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Vo, Huu-Phuc, PhD student
Alternative names
Publications (5 of 5) Show all publications
Vo, H.-P. (2019). Machine-Assisted Reformulation for MiniZinc. In: : . Paper presented at IEEE International Workshops on Foundations and Applications of Self* Systems (FAS*2019), Umeå, Sweden, 16-20 June 2019.
Open this publication in new window or tab >>Machine-Assisted Reformulation for MiniZinc
2019 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Model reformulation plays an important role in improving models and reducing search space so that solutions can be found faster. In solving Constraint Satisfaction Problems (CSPs), a model of a CSP may be solved rapidly, while a different model may take excessively long to solve. The efficient solution of CSP is significant in real-world applications, such as air traffic management, resource allocation, production scheduling, and bioinformatics. Many technologies such as constraint programming (CP), hybrid technologies, mixed integer programming (MIP), constraint-based local search (CBLS), boolean satisfiability (SAT) could have different solvers and backends to solve the real-time problems. Model reformulation can have a significant impact on solving time. Techniques from formal methods will be used to provide machine assistance for MiniZinc, which is the high-level modelling language to model CSPs. The verification tool, Isabelle, will be used to verify the correctness of reformulations. We plan to apply recent results in formal methods such as program analysis and synthesis to provide semi-automated frameworks for model analysis. In this paper, we identify the challenges, implement frameworks, and evaluate our experimental results in reformulations for future research.

Keywords
formal methods, implied constraint, reformula- tions, constraint programming, optimisation, modelling languages
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:uu:diva-392599 (URN)
Conference
IEEE International Workshops on Foundations and Applications of Self* Systems (FAS*2019), Umeå, Sweden, 16-20 June 2019
Available from: 2019-09-06 Created: 2019-09-06 Last updated: 2019-09-16Bibliographically approved
Vo, H.-P. (2019). Towards Efficient Algorithms for Constraint Satisfaction Problems. In: : . Paper presented at European Joint Conferences on Theory and Practice of Software (ETAPS 2019), Prague, Czech Republic, 6-11 april 2019.
Open this publication in new window or tab >>Towards Efficient Algorithms for Constraint Satisfaction Problems
2019 (English)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:uu:diva-392598 (URN)
Conference
European Joint Conferences on Theory and Practice of Software (ETAPS 2019), Prague, Czech Republic, 6-11 april 2019
Available from: 2019-09-06 Created: 2019-09-06 Last updated: 2019-09-16Bibliographically approved
Vo, H.-P. (2019). Towards Efficient Solvers for Optimisation Problems. In: Proc. 19th International Symposium on Cluster, Cloud and Grid Computing: . Paper presented at 19th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGRID), May 14-17, Cyprus.
Open this publication in new window or tab >>Towards Efficient Solvers for Optimisation Problems
2019 (English)In: Proc. 19th International Symposium on Cluster, Cloud and Grid Computing, 2019Conference paper, Published paper (Refereed)
Abstract [en]

 Constraint programming (CP) is pervasive and widely used to solve real-time problems which input data could be scaled up to the huge sizes, and the results are required to be given efficiently and dynamically. Many technologies such as CP, hybrid technologies, mixed integer programming (MIP), constraint-based local search (CBLS), boolean satisfiability (SAT) could have different solvers and backends to solve the real-time problems. Streaming videos problem is the problem that requires to decide which videos to put in which cache servers in order to minimise the waiting time for all requests with a description of cache servers, network endpoints and videos are given. In this paper, we model the streaming videos problem in two different ways. The first model is implemented using heuristics, and the global constraints are used in the second model. The experiments are benchmarked using MiniZinc, which is an open-source constraint modelling language that can be used to model constraint satisfaction and optimisation problems in the high-level, solver-independent way. The aim of the paper is to benchmark these technologies to evaluate the execution time and final scores of the two models using large instances of input data from Google Hash Code.

Series
International Symposium on Cluster, Cloud and Grid Computing (CCGRID)
Keywords
optimsation, constraint programming, modelling
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:uu:diva-392597 (URN)10.1109/CCGRID.2019.00030 (DOI)978-1-7281-0912-1 (ISBN)
Conference
19th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGRID), May 14-17, Cyprus
Available from: 2019-09-06 Created: 2019-09-06 Last updated: 2019-09-16Bibliographically approved
Fernandez-Reyes, K., Clarke, D., Castegren, E. & Vo, H.-P. (2018). Forward to a Promising Future. In: Conference proceedings COORDINATION 2018: . Paper presented at COORDINATION - 20th International Conference on Coordination Models and Languages, Madrid, June 18-21, 2018..
Open this publication in new window or tab >>Forward to a Promising Future
2018 (English)In: Conference proceedings COORDINATION 2018, 2018Conference paper, Published paper (Refereed)
Abstract [en]

In many actor-based programming models, asynchronous method calls communicate their results using futures, where the fulfilment occurs under-the-hood. Promises play a similar role to futures, except that they must be explicitly created and explicitly fulfilled; this makes promises more flexible than futures, though promises lack fulfilment guarantees: they can be fulfilled once, multiple times or not at all. Unfortunately, futures are too rigid to exploit many available concurrent and parallel patterns. For instance, many computations block on a future to get its result only to return that result immediately (to fulfil their own future). To make futures more flexible, we explore a construct, forward, that delegates the responsibility for fulfilling the current implicit future to another computation. Forward reduces synchronisation and gives futures promise-like capabilities. This paper presents a formalisation of the forward construct, defined in a high-level source language, and a compilation strategy from the high-level language to a low-level, promised-based target language. The translation is shown to preserve semantics. Based on this foundation, we describe the implementation of forward in the parallel, actor-based language Encore, which compiles to C.

Keywords
parallel, concurrency, futures, actors, tasks
National Category
Computer Systems
Identifiers
urn:nbn:se:uu:diva-351352 (URN)
Conference
COORDINATION - 20th International Conference on Coordination Models and Languages, Madrid, June 18-21, 2018.
Available from: 2018-05-23 Created: 2018-05-23 Last updated: 2018-05-24Bibliographically approved
Vo, H.-P., Berglund, A. & Daniels, M. (2017). A perspective from Vietnamese students on teaching of soft skills. In: Proc. 5th International Conference on Learning and Teaching in Computing and Engineering: . Paper presented at 5th International Conference on Learning and Teaching in Computing and Engineering (LaTiCE 2017), April 20–23 2017, Hong Kong (pp. 23-24). IEEE Computer Society
Open this publication in new window or tab >>A perspective from Vietnamese students on teaching of soft skills
2017 (English)In: Proc. 5th International Conference on Learning and Teaching in Computing and Engineering, IEEE Computer Society, 2017, p. 23-24Conference paper, Published paper (Refereed)
Abstract [en]

Soft skills are significant to the engineering labour market, especially in Information Technology where demands are high on for instance communication skill, teamwork skill, presentation skill, etc. Despite their importance, educating students in using those skills is not fully included in the bachelor education programmes, especially in developing countries. This project aims to gain insights in how soft skills are taught in Vietnamese universities, and which skills are missing in their bachelor education programmes. The findings are intended to support education in order to develop the teaching of soft skills for Vietnamese students, and decrease the unemployment rate of Vietnamese graduates. In this project, semi-structured interviews, by e-mail, have been used to collect the data. There are eight Vietnamese interviewees who have experiences from various education programmes. The interview transcripts were then analysed and categorised into themes. The results of our work are a preliminary identification of missing skills in the undergraduate programmes, and a set of proposed skills that could be considered to improve the education programmes.

Place, publisher, year, edition, pages
IEEE Computer Society, 2017
Series
International Conference on Teaching and Learning in Computing and Engineering, ISSN 2377-0309
National Category
Computer and Information Sciences Educational Sciences
Identifiers
urn:nbn:se:uu:diva-333570 (URN)10.1109/LaTiCE.2017.11 (DOI)000414514300004 ()978-1-5386-0892-0 (ISBN)
Conference
5th International Conference on Learning and Teaching in Computing and Engineering (LaTiCE 2017), April 20–23 2017, Hong Kong
Available from: 2017-10-12 Created: 2017-11-15 Last updated: 2018-03-21Bibliographically approved
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