Real Size Research Articles

Analysis of the population structure of a gorgonian forest (Placogorgia sp.) using a photogrammetric 3D modeling approach at Le Danois Bank, Cantabrian Sea

The presence of gorgonian forests and deep-sea sponge aggregations in the Le Danois Bank promoted its declaration as the “El Cachucho” Marine Protected Area (MPA) by the Spanish Ministry of Environment, and its inclusion in the Natura 2000 network. Both habitats are considered vulnerable, so follow-up surveys are being performed to monitor their conservation in compliance with the EU Habitats Directive. The use of a non-invasive methodology, which does not cause damage or alterations on benthic communities, is particularly necessary in vulnerable ecosystem studies and MPA monitoring.This study analyzed the assemblage structure of a Placogorgia sp. population using a 3D photogrammetry-based method. The study was carried out through the analysis of the video transects obtained at the Le Danois Bank, using the Politolana underwater towed vehicle during the July 2017 ECOMARG survey. Recent developments in specific software of photogrammetric image analysis allowed extracting valuable information from these video transects. Using the Pix4D Mapper Pro software, 3D point clouds were obtained, and the size and morphometry of yellow fan-shaped gorgonian population structure could be evaluated. Due to gorgonian's high structural complexity, the use of length (i.e. height) as the morphometric descriptor of the real size of the colonies is not appropriate. Instead of length, the fan surface area covered by each gorgonian colony was selected as a suitable parameter of size. The direct measurement of this parameter was possible through a complete 3D reconstruction of the gorgonian forest.A total of 426 colonies of Placogorgia sp. were digitalized to obtain surface measurements and fan spread orientation calculations in 3D models. The results show that gorgonian populations were mostly composed of a high proportion of small colonies (0–0.10 m2). The population structure distribution shows a high proportion (~27%) of recruits (<0.05 m2) and also many (19%) large colonies (>0.5 m2). In 78% of the gorgonian colonies, facing angles were grouped inside the first quadrant (0°-90°), in accordance with the main current direction in this zone. Colony distribution and fan orientation inside the gorgonian forest can be used as data sources to improve monitoring and management programs of these unique habitats in MPAs.

Experimental study of the thermal protection performance of the high reflectivity-phase change material (PCM) roof in summer

In order to reduce the building heat gain through the roof, a new kind of high reflectivity-PCM roof was proposed. That is to lay a layer of PCM outside the common roof, then a layer of high reflectivity film was laid outside the PCM layer. To compare the thermal protection performance of the high reflectivity-PCM roof with PCM roof, high reflectivity roof and common roof, three real size rooms were built. The three rooms were first installed with PCM roof, reflectivity roof and common roof. The thermal protection performance of the three roofs was compared for eight days (July 23rd to July 30th). Then the PCM roof and the high reflectivity roof were combined to form the high reflectivity-PCM roof, and the thermal protection performance of the high reflectivity-PCM roof was also compared to that of common roof for another eight days (Aug. 17th to Aug. 24th). Results showed that the high reflectivity-PCM roof performed more excellent in decreasing indoor air temperature, inner surface temperature and inner surface heat flux. Thermal balance results showed that the new type of roof can significantly reduce the solar radiation heat gain and storage most part of the heat passing through the high reflectivity film. The high reflectivity-PCM roof had better thermal protection performance than the other three roofs.

ПЕРЕХОДНЫЕ ПРОЦЕССЫ РЕАКТИВНО-ВЕНТИЛЬНОГО ЭЛЕКТРОПРИВОДА В ЭЛЕКТРОТЕХНИЧЕСКОЙ СИСТЕМЕ СОЛНЕЧНЫХ БАТАРЕЙ НА БОРТУ СУДНА

The article describes using small off-line solar power plants transforming solar energy into electric energy on shipboard for domestic needs: heating, lighting, pumping etc. It has been stated that in solving problems of increasing the reliability and efficiency of installing solar panels, as well as reducing the consumed electric power, electric solar power systems with jet-valve electric drives seem very promising. Using gearless electric drives in solar power plants contributes to increased accuracy of precision automatic control systems. In the researches related to jet valve machines there is found a lack in the description of a method for calculating engine parameters for a solar power system depending on the real area and panel size. For studying the characteristics of the drive transients a mathematical model is analyzed and its algorithm is presented, in which the end-to-end calculation method is used. According to this method, the initial parameters of the engine are set first, then the main dimensions and parameters of the magnetic circuit are calculated, and in the end the operating characteristics of the electric drive are determined. The dependences of the motor torque on the angle of rotation, current and inductance are calculated, as well as the flux linkage of the switched reluctance motor. The drive transient simulation has been performed. An increase of the mathematical model performance was achieved by introducing an angle identifier into the tracking system. The problem of using the rotor position sensors, which is not always possible, was solved by applying methods of indirect determining the position of angle of the rotor. It has been stated that the electrotechnical system with switched reluctance motor used in the tracking system (as well as in other types of electric drive) is widely popular due to high reliability of the solar power plant, simplicity of its design and low cost, as well as accurate positioning in the process of solar panel alignment.

Optimal charging and repositioning of electric vehicles in a free-floating carsharing system

Carsharing has received increased attention from the Operations Research community in recent years. Currently, many systems are adopting electric vehicles that require charging when battery levels fall below a given level. To do this, staff is often used to move cars to charging stations. Repositioning cars, rather than simply moving them to the closest charging station, might provide a better distribution of cars and in turn generate increased revenue and customer service while only marginally increase the operational costs. We present a mathematical model for the problem of charging and repositioning a fleet of shared electric cars. The model considers the assignment of cars to charging stations and the routing of staff and service vehicles. The complexity of the resulting mixed integer program makes it impossible to solve real world instances using a commercial solver. Therefore, we propose a new Hybrid Genetic Search with Adaptive Diversity Control algorithm. Tests based on data from a real life carsharing organization demonstrate that the proposed method can handle real size instances and that combining repositioning and charging operations can give significant benefits.

Conditions Monetaires Et Croissance Economique En Zone Cemac

The objective of this study is to track the monetary policy stance in CEMAC zone with GDP as target variable using a real size. The construction of reel monetary condition index use heterogeneous macropanels VAR approach with individual specification proposed par Fabio and al (2013). The inter-individual cointégration test confirm the long term relationship between GDP, real short run interest rate, real effective exchange rate and credit to economy making possible the combination of those instruments to forecast growth. But the result of intraindividual cointegration remains lukewarm compromising the possibility to combine the instruments above-mentioned in a single synthetic indicator for each country in CEMAC zone. The estimation of model parameters has been done through pooled mean group in Blackburn and Fran (2007) way. The construction of real ICM uses Canada Bank approach. One finds that real ICM is determined mainly by real effective exchange rate, then credit to economy and lastly the real short run interest rate. The construction of ICM must be included among the large range of indicators used by central bank to forecast growth in CEMAC zone.

Numerical Drag Reduction of a Ground Vehicle by NACA2415 Airfoil Structured Vortex Generator and Spoiler

Using of computational fluid dynamics (CFD) have big advanteges for design process components in the automotive industry. Flow structures around vehicle and drag forces can investigate in CFD without producing real size prototype vehicle. The drag force affect fuel efficiency and drivability too. In this study, the drag coefficient of 1/15 scale minibus model was minimizated by NACA 2415 airfoil structured vortex generator and front spoiler in Fluent®. Flow analyses were performed at the 5 different free stream velocities in the range of 2.8 × 105–6.6 × 105 Reynolds numbers, where the dynamic similarity condition was provided. The drag coefficient of base minibus model was 0.415. The CD coefficient of the model minibus was decreased 10.94 % with original designed NACA 2415 airfoil structured vortex generator in model 1. In total of 22.59 % drag reduction was obtained by designed front spoiler. The effect of this drag reduction on fuel consumption about 6 ~ 12 % at high vehicle speeds.

Tracheal Size and Morphology on the Reconstructed CT Imaging.

To characterize the real size and morphology of tracheas in childhood for the optimal selection of endotracheal tube. A retrospective cohort study of pediatric patients who received CT scan of the cervical spine from July 2011 to March 2018. Cross-sectional CT images vertical to trachea were reconstructed and the accurate tracheal diameters were measured. The validity of the traditional age-based formula for predicting the endotracheal tube size was assessed for the best fit to trachea. Tertiary Emergency and Critical Care Center of Kyushu University Hospital. Children, who are 1 month to 15 years old, received CT scan of the cervical spine. None. We enrolled 86 children with median age of 53 months. The cross-sectional shape of pediatric trachea was circular at the cricoid level and elliptical at the infraglottic level. The narrowest part of pediatric trachea was the transverse diameter at the infraglottic level at any age. Significant positive correlation between age and the narrowest diameter was observed. When compared the transverse diameter at the infraglottic level with the outer diameter of endotracheal tubes, uncuffed endotracheal tubes selection based on the traditional age-based formula ran a significant risk of oversized endotracheal intubation until 10 years old compared with cuffed endotracheal tubes selection (60.0% vs 23.8%; p < 0.05). These findings indicate the safety and efficacy of cuffed endotracheal tubes in infants and children and the reconsideration for the airway management in pediatric anesthesia and intensive care.

Targeted energy transfer from a resonant room to a hybrid electro-acoustic nonlinear membrane absorber: Numerical and experimental study

We present the first real size evidence of targeted energy transfer in a concrete building, with an efficient action on low frequency noise reduction. It is achieved by the means of a hybrid Electro-Acoustic Nonlinear Energy Sink (EA-NES). The EA-NES action is based on targeted energy transfer. As in previous works the EA-NES is made of two elements: a membrane with a nonlinear dynamics, and an active system based on a loudspeaker which controls the pressure applied to the rear face of the membrane. We study here a proportional feedback control law driving the loudspeaker in current mode, and compare it with the voltage mode command law. The experiment is fully modeled. A singular perturbation method around a 1:1 resonance is used to find the slow critical manifold of the system and its dependence on the control loop gain for the two driving modes, in view of finding conditions allowing Strongly Modulated Regime (SMR). A good quantitative agreement is found between the model and the experiments. In the experimental study we observe a range in the excitation level corresponding to SMR where the sound level in the room is limited. We study the influence of its parameters on the thresholds of the working range of the EA-NES. We measure up to 8 dB of attenuation around 43 Hz.

An exact scalarization method with multiple reference points for bi-objective integer linear optimization problems

This paper presents an exact scalarization method to solve bi-objective integer linear optimization problems. This method uses diverse reference points in the iterations, and it is free from any kind of a priori chosen weighting factors. In addition, two new adapted scalarization methods from literature and the modified Tchebycheff method are studied. Each one of them results in different ways to obtain the Pareto frontier. Computational experiments were performed with random real size instances of two special problems related to the manufacturing industry, which involve lot sizing and cutting stock problems. Extensive tests confirmed the very good performance of the new scalarization method with respect to the computational effort, the number of achieved solutions, the ability to achieve different solutions, and the spreading and spacing of solutions at the Pareto frontier.

Unveiling the impact of the effective particles distribution on strengthening mechanisms: A multiscale characterization of Mg+Y2O3 nanocomposites

Most models used to account for the hardening of nanocomposites only consider a global volume fraction of particles which is a simplified indicator that overlooks the particles size and spatial distribution. The current study aims at quantifying the effect of the real experimental particles spatial and size distribution on the strengthening of a magnesium based nanocomposites reinforced with Y2O3 particles processed by Friction Stir Processing (FSP). X-ray tomographic 3-D images allowed to identify the best FSP parameters for the optimum nanocomposite. A detailed analysis indicates that the observed hardening is mainly due to Orowan strengthening and the generation of geometrically necessary dislocations (GND) due to thermal expansion coefficients (CTE) mismatch between magnesium and Y2O3 particles. A multiscale characterization coupling 3D X-ray laboratory, synchrotron nanoholotomography and transmission electron microscopy (TEM) has been used to investigate particles size and spatial distribution over four orders of magnitude in length scales. Two dedicated micromechanical models for the two strengthening mechanisms are applied on the experimental particle fields taking into account the real particles size and spatial distribution, and compared to classical models based on average data. This required to develop a micromechanical model for CTE mismatch hardening contribution. This analysis reveals that the contribution from CTE mismatch is decreased by a factor two when taking into account the real distribution of particles instead of an average volume fraction.

Our global-scale cognitive map: is it influenced by our place of residence or education?

Abstract. Cognitive maps are defined as internal representations of the environment or of the globe. Several scientists of various disciplines (e.g. psychology, geography) have conducted cognitive research on issues related to maps aiming to understand how humans create and utilize mental representations of the earth. Concluding that several elements, such as wayfinding tasks, verbal explanations or maps contribute to the creation of these representations. Moreover, map projections of world maps and their distortions are presumed as a crucial factor when creating our global-scale cognitive map. Nevertheless, previous research (of Battersby and Montello in 2006 at University of Santa Barbara and Lapon in 2017 at Ghent University) could not provide any proof for the existence of an influence of map projections on our global-scale cognitive map. To go deeper into this topic, we want to research any other possible influence on our cognitive map. For example, does the place where you were educated or the place where you live and work has an impact on the development of your mental map? Are these influences defined by the age, the gender or the educational level of people?There are several measures to define the accuracy of our cognitive map: e.g. the distances between places or cities; the topologic relations between places, countries or other geographical elements; the land areas of countries and continents. The test developed for this research focussed on the latter one: participants are requested to estimate the size of one country or continent compared to another one (Figure 1). Therefore, an interactive playful online test was developed. The test is available in eight languages and consists of an instructive movie, ten pairs of countries or continents to estimate, a survey and a feedback tool which gives a score.This setup permits to collect data for our research, but it is also developed as a tool to create awareness about our misperception of region sizes among the participants. Furthermore, the test can easily be used in the classroom to introduce subjects such as map projections, cartography, world problems… By using personal contacts, mailing lists of the university, and social media, 100,000 fully completed tests were collected in two months’ time, from more than 150 different countries worldwide. For every estimation the relative estimated accuracy is calculated, this value gives an impression to what extent people over- or underestimate one region compared to another. Its absolute value is an indication of how good people are in estimating the real size of countries or continents. These values were used to calculate differences between the participants, and between groups of participants. Besides their gender, age, profession, educational level and cartographical background, people were asked to define the country where they received their education and the country where they are living now.Nine countries, with more than 400 participants, spread over the globe, were selected for further analyses. The preliminary results show that there is a low variation between the averages for each country of education or place of living separately. So, it seems that the ability to estimate the size of countries or continents is not determined by the place where one lives or received one’s education. In contrast, personal characteristics are more defining for the accuracy of the estimations. General results indicate that on the one side men achieve a better score than women, and on the other side young people between 12 and 18 years old perform quite better, in contrast with the participants older than 71 years. Also, the people with a higher educational level or a broader cartographical background perform better.The place where you grow up, get educated or where you live, does not have a substantial influence on the accuracy of the estimations. Surprisingly, personal characteristics and qualities seem to play a more determining role, worldwide, in the development of geographical knowledge or more specific, in the evolvement of the cognitive map. To support these preliminary results, the analyses will be extended and the group of participants further delimited. Furthermore, a geographical dataset with more than 100,000 participants offers plenty of possibilities that will be exploited in the upcoming months.

The Real Size of our Universe

The Real Size of our Universe

Unbiased Analysis Method for Measurement of Red Blood Cell Size and Velocity With Laser Scanning Microscopy.

Two-photon laser scanning microscopy is widely used to measure blood hemodynamics in brain blood vessels. Still, the algorithms used so far to extract red blood cell (RBC) size and velocity from line-scan acquisitions have ignored the extent to which scanning speed influences the measurements. Here, we used a theoretical approach that takes into account the velocity and direction of both scanning mirrors and RBCs during acquisition to provide an algorithm that measures the real RBC size and velocity. We validate our approach in brain vessels of anesthetized mice, and demonstrate that it corrects online measurement errors that can reach several 10s of percent as well as data previously acquired. To conclude, our analysis allows unbiased comparisons of blood hemodynamic parameters from brain capillaries and large vessels in control and pathological animal models.

Numerical analysis of the thermal and fluid dynamic behavior of the flue gases in a traditional furnace for panela production

Introduction: Panela is a product derived from sugar cane that is prepared using a traditional burner designed especially for this purpose. According to studies found in the literature, it was identified that the thermal efficiency of panela burners is 30% on average.&#x0D; Objective: The objective of this investigation is to contribute to the search for new alternatives for the improvement of the low efficiency present on these systems, mainly affecting the flue gases duct.&#x0D; Methodology: The development of this study is as follows: first, a research of the radiation and optical thickness effect in a simplified furnace is carried out. Afterward, a series of simulations with modifications in the design of the flue gas duct for a real size furnace are analyzed.&#x0D; Results: The results showed that the radiation effect must be considered and, even though the optical thickness is low, it has a relevant impact in the heat transfer process due to the high temperatures in the furnace. A chaotic movement of the gases implied more heat transferred to the heaters and high values of Nusselt with the addition of new elements in the duct were obtained.&#x0D; Conclusions: Arrangement 1, provides the best results with a Nusselt and thermal efficiency increase. No significant differences between the DOM and the P-1 radiation were found.

A connected driver advisory system framework for merging freight trains

This paper proposes an approach to facilitate smooth merging of freight trains into a stream of passenger trains with short headways, to help drivers better control freight trains and avoid red signals. An algorithm architecture is proposed for Driver Advisory Systems (DASs) to compute time/speed advice for freight train drivers. The framework includes four parts: buffer stairway prediction, freight train movement prediction, merging window detection and merging optimization. The basic idea is to predict the traffic state in the merging area regularly and find the feasible merging time window. Proper advice can be presented to freight train drivers and help them to merge smoothly, by comparing the freight train movement to the feasible merging window. The performance of the proposed algorithms is illustrated on examples of merging freight trains in the Meteren and Kijfhoek areas on the Dutch railway network. The experimental results show the efficiency and quality of the proposed algorithms on real world size problems.

Mass and Heat Transfer Coefficients in Automotive Exhaust Catalytic Converter Channels

Mass and heat transfer coefficients (MTC and HTC) in automotive exhaust catalytic monolith channels are estimated and correlated for a wide range of gas velocities and prevailing conditions of small up to real size converters. The coefficient estimation is based on a two dimensional computational fluid dynamic (2-D CFD) model developed in Comsol Multiphysics, taking into account catalytic rates of a real catalytic converter. The effect of channel size and reaction rates on mass and heat transfer coefficients and the applicability of the proposed correlations at different conditions are discussed. The correlations proposed predict very satisfactorily the mass and heat transfer coefficients calculated from the 2-D CFD model along the channel length. The use of a one dimensional (1-D) simplified model that couples a plug flow reactor (PFR) with mass transport and heat transport effects using the mass and heat transfer correlations of this study is proved to be appropriate for the simulation of the monolith channel operation.

Dead zone for hydrogenation of propylene reaction carried out on commercial catalyst pellets

AbstractHeterogeneous catalytic processes have for years been of crucial importance in the chemical industry, while biocatalitic processes have become more and more important. For both types of the processes the existence of zones without reactants were reported. Despite the fact that the dead zone can appear in real processes relatively often, the most important problem in practice is the real size of a dead zone inside a catalyst pellet or the real depth of penetration reagents in a biofilm and this is still unsolved. The knowledge of the parameters and some information about the process can allow improvement in yield, and selectivity, reduce consumption of catalyst by reducing the bed size etc. Presented in this work is a simple method of predicting the size of the inactive core of a uniformly activated catalyst pellet. The method is based on a simple mathematical model of catalyst pellet with inactive pellet centre and experimental investigations.

Cost-effectiveness of nanomedicine: estimating the real size of nano-costs.

Cost-effectiveness of nanomedicine: estimating the real size of nano-costs.

Supply function Nash equilibrium of joint day-ahead electricity markets and forward contracts

Forward contracts are one of the prevalent and useful tools for managing the risks associated with the volatility of the electricity market prices. Forward contracts and day-ahead electricity market are executed simultaneously, and hence, they affect each other. This paper proposes a comprehensive supply function equilibrium model to consider the mutual interactions between forward contracts and the associated day-ahead electricity market in a power system. Negotiation between each producer and consumer in forward market is taken into account in the model. In order to consider the risk management behaviors of all market players in the model, a new risk management method is presented. The proposed risk management method takes into account the concerns of market players about the future prices of day-ahead market over the delivery period. The model proposed in this paper is applied to a test system with forward and day-ahead markets. The results are compared with the case that there is no forward contract in the power system. Impacts of growing the concerns of producers and consumers about the future, impacts of increasing demand uncertainty, impacts of improving bargaining power of consumers in contracting period and impact of contracting obligations for producers on the simulation results are discussed. The proposed risk management method is compared with CVaR method and its efficiency is evaluated. Finally, applicability of the proposed model to real size power systems is examined.

Part segregation based on particle swarm optimisation for assembly design in additive manufacturing

ABSTRACTMinimising total production time in the additive or layered manufacturing is a critical concern, and in this respect, the idea of balancing assembly time and build time is rapidly gaining research attention. The proposed work intends to provide benefit in terms of reduced lead time to customers in a collaborative environment with simultaneous part printing. This paper formulates a mixed-integer non-linear programming (MINLP) model to evaluate the near optimal threshold area and support material allocation while segregating parts for a single material additive manufacturing set-up. The resulting time minimisation model is finitely bounded with respect to support material volume, total production time and total assembly cost constraints. A novel swarm intelligence-based part segregation procedure is proposed to determine the number of part assemblies and part division scheme that adheres to cross-sectional shape, cross-sectional area, and height restrictions. The proposed approach is illustrated and evaluated for objects with regular as well as free-form surfaces using two different hypothetically simulated real size 3D models. Results indicate that the proposed approach is able to reduce the total amount of manufacturing time in comparison with single part build time for all the tested cases.