A New MCMC Sampling Based Segment Model for Radar Target Recognition

One of the main tools in radar target recognition is high resolution range profile (HRRP)‎. ‎However‎, ‎it is very sensitive to the aspect angle‎. ‎One solution to this problem is to assume the consecutive samples of HRRP identically independently distributed (IID) in small frames of aspect angles‎, ‎an assumption which is not true in reality‎. ‎However, b‎‎ased on this assumption‎, ‎some models have been developed to characterize the sequential information contained in the multi-aspect radar echoes‎. ‎Therefore‎, ‎they only consider the short dependency between consecutive samples‎. ‎Here‎, ‎we propose an alternative model‎, ‎the segment model‎, ‎to address the shortcomings of these assumptions‎. ‎In addition‎, ‎using a Markov chain Monte-Carlo (MCMC) based Gibbs sampler as an iterative approach to estimate the parameters of the segment model‎, ‎we will show that the proposed method is able to estimate the parameters with quite satisfying accuracy and computational load‎

Polypill for prevention of cardiovascular disease in an Urban Iranian population with special focus on nonalcoholic steatohepatitis: A pragmatic randomized controlled trial within a cohort (PolyIran - Liver) – Study protocol

Background: Cardiovascular disease (CVD) is among the most common causes of mortality in all populations. Nonalcoholic steatohepatitis is a common finding in patients with CVD. Prevention of CVD in individual patients typically requires periodic clinical evaluation, as well as diagnosis and management of risk factors such as hypertension and hyperlipidemia. However, this is resource consuming and hard to implement, especially in developing countries. We designed a study to investigate the effects of a simpler strategy: a fixed-dose combination pill consisting of aspirin, valsartan, atorvastatin and hydrochlorthiazide (PolyPill) in an unselected group of persons aged over 50 years. Design: The PolyIran-Liver study was performed in Gonbad city as an open label pragmatic randomized controlled trial nested within the Golestan Cohort Study. We randomly selected 2,400 cohort study participants aged above 50 years, randomly assigned them to intervention or usual care and invited them to participate in an additional measurement study (if they met the eligibility criteria) to measure liver related outcomes. Those agreeing and randomized to the intervention arm were offered a daily single dose of PolyPill. We will follow participants for 5 years. The primary outcome is major cardiovascular events, secondary outcomes include all-cause mortality and liver related outcomes: liver stiffness and liver enzyme levels. Cardiovascular outcomes and mortality will be determined from the cohort study and liver-related outcomes in those consenting to follow up. Analysis will be by allocated group. Trial Status: Between October and December 2011, 1,320 intervention and 1,080 control participants were invited to participate in the additional measurement study. For all these participants, the major cardiovascular events will be determined using blind assessment of outcomes through the cohort study. In the intervention and control arms, 875 (66%) and 721 (67%) respectively, met the eligibility criteria and agreed to participate in the additional measurement study. Liver related outcomes will be measured in these participants. Of the 1,320 participants randomized to the intervention, 787 (60%) accepted the PolyPill. Conclusion: The PolyIran-liver urban study will provide us with important information on the effectiveness of PolyPill on major cardiovascular events, all-cause mortality and liver related outcomes. (ClinicalTrials.gov ID: NCT01245608). © 2015, Academy of Medical Sciences of I.R. Iran. All rights reserved

Motion Planning from Demonstrations and Polynomial Optimization for Visual Servoing Applications

Vision feedback control techniques are desirable for a wide range of robotics applications due to their robustness to image noise and modeling errors. However in the case of a robot-mounted camera, they encounter difficulties when the camera traverses large displacements. This scenario necessitates continuous visual target feedback during the robot motion, while simultaneously considering the robot's self- and external-constraints. Herein, we propose to combine workspace (Cartesian space) path-planning with robot teach-by-demonstration to address the visibility constraint, joint limits and “whole arm” collision avoidance for vision-based control of a robot manipulator. User demonstration data generates safe regions for robot motion with respect to joint limits and potential “whole arm” collisions. Our algorithm uses these safe regions to generate new feasible trajectories under a visibility constraint that achieves the desired view of the target (e.g., a pre-grasping location) in new, undemonstrated locations. Experiments with a 7-DOF articulated arm validate the proposed method.published_or_final_versio

The prevalence of hepatitis B surface antigen and anti-hepatitis B core antibody in Iran: A population-based study

Background: Hepatitis B virus infection is a very common cause of chronic liver disease worldwide. It is estimated that 3 of Iranians are chronically infected with hepatitis B virus. Current population-based studies on both rural and urban prevalence of hepatitis B virus infection in Iran are sparse with results that do not always agree. We performed this study to find the prevalence of hepatitis B surface antigen, anti-hepatitis B core antibody, and associated factors in the general population of three provinces of Iran. Methods: We randomly selected 6,583 subjects from three provinces in Iran, namely Tehran, Golestan, and Hormozgan. The subjects were aged between 18 and 65 years. Serum samples were tested for hepatitis B surface antigen and anti-hepatitis B core antibody. Various risk factors were recorded and multivariate analysis was performed. Results: The prevalence of hepatitis B surface antigen and anti-hepatitis B core antibody in Iran was 2.6 and 16.4, respectively. Predictors of hepatitis B surface antigen or anti-hepatitis B core antibody in multivariate analysis included older age, not having high-school diploma, living in a rural area, and liver disease in a family member. We did not find any significant differences between males and females. Conclusion: In spite of nationwide vaccination of newborns against hepatitis B virus since 1992, hepatitis B virus infection remains a very common cause of chronic liver disease in Iran which should be dealt with for at least the next 30-50 years

Three essays on institutions, religion, and economic development

This dissertation consists of three essays that provide empirical evidence on the importance of institutions, informal institutions and particularly religion in economic development. In the first chapter, the relationship between religious adherence rate in the U.S. counties and entrepreneurship is examined. After controlling for spatial dependencies, results indicate that more religious counties, meaning counties with higher rate of religious membership, have lower entrepreneurial potentials. Chapter 2 investigates the relevance of institutional quality in efficiency of public spending. This study is delivered in the state level. By using a nonparametric method, efficiency of public spending is calculated and then its relationship with some indicators of institutional quality is tested. It is shown that states with better judicial system and less restrictive labor market present more effective public spending. In the last chapter the role of state religiosity in the political and societal conflict is studied. The hypothesis states that if a country has a religious government, the chance and magnitude of having a domestic conflict due to religious heterogeneity would increase. After controlling for several covariates, there is not enough evidence found to reject the null hypothesis. Therefore religious heterogeneity in countries with religious state seems to be associated with larger magnitude of conflict

Enhancement of the properties of polymer blends by hydrogen bonding and transesterification

The importance of polymer rigidity on the extent of intermolecular hydrogen bonding in the blends of copolymers of 4-vinylphenol and styrene (PS-co-PVPh) and polyethers has been studied utilizing FT-IR spectroscopy. A series of polyethers containing mesogens with different rigidity including a liquid crystalline poly ether (LCP) are synthesized using phase transfer polyesterification and blended with PS-co-PVPh. The extent of intermolecular hydrogen bonding between the hydroxyl group ofPS-co-PVPh and the ethereal oxygen is correlated to the rigidity of polyethers. The results of this study indicate that extent of intermolecular hydrogen bonding in blends increases as the flexibility of polyethers increases, causing a shift in the frequency of the hydrogen bonded hydroxyl band towards lower frequency. The rigidity of the polyethers inhibits the formation of intermolecular hydrogen bonds, however this effect is not dramatic. It must be recognized that the LCP utilized in this study can not be considered as a rod-like LCP, as it contains flexible aliphatic spacers. Therefore, the result shows that the rigidity of LCP does not dramatically affect the formation of intermolecular hydrogen bonds is only applicable to non-rodlike LCP. The data also show that a lower concentration of the polyether in the blends induces better mixing and higher extent of intermolecular hydrogen bonding due to better dispersion of polyether in PS-co-PVPh. This suggests that a one-phase system may exist in the region of the phase diagram of the blends that are rich in PS-co-PVPh. The result also shows that the extent of intermolecular hydrogen bonding between PSco-PVPh and polyethers decreases at the higher temperatures. The concept of functional group accessibility of hydroxyl groups for intermolecular hydrogen bonding is also examined in these blends. The amount of intermolecular hydrogen bonds increases with an increase in spacing between the hydroxyl groups. The transesterification Reaction between poly(carbonate) (PC) and thermoplastic liquid crystalline poly (hydroxy benzoate)-poly(ethylene terephthalate) (PHB-PET) and its consequences on the blend morphology and mechanical properties of the blend has also been investigated. The transesterification reaction between PC and PHB-PET upon annealing at 260 °C is characterized and quantified by 13C NMR spectroscopy, showing peaks at 120.9 ppm, 148.3 ppm, and 165.9 ppm corresponding to bisphenol-A terephthalate and bisphenol-A oxybenzoate diads, respectively. These peaks are the result of the initial formation of block copolymer and eventual formation of random copolymer at the interface as the mole fraction of corresponding diads increases. Polarized optical microscopy and tensile measurements reveal that there is a direct correlation between the loss of liquid crystallinity character and mechanical properties of the blend to the extent of transesterification reaction. The results of this study indicate a trade-off between the loss of liquid crystallinity of the blend and its strength resulting from transesterification upon annealing

Artificial Intelligence Approach for Seismic Control of Structures

Abstract In the first part of this research, the utilization of tuned mass dampers in the vibration control of tall buildings during earthquake excitations is studied. The main issues such as optimizing the parameters of the dampers and studying the effects of frequency content of the target earthquakes are addressed. Abstract The non-dominated sorting genetic algorithm method is improved by upgrading generic operators, and is utilized to develop a framework for determining the optimum placement and parameters of dampers in tall buildings. A case study is presented in which the optimal placement and properties of dampers are determined for a model of a tall building under different earthquake excitations through computer simulations. Abstract In the second part, a novel framework for the brain learning-based intelligent seismic control of smart structures is developed. In this approach, a deep neural network learns how to improve structural responses during earthquake excitations using feedback control. Abstract Reinforcement learning method is improved and utilized to develop a framework for training the deep neural network as an intelligent controller. The efficiency of the developed framework is examined through two case studies including a single-degree-of-freedom system and a high-rise building under different earthquake excitation records. Abstract The results show that the controller gradually develops an optimum control policy to reduce the vibrations of a structure under an earthquake excitation through a cyclical process of actions and observations. Abstract It is shown that the controller efficiently improves the structural responses under new earthquake excitations for which it was not trained. Moreover, it is shown that the controller has a stable performance under uncertainties

Developing a Phenomenographic Argument for The Exit-Level Prospective Teachers’ Conceptions About Teaching and Learning

This study presents a phenomenographic argument regarding Turkish prospective teachers’ (PTs) beliefs about teaching and learning varying according to their experience. A phenomenographic research study was conducted in order to capture and interpret the PTs’ explanations and documentation regarding the conceptions of instruction. The participants were 54 senior pre-service student teachers. Qualitative data was gathered through phenomenographic interviewing. The data was analysed interpretatively, and categories of description were derived to establish an outcome space for supporting the phenomenographic argument. The outcome space incorporates three hierarchical levels of the PTs’ conceptions of teaching and learning: subject-centred teaching, individual-centred learning, and learner-centred teaching-learning. It was revealed that the PTs held considerably conventional, idealistic teaching and learning conceptions. Moreover, there was a sharp distinction between the individual-centred and learner-centred conceptions of the participant PTs. Concrete recommendations for teacher preparation are offered to enhance the PTs’ shallow conceptions of teaching and learning.

Artificial Intelligence Approach for Seismic Control of Structures

Abstract In the first part of this research, the utilization of tuned mass dampers in the vibration control of tall buildings during earthquake excitations is studied. The main issues such as optimizing the parameters of the dampers and studying the effects of frequency content of the target earthquakes are addressed. Abstract The non-dominated sorting genetic algorithm method is improved by upgrading generic operators, and is utilized to develop a framework for determining the optimum placement and parameters of dampers in tall buildings. A case study is presented in which the optimal placement and properties of dampers are determined for a model of a tall building under different earthquake excitations through computer simulations. Abstract In the second part, a novel framework for the brain learning-based intelligent seismic control of smart structures is developed. In this approach, a deep neural network learns how to improve structural responses during earthquake excitations using feedback control. Abstract Reinforcement learning method is improved and utilized to develop a framework for training the deep neural network as an intelligent controller. The efficiency of the developed framework is examined through two case studies including a single-degree-of-freedom system and a high-rise building under different earthquake excitation records. Abstract The results show that the controller gradually develops an optimum control policy to reduce the vibrations of a structure under an earthquake excitation through a cyclical process of actions and observations. Abstract It is shown that the controller efficiently improves the structural responses under new earthquake excitations for which it was not trained. Moreover, it is shown that the controller has a stable performance under uncertainties

Geochemistry of rare earth elements in the Baba Ali magnetite skarn deposit, western Iran – a key to determine conditions of mineralisation

The Baba Ali skarn deposit, situated 39 km to the northwest of Hamadan (Iran), is the result of a syenitic pluton that intruded and metamorphosed the diorite host rock. Rare earth element (REE) values in the quartz syenite and diorite range between 35.4 and 560 ppm. Although the distribution pattern of REEs is more and less flat and smooth, light REEs (LREEs) in general show higher concentrations than heavy REEs (HREEs) in different lithounits. The skarn zone reveals the highest REE-enriched pattern, while the ore zone shows the maximum depletion pattern. A comparison of the concentration variations of LREEs (La–Nd), middle REEs (MREEs; Sm–Ho) and HREEs (Er–Lu) of the ore zone samples to the other zones elucidates two important points for the distribution of REEs: 1) the distribution patterns of LREEs and MREEs show a distinct depletion in the ore zone while representing a great enrichment in the skarn facies neighbouring the ore body border and decreasing towards the altered diorite host rock; 2) HREEs show the same pattern, but in the exoskarn do not reveal any distinct increase as observed for LREEs and MREEs. The ratio of La/Y in the Baba Ali skarn ranges from 0.37 to 2.89. The ore zone has the highest La/Y ratio. In this regard the skarn zones exhibit two distinctive portions: 1) one that has La/Y >1 beingadjacent to the ore body and; 2) another one with La/Y < 1 neighbouring altered diorite. Accordingly, the Baba Ali profile, from the quartz syenite to the middle part of the exoskarn, demonstrates chiefly alkaline conditions of formation, with a gradual change to acidic towards the altered diorite host rocks. Utilising three parameters, Ce/Ce*, Eu/Eu* and (Pr/Yb)n, in different minerals implies that the hydrothermal fluids responsible for epidote and garnet were mostly of magmatic origin and for magnetite, actinolite and phlogopite these were of magmatic origin with low REE concentration or meteoric water involved