ElectricCOW : A simulator for mobile sensors and actuators mounted on herds of cattle

ElectricCOW is a network, animal behaviour and agent simulator designed to allow detailed simulation of an ad-hoc model network built from small mote-like devices called flecks. Detailed radio communications, cattle behaviour and sensor and actuator network modelling allows a closed-loop environment, where the network can influence the behaviour of its mobile platforms.

A programming language for software components

Component software has many benefits, most notably increased software re-use; however, the component software process places heavy burdens on programming language technology, which modern object-oriented programming languages do not address. In particular, software components require specifications that are both sufficiently expressive and sufficiently abstract, and, where possible, these specifications should be checked formally by the programming language. This dissertation presents a programming language called Mentok that provides two novel programming language features enabling improved specification of stateful component roles. Negotiable interfaces are interface types extended with protocols, and allow specification of changing method availability, including some patterns of out-calls and re-entrance. Type layers are extensions to module signatures that allow specification of abstract control flow constraints through the interfaces of a component-based application. Development of Mentok's unique language features included creation of MentokC, the Mentok compiler, and formalization of key properties of Mentok in mini-languages called MentokP and MentokL.

On model typing

Where object-oriented languages deal with objects as described by classes, model-driven development uses models, as graphs of interconnected objects, described by metamodels. A number of new languages have been and continue to be developed for this model- based paradigm, both for model transformation and for general programming using models. Many of these use single-object approaches to typing, derived from solutions found in object-oriented systems, while others use metamodels as model types, but without a clear notion of polymorphism. Both of these approaches lead to brittle and overly restrictive reuse characteristics. In this paper we propose a simple extension to object-oriented typing to better cater for a model-oriented context, including a simple strategy for typing models as a collection of interconnected objects. We suggest extensions to existing type system formalisms to support these concepts and their manipulation. Using a simple example we show how this extended approach permits more flexible reuse, while preserving type safety.

Optimal track access rights allocation for agent negotiation in an open railway market

In open railway access markets, a train service provider (TSP) negotiates with an infrastructure provider (IP) for track access rights. This negotiation has been modeled by a multi-agent system (MAS) in which the IP and TSP are represented by separate software agents. One task of the IP agent is to generate feasible (and preferably optimal) track access rights, subject to the constraints submitted by the TSP agent. This paper formulates an IP-TSP transaction and proposes a branch-and-bound algorithm for the IP agent to identify the optimal track access rights. Empirical simulation results show that the model is able to emulate rational agent behaviors. The simulation results also show good consistency between timetables attained from the proposed methods and those derived by the scheduling principles adopted in practice.

Analyzing requirements and approaches for sourcing software based services

Increasingly, software is no longer developed as a single system, but rather as a smart combination of so-called software services. Each of these provides an independent, specific and relatively small piece of functionality, which is typically accessible through the Internet from internal or external service providers. To the best of our knowledge, there are no standards or models that describe the sourcing process of these software based services (SBS). We identify the sourcing requirements for SBS and associate the key characteristics of SBS (with the sourcing requirements introduced). Furthermore, we investigate the sourcing of SBS with the related works in the field of classical procurement, business process outsourcing, and information systems sourcing. Based on the analysis, we conclude that the direct adoption of these approaches for SBS is not feasible and new approaches are required for sourcing SBS.

Analyzing requirements and approaches for sourcing software based services

Increasingly, software is no longer developed as a single system, but rather as a smart combination of so-called software services. Each of these provides an independent, specific and relatively small piece of functionality, which is typically accessible through the Internet from internal or external service providers. There are no standards or models that describe the sourcing process of these software based services (SBS). The authors identify the sourcing requirements for SBS and associate the key characteristics of SBS (with the sourcing requirements introduced). Furthermore, this paper investigates the sourcing of SBS with the related works in the field of classical procurement, business process outsourcing, and information systems sourcing. Based on the analysis, the authors conclude that the direct adoption of these approaches for SBS is not feasible and new approaches are required for sourcing SBS.

A prioritised fuzzy constraint satisfaction approach to model agent negotiation for railway scheduling

With the recent regulatory reforms in a number of countries, railways resources are no longer managed by a single party but are distributed among different stakeholders. To facilitate the operation of train services, a train service provider (SP) has to negotiate with the infrastructure provider (IP) for a train schedule and the associated track access charge. This paper models the SP and IP as software agents and the negotiation as a prioritized fuzzy constraint satisfaction (PFCS) problem. Computer simulations have been conducted to demonstrate the effects on the train schedule when the SP has different optimization criteria. The results show that by assigning different priorities on the fuzzy constraints, agents can represent SPs with different operational objectives.

Probabilistic load flow calculation for AC traction supplies with AT feeding

Power load flow analysis is essential for system planning, operation, development and maintenance. Its application on railway supply system is no exception. Railway power supplies system distinguishes itself in terms of load pattern and mobility, as well as feeding system structure. An attempt has been made to apply probability load flow (PLF) techniques on electrified railways in order to examine the loading on the feeding substations and the voltage profiles of the trains. This study is to formulate a simple and reliable model to support the necessary calculations for probability load flow analysis in railway systems with autotransformer (AT) feeding system, and describe the development of a software suite to realise the computation.

Proceedings of the 21st Australian Software Engineering Conference (ASWEC 2010) : 6-9 April 2010, Auckland, New Zealand.

ASWEC is a joint conference of Engineers Australia and the Australian Computer Society reporting through the Engineers Australia/ACS Joint Board on Software Engineering.