INTERFERENCE MANAGEMENT IN LTE SYSTEM AND BEYOUND

The key challenges to high throughput in cellular wireless communication system are interference, mobility and bandwidth limitation. Mobility has never been a problem until recently, bandwidth has been constantly improved upon through the evolutions in cellular wireless communication system but interference has been a constant limitation to any improvement that may have resulted from such evolution. The fundamental challenge to a system designer or a researcher is how to achieve high data rate in motion (high speed) in a cellular system that is intrinsically interference-limited. Multi-antenna is the solution to data on the move and the capacity of multi-antenna system has been demonstrated to increase proportionally with increase in the number of antennas at both transmitter and receiver for point-to-point communications and multi-user environment. However, the capacity gain in both uplink and downlink is limited in a multi-user environment like cellular system by interference, the number of antennas at the base station, complexity and space constraint particularly for a mobile terminal. This challenge in the downlink provided the motivation to investigate successive interference cancellation (SIC) as an interference management tool LTE system and beyond. The Simulation revealed that ordered successive interference (OSIC) out performs non-ordered successive interference cancellation (NSIC) and the additional complexity is justified based on the associated gain in BER performance of OSIC. The major drawback of OSIC is that it is not efficient in network environment employing power control or power allocation. Additional interference management techniques will be required to fully manage the interference.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Extent of Implementation of Safety and Management Practices in Senior Secondary Schools Biology Laboratory Resources in Enugu State, Nigeria

The study investigated extent of implementation of safety and management practices in senior secondary schools biology laboratory resources in Enugu State, Nigeria. Two research questions guided the study and one null hypothesis was tested at 0.05 level of significance. Descriptive survey research design was adopted for the study. The population of the study comprised 552 biology teachers in public secondary schools in Enugu State. A sample size of 417 biology teachers was drawn for the study using multistage sampling procedure. The researchers developed questionnaires titled “Extent of Implementation of Safety and Management Practices in Senior Secondary Schools Biology Laboratory Resources” (EISMPISSSBLR). The instrument was validated by five experts, one expert in measurement and evaluation unit of the Department of Educational Foundations, one from Department of Guidance and Counselling, two from the Department of Science Education all from NnamdiAzikiwe University, Awka and one secondary school Biology teacher from Community Secondary School, Amansea. Cronbach alpha was used to determine the reliability of the instrument which yielded coefficient value of 0.77. The researchers together, with three research assistants collected data for the study using the direct approach method and 97% return was recorded. Mean statistics was used to answer the research questions while one-tailed independent t-test was used to test the hypotheses at 0.05 statistical level of significance. The findings of the study revealed among others that appropriateness of design and fittings were to a high extent to implement safety practices in biology laboratory. Further results showed that management practices by male and female biology teachers in senior secondary schools biology laboratory resources were to a low extent for teaching secondary school biology in Enugu State, Nigeria. Also, there is no significant difference in the mean ratings of male and female biology teachers in the management of biology laboratory resources for teaching biology in secondary schools in Enugu State. Based on the findings, it was recommended among others that Enugu State government, individuals, science professional bodies and non-governmental, organization should assist improve the safety and management practices in senior secondary schools biology laboratory resources for teaching biology through funding, donations and supply of teaching materials

Long term adverse drug reaction to Efavirenz in a HIV infected adolescent

Efavirenz is one of the medications used in combined antiretroviral therapy (ART) for the management of HIV infection in adolescents. Various central nervous system adverse reactions have been reported in patients commencing antiretroviral therapy with a regimen containing Efavirenz. These reactions tend to be acute, commonly occurring in the first six months of therapy. Adverse reactions following long term use of Efavirenz for ART is rare among adults and rarer still among children and adolescents. There is only one published case of serious adverse reaction to Efavirenz in an adolescent after long-term use. The case of a male HIV Positive Nigerian patient aged 13 years. He presented with five-day history of Difficulty sleeping, abnormal dreams, inability to concentrate, restlessness, irrational behavior and long-term memory loss. There was no previous history of psychiatric illness and no suggestive social or family history. Patient was on Efavirenz containing regimen about 6.5 years till presentation with adverse reaction mainly affecting behavior, thought processes and memory. After discontinuing Efavirenz and replacing with Nevirapine in his combined ART regimen, all neuropsychiatric manifestations ceased .He regained his memory, no longer had bad dreams or demonstrated any irrational behavior or attitude. Physicians who are involved in the care of HIV infected patients need to be aware of the possibility of adverse Drug reactions occurring in patients who have been on antiretroviral drugs for years. This possibility should not be excluded from possible differential diagnosis.KEY WORDS: Adolescent; Efavirenz; HIV Infection; Reactions; Adverse drug; Psychomotor Agitation; Long ter

Anomaly Detection Approach Using Adaptive Cumulative Sum Algorithm for Controller Area Network

The modern vehicle has transformed from a purely mechanical system to a system that embeds several electronic devices. These devices communicate through the in-vehicle network for enhanced safety and comfort but are vulnerable to cyber-physical risks and attacks. A well-known technique of detecting these attacks and unusual events is by using intrusion detection systems. Anomalies in the network occur at unknown points and produce abrupt changes in the statistical features of the message stream. In this paper, we propose an anomaly-based intrusion detection approach using the cumulative sum (CUSUM) change-point detection algorithm to detect data injection attacks on the controller area network (CAN) bus. We leverage the parameters required for the change-point algorithm to reduce false alarm rate and detection delay. Using real dataset generated from a car in normal operation, we evaluate our detection approach on three different kinds of attack scenarios

Reverse Engineering Controller Area Network Messages using Unsupervised Machine Learning

The smart city landscape is rife with opportunities for mobility and economic optimization, but also presents many security concerns spanning the range of components and systems in the smart ecosystem. One key enabler for this ecosystem is smart transportation and transit, which is foundationally built upon connected vehicles. Ensuring vehicular security, while necessary to guarantee passenger and pedestrian safety, is itself challenging due to the broad attack surfaces of modern automotive systems. A single car contains dozens to hundreds of small embedded computing devices known as electronic control units (ECUs) executing 100s of millions of lines of code; the inherent complexity of this tightly-integrated cyber-physical system (CPS) is one of the key problems that frustrate effective security. We describe an approach to help reduce the complexity of security analyses by leveraging unsupervised machine learning to learn clusters of messages passed between ECUs that correlate with changes in the CPS state of a vehicle as it moves throughout the world. Our approach can help to improve the security of vehicles in a smart city, and can leverage smart city infrastructure to further enrich and refine the quality of the machine learning output

Toxoplasma Gondii Infection in HIV/AIDS: Prevalence and Risk Factors

BACKGROUND: Toxoplasmosis is an infection caused by the protozoan Toxoplasma gondii. It is common in severely immunecompromisedpersons.OBJECTIVE: To determine the seroprevalence of T. gondii infection and the risk factors associated with the infection and to investigate the association between T. gondii infection and CD4 cell count.METHODS: Sera collected from 242 HIV positive HAART- naive patients were tested for T. gondii specific immunoglobulin G antibodies. Information was obtained using a structured questionnaire. Baseline CD4 cell counts were obtained from patients case files. Data was managed using SPSS version 20 software and Microsoft Excel worksheet.RESULTS: One hundred and sixty eight (69.4%) subjects were females while 74(30.6%) were males. One hundred (41.3%) of study participants were Toxoplasma IgG antibody positive. Thirty two(32) HIV positive pregnant women were among this group studied with 12( 37.5%) being Toxo IgG antibody positive. Toxoplasma seropositivity was higher in females (42.8%) than in males (39.2%), P= 0.60. CD4 cell count level of < 200 was negatively associated with Toxoplasma seropositivity than CD4 count . 200 by logistic regression (OR= 0.6; 95% CI 0.3- 1.0). Living in proximity with cat was positively associated with T. gondii infection (P= 0.01).CONCLUSION: T. gondii infection is common in pregnant women indicating greater probability of congenital transmission of T. gondii. This could form a basis for recommending intensifying health education and prophylactic treatment for all HIV positive pregnant women. Measures should be taken to prevent stray cats from entering homes.Keywords: Toxoplasma gondii , IgG, Seroprevalence, HIV positive, CD4 cells

Selenium as adjunct to HAART in the management of HIV/Hepatitis B Virus coinfection: A Randomized open label study

Objective: Management of viral hepatitis in patients with HIV disease is quite challenging and  complex. With effective HIV treatment, people with HIV/HBV co-infection are living longer. HBV  epidemiologic surveys showed an inverse association between selenium (Se) level and regional cancer incidence, as well as viral infection. This study assessed effect of selenium as adjunct to HAART in management of HIV/HBV co-infection.Methods: A randomized open label study with participants allocated into three treatment groups: – HAART-only, Se-only and HAART-plus-Se. HIV viral load, HBV viral load, CD4 cell count, and alanine aminotransaminase (ALT), were analyzed at baseline and 18th month, analyzed using SPSS 5 v11. Ethical approval was obtained from Institute’s Ethical Review Board.Results: Sample size was 149 HIV/HBV patients. Rate of HBV clearance was higher among those on HAART-plus-Se at 18th month when compared with rate of clearance among those on HAART-only (p=0.046). CD4 count increment among HAARTplus- Se group compared with HAART-only group was higher (p=0.133), though not statistically significant. On comparison of baseline and 18th month ALT, there was significant decline for HAART-plus-Se (p=0.002) compared with HAART-only group.Conclusion: Selenium seems to have protective effect on liver cells; may be beneficial as adjunct to HAART in HIV/HBV management.Key words: HIV/HBV co-infection, Selenium adjunct, HAAR