scholarly journals Removal of Large-Scale Stripes Via Unidirectional Multiscale Decomposition

2019 ◽  
Vol 11 (21) ◽  
pp. 2472
Author(s):  
He ◽  
Wang ◽  
Chang ◽  
Zhang ◽  
Feng
Keyword(s):  
Large Scale ◽  
Imaging Systems ◽  
Small Scale ◽  
Layer By Layer ◽  
Multiscale Decomposition ◽  
Cumulative Error ◽  
Scale Characteristics ◽  
The Difference ◽  
Color Cast ◽  
Error Suppression

Stripes are common in remote sensing imaging systems equipped with multichannel time delay integration charge-coupled devices (TDI CCDs) and have different scale characteristics depending on their causes. Large-scale stripes appearing between channels are difficult to process by most current methods. The framework of column-by-column nonuniformity correction (CCNUC) is introduced to eliminate large-scale stripes. However, the worst problem of CCNUC is the unavoidable cumulative error, which will cause an overall color cast. To eliminate large-scale stripes and suppress the cumulative error, we proposed a destriping method via unidirectional multiscale decomposition (DUMD). The striped image was decomposed by constructing a unidirectional pyramid and making difference maps layer by layer. The highest layer of the pyramid was processed by CCNUC to eliminate large-scale stripes, and multiple cumulative error suppression measures were performed to reduce overall color cast. The difference maps of the pyramid were processed by a designed filter to eliminate small-scale stripes. Experiments showed that DUMD had good destriping performance and was robust with respect to different terrains.

scholarly journals Small-scale characteristics of extremely high latitude aurora

2009 ◽  
Vol 27 (9) ◽  
pp. 3335-3347 ◽  
Author(s):  
J. A. Cumnock ◽  
L. G. Blomberg ◽  
A. Kullen ◽  
T. Karlsson ◽  
Keyword(s):  
High Latitude ◽  
Large Scale ◽  
Small Scale ◽  
Strong Correlations ◽  
Polar Cap ◽  
Plasma Flows ◽  
Ionospheric Convection ◽  
Local Closure ◽  
Scale Characteristics

Abstract. We examine 14 cases of an interesting type of extremely high latitude aurora as identified in the precipitating particles measured by the DMSP F13 satellite. In particular we investigate structures within large-scale arcs for which the particle signatures are made up of a group of multiple distinct thin arcs. These cases are chosen without regard to IMF orientation and are part of a group of 87 events where DMSP F13 SSJ/4 measures emissions which occur near the noon-midnight meridian and are spatially separated from both the dawnside and duskside auroral ovals by wide regions with precipitating particles typical of the polar cap. For 73 of these events the high-latitude aurora consists of a continuous region of precipitating particles. We focus on the remaining 14 of these events where the particle signatures show multiple distinct thin arcs. These events occur during northward or weakly southward IMF conditions and follow a change in IMF By. Correlations are seen between the field-aligned currents and plasma flows associated with the arcs, implying local closure of the FACs. Strong correlations are seen only in the sunlit hemisphere. The convection associated with the multiple thin arcs is localized and has little influence on the large-scale convection. This also implies that the sunward flow along the arcs is unrelated to the overall ionospheric convection.

Will Different Scales Impact on Design Collaboration in 3D Virtual Environments?

2012 ◽  
pp. 185-198
Author(s):  
Jerry Jen-Hung Tsai ◽  
Jeff WT Kan ◽  
Xiangyu Wang ◽  
Yingsiu Huang
Keyword(s):  
Virtual Environments ◽  
Large Scale ◽  
Protocol Analysis ◽  
Small Scale ◽  
Design Collaboration ◽  
The Difference ◽  
Communication Control ◽  
The Impact ◽  
3D Virtual Environments ◽  
Electronic Circuit Design

This chapter presents a study on the impact of design scales on collaborations in 3D virtual environments. Different domains require designers to work on different scales; for instance, urban design and electronic circuit design operate at very different scales. However, the understanding of the effects of scales upon collaboration in virtual environment is limited. In this chapter, the authors propose to use protocol analysis method to examine the differences between two design collaboration projects in virtual environments: one large scale, and another small scale within a similar domain. It shows that the difference in scale impacted more on communication control and social communication.

Channel Quality Approximation Based on Shadow Fading Model in GEO Mobile Satellite System

2013 ◽  
Vol 791-793 ◽  
pp. 1941-1944
Author(s):  
Ya Dan Zheng ◽  
Ming Ke Dong ◽  
Jian Jun Wu
Keyword(s):  
Large Scale ◽  
Adaptive Modulation ◽  
Original Data ◽  
Satellite System ◽  
Adaptive Modulation And Coding ◽  
Small Scale ◽  
Shadow Fading ◽  
Channel Quality ◽  
The Difference ◽  
Mobile Satellite

CQI(Channel Quality Indicator) is an essential indicator for AMC(Adaptive Modulation and Coding) technique in LTE. Due to the long delay of GEO satellite channel, CQI prediction is necessary to ensure effective AMC. This paper proposes the approximation from real CQI data containing small scale fading to that containing only large scale fading to do prediction. The concrete correlation features and the difference between the approximation and the original data are all analyzed. Simulation is done for confirmation. It shows that the approximate large scale CQI data is feasible and rational for prediction and ensuring AMC efficiency.

Factors Contributing to the Occurrence of Antimicrobial Drug Residues in Kenyan Milk

2004 ◽  
Vol 67 (2) ◽  
pp. 399-402 ◽  
Author(s):  
ANAKALO SHITANDI ◽  
ÅSE STERNESJÖ
Keyword(s):  
Large Scale ◽  
Bacillus Stearothermophilus ◽  
Antimicrobial Drug ◽  
Penicillin G ◽  
Small Scale ◽  
Drug Residues ◽  
Maximum Residue Level ◽  
Antimicrobial Residues ◽  
Field Samples ◽  
The Difference

The study investigated factors contributing to the occurrence of antimicrobial drug residues in milk within four major milk production districts in Kenya. The frequency of contamination was studied among small- and large-scale dairy producers to determine if there were differences between the two types of producers. Field samples (n = 1,600) were analyzed with the improved Dutch tube diffusion test, a microbial inhibitor test ( Bacillus stearothermophilus). In total, 144 and 64 samples from small- and large-scale producers, respectively, were found to contain β-lactam antibiotics at levels exceeding the established Codex maximum residue level for penicillin G (4 μg/kg). The difference in results between the two categories of producers was found to be significant (P < 0.001). To explain the higher frequency of antibiotic contamination of milk from small-scale producers, a questionnaire was constructed and used with 220 randomly selected smallholders in the selected districts. The results suggested (i) lack of understanding of risks related to antibiotic contamination of food, (ii) poor or no treatment records, and (iii) lack of a monitoring system as major risks for contamination. It was concluded that intensification of the education among small-scale dairy producers would greatly reduce the occurrence of antimicrobial residues in milk.

scholarly journals TRANSFORMASI TEKS CERITA RAKYAT KE DALAM BENTUK CERITA BERGAMBAR SEBAGAI MODEL PEMBELAJARAN MEMBACA APRESIATIF

LITERA ◽  
2016 ◽  
Vol 15 (2) ◽  
pp. 389-401
Author(s):  
Titin Setiartin R.
Keyword(s):  
Research And Development ◽  
Large Scale ◽  
Reading Skills ◽  
Mixed Strategy ◽  
Learning Model ◽  
Posttest Score ◽  
T Test ◽  
Small Scale ◽  
Validation Test ◽  
The Difference

TRANSFORMASI TEKS CERITA RAKYATKE DALAM BENTUK CERITA BERGAMBARSEBAGAI MODEL PEMBELAJARAN MEMBACA APRESIATIFTitin Setiartin R.FKIP Universitas Siliwangi Tasikmalayaemail: [email protected] ini bertujuan mendeskripsikan transformasi teks cerita rakyat ke dalambentuk cerita bergambar sebagai model pembelajaran membaca apresiatif. Penelitianpengembangan ini menggunakan strategi campuran kualitatif-kuantitatif desaineksploratori sekuensial. Data dianalisis secara kualitatif dan kuantitatif dengan uji validasipola matching pretest posttest. Hasil analisis uji-t antara tes awal and tes akhir kelas uji cobaterbatas, uji coba luas, dan uji validasi menunjukkan adanya perbedaan yang signifikan.Hasil analisis perbedaan dua rerata terhadap data hasil uji coba pertama/terbatas diperolehnilai t sebesar 11,992 dengan besaran perbedaan antara nilai tes awal dan nilai tes akhirsebesar 16,785 dan nilai signifikansi sebesar 0,000. Dengan demikian dapat disimpulkanbahwa model pembelajaran transformasi teks cerita yang dikembangkan mampumeningkatkan kemampuan membaca apresiatif. Model pembelajaran transformasi tekscerita efektif dan layak digunakan untuk meningkatkan kemampuan membaca apresiatifsiswa kelas XII SMK.Kata kunci: transformasi teks, model pembelajaran, membaca apresiatifTHE TRANSFORMATION OF FOLKLORE TEXTSINTO ILLUSTRATED STORIES AS A LEARNING MODELOF APPRECIATIVE READINGAbstractThis study aims to describe the transformation of folklore texts into illustrated storiesas a learning model of appreciative reading. This was a research and development studyusing a qualitative-quantitative mixed strategy with a sequential exploratory design. Thedata were qualitatively and quantitatively analyzed using a validation test by matchingthe pretest and the posttest. The results of the analysis of the t-test for the pretest and theposttest in the small-scale tryout, large-scale tryout, and validation test showed significantdifferences. The results of the analysis of the difference between two means in the first orsmall-scale tryout showed t =11.992 with a difference of 16.785 between the pretest scoreand the posttest score and a significance value of 0.000. Therefore, it can be concludedthat the developed learning model using the transformation of story texts can improveappreciative reading skills. The model is effective and appropriate to be used to improvethe appreciative reading skills of Grade XII students of the vocational high school.Keywords: transformation of texts, learning model, appreciative reading

scholarly journals Hierarchy of climate and hydrological uncertainties in transient low flow projections

2015 ◽  
Vol 12 (12) ◽  
pp. 12649-12701 ◽  
Author(s):  
J.-P. Vidal ◽  
B. Hingray ◽  
C. Magand ◽  
E. Sauquet ◽  
A. Ducharne
Keyword(s):  
General Circulation ◽  
Large Scale ◽  
Internal Variability ◽  
General Circulation Models ◽  
Low Flow ◽  
Small Scale ◽  
Total Uncertainty ◽  
Low Flows ◽  
The Difference ◽  
Flow Variables

Abstract. This paper proposes a methodology for estimating the transient probability distribution of yearly hydrological variables conditional to an ensemble of projections built from multiple general circulation models (GCMs), multiple statistical downscaling methods (SDMs) and multiple hydrological models (HMs). The methodology is based on the quasi-ergodic analysis of variance (QE-ANOVA) framework that allows quantifying the contributions of the different sources of total uncertainty, by critically taking account of large-scale internal variability stemming from the transient evolution of multiple GCM runs, and of small-scale internal variability derived from multiple realizations of stochastic SDMs. The QE-ANOVA framework was initially developed for long-term climate averages and is here extended jointly to (1) yearly anomalies and (2) low flow variables. It is applied to better understand possible transient futures of both winter and summer low flows for two snow-influenced catchments in the southern French Alps. The analysis takes advantage of a very large dataset of transient hydrological projections that combines in a comprehensive way 11 runs from 4 different GCMs, 3 SDMs with 10 stochastic realizations each, as well as 6 diverse HMs. The change signal is a decrease in yearly low flows of around −20 % in 2065, except for the most elevated catchment in winter where low flows barely decrease. This signal is largely masked by both large- and small-scale internal variability, even in 2065. The time of emergence of the change signal on 30 year low-flow averages is however around 2035, i.e. for time slices starting in 2020. The most striking result is that a large part of the total uncertainty – and a higher one than that due to the GCMs – stems from the difference in HM responses. An analysis of the origin of this substantial divergence in HM responses for both catchments and in both seasons suggests that both evapotranspiration and snowpack components of HMs should be carefully checked for their robustness in a changed climate in order to provide reliable outputs for informing water resource adaptation strategies.

Scale interactions in a mixing layer – the role of the large-scale gradients

2016 ◽  
Vol 791 ◽  
pp. 154-173 ◽  
Author(s):  
D. Fiscaletti ◽  
A. Attili ◽  
F. Bisetti ◽  
G. E. Elsinga
Keyword(s):  
Reynolds Number ◽  
High Speed ◽  
Large Scale ◽  
Mixing Layer ◽  
Physical Space ◽  
Small Scale ◽  
Velocity Fluctuations ◽  
Small Scales ◽  
Low Pass ◽  
Scale Characteristics

The interaction between the large and the small scales of turbulence is investigated in a mixing layer, at a Reynolds number based on the Taylor microscale ($Re_{{\it\lambda}}$) of $250$, via direct numerical simulations. The analysis is performed in physical space, and the local vorticity root-mean-square (r.m.s.) is taken as a measure of the small-scale activity. It is found that positive large-scale velocity fluctuations correspond to large vorticity r.m.s. on the low-speed side of the mixing layer, whereas, they correspond to low vorticity r.m.s. on the high-speed side. The relationship between large and small scales thus depends on position if the vorticity r.m.s. is correlated with the large-scale velocity fluctuations. On the contrary, the correlation coefficient is nearly constant throughout the mixing layer and close to unity if the vorticity r.m.s. is correlated with the large-scale velocity gradients. Therefore, the small-scale activity appears closely related to large-scale gradients, while the correlation between the small-scale activity and the large-scale velocity fluctuations is shown to reflect a property of the large scales. Furthermore, the vorticity from unfiltered (small scales) and from low pass filtered (large scales) velocity fields tend to be aligned when examined within vortical tubes. These results provide evidence for the so-called ‘scale invariance’ (Meneveau & Katz, Annu. Rev. Fluid Mech., vol. 32, 2000, pp. 1–32), and suggest that some of the large-scale characteristics are not lost at the small scales, at least at the Reynolds number achieved in the present simulation.

Remarks on Crack-Bridging Concepts

1992 ◽  
Vol 45 (8) ◽  
pp. 355-366 ◽  
Author(s):  
G. Bao ◽  
Z. Suo
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Ceramic Matrix Composites ◽  
Notch Sensitivity ◽  
Small Scale ◽  
Matrix Composites ◽  
Crack Bridging ◽  
Scale Bridging ◽  
Hole Radius ◽  
The Difference

The article draws upon recent work by us and our colleagues on metal and ceramic matrix composites for high temperature engines. The central theme here is to deduce mechanical properties, such as toughness, strength and notch-ductility, from bridging laws that characterize inelastic processes associated with fracture. A particular set of normalization is introduced to present the design charts, segregating the roles played by the shape, and the scale, of a bridging law. A single material length, δ0E/σ0, emerges, where δ0 is the limiting-separation, σ0 the bridging-strength, and E the Young’s modulus of the solid. It is the huge variation of this length—from a few nanometers for atomic bond, to a meter for cross-over fibers—that underlies the richness in material behaviors. Under small-scale bridging conditions, δ0E/σ0 is the only basic length scale in the mechanics problem and represents, with a pre-factor about 0.4, the bridging zone size. A catalog of small-scale bridging solutions is compiled for idealized bridging laws. Large-scale bridging introduces a dimensionless group, a/(δ0E/σ0), where a is a length characterizing the component (e.g., hole radius). The group plays a major role in all phenomena associated with bridging, and provides a focus of discussion in this article. For example, it quantifies the bridging scale when a is the unbridged crack length, and notch-sensitivity when a is hole radius. The difference and the connection between Irwin’s fracture mechanics and crack bridging concepts are discussed. It is demonstrated that fracture toughness and resistance curve are meaningful only when small-scale bridging conditions prevail, and therefore of limited use in design with composites. Many other mechanical properties of composites, such as strength and notch-sensitivity, can be simulated by invoking large-scale bridging concepts.

scholarly journals The levels of language problem management

2020 ◽  
Vol 71 (2) ◽  
pp. 229-246
Author(s):  
István Lanstyák
Keyword(s):  
Theoretical Basis ◽  
Large Scale ◽  
Management Theory ◽  
Small Scale ◽  
Language Management ◽  
Problem Management ◽  
Language Problem ◽  
The Difference ◽  
Visible Language ◽  
Scale Management

AbstractThe paper deals with the question of levels of language problem management on the basis of the Language Management Theory as well as other approaches to language problem management. The aim is to contribute to bringing the theoretical basis of language problem management closer to the problem management theories in general. Within language problem management three levels of management are distinguished: 1. interactional level of small‐scale management of inadequacies; 2. supra‐interactional level of small‐scale management of metaproblems and 3. supra‐interactional level of large‐scale management of metaproblems. Inadequacies are individual instances of problems rising in concrete interactions and metaproblems are types of problems which can be identified suprainteractionally, by abstracting the idiosyncratic features of inadequacies. With the help of these concepts the difference between the Language Management Theory and other theories of problem management can be made more visible: Language Management Theory builds on the small‐scale management of inadequacies on interactional level, while other theories are based on the large‐scale management of metaproblems on suprainteractional level.

How essential of the balance between large and small scale features to reproduce precipitation during a sudden sharp turn from drought to flood

2020 ◽  
Author(s):  
Yuanyuan Ma
Keyword(s):  
Extreme Events ◽  
Large Scale ◽  
Climate Model ◽  
Regional Climate ◽  
Small Scale ◽  
Model Errors ◽  
Continuous Simulation ◽  
Spectral Nudging ◽  
Sharp Turn ◽  
The Difference

<p>Sudden turn from drought to flood (STDF) is a unique representation of intra-seasonal extreme events and occurs frequently. However, it is notoriously difficult to represent in climate simulations due to the accumulation of model errors. This study uses a regional climate model (RCM) with different initialization and nudging schemes to explore effective approaches for capturing a STDF event. Results show that the conventional continuous integration with single initialization cannot reproduce the STDF event, while nudging or re-initialization can. Furthermore, spectral nudging and re-initialization outperform the conventional continuous simulation in reproducing precipitation features, but grid nudging induces the largest biases for precipitation though it has the smallest biases for other meteorological elements. Scale separation analysis shows that the large-scale features of the conventional continuous simulation drift far from the actual fields and force erroneous small-scale features, whereas the nudging and re-initialization successfully prevent the model from drifting away from the forcing fields at large-scales. The different performance for simulating precipitation among spectral nudging, re-initialization and grid nudging can be attributed to that the former two methods generate their own small-scale information via the RCM, while grid nudging over-suppresses the small-scale information while retaining the large-scale features. The difference in small-scale features affects the simulation of different moisture fluxes and convergences, as well as clouds, and then results in diverse precipitation. These results illustrate that both the consistency with large-scale features and the local variability from small-scale features are both robust factors for reproducing precipitation features during extreme events using RCMs.</p>

Sign in / Sign up

Export Citation Format

Share Document