56 research outputs found
CARLA: A Convolution Accelerator with a Reconfigurable and Low-Energy Architecture
Convolutional Neural Networks (CNNs) have proven to be extremely accurate for
image recognition, even outperforming human recognition capability. When
deployed on battery-powered mobile devices, efficient computer architectures
are required to enable fast and energy-efficient computation of costly
convolution operations. Despite recent advances in hardware accelerator design
for CNNs, two major problems have not yet been addressed effectively,
particularly when the convolution layers have highly diverse structures: (1)
minimizing energy-hungry off-chip DRAM data movements; (2) maximizing the
utilization factor of processing resources to perform convolutions. This work
thus proposes an energy-efficient architecture equipped with several optimized
dataflows to support the structural diversity of modern CNNs. The proposed
approach is evaluated by implementing convolutional layers of VGGNet-16 and
ResNet-50. Results show that the architecture achieves a Processing Element
(PE) utilization factor of 98% for the majority of 3x3 and 1x1 convolutional
layers, while limiting latency to 396.9 ms and 92.7 ms when performing
convolutional layers of VGGNet-16 and ResNet-50, respectively. In addition, the
proposed architecture benefits from the structured sparsity in ResNet-50 to
reduce the latency to 42.5 ms when half of the channels are pruned.Comment: 12 page
Unprotected Sex with Injecting Drug Users among Iranian Female Sex Workers: Unhide HIV Risk Study
Purpose. To assess the prevalence and associated factors of unprotected sex with injecting drug users (IDUs) among a sample of female sex workers (FSWs) in Iran. Methods. This cross-sectional study included 144 FSWs who were interviewed as a part of Unhide HIV Risk Study, a national behavioral survey focusing on various high-risk populations, including IDUs, FSWs, and Men who have Sex with Men (MSMs) in 2009. The survey was conducted in eight provinces in Iran using respondent-driven sampling. Participants' sociodemographic status, HIV knowledge, and HIV attitude were analyzed via logistic regression to determine the predictors of unprotected sex with IDU(s) during the past month. Results. Nineteen percent of FSWs reported at least one occasion of unprotected sex with IDU(s) in the month preceding the study. Higher educational level (OR = −0.653, 95%CI = −1.192 to −0.115), perceived HIV risk (OR = −1.047, 95%CI = −2.076 to −0.019), and perceived family intimacy during childhood (OR = −1.104, 95%CI = −1.957 to −0.251) were all independently associated with lower odds of having unprotected sex with IDU(s) in the month preceding the study. Age, marital status, living condition, HIV knowledge, and perceived behavioral control did not affect the odds of FSWs having sex with IDUs. Conclusion. Perceived HIV risk, which is a modifiable factor, seems to be a promising target for harm reduction interventions amongst Iranian female sex workers. Data presented here may aid in reducing or eliminating the role of sex workers as a bridge for HIV transmission from IDUs to the general population in Iran
Oxygen-barrier films based on low-density polyethylene/ ethylene vinyl alcohol/ polyethylene-grafted maleic anhydride compatibilizer
In this research, high oxygen-barrier films were organized based on low-density polyethylene (LDPE)/ ethylene vinyl alcohol (EVOH)/ polyethylene-grafted maleic anhydride (LDPE-g-MA) compatibilizer. The effects of 10–30 wt. % EVOH and 0–10 wt. % LDPE-g-MA loadings on the properties of final films were evaluated. The morphology of specimens was observed by using scanning electron microscopy (SEM). Oxygen transfer rate (OTR) results revealed that the addition of EVOH up to 30 wt. % to neat LDPE could significantly decrease oxygen permeability. The LDPE-g-MA which increased the permeability needed to be fine-tuned its amount based on the EVOH loading in different samples. The experimental results revealed that the addition of 30 wt. % EVOH to the LDPE matrix without adding LDPE-g-MA gave the best oxygen barrier properties. Elastic modulus and tensile strength increased with incorporation of EVOH and LDPE-g-MA into the polyethylene matrix. On the other hand, elongation-at-break decreased with the addition of EVOH and increased with the introduction of compatibilizer to the samples. Incorporation of EVOH and LDPE-g-MA into the LDPE matrix and increasing their amounts led to higher storage modulus and zero shear rate viscosity, but lowered the frequency value at the intersection point of storage modulus (G') and loss modulus (G''). The only exception was that in the samples without compatibilizer, the increase in the EVOH content resulted in a lower zero shear rate viscosity and a higher frequency value at the intersection point of G' and G''
Drug Use among Iranian Drivers Involved in Fatal Car Accidents
Background: Although the problem of substance use among drivers is not limited to certain parts of the world, most epidemiological reports on this topic have been published from industrial world. Aim: To investigate pattern of drug use among Iranian drivers who were involved in fatal road accidents. Methods: This study enrolled 51 Iranian adults who were involved in fatal vehicle accidents and were imprisoned thereafter. Data came from a national survey of drug abuse that was done among Iranian prisoners. The survey collected data at the entry to seven prisons in different regions of the country during a 4-month period in 2008. Self-reported lifetime, last year, and last month drug use was measured. Commercial substance screening tests were applied to detect recent substance use (opioids, cannabinoids, methamphetamines, and benzodiazepines). Results: The commercial substance screening test showed three distinct patterns of recent illicit drug use: opioids (37.3%), cannabinoids (2.0%), opioids and cannabinoids (13.7%). 29.4% were also positive for benzodiazepines. The substance use screening test detected 23.5% of participants who had used drugs but did not disclose any substance use. Conclusion: Opioids are the most common illicit drugs being used by Iranian drivers who are involved in fatal car accidents. The high rate of substance use prior to fatal car accidents in Iran advocates for the need for drug use control policies and programs as major strategies for injury prevention in Iran. There is also a need for substance screening among all drivers involved in fatal car accidents in Iran, as more than 20% of users may not disclose substance use
Drug Injection to Sites other than Arm: A Study of Iranian Heroin Injectors.
For almost all injecting drug users (IDUs), the first site of injection is the arm. Years after injection, IDUs may shift to using other sites for intravenous (IV) access. Although injection to sites other than the arm is associated with higher risks, literature is limited regarding this behavior. We aimed to determine the prevalence and associated factors of using IV access points other than the arm among a national sample of IDUs in Iran. Data came from the National Drug Dependence Survey, 2007, which had enrolled 863 IDUs with at least one daily injection. Data on socio-demographics, pattern of drug use, and injection-related behaviors were entered into a logistic regression to determine predictors of injection to sites other than the arm. From all participants, 54.8% reported current injection sites in areas other than the arm. The other injection sites were the femoral venous sinus (17.0%), followed by the groin (14.5%) and neck (11.5%). Logistic regression revealed that living alone [odds ratio (OR) = 1.789, 95% confidence interval (CI) = 1.218-2.629], being Sunni (OR = 3.475, 95% CI = 1.775-6.801), having higher family income (OR = 1.002, 95% CI = 1.001-1.003), higher age at first drug use (OR = 1.039, 95% CI = 1.009-1.069), longer injection duration (OR = 1.071, 95% CI = 1.041-1.102), and more injection frequency (OR = 1.255, 95% CI = 1.072-1.471) were associated with higher likelihood of using injection sites other than the arm. Using sites other than the arm for IV injection is linked to socio-demographics, drug use data, and injection-related characteristics that can be used by policy makers. This information can be used for harm reduction planning
Distributed Optimization for Control and Estimation
Adopting centralized optimization approaches in order to solve optimization problem arising from analyzing large-scale systems, requires a powerful computational unit. Such units, however, do not always exist. In addition, it is not always possible to form the optimization problem in a centralized manner due to structural constraints or privacy requirements. A possible solution in these cases is to use distributed optimization approaches. Many large-scale systems have inherent structures which can be exploited to develop scalable optimization approaches. In this thesis, chordal graph properties are used in order to design tailored distributed optimization approaches for applications in control and estimation, and especially for model predictive control and localization problems. The first contribution concerns a distributed primal-dual interior-point algorithm for which it is investigated how parallelism can be exploited. In particular, it is shown how the computations of the algorithm can be distributed on different processors so that they can be run in parallel. As a result, the algorithm execution time is accelerated compared to the case where the algorithm is run on a single processor. Simulation studies on linear model predictive control and robust model predictive control confirm the efficiency of the framework. The second contribution is to devise a tailored distributed algorithm for nonlinear least squares with application to a sensor network location problem. It relies on the Levenberg-Marquardt algorithm, in which the computations are distributed using message passing over the computational graph of the problem, which is obtained from what is known as the clique tree of the problem. The results indicate that the algorithm provides not only a good localization accuracy, but also it requires fewer iterations and communications between computational agents in order to converge compared to known first-order methods. The third contribution is a study of extending the message passing idea in order to design tailored distributed algorithm for general non-convex problems. The framework relies on an augmented Lagrangian algorithm in which a primal-dual interior-point method is used for the inner iteration. Application of the framework for general model predictive control of systems with several interconnected sub-systems is extensively investigated. The performance of the framework is then compared with distributed methods based on the alternating direction method of multipliers, where the superiority of the framework is illustrated.ISBN has been added for the PDF version.Funded by the Knut and Alice Wallenberg Foundation</p
Investigating the effect of chitosan, nanopackaging, and modified atmosphere packaging on physical, chemical, and mechanical properties of button mushroom during storage
This study investigated the effect of chitosan coating, nanopackaging, and modified atmosphere packaging (MAP) to increase the shelf life and improve the quality of the white button mushroom. Uncoated and coated button mushrooms were stacked in three types of packages (normal, nano, and nano + MAP). The atmosphere inside the nano + MAP packages contained 10% oxygen and 10% carbon dioxide. The physical, chemical, mechanical properties and the evolution of oxygen and carbon dioxide inside the packages were investigated. The results showed that the triple interaction had significant effect (at 1% and 5% levels) on physical, mechanical properties and gas composition. The use of nanofilm (due to the low permeability to oxygen and carbon dioxide), as well as the modification of atmosphere had a positive effect on the control of mushroom respiration rate and the improvement in its physical, chemical, and mechanical properties
Parental Education or Household Income? Which Socioeconomic Status Indicator Can Better Reduce Body Mass Index Disparities among Latino Children?
Aim: We compared the effects of parental education and household income on children’s Body Mass Index (BMI) in Hispanic White (HW) and non-Hispanic White (NHW) families. Methods: In this cross-sectional study, we borrowed data from the Adolescent Brain Cognitive Development (ABCD) study and analyzed data of 5100 children between the ages of 9 and 10. The independent variables were parental education and household income. The primary outcome was BMI value. Ethnicity was the moderating variable. Confounders were age, sex, and family structure. Three mixed-effects regression models were used for data analysis. Results: Overall, higher parental education and household income were associated with lower BMI levels in children. While an interaction was reported between ethnicity and parental education, no relation was noted between ethnicity and household income regarding BMI. The interaction indicated weaker protective effects of high parental education on BMI in HW children than NHW children. Household income showed similar protective effects on children’s BMI in HW and NHW families. Conclusion: Parental education but not household income loses some of its protective effects on childhood BMI among HW families compared to NHW families. Distal social determinants of health may be more vulnerable to the MDRs (minorities’ diminished returns) than proximal ones. As a result, closing the income gap may be a good strategy towards closing the childhood BMI gap between highly educated HW and NHW families. Policies that raise the minimum wage and those that help HW families save money (e.g., earned income tax policies) maybe more promising strategies to eliminate the ethnic gap in BMI than increasing the education level of ethnic minority families
- …