Showing papers by "Geun-Sik Jo published in 2000"

Brokerage between buyer and seller agents using constraint satisfaction problem models

Abstract: We have proposed a two-layered multi-agent framework for brokerage between buyers and sellers. The brokerage is processed in two layers for efficient linking between buyers and sellers: the competition layer and the constraint satisfaction layer. In the competition layer, we match the constituents of brokerage process to agents and use a functional relationship of a multi-agent framework for the communication among them. The seller agents, as requested by the buyer agents, are selected through the competition in the competition layer. In the constraint satisfaction layer, we model the relationship between buyer agents and seller agents in Constraint Satisfaction Problems (CSP). The CSP solver finds an optimal solution by choosing the best brokerage to satisfy various preferential requirements for users. We have implemented a prototype system for dealing in real estate on the Internet by applying the proposed framework. Finally, we have modeled the brokerage system using CSP and have shown the experimentation about the satisfaction level of users regarding their preferences.

Ramp Activity Expert System for Scheduling and Coordination at an Airport

Abstract: In this project, we have developed the ramp activity coordination expert system (races) to solve aircraft-parking problems. races includes a knowledge-based scheduling system that assigns all daily arriving and departing flights to the gates and remote spots with domain-specific knowledge and heuristics acquired from human experts. races processes complex scheduling problems such as dynamic interrelations among the characteristics of remote spots-gates and aircraft with various other constraints, for example, customs and ground-handling factors, at an airport. By user-driven modeling for end users and near-optimal knowledge-driven scheduling acquired from human experts, races can produce parking schedules for about 400 daily flights in approximately 20 seconds; human experts normally take 4 to 5 hours to do the same. Scheduling results in the form of Gantt charts produced by races are also accepted by the domain experts. races is also designed to deal with the partial adjustment of the schedule when unexpected events occur. After daily scheduling is completed, the messages for aircraft change, and delay messages are reflected and updated into the schedule according to the knowledge of the domain experts. By analyzing the knowledge model of the domain expert, the reactive scheduling steps are effectively represented as the rules, and the scenarios of the graphic user interfaces are designed. Because the modification of the aircraft dispositions, such as aircraft changes and cancellations of flights, is reflected in the current schedule, the modification should be sent to races from the mainframe for the reactive scheduling. The adjustments of the schedule are made semiautomatically by races because there are many irregularities in dealing with the partial rescheduling.