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The optimization of the performance of optical modulators requires reasonably accurate predictive models for key figures of merit. The interleaved PN junction topology offers the maximum mode/junction overlap and enables the most efficient modulators for depletion-mode operation. Due to the structure of such devices, accurate modeling must be fully three dimensional (3D), representing a nontrivial computational problem. A rigorous 3D model for the modulation efficiency of a silicon-on-insulator interleaved-junction optical phase modulator with submicron dimensions is presented herein. The drift–diffusion and Poisson’s equations are solved on a 3D finite-element mesh, while Maxwell’s equations are solved using the finite-difference time-domain method on 3D Yee cells. The entire modeling process is presented in detail, and all the coefficients required by the model are presented. The model validation suggests

The fabrication process of a microparabolic reflector using isotropic xenon difluoride Xe F 2 etching technique is presented and analysed through this work for developing infrared antenna-coupled detectors. Although many parametric studies described the behaviour of this process in the literature, the non-linearity of the process and its dramatic dependency on the pattern definition result in great difficulties when adopting the process for developing a particular structure. The main focus of this work is, therefore, to present a detailed etching analysis as dictated in the proposed design providing the proper etching recipe according to the proposed structure design and its associated masking pattern. Deep insights into the process have been highlighted suggesting the necessity of the process assessment in terms of evaluating the three-dimensional etched volume rather than the etched depth. This will potentially solve the non-linearity behaviour and the pattern dependency problem. The optimum etching recipe yields approximately a total volume of 0.354 mm3 through the proper patterning mask. The resultant parabolic cavities have 75 and 13 μ m in their diameter and depth, respectively, as required for the proposed structure. The integration of a microparabolic reflector with such detectors will potentially enhance the specific detectivity of these detectors.

Silicon is a nonlinear material and optics based on silicon makes use of these nonlinearities to realize various functionalities required for on-chip communications. This article describes foundations of these nonlinearities in silicon at length. Particularly, self phase modulation and cross phase modulation in the context of integrated on-board and on-chip communications are presented. Important published results and principles of working of these nonlinearities are presented in considerable detail for non-expert readers.

The proliferation of embedded vision in today’s life has necessitated the development of System-on-Chips to perform utmost processing in a single chip rather than discrete components. Embedded vision is bounded by stringent requirements, namely real-time performance, limited energy, and adaptivity to cope with the standards evolution. In this article, an energy-aware self-adaptive System-on-Chip for real-time corner detection is realized on Zynq All Programmable System-on-Chip using Dynamic Partial Reconfiguration. A careful analysis of algorithm and efficient utilization of Zynq resources results in highly parallelized and pipelined architecture outperforms the state-of-the-art. A context-aware configuration scheduler application is developed to adhere to operating context and trades off between video resolution and energy consumption to sustain the uttermost operation time for battery-powered devices while delivering real-time performance. The experiments show that the self-adaptive method achieves 1.77 times longer operation time than a parametrized IP core, with negligible reconfiguration energy overhead. A marginal effect of partial reconfiguration overhead on performance is observed, for instance, only two video frames are dropped for HD1080p60 during the reconfiguration time.

This work is on the design of a fully integrated 0.13-µm CMOS multi-standard power constrained simultaneous noise and input matching low-noise amplifier (PCSNIM LNA). The multi-standard capability is obtained via the implementation of CMOS switches. The input and output matching are fully implemented on a chip, which is uncommon when compared to the existing multi-standard LNA topologies. The multi-standard LNA is operated at 0.9, 1.8, and 2.1 GHz frequencies. The design covered wireless standards of GSM900, DCS1800, and W-CDMA applications. The multi-standard LNA can obtain noise figure as low as 1.72 dB. The third-order intercept point, IIP3, is as high as −4 dBm, while IP1dB is −10 dBm. The power consumption of the design is only 7.4 mW. This resistorless multi-standard LNA design is not just able to operate at three different frequencies but also has a comparable performance with the rest. Its merits are contributed by high linearity and low power.

In this study, MWCNTs were used as a filler for epoxy thin film composites, where the thin film was fabricated using the spin coating method. We investigated the dielectric properties of the MWCNT-filled epoxy composite, with filler loading in the range from 0 to 1.5 vol%. Additionally, the effect of various type of MWCNT filler treatments using polyoxyethylene octyl phenyl ether (Triton X-100), sodium dodecyl sulfate (SDS) and 3-aminopropyltriethoxy silane (AMPTES) on the dielectric properties of epoxy thin film composites were investigated. The results showed that the increment of MWCNT loading increased the dielectric properties of the composite system. Meanwhile, chemically treated MWCNTs, especially MWCNT treated with SDS, showed good dielectric properties. Furthermore, morphological study showed an improvement in the dispersion of filler throughout the epoxy matrix in the treated composite system compared to the untreated system. TEM images also showed that treated MWCNT filler increased wall thickness of nanotube.

Since the 1940s, infrared (IR) detection and imaging at wavelengths in the two atmospheric windows of 3 to 5 and 8 to 14 μm has been extensively researched. Through several generations, these detectors have undergone considerable developments and have found use in various applications in different fields including military, space science, medicine and engineering. For the most recently proposed generation, these detectors are required to achieve high-speed detection with spectral and polarization selectivity while operating at room temperature. Antenna coupled IR detectors appear to be the most promising candidate to achieve these requirements and has received substantial attention from research in recent years. This paper sets out to present a review of the antenna coupled IR detector family, to explore the main concepts behind the detectors as well as outline their critical and challenging design considerations. In this context, the design of both elements, the antenna and the sensor, will be presented individually followed by the challenging techniques in the impedance matching between both elements. Some hands-on fabrication techniques will then be explored. Finally, a discussion on the coupled IR detector is presented with the aim of providing some useful insights into promising future work.

If we understand Moore's law and Amdahl's law then we can conclude that increasing number of CPU cores in a computing system is of no use just to attain high computation rate.We have designed a new arbitration technique which can use the CPU cores in a most optimised manner and can achieve high degree of task parallelism.The designed arbitration technique is superior to other existing arbitration technique in terms of CPU usage, bandwidth optimization and latency.The designed arbitration technique has been tested using high performance benchmark program to analyse its efficiency. Parallelization of task is considered to be a huge challenge for future extreme-scale computing system. Sophisticated parallel computing system necessitates solving the bus contention in a most efficient manner with high computation rate. The major challenge to deal with is the achievement of high CPU core usage through increased task parallelism by keeping moderate bus bandwidth allocation. In order to tackle the aforesaid problems, a novel arbitration technique, known as Parallel Adaptive Arbitration (PAA) has been proposed for the masters designed according to the traffic behaviour of the data flow. These masters are implemented using a synthetic benchmark program that measures sustainable memory bandwidth and the corresponding computational rate. The proposed arbitration technique is a strong case in favour of fair bandwidth optimization and high CPU utilization, as it consumes the processor cores up to 77% through high degree of task parallelization and also reduces bandwidth fluctuation. Some of the works published so far in this area are reviewed, classified according to their objectives and presented in an organised manner with a conclusion. Display Omitted

The ambient vibration-based micro electromechanical systems (MEMS) piezoelectric harvester has become an important subject in most research publications. Providing a green and virtually infinite alternative power source to traditional energy sources, this harvester will significantly expand the applications of wireless sensor networks and other technologies. Using piezoelectric materials to harvest the ambient vibrations that surround a system is one method that has seen a dramatic rise in the power-harvesting applications. The simplicity associated with piezoelectric micro-generators makes them very attractive for MEMS applications in which ambient vibrations are harvested and converted into electric energy. These micro generators can become an alternative to the battery-based solutions in the future, especially for remote systems. In this paper, we proposed a model and presented the simulation of a MEMS-based arrayed energy harvester under ambient vibration excitation using the Coventorware approach. This arrayed cantilever-based MEMS energy harvester that operates under ambient excitation of frequency band of 67 to 70 Hz, within a base acceleration of 0.2 to 1.3 g produces an output power of 6.8 μw and 0.4 volts at 20.1 k-ohms load.

This paper presents the development of a novel one-side-electrode-type fluidic-based capacitive pressure sensor. A pressure sensor using a one-side-electrode and an implementation of electrical double layer capacitance concept was proposed. Mechanical analysis of the membrane was carried out using the finite-element analysis in terms of deflection and Mises stress. A sensor with a circular membrane radius of 3.2 mm, membrane thickness of 0.8 mm, microchannel thickness of 0.5 mm, and microchannel width of 0.5 mm was fabricated using polydimethylsiloxane. The validation was made between the analytical and experimental results for fluid mechanisms inside the sensor. This showed that the displacement for all types of liquid, including methanol, ethanol, and silicon oil was linearly aligned. Methanol was chosen as an electrolyte due to its liquid properties, such as low surface tension and dielectric permittivity. From the experimental results, the operating frequency, response time, and sensitivity of the sensor were 1.2 kHz, 0.12 s, and 0.77 pF/kPa, respectively. The effects of vibration, temperature, and lifetime were also discussed in this paper.

The dome-shaped membrane was designed for the fluidic based flow sensor for the underwater sensing. It has the diameter of 5mm and thickness within 0.2mm. The simple fabrication process for the dome shaped structure was demonstrated using casting and molding processes. The effect of the fabrication process was investigated by measuring the thickness of the dome-shaped membrane for different sample. For the performance analysis, the actual shape which was the same with the fabricated shaped was simulated and compared with the ideal shape using finite element analysis for the same input flow rate. The membrane sensitivity of the actual shape decreased from 163.4 μm/ms-1 to 133.33 μm/ms-1 compared to the ideal shape based on the displacement of the membrane over input fluid velocity.

The structural integrity and aesthetic quality of concrete structure exposed to open-air area are vulnerable to sunlight, heat, moisture and rains, thus resulting in deposition of deteriogenic biofilms, especially on the floor surfaces. Apart from visual inspection, there is a need for scientific approach to assess and quantify the extent of bio-deposition. Our sample is a floor tile, fully exposed to outdoor environment. The study comprises of two folds: at first stage, we employ statistical image analysis technique to analyse and quantify various bio-depositories on the sample. In the next stage, we subject the sample image to undergo fusion process utilising discrete wavelet transform technique. Subsequently, we try to explore the change in the image quality and quantification aftermath image fusion.

The dome-shaped membrane is very important part of the micro/nano devices. The dome-shaped with the thickness of 150 μm and a radius of 3.2 mm was fabricated using the soft lithography process. The Polydimethylsiloxane (PDMS) was selected as a material because it deformable and suitable to implement as a membrane. Soft lithography is based on pattern transfer using a mold that is patterning the substrate material. In this paper, two techniques were suggested to fabricate the dome-shaped membrane which are reflow technique and stamping technique. The comparison was made for both techniques using a Scanning Electron Microscope (SEM) and it seems the stamping technique has an advantage where the uniform thickness of the dome-shaped membrane can be achieved. The discussion on the temperature effect of a stamping technique shows that the suitable temperature to harden the PDMS is in temperature room where the bubbles can be eliminated under this temperature.

This paper emphasis on state-of-the-art of the earlier until the current trend and demand, principles, design considerations, key performance and fabrication technology of RF MEMS switch devices developed over the past few years. RF MEMS switch performance and features such as actuation voltage, insertion loss, isolation and ease with cost of fabrication and applications are compared and discussed.

This paper presents the developments of microfluidic based multidirectional flow sensor inspired from artificial cupula. The proposed flow sensor consists of one-side-electrode and dome-shaped membrane that integrated with microchannel. When the flows impart the dome-shaped membrane, it will displace the liquid inside the microchannel and give changes in capacitance. Computational fluid dynamic analysis for dome structure using ANSYS Fluent software was discussed and compared with the hair structure. The Polydimethylsiloxane material was chosen for main material based on its potential properties to be implemented as a membrane. The micro-stamping technique to form a thin dome-shaped membrane was discussed where the uniform thickness was achieved by using this technique. The experiment was setup for water flow measurement, directionality test and moving object detection. For sensor characterization, the operating frequency and time response of the sensor obtained where respectively to 1.2 kHz and 0.35 s. The sensor was able to measure the flow rate as lower as 10 cm/s in water with the resolution of 5 cm/s. The experiment result also proved that the sensor was capable to detect the flow in multiple directions.

Kalman filtering is a well-established methodology used in various multi-sensor data fusion applications. In our experiment, we first obtain measurements from the accelerometer and gyroscope and fuse them using Kalman filter in an inertial measurement unit (IMU). We estimate Kalman filter output and estimation error. The affect of process noise and measurement noise on estimation error is tested. It is explored that the measurement noise has significant role to increase estimation error in the data fusion process.

Multisensor data fusion is an emerging technology applied in various engineering applications. It provides significant advantages over single-source data. The use of multiple types of sensors plays an important role in achieving reasonable accuracy and precision. A novel integrated heterogeneous multisensor data fusion approach in structural health monitoring is proposed. The study concerns to find a simple and affordable monitoring strategy for alkali-aggregate reaction (AAR), which is one of the root causes for structural deterioration in concrete.A standard method to accelerate AAR expansion is employed on four samples, which are prepared with different levels of alkali concentrations. Different sensor systems are used at surface and internal levels. Acoustic sensor system, electromechanical system, and optical systems are employed to obtain surface level damage. The internal level of damage is obtained by embedded sensors within the structure. Features extracted from heterogeneous sensors are fed to d...

The concern for the global environment ensues researchers from various disciplines to work in collaboration to tackle with the issues of sustainability and environmental conservation for well-being of the people. In this study, we have selected and focused on few basic environment-effecting factors such as temperature, humidity, carbon dioxide and oxygen concentration level and referred them as meteorological data. In this paper, we present the development of our own customized hardware setup, environmental monitoring device (EMD) to obtain the data. Utilizing the relationship among these basic parameters, represented in the form of formulas and equations, we tried to encode them using Matlab programming. Data visualization is achieved by plotting the graphs of basic parameters obtained from EMD as well for the derivatives using Matlab programs.

The world is facing the challenge of global warming and climate change issues. The objective of the study is to examine the meteorological data that constitute the environment and their balance has prevailing effect on the global warming. The meteorological data in our study refers to temperature, humidity, carbon dioxide and oxygen. We deploy our own customized hardware setup to obtain the data. Provided with this basic data, many significant parameters such enthalpy, dew point, humidity ratio, actual vapor pressure, saturated vapor pressure, partial vapor pressure and specific volume could be derived. We have presented simple functions in Matlab programming to derive these parameters. Our concluding Matlab program is as good as calculator, and the output is visualized by plotting function.

The rapid and widespread construction of structures calls for rigorous structural health monitoring (SHM) programs throughout the construction, operation and maintenance phases. Thus, much of a structure’s success or failure depends upon efficient SHM programs. The basic technology underlying the SHM program’s ability to detect cracks and failures can be incorporated with Wireless Sensor Network technology for more robust SHM. The agility of the WSN is, therefore, a prominent factor for a successful SHM program. Unpredictable external events, such as earthquakes or serious impacts are an inevitable fact of life. During such an event, the WSN should continue to be active and efficient enough to perform the assigned tasks without failure. The never miss an opportunity scheme (NMAOS) model, which is a prototype based on multi-agent technology, is proposed in this paper to provide agility to the Wireless Sensor Network.