Enrico Reiche and Michael Schneider
This paper aims to introduce design challenges of modern telecommunication satellite antennas. The antenna farms accommodated on a satellite are systems of high complexity. From…
Abstract
Purpose
This paper aims to introduce design challenges of modern telecommunication satellite antennas. The antenna farms accommodated on a satellite are systems of high complexity. From the radio frequency (RF) point of view, the most important design issues, e.g. high power applications in space (vacuum) or typical antenna scenarios (single/multi beam antennas), and their solution are considered.
Design/methodology/approach
The paper presents the application of electro-magnetic (EM) field simulation in the design and optimisation process. The design of a telecommunications satellite antenna splits into several areas, for which different types of EM field solvers are used.
Findings
The use of EM field solvers enables an accurate and efficient design approach of modern geostationary telecommunications satellite antennas. Due to the use of EM field solvers, an excellent agreement between predictions and measurement results on feed as well as antenna system level is achieved.
Originality/value
This paper gives an overview of state-of-the-art telecommunications satellite antenna architectures and their efficient RF design due to the use of EM field solvers. Typical high power effects and other design issues are explained. RF engineers are encouraged to work on this exciting topic to further improve the design process and to develop new satellite antenna and feed products.
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Paul L. Plener, Jasmin Grieb, Nina Spröber, Joana Straub, Alexander Schneider, Ferdinand Keller and Michael G. Kölch
The Children's Depression Rating Scale-Revised (CDRS-R) is a widely used instrument for research on depression in minors. A raw score of ?40 has often been used as indicator of…
Abstract
The Children's Depression Rating Scale-Revised (CDRS-R) is a widely used instrument for research on depression in minors. A raw score of ?40 has often been used as indicator of depressive symptomatology. As a validated German version of the CDRS-R has recently became available, we assessed CDRS-R raw summary scores of a video taped interview session in two different rater groups and compared them with clinical ratings of International Classification of Diseases (ICD-10) depression diagnosis as observed by a third independent group. We found that for the German version a raw score between 35 and 40 is indicative for mild depressive symptomatology as described by the ICD-10. CDRS-R scores show potential clinical applicability to deduct levels of depression.
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Comparative analyses in education science have traditionally focused on the category of geographic location as the comparative unit. However, comparison may involve many other…
Abstract
Comparative analyses in education science have traditionally focused on the category of geographic location as the comparative unit. However, comparison may involve many other units of analysis, such as culture, politics, curricula, education systems, social phenomena, and other categories of the lives of societies. Still, categories are inseparably linked to one or several geographic locations. Comparative approaches are often also dictated by the availability heuristic. Studying geographic units as the foci of comparative research is a necessary step for comparative presentation of the topic. According to Bray and Thomas, a researcher must always seek preliminary insight in the geographic unit to be analyzed before making the comparison. In social science research, a unit of analysis relates to the main object of the research, as it answers the question of “who” or “what” is going to be analyzed. The most common units of analysis are people, groups, organizations, artifacts or phenomena, and social interactions. Ragin and Amoroso have noted that comparative methods can be used to explain the commonness or diversity of results. This paper shows how comparative research can be approached in ways that have not been discussed, grounded in the historically variable understanding of the very term “comparison.” They are, for example, The Ogden-Richards triangle, The Porphyrian Tree, Classification strategies – Mill’s Canons, The chaos of the world – the order of science, Weber’s ideal types, Raymond Boudon’s formula, and the Möbius strip in comparativism.
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HOWARD SCHNEIDER, MICHAEL R. BUTOWSKY and MICHELE M. LEW
This article provides a comprehensive look at suitability rules, first in the traditional brokerage context and then in terms of their application to online brokerages in general…
Abstract
This article provides a comprehensive look at suitability rules, first in the traditional brokerage context and then in terms of their application to online brokerages in general. It outlines the arguments made by the online brokerages to differentiate their world from traditional broker‐dealers, and offers hypothetical scenarios in which suitability concepts may apply in the online brokerage setting. The authors suggest that online brokerages should be allowed time to determine the appropriate rules in light of how the technology itself evolves over the next several years.
APPLICATIONS OF MICROPROCESSORS TO INDUSTRIAL PROCESSES Controlling an industrial process using a large central main frame machine, or even an hierarchy of such machines, is…
Abstract
APPLICATIONS OF MICROPROCESSORS TO INDUSTRIAL PROCESSES Controlling an industrial process using a large central main frame machine, or even an hierarchy of such machines, is hardly new. But now it is becoming positively old‐fashioned as cheap micro‐processors are being developed to take control of industrial processes. Devolution is at work, with an army of micros controlling factory processes at the points where direct control is required. Each microprocessor can monitor and control a single part of the process and, if failure occurs, a second or even a third micro can take over the functioning or alternatively the rest of the process will be undisturbed. For example, it may still be necessary for a central computing machine to supervise a number of different functions such as initiation of some function like switching on a motor, or controlling a valve. But each function could be individually controlled in turn by its own micro‐processor unit.
J.Y. Park and M.G. Allen
In many systems which utilise magnetic components, e.g., miniaturised DC‐DC converters,PCMCIA cards, and modem stand‐off transformers, the magnetic device is the largest…
Abstract
In many systems which utilise magnetic components, e.g., miniaturised DC‐DC converters, PCMCIA cards, and modem stand‐off transformers, the magnetic device is the largest single component in the package. Surface‐mount magnetic devices may be unacceptably thick where low profiles are required. The authors's approach to this problem is to use micromachining techniques to realise inductors and transformers built into the multilayer structure of a multi‐chip package, allowing compact integration with chips, sensors and other components. Microinductors and micro‐transformers composed of thick cores and multiwinding conductors have high inductance, high saturation current, and low resistance compared with previous integrated inductors. The total size of the microinductive device is 4 mm ×4 mm× 0.145 mm, having 156 turns of multilevel electroplated copper coils (40 μm thick) and electroplated permalloy magnetic core (35 μm thick). These devices have inductances up to 1.5 μH and current‐carrying capability of up to 3A steady DC current, making them applicable to power converters. The processing steps chosen are all low‐temperature, which allow the use of low‐cost substrates such as MCM‐L compatible materials.
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A global electronic‐business course, delivered over the Internet, is helping to provide managers with an understanding of how electronic commerce is changing the way they think…
Abstract
A global electronic‐business course, delivered over the Internet, is helping to provide managers with an understanding of how electronic commerce is changing the way they think about business today. The program, developed and managed by FT Knowledge and the Wharton School of the University of Pennsylvania, USA, guides managers through the opportunities and threats presented by electronic commerce. It focuses upon areas such as marketing, electronic retailing, pricing, product design, supply‐chain management and communication.
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Qiang Zha and Derrick Tu
Mixed methods research is an approach for blending quantitative and qualitative data analyses in a single study. It emerged as an alternative to the dichotomy of qualitative and…
Abstract
Mixed methods research is an approach for blending quantitative and qualitative data analyses in a single study. It emerged as an alternative to the dichotomy of qualitative and quantitative traditions in the past 20 years. Some strengths of mixed methods research include the ability to generate and test theory, the capability to answer complex research questions, and the possibility of corroborating findings.
We argue the mixed methods approach fits well with comparative education studies because they seek to acquire data to make sound and meaningful comparisons about the experience and performance of education systems in different countries. By nature, comparative education attempts to explain why educational systems vary and to explore how education relates to wider social factors and forces. It consists of both confirmatory and exploratory inquiries that are based on the fundamental belief that education can be improved in all nations. Essentially, the mixed methods approach can adequately support the goals of comparative education studies, with its quantitative components serving the confirmatory objectives and the qualitative components attending to the exploratory end.
In this study, we conducted a survey of articles published between 2000 and 2014 in Comparative Education Review, Comparative Education, and Compare to discern the changes in patterns and preferences of dominant research methods. By surveying the three major journals in the field, we hope to reveal the means by which comparative education is conducted in its constituency. At the very least, we believe our study can provide important reference points for speculation about where comparative education might be headed in terms of methodology and methods.
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Michael Cohen, Sara Guciardo and Joel Schneider
Describes how educational media company Sesame Workshop has applied research to the development and evaluation of children’s TV programming; Sesame Workshop was the creator in…
Abstract
Describes how educational media company Sesame Workshop has applied research to the development and evaluation of children’s TV programming; Sesame Workshop was the creator in 1969 of the “Sesame Street” TV series, which intentionally blended entertainment and education, and it has now teamed up with Applied Research and Consulting LLC (ARC). Explains the historical background to television research, and the development by Sesame Workshop and ARC of New Kid City, a prototype media environment for children, and later of Noggin, an interactive “place to go” with a website and children’s TV channel. Illustrates the application of the Sesame Workshop approach in one of its programmes, “Rechov Sumsum/Shara’a Simsim”, which is aimed at Israeli and Arab/Palestinian children.
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Sandra L. Furterer, Kellie Schneider, Michael B. Key, Daniel Zalewski and Michael Laudenberger
The purpose of this study is to improve the utilization of walk-in tutors at the University of Dayton.
Abstract
Purpose
The purpose of this study is to improve the utilization of walk-in tutors at the University of Dayton.
Design/methodology/approach
This paper discusses the application of mixed methods participatory action research with the use of the lean six sigma (LSS) define-measure-analyze-improve-control (DMAIC) methodology combined with discrete event simulation to improve the tutoring processes at the University of Dayton.
Findings
The impact of these improvements provided a great balance between tutor utilization and student wait time, and as a result, an increase in pay was negotiated for tutors. Additionally, two schools within the University, Engineering and Business, have seen the value of the tutoring for their students and have provided additional financial support for tutoring services. Specifically, these schools now have dedicated by-appointment tutors for their students.
Originality/value
Incorporating simulation within the LSS methodology provides a “prototype” simulation of the potential solutions prior to changing the process in the real world. This approach can minimize the risk of implementing solutions that are costly or ineffective. The improvement of increased tutor pay helped to demonstrate the university’s commitment to tutors and tutoring. Through continuous improvement efforts, the tutoring department has tripled the number of courses that they support through these enhanced relationships, improved utilization and the overall culture and work environment. The LSS methodology and tools combined with discrete event simulation can be used as a guide for improving other repetitive processes within the university.