News: Success Stories

Faculty Exchange Program Is “First Step Towards Identifying Common Research Interests”

Jorge Sá Silva, assistant professor at the Universidade de Coimbra, spent four months at Carnegie Mellon University – Silicon Valley , between January and May 2014. According to the professor – who is also senior researcher at the Laboratory of Communication and Telematics of the Centre of Informatics Engineering (LCT) of the Universidade de Coimbra (CISUC) – when he decided to stay at the Silicon Valley campus of CMU his main goal was “to contact with a new research group at CMU that works in an area similar to mine.”

The opportunity to exchange ideas with scientific research groups from a different country was an asset to “conceptualize and develop new research subjects,” particularly the meetings with faculty members and with the director of CMU’s Silicon Valley, Bob Iannucci , and the participation in Pei Zhang ’s (one of the leading experts in Electrical and Computer Engineering at CMU Silicon Valley) research group activities.

Passionate by wireless sensor networks, mobile environments and next-generation networks, Jorge Sá Silva explains that this visit to CMU’s Silicon Valley campus, located in California, U.S., was a chance to “discuss the state-of-the-art, and to analyze and refine what I am currently working on,” as well as “to discuss future research projects,” he adds. The meetings with the Nokia and Renault teams, and the visit to the Nissan Research Centre, also highlighted by the professor, were examples of that.

While in the U.S., “we proposed and explored new joint models for the Internet of Things, integrating wireless sensor networks with Human in the Loop systems,” Jorge Sá Silva explains. As a result of this work, the visiting researcher, together with Pei Zhang, has been involved in the organization of two international conferences: ExtremeCom 2014 – Extreme Conference on Communication and Computing – The Galápagos Expedition, held between August 11 and 15, 2014, on the Galápagos Islands, in Ecuador; and Mobiquitous 2015 – 12 th International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services, which will take place in Coimbra, Portugal, between September 16 and 19, 2015.

The Faculty Exchange Program was also fruitful in the sense that Jorge Sá Silva was given the opportunity to attend some Master classes in Electrical and Computer Engineering, more specifically “Wireless Network Security,” taught by Patrick Tague , “Mobile and Pervasive Computing,” taught by Pei Zhang, and “Java for Smartphone Development,” taught by Bob Singh .

More specifically, during the four-month stay, Jorge Sá Silva, who r eceived his Ph.D. in Informatics Engineering in 2001, managed to improve his research about the Human in the Loop model, leading a joint research paper titled “Human in the Loop: state-of-the-art analysis,” submitted to IEEE Tutorials and Surveys . Having also worked on the development of new algorithms and protocols suitable for the Internet of Things, the visiting researcher is now working on a new joint research paper titled “Human in the Loop over Networks,” to be submitted to the INFOCOMM Conference .

“The main benefit of this visit was the contact with an excellent research center that necessarily has a different view on possible approaches to research objectives,” he states. Moreover, “this scientific mission opened new communication channels between the two research groups, which is a first step towards identifying common research interests,” he concludes.

The four-month stay was made possible by the Faculty Exchange Program, offered by Carnegie Mellon Portugal Program that is funded by the Fundação para a Ciência e a Tecnologia (FCT).

September 2014

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The Faculty Exchange Program is offered by the Carnegie Mellon Portugal Program and it allows academics from Portuguese universities to spend at least one term working in research and education at Carnegie Mellon, experiencing the culture of a top university in the United States. Carnegie Mellon professors are also given the opportunity to spend time in Portugal to engage in teaching and research activities with local higher education institutions and research labs.

Three Dual Degree Doctoral Students Successfully Defended Their Dissertation
André Regateiro, Ivonne Peña Cabra, and Sérgio Pequito successfully defended their dissertations, between July and August, 2014.

	André Regateiro [LinkedIn] 2008/2009 Advisors: Rui Baptista (IST-UL), Lee Branstetter (CMU) and Serguey Braguinsky (CMU) Research Interests: Social and Decision Sciences Dissertation Title: Three Essays on Portuguese Economic Growth, Firm Formation, and Productivity
	Ivonne Astrid Peña Cabra 2010/2011 Advisors: Luís Marcelino Ferreira (IST-UL) and Inês Lima Azevedo (CMU) Research Interests: Renewable Energy Dissertation Title: Retrospective and Prospective Analysis of Policy Incentives for Wind Power in Portugal
	Sérgio Pequito [ Profile | Homepage ] 2009/2010 Advisors: António Pedro Aguiar (FEUP), Diogo Gomes (IST-UL), and Soummya Kar (CMU) Research Interests: Design, analysis and optimization of large complex dynamical systems, Structural systems theory, Graph theory and combinatorial optimization Dissertation Title: A Structural Approach to Design, Analysis and Optimization of Large-Scale Dynamical Systems

Articles about their experiences and dissertations will be written shortly.

September 2014

Faculty Exchange Program is a Two-way Route for Learning and Teaching

Application Programing Interface (API) is a description of the way one piece of software asks another program to perform a service. André Leal Santos, assistant professor at ISCTE–IUL (Instituto Universitário de Lisboa), focused his research activity while at Carnegie Mellon University (CMU) on API usability, more concretely on the “development of a novel technique to annotate APIs towards improved learnability from an API usage perspective.” His research interests are in object- and aspect-oriented software development and programming, and he saw this visit as an opportunity to develop his research on program comprehension .

During four months at CMU, André Leal Santos was hosted by Brad Myers , a professor at the Human-Computer Interaction Institute (School of Computer Science) . But staying at CMU was also an opportunity to brush up on software research. While at CMU, “I attended the weekly research seminar on software engineering at the Institute for Software Research (School of Computer Science), and I gave a presentation about my ongoing research ,” he adds, confirming that the Faculty Exchange Program is a two-way route for learning and teaching. Another highlight of the stay at CMU was the participation in the Interaction Techniques course offered by Brad Myers at the Human-Computer Interaction Institute.

According to the researcher the idea now is to continue his research, together with the research group at CMU, capitalizing on the work that was carried out during the visit to address other aspects of API usability.

André Leal Santos , assistant professor at ISCTE-IUL, has spent the 2014 spring semester at Carnegie Mellon University (CMU), as part of the Faculty Exchange Program offered by the CMU Portugal Program.

September 2014

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The Faculty Exchange Program is offered by the Carnegie Mellon Portugal Program and it allows academics from Portuguese universities to spend at least one term working in research and education at Carnegie Mellon, experiencing the culture of a top university in the United States. Carnegie Mellon professors are also given the opportunity to spend time in Portugal to engage in teaching and research activities with local higher education institutions and research labs.

Cristina Carias Reflects on Lessons Learned for Life During Her Ph.D

Every day Cristina Carias remembers the extraordinary learning opportunity that was to get a dual degree Ph.D. in Technological Change and Entrepreneurship, at Instituto Superior Técnico of the Universidade de Lisboa (IST-UL) and Carnegie Mellon University (CMU). “It was very insightful to learn from the top experts in my field, and how they would always find innovative ways to advance research,” she says.

One of the most remarkable moments was the day she defended her dissertation in November 26, 2013. Entitled ” Worker exit, New Firm Formation, and the Effects of Quits on the Parent Firm ” , her research provided conclusions that are expected to improve the decision-making process of policy makers interested in programs that stimulate entrepreneurship, and regulate employer-employee contracts. “ Our results show that, overall, when employees leave their employers voluntarily, this has a negligible effect on the firm, regardless of where the employee chooses to work afterwards. This suggests that work contract clauses that limit the employee’s ability to work for competitors after he/she leaves the present employer (also known as non-compete covenants) may not be crucial to the firm and actually harmful to the economy,” Cristina Carias explains.

During her doctoral studies, Cristina Carias was advised by Lee Branstetter from CMU, Rui Baptista from IST-UL, and Steven Klepper from CMU, who passed away last year (2013). Cristina Carias insights were developed in the context of the research project “ Human Capital Entrepreneurial Careers and Knowledge Based Entrepreneurship , ” carried out in the scope of the CMU Portugal Program. We discussed Cristina’s work in further detail.

Cristina Carias Profile With a Ph.D. in Technological Change and Entrepreneurship, concluded as part of the CMU Portugal dual degree Ph.D. program at IST-UL and CMU, Cristina Carias has a Bachelor’s degree in Physics Engineering and a Master’s degree in Engineering and Management of Technology, both from IST-UL. She also holds a Certificate in Econometrics and Applied Prediction from the Instituto Superior de Economia e Gestão (ISEG). Prior to joining the dual degree doctoral program, Cristina Carias was a researcher at IN+ and worked at Portugal Telecom, the largest Portuguese telecommunications provider, experiences that she says that were crucial for her work. Today, Cristina is an economist/modeler at the Office of Science and Integrated Programs at the National Center for Immunization and Respiratory Diseases, of the Centers for Disease Control and Prevention, in Atlanta, GA.

CMU Portugal Program: In the abstract of your dissertation, you say that one of the results of your research shows “a negligible effect of voluntary quits on the parent firm, suggesting that job sorting among workers and firms occurs without much ado for the firm.” What method and data did you used that led to this result?
Cristina Carias (CC): Our results are strengthened by the fact, that, for the first time, we used a country wide data-set (Quadros de Pessoal) aggregating firms operating in different industries, and econometric methods tailored to the intricate problem of estimating the effects of employee quits on the employer. Econometrically, this problem is a challenge, as there are multiple confounders that may bias the results. We used several econometric techniques, including propensity scores, well-known methods to take into account fixed effects, and the usual ordinary least squares regression.

CMU Portugal Program: What is the impact of your findings?
CC: Entrepreneurs, business, and policy makers will find our results highly relevant. For policy makers and business, our results suggest non-compete agreements (or work clauses employees need to sign curbing their ability to work for competitors after they leave their current employer) may be of questionable importance. Policy makers may want to consider that, given the importance of new hires when starting successful ventures, and the relevance that these ventures have for the economy, curbing the employee’s ability to work for other firms after they leave their current employer may actually be detrimental to society. For entrepreneurs, we estimated that founders that hired people they knew well, and that started their company in a region and industry they had experience on were more successful in the long run.

CMU Portugal Program: You started your doctoral studies in 2007. In looking back, can you identify which were the most challenging stages and greatest learning experiences?
CC: A doctoral degree is always challenging the student’s limits. First, you learn the advanced techniques in your field, and then you need to learn how to use them to solve your problem. The greatest challenge for me was to find a problem that was both interesting and solvable with the techniques and data set I had available. The greatest learning experience was characterizing problems so they became tractable, and then adapting techniques to find the solution. This was the most important thing I learned from my advisors: how to frame the problem in terms of a research question, and then answer it in a way that was insightful beyond the specific question itself.

CMU Portugal Program: You have worked at Portugal Telecom before starting your Ph.D.. Did the experience of working at a company gave you another perspective of your research?
CC: Having worked on the private sector (in Portugal Telecom, the largest telecommunication provider in Portugal) before joining the Ph.D. program was extremely useful in that it allowed me to understand the organizational challenges faced by large firms, and kept my work more grounded in reality.

CMU Portugal Program: After finishing your Ph.D., what opportunities came up?
CC: I am assigned at the Centers for Disease Control and Prevention in Atlanta (to the Office of the Director of the National Center for Immunizations and Respiratory Diseases). In my current work, I evaluate vaccination programs, and quantify problems of interest to decision makers in emergency responses (which are set up to respond to outbreaks caused by a previously unknown pathogen such as new flu strains, or the Middle Eastern Respiratory Syndrome coronavirus; or large outbreaks such as the current Ebola outbreak in West Africa). I use a range of techniques and concepts that I previously studied, but my current position also requires me to adapt new techniques very quickly. At the same time, I had the opportunity to be a visiting Professor in Emory University (Atlanta), and to teach econometrics to undergraduates.

________________________________________________________________ “Worker exit, New Firm Formation, and the Effects of Quits on the Parent Firm”

Abstract
We analyze the literature on startups, regional networks, and employee turnover to i) understand which employees are more likely to exit and to where; ii) analyze how new employees use knowledge about previous hires to find a new firm; and iii) describe four different ways in which employee voluntary quits affect the parent firm: increase in strategic definition, alliance formation, increase in competition and adjustment costs.
We hypothesize and estimate that managers are more likely to exit the firm to find a new firm than other employees, and that specialized workers, following exit, are more likely to join incumbents in the same industry. We then theorize and estimate that startups entering the same industry of the founder’s previous employer are more likely to be located near the founder’s previous employer, more likely to employ former colleagues of the entrepreneur, and more likely to performing better than other startups.
We finally estimate the effects of voluntary quits on the parent firm. While voluntary quits are not observed, we define a voluntary quit as an exit followed by immediate entry in the dataset and salary raise or entry in entrepreneurship. We use several estimation methodologies, including General Method of Moments and regressing on the Propensity Score, to take into account firm heterogeneity, unobserved effects, and endogeneity bias. We further complement the analyses with regressions tailored to firms of different sizes, ages and ability managers. Our results show a negligible effect of voluntary quits on the parent firm, suggesting that job sorting among workers and firms occurs without much ado for the firm.

Committee: Lee Branstetter (CMU; Chair), Rui Baptista (IST-UL), Serguey Braguinsky (CMU) and Brian Kovak (CMU) .

Dual Degree Ph.D. Student Qiwei Han Wins Best Paper Award

Qiwei Han, a dual degree Ph.D. student in Engineering and Public Policy at Instituto Superior Técnico of the Universidade de Lisboa (IST-UL) and Carnegie Mellon University (CMU), has received a Best Paper Award for the paper “Role of Peer Influence in Churn in Wireless Networks,” at the 7th ASE International Conference on Social Computing, the premier international forum for research on Information and Communication Technologies that consider social context.

The winning paper was co-authored by Qiwei Han’s advisor at CMU Pedro Ferreira, and it addresses the problem of subscriber churn, which is the biggest problem for wireless carriers. The authors explain on the abstract that “carriers need to understand the determinants of churn to confidently apply effective retention strategies to ensure their profitability and growth.” In this paper, they “look at the effect of peer influence on churn and (…) try to disentangle it from other effects that drive simultaneous churn across friends but that do not relate to peer influence.” Using a random sample of roughly 10 thousand subscribers from a large dataset from a major Portuguese wireless carrier over a period of 10 months, the authors applied “survival models and generalized propensity score to identify the role of peer influence,” showing that “the propensity to churn increases when friends do and that it increases more when many strong friends churn.” According to the authors, the “results suggest that churn managers should consider strategies aimed at preventing group churn,” adding that “survival models fail to disentangle homophily from peer influence over-estimating the effect of peer influence.”

“Our paper provides a well-established methodology that disentangle peer influence from homophily and shows that even after controlling for confounding factors, we still see a positive effect of peer influence on churn,” Qwiei Han explained.

“This collaboration with the Portuguese wireless carrier was fundamental and could not have happened if it weren’t for the CMU Portugal Program,” the student states, adding that “I personally think that this is an important milestone for our work and the award certainly shows that what we are doing has been recognized in the field for its quality.” Qiwei Han enrolled in 2010-2011 and is also advised by João Paulo Costeira (IST-UL) .

The ASE International Conference on Social Computing was held in held in Tsinghua University, in Beijing, China, between August 4 and 7, 2014. The acceptance rate since inception is quite selective, with only about 9.9% (2013) acceptance.

September 2014
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Title: “The Role of Peer Influence in Churn in Wireless Networks”

Authors: Qiwei Han (IST-UL and CMU) and Pedro Ferreira (CMU)

Abstract: Subscriber churn remains a top challenge for wireless carriers. These carriers need to understand the determinants of churn to confidently apply effective retention strategies to ensure their profitability and growth. In this paper, we look at the effect of peer influence on churn and we try to disentangle it from other effects that drive simultaneous churn across friends but that do not relate to peer influence. We analyze a random sample of roughly 10 thousand subscribers from large dataset from a major wireless carrier over a period of 10 months. We apply survival models and generalized propensity score to identify the role of peer influence. We show that the propensity to churn increases when friends do and that it increases more when many strong friends churn. Therefore, our results suggest that churn managers should consider strategies aimed at preventing group churn. We also show that survival models fail to disentangle homophily from peer influence over-estimating the effect of peer influence.

Dual Degree Ph.D. Student Seeks Sentiments Behind Posts in Social Networks

Over the past years we have witnessed the emergence of a new paradigm of engagement between people in online social networks (OSNs). Facebook or Twitter, for instance, have become an intricate part of many lives. The staggering membership numbers and robust participation of the masses have turned these OSNs into a veritable data gold mine for organizations and individuals who have a strong social, political or economic interest in maintaining and enhancing their clout and reputation. Therefore, extracting and analyzing the embedded sentiment in the microblogs (or Tweets ) posted by the users about these organizations or individuals, or specific issues, products and events related to them or their competitors, is of great interest to them .

Beyond the content of these tweets lies another facet: The connectivity graph itself! Understanding and characterizing the role played by the structure of this connectivity graph in determining the ease of the embedded sentiment prediction is precisely what Vinay Uday Prabhu is doing as part of his doctoral work in the dual degree Ph.D. program in Electrical and Computer Engineering, at Faculdade de Ciências of the Universidade do Porto (FCUP) and Carnegie Mellon University (CMU), as part of the CMU Portugal Program.

Currently in the second part of his dual degree at CMU, after having spent the first half in Portugal at FCUP, Vinay Uday Prabhu is staying at CMU’s department of Electrical and Computer Engineering. Using mathematical models, algorithms, estimation theory and statistical signal processing, the Ph.D. student is trying to quantify, the statistical worth of these social networks in deciphering the latent sentiments expressed.

Network Aided Sentiment Classification Expressed in Tweets and Posts

Studying networks in general, and online social networks in particular, Vinay Uday Prabhu wants to understand and characterize the worth of utilizing the underlying network in classifying and clustering information generated by the users or in general, the nodes of the network.

“The oft-minable underlying network is an awfully precious side-information source that can potentially turn a really hard problem into a manageable one,” he indicates. “Let us say you gather a group of tweets and you would like to automatically classify the sentiment behind the tweet. Is it positive or negative? Is it a happy tweet or a sad tweet?” Simply by looking at the tweet, “it is very difficult to do that classification because there’s just a little text involved along with other subtle difficulties such as usage of sarcasm and so on,” Vinay Uday Prabhu explains. “However, if the tweeter belongs to a network of people and you know that many of his friends had exuded a positive sentiment, then on account of the social effect, or what the social scientists term ‘homophily,’ it becomes more likely that the tweet under analysis exudes positive sentiment too.” “Classifying the tweet is a difficult task, but when you have the network, the context, it becomes much easier,” he clarifies.

Monitoring and Enhancing Social Capital of Organizations with Large Followings

“Our goal is to also characterize the relationship between the topology of the networks, or at least macroscopic aspects of it, and the rate of error incurred in estimating the latent common sentiment or the majority sentiment, which is also of paramount importance to organizations. For instance, let us say I am an executive in a large supermarket chain in Portugal and I want to know if my online followers are exuding a net positive or negative sentiment with regard to an online campaign I am carrying out,” the Ph.D. student explains.”The error rate incurred in such tasks is ostensibly related to the nature of connectivity between the followers.”

“The basic idea here is that if the networks are weakly connected, you’d assume that people will be tweeting and posting on a more independent basis bereft of the peer pressure that might flow in through his or her connections” he explains. “In these cases, the network is not a strong driver of mass opinion. On the other hand, densely connected networks signify a flock mentality ecosystem where opinions polarize pretty fast,” he adds.

Harnessing the graphical models framework, including specialized focus on a particular kind called “the Ising model ,” that are used as a simplistic yet rich mathematical model of ferromagnetism in statistical mechanics, “we can organically model the network as a statistical prior” to understand social network behaviors. “Specifically with regard to my Ph.D. thesis, I’m basically looking at these novel applications where the underlying networks and network information can be used to perform classification tasks more efficiently,” the student explains.

According to the student, this is the first work that connects probability of error and topology when estimating the latent sentiment in social networks. “We brought in a whole new approach to this open problem that had not been tackled until now whilst amalgamating ideas from classical communication theory, statistical physics and Machine learning,” the student reveals, adding that “we have just presented the results of this work at the IEEE International Conference on Communications (ICC) in Sydney, Australia, a top-tier conference in communication sciences.”

The Dual Degree is “Wonderful and Extremely Challenging”

When asked about his experience as a dual degree Ph.D. student, Vinay Uday Prabhu – who is advised in Portugal by Miguel Rodrigues, professor at FCUP and at CMU by Rohit Negi – stated that the experience has been “wonderful and extremely challenging.” According to the student, “I’ve been receiving a lot of support from both advisors. They have very different personalities and take different approaches towards the same problem, albeit with the same level of insistence on correctness and rigor. This goads me to prepare for my meetings with them slightly differently and I think that that’s a very unique experience in itself that you might not get in other programs,” he explains, adding that “I get to learn so much from both of them and I have no one else but the CMU Portugal Program to thank.”

The student, who spoke fondly of his admiration for all the Portuguese characteristics, especially the cuisine and Port Wine, believes that Europe – and Portugal in particular – needs to advertise itself more aggressively. For instance, “you have lots of summer and winter schools happening all over Europe. I think it’s a truly unique aspect of the European ecosystem where we can learn a new mathematical technique or the latest state-of-the-art and the research being done by professors,” he exemplifies.

August 2014

 

” Innovation by Patients with Rare Diseases and Chronic Needs ” is the title of the first working paper published as part of “ TEIPL: Technology, Entrepreneurship and Innovation Policy Lab,” one of the six Entrepreneurial Research Initiatives (ERI) recently awarded for funding by the CMU Portugal Program. The paper was written during the submission of the proposal and provides, according to the authors, the first empirical exploration of disease-related innovation by patients and their caregivers. The paper was co-authored by Pedro Oliveira (Católica Lisbon School of Business and Economics, CLSBE), Leid Zejnilovic (dual degree Ph.D. student in Technology Change and Entrepreneurship at Instituto Superior Técnico of the Universidade de Lisboa, CLSBE and CMU), Helena Canhão (Faculdade de Medicina of the Universidade de Lisboa), and Eric A. Von Hippel (Massachusetts Institute of Technology).

“Our aims were to measure the frequency of innovation by these patients and their caregivers, and the improvement in well-being they experienced from using what they had developed. In addition, we explored the diffusion of their innovations to others, and factors associated with both patient innovation development, and patient innovation sharing,” the researchers explained.

In order to accomplish their goals, the team interviewed, by telephone, a sample of 500 patients with rare diseases and caregivers. One of the conclusions was that 52.6 per cent of the survey respondents reported having developed and used an innovative solution to improve the management of their diseases. Moreover, the authors concluded, “there is a positive relationship between the impact of a solution on the respondents’ overall quality of life and the probability of sharing that solution, and an inverted U relationship between age and solution sharing.” Their findings suggest that “many patients could be greatly assisted by an improved diffusion of the best known practices to and among patients and their caregivers,” the researchers explained .

The paper was written in the scope of the Entrepreneurial Research Initiative “ Technology, Entrepreneurship and Innovation Policy Lab – TEIPL ,” a new multidisciplinary organization that brings together leading academic and corporate partners to conduct research and policy analyses on the development and diffusion of entrepreneurship and innovation to unlock Portugal’s global competitiveness.

August 2014

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The Phase II of the Carnegie Mellon Portugal Program emphasizes advanced education and research that can lead to significant entrepreneurial impact. The activities of the program are for the most part configured in Entrepreneurial Research Initiatives (ERIs).

Trends in Non-Linear Analysis in Discussion
By José Matias* and Marco Morandotti**, organizers of the Workshop

The workshop “Trends in Non-Linear Analysis” took place at Instituto Superior Técnico of the Universidade de Lisboa (IST-UL) on July 31 st and August 1 st , 2014, with the aim of bringing together leading experts and young mathematician researchers to present and discuss recent developments in non-linear analysis. The workshop was very successful, it gathered more than 35 participants and it offered a space for engagement in discussions about the latest findings in a number of different directions in non-linear analysis, including homogenization, non-local variational problems, mechanics of defects in materials, fractures.

The research network of the CMU Portugal/UT Austin project “Thin Structures, Homogenization, and Multiphase Problems” (FCT-UTA_CMU/MAT/0005/2009) was pivotal in enabling this workshop, through the partial support of 6 keynote speakers (Bouchitté, Fonseca, Mascarenhas, Morini, Piatnitski, Zappale), and 12 young researchers (whose participation was supported by the Center for Mathematical Analysis, Geometry and Dynamical Systems -CAMGSD). We also acknowledge support from the CMU Portugal/UT Austin project “ Degenerate elliptic and parabolic equations and its applications to front propagation ” ( FCT-UTA_CMU/MAT/0007/2009).

The workshop fits squarely within the scope of the CMU Portugal collaboration, and facilitated the tightening of the networking between the Portuguese and Carnegie Mellon researchers in the field of Mathematics, and by stressing once more the success of this partnership, that will continue strong beyond the sun setting of this project. It is our strong belief that it should continue even after the deadline of the project. Indeed, at the conclusion of the workshop several open problems were identified that still need to be addressed and solved, and such a thriving project is one of the best ways to bring together top class researchers to develop science.

There are many open problems, for instance in the field, of homogenization, dynamics of defects in solids, fractures, the theory of A­ -quasiconvexity, that are worth investigating and will contribute to further develop science and its applications to physical and engineering problems.

* Instituto Superior Técnico of the Universidade de Lisboa (IST-UL)

** Post Doc in Mathematics at Instituto Superior Técnico of the Universidade de Lisboa (IST-UL) and Carnegie Mellon University (CMU)

Ph.D. Student Flávio Cruz Wins Best Paper Award at the 30th International Conference on Logic Programming

Flávio Cruz, dual degree doctoral student in Computer Science (Faculdade de Ciências of the Universidade do Porto – FCUP, and Carnegie Mellon University), with his three advisors Ricardo Rocha (FCUP and INESC TEC), Seth Copen Goldstein and Frank Pfenning (CMU), won a Best Paper Award at the 30th International Conference on Logic Programming (ICLP 2014) for the paper “A Linear Logic Programming Language for Concurrent Programming over Graph Structures.”

In this paper, the authors describe a new logic programming language called LM (Linear Meld) that aims to solve problems that can be specified as graphs. According to Flávio Cruz, “graphs can represent arbitrary relations between things and for that reason they are a suitable representation for many interesting problems. Due to the popularity of social networks and also the increased availability of biological and scientific data, graphs become more important since such information can be described as a graph.”

The new language shows how to concisely solve problems that operate on graphs and how to solve them concurrently. Flávio Cruz explains that with this language it is possible to “take advantage of multiple computers in order to reduce the time it takes to solve the problems,” and because it is based on logic “it is easier to prove that our programs will always work correctly.”

Because Linear Meld integrates both classical and linear logic, it tends to be more expressive than other logic programming languages, which is a differentiating factor. In this work, the authors present the syntax and operational semantics of the language and illustrate its use providing a number of examples. For Flávio Cruz, this award “means a lot because it is the culmination of a few years of work.”

Flávio Cruz is enrolled in CMU Portugal’s dual degree Ph.D. program in Computer Science since the academic year 2011/2012, at Faculdade de Ciências of the Universidade do Porto (FCUP) and Carnegie Mellon University (CMU). When asked to comment on his views on the CMU Portugal Program, Flávio Cruz stated that “it is a good experience, and I would recommend it to people who love their research field.”

The International Conference on Logic Programming (ICLP 2014) is the leading international conference for presenting research in logic programming. Its 30th edition took place between July 19 and 22, 2014, in Vienna, Austria.

August 2014

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Title: “A Linear Logic Programming Language for Concurrent Programming over Graph Structures”

Authors: Flávio Cruz (FCUP and CMU), Ricardo Rocha (FCUP and INESC TEC), Seth Copen Goldstein and Frank Pfenning (CMU).

Abstract: This paper describes the design of a new logic programming language called LM (Linear Meld) for programming graph-based algorithms in a declarative fashion. The language is based on linear logic, an expressive logical system where logical facts can be consumed. Because LM integrates both classical and linear logic, LM tends to be more expressive than other logic programming languages. LM programs are naturally concurrent because facts are partitioned by nodes of a graph data structure. This work presents the syntax and operational semantics of the language and illustrate its use through a number of examples.

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