Keynote Lectures

Abstract
Many models that are used to inform sustainable development policies are deterministic models, in which future parameter values are set according to some estimates or scenarios. However, the future is highly uncertain and ignoring this uncertainty when making decisions can be very costly. This talk will present the principles of a two-stage, stochastic, chance-constrained programming approach which can be used to derive policies suitable for a broad variation of uncertain parameters. It will also feature several examples of applications including pollution control and water allocation problems.
The benefits of incorporating uncertainty and missed opportunities from the lack of perfect information will be highlighted.

Abstract
Individuals are gaining more control of their personal data through recent data privacy laws such the General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA). An aspect of these laws is the ability to request a business to delete your information, the so called “right to be forgotten” or “right to erasure”. These laws have serious implications for companies and organizations that train large, highly accurate deep neural networks (DNNs) using these valuable consumer data sets. The initial training process can consume significant resources and time to create an accurate solution. Thus, once a solution is achieved, updates to the model are often incremental. Also, training data can be distributed or lost, making complete retraining impossible. As such, a received redaction request poses complex technical challenges on how to comply with the law while fulfilling core business operations.
DNNs are complex functions and the relationship between a single data point, the model weights, and the model output probabilities are not fully understood. In some cases, DNNs can leak information about their training data sets in subtle ways. In one type of attack, the membership inference (MI) attack, an attacker can query the model and gain an understanding about whether the data record was used in its training, which would be a serious breach of the GDPR and the CCPA.
In this talk, we introduce a DNN model training and lifecycle maintenance process that establishes how to handle specific data redaction requests and avoid completely retraining the model in certain scenarios. Our new process includes quantifying the MI attack vulnerability of all training data points and identifying and removing those most vulnerable from the training data set. An accurate model is then achieved upon which incremental updates can be performed to redact sensitive data points. We will discuss heuristics learned through experiments that train and redact data from DNNs, including new metrics that quantify this vulnerability and how we verify this redaction.

Abstract
We present a constructive preference learning methodology, called robust ordinal regression. Its aim is to learn Decision Maker’s (DM’s) preferences in multiattribute decision aiding. It links Operational Research with Artificial Intelligence, and as such, it confirms the current trend in mutual relations between OR and AI. In decision problems involving multiattribute evaluations of alternatives, the dominance relation in the set of alternatives is the only objective information that stems from their formulation. This is the case of multiple criteria decision making, group decision or decision under uncertainty. While the dominance relation permits to eliminate many irrelevant (i.e., dominated) alternatives, it leaves many alternatives incomparable. In order to recommend a decision concordant with a value system of a single or multiple DMs (best choice, classification or ranking), the analyst must take into account preferences of the DM(s). In the presented methodology of robust ordinal regression, the DM’s preferences are exhibited through decision examples. We show how to transform the decision examples into a mathematical model of preferences in one of three forms: utility functions, binary (outranking) relations, or logical “if…, then…” decision rules. In practical decision aiding, the process of preference elicitation, preference modeling, and DM’s analysis of a recommendation, loops until the DM (or a group of DMs) accepts the recommendation or decides to change the problem setting. Such an interactive process is called constructive preference learning.