A flexible liquid‐metal alloy bandpass filter

This article presents a liquid‐metal Galinstan alloy bandpass filter (BPF) with good flexibility, which is fabricated by an improved soft lithography process. The Galinstan alloy is enclosed in the microfluidic channels of elastomeric polydimethylsiloxane (PDMS) substrates. Together with the PDMS substrates, the Galinstan alloy based filter features bending, twisting and stretching capabilities along any direction. A second‐order open‐loop resonator filter with 2.4 GHz center frequency and 15% fractional bandwidth was designed and fabricated to verify this concept. Experiments show that frequency response of the filter is almost unaffected in the case of bending of the different radii or twisting, while its center frequency slightly shifts down in the stretching condition. The proposed filter can be used for the flexible and conformal electronics.     

Enhancing smart shop floor management with ubiquitous augmented reality

This paper describes a framework for implementing Smart manufacturing Shop floor systems based on the Ubiquitous Augmented Reality technology (SSUAR). The proposed system makes use of data sharing between shop floor resources and a sensor network in order to optimise the production schedules for carrying out projects. The optimisation is performed in real-time and the production scheduling responds to new projects as well as the changing status of resources, such as machines and workers. Ubiquitous augmented reality interface has been developed and utilised as a user interface for the shop floor workers to receive information, instructions and guidance from the experts and manufacturing systems, and to update the systems on task parameters, such as estimated completion times, progress and machine status. A review of related work, methodology and implementation of the proposed system, and a case study are presented in this paper. Using this architecture, real-time scheduling of tasks in the smart shop floor can be achieved. The case study demonstrated the ability of SSUAR to integrate task scheduling with two-way communication between the system and the users.     

Developing flow of Newtonian fluids over superhydrophobic transverse grooves in circular tube

Journal of Mechanical Science and Technology - In this paper, the effects of dimensionless gas area fraction (δ) and normalized groove-rib periodic spacing (Λ) on developing flow for...     

Influence of interface traps and surface mobility degradation on scanning capacitance microscopy measurement

Although scanning capacitance microscopy (SCM) is based on the MOS capacitance theory, the measurement frequency is 915-MHz instead of 100 kHz to 1 MHz in conventional MOS capacitance-voltage measurement. At this high frequency, the reactance of the probe tip-to-substrate capacitance can become smaller than the series resistance of the substrate inversion layer, particularly when the surface mobility is degraded. The response of the oxide-silicon interface traps to SCM measurement is also different due to the use of a 10-kHz signal to determine dC/dV. In this paper, we compare experimental and simulation data to demonstrate the effects of interface traps and surface mobility degradation on SCM measurement. Implications on the treatment of SCM data for accurate dopant profile extraction are also presented.     

Memory-free low-cost designs of advanced encryption standard using common subexpression elimination for subfunctions in transformations

In this paper, we propose area-efficient Advanced Encryption Standard (AES) processor designs by applying a new common-subexpression-elimination (CSE) algorithm to the subfunctions that realize the various transformations in AES encryption and decryption. The first category of subfunctions is derived by combining adjacent transformations in each AES round into a new transformation. The other category of subfunctions is from the integrated transformations in the AES encryption and decryption process with shared common operations. Then the proposed bit-level CSE algorithm reduces further the area cost of realizing the subfunctions by extracting the common factors in the bit-level expressions of these subfunctions. The separate area-reduction effects of combinations, integrations, and CSE optimization mentioned above are analyzed in order to examine the efficiency of each technique. Cell-based implementation results show that the proposed AES designs can achieve am area reduction rate of about 20% compared with Synopsys optimization results.     

IrSi Schottky-barrier infrared detectors with 10-μm cutoffwavelength

IrSi Schottky-barrier detectors were fabricated with ~40-Å-thick silicide electrodes formed on p-type Si substrates by in situ processing in a conventional electron-beam evaporator. High-resolution transmission electron microscopy shows that these detectors have clean, abrupt silicide-Si interfaces. For operation at a reverse-bias voltage of 2 V, the cutoff wavelength is ~10 μm, as determined by quantum efficiency measurements     

Finite element solution of a boundary integral equation for mode I embedded three-dimensional fractures

The singular integral equation governing the opening of a mode I embedded three-dimensional fracture in an infinite solid was solved by applying the finite element method. The strategy is to formulate the equation into weak form, and to transfer the differentiation from the singular term, 1/r, in the equation to the test function. A numerical algorithm was thus developed. The numerical solutions for circular and elliptical fractures under the action of polynomial pressure distributions were compared with the analytical solutions by Green and Sneddon,¹² Irwin,¹³ Shah and Kobayashi¹⁴ and Nishioka and Atluri.¹⁶ The results have demonstrated that the numerical method reported is accurate and efficient.     

On a class of suboptimal controls for infinite-dimensional bilinear systems

The suboptimal control of a bilinear system is considered with respect to a quadratic cost criterion. The feedback control is in the space of formal power series on a Hilbert space.     

Efficient estimation of continuous phase modulation with unknowncarrier phase

An efficient algorithm is presented for the estimation of continuous phase modulation (CPM) sequences over the Gaussian channel with unknown carrier phase. It operates on the excess phase trellis like the Viterbi algorithm, except that it is not a maximum-likelihood (ML) estimator. Its decision metric for survivor selection at each node is chosen so that it achieves the node error event probability of coherent ML estimation in the limit as the carrier phase remains constant over a long interval, so that the observation interval for forming the metric can be made large. It is shown for the case of minimum-shift-keying (MSK) that the bit-error probability (BEP) of perfectly coherent ML estimation is attained