scholarly journals Vegetated Target Decorrelation in SAR and Interferometry: Models, Simulation, and Performance Evaluation

2020 ◽  
Vol 12 (16) ◽  
pp. 2545 ◽  
Author(s):  
Andrea Monti-Guarnieri ◽  
Marco Manzoni ◽  
Davide Giudici ◽  
Andrea Recchia ◽  
Stefano Tebaldini

The paper addresses the temporal stability of distributed targets, particularly referring to vegetation, to evaluate the degradation affecting synthetic aperture radar (SAR) imaging and repeat-pass interferometry, and provide efficient SAR simulation schemes for generating big dataset from wide areas. The models that are mostly adopted in literature are critically reviewed, and aim to study decorrelation in a range of time (from hours to days), of interest for long-term SAR, such as ground-based or geosynchronous, or repeat-pass SAR interferometry. It is shown that none of them explicitly account for a decorrelation occurring in the short-term. An explanation is provided, and a novel temporal decorrelation model is proposed to account for that fast decorrelation. A formal method is developed to evaluate the performance of SAR focusing, and interferometry on a homogenous, stationary scene, in terms of Signal-to-Clutter Ratio (SCR), and interferometric coherence. Finally, an efficient implementation of an SAR simulator capable of handling the realistic case of heterogeneous decorrelation over a wide area is discussed. Examples are given by assuming two geostationary SAR missions in C and X band.

2021 ◽  
pp. 089020702110173
Author(s):  
Nadin Beckmann ◽  
Damian P Birney ◽  
Amirali Minbashian ◽  
Jens F Beckmann

The study aimed to investigate the status of within-person state variability in neuroticism and conscientiousness as individual differences constructs by exploring their (a) temporal stability, (b) cross-context consistency, (c) empirical links to selected antecedents, and (d) empirical links to longer term trait variability. Employing a sample of professionals ( N = 346) from Australian organisations, personality state data together with situation appraisals were collected using experience sampling methodology in field and repeatedly in lab-like settings. Data on personality traits, cognitive ability, and motivational mindsets were collected at baseline and after two years. Contingent (situation contingencies) and non-contingent (relative SD) state variability indices were relatively stable over time and across contexts. Only a small number of predictive effects of state variability were observed, and these differed across contexts. Cognitive ability appeared to be associated with state variability under lab-like conditions. There was limited evidence of links between short-term state and long-term trait variability, except for a small effect for neuroticism. Some evidence of positive manifold was found for non-contingent variability. Systematic efforts are required to further elucidate the complex pattern of results regarding the antecedents, correlates and outcomes of individual differences in state variability.


2021 ◽  
Vol 5 (1) ◽  
pp. 123-142
Author(s):  
Kim Foong Jee ◽  
Jia En Joanne Ngui ◽  
Pei Pei Jessica Poh ◽  
Wai Loon Chan ◽  
Yet Siang Wong

This paper examines the relationship between capital structure and performance of firms. The study is confined to plantation sector companies in Malaysia and is based on a sample of 39 firms which listed in Bursa Malaysia for the period from 2009 to 2019. This study uses two performance measures which are ROA and ROE as the dependent variable. Besides, the capital structure measures are the short-term debt, long-term debt, total debt and firm growth, which as the independent variables. Size will be the control variable in this study. Moreover, a fixed-effect panel regression analysis has been used to analyse the impact of capital structure on firm performance. The results indicate that firm performance, which is in term of ROA, have an insignificant relationship with short-term debt (STD) and long-term debt (LTD). For the total debt (TD) and growth, there is a significant relationship with ROA. However, for the performance measured by ROE, it has an insignificant relationship with short-term debt (STD), long-term debt (LTD) and total debt (TD). Furthermore, there is a significant relationship between the growth and the performance firms from plantation sector in Malaysia.


1991 ◽  
Vol 13 (2) ◽  
pp. 174-187 ◽  
Author(s):  
Gershon Tenenbaum ◽  
Saadia Pinchas ◽  
Gabi Elbaz ◽  
Michael Bar-Eli ◽  
Robert Weinberg

The purpose of the present investigation was to extend the literature on the relationship between goal specificity, goal proximity, and performance by using high school students and attempting to control for the effects of social comparison. Subjects (N=214) in Experiment 1 were randomly assigned to one of five goal-setting conditions: (a) short-term goals, (b) long-term goals, (c) short- plus long-term goals,(d) do-your-best goals, and (e) no goals. After a 3-week baseline period, subjects were tested once a week on the 3-minute sit-up over the course of the 10-week experimental period. Results indicated that the short- plus long-term group exhibited the greatest increase in performance although the short-term and long-term groups also displayed significant improvements. In Experiment 2, a short- plus long-term group was compared against a do-your-best group. Results again revealed a significant improvement in performance for the combination-goal group whereas the do-your-best group did not display any improvement.


2017 ◽  
Author(s):  
Evelien Heyselaar ◽  
Linda Wheeldon ◽  
Katrien Segaert

AbstractStructural priming is the tendency to repeat syntactic structure across sentences and can be divided into short-term (prime to immediately following target) and long-term (across an experimental session) components. This study investigates how non-declarative memory could support both the transient, short-term and the persistent, long-term structural priming effects commonly seen in the literature. We propose that these characteristics are supported by different subcomponents of non-declarative memory: Perceptual and conceptual non-declarative memory respectively. Previous studies have suggested that these subcomponents age differently, with only conceptual memory showing age-related decline. By investigating how different components of structural priming vary across the lifespan, we aim to elucidate how non-declarative memory supports two seemingly different components of structural priming. In 167 participants ranging between 20 and 85 years old, we find no change in short-term priming magnitude and performance on perceptual tasks, whereas both long-term priming and conceptual memory vary with age. We suggest therefore that the two seemingly different components of structural priming are supported by different components of non-declarative memory. These findings have important implications for theoretical accounts of structural priming.


2021 ◽  
Vol 5 (1) ◽  
pp. 76-87
Author(s):  
Yien Yien Lee

This study investigated the relationship between the listed firms’ debt level and performance in Bursa Malaysia during a five-year period. Based on the results of the Hausman test and Breusch-Pagan LM test, the fixed-effect model is the most appropriate model that used to analyze the panel data of 50 Malaysian listed companies within the property sector from the year 2015 to 2019. The results indicated that the short-term debt (STD) and long-term debt (LTD) have positive and insignificant effects on return on asset (ROA), which means that the increase in the short-term debt and long-term debt will lead to an increase in the return on assets. Besides that, account payables (AP) has a negative and insignificant effect on the profitability of property sector companies. According to the outcome of the Granger Causality test, the return on assets does not affect by the account payables, short-term debt, long-term debt and firm size. There is only one unidirectional causality relationship that proves that short-term debt is affected by long-term debt. Additionally, this study focuses on enhancing the existing empirical knowledge of debt financing's influence on the profitability of the listed firms in the property sector.


Author(s):  
Andy Hargreaves ◽  
Alma Harris

This paper draws on findings from the results of a study of leadership in high performing organizations in three sectors. Organizations were sampled and included on the basis of high performance in relation to no performance, past performance, performance among similar peers and performance in the face of limited resources or challenging circumstances. The paper concentrates on leadership in four schools that met the sample criteria.  It draws connections to explanations of the high performance ofEstoniaon the OECD PISA tests of educational achievement. The article argues that leadership in these four schools that performed above expectations comprised more than a set of competencies. Instead, leadership took the form of a narrative or quest that pursued an inspiring dream with relentless determination; took improvement pathways that were more innovative than comparable peers; built collaboration and community including with competing schools; and connected short-term success to long-term sustainability.


2018 ◽  
Vol 4 (4) ◽  
pp. 179-183
Author(s):  
Selin Tuysuzoglu Sagalowsky ◽  
Kimball A Prentiss ◽  
Robert J Vinci

IntroductionRepetitive paediatric simulation (scenario-debrief-scenario; RPS) is an instructional design that allows immediate application of learner-directed feedback, in contrast to standard simulation (scenario-debrief; STN). Our aim was to examine the impact of RPS embedded within a paediatric resident simulation curriculum, comparing it to STN.MethodsIn this prospective educational cohort study, paediatric residents were enrolled in STN (n=18) or RPS (n=15) groups from August 2012 through June 2013. Each group performed an initial high-fidelity simulation and another after 1–2 weeks. Attitudes, confidence and knowledge were assessed using anonymous surveys with each scenario and at 4–6 months. Skills were assessed in real time with a modified Tool for Resuscitation Assessment Using Computerised Simulation (TRACS). Two blinded reviewers assessed a subset of videotaped scenarios for TRACS inter-rater reliability.ResultsBoth STN and RPS designs were rated highly. The curriculum led to significant short-term and long-term improvements in confidence, knowledge and performance, with no significant differences between groups. All final respondents reported that they would prefer RPS to STN (n=6 STN, 4 RPS). TRACS intraclass correlation was 0.87 among all reviewers.ConclusionsPaediatric residents reported preference for RPS over STN, with comparable impacts on confidence, knowledge and performance. The modified TRACS was a reliable tool to assess individual resident performance. Further research is needed to determine whether RPS is a more effective instructional design for teaching resuscitation skills to paediatric residents.


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