scholarly journals Impact Analysis of Standardized GNSS Receiver Testing against Real-World Interferences Detected at Live Monitoring Sites

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1276 ◽  
Author(s):  
Mohammad Bhuiyan ◽  
Nunzia Ferrara ◽  
Amin Hashemi ◽  
Sarang Thombre ◽  
Michael Pattinson ◽  
...  

GNSS-based applications are susceptible to different threats, including radio frequency interference. Ensuring that the new applications can be validated against the latest threats supports the wider adoption and success of GNSS in higher value markets. Therefore, the availability of standardized GNSS receiver testing procedures is central to developing the next generation of receiver technologies. The EU Horizon2020 research project STRIKE3 (Standardization of GNSS Threat reporting and Receiver testing through International Knowledge Exchange, Experimentation and Exploitation) proposed standardized test procedures to validate different categories of receivers against real-world interferences, detected at different monitoring sites. This paper describes the recorded interference signatures, their use in standardized test procedures, and analyzes the result for two categories of receivers, namely mass-market and professional grade. The result analysis in terms of well-defined receiver key performance indicators showed that performance of both receiver categories was degraded by the selected interference threats, although there was considerable difference in degree and nature of their impact.

2019 ◽  
Vol 887 ◽  
pp. 72-79
Author(s):  
Barbora Nečasová ◽  
Pavel Liška ◽  
Jiří Šlanhof

The main objective of this case study is to compare whether standardized test methods are able reliably prognosticate the performance of joint sealants and adhesives after installation in a construction. The authors of presented study believe that existing testing procedures intended for testing of bonded and sealed joints do not fully reflect the weather changes exterior surfaces have to withstand. Based on previous experiences a unique geometry of testing sample was used for this purpose allowing the testing of a so-called real joint. A group of test samples was subjected to two normalized test procedures that may influence the resulting behavior of the joint in the exterior. The second group of test samples was exposed to the external environment for a particular period. The obtained results of tests show that the standardized methods are able to simulate an outdoor environment, however, only to a certain level. Unfortunately, these methods do not consider the possibility that the sealed or bonded joint might be damaged already during the application itself. While laboratory environment is clean and often dust free, it is not possible to ensure the same conditions in situ. Moreover, in some cases it was monitored that some of the selected sealants tested in an external environment aged rapidly compared to the ones cured and stored in the laboratory. In some cases, the difference between monitored failure modes for indoor and outdoor environment was substantial. The predominant type of sealant failure observed in-situ was adhesive while mainly cohesive failure was monitored in laboratory.


2017 ◽  
Vol 71 (3) ◽  
pp. 513-529 ◽  
Author(s):  
Sarang Thombre ◽  
M. Zahidul H. Bhuiyan ◽  
Patrik Eliardsson ◽  
Björn Gabrielsson ◽  
Michael Pattinson ◽  
...  

Vulnerability of satellite-based navigation signals to intentional and unintentional interference calls for a high-level overview of Global Navigation Satellite System (GNSS) threats occurring globally to understand the magnitude and evolution of the problem. Therefore, a mechanism needs to be developed whereby disparate monitoring systems will be capable of contributing to a common entity of basic information about the threat scenarios they experience. This paper begins with a literature survey of 37 state-of-the-art GNSS threat monitoring systems, which have been analysed based on their respective operational features - constellations monitored and whether they possess the capability to perform interference-type classification, spoofing detection, and interference localisation. Also described is a comparative analysis of four GNSS threat reporting formats in use today. Based on these studies, the paper describes the Horizon2020 Standardisation of GNSS Threat Reporting and Receiver Testing through International Knowledge Exchange, Experimentation and Exploitation (STRIKE3) proposed integrated threat monitoring demonstration system and related standardised threat reporting message, to enable a high-level overview of the prevailing international GNSS threat scenarios and its evolution over time.


2021 ◽  
pp. 1-24
Author(s):  
Avidit Acharya ◽  
Kirk Bansak ◽  
Jens Hainmueller

Abstract We introduce a constrained priority mechanism that combines outcome-based matching from machine learning with preference-based allocation schemes common in market design. Using real-world data, we illustrate how our mechanism could be applied to the assignment of refugee families to host country locations, and kindergarteners to schools. Our mechanism allows a planner to first specify a threshold $\bar g$ for the minimum acceptable average outcome score that should be achieved by the assignment. In the refugee matching context, this score corresponds to the probability of employment, whereas in the student assignment context, it corresponds to standardized test scores. The mechanism is a priority mechanism that considers both outcomes and preferences by assigning agents (refugee families and students) based on their preferences, but subject to meeting the planner’s specified threshold. The mechanism is both strategy-proof and constrained efficient in that it always generates a matching that is not Pareto dominated by any other matching that respects the planner’s threshold.


Author(s):  
Jacopo A. Vitale ◽  
Matteo Bonato ◽  
Lorenzo Petrucci ◽  
Giorgio Zucca ◽  
Antonio La Torre ◽  
...  

Purpose: Little is known about the effect of sleep restriction (SR) on different domains of athletes’ physical performance. Therefore, the aim of this randomized, counterbalanced, and crossover study was to evaluate the effect of acute SR on sport-specific technical and athletic performance in male junior tennis players. Methods: Tennis players (N = 12; age 15.4 ± 2.6 y) were randomly allocated to either a sleep-restriction condition (SR, n = 6), where they experienced acute sleep restriction the night before the test session (≤5 h of sleep), or to a control condition (CON, n = 6), where they followed their habitual sleep–wake routines. Testing procedures included 20 left and right serves, 15 forehand and backhand crosscourt shots, and a repeated-sprint-ability test (RSA). The accuracy of serves and shots was considered for further analysis. One week later, players of SR joined CON, and players of CON experienced SR, and all test procedures were repeated. Results: Significant decrease in the accuracy of right (−17.5%, P = .010, effect size [ES] = 1.0, moderate) and left serve (−14.1%, P = .014, ES = 1.2, large), crosscourt backhand (−23.9%, P = .003, ES ≥ 2.0, very large), and forehand shot (−15.6%, P = .014, ES = 1.1, moderate) were observed in SR compared to CON, while RSA was similar in both conditions. Conclusion: Coaches and athletes at the team and individual level should be aware that 1 night of SR affects sport-specific but not athletic performance in tennis players.


Chemosphere ◽  
2020 ◽  
Vol 259 ◽  
pp. 127473
Author(s):  
Edward R. Salinas ◽  
Jared S. Bozich ◽  
Sara Kolbenschlag ◽  
Miriam Kary-Heinrich ◽  
Philipp W. Hopp ◽  
...  

2020 ◽  
Vol 23 (11) ◽  
pp. 1302-1310
Author(s):  
Pochamana Phisalprapa ◽  
Chayanis Kositamongkol ◽  
Julajak Limsrivilai ◽  
Satimai Aniwan ◽  
Phunchai Charatcharoenwitthaya ◽  
...  

Author(s):  
Parissa Haghirian

Knowledge is widely recognized as a primary resource of organizations (Drucker, 1992). Some authors propose that knowledge is a company’s only enduring source of advantage in an increasingly competitive world (Birkinshaw, 2001). The problem and challenge companies encounter is managing it in an effective way to increase their competitive advantages. Knowledge management is therefore concerned with various aspects of creating, examining, distributing, and implementing knowledge. But knowledge management theory often leaves us with the impression that knowledge can be as easily managed like products and commodities (Shariq, 1999). This Cognitive Model of Knowledge Management (p. 82) is founded on the belief that knowledge is an asset that needs to be managed, but is strongly contrasted by the Communities in Practice Model of Knowledge Management (p. 83), which looks at knowledge managment and transfer from a sociological perspective (Kakabadse, Kakabadse & Kouzmin, 2003). In fact, the transfer of knowlege happens between individuals; it is a mainly human-to-human process (Shariq, 1999). Knowledge has no universal foundation; it is only based on the agreement and the consensus of communities (Barabas, 1990), which make people and communities the main players in the knowledge transfer process. They can share or conceal knowledge; they may want to know more and want to learn. For knowledge transfer on an individual as well as on a corporporate level, there “has to be a voluntary action on behalf of the individual” (Dougherty, 1999, p. 264). Knowledge transfer happens for individuals and is conducted by individuals. The base of knowledge transfer is therefore a simple communication process transferring information from one individual to another. Two components of the communication are essential: The source (or sender) that sends the message and the receiver to receive the message. Person A (sender) intends to send information to person B (receiver). Person A codifies the information into a suitable form and starts the process of sending the information or knowledge to B. This can take place via talking or writing. The channel which transmits the information might influence the flow of the message and its reception. Receiver B receives the information and decodes it. After this, B tries to understand the information received in his/her context and implements the knowledge in the surrounding environment. The communication model also includes the feedback of the receiver. B starts the whole process again and codifies and sends information back to A. A receives, decodes, and interprets the information or knowledge received. A prerequisite for effective knowledge transfer is a high level of trust among the individuals and work groups and a strong and pervasive culture of cooperation and collaboration. This trust is developed through work practices that encourage and allow individuals to work together on projects and problems (Goh, 2002). Knowledge transfer is thus performed by communities of practice, which are described as groups of professionals informally bound to one another through exposure to a common class of problems, common pursuit of solutions, and thereby embodying a store of knowledge (Manville & Foote, 1996). Their members show a collectively developed understanding of what their community is about. They interact with each other, establishing norms and relationships of mutuality that reflect these interactions. Communities of practice generally produce a shared repertoire of communal resources, for example, language, routines, sensibilities, artifacts, tools, stories, and so forth. Members need to understand the community well enough to be able to contribute to it. They furthermore need to engage with the community and need to be trusted as a partner. Finally, they need to have access to the shared communal resources and use them appropriately (Wenger, 2000). Communities of practice develop strong routines for problem solving via communication and knowledge exchange. If knowledge is transferred within communities of practice, both sender and receiver have a common understanding about the context, the way knowledge is transmitted, its relevance, and integration into the knowledge base of the corporation. Accordingly, communities of practice are generally agreed on to have a positive influence on knowledge transfer processes. Members of a community of practice are informally bound by the gains they find when learning from each other and by efficient problem-solving activities via communication (Wagner, 2000).


2017 ◽  
Vol 13 (3) ◽  
pp. 204-225 ◽  
Author(s):  
Ramya Tarakad Venkateswaran ◽  
Abhoy K. Ojha

Purpose Universalizing approaches to knowledge when combined with a dominating cultural discourse is problematic for management research paradigms as “West meets East”. This study aims to examine the case of the rapidly expanding, mainstream strategic management research in and on emerging economies through a critical perspective. Design/methodology/approach The authors analyze the strategic management society’s special conferences and workshops on “Emerging India” that aimed to write a fresh chapter of research on India as an emerging economy, using the methodology of critical discourse analysis (CDA). The authors treat this conference as representative of several such conferences and workshops being organized in emerging economies. Findings The results detect some troubling undercurrents of privilege and marginalization. The authors find support for a dominating cultural discourse embedded in the rapidly expanding, universalizing strategic management research perspectives in and on emerging economies. Research limitations/implications The implications for indigenous knowledge creation is discussed with a concluding call for academic reflexivity through revisiting different philosophies of science in management research and studying the social mechanisms of international knowledge exchange. Originality/value The theoretical framework combining the process of universalizing knowledge (Bourdieu and Wacquant, 1999) with a dominating cultural discourse sustained through a system of pressures and constraints (Said, 1978, 1993) is an original contribution. The choice of an emerging economy site is not very common, and the use of CDA on an event like a conference is valuable to research methodology.


2014 ◽  
Vol 663 ◽  
pp. 547-551
Author(s):  
Solah Mohd Syazwan ◽  
Hamzah Azhar ◽  
Aqbal Hafeez Ariffin ◽  
Md Isa Mohd Hafzi ◽  
Rahman Mohd Khairudin ◽  
...  

ASEAN New Car Assessment Program (ASEAN NCAP) is a newly established automobile safety rating program in the Southeast Asia region, which the primary objective is to provide consumers with vehicle safety information and concurrently acknowledge manufacturers’ effort in elevating vehicle safety level. This information is comprehensively gathered through scientific and objective testing procedures in full scale crash test simulation. To ensure consistency and high repeatability, ASEAN NCAP operates standardized test and assessment protocols which utilize high-tech equipment and sensors, data acquisition system and also human surrogates (instrumented “dummies”). A point system is derived for marking purposes and a star rating scheme is designed to reflect the level of safety afforded to occupants. To cater for variation in crash configurations, occupants’ sizes and kinematics as well as other potential risks during crash impacts, a point deduction system (penalty-based) named as “modifiers” were introduced. Hence, this work attempts to describe the modifiers, their basis and justifications for inclusion in the safety rating scheme. A few case studies are demonstrated in this paper to enhance the understandings of modifiers concept.


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