Discrete Event Systems TC Member(s)

Current

Ali Afzalian

Shahid Beheshti University

Iran

Email

Current

Wasseem Alrousan

Wayne State University

United States

Email

Current

Lucas Alves

Universidade Federal de Minas Gerais

Email

Current

Ramakalyan Ayyagari

National Institute of Technology

India

Email

Current

João Carlos Basilio

Federal University of Rio de Janeiro

Brazil

Email

Current

André Bittencourt Leal

Universidade do Estado de Santa Catarina

Email

Current

Hugo Bravo

Federal University of Minas Gerais

Email

Current

Marcos Vicent Brito Moreira

Federal University of Rio de Janeiro

Email

Current

Igor Cohen Calixto

Instituto Militar de Engenharia

Email

Current

Antonio Eduardo Carrilho da Cunha

Instituto Militar de Engenharia

Email

Current

Lilian Carvalho

Universidade Federal do Rio de Janeiro

Brazil

Email

Current

Christos G. Cassandras

Boston University

United States

Email

Christos G. Cassandras

Email

Biography

Christos G. Cassandras is Distinguished Professor of Engineering at Boston University, Head of the Division of Systems Engineering, Professor of Electrical and Computer Engineering, and co-founder of the Center for Information and Systems Engineering. He received degrees from Yale University, Stanford University, and Harvard University. In 1982-84 he was with ITP Boston, Inc. and in 1984-1996 he was with the Department of Electrical and Computer Engineering, University of Massachusetts/Amherst. He specializes in the areas of discrete event and hybrid systems, cooperative control, stochastic optimization, and computer simulation, with applications to computer and sensor networks, manufacturing systems, and transportation systems. He has published over 350 refereed papers in these areas, and five books. He has collaborated with The MathWorks, Inc. in the development of the discrete event and hybrid system simulator SimEvents. Dr. Cassandras was Editor-in-Chief of the IEEE Transactions on Automatic Control (1998-2009) and the 2012 President of the IEEE Control Systems Society. He is the recipient of several awards, including the 2011 IEEE Control Systems Technology Award, the Distinguished Member Award of the IEEE Control Systems Society (2006), IFAC’s 1999 Harold Chestnut Prize, 2011 and 2014 prizes for the IBM/IEEE Smarter Planet Challenge competition, the 2014 Engineering Distinguished Scholar Award at Boston University, several honorary professorships, a 1991 Lilly Fellowship and a 2012 Kern Fellowship. He is also a Fellow of the IEEE and a Fellow of the IFAC.

Affiliation(s)

Boston University

United States

Current

Graziana Cavone

Politecnico di Bari

Italy

Email

Current

Chun-Hung Chen

George Mason University

United States

Email

Current

Jun Chen

Oakland University

United States

Email

Current

Qinrui Chen

Xidian University

China

Email

Current

Edwin Chong

Colorado State University

United States

Email

Current

Abhra Roy Chowdhury

Indian Institute of Science

India

Email

Current

Xuya Cong

Xidian University

Email

Current

Gaochen Cui

Tsinghua University

China

Email

Current

Jose Cury

Universidade Federal de Santa Catarina

Email

Current

Gustavoda da Silva Viana

Federal University of Rio de Janeiro

Email

Current

Jin Dai

University of Notre Dame

United States

Email

Current

Bart De Moor

KU Leuven

Belgium

Email

Current

Samuel Silva de Oliveira

Universidade Federal do Amapá

Email

Current

Bart De Schutter

Delft University of Technology

Netherlands

Email

Current

Rami Debouk

General Motors

Email

Current

Mariagrazia Dotoli

Politecnico di Bari

Italy

Email

Website

Mariagrazia Dotoli

Email

Website

Biography

Mariagrazia Dotoli is a Full Professor in Systems and Control Engineering at Politecnico di Bari, Department of Electrical and Information Engineering, which she joined in 1999 as a tenured Assistant Professor. She was the 2011-2013 Vice-Rector for Research of Politecnico di Bari (Italy) and a 2012-2015 member-elect of the Academic Senate of the same University. She is currently Vice Director for Research of the Department of Electrical and Information Engineering at Politecnico di Bari. She received the Laurea degree in Electronic Engineering with honors in 1995 and the Ph.D. in Electrical Engineering in 1999, both from Politecnico di Bari.

She has been a visiting scholar at the Paris 6 University (France) and at the Technical University of Denmark. Since 2003 she is an expert evaluator of the European Commission, previously for the Sixth and Seventh RTD Framework Programmes, and subsequently for Horizon 2020. Her research interests include the modeling, identification, management, control, automation, optimization, and diagnosis of: discrete event industrial systems, Petri nets, manufacturing systems, supply chains, logistics and transportation systems, traffic networks, energy systems.

She is an Associate Editor of the IEEE Transactions on Automation Science and Engineering, the IEEE Transactions on Control Systems Technology, and the IEEE Transactions on Systems, Man, and Cybernetics: Systems. She was an Associate Editor of the IEEE Robotics and Automation Letters until 2018.

She is currently General Chair of the MED2021 29th Mediterranean Conference on Control and Automation, Program Chair of the CODIT2020 International Conference on Control, Decision and Information Technologies, Program Chair of the CASE2020 annual IEEE Conference on Automation Science and Engineering and Publicity Co-Chair of the IEEE International Conference on Systems, Man, and Cybernetics.

She was the Workshop and Tutorial chair of the 2015 IEEE Conference on Automation Science and Engineering, the Special Session co-chair of the 2013 IEEE Conference on Emerging Technology and Factory Automation, and chair of the National Committee of the 2009 IFAC Workshop on Dependable Control of Discrete Systems. She has been member of the International Program Committee of 70+ international Conferences and Symposia. She is a member of the following committees: IFAC Technical Committee on Discrete Event and Hybrid Systems (since 2011); IEEE Systems Man and Cybernetics Society Technical Committee on Discrete Event Systems (since 2007); IEEE Control Systems Society Technical Committee on Discrete Event Systems (since 2005).

She is author or co-author of 200+ printed publications, including 1 book (in Italian) and 70+ papers on international peer-reviewed journals. Her Scopus Researcher page is available at http://www.scopus.com/authid/detail.url?authorId=6603204493.

Affiliation(s)

Politecnico di Bari

Italy

Current

Wei Duan

Xidian University

Email

Current

Jaime Arturo Dulce Galindo

Universidade Federal de Minas Gerais

Email

Current

Mustafa Durmus

Pamukkale University

Email

Website

Current

Martin Fabian

Chalmers University of Technology

Sweden

Email

Current

Gregory Faraut

École normale supérieure Paris-Saclay

Email

Current

Jean-Marc Faure

LURPA ENS Paris Saclay

Email

Current

Karlijn Fransen

Vanderlande

Email

Current

Michael Fu

University of Maryland

United States

Email

Current

Alexei A. Gaivoronski

Norwegian University of Science and Technology

Email

Current

Chao Gao

Xidian University

China

Email

Current

Gokhan Gelen

Bursa Teknik Üniversitesi

Email

Current

Antonios Georgantas

University of Cyprus

Email

Current

Alessandro Giua

University of Cagliari

Italy

Email

Website

Current

Romulo Goes

Penn State University

United States

Email

Current

Wei-Bo Gong

University of Massachusetts Amherst

Email

Current

Martijn Goorden

Eindhoven University of Technology

Netherlands

Email

Current

Chao Gu

Xidian University

China

Email

Current

Stefan Haar

INRIA

Email

Website

Current

Salwa Habbachi

Macau University of Science and Technology

Email

Current

Christoforos Hadjicostis

University of Cyprus

Cyprus

Email

Christoforos Hadjicostis

Email

Biography

Christoforos Hadjicostis received S.B. degrees in Electrical Engineering, in Computer Science and Engineering, and in Mathematics, the M.Eng. degree in Electrical Engineering and Computer Science in 1995, and the Ph.D. degree in Electrical Engineering and Computer Science in 1999, all from the Massachusetts Institute of Technology, Cambridge, MA. In August 1999 he joined the Faculty at the University of Illinois at Urbana-Champaign (UIUC) where he reached the rank of Associate Professor with the Department of Electrical and Computer Engineering, Research Associate Professor with the Coordinated Science Laboratory, and Research Associate Professor with the Information Trust Institute. In 2007, Dr. Hadjicostis joined the Department of Electrical and Computer Engineering at the University of Cyprus, where he served as Chair of the ECE Department from 2008 to 2010, and as Dean of Engineering from 2014 to 2017. He currently serves as Interim Director of the FOSS Research Center for Sustainable Energy at the University of Cyprus.

Dr. Hadjicostis teaches and conducts research in the areas of systems and control, communication, and digital signal processing. His current research focuses on fault diagnosis and tolerance in distributed dynamic systems; error control coding; distributed algorithms for monitoring, diagnosis and control; discrete event systems; and applications to power distribution networks, network security, anomaly detection, medical diagnosis, and biosequencing. Dr. Hadjicostis serves as Editor in Chief for the Journal of Discrete Event Dynamic Systems and as Associate Editor for Automatica. He has also served as Associate Editor for IEEE Transactions on Automatic Control, IEEE Transactions on Automation Science and Engineering, IEEE Transactions on Circuits and Systems I (Regular Papers), IEEE Transactions on Control Systems Technology, the Journal of Nonlinear Analysis: Hybrid Systems, and the Journal of Discrete Event Dynamic Systems, and as Editor on the Conference Editorial Board of the IEEE Control Systems Society. At the University of Illinois, Dr. Hadjicostis received the Faculty Early Development (CAREER) award from the National Science Foundation in February 2001, the ECE Faculty Outstanding Teaching Award in 2003, and the Willett Faculty Scholar recognition from the College of Engineering in 2005; at the University of Cyprus, he received a 2008 Marie Curie International Reintegration Fellowship from the European Commission. As a graduate student at MIT, he served as president of the MIT Chapter of HKN, received the Harold L. Hazen Teaching Award and the Ernst A. Guillemin Thesis Prize, and received fellowships from the National Semiconductor Corporation and the Grass Instrument Company. Dr. Hadjicostis is a member of Eta Kappa Nu and Sigma Xi, and a Fellow of the IEEE.

Affiliation(s)

University of Cyprus

Cyprus

Current

Xiaoguang Han

Tianjin University of Science & Technology

Email

Current

Shahin Hashtrudi Zad

Concordia University

Email

Current

Zhou He

Shaanxi University of Science & Technology

China

Email

Current

Dennis Hendriks

ESI (TNO) and Radboud University

Email

Current

Michael Heymann

Technion - Israel Institute of Technology

Email

Current

Rick Hill

University of Detroit Mercy

Email

Current

Larry Ho

Harvard University

United States

Email

Current

Larry Holloway

University of Kentucky

Email

Current

Junyao Hou

Shanghai Jiao Tong University

Email

Current

Jian Qiang Hu

Fudan University

Email

Current

Xiao Hu

Tsinghua University

Email

Current

Yihui Hu

Xidian University

China

Email

Current

Yiding Ji

Boston University

United States

Email

Current

Qing-Shan (Samuel) Jia

Tsinghua University

China

Email

Qing-Shan (Samuel) Jia

Email

Biography

Qing-Shan (Samuel) Jia (S’02–M’06–SM’11) received the B.E. degree in automation and the Ph.D. degree in control science and engineering from Tsinghua University, Beijing, China, in 2002 and 2006, respectively.

He is an Associate Professor with the Centre for Intelligent and Networked Systems, Department of Automation, Beijing National Research Center for Information Science and Technology, Tsinghua University. He was a Visiting Scholar with Harvard University, Cambridge, MA, USA, in 2006, the Hong Kong University of Science and Technology, Hong Kong, in 2010, and the Laboratory for Information and Decision Systems, Massachusetts Institute of Technology, Cambridge, MA, USA, in 2013. His current research interests include integrated data-driven, statistical, and computational approaches to find designs and decision-making policies that have simple structures and guaranteed good performance. His research relies on strong collaborations with experts in manufacturing systems, energy systems, autonomous systems, and smart cities.

Dr. Jia is an Associate Editor of the IEEE Transactions on Automatic Control the IEEE Transactions on Automation Science and Engineering, and Discrete Event Dynamic Systems: Theory and Applications. He served as the Discrete Event Systems Technical Committee Chair of the IEEE Control Systems Society from 2012 to 2015 and currently serves as the Chair of the IFAC Technical Committee 9.3 on “Control for Smart Cities” and the Smart Buildings Technical Committee Co-Chair of the IEEE Robotics and Automation Society and the Beijing Chapter Chair of the IEEE Control Systems Society.

Affiliation(s)

Tsinghua University

China

Current

Ruicheng Jiang

Tsinghua University

Email

Current

Chanyoung Ju

Chonnam National University

Email

Current

Jeffrey Kantor

University of Notre Dame

United States

Email

Website

Current

Ali Karimoddini

North Carolina A&T State University

Email

Website

Ali Karimoddini

Email

Website

Biography

Ali Karimoddini received his Bachelor of Electrical and Electronics Engineering from the Amirkabir University of Technology (Tehran Polytechnic), Iran, in 2003. He then received his Master of Science in Instrumentation and Automation Engineering from Petroleum University of Technology in 2007. In 2008, he joined the National University of Singapore to pursue his Ph.D. degree, and in 2012, he joined the University of Notre Dame to conduct his postdoctoral studies.

Dr. Karimoddini is currently an Associate Professor at the Department of Electrical and Computer Engineering, North Carolina A&T State University. His teaching and research interests cover a variety of problems at the intersection of Control, Communication, Computer Science and Life Science. He is currently researching “Testing, evaluation, analysis, control, and decision making for large scale complex systems”, “Robotic swarms”, “Cyber-physical systems”, “Cooperative and distributed control of multi-agent systems”, “Reliable and fault-tolerant hybrid control systems”, “Biological systems”, “Aerial robotics”, “Flight control systems”, “Discrete event systems”, “Distributed optimization for coordination of multi-agent systems”, “Hybrid modeling and control”, and the applications to different fields such as smart grids, smart transportation systems, smart farming and cybersecurity.

Dr. Karimoddini is the director of Autonomous Cooperative Control of Emergent Systems of Systems (ACCESS) Lab and the deputy director and research thrust leader of Testing, Evaluation and Control of Heterogeneous Large-scale systems of Autonomous Vehicles (TECHLAV) Center. He is the recipient of the 2015 Rookie of the year award of NC A&T State University. He is also a senior member of IEEE, and a member of AIAA, ISA, and AHS.

Affiliation(s)

North Carolina A&T State University

Current

Moeto Kasahara

Osaka City University

Email

Current

Zahra Abedi Khouzani

Queen's University

Email

Current

Jan Komenda

The Czech Academy of Sciences

Czechia

Email

Current

P.R. Kumar

Texas A&M University

United States

Email

Current

Ratnesh Kumar

Iowa State University

United States

Email

Current

Stéphane Lafortune

The University of Michigan

United States

Email

Current

Aiwen Lai

Associate Professor

Xiamen University

China

Email

Current

Ryan Leduc

McMaster University

Canada

Email

Current

Feng Lei

KTH Royal Institute of Technology

Email

Current

Jean-Jaques Lesage

Ecole Normale Supérieure de Cachan

Email

Current

Jinglun Li

Osaka University

Email

Current

Kuo Li

Tsinghua University

Email

Current

Xiaoyan Li

Xidian University

Email

Current

Yuting Li

Macau University of Science & Technology

Email

Current

Hongwei Liao

GE Global Research

Email

Current

Feng Lin

Wayne State University

Email

Current

Hai Lin

University of Notre Dame

United States

Email

Current

Zhaochi Lin

Tsinghua University

Email

Current

Fuchun Liu

Guangdong University of Technology

Email

Current

Gaiyun Liu

Xidian University

Email

Current

Siwei Liu

Tsinghua University

Email

Current

Yuhang Liu

Xidian University

Email

Current

Teng Long

Tsinghua University

Email

Current

Ernesto Lopez

Cinvestav

Email

Current

Jan Lunze

Ruhr-Universität Bochum

Email

Current

Peng Lv

Shanghai Jiao Tong University

Email

Current

Dan Ma

Northeastern University

Email

Current

Ziyue Ma

Xidian University

Email

Website

Current

Cristian Mahulea

University of Zaragoza

Spain

Email

Cristian Mahulea

Email

Biography

Cristian Mahulea is an Associate Professor (Profesor Titular de Universidad) at the University of Zaragoza (Spain) with the Department of Computer Science and Systems Engineering.

He received the Laurea and M.S. degrees in control engineering from the "Gheorghe Asachi" Technical University of Iasi (Romania), in 2001 and 2002, respectively, and Ph.D. degree in systems engineering from the University of Zaragoza (Spain) in 2007. He joined the University of Zaragoza in 2008 as assistant professor, becoming associate professor in 2017. He was visiting professor at the University of Cagliari (Italy) with the Department of Electrical and Electronic Engineering during five months in 2008 and 2010.

His research interests include discrete-event systems, hybrid systems, automated manufacturing, Petri nets, mobile robotics and healthcare systems. He co-authored, with Mihaela Matcovschi and Octavian Pastravanu the book Applications of Petri Nets in Studying Discrete Event Systems, Iasi, Romania in 2002 and co-authored with Marius Kloetzer and Ramon Gonzalez the book Path Planning of Cooperative Mobile Robots Using Discrete Event Models, Wiley-IEEE Press, January 2020. He participated and was the main developer of one MATLAB toolbox called Petri Net Toolbox for the simulation, analysis and synthesis of discrete-event systems modeled with discrete Petri nets and one Matlab toolbox called RMTool for path planning and motion control of mobile robots.

He has been a Visiting Researcher at the University of Sheffield (U.K.), University of Cagliari (Italy), Boston University (USA) and ENS Paris-Saclay (France).

He is a Senior Member of IEEE.

Affiliation(s)

University of Zaragoza

Spain

Current

Omar Makke

Wayne State University

Email

Current

Robi Malik

University of Waikato

Email

Current

Hervé Marchand

INRIA

Email

Current

Tomas Masopust

Palacky University in Olomouc

Email

Current

Shoma Matsui

Queen's University

Email

Current

Mohammad Rasool Mojallizadeh

INRIA

Email

Current

Thiago Monteiro Tuxi

Universidade Federal do Rio de Janeiro

Email

Current

Joanna Mortel

Eindhoven University of Technology

Email

Current

Richard Moulton

Queen's University

Canada

Email

Current

Dmitry Myadzelets

University of Bologna

Email

Current

Mohammad Noorbakhsh

Isfahan University of Technology

Email

Current

Zhiyang Ong

Texas A&M University

Email

Current

Vera Pantelic

McMaster University

Email

Current

Alexandre Parant

Université de Reims Champagne-Ardenne

Email

Current

Patrícia Nascimento Pena

Universidade Federal de Minas Gerais

Email

Website

Current

Alexandre Philippot

Université de Reims Champagne-Ardenne

Email

Current

Sasinee Pruekprasert

National Institute of Informatics

Email

Current

Naly Rakoto

IMT Atlantique

Email

Current

Peter J. Ramadge

Princeton University

Email

Current

Tom Ranger

Université de Reims Champagne-Ardenne

Email

Current

Ferdie Reijnen

Eindhoven University of Technology

Email

Current

Michel Reniers

Eindhoven University of Technology

Netherlands

Email

Website

Michel Reniers

Email

Website

Biography

Michel Reniers is an Associate Professor at the Mechanical Engineering Department at Eindhoven University of Technology (TU/e). His research interests include model-based engineering of supervisory controllers, synthesis of supervisory controllers for modal logics, engineering of cyber-physical systems (of systems) and development of modeling languages (CIF) and model transformations.

In Reniers’ research the emphasis is on application of formal methods in engineering of supervisory controllers for high-tech and embedded systems. The research focuses on furthering the state-of-the-art and the state-of-the-practice in model-based systems engineering approaches for supervisory controllers. This includes research themes such as supervisory controller synthesis for networked systems, the combination of supervisory control and throughput optimization, and supervisory control for system product lines.

Application areas for the research are manufacturing and high-tech systems such as lithography manufacturing, automotive systems, waterway locks and tunnel installations, robotics and autonomous systems.

Michel Reniers obtained his MSc in Computer Science from TU/e in 1994 followed by a PhD in 1999. He began working for TU/e in 1999 as an assistant professor in the section Analysis and Design of Systems (OAS), followed by an assistant professorship in the section Systems Engineering (SE). He was appointed Associate Professor in 2015.

Michel is a member of various organizations, including IEEE (senior member), IEEE CSS Technical Committee on Discrete Event Systems, and IFAC Technical Committee 1.3 on Discrete Event and Hybrid Systems. Michel has been chair of Working Group 3 on Tools for systems of systems engineering and management of the Communication and Support Action CPSoS and was coauthor of the Proposal of a European Research and Innovation Agenda on Cyber-physical Systems of Systems – 2016-2025.

Affiliation(s)

Eindhoven University of Technology

Netherlands

Current

Thalys Rezende

Universidade do Estado de Santa Catarina

Email

Current

Laurie Ricker

Mount Allison

Email

Current

Michel Rodrigo

Universidade Federal de Minas Gerais

Email

Current

Karen Rudie

Queen's University

Canada

Email

Current

Eric Rutten

INRIA Grenoble - Rhone-Alpes

France

Email

Current

Vahid Saeidi

National Iranian Oil Company

Email

Current

Ami Sakakibara

KTH Royal Institute of Technology

Email

Current

Matteo Sartini

LIAMLAB

Email

Current

Anne-Kathrin Schmuck

Max Planck Institute

Germany

Email

Current

Bryony Schonewille

Queen's University

Email

Current

Carla Seatzu

University of Cagliari

Italy

Email

Current

Renan Sebem

Universidade do Estado de Santa Catarina

Email

Current

Hu Shaopeng

Xidian University

Email

Current

Shaolong Shu

Tongji University

China

Email

Current

Spiridon (Spyros) Reveliotis

Georgia Institute of Technology

Email

Website

Current

Olaf Stursberg

University of Kassel

Germany

Email

Current

Rong Su

Nanyang Technological University

Email

Current

Dajiang Sun

Xidian University

China

Email

Current

Rajan Suri

University of Wisconsin, Madison

Email

Current

Shigemasa Takai

Osaka University

Japan

Email

Current

Sander Thuijsman

Eindhoven University of Technology

Email

Current

Dawn Tilbury

University of Michigan

United States

Email

Website

Current

Tahan Lumban Tobing

Institut Teknologi Bandung

Email

Current

Gianmaria Tommasi

Università degli Studi di Napoli Federico II

Email

Current

Toshimitsu Ushio

Osaka University

Email

Current

Jan H. van Schuppen

TU Delft

Email

Current

Jingxian Tang

Tsinghua University

Email

Current

Nina Verstraete

Cancer Research Institute (CRCT) Toulouse

Email

Current

J. Enrique Vidal

PUCP / Technische Universität Ilmenau

Email

Current

Juliana Vilela

University of Detroit Mercy

Email

Current

Marcos Vinícios Gonçalves

Military Engineering Institute

Email

Current

Xiaojun Wang

Xidian University

Email

Current

Yu Wang

Duke University

Email

Current

Zheng Wang

Southeast University

Email

Current

Yorai Wardi

Georgia Tech

United States

Email

Current

Andrew Wintenberg

University of Michigan

United States

Email

Current

Walter Murray Wonham

University of Toronto

Canada

Email

Current

Bo Wu

University of Texas, Austin

Email

Current

Changshun Wu

Université Grenoble Alpes

Email

Current

Yifan Xie

Shanghai Jiao Tong University

Email

Current

Jia Xu

Tongji University

Email

Current

Richard Yan

Queen's University

Email

Current

Benyuan Yang

Xidian University

Email

Current

Jianan Yang

Email

Current

Lan Yang

Xidian University

Email

Current

Wenjing Yang

Northwest University of China

Email

Current

David D. Yao

Columbia University

Email

Current

Jingshi Yao

Shanghai Jiao Tong University

Email

Current

Yin Tong

Southwest Jiaotong University

China

Email

Current

Xiang Yin

Shanghai Jiao Tong University

China

Email

Website

Current

Liu Yipei

Tsinghua University

Email

Current

Ana Teruko Yokomizo Watanabe

Universidade do Estado de Santa Catarina

Email

Current

Majid Zamani

University of Colorado, Boulder

United States

Email

Website

Current

Huimin Zhang

GuangXi Normal University

Email

Current

Kuize Zhang

Harbin Engineering University

Email

Current

Renyuan Zhang

Northwestern Polytechnical University

Email

Current

Ruijiang Zhang

Tsinghua University

Email

Current

Qianchuan Zhao

Tsinghua University

Email

Current

Wenjie Zhao

Xidian University

Email

Current

Zhenjie Zhao

Nanjing University of Information Science and Technology

Email

Current

Guanghui Zhu

Macau University of Science and Technology

Email

Current

Yimin Zhu

Email

Current

Yuhang Zhu

Tsinghua University

Email

Incumbent(s)