1.

Record Nr.

UNINA9910454070703321

Autore

Wang Jung-Der

Titolo

Basic principles and practical applications in epidemiological research [[electronic resource] /] / Jung-Der Wang

Pubbl/distr/stampa

Singapore ; ; River Edge, N.J., : World Scientific, c2002

ISBN

1-281-92834-8

9786611928346

981-277-572-2

Descrizione fisica

1 online resource (379 p.)

Collana

Quantitative sciences on biology and medicine ; ; v. 1

Disciplina

614.4072

Soggetti

Epidemiology - Research

Epidemiology

Electronic books.

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

Note generali

Description based upon print version of record.

Nota di bibliografia

Includes bibliographical references (p. 341-361) and index.

Nota di contenuto

Contents; Preface; 1 Introduction to Epidemiological Research; 1.1 Definition of epidemiology; 1.2 Evolving trends of epidemiological research; 1.3 Types of inferences in epidemiological research; 1.4 Outline of the basic principles of epidemiological research; 1.5 Summary; Quiz of Chapter 1; 2 Principles of Scientific Research: Deductive Methods and Process of Conjecture and Refutation; 2.1 The process of scientific research; 2.2 Deductive methods: Common logical reasoning; 2.3 Conjectures and Refutations; 2.4 Why take a refutational attitude?

2.5 The limitations of conjectures and refutations2.6 Summary; Quiz of Chapter 2; 3 Scientific Hypothesis and Degree of Corroboration; 3.1 Hypothesis Formation - How to form a conjecture?; 3.2 What makes a hypothesis scientific?; 3.3 Successful refutation and auxiliary hypotheses - Has one disproved the primary hypothesis?; 3.4 Failure to falsify and degree of corroboration - Do the results of the study corroborate the primary hypothesis?; 3.5 Credibility of a hypothesis and decision-making; 3.6 Summary; Quiz of Chapter 3; 4 Causal Inference and Decision

4.1 Causal concepts in medicine and public health4.2 Proposed criteria



for causal decisions; 4.2.1 Necessary criteria; 4.2.2 Quasi-necessary criteria; 4.2.3 Other supportive criteria; 4.3 Objective knowledge and consensus method; 4.4 Summary; Quiz of Chapter 4; 5 Basic Principles of Measurement; 5.1 What is measurement?; 5.2 Why does one perform measurement?; 5.3 How does one measure?; 5.3.1 Measurements in socio-behavioral science; 5.4 Accuracy of measurement: Validity and reliability; 5.5 Scales of measurement; 5.5.1 Nominal scale: A scale of qualitative measurement

5.5.2 Ordinal scale: A scale of semi-quantitative measurement5.5.3 Interval scale: Quantitative measurement with or without an absolute zero starting point; 5.5.4 Ratio scale: Quantitative measurement with an absolute zero starting point; 5.6 Common evaluation method in medical diagnostic tests; 5.7 Validity and reliability of physico-chemical, biological and socio-behavioral measurements from a refutationist's point of view; 5.7.1 Measurement of chemicals in the environment or inside the human body

5.7.2 Conceptualization of exposure dose and its measurement in occupational and environmental medicine5.7.3 Validity and reliability of socio-behavioral measurement; 5.8 How to perform accurate measurement by questionnaire Limitations of questionnaire information; 5.8.1 Construction of a questionnaire; 5.8.2 Interview procedures; 5.9 Summary; Quiz of Chapter 5; 6 Basic Measurements in Epidemiological Research; 6.1 Evolving trends in epidemiological measurement; 6.2 Basic measurements of outcome in epidemiology

6.2.1 Outcome measurement: Counting of events and states, rate, proportion, and ratio

Sommario/riassunto

Based on the concept of "conjecture and refutation" from the Popperian philosophy of science, i.e. looking for alternative causes, this book simplifies the design and inferences of human observational studies into two types: descriptive and causal. It clarifies how and why causal inference should be considered from the search for alternative explanations or causes, and descriptive inference from the sample at hand to the source population. Furthermore, it links the health policy and epidemiological concept with decisional questions, for which the basic measurement can be quality-adjusted surv



2.

Record Nr.

UNINA9911019475003321

Autore

Riehle Fritz

Titolo

Frequency standards : basics and applications / / Fritz Riehle

Pubbl/distr/stampa

Weinheim, : Wiley-VCH, c2004

ISBN

9786610520831

9781280520839

1280520833

9783527605996

3527605991

9783527605958

3527605959

Descrizione fisica

1 online resource (542 p.)

Disciplina

529.750971

621.3815363

Soggetti

Frequency standards

Standards, Engineering

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

Note generali

Description based upon print version of record.

Nota di bibliografia

Includes bibliographical references (p. [465]-520) and index.

Nota di contenuto

Frequency Standards Basics and Applications; Contents; Preface; 1 Introduction; 1.1 Features of Frequency Standards and Clocks; 1.2 Historical Perspective of Clocks and Frequency Standards; 1.2.1 Nature's Clocks; 1.2.2 Man-made Clocks and Frequency Standards; 2 Basics of Frequency Standards; 2.1 Mathematical Description of Oscillations; 2.1.1 Ideal and Real Harmonic Oscillators; 2.1.2 Amplitude Modulation; 2.1.3 Phase Modulation; 2.2 Oscillator with Feedback; 2.3 Frequency Stabilisation; 2.3.1 Model of a Servo Loop; 2.3.2 Generation of an Error Signal; 2.4 Electronic Servo Systems

2.4.1 Components2.4.2 Example of an Electronic Servo System; 3 Characterisation of Amplitude and Frequency Noise; 3.1 Time-domain Description of Frequency Fluctuations; 3.1.1 Allan Variance; 3.1.2 Correlated Fluctuations; 3.2 Fourier-domain Description of Frequency Fluctuations; 3.3 Conversion from Fourier-frequency Domain to Time Domain; 3.4 From Fourier-frequency to Carrier-frequency Domain;



3.4.1 Power Spectrum of a Source with White Frequency Noise; 3.4.2 Spectrum of a Diode Laser; 3.4.3 Low-noise Spectrum of a Source with White Phase Noise; 3.5 Measurement Techniques

3.5.1 Heterodyne Measurements of Frequency3.5.2 Self-heterodyning; 3.5.3 Aliasing; 3.6 Frequency Stabilization with a Noisy Signal; 3.6.1 Degradation of the Frequency Stability Due to Aliasing; 4 Macroscopic Frequency References; 4.1 Piezoelectric Crystal Frequency References; 4.1.1 Basic Properties of Piezoelectric Materials; 4.1.2 Mechanical Resonances; 4.1.3 Equivalent Circuit; 4.1.4 Stability and Accuracy of Quartz Oscillators; 4.2 Microwave Cavity Resonators; 4.2.1 Electromagnetic Wave Equations; 4.2.2 Electromagnetic Fields in Cylindrical Wave Guides; 4.2.3 Cylindrical Cavity Resonators

4.2.4 Losses due to Finite Conductivity4.2.5 Dielectric Resonators; 4.3 Optical Resonators; 4.3.1 Reflection and Transmission at the Fabry-Pérot Interferometer; 4.3.2 Radial Modes; 4.3.3 Microsphere Resonators; 4.4 Stability of Resonators; 5 Atomic and Molecular Frequency References; 5.1 Energy Levels of Atoms; 5.1.1 Single-electron Atoms; 5.1.2 Multi-electron Systems; 5.2 Energy States of Molecules; 5.2.1 Ro-vibronic Structure; 5.2.2 Optical Transitions in Molecular Iodine; 5.2.3 Optical Transitions in Acetylene; 5.2.4 Other Molecular Absorbers

5.3 Interaction of Simple Quantum Systems with Electromagnetic Radiation5.3.1 The Two-level System; 5.3.2 Optical Bloch Equations; 5.3.3 Three-level Systems; 5.4 Line Shifts and Line Broadening; 5.4.1 Interaction Time Broadening; 5.4.2 Doppler Effect and Recoil Effect; 5.4.3 Saturation Broadening; 5.4.4 Collisional Shift and Collisional Broadening; 5.4.5 Influence of External Fields; 5.4.6 Line Shifts and Uncertainty of a Frequency Standard; 6 Preparation and Interrogation of Atoms and Molecules; 6.1 Storage of Atoms and Molecules in a Cell; 6.2 Collimated Atomic and Molecular Beams

6.3 Cooling

Sommario/riassunto

Of all measurement units, frequency is the one that may be determined with the highest degree of accuracy. It equally allows precise measurements of other physical and technical quantities, whenever they can be measured in terms of frequency.This volume covers the central methods and techniques relevant for frequency standards developed in physics, electronics, quantum electronics, and statistics. After a review of the basic principles, the book looks at the realisation of commonly used components. It then continues with the description and characterisation of important frequency standards