Daniel Deavours's Publications

Publications are listed in reverse chronological order (most recent first) within the following categories:

For most, an abstract is provided. For some, an online version can be retrieved.

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Journal Papers

Supreetha Rao Aroor and Daniel D. Deavours. Evaluation of the State of Passive UHF RFID: An Experimental Approach. IEEE Systems Journal, 1(2), December 2007, pp. 168-176.

In this paper, we identify the state of the technical capabilities of passive UHF RFID tags and readers using a simple, empirical, experimental approach. This paper does not focus on theoretical capabilities of RFID systems in ideal environments, but rather a pragmatic evaluation of the state of commercially available ISO 18000-6c systems and identifying areas where there are opportunities for improvements in the technology. We examine the free-space read distance of tags by readers, near-metal read distance, near-water read distance, frequency-dependence of read distances in those environments, near-field read distance in those environments, read speeds, and a determination of forward or reverse channel limits.

M. Eunni, M. Sivakumar, D. D. Deavours. A Novel Planar Microstrip Antenna Design for UHF RFID. JSCI, vol. 5, no. 1, January 2007, pp. 6-10.

Passive UHF RFID tags generally do not work well near metal or water. Microstrip antennas offer a potential solution, but suffer from manufacturing complexity because a need for via or some other reference to ground. We present a new antenna and matching circuit design using a balanced feed that eliminates any reference to ground and thus simplifies the antenna's construction.

D. D. Deavours, G. Clark, T. Courtney, D. Daly, S. Derisavi, J. M. Doyle, W. H. Sanders, and P. K. Webster. The Möbius Modeling Framework and Its Implementation. IEEE Trans. Software Engineering, vol. 28, no. 10, October 2002, pp. 956-969.

The Möbius framework is an environment for supporting multiple modeling formalisms and solution techniques. Models expressed in formalisms that are compatible with the framework are translated into equivalent models using Möbius framework components. However, this translation preserves the structure of the models, allowing efficient solutions. The framework is implemented in the tool by a well-defined abstract functional interface. Models and solution techniques interact with one another through the use of the standard interface, allowing them to interact with Möbius framework components, not formalism components. This permits novel combinations of modeling techniques, and will be a catalyst for new research in modeling techniques. This paper describes our approach, focusing on the ``atomic model.'' We describe the formal description of these components as well as their implementations in our software tool.

D. D. Deavours and W. H. Sanders. ``On-the-fly'' Solution Techniques for Stochastic Petri Nets and Extensions. IEEE Transactions on Software Engineering, vol. 24, no. 10, October 1998, pp.889-902.

High-level modeling representations, such as stochastic Petri nets, frequently generate very large state spaces and corresponding state-transition-rate matrices. In this paper, we propose a new steady-state solution approach that avoids explicit storing of the matrix in memory. This method does not impose any structural restrictions on the model, uses Gauss-Seidel and variants as the numerical solver, and uses less memory than current state-of-the-art solvers. An implementation of these ideas shows that one can realistically solve very large, general models in relatively little memory.

D. D. Deavours and W. H. Sanders. An Efficient Disk-based Tool for Solving Large Markov Models. Performance Evaluation, vol. 33, 1998, pp. 67-84.

Very large Markov models often result when modeling realistic computer systems and networks. We describe an efficient tool for solving general, large Markov models on a typical engineering workstation. It uses a disk to hold the state-transition-rate matrix (possibly compressed), a variant of block Gauss-Seidel as the iterative solution method, and an innovative implementation that involves two parallel processes communicating by shared memory. We demonstrate its use on two large, realistic performance models.

Conference Papers

Daniel D. Deavours, Analysis and Design of Wideband Passive UHF RFID Tags Using a Circuit Model Proc. IEEE RFID April 27--28, 2009, Orlando, FL. To Appear.

The great majority of commercial UHF RFID tags are based on dipole antennas using a modification of a T-match as a matching circuit. The literature contains examples of wideband matching, but provides little insight as to how wideband behavior is achieved. Here, we present a simple circuit-based theory to describe the antenna, matching circuit, and IC behavior; we present an approach for developing an impeding matching strategy to maximize bandwidth; and we present a concrete example and analysis using a method of moments (MoM) numerical solver. The results show very good agreement with theory.

Daniel D. Deavours, A Circularly Polarized Planar Antenna Modi?ed for Passive UHF RFID Proc. IEEE RFID April 27--28, 2009, Orlando, FL. To Appear.

The majority of RFID tags are linearly polarized dipole antennas, but a few use a planar, dual-dipole antenna that facilitates circular polarization, but requires a three- terminal IC. In this paper, we present a novel way to achieve circular polarization with a planar antenna using a two- terminal IC. We present an intuitive methodology for design, and perform experiments that validate circular polarization. The results show that the tag exhibits strong circular polariza- tion, but the precise axial ratio of the tag remains uncertain due to lack of precision in the experimental system.

Naaser A. Mohammed, Mutharasu Sivakumar, and Daniel D. Deavours, An RFID Tag Capable of Free-Space and On-Metal Operation. In Proc. IEEE Radio and Wireless Symposium January 18--22, 2009, San Diego, CA.

The majority of commercial UHF RFID tags are based on the dipole antenna, and it is well known that tag performance degrades significantly when the tag is placed near a conducting surface. Here, we present a new antenna that operates as a dipole when in free space, but when placed on a conducting surface, it operates as a relatively efficient microstrip antenna. The antenna is shown to have near-optimal free-space performance and yield a peak gain of approximately 6 dBi of effective gain on a copper surface.

Supreetha Aroor and Daniel D. Deavours, Dual-Resonant Microstrip-Based UHF RFID "Cargo" Tag. In Proc. IEEE MTT-S International Microwave Symposium 2008 (IMS2008) June 15-20, 2008, Atlanta, TX.

We present a novel passive UHF RFID "cargo tag" capable of operating in two different graphic regions such as Europe and North America. The tag utilizes a dual- resonant, dual-polarized, microstrip antenna. The resulting tag operates effciently over ETSI and FCC frequency ranges and achieves excellent effciency. The tag antenna elimi- nates any cross-layer structures such as a via and may be manufactured effciently using traditional, low-cost "inlay" technology. We estimate the free-space read distance to be between 9.3 and 13.1 meters (30 and 43 feet).

Mutharasu Sivakumar and Daniel D. Deavours, A Dual-Resonant Microstrip Antenna for Paperboard in the Cold Chain In 2008 IEEE Sarnoff Symposium . April 28-30, 2008, Princeton, NJ.

Passive UHF RFID tags have proved to be useful to serialize and automate tracking of goods through the supply chain, and the application of RFID to the cold chain is especially useful, where food safety and product quality are of special concern. The environment in the cold chain provides unique challenges to RFID, where water-based contents are the norm, and moisture and humidity can range widely. In this paper, we present a novel approach to addressing these challenges: using a microstrip antenna that uses the cardboard as the substrate. This introduces a new problem, namely the wide variation in the dielectric properties of the cardboard makes it diffcult to use traditional microstrip antennas. In this paper, we show a novel antenna structure and matching circuit that overcomes these challenges. The resulting design provides nearly uniform level of performance regardless of content and moisture condition. The antenna is readily manufacturable using traditional inlay manufacturing techniques.

Afzal Syed, Kenneth Demarest, Daniel D. Deavours, Effects of Antenna Material on the Performance of UHF RFID Tags. In IEEE RFID 2007 . March 26--28, 2007, Grapevine, TX, pp. 57-62.

The RFID industry is growing rapidly, especially in the UHF frequency band that is being used extensively in supply chain management. Traditionally, inlays have been constructed from etched copper or aluminum. Etching is a subtractive process that uses chemicals and can creates waste. Recently, inlays are manufactured using silver-based inks. Printing is an additive process, so it has a number of advantages. However, silver inks suffer from two important drawbacks: relatively poor conductivity and environmental concerns. Those concerns have spurred developments in other additive technologies, such as vapor-deposited aluminum, electroplated, and electro-less deposited copper. This paper quantizes by measurement the performance of antennas with three materials, four line widths, and various thicknesses, which may serve as guidelines about how to design antennas with the various materials.

Madhuri Eunni, Mutharasu Sivakumar, and Daniel D. Deavours. A Novel Planar Microstrip Antenna Design for UHF RFID in The 4th International Conference on Computing, Communications and Control Technologies: CCCT '06 . July 20-23, 2006, Orlando, FL, pp. 6-10.

Passive UHF RFID tags generally do not work well near metal or water. Microstrip antennas offer a potential solution, but suffer from manufacturing complexity because a need for a via or some other reference to ground. We present a new antenna and matching circuit designed using a balanced feed that eliminates any reference to ground and thus simplifies the antenna's construction.

Karthik Moncombu Ramakrishnan and Daniel D. Deavours. Performance Benchmarks for Passive UHF RFID Tags in Proceedings of the 13th GI/ITG Conference on Measurement, Modeling, and Evaluation of Computer and Communication Systems. Nurenberg, Germany, March 27-29, 2006, pp. 137-154.

This paper describes the first comprehensive benchmark suite for passive UHF RFID tags. These benchmarks give good indications as to how well RFID products will work in ``real world'' scenarios. We present benchmarks and give some experimental results, as well as key insights that these benchmarks have revealed about the nature of current UHF RFID tags on the market.

W. H. Sanders, T. Courtney, D. Deavours, D. Daly, S. Derisavi, and V. Lam. Multi-formalism and Multi-solution-method Modeling Frameworks: The Möbius Approach. In Proceedings of the Symposium on Performance Evaluation - Stories and Perspectives. Vienna, Austria, December 5-6, 2003, pp. 241-256.

Abstract.

W. H. Sanders and C. Polychronopoulos and T. Huang and T. Courtney and D. Daly and D. Deavours and S. Derisavi. Overview: An Integrated Framework for Performance Engineering and Resource-Aware Compilation. In Proceedings of the NSF Next Generation Systems Program Workshop, Fort Lauderdale, FL, April 15, 2002.

Design of next-generation computing and communication systems will be application-driven, and requires fundamental advances in 1) performance engieering frameworks, methods, and tools, and 2) adaptive compilation and runtime support techniques. Our work is taking a systematic and synergetic approach to developing both of these capabilities, and is demonstrating their use via application to several important distributed applications. In conducting the work, we are making fundamental advances in techniques for system and model compsotion, multi-level/formalism modeling and performance evaluation, adaptive compilation, and dynamic runtime support.

D. D. Deavours and W. H. Sanders. Möbius: Framework and Atomic Models. In Proc. 9th Int. Workshop on Petri Nets and Performance Models (PNPM '01), Aachen, Germany, September 11-14, 2001, pp. 251-260, IEEE Comp. Soc. Press.

This paper gives an overview of the Möbius framework, and gives a formal specification for defining atomic models within the framework. The framework is designed to be capable of incorporating multiple modeling formalisms, including atomic models (e.g, SPNs), composition formalisms (e.g., Replicate/Join), measure specification formalisms, connection formalisms, and solvers. We focus on atomic models, which are composed of actions, state variables, and properties. We argue that these are sufficient to specify a large number of atomic model formalisms in the Möbius framework. The framework serves as a basis for the \mobius tool.

D. D. Deavours and W. H. Sanderse. The Möbius Execution Policy. In Proc. 9th Int. Workshop on Petri Nets and Performance Models (PNPM '01), Aachen, Germany, September 11-14, 2001, pp. 135-144, IEEE Comp. Soc. Press.

Möbius is an extensible framework and tool for performance and dependability modeling, and supports multiple modeling formalisms and solvers. As a framework, Möbius must be sufficiently general to capture the various formalism behaviors. Specifically, the Möbius execution policy must be flexible enough to accommodate the execution policies of all formalisms implemented in the framework. We know of no existing execution policy which is capable of doing this and meeting the many other goals of the framework. We present the Möbius execution policy that addresses these needs. In developing the policy, we have generalized the various preemption policies and made all aspects of the execution policy state-dependent, which has never before been considered. Because all aspects may be state-dependent, we also had to relax the assumption that work proceeds at a constant rate; this is also novel. Finally, we show that within the context of Möbius, the extra structure and overhead needed to implement a particular behavior can largely be avoided except when that behavior is present in a model.

G. Clark, T. Courtney, D. Daly, D. Deavours, S. Derisavi, J. M. Doyle, W. H. Sanders, and P. Webster. The Möbius Modeling Tool. In Proc. 9th Int. Workshop on Petri Nets and Performance Models (PNPM '01), Aachen, Germany, September 11-14, 2001, pp. 241-250, IEEE Comp. Soc. Press.

Despite the development of many modeling formalisms and model solution methods, most tool implementations support only a single formalism. Furthermore, models expressed in the chosen formalism cannot be combined with models expressed in other formalisms. This monolithic approach both limits the usefulness of such tools to practitioners, and hampers modeling research, since it is difficult to compare new and existing formalisms and solvers. This paper describes the method that a new modeling tool, called Möbius, uses to eliminate these limitations. Möbius provides an infrastrcture to support multiple interacting formalisms and solvers, and is extensible in that new formalisms and solvers can be added to the tool without changing those already implemented. Möbius provides this capability through the use of an abstract functional interface, which provides a formalism-independent interface to models. This allows models expressed in multiple formalisms to interact with each other, and with multiple solvers.

D. D. Deavours and W. H. Sanders. An Efficient Well-Specified Check. In P. Bucholz and M. Silva, editors, Proc. 8th Int. Workshop on Petri Nets and Performance Models (PNPM '99), Zaragosa, Spain, September 1999, pp. 124-133, IEEE Comp. Soc. Press.

A longstanding problem with generalized stochastic Petri nets and extensions is that of what to do when more than one zero-timed event is scheduled to occur at the same time. If the order is left unspecified, it could lead to ambiguity that affects reward variables. Stochastic activity nets (SANs) have used the well-specified condition to avoid this problem. However, the existing algorithm to perform the well-specified check is computationally complex, proportional to the number of paths through unstable markings. We provide some theoretical results that allow us to make use of a much more efficient algorithm, with complexity proportional to the number of arcs between unstable markings.

D. D. Deavours and W. H. Sanders. "On-the-fly" Solution Techniques for Stochastic Petri Nets and Extensions. In Proc. 7th Int. Workshop on Petri Nets and Performance Models (PNPM '97), Saint Malo, France, June, 1997, pp. 132-141, IEEE Comp. Soc. Press.

Use of a high-level modeling representation, such as stochastic Petri nets, frequently results in a very large state space. In this paper, we propose new methods that can tolerate such large state spaces and that do not require any special structure in the model. First, we develop methods that generate rows and columns of the state transition-rate-matrix on-the-fly, eliminating the need to explicitly store the matrix at all. Next, we introduce a new iterative solution method, called modified adaptive Gauss-Seidel, that exhibits locality in its use of data from the state transition-rate-matrix. This permits the caching of portions of the matrix, hence reducing the solution time. Finally, we develop a new memory- and computationally-efficient technique for Gauss-Seidel-based solvers that avoids the need for generating rows of $A$ in order to solve $Ax=b$. Taken together, these new results show that one can solve very large SPN, GSPN, SRN, and SAN models without any special structure.

D. D. Deavours and W. H. Sanders An Efficient Disk-Based Tool for Solving Very Large Markov Models In Proc. Int. Conference on Modeling Techniques and Tools for Computer Performance Evaluation (TOOLS '97), Saint Malo, France, June, 1997, pp. 58-71, Springer.

Very large Markov models often result when modeling realistic computer systems and networks. We describe a new tool for solving large Markov models on a typical engineering workstation. This tool does not require any special properties or a particular structure in the model, and it requires only slightly more memory than what is necessary to hold the solution vector itself. It uses a disk to hold the state-transition-rate matrix, a variant of block Gauss-Seidel as the iterative solution method, and an innovative implementation that involves two parallel processes: the first process retrieves portions of the iteration matrix from disk, and the second process does repeated computation on small portions of the matrix. We demonstrate its use on two realistic models: a Kanban manufacturing system and the Courier protocol stack, which have up to 10 million states and about 100 million nonzero entries. The tool can solve the models efficiently on a workstation with 128 Mbytes of memory and 4 Gbytes of disk.

Invited Talks

Supreetha Aroor and Daniel D. Deavours, "A Dual-Resonant Microstrip-Based UHF RFID `Cargo' Tag." Presentation at IEEE MTT-S International Microwave Symposium 2008 (IMS2008), Atlanta, GA, June 18, 2008. Gary Clancy and Daniel D. Deavours, "Tracking Industrial Sized Containers." Presentation at EPC Connection, Chicago, IL, October 3, 2007.
Daniel D. Deavours, "Don't Mitigate the Metal/Water Problem; Solve It!" Presentation to the Reusable Plastic Container Coalition (RPCC), Dallas, TX, September 20, 2007.
Daniel D. Deavours, "From Pilot to Production: Practical Considerations in Your RFID Deployment." Tutorial for RFID World 2007 Cold Chain track, Grapevine, Tx, March 26, 2007.

Daniel D. Deavours, "RFID TSC110: UHF RFID - Tag Antennas." Tutorial for MTT-S, San Francisco, CA, June 11, 2006.

Daniel D. Deavours, "Deploying Gen 2," RFID Journal Live!, Las Vegas, NE, May 2, 2006.

Daniel D. Deavours, Weichao Wang, and Shannon D. Blunt, "Privacy and Opportunity in Passive RFID: Authentication and Identification using CDMA", Academic Convocation at RFID Journal Live! Las Vegas, NE, May 1, 2006.

Daniel D. Deavours "Gen 2 vs. Gen 1", RFID Journal Live! Las Vegas, NE, May 2-3, 2006.

Daniel D. Deavours "Gen 1 and Gen 2", RFID Journal Live! Las Vegas, NE, May 2-3, 2006.

Daniel D. Deavours "Data Rates", RFID Journal Live! Las Vegas, NE, May 2-3, 2006.

Daniel D. Deavours "Gen 2 and Q", RFID Journal Live! Las Vegas, NE, May 2-3, 2006.

Daniel D. Deavours, "RFID Alliance Lab: Testing Performance," Workshop presentation for RFID World, Dallas, TX, February 27, 2006.

Daniel D. Deavours, "Passive UHF RFID Performance on Materials," Poster for RFID Research Convocation, Boston, MA, January 23-24, 2006.

Daniel D. Deavours, "RFID: Measurement and Practice," University of Illinois, Champaign, IL, October 29, 2005.

Daniel D. Deavours, "Evaluating EPC Tag performance," RFID Journal Webinar, June 29, 2005.

Daniel D. Deavours, "EPC Tag Performance," RFID Journal Live!, Chicago, IL, April 10-12, 2005.

Daniel D. Deavours, "Performance of Pharma Tags - An Empirical Approach," RFID Pharmaceuticals Focus, Philadelphia, PA, March 30-31, 2005.

Daniel D. Deavours, "RFID Performance Characteristics," Midwest RFID Symposium,, Kansas City, KS, March 3, 2005.

Daniel D. Deavours, "User Perceived Bluetooth Interoperability," Computer Measurement Group, Fall Impact Conference, Overland Park, KS, October 5-6, 2004.

Tool descriptions

D. Daly, D. D. Deavours, J. M. Doyle, P. G. Webster, and W. H. Sanders. Möbius: An Extensible Tool for Performance and Dependability Modeling. In Computer Performance Evaluation: Modelling Techniques and Tools: Proceedings of the 11th International Conference, TOOLS 2000, Schaumburg, IL, March 27-31, 2000. In B. R. Haverkort, H. C. Bohnenkamp, and C. U. Smith (Eds.), Lecture Notes in Computer Science No. 1786, pp. 332-336. Berlin: Springer, 2000.

A brief, 4 page description of Möbius.

D. Daly, D. D. Deavours, J. M. Doyle, A. J. Stillman, and P. G. Webster. Möbius: An Extensible Tool for Performance and Dependability Modeling. In Digest of FastAbstracts presented at the 29th Annual International Symposium on Fault-Tolerant Computing (FTCS-29), Madison, Wisconsin, USA, June 15-18, 1999, pp 15-16.

A brief, 2 page description of Möbius.

D. Daly, D. D. Deavours, J. M. Doyle, A. J. Stillman, P. G. Webster, and W. H. Sanders. Möbius: An Extensible Framework for Performance and Dependability Modeling. In Tool Descriptions from the Multi-Workshop on Formal Methods in Performance Evaluation and Applications, Zaragoza, Spain, September 6-10, 1999.

A brief, 5 page description of Möbius.

W. D. Obal II, M. A. Qureshi, D. D. Deavours, W. H. Sanders. Overview of UltraSAN. In Proceedings IEEE Int. Performance and Dependability Symposium, Urbana, IL, September 4-6, 1996, p. 63.

A 1 page overview of UltraSAN.

D. D. Deavours, W. D. Obal II, M. A. Qureshi, W. H. Sanders, and A. P. A. van Moorsel. UltraSAN Version 3 Overview. In Proceedings of the 6th Int. Workshop on Petri Nets and Performance Models, Durham, NC, October 3-6, 1995, pp. 216-217.

A two-page overview of UltraSAN Version 3.0.

Theses, Tutorials, Reports, etc.

D. D. Deavours, Formal Specification of the Möbius Modeling Framework. PhD Disseration, University of Illinois at Urbana Champaign, 2001.

My PhD dissertation.

D. D. Deavours, It's Time for Open RFID. Column for Pharmaceutical Manufacturing March 10, 2005.

Last updated: May 6, 2006. Report suggestions and problems to author.