Cinema visit organizer A mini-project in the course Agent-oriented modeling and multi-agent systems

Transcription

1 Tallinn University of Technology Department of Informatics Chair of Software Engineering Cinema visit organizer A mini-project in the course Agent-oriented modeling and multi-agent systems Students: Student Name 1, Number 1 Student Name 2, Number 2 Student Name 3, Number 3 Supervisor: Professor Kuldar Taveter Tallinn 2012

2 Overview The following material represents the report on a mini-project assignment completed during the course Agent-oriented modeling and multi-agent systems. For this assignment we ended examining the idea of cinema visit organizer, a mobile application that allows its owners to arrange and manage their visit to the cinemas available in the area. This application is capable of identifying its owner s current location and can provide contextual suggestions. Moreover, arrangement of group visits is the foundational functionality of the system and it became the main feature of the prototype. The prototype application was implemented using JADE (Java Agent Development Framework), a platform that supports agent-oriented programming paradigm. The source code for the prototype is provided as an attachment to this document. 2

3 1. Motivation layer This section contains the following models pertaining to motivation layer of conceptual space: goal models, role models, organizational model, domain model. 1.1 System Flow The simplified interaction of a user with this application could be described by the following scenario. The cinema visit organizer application is installed on mobile device. It allows the owner of this device to arrange and manage his visit to the cinema. The application stores a profile of owner s personal data and exchanges it in the interactions with other owners. Let s imagine a situation where an owner has just arrived in new city and wouldn t mind to pay a visit to one of the cinemas available in the area this evening. For this purpose he launches the organizer application that determines his current location and establishes a search for the cinemas available in the area. For the simplicity sake, it is implied that this search was successful and the owner now is able to arrange a visit to the cinema. In order to do this, he can search for the movie schedules available for specific date and compare prices for similar movie sessions offered by different providers. Moreover, he could choose if he wants to go to the cinema alone or in a group with other people. Other mobile device owners with this application installed can come up with analogous initiatives. Finally, the organizer in a timely fashion informs the owner about incoming invitation requests or any other relevant information. 3

4 1.2 Goal models On the one hand, system s meaning for existence is defined by a set of goals. On the other hand, the system needs some capacity to achieve these goals and this capacity in terms of goal models is described by roles enacted by agents. In this context the purpose of a goal model is to represent the relationships between goals and roles, as well as to express the quality goals, that is, the non-functional requirements of the system [1] General goal model Figure 1 General goal model Goal Arrange visit This section describes Arrange visit goal in more details. 4

5 Figure 2 Goal "arrange visit" in details 1.3 Role models The role model provides a textual description of a role, a list of responsibilities that must be performed and a list of constraints that must be considered by the agent enacting this role [1] Role Owner Role name Description Responsibilities Constraints Owner The role of the owner Change location Edit profile Respond to notifications Initiate visit to the cinema Search for movies Select movie session Initiate invitation request Respond to invitation request Buy tickets The owner should have a compatible mobile device. The organizer application should be installed. User profile should be filled prior to doing anything with organizer. 5

6 1.3.2 Role Owner s organizer / Other owner s organizer Role name Owner s organizer Description Responsibilities Constraints The role of owner s organizer Determine owner s location Manage owner s profile Find cinemas Arrange a visit to cinema Keep owner informed Find movies Compare search results Invite participants Pay for the ticket Prior to initiating a movie search the organizer should determine the current location of the owner and the availability of cinemas in the area. Cinemas have to participate in this initiative Role Provider system Role name Provide system Description Responsibilities The role of cinema system Find movies in cinema s database Deliver regular updates about upcoming movies On request deliver schedules for specified movies Sell tickets Constraints Cinemas have to update their data in a timely fashion Role Banking system Role name Banking system Description Responsibilities Constraints The role of banking system Verify the exchange of money and tickets between cinema and a group of visitors The owner have to authenticate himself The money transfer operation should be safe and secure 6

7 1.4 Organization model The purpose of organizational model is to represent the different types of relationships between roles available in the system [1]. Figure 3 Organization model 7

8 1.5 Domain model The purpose of domain model is to represent at the abstract level the knowledge available within the system, that is, the relationships between roles, environments and types of resources produced and stored in these environments [1]. Figure 4 Domain model 8

9 2. System design layer This section contains the following models pertaining to system design layer of conceptual space: agent models, acquaintance model, interaction models, knowledge model, scenarios, behavior models. 2.1 Agent models The agent model defines the agent types available in the system by establishing a mapping between roles and agent types that fulfill them [1] Agent type Person Agent type name Description Role(s) Environmental considerations Person Human agent type owner other owner Organizer Agent type Organizer Agent type name Description Role(s) Environmental considerations Organizer Software agent acting on behalf of human owner to arrange and manage a cinema visit owner s organizer other owner s organizer Owner Provider system Banking system Localization system 9

10 2.1.3 Agent type Provider system Agent type name Provider system Software agent acting on behalf of the cinema Description network to satisfy organizer s owner requests. Role(s) provider system Organizer Environmental considerations Owner Banking system Agent type Banking system Agent type name Banking system Software agent acting on behalf of banking system Description to arrange and manage money transfer between the group of cinema visitors and the cinema itself. Role(s) banking system Organizer Environmental considerations Owner Provider system Agent type Localization system Agent type name Localization system Software agent required to determine owner s Description current location. Role(s) localization system Organizer Owner Environmental considerations Satellites Radio masts 10

11 2.2 Acquaintance model The purpose of acquaintance model is to represent interaction paths between agent types, thus visualizing the degree of coupling between agents [1]. Figure 5 Combined agent and acquaintance model 2.3 Interaction models The interaction model describes the interaction patterns carried out between the agents [1] Interaction sequence diagram Manage profile Figure 6 Interaction-sequence diagram "Manage profile" 11

12 2.3.2 Interaction sequence diagram Determine location Figure 7 Interaction-sequence diagram "Determine location" Interaction sequence diagram Find movies Figure 8 Interaction-sequence diagram "Find movies" 12

13 2.3.4 Interaction sequence diagram Arrange group visit Figure 9 Interaction-sequence diagram "Arrange group visit" 2.4 Knowledge model The knowledge model provides a more elaborate representation of knowledge available in the system than the domain model. In this case the knowledge is carried by the agents. It defines what these agents know about themselves and about other agents / objects in the surrounding environment [1]. 13

14 Figure 10 Knowledge model 2.5 Scenarios A scenario describes how a set of goals identified in the goal model can be fulfilled by the agents [1]. SCENARIO 1 Goal Arrange visit Initiator Owner Trigger The owner searching for the movies Failure DESCRIPTION Condition Step Activity Agent types and roles Resources Quality goals 1 Person / owner, Cinema, Find movie Provider system / Schedule, schedules provider system, Movie Organizer / organizer Compare search results Invite participants Pay for the session ticket Person / owner, Organizer / organizer. Person / owner, Organizer / organizer, Organizer / other organizer Person / owner, Banking system / banking system. Cinema, Schedule, Movie Profile, Session, Visit Ticket Conveniently Reliably Safely 14

15 2.6 Behavior models In contrast to scenarios that describe how a system of agents achieves the goals, the behavior model describes the process of achieving the goals in terms of individual agents [1]. 3. Prototype implementation The proposed system was implemented using JADE (Java Agent Development Framework). The source code for the prototype solution is provided as an attachment to this document. Figure 11 Agents and external systems interaction In our implementation a lot of efforts went to simulate the cinema system. We have created individual models for the movie theater itself and for its visitors. The movie theater uses a database to store and retrieve relevant information about the movies. For the database role HSQLDB (Hyper Structured Query Language Database) was selected, a relational database 15

16 management system written in Java. A few of entries were added to the database to demonstrate its interaction with agents. Figure 12 Agents queries to the database Throughout the system we have chosen a so called transducer approach for agents interaction with other parts of the system. The transducer agent serves as an interface between the external system and the other agents. It accepts messages from the other agents and translates them into the native language that is understood by the external system and vice versa. 16

17 Figure 13 Different approaches to agents implementation For the interaction between agents we have used the standard protocols specified by FIPA and implemented by JADE. Such as FIPA Request, Query-Ref and others. In order for agents to operate with a common set of concepts during their interaction the ontology was defined based on the models that were mentioned earlier in the text. For the user-agent interaction the local GUI approach was chosen and implemented using Java Swing graphical toolkit. Hereafter you can see some examples of a rudimentary graphical user interface that was implemented for this system. 17

18 Cinema agent interface Visitor agent interface 18

19 4. Conclusion As a result of a carried out work in the analysis and design phases the required models introduced by professor Kuldar during the course were constructed. Based on these artifacts the envisioned multi-agent system was implemented and tested to function according to specification. While working on the mini-project assignment we gained some familiarity and experience with JADE, a Java-based framework that was used to implement the proposed cinema visit organizer application. It should be noted that this implementation is not a fully-fledged and final product, but just a prototype that is supposed to demonstrate the skills and knowledge acquired during the course by students that completed the task. As is quite often the case, due to severe time constraints not all of the envisioned scenarios for agents behavior were implemented and this could be the area of further improvement. Nevertheless, we believe that the functionality available in this application entirely justifies the requirements for the mini-project. References 1. Lean S. Sterling and Kuldar Taveter, The art of agent-oriented modeling, The MIT Press; First Edition (July 24, 2009). 2. Magid Nikraz, Giovanni Caire and Parisa A. Bahri, A Methodology for the Analysis and Design of Multi-Agent Systems using JADE, (May, 2006). 3. Mini-project Free Flight, TUT Tallinn