Browsing by Author "Bekele, Dawit (PhD)"

Now showing 1 - 12 of 12
  • No Thumbnail Available
    Item
    Distributed Clients’ Profile Management System for Pervasive Systems
    (Addis Ababa University, 2005-11) Tegene, Haileleul; Bekele, Dawit (PhD)
    The heterogeneity of device capabilities, user’s context and communication network that exists in pervasive systems has accentuated the need for a content adaptation. The purpose of the content adaptation is to convert the original content before delivery so that the new content would fit to the capability of the client’s device being used, the available bandwidth of the communication network, and the specific need of the user. In order to perform such an adaptation, the adaptation system is required to maintain adequate information about the clients’ profile, the network profile, the content profile and others. This thesis work deals with the management of the clients’ profile that includes device and user profile. Specifically, it tries to set up an appropriate way of managing clients’ profile in pervasive environment in relation to content adaptation. To this end, a distributed clients’ profile management scheme is proposed in the current work. In the design of the management scheme, two issues have been considered: (a) client’s profile characteristics such as existence of confidential information in the client’s profile, temporal nature of some of the profiles, etc. (b) constraints that exist in the pervasive systems such as heterogeneity of the client devices in terms of storage, processing, and display capabilities, mobility of the clients, etc. Based on the profile characteristics and the constraints of pervasive systems, we proposed to fragment the client’s profiles into two: those that can be kept on the client devices and those that can be kept on the server side. The main consideration of this fragmentation is the security issue of confidential profiles and the storage size constraint of the client devices. In the proposed architecture, the server side profiles are, in turn, distributed on the local servers to meet the requirements such as availability of profile information in partial failure of the system, performance, scalability, etc. The proposed system consists of different components that interact with each other through web interfaces for the management of distributed client’s profile in a transparent way. It also provides interfaces to external components such as automatic profile extractors so that the dynamic profiles will be built in the course of service provision.
  • No Thumbnail Available
    Item
    Distributed Clients’ Profile Management System for Pervasive Systems
    (Addis Ababa University, 2005-11) Tegene, Haileleul; Bekele, Dawit (PhD)
    The heterogeneity of device capabilities, user’s context and communication network that exists in pervasive systems has accentuated the need for a content adaptation. The purpose of the content adaptation is to convert the original content before delivery so that the new content would fit to the capability of the client’s device being used, the available bandwidth of the communication network, and the specific need of the user. In order to perform such an adaptation, the adaptation system is required to maintain adequate information about the clients’ profile, the network profile, the content profile and others. This thesis work deals with the management of the clients’ profile that includes device and user profile. Specifically, it tries to set up an appropriate way of managing clients’ profile in pervasive environment in relation to content adaptation. To this end, a distributed clients’ profile management scheme is proposed in the current work. In the design of the management scheme, two issues have been considered: (a) client’s profile characteristics such as existence of confidential information in the client’s profile, temporal nature of some of the profiles, etc. (b) constraints that exist in the pervasive systems such as heterogeneity of the client devices in terms of storage, processing, and display capabilities, mobility of the clients, etc. Based on the profile characteristics and the constraints of pervasive systems, we proposed to fragment the client’s profiles into two: those that can be kept on the client devices and those that can be kept on the server side. The main consideration of this fragmentation is the security issue of confidential profiles and the storage size constraint of the client devices. In the proposed architecture, the server side profiles are, in turn, distributed on the local servers to meet the requirements such as availability of profile information in partial failure of the system, performance, scalability, etc. The proposed system consists of different components that interact with each other through web interfaces for the management of distributed client’s profile in a transparent way. It also provides interfaces to external components such as automatic profile extractors so that the dynamic profiles will be built in the course of service provision
  • No Thumbnail Available
    Item
    Distributed Clients’ Profile Management System for Pervasive Systems
    (Addis Ababa University, 2005-11) Tegene, Haileleul; Bekele, Dawit (PhD)
    The heterogeneity of device capabilities, user’s context and communication network that exists in pervasive systems has accentuated the need for a content adaptation. The purpose of the content adaptation is to convert the original content before delivery so that the new content would fit to the capability of the client’s device being used, the available bandwidth of the communication network, and the specific need of the user. In order to perform such an adaptation, the adaptation system is required to maintain adequate information about the clients’ profile, the network profile, the content profile and others. This thesis work deals with the management of the clients’ profile that includes device and user profile. Specifically, it tries to set up an appropriate way of managing clients’ profile in pervasive environment in relation to content adaptation. To this end, a distributed clients’ profile management scheme is proposed in the current work. In the design of the management scheme, two issues have been considered: (a) client’s profile characteristics such as existence of confidential information in the client’s profile, temporal nature of some of the profiles, etc. (b) constraints that exist in the pervasive systems such as heterogeneity of the client devices in terms of storage, processing, and display capabilities, mobility of the clients, etc. Based on the profile characteristics and the constraints of pervasive systems, we proposed to fragment the client’s profiles into two: those that can be kept on the client devices and those that can be kept on the server side. The main consideration of this fragmentation is the security issue of confidential profiles and the storage size constraint of the client devices. In the proposed architecture, the server side profiles are, in turn, distributed on the local servers to meet the requirements such as availability of profile information in partial failure of the system, performance, scalability, etc. The proposed system consists of different components that interact with each other through web interfaces for the management of distributed client’s profile in a transparent way. It also provides interfaces to external components such as automatic profile extractors so that the dynamic profiles will be built in the course of service provision.
  • No Thumbnail Available
    Item
    Distributed Clients’ Profile Management System for Pervasive Systems
    (Addis Ababa University, 2005-11) Tegene, Haileleul; Bekele, Dawit (PhD)
    The heterogeneity of device capabilities, user’s context and communication network that exists in pervasive systems has accentuated the need for a content adaptation. The purpose of the content adaptation is to convert the original content before delivery so that the new content would fit to the capability of the client’s device being used, the available bandwidth of the communication network, and the specific need of the user. In order to perform such an adaptation, the adaptation system is required to maintain adequate information about the clients’ profile, the network profile, the content profile and others. This thesis work deals with the management of the clients’ profile that includes device and user profile. Specifically, it tries to set up an appropriate way of managing clients’ profile in pervasive environment in relation to content adaptation. To this end, a distributed clients’ profile management scheme is proposed in the current work. In the design of the management scheme, two issues have been considered: (a) client’s profile characteristics such as existence of confidential information in the client’s profile, temporal nature of some of the profiles, etc. (b) constraints that exist in the pervasive systems such as heterogeneity of the client devices in terms of storage, processing, and display capabilities, mobility of the clients, etc. Based on the profile characteristics and the constraints of pervasive systems, we proposed to fragment the client’s profiles into two: those that can be kept on the client devices and those that can be kept on the server side. The main consideration of this fragmentation is the security issue of confidential profiles and the storage size constraint of the client devices. In the proposed architecture, the server side profiles are, in turn, distributed on the local servers to meet the requirements such as availability of profile information in partial failure of the system, performance, scalability, etc. The proposed system consists of different components that interact with each other through web interfaces for the management of distributed client’s profile in a transparent way. It also provides interfaces to external components such as automatic profile extractors so that the dynamic profiles will be built in the course of service provision
  • No Thumbnail Available
    Item
    Fault Tolerance Mobile Software Agents Communication Mechanism
    (Addis Ababa University, 7/7/2004) Negash, Addisalem; Bekele, Dawit (PhD)
    Mobile software agent systems have becomes an important tool for developing distributed applications. The use of mobile software agents is recommended in environment where network connection is not reliable and where there is low bandwidth. This is because mobile agents can perform the work with limited communication with the system that has created them. One important feature of mobile software agents is their ability to communicate to each other. Providing communication mechanism that guarantees delivery of message is that mobile software agent systems developer has to solve. A number of algorithms have been proposed to guarantee message delivery to highly mobile agents [13,8], but in our knowledge only one of them considers the existence of fault [8] and even that algorithm give responsibility transmitting message to a mailbox. In this thesis we have developed an algorithm that provides guaranteed delivery of message in the existence of fault particularly without assuming the location of mobile agent and without inhibiting movement of mobile software agent.
  • No Thumbnail Available
    Item
    Fault Tolerance Mobile Software Agents Communication Mechanism
    (Addis Ababa University, 2004-07-07) Negash, Addisalem; Bekele, Dawit (PhD)
    Mobile software agent systems have becomes an important tool for developing distributed applications. The use of mobile software agents is recommended in environment where network connection is not reliable and where there is low bandwidth. This is because mobile agents can perform the work with limited communication with the system that has created them. One important feature of mobile software agents is their ability to communicate to each other. Providing communication mechanism that guarantees delivery of message is that mobile software agent systems developer has to solve. A number of algorithms have been proposed to guarantee message delivery to highly mobile agents [13,8], but in our knowledge only one of them considers the existence of fault [8] and even that algorithm give responsibility transmitting message to a mailbox. In this thesis we have developed an algorithm that provides guaranteed delivery of message in the existence of fault particularly without assuming the location of mobile agent and without inhibiting movement of mobile software agent.
  • No Thumbnail Available
    Item
    MDA APPROACH for the DEVELOPMENT of EMBEDDABLE APPLICATIONS on COMMUNICATING OBJECTS
    (Addis Ababa University, 2005-10) Alemu, Eyob; Bekele, Dawit (PhD)
    Complexity is an ever increasing and inherent characteristic of software development. A major source of complexity in software development is technology, which produces a variety of implementation platforms that exist at the time of development and that arrive as future inventions. Changing existing software developed due to the growing variation of implementation platforms is becoming almost impossible. Hence a new development methodology called MDA (Model Driven Architecture) has been recently introduced with a strategy of separating the specification of the software system from the specification of its implementation on platforms as two different concerns of development. The two concerns are described as Platform Independent Model (PIM) and Platform Specific Model (PSM). MDA is now being successfully practiced as a promising solution at enterprise level software systems. Recent technological advances are making possible the embedding of both processing and communication functions in highly integrated, low-cost objects such as PDA’s and cell phones. This is promoting the use of a distributed approach in many application fields including embedded systems, which is now leading to the current and future realm of pervasive computing. The MDA success at the enterprise level has made it a viable choice for other domains that face a similar or even worse level of complexity such as the domain of embedded systems. However, recent efforts focused on extending the modeling capability of the core standards of MDA, particularly UML, towards the concepts in embedded systems such as Resource and Quality of Service (QoS). In addition, unlike the enterprise level platforms, there is no abstraction or middleware layer that can encapsulate all the variation in this domain that makes the variety of the platforms to appear as different choices. Therefore, adapting the MDA towards this domain requires a new approach that recognizes such peculiarities. Focusing on the communications subsystem, this work introduces an MDA based approach for the development of embeddable applications on communicating objects. A QoS aware and resource oriented approach, which exhibits the runtime interaction between applications and platforms, is proposed. The reservation based (typically connection oriented) networks are considered in this work. The applicability of the approach is also presented for Bluetooth and IrDA that shows the separation of application level reservation request from the actual network level reservation provided. We believe that this way the concerns of application level modeling and implementation could be separated from the platform level service specification and implementation as two different concerns of development in this domain.
  • No Thumbnail Available
    Item
    MDA APPROACH for the DEVELOPMENT of EMBEDDABLE APPLICATIONS on COMMUNICATING OBJECTS
    (Addis Ababa University, 2005-10) Alemu, Eyob; Bekele, Dawit (PhD)
    Complexity is an ever increasing and inherent characteristic of software development. A major source of complexity in software development is technology, which produces a variety of implementation platforms that exist at the time of development and that arrive as future inventions. Changing existing software developed due to the growing variation of implementation platforms is becoming almost impossible. Hence a new development methodology called MDA (Model Driven Architecture) has been recently introduced with a strategy of separating the specification of the software system from the specification of its implementation on platforms as two different concerns of development. The two concerns are described as Platform Independent Model (PIM) and Platform Specific Model (PSM). MDA is now being successfully practiced as a promising solution at enterprise level software systems. Recent technological advances are making possible the embedding of both processing and communication functions in highly integrated, low-cost objects such as PDA’s and cell phones. This is promoting the use of a distributed approach in many application fields including embedded systems, which is now leading to the current and future realm of pervasive computing. The MDA success at the enterprise level has made it a viable choice for other domains that face a similar or even worse level of complexity such as the domain of embedded systems. However, recent efforts focused on extending the modeling capability of the core standards of MDA, particularly UML, towards the concepts in embedded systems such as Resource and Quality of Service (QoS). In addition, unlike the enterprise level platforms, there is no abstraction or middleware layer that can encapsulate all the variation in this domain that makes the variety of the platforms to appear as different choices. Therefore, adapting the MDA towards this domain requires a new approach that recognizes such peculiarities. Focusing on the communications subsystem, this work introduces an MDA based approach for the development of embeddable applications on communicating objects. A QoS aware and resource oriented approach, which exhibits the runtime interaction between applications and platforms, is proposed. The reservation based (typically connection oriented) networks are considered in this work. The applicability of the approach is also presented for Bluetooth and IrDA that shows the separation of application level reservation request from the actual network level reservation provided. We believe that this way the concerns of application level modeling and implementation could be separated from the platform level service specification and implementation as two different concerns of development in this domain.
  • No Thumbnail Available
    Item
    Open Source Content Management Software Customization for the Ethiopian Government
    (Addis Ababa University, 2004-06) Adgo, Zemene; Bekele, Dawit (PhD)
    Most Ethiopian government organizations maintain and exchange documents traditionally. This method of document management is time consuming, costly and unsecured. However, managing documents electronically, greatly improves the internal operations of an organization, raises community satisfaction, and simplifies document management and exchange. In this project, OpenCms which is one of the open source content management software is adapted to enable the government organizations to manage their documents. Language is another barrier for the growth and development of Information and Communication Technology (ICT) in the country. This is because most software systems are developed in English language but a small percentage of the population understands that language very well. However, by localizing a software product to the country’s locales, i.e. languages, cultural norms and standards as well as needs and expectations, the users can interact with the software in the settings that feel natural to them. In this project, OpenCms is localized to Ethiopian locales. Open source software are appropriate technology for Ethiopia. This is because they can be acquired free of charge and allow users to redistribute, modify and resell the software. However, they are not widely used in the country, there are III many reasons for this some of them are piracy of proprietary software, lack of awareness about open source software and shortage of open source software experts.
  • No Thumbnail Available
    Item
    Open Source Content Management Software Customization for the Ethiopian Government
    (Addis Ababa University, 2004-06) Adgo, Zemene; Bekele, Dawit (PhD)
    Most Ethiopian government organizations maintain and exchange documents traditionally. This method of document management is time consuming, costly and unsecured. However, managing documents electronically, greatly improves the internal operations of an organization, raises community satisfaction, and simplifies document management and exchange. In this project, OpenCms which is one of the open source content management software is adapted to enable the government organizations to manage their documents. Language is another barrier for the growth and development of Information and Communication Technology (ICT) in the country. This is because most software systems are developed in English language but a small percentage of the population understands that language very well. However, by localizing a software product to the country’s locales, i.e. languages, cultural norms and standards as well as needs and expectations, the users can interact with the software in the settings that feel natural to them. In this project, OpenCms is localized to Ethiopian locales. Open source software are appropriate technology for Ethiopia. This is because they can be acquired free of charge and allow users to redistribute, modify and resell the software. However, they are not widely used in the country, there are III many reasons for this some of them are piracy of proprietary software, lack of awareness about open source software and shortage of open source software experts.
  • No Thumbnail Available
    Item
    Semantic Description of Multimedia Content Adaptation Web Services
    (Addis Ababa University, 2005-07-07) Lemma, Surafel; Bekele, Dawit (PhD)
    In pervasive computing, multimedia information is accessed using different devices with different processing power, storage size, display size, etc. Hence, the information that needs to be displayed has to be modified in order to meet the devices’ requirements. This modification is called content adaptation. Multimedia content adaptation can be done at various places in different frameworks. Some frameworks propose that content adaptation should be done by content servers, while others consider that it should be done at the client side. Another approach considers that content adaptation should be performed by third party services that can be implemented using web services. The objective of this research is to find ways of facilitating discovery of these third party content adaptation web services by users of these services. In order to use these web services, one has to be able to find them on the Web. However, today, finding the right web service for a specific task (multimedia content adaptation in our case) is difficult. This is mainly because of the type of description used to advertise the web services. Current standards that are used to describe web services are syntactic. Syntactic description of web services contains some keywords and signature of the web service, which is later, used for searching the services. However, this information does not allow high rate of success during service discovery. These limitations of the current standards can be improved by using semantic description methods. Semantic description gives the meanings and relationships of the terms and concepts used in describing a web service, which improves the discovery of a web service. In order to allow semantic description of multimedia content adaptation web services, we have developed an ontology for multimedia content adaptation web services. To develop this ontology, we first studied different ontology development methods based on which we formulated an approach using which we have developed the ontology by identifying different types of audio content adaptation web services and their properties that can be used to increase the semantic information of the audio content adaptation web services. In this research, we have also developed a prototype to show the usability of the ontology that we developed. The prototype allows a user to advertise a web service using the ontology and look for a specific web service.
  • No Thumbnail Available
    Item
    Semantic Description of Multimedia Content Adaptation Web Services
    (Addis Ababa University, 7/7/2005) Lemma, Surafel; Bekele, Dawit (PhD)
    In pervasive computing, multimedia information is accessed using different devices with different processing power, storage size, display size, etc. Hence, the information that needs to be displayed has to be modified in order to meet the devices’ requirements. This modification is called content adaptation. Multimedia content adaptation can be done at various places in different frameworks. Some frameworks propose that content adaptation should be done by content servers, while others consider that it should be done at the client side. Another approach considers that content adaptation should be performed by third party services that can be implemented using web services. The objective of this research is to find ways of facilitating discovery of these third party content adaptation web services by users of these services. In order to use these web services, one has to be able to find them on the Web. However, today, finding the right web service for a specific task (multimedia content adaptation in our case) is difficult. This is mainly because of the type of description used to advertise the web services. Current standards that are used to describe web services are syntactic. Syntactic description of web services contains some keywords and signature of the web service, which is later, used for searching the services. However, this information does not allow high rate of success during service discovery. These limitations of the current standards can be improved by using semantic description methods. Semantic description gives the meanings and relationships of the terms and concepts used in describing a web service, which improves the discovery of a web service. In order to allow semantic description of multimedia content adaptation web services, we have developed an ontology for multimedia content adaptation web services. To develop this ontology, we first studied different ontology development methods based on which we formulated an approach using which we have developed the ontology by identifying different types of audio content adaptation web services and their properties that can be used to increase the semantic information of the audio content adaptation web services. In this research, we have also developed a prototype to show the usability of the ontology that we developed. The prototype allows a user to advertise a web service using the ontology and look for a specific web service.