373 research outputs found

    The Effect of Sensory-Motor Training on Visual Perception Skills and Attention in 8- and 9-Year- Old Students with Slow and Normal Handwriting Speed in Hamedan

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    Introduction: The aim of this study was to evaluate the effect of sensory-motor training on visual perception skills and attention of 8- and 9-year-old students with slow and normal handwriting speed in the city of Hamedan. Materials and Methods: This study was a quasi-experimental study with a pre- and post-test design. Fourteen slow hand writers (I) and 30 normal hand writers were selected using a purposeful sampling method. Normal hand writers were randomly divided into experimental (II) and control (III) groups. The two experimental groups (I, II) participated in sensory-motor training with emphasized visual perception (16 sessions of 45 minutes) and the control group performed the normal school activities. All participants underwent the Stroop color test and Frostig Visual-Perceptual before and after the training. Results: Frostig and Stroop scores increased significantly in both training groups I and II (P<0.05). Writing speed increased in both experimental groups, but only in third grade students of group II was there a significant increase (P<0.05). Conclusion: Sensory-motor training increased visual perception and attention abilities in second- and third-grade elementary school students. Therefore, it can be concluded that increasing the ability to perceive vision and attention can affect the performance of fine skills such as writing

    Methodologies and Techniques for Determining the Value of an Aircraft

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    Aircraft valuation and the estimation of an accurate aircraft price is undoubtedly a challenging task that has significant consequences for airlines. This paper presents an asset valuation model to show how a series of endogenous as well as exogenous factors can influence the value of an aircraft. Specifically, a discounted cash flow methodology is used to forecast the valuation of an old or new generation aircraft. Both total operating revenue and aircraft operating costs are taken into account to devise a reliable pre-tax profit measurement that is used as the basis of the discounted cash flow analysis. A sensitivity analysis based on Monte Carlo simulation is utilized to identify which factors have a more significant influence on the suggested aircraft value. Therefore, it addresses how value fluctuates in response to economic fluctuations. Indeed, the calculated value of an aircraft highly depends on the underlying assumptions used. The calculated value is compared with available data in a case study for verification

    A general approach toward building integrated photovoltaic systems and its implementation barriers: A review.

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    Building integrated photovoltaic (BIPV) systems is one of the most promising technologies and has recently experienced extraordinary growth. There is a huge consensus that these advancements lead to novel methods for domestic energy generation. Technical improvements, governmental supportive laws and financial aids are some of the contributors to this development. However, the proportion of solar power production as compared to conventional electricity generation methods is still negligible and needs more dedication. In this study, a large number of previous research works have been reviewed and reasons and solutions for BIPV success or failure are discussed

    An integrated framework for freight forwarders:exploitation of dynamic information for multimodal transportation

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    Advent of real-time information broadcasting technologies, growth in demand for air-cargo, and increased congestion and variability on air-road network, are the main forces compelling today\u27s air-freight forwarders to improve their operational decision-making to be more competitive and responsive to needs of customers. This research studies the air-cargo transportation on both road (short-haul) and air (long haul) network from the perspective of a mid-size freight forwarder. We develop a routing algorithm for congestion avoidance on air-network based on historical data and introduce an innovative approach to incorporate real-time information to enable dynamic routing of cargo on a stochastic air-network. In the road network, we introduce a new class of pickup and delivery problems to carry out the customer load pickups, fleet management, cargo-to-flight assignments, and airport deliveries in a multiple airport region under alternative access airport policy. The main contributions of this research to the air-cargo literature are the study of the value of real-time information and introduction of the concept of dynamic air-cargo routing. In addition, this is the first study that provides an operational framework to implement the alternative access airport policy. This research also contributes to operations research and logistics literature by introducing a new class of pickup and deliveries with time-sensitive and pair-dependent cost structure. It also contributes an innovative algorithm based on successive subproblem solving for Lagrangian decomposed mixed integer programming that shows to be efficient in obtaining near optimal solutions in reasonable time. The performances of the algorithms presented in this research are tested through experimental and real-world case studies. The results demonstrate that dynamic routing with real-time information can dramatically improve delivery reliability and reduce expected cost on the air-network. Moreover, they confirm that alternative access airport policy can greatly enhance a forwarder\u27s options and reduce the operational and service costs while improving the service levels

    Production of protein isolate and surimi from silver carp (Hypophthalmichthys molitrix) and survey their gel and powder colorimetric and chemical parameters

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    The purpose of this study was production of fish protein isolate and surimi from silver carp (Hypophthalmichthys molitrix) and survey of color characteristics as well as chemical changes of gel and powders of those products. In this research, proteins were isolated using pH shifts method. Acidic pH (2.5 and 3.5) and basic pH (11 and 12) were used to produce fish protein isolate. Three steps of washing cycles were used for surimi production, and in the third step 0.2% NaCl was used for more dehydration. Results showed that the product efficiency for fish protein isolate was significantly more than the surimi. Furthermore, the produced fish protein isolate using acidic pH had the highest production efficiency amongst the samples. As a result, fish protein isolate had more recovery protein content compared to surimi. Determination of fat content of the samples showed that surimi contained significantly lower reduction in fat compared to fish protein isolate. Investigation and comparison of color characteristics (L, a, b) attributed to gel and powder forms of the samples demonstrated that the produced fish protein isolate using pH 2.5 had the most intense lightness (L parameter) amongst the other samples. This study clearly showed that the production efficiency of fish protein isolate was higher than surimi. In addition, due to the process of surimi production, fish protein isolate had more protein content. The higher reduction of fat content of fish protein isolate can be considered as an advantage because of possible increase in durability and safety of the products

    A comprehensive review and performance evaluation in solar (PV) systems fault classification and fault detection techniques

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    The renewable energy industry is growing faster than ever before and in particular solar systems have significantly expanded. Abnormal conditions lead to a reduction in the maximum available power from solar (photovoltaic) systems. Thus, it is necessary to identification, detection, and monitoring of various faults in the PV system that they are the key factors to increase the efficiency, reliability, and lifetime of these systems. Up to now, faults on PV components and systems have been identified; some of them have physical damage on PV systems and some of them are electrical faults that occur on the DC side or AC side of the PV system. Here, the faults will be divided into groups based on their location of occurrence. This paper provides a comprehensive review of almost all PV system faults and fault detection techniques of PV system proposed in recent literature

    Clinical utility and cost-effectiveness of bacterial 16S rRNA and targeted PCR based diagnostic testing in a UK microbiology laboratory network

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    16S ribosomal-ribonucleic acid polymerase chain reaction (PCR) and targeted PCR aid microbiological diagnosis in culture-negative clinical samples. Despite routine clinical use, there remains a paucity of data on their effectiveness across a variety of clinical sample types, and cost-effectiveness. In this 4 year multicentre retrospective observational study, all clinical samples referred for 16S PCR and/or targeted PCR from a laboratory network serving seven London hospitals were identified. Laboratory, clinical, prescribing, and economic variables were analysed. 78/607 samples were 16S PCR positive; pus samples were most frequently positive (29/84; p < 0.0001), and CSF least (8/149; p = 0.003). 210/607 samples had targeted PCR (361 targets requested across 23 organisms) with 43/361 positive; respiratory samples (13/37; p = 0.01) had the highest detection rate. Molecular diagnostics provided a supportive microbiological diagnosis for 21 patients and a new diagnosis for 58. 14/91 patients with prescribing information available and a positive PCR result had antimicrobial de-escalation. For culture-negative samples, mean cost-per-positive 16S PCR result was £568.37 and £292.84 for targeted PCR, equating to £4041.76 and £1506.03 respectively for one prescription change. 16S PCR is more expensive than targeted PCR, with both assisting in microbiological diagnosis but uncommonly enabling antimicrobial change. Rigorous referral pathways for molecular tests may result in significant fiscal savings

    An approach to microstructure modelling in nickel based superalloys

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    Mechanical properties of components made from nickel based superalloys rely on the microstructure that forms during their thermomechanical processing. The ability for predicting and controlling microstructure during the processing is of the utmost importance for this class of alloys. In this work, the applicability of JMAK-type (Johnson-Mehl-Avrami-Kolmogorov) models is studied in the context of industrial manufacturing processes. The results of FEA (finite element analysis) based predictions of microstructure evolution in ATI 718Plus® alloy during the hot deformation process are presented. The limitations of the JMAK-type approach are discussed in the paper and concepts for an alternative modelling approach for microstructure prediction in nickel based superalloys are presented
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