scholarly journals Technical note: Long-term persistence loss of urban streams as a metric for catchment classification

2018 ◽  
Vol 22 (6) ◽  
pp. 3551-3559 ◽  
Author(s):  
Dusan Jovanovic ◽  
Tijana Jovanovic ◽  
Alfonso Mejía ◽  
Jon Hathaway ◽  
Edoardo Daly
Keyword(s):  
Negative Relationship ◽  
Technical Note ◽  
Annual Rainfall ◽  
Fluctuation Analysis ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Climatic Regions ◽  
Catchment Size ◽  
The Usa ◽  
The Impact

Abstract. Urbanisation has been associated with a reduction in the long-term correlation within a streamflow series, quantified by the Hurst exponent (H). This presents an opportunity to use the H exponent as an index for the classification of catchments on a scale from natural to urbanised conditions. However, before using the H exponent as a general index, the relationship between this exponent and level of urbanisation needs to be further examined and verified on catchments with different levels of imperviousness and from different climatic regions. In this study, the H exponent is estimated for 38 (deseasonalised) mean daily runoff time series, 22 from the USA and 16 from Australia, using the traditional rescaled-range statistic (R∕S) and the more advanced multifractal detrended fluctuation analysis (MF-DFA). Relationships between H and catchment imperviousness, catchment size, annual rainfall and specific mean discharge were investigated. No clear relationship with catchment area was found, and a weak negative relationship with annual rainfall and specific mean streamflow was found only when the R∕S method was used. Conversely, both methods showed decreasing values of H as catchment imperviousness increased. The H exponent decreased from around 1.0 for catchments in natural conditions to around 0.6 for highly urbanised catchments. Three significantly different ranges of H exponents were identified, allowing catchments to be parsed into groups with imperviousness lower than 5 % (natural), catchments with imperviousness between 5 and 15 % (peri-urban) and catchments with imperviousness larger than 15 % (urban). The H exponent thus represents a useful metric to quantitatively assess the impact of catchment imperviousness on streamflow regime.

scholarly journals Technical note: Long-term memory loss of urban streams as a metric for catchment classification

2017 ◽  
Author(s):  
Dusan Jovanovic ◽  
Tijana Jovanovic ◽  
Alfonso Mejía ◽  
Jon Hathaway ◽  
Edoardo Daly
Keyword(s):  
Negative Relationship ◽  
Memory Loss ◽  
Technical Note ◽  
Annual Rainfall ◽  
Long Term Memory ◽  
Fluctuation Analysis ◽  
Climatic Regions ◽  
The Usa ◽  
The Impact

Abstract. Urbanisation has been associated with a reduction in the long-term correlation within a streamflow series, quantified by the Hurst exponent (H). This presents an opportunity to use the H exponent as an index for the classification of catchments on a scale from natural to urbanised conditions. However, before using the H exponent as a general index, the relationship between this exponent and level of urbanisation needs to be further examined and verified on catchments with different levels of imperviousness and from different climatic regions. In this study, the H exponent is estimated for 38 (deseasonalized) mean daily runoff time series, 22 from the USA and 16 from Australia, using the traditional rescaled-range statistic (R/S) and the more advanced multi-fractal detrended fluctuation analysis (MF-DFA). Relationships between H and catchment imperviousness, catchment size, annual rainfall and specific mean discharge were investigated. No clear relationship with catchment area was found, and a weak negative relationship with annual rainfall and specific mean streamflow was found only when the R/S method was used. Conversely, both methods showed decreasing values of H as catchment imperviousness increased. The H exponent decreased from around 1.0 for catchments in natural conditions to around 0.6 for highly urbanised catchments. Three significantly different ranges of H exponents were identified, allowing catchments to be parsed into groups with imperviousness lower than 5 % (natural), catchments with imperviousness between 5 and 15 % (peri-urban), and catchments with imperviousness larger than 15 % (urban). The H exponent thus represents a useful metric to quantitatively assess the impact of catchment imperviousness on streamflow regime.

Risk Attitude and Corporate Investment under Output Market Uncertainty: Evidence from The Mekong River Delta, Vietnam

2016 ◽  
pp. 59-70
Author(s):  
Ninh Le Khuong ◽  
Nghiem Le Tan ◽  
Tho Huynh Huu
Keyword(s):  
Negative Relationship ◽  
Risk Attitude ◽  
Business Strategies ◽  
Risk Averse ◽  
Market Uncertainty ◽  
Firm Investment ◽  
Output Market ◽  
The Impact ◽  
The Relationship

This paper aims to detect the impact of firm managers’ risk attitude on the relationship between the degree of output market uncertainty and firm investment. The findings show that there is a negative relationship between these two aspects for risk-averse managers while there is a positive relationship for risk-loving ones, since they have different utility functions. Based on the findings, this paper proposes recommendations for firm managers to take into account when making investment decisions and long-term business strategies as well.

A multifractal detrended fluctuation analysis of housing market: a role of financial crises in developed economies

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Syed Ali Raza ◽  
Nida Shah ◽  
Muhammad Tahir Suleman ◽  
Md Al Mamun
Keyword(s):  
Financial Crisis ◽  
Housing Market ◽  
Market Efficiency ◽  
House Price ◽  
Fluctuation Analysis ◽  
Content Type ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Long Run ◽  
Before And After

Purpose This study aims to examine the house price fluctuations in G7 countries by using the multifractal detrended fluctuation analysis (MF-DFA) for the years 1970–2019. The study examined the market efficiency between the short-term and long-term in the full sample period, before and after the global financial crisis period. Design/methodology/approach This study uses the MF-DFA to analyze house price fluctuations. Findings The findings confirmed that the housing market series are multifractal. Furthermore, all the markets showed long-term persistence in both the short and long-term. The USA is identified as the most persistent house market in the short run and Japan in the long run. Moreover, in terms of efficiency, Canada is identified as the most efficient house market in the long run and the UK in the short run. Finally, the result of before and after the financial crisis period is consistent with the full sample result. Originality/value The contribution of this study in the literature is fourfold. This is the first study that has examined the house prices efficiency by using the MF-DFA technique given by Kantelhardt et al. (2002). Previously, the house market prices and efficiency has been investigated using generalized Hurst exponent (Liu et al., 2019), Quantile Regression Approach (Chae and Bera, 2019; Tiwari et al., 2019) but no study to the best of the knowledge has been done that has used the MF-DFA technique on the housing market. Second, this is the first study that has focused on the house markets of G7 countries. Third, this study explores the house market efficiency by dividing the market into two periods i.e. before and after the financial crisis. The study strives to investigate if the financial crisis determines the change in the degree of market efficiency or not. Finally, the study gives valuable insights to the investors that will help them in their investment decisions.

scholarly journals Price Appreciation and Roughness Duality in Bitcoin: A Multifractal Analysis

Mathematics ◽  
2021 ◽  
Vol 9 (17) ◽  
pp. 2088
Author(s):  
Cristiana Vaz ◽  
Rui Pascoal ◽  
Helder Sebastião
Keyword(s):  
Fluctuation Analysis ◽  
Informational Efficiency ◽  
Comprehensive Overview ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Long Range Correlations ◽  
The Public ◽  
Long Run ◽  
Short Run ◽  
The Relationship

Since its launch in 2009, bitcoin has thrived, attracting the attention of investors, regulators, academia, and the public in general. Its price dynamics, characterized by extreme volatility, severe jumps, and impressive long-term appreciation, suggest that bitcoin is a new digital asset. This study presents a comprehensive overview of the fractality of bitcoin in a high-frequency framework, namely by applying Multifractal Detrended Fluctuation Analysis (MF-DFA) and a Multifractal Regime Detecting Method (MRDM) to Bitstamp 1 min bitcoin returns from January 2013 to July 2020. The results suggest that bitcoin is multifractal, with smaller and larger fluctuations being persistent and anti-persistent, respectively. Multifractality comes from significant long-range correlations, which cast some doubts on the informational efficiency at this frequency, but mainly comes from fat-tails, which highlights the significant risks undertaken by investors in this market. Our most important result is that the degree and richness of multifractality is time-varying and increased after 2017, when volumes and prices experienced an explosive behaviour. This complexity puts into perspective the duality of bitcoin: while it is characterized by long-run attractiveness and increasing valuation, it also has a high short-run instability. Hence, this study provides some empirical evidence supporting the relationship between these two observable features.

scholarly journals The relationship between corporate governance and firm performance revisited: where do we stand?

2010 ◽  
Vol 7 (3) ◽  
pp. 124-137 ◽  
Author(s):  
Stefan Hilger
Keyword(s):  
Corporate Governance ◽  
Business Models ◽  
Corporate Performance ◽  
Holistic Approach ◽  
Governance Mechanisms ◽  
Governance Practices ◽  
The Usa ◽  
The Impact ◽  
The Relationship

How is corporate governance measured, and what is the relationship between corporate governance mechanisms and corporate performance? This paper aims to shed light on these questions by providing an overview of the most important research findings in this area with a focus on the USA and Germany. My analysis gives rise to the following remarks. First, studies examining the impact of singles governance mechanisms are inconclusive and mixed in their findings, and especially the question of causality is still unanswered. Second, when a holistic approach is used, the proposition that good corporate governance enhances long-term performance is supported. However, corporate governance practices alone cannot assure long-term corporate performance and good standards of corporate governance are no substitute for the solidity of business models.

scholarly journals The effects of ownership concentration on sustainability: A case of listed firms from USA, UK and German

2017 ◽  
Vol 14 (3) ◽  
pp. 113-121 ◽  
Author(s):  
Zahid Irshad Younas ◽  
Christian Klein ◽  
Bernhard Zwergel
Keyword(s):  
Firm Growth ◽  
Ownership Concentration ◽  
Direct Role ◽  
Listed Firms ◽  
Concentrated Ownership ◽  
The Usa ◽  
National Trends ◽  
Different Characteristics ◽  
The Impact

Concentrated ownership has been speculated to play a direct role in leading firms to focus more on long-term sustainability. Concentrated ownership, however, can take many different forms, with some forms more common in certain countries, and we posit that the specific form of ownership mediates the impact on sustainability. Additionally, we posit that firms operating at different scales have fundamentally different characteristics which can further impact this relationship. Analyzing a sample of firms from the USA, UK, and Germany using Arellano- Bond GMM, we investigate the relationship between ownership concentration, firm growth and sustainability measures comparatively. Our results show that these relationships are not linear, but are rather dependent on the prevalent form of ownership concentration (determined by country) and the scale (small, medium or large) of the firm. Approaches to sustainability appear to be influenced by not just the owners / investors but also by the type of control and broader contexts, explaining differing national trends.

Corporate Governance

2018 ◽  
Author(s):  
Jackie Krafft ◽  
Jacques-Laurent Ravix
Keyword(s):  
Corporate Governance ◽  
High Risk ◽  
Empirical Evidence ◽  
Negative Relationship ◽  
Positive Relationships ◽  
Shareholder Primacy ◽  
Innovative Performance ◽  
Governance Practices ◽  
The Impact

Little attention has been devoted to the impact of corporate governance practices on firms’ innovative performance. This chapter reviews the literature to show that there is theoretical ambiguity. There is the argument that corporate governance and new forms of finance realign managers’ interests, with greater efficiency for all types of investments. However, some argue that innovative R&D has distinctive characteristics, like high risk and long-term horizon, that may modify the efficiency effect. The issue has generated many studies where the long tradition of positive relationships between governance and efficiency is now contrasted by some recent empirical evidence suggesting a negative relationship. The chapter argues that shareholder primacy or owner activism in corporate governance and new forms of finance represent a potential mismatch with innovation.

Institutional volume affects long-term survival following lung transplantation in the USA

2019 ◽  
Vol 56 (2) ◽  
pp. 271-276 ◽  
Author(s):  
Arman Kilic ◽  
Thomas G Gleason ◽  
Hiroshi Kagawa ◽  
Ahmet Kilic ◽  
Ibrahim Sultan
Keyword(s):  
Lung Transplantation ◽  
High Volume ◽  
Term Survival ◽  
Long Term Survival ◽  
Kaplan Meier ◽  
The Usa ◽  
Institutional Volume ◽  
Low Volume ◽  
The Impact

Abstract OBJECTIVES The aim of this study was to evaluate the impact of institutional volume on long-term outcomes following lung transplantation (LTx) in the USA. METHODS Adults undergoing LTx were identified in the United Network for Organ Sharing registry. Patients were divided into equal size tertiles according to the institutional volume. All-cause mortality following LTx was evaluated using the risk-adjusted multivariable Cox regression and the Kaplan–Meier analyses, and compared between these volume cohorts at 3 points: 90 days, 1 year (excluding 90-day deaths) and 10 years (excluding 1-year deaths). Lowess smoothing plots and receiver-operating characteristic analyses were performed to identify optimal volume thresholds associated with long-term survival. RESULTS A total of 13 370 adult LTx recipients were identified. The mean annual centre volume was 33.6 ± 20.1. After risk adjustment, low-volume centres were found to be at increased risk for 90-day mortality, [hazard ratio (HR) 1.56, P < 0.001], 1-year mortality excluding 90-day deaths (HR 1.46, P < 0.001) and 10-year mortality excluding 1-year deaths (HR 1.22, P < 0.001). These findings persisted when the centre volume was modelled as a continuous variable. The Kaplan–Meier analysis also demonstrated significant reductions in survival at each of these time points for low-volume centres (each P < 0.001). The 10-year survival conditional on 1-year survival was 37.4% in high-volume centres vs 28.0% in low-volume centres (P < 0.001). The optimal annual volume threshold for long-term survival was 26 LTx/year. CONCLUSIONS The institutional volume impacts long-term survival following LTx, even after excluding deaths within the first post-transplant year. Identifying the processes of care that lead to longer survival in high-volume centres is prudent.

The Locked Cage

2021 ◽  
pp. 162-174
Author(s):  
Kenya Johns ◽  
Natasha Barnes
Keyword(s):  
School System ◽  
Mass Incarceration ◽  
Traumatic Experiences ◽  
Academic Environment ◽  
It Impacts ◽  
The Family ◽  
Negative Effect ◽  
The Usa ◽  
The Impact

This chapter aims to discuss the on-going problems of mass incarceration within the USA and the impact it has on the family and the school system. Mass incarceration is a societal concern because it impacts those that are incarcerated and the families that they leave behind outside the cage. Those that are parents and are incarcerated not only have to deal with their decisions, their children do as well. It is estimated that more than 1.7 million children within the USA have experienced a parent or caregiver being incarcerated. Incarceration can have a negative effect on the students development within the classroom, leading to long-term traumatic experiences and negative behavioral, emotional academic performances within the classroom. This chapter explores the impact it has on the students and academic environment while provide tools to best support these students and families.

scholarly journals The Impact of the Global Financial Crisis, Does It Sustain?

2016 ◽  
Vol 8 (10) ◽  
pp. 82 ◽  
Author(s):  
Bashar Al-Zu'bi ◽  
Hussein Salameh ◽  
Qasim Mousa Abu Eid
Keyword(s):  
Financial Crisis ◽  
Stock Market ◽  
Global Financial Crisis ◽  
Stock Market Index ◽  
The World ◽  
The Usa ◽  
Short And Long Term ◽  
The Global Financial Crisis ◽  
The Impact

<p>This paper studies the short and long term relationship between S&amp;P500 USA stock market index and the stock market indices of 30 countries around the world over the period June 2010-April 2015. We implement OLS regression and use error correction model to examine the short and long term relationship between the variables. Empirically, we find that there is a relationship on the short and long term between S&amp;P500 and the indices of 27 countries from East Asia, Europe, Latin America, Middle East as well as the countries of Australia and Canada. These results conclude that the global financial crisis of 2007-2008 significantly and lengthy increased the already high level of co-movement between the USA financial market and the observed stock market for 27 countries around the world. The findings from our research are important; however, we believe that further research based on our findings is necessary.</p>

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