503 research outputs found
Optimal Correction of Infeasible System in Linear Equality via Genetic Algorithm
This work is focused on the optimal correction of infeasible system of linear equality. In this paper, for correcting this system, we will make the changes just in the coefficient matrix by using l norm and show that solving this problem is equivalent to solving a fractional quadratic problem. To solve this problem, we use the genetic algorithm. Some examples are provided to illustrate the efficiency and validity of the proposed method
A Morphometric Survey among Three Iranian Horse Breeds with Multivariate Analysis
Three Iranian horse breeds, Turkoman, Caspian, and Kurdish, are the most important Iranian horse breeds which are well known in all around of the world because of their beauty, versatility, great stamina, and  intelligence. Phenotypic characterization was used to identify and document the diversity within and between distinct breeds, based on their observable attributes. Phenotypic characterization and body biometric in 23 traits were measured in 191 purebred horses belonging to three breeds, i.e. Turkoman (70 horses), Kurdish (77 horses), and Caspian (44 horses). Caspian breed was sampled from the Provinces of Alborz and Gilan. Kurdish breed was sampled from the Provinces of Kurdistan, Kermanshah, and Hamadan. Turkoman breed was sampled from the Provinces of Golestan, Markazi, and Isfahan. Multivariate analysis of variance (MANOVA) was implemented. In addition, Canonical Discriminate Analysis (CDA), Principal Component Analysis (PCA), and Custer analysis were executed for assessing the relationship among the breeds. All statistical analysis was executed by SAS statistical program. The results of our investigation represented the breeds classification into 3 different classes (Caspian, Turkoman, and Kurdish) based on different morphometrical traits. Caspian breed with smaller size in most variables was detached clearly from the others with more distance than Kurdish and Turkoman breeds. The result showed that the most variably trait for classification was Hind Hoof Length. Adaptation with different environments causes difference in morphology and difference among breeds. We can identify and classify domestic population using PCA, CDA, and cluster analysis
Supervised and non-supervised AE data classification of nanomodified CFRP during DCB tests
Aim of the paper is to use acoustic emissions to study the effect of electrospun nylon 6,6 Nanofibrous mat on carbon-epoxy composites during Double Cantilever beam (DCB) tests. In order to recognize the effect of the nanofibres and to detect different damage mechanisms, k-means clustering of acoustic emission signals applied to rise time, count, energy, duration and amplitude of the events is used. Supervised neural network (NN) is then applied to verify clustered signals. Results showed that clustered acoustic emission signals are a reliable tool to detect different damage mechanisms; neural network showed the method has a 99% of accuracy
Confusion at the beginning of sexual intercourse, the challenge of patients after coronary artery bypass graft surgery in Iran: A qualitative study.
BackgroundMany patients suffer from sexual dysfunction after coronary artery bypass graft surgery, but they refuse to propose and follow up on the problem due to the cultural structures prevailing in Iranian society. Untreated sexual dysfunction will disturb the quality of life of these patients. This study was performed to explain the experiences of male patients from sexual problems after coronary artery bypass graft surgery.Materials and methodsThis qualitative study was performed with the approach of conventional content analysis in Tehran in 2020. The data were collected through semi-structured interviews with 12 men after coronary artery bypass graft surgery at the hospital's cardiac surgery clinic, as well as the surgeon's clinic. Participants were selected by the targeted sampling method. After obtaining informed consent, the collected data were written word by word, and the content analysis approach was used to name the data, create analytical codes, and determine subcategories and categories. The data were analyzed by MAXQDA 10 software.ResultsThe findings of this study show that the dimensions of confusion in patients' sexual intercourse after coronary artery bypass graft surgery in four subcategories of challenges of the first intercourse after surgery, ambiguity in how to obtain information, the ambiguity of sexual issues after surgery, and spouse are concerned about having sexual intercourse.ConclusionThe results of this study show that male patients who have undergone coronary artery bypass graft surgery have many ambiguities in the process of sexual intercourse, which passes the beginning of sexual intercourse with fear and avoidance of intercourse. Postoperative patients do not propose these problems with the medical staff when they suffer from sexual dysfunction or ambiguity due to the taboo of talking about sexual intercourse. Eventually, the patient and his or her partner become confused about sexual intercourse after surgery. Therefore, it is recommended that policymakers in the field of health create the culture and planning for solving the ambiguities created in the path of sexual intercourse of these patients
Psychological Violence in the Health Care Settings in Iran: A Cross-Sectional Study
Background: Psychological violence is the most common form of workplace violence that can affect professional performance and job satisfaction of health care workers. Although several studies have been conducted in Iran, but there is no consensus regarding current status of such violence.
Objectives: This study aimed to investigate the prevalence of psychological violence among healthcare workers employed at teaching hospitals in Iran.
Patients and Methods: In this cross-sectional study, 5874 health professionals were selected using multistage random sampling. Data were collected using a self-administered questionnaire developed by the International Labor Organization, International Council of Nurses, World Health Organization, and Public Services International. Descriptive statistics were used to analyze the data.
Results: It was found that 74.7% of the participants were subjected to psychological violence during the past 12 months. Totally, 64.5% of psychological violence was committed by patients’ families, but 50.9% of participants had not reported the violence, and 69.9% of them believed that reporting was useless.
Conclusions: The results are indicative of high prevalence of psychological violence against healthcare workers. Considering non-reporting of violence in more than half of participants, use of an appropriate reporting system and providing training programs for health professionals in order to prevent and manage workplace violence are essential
Influence of Connector Width on the Stress Distribution of Posterior Bridges under Loading
Objective: In all ceramic fixed partial dentures the connector area is a common fracture location. The survival time of three-unit fixed partial dentures may be improved by altering the connector design in regions of maximum tension. The purpose of this study was to determine the effect of buccolingual increase of the connector width on the stress distribution in posterior fixed partial dentures made of IPS Empress 2. To simulate the anatomical condition, we used three-dimensional finite element analysis to generate.Materials and Methods: Three models of three-unit bridges replacing the first molar were prepared. The buccolingual connector width varied from 3.0 to 5.0 mm. Bridges were vertically loaded with 600 N at one point on the central fossa of the pontic, at 12 points along the cusp-fossa contact (50 N each), or at eight points along the cusp-marginal ridge contact (75 N each). Alternatively, a load of 225 N was applied at a 45Âş angle from the lingual side.Results: Stress concentrations were observed within or near the connectors. The von Mises stress decreased by increasing connector width, regardless of whether the loading was applied vertically or at an angle.Conclusion: Within the limitations of this study, we conclude that increasing the connector width decreases the failure probability when a vertical or angled load is applied
Urban Horticulture, from Local Initiatives to Global Success Stories
Urban horticulture describes economically viable horticultural production activities conducted in a city or suburb. It is a growing segment of horticulture in the United States as well as in developing countries, where the enormous growth of megalopolis is not backed by a simultaneous increase of farmland or agricultural productivity. Today, urban horticulture includes food sovereignty in underprivileged neighborhoods, increased availability of vegetables and fruits in big cities, healthy and diverse diets, improved food safety, low transportation costs, efficient resource use, and the mitigation of environmental impacts of horticultural production such as the emission of greenhouse gases. The workshop “Urban horticulture: From local initiatives to global success stories,” held at the 2018 American Society for Horticultural Science (ASHS) conference in Washington, DC, featured present and historical success stories of urban horticulture from Asia, Africa, Latin America, and the United States
Full Stokes imaging polarimetry using dielectric metasurfaces
Polarization is a degree of freedom of light carrying important information
that is usually absent in intensity and spectral content. Imaging polarimetry
is the process of determining the polarization state of light, either partially
or fully, over an extended scene. It has found several applications in various
fields, from remote sensing to biology. Among different devices for imaging
polarimetry, division of focal plane polarization cameras (DoFP-PCs) are more
compact, less complicated, and less expensive. In general, DoFP-PCs are based
on an array of polarization filters in the focal plane. Here we demonstrate a
new principle and design for DoFP-PCs based on dielectric metasurfaces with the
ability to control polarization and phase. Instead of polarization filtering,
the method is based on splitting and focusing light in three different
polarization bases. Therefore, it enables full-Stokes characterization of the
state of polarization, and overcomes the 50% theoretical efficiency limit of
the polarization-filter-based DoFP-PCs.Comment: 20 pages, 4 figure
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