A Current-Mode Logic for Low-Voltage, High-Speed Mixed-Mode VLSI Circuits

A wired-AND current-mode logic (WCML) circuit is designed for high performance mixed analog and digital system designs on a common silicon substrate, using standard CMOS process. Current is used for digital information carrier in order to be able to reduce supply voltage, power consumption, digital switching noise and to increase operating frequency. The WCML circuit uses current-steering technique. It is composed of a simple current mirror with a current injector. Wired-AND connections cause the logic circuit to operate as a NAND logic gate which provides to implement any boolean function. High-speed is achieved by varying the injection current level even at low-voltage supply (<1.5 V) with low-power consumption.     

Fracture path prediction of diamond segment in a marble cutting disc

This study investigates the fracture path behaviour of diamond segments that have been brazed on a marble cutting disc. The segments are braze‐joined using the oxy‐gas welding technique. The micro‐structure of the brazing zone and the disc were investigated using standard metallographic techniques and scanning electron microscope (SEM). Additionally, we used numerical modelling to study crack growth at the welding zone. Two dimensional linear elastic fracture mechanics principles were used to analyze propagation behaviour of the crack. Stress intensity factors were calculated using displacement correlation method. It was deduced from the SEM analysis of the fractured segment surface that the fracture occurred in the diamond segment due to stress concentration near the sharp corners of the diamond particles that are embedded into the matrix. The existence of such sharp artefacts within the matrix leads to the formation of cracks.     

A modification to temperature-composition pdf method and its application to the simulation of a transitional bluff-body flame

This study proposes a modification to the temperature-composition pdf approach. Instead of equilibrium mass fractions, values of a time-varying homogeneous reacting system are used in the simplification of the joint-pdf into the multiplication of marginal pdfs. The approach takes into consideration of local time scales which are defined on the basis of energy balance with two competing transport mechanisms on the flame surface; these are the turbulent convective transport perpendicular to the flame and the diffusive flux tangent to the flame. The flame surface and flux directions are described by the gradient of mixture fraction and unitary tangent vector which is defined by the scalars. The new approach in combination with the ILDM chemistry is used in the numerical simulation of a transitional bluff-body flame. Despite the use of simple pdf models, the present formulation appears to be very successful in predicting the flow field, the temperature and progress variables and, except for the mixture fraction, show relatively good agreement with the experimental data. The profiles of the time scale show that the flame develops in relation to the distributions of progress variables in the $\mathit{T}?\xi$ parameter space. Hence, the approach offers the possibility of local flame extinction. It also gives a rational explanation of the bimodal distributions of the reactive scalar pdfs in a turbulent flow with fluctuations of a wide spectrum of scales.     

The analysis of architectural languages for the needs of practitioners

Architectural languages (ALs) have attracted much attention as the modeling notations for specifying and reasoning about important design decisions. In this study, 124 different existing ALs have been analyzed for a set of requirements that are crucial for practitioners. These requirements are concerned with language definition, language features, and tool support. Some of the important findings obtained from the analysis are as follows: (1) performance is the top popular nonfunctional requirement supported by ALs; (2) no ALs offer both textual and visual notation sets, one of which could be used independently; (3) process algebras are the top preferred formal method by formal ALs; (4) the physical, deployment, and operational viewpoints are rarely supported by ALs; (5) the top preferred extension mechanism of the extensible ALs is XML for syntax extension; (6) Java is the top preferred programming language in generating software code; (7) the exhaustive model checking is the top preferred automated analysis method; (8) the logic‐based formal techniques are so popular in specifying system requirements; (9) among the analysis properties considered, consistency is the top supported property for the automated checking; and (10) most ALs do not provide any discussion platform (eg, forums). Hence, these findings can be used by the new AL developers in addressing the needs of practitioners and bridging the gaps in the field. Practitioners can also use the findings to find out about the existing ALs and compare them to choose the one(s) that suits their needs best.     

Improved transmission line model for high-frequency modelling of through silicon vias

Accurate and reliable models can support Through Silicon Via (TSV) testing methods and improve the quality of 3D ICs. A model for expressing resistance and inductance of TSVs at frequencies up to 50 GHz is proposed. It is based on the two-parallel transmission cylindrical wires model, known also as the Transmission Line Model and improved through the fitting to ANSYS Q3D simulation results. The proximity effect between neighbouring TSVs that alters the paths through which current flows is empowered at high frequencies. The consideration of the dependence of the proximity effect on frequency for calculating TSV resistance and inductance is the main contribution of this work. Additionally, the modelling of resistance is extended to accurately correspond to a TSV in an array. The proposed models are in good agreement with the simulator results with an average error below 2% and 5.4% for the resistance and the inductance, respectively. The maximum error is 3% and 9.1%, respectively. In the case of the resistance of a TSV in an array, the maximum error is 4.7%. As long as the coefficients of the proposed equations have been extracted, the time for resistance and inductance calculation based on the presented models is negligible, compared to the time-consuming EM simulation.     

Random subspace method with class separability weighting

The random subspace method (RSM) is one of the ensemble learning algorithms widely used in pattern classification applications. RSM has the advantages of small error rate and improved noise insensitivity due to ensemble construction of the base‐learners. However, randomness may cause a reduction of the final ensemble decision performance because of contributions of classifiers trained by subsets with low class separability. In this study, we present a new and improved version of the RSM by introducing a weighting factor into the combination phase. One of the class separability criteria, J3, is used as a weighting factor to improve the classification performance and eliminate the drawbacks of the standard RSM algorithm. The randomly selected subsets are quantified by computing their J3 measure to determine voting weights in the model combination phase, assigning lower voting weight to classifiers trained by subsets with poor class separability. Two models are presented including J3‐weighted RSM and optimized J3 weighted RSM. In J3 weighted RSM, computed weighting values are directly multiplied by class assignment posteriors, whereas in optimized J3 weighted RSM, computed weighting values are optimized by a pattern search algorithm before multiplying by posteriors. Both models are shown to provide better error rates at lower subset dimensionality.     

Multi-Criteria Analysis of Water Allocation Scenarios in a Water Scarce Basin

In 2015, a “Post-2015 Development Agenda” is defined for future global developments in water management. The proposed goal is referred to as SDG’s or Sustainable Development Goals, which will balance the economic, social and environmental dimensions of sustainable development with a strong linkage between environment and socio-economic goals. One of the major concepts of SDG’s is water security, which is the basic element of the Global Goal on Water, now defined as: “Securing Sustainable Water for All”. The proposal for a Global Goal for Water is associated with targets and indicators to help countries reach the goal by 2030. Among the five main targets specified, two major ones emphasize “water allocation” as an important support of water security, particularly in conditions of water security. This paper focuses on this latter issue in the case of water scarce Gediz Basin along the Aegean coast of Turkey, where irrigation is the major water consuming activity. In addition to allocation of water among other water use sectors and irrigation, it is important in the basin how irrigation water is allocated to various crops, as previous droughts struck crop yields the most. Thus, 16 alternative allocation scenarios are developed to assess the crop yield produced by each scenario. These alternatives are represented by social, economic and environmental indicators as criteria for selection the most favorable alternative. The selection is realized by Multi Criteria Analysis (MCA) methodology, using the Reference Point Approach (RPA). In terms of methodology, presented paper shows that RPA is a powerful tool to guide engineers and decision makers to rationally select among several possible alternatives in water allocation.     

Virtual factory approach for implementation of holonic control in industrial applications: A case study in die-casting industry

Design and implementation of holonic manufacturing control systems for the real industrial applications require risky, careful decisions to ensure that the manufacturing system will successfully satisfy the demands of an ever-changing market. This paper suggests a virtual reality (VR)-based methodology for enhancing the design and implementation process of holonic control systems in manufacturing practice. The major focus has been given to the implementation of holonic control into the small to medium size manufacturing enterprises (SMEs).     

Evaluation of bagging ensemble method with time-domain feature extraction for diagnosing of arrhythmia beats

We explore the effect of using bagged decision tree (BDT) as an ensemble learning method with proposed time-domain feature extraction methods on electrocardiogram (ECG) arrhythmia beat classification comparing with single decision tree (DT) classifier. RR interval is the main property which defines irregular heart rhythm, and its ratio to the previous value and difference from mean value are used as morphological feature extraction methods. Form factor, its ratio to the previous value and difference from mean value are used to express ECG waveform complexity. In addition, skewness and second-order linear predictive coding coefficients are added to the feature vector of 56,569 ECG heart beats obtained from MIT–BIH arrhythmia database as time-domain feature extraction methods. The quarter of ECG heart beat samples are used as test data for DT and BDT. The performance measures of these classifiers are evaluated using the metrics such as accuracy, sensitivity, specificity and Kappa coefficient for both classifiers, and the performance of BDT classifier is examined for number of base learners up to 75. The BDT results in more predictive performance than DT according to the performance measures. BDT with 69 base learners has 99.51 % of accuracy, 97.50 % of sensitivity, 99.80 % of specificity and 0.989 of Kappa coefficient while DT gives 98.78, 96.05, 99.57 and 0.975 %, respectively. These metrics show that the suggested BDT increases the numbers of successfully identified arrhythmia beats. Moreover, BDT with at least three base learners has higher distinguishing capability than DT.     

Synthesis of β-myrcene-based macroporous nanocomposite foams: Altering the morphological and mechanical properties by using organo-modified nanoclay

Organo-modified nanoclay incorporated high internal phase emulsions (HIPEs) were successfully used for the preparation of macroporous nanocomposite foams. Due to the aim of obtaining mechanically improved foams, HIPEs were prepared by using a monomer mixture composed of β-myrcene and ethylene glycol dimethacrylate. Accordingly, two groups of macroporous nanocomposite foams were synthesized depending on the nanoclay type. The morphological analysis demonstrated that the pore openness of the resulting nanocomposites were significantly improved due to the decrease in the average cavity size and increase in the interconnected pore size. In terms of mechanical properties, it was found that filling 1 wt% of nanoclay which is surface modified by hydrogenated tallow lead to a 33% of increment in the compression modulus, as compared to the neat foam. However, loading 5 wt% of nanoclay having octadecylamine and aminopropyltriethoxysilane surface groups caused only 11% of increment in the compression modulus, as compared to the neat foam.