1,912 research outputs found
Budget Feasible Mechanisms for Experimental Design
In the classical experimental design setting, an experimenter E has access to
a population of potential experiment subjects , each
associated with a vector of features . Conducting an experiment
with subject reveals an unknown value to E. E typically assumes
some hypothetical relationship between 's and 's, e.g., , and estimates from experiments, e.g., through linear
regression. As a proxy for various practical constraints, E may select only a
subset of subjects on which to conduct the experiment.
We initiate the study of budgeted mechanisms for experimental design. In this
setting, E has a budget . Each subject declares an associated cost to be part of the experiment, and must be paid at least her cost. In
particular, the Experimental Design Problem (EDP) is to find a set of
subjects for the experiment that maximizes V(S) = \log\det(I_d+\sum_{i\in
S}x_i\T{x_i}) under the constraint ; our objective
function corresponds to the information gain in parameter that is
learned through linear regression methods, and is related to the so-called
-optimality criterion. Further, the subjects are strategic and may lie about
their costs.
We present a deterministic, polynomial time, budget feasible mechanism
scheme, that is approximately truthful and yields a constant factor
approximation to EDP. In particular, for any small and , we can construct a (12.98, )-approximate mechanism that is
-truthful and runs in polynomial time in both and
. We also establish that no truthful,
budget-feasible algorithms is possible within a factor 2 approximation, and
show how to generalize our approach to a wide class of learning problems,
beyond linear regression
Draining the Water Hole: Mitigating Social Engineering Attacks with CyberTWEAK
Cyber adversaries have increasingly leveraged social engineering attacks to
breach large organizations and threaten the well-being of today's online users.
One clever technique, the "watering hole" attack, compromises a legitimate
website to execute drive-by download attacks by redirecting users to another
malicious domain. We introduce a game-theoretic model that captures the salient
aspects for an organization protecting itself from a watering hole attack by
altering the environment information in web traffic so as to deceive the
attackers. Our main contributions are (1) a novel Social Engineering Deception
(SED) game model that features a continuous action set for the attacker, (2) an
in-depth analysis of the SED model to identify computationally feasible
real-world cases, and (3) the CyberTWEAK algorithm which solves for the optimal
protection policy. To illustrate the potential use of our framework, we built a
browser extension based on our algorithms which is now publicly available
online. The CyberTWEAK extension will be vital to the continued development and
deployment of countermeasures for social engineering.Comment: IAAI-20, AICS-2020 Worksho
Algorithms for the continuous nonlinear resource allocation problem---new implementations and numerical studies
Patriksson (2008) provided a then up-to-date survey on the
continuous,separable, differentiable and convex resource allocation problem
with a single resource constraint. Since the publication of that paper the
interest in the problem has grown: several new applications have arisen where
the problem at hand constitutes a subproblem, and several new algorithms have
been developed for its efficient solution. This paper therefore serves three
purposes. First, it provides an up-to-date extension of the survey of the
literature of the field, complementing the survey in Patriksson (2008) with
more then 20 books and articles. Second, it contributes improvements of some of
these algorithms, in particular with an improvement of the pegging (that is,
variable fixing) process in the relaxation algorithm, and an improved means to
evaluate subsolutions. Third, it numerically evaluates several relaxation
(primal) and breakpoint (dual) algorithms, incorporating a variety of pegging
strategies, as well as a quasi-Newton method. Our conclusion is that our
modification of the relaxation algorithm performs the best. At least for
problem sizes up to 30 million variables the practical time complexity for the
breakpoint and relaxation algorithms is linear
Min-Max Regret Scheduling To Minimize the Total Weight of Late Jobs With Interval Uncertainty
We study the single machine scheduling problem with the objective to minimize
the total weight of late jobs. It is assumed that the processing times of jobs
are not exactly known at the time when a complete schedule must be dispatched.
Instead, only interval bounds for these parameters are given. In contrast to
the stochastic optimization approach, we consider the problem of finding a
robust schedule, which minimizes the maximum regret of a solution. Heuristic
algorithm based on mixed-integer linear programming is presented and examined
through computational experiments
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