- Invited Speaker in the 7th Conference of Southeast Mathematical Society, Universitas Gadjah Mada, August 18th-21st 2015, Yogyakarta.
- Speaker in 7th National Seminar on mathematics “Life Essence Bring It Up by Mathematics Language“, November 22nd, 2014, Gadjah Mada University, Yogyakarta.
- Symposiast in Te Taunga Whaka: Asia-Pactific Symposium on Cultures-Based Innovation, Whakatane, New Zealand, August 4th-9th, 2013.
- Keynote Speaker in Nicograph International Conference 2012, Bali, July 2nd-3rd, 2012.
- Speaker in the International Workshop on Agent-Based Modeling and Simulation for Policy Development, System Modeling for Policy Development, Unit Kerja Presiden Bidang Pengawasan dan Pengendalian Pembangunan, Jakarta, March 31st, 2012.
- Speaker in Seminar “Dynamics of Political Economy in Latin America and Caribbean”, March 6th 2012, Jakarta, Center of Latin America, International Relations Study Programme Faculty of Social and Political Sciences, University of Prof. Dr. Moestopo (Beragama).
- Speaker in Public Lecture of Pengayaan Mata Kuliah Teori-teori Sosial dan Kewarganegaraan, Universitas Pendidikan Indonesia, December, 19th, 2011, with topics “Dunia Kita Membutuhkan Perspektif yang Sederhana atas Dunia yang Kompleks“.
- Speaker in International Math & Science Camp, with topics “Let’s use contemporary science & math to enjoy the Indonesian traditional & ancient batik!“, Sari Ater, Lembang, November 24th 2011.
- Speaker in National Discussion Forum “Membangun Habitus Baru Pendidikan”, Auditorium Prasetya Mulya Business School, Jakarta, November 3rd,2011.
- Speaker in serial Discussion of Complexity Sciences in Freedom Institute, “Menuju Wawasan Kompleksitas untuk Memahami Narasi Kompleksitas Negeri” (September 14th, 2011) and “Menggambar Nexus Tiga Titik: Peluang Renesans Asia?” (Oktober 19th,2011).
- Speaker at National Seminar of Statistics “Data Mining menjawab Tantangan di Bidang Social Complexity, Banking Risk Management, & Customer Relationship Management“, Gadjah Mada University, Yogyakarta, May14th, 2011.
- Speaker at Focus Group Discussion on Indonesian Intangible Cultural Heritage, Ministry of Culture and Tourism RI, Jakarta, December, 22nd, 2010.
- Lecture at Philosophy Extension Course: “Life at the Edge of Chaos“, Parahyangan University, Bandung, December 3rd 2010.
- Speaker at National Workshop “Intellectual Property and the Documentation and Establishment of Database of Traditional Knowledge, Folklore, and Intangible Cultural Heritage” Ministry of Foreign Affairs & Ministry of Culture Republic of Indonesia, Univesitas Padjajaran, Bandung, November 26th 2010.
- Speaker in Workshop on Integrated Cultural Heritage Database System, Direktorat Jenderal Sejarah & Purbakala, Ministry of Culture and Tourism RI, Puncak-Bogor, March, 7-9, 2010.
- Speaker in Seminar “Imperatif Pembalikan Krisis Sosial Ekologis dan Pengurusan Publik“, Aula Barat, Institut Teknologi Bandung, 11 February 2010.
- Speaker in Workshop entitled “Development of Archiving and Access to Audio Visual Culture and Art“, Jakarta, 9-10 Desember 2009, Higher Education General Director Republic of Indonesia.
- Speaker in Seminar Nasional Rescuing Our Culture in Fakultas Ilmu Pengetahuan Budaya Universitas Indonesia, 8 Desember 2009.
- Speaker in TEDx Jakarta Event, November 22nd 2009. Presentation entitled “The Scientific Amazement on Indonesian Batik”.
- Speaker in Seminar with Topics “Applications of Physics in the Stock Market” in Universitas Bina Nusantara, Jakarta, April 13th 2007. Paper entitled “Konsep Kompleksitas dalam Ekonofisika “.
- Speaker in 9th Joint Conference on Information Sciences (JCIS), Computational Intelligence in Economics and Finance, Kaohsiung - Taiwan, October 8th-11th 2006, with paper presentation “Theorizing Corruption through Agent-Based Modeling“
- Speaker in Introductory to Econophysics Seminar in cooperation between Surya Research International and LPEM Universitas Indonesia (LPEM-UI) Jakarta, June 12th 2006 with presentation entitled “Perspektif Kompleksitas dalam Melihat Fenomena Empiris Sistem Ekonomi”
- Contributed Speaker in Workshop on Non-linearity 2K6, Institut Pertanian Bogor, June 7th 2006 with paper presentation “Statistical Properties of Artificial Stock Market“.
- Speaker in Seminar of 38th Euro - Working Group Meeting themed “Trends in Finance and Investment Research”, Jakarta, May 1st, 2006. Presentation with Professor Roy Sembel entitled “Recent Applied Research in Investment and Risk Management in Indonesia”.
- Speaker in Seminar on Econophysics by Indonesian Physics Student Association Meeting in Universitas Negeri Padang, Padang, March 18th 2006. Paper entitled “Korelasi & Kompleksitas dalam Pengembangan Perekonomian Indonesia”.
- Speaker in Seminar on Econophysics Universitas Islam Indonesia, Yogyakarta, September 29th 2004. Paper presented entitled “Konsep Korelasi dan Kompleksitas dalam Ekonofisika” .
- Speaker in National Symposium for Physics 20th, Indonesian Physical Society, Pekanbaru, August 25-26 2004. Paper presented entitled “Stylized Statistical Facts of Indonesian stock market: a view from econophysics“.
- Speaker in Seminar “Pengenalan Ekonofisika”, Universitas Kristen PETRA, Surabaya, June 14 2004, with paper presentation entitled “Ekonofisika: Korelasi dan Kompleksitas dalam Ekonomi”.
- Speaker in Workshop on Economics and Heterogenous Interacting Agents (WEHIA), Kyoto University, Kyoto, Japan, May 27-29 2004, with research paper presentation “Metabolism of Social System” in co-authorship with BFI research assistant, Deni Khanafiah.
- Visiting Lecture in Graduate Studies Program in Management, Universitas Indonesia, UI Campus, Depok, May 14 2004, on “Introduction to the Application of Physics in Financial Analysis”, together with Rendra Suroso (Dept. Cog. Sci. BFI) and Yun Hariadi (Dept. Dyn. Sys. BFI).
- Speaker in Conference on “COMPLEXITY in Literary Studies“, Aalborg University, Aalborg, Denmark, January 23-24 2004, with presentation “Cultural Studies through Complexity Sciences”
- Speaker in Semi-conference on “Cultural Studies in the Perspective of Complexity“, Pusat Studi Islam dan Demokrasi Universitas Paramadina Jakarta. January 14th 2004.
- Conference on Applications of Physics in Financial Analysis 4th, Warsaw, Poland, November 13th-15th 2003, with scientific poster “Neural Network Revisited: Perception On Modified Poincare Map of Financial Time Series Data” - in co-authorship with Yohanes Surya (Universitas Pelita Harapan)
- Invited Speaker in Presentation of the paper entitled “Sociological Strategies in Indonesia Mining Site: The Prisoner Dilemma Approach” in 5th Congress of Association of Indonesian Mining Professionals (Persatuan Ahli Pertambangan Indonesia, PERHAPI). Mulia Hotel, Jakarta, September 15-16th 2003.
- Limited Academic Discussion on presentation of the paper entitled “Frequently Asked Question on Social Complexity Science”, Universitas Paramadina, Jakarta, October 12th 2003.
- Invited Spekaer in Semi-seminar with paper entitled “The Dawn of the Social Complexity Science” arranged by Centre for Strategic and International Studies (CSIS), Jakarta, June 5th 2003. .
- Invited Speaker in Public Discussion with paper entitled “Chronic Impotency of our Social Sciences” arranged by YLBHI, Lembaga Kajian Sosial Politik, Bandung Fe Institute. YLBHI, Jakarta, March 31st 2003.