Purposes, concepts, misfits, and a redesign of git

Git is a widely used version control system that is powerful but complicated. Its complexity may not be an inevitable consequence of its power but rather evidence of flaws in its design. To explore this hypothesis, we analyzed the design of Git using a theory that identifies concepts, purposes, and misfits. Some well-known difficulties with Git are described, and explained as misfits in which underlying concepts fail to meet their intended purpose. Based on this analysis, we designed a reworking of Git (called Gitless) that attempts to remedy these flaws. To correlate misfits with issues reported by users, we conducted a study of Stack Overflow questions. And to determine whether users experienced fewer complications using Gitless in place of Git, we conducted a small user study. Results suggest our approach can be profitable in identifying, analyzing, and fixing design problems.SUTD-MIT International Design Centre (IDC

Translating Erlang to /spl mu/CRL

The language Erlang has been developed by Ericsson to implement large switching systems. Erlang is nowadays used by several companies for complex embedded systems. The language /spl mu/CRL is a process algebra with data. Several verification tools are available for /spl mu/CRL and other process algebras, including a tool to create labelled transition systems from /spl mu/CRL specifications. By having a translation from Erlang to /spl mu/CRL we can apply the verification tools for process algebras and labelled transition systems to industrial code. The translation is aware of the major design component in the switching software. This knowledge is used to ensure that the size of the labelled transition system generated by the tools is smaller than with a naive translation

Progress in Research on Autonomous Vehicle Motion Planning

Operation of an autonomous vehicle in a real-world environment requires capabilities for real-time processing of uncertain, incomplete, and approximate information. We report progress in the development of methods for robust autonomous navigation of autonomous vehicles in unstructured environments. We focus in particular on those issues where the use of techniques based on fuzzy logic has proved to be particularly helpful with emphasis on the representation and execution of complex navigation plans. We illustrate our discussion with examples taken from experimental implementation of these techniques on Flakey, the mobile robot of the Artificial Intelligence Center of SRI International. On leave from Iridia, Universit'e Libre de Bruxelles, Brussels, Belgium. 1 Introduction The development of techniques to plan and execute autonomous-vehicle actions in a real-world unstructured environment requires consideration of multiple issues. First, knowledge about the environment is, in gene..

Data mining for gene mapping

Localization of disease susceptibility genes to certain areas in the human genome, or gene mapping, requires careful analysis of genetic marker data. Gene mapping is often carried out using a sample of individuals affected by the disease of interest and a sample of healthy controls. From a data mining perspective, gene mapping can then be cast as a pattern discov-ery and analysis task: which genetically motivated marker patterns help to separate affected individuals from healthy ones? The marker data constitutes haplotypes: a haplotype is a string of genetic markers from one chromosome. Individuals who share a common ancestor, such as those that have inherited the disease gene from this individual, potentially share a substring in their haplotypes. Classi-fication or association analysis of haplotypes is thus one approach to gene mapping. Further, analyzing the similarities of haplotypes and clustering them can provide insight to genetic rela-tionships of individuals, to different mutations, and thus to the genetic etiology of the disease. We describe and illustrate data mining approaches to gene mapping using haplotypes: as-sociation analysis, similarity analysis, and clustering. The association-based gene mapping methods have been found to perform well and are being routinely applied in gene mapping projects