M.S. Obrecht, E.L. Heasell and M.I. Elmasry
Computational speed and robustness of the coupled (MEDICI) and decoupled (TRASIM) method based simulators are compared. Transient and steady‐state avalanche simulations are…
Abstract
Computational speed and robustness of the coupled (MEDICI) and decoupled (TRASIM) method based simulators are compared. Transient and steady‐state avalanche simulations are presented. The decoupled method shows significantly lower memory requirements, higher robustness and up to 30 times higher speed.
James W. ROBERTS and Savvas G. CHAMBERLAIN
An energy‐momentum transport model for sub‐micron silicon devices is modified to include new sets of simple interband scattering models representing impact ionization, auger…
Abstract
An energy‐momentum transport model for sub‐micron silicon devices is modified to include new sets of simple interband scattering models representing impact ionization, auger recombination, trapping and photo generation. These have been developed using a simplified physical modelling approach. A discretization scheme suitable for application to an irregular spatial grid is presented. The resulting model is suitable for the study of small geometry effects in silicon devices.
A discretization technique is proposed for the multi‐dimensional, steady‐state hydrodynamic model of semiconductor devices, and a derivation of the model's appropriate boundary…
Abstract
A discretization technique is proposed for the multi‐dimensional, steady‐state hydrodynamic model of semiconductor devices, and a derivation of the model's appropriate boundary conditions is given. The model includes the complete balance equations for charge, momentum and energy, coupled with Poisson's equation, thus accounting for both diffusion and convection phenomena. The technique, like the Scharfetter—Gummel scheme for the simpler drift‐diffusion model, provides an efficient method for solving the hydrodynamic equations, allowing for a more detailed investigation of carrier dynamics in semiconductor devices.
The Boltzmann transport equation applied to electron transport in a heterostructure semiconductor is discussed. The closed‐form methods for solving the heterostructure…
Abstract
The Boltzmann transport equation applied to electron transport in a heterostructure semiconductor is discussed. The closed‐form methods for solving the heterostructure energy‐momentum conservation equations are considered and the energy flux conservation equation is suggested as an additional equation to be solved in the hydrodynamic hot electron transport model. Suitable numeric stable discretisation schemes for the conservation equations are presented.
An efficient method is shown to calculate the temperature distribution and the thermal coupling elements in integrated circuits. With that it is possible to treat circuits under…
Abstract
An efficient method is shown to calculate the temperature distribution and the thermal coupling elements in integrated circuits. With that it is possible to treat circuits under nonisothermal conditions. The algorithm combines several methods of the three‐dimensional solution of the FOURIER equation to analyse real heat problems of integrated circuits in a short computation time. Some examples illustrate the application of the algorithm.
This Society, originally known as “The National Pure Food Association,” has been reconstituted under the above title. The objects of the Society are to assist as far as possible…
Abstract
This Society, originally known as “The National Pure Food Association,” has been reconstituted under the above title. The objects of the Society are to assist as far as possible in checking the widespread evils of food adulteration, for this purpose to bring about a public realisation of the admittedly serious character of food frauds, and, under expert advice, to co‐operate with constituted authority in effecting their repression. The policy of the Society is directed by a representative Council, and, the Society being thus established on an authoritative basis, cannot fail to become a powerful and valuable organisation if adequately and generously supported by the public. The governing body of the Society is constituted as follows:—
The purpose of this paper is to propose a new performance analysis and measurement regarding reconfigurable manufacturing systems (RMS) taken into consideration new circumstances…
Abstract
Purpose
The purpose of this paper is to propose a new performance analysis and measurement regarding reconfigurable manufacturing systems (RMS) taken into consideration new circumstances which include changes in the market demand, changes in a product design, and/or introduction of a new product. As the reconfiguration process is applied to a manufacturing system to improve the system's performance due to new circumstances, the RMS process has potential quantitative and qualitative measures.
Design/methodology/approach
The manufacturing system has a great impact on the performance measurement and the selection of the objectives to measure the performance is very important. These objectives include the critical requirements for a RMS and they are as follows: product cost, manufacturing response, system productivity, people behavior, inventory, and quality of the finished products. Because each criterion measure in a RMS is a potential source of evaluation, it should have a relative weight with respect to the other measures. First, each criterion will be measured individually. Second, these measures need to be evaluated through an aggregate quantitative metric because there is a lack of analytical techniques to analyze and evaluate both qualitative and quantitative measures.
Findings
Performance evaluation of a RMS from one circumstance to another is highly desired by using the new quantitative metric regarding updating (upgrading) the system for the next period based on the previous one. The results show that the applicable of using this new technique in evaluating the RMS. The results also support the new quantitative metric.
Originality/value
The suggestion of a new aggregate performance measurement metric including the all potential objectives is highly considered. This paper provides an insight into each objective individually to measure it. It is also used from 0 to 1 as range of measure to evaluate the potential and aggregate metrics toward next reconfiguration with respect to the existing one.
Details
Keywords
The purpose of this paper is to propose a “Reconfiguration Methodology” in manufacturing systems that they can become more economically sustainable and can operate efficiency and…
Abstract
Purpose
The purpose of this paper is to propose a “Reconfiguration Methodology” in manufacturing systems that they can become more economically sustainable and can operate efficiency and effectively. This methodology will allow customized flexibility and capacity not only in producing a variety of products (parts) and with changing market demands, but also in changing and reengineering the system itself.
Design/methodology/approach
Reconfigurable manufacturing system (RMS) is a philosophy or strategy which was introduced during the last decade to achieve agility in manufacturing systems. Until now, the RMS philosophy was based changing activities such routing, planning, programming of machines, controlling, scheduling, and physical layout or materials handling system. But the RMS concept can be based on the needed reconfiguration level (NRL), operational status of production systems, and new circumstances (NC). The NRL measure is based on the agility level of the manufacturing systems which is based on technology, people, management, and manufacturing strategies. The components of the manufacturing system design (MSD) consist of production system design, plant layout system, and material handling system. Operational status of production systems includes machine capability (flexibility) and capacity (reliability), production volume or demand, and material handling equipment in addition to the plant layout. The NC are also consisting of new product, developing the existing ones, and changing in demand.
Findings
Reconfiguration manufacturing systems from one period to another period is highly desired and is considered as a novel manufacturing philosophy and/or strategy toward creating new sustainable manufacturing systems. A new reconfiguration methodology for the manufacturing systems will be analyzed and proposed. Two Case studies will be introduced.
Originality/value
The suggestion of a new methodology of reconfiguration including the NRL (configurability index) and the operational status of manufacturing systems with respect to any circumstance is highly considered. The reconfiguration methodology also provides a framework for sustainability in the manufacturing area which mainly focussed on manufacturing systems design.