55 research outputs found

    Input Prioritization for Testing Neural Networks

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    Deep neural networks (DNNs) are increasingly being adopted for sensing and control functions in a variety of safety and mission-critical systems such as self-driving cars, autonomous air vehicles, medical diagnostics, and industrial robotics. Failures of such systems can lead to loss of life or property, which necessitates stringent verification and validation for providing high assurance. Though formal verification approaches are being investigated, testing remains the primary technique for assessing the dependability of such systems. Due to the nature of the tasks handled by DNNs, the cost of obtaining test oracle data---the expected output, a.k.a. label, for a given input---is high, which significantly impacts the amount and quality of testing that can be performed. Thus, prioritizing input data for testing DNNs in meaningful ways to reduce the cost of labeling can go a long way in increasing testing efficacy. This paper proposes using gauges of the DNN's sentiment derived from the computation performed by the model, as a means to identify inputs that are likely to reveal weaknesses. We empirically assessed the efficacy of three such sentiment measures for prioritization---confidence, uncertainty, and surprise---and compare their effectiveness in terms of their fault-revealing capability and retraining effectiveness. The results indicate that sentiment measures can effectively flag inputs that expose unacceptable DNN behavior. For MNIST models, the average percentage of inputs correctly flagged ranged from 88% to 94.8%

    Controller Placement in Vehicular Networks: A Novel Algorithm Utilizing Elite Opposition-Based Salp Swarm and an Adaptable Approach

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    The rapid advancement of networking technology has enabled small devices to have communication capabilities, but the current decentralized communication system is not ideal for heterogeneous networks like vehicular networks. The integration of routing, switching, and decision-making capabilities in the same network device limits innovation and impedes performance in decentralized networks, especially in vehicular networks where network topologies change frequently. To address the demands of such networks, Software-Defined Networking (SDN) provides a promising solution that supports innovation. However, SDN's single-controller-based system may restrict the network's operational capabilities, despite being programmable and flexible. This paper suggests two methods to tackle the complex problem of controller placement in SDN: an adaptable approach based on OpenFlow protocol in OpenNet and an evolutionary algorithm called Elite Opposition-Based Salp Swarm Algorithm (EO-SSA) to minimize propagation latency, load imbalance, and network resilience. Multiple controllers increase the network's capabilities and provide fault tolerance, but their placement requires a trade-off among various objectives. The proposed methods have been evaluated and analyzed to confirm their effectiveness. The current decentralized network system is not adequate for vehicular networks, and SDN offers a promising solution that supports innovation and can meet the current demands of such networks

    Antibacterial Performance Evaluation of Silver Coated River Sand for Water Decontamination Application

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    The presence of microbes in drinking water is a serious health hazard demanding immediate attention. Silver is known for centuries for its highly effective antimicrobial properties against a variety of microorganisms. Sand is a natural filter media that is widely used in water purification systems for the removal of dirt and suspended matter from water. Hence the development of additional antimicrobial features in commonly used filter material i.e. sand by coating with silver is an alternative technology for providing a safe drinking-water free from microbes. The present study was performed to develop a cost-effective material with antimicrobial properties by coating locally available river sand with silver. The coated material was subsequently used for its antimicrobial performance by using standard methods. To perform the tests E.coli was isolated from wastewater by using standard microbiological protocols. Thereafter, a biochemical test and antibiotic sensitivity assay were performed. Synthesised silver-coated sand was tested for its antibacterial activity against E.coli through the agar well diffusion method. The results showed a zone of clearance ≥40 mm with 700 mg of synthesised sample. To further determine the efficacy of developed material against E.coli load in artificially contaminated water, experiments were conducted by passing contaminated water through the material stuffed inside a hollow tube filter. A colony count reduction of 86.67 per cent was observed on passing 1000 ml of 3x103 CFU/ml contaminated water through the filter. The present study suggests that additional functionality of microbial reduction can be introduced in the sand through the silver coating. The developed material can be effectively used for the removal of fecal coliforms (E.coli) present in water bodies at an effective cost in addition to the removal of traditional impurities like dirt and suspended materials

    The prognostic significance of ploidy analysis in operable breast cancer

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    The nuclear DNA content of 98 operable breast cancers was determined by flow cytometric analysis using paraffin-embedded tissue. All patients were on follow-up and failure of treatment or recurrences were identified. DNA ploidy data in the form of ploidy status and DNA index (DI) has been correlated with various clinical and histopathologic factors. The only significant correlation using univariate analysis exists between the histologic grade and DI (P < 0.025), recurrence of the disease and ploidy status (P < 0.005), and recurrence of the disease and DI (P < 0.005). The absence of correlation of ploidy status with other tumor derived factors indicates the independent nature of ploidy as a prognostic factor. Multivariate analysis showed that in the whole-group ploidy (P < 0.01), tumor margin (P < 0.01), and menopausal status (P < 0.01) were significant factors in the order mentioned. DI with a cut of at 1.29 is not found to be a significant factor in the multivariate analysis. The maximum prognostic value of ploidy status was observed in the postmenopausal group (P < 0.0005). In the node-negative group ploidy status (P < 0.05) is the only independent significant factor predicting for early relapse. It is concluded that ploidy status is an independent prognostic factor predicting for recurrence of the disease. In the node-negative subgroup this could be used to identify the subset of patients who may benefit from adjuvant treatment

    Synthesis of 2, 5 Dimethyl Furan from Renewable Lignocellulosic Biomass

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    Renewable biomass resources could reduce the dependency on the fossil fuels by conversion of its lignocellulose into bio-fuels and other valuable chemicals. Depolymerisation of lignocellulose, hydrolysis of cellulose to monomer glucose and its subsequent dehydration results 5-hydroxymethyl furfural (HMF). HMF is an important platform chemical for fuels and various other applications. The hydrogenation of HMF results 2, 5-dimethylfuran (DMF), which may be a biofuel with 40 per cent greater energy density than that of ethanol. The homogeneous catalytic method is preferred for lignocellulosic biomass conversion to cellulose, its hydrolysis and further dehydration to HMF. The Cu-Ru/C and related catalysts are preferred for hydrogenation of HMD to 2, 5-dimethylfuran. This review is an attempt to summarise the current research and developments in the field of lignocellulose derived HMF and further conversion to DMF as a potential biofuel

    Gene expression and splicing alterations analyzed by high throughput RNA sequencing of chronic lymphocytic leukemia specimens.

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    BackgroundTo determine differentially expressed and spliced RNA transcripts in chronic lymphocytic leukemia specimens a high throughput RNA-sequencing (HTS RNA-seq) analysis was performed.MethodsTen CLL specimens and five normal peripheral blood CD19+ B cells were analyzed by HTS RNA-seq. The library preparation was performed with Illumina TrueSeq RNA kit and analyzed by Illumina HiSeq 2000 sequencing system.ResultsAn average of 48.5 million reads for B cells, and 50.6 million reads for CLL specimens were obtained with 10396 and 10448 assembled transcripts for normal B cells and primary CLL specimens respectively. With the Cuffdiff analysis, 2091 differentially expressed genes (DEG) between B cells and CLL specimens based on FPKM (fragments per kilobase of transcript per million reads and false discovery rate, FDR q < 0.05, fold change >2) were identified. Expression of selected DEGs (n = 32) with up regulated and down regulated expression in CLL from RNA-seq data were also analyzed by qRT-PCR in a test cohort of CLL specimens. Even though there was a variation in fold expression of DEG genes between RNA-seq and qRT-PCR; more than 90 % of analyzed genes were validated by qRT-PCR analysis. Analysis of RNA-seq data for splicing alterations in CLL and B cells was performed by Multivariate Analysis of Transcript Splicing (MATS analysis). Skipped exon was the most frequent splicing alteration in CLL specimens with 128 significant events (P-value <0.05, minimum inclusion level difference >0.1).ConclusionThe RNA-seq analysis of CLL specimens identifies novel DEG and alternatively spliced genes that are potential prognostic markers and therapeutic targets. High level of validation by qRT-PCR for a number of DEG genes supports the accuracy of this analysis. Global comparison of transcriptomes of B cells, IGVH non-mutated CLL (U-CLL) and mutated CLL specimens (M-CLL) with multidimensional scaling analysis was able to segregate CLL and B cell transcriptomes but the M-CLL and U-CLL transcriptomes were indistinguishable. The analysis of HTS RNA-seq data to identify alternative splicing events and other genetic abnormalities specific to CLL is an added advantage of RNA-seq that is not feasible with other genome wide analysis

    Spirituality and religiosity at the junction of consumerism: Exploring Consumer Preference for Spiritual Brands

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    This paper extends the growing research on the influence of religion and spiritualism on consumer behavior by exploring the relationship between spirituality and religiosity (intrinsic vs. extrinsic) as well as their effects on consumers’ purchase of FMCG (Fast Moving Consumer Goods) brands promoted by spiritual leaders (spiritual brands). Results from an online survey of 238 Indian consumers across four food product categories (honey, cheese, biscuits and cooking oil) shows that both intrinsic and extrinsic religiosity have significant positive effects, but spirituality has no significant effect on the purchase of spiritual brands. We discuss the theoretical and managerial implications of these findings as well as some limitations of our study and useful directions for future research

    Early versus delayed initiation of antiretroviral therapy for Indian HIV-Infected individuals with tuberculosis on antituberculosis treatment

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    BACKGROUND: For antiretroviral therapy (ART) naive human immunodeficiency virus (HIV) infected adults suffering from tuberculosis (TB), there is uncertainty about the optimal time to initiate highly active antiretroviral therapy (HAART) after starting antituberculosis treatment (ATT), in order to minimize mortality, HIV disease progression, and adverse events. METHODS: In a randomized, open label trial at All India Institute of Medical Sciences, New Delhi, India, eligible HIV positive individuals with a diagnosis of TB were randomly assigned to receive HAART after 2-4 or 8-12 weeks of starting ATT, and were followed for 12 months after HAART initiation. Participants received directly observed therapy short course (DOTS) for TB, and an antiretroviral regimen comprising stavudine or zidovudine, lamivudine, and efavirenz. Primary end points were death from any cause, and progression of HIV disease marked by failure of ART. FINDINGS: A total of 150 patients with HIV and TB were initiated on HAART: 88 received it after 2-4 weeks (early ART) and 62 after 8-12 weeks (delayed ART) of starting ATT. There was no significant difference in mortality between the groups after the introduction of HAART. However, incidence of ART failure was 31% in delayed versus 16% in early ART arm (p = 0.045). Kaplan Meier disease progression free survival at 12 months was 79% for early versus 64% for the delayed ART arm (p = 0.05). Rates of adverse events were similar. INTERPRETATION: Early initiation of HAART for patients with HIV and TB significantly decreases incidence of HIV disease progression and has good tolerability. TRIAL REGISTRATION: CTRI/2011/12/00226
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