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The purpose of this paper is to demonstrate the theoretical relationship between the layout of four‐sensor dynamic acoustic array tracking system and systematic observation accuracy, and provide an algorithm to determine the optimal arrangement of four‐sensor acoustic array and an indicator to evaluate acoustic array system measurement accuracy.

In the present paper, the measurement principle of the four‐sensor dynamic acoustic array tracking system is analyzed, and the system observation model and the conversion relationship between models are established. Subsequently, the optimization algorithm for the four‐sensor dynamic acoustic array is deduced, the theoretical optimal arrangement of the four‐sensor dynamic acoustic array tracking measurement system is obtained based on the optimal position dilution of precision function (PDOPF) of 2D target, and the static experimental study on sound‐source bearing estimation is designed. The theoretical results are compared with the experimental results of the present study.

The measurement accuracy of the four‐sensor dynamic acoustic array tracking system is largely dependent on the layout of the acoustic sensor. Theoretical studies and experimental results demonstrated that an optimal PDPOF can be used to analyze the rationality of the layout. It can also serve as an indicator for the layout of the four‐sensor dynamic acoustic array tracking system.

The PDOPF value is presented as an indicator for the evaluation of the four‐sensor dynamic acoustic array systematic observation accuracy based on theoretical analysis. The feasibility of the indicator and the rationality of the sensor layout in practical engineering application are verified through experimental studies on sound‐source bearing estimation. The higher the PDOPF value is, the lower the accuracy of the system will be.

This article aims to provide an insight into recent deliberations on the possibility of a global sensor market reaching one trillion units per annum within the next decade.

Following an introduction, which includes details of the TSensors Summit, this article discusses existing high volume sensor applications with multi-billion unit growth prospects. It then considers certain new and emerging applications, including the Internet of Things. This is followed by technological considerations and a brief discussion.

The possibility of a global sensor market reaching one trillion units per annum within the next decade is the topic of serious debate. Several applications representing multi-billion levels have been identified and the ongoing TSensors Summit activities seek to identify further high volume, high growth uses and the factors that will stimulate them. While MEMS will play a central role, other, often new sensor technologies will be vital to achieving the trillion unit level.

This article provides a timely review of recent deliberations surrounding the feasibility of achieving a global, trillion sensor market.

Recent wireless communication and electronics technology has enabled the development of low‐cost, low‐power, and multi‐functional sensor nodes. However, the fact that sensor nodes are severely energy‐constrained has been an issue and many energy‐efficient routing protocols have been proposed to resolve it. Cluster‐based routing protocol is one of them. To achieve longer lifetime, some cluster‐based routing protocols use information on GPS‐based location of each sensor node. However, because of high cost, not all sensor nodes can be GPS‐enabled. The purpose of this paper is to propose a simple dynamic clustering approach to achieve energy efficiency for wireless sensor networks (WSN).

Instead of using location information of each sensor node, this approach utilizes information of remaining energy of each sensor node and changes in the number of cluster head nodes dependent on the number of sensor nodes alive. Performance results are presented and compared with some related protocols.

The simulations described in the paper show that both residual energy of each sensor node and changing cluster head nodes depending on the number of sensor nodes alive are very critical factors to obtain performance enhancement in terms of lifetime and data transmission. Especially, in some special environment, the proposal has better performance than GPS‐enabled protocol.

The paper is of value in proposing a simple dynamic clustering approach to achieve energy efficiency for WSN.

The purpose of this paper is to provide details of a high sensitivity electric field sensor developed by Plessey Semiconductors.

Following a background to the sensor's origins, this paper describes the principle of operation and then discusses three recently launched products and their applications. Finally, a range of other potential uses are considered.

This shows that the sensors offer the unique ability to detect very low electric fields, with or without physical contact. Products have been launched which are finding applications in healthcare and motion detection but many other uses are anticipated in such diverse areas as material testing, forensics, automotive safety, analytical technology and even earthquake prediction.

The paper describes a new type of electric field sensor which has the potential to satisfy a diversity of medical and industrial applications.

Develop a method for the optimal placement of sensors in order to detect the largest number of contaminant release scenarios with the minimum amount of sensors.

The method considers the general sensor placement problem. Assuming a given number of sensors, every release scenario leads to a sensor input. The data recorded from all the possible release scenarios at all possible sensor locations allow the identification of the best or optimal sensor locations. Clearly, if only one sensor is to be placed, it should be at the location that recorded the highest number of releases. This argument can be used recursively by removing from further consideration all releases already recorded by sensors previously placed.

The method developed works well. Examples showing the effect of different wind conditions and release locations demonstrate the effectiveness of the procedure.

The method can be used to design sensor systems for cities, subway stations, stadiums, concert halls, high value residential areas, etc.

The method is general, and can be used with other physics‐based models (puff, mass‐conservation, RANS, etc.). The investigation also shows that first‐principles CFD models have matured sufficiently to be run in a timely manner on PCs, opening the way to optimization based on detailed physics.

To measure the force applied to the tissue, the traditional endoscopic graspers might be equipped with a kind of tactile force sensor.

This paper presents the design, analysis, microfabrication and testing of a piezoelectric and capacitive endoscopic tactile sensor with four teeth. This tactile sensor, which is tooth‐like for safe grasping, comprises a Polyvinylidene Fluoride, PVDF film for high sensitivity and is silicon‐based for micromachinability. Being a hybrid sensor, employing both capacitive and piezoelectric techniques, it is possible to measure both the static and dynamic loads. Another feature, to be considered in its design, is the ability to detect pulse. The proposed sensor can be integrated with the tip of any current commercial endoscopic grasper without changing its original design. It is shown that using an array of sensor units, the position of the applied load can still be determined.

The static response of the sensor is obtained by applying a static force on the tooth and measuring the change in capacitance between the bottom electrode of the PVDF film and the electrode deposited on the surface of the etched cavity. The dynamic response of the device is determined by applying a sinusoidal force on the tooth of the sensor and measuring the output voltage from the PVDF film. The experimental results are compared with both analytical and finite element results. The sensor exhibits high sensitivity and linearity.

Capaciyive and piezoelectic are used to obtain both dynamic,pulse, and static loads. The sensor micromachined so, it can be used in various endoscopic applications.

Reviews the Institute of Physics conference “Sensors & their Applications XI”, held at City University, UK in September 2001. Highlights a selection of key papers covering gas sensor arrays for fire detection, fibre optic sensors for structural strain monitoring and detection of biofouling, fluorescent sensor for detecting algae and thick film sensors for smartcard biometrics. Reviews briefly other papers and draws conclusions.

The purpose of this paper is to develop a digital hydrostatic pressure sensor with the required metrological and operational characteristics. The developed sensor is designed to control hydrostatic pressure in wells during various geophysical works and studies.

To obtain the required metrological and operational characteristics of the sensor, a method was developed and applied to reduce the measurement error based on the calibration algorithm and the sensor model.

By using the developed calibration algorithm and the mathematical model of the sensor, it was possible to compensate for the measurement errors of the hydrostatic pressure sensor.

In the course of this research, tests of the developed sensor were carried and the maximum/minimum of measurement result errors was determined.

It has been noted that the spin-valve sensor exhibits lower sensitivity with higher temperature because of the variation of GMR ratio, which could lead to the measurement error in applications where working temperature changes largely over seasons or times. This paper aims to investigate and compensate the temperature effect of the spin-valve sensor.

A spin-valve sensor is fabricated based on microelectronic process, and its temperature relevant properties are investigated, in which the transfer curves are acquired within a temperature range of −50°C to 125°C with a Helmholtz coil and temperature chamber.

It is found that the sensitivity of spin-valve sensor decreases with temperature linearly, where the temperature coefficient is calculated at −0.25 %/°C. The relationship between sensitivity of spin-valve sensor and temperature is well-modeled.

The temperature drift model of the spin-valve sensor’s sensitivity is highly correlated with tested results, which could be used to compensate the temperature influence on the sensor output. A self-compensation sensor system is proposed and built based on the expression modeled for the temperature dependence of the sensor, which exhibits a great improvement on temperature stability.

To establish an accurate and sensitive method to characterize the moisture content of a particular environment.

This paper proposes a relatively simple humidity sensor design consisting of electrodes on a suitable substrate coated with a polyimide material. The changes in relative humidity are denoted by a corresponding change in the polyimide material's electrical resistance profile. The design proposed in this work can be microfabricated and integrated with electronic circuitry. This sensor can be fabricated on alumina or silicon substrates. The electrode material can be made up of nickel, gold or aluminum and the thickness of the electrodes ranges typically between 0.2 and 0.3 μm. The sensor consists of an active sensing layer on top of a set of electrodes. The design of the electrodes can be configured for both resistive and capacitive sensing.

The polyimide material's ohmic resistance changes significantly with humidity variations. Changes in resistance as large as 4‐6 orders of magnitude are attainable over the entire operational humidity range.

As the sensitivity varies non‐linearly with the humidity, the measurement has to be carried out over a very wide range in order to calibrate the sensor. The sensitivity and output range of the sensor can be easily controlled by changing the electrode spacing or geometry.

The control of humidity is important in many applications ranging from bio‐medical to space exploration.

A simple, easy to fabricate and measure, and low cost resistive‐type humidity sensor was developed. The realized sensor is suitable for integrating with microfabrication. Hence, multiple sensors of varying sensitivities and output ranges could be integrated on the same chip. Over the last few years, newly emerging micro‐electro‐mechanical‐systems technology and micro‐fabrication techniques have gained popularity and importance in the miniaturization of a variety of sensors and actuators.