Seminar 7 : Solving the Halting Problem (One Language at a Time)


Date: April 7
Time: 1:00-2:00pm
Location: McConnell Room 320

Speaker: Rohan Jacob-Rao
Title: Solving the Halting Problem (One Language at a Time)

Abstract: In the CompLogic group, we study the design of programming languages that can enforce safety properties at compile time. In this talk, I will describe a small language in which program termination is enforced by the typechecker. Though it restricts the programs one can write, the technique can be extended to more expressive languages. I will show the steps involved in proving the termination property, from defining a formal semantics to writing a machine-checked proof.

Proposed Changes to Constitution

CSGS is proposing the following changes to constitution. The voting period will be March 28th – April 4th.

  • Amendment 1: Add the following point to the constitution. CSGS execs have to appoint one executive the task of supervision and guardianship of CSGS-owned equipments which must be listed on the CSGS webpage. This list shall be kept up-to-date and all the documents/receipts must be with the current CSGS accountant. (Suggested exec for the job – VP social, but a new exec for this job can also be hired).
 In particular, this exec has to take care of the maintenance of the espresso machine of the graduate lounge. The responsibilities include to check the performance of the machine 

weekly, to make sure it is kept in order as recommended in the specifications of the machine and the instructions how to use the machine are in proper order, attached next to the machine. Once a year the exec would need to call the corresponding shop (Espresso Mali) and make an appointment  for technical checkup which would include also changing the water filter. The latter is supposed to cost 300$ starting second year (150$ for the filter and 150$ for the checkup). The first year is included in the warranty.The failure to do so will cause the expiration of the guarantee on the machine.
  •  Amendment 2: Change 5b  to “The Executive shall hold office from October 1st of each year until the following September 31st”
This is suggested to ensure that the new incoming students get the chance of getting involved in CSGS elections and the old execs to transfer their knowledge to the new ones.

Seminar 6 : The dual view of Markov Processes

Date: March 17, 2016
Time: 1:00-2:00pm
Location: McConnell Room 320

Speaker: Florence Clerc
Title: The dual view of Markov Processes

I will describe how to view a probabilistic transition system as a transformer of functions rather than as a transformer of probability distributions. A Markov process is normally viewed as a Markov kernel i.e. a map from S x Σ → [0,1] where S is a state space and Σ is a σ-algebra on S. These Markov kernels are morphisms in the Kleisli category of the Giry monad. In recent work by Chaput, Danos, Panangaden and Plotkin, Markov processes were reinterpreted as linear maps on the space of positive L1 functions on S. This is analogous to taking the predicate transformer view of Markov processes. A number of dualities and isomorphisms emerge in this picture. Most interestingly conditional expectation can be understood functorially.

Seminar 5 : Time, bounded rationality and representations in reinforcement learning

Date: February 18 (next Thursday)
Time: 1:00-2:00pm
Location: McConnell Room 320
Speaker: Pierre-Luc Bacon
Title: Time, bounded rationality and representations in reinforcement learning

In this talk, I will tell about some of the research that I’ve been conducting with Prof. Doina Precup over the last couple years.  The main topic will be the problem of “temporal representation learning” in reinforcement learning. Reinforcement learning is an Artificial Intelligence approach to the problem of sequential decision making, in a world full of uncertainty and under limited computational capacity. As for “representation learning”,  it refers to the problem of autonomously finding and  expressing knowledge within a particular reasoning structure while also improving it over time through experience. I will develop  these ideas through the notion of “bounded rationality” and present some recent mathematical tools that we developed to tackle  this problem. In a sense, the title of this talk also reflects my experience through PhD: a journey to improve and refine my own subjective understanding of the world (and of myself) under limited capacity. Just as for our reinforcement learning agents, I had to  embrace the stochasticity of life while leveraging its regularities. I will try to share both sides of the story: how the research results came about, and how I became more of a researcher over time.

Seminar 4 : Code Fragment Summarization

The Computer Science Graduate Society is pleased to present a talk by Annie Ying on February 11, Thursday. To help us know how much food to order, please fill this Google form if you plan to attend:


Date: February 11

Time: 1:00-2:00pm

Location: McConnell Room 320

Speaker: Annie Ying

Title: Code Fragment Summarization

Code fragments are an important resource for understanding the Application Programming Interface (API) of software libraries. Many usage scenarios for code fragments require them to be distilled to their essence: for example, when serving as cues to longer documents, for reminding developers of a previously known idiom, or for displaying search results. This dissertation reports on research on shortening, or summarizing, code fragments and makes three main contributions: a set of lessons learned from a case study on a supervised machine learning approach to the generating code fragment summaries; an empirically grounded catalog of source code summarization practices; and the design, implementation and evaluation of a novel optimization-based summarization technique for code fragments.

Afternoon Tea Every Wednesday

We are starting “Afternoon tea” events for graduate students and faculty members.  Every Wednesday from 3-4 pm the lounge will be reserved for us.  CSGS will provide the tea and cookies! We will also buy a new tea boiler for the lounge. (yaaaay!).  Please come with your own mug.  We hope this will be a good way for all of us to connect and to share our research and non-research interests! There will be plenty of chalks available as well (maybe colourful ones too)!

We start this week!

Seminar 3 : Marrying Reinforcement Learning and Deep Learning

The Computer Science Graduate Society is pleased to present the first talk of the winter semester by Emmanuel Bengio on 15th January. To help us know how much food to order, please fill this Google form if you plan to attend:


Date: January 15
Time: 13:00-14:00
Location: McConnell Room 103

Speaker: Emmanuel Bengio
Title: Marrying Reinforcement Learning and Deep Learning

Abstract: In the last few years Machine Learning has boosted in popularity thanks to the outrageously successful applications of Deep Learning, in many areas including speech recognition, fraud detection, advertisement, recommendation systems, and, probably most famously, computer vision.
Taking advantage of these techniques, we have also very recently seen successful use of Deep Learning as a tool inside of Reinforcement Learning tasks, such as DeepMind’s popular Atari model. A new approach, which is the main concern of my research, consists in studying the opposite direction: using Reinforcement Learning to augment Deep Learning models. This takes the form of conditional computing, visual attention, memory mechanisms, and much more, which I will discuss during this talk.

Seminar 2 : Efficient Collaborations with Trust-Aware Robots

The Computer Science Graduate Society is pleased to present a talk by Anqi Xu on 2nd December (next Wednesday). To help us know how much food to order, please fill this Google form if you plan to attend:

Date: December 2 (next Wednesday)

Time: 12:00-13:00

Location: McConnell Room 103

Speaker: Anqi Xu

Title: Efficient Collaborations with Trust-Aware Robots


In this work, we give autonomous robot agents the ability to infer their human collaborator’s changing trust states, and consider how this signal can be capitalized to improve the efficiency of human-robot teams. This trust-aware robot framework incorporates advances in online human-robot trust modeling and interactive behavior adaptation for autonomous agents. We build upon these components by introducing the novel formulation of trust-induced conservative control. This enables the robot agent to momentarily alter its behaviors in response to the human’s trust losses, as an active means to mend damage to the team relationship. We present two end-to-end instantiations of trust-aware robots for distinct task domains of aerial terrain coverage and interactive autonomous driving. Our empirical assessments comprise of a large-scale controlled study, as well as field evaluations with a smart car platform. These assessments quantitatively demonstrate the diverse efficiency gains of trust-aware robots.

Financial Statement

Transparency is next to Godliness!! Here we tell you, most cherished CS grads, about the ways in which we are spending your money. Don’t hesitate to contact us if you feel we are over- or  under-spending on some criteria!.

11/09/2015$191.80Seminar1st seminar food and drinks for grad studentsMcConnell 320
11/06/2015$37.56Seminar1st seminar hoodie gift and gift bag for speakerMcConnell 320
11/30/2015$76.85Seminar2nd seminar hoodie gift and gift bag for speakerMcConnell 320
12/02/2015$170.40Seminar2nd seminar foodMcConnell 103
01/13/2016$438.41Seminar10 hoodies for the upcoming 10 seminar+1.5 e-transfer feeMcConnell 103
01/13/2016$190.05Seminar3rd seminar foodMcConnell 103
02/08/2016$246.61Board Games NightFood, drinks and gamesThomson House
02/10/2016$22.70Tea & Cookie1st tea & cookiesMcConnell 321
02/11/2016$191.60Seminar4th seminar foodMcConnell 103
02/16/2016$17.01Tea & Cookie2nd tea & cookiesMcConnell 321
02/16/2016$62.99Tea pot for graduate student loungeTea pot for graduate student loungeMcConnell 321
03/17/2016$158.70Seminar5th seminar foodMcConnell 103
03/17/2016$9.60Tea & Cookie3rd tea & cookiesMcConnell 321
03/18/2016$156.80Seminar6th seminar foodMcConnell 103