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•Smoothing effect is found more pronounced for W/Si multilayer growth than Si film.•Smoothing effect is damped in the case of strongly corrugated nanograting comparing to the flat ...substrate.•New method is provided to predict and control the layer growth on periodic nanostructures.
Coating nano/micro-structured elements with a single or multi-layered film can greatly enhance their functionality. The experimental enhancement, however, is significantly limited by the smoothing and distortion of the structural profile after coating. This requires a comprehensive understanding of the layer growth behavior on nanoscale non-isotropic surface with a proper model to analyze and predict the structure evolution. Here, a simplified linear growth model with single free parameter was successfully used for analysis of the smoothening of grating grooves. The model enables a quantitative description of the evolution of surface morphology from substrate to the top surface with sub-nanometer accuracy. Based on this, the smoothing behavior of single-Si layer and W/Si multilayer growth on nanoscale gratings (period ∼ 40 nm) and flat substrates were studied experimentally, for applications in X-ray optics. The smoothing effect of the W/Si multilayer coating is more pronounced than that of the single Si layer for both substrate types. The corrugated nanogratings suppressed the smoothing effect as compared to the flat isotropic surface. These works provide new guidance to predict and control the growth of layers on nanostructures.
This paper argues that long-run trends in R&D and TFP are more supportive of fully endogenous "Schumpeterian" growth theory than they are of endogenous growth theory. The distinctive prediction of ...semi-endogenous theory that sustained TFP growth requires sustained growth of R&D input is not supported by co-integration tests and forecasting exercises, as TFP growth has been stationary even though the growth rate of R&D input has fallen three-fold since the early 1950s. In contrast, the prediction of Schum- peterian theory that sustained TFP growth requires a sustained fraction of GDP to be spent on R&D is not contradicted by similar tests.
ABSTRACT
Metabolic theory aims to tackle ecological and evolutionary problems by explicitly including physical principles of energy and mass exchange, thereby increasing generality and deductive ...power. Individual growth models (IGMs) are the fundamental basis of metabolic theory because they represent the organisational level at which energy and mass exchange processes are most tightly integrated and from which scaling patterns emerge. Unfortunately, IGMs remain a topic of great confusion and controversy about the origins of the ideas, their domain and breadth of application, their logical consistency and whether they can sufficiently capture reality. It is now 100 years since the first theoretical model of individual growth was put forward by Pütter. His insights were deep, but his model ended up being attributed to von Bertalanffy and his ideas largely forgotten. Here I review Pütter's ideas and trace their influence on existing theoretical models for growth and other aspects of metabolism, including those of von Bertalanffy, the Dynamic Energy Budget (DEB) theory, the Gill‐Oxygen Limitation Theory (GOLT) and the Ontogenetic Growth Model (OGM). I show that the von Bertalanffy and GOLT models are minor modifications of Pütter's original model. I then synthesise, compare and critique the ideas of the two most‐developed theories, DEB theory and the OGM, in relation to Pütter's original ideas. I formulate the Pütter, DEB and OGM models in the same structure and with the same notation to illustrate the major similarities and differences among them. I trace the confusion and controversy regarding these theories to the notions of anabolism, catabolism, assimilation and maintenance, the connections to respiration rate, and the number of parameters and state variables their models require. The OGM model has significant inconsistencies that stem from the interpretation of growth as the difference between anabolism and maintenance, and these issues seriously challenge its ability to incorporate development, reproduction and assimilation. The DEB theory is a direct extension of Pütter's ideas but with growth being the difference between assimilation and maintenance rather than anabolism and catabolism. The DEB theory makes the dynamics of Pütter's ‘nutritive material’ explicit as well as extending the scheme to include reproduction and development. I discuss how these three major theories for individual growth have been used to explain ‘macrometabolic’ patterns including the scaling of respiration, the temperature–size rule (first modelled by Pütter), and the connection to life history. Future research on the connections between theory and data in these macrometabolic topics have the greatest potential to advance the status of metabolic theory and its value for pure and applied problems in ecology and evolution.
As fintech chatbots become more and more popular in online banking services, most banks have discovered their business potential. To understand why fintech chatbots can be used quickly and widely to ...realize commercial benefits, this research uses social response theory to detect the continuous intention mechanism behind fintech chatbots. This research includes social capital (social cues) and attitudes toward fintech chatbots to describe how social cues based on social response theory evoke users' social behaviors, which in turn may affect continuous intention. Based on the potential growth model, the growth trends and relationships of these variables were analyzed based on the longitudinal data of 455 fintech chatbot users in Taiwan in three stages over six months. The results of the survey support all hypotheses and can enable vendors to understand the mechanism of how to enhance users' continuous intention for fintech chatbots.
•This research investigates how social cues can influence continuance intention in a fintech chatbot setting.•This research attempts to extend social response theory to the field of fintech and predict continuance intention.•This research presents a new stream through social response theory rather than the traditional behavior model of information technology.
Abstract
Rich behavioural biases, mistakes, and limits on rational decision-making are often thought to make equilibrium analysis much more intractable. We establish that this is not the case in the ...context of one-sector growth models such as Ramsey–Cass–Koopmans or Bewley–Aiyagari models. We break down the response of the economy to a change in the environment or policy into two parts: the direct response at the given (pre-tax) prices, and the equilibrium response which plays out as prices change. Our main result demonstrates that under weak regularity conditions, regardless of the details of behavioural preferences, mistakes and constraints on decision-making, the long-run equilibrium will involve a greater capital-labour ratio if and only if the direct response (from the corresponding consumption-saving model) involves an increase in aggregate savings. One implication of this result is that, from a qualitative point of view, behavioural biases matter for long-run equilibrium if and only if they change the direction of the direct response. We provide detailed illustrations of how this result can be applied and generate new insights using models of misperceptions, self-control and temptation, and naive and sophisticated quasi-hyperbolic discounting.
The COVID-19 global pandemic has rapidly expanded, with the UK being one of the countries with the highest number of cases and deaths in proportion to its population. Major clinical and human ...behavioural measures have been taken by the UK government to control the spread of the pandemic and to support the health system. It remains unclear how exactly human mobility restrictions have affected the virus spread in the UK. This research uses driving, walking and transit real-time data to investigate the impact of government control measures on human mobility reduction, as well as the connection between trends in human-mobility and severe COVID-19 outcomes. Human mobility was observed to gradually decrease as the government was announcing more measures and it stabilized at a scale of around 80% after a lockdown was imposed. The study shows that human-mobility reduction had a significant impact on reducing COVID-19-related deaths, thus providing crucial evidence in support of such government measures.
•Initial measures aimed at human-mobility reduction had a direct impact on the number of COVID-19 related deaths in the UK•Social-distancing measures may need to continue to reduce the risk of a resurgence in COVID-19 transmission in the UK•UK’s human mobility gradually decreased as measures were announced and stabilized at around 80% after lockdown was imposed•A shift in transport mode from public transport to driving was observed
Women entrepreneurship research in the developing world relies on theoretical perspectives derived elsewhere. Hence, understanding the original business-development approaches adopted by women ...entrepreneurs in developing economies remains elusive. Accordingly, we collected and analyzed rich data generated through 31 in-depth interviews and artifacts of Nigerian women entrepreneurs in the garment manufacturing business. Our analysis revealed distinct constructs that account for their business-development activities. It shows money (access and utilization), market (customer intelligence), and management (nonformal education and experience) as crucial enterprise development components in women entrepreneurship. Motherhood (household responsibilities), meso- and macro-environments (socioeconomic and cultural factors) not only affected business development but also inhibited women entrepreneurs' access and utilization of money, management, and markets and shaped their business development actions. Theoretical and practical implications for entrepreneurship research and policy development initiatives in the developing world are offered.
It has been established across several contexts that political attitudes are informed by heritable factors. However, it remains unclear how much of the stability we observe in political attitudes can ...be ascribed to environmental factors and how much of the stability is due to genetics. In this paper we show, using a unique three-wave panel dataset of twins (N = 2471) spanning ten years, that both environmental and genetic influences are important in explaining the stability of social and economic ideology. However, we find that changes in ideology over time are explained by environmental factors for both social and economic ideology. For social ideology, only the shared environment is important in explaining changes over time. For economic ideology, both shared and unique environmental factors influence changes over time. Our results suggest that stability and change in political attitudes is a complex phenomenon that is best understood when examining heritable as well as social factors.
•Environmental and genetic factors explain the stability of ideology.•Only environmental influences explain changes over time for ideology.•For social ideology, only the shared environment explains changes over time.•For economic ideology, the shared and unique environment explain changes over time.
Financial empowerment interventions are often used with survivors of intimate partner violence (IPV) to improve their financial well‐being. However, few evaluations actually measure financial ...empowerment as an outcome. Thus, the purpose of this study was to develop and test a conceptual model for financial empowerment and then use the model to evaluate the effectiveness of a financial literacy intervention at increasing financial empowerment for survivors. The conceptual model was guided by Christens’ nomological network for psychological empowerment and included four components: emotional, cognitive, relational, and behavioral. The analyses used data from a randomized controlled trial evaluating Moving Ahead, a financial literacy program developed for IPV survivors (n = 449). To determine whether this intervention was effective at increasing financial empowerment for survivors over time, confirmatory factor analyses were run to test for longitudinal measurement invariance, followed by a curve‐of‐factors growth model (CFM) with assignment as a time‐invariant predictor of change. Strict partial longitudinal measurement invariance was achieved and CFM results found assignment to be significantly associated with both initial status (.054, p = .042) and change over time (.114, p = .000). Results suggest that this conceptual model for financial empowerment fit the data well and the intervention was effective.
Highlights
The goal of financial empowerment is to increase one’s personal power within the financial domain.
Financial literacy programs can be effective at financially empowering survivors of abuse.
Financial empowerment should engage emotional, cognitive, relational, and behavioral domains.
Financial interventions should measure financial empowerment in addition to resource acquisition.
Novel coronavirus respiratory disease COVID-19 has caused havoc in many countries across the globe. In order to contain infection of this highly contagious disease, most of the world population is ...constrained to live in a complete or partial lockdown for months together with a minimal human-to-human interaction having far reaching consequences on countries’ economy and mental well-being of their citizens. Hence, there is a need for a good predictive model for the health advisory bodies and decision makers for taking calculated proactive measures to contain the pandemic and maintain a healthy economy. This paper extends the mathematical theory of the classical Susceptible–Infected–Removed (SIR) epidemic model and proposes a Generalized SIR (GSIR) model that is an integrative model encompassing multiple waves of daily reported cases. Existing growth function models of epidemic have been shown as the special cases of the GSIR model. Dynamic modeling of the parameters reflect the impact of policy decisions, social awareness, and the availability of medication during the pandemic. GSIR framework can be utilized to find a good fit or predictive model for any pandemic. The study is performed on the COVID-19 data for various countries with detailed results for India, Brazil, United States of America (USA), and World. The peak infection, total expected number of COVID-19 cases and thereof deaths, time-varying reproduction number, and various other parameters are estimated from the available data using the proposed methodology. The proposed GSIR model advances the existing theory and yields promising results for continuous predictive monitoring of COVID-19 pandemic.
•Proposed a generalized SIR (GSIR) framework for pandemic modeling and prediction.•An integrative model that captures the pandemic data via distinct waves emerging at different times.•Explicit expressions are derived for the susceptible, infected and removed populations.•Dynamic modeling of system parameters that can capture the impact of policy decisions.•GSIR model is tested on COVID-19 data and can serve as a good alternative to existing methods.
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