"A number of representation schemes have been presented for use within Learning Classifier Systems, ranging from binary encodings to neural networks. This paper presents results from an investigation into using a discrete dynamical system representation within the XCS Learning Classifier System. In particular, asynchronous random Boolean networks are used to represent the traditional condition-action production system rules. It is shown possible to use self-adaptive, open-ended evolution to design an ensemble of such discrete dynamical systems within XCS to solve a number of well-known test problems."

"An important problem in computational social choice theory is the complexity of undesirable behavior among agents, such as control, manipulation, and bribery in election systems. These kinds of voting strategies are often tempting at the individual level but disastrous for the agents as a whole. Creating election systems where the determination of such strategies is difficult is thus an important goal. …"

"We consider the age-old problem of allocating items among different agents in a way that is efficient and fair. Two papers, by Dolev et al. and Ghodsi et al., have recently studied this problem in the context of computer systems. Both papers had similar models for agent preferences, but advocated different notions of fairness. We formalize both fairness notions in economic terms, extending them to apply to a larger family of utilities. Noting that in settings with such utilities efficiency is easily achieved in multiple ways, we study notions of fairness as criteria for choosing between different efficient allocations. Our technical results are algorithms for finding fair allocations corresponding to two fairness notions: Regarding the notion suggested by Ghodsi et al., we present a polynomial-time algorithm that computes an allocation for a general class of fairness notions, in which their notion is included. For the other, suggested by Dolev et al., we show that a competitive market equilibrium achieves the desired notion of fairness, thereby obtaining a polynomial-time algorithm that computes such a fair allocation and solving the main open problem raised by Dolev et al."

"...Common misconceptions regarding the embedding approach are addressed including whether or not it results in an average value control model (no), is necessary to "tweak" the algorithm to get bang-bang solutions (no), requires infinite switching (no), has real-time capability (yes), or reduction to a classical nonlinear optimization problem (a desirable yes)."

"Lately I've been thinking a lot about the impact of the move to a thick client architecture for web applications, and I'm becoming more and more certain that this means that Rails-style MVC frameworks on the server-side are going to end up being phased out in favour of leaner and meaner frameworks that better address the new needs of thick-client architecture."

"This deck of 91 full-colour cards names what skilled facilitators and other participants do to make things work.  The content is more specific than values and less specific than tips and techniques, cutting across existing methodologies with a designer's eye to capture the patterns that repeat.  The deck can be used to plan sesssions, reflect on and debrief them, provide guidance, and share responsibility for making the process go well.  It has the potential to provide a common reference point for practitioners, and serve as a framework and learning tool for those studying the field. "

"Good database design is crucial to obtain a sound, consistent database, and - in turn - good database design methodologies are the best way to achieve the right design. These methodologies are taught to most Computer Science undergraduates, as part of any Introduction to Database class. They can be considered part of the "canon", and indeed, the overall approach to database design has been unchanged for years. Moreover, none of the major database research assessments identify database design as a strategic research direction.

Should we conclude that database design is a solved problem?

Our thesis is that database design remains a critical unsolved problem. Hence, it should be the subject of more research. Our starting point is the observation that traditional database design is not used in practice - and if it were used it would result in designs that are not well adapted to current environments. In short, database design has failed to keep up with the times. In this paper, we put forth arguments to support our viewpoint, analyze the root causes of this situation and suggest some avenues of research."

"Think of branches in two categories: public and private.

Public branches are the authoritative history of the project. In a public branch, every commit should be succinct, atomic, and have a well documented commit message. It should be as linear as possible. It should be immutable. Public branches include Master and release branches.

A private branch is for yourself. It’s your scratch paper while working out a problem.

It’s safest to keep private branches local. If you do need to push one, maybe to synchronize your work and home computers, tell your teammates that the branch you pushed is private so they don’t base work off of it."

"Form-backing objects, also known as Presenters (not to be confused with the concept of view presenters), are objects whose sole purpose is to take user-entered form data and perform some unit of work. Creating and testing form-backing objects is simple. In this situation, you might add a Registration object."

"This means that each time the document is updated, the client will also store the previous version as an attachment to the latest version. At any time, a user can load any of the old versions."

"In this paper we consider spatial networks that realize a balance between an infrastructure cost (the cost of wire needed to connect the network in space) and communication efficiency, measured by average shortest pathlength. A global optimization procedure yields network topologies in which this balance is optimized. These are compared with network topologies generated by a competitive process in which each node strives to optimize its own cost-communication balance. Three phases are observed in globally optimal configurations for different cost-communication trade-offs: (i) regular small worlds, (ii) star-like networks and (iii) trees with a centre of interconnected hubs. In the latter regime, i.e. for very expensive wire, power laws in the link length distributions $P(w)\propto w^{-\alpha}$ are found, which can be explained by a hierarchical organization of the networks…"

"Parallel Global Optimization Algorithms (PGOA) provide an efficient way of dealing with hard optimization problems. One method of parallelization of GOAs that is frequently applied and commonly found in the contemporary literature is the so-called Island Model (IM). In this paper we analyze the impact of the migration topology on the performance of a PGOA which uses the Island Model. In particular we consider parallel Differential Evolution and Simulated Annealing with Adaptive Neighborhood and draw first conclusions that emerge from the conducted experiments."

"As Alexander repeatedly points out, you can’t consider a construction in isolation, you have to consider the construction in context. And the context for this bench is rather remarkable: you have rather steep hills covered with trees behind you and to your right, you have the Fort Mason buildings to your left, and in front of you you have a gorgeous view of the San Francisco Bay, with Alcatraz and Angel Island in the distance."

"In the current refactoring of Apotomo I finally extracted the bubbling event library into a separate ruby gem Onfire.

Bubbling events is, in contrast to Ruby’s own Observable module, focused on observing events triggered by business objects, not watching the objects themselves.

In addition, a triggered event will bubble up the tree branch and subsequently inform all ancestors- you get automatic organic event filtering.

Complete instructions are on the github page."

facepalm; this makes a lot of sense, but I have to say CH does a very poor job explaining very complicated design principles

"Orchestra provides an instrumentation API for Ruby."

"How do you name step files? What to put in each step? What not to put in steps? Here are some guidelines that will lead to better scenarios. If you are new to steps and the general syntax, please read Feature Introduction first."

Proof-of-concept of distributed population-based metaheuristics running on a number of phones.

"Working in an collaborative environment that simultaneously supports business, technology, creativity, and performance give rise to new concepts. Below we list of some of the ideas we use in our work--terms you may hear or things you may experience if you become a member and spend some time in this unique environment."

"Variation: Saboteur
A Test Stub that is used to inject invalid indirect inputs into the SUT is often called a "Saboteur" because its purpose is to derail whatever the SUT is trying to do so we can see how the SUT copes with these circumstances. The "derailment" can be caused by returning unexpected values or objects, or it can be caused by raising an exception or causing a runtime error. Each test may either be a Simple Success Test or an Expected Exception Test (see Test Method) depending on how the SUT is expected to behave in response to the indirect input."

"php is the "language of choice" for the majority of web development, and it can be described as "The Visual Basic of Free Software" for very good reasons. Visual Basic gets a poor rap, because it is so easy to write bad code with. It takes years to become properly familiar with and proficient in Visual Basic, and php is no different. By the time a developer is familiar with php's rich and wonderful methods for self-mutilation, their lives have become so degraded that they wish they had never become programmers."

via http://growabrain.typepad.com

"When the semantics comes baked in then the semantic web will fly and the metadata that everyone knows they want, but can’t be bothered putting in, will be available and re-useable, along with the content."