Browsing by Author "Kassahun, Ashenafi"

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    An Assessment of the Major Psychological and Social Problems of Female Child Commercial Sex Workers in Some Selected Tourist Sites: the Case of Addis Ababa, Bahir Dar and Gondar
    (Addis Ababa University, 2010-06) Kassahun, Ashenafi; Tadesse, Sentayehu (PhD)
    The study focused on the assessment of the major psychological and social problems oj child commercial sex workers in some selected tourist sites in Ethiopia. It was conducted on 103 purposively selected child commercial sex workers and 1 broker in Addis Ababa, Bahir Dar and Gondar. InJormation was gathered through questionnaire, the Center Jor Epidemiological Studies Depression Scale Jor Children (CES-DC), the Children Hope Scale (CHC), and interview. The collected data were analyzed through percentage, t-test and one way ANOVA. A lthough the clients oj the majority oj the participants were predominantly the local people (69%), 31% oj the respondents reported that they had contact with Joreigner clients. In the interview, in addition to public places, it was explored that there were hidden places organized to connect foreigners with children for commercial sexual exploitation. On the Center Jor Epidemiological Studies Depression Scale Jor Children (CES-DC), most oj the participants 63% of them reported total scores above the cut off point 15, which is suggestive oj existence oj significant depression symptom. On the children hope scale, the majority (61%) scored below the cut point 21 which is an indication of low level oj hope. The participants score on CES-DC and CHS were compared across different background variables and significant differences were observed. In addition to these psychological variables, the social problems oj the child commercial sex workers were explored. Most oj the participants reported that they spent the day time by chewing chat (62.9%) and sleeping (47.1%). One oJthejustificationsJor spending their time these ways was a feeling oj a sense oj embarrassment to go out side in the day time and these helped them to hide themselves Fom the society. Frequent quarrel (51%) with other persons was the other major inter personal problem investigated in this study. Finally, all stake holders are recommended to organize activities that help child commercial sex workers to cope with the psychological and social problems identified in one way or another
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    An Assessment of the major psychological and social problems of female child commercial sex workers In some selected tourist sites: the case of Addis Ababa, Bahir Dar and Gondar
    (Addis Ababa Universty, 2010-06) Kassahun, Ashenafi; Tadesse, Sentayehu(PhD)
    The study focused on the assessment of the major psychological and social problems oj child commercial sex workers in some selected tourist sites in Ethiopia. It was conducted on 103 purposively selected child commercial sex workers and 1 broker in Addis Ababa, Bahir Dar and Gondar. InJormation was gathered through questionnaire, the Center Jor Epidemiological Studies Depression Scale Jor Children (CES-DC), the Children Hope Scale (CHC), and interview. The collected data were analyzed through percentage, t-test and one way ANOVA. A lthough the clients oj the majority oj the participants were predominantly the local people (69%), 31% oj the respondents reported that they had contact with Joreigner clients. In the interview, in addition to public places, it was explored that there were hidden places organized to connect foreigners with children for commercial sexual exploitation. On the Center Jor Epidemiological Studies Depression Scale Jor Children (CES-DC), most oj the participants 63% of them reported total scores above the cut off point 15, which is suggestive oj existence oj significant depression symptom. On the children hope scale, the majority (61%) scored below the cut point 21 which is an indication of low level oj hope. The participants score on CES-DC and CHS were compared across different background variables and significant differences were observed. In addition to these psychological variables, the social problems oj the child commercial sex workers were explored. Most oj the participants reported that they spent the day time by chewing chat (62.9%) and sleeping (47.1%). One oJthejustificationsJor spending their time these ways was a feeling oj a sense oj embarrassment to go out side in the day time and these helped them to hide themselves Fom the society. Frequent quarrel (51%) with other persons was the other major inter personal problem investigated in this study. Finally, all stake holders are recommended to organize activities that help child commercial sex workers to cope with the psychological and social problems identified in one way or another.
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    Computational Effort Reduction of Fault Tolerance in Scalable Agent Support Systems
    (Addis Ababa University, 2008-09) Kassahun, Ashenafi; Libsie, Mulugeta (PhD)
    Distributed systems are characterized by partial failures. These partial failures might prohibit the application from performing a system-wide computation and reaching consensus among its components (probably agents). Partial failure might happen due to several reasons, but one of the reasons is the Byzantines failure. Many researches have dealt with Byzantine failure by proposing different algorithms to solve the problem. Most of the algorithms focus on how to reach on agreement and tolerate fault, while Query/Update (Q/U) protocol discusses the problem of fault tolerance with respect to scalability. However, these algorithms do not take into account the computational effort it requires, thus making it unattractive for practical use. These techniques do not address the fault scalability of Byzantine faults thoroughly. Hence in this research we looked for better technique to address fault-scalability of Byzantine failures. To address the Byzantine failure two approaches have been used: the agreement protocol and the quorum protocol. The quorum protocol has been proven to be fault scalable and efficient. The protocol has used the combination of the agreement based and quorum based approaches for the agreement sub-protocol. The agreement sub-protocol focuses on how to achieve a common value from quorums and between quorums. The election sub-protocol has to conduct election of a primary among the existing replicas. The integration of AgentScape/DARX has been used in the experiment to test the fault tolerance in scalable agent support systems. Performance evaluation through experimentation has been done to assess the scalability fault tolerance support system. xi The protocol executes requests in three one-way message delays, which is acceptable latency for agreement on a client request. The protocol is robust to increasing the number of tolerated Byzantine faults and continues to provide significantly higher throughput, achieving scalability feature of the fault tolerant multi-agent support system. Keywords: Multi-agent support system, Scalable fault tolerance, Byzantine faults
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    Computational Effort Reduction of Fault Tolerance in Scalable Agent Support Systems
    (Addis Ababa University, 2008-09) Kassahun, Ashenafi; Libsie, Mulugeta (PhD)
    Distributed systems are characterized by partial failures. These partial failures might prohibit the application from performing a system-wide computation and reaching consensus among its components (probably agents). Partial failure might happen due to several reasons, but one of the reasons is the Byzantines failure. Many researches have dealt with Byzantine failure by proposing different algorithms to solve the problem. Most of the algorithms focus on how to reach on agreement and tolerate fault, while Query/Update (Q/U) protocol discusses the problem of fault tolerance with respect to scalability. However, these algorithms do not take into account the computational effort it requires, thus making it unattractive for practical use. These techniques do not address the fault scalability of Byzantine faults thoroughly. Hence in this research we looked for better technique to address fault-scalability of Byzantine failures. To address the Byzantine failure two approaches have been used: the agreement protocol and the quorum protocol. The quorum protocol has been proven to be fault scalable and efficient. The protocol has used the combination of the agreement based and quorum based approaches for the agreement sub-protocol. The agreement sub-protocol focuses on how to achieve a common value from quorums and between quorums. The election sub-protocol has to conduct election of a primary among the existing replicas. The integration of AgentScape/DARX has been used in the experiment to test the fault tolerance in scalable agent support systems. Performance evaluation through experimentation has been done to assess the scalability fault tolerance support system. xi The protocol executes requests in three one-way message delays, which is acceptable latency for agreement on a client request. The protocol is robust to increasing the number of tolerated Byzantine faults and continues to provide significantly higher throughput, achieving scalability feature of the fault tolerant multi-agent support system. Keywords: Multi-agent support system, Scalable fault tolerance, Byzantine faults