Core Failure Mitigation in Integer Sum-of-Product Computations on Cloud Computing Systems

The decreasing mean-time-to-failure estimates in cloud computing systems indicate that multimedia applications running on such environments should be able to mitigate an increasing number of core failures at runtime. We propose a new roll-forward failure-mitigation approach for integer sumof-product computations, with emphasis on generic matrix multiplication (GEMM)and convolution/crosscorrelation (CONV) routines. Our approach is based on the production of redundant results within the numerical representation of the outputs via the use of numerical packing.This differs fromall existing roll-forward solutions that require a separate set of checksum (or duplicate) results. Our proposal imposes 37.5% reduction in the maximum output bitwidth supported in comparison to integer sum-ofproduct realizations performed on 32-bit integer representations which is comparable to the bitwidth requirement of checksummethods for multiple core failure mitigation. Experiments with state-of-the-art GEMM and CONV routines running on a c4.8xlarge compute-optimized instance of amazon web services elastic compute cloud (AWS EC2) demonstrate that the proposed approach is able to mitigate up to one quadcore failure while achieving processing throughput that is: 1) comparable to that of the conventional, failure-intolerant, integer GEMM and CONV routines, 2) substantially superior to that of the equivalent roll-forward failure-mitigation method based on checksum streams. Furthermore, when used within an image retrieval framework deployed over a cluster of AWS EC2 spot (i.e., low-cost albeit terminatable) instances, our proposal leads to: 1) 16%-23% cost reduction against the equivalent checksum-based method and 2) more than 70% cost reduction against conventional failure-intolerant processing on AWS EC2 on-demand (i.e., highercost albeit guaranteed) instances

Generalized Numerical Entanglement For Reliable Linear, Sesquilinear And Bijective Operations On Integer Data Streams

We propose a new technique for the mitigation of fail-stop failures and/or silent data corruptions (SDCs) within linear, sesquilinear or bijective (LSB) operations on M integer data streams (M ⩾ 3). In the proposed approach, the M input streams are linearly superimposed to form M numerically entangled integer data streams that are stored in-place of the original inputs, i.e., no additional (aka. “checksum”) streams are used. An arbitrary number of LSB operations can then be performed in M processing cores using these entangled data streams. The output results can be extracted from any (M-K) entangled output streams by additions and arithmetic shifts, thereby mitigating K fail-stop failures (K ≤ ⌊(M-1)/2 ⌋ ), or detecting up to K SDCs per M-tuple of outputs at corresponding in-stream locations. Therefore, unlike other methods, the number of operations required for the entanglement, extraction and recovery of the results is linearly related to the number of the inputs and does not depend on the complexity of the performed LSB operations. Our proposal is validated within an Amazon EC2 instance (Haswell architecture with AVX2 support) via integer matrix product operations. Our analysis and experiments for failstop failure mitigation and SDC detection reveal that the proposed approach incurs 0.75% to 37.23% reduction in processing throughput in comparison to the equivalent errorintolerant processing. This overhead is found to be up to two orders of magnitude smaller than that of the equivalent checksum-based method, with increased gains offered as the complexity of the performed LSB operations is increasing. Therefore, our proposal can be used in distributed systems, unreliable multicore clusters and safety-critical applications, where robustness against failures and SDCs is a necessity

Mitigating Silent Data Corruptions In Integer Matrix Products: Toward Reliable Multimedia Computing On Unreliable Hardware

The generic matrix multiply (GEMM) routine comprises the compute and memory-intensive part of many information retrieval, machine learning and object recognition systems that process integer inputs. Therefore, it is of paramount importance to ensure that integer GEMM computations remain robust to silent data corruptions (SDCs), which stem from accidental voltage or frequency overscaling, or other hardware non-idealities. In this paper, we introduce a new method for SDC mitigation based on the concept of numerical packing. The key difference between our approach and all existing methods is the production of redundant results within the numerical representation of the outputs, rather than as a separate set of checksums. Importantly, unlike well-known algorithm-based fault tolerance (ABFT) approaches for GEMM, the proposed approach can reliably detect the locations of the vast majority of all possible SDCs in the results of GEMM computations. An experimental investigation of voltage-scaled integer GEMM computations for visual descriptor matching within state-of-the art image and video retrieval algorithms running on an Intel i7- 4578U 3GHz processor shows that SDC mitigation based on numerical packing leads to comparable or lower execution and energy-consumption overhead in comparison to all other alternatives

Validation of Wound-QoL Questionnaire among Patients with Acute Wounds in Enugu, South-east Nigeria

Globally, health related quality of life (HRQoL) has become an essential wound outcome measure in evaluating holistic care, clinical practice and research. In Nigeria, there is a dearth of validated studies on standardised instruments to assess quality-of-life in patients with acute wounds. This study validated the Wound-QoL questionnaire in Nigeria. It was a single-blinded randomized controlled study, carried out amongst 42 participants using simple blocked randomization to assign patients to different groups (Biodress, honey and povidone-iodine). Wound-QoL was used for data collection with due ethical consideration and data analysis. The median age of the participants was 32.5 years, with a slight male preponderance (52.4%). The global score was above 0.7 at both times tested with the subscale scores ranging from 0.420 to 0.754. The mean values for both Wound-QoL global scores (T0: 0.83, T1: 0.79) and two subscale scores (body: T0: 1.28, T1: 1.17, everyday life: T0: 0.61, T1: 0.58) decreased over time while the psyche subscale remained unchanged (T0: 0.53, T1: 0.53). On item selectivity, the global score was significantly correlated to each of the items and the subscales. This result showed that acute wounds affect patients’ quality of life. It also indicates that the Wound-QoL questionnaire has positive psychometric properties. The Wound-QoL is a valid and reliable tool in assessing quality of life of people with acute wounds in Nigeria. A large-scale study in different regions of the country is recommended bearing in mind the cultural differences

A Comparison of the Performance of the Midarm Circumference and the Nelson Weight Estimation Formulas in Nigerian Children

Background: In emergencies, two commonly used weight estimation methods are Nelson and mid‑arm circumference (MAC)‑based formulae. Nelson’s method requires the child’s age while the MAC formula offers weight estimation without any prior details of the child, which is useful in our environment due to the lack of proper vital statistics documentation. Methodology: We measured the weight, height, and MAC of 1390 children aged 1–12 years. Values got from the measurements were substituted in MAC and Nelson formulae for weight estimation. The estimated weights were compared to the actual weights of the children. Results: Atotal of 1390 children were enrolled. The mean of enrolled children’s actual weight was significantly higher than the mean weight estimated using MAC and Nelson formula. MAC method overestimated weight in children 1–7 years and underestimated weight in those 8–12 years old. On the other hand, the Nelson formula underestimated weights in children 2–11 years and overestimated weight in 1 and 12-year olds. Conclusions: Both the MAC and Nelson method have their deficiencies in weight estimation. Though the Nelson formula  appears slightly more accurate than the MAC, weight estimates from both methods were mostly within the actual weight agreement limits. Keywords: Actual weight, children, comparison, formulae, mid‑arm circumference, nelso

Novel 3-Hydroxy-2-naphthoic hydrazone and Ni(II), Co(II) and Cu(II) Complexes: Synthesis, Spectroscopic Characterization, Antimicrobial, DNA Cleavage and Computational Studies

A novel hydrazone ligand derived from condensation reaction of 3-hydroxy-2-naphthoic hydrazide with dehydroacetic acid, and its Ni(II), Cu(II) and Co(II) complexes were synthesized, characterized by spectroscopic, elemental analyses, magnetic susceptibility and conductivity methods, and screened for antimicrobial, DNA binding and cleavage properties. Spectroscopic analysis and elemental analyses indicated the formula, [MLCl 2 ], for the complexes; square planar geometry for the nickel, and tetrahedral geometry for copper and cobalt complexes. The non-electrolytic natures of the complexes in Dimethyl Sulphoxide (DMSO) were confirmed by their molar conductance values in the range of 6.11–14.01 ? -1 cm 2 mol -1 . The copper complex had the best antibacterial activity against Staphylococcus aureus (ATCC 29213). DNA cleavage activities of the compounds, evaluated on pBR322 DNA, by agarose gel electrophoresis, in the presence and absence of oxidant (H 2 O 2 ) and free radical scavenger (DMSO), indicated no activity for the ligand, and moderate activity for the complexes, with the copper complex cleaving pBR322 DNA more efficiently in the presence of H 2 O 2 . When the complexes were evaluated for antibacterial and A-DNA activity using Molecular docking technique, the copper complex was found to be most effective against Gram-positive (S. aureus) bacteria. [CuLCl 2 ] showed good hydrogen bonding interaction with the major-groove (C 2 . G 13 base pair) of A-DNA. Density functional theory (DFT) calculations of the structural and electronic properties of the complexes revealed that [CuLCl 2 ] had a smaller HOMO-LUMO gap, suggesting a higher tendency to donate electrons to electron-accepting species of biological targets. © 2019 John Wiley & Sons, Ltd

Barriers to Cervical Cancer Screening Uptake among Women of an urban community in south-Eastern Nigeria

Objective: This survey examined the barriers to cervical cancer screening uptake by adult women in Nnewi, a town located in southeast Nigeria. Methods: In this descriptive survey, data were collected data from 379women aged between 21 and 65 years using the adapted version of the Health Belief Model Scale for Cervical Cancer and Pap smear test questionnaire. Results: The major perceived barriers to the practice of cervical cancer screening were fear of the result (2.32±1.05), lack of knowledge of what pap smear is (2.32±0.90), and lack of information about when and where pap smear could be done (2.25±1.07). The logistic regression model showed that the following perceived barriers predicted uptake of cervical cancer screening (P< 0.05): time constraint (P = 0.001, OR= 3.368, CI= 1.455, 4.11); attitude of healthcare workers (P = 0.008, OR= 6.642; CI= 2.764, 18.196); knowledge of test frequency (P = 0.005, OR= 1.443; CI 0.946, 3.811); fear of result(P = 0.001, OR= 3.660, CI=0.679, 4.061); lack of information on when and where pap smear could be obtained (P = 0.010; OR= 6.732; CI= 2.286, 10.490); distance from test centre (P = 0.003; OR= 1.387; CI=0.126, 2.193); not knowing what it is for (P = 0.024, OR10.895, CI = 2.938, 14.401)