21639
Strategic Sales Management in an Autonomous Trading Agent for TAC SCM
To operate successfully in a competitive trading environment such as the Trading Agent Competition for Supply Chain Management (Collins et al. 2004) (TAC SCM), an agent has to allocate resources and set prices in a way that maximizes its expected profit. This requires the ability to detect changing market conditions and act accordingly. In TAC SCM six agents buy parts, assemble personal computers, and sell them in daily auctions to customers. Sales decisions in our agent, MinneTAC, are driven by three different models: an automated characterization and prediction of market conditions, which we call economic regimes (Ketter 2005), a linear program that optimizes daily sales quotas, and a model of order acceptance probability. While economic regime models are commonly used at the macro economic level (Osborn & Sensier 2002), such predictions are rarely done for a micro economic environment. We focus on the sales decisions the agent has to make, where predicting prices and customer demand play an essential role. The strategies we present have been inspired, among others, by the work of Kephart et al. (Kephart, Hanson, & Greenwald 2000). MinneTAC makes sales decisions in two steps. The first step is a strategic decision, where resources are allocated over a planning horizon in a way that maximizes expected profit over the horizon. The second step is a tactical decision, which determines the offer prices that are expected to sell the quantities determined by the strategic decision, given the current demand and the pricing model.
11333929
Mixed-initiative decision support in agent-based automated contracting
Using principles from Expected Utility Theory, we analyze the criteria that a customer agent in agent-based automated contracting would use in making decisions during the bidding cycle. We use the University of Minnesota's MAGNET automated-contracting environment as a framework for this analysis. Two decisions must be made by a customer agent during this process: deciding the composition of the Request for Quotes, and evaluating and awarding bids. We show how principles from Expected Utility Theory can be applied in a mixed-initiative environment, where user preferences control the decision-making process, and user decisions are nal. Finally, we show how the market infrastructure can support agent decision-making by gathering and analyzing statistical data on activities in the market.
35532626
Bid Selection Strategies for Multi-agent Contracting in the Presence of Scheduling Constraints
Bid evaluation in a multi-agent automated contracting environment presents a challenging search problem. We introduce a multicriterion, anytime bid evaluation strategy that incorporates cost, task coverage, temporal feasibility, and risk estimation into a simulated annealing framework. We report on an experimental evaluation using a set of increasingly informed search heuristics within simulated annealing. The results show that excess focus on improvement leads to faster improvement early on, at the cost of a lower likelihood of finding a solution that satisfies all the constraints. The most successful approach used a combination of random and focused bid selection methods, along with pruning and repeated restarts.
14718930
Decision Processes in Agent-Based Automated Contracting
The Magnet system meets many of the challenges of modeling decision making for customer agents in automated contract negotiation. In order to model decision making in the uncertain environment of contract negotiation, we use the Expected Utility Theory. We describe that theory, followed by more detailed descriptions of the customer agents' key decision-making processes and our search algorithm. First, we offer an overview of the Magnet environment.
2312899
Risk and expectations in a-priori time allocation in multi-agent contracting
In related research we have proposed a market architecture for multi-agent contracting and we have implemented prototypes of both the market architecture and the agents in a system called MAGNET. A customer agent in MAGNET solicits bids for the execution of multi-step plans, in which tasks have precedence and time constraints, by posting a Request for Quotes to the market. The Request for Quotes needs to include for each task its precedence constraints and a time window. In this paper, we study the problem of optimizing the time windows in the Requests for Quotes. Our approach is to use the Expected Utility Theory to reduce the likelihood of receiving unattractive bids, while maximizing the number of bids that are likely to be included in the winning bundle. We describe the model, illustrate its operation and properties, and discuss what assumptions are required for its successful integration into MAGNET or other multi-agent contracting systems.
9735857
Scheduling tasks with precedence constraints to solicit desirable bid combinations
In our previous research we suggested an approach to maximizing agents preferences over schedules of multiple tasks with temporal and precedence constraints. The proposed approach is based on Expected Utility Theory. In this paper we address two mutually dependent questions: (a) what are the properties of the problem domain that can facilitate efficient maximization algorithms, and (b) what criteria determine attractiveness of one or another potential solution to the agent. We discuss different ways of exploring the problem domain. We show that naive optimization approaches often fail to find solutions for risk-averse agents and propose ways of using properties of the domain to improve upon naive approaches.
15801066
Dimensional Inference Using Symbol Lives
Scientific equations embedded in computer programs must obey the rules for dimensional consistency. Many efforts have been made to enforce these rules within computer programs. Some methods require the user to modify the program by adding dimensional information either as extensions to the programming language or else by using existing language facilities. The large amount of effort required to modify large scientific and engineering programs in this way is usually uneconomic and can be prone to error if done manually. Consequently, methods that do not require modifications to the program have been developed. However, these methods are limited in what they can discover and find it hard to tell the user where, precisely, in his program the error has been made. This paper describes a novel approach which employs the concept of symbol lives to analyse the dimensional implications of the users source code. The method, implemented for Fortran programs in the software engineering toolkit, WinFPT, is fast, systematic and identifies the locations of errors in the user's source code. Keywords--Software Engineering, Dimensional Analysis, Static Analysis, Fortran
59716230
Outline or bitmap type
39929543
Spike: A Six Legged Cube Style Robot
This paper describes a six legged cube based robot named ‘Spike’, which uses three axes of symmetry with a collinear pair of legs mounted on each axis. Spike is designed to implement a novel form of locomotion which uses a tilting and falling motion as a result of leg movements to form its gait. Due to the triangular symmetry inherent in the robot’s footprint, each step the robot takes is limited to one of three directions. At rest, the robot has three points of contact with the ground and all sides share equal length to form a tripedal stance. The gait is generated by directing a single leg toward the bisector of the opposing side, causing the robot to tumble, and fall into a new leg configuration. It was found that the robot was able to move along an angle of trajectory, where the accuracy of following the trajectory over time was dependant on the number of steps made.
34266504
The BBC Television Management Information System
114125959
Documenting protocols in CLOS: keeping the promise of reuse