Reducing the Complexity of Equalisation and Decoding of Shingled Writing

Full version: Access restricted permanently due to 3rd party copyright restrictions. Restriction set on 24/05/2017 by SC, Graduate schoolShingled Magnetic Recording (SMR) technology is important in the immediate need for expansion of magnetic hard disk beyond the limit of current disk technology. SMR provides a solution with the least change from current technology among contending technologies. Robust easy to implement Digital Signal Processing (DSP) techniques are needed to achieve the potentials of SMR. Current DSP techniques proposed border on the usage of Two Dimensional Magnetic Recording (TDMR) techniques in equalisation and detection, coupled with iterative error correction codes such as Low Density Parity Check (LDPC). Currently, Maximum Likelihood (ML) algorithms are normally used in TDMR detection. The shortcomings of the ML detections used is the exponential complexities with respect to the number of bits. Because of that, reducing the complexity of the processes in SMR Media is very important in order to actualise the deployment of this technology to personal computers in the near future. This research investigated means of reducing the complexities of equalisation and detection techniques. Linear equalisers were found to be adequate for low density situations. Combining ML detector across-track with linear equaliser along-track was found to provide low complexity, better performing alternative as compared to use of linear equaliser across track with ML along track. This is achieved if density is relaxed along track and compressed more across track. A gain of up to 10dB was achieved. In a situation with high density in both dimensions, full two dimensional (2D) detectors provide better performance. Low complexity full 2D detector was formed by serially concatenating two ML detectors, one for each direction, instead of single 2D ML detector used in other literature. This reduces complexity with respect to side interference from exponential to linear. The use of a single bit parity as run length limited code at the same time error correction code is also presented with a small gain of about 1dB at BER of 10^-5 recorded for the situation of high density.Emerging Markets Telecommunication Services Limited (Etisalat Nigeria)

An Improved Throughput for Non-Binary Low-Density-Parity-Check Decoder

Low-Density-Parity-Check (LDPC) based error control decoders find wide range of application in both storage and communication systems, because of the merits they possess which include high appropriateness towards parallelization and excellent performance in error correction. Field-Programmable Gate Array (FPGA) has provided a robust platform in terms of parallelism, resource allocation and excellent performing speed for implementing non-binary LDPC decoder architectures. This paper proposes, a high throughput LDPC decoder through the implementation of fully parallel architecture and a reduction in the maximum iteration limit, needed for complete error correction. A Galois field of eight was utilized alongside a non-uniform quantization scheme, resulting in fewer bits per Log Likelihood Ratio (LLR) for the implementation. Verilog Hardware Description Language (HDL) was used in the description of the non-binary error control decoder. The propose decoder attained a throughput of 10Gbps at 400-MHz clock frequency when synthesized on a ZYNQ 7000 Series FPGA

CICM: A Collaborative Integrity Checking Blockchain Consensus Mechanism for Preserving the Originality of Data the Cloud for Forensic Investigation

The originality of data is very important for achieving correct results from forensic analysis of data for resolving the issue. Data may be analysed to resolve disputes or review issues by finding trends in the dataset that can give clues to the cause of the issue. Specially designed foolproof protection for data integrity is required for forensic purposes. Collaborative Integrity Checking Mechanism (CICM), for securing the chain-of-custody of data in a blockchain is proposed in this paper. Existing consensus mechanisms are fault-tolerant, allowing a threshold for faults. CICM avoids faults by using a transparent 100% agreement process for validating the originality of data in a blockchain. A group of agreement actors check and record the original status of data at its time of arrival. Acceptance is based on general agreement by all the participants in the consensus process. The solution was tested against practical byzantine fault tolerant (PBFT), Zyzzyva, and hybrid byzantine fault tolerant (hBFT) mechanisms for efficacy to yield correct results and operational performance costs. Binomial distribution was used to examine the CICM efficacy. CICM recorded zero probability of failure while the benchmarks recorded up to 8.44%. Throughput and latency were used to test its operational performance costs. The hBFT recorded the best performance among the benchmarks. CICM achieved 30.61% higher throughput and 21.47% lower latency than hBFT. In the robustness against faults tests, CICM performed better than hBFT with 16.5% higher throughput and 14.93% lower latency than the hBFT in the worst-case fault scenario

Prevalence and genetic determinant of drug-resistant tuberculosis among patients completing intensive phase of treatment in a Tertiary Referral Center in Nigeria

Background: Drug-resistant tuberculosis (DR-TB) continues to be a challenge in developing countries with poor resources. Despite the high prevalence of primary DR-TB, its routine screening prior to the treatment is not performed in public hospitals in Nigeria. Data regarding drug resistance and its genetic determinant among follow-up patients with TB are lacking in Nigeria. Hence, the aim of this study was to determine the prevalence and genetic determinant of drug resistance among the follow-up patients with TB in a tertiary hospital in Nigeria. Materials and Methods: This was a cross-sectional, laboratory-based study conducted on 384 sputum samples collected from consented follow-up patients with TB. Standard microbiology methods (Ziehl–Neelsen staining and microscopy) and polymerase chain reaction (PCR; line probe assay [LIPA]) were used to analyze the collected samples. Pearson's Chi-square test was used to analyze the generated data. Results: Out of 384 sputum samples analyzed for Mycobacterium tuberculosis and DR-TB, 25 (6.5%) tested positive for acid-fast bacilli. These samples were subjected to PCR (LIPA), of which 18 (72%) tested positive for DR-TB. Of these 18 samples, mutations conferring resistance to rifampicin (rpoB) and isoniazid (katG and/or inhA) were detected in 12 (66.7%) and 6 (33.3%) samples, respectively. Transmission dynamics of DR-TB was not significantly (P > 0.05) dependent on demographic characteristics. Conclusion: There is a need to strengthen the laboratory capacity for the diagnosis of TB and drug resistance testing and make these services available, affordable, and accessible to the patients who need them

Response to Ebola Virus Disease Outbreak in Nigeria, West Africa: The Zaria experience

ObjectiveTo assess the formation and function of a joint committee of the Ahmadu Bello University (ABU) and the Ahmadu Bello University Teaching Hospital (ABUTH) to prevent and control EVD in Zaria and the North West sub region of Nigeria.IntroductionThe Ebola Virus Disease (EVD) outbreak in West Africa was unprecedented in spread and its attendant response. There were over 15 000 confirmed cases and over 9 000 suspected cases. The response to the outbreak was massive within Africa and beyond. The outbreak in Nigeria affected 19 people and led to 7 deaths (CFR 37%).There were more than 891 contacts of these cases under surveillance as at 23rd September 2014. Nigeria was declared EVD free by the World Health Organization in October 2014.Nationwide there was targeted preparedness to prevent and control EVD. In Zaria, this led to the formation of a joint committee of the Ahmadu Bello University (ABU) and the Ahmadu Bello University Teaching Hospital (ABUTH) to prevent and control EVD in Zaria and the sub region as a whole.MethodsA joint multidisciplinary committee was formed by ABU and ABUTH with representatives from the Department of Community Medicine, Internal Medicine, Nursing sciences, Veterinary Public Health, Medical Microbiology, Mass Communication, Directorate of Public Affairs ABU Zaria, General Administration and Management services division ABUTH, the University Health Services and the Centre for Disease Risk Management under the Department of Geography. Four subcommittees were created steered by the main committee. The subcommittees were Surveillance; Case Management; Infection Control and Social and Mass mobilization subcommitteesResultsThe committee conducted seminars and trainings in case management, surveillance and infection control. Mass media campaigns included radio jingles production and airing as well as production of flyers and posters on EVD prevention and control. There was a phone in live radio programme. Screening exercise for raised temperature was conducted using laser thermometers at main entry points. A case of suspected EVD was managed who turned out to be a case of dengue haemorrhagic fever.ConclusionsThe committee was enriched by its multidisciplinary nature and a blueprint for the control and prevention of EVD was developed in line with national and global standards. The committee was hampered with lack of funds to implement fully the blueprint for the prevention and control of EVD in Zaria and its environs. The committee transformed into the ABU/ABUTH Epidemic Preparedness and Response Committee after the outbreak was over to address other emerging epidemics.ReferencesABU/ABUTH Joint Committee For The Prevention And Control Of Ebola Virus Disease (ABUPACE) Blueprint For Prevention And Control Of Ebola Virus Disease In ABU/ABUTH Zaria 2014. Pages 1-44World Health Organization. WHO declares end of Ebola outbreak in Nigeria www.who.int/mediacentre/news/statements/2014/nigeria-ends-ebola/en/