El seguimiento de un vehículo en el desplazamiento en línea: caracterización psicofisiológica y conductual de dos formas básicas de conducción

Esta Tesis Doctoral parte de una observación: el coste personal, material, económico y medioambiental que originan las congestiones en el tráfico. (Levinson et al., 1998; UNHSP, 2007). Nos hacemos así eco de una constatación básica a juicio de los expertos: “La mayor parte de la conducción se da bajo el constreñimiento de un vehículo que precede al nuestro” (Evans, 1991; p. 114). Hace más de medio siglo que la ingeniería del tráfico trata de comprender el desplazamiento conjunto de los conductores en el movimiento en línea (Brackstone & McDonald, 1999). Este objetivo parte de un implícito importante: los conductores tienen un modo específico de desplazarse cuando avanzan colectivamente en una vía. Una vez asumido que los conductores tienen ese modo específico de conducir, queda observarlo adecuadamente y tratar de abstraerlo en una ecuación matemática, que a su vez habrá que proponer y cuyos pesos habrá que ajustar. Este procedimiento, sin duda sofisticado y complejo, debe permitir obtener modelos y efectuar predicciones de flujos vehiculares masivos (Ranjitkar et al., 2005; Li y Sun, 2012). Pero este planteamiento, más bien nomotético, ha sido visto de forma crítica desde la psicología aplicada al tráfico (Winsum, 1999; Ranney, 1999). Para los psicólogos, la unidad de análisis es el conductor individual y el movimiento colectivo en línea debe ser explicado partiendo de qué hace, de cómo desempeña su tarea cada conductor individual, para después explicar –en un segundo nivel- el movimiento colectivo en línea observado. Siendo la conducción una tarea eminentemente visual, se sugiere que el aspecto fundamental a tener en cuenta concierne a las variaciones psicofísicas del aparato perceptivo que ocurren a tenor del desplazamiento colectivo en línea (Evans y Rothery, 1977; Brackstone et al. 2002). Pero tanto la ingeniería como la psicología del tráfico comparten un implícito básico: los conductores tienen un modo específico (normativo) de desplazarse colectivamente en una vía. Tal vez se trate de una simplificación conveniente y funcional, pero lo cierto es que los conductores saben que deben conducir manteniendo la distancia de seguridad. Nuestro objetivo es explorar la ampliación de este marco, centrándonos en una visión alternativa de la modelización del movimiento en línea (Sugiyama et al., 2008; Melchor y Sánchez, 2014) y anclada en el aspecto cognitivo-emocional del conductor. La conducción es una tarea orientada a una meta que recibe información sobre el desempeño en curso (retroalimentación) que es visual pero también de índole cognitivo-emocional (Carver y Scheier, 2008). Partimos de la idea de que se puede entender el seguimiento vehicular desde dos puntos de vista. O bien considerando un mínimo margen de espacio, o distancia de seguridad, tratando de maximizar la capacidad tal como se ha venido haciendo hasta ahora (le llamaremos Conducción centrada en el mantenimiento de la Distancia, CD). O bien estableciendo un margen de eficiencia en la conducta de seguimiento que nos permita mantener una velocidad uniforme (esto es, nuestra velocidad media es equivalente al promedio de las velocidades instantáneas del vehículo precedente). Llamaremos a este segundo tipo Conducción centrada en el mantenimiento de la Inercia (CI). De modo complementario, vamos a explorar la posible relación entre un aspecto de meta-cognición, la atención plena (Brown et al., 2003; Delgado, 2009), y los posibles efectos derivados en la manera en que se asume la conducción tipo CD vs CI. Los objetivos fundamentales de este trabajo son los siguientes: 1. Comprobar, en primer lugar, que los conductores son capaces de entender y desempeñar la tarea de las dos formas ya definidas, CD vs.CI, partiendo de instrucciones verbales simples. 2. Comprobar que su conducta se mantiene estable en el tiempo.3. Caracterizar cada tipo de conducción a partir de registros psicofisiológicos y cognitivo-emocionales en el propio conductor. 4. Caracterizar cada tipo de conducción según sus efectos en la conducción. 5. Caracterizar el impacto relativo en las medidas de desempeño y valoración posterior de la tarea de variables antecedentes (nivel de mindfulness). Las conclusiones de este trabajo pueden tener repercusiones en nuestra comprensión del seguimiento vehicular, de la aparición y desaparición de la congestión (phantom traffic jam), del comportamiento normativo del conductor, y ofrecer una visión complementaria, con gran demanda en un momento que parece ser antesala de una posible automatización o pseudo-automatización de la conducción dentro del ámbito general de los ITS.This doctoral dissertation was pushed by the awareness of the personal, material, financial and environmental costs resulting from traffic congestion (Levinson et al., 1998; UNHSP, 2007). We actually echo a basic finding in the judgment of the experts: "Most of the driving is done under the constraint of a vehicle that precedes us" (Evans, 1991, p. 114). It was more than half a century ago that traffic engineers first attempted to model and understand car-following (Brackstone & McDonald, 1999). Their goal assumed a significant implicit though: drivers have a specific mode of travel when moving collectively. Taking for granted that drivers follow that specific pattern when driving after other drivers, the next step was obtaining data and then trying to abstract them into a mathematical equation, then adjusting its parameters, and so on. This procedure certainly sophisticated and complex, should allow obtaining models and make predictions of massive traffic flows (Ranjitkar et al., 2005; Li and Sun, 2012). But this approach, rather nomothetic, has been seen critically from traffic psychology (Winsum, 1999; Ranney, 1999). For psychologists, the unit of analysis is the individual driver and car-following must be first explained on the basis of what it does, how it performs its task each individual driver. Then, in a second step, the collective movement observed may then be explained on that basis. Driving is commonly assumed as a predominantly visual task, and so it is suggested that the key aspect to consider concerns the variations of the psychophysical perceptual apparatus occurring under collective displacement (Evans and Rothery, 1977; Brackstone et al., 2002). But both engineering and traffic psychology share a basic implicit: drivers have a specific (normative) way to follow other drivers. Maybe it comes as a convenient and functional simplification, but the truth is that drivers know they must drive keeping the safety distance. Our goal is to explore the extension of this framework, focusing on an alternative way to model car-following (Sugiyama et al, 2008; Melchor & Sánchez, 2014) also anchored in cognitive-emotional parameters. Driving is a goal-oriented task and drivers receive performance feedback that is visual but also of cognitive-emotional nature (Carver and Scheier, 2008). Our departure point is that drivers can set up such goals assuming car-following in two distinct ways. Drivers can focus on leaving a minimum margin of space or safety distance, trying to maximize capacity as it has been done so far (we may call it Driving with a focus on keeping Distance, DD). Or drivers may focus on leaving an efficiency margin on car-following so they may keep a uniform speed (that is, our average speed equates the average of the instantaneous speeds of the preceding vehicle). We call this Driving with a focus on keeping Inertia, DI). Complementarily, we will explore the possible relationship between an aspect of meta-cognition, mindfulness (Brown et al., 2003; Delgado, 2009), and the possible effects on the way each driving technique (DI, DD) is assumed. The main objectives of this work are: 1. Check that drivers are able to understand and perform the task, according to DD or DI, by following simple verbal instructions. 2. Check that their behavior remains relatively stable over time. 3. Characterize each driving technique in psychophysiological and cognitive-emotional terms. 4. Featuring each driving technique considering driving performance indicators. 5. Characterize the relative impact on performance and appraisal measures of the background task variables (level of mindfulness). The findings of this work may have implications for our understanding of car-following, the advent and disappearance of congestion (phantom traffic jam), as well as the normative behavior of drivers. It may offer as well a complementary and necessary vision in a time that runs towards pseudo-automation or automation of driving within the general field of ITS

Estímulos verbales y trastornos emocionales : un estudio sobre palabras con contenido emocional

Este trabajo tiene como objetivo fundamental el proporcionar datos normativos sobre un listado de palabras que pueda ser utilizado por los investigadores interesados en el estudio cognitivo de los trastornos emocionales. Se analizan datos relativos a la frecuencia subjetiva de uso de las palabras que normalmente se usan en estos estudios, en qué medida estas palabras se relacionan con ansiedad y con depresión, hasta qué punto son comprendidas por los sujetos, y en qué grado pueden evocar una imagen. Además, se ofrecen resultados sobre las diferencias en estas categorías en función del sexo, ser o no psicólogo/a, la edad y el nivel educativo. Creemos que este trabajo puede ser de cierta utilidad para los investigadores interesados en el estudio experimental de los factores cognitivos involucrados en los trastornos emocionales, aportando información que a veces no es fácil obtener, pero que supone un paso preliminar para seleccionar el material estimular necesario en diversos paradigmas experimentales

ELECTRONIC TRAFFIC SIGNS: REFLECTING UPON ITS TRANSITION

[EN] In our days we face a fundamental issue concerning road signs. We may display contents in vertical and horizontal format (static signs, variable message signs, road markings), either on a post, a gantry or a dashboard. And we foresee a coming age where the excellent matrix resolution of painted signs will be truly approached by the resolution of full matrix displays. But we also risk a babel context threatening the universal approach encouraged by international catalogues as the 1968 Convention (ECE/TRANS/196, 2007). And the fundamental risk comes from our decisions regarding how the transition from the contents and formats displayed on static message signs to the ones displayed on electronic signs (in gantries or dashboards) should be. Our work explores this issue specifically, considering the transition from Advance Direction Signs (static message signs, class G, 1 in the 1968 Convention) to what could be termed Advance Location Signs (signs concerning the location of variable events with regards to certain landmarks) developed as an adaptation of the G, 1 class to electronic traffic signs.DOI: http://dx.doi.org/10.4995/CIT2016.2016.3217  http://ocs.editorial.upv.es/index.php/CIT/CIT2016Arbaiza Martin, A.; Lucas Alba, A.; Hernando Mazón, A.; Blanch Micó, MT. (2016). ELECTRONIC TRAFFIC SIGNS: REFLECTING UPON ITS TRANSITION. Editorial Universitat Politècnica de València. 2038-2045. https://doi.org/10.4995/CIT2016.2015.3217OCS2038204

Sterol Oxidation in Ready-to-Eat Infant Foods During Storage

The effect of storage on sterol oxidation of ready-to-eat infant foods was evaluated. Two different liquid infant foods (honey or fruits flavors), prepared with milk and cereals, were stored for 0, 2, 4, 7 and 9 months at 25 °C. Sterol oxidation products (SOP) were isolated by cold saponification, purified by silica solid-phase extraction, and analyzed by gas chromatography (GC) and GC-mass spectrometry. β-Sitosterol was the most representative sterol, followed by cholesterol and campesterol. No significant differences in the total and single SOP content (0.81 mg/kg of product) were observed with respect to storage time and type of sample; the main SOP found was 7-ketositosterol (<0.2 mg/kg of product). The extent of stigmasterol oxidation (2.9%) was higher than that of cholesterol (1.9%) and β-sitosterol (1.4%). The type and quality of raw materials, as well as the processing conditions, seem to greatly influence SOP formation and accumulation in infant foods

On drivers’ reasoning about traffic signs: The case of qualitative location

This article explores the most appropriate arrangement (vertical, horizontal) and the frame of reference adopted by drivers (intrinsic, relative) as determinants of the comprehension of new traffic messages (e.g., congestion before arriving to Milan). Two specific cases for location (event-before-city, event-after-city) were tested following two layouts: H (horizontal, left-right) and V (vertical, bottom-up). Four comprehension tests carried out between 2006 and 2013 with 10, 099 drivers in four countries (Italy, Netherlands, Spain, Sweden) were analyzed in a 2 (case: Before vs. After) x 2 (disposition: H, V) x 4 (Country) between-subject design. The comprehension of the V variants (78.1%) exceeded the comprehension of the H variants (54.1%) in all the countries in the "before" case. In no country did the V or H variants come close to functional understanding in the "after" case. The results provided evidence of the preferred model and relative frame of reference as determinants of message understanding. General Audience Summary A controversial aspect that arises from the use of different traffic signaling devices is that drivers often have to understand messages they are seeing for the very first time. This article analyzes the results of a series of empirical studies carried out with the aim of internationalizing variable message signs (VMS) by substituting keywords (e.g., prepositions) for abstract graphic signs (e.g., an arrow). Faced with novel elements in a traffic message about which drivers must conclude something in real time, they have no choice but to reason. This article explores the most appropriate arrangement (vertical, horizontal) and the frame of reference adopted by drivers (intrinsic, relative) as determinants of the comprehension of novel and complex VMS (e.g., congestion before arriving to Milan). Our study focuses on the design variants tested to inform drivers about two cases for location (event-before-city and event-after-city), following two basic layouts: H (horizontal, left-right) and V (vertical, bottom-up). Four comprehension tests carried out between 2006 and 2013 with 10, 099 drivers in four countries (Italy, Netherlands, Spain, Sweden) were analyzed in a 2 (case: Before vs. After) x 2 (disposition: H, V) x 4 (Country) between-subject design. The comprehension of the V variants (78.1%) exceeded the comprehension of the H variants (54.1%) in all the countries in the "before" case. However, in no country did the V or H variants come close to functional understanding in the "after" case. The results provided evidence of the preferred model and relative frame of reference as determinants of message understanding. Although it is not realistic to expect national or international drivers to memorize all possible traffic messages, it is feasible to understand how their prior knowledge and preferences modulate their conclusions to design more functional traffic messages

CAR FOLLOWING TECHNIQUES: THE ROLE OF THE HUMAN FACTOR RECONSIDERED

[EN] Engineering and psychophysiological car following models emerge in the late 1950s (Saifuzzaman & Zheng, 2014). Such models differ in their ground concepts and explanatory mechanisms, but both assume a fundamental tenet: following each other, drivers invariably attempt to couple, keeping safety distance. More recent models focus on the spontaneous emergence of traffic jams that results from the properties of a system of interacting vehicles (i.e., without bottlenecks). In an experimental setting Sugiyama et al., (2008) have successfully recreated the conditions that allow the observation of the typical soliton wave going backwards through several car clusters. When certain speed, density and inter-vehicular distance join, so do traffic jams. Some of us have built upon these and other factors (e.g., wave movement in nature) exploring the mathematical properties of a system with three incognita that also needs three variables to be solved (Melchor & Sánchez, 2014). Two canonical car-following techniques emerge as a consequence: Driving to keep safety Distance (DD) vs Inertia (DI). Also a basic question: can drivers actually understand and follow either way, or do they stick to a basic normative driving behavior? This paper summarizes the results after three experimental studies done with a driving simulator. Several performance measures from individual drivers (accelerations, decelerations, average speed, distance to leader, and so on) were taken. As an overall indicator, results consistently announce in the three studies that DI trips consume less fuel (about 20%) than DD ones.Blanch Micó, MT.; Lucas Alba, A.; Bellés Rivera, T.; Ferruz Gracia, AM.; Melchor-Galán, Ó.; Delgado Pastor, L.; Ruíz Jimenez, F.... (2016). CAR FOLLOWING TECHNIQUES: THE ROLE OF THE HUMAN FACTOR RECONSIDERED. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat Politècnica de València. 851-858. https://doi.org/10.4995/CIT2016.2015.3341OCS85185

An improved high-pressure roll crusher model for tungsten and tantalum ores

An improved approach is presented to model the product particle size distribution resulting from grinding in high-pressure roll crusher with the aim to be used in standard high-pressure grinding rolls (HPGR). This approach uses different breakage distribution function parameter values for a single particle compression condition and a bed compression condition. Two materials were used for the experiments; altered Ta-bearing granite and a calc-silicate tungsten ore. A set of experiments was performed with constant operative conditions, while varying a selected condition to study the influence of the equipment set-up on the model. The material was comminuted using a previously determined specific pressing force, varying the feed particle size, roll speed and the static gap. A fourth group of experiments were performed varying the specific pressing force. Experimental results show the high performance of the comminution in a high-pressure environment. The static gap was the key in order to control the product particle size. A mathematical approach to predict the product particle size distribution is presented and it showed a good fit when compared to experimental data. This is the case when a narrow particle size fraction feed is used, but the fit became remarkably good with a multi-size feed distribution. However, when varying the specific pressing force in the case of the calc-silicate material, the results were not completely accurate. The hypothesis of simultaneous single particle compression and bed compression for different size ranges and with different parameters of the distribution function was probed and reinforced by various simulations that exchanged bed compression parameters over the single particle compression distribution function, and vice versa.Peer ReviewedPostprint (published version

ELECTRONIC TRAFFIC SIGNS: THE INTERPLAY BETWEEN HYBRID AND FULL MATRIX E-SIGNS

[EN] Road signs constitute a complex and growing communication system where different elements (pictograms, shapes, texts, etc.) are combined following different strategies. In this paper we have confronted drivers with a number of messages (congestion or road works, before, between, after location/s) developed as an adaptation of Advance Location Signs (class G, 1c in the 1968 Convention) to electronic displays. We manipulate two main factors a) the reading strategy (top-down vs. bottom-up) and the type of matrix display (hybrid, dissociating pictogram and text, vs. full matrix), in a repeated measures experimental design. The time taken to answer and the response given (correct, incorrect) was measured for each of the 24 message-blocks. Results show that the organization of the elements displayed is a key determinant for driver comprehension. Further thoughts on the need to understand the interplay between the formats adopted by static vs electronic message signs are provided.Lucas-Alba, A.; Hernando Mazón, A.; Blanch Micó, MT.; Gutiérrez Pérez, D.; Echeverría Villaspí, J.; Landa Tejero-Garcés, N. (2016). ELECTRONIC TRAFFIC SIGNS: THE INTERPLAY BETWEEN HYBRID AND FULL MATRIX E-SIGNS. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat Politècnica de València. 2038-2045. https://doi.org/10.4995/CIT2016.2015.3327OCS2038204

Breakage function for HPGR: mineral and mechanical characterization of tantalum and tungsten ores

The modelling of high pressure grinding rolls is described by the population balance model, a mass balance which includes several functions that are related to the mineral characteristics, material kinetics and operative conditions of the device. The breakage distribution function is one of these functions and refers to the way in which the daughter particles are generated by the process of comminution. The piston-die press is presented as a methodology to determine the breakage distribution function of two different materials, from the mechanical response point of view: altered granite and a cal-silicate material. The aim is to determine the relation between the operative conditions and the mineral characteristics in order to explain and predict the breakage function parameters. The materials were characterised using XRD and single compression strength tests. The altered granite is a brittle material, which generates more fines under single compression conditions compared to bed compression conditions, mainly due to the mineral composition and the response of the material to the breakage action. The cal-silicate material shows a normal trend in its breakage behaviour. As is expected, the mineralogical characterisation is a useful tool to predict the values of the parameters of the breakage distribution function.Peer ReviewedPostprint (published version

First-line treatment in lymphomatoid papulosis: a retrospective multicentre study

Background: Data regarding response to treatment in lymphomatoid papulosis (LyP) are scarce. Aim: To assess the daily clinical practice approach to LyP and the response to first-line treatments. Methods: This was a retrospective study enrolling 252 patients with LyP. Results: Topical steroids, methotrexate and phototherapy were the most common first-line treatments, prescribed for 35%, 20% and 14% of the patients, respectively. Complete response (CR) was achieved in 48% of treated patients. Eczematous lesions significantly increased relative risk (RR) of not achieving CR (RR = 1.76; 95% CI 1.16-2.11). Overall median time to CR was 10 months (95% CI 6-13 months), and 78% of complete responders showed cutaneous relapse; both results were similar for all treatment groups (P > 0.05). Overall estimated median disease-free survival (DFS) was 11 months (95% CI 9-13 months) but DFS for patients treated with phototherapy was 23 months (95% CI 10-36 months; P < 0.03). Having the Type A LyP variant (RR = 2.04; 95% CI 0.96-4.30) and receiving a first-line treatment other than phototherapy (RR = 5.33; 95% CI 0.84-33.89) were significantly associated with cutaneous early relapse. Of the 252 patients, 31 (13%) had associated mycosis fungoides unrelated to therapeutic approach, type of LyP or T-cell receptor clonality. Conclusions: Current epidemiological, clinical and pathological data support previous results. Topical steroids, phototherapy and methotrexate are the most frequently prescribed first-line treatments. Although CR and cutaneous relapse rates do not differ between them, phototherapy achieves a longer DFS. Presence of Type A LyP and use of topical steroid or methotrexate were associated with an increased risk of early relapse