Operational noise optimization of aircraft approaches - Initial findings

2021 ◽  
Vol 263 (6) ◽  
pp. 499-507
Author(s):  
Bengt Moberg ◽  
Anders Johansson ◽  
Johan Rignér ◽  
Per Näsman
Keyword(s):  
Noise Source ◽  
Theoretical Models ◽  
Landing Gear ◽  
Scenario Generation ◽  
Future Research ◽  
Noise Generation ◽  
Flight Data ◽  
Noise Optimization ◽  
Noise Measurements ◽  
Ground Noise

As the pilots slow the aircraft down and extend flaps and landing gear in preparation for landing the characteristics of the aircraft as a noise source changes. In the OPNOP project, the possibility to use this variation in noise generation to minimize noise at a specified location is examined. Such analysis requires an increased understanding about aircraft noise generation as the aircraft changes configuration and speed during the approach, where theoretical models available can be overly simplistic and of little use for this purpose. Using flight data from 113 actual Airbus A321 flights, and corresponding noise measurements on the ground, this study reports on the initial findings forming the foundation on which further analysis will be conducted. Intermediary findings relate to: a comparison between models and actual measurements, the distance variability to the runway for various flap selections and extension of the landing gear as well as a comparison between flight data and on-ground noise measurements. Captured data suggest that it should be possible to use speed and configuration recommendations to reduce noise over selected approach areas. Future research will include scenario generation and incorporate flight data from an earlier study to increase validity.

The Social Neuroscience of Cooperation

2018 ◽  
Author(s):  
Jay Joseph Van Bavel
Keyword(s):  
Theoretical Models ◽  
Brain Regions ◽  
Review Literature ◽  
Social Neuroscience ◽  
Future Research ◽  
A Value ◽  
Group Cooperation ◽  
Neural Processes ◽  
The Social ◽  
Cooperative Decision Making

We review literature from several fields to describe common experimental tasks used to measure human cooperation as well as the theoretical models that have been used to characterize cooperative decision-making, as well as brain regions implicated in cooperation. Building on work in neuroeconomics, we suggest a value-based account may provide the most powerful understanding the psychology and neuroscience of group cooperation. We also review the role of individual differences and social context in shaping the mental processes that underlie cooperation and consider gaps in the literature and potential directions for future research on the social neuroscience of cooperation. We suggest that this multi-level approach provides a more comprehensive understanding of the mental and neural processes that underlie the decision to cooperate with others.

Cancer and Cancer Treatment-Related Cognitive Impairment

2019 ◽  
pp. 60-83
Author(s):  
James C.  Root ◽  
Elizabeth Ryan ◽  
Tim A. Ahles
Keyword(s):  
Cancer Survivors ◽  
Cancer Treatment ◽  
Clinical Presentation ◽  
Functional Neuroimaging ◽  
Theoretical Models ◽  
Future Research ◽  
Cognitive Changes ◽  
Central Nervous System Cancer ◽  
Pharmacologic Treatments

As the population of cancer survivors has grown into the millions, there is increasing emphasis on understanding how late effects of treatment impact survivors’ ability return to work/school, ability to function and live independently, and overall quality of life. Cognitive changes are one of the most feared problems among cancer survivors. This chapter describes the growing literature examining cognitive changes associated with non-central nervous system cancer and cancer treatment. Typical elements of cancer treatment are discussed, followed by a description of clinical presentation, self-reported and objectively assessed cognitive findings, and results of structural and functional neuroimaging research. Genetic and other risk factors for cognitive decline following treatment are identified and discussed, together with biomarkers and animal models of treatment-related effects. This is followed by a discussion of behavioral and pharmacologic treatments. Finally, challenges and recommendations for future research are provided to help guide subsequent research and theoretical models.

Emerging Syndromes

2017 ◽  
Author(s):  
Kelly C. Allison ◽  
Jennifer D. Lundgren
Keyword(s):  
Empirical Studies ◽  
Theoretical Models ◽  
Future Research ◽  
Night Eating Syndrome ◽  
Statistical Manual ◽  
Night Eating ◽  
Diagnostic And Statistical Manual ◽  
Impairment In Functioning ◽  
Atypical Anorexia Nervosa ◽  
Comorbid Psychopathology

The Diagnostic and Statistical Manual, fifth edition, of the American Psychiatric Association (2013) has designated several disorders under the diagnosis of otherwise specified feeding and eating disorder (OSFED). This chapter evaluates three of these, night eating syndrome (NES), purging disorder (PD), and atypical anorexia nervosa (atypical AN). It also reviews orthorexia nervosa, which has been discussed in the clinical realm as well as the popular press. The history and definition for each is reviewed, relevant theoretical models are presented and compared, and evidence for the usefulness of the models is described. Empirical studies examining the disorders’ independence from other disorders, comorbid psychopathology, and, when available, medical comorbidities, are discussed. Distress and impairment in functioning seem comparable between at least three of these emerging disorders and threshold eating disorders. Finally, remaining questions for future research are summarized.

THE INFLUENCE OF SOCIAL TIES AND SELF-EFFICACY IN FORMING ENTREPRENEURIAL INTENTIONS AND MOTIVATING NASCENT BEHAVIOR

2007 ◽  
Vol 12 (03) ◽  
pp. 275-293 ◽  
Author(s):  
JENNIFER SEQUEIRA ◽  
STEPHEN L. MUELLER ◽  
JEFFREY E. MCGEE
Keyword(s):  
Self Efficacy ◽  
Strong Predictor ◽  
Theoretical Models ◽  
Entrepreneurial Intentions ◽  
Future Research ◽  
Personal Network ◽  
Network Ties ◽  
Strong Ties ◽  
Business Knowledge ◽  
Entrepreneurial Action

Theoretical models of entrepreneurship suggest that an individual's intention to start an enterprise is a strong predictor of eventual entrepreneurial action. Less understood are factors that influence the likelihood of entrepreneurial intentions and nascent behavior. In this study, we develop and test several hypotheses about how social network ties and self-efficacy affect entrepreneurial intentions and nascent behavior. We found that a personal network of supportive strong ties coupled with high entrepreneurial self-efficacy increases the likelihood of entrepreneurial intentions and nascent behavior. A personal network of weak ties with practical business knowledge and experience also increases the likelihood of entrepreneurial nascent behavior but not entrepreneurial intentions. In contrast, a personal network of strong ties with practical business knowledge and experience has little effect on either intentions or nascent behavior and may, in fact, suppress both. The contribution of this study to nascent entrepreneurship research and implications for future research are discussed.

Perceived Exertion: An Active or Passive Process?

1985 ◽  
Vol 7 (4) ◽  
pp. 371-378 ◽  
Author(s):  
W. Jack Rejeski
Keyword(s):  
Parallel Processing ◽  
Empirical Study ◽  
Perceived Exertion ◽  
Theoretical Models ◽  
Physical Work ◽  
Future Research ◽  
Work Intensity ◽  
Ratings Of Perceived Exertion ◽  
Subjective Estimates ◽  
Parallel Processing Model

Subjective estimates of physical work intensity are considered of major importance to those concerned with prescription of exercise. This article reviews major theoretical models which might guide research on the antecedents for ratings of perceived exertion (RPE). It is argued that an active rather than passive view of perception is warranted in future research, and a parallel-processing model is emphasized as providing the needed structure for such reconceptualization. Moreover, existing exercise research is reviewed as support for this latter approach and several suggestions are offered with regard to needed empirical study.

Historical Economics and the Minor Prophets

2021 ◽  
pp. 322-340
Author(s):  
Jason M. Silverman
Keyword(s):  
Social Justice ◽  
Economic Models ◽  
Theoretical Models ◽  
Social Structures ◽  
Future Research ◽  
Southern Levant ◽  
Production And Consumption ◽  
Minor Prophets

This essay calls for a thorough reassessment of economics and the Minor Prophets. Since existing economic models based on both Marxism or (Neo-) liberalism are problematic as are many basic economic concepts, new theorizing based on ancient data is necessary. Taking Bourdieu’s “economic field” as a starting frame, this essay considers the material elements of production and consumption in the ancient southern Levant, their patterns and social structures, and some issues in the socioeconomic world of the Minor Prophets. These then raise new questions for sample prophetic passages (Amos, Joel, Haggai, Micah, and Zechariah). The essay points to some issues these considerations raise for analyzing the famous calls for social justice, and it closes by pointing in some potential directions for improved theoretical models in future research.

Assessment of flight dynamic and static aeroelastic behaviors for jet transport aircraft subjected to instantaneous high g-loads

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yonghu Wang ◽  
Ray C. Chang ◽  
Wei Jiang
Keyword(s):  
Numerical Approach ◽  
Future Research ◽  
Inspection Method ◽  
Content Type ◽  
Flight Data ◽  
Transport Aircraft ◽  
Different Types ◽  
Static Aeroelasticity ◽  
Safety Operation ◽  
Structural Inspection

Purpose The purpose of this paper is to present a quick inspection method based on the post-flight data to examine static aeroelastic behavior for transport aircraft subjected to instantaneous high g-loads. Design/methodology/approach In the present study, the numerical approach of static aeroelasticity and two verified cases will be presented. The non-linear unsteady aerodynamic models are established through flight data mining and the fuzzy-logic modeling of artificial intelligence techniques based on post-flight data. The first and second derivatives of flight dynamic and static aeroelastic behaviors, respectively, are then estimated by using these aerodynamic models. Findings The flight dynamic and static aeroelastic behaviors with instantaneous high g-load for the two transports will be analyzed and make a comparison study. The circumstance of turbulence encounter of the new twin-jet is much serious than that of four-jet transport aircraft, but the characteristic of stability and controllability for the new twin-jet is better than those of the four-jet transport aircraft; the new twin-jet transport is also shown to have very small aeroelastic effects. The static aeroelastic behaviors for the two different types can be assessed by using this method. Practical implications As the present study uses the flight data stored in a quick access recorder, an intrusive structural inspection of the post-flight can be avoided. A tentative conclusion is to prove that this method can be adapted to examine the static aeroelastic effects for transport aircraft of different weights, different sizes and different service years in tracking static aeroelastic behavior of existing different types of aircraft. In future research, one can consider to have more issues of other types of aircraft with high composite structure weight. Originality/value This method can be used to assist airlines to monitor the variations of flight dynamic and static aeroelastic behaviors as a complementary tool for management to improve aviation safety, operation and operational efficiency.

scholarly journals A Systematic Review on Attachment and Sleep at Preschool Age

Children ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 895
Author(s):  
Catarina Perpétuo ◽  
Eva Diniz ◽  
Manuela Veríssimo
Keyword(s):  
Systematic Review ◽  
Attachment Security ◽  
Biological Process ◽  
Sleep Problems ◽  
Empirical Studies ◽  
Theoretical Models ◽  
Preschool Age ◽  
Future Research ◽  
Parent Child Relationships ◽  
Present Systematic Review

Sleep is a biological process that impacts nearly every domain of a child’s life. Sleep-wake regulation influences and it is highly influenced by developmental variables related to parent-child relationships, such as attachment. The main goal of the present systematic review is to analyze and integrate the findings of empirical studies investigating the relations between attachment and sleep in preschool age, a period marked by important developmental changes that challenge both attachment system and sleep-wake regulation. A database search was performed using a combination of relevant keywords, leading to the identification of 524 articles, with 19 manuscripts assessed for eligibility; finally, seven studies (2344 children) were included. Overall, the findings were not consistent, with some studies reporting significant associations between attachment security and sleep quality, as well as between attachment insecurity and sleep problems, whereas others did not find significant associations. The results are discussed in light of the available theoretical models and integrated in the context of measurement approaches to attachment and sleep heterogeneity, aiming to guide future research on the topic.

Research on capital structure determinants: a review and future directions

2017 ◽  
Vol 13 (2) ◽  
pp. 106-132 ◽  
Author(s):  
Satish Kumar ◽  
Sisira Colombage ◽  
Purnima Rao
Keyword(s):  
Capital Structure ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Secondary Data ◽  
Theoretical Models ◽  
Order Theory ◽  
Organizational Level ◽  
Future Research ◽  
Content Type ◽  
The Impact

Purpose The purpose of this paper is to study the status of studies on capital structure determinants in the past 40 years. This paper highlights the major gaps in the literature on determinants of capital structure and also aims to raise specific questions for future research. Design/methodology/approach The prominence of research is assessed by studying the year of publication and region, level of economic development, firm size, data collection methods, data analysis techniques and theoretical models of capital structure from the selected papers. The review is based on 167 papers published from 1972 to 2013 in various peer-reviewed journals. The relationship of determinants of capital structure is analyzed with the help of meta-analysis. Findings Major findings show an increase of interest in research on determinants of capital structure of the firms located in emerging markets. However, it is observed that these regions are still under-examined which provides more scope for research both empirical and survey-based studies. Majority of research studies are conducted on large-sized firms by using secondary data and regression-based models for the analysis, whereas studies on small-sized firms are very meager. As majority of the research papers are written only at the organizational level, the impact of leverage on various industries is yet to be examined. The review highlights the major determinants of capital structure and their relationship with leverage. It also reveals the dominance of pecking order theory in explaining capital structure of firms theoretically as well as statistically. Originality/value The paper covers a considerable period of time (1972-2013). Among very few review papers on capital structure research, to the best of authors’ knowledge; this is the first review to identify what is missing in the literature on the determinants of capital structure while offering recommendations for future studies. It also synthesize the findings of empirical studies on determinants of capital structure statistically.

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