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The purpose of this study is to build a high accuracy thrust model under various small turbojet engine shaft speeds by using robust, ordinary, linear and nonlinear least squares estimation methods for target drone applications.

The dynamic shaft speeds from the test experiment of a target drone engine is conducted. Then, thrust values are calculated. Based on these, the engine thrust is modeled by robust linear and nonlinear equations. The models are benefited from quadratic, power and various series expansion functions with several coefficients to optimize the model parameters.

The error terms and accuracy of the model are given using sum of squared errors, root mean square error (RMSE) and R-squared (R²) error definitions. Based on the multiple analyses, it is seen that the RMSE values are no more than 17.7539 and the best obtained result for robust least squares estimation is 15.0086 for linear at all cases. Furthermore, the R² value is found to be 0.9996 as the highest with the nonlinear Fourier series expansion model.

The motivation behind this paper is to propose robust nonlinear thrust models based on power, Fourier and various series expansion functions for dynamic shaft speeds from the test experiments.

Contemporary life is replete with all manner of rankings, metrics, and benchmarks (Power, 1997; Espeland & Stevens, 1998). From J.D. Power evaluations of cars to Zagat restaurant reviews to US News and World Report ratings of colleges and universities, modern life seems to be deep in the grip of assessment and evaluation. In the early decades of the twentieth century, the introduction of scientific management transformed the workplace, altering relations between labor and capital, and embedding control over the nature and pace of work into the technical organization of production (Edwards, 1979; Shenhav, 1995). In a similar fashion, the current embrace of rankings may reflect a new “Taylorism,” as metrics have the capacity to not only reorder the social institutions they are purported to assess, but also provide a patina of objectivity, especially for the uninitiated.

This article is aims to inform aircraft propulsion system designers of the implications which fundamental power distribution design assumptions have on the effectiveness and viability of turboelectric distributed propulsion (TeDP) systems. Improvements and challenges associated with selecting alternating or direct current for normal- and superconducting distribution systems are presented. Additionally, for superconducting systems, the benefits of bi-polar DC distribution are discussed, as well as the implications of operating voltage on the mass and efficiency of TeDP grid components.

The approach to this paper selects several high-level fundamental configuration decisions, which must be made, and it qualitatively discusses potential implications of these decisions.

Near term TeDP architectures which employ conventionally conducting systems may benefit from alternating current (AC) distribution concepts to eliminate the mass and losses associated with power conversion. Farther term TeDP concepts which employ superconducting technologies may benefit from direct current (DC) distribution to reduce the cryocooling requirements stemming from AC conduction losses. Selecting the operating voltage for superconducting concepts requires a divergence from the present day criteria employed with terrestrial superconducting transmission systems.

The criteria presented in the paper will assist in the early conceptual architecting of TeDP systems.

The governing principles behind the configuration of multi-MW airborne electrical microgrid systems are presently immature. This paper represents a unique look and the motivating principles behind fundamental electrical configuration decisions in the context of TeDP.

IN recent years the problems involved in flight on asymmetric power have attracted increasing attention and curiosity. It is safe to state that at the beginning of the British era of high‐powered twin‐engined aircraft, of which the Blenheim I is a representative type, pilots regarded an engine failure at any time as a major problem. A failure of the worst type—on take‐off—was thought to result invariably in loss of control, with the attendant after‐effects on aircraft and crew.

Much has been made of economizing. Yet, social scientists have paid little attention to the moment of economic failure, the moments that precede it, and the calculative infrastructures and related processes through which both failing and failure are made operable. This chapter examines the shift from the economizing of the market economy, which took place across much of the nineteenth century, to the economizing and marketizing of the social sphere, which is still ongoing. The authors consider a specific case of the economizing of failure, namely the repeated attempts over more than a decade to create a failure regime for National Health Service (NHS) hospitals. These attempts commenced with the Health and Social Care Act 2003, which drew explicitly on the Insolvency Act 1986. This promised a “failure regime” for NHS Foundation Trusts modeled on the corporate sector. Shortly after the financial crash, and in the middle of one of the biggest scandals to face NHS hospitals, these proposals were abandoned in favor of a regime based initially on the notion of “de-authorization.” The notion of de-authorization was then itself abandoned, in favor of the notion of “unsustainable provider,” most recently also called the Trust Special Administrators regime. The authors suggest that these repeated attempts to devise a failure regime for NHS hospitals have lessons that go beyond the domain of health care, and that they highlight important issues concerning the role that “exit” models and associated calculative infrastructures may play in the economizing and regulating of public services and the social sphere more broadly.

This paper aims to focus on the use of qualitative research methods to gain a better understanding of the performance management system (PMS) of one of the largest retailers in North America. The motivation for the research was to assess whether the PMS at one of the world’s largest retail companies was congruent with the most recent thinking and research in the management accounting literature.

Using open-ended interviews, the paper seeks to develop relevant hypotheses emerging from the dimensions of the Strauss and Corbin’s qualitative research methodology (1998). A qualitative methodology was used because it provides a structured approach and analytical techniques that can build upon existing theory and literature.

The qualitative evidence collected during the course of the research indicates that financial measures were predominantly used by the company in its PMS, and that this reliance on financial measures may be an artifact of the industry in which the company operates. The retail industry is highly competitive, and it is very sensitive to changes in customer tastes and behavior, as well as shareholder and financial market pressures. In addition to financial measures, it was found that operational management developed certain non-financial performance measures and that this development may have been a response by operational managers to wider stakeholder pressures and external influences. However, these performance measures appear to be not fully integrated in the PMS and are therefore de-coupled and relatively unimportant in, or entirely absent from, top-level decision-making.

The conclusions of the paper provide support for the concepts of isomorphism and de-coupling as found in the literature of new institutional theory.

The case study approach has enabled to explore and gain further understanding of management accounting practices, particularly performance measurement and management, in their natural setting. Strauss and Corbin’s (1998) grounded theory methodology was adopted because it provides a structured set of analytical steps and systematic analytical techniques for handling and interpreting data and theory building.

This paper aims to determine the network efficient topology for low power and lossy networks (LLNs) using routing protocol for LLN (RPL) with respect to the increase in network size and propose a novel approach to overcome the shortcomings of the existing models.

The authors have used Contiki OS/Cooja simulator to conduct experiments on primarily four topologies (star, bus/linear, ring/eclipse and random). They have implemented RPL protocol using Sky motes for each topology from 10, 20, 30 and up to 70 nodes. Consequently, after 24 h of experimentation, the readings have been noted and, alongside, a comprehensive comparative analysis has been performed based on the network density and metric parameters: packet delivery ratio (PDR), expected transmission (ETX) and power consumption. Further, a hybrid model is proposed where the additional factors of mobility, multiple sink and a combination of static and mobile nodes are introduced. The proposed model is then compared with the star model (all static nodes and star topology) and the dynamic model (all mobile nodes) to analyze the efficiency and network performance for different network sizes (28, 36, 38 and 44 nodes). The mobility is introduced using BonnMotion tool in Contiki OS.

Simulation results have shown that the star topology is most network efficient when compared with bus/linear, ring/eclipse and random topologies for low density and high scalable network. But when the same setup is compared with the proposed hybrid model, the proposed model shows a significant improvement and gives the best and efficient network performance with highest PDR (average improvement approximately 44.5%) and lowest ETX (average improvement approximately 49.5%) comparatively.

Also, these findings will benefit the deployment of smart devices used in advanced metering infrastructure, road side units and in various industrial applications such as traffic monitoring system, electronic toll collection and traffic analysis in the smart grid infrastructure.

The impact of topology is significant and detailed analysis is required to understand the impact of different topologies of the nodes in the network for the present and the future scenarios. As very few research studies have discussed this gap, this research paper is quintessential and shall open novel future potential direction. Also, the proposed approach of hybrid model with mobility has not been considered in the literature yet.

This essay presents models of multiparty negotiation as a means to compare the conventional public meetings format of planning to a preliminary process, the technical advisory committee. A metric of market concentration, the Herfindahl-Hirschman Index, is used to quantify the structural advantages in each, and presented within the context of municipal planning processes. In doing so, this work advances several propositions: First, open meetings expand power differentials between parties, which lead to outcomes that reflect the political efficacy of participants over the regulatory purpose of government. Second, such meetings create substantial transaction costs for the public, creating a barrier to the expression of community values. Finally, preliminary processes constitute a more effective forum for citizen participation than open meetings.

The aim of this study is o examine the advantages and disadvantages of different existing scoring systems in the cybersecurity domain and their applicability to the AEC industry and to systematically apply a scoring system to determine scores for some of the most significant construction participants.

This study proposes a methodology that uses the Common Vulnerability Scoring System (CVSS) to calculate scores and the likelihood of occurrence based on communication frequencies to ultimately determine risk categories for different paths in a construction network. As a proof of concept, the proposed methodology is implemented in a construction network from a real project found in the literature.

Results show that the proposed methodology could provide valuable information to assist project participants to assess the overall cybersecurity vulnerability of construction and assist during the vulnerability-management processes. For example, a project owner can use this information to get a better understanding of what to do to limit its vulnerability, which will lead to the overall improvement of the security of the construction network.

It has to be noted that the scoring systems, the scores and categories adopted in the study need not necessarily be an exact representation of all the construction participants or networks. Therefore, caution should be exercised to avoid generalizing the results of this study.

The proposed methodology can provide valuable information and assist project participants to assess the overall cyber-vulnerability of construction projects and support the vulnerability-management processes. For example, a project owner can use this approach to get a better understanding of what to do to limit its cyber-vulnerability exposure, which will ultimately lead to the overall improvement of the construction network's security. This study will also help raise more awareness about the cybersecurity implications of the digitalization and automation of the AEC industry among practitioners and construction researchers.

Given the amount of digitized services and tools used in the AEC industry, cybersecurity is increasingly becoming critical for society in general. In some cases, (e.g. critical infrastructure) incidents could have significant economic and societal or public safety implications. Therefore, proper consideration and action from the AEC research community and industry are needed.

To the authors' knowledge, this is the first attempt to measure and assess the cybersecurity of individual participants and the construction network as a whole by using the Common Vulnerability Scoring System.