格网中p-cycles重配置的快速实现算法

提出了一种用于双链路故障恢复和为动态业务提供保护的p-cycles重配置启发式算法.该算法可以提供网络生存性设计和网络管理的高效性和简洁性,并能提供快速的恢复操作.仿真结果表明,这种算法用于双链路故障恢复的重配置容量冗余度可达74%,平均计算时间为48ms;用于增量重配置的双故障冗余度为118%,计算时间为81ms.基于该算法的业务恢复可以满足大多数业务的最低可中断时间要求.分析表明该算法亦适用于动态业务的p-cycles重配置.     

基于Local-map的Mesh光网络简单p圈构造法

圈构造算法是Mesh光网络中p圈法设计的前提。根据简单p圈的特点，针对圈构造算法问题，提出将原来圈上边变为跨接边的图扩展算法。该圈扩展算法构造的圈具有保护性能优良，并且包含所有原来的圈上的点。在圈扩展算法和Local-map概念的基础上提出了基于Local-map的p圈启发式算法，该算法在Local-map中运行固扩展算法，这样既能提高p圈的保护性能，又能使p圈位于局域范围内，保证快速恢复。对比分析Local-map和DFS两种找圈算法的实验结果，该方案构造的圈恢复速度快，容量利用率高，比较适合网状光网络中的p图设计。     

Reconfigurability consideration and scheduling of products in a manufacturing industry

Reconfigurable manufacturing system is a new type of manufacturing system which can change its capacity and functionality very easily and quickly whenever required. RMS (reconfigurable manufacturing system) has capacity and functionality exactly what is required. RMS is adjustable to the fluctuating demands and it can be easily upgraded with new process technology. Reconfigurability of a manufacturing system is measured in terms of cost, effort and time. It is the ability of a manufacturing system to be reconfigured quickly with low reconfiguration effort at low cost. In the present work, reconfigurability has been considered in Continental Automotive Components Pvt. Ltd. on the basis of RMS principles. A modified reconfigurable layout has been proposed for an assembly line and scheduling of the products has been done for the criteria reconfiguration effort, profit over cost and due date. Scheduling of the products has been done using the integrated approach of Shannon entropy and RIM (Reference Ideal Method). R program has been written for scheduling. Sensitivity analysis has been conducted for the problem.     

Reservation signalling mechanism for reducing blocking probability in optical burst switching networks with limited wavelength conversion capabilities

First, the optical burst switching (OBS) network with limited wavelength conversion capability (LWCC) is decomposed into multiple wavelength continuous segments according to the position of wavelength converters. Based on the decomposed network model, two reservation signalling mechanisms for OBS-LWCC networks, namely wavelength-amend-on-demand (WAoD) and contention-based limited signalling protocol (CLSP), are proposed to reduce the blocking probability in the OBS-LWCC networks. In WAoD, the congested node sends a feedback message to the closest upstream switch with wavelength conversion capability. The notified switch will change the burst wavelength to the one assigned by the congested node to avoid collision in advance. Extensive simulation results indicate that by applying the wavelength reconfiguration method to the core nodes without wavelength conversion capability, the proposed WAoD scheme can improve the blocking performance in the OBS-LWCC networks significantly. Furthermore, CLSP, which combines the burst time-slot reconfiguration with the wavelength reconfiguration of WAoD, always has the lowest burst loss probability when compared with both the conventional and the proposed reservation mechanisms.     

Simulation and analysis of reconfigurable assembly systems based on R-TNCES

ABSTRACT

Recent research indicates that dynamic reconfiguration techniques can be applied to manufacturing systems to reduce energy consumption by switching energy-intensive components in a timely manner between their working and idle modes during system runtime because these components consume less energy in their idle modes than in their working modes. The current work studies reconfigurable assembly systems with such dynamic reconfiguration techniques by abstracting them as reconfigurable discrete event systems, considering only their logic behavior and properties. The formalism, R-TNCES (reconfigurable timed net condition/event systems), a modular extension of the well-known Petri nets, is used as a system modeling and analysis tool. The simulation of system global reconfigurations is guided by command inserting, whereas the simulation of local reconfigurations is automatic because their execution time is computed a priori by a proposed algorithm. Finally, qualitative properties specified by computation tree logic and quantitative analysis regarding energy-efficiency are performed by using the software SESA.     

On Cost‐effective Reuse of Components in the Design of Complex Reconfigurable Systems

Design strategies that benefit from the reuse of system components can reduce costs while maintaining or increasing dependability—we use the term dependability to tie together reliability and availability. D3H2 (aDaptive Dependable Design for systems with Homogeneous and Heterogeneous redundancies) is a methodology that supports the design of complex systems with a focus on reconfiguration and component reuse. D3H2 systematizes the identification of heterogeneous redundancies and optimizes the design of fault detection and reconfiguration mechanisms, by enabling the analysis of design alternatives with respect to dependability and cost. In this paper, we extend D3H2 for application to repairable systems. The method is extended with analysis capabilities allowing dependability assessment of complex reconfigurable systems. Analysed scenarios include time‐dependencies between failure events and the corresponding reconfiguration actions. We demonstrate how D3H2 can support decisions about fault detection and reconfiguration that seek to improve dependability while reducing costs via application to a realistic railway case study. Copyright © 2017 John Wiley & Sons, Ltd.     

Configuration design of scalable reconfigurable manufacturing systems for part family

Intense global competition, dynamic product variations, and rapid technological developments force manufacturing systems to adapt and respond quickly to various changes in the market. Such responsiveness could be achieved through new paradigms such as Reconfigurable manufacturing systems (RMS). In this paper, the problem of configuration design for a scalable reconfigurable RMS that produces different products of a part family is addressed. In order to handle demand fluctuations of products throughout their lifecycles with minimum cost, RMS configurations must change as well. Two different approaches are developed for addressing the system configuration design in different periods. Both approaches make use of modular reconfigurable machine tools (RMTs), and adjust the production capacity of the system, with minimum cost, by adding/removing modules to/from specific RMTs. In the first approach, each production period is designed separately, while in the second approach, future information of products’ demands in all production periods is available in the beginning of system configuration design. Two new mixed integer linear programming (MILP) and integer linear programming (ILP) formulations are presented in the first and the second approaches respectively. The results of these approaches are compared with respect to many different aspects, such as total system design costs, unused capacity, and total number of reconfigurations. Analyses of the results show the superiority of both approaches in terms of exploitation and reconfiguration cost.     

Evaluating the effects of capacity constraints and demand patterns on supply chain replenishment strategies

This research considers inventory replenishment in a stochastic, multi-echelon supply chain involving both production and distribution functions. Simulation is used to compare distribution/material requirements planning (DRP/MRP), re-order point (ROP) and Kanban (KBN) replenishment strategies. Additional experimental factors include the demand pattern and the existence of manufacturing capacity constraints. Trade-off curves between inventory and delivery performance are generated. Statistical techniques, including analysis of variance (ANOVA), are then used to compare the areas under the trade-off curves and determine the relative dominance among the replenishment strategies. The methodology is used to identify both main and interaction effects. With seasonal demand, DRP/MRP performance is found to be best, followed by ROP and KBN, respectively. Without seasonal demand, the relative performance ranking depends on the presence of capacity constraints. Without capacity constraints, ROP performs best, followed by DRP/MRP and KBN. With capacity constraints, the ranking is reversed. This difference in behaviour can be explained using queuing analysis.     

Deterministic addressing of nanoscale devices assembled at sublithographic pitches

Multiple techniques have now been proposed using random addressing to build demultiplexers which interface between the large pitch of lithographically patterned features and the smaller pitch of self-assembled sublithographic nanowires. At the same time, the relatively high defect rates expected for molecular-sized devices and wires dictate that we design architectures with spare components so we can map around defective elements. To accommodate and mask both of these effects, we introduce a programmable addressing scheme which can be used to provide deterministic addresses for decoders built with random nanoscale addressing and potentially defective wires. We describe how this programmable addressing scheme can be implemented with emerging, nanoscale building blocks and show how to build deterministically addressable memory banks. We characterize the area required for this programmable addressing scheme. For 2048/spl times/2048 memory banks, the area overhead for address correction is less than 33%, delivering net memory densities around 10/sup 11/ b/cm/sup 2/.     

Recent advances in research on reconfigurable machine tools: a literature review

A recent trend in research on reconfigurable manufacturing systems is the development of reconfigurable machine tools (RMTs). A RMT can be used as a group of machines through change of its configuration to satisfy different manufacturing requirements. A literature review is provided in this paper to demonstrate the state-of-the-art advances and challenges on research and development of RMTs from the perspectives of architecture design, configuration design and optimisation, and system integration and control. In architecture design, semi-open and open architectures based on modular design approach are often selected to allow different modules of the machine to be added and removed. In configuration design and optimisation, operations of reconfiguration processes are analysed and optimised to achieve variety of configurations with the minimum reconfiguration effort. In system integration and control, transfers of motion, energy and data among different modules of the RMT are carried out. The challenges in research on RMTs are also discussed.     

Improved in vitro anti-tumoral activity, intracellular uptake and apoptotic induction of gemcitabine-loaded pegylated unilamellar liposomes

Anaplastic thyroid carcinoma is one of the most aggressive and lethal solid carcinomas affecting humans. A major limit of the chemotherapeutic agents is represented by their low therapeutic index. In this work, we investigated the possibility of improving the anti-tumoral activity of gemcitabine by using pegylated unilamellar liposomes. Liposomes were made up of 1,2-dipalmitoyl-sn-glycero-3-phospocholine monohydrate/cholesterol/N-(carbonyl-methoxypolyethylene glycol-2000)-1, 2-distearoyl-sn-glycero-3-phosphoethanolamine (6:3:1 molar ratio) and they were prepared with a pH gradient to improve the gemcitabine loading capacity. The anti-tumoral efficacy of the liposomal formulation was tested in vitro on human anaplastic thyroid carcinoma cells (ARO) in culture, comparing the effects with those of the free drug. Gemcitabine-loaded unilamellar liposomes had a mean size approximately 200 nm with a zeta potential approximately -2 mV. The liposomal carrier noticeably improved the anti-tumoral activity of gemcitabine against ARO cells in terms of both dose-dependent cytotoxic effect and of drug exposition effect. Namely, gemcitabine-loaded liposomes showed a cytotoxic effect (58.2% increase of cell mortality at 1 microM with respect to free drug) after 12 h incubation, while the free drug showed a significant activity only after 72 h incubation. Moreover, a significant effect on the cell mortality appeared at 0.1 microM and 100% mortality was detected at a concentration of 1 microM of gemcitabine-loaded liposomes, while the free drug elicited the same effect at a concentration of 100 microM. The improved anti-tumoral activity of gemcitabine determined by the liposomal carrier was due to a greater intracellular uptake. The intracellular gemcitabine levels as a function of time showed a sinusoidal profile with peaks after 2 h, 6 h and 11 h, related to the cellular cycle of ARO. PARP cleavage and DNA fragmentation analysis provided clear evidence of the apoptosis induction in ARO cells by treatment with liposomally entrapped gemcitabine after 72 h incubation. Thus, gemcitabine-loaded liposomes may have a potential therapeutic relevance for the treatment of anaplastic thyroid carcinoma.     

Reconfigurable core-satellite nanoassemblies as molecularly-driven plasmonic switches

Molecular control of plasmon coupling is investigated in sub-100 nm assemblies composed of 13 nm gold "satellite" particles tethered by reconfigurable DNA nanostructures to a 50 nm gold "core" particle. Reconfiguration of the DNA nanostructures from a compact to an extended state results in blue shifting of the assembly plasmon resonance, indicating reduced interparticle coupling and lengthening of the core-satellite tether. Scattering spectra of the core-satellite assemblies before and after reconfiguration are compared with spectra calculated using a structural model that incorporates the core/satellite ratio determined by TEM imaging and estimates of tether length based upon prior measurements of interparticle separation in DNA linked nanoparticle networks. A strong correspondence between measured and simulated difference spectra validates the structural models that link the observed plasmon modulation with DNA nanostructure reconfiguration.     

A Blockchain-Based Architecture for Securing Industrial IoTs Data in Electric Smart Grid

There are numerous internet-connected devices attached to the industrial process through recent communication technologies, which enable machine-to-machine communication and the sharing of sensitive data through a new technology called the industrial internet of things (IIoTs). Most of the suggested security mechanisms are vulnerable to several cybersecurity threats due to their reliance on cloud-based services, external trusted authorities, and centralized architectures; they have high computation and communication costs, low performance, and are exposed to a single authority of failure and bottleneck. Blockchain technology (BC) is widely adopted in the industrial sector for its valuable features in terms of decentralization, security, and scalability. In our work, we propose a decentralized, scalable, lightweight, trusted and secure private network based on blockchain technology/smart contracts for the overhead circuit breaker of the electrical power grid of the Al-Kufa/Iraq power plant as an industrial application. The proposed scheme offers a double layer of data encryption, device authentication, scalability, high performance, low power consumption, and improves the industry’s operations; provides efficient access control to the sensitive data generated by circuit breaker sensors and helps reduce power wastage. We also address data aggregation operations, which are considered challenging in electric power smart grids. We utilize a multi-chain proof of rapid authentication (McPoRA) as a consensus mechanism, which helps to enhance the computational performance and effectively improve the latency. The advanced reduced instruction set computer (RISC) machines ARM Cortex-M33 microcontroller adopted in our work, is characterized by ultra-low power consumption and high performance, as well as efficiency in terms of real-time cryptographic algorithms such as the elliptic curve digital signature algorithm (ECDSA). This improves the computational execution, increases the implementation speed of the asymmetric cryptographic algorithm and provides data integrity and device authenticity at the perceptual layer. Our experimental results show that the proposed scheme achieves excellent performance, data security, real-time data processing, low power consumption (70.880 mW), and very low memory utilization (2.03% read-only memory (RAM) and 0.9% flash memory) and execution time (0.7424 s) for the cryptographic algorithm. This enables autonomous network reconfiguration on-demand and real-time data processing.     

Evaluation of the logistic model of the reconfigurable manufacturing system based on generalised stochastic Petri nets

To reveal the influence on system performance by the logistic model of reconfigurable manufacturing system (RMS), the generalised stochastic Petri nets (GSPN) modular modelling approach is presented in this paper. It is based upon the characteristics of a bottleneck service. According to this approach, the bottleneck service in the production process is found first. By corresponding different resources in the service to different modules of the GSPN, the module is reconfigured. The analysis of the model using the Markov chain is hereby presented, as is the average utilisation factor of RMS. Following this, the production capacity of different products and the average productivity of reconfigurable manufacturing cells (RMCs) are discussed.     

JOINT CONFIGURATION OF BACKBONE AND LOGICAL NETWORKS ON A RECONFIGURABLE PACKET-SWITCHED NETWORK WITH UNRELIABLE LINKS

Abstract

This paper considers a problem of configuring both backbone and logical networks in a reconfigurable packet-switched network where links are subject to failures. The objective is to design feasible backbone and logical networks at least cost where the network cost includes backbone link capacity expansion cost and average packet delay penalty cost due to link failures. The problem is formulated as a zero-one non-linear mixed integer programming problem, for which an effective solution procedure is developed by using a Lagrangean relaxation technique for finding a lower bound and a heuristic method is exploited for improving the upper bound of an intermediate solution. The solution procedure is tested for its effectiveness with various numerical examples.     

A reconfigurable platform in support of one-of-a-kind product development

In recent years, a variety of Internet-based systems has been developed for the purpose of Rapid One-of-a-Kind or customized Product Development (ROKPD). They can be applied in different stages of the product development process such as to rapidly capture customer requirements, and help produce high-quality products at low cost and short lead-time. Many of the systems, however, do not support rapid adaptation or dynamic reconfiguration of systems and tools for supporting ROKPD in a distributed manufacturing environment. To the authors’ knowledge, the infrastructure of such a reconfigurable platform for supporting distributed manufacturing has never been directly studied. This paper proposes an Internet-based reconfigurable ROKP platform that has been prototyped to serve as a substrate for integrating innovative tools and systems for One-of-a-Kind Production (OKP) companies in New Zealand. The main emphasis of this paper is to investigate how to build the Internet-based reconfigurable ROKPD platform and to design appropriate intelligent tools and systems for the purpose of rapidly and economically producing OKP products in the global environment. A number of recent developments are discussed, including the four open-domain infrastructure of the ROKPD platform, Internet-based data management systems, an integrated product data environment and a cost/lead time control tool.     

Identification of the domain of opportunities for a market of resources for virtual enterprise integration

In the aggressive and competitive business environment of today, enterprises are expected to achieve competitive advantages in synergy, under the format of reconfigurable global networked structures, such as the virtual enterprise (VE) organizational model, integrating the optimal resources (products, operations, services) for each of the functions that the enterprise undertakes, in order to produce a product that meets the market requirements. The literature shows that several Internet-based tools can be used to enable some activities of VE integration. However, as we demonstrate, these do not support the reconfiguration dynamics required by this organizational model. Alternatively, the authors propose the market of resources (MR) as an environment to fully support VE integration, coping with its intrinsic requirement of high reconfigurability. Based on a demonstrator developed for the MR and on cost models traducing VE integration, one for the (traditional) Internet-based tools and the other for the MR, to support an analytical simulation, the paper validates the thesis that the traditional tools cannot support agility and dynamics, presenting the MR as a VE enabler, and identifying the domain of situations where the utilization of the MR reveals increased efficiency in terms of search and selection time and cost—designated as opportunities domain.     

Reconfigurable optical neuron based on photoelectret materials

An all-optical reconfigurable neuron based on a photoelectret-electro-optic medium with a sandwich-type structure is presented. Both the inputs and the output of the neuron and the reconfiguration of the weights of the inputs are optical. The structure presented is very versatile and exhibits low energy consumption, as the numerical estimates indicate. The number of inputs can be varied (to an upper limit that is determined by the diffraction effect) without changing the structure of the optical neuron; the same is true for the neurons' weights.     

Reliability assessment of an automated distribution system

Automation can greatly enhance distribution-network reliability by speeding up service restoration and thus significantly reduce customer-outage time. The paper presents an approach to assess quantitatively the adequacy of a particular automated distribution scheme designated as the `low interruption system' (LIS). Owing to the use of a high-speed communication system and line sensors, this automated scheme can reduce drastically the number of interruptions, the service interruption time and also the area affected by the fault. This scheme provides a simple and cost-effective way to automate distribution systems in which the remotely controlled switches speed up isolation of faulted sections and the restoration of healthy sections through alternative routes. The step-by-step calculation procedure is presented using a typical small automated distribution system. The proposed technique is then applied to a larger distribution system to examine the effectiveness of the technique and also to examine the level of reliability improvement achieved by automation     

一种面向可重构ERP系统的作业成本法

在对传统企业资源计划(ERP)中的成本方法和传统作业成本法的缺点进行分析的基础上,提出了一种面向可重构ERP系统的作业成本法.该方法建立在广义工作中心的动态可扩展结构基础之上,由将企业资源消耗分配到基本工作中心、将基本工作中心资源消耗分配到作业、将作业资源消耗分配到成本对象以及各级广义工作中心成本滚加计算等四个步骤组成.该方法继承了传统作业成本法面向过程的特点,能够支持过程重构驱动的ERP系统企业内和企业间重构,实现了最大程度降低过程结构成本.算例表明,与传统制造成本法和作业成本法相比,该方法能够为可重构ERP系统提供更有效、准确和集成化的成本信息和决策支持.