35 research outputs found

    Defensive Approximation: Securing CNNs using Approximate Computing

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    In the past few years, an increasing number of machine-learning and deep learning structures, such as Convolutional Neural Networks (CNNs), have been applied to solving a wide range of real-life problems. However, these architectures are vulnerable to adversarial attacks. In this paper, we propose for the first time to use hardware-supported approximate computing to improve the robustness of machine learning classifiers. We show that our approximate computing implementation achieves robustness across a wide range of attack scenarios. Specifically, for black-box and grey-box attack scenarios, we show that successful adversarial attacks against the exact classifier have poor transferability to the approximate implementation. Surprisingly, the robustness advantages also apply to white-box attacks where the attacker has access to the internal implementation of the approximate classifier. We explain some of the possible reasons for this robustness through analysis of the internal operation of the approximate implementation. Furthermore, our approximate computing model maintains the same level in terms of classification accuracy, does not require retraining, and reduces resource utilization and energy consumption of the CNN. We conducted extensive experiments on a set of strong adversarial attacks; We empirically show that the proposed implementation increases the robustness of a LeNet-5 and an Alexnet CNNs by up to 99% and 87%, respectively for strong grey-box adversarial attacks along with up to 67% saving in energy consumption due to the simpler nature of the approximate logic. We also show that a white-box attack requires a remarkably higher noise budget to fool the approximate classifier, causing an average of 4db degradation of the PSNR of the input image relative to the images that succeed in fooling the exact classifierComment: ACM International Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS 2021

    Defending with Errors: Approximate Computing for Robustness of Deep Neural Networks

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    Machine-learning architectures, such as Convolutional Neural Networks (CNNs) are vulnerable to adversarial attacks: inputs crafted carefully to force the system output to a wrong label. Since machine-learning is being deployed in safety-critical and security-sensitive domains, such attacks may have catastrophic security and safety consequences. In this paper, we propose for the first time to use hardware-supported approximate computing to improve the robustness of machine-learning classifiers. We show that successful adversarial attacks against the exact classifier have poor transferability to the approximate implementation. Surprisingly, the robustness advantages also apply to white-box attacks where the attacker has unrestricted access to the approximate classifier implementation: in this case, we show that substantially higher levels of adversarial noise are needed to produce adversarial examples. Furthermore, our approximate computing model maintains the same level in terms of classification accuracy, does not require retraining, and reduces resource utilization and energy consumption of the CNN. We conducted extensive experiments on a set of strong adversarial attacks; We empirically show that the proposed implementation increases the robustness of a LeNet-5, Alexnet and VGG-11 CNNs considerably with up to 50% by-product saving in energy consumption due to the simpler nature of the approximate logic.Comment: arXiv admin note: substantial text overlap with arXiv:2006.0770

    Morphological Analysis of White Cement Clinker Minerals: Discussion on the Crystallization-Related Defects

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    The paper deals with a formation of artificial rock (clinker). Temperature plays the capital role in the manufacturing process. So, it is useful to analyze a poor clinker to identify the different phases and defects associated with their crystallization. X-ray fluorescence spectroscopy was used to determine the clinker’s chemical composition. The amounts of the mineralogical phases are measured by quantitative XRD analysis (Rietveld). Scanning electron microscopy (SEM) was used to characterize the main phases of white Portland cement clinker and the defects associated with the formation of clinker mineral elements. The results of a study which focused on the identification of white clinker minerals and defects detected in these noncomplying clinkers such as fluctuation of the amount of the main phases (alite (C3S) and belite (C2S)), excess of the free lime, occurrence of C3S polymorphs, and occurrence of moderately-crystallized structures are presented in this paper

    Antifungal activity of four plant extracts against Botrytis cinerea

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    Botrytis cinerea, responsible for the gray mold disease of tomato, is one of the main problems in fruit exporting countries. Synthetic antifungals are used for their control. However, these products lead to serious damage to environment ant human. Furthermore, it has developed a resistance towards many of them. Therefore, the use of botanical biopesticides as natural alternatives that are friendly to the environment has increased in the last decade. The objective of the present study is the evaluation of the antifungal activity of extracts of four plants, Marrubium vulgare, Moringa oleifera, Psidium guajava and Casimiroa edulis against B. cinerea and the phytochemical characterization of these extracts. The extraction was carried out by maceration, decoction, and ultrasonic-assisted extraction. The high extraction yields of 18.91%, 31.05%, 33.01% and 24.67% were obtained respectively with maceration for M. vulgare, M. oleifera, P. guajava and C. edulis. Qualitative phytochemical tests revealed the presence of terpenoids in all extracts, while saponosides were present only in a few extracts. The highest contents of polyphenols were noted for P. guajava and C. edulis. Also, the highest flavonoid content was noted for C. edulis and M. oleifera. The evaluation of the activity of the studied extracts against the mycelial growth and the germination of the spores of B. cinerea showed that the extracts obtained by maceration and by ultrasonic-assisted extraction of P. guajava and C. edulis are the most efficient against the mycelial growth with an inhibition percentage of 100% for all the tested concentrations. Similarly, the maceration extract of M. vulgare allowed the total inhibition of the germination of the pathogen spores. Finally, the extracts of M. oleifera were the least effective against B. cinerea

    Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017.

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    The Global Burden of Diseases, Injuries and Risk Factors 2017 includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data. METHODS: We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

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    The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017) includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data.; We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting. Globally, for females, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and haemoglobinopathies and haemolytic anaemias in both 1990 and 2017. For males, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and tuberculosis including latent tuberculosis infection in both 1990 and 2017. In terms of YLDs, low back pain, headache disorders, and dietary iron deficiency were the leading Level 3 causes of YLD counts in 1990, whereas low back pain, headache disorders, and depressive disorders were the leading causes in 2017 for both sexes combined. All-cause age-standardised YLD rates decreased by 3·9% (95% uncertainty interval [UI] 3·1-4·6) from 1990 to 2017; however, the all-age YLD rate increased by 7·2% (6·0-8·4) while the total sum of global YLDs increased from 562 million (421-723) to 853 million (642-1100). The increases for males and females were similar, with increases in all-age YLD rates of 7·9% (6·6-9·2) for males and 6·5% (5·4-7·7) for females. We found significant differences between males and females in terms of age-standardised prevalence estimates for multiple causes. The causes with the greatest relative differences between sexes in 2017 included substance use disorders (3018 cases [95% UI 2782-3252] per 100 000 in males vs s1400 [1279-1524] per 100 000 in females), transport injuries (3322 [3082-3583] vs 2336 [2154-2535]), and self-harm and interpersonal violence (3265 [2943-3630] vs 5643 [5057-6302]). Global all-cause age-standardised YLD rates have improved only slightly over a period spanning nearly three decades. However, the magnitude of the non-fatal disease burden has expanded globally, with increasing numbers of people who have a wide spectrum of conditions. A subset of conditions has remained globally pervasive since 1990, whereas other conditions have displayed more dynamic trends, with different ages, sexes, and geographies across the globe experiencing varying burdens and trends of health loss. This study emphasises how global improvements in premature mortality for select conditions have led to older populations with complex and potentially expensive diseases, yet also highlights global achievements in certain domains of disease and injury

    Viabilité et dormance des semences d'arganier (Argania spinosa (L.) Skeels)

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    Argan (Argante spinosa (L.) Skeels) seed viability and dormancy. Argan (Argania spinosa (L.) Skeels) seed germination is low because of the combined effects of low seed viability and dormancy. We undertook four subsequent experiments in the prospect of testing the effects of three treatments (cold storage, fungicide and gibberellic acid) on nuts and stones (intact or scarified) using 34 different mother-tree genotypes. Germination of whole stones stored at room temperature remains below 27%. When scarified, this percentage doubled because coat dormancy was overcome. A similar behaviour would be expected from bare nuts. However, these are five times less viable than whole stones, which would exclude their use as a seed source. Therefore the shell is protective, and it becomes necessary to protect the nut with adapted fungicides when the shell is scarified. Seeds stored at low temperatures (4°C) germinate twice as much as the control but the treatment was not efficient enough to overcome embryo dormancy since average germination did not exceed 50%. Gibberellic acid strengthens the low temperature effect, adding a 20% germination increase. Even with the combined effects of scarification, low temperature and gibberellic acid, we do not reach 100% germination because of seed viability limitations. For all the observed aspects, the genotype effect is highly significant outlining the importance of the seed source to be used for argan seed propagation. Hence, to overcome low argan seedling production, higher germination percentages are attainable (80% and higher) through the use of selected genotypes, seed storage at low temperature (4°C), the use of fungicide, scarification and gibberellic acid.La germination des semences d'arganier (Argania spinosa (L.) Skeels) est faible à cause de l'effet combiné de la non-viabilité et de la dormance. On a entrepris quatre essais consécutifs dans le but de tester l'effet de trois traitements (conservation au froid, fongicide et acide gibbérellique) sur la germination des amandes nues ou des noyaux (entiers ou scarifiés mécaniquement) sur un total de 34 pied mères de génotypes différents. Le pourcentage de germination des noyaux entiers conservés à température ambiante ne dépasse pas 27%. Le pourcentage de germination des noyaux scarifiés est deux fois plus important, mettant en évidence la dormance tégumentaire due à la coque de l’arganier. Le même résultat aurait pu être obtenu avec les amandes nues mais la non-viabilité de celles-ci est cinq fois plus élevée que celle des noyaux entiers, ce qui exclut leur utilisation. Ainsi la coque constitue une protection de l’amande que l’on doit renforcer par le traitement antifongique des noyaux scarifiés. Les semences d'arganier conservées au froid (4°C) germent deux fois plus que le témoin. Si le froid lève la dormance embryonnaire, il n’est pas totalement efficace puisque le pourcentage de germination moyen n’a pas dépassé 50%. L'application de l'acide gibbérellique renforce l'effet du froid et permet d’augmenter la levée de 20% supplémentaires. Cependant, le froid combiné à l’acide gibbérellique ne concernant que la dormance embryonnaire ne permettent pas d’atteindre une levée de 100%, même quand les noyaux sont scarifiés, à cause de la non-viabilité d’une proportion plus ou moins importante de semences. Quelque soit l’aspect observé, la variabilité des réponses des génotypes est considérable, ce qui souligne l’importance du pied mère source de semences à utiliser pour la réussite de la production de plants d’arganier. La germination peut atteindre des pourcentages élevés (plus de 80%) par l’identification des génotypes performants, la conservation des noyaux au froid (4°C), le traitement fongicide, la scarification et le traitement à l'acide gibbérellique des noyaux.Bani-Aameur Fouzia, Alouani Mohamed. Viabilité et dormance des semences d'arganier (Argania spinosa (L.) Skeels). In: Ecologia mediterranea, tome 25 n°1, 1999. pp. 75-86

    Argan (Argania spinosa (L.) Skeels) seed germination under nursery conditions: Effect of cold storage, gibberellic acid and mother-tree genotype

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    The aim of this study is to assess argan (Argania spinosa) seed germination of ten argan mother-trees after four different cold storage durations with or without gibberellic acid (GA) treatment for the purpose of establishing a simple germination procedure adaptable to various nursery situations. The beginning of germination of argan seeds which, were stored at room temperature in the absence of GA treatment, was delayed for 3.4 days in average in comparison with chilled and GA-treated seeds. Germination was as low as 35.5% and seed deterioration as well as pre-emergence seedling dumping-off was important. In contrast, either GA application or cold storage at 4 °C for at least one month significantly led to a two-fold increase of germination attaining approximately 60% and a better control of dormancy. Indeed, average germination was even higher when both treatments were combined (79.5%), mostly because GA combined to cold storage of the seeds for longer than one month periods decreased losses due to seed fungi contamination or to pre-emergence seedling dumping-off. Final germination percentage was enhanced by cold storage for the longest periods (three months) attaining values higher than 95.0% depending on mother tree genotype.Germination des semences d’arganier (Argania spinosa (L.) Skeels) en pépinière : effet du froid, de l’acide gibbérellique et du génotype du pied-mère. Cette étude porte sur les effets de quatre durées de conservation des semences au froid, avec ou sans traitement à l’acide gibbérellique (GA), sur la germination des noyaux de dix pied-mères d’arganier (Argania spinosa) en vue d’établir un protocole simple de germination adaptable à des situations diverses. Le début de la germination des semences d’arganier non traitées par GA et conservées à la température ambiante est retardé de trois jours par comparaison avec les semences stockées au froid ou traitées par GA. La germination est faible (35,5 %) et la contamination des semences ainsi que la fonte de semis en pré-émergence sont importantes. Par contraste, l’application de GA ou le stockage au froid à 4 °C pendant un minimum de un mois permet une augmentation significative de la germination qui atteint 60 %. La germination moyenne augmente remarquablement quand les deux traitements sont combinés (79,5 %), ceci étant surtout du au fait que l’application de GA après stockage au froid réduit les pertes dues à la contamination par les champignons et à la fonte de semis en pré-émergence. Dans ces conditions, et quand les semences ont été stockées au froid pendant trois mois, le pourcentage final de germination a pu atteindre 95,0 % en fonction du pied-mère
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