A simulation study of semiparametric estimation in copula models based on minimum Alpha-Divergence

The purpose of this paper is to introduce two semiparametric methods for the estimation of copula parameter. These methods are based on minimum Alpha-Divergence between a non-parametric estimation of copula density using local likelihood probit transformation method and a true copula density function. A Monte Carlo study is performed to measure the performance of these methods based on Hellinger distance and Neyman divergence as special cases of Alpha-Divergence. Simulation results are compared to the Maximum Pseudo-Likelihood (MPL) estimation as a conventional estimation method in well-known bivariate copula models. These results show that the proposed method based on Minimum Pseudo Hellinger Distance estimation has a good performance in small sample size and weak dependency situations. The parameter estimation methods are applied to a real data set in Hydrology.Comment: 14 page

Modeling, identification and active vibration control of a funnel-shaped structure used in MRI throat

The purpose of this paper is designing an optimal controller for vibration suppression of a funnel-shaped smart structure with distributed piezoelectric actuators and sensors applicable in Magnetic Resonance Imaging (MRI) system. This can help sensitive human beings from vibration and acoustic noise syndrome. Also, the vibration suppression in this structure prevents the test results to be damaged, which is an important issue in medical tests. For this aim, the problem of the vibration control for the funnel-shaped inlet structure of the MRI tomography is stated and the structure is described, first. Then the task of the structure modeling is tackled applying the FEM approach. Identification of the dynamic frequency response of the desired funnel is performed using the modal-based identification method and the state space model is obtained. Then, the control design for the structure is considered using LQG control method. Complete design and control development procedure is implemented in order to reduce the vibration magnitude of a funnel-shaped shell. Finally, the performance of the designed controllers in both frequency domain and time domain are compared with the open loop systems and results are discussed

Mn oxide as a kinetically dominant “true” catalyst for water oxidation

Nature uses an Mn cluster for water oxidation, and thus, water oxidation using Mn clusters is interesting when used in artificial water-splitting systems. An important question is whether an Mn cluster is a true catalyst for water oxidation or not. Herein, an Mn–K cluster was investigated for electrochemical water oxidation to find the true and the kinetically dominant catalyst using X-ray absorption spectroscopy, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and electrochemical methods. The experiments showed that conversion into nanosized Mn oxide occurred for the cluster, and the nanosized Mn oxides are the true catalyst for water oxidation

4D printing technology in medical engineering: a narrative review

The addition of the time dimension to three-dimensional (3D) printing has introduced four-dimensional (4D) printing technology, which has gained considerable attention in different fields such as medical, art, and engineering. Nowadays, bioscience has introduced some ideas which can be fulfilled by 4D printing. Blending time with variations caused by the situation has many beneficial aspects such as perceptibility and adaptability. Since 4D printing can create a dynamic structure with stimuli-responsive materials, the applications of smart materials, stimulus, and 3D printing are the effective criteria in 4D printing technology. Smart materials with their flexible properties can reshape, recolor, or change function under the effect of the internal or exterior stimuli. Thus, an attractive prospect in the medical field is the integration of the 4D printing approach along with smart materials. This research aims to show the most recent applications of 4D printing technology and smart materials in medical engineering which can show better prospective of 4D printing applications in the future. Also, it describes smart medical implants, tissue engineering, and bioprinting and how they are being used for the 4D printing approach in medical engineering applications. In this regard, a particular emphasis is dedicated to the latest progress in the innovation and development of stimuli-responsive materials that are activated and respond over time to physical, chemical, and biological stimuli and their exploitation through 3D printing methods to fabrication 4D printing smart parts such as intelligent tissue-engineered scaffolds, smart orthopedic implants, and targeted drug delivery systems. On the other hand, major challenges in this technology are explained along with some suggestions for future works to address existing limitations. It is worth noting that despite significant research that has been carried out into 4D printing, it might be more valuable if some investigation is done into 4D bio-printing applications and how this approach will be developed

Study of Translating Semantic Oppositions of Hafez's Poems in Translation of Ali Abbas Zoleikhe

The language of Hafez's poetry is very delicate and mysterious. In his sonnets (Qazals), the words have been accurately selected with great aesthetic taste. In such a way, all the words are somehow connected and intertwined with each other. One of the linguistic features of Hafez is the collocation of oppositions together. Oppositions used in Hafez's poems not only have explicit and implicit semantic connections but also are related to other words. Therefore, understanding the conceptual relationship of words, and in particular, oppositions, plays a great role in discovering the meaning and the elegance of Hafez's poetry. Hence, in this study, an attempt has been made to select examples of "gradable, complementary, symmetrical, directional, lexical, and implicit” oppositions in Hafez's sonnets. Also, the conceptual relationship with other words of the verse will be analyzed and its semantic and aesthetic function will be explained. Subsequently, Ali Abbas Zoleikhe's translation of semantic oppositions and their functions will be discussed and criticized. The results of the research indicate that the oppositions in question, especially implicit oppositions, have created many clear and hidden rhetorical meanings in poetry and the slightest change in the oppositions and balance of words leads to the reduction of coherence and meaning of the verse

Investigation of Iranian pomegranate cultivars for wound healing components

One of the most important issues which medical science has been facing is wound healing for the tissue repair with the least complications. In this study, we aimed to isolate, purify and quantitate tannins and phenolic compounds from exocarp and pulp of fruits of Iranian pomegranate cultivars. Our findings demonstrate that the highest amount of tannin extracts from ethanol extract of the black peel exocarp was 201.76 ± 1.93. The highest amount of flavonoids from the ethanol extract of Sweet Alac exocarp was119.69 ± 1.02 as well as antioxidant compounds activity in the exocarp and pulp showed that the highest activity is in the ethanol extract of the black peel was 95.65 ± 3.1. The total phenolic activity indicated that the Sour white peel ethanol extract has the highest phenolic activity 327.05 ± 863. Our data suggest that the ethanol extract of pomegranate exocarp has the higher amounts of tannins and flavonoids, compounds that are known to be beneficial for wound healing. Taken together, these data suggest that compounds isolated from Iranian pomegranate cultivars offer new options for managements of wound healing

Investigating the effects of cow manure, vermicompost and Azolla fertilizers on hydraulic properties of saline-sodic soils

Purpose Soil salinity and sodicity are among the factors involved in soil degradation, especially in arid and semi-arid areas of the world. The use of modifiers, including organic matters, can be considered as an appropriate strategy to improve the fertility of saline-sodic soils.  Method In this study, saline-sodic control soil was collected from Karaj and mixed with three levels of 1%, 3% and 5% of cow manure, vermicompost and Azolla. The soil columns were then incubated at 20 °C and field capacity moisture for 5 months. The physical and chemical properties of the treatments were evaluated before and after incubation. Results After the incubation period, the lowest salinity level was observed in 5% Azolla and vermicompost treatments. The highest amount of change in sodium absorption ratio was related to 5% cow manure treatment. There was an insignificant difference in moisture levels in a given suction among the different treatments. After the incubation period, salinity and sodium absorption decreased and increased in most of the treatments, respectively. Moreover, the decrease of saturation dehydration coefficient in the treatments revealed the disruption of soil structure and conversion of large pores to fine grains as a result of adding the mentioned organic matters. Conclusion According to the results, cow manure at 1% level had no significant effect on soil properties. However, at higher levels, it had a negative effect on quality and conditions of the saline-sodic soil in terms of physical and chemical properties. In contrast, Azolla and vermicompost fertilizers at 5% proved to be suitable for correcting the saline-sodic soil