bluuebunny/crossref_metadata_2025 huggingface dataset:
Extension of Negative Binomial GARCH Model
Authors: Ye Fan , Garcia Tanya P. , Pourahmadi Mohsen , Lord Dominique
Published: November 2012

Traditional crash count models, such as the Poisson and negative binomial models, do not account for the temporal correlation of crash data. In reality, crashes that occur in the same time frame are likely to share unobserved effects that may have been excluded from the model. If the temporal correlation of crash data is ignored, the estimated parameters can be biased and less precise. Therefore, there is a need to extend the standard crash count data models by incorporating temporal dependence. Whereas the literature for modeling time series count data is well developed, its applications for traffic crash data are limited. A particularly flexible model for the time series of counts is the negative binomial integer-valued generalized autoregressive conditional heteroscedastic (NBINGARCH) model, which properly accounts for the overdispersion, nonnegativity, and integer-valued features of count data. In this paper, the NBINGARCH model is extended to incorporate covariates so that the relationship between a time series of counts and correlated external factors may be properly modeled. The improved performance of the NBINGARCH model is demonstrated through a simulation study and an application to monthly driving under the influence (DUI) fatal crashes in Texas between 2003 and 2009. In addition, the relationship between monthly vehicle miles traveled (VMT) and gasoline prices in Texas is also examined. Ultimately, gasoline prices had no significant effect on DUI fatal crashes in Texas during that time period, and VMT had a positive effect.
Statistical Test for 85th and 15th Percentile Speeds with Asymptotic Distribution of Sample Quantiles
Authors: Hou Yi , Sun Carlos , Edara Praveen
Published: November 2012

The 85th and 15th percentiles are two parameters that are commonly used in traffic engineering and traffic safety. For example, 85th percentile speeds are used to set speed limits and to evaluate the effectiveness of safety countermeasures, and 15th percentile speeds are used to establish typical walking speeds for traffic signal timing. But the lack of a simple statistical test for percentiles has led some researchers to omit statistical analysis or apply nonideal approaches, such as averaging the 85th percentiles or using the binomial proportion test. This paper presents a statistical test for the 85th and 15th percentiles that is based on Crammer's theory of the asymptotic distribution of sample quantiles. This test is simpler to apply than the double bootstrapping or quantile regression methods. To illustrate its practical use, this quantile test is applied to three sample case studies: sequential warning lights at nighttime work zones, residential speed limits, and pedestrian signal timing.
Use of Computer Vision to Identify Pedestrians' Nonconforming Behavior at Urban Intersections
Authors: Zaki Mohamed H. , Sayed Tarek , Ismail Karim , Alrukaibi Fahad
Published: November 2012

The detection and understanding of nonconforming behavior (violations) can be useful in forming safety diagnoses and developing safety countermeasures. Traffic violations occur when road users, including pedestrians, seek increased mobility and disregard traffic laws and regulations. Such behavior can cause additional collision risks. This paper's objective is to demonstrate the automated identification of pedestrian crossing violations with computer vision techniques. Two types of violations are considered. The first is spatial violations: pedestrians cross an intersection in nondesignated crossing regions. The second is temporal violations: pedestrians cross an intersection during an improper signal phase. The methodology primarily relies on the identification of road users' trajectories and separating pedestrians with nonconforming behavior from those with conforming behavior. The methodology is demonstrated on two urban intersections, one in downtown Vancouver, Canada, the other in Kuwait City, Kuwait. The results show satisfactory accuracy in the detection of spatial and temporal violations, with an approximately 90% correct violation detection rate having been achieved in both case studies.
Crash Modification Factors
Authors: Hauer Ezra , Bonneson James A. , Council Forrest , Srinivasan Raghavan , Zegeer Charles
Published: November 2012

Crash modification factors (CMFs) are listed in the Highway Safety Manual and other authoritative publications. This information does not allow the reader to distinguish between the predictions of safety effect that can be made confidently and are likely to lead to correct decisions and those that can easily be wrong. Nor can it be known how transferable past research results are to decisions about future actions to be implemented under different circumstances. The conceptual framework described in this paper aims to provide guidance for research about CMFs and for meta-analyses. The central claim is that CMFs are random variables and are not universal constants that apply everywhere at all times. The smaller the standard deviation of a CMF, the more confident the related decision making can be. Therefore, the aim of research into CMFs is to reduce their standard deviations. Ways to do so efficiently are indicated. The requisite theory and equations are provided.
Sensitivity Analysis of Data Set Sizes for Highway Safety Manual Calibration Factors
Authors: Banihashemi Mohamadreza
Published: November 2012

The Highway Safety Manual (HSM), Part C, presents crash prediction models for three types of facilities. Each of these models was developed with data from a few states. As noted in the HSM, “The general level of crash frequencies may vary substantially from one jurisdiction to another for a variety of reasons… . Therefore, for the Part C predictive models to provide results that are meaningful and accurate for each jurisdiction, it is important that they be calibrated for application in each jurisdiction.” However, states may find the data requirements for calibration to be challenging. The HSM offers general recommendations for the size of the calibration data sets, but not much research is available to provide guidance to the states on how the quality of the calibration factor relates to the size of the calibration data set. This research uses data from Washington State for rural two-lane, rural multilane, and urban or suburban arterial highway segments and evaluates the quality of the calibration factors generated from data sets of different sizes, that is, from various percentages of the complete data set. Roadway and crash data are for the 3-year period from 2006 to 2008. The calibration factors generated from the whole data set for each highway type are considered the ideal calibration factors, and factors generated from different data set sizes are compared with these. The probability that the generated calibration factors fall within 5% and 10% of the ideal calibration factor is calculated. The results of this sensitivity analysis are reviewed, and recommendations are derived and presented.
Calibration of Highway Safety Manual Safety Performance Function
Authors: Brimley Bradford K. , Saito Mitsuru , Schultz Grant G.
Published: November 2012

This paper documents the calibration of the Highway Safety Manual (HSM) safety performance function (SPF) for rural two-lane two-way roadway segments in Utah and the development of new SPFs through negative binomial regression. Crash data from 2005 to 2007 on 157 selected study segments in Utah provided a 3-year frequency of observed crashes to calibrate the HSM SPF and develop new models. The calibration factor for the HSM SPF for rural two-lane two-way roads in Utah is 1.16, indicating that the original HSM model under predicts crashes in Utah. The HSM suggests that jurisdiction-specific SPFs may predict crashes with greater reliability than calibrated SPFs. The following variables were significant in each of the four models developed by this research: annual average daily traffic (AADT), segment length, speed limit, and the percentage of AADT composed of multiple-unit trucks. AADT and segment length are used in the HSM SPF; speed limit and the percentage of AADT composed of multiple-unit trucks were found to correlate significantly with observed crash frequencies. The fourth negative binomial model developed in the study would be the best SPF to predict crashes on rural highways in Utah. As encouraged by the HSM and contemporary research, the empirical Bayes method can be applied with each jurisdiction-specific SPF because the analysis provided an overdispersion parameter for each model.
Assessing International Transferability of Highway Safety Manual Crash Prediction Algorithm and Its Components
Authors: Sacchi Emanuele , Persaud Bhagwant , Bassani Marco
Published: November 2012

The Highway Safety Manual (HSM) provides an algorithm and associated knowledge to predict crashes on different types of facilities. This algorithm requires calibration to current local conditions through a procedure prescribed in the HSM to enhance its transferability. However, no procedure assesses the transferability. To fill this void, this paper focuses on a methodology to assess the transferability of the key HSM algorithm components—the baseline safety performance function and the crash modification factors (CMFs)—and uses the Italian road network as an illustrative case study. The calibration of the HSM crash prediction model is investigated with a data set for two-lane two-way rural highways to demonstrate some tools that could be used by jurisdictions around the world to assess the validity and compatibility of the CMFs and the base models, as well as the performance of the complete algorithm. A comparison with the results from a similar study carried out in Canada is provided to supplement the conclusions on the transferability of the HSM algorithm outside the United States.
Estimation of Safety Effectiveness of Composite Shoulders on Rural Two-Lane Highways
Authors: Zeng Huanghui , Schrock Steven D.
Published: November 2012

A paved shoulder is regarded as an effective safety improvement to reduce crashes. It is believed that there is a diminishing safety benefit for each additional increment of paved shoulder over a certain width. Thus, there might be greater systemwide safety benefits from paving longer roadway segments with a composite shoulder than from paving shorter roadway segments with a full-width paved shoulder. The objective of this study was to determine the safety benefits of composite shoulders, such as a small paved shoulder combined with turf on the outside. This approach was part of the Kansas Department of Transportation's effort to find practical improvements to maximize the benefits of shoulders relative to the input costs. Of the 8,300 mi (13,358 km) of rural two-lane highways in Kansas, approximately 25% are equipped with composite shoulders consisting of 3 ft (0.9 m) of pavement, with the remainder being turf. The safety effectiveness of these shoulders was studied with a combined empirical Bayes method. Three safety performance functions were used to create Kansas-specific crash modification factors for composite shoulders compared with segments with no or unpaved shoulders. It was found that upgrading narrow unpaved shoulders to composite shoulders could reduce shoulder-related crashes by up to 61% and fatal and injury crashes by 31%. On the basis of these results, 20-year projections were developed that estimated the safety effectiveness that could be achieved through the implementation of these safety improvements.
Relationship between Freeway Flow Parameters and Safety and Its Implication for Adding Lanes
Authors: Kononov Jake , Reeves David , Durso Catherine , Allery Bryan K.
Published: November 2012

The decision to add lanes to a freeway is motivated by the need to relieve congestion. Practicing engineers and planners generally believe that the decreased congestion that results from adding lanes is associated with some degree of improved safety, yet the majority opinion of researchers is that accident rates increase as the number of lanes increases. In more than 70 years of modern road building, these conflicting views have not been reconciled. This paper first examines the relationship of traffic flow parameters, such as volume, density, and speed, with safety by calibrating corridor-specific safety performance functions. On the basis of an understanding of this relationship, a possible explanation of the effect that adding lanes has on safety is formulated. An empirical examination of the relationship of flow, density, and speed to the crash rate on selected freeways in Colorado suggests that, as the flow increases, the crash rate initially remains constant until a certain critical threshold combination of speed and density is reached. Once this threshold is exceeded, the crash rate rapidly rises. The rise in the crash rate may be because an increase in density without a notable reduction in speed produces headways so small that it becomes difficult or impossible to compensate for driver error. This model suggests that, after the construction of additional lanes, crash rates initially decline because of the lower traffic volume and density per lane. However, as development and rerouting occur, freeways with more lanes are expected to have higher crash rates that are attributable to the increased opportunities for lane change–related conflicts.
Horizontal Curves, Signs, and Safety
Authors: Khan Ghazan , Bill Andrea R. , Chitturi Madhav , Noyce David A.
Published: November 2012

Although the safety of horizontal curves has been researched, data availability and quality have been the Achilles' heel of many studies. Furthermore, safety at horizontal curves has become more significant in view of the changes in the latest Manual on Uniform Traffic Control Devices with respect to traffic control devices at horizontal curves. The objective of this research was to evaluate the safety of horizontal curves through the use of curve geometric characteristics and sign data. The focus was on collecting a good-quality large data set to develop models and explore the relationship between safety at horizontal curves and sign types, specifically curve and turn signs. The data set included curves on different types of roads to determine the difference in safety characteristics that had not been examined in the literature. The crash prediction models displayed highly significant variables, which showed a positive relationship with annual average daily traffic, posted speed, and curve length, and a negative relationship with curve radius. The results show that sharper curves (Classes B–F) on two-lane roads are less safe than curves on freeways and multilane and urban roads. However, further investigation is required into the safety characteristics of Class A curves on freeways and multilane roads, compared with two-lane roads. Moreover, sign usage was not found to be a significant factor for sharper curves, which suggests that, regardless of the presence of the curve or turn sign, other influencing factors take over. The crash prediction model results provided greater detail and identified variables with large significance.
An Eco-Evolutionary Model for Demographic and Phenological Responses in Migratory Birds
Authors: Johansson Jacob , Smallegange Isabel M. , Jonzén Niclas
Published: November 2012

Many migratory birds have changed their timing of arrival at breeding grounds in response to recent climate change. Understanding the adaptive value and the demographic consequences of these shifts are key challenges. To address these questions we extend previous models of phenological adaptation to climate change under territory competition to include feedback from population dynamics, winter survival and habitat productivity. We study effects of improved pre-breeding survival and of earlier food abundance peak. We show that phenological responses depend strongly on equilibrium population density via effects on territory competition. When density is high, improved pre-breeding survival affects selection pressures more than shifts of the resource peak. Under certain conditions, an advanced food peak can even select for later arrival due to competitive release. Improved pre-breeding survival has positive effects on population density that in many cases is stronger than negative effects of an advanced food peak. The fraction of young in the population decreases in all scenarios of change, but food peak shifts only affect population structure marginally unless population density is low. This work thus provides several missing links between phenological adaptation and demographic responses, and augments the toolbox for interpreting ongoing phenological shifts in migratory birds. We illustrate the utility of our model by explaining different patterns in demographic trends and phenological shifts in populations of Pied flycatchers (Ficedula hypoleuca) across Western Europe.
Cross-sectional Study on the Effects of Socioeconomic Factors on Lead Exposure in Children by Gender in Serpong, Indonesia
Authors: Iriani Dewi U. , Matsukawa Takehisa , Tadjudin Muhammad K. , Itoh Hiroaki , Yokoyama Kazuhito
Published: November 2012

To elucidate the socioeconomic factors influencing lead exposure in elementary school children by gender, 108 children (56 male, 52 female), aged 6–7 years, were randomly selected from 39 elementary state schools in Serpong, Banten, Indonesia. Their parents were interviewed to obtain information on sociodemographic characteristics. Their blood lead (BPb) levels were measured by atomic absorption spectrophotometry. BPb concentrations were significantly higher in males than in females, i.e., 6.8 ± 2.0 (2.9–12.5) µg/dL and 5.9 ± 1.9 (3.1–11.7) µg/dL, respectively (p < 0.05). Lower socioeconomic status and well water use were associated with increased BPb concentrations, especially in females. The proportion of well water use was related to lower socioeconomic status. Lower socioeconomic status linked with well water drinking seemed to be associated with increased lead exposure in children in Serpong. Their exposure levels possibly varied according to gender differences in behavior. An intervention should be instituted among children in Serpong with BPb concentrations of 10 µg/dL or above.
A DNA Repair BRCA1 Estrogen Receptor and Targeted Therapy in Breast Cancer
Authors: Ratanaphan Adisorn
Published: November 2012

BRCA1 is a key mediator of DNA repair pathways and participates in the maintenance of the genomic integrity of cells. The control of DNA damage repair mechanisms by BRCA1 is of great interest since molecular defects in this pathway may reflect a predictive value in terms of a cell’s sensitivity to DNA damaging agents or anticancer drugs. BRCA1 has been found to exhibit a hormone-dependent pattern of expression in breast cells. Wild-type BRCA1 is required for the inhibition of the growth of breast tumor cells in response to the pure steroidal ERα antagonist fulvestrant. Also a loss of BRCA1-mediated transcriptional activation of ERα expression results in increased resistance to ERα antagonists. Platinum-based drugs, poly(ADP-ribose) polymerase (PARP) inhibitors, and their combination are currently included in chemotherapy regimens for breast cancer. Preclinical and clinical studies in a BRCA1-defective setting have recently indicated a rationale for the use of these compounds against hereditary breast cancers. Initial findings indicate that neoadjuvant use of cisplatin results in high rates of complete pathological response in patients with breast cancer who have BRCA1 mutations. Cisplatin produces a better response in triple-negative breast cancer (TNBC) than in non-TNBC diseases in both the neoadjuvant and adjuvant settings. This implies that TNBC cells may harbor a dysfunctional BRCA1 repair pathway.
Enhancing the Search in MOLAP Sparse Data
Authors: Zalaket Joseph
Published: November 2012

Multidimensional on-line analytical processing (MOLAP) systems deal well with dense data than relational ones (ROLAP). In the existence of sparse data, MOLAP systems become memory consuming, which may limit and slow down data processing tasks. Many compression techniques have been proposed to deal with the sparsity of data in MOLAP systems. One of these techniques is the bitmap compression, which allows a significant reduction of the memory space used for data processing. In this article, we propose an extension to the bitmap compression technique by storing the compressed data as bits into multiple efficient data structures based on a new indexing strategy instead of the linear structure. Compared with the classical bitmap, the proposed enhancement not only allows space reduction but also reduces the search time through the compressed data. We present some algorithms that allow maintaining and searching within the compressed structure without the need for decompression. We demonstrate that the complexity of the proposed algorithms varies from logarithmic to constant, compared with the linear complexity of the classical bitmap technique.
Mineralization Content Alters Osteogenic Responses of Bone Marrow Stromal Cells on Hydroxyapatite/Polycaprolactone Composite Nanofiber Scaffolds
Authors: Ruckh Timothy , Carroll Derek , Weaver Justin , Popat Ketul
Published: November 2012

Synthetic tissue scaffolds have a high potential impact for patients experiencing osteogenesis imperfecta. Using electrospinning, tissue scaffolds composed of hydroxyapatite/polycaprolactone (HAp/PCL) composite nanofibers were fabricated with two different HAp concentrations—1% and 10% of the solid scaffold weight. After physico-chemical scaffold characterization, rat bone marrow stromal cells were cultured on the composite scaffolds in maintenance medium and then in osteogenic medium. Quantitative PCR, colorimetric assays, immunofluorescent labeling, and electron microscopy measured osteogenic cell responses to the HAp/PCL scaffolds. In maintenance conditions, both Hap/PCL scaffolds and control scaffolds supported cell colonization through seven days with minor differences. In osteogenic conditions, the 10% HAp scaffolds exhibited significantly increased ALP assay levels at week 3, consistent with previous reports. However, qPCR analysis demonstrated an overall decrease in bone matrix-associated genes on Hap/PCL scaffolds. Osteopontin and osteocalcin immunofluorescent microscopy revealed a trend that both mineralized scaffolds had greater amounts of both proteins, though qPCR results indicated the opposite trend for osteopontin. Additionally, type I collagen expression decreased on HAp scaffolds. These results indicate that cells are sensitive to minor changes in mineral content within nanofibers, even at just 1% w/w, and elucidating the sensing mechanism may lead to optimized osteogenic scaffold designs.
Le packing, son aventure et ses avatars
Authors: Delion Pierre
Published: November 2012

Résumé La technique du packing est éclairée par la psychopathologie psychanalytique. Toutefois, les études récentes, neuro-physiologiques, développementales, psychopathologiques et institutionnelles viennent converger pour donner à ce soin une possibilité de construire un cadre psychothérapique avec les enfants et les adolescents autistes et psychotiques, à condition de l’intégrer dans une complexité institutionnelle qui prend en compte tous les aspects nécessaires à la prise en charge du sujet en question. Les menées violentes de ses détracteurs sont relativisées par rapport aux bons résultats cliniques obtenus, dont un programme de recherche clinique hospitalier doit rendre compte dans les prochains mois.
Faut-il un ou une thérapeute pour ce jeune patient ?
Authors: Chekroun Laurence
Published: November 2012

Résumé Ce texte est issu de discussions et de réflexions entre mon travail de psychanalyste et celui de superviseuse. Je l’ai écrit suite à une discussion avec une assistante que je supervise. Elle me parlait de ses préoccupations concernant des entretiens avec de tout jeunes adolescents très inhibés et silencieux en séance avec elle. Cette difficulté récurrente l’avait conduite à se/me demander s’il n’aurait pas été plus judicieux de les adresser à des thérapeutes hommes ? J’ai alors essayé de réfléchir aux moyens de sortir de l’impasse dans laquelle elle se sentait prise avec eux.
Le régionalisme commercial en Asie orientale
Authors: Guilhot Laëtitia
Published: November 2012

Résumé Cet article vise à estimer l’impact des trois principaux accords de libre-échange est-asiatiques (Asean, Asean-Chine, Asean-Corée du Sud) sur le commerce intra-zone et extra-zone. Il s’appuie, pour ce faire, sur un modèle de gravité en données de panel doté de trois variables indicatrices régionales. Les résultats de ces estimations permettent de conclure que l’accord au sein de l’Asean favorise le commerce régional et multilatéral. L’accord Asean-Chine impacte positivement sur les flux intra-régionaux et permet la création d’exportations extra-régionales, mais aucun effet n’a été révélé sur les importations extra-régionales. L’accord Asean-Corée du Sud n’a, pour l’instant, aucun impact sur les flux commerciaux est-asiatiques.
Ferenczi, patient somatisant. Homosexualité latente et équilibre psychosomatique
Authors: Press Jacques
Published: November 2012

Résumé L’auteur émet l’hypothèse que Ferenczi s’est trouvé pris dans une impasse psychique dans son lien à Freud, impasse l’ayant conduit à des somatisations de gravité croissante. Il en analyse les enjeux.
Ferenczi, ou le mal de l'introjection
Authors: Duparc François
Published: November 2012

Résumé Passionnantes, l’œuvre de Ferenczi, aux limites de la vie psychique, mais aussi sa vie et sa maladie. Ses deux affections auto-immunes, maladie de Basedow puis de Biermer, sa Correspondance et son Journal évoquent l’analyse insuffisante par Freud de son transfert maternel négatif. Ses travaux sur le clivage du moi, la prématurité du moi de l’enfant thérapeute par introjection du parent qui le maltraite, sa difficulté à exprimer son agressivité envers l’objet, et son hyperactivité psychique (manie blanche), sont communs entre lui et beaucoup de patients souffrant de maladies auto-immunes.
La contribution de Ferenczi au concept de contre-transfert
Authors: Martín Cabré Luis J. , Michaud Henriette
Published: November 2012

Résumé L’auteur reprend la notion de contre-transfert depuis les premiers travaux freudiens, à partir de l’optique de Ferenczi. Il montre comment Ferenczi a mis en place l’usage du contre-transfert comme instrument clinique fondamental, tout comme celui d’ Einfühlung (empathie) et celui de la seconde règle fondamentale (la nécessité incontournable de l’analyse de l’analyste). Il reprend à partir de la perspective de Ferenczi certains concepts comme la compulsion de répétition, la régression thérapeutique ou la dynamique transfert/contre-transfert et les rapproche de travaux d’autres auteurs comme Racker, Winnicott, Searles, M. Little et P. Heimann auxquels on a attribué de nombreux apports théoriques avancés par Ferenczi, comme l’utilité du contre-transfert ou de la contre-identification projective et de la participation émotionnelle de l’analyste.
Le transplant étranger, un écart qui estrange
Authors: Garon Josette
Published: November 2012

Résumé L’auteur met en lumière un concept de Ferenczi inséparable de celui de traumatisme : le transplant étranger. Ce concept permet de prendre en compte ce qui, de l’inconscient des parents, est implanté dans le psychisme de l’enfant du fait du désaveu. Il s’avère particulièrement précieux pour penser l’empreinte des traumatismes transgénérationnels, objets de déni, donc soustraits au travail de négation. Ni représentés ni symbolisés, mais répétés, ceux-ci sont agis dans la relation passionnelle que les parents entretiennent avec leur enfant. D’où l’importance dans l’analyse d’adulte de donner voix à l’enfant traumatisé et accès à la représentation.
La transmission disjointe
Authors: Schneider Monique
Published: November 2012

Résumé L’héritage freudien s’impose comme dédoublé dès sa fondation, puisqu’il repose sur la négation d’une croyance − « je ne crois plus à mes Neurotica  » − qui restera souterrainement agissante. C’est le réseau théorique enterré dès le début que Ferenczi, en une contestation qu’il présente comme retour aux sources, s’acharnera à exhumer pour apporter à l’entreprise analytique un commencement différé.
La dépression de transfert de Ferenczi
Authors: Bokanowski Thierry
Published: November 2012

Résumé L’auteur, s’appuyant sur la Correspondance Freud-Ferenczi , propose d’envisager les reproches de « transfert négatif non analysé » formulés par Ferenczi à l’égard de son analyste Freud lors des dernières années de leur relation comme ayant pu être liés à une dépression primaire, transformée en « dépression de transfert », laquelle semble cependant avoir été à la racine de nombreux concepts qui ont, depuis, profondément marqué la psychanalyse de leur empreinte.
Psychisme et cancer
Authors: Jean-Strochlic Christine
Published: November 2012

Résumé Cet ouvrage retrace l’historique de la création du Centre P. Cazenave à partir d’entretiens avec P. Cazenave avant son décès et d’autres thérapeutes du Centre et montre la proximité entre certains concepts de S. Ferenczi et les points de vue développés.
Réflexions autour des tables interactives : expérience utilisateur, utilisabilité, évaluation
Authors: Kubicki S. , Borgiel K. , Lepreux S. , Wolff Marion , Kolski Christophe
Published: November 2012

Résumé Depuis le début des années 1990, les tables interactives soulèvent un intérêt croissant tant dans les recherches académiques qu’industrielles. L’engouement pour ces nouvelles plate-formes d’interaction ne cessant d’augmenter chaque année, nous proposons dans cet article un état de l’art associé à un ensemble de réflexions. Il s’avère que les applications sur tables interactives évoluent : celles-ci passent progressivement de l’exploitation d’objets virtuels à celle d’objets tangibles. Les usages étant différents des plate-formes courantes (ordinateur, appareils mobiles, etc.), nous proposons de présenter des pistes de réflexion tant sur l’expérience (multi-)utilisateur(s) que sur l’utilisabilité des tables interactives. Nous commençons par la description des facteurs influençant les interactions humain-machine sur tables interactives. Ensuite, nous présentons et discutons de la perception des qualités instrumentales (par ex. utilité et utilisabilité) et non instrumentales (telles que les qualités esthétiques, symboliques et motivationnelles) des tables interactives. L’article continue avec un ensemble de perspectives relatives aux évaluations potentielles liées à l’utilisation de ces nouvelles plate-formes qui, comme chaque type de nouveau dispositif, doit être évaluée à de nombreuses reprises en termes de critères d’utilisabilité mais aussi selon un ensemble de critères liés à l’expérience utilisateur. Cinq types d’évaluations peuvent être distingués : (1) des études comparatives avec d’autres plate-formes et des tâches comparables ; (2) des études détaillées de nouvelles applications destinées aux tables interactives ; (3) des études focalisées sur la collaboration ; (4) des études impliquant des observations d’utilisation libre et (5) des études longitudinales. L’article se termine avec une conclusion et des perspectives de recherche.
Développement d'une plate-forme d'évaluation personnalisable et adaptable pour l'étude du comportement émotionnel en situation de multisollicitation
Authors: Mollard Régis , Wolff Marion , Couture Nadine , Clay Alexis
Published: November 2012

Résumé Cet article présente une plate-forme qui permet d’évaluer l’expérience utilisateur face à des concepts innovants dans des systèmes sociotechniques évolutifs. Développer un système nécessite d’effectuer des évaluations qui soient formatives (tout au long de la phase de conception) et sommatives (en fin de conception). Concevoir ou reconcevoir des systèmes, c’est créer de nouvelles interactions humain-humain et humain-système. Au travers d’innovations technologiques c’est aussi créer de nouveaux usages. Prévoir ces usages et évaluer ces interactions nécessite de mettre en place des expérimentations et des essais faisant appel à des méthodes et des outils permettant d’enregistrer, d’analyser et d’interpréter les activités mais aussi les comportements des personnes en interaction. Au-delà de l’usage (utilité, utilisabilité, sens), l’émotion ressentie au cours de l’action peut être un facteur déterminant de la conduite et de la performance d’un système. La plate-forme pepss réunit à la fois des prototypes, des méthodes et des outils associés. Dans cet article, nous présentons une méthode permettant d’évaluer les processus émotionnels d’opérateurs confrontés à des multisollicitations pendant la réalisation d’une tâche de surveillance. Le protocole utilisé se base sur un test attentionnel multisollicitation (dérivé de la MultiAttribute Task ou mat ), où les sujets se voient détournés de leur tâche principale par des agents distracteurs/stresseurs. La plate-forme pepss et la méthode statistique associée que nous décrivons dans cet article soulignent l’importance de la synchronisation d’un maximum de moyens en temps réel, tout en effectuant des choix afin de limiter l’intrusivité des outils mis en œuvre.
A methodological proposal to assist scenario-based design in the early stages of innovation projects
Authors: Nelson Julien , Buisine Stéphanie , Aoussat Améziane
Published: November 2012

Résumé Les ergonomes sont de plus en plus sollicités pour intervenir dans les phases initiales des projets de conception innovante. Leur contribution s’appuie le plus souvent sur l’analyse d’activités existantes ou de situations permettant d’appréhender l’activité future des usagers (ex. simulations). Ceci repose sur les postulats que (a) l’énoncé initial du problème de conception permet d’identifier clairement des situations de référence pour décrire l’activité future, et (b) le concept de produit est suffisamment mûr pour permettre la production d’objets intermédiaires (maquettes, prototypes) dont l’usage pourra être analysé. Dans les étapes initiales de projets d’innovation, ces postulats ne sont pas toujours vérifiés. Les ergonomes peuvent alors être appelés dans les étapes idéatives du projet, pour proposer et examiner des concepts de produits et d’usages nouveaux. Dans cet article, nous évaluons l’apport d’outils empruntés à la résolution créative de problèmes et à la fiabilité industrielle pour générer et analyser des scénarios d’usage dans ce cadre. Lors de simulations de réunions de conception, nous avons invité des équipes pluridisciplinaires de concepteurs à anticiper les usages de deux produits innovants : une table interactive et un dispositif de prévention de la noyade infantile. Les participants travaillaient soit librement, soit en utilisant les méthodes du brainwriting et de la matrice de découverte, pour construire des scénarios. Ils généraient ensuite, suivant une méthode dérivée de l’analyse des modes de défaillance, de leurs effets et de leur criticité, des revendications (claims) pour la conception. à partir de l’analyse de traces écrites et orales de l’activité et d’un questionnaire ad hoc , nous avons évalué la performance créative et le ressenti des participants. Notre méthodologie originale associe une approche de l’analyse de l’activité répandue dans l’étude des activités de conception, avec le cadre théorique de la génération d’idées en groupe utilisé dans des travaux en psychologie de la créativité. Comme les autres métiers de la conception représentés (ingénieurs et designers industriels), les ergonomes ont pu générer des idées sur les usages futurs possibles des produits, mais leur expertise leur a permis d’en produire davantage. Les outils proposés montrent un besoin de structurer l’exploration d’usages dans les phases en amont du processus. Ils ont permis de meilleures performances chez les concepteurs travaillant sur la table interactive, mais les résultats ont été moins concluants pour le travail sur l’équipement de sécurité. L’AMDEC modifiée pourrait, enfin, permettre de répartir l’interprétation des scénarios sur plusieurs équipes de travail. Ces résultats, enfin, encouragent au développement d’une ergonomie prospective de l’innovation.
Développement d'un système d'assistance à la détection des usagers vulnérables pour véhicules industriels en milieu urbain
Authors: Tattegrain Hélène , Maincent Annick , Bruyas Marie-Pierre , Bonnard Arnaud
Published: November 2012

Résumé La sécurité des usagers vulnérables une question importante en termes de santé publique : la plupart des accidents impliquant des camions et des usagers vulnérables dans des zones urbaines ont des conséquences dramatiques pour ces derniers. Le projet VIVRE2 ( anr 05- pdit ) avait pour objectif l’étude et la conception de solutions technologiques pour réduire significativement le nombre de ces accidents. Pour concevoir ce système, l’approche User Centred Design , basée sur les étapes itératives décrites par Maguire (2001), a été adoptée en incluant des créations d’outils pour pouvoir l’appliquer dans le contexte industriel. Une plate-forme d’intégration a été conçue pour réduire le temps d’intégration du système d’assistance dans l’environnement de simulateur de conduite et ainsi faciliter le processus itératif. De plus, un générateur de scénario dynamique a permis la conception en laboratoire d’un système d’assistance actif en prenant en compte l’ensemble des cas d’utilisation. Le contexte d’utilisation a été analysé selon le point de vue de conducteurs et selon celui des usagers vulnérables. Les spécifications ont été définies pour améliorer l’utilisation de système dans la tâche de conduite selon les contraintes de cette dernière (l’aspect temporel, la complexité, la demande attentionnelle). Le système, basé sur une technologie adaptative, a été développé en prenant en compte le comportement du conducteur pour adapter les alertes de l’Interface Humain-Machine et les commandes actives. Le système retenu a été évalué sur simulateur dynamique de conduite et a prouvé son acceptabilité par les conducteurs et son efficacité sur des situations critiques sélectionnées (il a permis d’éviter 89 % des situations potentiellement critiques sur simulateur).
Le jardin individuel au cœur des enjeux fonciers et écologiques dans une métropole régionale : le cas de Tours en France
Authors: Oillic Pascal , Yengué Jean Louis , Génin Alain
Published: November 2012

Le travail présenté est une tentative pour saisir l’évolution de la place des espaces verts et la structuration des grandes villes qu’ils induisent à travers le sol, compris ici à la fois dans son horizontalité, composante foncière, et dans sa verticalité, entité vivante. Le sol est de fait le support des espaces verts, enjeu foncier de premier ordre, mais aussi investissement social et écologique. Le travail porte sur une métropole moyenne de rayonnement régional, Tours, caractérisée comme ville verte et plus précisément sur Saint-Cyr-sur-Loire, commune de l’agglomération, banlieue verte et aisée, riche en espaces verts avant tout de types privés. Fondée sur des entretiens menés auprès d’associations, d’habitants et de représentants de la municipalité, la recherche fait ressortir que le jardin individuel est le médiateur entre le sol, l’usager et la municipalité. Les pratiques spatiales des habitants dans les jardins sont au cœur de leur relation au sol comme entité vivante. Les représentations de la nature qui les motivent sont majoritairement celles d’un espace d’agrément dans lequel le sol est perçu comme une contrainte engendrant des stratégies d’adaptation variées.
A Novel Multi-Scale Modeling Approach to Infer Whole Genome Divergence
Authors: Reuveni Eli , Giuliani Alessandro
Published: November 2012

We propose a novel and simple approach to elucidate genomic patterns of divergence using principal component analysis (PCA). We applied this methodology to the metric space generated by M. musculus genome-wide SNPs. Distance profiles were computed between M. musculus and its closely related species, M. spretus, which was used as external reference. While the speciation dynamics were apparent in the first principal component, the within M. musculus differentiation dimensions gave rise to three minor components. We were unable to obtain a clear divergence signature discriminating laboratory strains, suggesting a stronger effect of genetic drift. These results were at odds with wild strains which exhibit defined deterministic signals of divergence. Finally, we were able to rank novel and previously known genes according to their likelihood to be under selective pressure. In conclusion, we posit PCA as a robust methodology to unravel diverging DNA regions without any a priori forcing.
On the asymptotics of visible elements and homogeneous equations in surface groups
Authors: Antolín Yago , Ciobanu Laura , Viles Noèlia
Published: November 2012

Let

F

be a group whose abelianization is

\mathbb{Z}^k

,

k\geq 2

. An element of

F

is called visible if its image in the abelianization is visible, that is, the greatest common divisor of its coordinates is 1.

In this paper we compute three types of densities, annular, even and odd spherical, of visible elements in surface groups. We then use our results to show that the probability of a homogeneous equation in a surface group to have solutions is neither 0 nor 1, as the lengths of the right- and left-hand side of the equation go to infinity.
$N$-step energy of maps and the fixed-point property of random groups
Authors: Izeki Hiroyasu , Kondo Takefumi , Nayatani Shin
Published: November 2012

We prove that a random group of the graph model associated with a sequence of expanders has the fixed-point property for a certain class of CAT(0) spaces. We use Gromov’s criterion for the fixed-point property in terms of the growth of

n

-step energy of equivariant maps from a finitely generated group into a CAT(0) space, for which we give a detailed proof. We estimate a relevant geometric invariant of the tangent cones of the Euclidean buildings associated with the groups PGL(

m,\mathbb{Q}_r

), and deduce from the general result above that the same random group has the fixed-point property for all of these Euclidean buildings with

m

bounded from above.
Arithmetic aspects of self-similar groups
Authors: Kapovich Michael
Published: November 2012

We prove that an irreducible lattice in a semisimple algebraic group is virtually isomorphic to an arithmetic lattice if and only if it admits a faithful self-similar action on a rooted tree of finite valency.
Interval exchanges that do not occur in free groups
Authors: Novak Christopher F.
Published: November 2012

A disjoint rotation map is an interval exchange transformation (IET) on the unit interval that acts by rotation on a finite number of invariant subintervals. It is currently unknown whether the group

\mathcal{E}

of all IETs possesses any non-abelian free subgroups. It is shown that it is not possible for a disjoint rotation map to occur in a subgroup of

\mathcal{E}

that is isomorphic to a non-abelian free group.
A criterion to identify the equilibration time in lipid bilayer simulations
Authors: Porasso Rodolfo D. , López Cascales José J.
Published: November 2012

With the aim of establishing a criterion for identifying when a lipid bilayer has reached steady state using the molecular dynamics simulation technique, lipid bilayers of different composition in their liquid crystalline phase were simulated in aqueous solution in presence of CaCl$_2$ as electrolyte, at different concentration levels. In this regard, we used two different lipid bilayer systems: one composed by 288 DPPC (DiPalmitoylPhosphatidylCholine) and another constituted by 288 DPPS (DiPalmitoylPhosphatidylSerine). In this sense, for both type of lipid bilayers, we have studied the temporal evolution of some lipids properties, such as the surface area per lipid, the deuterium order parameter, the lipid hydration and  the lipid-calcium coordination. From their analysis, it became evident how each property has a different time to achieve equilibrium. The following order was found, from faster property to slower property: coordination of ions $\approx$ deuterium order parameter $>$ area per lipid $\approx$ hydration. Consequently, when the hydration of lipids or the mean area per lipid are stable we can ensure that the lipid membrane has reached the steady state.Received: 3 September 2012,  Accepted: 24 October 2012; Edited by: M. C. Barbosa; DOI:http://dx.doi.org/10.4279/PIP.040005Cite as: R. D. Porasso, J. J. López Cascales, Papers in Physics 4, 040005 (2012)
Anisotropy of small-scale stratospheric irregularities retrieved from scintillations of a double star α-Cru observed by GOMOS/ENVISAT
Authors: Kan V. , Sofieva V. F. , Dalaudier F.
Published: November 2012

Abstract. In this paper, we discuss estimating anisotropy of air density irregularities (ratio of characteristic horizontal and vertical scales) from satellite observations of bi-chromatic scintillations of a double star whose components are not resolved by the detector. The analysis is based on fitting experimental auto- and cross-spectra of scintillations by those computed using the 3-D spectral model of atmospheric irregularities consisting of anisotropic and isotropic components. Application of the developed method to the scintillation measurements of the double star α-Cru by GOMOS (Global Ozone Monitoring by Occultation of Stars) fast photometers results in estimates of anisotropy coefficient of ~15–20 at altitudes 30–38 km, as well as other parameters of atmospheric irregularities. The obtained estimates of the anisotropy coefficient correspond to small-scale irregularities, close to the buoyancy scale.
Short and long term consequences of larval stage exposure to constantly and ephemerally elevated carbon dioxide for marine bivalve populations
Authors: Gobler C. J. , Talmage S. C.
Published: November 2012

Abstract. While larval bivalves are highly sensitive to ocean acidification, the basis for this sensitivity and the longer term implications of this sensitivity are unclear. Experiments were performed to assess the short term (days) and long term (months) consequences of larval stage exposure to varying CO2 concentrations for calcifying bivalves. Higher CO2 concentrations depressed both calcification rates assessed using 45Ca uptake and RNA:DNA ratios in Mercenaria mercenaria and Argopecten irradians larvae with RNA:DNA ratios being highly correlated with larval growth rates r2 > 0.9). These findings suggested that high CO2 has a cascading negative physiological impact on bivalve larvae stemming in part from lower calcification rates. Exposure to elevated CO2 during the first four days of larval development significantly depressed A. irradians larval survival rates, while a 10 day exposure later in larval development did not, demonstrating the extreme CO2-sensitivity of bivalve larvae during first days of development. Short- (weeks) and long-term (10 month) experiments revealed that individuals surviving exposure to high CO2 during larval development grew faster when exposed to normal CO2 as juveniles compared to individuals reared under ambient CO2 as larvae. These increased growth rates could not, however, overcome size differences established during larval development, as size deficits of individuals exposed to even moderate levels of CO2 as larvae were evident even after 10 months of growth under normal CO2 concentrations. This `legacy effect' emphasizes the central role larval stage CO2 exposure can play in shaping the success of modern day bivalve populations.