Publications - Institut für Angewandte Mikroelektronik und Datentechnik

Collection ...

... of various publications by members of the NOC Research Group:

Papers, journals ...
List of reviewed publications, e.g. conferences, workshops, journals

Talks, reports ...
Collection of non-reviewed publications, e.g. presentations, reports

Papers, journals ...

..: 2013 :..

Centralized Traffic Monitoring for online-resizable Clusters in Networks-on-Chip (Paper & Slides)
Philipp Gorski, Dirk Timmermann
8th International Workshop on Reconfigurable Communication-centric Systems-on-Chip, Darmstadt, Germany, July 2013
System level modeling of Networks-on-Chip for power estimation and design space exploration (Paper)
Martin Gag, Tim Wegner, Philipp Gorski, Andreas Tockhorn, Dirk Timmermann
16. Workshop Methoden und Beschreibungssprachen zur Modellierung und Verifikation von Schaltungen und Systemen (MBMV 2013), pp. 25-34 , ISBN: 978-3-86009-147-0, Rostock-Warnemünde, Germany, March 2013
RedNoCs: A Runtime Configurable Solution for Cluster-based and Multi-objective System Management in Networks-on-Chip (Paper & Slides)
Philipp Gorski, Claas Cornelius, Dirk Timmermann, Volker Kühn
8th International Conference on Systems (ICONS 2013), pp. 192-201, ISBN: 978-1-61208-246-2, Seville, Spain, January 2013
Centralized Adaptive Source-Routing for Networks-on-Chip as HW/SW-Solution with Cluster-based Workload Isolation (Paper)
Philipp Gorski, Claas Cornelius, Dirk Timmermann, Volker Kühn
8th International Conference on Systems (ICONS 2013), pp. 192-201, ISBN: 978-1-61208-246-2, Seville, Spain, January 2013

https://typo3.uni-rostock.de/ ..: 2012 :..

Performance analysis of Temperature Management Approaches in Networks-on-Chip Tim Wegner, Martin Gag, Dirk Timmermann International Journal of Embedded and Real-Time Communication Systems (IJERTCS), ISBN: 1947-3184, Hershey, PA, USA, Dezember 2012
Selective redundancy to improve reliability and to slow down delay degradation due to gate oxide breakdown(Paper)
Hagen Sämrow, Claas Cornelius, Philipp Gorski, Andreas Tockhorn, Dirk Timmermann
15th IEEE Symposium on Design and Diagnostics of Electronic Circuits and Systems (DDECS), Tallinn, Estonia, April 2012
Temperature and On-chip Crosstalk Measurement using Ring Oscillators in FPGA(Paper & Slides)
Martin Gag, Tim Wegner, Ansgar Waschki, Dirk Timmermann
15th IEEE Symposium on Design and Diagnostics of Electronic Circuits and Systems (DDECS), Tallinn, Estonia, April 2012
Effiziente Simulation von Gateoxiddefekten auf Gatterebene mit Transistorlevel-Genauigkeit (Paper & Slides)
Hagen Sämrow, Claas Cornelius, Philipp Gorski, Jakob Salzmann, Dirk Timmermann
15th Workshop Methoden und Beschreibungssprachen zur Modellierung und Verifikation von Schaltungen und Systemen (MBMV), ISBN: 978-3-8300-6201-1, Kaiserslautern, Germany, March 2012

..: 2011 :..

Impact of Proactive Temperature Management on Performance of Networks-on-Chip (Paper & Slides)
Tim Wegner, Martin Gag, Dirk Timmermann
International Symposium on System-on-Chip 2011 (SoC 2011), Tampere, Finland, November 2011
Power-efficient application of Sleep Transistors to enhance the reliability of integrated circuits
Claas Cornelius, Frank Sill Torres, Dirk Timmermann
Journal of Low Power Electronics (JOLPE), Vol. 7, N° 4, pp. 552-561, October 2011
Reduction of Thermal Imbalances and Hot Spots in Networks-on-Chip Using Proactive Temperature Management (Paper & Slides)
Tim Wegner, Martin Gag, Dirk Timmermann, Adelinde Uhrmacher
5. GMM/GI/ITG- Fachtagung Zuverlässigkeit und Entwurf (ZuE 2011), Hamburg, Germany, September 2011
Evaluation of Switch-to-Switch Header Flit Protection Schemes in Networks-on-Chip (Paper & Slides)
Martin Gag, Philipp Gorski, Tim Wegner, Dirk Timmermann
5. GMM/GI/ITG- Fachtagung Zuverlässigkeit und Entwurf (ZuE 2011), Hamburg, Germany, September 2011
Functional Enhancements of TMR for Power Efficient and Error Resilient ASIC Designs (Paper & Slides)
Hagen Sämrow, Claas Cornelius, Philipp Gorski, Jakob Salzmann, Andreas Tockhorn, Dirk Timmermann
14th IEEE Symposium on Design and Diagnostics of Electronic Circuits and Systems (DDECS), ISBN: 978-1-4244-9754-6, pp. 183-188, Cottbus, Germany, April 2011
Monitoring and Control of Temperature in Networks-on-Chip (Paper)
Tim Wegner, Claas Cornelius, Andreas Tockhorn, Dirk Timmermann
OpenAccess Series in Informatics (OASIcs) - Selected Papers from MEMICS, ISBN: 978-3-939897-22-4, pp. 124-131, Schloss Dagstuhl, Germany, March 2011
Reliability Enhancement via Sleep Transistors (Paper & Slides)
Frank Sill Torres, Claas Cornelius, Dirk Timmermann
12th IEEE Latin-American Test Workshop (LATW), ISBN: 978-1-4577-1489-4, pp. 1-6, Porto de Galinhas, Brazil, March 2011

..: 2010 :..

Utilizing Parallelism of TMR to Enhance Power Efficiency of Reliable ASIC Designs (Paper & Slides)
Hagen Sämrow, Claas Cornelius, Jakob Salzmann, Andreas Tockhorn, Dirk Timmermann
6th International Conference on Computer Engineering and Systems (ICCES), ISBN: 978-1-4244-7041-9, pp. 251-256, Cairo, Egypt, December 2010
Simulation of Thermal Behavior for Networks-on-Chip (Paper)
Tim Wegner, Claas Cornelius, Martin Gag, Andreas Tockhorn, Adelinde Uhrmacher, Dirk Timmermann
28th NORCHIP Conference, ISBN: 978-1-4244-8971-8, Tampere, Finland, November 2010
Monitoring and Control of Temperature in Networks-on-Chip (Paper & Slides)
Tim Wegner, Claas Cornelius, Andreas Tockhorn, Dirk Timmermann
6th Workshop on Mathematical and Engineering Methods in Computer Science (MEMICS), ISBN: 978-80-87342-10-7, pp. 184-192, Mikulov, Czech Republic, October 2010
System Level Power Estimation of System-on-Chip Interconnects in Consideration of Transition Activity and Crosstalk
Martin Gag, Tim Wegner, Dirk Timmermann
20th International Workshop on Power and Timing Modeling, Optimization and Simulation (PATMOS), ISBN: 978-3-642-17751-4, pp. 21-30, Grenoble, France, September 2010
Router layout for reduced area costs in networks-on-chip (Paper & Slides)
Claas Cornelius, Hagen Sämrow, Dirk Timmermann
13th Symposium Maritime Elektrotechnik, Elektronik und Informationstechnik, Rostock, Germany, September 2010
Reliability Enhancement of Pipelined ADC (Paper & Slides)
Frank Sill Torres, Claas Cornelius, Dirk Timmermann
13th Symposium Maritime Elektrotechnik, Elektronik und Informationstechnik, Rostock, Germany, September 2010
Trading hardware overhead for communication performance in mesh-type topologies (Paper & Slides)
Claas Cornelius, Philipp Gorski, Stephan Kubisch, Dirk Timmermann
13th Euromicro Conference on Digital System Design (DSD), ISBN: 978-0-7695-4171-6, pp. 173-180, Lille, France, September 2010
Modeling Temperature Distribution in Networks-on-Chip using RC-Circuits (Paper & Poster)
Andreas Tockhorn, Claas Cornelius, Hagen Sämrow, Dirk Timmermann
13th Intern. IEEE Symposium on Design and Diagnostics of Electronic Circuits and Systems (DDECS), ISBN: 978-1-4244-6610-8, pp. 229-232, Vienna, Austria, April 2010

..: 2009 :..

Twin Logic Gates - Improved Logic Reliability concerning Gate Oxide Breakdown (Paper)
Hagen Sämrow, Claas Cornelius, Frank Sill, Andreas Tockhorn, Dirk Timmermann
22st Symposium on Integrated Circuits and Systems Design (SBCCI), ISBN: 978-1-60558-705-9, Natal, Brasil, September 2009
Automated Insertion of Twin Gates to improve Gate Oxide Breakdown(Paper)
Hagen Sämrow, Claas Cornelius, Frank Sill, Andreas Tockhorn, Dirk Timmermann
SPIE Europe Microtechnologies for the New Millennium, ISBN: 978-0-81947-637-1, Dresden, Germany, May 2009
Differences and Commonalities of Service-Oriented Device Architectures, Wireless Sensor Networks and Networks-On-Chip (Paper & Slides)
Guido Moritz, Claas Cornelius, Frank Golatowski, Dirk Timmermann, Regina Stoll
4th Intern. IEEE Workshop on Service Oriented Architectures in Converging Networked Environments (SOCNE), Bradford, United Kingdom, May 2009
Comparison of Strategies for Redundancy to improve Reliability concerning Gate Oxide Breakdown (Paper & Slides)
Hagen Sämrow, Claas Cornelius, Frank Sill, Andreas Tockhorn, Dirk Timmermann
21st Workshop für Testmethoden und Zuverlässigkeit von Schaltungen und Systemen (TUZ), pp. 97-102, Bremen, Germany, February 2009
Trust-by-Wire in Packet-Switched IPv6 Networks: Tools and FPGA Prototype for the IPclip System (Paper)
Peter Danielis, Stephan Kubisch, Harald Widiger, Jens Rohrbeck, Vladyslav Altman, Jan Skodzik, Daniel Duchow, Thomas Bahls, Dirk Timmermann
6th Annual IEEE Consumer Communications and Networking Conference (CCNC), ISBN: 978-1-4244-2309-5, pp. 1-2, Las Vegas/Nevada, USA, January 2009

..: 2008 :..

IPclip: An Architecture to restore Trust-by-Wire in Packet-switched Networks (Paper & Slides)
Harald Widiger, Stephan Kubisch, Peter Danielis, Jens Schulz, Daniel Duchow, Thomas Bahls, Dirk Timmermann
33rd IEEE Conference on Local Computer Networks (LCN), ISBN: 978-1-4244-2413-9, pp. 312-319, Montreal, Quebec, Canada, October 2008
Encountering gate oxide breakdown with shadow transistors to increase reliability (Paper & Slides)
Claas Cornelius, Frank Sill, Hagen Sämrow, Jakob Salzmann, Dirk Timmermann, Diógenes da Silva
21st Symposium on Integrated Circuits and Systems Design (SBCCI), ISBN: 978-1-60558-231-3, pp. 111-116, Gramado, Brasil, September 2008
Trust-by-Wire in Packet-switched IP Networks: Calling Line Identification Presentation for IP (Paper)
Stephan Kubisch, Harald Widiger, Peter Danielis, Jens Schulz, Daniel Duchow, Thomas Bahls, Dirk Timmermann
1st ITU-T Kaleidoscope Conference: Innovations in Next Generation Networks - Future Network and Services, Geneva, Switzerland, May 2008
Networks: Complexity and Scalability (Paper)
Stephan Kubisch
22nd IEEE Intern. Parallel and Distributed Processing Symposium (IPDPS), IPDPS TCPP PhD-Forum, Miami/Florida, USA, April 2008
Countering Phishing Threats with Trust-by-Wire in Packet-switched IP Networks - A Conceptual Framework
Stephan Kubisch, Harald Widiger, Peter Danielis, Jens Schulz, Dirk Timmermann, Thomas Bahls, Daniel Duchow
22nd IEEE Intern. Parallel and Distributed Processing Symposium (IPDPS), 4th International Workshop on Security in Systems and Networks (SSN 2008), Miami/Florida, USA, April 2008
IPclip - An Innovative Mechanism to Reestablish Trust-by-Wire in Packet-switched IP Networks (Paper)
Peter Danielis, Stephan Kubisch, Harald Widiger, Jens Schulz, Dirk Timmermann, Thomas Bahls, Daniel Duchow
3. Essener Workshop "Neue Herausforderungen in der Netzsicherheit" (Prospective Challanges in Network Security), Essen, Germany, April 2008
Complementing E-Mails with Distinct, Geographic Location Information in Packet-switched IP Networks" (Paper)
Stephan Kubisch, Harald Widiger, Peter Danielis, Jens Schulz, Dirk Timmermann, Thomas Bahls, Daniel Duchow
MIT 2008 Spam Conference, Cambridge/Massachusetts, USA, March 2008

..: 2007 :..

A Design Tool for Modeling Asynchronous Dynamic Logic (Paper)
Frank Sill, Frank Grassert, Claas Cornelius, Dirk Timmermann
Forschung und wissenschaftliches Rechnen: Beiträge zum Heinz-Billing-Preis 2006, Göttingen, Germany, November 2007
A Mesochronous Network-on-Chip for an FPGA (Paper & Slides)
Stephan Kubisch, Enrico Heinrich, Dirk Timmermann
Annual Doctoral Workshop on Mathematical and Engineering Methods in Computer Science (MEMICS), ISBN: 978-80-7355-077-6, pp. 113-120, Znojmo, Czechia, October 2007 (*** Best Paper Award ***)
Realisierung und Implementierung eines Algorithmus zur Echtzeit-Mustererkennung in einem Ethernet-Datenstrom (Paper & Slides)
Peter Danielis, Stephan Kubisch and Dirk Timmermann
12th Symposium Maritime Elektrotechnik, Elektronik und Informationstechnik, Universitätsdruckerei Rostock 685-07, pp. 191-196, Rostock, Germany, October 2007
Modeling the power-reliability tradeoff in on-chip Networks (Paper & Slides)
Claas Cornelius, Frank Sill, Dirk Timmermann
12th Symposium Maritime Elektrotechnik, Elektronik und Informationstechnik, Universitätsdruckerei Rostock 685-07, pp. 321-326, Rostock, Germany, October 2007
Leckstromreduzierung in Nanometer-Technologien ohne Performanceverluste (Paper & Slides)
Frank Sill, Claas Cornelius, Dirk Timmermann
12th Symposium Maritime Elektrotechnik, Elektronik und Informationstechnik, Universitätsdruckerei Rostock 685-07, pp. 329-334, Rostock, Germany, October 2007
A Structural Architecture for HW Packet Processing (Paper & Slides)
Harald Widiger, Stephan Kubisch, Dirk Timmermann
11th IEEE Pacific Rim Conference on Communications, Computers and Signal Processing (PACRIM), ISBN: 1-4244-1190-4, pp. 363-366, Victoria, B.C., Canada, August 2007
Mapping a Pipelined Data Path onto a Network-on-Chip (Paper & Slides)
Stephan Kubisch, Claas Cornelius, Ronald Hecht, Dirk Timmermann
2nd IEEE Intern. Symposium on Industrial Embedded Systems (SIES), ISBN: 1-4244-0840-7, pp. 178-185, Lisbon, Portugal, July 2007
sMAT - A Simplified MAC Address Translation Scheme for Ethernet-based DSL Access Networks (Poster)
Stephan Kubisch, Harald Widiger, Dirk Timmermann, Daniel Duchow, Thomas Bahls
15th IEEE Workshop on Local and Metropolitan Area Networks (LANMAN), Princeton, USA, June 2007
E-Core - A Configurable IP Core for Application-specific NoC Performance Evaluation (Paper & Slides)
Stephan Kubisch, Harald Widiger, Claas Cornelius, Dirk Timmermann, Andy Strzeletz
Design Automation and Test in Europe (DATE), Workshop on Diagnostic Services in Network-on-Chips, Nice, France, April 2007
Architektur einer Flexiblen, Wiederverwendbaren Testbench zur Verifikation Paketverarbeitender Hardware in SystemC (Paper & Slides)
Stephan Kubisch, Harald Widiger, Ronald Hecht, Dirk Timmermann, Martin Siemroth
10th GI/ITG/GMM Workshop "Methoden und Beschreibungssprachen zur Modellierung und Verifikation von Schaltungen und Systemen", ISBN: 978-3-8322-5965-3, pp. 9-18, Erlangen, Germany, March 2007
Network-on-Chip Communication Grids for High Performance Packet Processing (Poster & Abstract)
Stephan Kubisch, Harald Widiger, Ronald Hecht, Dirk Timmermann
15th ACM/SIGDA Intern. Symposium on Field-Programmable Gate Arrays (FPGA), ISBN: 978-1-59593-600-4, p. 228, Monterey, CA, USA, February 2007
Deep Submicron Technology: Opportunity or Dead End for Dynamic Circuit Techniques (Paper & Slides)
Claas Cornelius, Frank Grassert, Siegmar Köppe, Dirk Timmermann
20th Intern. Conference on VLSI Design (VLSI Design), ISBN: 978-0-7695-2762-8, pp. 330-335, Bangalore, India, January 2007

..: 2006 :..

LoGen - Generation and Simulation of Digital Logic on the Gate-Level via Internet (Paper & Slides)
Stephan Kubisch, Rüdiger Rennert, Hartmut Pfüller, Dirk Timmermann
1st IEEE Intern. Conference on E-Learning in Industrial Electronics (ICELIE), ISBN: 1-4244-0324-3, Hammamet, Tunisia, December 2006
An Integrated Hardware Solution for Mac Address Translation, MPLS, and Traffic Management in Access Networks (Paper & Slides)
Harald Widiger, Stephan Kubisch, Dirk Timmermann, Thomas Bahls
31st IEEE Conference on Local Computer Networks (LCN), ISBN: 1-4244-0419-3, pp. 272-279, Tampa, Florida, USA, November 2006
ACIP: An Access Control and Information Protocol for Ethernet-based Broadband Access Networks (Paper & Slides)
Daniel Duchow, Thomas Bahls, Dirk Timmermann, Harald Widiger, Stephan Kubisch
12th Intern. Telecommunications Network Strategy and Planning Symposium (Networks) on CD-Rom, ISBN: 978-3-8007-2999-9, New Delhi, India, November 2006
Service-oriented Approaches for the Operation of large on-chip Networks (Paper & Poster)
Claas Cornelius, Hendrik Bohn, Dirk Timmermann
24th NORCHIP Conference, ISBN: 1-4244-0772-9, pp. 183-186, Linköping, Sweden, November 2006
Development and Operation of Networks-on-Chip (Paper & Poster)
Claas Cornelius, Dirk Timmermann
14th IFIP Intern. Conference on Very Large Scale Integration (VLSI-SoC), (PhD-Forum), pp. 19-23, Nice, France, October 2006
High-Level Simulations of On-Chip Networks (Paper & Slides)
Claas Cornelius, Frank Sill, Dirk Timmermann
9th Euromicro Conference on Digital System Design (DSD), (WiP), ISBN: 3-902457-11-2, pp. 57-58, Cavtat, Croatia, August 2006
Intrinsic Flexibility and Robustness in Adaptive Systems: A Conceptual Framework (Paper & Slides)
Stephan Kubisch, Ronald Hecht, Ralf Salomon, Dirk Timmermann
IEEE Mountain Workshop on Adaptive and Learning Systems (SMCals), ISBN: 1-4244-0166-6, Logan, Utah, USA, July 2006
Mixed Gates: Leakage Reduction techniques applied to Switches for Networks-on-Chip (Paper & Slides)
Frank Sill, Claas Cornelius, Stephan Kubisch, Dirk Timmermann
2nd Intern. Workshop on Reconfigurable Communication-centric System-on-Chips (ReCoSoC), ISBN: 2-9517461-2-1, pp. 76-82, Montpellier, France, July 2006(*** Top-ten rated Paper***)
Efficient Port-based Network Access Control for IP DSLAMs in Ethernet-based Fixed Access Networks (Paper & Slides)
Daniel Duchow, Thomas Bahls, Dirk Timmermann, Stephan Kubisch, Harald Widiger
World Telecommunications Congress (WTC), Budapest, Hungary, May 2006
Dynamic Circuit Techniques in Deep Submicron Technologies: Domino Logic reconsidered (Paper & Poster)
Claas Cornelius, Siegmar Köppe, Dirk Timmermann
Intern. Conference on IC Design and Technology (ICICDT), ISBN: 1-4244-0097-X, pp. 53-56, Padova, Italy, May 2006
Wirespeed MAC Address Translation and Traffic Management in Access Networks (Paper & Slides)
Stephan Kubisch, Harald Widiger, Daniel Duchow, Thomas Bahls, Dirk Timmermann
World Telecommunications Congress (WTC), Budapest, Hungary, May 2006
A Simplified, Cost-Effective MPLS Labeling Architecture for Access Networks (Paper & Slides)
Harald Widiger, Stephan Kubisch, Daniel Duchow, Thomas Bahls, Dirk Timmermann
World Telecommunications Congress 2006 (WTC), Budapest, Hungary, May 2006
A Distributed Object System Approach for Dynamic Reconfiguration (Paper)
Ronald Hecht, Stephan Kubisch, Harald Michelsen, Elmar Zeeb, Dirk Timmermann
Proceedings of the 20th IEEE Intern. Parallel & Distributed Processing Symposium (IPDPS), 13th Reconfigurable Architectures Workshop (RAW 2006), ISBN: 1-4244-0054-6, p. 196, Rhodos, Greece, April 2006
Statistische Analyse des Zeitverhaltens von CMOS Schaltungen und Modellierung von Parametervariationen (Paper & Poster)
Frank Sill, Claas Cornelius, Dirk Timmermann
18th Workshop "Testmethoden und Zuverlässigkeit von Schaltungen und Systemen", pp. 117-118, Titisee-Neustadt, Germany, March 2006
Reduzierung des Leckstromverbrauchs mit gemischten Gattern in Deep Submicron Technologien (Paper & Slides)
Frank Sill, Claas Cornelius, Dirk Timmermann
9th GI/ITG/GMM Workshop "Methoden und Beschreibungssprachen zur Modellierung und Verifikation von Schaltungen und Systemen", ISBN: 3-9810287-1-6, pp. 275-283, Dresden, Germany, February 2006
Adaptive Hardware In Autonomous And Evolvable Embedded Systems (Paper & Slides)
Stephan Kubisch, Ronald Hecht, Dirk Timmermann
Embedded World 2006, ISBN: 3-7723-0143-6, Nürnberg, Germany, February 2006

..: 2005 :..

Verlustleistungsreduzierung bei dynamischen TSPC-Schaltungstechniken (Paper & Slides)
Frank Grassert, Frank Sill, Claas Cornelius, Dirk Timmermann
35th GI Conference: Workshop for the DFG-SPP: VIVA, ISBN: 3-88579-396-2, p. 450, Bonn, Germany, September 2005
Dynamic Reconfiguration with hardwired Networks-on-Chip on future FPGAs (Paper)
Ronald Hecht, Stephan Kubisch, Aandreas Herrholtz, Dirk Timmermann
15th Intern. Conference on Field Programmable Logic and Applications (FPL), ISBN: 0-7803-9362-7, pp. 527-530, Tampere, Finland, August 2005
Design Flow on a Chip - An Evolvable HW/SW-Platform (Paper & Poster)
Stephan Kubisch, Ronald Hecht, Dirk Timmermann
2nd Intern. Conference on Autonomic Computing (ICAC), ISBN: 0-7695-2276-9, pp. 393-394, Seattle, Washington, USA, June 2005

..: 2004 :..

Network-on-Chip basierte Laufzeitsysteme für dynamisch rekonfigurierbare Hardware (Paper & Slides)
Ronald Hecht, Dirk Timmermann, Stephan Kubisch, Elmar Zeeb
17th Intern. Conference on Architecture of Computing System - Organic and Pervasive Computing (ARCS), ISBN: 3-88579-370-9, pp. 185-194, Augsburg, Germany, March 2004

..: 2003 :..

vcOS: An Operating System supporting Virtual Circuitry
Ronald Hecht, Jens Hildebrandt, Dirk Timmermann
29th Euromicro Conference, (WiP-session), pp. 15-16, ISBN: 3-902457-21-X, Belek, Turkey, September 2003

..: 2002 :..

Scalable VHDL Architectures for Non-uniform Sampling Driver Designs
Frank Papenfuß, Ronald Hecht, Dirk Timmermann
8th Baltic Electronics Conference (BEC), ISBN: 9985-59-292-1, pp. 249-252, Tallinn, Estonia, October 2002

Talks, reports ...

..: 2012 :..

Reliability and adaptability of future nanoelectronic systems
(Poster)
Tim Wegner
Contribution in the course of the evaluation of the department Life, Light and Matter of the Interdisciplinary Faculty of the University of Rostock, May 2012