Dharmaraj Veeramani

Radar Cross-Section Analysis of Backscattering RFID Tags

In this letter, we present a graphical method based on Greens analysis of scattering antennas to optimize the load impedances for achieving maximum modulated radar cross-section (RCS) of backscattering radio-frequency identification (RFID) tags. A planar tag antenna specifically designed for working in the ultra-high-frequency band is used to experimentally validate the method. The measured RCS of the loaded tag antenna shows acceptable agreement with the theory and simulated results. This method is especially valuable to the design of semipassive RFID tags when the communication range is solely determined by the backscattering modulation efficiency of tags.

Selection of an optimal set of cutting-tool sizes for 2D pocket machining

Abstract The availability of high speed automatic tool change mechanisms in modem CNC machining centers is making it practical to consider the use of multiple cutting-tool (specifically, flat end-mill) sizes to reduce the total time for machining a 2 1 2 D) pocket. However, current CAD/CAM systems do not support pocket machining using multiple cutting-tool sizes. In this paper, we describe a two-phase methodology for selecting an optimal set of cutting-tool sizes to machine a 2 1 2 D pocket. In the first phase, we employ a new concept called the Voronoi mountain in order to calculate the material volume that can be removed by a specific cutting-tool size, the material volume that will subsequently remain to be machined, and the cutter-paths (and corresponding processing times) for each cutting-tool. In the second phase, we apply a dynamic programming approach for optimal selection of cutting-tool sizes on the basis of the processing time. Our computational experiments indicate that substantial savings in processing time can be achieved by using multiple cutting-tool sizes to machine 2 1 2 D pockets.

Cutting-tool management in computer-integrated manufacturing

The problem of cutting tool management has been brought to the forefront with the emergence of computer-integrated manufacturing (CIM) and, in particular, flexible manufacturing systems (FMSs). The financial and operational ramifications of effective tool management has spurred considerable research in this area during the past decade and many researchers are proposing sound solutions to various facets of this broad-ranging and difficult problem. This paper identifies critical areas of research for the development of tool management systems in CIM. To develop a framework for this, the paper examines and categorizes work in academia and in industry on the management of cutting-tools in CIM and describes some key implementations, particularly in the metal-cutting industry. The solution of manufacturing problems generally demands an eclectic approach, and for this reason, we have tried to taxonomize, describe, and critique the various research thrusts in an attempt to provide a synthesis of use in more unified approaches.

Methodologies for rapid and effective response to requests for quotation (RFQs)

The ability to respond quickly and effectively to requests for quotation (RFQs) from customers can be a significant source of competitive advantage to manufacturing companies. This paper presents a new paradigm for processing RFQs and describes methodologies for rapid and accurate estimation of manufacturing cost for modified standard products and custom-made products. Insights gained through industry collaboration on the development of rapid cost estimation systems are also discussed. The work presented in this paper complements ongoing efforts by government and industry to establish the infrastructure and enabling technologies for electronic commerce, and can therefore contribute to significant gains in supply chain agility.

Tracking blood products in blood centres using radio frequency identification: a comprehensive assessment

Background and Objectives  Radio frequency identification (RFID) can be a key enabler for enhancing productivity and safety of the blood product supply chain. This article describes a systematic approach developed by the RFID Blood Consortium for a comprehensive feasibility and impact assessment of RFID application in blood centre operations.

Performance Analysis of Auction-Based Distributed Shop-Floor Control Schemes from the Perspective of the Communication System

A growing level of interest in academia and industry centers on the paradigm of distributed shop-floor control in which task and resource allocation in the manufacturing system is accomplished in a distributed manner through message passing and auction-based decision making among autonomous entities. Due to the prominent role played by the communication system in this paradigm, it is important to consider the requirements and performance characteristics of the communication system during the design and evaluation of distributed shop-floor control schemes. In this paper, we propose a two-phase methodology for analyzing auction-based shop-floor control schemes from the perspective of the communication system. In the first phase, the control scheme is modeled as a closed queueing network and performance measures related to the auctioning process and the communication system are obtained rapidly using asymptotic bounding analysis and mean value analysis. Control schemes identified as attractive in the first phase are then evaluated in greater detail during the second phase, using a discrete event simulation model. We illustrate this methodology using two-class and four-class control schemes and discuss insights learned about the impact of various control-scheme-related factors on the performance of the auctioning process and the communication system.

Computer-integrated collaborative design and operation in the construction industry

The construction industry is emerging as the next frontier for computer-integrated technologies, just as the manufacturing industry did 25 years ago. More recently, the emergence of Internet–Intranet technologies is creating new mechanisms for collaborative design and operation that were previously impossible. The advances that have occurred in the manufacturing industry in the areas of collaborative design, intelligent process planning and computer-integrated manufacturing provide significant insights for formulating analogous paradigms for computer-integrated construction. However, in many aspects, the development of enabling technologies (for design, operation and decision-making) to achieve this transformation in the construction industry is not as trivial as repackaging existing technologies and tools that have been developed for the manufacturing industry. In this paper, we draw attention to some of the significant research opportunities and challenges that exist in these areas of collaborative design and computer-integrated construction, and outline some related researches at the University of Wisconsin-Madison.

Vickrey–Dutch procurement auction for multiple items

We consider a setting where there is a manufacturer who wants to procure multiple items from a set of suppliers each of whom can supply one or more of these items (bundles). We design an ascending price auction for such a setting which implements the Vickrey–Clarke–Groves outcome and truthful bidding is an ex post Nash equilibrium. Our auction maintains non-linear and non-anonymous prices throughout the auction. This auction has a simple price adjustment step and is easy to implement in practice. As offshoots of this auction, we also suggest other simple auctions (in which truthful bidding is not an equilibrium by suppliers) which may be suitable where incentives to suppliers are not a big concern. Computer simulations of our auction show that it is scalable for the multi-unit case, and has better information revelation properties than its descending auction counterpart.

A polynomial-time algorithm for optimal clustering in a special class of {0, l} -matrices

The process of forming group technology based families for cellular manufacturing applications often entails the identification ofclusters in {0, l}-matrices. Most of the methods developed to date for cluster formation in this context employ heuristics that typically generate sub-optimal solutions (in terms of the number of exceptional elements). In this paper, we will describe a polynomial-time algorithm, based on a graph-theoretic approach, for optimal cluster formation in a class of {0, l}-matrices called vertex-tree graphic matrices. A comparison of the performance of this algorithm with popular heuristics is also provided. The algorithm can be used as a benchmarking tool for cluster formation heuristics.

Absence of acute adverse in-vitro effects on AS-1 RBCs and whole blood-derived platelets following prolonged exposure to 13.56 MHz radio energy.

BACKGROUND: There is growing interest in radio frequency identification (RFID) technology application for tracking blood products to achieve higher productivity and safety in the transfusion medicine supply chain. We have conducted a limited study to assess the temperature and biological effects of 13.56 MHz RF radiation on RBCs and whole blood–derived platelets (WBDP) under extreme exposure conditions.