Composing first species counterpoint with a variable neighbourhood search algorithm

In this article, a variable neighbourhood search (VNS) algorithm is developed that can generate musical fragments consisting of a melody for the cantus firmus and the first species counterpoint. The objective function of the algorithm is based on a quantification of existing rules for counterpoint. The VNS algorithm developed in this article is a local search algorithm that starts from a randomly generated melody and improves it by changing one or two notes at a time. A thorough parametric analysis of the VNS reveals the significance of the algorithm's parameters on the quality of the composed fragment, as well as their optimal settings. A comparison of the VNS algorithm with a developed genetic algorithm shows that the VNS is more efficient. The VNS algorithm has been implemented in a user-friendly software environment for composition, called Optimuse. Optimuse allows a user to specify a number of characteristics such as length, key and mode. Based on this information, Optimuse 'composes' both cantus firmus and first species counterpoint. Alternatively, the user may specify a cantus firmus, and let Optimuse compose the accompanying first species counterpoint. © 2012 Taylor & Francis

Use of magnetic resonance imaging in rectal cancer patients: Society of Abdominal Radiology (SAR) rectal cancer disease-focused panel (DFP) recommendations 2017

International audiencePURPOSE:To propose guidelines based on an expert-panel-derived unified approach to the technical performance, interpretation, and reporting of MRI for baseline and post-treatment staging of rectal carcinoma.METHODS:A consensus-based questionnaire adopted with permission and modified from the European Society of Gastrointestinal and Abdominal Radiologists was sent to a 17-member expert panel from the Rectal Cancer Disease-Focused Panel of the Society of Abdominal Radiology containing 268 question parts. Consensus on an answer was defined as ≥ 70% agreement. Answers not reaching consensus (< 70%) were noted.RESULTS:Consensus was reached for 87% of items from which recommendations regarding patient preparation, technical performance, pulse sequence acquisition, and criteria for MRI assessment at initial staging and restaging exams and for MRI reporting were constructed.CONCLUSION:These expert consensus recommendations can be used as guidelines for primary and post-treatment staging of rectal cancer using MRI

Efficient Parallelism vs Reliable Distribution: A Trade-Off for Concurrent Computations

Concurrent computations should combine efficiency with reliability, where efficiency is usually associated with parallel and reliability with distributed computing. Such a desirable combination is not always possible, because of an intuitive trade-off: efficiency requires removing redundancy from computations whereas reliability requires some redundancy. We survey a spectrum of algorithmic models (from fail-stop, synchronous to asynchronous and from approximate to exact computations) in which reliability is guaranteed with small trade-offs in efficiency. We illustrate a number of cases where optimal trade-offs are achievable. A basic property of all these models, which is of some interest in the study of concurrency, is that &quot;true&quot; read/write concurrency is necessary for fault tolerance. In particular, we outline (from [14]) how algorithms can be designed so that, in each execution, the total &quot;true&quot; concurrency used can be closely related to the faults that can be tolerated