Improving performance and energy efficiency of embedded processors via post-fabrication instruction set customization

Encapsulating critical computation subgraphs as application-specific instruction set extensions is an effective technique to enhance the performance and energy efficiency of embedded processors. However, the addition of custom functional units to the base processor is required to support the execution of custom instructions. Although automated tools have been developed to reduce the long design time needed to produce a new extensible processor for each application, short time-to-market, significant non-recurring engineering and design costs are issues. To address these concerns, we introduce an adaptive extensible processor in which custom instructions are generated and added after chip-fabrication. To support this feature, custom functional units (CFUs) are replaced by a reconfigurable functional unit (RFU). The proposed RFU is based on a matrix of functional units which is multi-cycle with the capability of conditional execution. To generate more effective custom instructions, they are extended over basic blocks and hence, multiple-exits custom instruction and intuition behind it are introduced. Conditional execution capability has been added to the RFU to support the multi-exit feature of custom instructions. Because the proposed RFU has limitations on hardware resources (i.e., connections and processing elements), an integrated mapping-temporal partitioning framework is proposed to guarantee that the generated custom instructions can be mapped on the RFU (mappable custom instructions). Experimental results show that multi-exit custom instructions enhance the performance and energy efficiency by an average of 32% and 3% compared to custom instructions limited to one basic block, respectively. A maximum speedup of 4.9, compared to a single-issue embedded processor, and an average speedup of 1.9 was achieved on MiBench benchmark suite. The maximum and average energy saving are 56% and 22%, respectively. These performance and energy efficiency are obtained at the cost of 30% area overhead.     

The Effect of Operating Conditions and Design Parameters on the Dynamic Behaviour of Agitated Pulp Stock Chests

Agitated pulp chests provide attenuation of high‐frequency disturbances in pulp properties ahead of many pulping and papermaking unit operations. The effect of process and design variables on the extent of non‐ideal flows was examined in a laboratory‐scale pulp chest. Dynamic tests were made using the frequency‐modulated random binary input of a brine solution with the pulp feed to determine the magnitude of non‐ideal flows (channeling, recirculation and stagnant zones). Results showed that the degree of upset attenuation is a function of impeller momentum flux and fibre mass concentration and that existing design criteria underpredict the power needed to produce a fully mixed system.     

Measurement of creep of optical fiber by a low coherent white light double interferometer system

The creep properties of optical fiber used in fiber optical sensors were studied in this paper. A low co- herent white light double interferometer system was designed and calibrated and the creep deforma- tions of optical fibers under static and cyclic loadings were measured with this device. The research results showed that polymer coated optical fibers crept at the beginning when they were under static or cyclic load. As the number of the cyclic loading or the static loading times increased the creep tend...     

An awareness-based meta-mechanism for e-commerce buyer coalitions

Many of the existing theories in e-Commerce and Buyer Coalition assume that all persons involved adopt self-interested strategies by seeking their own gains using environmental/market information. In reality however, such information may not be complete. Also, each person’s knowledge may differ from others. By adopting a collaborative perspective towards the buyer coalition process, this study introduces and validates an awareness-based mechanism for buyer coalitions that generates various outcomes corresponding to different levels of awareness of the collaborating roles within the process, where ‘awareness’ is defined in terms of the knowledge of the collaboration context of the coalition. The theoretical foundation of the study is an overlapping space of Game Theory (Hassan et al. Information Systems Frontiers 16(4):523–542, 2014), e-Commerce (Yang et al. Information Systems Frontiers 16(1):7–18, 2014), and Knowledge Management (Daneshgar & Wang Knowledge Based Systems 20(8):736–744, 2007). The research methodology is design science using simulation software for demonstration and proof of concept. Results indicate that higher levels of awareness of buyers do not necessarily increase total coalition discount but it enables individual buyers to make more opportunistic and calculated decisions to protect their personal interests.     

Robust Output Feedback Model Predictive Control: A Stochastic Approach

This paper addresses the robust explicit model predictive control scheme for linear systems with input and output constraint in the presence of disturbances and noise. Conditions for disturbance rejection are established by incorporating a full state/disturbance observer. The separation principle is applied to design an optimal observer in the unconstrained problem. Then, an efficient algorithm is developed to explicitly design observer gains by minimizing a quadratic performance criterion. It is shown that the solution includes a set of regions with piecewise affine functions of the state and reference vectors and a set of regions with optimal observers. In the proposed method, two sets of partitions associated with the control law and the observer gains are obtained. Therefore, the online computation includes finding the active regions of both observer and control law partitions in which the current state is located. The proposed technique is particularly attractive for a wide range of practical problems where the exact model of the actual system is not available.     

Global asymptotic stabilisation of rational dynamical systems based on solving BMI

In this paper, the global asymptotic stabiliser design of rational systems is studied in detail. To develop the idea, the state equations of the system are transformed to a new coordinate via polynomial transformation and the state feedback control law. This in turn is followed by the satisfaction of the linear growth condition (i.e. Lipschitz at zero). Based on a linear matrix inequality solution, the system in the new coordinate is globally asymptotically stabilised and then, leading to the global asymptotic stabilisation of the primary system. The polynomial transformation coefficients are derived by solving the bilinear matrix inequality problem. To confirm the capability of this method, three examples are highlighted.     

Allocating fixed resources and setting targets using a common-weights DEA approach

Data envelopment analysis (DEA) is a data-driven non-parametric approach for measuring the efficiency of a set of decision making units (DMUs) using multiple inputs to generate multiple outputs. Conventionally, DEA is used in ex post evaluation of actual performance, estimating an empirical best-practice frontier using minimal assumptions about the shape of the production space. However, DEA may also be used prospectively or normatively to allocate resources, costs and revenues in a given organization. Such approaches have theoretical foundations in economic theory and provide a consistent integration of the endowment-evaluation-incentive cycle in organizational management. The normative use, e.g. allocation of resources or target setting, in DEA can be based on different principles, ranging from maximization of the joint profit (score), combinations of individual scores or game-theoretical settings. In this paper, we propose an allocation mechanism that is based on a common dual weights approach. Compared to alternative approaches, our model can be interpreted as providing equal endogenous valuations of the inputs and outputs in the reference set. Given that a normative use implicitly assumes that there exists a centralized decision-maker in the organization evaluated, we claim that this approach assures a consistent and equitable internal allocation. Two numerical examples are presented to illustrate the applicability of the proposed method and to contrast it with earlier work.     

The synthesize of CuWO<Subscript>4</Subscript> nano particles by a new morphological control method,characterization of its photocatalytic activity

In various branch of health sciences the nanoparticles are widely used for removing of bacteria, pollutes and etc. However, remove of chemical pollutes like azo dyes, pesticides, cyanide, colors, bacteria, parasites, antibiotics drugs and etc under photocatalytic conditions are still interest. In this work, we synthesized a nonparticle of copper tungstate (CuWO₄) via a co-precipitation method. We also investigated the effect of amino acids such as cysteine, glycine, and valine on morphology and particle size of nanoparticles. The structure and morphology of nano particles were characterized by XRD, SEM, VSM, EDS and DRS spectroscopy methods. The methyl orange (MO) degradation model was used for assessment of photocatalytic properties of as-prepared nanoparticles under UV irradiation. The results have been shown that the CuWO₄ nanoparticles can be decomposed about 81% of MO after 80 min UV irradiation.     

A Simplified Analytical Model for a Current-Fed Force-Commutated Converter

The current-fed force-commutated converter (CFFCC) has recently received considerable attention in the electric drives area. It may also have future power conversion applications in electric utility systems. In order to facilitate the study of CFFCC systems a simplified converter model is developed and investigated in this paper. The simplified model is a quasi-steady-state representation based on an average value and fundamental frequency formulation of the circuit equations. Comparisons with exact circuit solutions and a detailed analog computer simulation demonstrate the validity of the simplified model under steady-state and transient conditions.