Interconnection Model Research Articles

SIMULATION OF THE GRAIN DRYING PROCESS IN BUNKER DRYERS USING HELIOCOLLECTORS

Drying is the main method of preparing agricultural materials for storage. Today, there are a variety of drying plants in the world that use solar radiation energy to heat a drying agent or drying material. But most designs of solar dryers are adapted to work in stationary conditions, special rooms. Reducing energy consumption for drying grain materials is an urgent problem, which is solved in two main ways - technical modernization of existing drying equipment and development of new energy-saving methods and modes of drying agricultural materials and their implementation on existing and upgraded facilities. Both the first and second way of solving the problem of energy saving is based on a mathematical description of the processes of heat and mass transfer.The mathematical model of thermal modes of the drying unit is a set of interconnected models of its individual elements with external kinematic parameters (atmospheric air temperature, intensity of solar radiation, etc.). The model of a single element of the system is a system of differential equations in differential form, limit and initial conditions, which reflect the basic physical dependences of the studied processes.The aim of the research was to formulate a mathematical model based on the theory of heat and mass transfer to determine the dynamics of the development of interconnected nonstationary fields of temperature and moisture content of the material and the drying agent - air.Numerical implementation of the proposed mathematical models in a standard mathematical package allows to analyze the performance of equipment, in particular film solar collectors, for convective drying of dispersed agricultural materials in the layer depending on the parameters of the feed material, solar radiation intensity or (and) heat generator capacity atmospheric air.

Effect of the Electromagnetic Susceptibility of Metal Interconnects: A Simulation Study

Large induced electromotive force will be generated on the metal interconnections under the action of strong electromagnetic pulse, thereby generating a large induced current. For copper metal interconnects commonly used in modern integrated circuits, large currents will cause electromigration, resulting in short or open in the circuit, causing damage to devices and circuits. In order to study the damage of metal interconnects under the action of electromagnetic pulse, in this paper, the induced electromotive force of metal interconnects under the action of HPM is derived through theoretical analysis, then analyzing the influence of different electromagnetic pulse parameters on the induced electromotive force of interconnects by the use of electromagnetic simulation software COMSOL. Using the established metal interconnect model, the electromagnetic sensitivity effect of metal interconnect is studied by analyzing the electric field distribution, current density and temperature distribution on the interconnect under electromagnetic pulse.

What's New with IBIS and Upcoming Opportunities for SI and PI Engineers to Learn More

IBIS (I/O Buffer Information Specification) is a standard that enables silicon vendors, simulation software vendors, and end customers to exchange modeling data and electronic behavioral specifications of integrated circuit input/output analog characteristics. The intention of this standard is to specify a consistent format that can be parsed by software, allowing simulation vendors to derive models compatible with their own products. The reach of IBIS extends beyond I/O circuits to include standard formats for interconnect modeling of on-die, package, and board-level routing.

A Closed-form Delay Estimation Model for Current-mode High Speed VLSI Interconnects

Closed-form model for the delay estimation of current-mode Resistance Inductance Capacitance (RLC) interconnects in VLSI circuits is presented. The existing Eudes model for interconnect transfer function approximation is extended and applied for further accurate estimation of delay. With the equivalent lossy interconnect transfer function, finite ramp responses are obtained and line delay is estimated for various line lengths, per unit length inductances and load capacitances. The estimated delay values of extended Eudes model are compared with the existing Eudes model against HSPICE W-element model. The obtained delay values of Eudes model worst-case error percentage is 14.3% whereas our extended Eudes model is in good agreement with those of HSPICE results within 2% for the line lengths of 1mm to 10mm.

Standardization of the Distributed Ledger Technology cybersecurity stack for power and energy applications

The global trend toward integration of distributed energy resources is opening doors to advanced, complex, and distributed marketplaces. Such advanced ecosystems, where utility-owned and non utility-owned assets can contribute toward grid operations, generally require distributed communication and grid architectures. We posit the potential of using Distributed Ledger Technologies (DLTs) in supporting such applications, although their full potential has not been fully used, for example in designing long-term scalable solutions in operational technology applications. This is partly due to the lack of standardization across and between different DLTs, as well as other supporting building blocks (e.g., communication protocols). This paper attempts to address this gap by proposing a DLT cybersecurity stack specifically designed for researchers, DLT technology developers, and end users (such as utilities). The DLT cybersecurity stack has been notionally mapped to related cybersecurity components, namely the Open Systems Interconnection (OSI) model, the Transmission Control Protocol/Internet Protocol (TCP/IP) suite, and existing Smart Grid architecture frameworks. In addition, the paper discusses several cybersecurity implications, and demonstrates the potential uses of the DLT cybersecurity stack through multiple power and energy use cases. It is important to note that the stack can be also applied to the DLT use cases that are outside the power and energy domain. This work was performed by the Cybersecurity Task Force under the IEEE P2418.5 Blockchain for Energy Standard working group that part of the IEEE Power and Energy Society’s Smart Buildings, Loads, and Customer Systems (SBLC) technical committee.

Decentralised PI controller design based on dynamic interaction decoupling in the closed-loop behaviour of a flotation process

An enhanced method for design of decenralised proportional integral (PI) controllers to control various variables of flotation columns is proposed. These columns are multivariable processes characterised by multiple interacting manipulated and controlled variables. The control of more than one variable is not an easy problem to solve as a change in a specific manipulated variable affects more than one controlled variable. Paper proposes an improved method for design of decentralized PI controllers through the introduction of decoupling of the interconnected model of the process. Decoupling the system model has proven to be an effective strategy to reduce the influence of the interactions in the closed-loop control and consistently to keep the system stable. The mathematical derivations and the algorithm of the design procedure are described in detail. The behaviour and performance of the closed-loop systems without and with the application of the decoupling method was investigated and compared through simulations in MATLAB/Simulink. The results show that the decouplers - based closed-loop system has better performance than the closed-loop system without decouplers. The highest improvement (2 to 50 times) is in the steady-state error and 1.2 to 7 times in the settling and rising time. Controllers can easily be implemented.

GPS Week Number Rollover Timestamp Complement.

Global Positioning System (GPS) is a global navigation satellite system and the most common satellite system used in navigation and tracking devices. The phenomenon of week number rollover happened recently—a year ago—due to a design limitation in the week number variable that counting weeks which causes vast losses. As many fleet management systems depend on GPS raw data, such systems stopped working due to inaccurate data provided by GPS receivers. In this paper, we propose a technical and mathematical analysis for the GPS week number rollover phenomenon and suggest a solution to avoid the resulting damage to other subsystems that depend on the GPS device’s raw data. In addition, this paper seeks to provide precautionary measures to deal with the problem proactively. The Open Systems Interconnection model (OSI) and transport layer level solution that has been suggested depends on a TCP packet reforming tool that re-formats the value of the week number according to a mathematical model based on a timestamp complement. At the level of the database, a solution is also suggested which uses triggers. A hardware-level solution is suggested by applying a timestamp complement over the GPS internal controller. Complete testing is applied for all suggested solutions using actual data provided by Traklink—a leading company in navigation and fleet management solutions. After testing, it is evident that the transport layer level solution was the most effective in terms of speed, efficiency, accuracy, cost, and complexity. Applying a transport layer level complement mathematical model can fix the consequences of GPS week number rollover and provide stability to all subsystems that used GPS data from infected devices.

Study on circuit modeling of stretchable serpentine interconnects

AbstractA 2π equivalent circuit model of serpentine interconnect fabricated by transfer printing technology is proposed considering the stretching deformation of the interconnect. The S parameters are measured, and the RLC parameters are extracted by quasi‐linearization method at various elongations. A V‐shaped model is built to illustrate the change of Lc increasing by 9.7% due to elongation. A branch of Rf and Lf in parallel is utilized to model the impact of high‐frequency effects, Rf decreases by 56.7%, and Lf remains ~0.65 nH. A branch of Rsub and Csub characterizing the electrical loss of substrate increases due to substrate thinning with elongation, Rsub increases by 87.1%, and Csub remains 100 fF. S parameters are measured and compared to verify the accuracy of the model and study the effect of elongation on the transmission characteristics; it is found that the amplitude at S11 minimum decreases from −7 to −10 dB during stretching, and the corresponding frequency points also decrease.

Stability- and Crosstalk-Based Performance of Multi- and Double-walled Mixed CNT Bundles as Interconnect for Next-Generation Technology Nodes

The temperature-dependent modeling technique (in the temperature range of 200–500[Formula: see text]K) for a mixed class of carbon nanotube (CNT) bundle interconnects is proposed. The equivalent single conductor (ESC) transmission line models of multi-walled carbon nanotube (MWCNT) and double-walled carbon nanotube (DWCNT) are combined to develop multiple single conductor (MSC) model of mixed CNT interconnects. Various possible arrangements of densely packed MWCNT and DWCNT bundles (MDCB) are considered to form different types of mixed CNT bundle structures (MDCB-1, MDCB-2, MDCB-3 and MDCB-4). The integrated circuit emphasis simulation is performed and the performances of these mixed CNT bundle interconnects are investigated in terms of propagation delay (with and without crosstalk), power dissipation, power-delay product (PDP). Switching times, overshoot voltages and Nyquist plots are analyzed to check the stability of these mixed CNT structures for global interconnect length for 32-nm, 22-nm and 16-nm technology nodes. It is observed that the MDCB-1 structure yields the most promising result in all aspects for interconnect applications in the near future.

Melville's Quixoticism and the Modern World-System

Melville's Quixoticism and the Modern World-System

Basic bases of calculations and optimization of NPP power unit equipment parameters methods of mathematical modelling

The materials of the article consider the optimization of certain parameters and characteristics of the equipment of NPP power units, which are closely related to the processes of their design and construction. Modern NPP power units are complex technical systems. They include a set of interconnected equipment for different technological purposes, which ensures the performance of power units of a complex function of electricity production and heat of the specified quality and according to a given load schedule. Complete mathematical models of the functional state of steam turbine power units are characterized by a large number of nonlinear connections and contain implicit functions. This complicates their widespread use to solve problems of systematic analysis of the quality of operation of power units. The aim of the work is to analyze the basic theoretical foundations, methods and approaches to the calculation and optimization of the parameters of the equipment of NPP power units by methods of mathematical modeling. The solution of the problem of optimization of NPP power unit parameters includes the following stages: selection of optimality criteria (objective functions); development of a system of interconnected mathematical models in accordance with the required hierarchical level of optimization research; selection of computational methods and optimization algorithms. Taking into account the above methodological provisions and approaches increases the efficiency of mathematical modeling to solve problems of calculations and optimization of NPP power unit parameters.

A prominent unified crosstalk model for linear and sub-threshold regions in mixed CNT bundle interconnects

With the feasibility to scale the devices and interconnects in highly sophisticated VLSI technology, the demand for high-speed and low-power e-applications have also subsequently increased stupendously. Based on the applications and requirements, a VLSI system is operated in different modes as linear or sub-threshold. A unified analytical model for describing both these linear and sub-threshold modes is highly desirable. This has been innovatively presented in the current paper. Moreover, the futuristic and emerging mixed carbon nanotube bundle (MCB) as interconnects for both linear and sub-threshold region of operations has been considered. The essential signal integrity analysis comprising of several crosstalk effects such as associated transient response, delay and power have been analyzed. To evaluate this, analytical model is formulated and proposed using accurate unconditionally-stable finite-difference time-domain (USFDTD) technique. Utilizing the proposed model, it is investigated that linear mode of operation is good for realizing high-speed systems while sub-threshold is a preferable operation for applications targeted for low-power. Comprehensively, it is envisaged that the average power-delay-product in MCB interconnects operating in sub-threshold region is low and reduced by 74% compared to corresponding linear region of operation. Also, it is demonstrated that the proposed unified USFDTD based model for MCB interconnects operating in different modes of operation is stable and not constricted by the Courant condition. At maximum allowable time step, the proposed model is nearly 10 and 25 times faster than the conventional FDTD analytical and HSPICE simulation models, respectively. The results reveal that USFDTD technique provides better accuracy than the FDTD technique. The different performance analyses are performed at 22 nm technology node.

The hair follicle‐psoriasis axis: Shared regulatory mechanisms and therapeutic targets

It has long been known that there is a special affinity of psoriasis for the scalp: Here, it occurs most frequently, lesions terminate sharply in frontal skin beyond the hair line and are difficult to treat. Yet, surprisingly, scalp psoriasis only rarely causes alopecia, even though the pilosebaceous unit clearly is affected. Here, we systematically explore the peculiar, insufficiently investigated connection between psoriasis and growing (anagen) terminal scalp hair follicles (HFs), with emphasis on shared regulatory mechanism and therapeutic targets. Interestingly, several drugs and stressors that can trigger/aggravate psoriasis can inhibit hair growth (e.g. beta-blockers, chloroquine, carbamazepine, interferon-alpha, perceived stress). Instead, several anti-psoriatic agents can stimulate hair growth (e.g. cyclosporine, glucocorticoids, dithranol, UV irradiation), while skin/HF trauma (Köbner phenomenon/depilation) favours the development of psoriatic lesions and induces anagen in "quiescent" (telogen) HFs. On this basis, we propose two interconnected working models: (a) the existence of a bidirectional "hair follicle-psoriasis axis," along which keratinocytes of anagen scalp HFs secrete signals that favour the development and maintenance of psoriatic scalp lesions and respond to signals from these lesions, and (b) that anagen induction and psoriatic lesions share molecular "switch-on" mechanisms, which invite pharmacological targeting, once identified. Therefore, we advocate a novel, cross-fertilizing and integrative approach to psoriasis and hair research that systematically characterizes the "HF-psoriasis axis," focused on identification and therapeutic targeting of selected, shared signalling pathways in the future management of both, psoriasis and hair growth disorders.

Interconnected model with distributed thermal comfort for model based shading control

Modern buildings have a growing tendency to have large window fronts, with this design aspect leading to extensive solar heat gain and lighting in the rooms. Well-known thermal space models for control applications use simplifications of the spatial distribution of radiation and temperature. In this paper, a new modeling approach for efficient control of shading systems in rooms with large glass facades is presented and thermal comfort at multiple distributed positions in the room is more accurately captured. The idea of an interconnected system with submodels with lumped parameters and submodels with distributed parameters is introduced which can subsequently be used for model predictive control. With model-based shading control and the distributed thermal model presented, individual comfort control is possible at multiple positions in a room. The model is physically motivated, based on the material parameters and no calibration method is currently used, but realistic initial conditions are set for the simulations. Temperature variations due to incident solar radiation are included in the system part with distributed parameters and allow local thermal comfort measures. The resulting model is designed to be used in the context of model based shading control considering thermal comfort at multiple distributed locations. The introduced model is validated with simulations for temperature accuracy, distributed thermal comfort, and control characteristics. The main results are the interconnected model with additional benefits for distributed thermal comfort. Moreover, the presented modelling approach is designed for control applications, especially for model predictive control.

Testing the structure of human cognitive ability using evidence obtained from the impact of brain lesions over abilities

Here we examine three classes of models regarding the structure of human cognition: common cause models, sampling/network models, and interconnected models. That disparate models can accommodate one of the most globally replicated psychological phenomena—namely, the positive manifold—is an extension of underdetermination of theory by data. Statistical fit indices are an insufficient and sometimes intractable method of demarcating between the theories; strict tests and further evidence should be brought to bear on understanding the potential causes of the positive manifold. The cognitive impact of focal cortical lesions allows testing the necessary causal connections predicted by competing models. This evidence shows focal cortical lesions lead to local, not global (across all abilities), deficits. Only models that can accommodate a deficit in a given ability without effects on other covarying abilities can accommodate focal lesion evidence. After studying how different models pass this test, we suggest bifactor models (class: common cause models) and bond models (class: sampling models) are best supported. In short, competing psychometric models can be informed when their implied causal connections and predictions are tested.

Port-Hamiltonian Modeling and IDA-PBC Control of an IPMC-Actuated Flexible Beam

In this paper, the infinite-dimensional port-Hamiltonian modelling and control problem of a flexible beam actuated using ionic polymer metal composite (IPMC) actuators is investigated. The port-Hamiltonian framework is used to propose an interconnected control model of the mechanical flexible beam and the IPMC actuator. The mechanical flexible dynamic is modelled as a Timoshenko beam, and the electric dynamics of the IPMCs are considered in the model. Furthermore, a passivity-based control-strategy is used to obtain the desired configuration of the proposed interconnected system, and the closed-loop stability is analyzed using the early lumped approach. Lastly, numerical simulations and experimental results are presented to validate the proposed model and the effectiveness of the proposed control law.

Multiparameter optimization of nonuniform passive diffusion properties for creating coarse-grained equivalent models of cardiac propagation

The arrhythmogenic role of discrete cardiac propagation may be assessed by comparing discrete (fine-grained) and equivalent continuous (coarse-grained) models. We aim to develop an optimization algorithm for estimating the smooth conductivity field that best reproduces the diffusion properties of a given discrete model. Our algorithm iteratively adjusts local conductivity of the coarse-grained continuous model by simulating passive diffusion from white noise initial conditions during 3–10 ms and computing the root mean square error with respect to the discrete model. The coarse-grained conductivity field was interpolated from up to 300 evenly spaced control points. We derived an approximate formula for the gradient of the cost function that required (in two dimensions) only two additional simulations per iteration regardless of the number of estimated parameters. Conjugate gradient solver facilitated simultaneous optimization of multiple conductivity parameters. The method was tested in rectangular anisotropic tissues with uniform and nonuniform conductivity (slow regions with sinusoidal profile) and random diffuse fibrosis, as well as in a monolayer interconnected cable model of the left atrium with spatially-varying fibrosis density. Comparison of activation maps served as validation. The results showed that after convergence the errors in activation time were < 1 ms for rectangular geometries and 1–3 ms in the atrial model. Our approach based on the comparison of passive properties (<10 ms simulation) avoids performing active propagation simulations (>100 ms) at each iteration while reproducing activation maps, with possible applications to investigating the impact of microstructure on arrhythmias.

AAA Algorithm for Rational Transfer Function Approximation With Stable Poles

Signal and power integrity analysis in time-domain requires suitable models for interconnects and power distribution networks, which are often available only in terms of their frequency responses from electromagnetic simulations or measured data. A rational transfer function approximation of such data allows its integration in circuit simulators. Recently the AAA (adaptive Antoulas-Anderson) algorithm has been introduced for rational function approximation. This letter introduces a modification of that algorithm for fitting in terms of the squared variable ( s <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ), called AAA <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> algorithm, for generating rational transfer functions with stable poles from frequency response available from simulated or measured data.

Vibrations of Misaligned Rotor System with Hysteretic Friction Arising from Driveshaft–Stator Contact under Dispersed Viscous Fluid Influences

Dynamic analysis of a combination of misaligned rotors, the disturbance of the Cardan joint and the rotor–stator rubbing within a restricted clearance space in a viscous fluid is complex and can result in persistent vibration anomalies that are often misunderstood. It becomes increasingly important to gain some insights into how the transmission of coupled motion responds dynamically under a variety of conditions. This paper introduces an efficient simulation of the misaligned multi-degree-of-freedom rotor’s model, which was developed to predict the transient dynamic behaviours of a driveshaft deflection. The model accounts for tight clearance as a function of contact deformation according to nonlinear Hertzian contact theory. The paper also examines recent research by considering the influence of parameters such as eccentric masses, applied torques and flexible coupling joint perturbation introduced in the proposed rotor system. The simulation results indicated that the viscous fluid surrounding the driveshaft had sufficient torsional flexibility to dampen the rubbing impact to the driven shaft displacement. In addition, the torsional fluctuations of the flexible coupling abruptly increased, and then significantly impacted the vibration of the submerged driveshaft. Parametric studies involving the interconnected rotor models indicated that the effects of fluid on a close-bounds contact area can create partial disturbance reduction. The high rubbing contact is shown to be lost through the Hooke’s joints during power transmission. The speed-frequency spectrum maps provide valuable information on all the modelled excitations over the frequency of the twice-running speed resonance in a viscous medium. Further, nonlinear characteristics are reconstructed through orbit shapes and can be adopted in the condition monitoring of rotors in engineering practice.

Cyber-Physical Vulnerability Assessment in Smart Grids Based on Multilayer Complex Networks.

In the last decade, the main attacks against smart grids have occurred in communication networks (ITs) causing the disconnection of physical equipment from power networks (OTs) and leading to electricity supply interruptions. To deal with the deficiencies presented in past studies, this paper addresses smart grids vulnerability assessment considering the smart grid as a cyber-physical heterogeneous interconnected system. The model of the cyber-physical system is composed of a physical power network model and the information and communication technology network model (ICT) both are interconnected and are interrelated by means of the communication and control equipment installed in the smart grid. This model highlights the hidden interdependencies between power and ICT networks and contains the interaction between both systems. To mimic the real nature of smart grids, the interconnected heterogeneous model is based on multilayer complex network theory and scale-free graph, where there is a one-to-many relationship between cyber and physical assets. Multilayer complex network theory centrality indexes are used to determine the interconnected heterogeneous system set of nodes criticality. The proposed methodology, which includes measurement, communication, and control equipment, has been tested on a standardized power network that is interconnected to the ICT network. Results demonstrate the model’s effectiveness in detecting vulnerabilities in the interdependent cyber-physical system compared to traditional vulnerability assessments applied to power networks (OT).