The Practice of Short-Term Climate Prediction

2006 ◽  
Author(s):  
Huug van den Dool
Keyword(s):  
Real Time ◽  
Seasonal Prediction ◽  
Data Sets ◽  
Short Term ◽  
Pressure Time ◽  
Methodical Approach ◽  
Long Time ◽  
The Usa ◽  
The One ◽  
Forecast Assumptions

While previous chapters were about methods and their formal backgrounds, we here present a description of the process of making a forecast and the protocol surrounding it. A look in the kitchen. It is difficult to find literature on the subject, presumably because a real-time forecast is not a research project and potential authors (the forecasters) work in an ever-changing environment and may never feel the time is right to write an overview of what they are doing. Moreover, it may be very difficult to describe real-time forecasts and present a complete picture. Nearly all of the material presented here specifically applies to the seasonal prediction made at the NWS in the USA, but should be relevant elsewhere. A real-time operational forecast setting lacks the logic and methodical approach one should strive for in science. This is for many reasons. There is pressure, time schedules are to be met, input data sets could be missing or incorrect, and one can feel the suspense, excitement and disappointment associated with a forecast in real time. There are habits that are carried over from years past—forecasters are partly set in their ways or find it difficult to make major changes in mid-stream. The interaction with the user influences the forecast, and/or the way the information is conveyed. Psychology enters the forecast. Assumptions about what users want or understand do play a role. Generally speaking a forecast is thus a mix of what is scientifically possible on the one hand and what is presumably useful to the customer on the other. The CPC/NWS forecasts are moreover for the general user, not one user specifically. Users for short-term climate forecasts range from the highly sophisticated (energy traders, selling of weather derivatives, hydrologists) via the (wo)man in the street to entertainment. The seasonal forecast has been around a long time in the USA. Jerome Namias started in-house seasonal forecasts at the NWS in 1958. After 15 years of testing, his successor Donald Gilman made the step to public release in 1973.

scholarly journals HST-LSTM: A Hierarchical Spatial-Temporal Long-Short Term Memory Network for Location Prediction

2018 ◽  
Author(s):  
Dejiang Kong ◽  
Fei Wu
Keyword(s):  
Real Time ◽  
Short Term Memory ◽  
Location Based Services ◽  
Location Prediction ◽  
Trajectory Data ◽  
Short Term ◽  
Data Set ◽  
Term Memory ◽  
Long Time ◽  
Long Short Term Memory

The widely use of positioning technology has made mining the movements of people feasible and plenty of trajectory data have been accumulated. How to efficiently leverage these data for location prediction has become an increasingly popular research topic as it is fundamental to location-based services (LBS). The existing methods often focus either on long time (days or months) visit prediction (i.e., the recommendation of point of interest) or on real time location prediction (i.e., trajectory prediction). In this paper, we are interested in the location prediction problem in a weak real time condition and aim to predict users' movement in next minutes or hours. We propose a Spatial-Temporal Long-Short Term Memory (ST-LSTM) model which naturally combines spatial-temporal influence into LSTM to mitigate the problem of data sparsity. Further, we employ a hierarchical extension of the proposed ST-LSTM (HST-LSTM) in an encoder-decoder manner which models the contextual historic visit information in order to boost the prediction performance. The proposed HST-LSTM is evaluated on a real world trajectory data set and the experimental results demonstrate the effectiveness of the proposed model.

Technical Challenges Facing Regulators–Assessment of Long-Term Materials Performance

1987 ◽  
Vol 112 ◽  
Author(s):  
Kenneth W. Stephens
Keyword(s):  
Real Time ◽  
Waste Disposal ◽  
Time Frame ◽  
High Level Waste ◽  
Short Term ◽  
Long Time ◽  
Computer Codes ◽  
High Level ◽  
Term Data

AbstractFor a number of years, nuclear regulators have grappled with difficult questions such as: “How safe is safe enough?” Such issues take on new dimensions in the long time-frame of high-level waste disposal.Many of the challenges facing regulators involve assessment of long-term materials performance. Because real-time experiments cannot be conducted, it is necessary to rely extensively on modeling. This raises issues regarding the extent to which long-term extrapolations of short-term data are justified, the question of how closely models must represent reality to be trusted, and practical matters such as methods for validating unique computer codes.Issues such as these illustrate how regulators must make decisions in a climate of uncertainty. Methods used by non-technical disciplines to make decisions under uncertainty have been examined and offer solutions for regulators and licensees alike.

scholarly journals The CMEMS GlobColour chlorophyll <i>a</i> product based on satellite observation: multi-sensor merging and flagging strategies

Ocean Science ◽  
2019 ◽  
Vol 15 (3) ◽  
pp. 819-830 ◽  
Author(s):  
Philippe Garnesson ◽  
Antoine Mangin ◽  
Odile Fanton d'Andon ◽  
Julien Demaria ◽  
Marine Bretagnon
Keyword(s):  
Remote Sensing ◽  
Chlorophyll A ◽  
Spatial Resolution ◽  
Remote Sensing Data ◽  
Satellite Observation ◽  
Data Sets ◽  
In Situ Data ◽  
Long Time ◽  
The One ◽  
Monitoring Service

Abstract. This paper concerns the GlobColour-merged chlorophyll a products based on satellite observation (SeaWiFS, MERIS, MODIS, VIIRS and OLCI) and disseminated in the framework of the Copernicus Marine Environmental Monitoring Service (CMEMS). This work highlights the main advantages provided by the Copernicus GlobColour processor which is used to serve CMEMS with a long time series from 1997 to present at the global level (4 km spatial resolution) and for the Atlantic level 4 product (1 km spatial resolution). To compute the merged chlorophyll a product, two major topics are discussed: The first of these topics is the strategy for merging remote-sensing data, for which two options are considered. On the one hand, a merged chlorophyll a product computed from a prior merging of the remote-sensing reflectance of a set of sensors. On the other hand, a merged chlorophyll a product resulting from a combination of chlorophyll a products computed for each sensor. The second topic is the flagging strategy used to discard non-significant observations (e.g. clouds, high glint and so on). These topics are illustrated by comparing the CMEMS GlobColour products provided by ACRI-ST (Garnesson et al., 2019) with the OC-CCI/C3S project (Sathyendranath et al., 2018). While GlobColour merges chlorophyll a products with a specific flagging, the OC-CCI approach is based on a prior reflectance merging before chlorophyll a derivation and uses a more constrained flagging approach. Although this work addresses these two topics, it does not pretend to provide a full comparison of the two data sets, which will require a better characterisation and additional inter-comparison with in situ data.

scholarly journals Subtle flickering in Cepheids: Kepler and MOST

2013 ◽  
Vol 9 (S301) ◽  
pp. 55-58 ◽  
Author(s):  
Nancy Remage Evans ◽  
Robert Szabó ◽  
Laszlo Szabados ◽  
Aliz Derekas ◽  
Jaymie M. Matthews ◽  
...  
Keyword(s):  
Light Curve ◽  
Fundamental Mode ◽  
Fourier Spectrum ◽  
Amplitude Ratio ◽  
Fourier Amplitude ◽  
Short Term ◽  
Classical Cepheids ◽  
Long Time ◽  
Change Period ◽  
The One

AbstractFundamental mode classical Cepheids have light curves which repeat accurately enough that we can watch them evolve (change period). The new level of accuracy and quantity of data with the Kepler and MOST satellites probes this further. An intriguing result was found in the long time-series of Kepler data for V1154 Cyg the one classical Cepheid (fundamental mode, P = 4.9 d) in the field, which has short term changes in period (≃20 minutes), correlated for ≃10 cycles (period jitter). To follow this up, we obtained a month long series of observations of the fundamental mode Cepheid RT Aur and the first overtone pulsator SZ Tau. RT Aur shows the traditional strict repetition of the light curve, with the Fourier amplitude ratio R1/R2 remaining nearly constant. The light curve of SZ Tau, on the other hand, fluctuates in amplitude ratio at the level of approximately 50%. Furthermore prewhitening the RT Aur data with 10 frequencies reduces the Fourier spectrum to noise. For SZ Tau, considerable power is left after this prewhitening in a complicated variety of frequencies.

Research on High-Quality Soft Shadow of Building Based Shadow Map

2012 ◽  
Vol 174-177 ◽  
pp. 1927-1930 ◽  
Author(s):  
Tao Shang ◽  
Shui Peng Zhang
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Data Sets ◽  
Depth Data ◽  
Soft Shadow ◽  
Shadow Map ◽  
Long Time ◽  
Depth Buffer ◽  
And Performance ◽  
The One

Image rendering of shadow faces a problem existed for a long time,that is the contradiction of quality and performance. Variant algorithms are presented to ameliorate this problem,shadow map is the one which is representative for that. Even though shadow maps have been widely used for the shadow of Three-dimensional scene,some imperfection still exist in this method like aliasing problem.So,the focus of the paper is introduce an algorithm which layering the data sets of the large scale building's shadow rapidly and intelligently based shadow map. First, we ascertain the fragment which create the shadow by shadow mapping's two scan. Second, we process the float data in the depth buffer by using uniformization and render the two depth data in the texture.Then use Gauss Filter to blur.Finally,use the algorithm of BIRCH cluster the uniformization data to improve the obscure and tweened effect.This method brings reduction of aliasing problem with low overhead as well as performance to a certain extent .

Catheter-directed foam sclerotherapy treatment of saphenous vein incompetence

VASA ◽  
2012 ◽  
Vol 41 (2) ◽  
pp. 120-124 ◽  
Author(s):  
Asciutto ◽  
Lindblad
Keyword(s):  
Saphenous Vein ◽  
Short Term ◽  
Foam Sclerotherapy ◽  
Results Of Treatment ◽  
Ulcer Healing Rate ◽  
Complete Obliteration ◽  
Ceap Classification ◽  
One Year ◽  
The One

Background: The aim of this study is to report the short-term results of catheter-directed foam sclerotherapy (CDFS) in the treatment of axial saphenous vein incompetence. Patients and methods: Data of all patients undergoing CDFS for symptomatic primary incompetence of the great or small saphenous vein were prospectively collected. Treatment results in terms of occlusion rate and patients’ grade of satisfaction were analysed. All successfully treated patients underwent clinical and duplex follow-up examinations one year postoperatively. Results: Between September 2006 and September 2010, 357 limbs (337 patients) were treated with CDFS at our institution. Based on the CEAP classification, 64 were allocated to clinical class C3 , 128 to class C4, 102 to class C5 and 63 to class C6. Of the 188 patients who completed the one year follow up examination, 67 % had a complete and 14 % a near complete obliteration of the treated vessel. An ulcer-healing rate of 54 % was detected. 92 % of the patients were satisfied with the results of treatment. We registered six cases of thrombophlebitis and two cases of venous thromboembolism, all requiring treatment. Conclusions: The short-term results of CDFS in patients with axial vein incompetence are acceptable in terms of occlusion and complications rates.

Time Window from Visual Images to Visual Short-Term Memory: Consolidation or Integration?

2004 ◽  
Vol 51 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Yuhong Jiang
Keyword(s):  
Short Term Memory ◽  
Time Window ◽  
Short Interval ◽  
Visual Images ◽  
Short Term ◽  
Temporal Window ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
Probe Task ◽  
Long Time

Abstract. When two dot arrays are briefly presented, separated by a short interval of time, visual short-term memory of the first array is disrupted if the interval between arrays is shorter than 1300-1500 ms ( Brockmole, Wang, & Irwin, 2002 ). Here we investigated whether such a time window was triggered by the necessity to integrate arrays. Using a probe task we removed the need for integration but retained the requirement to represent the images. We found that a long time window was needed for performance to reach asymptote even when integration across images was not required. Furthermore, such window was lengthened if subjects had to remember the locations of the second array, but not if they only conducted a visual search among it. We suggest that a temporal window is required for consolidation of the first array, which is vulnerable to disruption by subsequent images that also need to be memorized.

Alkohol im Tank – Bio-Kraftstoffe und die Grenzen moderner Mobilität

2004 ◽  
Vol 34 (136) ◽  
pp. 455-468
Author(s):  
Hartwig Berger
Keyword(s):  
Third World ◽  
Fossil Fuel ◽  
Energy Resources ◽  
The Third ◽  
Political Conflicts ◽  
The Future ◽  
Long Time ◽  
Food Market ◽  
The One ◽  
The Third World

The article discusses the future of mobility in the light of energy resources. Fossil fuel will not be available for a long time - not to mention its growing environmental and political conflicts. In analysing the potential of biofuel it is argued that the high demands of modern mobility can hardly be fulfilled in the future. Furthermore, the change into using biofuel will probably lead to increasing conflicts between the fuel market and the food market, as well as to conflicts with regional agricultural networks in the third world. Petrol imperialism might be replaced by bio imperialism. Therefore, mobility on a solar base pursues a double strategy of raising efficiency on the one hand and strongly reducing mobility itself on the other.

Hidden “holes” in the capital of banks and the supply of credit to the real sector of economy

2018 ◽  
pp. 49-68 ◽  
Author(s):  
M. E. Mamonov
Keyword(s):  
Credit Risk ◽  
The Other ◽  
Real Sector ◽  
Capital Management ◽  
Loan Loss ◽  
Short Term ◽  
The Real ◽  
Ex Post ◽  
The One

Our analysis documents that the existence of hidden “holes” in the capital of not yet failed banks - while creating intertemporal pressure on the actual level of capital - leads to changing of maturity of loans supplied rather than to contracting of their volume. Long-term loans decrease, whereas short-term loans rise - and, what is most remarkably, by approximately the same amounts. Standardly, the higher the maturity of loans the higher the credit risk and, thus, the more loan loss reserves (LLP) banks are forced to create, increasing the pressure on capital. Banks that already hide “holes” in the capital, but have not yet faced with license withdrawal, must possess strong incentives to shorten the maturity of supplied loans. On the one hand, it raises the turnovers of LLP and facilitates the flexibility of capital management; on the other hand, it allows increasing the speed of shifting of attracted deposits to loans to related parties in domestic or foreign jurisdictions. This enlarges the potential size of ex post revealed “hole” in the capital and, therefore, allows us to assume that not every loan might be viewed as a good for the economy: excessive short-term and insufficient long-term loans can produce the source for future losses.

Making it abstract, making it contestable: Gender/sex as a politicized concept

2020 ◽  
Author(s):  
Claudia Mazzuca ◽  
Matteo Santarelli
Keyword(s):  
Social Sciences ◽  
Main Question ◽  
Abstract Concepts ◽  
Biological Feature ◽  
Dynamic Approach ◽  
Cognitive Sciences ◽  
Long Time ◽  
Cultural Construct ◽  
Science Framework ◽  
The One

The concept of gender has been the battleground of scientific and political speculations for a long time. On the one hand, some accounts contended that gender is a biological feature, while on the other hand some scholars maintained that gender is a socio-cultural construct (e.g., Butler, 1990; Risman, 2004). Some of the questions that animated the debate on gender over history are: how many genders are there? Is gender rooted in our biological asset? Are gender and sex the same thing? All of these questions entwine one more crucial, and often overlooked interrogative. How is it possible for a concept to be the purview of so many disagreements and conceptual redefinitions? The question that this paper addresses is therefore not which specific account of gender is preferable. Rather, the main question we will address is how and why is even possible to disagree on how gender should be considered. To provide partial answers to these questions, we suggest that gender/sex (van Anders, 2015; Fausto-Sterling, 2019) is an illustrative example of politicized concepts. We show that no concepts are political in themselves; instead, some concepts are subjected to a process involving a progressive detachment from their supposed concrete referent (i.e., abstractness), a tension to generalizability (i.e., abstraction), a partial indeterminacy (i.e., vagueness), and the possibility of being contested (i.e., contestability). All of these features differentially contribute to what we call the politicization of a concept. In short, we will claim that in order to politicize a concept, a possible strategy is to evidence its more abstract facets, without denying its more embodied and perceptual components (Borghi et al., 2019). So, we will first outline how gender has been treated in psychological and philosophical discussions, to evidence its essentially contestable character thereby showing how it became a politicized concept. Then we will review some of the most influential accounts of political concepts, arguing that currently they need to be integrated with more sophisticated distinctions (e.g., Koselleck, 2004). The notions gained from the analyses of some of the most important accounts of political concepts in social sciences and philosophy will allow us to implement a more dynamic approach to political concepts. Specifically, when translated into the cognitive science framework, these reflections will help us clarifying some crucial aspects of the nature of politicized concepts. Bridging together social and cognitive sciences, we will show how politicized concepts are abstract concepts, or better abstract conceptualizations.

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