44 research outputs found

    RPCA-KFE: Key Frame Extraction for Consumer Video based Robust Principal Component Analysis

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    Key frame extraction algorithms consider the problem of selecting a subset of the most informative frames from a video to summarize its content.Comment: This paper has been withdrawn by the author due to a crucial sign error in equation

    Fuzzy AHP Method for Selection of a Suitable Seismic Retrofitting Alternative in Low-Rise Buildings

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    Decision making for selecting an appropriate alternative among nominated alternatives is still a problem among retrofit designers. It is clear that selected alternative should comply the current codes in terms of structural criteria, but the other criteria may not be considered. The main goal of this study is to introduce a suitable method for making a decision in order to find the best alternative considering the effective criteria in retrofitting of low-rise buildings. Analytic Hierarchy Process (AHP), as a technique of Multi-Criteria Decision Making (MCDM), is compatible to solve the problem. Effective criteria have been categorized to structural, operational, economic and functional criteria and sixteen sub-criteria considered as a pattern that satisfies the entire involved group including structural and architectural engineers, contractor, client, and authorities in retrofitting of low-rise buildings. Since most of the involved criteria such as aesthetic, durability, and compatibility have fuzzy nature and cannot be compared numerically, fuzzy AHP can be a compatible method for comparison different retrofitting alternatives among both fuzzy and non-fuzzy criteria. A matrix of pair-wise comparison (MPC) is used for determining the weight of criteria and also for scoring the alternatives respect to each criterion. A Fuzzy Importance scale with Triangular Fuzzy Numbers (TFN) is applied for comparing the criteria. The method is examined by a case study and the results show the used method can help designers for selecting the appropriate alternative

    Finite Element Analysis of Load Bearing Capacity of a Reinforced Concrete Frame Subjected to Cyclic Loading

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    Many methods have been developed in order to study the impact behavior of solids and structures. Two common methods are finite element and experimental method. The nonlinear finite element method is one the most effective methods of predicting the behavior of RC beams from zero-load to failure and its fracture, yield and ultimate strengths. The advantage of this method is its ability to make this prediction for all sections of the assessed RC beam and all stages of loading. This paper compares the experimental results obtained for a RC frame with the numerical results calculated by ABAQUS software, and plots both sets of results as hysteresis–displacement diagrams. This comparison shows that the numerical FEM implemented via ABAQUS software produce valid and reliable results for load bearing capacity of RC frames subjected to cyclic loads, and therefore has significant cost and time efficiency advantages over the alternative approac

    Adaptive response of slow and fast skeletal muscle following mechanical hindlimb suspension in Wistar male rats

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    Mechanical hindlimb suspension of lower extremities leads to prompt atrophy in rats' skeletal muscles. The present research was designed to study cross-section area (CSA) and the expression level of the genes ATF4, P53, MST1, and atrogin-1 in slow and fast skeletal muscles following mechanical hindlimb suspension. 20 male Wistar rats were assigned randomly in to two groups: control (Con) and hind-limb suspension (HU) (10 rats per each group). In HU group, tail suspension was designed for 14 constitutive days; however, animals in the control group passed a normal life.  The findings indicated that hind-limb suspension could relatively diminish CSA, myonuclei number per fiber and the weight of both soleus and EDL muscles. However, these reductions were not significant for EDL muscle. Furthermore, the expression level of the MST1, atrogin-1, ATF4, and p53 in soleus muscles elevated significantly. Moreover, the expression level of all four genes increased significantly in EDL muscle. Comparison of genes expression level between two soleus and EDL muscles showed that expression of MST1, ATF4, and p53 genes were higher in soleus than EDL, but it was not the case for atrogin-1 as its expression level was more in EDL compared to soleus. Our study provides novel evidence that immobilization of hind-limbs can induce a more powerful atrophic response in slow muscles in comparison to fast ones

    Investigation of Water Quality of Urban Rivers and Assessing their Suitability to Protect the Environment (Case Study: Kan River, Tehran City)

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    The Kan River is the largest and most important river that enters the Tehran plain. The river water quality (in Tehran city), is affected by agricultural and industrial activities and population spots. The aim of this study was to investigate the quality of the Kan River using Iran Water Quality Index for Surface Water to protect the environment. For selecting sampling stations, the study area was divided into eight longitudinal ranges, and sampling was done in two periods of minimum and maximum flow. Kan River is of poor to relatively bad quality. The pH was at standard level but some parameters such as BOD in 2 stations (minimum flow‌‌ rate) and 9 stations (maximum flow rate), TSS in 4 stations (minimum flow rate) and 5 stations (maximum flow rate), DO in all samples except station S1(minimum flow rate) and coliform in all samples were more than permissible level of the national standard for river water quality. Entering industrial, municipal, and agricultural wastewater is the most important reason for the decrease in water quality. In terms of the standard classification base of the Iran Department of Environment for Protection of aquatic life, class 2 (suitable for Cyprinid (is recommended

    OpenSRANE, a Flexible and Extensible Platform for Quantitative Risk Assessment of NaTech Events

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    The effects of natural hazards triggering technological disaster (NaTech) on a society, economy and the environment is a multi-disciplinary research topic. The novelty of the issue and the lack of a standard procedure for risk assessment of this category of incidents show the need for more research in this area. This article introduces OpenSRANE as an open-source, extensible, flexible and object-oriented software for calculating the quantitative risk of NaTech events in process plants. Implementing the software in the Python programming environment provides high flexibility for the modeling and evaluations desired by users. The possibility of implementing the modifications and developments to the existing software as needed by users allows them to add their desired algorithms, elements and models to it, if needed. The software is based on the Monte Carlo method, but it is possible to implement other algorithms and approaches to it. Object-oriented programming and separation of the different parts of the software can increase the readability of the program, allowing researchers in different disciplines to focus easily on studying or developing the desired part with minimal interference from other parts. The applicability of the software has been demonstrated in a case study as well as the ability of the software to calculate results such as the individual risk, scenarios that consider domino effects and physical effects

    Study of the seismic performance of steel frames in the elliptic bracing

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    This article appraises the seismic performance of a new braced steel structural system called elliptic braced moment resisting frame (ELBRF). Apart from improving the behavior of a structure, ELBRF is found non-problematic for the bracing system in a given architectural space. In this study, a single cycle time has been used for evaluating the proposed ELBRF. Here, methods of seismic design of structures as well as effective parameters in the seismic design of steel braced including ductility factor, overstrength coefficient and behavior factors, which were obtained by using capacity curves, have been presented through an adaptive pushover analysis (APA). Result of the nonlinear analysis showed that the strength and capacity of energy dissipation in the elliptic bracing system (ELBRF) is more than the system of special moment resisting frames (SMRF), coaxial braced frame (CBF) X-Braced, Inverted-V Braced CBF. Likewise, the permitted relative displacement, where the braced frame reaches to step buckling, is more in ELBRF

    Results of Nasolacrimal Duct Probing in Children between 9-48 Months

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    Congenital nasolacrimal duct obstruction (CNLDO) is a common disease in children. The classic treatment of CNLDO is probing that was done around one year old. However, controversy exists regarding the outcome of probing in children older than one year. This study aimed to find the cure rate of initial probing for CNLDO and identify factors producing the failure rate in old age. In this retrospective interventional case series study, 100 eyes of 92 patients aged 9-48 months with CNLDO underwent probing with general anesthesia. According to the intraoperative results of probing, CNLDO were categorized in two groups of membranous obstruction at the end of nasolacrimal duct obstruction (NLD) and complex obstruction at canaliculus, lacrimal sac and N LD. Patients were categorized in three groups according to the age of probing into under 12, 12 to 24 and over 24 months. Success rate was defined as successful irrigation of NLD intraoperatively and absence of lacrimation and discharge at 1 week, one, three and six months postoperatively. The average age of patients and probing were 47.35±25.59 and 17.32±7.85 months respectively. Membranous obstruction accounted for 72% of patients and remainder had complex type. An overall cure rate of 91%, 89% and 60% was found in patients aged 9-12, 12-24 and 24-48 months respectively. Surgery success rate after six months was 91% in membranous group and 52% in complex group. There was a significant relation between the type of obstruction and opening of NLD (p<0.O01). This study showed that the probing failure of probing after one year was related to the complexity of obstruction rather than the age of the patient. It is recommended that probing could safely be done in under 4 years old
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