Impact of Human Factors on Measurement Errors

Measurement is the act or the result, of a quantitative comparison between a given quantity and a quantity of the same kind chosen as a unit. It is for observing and testing scientific and technological investigations and generally agreed that all measurements contain errors. In a measuring system where both a measuring instrument and a human being taking the measurement using a preset process, the measurement error could be due to the instrument, the process or human error. This study is devoted to understanding the human errors in measurement. Work and human involvement related factors that could affect measurement errors have been identified. An experimental study has been conducted using different subjects where the factors were changed one at a time and the measurements made by them recorded. Errors in measurement were then calculated and the data so obtained was subject to statistical analysis to draw conclusions regarding the influence of different factors on human errors in measurement. The findings are presented in the paper.

AC Magnetic Measurements on Superconductors

This work describes the design and realisation of an apparatus to measure simultaneously the AC magnetic properties and the temperature distribution on the top surface of bulk superconducting samples (up to 32 mm in diameter) in cryogenic conditions (temperature range 78-120 K). First the authors describe the experimental set-up used for simultaneous thermal and magnetic characterization of the sample. Next, the authors describe the practical considerations required for generating the large AC magnetic fields, possibly in the presence of DC fields. Then the authors present the data acquisition system allowing both temperature and magnetic data to be recorded at high a sampling rate.” The performances and limitations of the system are discussed.

Design, Measurements and Characterization of Smart Electronic Board for PV Streetlight based on LED and High Intensity Discharge Lamps

This work presents an electronic board for driving and control of High Intensity Discharge (HID) lamps and Light Emitting Diode (LED) lamps. The proposed electronic board is able to drive HID or LED lamps by means of a reconfigurable output. This feature allows using the ballast in lighting systems that currently use traditional discharge lamps, as well as keeping the same ballast when discharge lamps are replaced by LED modules in the near future, when LED street lighting systems will be more affordable. Additionally, since the lighting system is designed to be used in rural areas where there is no public electricity, each lighting point incorporates a system to convert solar energy into continuous voltage by means of photovoltaic panels. In this work, energy saving issues are taken into account.

Measurements and Characterization of Photovoltaic Modules for Tolerance Verification

One of the most important aspects of photovoltaic modules is reliability for future uses, that is, a certain module will last certain number of years in use (generally 30 or 35 years). Reliability yields from excellent qualification tests on photovoltaic (PV) modules. Testing for reliability identifies unknown failure mechanisms and whether modules are susceptible to known failure mechanisms. This paper illustrates techniques of outdoor measurements and qualification characterization to know PV module conditions for commercial uses. Matrix methods are used for energy prediction. Failure material tests, using digital imaging and thermography, have also been conducted.

Exploitation of the EDF Scheduling in the Wireless Sensors Networks

Today, due to recent advances in wireless technology, new products using wireless sensor networks are being employed. However, despite the excitement surrounding wireless sensor networks, it is not immune to the problem of energy consumption. To overcome this deficiency and enhance the real time aspect, a growing interest lies in the implementation of an “Earliest Deadline First” (EDF) scheduler. Thus, in this paper, the authors establish a management policy of periodic tasks that is preemptive, multiprocessor, and dynamic. The authors implement a real-time scheduling policy as a part of a user-level threads package under the Linux operating system as Linux does not support EDF. Furthermore, this paper describes the technique of the EDF scheduler and how it can yield to significant power savings.

Impedance-Based Wireless Sensor Network for Metal-Protective Coating Evaluation

Researchers have been focused on the influences of flowing fluid on the corrosion of bare metals, but there is little emphasis on the degradation of metal-protective coating. Evaluating the metal-protective coating usually uses the Electrochemical Impedance Spectroscopy (EIS) method. EIS is a technique used for evaluating coating permeability or barrier performance based on the electrical impedance of coating. This paper presents a new impedance-based wireless sensor network for metal-protective coating evaluation. This wireless sensor network consists of two parts: impedance-based wireless sensor nodes and a wireless data base that are equipped with a network analyzer (AD5933) and a RF transceiver (CC1111/CC1110). In the experiment, there are three coating panels immersed in flowing deionized water (DI water) and one coating panel immersed in stationary DI water. Experimental results demonstrate that the proposed wireless sensor network is capable to evaluate the coating degrading.

Seismocardiogram and Ballistocardiogram Sensing

The paper describes the latest development in seismocardiography and ballistocardiography, including sensors with or without mechanical contact with the body, for cardiac functions monitoring in common daily activity. The authors discuss the information related with the seismocardiogramn (SCG) and ballistocardiogram (BCG) and the work on SCG and BCG modeling. The latest advances reported on the devices aiming at BCG and SCG cardiovascular system evaluation are covered, highlighting their key features and novel concepts. The authors also underscore the applications of ElectroMechanical film (EMFi) sensors, MEMS accelerometers and radar sensing technology for vital signs monitoring. Discussion on the current developments and future improvements are included in the paper.

A Real Time Attachment Free, Psycho Physiological Stress and Heart Rate Measurement System

The challenges in the development of a system performing real time detection of physiological parameters are fundamentally aversive because of the incommodities caused by the wires and sensing attachments onto the user, making the measurement sessions uncomfortable. Another factor is that the sensing accessories influence the plausibility of the measurements. In this paper, the authors introduce a system based on a device that can acquire physiological signals from a computer user with no prerequisites, postural, kinetic, or other constraints in the environment of normal usage of the home computer for the detection of their psychosomatic state and optimally their affect and emotional responses. The authors also discuss issues that could otherwise compromise the credibility of the results. Redundancy and special adaptive and corrective algorithms have been developed to improve reliability and achieve acceptable standards of quality. Measurements include skin conductance (SC) and heart rate (HR) detected by sensors positioned on the vertical sides of a computer mouse. The system is intended for interactive educational environments, during assessment, e-learning, psychosomatic user profiling, mobile and web based interfaces, and for Human Computer Interaction (HCI) platforms.

New Approaches of Nanocomposite Materials for Electromagnetic Sensors and Robotics

In this paper, the authors define new classes of devices based on nanocomposite materials (NMs). The work introduces approaches about the design and the experimental characterization of these materials. A wide range of applications is presented by discussing novel devices implemented by nanocomposite techniques including sensing and robotic in micro/nano scale. The approaches are oriented on the electromagnetic (EM) characterization of tailored devices such as sensors, and micro/nano antennas. New EM numerical approaches for the design are presented.

A Data Acquisition System to Detect Bubble Collapse Time and Pressure Losses in Water Cavitation

This paper presents a data acquisition system oriented to detect bubble collapse time and pressure losses in water cavitation in an internal orifice. An experimental campaign on a cavitating flow of water through an orifice has been performed to analyze the flow behavior at different pressures and temperatures. The experiments were based on visual observations and pressure fluctuations frequency analysis. Comparing the visual observations and the spectral analysis of the pressure signals, it is evident that the behavior of the different cavitating flows can be correlated to the frequency spectrum of the upstream, downstream and differential pressure fluctuations. The further reduction of the cavitation number and the consequent increase in the width of the cavitating area are related to a corresponding significant increase of the amplitude of typical frequency components. The spectrogram analysis of the pressure signals leads to the evaluation of the bubble collapse time, also compared with the numerical results calculated by the Rayleigh–Plesset equation.