Experimental comparison between proportional and PWM-solenoid valves controlled servopneumatic positioning systems

The performance of the Dynamical Adaptive Backstepping-Sliding Mode Control (DAB-SMC) scheme for positioning of a pneumatic cylinder regulated by two types of PWM-solenoid valves is experimentally investigated. The goal is to study the compromise in controller’s performance as the system moves from using a proportional valve to employing the low-cost PWM-solenoid valves. Sinusoidal and multiple-step inputs are used as the reference position trajectories. Experimental results show that the DAB-SMC scheme works best with the proportional valve. The performance, however, deteriorates by more than twofold, once the system utilizes PWM- solenoid valves of 3/2-way or 2/2-way configurations. From this study, tradeoff between performances of different types of valves applied on a DAB-SMC scheme-controlled servo positioning system is successfully documented. This information helps to configure appropriate servopneumatic system for positioning applications

Consumer Appraisals of Mobile Marketing Communications

This paper reports on a study that investigates the emotions elicited from appraising SMS-based mobile marketing (m-marketing) communications under three marketing conditions: product consistency, incentives and permission giving. Results from the experimental design show that appraising m-marketing communications elicits both single emotions and mixed emotions; that is, a mixture of positive and negative emotions in the same response. Additionally, the results show that the influence of specific marketing conditions may increase or reduce the intensity of the emotions elicited. This study contributes to marketing practice by examining consumer appraisals of m-marketing communications under different combinations of marketing conditions. The results provide insights into which emotions are likely to be elicited as a result, and how a specific marketing condition might influence their levels of intensity. The study contributes to marketing theory also through combining appraisal theory with Richins (1997) consumption emotion set

Numerical simulation of needle movement nozzle flow coupled with spray for a diesel injector using an Eulerian spray atomization model

[EN] The injector dynamics have a strong impact on spray behavior, therefore on combustion efficiency and pollutant emissions. Nozzle flow and spray coupled simulations are useful tools to analyze the effect of nozzle geometry, and they could be used also to study the effect of needle movement. In this work, three different approximations to the same needle lift law are employed in an Eulerian Spray Atomization (ESA) model. The main advantage of this model is that is able to simulate nozzle flow and spray seamlessly. Engine Combustion Network (ECN) Spray A conditions are simulated. Results show that the experimental needle lift law can be used without any fitting to a smoothed expression, but all details of the needle dynamics must be considered in order to properly predict mass flow rate and spray penetration. Additionally, it has been shown that needle dynamics has a strong impact on heating effects inside the nozzle.This research was performed in the frame of the project "Estudio de la interaccion chorro-pared en condiciones realistas de motor (SPRAY WALL)" reference TRA2015-67679-c2-1-R from Ministerio de Economia y Competitividad (Spanish Ministry of Economy).Payri, R.; Gimeno, J.; Marti-Aldaravi, P.; Alarcón-Herrera, MY. (2017). Numerical simulation of needle movement nozzle flow coupled with spray for a diesel injector using an Eulerian spray atomization model. Journal of the Brazilian Society of Mechanical Sciences and Engineering. 7(39):2585-2592. https://doi.org/10.1007/s40430-017-0801-1S25852592739Fajgenbaum R, dos Santos RG (2016) Influence of fuel temperature on atomization parameters in a pressure-swirl atomizer from a port fuel injector by Shadowgraphy technique. J Braz Soc Mech Sci Eng 38:1877–1892. doi: 10.1007/s40430-015-0443-0He Z, Guo G, Tao X, Zhong W, Leng X, Wang Q (2016) Study of the effect of nozzle hole shape on internal flow and spray characteristics. Int Commun Heat Mass Transf 71:1–8. doi: 10.1016/j.icheatmasstransfer.2015.12.002Loaiza JCV, Sánchez FZ, Braga SL (2016) Combustion study of reactivity-controlled compression ignition (RCCI) for the mixture of diesel fuel and ethanol in a rapid compression machine. J Braz Soc Mech Sci Eng 38:1073–1085. doi: 10.1007/s40430-015-0400-ySalvador FJ, Romero JV, Roselló MD, Jaramillo D (2015) Numerical simulation of primary atomization in diesel spray at low injection pressure. J Comput Appl Math 291:94–102. doi: 10.1016/j.cam.2015.03.044Strotos G, Koukpuvinis P, Theodorakakos A (2015) Transient heating effects in high pressure Diesel injector nozzles. Int J Heat Fluid Flow 51:257–267. doi: 10.1016/j.ijheatfluidflow.2014.10.010Macian V, Bermúdez V, Payri R, Gimeno J (2003) New technique for determination of internal geometry of a Diesel nozzle with the use of silicone methodology. Exp Tech 39:39–43. doi: 10.1111/j.1747-1567.2003.tb00107.xKastengren AL, Tiloco FZ, Powell CF, Manin J, Pickett LM, Payri R, Bazyn T (2013) Engine combustion network (ECN): measurements of nozzle geometry and hydraulic behavior. Atom Sprays 22:1011–1052. doi: 10.1615/AtomizSpr.006309Kastengren AL, Tiloco FZ, Duke DJ, Powell CF, Zhang X, Moon S (2014) Time-resolved X-ray radiography of sprays from engine combustion network Spray A diesel injectors. Atom Sprays 24:251–272. doi: 10.1615/AtomizSpr.2013008642Payri R, Gimeno J, Viera JP, Plazas AH (2013) Needle lift profile influence on the vapor phase penetration for a prototype diesel direct acting piezoelectric injector. Fuel 113:257–265. doi: 10.1016/j.fuel.2013.05.057Lee WG, Reitz RD (2009) A numerical investigation of transient flow and cavitation within Minisac and VCO Diesel injector nozzles. In: Proceedings of the 2009 spring technical conference of the ASME internal combustion engine division, pp 643–653. doi: 10.1115/ICES2009-76148Bermúdez V, Payri R, Salvador FJ, Plazas AH (2005) Study of the influence of nozzle seat type on injection rate and spray behavior. IMechE. Part D. J Autom Eng 219:677–689. doi: 10.1243/095440705X28303Vallet A, Burluka AA, Borghi R (2001) Development of a Eulerian model for the “Atomization” of a liquid jet. Atom Sprays 11:619–642. doi: 10.1615/AtomizSpr.v11.i6.20García-Oliver JM, Pastor JM, Pandal A, Trask N, Baldwing E (2013) Diesel Spray CFD simulations based on the $$\Sigma$$ Σ - $$Y$$ Y Eulerian atomization model. Atom Sprays 23:71–95. doi: 10.1615/AtomizSpr.007198Bardi M, Payri R, Malbec LM, Bruneaux G, Pickett LM, Manin J, Bazyn T, Genzale C (2012) Engine combustion network: comparison of spray development, vaporization, and combustion in different combustion vessels. Atom Sprays 22:807–842. doi: 10.1615/AtomizSpr.2013005837Kösters A, Karlsson A (2016) Validation of the VSB2 spray model against Spray A and Spray H. Atom Sprays 26(8):775–798. doi: 10.1615/AtomizSpr.2015011670Salvador FJ, Gimeno J, Pastor JM, Martí-Aldaraví P (2015) Effect of turbulence model and inlet boundary condition on the Diesel spray behavior by an Eulerian spray atomization (ESA) model. Int J Multiph Flow 65:108–116. doi: 10.1016/j.ijmultiphaseflow.2014.06.003Desantes JM, García-Oliver JM, Pastor JM, Pandal A, Baldwin E, Shcmidt DP (2015) Coupled/decoupled spray simulation comparison of the ECN spray A condition with the $$\Sigma$$ Σ - $$Y$$ Y Eulerian atomization model. Int J Multiph Flow 80:89–99. doi: 10.1016/j.ijmultiphaseflow.2015.12.002Petranović Z, Edelbauer W, Vujanović M, Duić N (2016) Modelling of spray and combustion processes by using the Eulerian multiphase approach and detailed chemical kinetics. Fuel 191:25–35. doi: 10.1016/j.fuel.2016.11.051Anvari S, Taghavifar H, Khalilarya S, Jafarmadar S (2016) Numerical simulation of diesel injector nozzle flow and in-cylinder spray evolution. Appl Math Model 40:8617–8629. doi: 10.1016/j.apm.2016.05.017Desantes JM, Payri R, Gimeno J, Martí-Aldaraví P (2014) Simulation of the first millimeters of the diesel Spray by an Eulerian spray atomization model applied on ECN Spray A injector. SAE Technical Paper 2014-01-1418. doi: 10.4271/2014-01-1418Payri R, Ruiz S, Gimeno J, Martí-Aldaraví P (2015) Verification of a new CFD compressible segregated and multi-phase solver with different flux update-equations sequences. Appl Math Model 39:851–861. doi: 10.1016/j.apm.2014.07.011Weller HG, Tabor G, Jasak H, Fureby C (1998) A tensorial approach to computational continuum mechanics using object-oriented techniques. Comp Phys 12:620–631. doi: 10.1063/1.168744Desantes JM, Payri R, Pastor JM, Gimeno J (2005) Experimental characterization of internal nozzle flow and diesel spray behavior. Part 1: non-evaporative conditions. Atom Sprays 17:315–345. doi: 10.1615/AtomizSpr.v15.i5.20Payri R, Gimeno J, Martí-Aldaraví P, Carreres M (2015) Assessment on internal nozzle flow initialization in diesel spray simulations. SAE Technical Paper 2015-01-0921. doi: 10.4271/2015-01-0921Rybdylova O, Al Qubeissi M, Braun M, Crua C, Manin J, Pickett LM, de Sercey G, Sazhina EM, Sazhin SS, Heikal M (2016) A model for droplet heating and its implementation into ANSYS Fluent. 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Learning User Preferences to Incentivize Exploration in the Sharing Economy

We study platforms in the sharing economy and discuss the need for incentivizing users to explore options that otherwise would not be chosen. For instance, rental platforms such as Airbnb typically rely on customer reviews to provide users with relevant information about different options. Yet, often a large fraction of options does not have any reviews available. Such options are frequently neglected as viable choices, and in turn are unlikely to be evaluated, creating a vicious cycle. Platforms can engage users to deviate from their preferred choice by offering monetary incentives for choosing a different option instead. To efficiently learn the optimal incentives to offer, we consider structural information in user preferences and introduce a novel algorithm - Coordinated Online Learning (CoOL) - for learning with structural information modeled as convex constraints. We provide formal guarantees on the performance of our algorithm and test the viability of our approach in a user study with data of apartments on Airbnb. Our findings suggest that our approach is well-suited to learn appropriate incentives and increase exploration on the investigated platform.Comment: Longer version of AAAI'18 paper. arXiv admin note: text overlap with arXiv:1702.0284

Mission Completion, Troop Welfare and Destructive Idealism: A Case Study on the Phenomenology of a Combat Veteran’s Social Reintegration

Post-traumatic Stress Disorder (PTSD) among combat veterans remains an urgent and intractable problem for those who have served in the wars in Iraq and Afghanistan. In this paper, we argue that one of the reasons that combat related PTSD remains so difficult to treat is because psychologists - and American culture at large - do not fully understand it yet. It is our contention that there are two contributing factors that currently hinder our ability to successfully treat combat related PTSD. The first is a failure to look critically at the theoretical underpinnings that ground our current understanding of the disorder. The second related issue is our tendency to look to reductionist explanations and treatments. We use the theoretical framework of phenomenology alongside a case study of a man we call James in order to present this argument

Dynamic Prediction of retail Website Visitors\u27 Intentions

This paper presents a model for identifying general intentions of consumers visiting a retail website. When visiting a transactional website, consumers have various intentions such as browsing (i.e., no purchase intention), purchasing a product in the near future, or purchasing a particular product during their current visit. By predicting these intentions early in the visit, online merchants could personalize their offer to better fulfill the needs of consumers. We propose a simple model which enables classifying visitors according to their intentions after only four traversals (clicks). The model is based solely on navigation patterns which can be automatically extracted from clickstream. The results are presented and extensions of the model are proposed