scholarly journals Characterizing and Correcting Phase Biases in Short-Term, Multilooked Interferograms

2021 ◽  
Author(s):  
Yasser Maghsoudi ◽  
Andy Hooper ◽  
Tim Wright ◽  
Homa Ansari ◽  
Milan Lazecky
Keyword(s):  
Ground Cover ◽  
Short Term ◽  
Western Turkey ◽  
Time Period ◽  
Interferometric Phase ◽  
Common Strategy ◽  
Long Time ◽  
Phase Bias ◽  
Time Periods

Interferometric Synthetic Aperture Radar (InSAR) is widely used to measure deformation of the Earth’s surface over large areas and long time periods. A common strategy to overcome coherence loss in long-term interferograms is to use multiple multilooked shorter interferograms, which can cover the same time period but maintain coherence. However, it has recently been shown that using this strategy can introduce a bias (also referred to as “fading signals”) in the interferometric phase, particularly over vegetated areas. We isolate the signature of the phase bias by constructing daisy chain sums of short-term interferograms covering identical 1-year time periods, but using interferograms of different time spans. This shows that the shorter interferograms are more affected by this phenomenon and that different ground cover types are affected differently. We, propose a method for correcting the phase bias, based on the assumption that the bias in an interferogram is linearly related to the sum of the bias in shorter interferograms spanning the same time. We tested the algorithm over a study area in western Turkey by comparing average velocities against results from a phase linking approach that has been shown to be rather insensitive to the phase bias. Our corrected velocities agree well with those from phase linking approach. Our approach can be applied to global compilations of short-term interferograms and offer the possibility of accurate long-term velocities without a requirement for coherence in long-term interferograms.

Use of tilt sensing equipment for monitoring long-term bridge movement

1991 ◽  
Vol 18 (6) ◽  
pp. 1033-1046 ◽  
Author(s):  
Terry J. Wipf
Keyword(s):  
Key Words ◽  
Reference Point ◽  
Structural Engineering ◽  
Field Tests ◽  
Measurement Instruments ◽  
Time Period ◽  
Long Time ◽  
Time Periods ◽  
Tilt Sensors

Accurate monitoring of long-term movements in bridges can be difficult primarily because of the relatively long time period over which the movements occur and inadequate instrumentation and technique. A stable reference point for measurements is difficult to obtain over these long time periods. Two bridges were monitored for long-term structural movement; the results are presented here. Instrumentation including temperature transducers and tilt sensors placed on and near piers determined the pier movement. The results of the study indicate that a superstructure expansion pier on one of the bridges monitored actually behaved as a fixed pier. The equipment used in the study, including data acquisition components and tilt sensors, proved reliable and accurate. Key words: bridges, girder, field tests, foundations, measurement instruments, piers, structural engineering.

ON THE CONSUMPTION/DISTRIBUTION THEOREM UNDER THE LONG-RUN GROWTH CRITERION SUBJECT TO A DRAWDOWN CONSTRAINT

2010 ◽  
Vol 13 (06) ◽  
pp. 931-957 ◽  
Author(s):  
MICHAEL J. KLASS ◽  
KRZYSZTOF NOWICKI
Keyword(s):  
Growth Rate ◽  
Short Term ◽  
Long Run ◽  
Time Period ◽  
Total Capital ◽  
Growth Criterion ◽  
Drawdown Constraint ◽  
Riskless Asset ◽  
Distribution Theorem

Consider any discrete time sequence of investment fortunes Fn which has a finite long-run growth rate [Formula: see text] when subject to the present value capital drawdown constraint Fne-rn ≥ λ* max 0≤k≤nFke-rk, where 0 ≤ λ* < 1, in the presence of a riskless asset affording a return of er dollars per time period per dollar invested. We show that money can be withdrawn for consumption from the invested capital without either reducing the long-run growth rate of such capital or violating the drawdown constraint for our capital sequence, while simultaneously increasing the amount of capital withdrawn for consumption at the identical long-term rate of V(r, λ*). We extend this result to an exponentially increasing number of consumption categories and discuss how additional yearly contributions can temporarily augment the total capital under management. In addition, we assess the short-term practicality of creating such an endowment/consumption/distribution program.

scholarly journals Methods of long-term and short-term adaptation for biometric image of keystroke dynamics

2021 ◽  
Vol 7 (3D) ◽  
pp. 450-457
Author(s):  
Dmitry V. Pashchenko ◽  
Dmitry A. Trokoz ◽  
Alexey I. Martyshkin ◽  
Elena A. Balzannikova
Keyword(s):  
Working Capacity ◽  
Keystroke Dynamics ◽  
Short Term ◽  
User Identification ◽  
New Device ◽  
Short Term Adaptation ◽  
Long Time

This article discusses one of the main problems of user identification by keyboard handwriting - short-term changes in the keystroke dynamics of users in connection with its psychophysical state, as well as changes over a long time associated with the formation of keystroke dynamics by a new user or when switching to a new device. A method for determining the phase of working capacity by the time characteristics of the keystroke dynamics is proposed.

scholarly journals Are stock returns an inflation hedge for the UK? Evidence from a wavelet analysis using over three centuries of data

2018 ◽  
Vol 23 (3) ◽  
Author(s):  
Aviral Kumar Tiwari ◽  
Juncal Cunado ◽  
Rangan Gupta ◽  
Mark E. Wohar
Keyword(s):  
South Africa ◽  
Wavelet Analysis ◽  
Stock Returns ◽  
Time Period ◽  
Inflation Rates ◽  
The Us ◽  
Long Time ◽  
Time Periods ◽  
The Uk ◽  
The Relationship

Abstract This paper analyzes the relationship between stock returns and the inflation rates for the UK over a long time period (February 1790–February 2017) and at different frequencies, by employing a wavelet analysis. We also compare the results for the UK economy with those for the US and two developing countries (India and South Africa). Overall, our results tend to suggest that, while the relationship between stock returns and inflation rates varies across frequencies and time periods, there is no evidence of stock returns acting as an inflation hedge, irrespective of whether we look at the two developed or the two developing markets in our sample.

The effect of the financing structure on the return on the market share in Saudi companies An Empirical Study: أثر هيكل التمويل على عائد السهم السوقي في الشركات السعودية: دراسة تطبيقية

2020 ◽  
Vol 4 (11) ◽  
Author(s):  
Fatimah Mohammad Asiri
Keyword(s):  
Market Share ◽  
Food Production ◽  
Analytical Approach ◽  
Negative Impact ◽  
Short Term ◽  
Financing Structure ◽  
Time Period ◽  
Comprehensive Survey ◽  
Study Population

The study aimed to identify the influence of the financing structure on the return of the market share in Saudi corporations/companies. The study applied the descriptive-analytical approach, and the study population consisted of some joint-stock companies in the Saudi stock market, where the study sample consisted of (75) companies in five productive sectors where concentration was made on the following sectors: (basic materials, long-term commodities, energy, food production, capital goods). Method of the comprehensive survey was used for all companies. The data was analyzed using the Panel Data method through the STATA program. The study concluded several findings, the most important of which are that short-term debt (liabilities) have a negative impact on the return on the market share, as increasing short debts (liabilities) lead to a decrease in the return on the market share, and that long-term debt (liabilities) have no effect on the return on the market share, and equity has a negative impact on the return on the market share, as the increase in financing through equity leads to a decrease in the return on the market share. The study recommended the necessity of diversification between sources of financing and not limited to debt and long & short-term liabilities only. It also recommended conducting such a study on other sectors or conducting it on the whole market which may result in improving results, and also recommends expanding the time period more than five years, which may lead to improve results.

scholarly journals Planting and harvesting innovation - an analysis of Samsung Electronics

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Seung Hoon Jang ◽  
Sang M. Lee ◽  
Taewan Kim ◽  
Donghyun Choi
Keyword(s):  
Early Stage ◽  
New Products ◽  
Limited Resources ◽  
High Tech ◽  
Short Term ◽  
Entire Life ◽  
Entire Life Cycle ◽  
Time Period ◽  
Innovation Projects ◽  
Long Time

Abstract This study explores how firms manage the entire life cycle of innovation projects based on the framework of harvesting and planting innovation. While harvesting innovation seeks new products in the expectation of financial performance in the short term, planting innovation pursues creating value over a long time period. Without proper management of the process of planting and harvesting innovation, firms with limited resources may not be successful in launching innovative new products to seize a momentum in high tech industries. To examine this issue, the case of Samsung Electronics (SE), now an electronics giant originated from a former developing country, is analyzed. SE has shown to effectively utilize co-innovation to maintain numerous planting and harvesting innovation projects. Both researchers and practitioners would be interested in learning about how SE shared risks of innovation investment with external partners at the early stage of innovation cycles.

Long-Term Interaction

2011 ◽  
pp. 169-183
Author(s):  
Christoph Haffner ◽  
Thorsten Völkel
Keyword(s):  
Working Memory ◽  
Interactive Television ◽  
Theoretical Models ◽  
Short Term ◽  
Time Periods ◽  
Potential Impact

This chapter introduces the application of concepts for long-term interaction to support long-term relationship in the interactive television (iTV) domain. While classical interaction concepts cover short-term interaction cycles only, theoretical models for long-term interaction and relationships deal with time periods exceeding the human short-term working memory. The user must be supported by memory cues to resume interrupted long-term interactions immediately. The iTV domain offers many long-term interaction scenarios in the context of establishing long-term relationships of recipients and broadcasters. The authors adopt concepts for long-term interaction towards iTV and develop a basic classification of long-term interaction. Three scenarios within the iTV domain illustrate the potential impact for the design of iTV applications.

Simulation of Hydrogen Distribution due to In-Vessel Severe Accident in WWER-1000 NPP Containment: A Comparison of CONTAIN and MELCOR Codes Results

2018 ◽  
Author(s):  
Omid Noorikalkhoran ◽  
Massimiliano Gei
Keyword(s):  
Severe Accident ◽  
Second Step ◽  
Hydrogen Distribution ◽  
Short Term ◽  
Long Time ◽  
Design Basis Accident ◽  
Safety Features ◽  
Design Pressure ◽  
Good Agreement

During a severe accident or Beyond Design Basis Accident (BDBA), the reaction of water with zirconium alloy as fuel clad, radiolysis of water, molten corium-concrete interaction (MCCI) and post-accident corrosion can generate a source of hydrogen. In the present work, hydrogen distribution due to in-vessel reaction (between zircaloy and steam) has been simulated inside a WWER-1000 reactor containment. In the first step, the thermal hydraulic parameters of containment have been simulated for a DECL (Double Ended Cold Leg) accident (DBA phase) in both short and long time and the effects of spray as Engineering Safety Features (ESFs) on mitigating the parameters have been studied. In the second step, it has been assumed that the accident developed into an in-vessel core melting accident. While in pre-phase of core melting (severe accident phase), hydrogen will be produced as a result of zircaloy and steam reaction (BDBA phase), the hydrogen distribution has been simulated for 23 cells inside the reactor containment by using CONTAIN 2.0 (Best estimate code) and MELCOR 1.8.6 codes. Finally, the results have been compared to FSAR results. As it can be seen from the comparisons, both CONTAIN and MELCOR codes can predict the results in good agreement with FSAR (ANGAR code) results. CONTAIN shows peak pressure around 0.36 MPa in short-term and this amount is about 0.38 and 0.4 MPa for MELCOR and ANGAR (FSAR) results respectively. All these values are under design pressure that is around 0.46 MPa. Cell 20 has the maximum mole fraction of hydrogen in long-term about 9.5% while the maximum amount of hydrogen takes place in cell 22. The differences between the results of codes are because of different equations, Models, Numerical methods and assumptions that have been considered by the codes. The simulated Hydrogen Distribution Map (HDM) can be used for upgrading the location of HCAV systems and Hydrogen Mitigator features (like the recombiners and ignitors) inside the containment to reduce the risk of hydrogen explosion.

scholarly journals Temporal and spatial analysis of ozone concentrations in Europe based on time scale decomposition and a multi-clustering approach

2019 ◽  
Author(s):  
Eirini Boleti ◽  
Christoph Hueglin ◽  
Stuart K. Grange ◽  
André S. H. Prévôt ◽  
Satoshi Takahama
Keyword(s):  
Time Scale ◽  
Seasonal Cycle ◽  
Clustering Algorithm ◽  
Short Term ◽  
Ozone Concentrations ◽  
Time Period ◽  
Term Variation ◽  
Long Term Trends ◽  
Time Scale Decomposition

Abstract. Air quality measures that were implemented in Europe in the 1990s resulted in reductions of ozone precursors concentrations. In this study, the effect of these reductions on ozone is investigated by analyzing surface measurements of ozone for the time period between 2000 and 2015. Using a non-parametric time scale decomposition methodology, the long-term, seasonal and short-term variation of ozone observations were extracted. A clustering algorithm was applied to the different time scale variations, leading to a classification of sites across Europe based on the temporal characteristics of ozone. The clustering based on the long-term variation resulted in a site type classification, while a regional classification was obtained based on the seasonal and short-term variations. Long-term trends of de-seasonalized mean and meteo-adjusted peak ozone concentrations were calculated across large parts of Europe for the time period 2000–2015. A multi-dimensional scheme was used for a detailed trend analysis, based on the identified clusters, which reflect precursor emissions and meteorological influence either on the inter-annual or the short-term time scale. Decreasing mean ozone concentrations at rural sites and increasing or stabilizing at urban sites were observed. At the same time downward trends for peak ozone concentrations were detected for all site types. The effect of hemispheric transport of ozone can be seen either in regions affected by synoptic patterns in the northern Atlantic or at sites located at remote high altitude locations. In addition, a reduction of the amplitude in the seasonal cycle of ozone was observed, and a shift in the occurrence of the seasonal maximum towards earlier time of the year. Finally, a reduced sensitivity of ozone to temperature was identified. It was concluded that long-term trends of mean and peak ozone concentrations are mostly controlled by precursors emissions changes, while seasonal cycle trends and changes in the sensitivity of ozone to temperature are driven by regional climatic conditions.

The remote results of laser destruction of proliferating colloidal goiter

2016 ◽  
Vol 22 (1) ◽  
pp. 7-9
Author(s):  
Yu. K Aleksandrov ◽  
Vasiliy I. Semikov ◽  
V. A Kudachkov ◽  
E. I Sokolova
Keyword(s):  
Thyroid Gland ◽  
Connective Tissue ◽  
Morphological Analysis ◽  
Nodular Goiter ◽  
Early Time ◽  
Follicular Epithelium ◽  
Time Period ◽  
Time Periods ◽  
Tissue Structures

The article presents the remote results (time-period more than 1 year) of application of percutaneous laser destruction in treatment of nodular goiter in 164 patients. The reliable decreasing of dimensions and size of nodular formations of thyroid gland in early time-periods with continuation of regression during a year is established. In the following, slight regression was marked during 3,5-5 years. The morphological analysis established that in remote time-periods after percutaneous laser destruction of nodular proliferating colloid goiter the destroyed follicular epithelium and colloid are replaced by connective tissue structures with large amount of collagen guaranteeing long-term predictive result.

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