What Cannot Be Deconstructed? Truth

Simulating what cannot be simulated

The background to these notes is the expectation that mathematical modelling and simulation is going to play increasingly important role in the understanding of the organization and control of genetic-, metabolic-, and signalling pathways. I am going to argue that for modelling and simulation to help our understanding of cellular dynamics, the current practice of experimental design has to chan...

Why Propositions Cannot be Sets of Truth-supporting Circumstances

What Cannot be Learned with Bethe Approximations

We address the problem of learning the parameters in graphical models when inference is intractable. A common strategy in this case is to replace the partition function with its Bethe approximation. We show that there exists a regime of empirical marginals where such Bethe learning will fail. By failure we mean that the empirical marginals cannot be recovered from the approximated maximum likel...

Valency Ambiguity Interpretation: What Can and What Cannot be Done

Russian constructions that involve the ambiguity of valencies are considered regarding the extent in which it can be successfully resolved by man or machine. The material includes two types of phenomena: 1) Russian counterparts of noun phrases like (a) the phases of sleep vs. (b) the phase of active sleep – in (a), sleep instantiates the subject valency of phase whereas in (b) sleep is the cont...

What Cannot Be Read, Cannot Be Leveraged? Revisiting Assumptions of JIT-ROP Defenses

Despite numerous attempts to mitigate code-reuse attacks, Return-Oriented Programming (ROP) is still at the core of exploiting memory corruption vulnerabilities. Most notably, in JIT-ROP, an attacker dynamically searches for suitable gadgets in executable code pages, even if they have been randomized. JIT-ROP seemingly requires that (i) code is readable (to find gadgets at run time) and (ii) ex...