Representation Learning by Learning to Count

We introduce a novel method for representation learning that uses an artificial supervision signal based on counting visual primitives. This supervision signal is obtained from an equivariance relation, which does not require any manual annotation. We relate transformations of images to transformations of the representations. More specifically, we look for the representation that satisfies such relation rather than the transformations that match a given representation. In this paper, we use two image transformations in the context of counting: scaling and tiling. The first transformation exploits the fact that the number of visual primitives should be invariant to scale. The second transformation allows us to equate the total number of visual primitives in each tile to that in the whole image. These two transformations are combined in one constraint and used to train a neural network with a contrastive loss. The proposed task produces representations that perform on par or exceed the state of the art in transfer learning benchmarks.Comment: ICCV 2017(oral

The correlation between strength and range of motion of the neck muscles and opium smoking in Iran

ObjectivesOpium smoking is commonly practiced via traditional and novel routes in Iran. Both smoking methods are practiced in a non-ergonomic position. According to previous studies and our hypothesis, it can be potentially harmful to the cervical spine. Thus, the present study aimed to investigate the relationship between opium smoking and neck range of motion and neck muscle strength.MethodsIn this cross-sectional and correlational study, the range of motion and strength of the neck muscles of 120 men with drug use disorder were measured by a CROM goniometer and a hand-held dynamometer. Other data gathering was performed using a demographic questionnaire, the Maudsley Addiction Profile, and the Persian version of Leeds Dependence Questionnaire. The obtained data were analyzed by Shapiro–Wilks test, Pearson’s correlation coefficient and stepwise linear regression.ResultsThere was no significant correlation between the age of drug use onset and range of motion and muscle strength of the neck; however, the daily duration of opium smoking and the number of years of opium smoking were inversely and significantly correlated with the range of motion and muscle strength of the neck in some directions. Daily opium smoking time for decreasing in neck range of motion and total duration of opium smoking for reduction of neck muscles strength are stronger predictor variables.ConclusionOpium smoking by traditional routes causes non-ergonomic positions and has a moderate significant correlation with reduced range of motion and neck muscle strength, in Iran.Highlights– The harm of drug use disorder is not only AIDS and hepatitis, and harm reduction programs should go beyond the prevention of AIDS and hepatitis. According to more than 90% of smoking use of drug compared to other methods (oral and injectable, etc.) musculoskeletal disorders caused by the smoking use of drugs, have a greater cost burden in reducing the quality of life and the need for rehabilitation.– Drug abuse treatment and harm reduction programs should focus more seriously on replacing smoking use of drugs with oral medications assisted treatment.– Although in Iran and some countries in the region, a large number of people smoke opium for many years and sometimes all their lives, daily in a completely non-ergonomic position, but studying the deformation of the posture and musculoskeletal disorders related to the body position in them, is not a scientific concern and neither physical therapy researchers have paid attention to it nor addiction researchers.– Neck muscles strength and range of motion in opium addicts are correlated to the number of years of opium smoking and daily minutes of opium smoking, but not to its oral use.– There is no significant correlation between the onset age of continues and permanent opium smoking and substance dependence severity with neck range of motion and muscles strength.– People with drug use disorder (especially smoking users) as a large group of vulnerable people, should be the target population of musculoskeletal disorders researchers and addiction harm reduction researchers, and more experimental, comparative, cohort, etc. researches should be designed and implemented for them

Boosting Self-Supervised Learning via Knowledge Transfer

In self-supervised learning, one trains a model to solve a so-called pretext task on a dataset without the need for human annotation. The main objective, however, is to transfer this model to a target domain and task. Currently, the most effective transfer strategy is fine-tuning, which restricts one to use the same model or parts thereof for both pretext and target tasks. In this paper, we present a novel framework for self-supervised learning that overcomes limitations in designing and comparing different tasks, models, and data domains. In particular, our framework decouples the structure of the self-supervised model from the final task-specific fine-tuned model. This allows us to: 1) quantitatively assess previously incompatible models including handcrafted features; 2) show that deeper neural network models can learn better representations from the same pretext task; 3) transfer knowledge learned with a deep model to a shallower one and thus boost its learning. We use this framework to design a novel self-supervised task, which achieves state-of-the-art performance on the common benchmarks in PASCAL VOC 2007, ILSVRC12 and Places by a significant margin. Our learned features shrink the mAP gap between models trained via self-supervised learning and supervised learning from 5.9% to 2.6% in object detection on PASCAL VOC 2007

X-ray Diffraction Analysis of ProRoot Mineral Trioxide Aggregate Hydrated at Different pH Values

Introduction: The aim of this study was to compare the chemical compounds of white ProRoot mineral trioxide aggregate (WMTA) hydrated at different pH environments. Methods and Materials: Mixed samples of WMTA were kept in acidic (pH=5.4), neutral (pH=7.4) and alkaline (pH=9.4) environments for 48 h. Then, X-ray diffraction (XRD) analysis was performed for both hydrated and powder forms of WMTA. Portlandite crystalline structures of environments were compared from three aspects: intensity (height of the peak, corresponding to the concentration), crystallinity (peak area/total area) and crystal size (full-width at half-maximum of the peak). Results: After matching the peaks of each sample with those of the International Center for Diffraction Data (ICDD) database, the main constituent of all set cements and powder form was found to be bismuth oxide. Acidic environment exhibited lower intensity and crystallinity of portlandite in comparison with neutral environment. Conclusion: The highest concentration and crystallinity of portlandite were observed in WMTA samples hydrated at neutral pH and the highest crystal size was detected after hydration in alkaline pH.Keywords: Mineral Trioxide Aggregate; pH; X-ray Diffractio

PREDVIĐANJA MEHANIČKE BRZINE BUŠENJA KORIŠTENJEM STIJENSKO-INŽENJERSKE METODE, ANALIZA SLUČAJA BUŠOTINE S NAFTNOGA POLJA AZADEGAN

One of the criteria in the operational efficiency of drilling is the rate of penetration of the drill bit. Numerous factors affect the rate of penetration. Identification of the effective factors on rate of penetration may lead to a more accurate assessment of drilling time, and as a result, the controlling of operational costs. The concurrent effect of the entire influential factors as well as the differing significance of each of them on the rate of penetration makes the study and optimization of drilling operations much more complicated and difficult. Using the rock engineering systems (RES), the impact of effective operational and geomechanical factors on the rate of penetration has been assessed in this article and a model has been proposed for the prediction of the rate of penetration. Data from one of the wells within the Azadegan oilfield have been used in order to study the impact of effective factors on the rate of penetration. To this end, the effective factors on rate of penetration are initially identified and then an index called “the rate of penetration index (ROPi)” is proposed through the application of the rock engineering systems approach. This index has been calculated at four different depths along the aforementioned well. The results suggested the compliance of penetration rate predictions with field observations. Moreover, porosity and uniaxial compressive strength are the most effective factors on the rate of penetration whereas the weight of drilling fluid has the smallest impact. Finally, a classification for the penetration rate index is presented.S obzirom na to da su čimbenici koji izravno utječu na troškove izrade bušotina, vrijeme i operativna učinkovitost imaju veliku važnost tijekom bušenja. Jedan od kriterija operativne učinkovitosti bušenja jest mehanička brzina bušenja (engl. rate of penetration, ROP). Velik broj čimbenika utječe na mehaničku brzinu bušenja. Njihova identifikacija omogućuje točnu procjenu vremena bušenja, a time i kontrolu operativnih troškova. S obzirom na istodobno djelovanje navedenih čimbenika, kao i specifičnosti njihova pojedinačnog djelovanja na ROP, analize i optimizacija operacija bušenja vrlo su složene i teške. U ovome je radu vrednovan utjecaj operativnih i geomehaničkih čimbenika na ROP korištenjem stijensko-inženjerske metode (engl. rock engineering system, RES), temeljem čega je predložen model predviđanja mehaničke brzine bušenja. Podatci korišteni u radu dobiveni su iz jedne bušotine s naftnoga polja Azadegan (Iran). Do sada su početno utvrđeni čimbenici koji utječu na ROP te je, korištenjem RES metode, predložen tzv. indeks ROP (ROPi). Navedeni je indeks za ranije spomenutu bušotinu izračunan za četiri različite dubine. Dobiveni rezultati upućuju na poklapanje predviđene brzine bušenja i stvarnih terenskih podataka. Također, rezultati su pokazali da na mehaničku brzinu bušenja najveći utjecaj imaju šupljikavost i jednoosna tlačna čvrstoća, dok gustoća isplake ima najmanji utjecaj. U radu je također prikazana klasifikacija indeksa ROP

Effect of metabolic syndrome and its components on survival in colorectal cancer: a prospective study.

INTRODUCTION Metabolic syndrome (MetS) may affect prognosis of the patients diagnosed with colorectal cancer (CRC). OBJECTIVES This study was aimed to design a model and to examine the prognostic effect of MetS on survival time in the patients with CRC. PATIENTS AND METHODS Data were collected from 1127 cases of CRC from Cancer Registry Center of the Research Institute of Gastroenterology and Liver Disease, Shahid Beheshti University of Medical Sciences, Tehran, Iran. In this cohort study, patients were divided into two groups based on the presence of MetS. We tested the prognostic value of MetS in the patients by Cox proportional hazard modeling. RESULTS Mean ± standard deviation of the patients' age at diagnosis in MetS group and non-MetS group was 56 ± 13 years old and 53 ± 15 years old respectively. Tumor stage as an independent variable affected CRC survival. The mean survival time of the MetS and non-MetS groups was 23 and 27 months respectively. Independent variables like tumor stage (hazard ratio [HR], 1.76; 95% CI, 0.29-0.90) and educational level (HR, 0.50; 95% CI, 0.23-0.97) had significant effect on CRC survival and MetS (HR, 0.95; 95% CI, 0.52-1.5), tumor size (HR, 1.390; 95% CI, 1.237-1.560), family history, age, gender, and smoking had non-significant effect on CRC survival. CONCLUSION MetS could be a prognostic factor for survival in the patients with CRC. The results suggested that effect of MetS was not significant