Approximation and the point of flicker-noise formation

Author(s):  
A.S. Matsaev

The article refers to the field of research of noise fluctuations or flicker noise in electronic amplifiers and is devoted to the exact definition of the magnitude and shape of the spectral density of flicker-noise. The 1/f approximation of flicker noise is analyzed and the problem of its non-constructiveness in analyzing the noise characteristics of electronic amplifiers is shown. To eliminate this problem, the mechanism of physical formation of the envelope, a form of spectral density flicker-noise is defined. The physics of flicker-noise is detailed by accurate definition of the place of its formation. An accurate definition of the maximum difference of the amplifier flickernoise on the flat section of noise characteristics is given, using an explanation of the physics of flicker noise. The mechanism and conditions of the exponential increase of flicker noise and its subsequent exponential desire for maximum magnitude are explained. A simple physical approximation is given to determine the processes of forming the envelope form of the spectral density of flickernoise. The physical understanding of the formation of spectral density of flicker-noise tension in the internal structure of the transistor with the participation of external circuits of the amplifier electrical circuit is detailed. The results of the study will help developers to solve many problems of building electronic devices and optimizing their characteristics at a qualitatively new level.

Author(s):  
Michael T. Postek

The term ultimate resolution or resolving power is the very best performance that can be obtained from a scanning electron microscope (SEM) given the optimum instrumental conditions and sample. However, as it relates to SEM users, the conventional definitions of this figure are ambiguous. The numbers quoted for the resolution of an instrument are not only theoretically derived, but are also verified through the direct measurement of images on micrographs. However, the samples commonly used for this purpose are specifically optimized for the measurement of instrument resolution and are most often not typical of the sample used in practical applications.SEM RESOLUTION. Some instruments resolve better than others either due to engineering design or other reasons. There is no definitively accurate definition of how to quantify instrument resolution and its measurement in the SEM.


Author(s):  
Carlos Ortiz de Landázuri

Heidegger, Zubiri, Apel y Polo habrían propuesto una definición más correcta de las respectivas nociones de sujeto relacional humano, a saber: “Dasein” o “ser-ahí”; “personeidad” o “esencia abierta”; “intersubjetividad” o “la llamada por parte de los entes a diversos interlocutores”; y, finalmente, “persona-núcleo” o “agente mediador entre los entes y el ser”. Se pretendía así evitar una vuelta a las paradojas del “sujeto transcendental” en Kant, del “yo absoluto” en Hegel o del “sujeto fenomenológico” en Husserl. Sin embargo en cada caso se siguieron estrategias heurísticas específicamente distintas a la hora de conceptualizar dicho sujeto relacional: Heidegger propuso una superación de la noción de “sujeto fenomenológico” en Husserl; Zubiri, en cambio, defendería una recuperación de la noción de “sujeto fenomenológico” en Husserl; por su parte, Apel propondría una reformulación semióticamente transformada del “Dasein” heideggeriano; finalmente, Polo propondría una reformulación gnoseológica de la noción de “Dasein” heideggeriano.Heidegger, Zubiri, Apel, and Polo have proposed a more accurate definition of the respective notions of human relational subject: “Dasein” or “being-there”; “Personhood” or “open essence”; “inter-subjectivity” or “entities’ appeal to diverse interlocutors”; and, finally, “nucleus-person” or “mediator between entities and being”. The aim is to avoid a return to Kant’s transcendental subject paradoxes and Hegel’s “absolute I” or Husserl´s “fenomenological subject”. But in each case specifically different heuristic strategies were followed when conceptualizing said relational subject: Heidegger proposed overcoming the notion of “phenomenological subject” in Husserl; Zubiri, however, defend the recovery of the notion of “phenomenological subject” in Husserl; meanwhile, Apel propose a transformed semiotically reformulation of Heidegger’s “Dasein”; finally, Polo propose a reformulation of the epistemological notion of Heidegger’s “Dasein”.


Author(s):  
Samantha Cruz Rivera ◽  
Barbara Torlinska ◽  
Eliot Marston ◽  
Alastair K. Denniston ◽  
Kathy Oliver ◽  
...  

Abstract Background The UK’s transition from the European Union creates both an urgent need and key opportunity for the UK and its global collaborators to consider new approaches to the regulation of emerging technologies, underpinned by regulatory science. This survey aimed to identify the most accurate definition of regulatory science, to define strategic areas of the regulation of healthcare innovation which can be informed through regulatory science and to explore the training and infrastructure needed to advance UK and international regulatory science. Methods A survey was distributed to UK healthcare professionals, academics, patients, health technology assessment agencies, ethicists and trade associations, as well as international regulators, pharmaceutical companies and small or medium enterprises which have expertise in regulatory science and in developing or applying regulation in healthcare. Subsequently, a descriptive quantitative analyses of survey results and directed thematic analysis of free-text comments were applied. Results Priority areas for UK regulatory science identified by 145 participants included the following: flexibility: the capability of regulations to adapt to novel products and target patient outcomes; co-development: collaboration across sectors, e.g. patients, manufacturers, regulators, and educators working together to develop appropriate training for novel product deployment; responsiveness: the preparation of frameworks which enable timely innovation required by emerging events; speed: the rate at which new products can reach the market; reimbursement: developing effective tools to track and evaluate outcomes for “pay for performance” products; and education and professional development. Conclusions The UK has a time-critical opportunity to establish its national and international strategy for regulatory science leadership by harnessing broader academic input, developing strategic cross-sector collaborations, incorporating patients’ experiences and perspectives, and investing in a skilled workforce.


1994 ◽  
Vol 4 (5) ◽  
pp. 348-351 ◽  
Author(s):  
R. Chenoy ◽  
S. Manohar ◽  
C. W.E. Redman ◽  
D. M. Luesley

Colposcopic assessment may be normal in the presence of severe or persistent minor cytologic abnormality. To assess the significance of negative satisfactory colposcopy in patients with abnormal cervical smears, a retrospective review was carried out on 1170 patients who had undergone out-patient loop diathermy excision for abnormal cervical cytology. Of these, 69 patients were treated for abnormal cervical cytology, despite normal colposcopic findings. Cytologic abnormalities ranged from persistent borderline changes to severe dyskariosis. Histologic assessment of the excision specimens revealed cervical intraepithalial neoplasia (CIN) in 43 (62.3%) cases, of which high-grade CIN accounted for 24 (34.8%) cases. There was good correlation between cytologic and histologic diagnosis. Simple regression analysis showedr= 0.46,P< 0.0001. The cytologic abnormality was highly predictive of the corresponding histologic diagnosis. This analysis has shown that significant intraepithelial lesions may exist despite negative colposcopic examination and highlights the need for histologic evaluation in such cases. In these circumstances, loop cone biopsy permits accurate definition of lesion severity, avoids potential undertreatment of significant lesions and causes less morbidity than conventional cone biopsy.


1981 ◽  
Vol 35 (3) ◽  
pp. 317-324 ◽  
Author(s):  
N. W. Bower ◽  
J. D. Ingle

Theoretical equations and experimental evaluation procedures for the determination of the precision of flame atomic absorption, emission, and fluorescence measurements are presented. These procedures and noise power spectra are used to evaluate the precision and noise characteristics of atomic copper measurements with all three techniques under the same experimental conditions in an H2-air flame. At the detection limit, emission and fluorescence measurements are limited by background emission shot and flicker noise whereas absorption measurements are limited by flame transmission lamp flicker noise. Analyte flicker noise limits precision at higher analyte concentrations for all three techniques. Fluctutations in self-absorption and the inner filter effect are shown to contribute to the noise in atomic emission and fluorescence measurements.


1943 ◽  
Vol 36 (1) ◽  
pp. 63-81
Author(s):  
John Laird

Theists, I suppose, are persons who believe in “God's” existence. Atheists are persons who deny the same.Such statements may be suitable, and even adequate, for many proper purposes. In several contexts it is silly or malicious to interrogate them closely. Even in theology, which is, or should be, some kind of science, they may have, and they do have, their use and their propriety. For many theological purposes, however (and also for some others) they are far too vague. It may be wrong, no doubt, to tell a theologian that he must either produce an accurate definition of what he means by “God” or be forever shamed.


2013 ◽  
Vol 11 (6) ◽  
pp. 697-703 ◽  
Author(s):  
Gurpreet S. Gandhoke ◽  
Paolo Frassanito ◽  
Nagesh Chandra ◽  
Bal K. Ojha ◽  
Anoop Singh

Object In this paper the authors' goal was to investigate the clinical usefulness of Gd-enhanced MR ventriculography (MRV) in pediatric patients affected by multiloculated hydrocephalus. Methods Eighteen patients (11 boys and 7 girls, age range 2–14 months) with a diagnosis of multiloculated hydrocephalus were included in the study. After injection of gadodiamide (0.02–0.04 mmol) into the lateral ventricle by tapping the anterior fontanel, sagittal, coronal, and axial T1-weighted MR images were acquired. The location of the septations and the sites of obstruction of CSF flow were assessed. Postoperative MRV was obtained to confirm the results of endoscopic treatment in most complex cases. Results No adverse events were observed after injection of contrast medium into the ventricular system. Preoperative MRV accurately defined the exact morphology of septae and ventricular walls in all cases. In 1 case the diagnosis of multiloculated hydrocephalus was ruled out. Sites of obstruction of CSF flow within the ventricular system were also well established. In 4 cases the multiple compartments were proven to intercommunicate. Postoperative MRV was useful in assessing the functional status of third ventriculostomy, aqueductoplasty, and other endoscopic fenestrations. Conclusions Magnetic resonance ventriculography is a safe, effective, and reliable technique. The accurate definition of the anatomy of the ventricles and the site of obstruction in multiloculated hydrocephalus can help to plan the most appropriate treatment and minimize the number of procedures. Although MRV is also useful during postoperative follow-up to determine the results of endoscopic treatment, it should be limited to particularly complex cases, due to its invasiveness.


2021 ◽  
pp. 147592172110446
Author(s):  
Claudia Barile ◽  
Caterina Casavola ◽  
Giovanni Pappalettera ◽  
Vimalathithan Paramsamy Kannan

Signal-based acoustic emission data are analysed in this research work for identifying the damage modes in carbon fibre–reinforced plastic (CFRP) composites. The research work is divided into three parts: analysis of the shifting in the spectral density of acoustic waveforms, use of waveform entropy for selecting the best wavelet and implementation of wavelet packet transform (WPT) for identifying the damage process. The first two methodologies introduced in this research work are novel. Shifting in the spectral density is introduced in analogous to ‘flicker noise’ which is popular in the field of waveform processing. The entropy-based wavelet selection is refined by using quadratic Renyi’s entropy and comparing the spectral energy of the dominating frequency band of the acoustic waveforms. Based on the method, ‘dmey’ wavelet is selected for analysing the waveforms using WPT. The slope values of the shifting in spectral density coincide with the results obtained from WPT in characterising the damage modes. The methodologies introduced in this research work are promising. They serve the purpose of identifying the damage process effectively in the CFRP composites.


2018 ◽  
Vol 51 (3) ◽  
pp. 485-502 ◽  
Author(s):  
Ezequiel Heffes

This review explores certain challenges related to the notion of customary international law. It seems that it was a long time ago when international law academics and practitioners ever thought that the nature of this source was a well-settled topic. Nowadays international lawmaking processes involve an extraordinary number of interactions, taking place both formally and informally. Such complex features are reflected by an exponential increase in the scholarly study of international legal sources. The legal nature, its applicability and principles regulating customary international law are addressed in the book under review (Brian D Lepard (ed), Reexamining Customary International Law (Cambridge University Press 2017)) through several topical essays. The chapters offer a comprehensive analysis of these lawmaking processes and the challenges they portray from various perspectives and in various fields, such as: What is customary international law and why is it law? Is it law because it reflects a ‘global legislative’ model? What is the current value of the persistent objector theory? Is the two-element definition of customary international law still applicable? By meticulously addressing these and other inquiries, the book presents novel arguments and represents a stimulating addition to the literature on sources of international law.


Author(s):  
Richa Srivastava ◽  
Ram Singh

The petrochemical-based plastics are causing a strong challenge for the natural ecosystem leading to global environmental pollution due to their non-biodegradable nature. Hence, the requirement of alternative materials possessing environmental advantages received attention and leads to the development of bioplastics. Definition of bioplastics is not universal but broadly it can be defined as biodegradable plastic derived from biodegradable substances. Although, all types of bioplastics are not biodegradable, still their many advantages towards the environment cannot be ruled out and hence, their applications in varied areas have increased many-folds world-wide. Bioplastics are being used in rigid and flexible packaging materials, food and drinks containers, dining utensils, electronic devices, automotive and airplane parts, cable sheaths and casings, noise and thermal insulation panels and many more. The list is growing up. Bioplastics have shown their potential for a sustainable society and presents some advantages such as lower carbon footprint, energy efficiency, and eco-safety. This article discusses the basic information, sources, biodegradability, and applications of bioplastics.


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