José Francisco Villarreal Valderrama, Luis Takano, Eduardo Liceaga-Castro, Diana Hernandez-Alcantara, Patricia Del Carmen Zambrano-Robledo and Luis Amezquita-Brooks
Aircraft pitch control is fundamental for the performance of micro aerial vehicles (MAVs). The purpose of this paper is to establish a simple experimental procedure to calibrate…
Abstract
Purpose
Aircraft pitch control is fundamental for the performance of micro aerial vehicles (MAVs). The purpose of this paper is to establish a simple experimental procedure to calibrate pitch instrumentation and classical control algorithms. This includes developing an efficient pitch angle observer with optimal estimation and evaluating controllers under uncertainty and external disturbances.
Design/methodology/approach
A wind tunnel test bench is designed to simulate fixed-wing aircraft dynamics. Key elements of the instrumentation commonly found in MAVs are characterized in a gyroscopic test bench. A data fusion algorithm is calibrated to match the gyroscopic test bench measurements and is then integrated into the autopilot platform. The elevator-angle to pitch-angle dynamic model is obtained experimentally. Two different control algorithms, based on model-free and model-based approaches, are designed. These controllers are analyzed in terms of parametric uncertainties due to wind speed variations and external perturbation because of sudden weight distribution changes. A series of experimental tests is performed in wind-tunnel facilities to highlight the main features of each control approach.
Findings
With regard to the instrumentation algorithms, a simple experimental methodology for the design of optimal pitch angle observer is presented and validated experimentally. In the context of the platform design and identification, the similitude among the theoretical and experimental responses shows that the platform is suitable for typical pitch control assessment. The wind tunnel experiments show that a fixed linear controller, designed using classical frequency domain concepts, is able to provide adequate responses in scenarios that approximate the operation of MAVs.
Research limitations/implications
The aircraft orientation observer can be used for both pitch and roll angles. However, for simultaneousyaw angle estimation the proposed design method requires further research. The model analysis considers a wind speed range of 6-18 m/s, with a nominal operation of 12 m/s. The maximum experimentally tested reference for the pitch angle controller was 20°. Further operating conditions may require more complex control approaches (e.g. scheduling, non-linear, etc.). However, this operating range is enough for typical MAV missions.
Originality/value
The study shows the design of an effective pitch angle observer, based on a simple experimental approach, which achieved locally optimum estimates at the test conditions. Additionally, the instrumentation and design of a test bench for typical pitch control assessment in wind tunnel facilities is presented. Finally, the study presents the development of a simple controller that provides adequate responses in scenarios that approximate the operation of MAVs, including perturbations that resemble package delivery and parametric uncertainty due to wind speed variations.
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Alfonso J. Gil, Jorge Luis García-Alcaraz, Mara Mataveli and Claudia Tobias
The purpose of this paper is to analyse the relationship between a supportive organisational climate and training process outcomes; to analyse the mediating effect of job…
Abstract
Purpose
The purpose of this paper is to analyse the relationship between a supportive organisational climate and training process outcomes; to analyse the mediating effect of job satisfaction between a supportive organisational climate and training process outcomes; and to analyse the moderating effect of a proactive attitude on a supportive organisational climate and training process outcomes.
Design/methodology/approach
The participants consisted of 359 employees recruited from 18 companies in Spain. The hypotheses were tested with structural equations via partial least squares regression.
Findings
The data indicated a positive and statistically significant relationship between a supportive organisational climate and training process outcomes. The proposed moderating and mediating effects are also verified.
Originality/value
This work contributes to the literature on human resource management and the relationship between organisational behaviour and training outcomes. In addition, it shows the role of attitudes between organisational climate and training outcomes.
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Presents a review on implementing finite element methods on supercomputers, workstations and PCs and gives main trends in hardware and software developments. An appendix included…
Abstract
Presents a review on implementing finite element methods on supercomputers, workstations and PCs and gives main trends in hardware and software developments. An appendix included at the end of the paper presents a bibliography on the subjects retrospectively to 1985 and approximately 1,100 references are listed.
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Ravi K. Perry and Joseph P. McCormick
To identify the Obama administration’s policy responsiveness to the (African) American LGBT communities.
Abstract
Purpose
To identify the Obama administration’s policy responsiveness to the (African) American LGBT communities.
Methodology/approach
Theory development and content analysis.
Findings
Civic universalism, as a theory, can explain President Obama’s evolution on his support for marriage rights for same-sex couples. Obama employed the concept of e pluribus unum in his many approaches to LGBT responsive politics.
Research limitations
To date, theoretical development within the social sciences of LGBT policy responsiveness is limited.
Originality/value
Very little is written on the subject of LGBT (Lesbian, Gay, Bisexual, and Transgendered) politics in the 21st century. The study of the LGBT experience generally has been devoid of political variables because of a lack of attention toward LGBT issues, until recently, in national political party agendas. In this chapter, we review some of the contours of the LGBT community’s fight for political recognition in the United States as a precursor to the election and reelection of President Obama. Drawing parallels with presidential responsiveness toward Blacks in their quest for rights, we examine the Obama administration’s LGBT public policy initiatives as administrative policy and programs. We conclude by identifying new areas of research to explore on LGBT politics.
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Chu-Hsiang (Daisy) Chang and Samantha K. Baard
Given the increasing global focus of many aspects of our society, researchers have taken significant steps in understanding the impact of culture on various psychological states…
Abstract
Given the increasing global focus of many aspects of our society, researchers have taken significant steps in understanding the impact of culture on various psychological states. This review focuses on the stressor–strain relationships within the context of cross-cultural and cross-national studies. Using research findings from the United States as a baseline, we identify common and unique themes concerning the stressor–strain relationships between different countries, and clarify the differences between cross-national and cross-cultural studies. Furthermore, we consider cross-cultural and cross-national occupational stress research from an individual differences perspective. We encourage future studies to adopt this perspective and carefully consider the implications of cultural values on occupational stress research at the individual, group, and country levels.
Francisco Villarreal-Valderrama, Carlos Santana Delgado, Patricia Del Carmen Zambrano-Robledo and Luis Amezquita-Brooks
Reducing fuel consumption of unmanned aerial vehicles (UAVs) during transient operation is a cornerstone to achieve environment-friendly operations. The purpose of this paper is…
Abstract
Purpose
Reducing fuel consumption of unmanned aerial vehicles (UAVs) during transient operation is a cornerstone to achieve environment-friendly operations. The purpose of this paper is to develop a control scheme that improves the fuel economy of a turbojet in its full operating envelope.
Design/methodology/approach
A novel direct-thrust linear quadratic integral (LQI) approach, comprised by an optimal observer/controller satisfying specified performance parameters, is presented. The thrust estimator, based in a Wiener model, is validated with the experimental data of a micro-turbojet. Model uncertainty is characterized by analyzing variations between the identified model and measured data. The resulting uncertainty range is used to verify closed-loop stability with the circle criterion. The proposed controller provides stable responses with the specified performance in the whole operating range, even with after considering plant nonlinearities. Finally, the direct-thrust LQI is compared with a standard thrust controller to assess fuel economy and performance.
Findings
The direct-thrust LQI approach reduced the fuel consumption by 2.1090% in the most realistic scenario. The controllers were also evaluated using the environmental effect parameter (EEP) and transient-thrust-specific fuel consumption (T-TSFC). These novel metrics are proposed to evaluate the environmental impact during transient-thrust operations. The direct-thrust LQI approach has a more efficient fuel consumption according to these metrics. The results also show that isolating the thrust dynamics within the feedback loop has an important impact in fuel economy. Controllers were also evaluated using the EEP and T-TSFC. These novel metrics are proposed to evaluate the environmental impact during transient-thrust operations. The direct-thrust LQI approach has a more efficient fuel consumption according to these metrics. The results also show that isolating the thrust dynamics within the feedback loop has an important impact in fuel economy.
Originality/value
This study shows the design of an effective direct-thrust control approach that minimizes fuel consumption, ensures stable responses for the full operation range, allows isolating the thrust dynamics when designing the controller and is compatible with classical robustness and performance metrics. Finally, the study shows that a simple controller can reduce the fuel consumption of the turbojet during transient operation in scenarios that approximate realistic operating conditions.
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Edwin Chan, Chung Yim Yiu, Andrew Baldwin and Grace Lee
After the outbreak of the disease of “Severe Acute Respiratory Syndrome (SARS)” in Asia in 2003, a healthy living environment is a major concern. The purpose of this paper is to…
Abstract
Purpose
After the outbreak of the disease of “Severe Acute Respiratory Syndrome (SARS)” in Asia in 2003, a healthy living environment is a major concern. The purpose of this paper is to study the value of healthy building parameters by the Contingent Valuation Method (CVM), which gives a direct appraisal of the occupants' value.
Design/methodology/approach
Healthy building parameters were identified in previous studies. Questionnaires are distributed to residents of a large‐scale high‐rise private housing estate in Hong Kong to find out their willingness to pay (WTP) for individual healthy building parameters.
Findings
The results suggest that most residents are willing to pay for healthy building parameters, each with a different value.
Research limitations/implications
The paper is limited to studying the eight identified building parameters for healthy buildings. The sample of the study is confined in a private housing estate only and all the occupants are middle class citizens of Hong Kong. The results of the study can be further validated by carrying out similar research with the support of the government or quasi‐government bodies to cover a larger sample size for a better return rate.
Practical implications
The findings have practical implications on cost‐and‐benefit analysis of housing design.
Originality/value
Housing price is commonly regarded as the total value of a bundle of housing quality and environmental characteristics. The implicit price of individual quality and characteristic is often identified by the hedonic pricing model. However, its validity depends on a lot of econometric assumptions. The study is the first to be conducted after the outbreak of SARS in Hong Kong to gauge the opinions of residents on health/economy issues
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Ishita Batra, Megha Gupta and Sanjay Dhir
The last two decades have witnessed a substantial increase in the body of research on the theoretical perspective of the performance of international joint ventures (IJVs)…
Abstract
Purpose
The last two decades have witnessed a substantial increase in the body of research on the theoretical perspective of the performance of international joint ventures (IJVs). However, the evidence on the antecedents of IJVs performance is inconsistent. The purpose of this paper is to critically review the quantitative studies on the antecedents of the performance of IJVs to identify the research gaps in this area and to prepare a future research agenda using the theory, context, characteristics and methodology (TCCM) framework.
Design/methodology/approach
Meta-Analysis review is conducted on 97 papers from A*, A and B category journals from the Australian Business Deans Council (ABDC) Journal Quality List.
Findings
The results reveal the homogeneity in antecedents such as administrative distance, BOD (board of directors) involvement, resource interdependency, flexibility, learning, competitive overlap, cultural distance, R&D (research and development) intensity, contract, relatedness, the existence of a local IJVs partner, trust, operational experience, partners capability, size asymmetry, goal congruency, capital adequacy, economic distance and heterogeneity in the antecedents such as equity ownership, commitment, control, cooperation and conflict are heterogeneous.
Originality/value
This review seeks to provide deeper insights, which help us to contribute toward the development of the research field of antecedents of the performance of IJVs. The authors have synthesized 97 independent samples with a total sample size of 52,268.
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Walter Leal Filho, Maria Alzira Pimenta Dinis, Subarna Sivapalan, Halima Begum, Theam Foo Ng, Abul Quasem Al-Amin, Gazi Mahabubul Alam, Ayyoob Sharifi, Amanda Lange Salvia, Qudsia Kalsoom, Mustafa Saroar and Samara Neiva
It is still unclear how Asian universities incorporate the theory or practice of sustainable development (SD) in their research and education programmes. To address this gap, the…
Abstract
Purpose
It is still unclear how Asian universities incorporate the theory or practice of sustainable development (SD) in their research and education programmes. To address this gap, the purpose of this paper is to report on a study that has examined how universities in Asian countries handle and address matters related to SD.
Design/methodology/approach
The study used a bibliometric analysis and an online survey-method. The online survey data were analysed through descriptive analysis and one-sample student’s t-test.
Findings
The study indicates that there is considerable variation among the Asian countries regarding sustainability practices in higher education institutions (HEIs). The HEIs in far eastern countries, such as Indonesia, Malaysia and Thailand are perceived to demonstrate more sustainability practices.
Research limitations/implications
Even though a substantial number of participants participated in the survey, it did not cover all Asian countries. The online survey was carried out over a limited period of time, and not all HEIs in the field may have received information about the study.
Practical implications
Asia is the largest continent facing a number of sustainability challenges. In this context, the contribution of HEIs is very important. The findings of the current study may serve as a baseline for Asian HEIs to take more initiatives towards SD goals, as HEIs are responsible for the education and training of hundreds of thousands of students who will be occupying key positions in industry, government or education in the coming years.
Originality/value
The study contributes to the existing literature in two distinct ways. First, it was possible to develop a comprehensive instrument to measure sustainability practices in HEIs. Second, this study has filled the gap of the scarcity of studies regarding sustainability practices in HEIs in Asia.