## 4 Conclusion  
In this paper, we have proposed a novel approach to the E-barter system. We have proposed a novel approach to the E-barter system. Figure 7: The ontology for food semantics web service. The services used in E-barter system also need to have semantic web service documents to provide semantic web service functionality. For this purpose, the draft documents produced through SEA_ML have been used. Listing 4 shows the draft Profile.owl document produced by SEA_ML for the food service. The document generated by SEA_ML basically provides a draft of the resources imported with the owl: ontology tag in the rdf:RDF tag (Listing 4-- Lines 16-25). ```
1<?xmlversion=\"1.0\">
2
3<rdf:RDFxmlns:rdf=\"&rdf:#\"
4 xmlns:rdfs=\"&rdfs:#\"
5 xmlns:owl=\"&owl;#\"
6 xmlns:actor=\"&actor;#\"
7 xmlns:service=\"&service;#\"
8 xmlns:process=\"&traderFlyer;#\"
9 xmlns:profile=\"&traderlyer;#\"
10 xmlns:profileHierarchy=\"&profileHierarchy;#\"
11 xmlns:xsd=\"&xsd;#\"
12 xmlns=\"&DEFAULT;#\"
13 xml:base=\"&DEFAULT;\">
14
15<owl:ontologyrdf:about=\"\">
16<owl:importsrdf:resource=\"&service;\"/>
17<owl:importsrdf:resource=\"&process;\"/>
18<owl:importsrdf:resource=\"&profile;\"/>
19<owl:importsrdf:resource=\"&foodService_process;\"/>
20<owl:importsrdf:resource=\"&foodService_profile;\"/>
21
22<owl:importsrdf:resource=\"&time;/>
23<owl:importsrdf:resource=\"&profileHierarchy;/>
24</owl:ontology>
25</rdf:RDF>
26
27<l--. The Matchmaker returns the WSDL addresses of the appropriate services to the Customer agent after determining the appropriate services. When the Customer agent sends a request to a service which is just found, its repository is used which is an XML file containing the names, requests, and offers of agents eligible for bartering. The service searches for those agents which can match with the Customer agent on this XML file. If some agents are found, the service will return the names of these agents to the Customer agent. ## 4 Demonstration Scenario

For a detailed demonstration of the implemented system, this section illustrates a system execution consisting of three Customer agents and two semantic web services. When the system is started to run on the client side, the initial interface is shown. On this interface, the user can add a service agent that represents a semantic web service or a Customer agent which represents himself/herself to propose a bargaining. First, service agents, that represent semantic web services, should be added to the system. When the \"Add Service Agent\" in the initial user interface is selected, the interface for adding a service agent appears (see Figure 8) to get the information necessary for registering the semantic web service. Then an agent is run to represent the relevant semantic web service and sends a message to Matchmaker agent to register the semantic web service. In our demonstration scenario, there are two semantic web services called \"Food Service\" and \"Electronic Device\". For each one, a separate service agent must be established. After the services are registered in the system, Customer agents can be included in the system. For this purpose, \"Adding Customer Agent\" interface (an example shown in Figure 9) needs to be launched from the initial user interface. Using this interface, the agent is created after the information for the Customer agent is entered. To instantiate a Customer agent, the product which is needed and offered as well as the lower and upper limits must be prescribed by the user for the bartering. In this scenario, three agents named CUSTOMER A, CUSTOMER B, and CUSTOMER C, are included to the system with the details (such as Name, Need, Offer, Lower and Upper limits) provided in Table 1. Figure 9 shows, as an example, the instantiation of \"CUSTOMER C\" agent in the system. Figure 8: The user interface for adding a service agent to the system. Figure 9: Instantiation of “CUSTOMER C” agent. CUSTOMER A agent would like to barter with some other agents who offer netbooks. Meanwhile, this agent offers coconouts for netbooks.