Sverker Janson

TAC-03: a supply-chain trading competition

The Trading Agent Competition (TAC) has now become an annual fixture since its inception in 2000. The competition was conceived with the objective of studying automated trading strategies by focusing the research community on the development of competing solutions to a common trading scenario. The success of past TAC events has motivated broadening the scope of the competition beyond the context of the travel agent scenario used thus far. For the fourth edition of this competition, TAC-03, to be held in August 2003, the authors have created a novel supply-chain trading game with the aim of investigating automated agents in the context of dynamic supply-chain management.

Agents, self-interest and electronic markets

How free are our software agents to take the best possible care of our interests? How free can we make them? In what sense and to what extent do currently proposed mechanisms and agent behaviors consider self-interest? What current research addresses these issues? What needs to be done? We address these issues in the context of electronic markets, such as consumer goods markets and (future, more fine-grained) markets for electric power or communication bandwidth.

SICS MarketSpace - An Agent-Based Market Infrastructure

We present a simple and uniform communication framework for an agent-based market infrastructure, the goal of which is to enable automation of consumer goods markets distributed over the Internet. The framework consists of an information model for participant interests and an interaction model that defines a basic vocabulary for advertising, searching, negotiating and settling deals. The information model is based on structured documents representing contracts and representations of constrained sets of contracts called interests. The interaction model is asynchronous message communication in a speech act based language, similar to, but simpler than, KQML [7] and FIPA ACL [8]. We also discuss integration of an agent-based market infrastructure with the web.

Embla - Data Dependence Profiling for Parallel Programming

With the proliferation of multicore processors, there is an urgent need for tools and methodologies supporting parallelization of existing applications. In this paper, we present a novel tool for aiding programmers in parallelizing programs. The tool, Embla, is based on the Valgrind framework, and allows the user to discover the data dependences in a sequential program, thereby exposing opportunities for parallelization. Embla performs an off-line dynamic analysis, and records dependences as they arise during program execution. It reports an optimistic view of parallelizable sequences, and ignores dependences that do not arise during execution. Moreover, since the tool instruments the machine code of the program, it is largely language independent. Since Embla finds the dependencies that occur for particular executions, the confidence one would assign to its results depend on whether different executions yield different (bad) or largely the same (good) dependencies. We present a preliminary investigation into this issue using 84 different inputs to the SPEC CPU2006 benchmark 403.gcc. The results indicate that there is a strong correlation between coverage and finding dependencies; executing the entire program is likely to reveal all dependencies.

Estimating and exploiting potential parallelism by source-level dependence profiling

Manual parallelization of programs is known to be difficult and error-prone, and there are currently few ways to measure the amount of potential parallelism in the original sequential code. We present an extension of Embla, a Valgrind-based dependence profiler that links dynamic dependences back to source code. This new tool estimates potential task-level parallelism in a sequential program and helps programmers exploit it at the source level. Using the popular forkjoin model, our tool provides a realistic estimate of potential speed-up for parallelization with frameworks like Cilk, TBB or OpenMP 3.0. Estimates can be given for several different parallelization models, varying in programmer effort and capabilities required of the underlying implementation. Our tool also outputs source-level dependence information to aid the parallelization of programs with lots of inherent parallelism, as well as critical paths to suggest algorithmic rewrites of programs with little of it. We validate our claims by running our tool over serial elisions of sample Cilk programs, finding additional inherent parallelism not exploited by the Cilk code, as well as over serial C benchmarks where the profiling results suggest parallelism-enhancing algorithmic rewrites.

An Introduction to AKL A Multi-Paradigm Programming Language

AKL is a multi-paradigm programming language based on a concurrent constraint framework (Janson and Haridi 1991), directly or indirectly supporting the following paradigms. processes and process communication object-oriented programming functional and relational programming constraint programming.

Agent-Mediated Electronic Commerce - Designing Trading Agents and Mechanisms

htmlabstractThis book constitutes the thoroughly refereed post-proceedings of the 7th International Workshop on Agent-Mediated Electronic Commerce, AMEC VII 2005, held in Utrecht, Netherlands in July 2005, as part of AAMAS 2005, and the third Workshop on Trading Agent Design and Analysis, TADA 2005, held in Edinburgh, UK in August 2005, in the course of the IJCAI 2005 conference meetings. The 7 revised full AMEC 2005 papers presented were carefully selected and address a mix of both theoretical and practical issues, looking at behavioral and organizational dimensions of agent-mediated electronic commerce as well as at complex computational, information and system-level challenges. An extended version of an article originally presented at AMEC 2004 has also been included. The second part of the book comprises 8 revised full papers of TADA 2005 that focus on trading agent technologies and mechanism design, including discussions of agent architectures and decision-making algorithms along with theoretical analyses and empirical evaluations of agent strategies in different trading contexts.