On the QoS Behavior of Self-Similar Traffic in a Converged ONU-BS Under Custom Queueing

Obele, Brownson Obaridoa,Iftikhar, Mohsin,Kang, Min-Ho The Korea Institute of Information and Commucation 2011 Journal of communications and networks Vol.13 No.3

A novel converged optical network unit (ONU)-base station (BS) architecture has been contemplated for next-generation optical-wireless networks. It has been demonstrated through high quality studies that data traffic carried by both wired and wireless networks exhibit self-similar and long range dependent characteristics; attributes that classical teletraffic theory based on simplistic Poisson models fail to capture. Therefore, in order to apprehend the proposed converged architecture and to reinforce the provisioning of tightly bound quality of service (QoS) parameters to end-users, we substantiate the analysis of the QoS behavior of the ONU-BS under self-similar and long range dependent traffic conditions using custom queuing which is a common queuing discipline. This paper extends our previous work on priority queuing and brings novelty in terms of presenting performance analysis of the converged ONU-BS under realistic traffic load conditions. Further, the presented analysis can be used as a network planning and optimization tool to select the most robust and appropriate queuing discipline for the ONU-BS relevant to the QoS requirements of different applications.

A Systematic Review of Cervical Cancer Incidence and Mortality in the Pacific Region

Obel, J.,Souares, Y.,Hoy, D.,Baravilala, W.,Garland, S.M.,Kjaer, S.K.,Roth, A. Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.21

This study provides the first systematic literature review of cervical cancer incidence and mortality as well as human papillomavirus (HPV) genotype prevalence among women with cervical cancer in the Pacific Island countries and territories. The cervical cancer burden in the Pacific Region is substantial, with age standardized incidence rates ranging from 8.2 to 50.7 and age standardized mortality rate from 2.7 to 23.9 per 100,000 women per year. The HPV genotype distribution suggests that 70-80% of these cancers could be preventable by the currently available bi- or quadrivalent HPV vaccines. There are only few comprehensive studies examining the epidemiology of cervical cancer in this region and no published data have hitherto described the current cervical cancer prevention initiatives in this region.

Mapping HPV Vaccination and Cervical Cancer Screening Practice in the Pacific Region-Strengthening National and Regional Cervical Cancer Prevention

Obel, J,McKenzie, J,Buenconsejo-Lum, LE,Durand, AM,Ekeroma, A,Souares, Y,Hoy, D,Baravilala, W,Garland, SM,Kjaer, SK,Roth, A Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Objective : To provide background information for strengthening cervical cancer prevention in the Pacific by mapping current human papillomavirus (HPV) vaccination and cervical cancer screening practices, as well as intent and barriers to the introduction and maintenance of national HPV vaccination programmes in the region. Materials and Methods: A cross-sectional questionnaire-based survey among ministry of health officials from 21 Pacific Island countries and territories (n=21). Results: Cervical cancer prevention was rated as highly important, but implementation of prevention programs were insufficient, with only two of 21 countries and territories having achieved coverage of cervical cancer screening above 40%. Ten of 21 countries and territories had included HPV vaccination in their immunization schedule, but only two countries reported coverage of HPV vaccination above 60% among the targeted population. Key barriers to the introduction and continuation of HPV vaccination were reported to be: (i) Lack of sustainable financing for HPV vaccine programs; (ii) Lack of visible government endorsement; (iii) Critical public perception of the value and safety of the HPV vaccine; and (iv) Lack of clear guidelines and policies for HPV vaccination. Conclusion: Current practices to prevent cervical cancer in the Pacific Region do not match the high burden of disease from cervical cancer. A regional approach, including reducing vaccine prices by bulk purchase of vaccine, technical support for implementation of prevention programs, operational research and advocacy could strengthen political momentum for cervical cancer prevention and avoid risking the lives of many women in the Pacific.

Analysis of the Behavior of Self-Similar Traffic in a QoS-Aware Architecture for Integrating WiMAX and GEPON

Obele, B.O.,Iftikhar, M.,Manipornsut, S.,Minho Kang IEEE 2009 Journal of optical communications and networking Vol.1 No.4

<P>The access network has remained the bottleneck in efforts to deliver bandwidth-intensive new-generation applications and services to subscribers. In the wired access network, the gigabit Ethernet passive optical network (GEPON) is a promising technology for relieving this bottleneck, while its counterpart in the wireless access network is worldwide interoperability for microwave access (WiMAX). A converged quadruplet-service-enabled (video, voice, data, and mobility) network, which takes full advantage of the strengths and weaknesses of each of these promising technologies, has been proposed. Besides, research and Internet measurements have revealed that actual Ethernet and wireless data traffic are self-similar and long-range dependent. Therefore, we review the quality of service (QoS) architecture for integrating WiMAX and GEPON access networks that we proposed in previous work. Then, we present an analysis of the queuing behavior of the QoS architecture under self-similar and long-range-dependent data traffic conditions and derive closed-form expressions of the expected waiting time in queue (queuing delay) and the packet loss rate per QoS traffic class. This work brings novelty in terms of presenting performance analysis of the proposed QoS-aware integrated architecture under realistic load conditions and facilitates the provisioning of tightly bound QoS parameters to end users of the converged access network.</P>

A Test Automation Framework for Heterogeneous Automotive Embedded Software Systems

Brownson Obaridoa Obele,Youngho Lee,Hyunduk Choi,Dongyul Kim,Seungyong Lee 한국자동차공학회 2016 한국자동차공학회 학술대회 및 전시회 Vol.2016 No.11

On the QoS Behavior of Self-Similar Traffic in a Converged ONU-BS Under Custom Queueing

Brownson Obaridoa Obele,Mohsin Iftikhar,강민호 한국통신학회 2011 Journal of communications and networks Vol.13 No.3

A novel converged optical network unit (ONU)-base station (BS) architecture has been contemplated for next-generation optical-wireless networks. It has been demonstrated through high quality studies that data traffic carried by both wired and wireless networks exhibit self-similar and long range dependent characteristics;attributes that classical teletraffic theory based on simplistic Poisson models fail to capture. Therefore, in order to apprehend the proposed converged architecture and to reinforce the provisioning of tightly bound quality of service (QoS) parameters to end-users, we substantiate the analysis of the QoS behavior of the ONU-BS under self-similar and long range dependent traffic conditions using custom queuing which is a common queuing discipline. This paper extends our previous work on priority queuing and brings novelty in terms of presenting performance analysis of the converged ONU-BS under realistic traffic load conditions. Further,the presented analysis can be used as a network planning and optimization tool to select the most robust and appropriate queuing discipline for the ONU-BS relevant to the QoS requirements of different applications.

무선 네트워크를 위한 파운틴 코드 기반 응용계층 순방향오류정정

황영학(Younghak Hwang),Brwonson O. Obele,임혁(Hyuk Lim) 한국정보과학회 2011 한국정보과학회 학술발표논문집 Vol.38 No.1D

본 논문은 파운틴 코드를 기반으로 하는 응용계층 순방향오류정정을 설계하고 무선 네트워크 사용자에게 효율적으로 정보를 전송하기 위한 방안에 관하여 논한다. 파운틴 코드는 이진 대칭 소실 (erasure) 채널에서 데이터 전송을 효율적으로 하기 위해 개발된 채널 부호화 방식이다. 송신단은 원 정보를 부호화하여 전송하고, 수신단은 일정량 이상의 부호화된 데이터 수신한 후 원 정보를 복원한다. 파운틴 코드의 복호화 성능은 정해진 변수 c값에 따라 달라질 수 있으며, 적절한 값으로 설정되지 않을 경우, 필요이상의 부호화된 데이터를 수신하게 될 수 있다. 본 논문에서는 파운틴 코드의 특성을 분석하고, 실험을 통하여 원하는 복호화 성능을 유지할 수 있는 적절한 c의 값을 찾는다. 또한, 무선 네트워크 테스트베드 환경에서 파운틴 코드 기반의 응용계층 순방향오류정정을 구현하고 부호화 및 복호화 성능을 평가한다.

The Book-keeping Fermion Analysis of the Double Exchange Model with Antiferromagnetic Background

Kyohei Nakano,Yukinori Ohta,Robert Eder,Piotr Wr´obel 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.3

We analyze the double exchange model with antiferromagnetic background by the book-keepingfermion method. First, we consider the motion of a single conduction electron. We assume that thelocalized spins form the N´eel state and the added conduction electron forms only three types of statesunder the strong Hund’s-rule coupling, and we regard these states as the book-keeping fermions. Under these assumptions, we first calculate the spectral functions and find a good agreement withthe results given by the exact diagonalizations for finite-size clusters. We next consider the situationwhere there are finite numbers of spin flips occurring in the down-spin sublattice in the N´eel orderedstate. Considering the effects of the spin defects, we add a new book-keeping fermion and estimatethe energy of the spin defects by a perturbation theory. This theory gives the phase diagramcomparable with the numerical results.