A Generic Approach to Flow-Sensitive Polymorphic Effects

Effect systems are lightweight extensions to type systems that can verify a wide range of important properties with modest developer burden. But our general understanding of effect systems is limited primarily to systems where the order of effects is irrelevant. Understanding such systems in terms of a lattice of effects grounds understanding of the essential issues, and provides guidance when designing new effect systems. By contrast, sequential effect systems --- where the order of effects is important --- lack a clear algebraic characterization. We derive an algebraic characterization from the shape of prior concrete sequential effect systems. We present an abstract polymorphic effect system with singleton effects parameterized by an effect quantale --- an algebraic structure with well-defined properties that can model a range of existing order-sensitive effect systems. We define effect quantales, derive useful properties, and show how they cleanly model a variety of known sequential effect systems. We show that effect quantales provide a free, general notion of iterating a sequential effect, and that for systems we consider the derived iteration agrees with the manually designed iteration operators in prior work. Identifying and applying the right algebraic structure led us to subtle insights into the design of order-sensitive effect systems, which provides guidance on non-obvious points of designing order-sensitive effect systems. Effect quantales have clear relationships to the recent category theoretic work on order-sensitive effect systems, but are explained without recourse to category theory. In addition, our derived iteration construct should generalize to these semantic structures, addressing limitations of that work

Sine wave in music and sound art : a typology of artistic approaches

Project : Towards an Aesthetics of the Sine Wave Chercheur.e.s : Nicolas Bernier, Guillaume Boutard, Caroline TraubeDespite the sine wave’s close links to the birth of electronic music in the mid-twentieth century, it has been little studied aesthetically, and no systematic review of its artistic usages exists. This article presents a brief literature review, followed by the results of a survey on the principles guiding sine wave-based works. This allows to put forward a typological framework contributing to an understanding of the application of the sine wave in music

Isolated metal atoms and clusters for alkane activation: translating knowledge from enzymatic and homogeneous to heterogeneous systems

[EN] Activation of alkanes can be achieved with different types of catalysts, spanning over enzymes, homogeneous and heterogeneous metal catalysts. Though a tremendous amount of knowledge has been accumulated in the literature, the connections between different types of catalysts are rarely discussed due to the differences among the three catalysis fields in terms of catalyst structures, reaction conditions, and catalytic performances. There are also similarities among the various systems in terms of the structural features of the active sites and reaction mechanisms. In this review, we attempt to show the interconnections among the three catalysis fields regarding the nature of active sites and reaction mechanism for metal-catalyzed alkane activation reactions. We will show the lessons obtained from well-defined enzymatic and molecular catalysts developed in bio- and homogeneous catalysis, and how these can be translated into fundamental understanding and further developments of heterogeneous metal catalysts, for practical applications related to alkane activation.We are grateful for the financial supports from the Spanish Government through the "Severo Ochoa Program'' (SEV-2016-SEV-0683).Liu, L.; Corma Canós, A. (2021). Isolated metal atoms and clusters for alkane activation: translating knowledge from enzymatic and homogeneous to heterogeneous systems. Chem. 7(9):2347-2384. https://doi.org/10.1016/j.chempr.2021.04.001S234723847

Linux Kernel Memory Safety

Linux kernel vulnerabilities are often long lived and in some cases challenging to patch after discovery. The current focus in upstream Linux security has therefore been on categorical protections against whole error classes, not only reactive patching of specific vulnerabilities. Our work contributes to these efforts by tackling memory errors in the Linux kernel from two different fronts. First, we contributed to the upstream Linux kernel by working on a mechanism to prevent use-after-free errors caused by reference counter overflows. Second, we explored the applicability of Intel MPX as a general mechanism to prevent spatial memory errors in the Linux kernel