1,721,137 research outputs found
Application of general finite mixture models to reliability data using likelihood estimation
No full textApplication of general finite mixture models to reliability data using likelihood estimation
No full textA method to minimize test times for accelerated testing of pHEMT's by analysis of the elctronic fingerprint of the initial stage of degradation
No full textAccelerated life testing provides a necessary tool for reliability validation but is generally very time-consuming as standard test take up to 2000 hours to proceed. In this article, results on the early stages of the ageing of pHEMT transistors are presented and it is shown that the necessary test time can be decreased from 2000 hours to 144 hours without loss of data confidence. This has been enabled by the application of an insitu measurement method where the ageing of the device under test is characterized during the stress phase. Two main degradation factors can be identified in good agreement with findings reported in literature. The data have been successfully correlated with standard test results performed on a 2000 hours time scale
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Modelling of the Hot-Carrier Degradation Behaviour of Submicron nMOSFETs making use of High-Resolution Measurements
No full textThis thesis deals with the study of the reliability of one specific type of electronic component, the Metal-Oxide-Semiconductor Field-Effect-Transistor (MOSFET). MOSFETs have been in use since the beginning of the sixties. They have several advantages: The LOCOS (Local Oxidation of Silicon) isolation enables the separation of devices. The structure has superb scaling possibilities . The use of n-type and p-type devices on the same substrate allows building circuits with complementary MOS structures (CMOS), which results in ultra-low power consumption. These advantages have made the MOSFET the basic building block of semiconductor very-large-scale integration (VLSI) and ultra-large-scale integration (ULSI) products, such as memory cells and microprocessors. ..
Modelling of the Hot-Carrier Degradation Behaviour of Submicron nMOSFETs making use of High-Resolution Measurements
No full textThis thesis deals with the study of the reliability of one specific type of electronic component, the Metal-Oxide-Semiconductor Field-Effect-Transistor (MOSFET). MOSFETs have been in use since the beginning of the sixties. They have several advantages: The LOCOS (Local Oxidation of Silicon) isolation enables the separation of devices. The structure has superb scaling possibilities . The use of n-type and p-type devices on the same substrate allows building circuits with complementary MOS structures (CMOS), which results in ultra-low power consumption. These advantages have made the MOSFET the basic building block of semiconductor very-large-scale integration (VLSI) and ultra-large-scale integration (ULSI) products, such as memory cells and microprocessors. ..
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Elektrisch gedrag en falingsmechanismen van glas-keramische dielektrica in dikke-film multilagen bij hoge temperaturen
No full textGlass-ceramics are polycrystalline materials obtained from glasses after an appropriate thermal treatment. They are of importance because they offer combinations of physical properties not available with other classes of materials. Glass-ceramics have become established as commercially important materials in fields such as consumer products, applications for the aerospace industry and protective coatings for metals. Recently, their technological importance has also been recognized in the field of microelectronics. Since the end of the eighties great effort has been spent in the development of glass-ceramics suitable as dielectrics in thick film multilayer systems. The construction of complex thick film multilayers can be seriously obstructed by the occurrence of failures during production at high temperatures, and therefore a reliable dielectric is needed. The most important high temperature failures in thick film multilayers are shorting and blistering of the dielectric in between two metal layers. The basic physico-chemical processes causing these failures are insufficiently understood. In particular, the correlation between electrical properties of the glass-ceramic material and the occurrence of these failures is not clear. The temperature region of interest in the study of these failures ranges from room temperature up to 850°C, which complicates the observation of the governing material properties. A further difficulty in the study of the underlying failure mechanisms is given by the intrinsic complexity of the multilayer systems. Thick film dielectrics are composite materials containing amorphous and crystalline phases of various size and chemical composition, which furthermore can interact with the adjacent conductors. In the present work a new approach is undertaken in the study of the high temperature shorting and blistering of glass-ceramic dielectrics in thick film multilayers. While other studies concerning these phenomena often concentrate on off-line results, here the study is mainly based on in-situ observation of the high temperature electrical behaviour of the given materials. The temperature region of interest has been made accessible for in-situ monitoring by the development of an appropriate measurement equipment. With this equipment several properties have been systematically investigated for a set of dielectric materials in different conditions. Since the in-situ resistance and current measurements, normally performed with the patented in-situ electrical measurement method, are inadequate for the study of high ohmic materials, new measurement techniques have been introduced. The in-situ electrical measurement equipment has been modified in order to allow the performance of impedance spectroscopy, e.m.f.'s measurements and the newly developed leakage current measurements with voltage polarity switching. With the various in-situ electrical measurements and analytical techniques, important results have been obtained concerning electrical conduction mechanisms and electrochemical behaviour of glass-ceramic materials in thick film multilayers. It has been possible to detect the occurrence of the high temperature failures and to indicate the most important failure parameters. By combining and comparing the gathered information, important conclusions can be drawn concerning the occurring high temperature processes
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