Design considerations for plasmonic-excitation based optical detection of liquid and gas media in infrared

Surface plasmon resonance (SPR) sensor schemes based on silicon (Si) and chalcogenide glass are evaluated and compared for chemical as well as gas detection in a wide range of infrared (IR) wavelengths. The plasmonic characteristics in IR are critically dependent on the dispersive behavior of the coupling substrate material. The performance of sensor has been evaluated in terms of its intrinsic sensitivity (IS) that includes the FWHM and angular shift of SPR curve for a given change in refractive index of sensing medium. Both these materials are potential candidates for opening up new routes for detection in near- and mid-IR due to their strong dispersion capabilities as compared to normal silica-based glass. The IS of chalcogenide glass-based SPR sensor is found to be larger than Si-based one for a broad wavelength range of 700–2500 nm indicating that chalcogenide glass-based probe provides more sensitive as well as accurate sensing procedure than Si-based probe. Further, for both glasses, the single probe can be used for both aqueous as well as gaseous sensing. Furthermore, for both glasses, it is found that the values of IS are much larger for gaseous sensing in comparison to liquid sensing.     

Extended conceptualisation of perceived usefulness: empirical test in the context of information system use continuance

A technology or an information system provides value to its users. Technology Acceptance Model (TAM) successfully operationalised such value as the degree that a system can improve users' job performance. The proposed construct, perceived usefulness, has been proved to be the most important factor for technology adoption. However, many scholars have called for further theoretical development to enrich this critical construct but not much effort has been put forward (Bagozzi, R.P., 2007. The legacy of the technology acceptance model and a proposal for a paradigm shift. Journal of the Association for Information Systems, 8 (4), 244–254; Benbasat, I. and Barki, H., 2007. Quo vadis, TAM? Journal of the Association for Information Systems, 8 (4), 212–218). To respond to this call on deepening the conceptualisation of perceived usefulness, this article argues that system usefulness can be formulated beyond job performance improvement and explores several additional usefulness constructs based on well-established management concepts and human need theory. The information system (IS) use continuance model (Bhattacherjee, A., 2001. Understanding information systems continuance: An expectation-confirmation model. MIS Quarterly, 25 (3), 351–370) has been adopted as the theoretical foundation of this study because certain types of system usefulness can be recognised only in a use continuance stage. The empirical results of the research have validated most of the proposed constructs. Significant contributions to research and practice are identified and discussed.     

Field calibration and validation of remote-sensing surveys

The Optical Collection Suite (OCS) is a ground-truth sampling system designed to perform in situ measurements that help calibrate and validate optical remote-sensing and swath-sonar surveys for mapping and monitoring coastal ecosystems and ocean planning. The OCS system enables researchers to collect underwater imagery with real-time feedback, measure the spectral response, and quantify the water clarity with simple and relatively inexpensive instruments that can be hand-deployed from a small vessel. This article reviews the design and performance of the system, based on operational and logistical considerations, as well as the data requirements to support a number of coastal science and management projects. The OCS system has been operational since 2009 and has been used in several ground-truth missions that overlapped with airborne lidar bathymetry (ALB), hyperspectral imagery (HSI), and swath-sonar bathymetric surveys in the Gulf of Maine, southwest Alaska, and the US Virgin Islands (USVI). Research projects that have used the system include a comparison of backscatter intensity derived from acoustic (multibeam/interferometric sonars) versus active optical (ALB) sensors, ALB bottom detection, and seafloor characterization using HSI and ALB.     

Lumped model of a non-linear distributed system by finite element method

The finite element method has been used to find an approximate lumped parameter model of a non-linear distributed parameter system. A one dimensional non-linear dispersion system is considered. The space domain is divided into a finite set of k elements. Each element, has n nodes. Within each element the concentration is represented by C(x,t)^(e) = [N][C] ^T where [N] = [n₁(x),n₂(x), [tdot] n_n(x)] and [C] = [C₁(t),C₂(t), [tdot] C_n(t)]. By using Galerkin's criterion a set of (k × n ? n+ 1) first order differential equations are obtained for C_i(t). These equations are solved by an iterative method. The concepts are illustrated by an example taking five three-node elements in the space domain. The results are compared with those obtained by a finite difference method. It is shown that the finite element method can be used effectively in modelling of a distributed system by a lumped system.     

Performance evaluation of hybrid FFA-ANFIS and GA-ANFIS models to predict particle size distribution of a muck-pile after blasting

Accurately predicting the particle size distribution of a muck-pile after blasting is always an important subject for mining industry. Adaptive neuro-fuzzy inference system (ANFIS) has emerged as a synergic intelligent system. The main contribution of this paper is to optimize the premise and consequent parameters of ANFIS by firefly algorithm (FFA) and genetic algorithm (GA). To the best of our knowledge, no research has been published that assesses FFA and GA with ANFIS for fragmentation prediction and no research has tested the efficiency of these models to predict the fragmentation in different time scales as of yet. To show the effectiveness of the proposed ANFIS-FFA and ANFIS-GA models, their modelling accuracy has been compared with ANFIS, support vector regression (SVR) and artificial neural network (ANN). Intelligence predictions of fragmentation by ANFIS-FFA, ANFIS-GA, ANFIS, SVR and ANN are compared with observed values of fragmentation available in 88 blasting event of two quarry mines, Iran. According to the results, both ANFIS-FFA and ANFIS-GA prediction models performed satisfactorily; however, the lowest root mean square error (RMSE) and the highest correlation of determination (R²) values were obtained from ANFIS-GA model. The values of R² and RMSE obtained from ANFIS-GA, ANFIS-FFA, ANFIS, SVR and ANN models were equal to (0.989, 0.974), (0.981, 1.249), (0.956, 1.591), (0.924, 2.016) and (0.948, 2.554), respectively. Consequently, the proposed ANFIS-GA model has the potential to be used for predicting aims on other fields.

     

Eutectic bonding of Al-based high aspect ratio microscale structures

Metal-based microelectromechanical systems (MEMS) have important advantages over Si-based MEMS. To form any functional metal-based microdevice from metallic high-aspect-ratio microscale structures (HARMS), proper assembly and packaging are required. In this paper, we report successful eutectic bonding of Al-based HARMS using Al–Ge intermediate layers. A series of Al–Ge composite thin films were vapor deposited. Their composition and micro-/nano-scale structure were characterized. The morphology of bonded Al structures was examined, including the morphology of separated surfaces.     

An important property of non-minimum-phase multiple-input-multiple-output feedback systems

The non-minimum-phase (NMP( property is easily determined from the requirement that the plant input is bounded. In the single-input-single-output (SISO) system, a right-half-plane (RHP) plant zero at s = b constrains the system transfer function to have a zero at b. Also, the available feedback benefits are significantly restricted. The n × n multiple-input-multiple-output (MIMO) system is NMP if the plant determinant δhas any RHP zeros, say at plant transfer matrix and T = [t_ij is the closed-loop system transfer matrix. It has been thought that all n²t_ij (and the n₂ plant disturbance response function rfj), must suffer from the NMP liability in their feedback properties. It is shown that only one row of need so suffer, with a any fixed integer in [1, n].The remaining n(n — 1) elements can be completely free of the NMP liability. A mathematically rigorous synthesis technique previously developed for MP systems is shown to be well suited for precise numerical design for such NMP MIMO plants with significant uncertainties. In this technique, the MIMO design problem is converted into a number of equivalent SISO problems. An example involving disturbance attenuation in a highly uncertain 2×2 NMP plant is included.     

A hybrid medical decision making system based on principles component analysis, k-NN based weighted pre-processing and adaptive neuro-fuzzy inference system

Proper interpretation of the thyroid gland functional data is an important issue in diagnosis of thyroid disease. The primary role of the thyroid gland is to help regulation of the body's metabolism. Thyroid hormone produced by thyroid gland provides this. Production of too little thyroid hormone (hypo-thyroidism) or production of too much thyroid hormone (hyper-thyroidism) defines the types of thyroid disease. It is evident that usage of machine learning methods in disease diagnosis has been increasing gradually. In this study, diagnosis of thyroid disease, which is a very common and important disease, was conducted with such a machine learning system. In this study, we have detected on thyroid disease using principles component analysis (PCA), k-nearest neighbor (k-NN) based weighted pre-processing and adaptive neuro-fuzzy inference system (ANFIS). The proposed system has three stages. In the first stage, dimension of thyroid disease dataset that has 5 features is reduced to 2 features using principles component analysis. In the second stage, a new weighting scheme based on k-nearest neighbor (k-NN) method was utilized as a pre-processing step before the main classifier. Then, in the third stage, we have used adaptive neuro-fuzzy inference system to diagnosis of thyroid disease. We took the thyroid disease dataset used in our study from the UCI machine learning database. The obtained classification accuracy of our system was 100% and it was very promising with regard to the other classification applications in literature for this problem.     

A wavelet Petrov–Galerkin method for solving integro-differential equations

In this paper, we solve integro-differential equation by using the Alpert multiwavelets as basis functions. We also use the orthogonality of the basis of the trial and test spaces in the Petrov–Galerkin method. The computations are reduced because of orthogonality. Thus the final system that we get from discretizing the integro-differential equation has a very small dimension and enough accuracy. We compare the results with [M. Lakestani, M. Razzaghi, and M. Dehghan, Semiorthogonal spline wavelets approximation for Fredholm integro-differential equations, Math. Probl. Eng. 2006 (2006), pp. 1–12, Article ID 96184] and [A. Ayad, Spline approximation for first-order Fredholm integro-differential equation, Stud. Univ. Babes-Bolyai. Math., 41(3), (1996), pp. 1–8] which used a much larger dimension system and got less accurate results. In [Z. Chen and Y. Xu, The Petrov–Galerkin and iterated Petrov–Galerkin methods for second kind integral equations, SIAM J. Numer. Anal. 35(1) (1998), pp. 406–434], convergence of Petrov–Galerkin method has been discussed with some restrictions on degrees of chosen polynomial basis, but in this paper convergence is obtained for every degree.     

Solving inverse eigenvalue problems by a projected Newton method

The inverse eigenvalue problem for symmetric matrices (IEP) can be formulated as a system of two matrix equations. For solving the system a variation of Newton's method is used which has been proposed by Fusco and Zecca [Calcolo XXIII (1986), pp. 285–303] for the simultaneous computation of eigenvalues and eigenvectors of a given symmetric matrix. An iteration step of this method consists of a Newton step followed by an orthonormalization with the consequence that each iterate satisfies one of the given equations. The method is proved to convergence locally quadratically to regular solutions. The algorithm and some numerical examples are presented. In addition, it is shown that the so-called Method III proposed by Friedland, Nocedal, and Overton [SIAM J. Numer. Anal., 24 (1987), pp. 634–667] for solving IEP may be constructed similarly to the method presented here.     

Surface micromachined on-chip transformer fabricated on glass substrate

On-chip micro-transformer on high resistive glass substrate has been developed. The transformer consists of stacked spiral coil with square interwinding coil structure which is fabricated using surface micromachining technique. The performance of the micro-transformer is illustrated through low and high frequency measurements. The characteristics of glass based transformer are compared with conventional Si-based micro-transformer. The results show that the RF performance of the glass-based transformer is improved compared to that of silicon-based transformer. The process fabrication of the device is simple, highlighting a good prospect for the future three-dimensional RF-MEMS device application.     

Remote sensing of alpine treeline ecotone dynamics and phenology in Arunachal Pradesh Himalaya

Global warming is inducing the elevational alpine treeline ecotone (ATE) to migrate to higher elevations in the Himalaya. Prior research on ATE dynamics has been primarily based on field inventory and studied at the community level. The potential of using remote sensing and geographic information system for the delineation of the treeline ecotone has been explored. In this study, we used satellite-derived Normalized Difference Vegetation Index (NDVI) data from Landsat-1/2 Multispectral Scanner (MSS), Resourcesat-1/2 Linear Imaging Self Scanning Sensor (LISS-III), and National Oceanographic and Atmospheric Administration-Advanced Very High-Resolution Radiometer (NOAA-AVHRR) to investigate long-term ATE dynamics. Satellite remote sensing of treeline in Arunachal Pradesh Himalaya revealed an upward shift over the past four decades. The ATE has shifted c. 452 m ± 74 m upward in vertical dimension at a rate c. 113 m decade^?1. Furthermore, the land surface phenology along ATE and forest area has changed significantly over the past 33 years. The significant positive trend in length of the growing season (LOS; p < 0.05) and delay in the end of the growing season (EOS) was observed. The start of the growing season (SOS) had a negative tendency with non-significant linear trend. The treeline upward shift and significant lengthening of the growing season at ATE and forest area indicate changing climatic patterns and processes.     

Assessing the suitability of process and information technology in supporting tacit knowledge transfer

The transfer of tacit knowledge, one of the most important issues in the knowledge sharing context, needs a multi-dimensional perception in its process. Information technology's (IT) supporting role has already been addressed in the process of tacit knowledge transfer. However, IT has its own characteristics, and in turn, may have dissimilar support suitability. On the basis of the knowledge transfer process proposed by Garavelli et al. (Garavelli, C., Gorgoglione, M., Scozzi, B., 2002. Managing knowledge transfer by knowledge technologies. Technovation 22, 269–279), this study conducts an assessment using the analytic hierarchy process (AHP) technique to disclose (1) importance rank of transfer stages for the transfer efficacy and (2) the support suitability of IT types for the transfer stages. The assessment hierarchy has three levels, which are the goal, process and support levels. According to the 21 domain scholars and specialists' assessment analysis, the main results suggest that (1) for goal level, both the knowledge provider's and receiver's cognitive system are of more importance, (2) for process level, database techniques and information system applications obtain the higher importance in supporting the provider's cognitive system and externalisation, and (3) software tools and information system applications are more likely to support the receiver's cognitive system and interpretation. Discussion and implications are also addressed.     

Designing communicating transaction processes by supervisory control theory

A Communicating Transaction Process (CTP) is a computational model that serves as a high level specification language for reactive embedded system components and their interactions. It consists of a network of communicating processes coordinating their behaviors via common actions and the common actions are refined as a set of guarded Message Sequence Charts (MSCs). There has been little work devoted to developing CTP models systematically. This paper takes the first step towards bridging this gap. In our work, communicating processes of embedded components are modeled and controlled as Discrete-Event Systems (DES). The control logic among communicating components is derived by Supervisory Control Theory (SCT), so as to guarantee that the communicating processes meet all predefined constraints and possess other desirable system behavioral properties. The control logic is then translated into propositional formulas for guarded MSCs which then results in a CTP model with guaranteed behavioral properties.     

Crumbling walls: a class of practical and efficient quorum systems

Summary.  A quorum system is a collection of sets (quorums) every two of which intersect. Quorum systems have been used for many applications in the area of distributed systems, including mutual exclusion, data replication and dissemination of information. In this paper we introduce a general class of quorum systems called Crumbling Walls and study its properties. The elements (processors) of a wall are logically arranged in rows of varying widths. A quorum in a wall is the union of one full row and a representative from every row below the full row. This class considerably generalizes a number of known quorum system constructions. The best crumbling wall is the CWlog quorum system. It has small quorums, of size O(lg n), and structural simplicity. The CWlog has optimal availability and optimal load among systems with such small quorum size. It manifests its high quality for all universe sizes, so it is a good choice not only for systems with thousands or millions of processors but also for systems with as few as 3 or 5 processors. Moreover, our analysis shows that the availability will increase and the load will decrease at the optimal rates as the system increases in size. Received: August 1995 / Accepted: August 1996     

Optimal control system design of a nuclear reactor by generalized spectral factorization

Optimal feedback control system design of a nuclear power plant has usually been conducted in the time domain by solving the Riccati equation. In this paper, the problem will be treated in the s-domain by means of the MacFarlane extension criterion (MEC). The algorithm is based on generalized spectral factorization (GSF), and the MEC is resolved by the Newton-Raphson method featuring rapid convergence and high precision. Whether the plant is stable or unstable, the initial matrix can be chosen effectively and a general computer code for finding the optimal feedback gain matrix of the multi-input system is presented. The control system design of a boiling water reactor (BWR) shows that the results obtained from the proposed method are consistent with those from solving the conventional Riccati equation. A satisfactory closed-loop multivariable system with a prescribed degree of stability can also be designed in the s-domain. The methodology of this paper can also be generalized to treat similar control system design problems in other engineering fields.     

Development of a collaborative CAD/CAM system

This paper presents the development of a collaborative CAD/CAM system (COCADCAM). COCADCAM extends an existing single-location CAD/CAM system to a multi-location CAD/CAM application so that two geographically dispersed CAD/CAM users can work together on a three-dimensional CAD-geometry coediting and CAD-related tasks collaboratively and dynamically. COCADCAM dynamically supports CAD data communication that are not available in traditional single-location CAD/CAM. The dynamic data communication is achieved through the development of networking algorithms and CAD/CAM functions in this paper. The networking algorithms based on UNIX Interprocess Communication (IPC), the Network File System (NFS), and a connection-oriented client and server model under the Transmission Control Protocol/Internet Protocol (TCP/IP) suite. The CAD/CAM functions included surface modelling, simulation of a milling toolpath, and post-processing of an NC program following collaborative CAD-geometry coediting, which are directly or indirectly supported by the Application Programming Interface (API) of the CAD/CAM software. The networking algorithms and CAD/CAM functions together can facilitate an environment for CAD-geometry coediting and related tasks such as design, analysis and manufacture. COCADCAM has been successfully implemented through local area network (LAN) and the Internet; a remote machining cell is also linked so that the generated NC program based on a coedited free-form surface can be used for the physical machining operation. The algorithm proposed by COCADCAM can be referenced for the extension of other single-location CAD/CAM systems to multi-location applications.