Detection principles and development of microfluidic sensors in the last decade

Microfluidic sensor converts a physical quantity to useful signal with the help of microfluidic platform. Microfluidic sensors have got a wide attention in the last decade because of the increased demands from the automation and control in microsystems. This review on microfluidic sensors focuses on various types of sensors which have been developed for the microfluidic systems or applications based on the research contributions in the last decade. We start with a detailed comparison on the research developments in the last decade on microfluidic sensors with the help of year and country wise statistical charts on published works in the area. The review continues with the basics of microfluidic sensors and the working principles of microfluidic sensors by classifying various microfluidic sensors based on the parameter to be sensed. This review concludes with the attempt to provide an idea on research gap in the area of microfluidic sensors.     

On Uniformity and Circuit Lower Bounds

We explore relationships between circuit complexity, the complexity of generating circuits, and algorithms for analyzing circuits. Our results can be divided into two parts:

1. Lower bounds against medium-uniform circuits. Informally, a circuit class is “medium uniform” if it can be generated by an algorithmic process that is somewhat complex (stronger than LOGTIME) but not infeasible. Using a new kind of indirect diagonalization argument, we prove several new unconditional lower bounds against medium-uniform circuit classes, including: ? For all k, P is not contained in P-uniform SIZE(n ^k ). That is, for all k, there is a language \({L_k \in {\textsf P}}\) that does not have O(n ^k )-size circuits constructible in polynomial time. This improves Kannan’s lower bound from 1982 that NP is not in P-uniform SIZE(n ^k ) for any fixed k. ? For all k, NP is not in \({{\textsf P}^{\textsf NP}_{||}-{\textsf {uniform SIZE}}(n^k)}\) .This also improves Kannan’s theorem, but in a different way: the uniformity condition on the circuits is stronger than that on the language itself. ? For all k, LOGSPACE does not have LOGSPACE-uniform branching programs of size n ^k .
2. Eliminating non-uniformity and (non-uniform) circuit lower bounds. We complement these results by showing how to convert any potential simulation of LOGTIME-uniform NC ¹ in ACC ⁰/poly or TC ⁰/poly into a medium-uniform simulation using small advice. This lemma can be used to simplify the proof that faster SAT algorithms imply NEXP circuit lower bounds and leads to the following new connection: ? Consider the following task: given a TC ⁰ circuit C of n ^O(1) size, output yes when C is unsatisfiable, and output no when C has at least 2 ^n-2 satisfying assignments. (Behavior on other inputs can be arbitrary.) Clearly, this problem can be solved efficiently using randomness. If this problem can be solved deterministically in 2 ^n-ω(log n) time, then \({{\textsf{NEXP}} \not \subset {\textsf{TC}}^0/{\rm poly}}\) .

Another application is to derandomize randomized TC ⁰ simulations of NC ¹ on almost all inputs: ?Suppose \({{\textsf{NC}}^1 \subseteq {\textsf{BPTC}}^0}\) . Then, for every ε > 0 and every language L in NC ¹, there is a LOGTIME?uniform TC ⁰ circuit family of polynomial size recognizing a language L′ such that L and L′ differ on at most \({2^{n^{\epsilon}}}\) inputs of length n, for all n.     

Adaptive binarization of severely degraded and non-uniformly illuminated documents

This paper presents a new adaptive binarization method for the degraded document images. Variable background, non-uniform illumination, and blur caused by humidity are the addressed degradations. The proposed method has four steps: contrast analysis, which calculates the local contrast threshold; contrast stretching, thresholding by computing global threshold; and noise removal to improve the quality of binarized image. Evaluation of proposed method has been done using optical character recognition, visual criteria, and established measures: execution time, F-measure, peak signal-to-noise ratio, negative rate metric, and information to noise difference. Our method is tested on the four types of datasets including Document Image Binarization Contest (DIBCO) series datasets (DIBCO 2009, H-DIBCO 2010, and DIBCO 2011), which include a variety of degraded document images. On the basis of evaluation measures, the results of proposed method are promising and achieved good performance after extensive testing with eight techniques referred in the literature.     

Dynamic mechanical behavior of copolymers containing carbon black

The storage and loss moduli of random copolymers of styrene and butyl methacrylate containing carbon black of varied surface area were determined by dynamic mechanical analysis at several temperatures about 100°C above the glass-transition temperature, T_g. At low frequencies, the pure polymers exhibit linear double log plots of moduli against frequency, with slopes of unity and approaching two for G″ and G′, respectively. With the addition of carbon black filler, both G′ and G″ become independent of frequency and temperature at low frequencies, consistent with yield behavior arid the formation of a carbon black network. The limiting dynamic complex modulus exceeds the yield stress from steady shear rheology, perhaps indicating the extent of the carbon black network, which was highest for low-molecular-weight copolymer and polystyrene. The filled random copolymers behaved Theologically like similarly filled polystyrenes of comparable molecular weights. Plasticization effects observed in the steady shear rheology of filled copolymers containing small concentrations of carbon black were not observed in dynamic mechanical analysis, although dynamic moduli converge at high frequency.     

Effect of aperture averaging and spatial diversity on capacity of optical wireless communication systems over lognormal channels

In this paper it is evaluated average channel capacity of an optical wireless communication system with aperture averaging and diversity reception over lognormal channels using a simple approximate closed form expression. The qualitative improvement in channel capacity is compared and investigated for various turbulence mitigation techniques: namely aperture averaging, diversity techniques such as maximal ratio combining and equal gain combining. Based on our study it is found that aperture averaging gives reasonably improved performance as compared to both types of diversity reception beyond certain turbulence strength. However, irrespective of turbulence strength, substantial improvement in capacity may be achieved with an array of direct detection receivers. Results obtained using the proposed expressions are in excellent agreement with those based on Monte Carlo simulations.     

Benchmarking Explicit State Parallel Model Checkers

This paper presents a set of benchmarks and metrics for performance reporting in explicit state parallel model checking algorithms. The benchmarks are selected for controllability, and the metrics are chosen to measure speedup and communication overhead. The benchmarks and metrics are used to compare two parallel model checking algorithms: partition and random walk. Implementations of the partition algorithm using synchronous and asynchronous communication are used. Metrics are reported for each benchmark and algorithm for up to 128 workstations using a network of dynamically loaded workstations. Empirical results show that load balancing becomes an issue for more than 32 workstations in the partition algorithm and that random walk is a reasonable, low overhead, approach for finding errors in large models. The synchronous implementation is consistently faster than the asynchronous. The benchmarks, metrics and results given here are intended to be a starting point for a larger discussion of performance reporting in parallel explicit state model checking.     

Cluster-based centralized data fusion for tracking maneuvering targets using interacting multiple model algorithm

The interacting multiple model (IMM) algorithm has proved to be useful in tracking maneuvering targets. Tracking accuracy can be further improved using data fusion. Tracking of multiple targets using multiple sensors and fusing them at a central site using centralized architecture involves communication of large volumes of measurements to a common site. This results in heavy processing requirement at the central site. Moreover, track updates have to be obtained in the fusion centre before the next measurement arrives. For solving this computational complexity, a cluster-based parallel processing solution is presented in this paper. In this scheme, measurements are sent to the data fusion centre where the measurements are partitioned and given to the slave processors in the cluster. The slave processors use the IMM algorithm to get accurate updates of the tracks. The master processor collects the updated tracks and performs data fusion using ‘weight decision approach’. The improvement in the computation time using clusters in the data fusion centre is presented in this paper     

Application of Electron Energy Loss Spectroscopy and Energy Filtering Transmission Electron Microscopy for Microchemical Studies in 2.25Cr-1Mo Steel

Electron enregy loss spectroscopy (EELS) and energy filtering transmission electron microscopy (EFTEM) investigation on 2.25Cr-lMo steel was carried out to understand the nature of evolution of secondary carbides. The filtered images obtained from two different ageing treatments indicate that the steel evolves to a more stable carbide namely M23C6 in comparison to M2C. Microchemical information was generated from EELS spectra. Suitable choice for estimating the microchemical state was discussed. To evaluate the behaviour of ageing an elemental ratio of Fe to Cr is employed.     

Modeling machine loading problem of FMSs and its solution methodology using a hybrid tabu search and simulated annealing-based heuristic approach

In this article, a machine loading problem of a flexible manufacturing system (FMS) is discussed having the bicriterion objectives of minimizing system unbalance and maximizing throughput in the presence of technological constraints such as available machining time and tool slots. A generic 0–1 integer programming formulation with the objective functions and constraints described above has been proposed. A hybrid algorithm based on tabu search and simulated annealing (SA) is employed to solve the problem. The main advantage of this approach is that a short-term memory provided by the tabu list can be used to avoid revisiting the solution while preserving the stochastic nature of the SA method. The proposed methodology has been tested on ten standard problems and the results obtained are compared with those from some of the existing heuristics.