the flash, and therefore the authors of this paper suggest that the flash was a
series of cosmic-ray hits, meteors, or satellite glints. Another proposed
hypothesis is that the flash was an astronomical transient with variable
luminosity. In this paper we discuss bright optical transient detection using
fish-eye all-sky monitors, analyze the apparently false-positive optical
transient, and propose possible causes to false optical transient detection in
all-sky cameras.Comment: 7 figures, 3 tables, accepted PAS
Recommended from our members
The role of hydrograph indices in parameter estimation of rainfall-runoff models
A reliable prediction of hydrologic models, among other things, requires a set of plausible parameters that correspond with physiographic properties of the basin. This study proposes a parameter estimation approach, which is based on extracting, through hydrograph diagnoses, information in the form of indices that carry intrinsic properties of a basin. This concept is demonstrated by introducing two indices that describe the shape of a streamflow hydrograph in an integrated manner. Nineteen mid-size (223-4790 km2) perennial headwater basins with a long record of streamflow data were selected to evaluate the ability of these indices to capture basin response characteristics. An examination of the utility of the proposed indices in parameter estimation is conducted for a five-parameter hydrologic model using data from the Leaf River, located in Fort Collins, Mississippi. It is shown that constraining the parameter estimation by selecting only those parameters that result in model output which maintains the indices as found in the historical data can improve the reliability of model predictions. These improvements were manifested in (a) improvement of the prediction of low and high flow, (b) improvement of the overall total biases, and (c) maintenance of the hydrograph's shape for both long-term and short-term predictions. Copyright © 2005 John Wiley & Sons, Ltd
Fourier-based Function Secret Sharing with General Access Structure
Function secret sharing (FSS) scheme is a mechanism that calculates a
function f(x) for x in {0,1}^n which is shared among p parties, by using
distributed functions f_i:{0,1}^n -> G, where G is an Abelian group, while the
function f:{0,1}^n -> G is kept secret to the parties. Ohsawa et al. in 2017
observed that any function f can be described as a linear combination of the
basis functions by regarding the function space as a vector space of dimension
2^n and gave new FSS schemes based on the Fourier basis. All existing FSS
schemes are of (p,p)-threshold type. That is, to compute f(x), we have to
collect f_i(x) for all the distributed functions. In this paper, as in the
secret sharing schemes, we consider FSS schemes with any general access
structure. To do this, we observe that Fourier-based FSS schemes by Ohsawa et
al. are compatible with linear secret sharing scheme. By incorporating the
techniques of linear secret sharing with any general access structure into the
Fourier-based FSS schemes, we show Fourier-based FSS schemes with any general
access structure.Comment: 12 page
Toward 'socially constructive' social constructions of leadership
In their introductory editorial essay for this special issue, David Grant and Gail Fairhurst have done us a great service by valiantly producing a "Sailing Guide" to the Social Construction of Leadership (Fairhurst & Grant, 2010). As with rounding the Capes, this is not a task for the faint of heart. A sailing guide is designed to provide vital knowledge about a particular sea or coast, providing us with charts, warnings about potential hazards and an indication where we might find safe havens in a storm. Their sailing guide does this to great effect as it skilfully "boxes the compass" by revealing all of the potential directions that one might set one‟s sail by if one was sufficiently foolhardy to embark on a cruise of the social construction of leadership
One loop renormalization for the axial Ward-Takahashi identity in Domain-wall QCD
We calculate one-loop correction to the axial Ward-Takahashi identity given
by Furman and Shamir in domain-wall QCD. It is shown perturbatively that the
renormalized axial Ward-Takahashi identity is satisfied without fine tuning and
the ``conserved'' axial current receives no renormalization, giving .
This fact will simplify the calculation of the pion decay constant in numerical
simulations since the decay constant defined by this current needs no lattice
renormalization factor.Comment: 16 pages, 3 axodraw.sty figure
Charisma: An ill-defined and ill-measured gift
We take historical stock of charisma, tracing its origins and how it has been conceptualized in the sociological and organizational sciences literatures. Although charisma has been intensely studied, the concept is still not well understood and much of the research undertaken cannot inform policy. We show that the major obstacles to advancing our understanding of charisma have included issues with its definition, its confusion with transformational leadership, the use of questionnaire measures, and that it has not been studied using correctly-specified causal models. To help spawn a new genre of research in charisma, we use signaling theory to provide a general definition of charisma, and make suggestions about how charisma should be conceptualized, operationalized, and modeled. We also describe trends and patterns in articles we reviewed, using co-citation as well as bibliometric analyses, and discuss the practical implications of our findings
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