"When you want to build a ship, then do not drum the men together in order to procure wood, to give instructions or to distribute the work, but teach them longing for the wide endless sea." - A. de Saint-Exupery


This is the official web site of the Algorithms and Complexity Laboratory (ACLab) of the Department of Computer Science at the University of the Philippines Diliman. ACLab was founded in 2007 by Henry N. Adorna, Professor of Computer Science.

ACLab regular members, (under)graduate students, and collaborators conduct investigations on a diverse range of topics, all anchored on a theoretical computer science perspective. Current active research areas include formal models, natural computing, algorithmics for hard problems, bioinformatics, and data analysis and visualization.

Recent News and Announcements

19 June 2018

Theory Days 2018

Synopsis: Theory Days 2018 celebrates two main reasons: 11 years of Algorithms and Complexity at the Department of Computer Science in UP Diliman, as well as 106 years since the birth of Alan Turing, the founder of computer science. Theory Days 2018 aims to celebrate both these reasons by providing invited talks under the general theme of discrete mathematics and theoretical computer science and their related practice.

Talks and other activities in Theory Days 2018, such as brainstorming or break-out sessions, are largely informal in nature: the main reason is to initiate discussions which may lead to (in)formal collaborations, conference or journal articles, open problems for (under)graduate students and the computing community, or just for fun!

Coordinates: 21 June (9:00 AM - 2:45 PM) and 22 June (9:00 AM - 5:40 PM) 2018, ERDT Room, 2nd floor, UP Alumni Engineers Centennial Hall (UP AECH), P. Velasquez Street, Diliman, Quezon City, Philippines.

Map to venue: Google maps link HERE

Registration form: Link to free registration is HERE
Download program: PDF file of program is HERE.

Abstract: Membrane computing is a field of computer science that studies unconventional models of computa- tion known as P systems which are inspired by the biological and chemical processes in a biological cell or group of cells. In 2006, a model of computation known as spiking neural P system (SNP system) was introduced. SNP systems were inspired by networks of spiking neurons. In 2015, a variant of SNP systems known as spiking neural P system with structural plasticity (SNPSP sys- tem) was introduced. SNPSP systems incorporate the ideas of synaptogenesis and synaptic pruning (structural plasticity) as features of the model. To study structural plasticity as feature of SNPSP systems, we used SNPSP systems to generate families of languages in the Chomsky hierarchy: finite languages, regular languages, context-free languages, and recursively enumerable languages. We created procedures for constructing SNPSP systems that generate the families of languages. We discussed how structural plasticity is used for constructing the language generator SNPSP systems. We also compared the language generator SNPSP systems to existing language generator SNP systems.

"Ten years of Computer Science Theory at UP Diliman" 
presented by Henry N. Adorna during Theory Days 2017.

Selected and Recent Publications

  1. Z.B. Jimenez, F.G.C. Cabarle, R.T.A. de la Cruz, K.C. Buño, H.N. Adorna, N.H.S. Hernandez, and X. Zeng. Matrix Representation and Simulation Algorithm of Spiking Neural P Systems with Structural Plasticity. Pre-Proc. Asian Conf. Membrane Computing (ACMC2018), 10-14 December, 2018, Auckland (New Zealand) and in CDMTCS-530 research report. [tr]
  2. R.T.A. de la Cruz, F.G.C. Cabarle, and H.N. Adorna. Generating Context-Free Languages using Spiking Neural P Systems with Structural PlasticityPre-Proc. Asian Conf. Membrane Computing (ACMC2018), 10-14 December, 2018, Auckland (New Zealand) and in CDMTCS-530 research report. [tr]
  3. J.P. Carandang, F.G.C. Cabarle, H.N. Adorna, N.H.S. Hernandez, M.A. Martinez-del-Amor. Handling Non-determinism in Spiking Neural P Systems: Algorithms and Simulations. Fundamenta Informaticae 164 (2019) 139–155 DOI 10.3233/FI-2019-1759 [jour/ISI/SCI]
  4. F.G.C. Cabarle, R.T.A. de la Cruz, H.N. Adorna, M.D. Dimaano, F.T. Peña, X. Zeng. (2018) Small Spiking Neural P Systems with Structural Plasticity. In: Graciani C., Riscos-Núñez A., Păun G., Rozenberg G., Salomaa A. (eds) Enjoying Natural Computing. Lecture Notes in Computer Science, vol 11270. https://doi.org/10.1007/978-3-030-00265-7_4 Springer, Cham [ch]
  5. I. Ordanel, H. Adorna. Optimal Deterministic Algorithm for the Hammock(2,2)-Poset Cover Problem Philippine Journal of Science 147 (4): 733-748, December 2018, ISSN 0031 - 7683  [jour/ISI/SCI]
  6. B. Song, Y, Hu, H. Adorna, F. Xu.  A Quick Survey of Tissue-Like P Systems. Romanian Journal of Information Science and Technology, Vol 21, No. 3, (2018), 310-321  [jour/ISI/SCI]
  7. F.G.C. CabarleR.T.A. de la Cruz, X. Zhang, M. Jiang, X. Liu, X. Zeng. On String Languages Generated by Spiking Neural P Systems with Structural Plasticity. DOI:10.1109/TNB.2018.2879345. IEEE Transactions on NanoBioscience,  vol 17, No 4,  560--566, 2018. [jour/ISI/SCI]
  8. K.C.Buño, F.G.C. Cabarle, M.D. Calabia, H.NAdorna. Solving the N-Queens problem using dP systems with active membranes  Theoretical Computer Science, Vol. 736 (2018), 1-14   [jour/ISI/SCI]
  9. H.N. Adorna, L. PanB. SongOn Distributed Solution to SAT by Membrane Computing." International Journal of Computers Communications & Control 13.3 (2018): 303-320. [jour/ISI/SCI]
  10. R. Juayong, H. Adorna. On Simulating Cooperative Transition P Systems in Evolution–Communication P systems with Energy. Nat Comput (2018) 17: 333-343 [jour/ISI/SCI]