Development Strategy and Governance Division

agricultural research centers that receive principal funding from governments, private foundations, and international and regional organizations, most of which are members of the Consultative Group on International Agricultural Research. FINANCIAL CONTRIBUTORS AND PARTNERS IFPRI’s research, capacity strengthening, and communications work is made possible by its financial contributors and partners. IFPRI gratefully acknowledges generous unrestricted funding from Australia

Agents and Complex Systems James Odell

Traditional objects can be thought of as passive, because they wait for a message before performing an operation. Then, once invoked, they execute their method and go back to “sleep ” until the next message. A trend in many systems now is to design objects that react to events in their environment, as well as be proactive. In UML 2.0, these are known as active objects; in the agent community, they are known as agents. Whether they are called active objects or agents, this new direction is going to radically change how we design systems. The biggest challenge, however, that we face is the degree of complexity that we are about to unleash. Imagine setting free a million proactive entities to run a supply chain. We are no longer choreographing their every movement as we would with traditional agents; instead, they decide when and how to execute their methods. This is both liberating- and scary. We can create complex systems, but we will not always know how to control them. In complex systems: designing the parts is not the same as designing the whole.

Agent-Based Manufacturing: A Case Study

In traditional manufacturing, information systems mimic organizational structures, utilizing a top-down, command-and-control structure. Communicating decisions and information down through the organization is time consuming—making it impossible to respond and adapt quickly to external forces

Adding dynamic interface to Smalltalk

The concept of interfaces is central to object-oriented methodologies and is one of the most attractive features of Java and COM. Although Smalltalk always had interfaces implicitly, in Smalltalk interfaces are not first-class objects: they cannot be conversed with, referred to, or reflected upon. Consequently, Smalltalkers have been deprived of such an important and useful tool. Since a fundamental feature of Smalltalk is that just about everything in the language is an implementation feature, explicit, static interfaces can be added to Smalltalk using Smalltalk itself with ease. However, such an addition would short-change the powerful dynamic aspects of Smalltalk. In this article we present SmallInterfaces; a new ontology of dynamic interfaces which makes a powerful use of the dynamic nature of Smalltalk. SmallInterfaces adds interfaces as honorary members to Smalltalk’s extensive reflection mechanism, in a manner portable across the many Smalltalk variants