Literatura académica sobre el tema "Four à soles multiples"
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Artículos de revistas sobre el tema "Four à soles multiples"
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Tsamago, Hodi y Anass Bayaga. "Exploring secondary school learners' perceptions of the effectiveness of SOLEs pedagogy in physical sciences as a component of STEM". F1000Research 13 (22 de febrero de 2024): 130. http://dx.doi.org/10.12688/f1000research.142056.1.
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The exploratory case study design investigated learners’ perceptions of the effectiveness of self-organized learning environments (SOLEs) pedagogy in physical sciences. Fifteen Grade 11 learners were selected using a purposive sampling method and underwent SOLEs pedagogy instruction for four weeks before they were interviewed through focus group interviews (FGIs). Data were analyzed thematically using the coding method, which was conducted on a sentence-by-sentence basis. The results indicated that learners have a positive perception towards SOLEs pedagogy, because they believe that SOLEs pedagogy enables them to link their classroom experiences with their real-life experiences; it provides them (learners) with an opportunity to simulate practical experiments in the physical sciences; it provides them with multiple channels for receiving information; it enables them to learn collaboratively and limits their reliance on the teacher. Consequently, this study’s findings justify the implementation of SOLEs pedagogy in science education at the secondary school level.
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Mulder van Staden, Suné, Carl de Villiers, Julandi Alwan, Mpho Moloi y Sibongile Mahlangu. "Oral Manifestations of Syphilis: Report of Four Cases". Pathogens 11, n.º 6 (24 de mayo de 2022): 612. http://dx.doi.org/10.3390/pathogens11060612.
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Syphilis is an infectious disease caused by Treponema pallidum. Syphilis can present with an array of oral manifestations at different stages of disease progression. This article reports on four cases of syphilis with oral manifestations diagnosed by oral health professionals. Case 1: 18-year-old female presented with multiple ulcerations and patches involving the hard palate, uvula, retromolar area, and papillary nodules on the tongue. Case 2: 25-year-old male presented with a solitary, exophytic lesion on the anterior tongue. Case 3: 17-year-old female presented with multiple pigmented macules on the palms of hands and soles of feet, as well as multiple exophytic, sessile, soft tissue masses throughout the oral cavity. Case 4: 14-year-old female presented with a solitary, exophytic, verrucous lesion in the incisive papilla area, as well as multiple, coalescing patches involving the soft palate, uvula, and tonsillar areas. All patients were managed by biopsy and serological investigations. Treatment of syphilis was performed at infectious disease clinics with 2.4 million units (MUs) benzathine benzylpenicillin intramuscular (IM) weekly. Oral health professionals need to have knowledge of the oral manifestations of syphilis to ensure that patients are accurately identified and appropriately treated.
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Rickards, Tracey y Tammy Cornish. "Reaching out to diabetic soles: Outreach foot care pilot project". SAGE Open Medicine 6 (enero de 2018): 205031211882003. http://dx.doi.org/10.1177/2050312118820030.
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Objectives: To assess the effectiveness of outreach foot care services as a tool for engagement with isolated vulnerable seniors. To improve foot health of diabetic seniors, thus avoiding expensive and potentially life-threatening diabetic complications. Methods: Four validated tools are used to gather data: InLow 60-second Diabetic Foot Screen©, Short Diabetes Knowledge Instrument for Older and Minority Adults, Brief Healthcare Questionnaire (Patient Health Questionnaire-9), and the Health-Related Quality of Life Questionnaire. Results: Five monthly visits to 20 participants resulted in multiple co-morbidities being identified, improvements in foot status and diabetic knowledge realized, and determinants of health addressed. Seniors needed support and resources to engage in diabetes self-management. Conclusion: The importance of regular foot care as a key element of any self-management plan for diabetes cannot be understated, nor can increasing social services spending to include coverage for foot care thereby avoiding expensive healthcare. Using foot care as a tool for engagement conferred access to vulnerable seniors who ultimately benefited from healthcare and social interactions with a provider.
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Chaudhry, Shahrukh, Idris Akinlusi, Ted Shi y Jorge Cervantes. "Secondary Syphilis: Pathophysiology, Clinical Manifestations, and Diagnostic Testing". Venereology 2, n.º 2 (11 de abril de 2023): 65–75. http://dx.doi.org/10.3390/venereology2020006.
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The subspecies T. pallidum pallidum is the cause of the most infamous sexually and congenitally transmitted disease, syphilis. This disease has an estimated incidence of six million infections every year. Multiple studies have noted that the prevalence of syphilis has been steadily increasing worldwide in recent decades, especially among MSMs and HIV-positive patients. Clinically, syphilis presents in four stages with multiple different clinical manifestations. In this paper, we examine the current literature to determine the history and progression, pathogenesis, clinical features, and testing of secondary syphilis. Secondary syphilis is a stage of the disease with the most exuberant local and systemic clinical manifestations. The basis of the pathogenesis of SS underscores the unique mechanisms by which Treponema pallidum utilizes to escape immune recognition while simultaneously induces inflammation. SS can affect multiple organ systems and become more than just an STD. The most common presentation of secondary syphilis is rash, which manifests as a copper-colored maculopapular lesion on the trunk, palms, and soles. Although the RPR, VDRL, and FTA-ABS tests are perhaps the most commonly used diagnostic tools for syphilis and make up the traditional and reverse algorithms, there are other methods, including morphology and immunohistochemistry.
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Frioui, Refka, Mariem Tabka, Sana Mokni, Azza Ghanem, Nedia Fetoui, Amina Ounallah, Colandane Belajouza y Mohamed Denguezli. "Warty papules on the hands and feet: Acrokeratosis verruciformis of Hopf". Our Dermatology Online 13, n.º 2 (1 de abril de 2022): 215–16. http://dx.doi.org/10.7241/ourd.20222.25.
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A 47-year-old female was referred to our department because of skin-colored lesions located mainly on the dorsum of the hands and feet. The patient had no diseases and had not taken continuous medication. The lesions were present at birth and had increased in number since then. Four more members of the family, including the mother and the uncle (mother’s brother), had similar skin lesions. A dermatological examination revealed multiple flesh-colored, flat-topped papules, about 2–5 mm in size, which were reminiscent of flat warts on the dorsum of the hands and feet (Fig. 1). A nail examination revealed thickened nails with V-shaped nicks at their free margins on the fingers of both hands (Fig. 2). The patient declined skin biopsy. We retained the diagnosis of acrokeratosis verruciformis of Hopf (AVH). AVH is a rare inherited disorder of keratinization caused by an abnormal ATP2A2 gene [1,2]. Familial cases indicate an autosomal dominant pattern of inheritance, yet sporadic cases of the disease have also been reported [2]. It is characterized by multiple asymptomatic, flat-topped, skin-colored papules on the dorsum of the hands and feet. Other features may include pits on the palms and soles and nail dystrophy (pearly white nails or nails with longitudinal ridges and nicks in the free edge) [3]. AVH is diagnosed clinically, which becomes easier if there are family members with similar skin findings. Sometimes, a skin biopsy is performed to assist the diagnosis. The key features on histology are hyperkeratosis, hypergranulosis, acanthosis, papillomatosis, and circumscribed epidermal elevations known as church spires, which are a distinctive finding [1,2].
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Mahono, Charles Kurnia y Nurdjannah Jane Niode. "Secondary Syphilis Reinfection with Suspected Asymptomatic Neurosyphilis". Indonesian Journal of Case Reports 1, n.º 2 (1 de diciembre de 2023): 35–38. http://dx.doi.org/10.60084/ijcr.v1i2.119.
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Syphilis, a sexually transmitted disease caused by Treponema pallidum, poses a significant global health threat, with an annual incidence of around 12 million cases, predominantly affecting individuals aged 15-49. Reinfection occurs in 11 out of 120 patients, underscoring the importance of effective management. If untreated, 4-9% of cases may progress to early neurosyphilis, often presenting asymptomatically. We present the case of a 22-year-old male with reddish-brown patches on the face, palms, and soles, along with erythematous papules on the genital region, following a history of recent promiscuity. Physical examination revealed distinctive manifestations, including nickels and dimes on the face, syphilitic roseola, Biett's collarette on the palmoplantar region, and erythematous papules-plaques on the scrotal and penile areas. The VDRL test indicated a titer of 1:32, TPHA test >1:5120, and a non-reactive HIV rapid test. Initiating treatment with a single intramuscular injection of benzyl benzathine penicillin G (2.4 million IU) resulted in successful symptom resolution, accompanied by a four-fold decrease in VDRL titer to 1:8 by the third month. However, a subsequent increase to 1:32, following sexual intercourse in the sixth month, indicated reinfection and raised suspicions of asymptomatic neurosyphilis. The patient received oral doxycycline (100 mg twice daily) for 30 days. Unfortunately, treatment success could not be determined as the patient was lost to follow-up. This case report highlights that elevated VDRL titers signify reinfection, treatment failure, or neurosyphilis. Asymptomatic reinfection is common due to lead-time bias and partial immunity, especially with multiple episodes of syphilis. Early neurosyphilis may coexist with primary or secondary syphilis and is frequently asymptomatic. Continued efforts in monitoring and treatment adherence are crucial for effective syphilis management on a global scale.
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Mooney, Edward S. "Solve It! Multiples of Four". Mathematics Teaching in the Middle School 12, n.º 6 (febrero de 2007): 319–23. http://dx.doi.org/10.5951/mtms.12.6.0319.
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The Editorial Panel is present ing the following problem to stimulate submissions to “The Thinking of Students” department. We encourage teachers to try this problem with students and analyze the different ways that students solve it.
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Hashimoto, Kenji, Yusuke Sugahara, Hun-ok Lim y Atsuo Takanishi. "New Biped Foot System Adaptable to Uneven Terrain". Journal of Robotics and Mechatronics 18, n.º 3 (20 de junio de 2006): 271–77. http://dx.doi.org/10.20965/jrm.2006.p0271.
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Many types of control have been studied assuming that soles of a biped robot’s feet contact the ground at four points. The rigid, flat soles of most such robots rarely maintain four-point contact on uneven terrain, however, and may lose balance. Solving this problem requires that both control and the foot itself be studied. We developed a new foot system, Waseda Shoes - No.1 (WS-1) to maintain four-point contact on uneven terrain, followed by Waseda Shoes - No.1 Refined (WS-1R), which solved problems with WS-1. Hardware experiment confirmed WS-1R feasibility.
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Mooney, Edward S. "The Thinking of Students: Multiples of Four". Mathematics Teaching in the Middle School 13, n.º 9 (mayo de 2008): 535–37. http://dx.doi.org/10.5951/mtms.13.9.0535.
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Page, Donna. "Two, Three, Four: Multiples in African Art". African Arts 20, n.º 4 (agosto de 1987): 88. http://dx.doi.org/10.2307/3336648.
Texto completoTesis sobre el tema "Four à soles multiples"
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Lacombe, Elie. "Modélisation de la torréfaction de biomasse dans un four à soles multiples". Electronic Thesis or Diss., Université Grenoble Alpes, 2023. https://thares.univ-grenoble-alpes.fr/2023GRALI086.pdf.
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Dans le contexte énergétique actuel, la biomasse est une ressource abondante et renouvelable qui peut être valorisée énergétiquement directement sous forme de chaleur ou indirectement sous forme de gaz ou de biocarburants. Pour cela, plusieurs procédés thermochimiques de dégradation de la biomasse sèche tels que la gazéification, la pyrolyse ou la combustion sont mis en œuvre. Cependant, la biomasse exploitable (forestière ou agricole) est caractérisée par un fort taux d'humidité, une broyabilité énergivore, une mauvaise coulabilité de sa poudre ainsi qu’une faible densité énergétique par rapport au charbon. La torréfaction est un prétraitement thermique entre 200 et 300 °C sous atmosphère inerte permettant d’améliorer la qualité de la biomasse en vue de sa valorisation énergétique. La biomasse torréfiée obtenue est hydrophobe, sèche et son pouvoir calorifique est plus élevé que la ressource brute.La description des mécanismes de dégradation de la biomasse au cours de la torréfaction a fait l’objet de nombreux travaux scientifiques. Cependant, il y a un manque d’études sur des procédés pilotes et de démonstration qui se limitent pour la plupart à l’analyse du produit principal : le solide.En considérant les phénomènes prépondérants influençant la dégradation thermique de la biomasse, l’objectif de ce travail est d’approcher cette problématique du passage à l’échelle, en cherchant à modéliser les rendements de torréfaction dans un four à soles multiples, qui constitue l’une des technologies de référence. Pour mener à bien ce travail, une étude cinétique réalisée à partir de mesures dans un analyseur thermogravimétrique a permis de valider sur les biomasses étudiées (le chêne et noyaux d’olives) le schéma semi-détaillé de dégradation développé par Ranzi et Anca-Couce. Ensuite, des mesures de distribution de temps de séjour dans ce four ont permis d’estimer l’influence des paramètres opératoires sur le mouvement des particules et d’identifier les principaux mécanismes en jeu. Si la vitesse de rotation de l’axe du four est le levier principal pour contrôler le temps de séjour de la ressource, le débit d’alimentation et l’espacement entre les dents d’un même bras ont une influence importante sur la distribution de temps de séjour. Le transport des particules dans le four est fortement dispersif. Sur l’ensemble des essais, le temps de séjour des particules dans le four est compris entre 50 % et 150 % du temps de séjour moyen. La dernière étape consiste à développer un modèle thermique complet du four à soles multiples intégrant la cinétique chimique et un modèle de transport de la biomasse. Les résultats sont alors confrontés à des mesures expérimentales réalisées dans un four à soles multiples traitant entre 40 et 80 kg/h de ressource de 250 à 300 °C. Le modèle développé décrit de manière satisfaisante les tendances observables expérimentalement. Le rendement solide est correctement décrit par le modèle mais le rendement en gaz permanent est sous-estimé de 34 % en moyenne. L’erreur relative sur le pouvoir calorifique supérieur de la ressource torréfiée est inférieure à 8 %. Expérimentalement, comme attendu, la température de torréfaction influence significativement les rendements et produits de torréfaction. Plus rarement rapporté dans la littérature, l’impact du taux d’humidité de la ressource traitée sur les rendements obtenues est également considérableIn the current energy context, biomass is an abundant and renewable resource that can be energetically recovered directly into heat or indirectly into gas or biofuels. Several thermochemical processes, such as gasification, pyrolysis or combustion can be implemented. However, biomass is characterized by a high humidity rate, a high grinding energy and a low energy density compared to coal. Torrefaction is a thermal pre-treatment between 200 and 300 °C under an inert atmosphere that improves biomass quality for energy uses. The torrefied biomass obtained is hydrophobic, dry and has a higher calorific value than raw biomass.Researchers have put a lot of effort into understanding the mechanisms of biomass degradation during torrefaction on small-scale experiments for various resources. Those works are useful for investigating chemical kinetics during torrefaction. However, there is a lack of studies on pilot and demonstration processes, which are limited for the most part to the analysis of the main product: the torrefied solid.By considering predominant phenomena influencing the thermal degradation of biomass, this work aims to model torrefaction yields in a multiple hearth furnace, which constitutes one of the reference technologies. To carry out this work, a kinetic study based on thermogravimetric measurements aims to validate the Ranzi Anca-Couce degradation scheme on two biomasses (oak and olive stones). Then, residence time distribution measurements in this furnace are achieved to estimate the influence of operating parameters on particle transport and identify the main mechanisms involved. The shaft speed of the furnace is the main parameter to control the residence time of the resource. The feed rate and the spacing between the teeth of an arm also have an important influence on the distribution of the residence time of particles. Particle transport in the furnace is dispersive. The particles' residence time is comprised between 50 % and 150 % of the average residence time. The last step consists of developing a complete thermal model of this furnace, integrating a chemical kinetic and a biomass transport model. Results are compared with experimental measurements achieved in a semi-industrial multiple hearth furnace processing between 50 and 70 kg/h of biomass at 250 to 300 °C. The model satisfactorily describes experimentally observable trends. Solid yield is correctly described by the model but the dry gas yield is underestimated by 34 %. The relative error on the higher calorific value of the solid product is less than 8 %. Experimentally, torrefaction temperature influences torrefaction yields and products as expected. More rarely reported in the literature, the impact of the moisture content of raw biomass on yields is also significant
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Ma, Shouyu. "Modeling and Analysis of New Extensions for the News-Vendor Problem". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC040/document.
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Le NVP (Problème du Vendeur de Journaux) a été étudiée de façon continue au cours des dernières décennies pour la prise de décision dans les industries manufacturières et de services. Bien que beaucoup de travail a été fait dans le domaine du NVP, l'intérêt sur ce sujet ne diminue pas. Alors que de nouvelles tendances émergent dans les affaires, par exemple flux internationaux de produits et de e-commerce, les détaillants sont confrontés à de nouvelles situations et la littérature de NVP doit être enrichi. Dans ce travail, nous proposons trois nouvelles extensions NVP compte tenu des questions importantes rencontrées par le NV: plusieurs soldes, variété de produits et d'assortiment ainsi que des problèmes de drop-shipping et de retour des produits qui sont liés à l'e-commerce. Notre travail ajoute de la valeur à partir des travails antérieurs dans plusieurs aspects: assouplissement des hypothèses, l'examen de nouvelles questions, de nouvelles formulations et de la méthodologie ainsi que des aperçus intéressants. Nous formulons les modèles et donner les conditions d'optimalité de la quantité de commande. Aperçus utiles sont fournis sur la base des études numériques.En particulier, pour faire face à surstock, nous présentons un modèle NVP avec le prix dépendant de la demande et de multiples soldes. Nous prouvons la concavité de l’espérance de profit sur la quantité avec les distributions générales de la demande. Le prix initial et les pourcentages de soldes sont également analysés. La variété de produit est traité dans un multi-produits Problème avec le transfert de la demande (les demandes de produits non inclus dans l'assortiment proposé dans le magasin sont en partie transférés aux produits conservés dans l'assortiment) et substitution de la demande entre les produits qui sont inclus dans l'assortiment, en faisant la détermination conjointe de décision optimale de l'assortiment et des quantités de commande pour les produits qui sont inclus dans l'assortiment, pour optimiser le profit total prévu. Pour e-commerce, nous considérons un NV qui gère à la fois un magasin physique et un canal de vente sur Internet qui est remplie par une option drop-shipping, ainsi que la possibilité de revendre les produits qui sont retournés par les consommateurs au cours de la saison de vente. La concavité de l’espérance profit est prouvée et différents résultats sont obtenus à partir d'une analyse numériqueThe NVP (News-Vendor Problem) has been continuously studied over the last decades for decision making in manufacturing and service industries. Although a lot of work has been done in the NVP area, interest on this topic does not decrease. As new trends emerge in business, e.g. international flow of products and e-commerce, retailers are facing new situations and the literature of NVP needs to be enriched. In this work, we propose three new NVP extensions considering important issues faced by the NV: multiple discounts, product variety and assortment as well as drop-shipping and product return problems that are related to e-commerce. Our work adds value from earlier achievements in several aspects: relaxation of assumptions, consideration of new issues, new formulations and methodology as well as interesting insights. We formulate the models and give the optimality conditions of the order quantity. Useful insights are provided based on numerical studies.In particular, for dealing with overstock, we present a NVP model with price-dependent demand and multiple discounts. We prove the concavity of the expected profit on order quantity under general demand distributions. The optimal initial price and discount scheme are also analyzed. The product variety is treated in a multi-product News-Vendor Problem with demand transfer (the demands of products not included in the assortment proposed in the store are partly transferred to products retained in the assortment) and demand substitution between products that are included in the assortment, by focusing on the joint determination of optimal product assortment decision and optimal order quantities for products that are included in the assortment to optimize the expected total profit. For e-commerce, we consider a NV managing both a physical store inventory and a sale channel on internet that is fulfilled by a drop-shipping option, as well as the possibility of reselling products that are returned by consumers during the selling season. The concavity of the expected profit is proven and various results are obtained from a numerical analysis
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Norheim-Hansen, Anne. "Sustainable development and strategic alliances : four essays on implications of firms' environmental performance for their cooperative strategies". Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM1035.
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Les alliances stratégiques sont devenues autant une nécessité qu'un choix pour les entreprises afin d'être compétitif sur les marchés d'aujourd'hui. Toutefois, faire fonctionner les alliances stratégiques n'est pas une évidence. Des taux de défaillance entre 30% et jusqu'à 70% ont été régulièrement signalés. Un nombre important de recherches a examiné comment ces chiffres pouvaient être améliorés. La sélection de partenaires a été identifiée comme l'un des facteurs clés de la réussite. En fait, les attributs spécifiques de chaque partenaire, influant même sur la sélection de ces mêmes partenaires, ont tendance à avoir des effets boule de neige au-delà de la phase de formation, jusqu'aux phases de conception et de post-formation. S'appuyant sur des recherches antérieures étudiant l'attribut « réputation », cette thèse vient combler une lacune en explorant le rôle que peut jouer la réputation pour la performance environnementale dans la détermination des avantages individuels et communs dans les différentes phases des alliances stratégiques. Dans quatre essais indépendants mais interconnectés, des questions de recherche spécifiques sont théoriquement examinées sous la « Natural-Resource-Based View (NRBV) » et la « Strategic Cognition Perspective ». Les hypothèses de l'étude sont testées empiriquement à partir des données recueillies auprès des PDG et des cadres supérieurs dans 176 entreprises manufacturières norvégiennesStrategic alliances have become as much a necessity as a choice for companies to be competitive in today's markets. However, making strategic alliances work is not evident. Failure rates between 30% and as high as 70% have been regularly reported. A substantial stream of research has examined how these numbers can be improved. Partner selection has been identified as a key success factor. In fact, partner-specific attributes, affecting which partners are selected, tend to have snowball effects beyond the formation phase to the design and postformation phases. Building on previous studies investigating the attribute of reputation, this thesis fills a gap by exploring the role reputation for environmental performance can play in determining firm-specific and joint competitive advantages in the different phases of strategic alliances. In four individual but connected Essays, specific research questions are theoretically examined under the Natural-Resource-Based View (NRBV) and Strategic Cognition Perspective. The study's hypotheses are empirically tested using data collected from CEOs and top managers in 176 Norwegian manufacturing firms
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Norheim-Hansen, Anne. "Sustainable development and strategic alliances : four essays on implications of firms' environmental performance for their cooperative strategies". Electronic Thesis or Diss., Aix-Marseille, 2014. http://www.theses.fr/2014AIXM1035.
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Les alliances stratégiques sont devenues autant une nécessité qu'un choix pour les entreprises afin d'être compétitif sur les marchés d'aujourd'hui. Toutefois, faire fonctionner les alliances stratégiques n'est pas une évidence. Des taux de défaillance entre 30% et jusqu'à 70% ont été régulièrement signalés. Un nombre important de recherches a examiné comment ces chiffres pouvaient être améliorés. La sélection de partenaires a été identifiée comme l'un des facteurs clés de la réussite. En fait, les attributs spécifiques de chaque partenaire, influant même sur la sélection de ces mêmes partenaires, ont tendance à avoir des effets boule de neige au-delà de la phase de formation, jusqu'aux phases de conception et de post-formation. S'appuyant sur des recherches antérieures étudiant l'attribut « réputation », cette thèse vient combler une lacune en explorant le rôle que peut jouer la réputation pour la performance environnementale dans la détermination des avantages individuels et communs dans les différentes phases des alliances stratégiques. Dans quatre essais indépendants mais interconnectés, des questions de recherche spécifiques sont théoriquement examinées sous la « Natural-Resource-Based View (NRBV) » et la « Strategic Cognition Perspective ». Les hypothèses de l'étude sont testées empiriquement à partir des données recueillies auprès des PDG et des cadres supérieurs dans 176 entreprises manufacturières norvégiennesStrategic alliances have become as much a necessity as a choice for companies to be competitive in today's markets. However, making strategic alliances work is not evident. Failure rates between 30% and as high as 70% have been regularly reported. A substantial stream of research has examined how these numbers can be improved. Partner selection has been identified as a key success factor. In fact, partner-specific attributes, affecting which partners are selected, tend to have snowball effects beyond the formation phase to the design and postformation phases. Building on previous studies investigating the attribute of reputation, this thesis fills a gap by exploring the role reputation for environmental performance can play in determining firm-specific and joint competitive advantages in the different phases of strategic alliances. In four individual but connected Essays, specific research questions are theoretically examined under the Natural-Resource-Based View (NRBV) and Strategic Cognition Perspective. The study's hypotheses are empirically tested using data collected from CEOs and top managers in 176 Norwegian manufacturing firms
Libros sobre el tema "Four à soles multiples"
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Page, Donna. Two, three, four: Multiples in African art : essay. New York City (48 E. 57th St., New York City): L. Kahan Gallery, African Arts, 1987.
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Two, three, four: Multiples in African art : essay. New York City (48 E. 57th St., New York City): L. Kahan Gallery, African Arts, 1987.
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Yajnas, The. Four Weathered Soles + Light the Dark. Lulu Press, Inc., 2017.
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Zhu, Yang y Miroslav Krstic. Delay-Adaptive Linear Control. Princeton University Press, 2020. http://dx.doi.org/10.23943/princeton/9780691202549.001.0001.
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Actuator and sensor delays are among the most common dynamic phenomena in engineering practice, and when disregarded, they render controlled systems unstable. Over the past sixty years, predictor feedback has been a key tool for compensating such delays, but conventional predictor feedback algorithms assume that the delays and other parameters of a given system are known. When incorrect parameter values are used in the predictor, the resulting controller may be as destabilizing as without the delay compensation. This book develops adaptive predictor feedback algorithms equipped with online estimators of unknown delays and other parameters. Such estimators are designed as nonlinear differential equations, which dynamically adjust the parameters of the predictor. The design and analysis of the adaptive predictors involves a Lyapunov stability study of systems whose dimension is infinite, because of the delays, and nonlinear, because of the parameter estimators. This book solves adaptive delay compensation problems for systems with single and multiple inputs/outputs, unknown and distinct delays in different input channels, unknown delay kernels, unknown plant parameters, unmeasurable finite-dimensional plant states, and unmeasurable infinite-dimensional actuator states. Presenting breakthroughs in adaptive control and control of delay systems, the book offers powerful new tools for the control engineer and the mathematician.
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Hall, Linda Jones. The Poems of Optatian. Bloomsbury Publishing Plc, 2024. http://dx.doi.org/10.5040/9781350374409.
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For the first time, the poems and accompanying letters of Publilius Optatianus Porfyrius (Optatian) are published here with a translation and detailed commentary, along with a full introduction to Optatian’s work during this period. Optatian was sent into exile by Constantine sometime after the emperor’s ascent to power in Rome in 312 AD. Hoping to receive pardon, Optatian sent a gift of probably twenty design poems to Constantine around the time of the ruler’s twentieth anniversary (325/326 AD). To enable the reader to experience the multiple messages of the poems, the Latin text is presented near the English translation with any related design close by. Some poems, laid out on a grid of up to 35 letters across and down, have an interwoven poem marking key letters in the primary poem, thereby revealing a highlighted image. Some designs include the chi-rho or numerals created from V’s and X’s to mark imperial anniversaries. Other (previously unrecognised) designs seem to represent senatorial, imperial, military or bureaucratic motifs or to derive from coin images. Shape poems representing a water organ, an altar and a panpipe reveal their relevance immediately. The introduction and commentary elucidate literary allusions from over 100 authors (lines from Vergil, Ovid, Lucan, Silius Italicus, Statius, and lesser-known writers abound) and mythological references, mostly to the Muses and Apollo. Optatian’s prestige as an official in both Greece and Rome is well attested - these poems mark Optatian as a fascinating writer of his time, holding onto the classical past while acknowledging Christian symbolism. Late Antique poets, such as Publilius Optatianus Porfyrius, straddled a divide between inspiration by the Muses and Phoebus Apollo and acceptance of Christianity, which the emperor Constantine had clearly embraced. Optatian solves this dilemma by referring to divine inspiration while marking many of his figural poems with the Chi-Rho, Constantine’s logo on his soldiers’ shields and some coins. The celebration of Constantine’s vicennalia (twentieth anniversary) in 325-326 provides the key impetus. The roles of the young Caesars, especially Crispus, are central; many of the poems celebrate the defeat of Licinius and the re-unification of the Roman Empire. In addition to the twenty poems and letter dedicated to Constantine (and his response), there are ten poems addressed to friends or acquaintances. Optatian is noted for his composition of cento poems which are fabricated from small snippets from over 36 Latin authors, especially Ovid and Vergil, but also from lesser-known writers. Linda Jones Hall explores the political implications of these quotes and finds that many of them can be seen as opposed to civil war. Optatian, a member of the senatorial elite, was redeemed from exile and gained appointments as governor of Achaia and as Prefect of the City. The elaborate usage of acrostic designs which incorporate additional messages, sometimes even in Greek, attracted both attention and imitation in the Middle Ages. Although some of the chronology is obscure, much can be learned about the rise of Constantine due to victories in West and East, by an analysis of Optatian’s panegyrical poems.
Capítulos de libros sobre el tema "Four à soles multiples"
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van Dijk, Tom, Feije van Abbema y Naum Tomov. "Knor: reactive synthesis using Oink". En Tools and Algorithms for the Construction and Analysis of Systems, 103–22. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-57246-3_7.
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AbstractWe present an innovative approach to the reactive synthesis of parity automaton specifications, which plays a pivotal role in the synthesis of linear temporal logic. We find that our method efficiently solves the SYNTCOMP synthesis competition benchmarks for parity automata from LTL specifications, solving all 288 models in under a minute. We therefore direct our attention to optimizing the circuit size and propose several methods to reduce the size of the constructed circuits: (1) leveraging different parity game solvers, (2) applying bisimulation minimisation to the winning strategy, (3) using alternative encodings from the strategy to an and-inverter graph, (4) integrating post-processing with the ABC tool. We implement these methods in the Knor tool, which has secured us multiple victories in the PGAME track of the SYNTCOMP competition.
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Saxena, Gaurav, Miguel Ponce-de-Leon, Arnau Montagud, David Vicente Dorca y Alfonso Valencia. "BioFVM-X: An MPI+OpenMP 3-D Simulator for Biological Systems". En Computational Methods in Systems Biology, 266–79. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-85633-5_18.
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AbstractMulti-scale simulations require parallelization to address large-scale problems, such as real-sized tumor simulations. BioFVM is a software package that solves diffusive transport Partial Differential Equations for 3-D biological simulations successfully applied to tissue and cancer biology problems. Currently, BioFVM is only shared-memory parallelized using OpenMP, greatly limiting the execution of large-scale jobs in HPC clusters. We present BioFVM-X: an enhanced version of BioFVM capable of running on multiple nodes. BioFVM-X uses MPI+OpenMP to parallelize the generic core kernels of BioFVM and shows promising scalability in large 3-D problems with several hundreds diffusible substrates and $$\approx $$ ≈ 0.5 billion voxels. The BioFVM-X source code, examples and documentation, are available under the BSD 3-Clause license at https://gitlab.bsc.es/gsaxena/biofvm_x.
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Moreira, Daniel, William Theisen, Walter Scheirer, Aparna Bharati, Joel Brogan y Anderson Rocha. "Image Provenance Analysis". En Multimedia Forensics, 389–432. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-7621-5_15.
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AbstractThe literature of multimedia forensics is mainly dedicated to the analysis of single assets (such as sole image or video files), aiming at individually assessing their authenticity. Different from this, image provenance analysis is devoted to the joint examination of multiple assets, intending to ascertain their history of edits, by evaluating pairwise relationships. Each relationship, thus, expresses the probability of one asset giving rise to the other, through either global or local operations, such as data compression, resizing, color-space modifications, content blurring, and content splicing. The principled combination of these relationships unveils the provenance of the assets, also constituting an important forensic tool for authenticity verification. This chapter introduces the problem of provenance analysis, discussing its importance and delving into the state-of-the-art techniques to solve it.
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Douglas, Heather. "Science and Values:". En Democratizing Risk Governance, 55–77. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-24271-7_3.
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AbstractSince the mid-twentieth century, insulating science from social and ethical values has been something of an obsession for philosophers of science. Philosophers articulated, and then staunchly defended, a value-free ideal for science. Philosophers were willing to concede the “context of discovery” to the influence of values, but argued that the “context of justification” had no place for social values. This view was supported by three ideas: (1) that societal values can add no confirmatory weight to empirical claims; (2) that values distinctive to scientific theory choice could guide scientists when faced with inferential decisions; and (3) that the authority of science in the public sphere rested on the separation and disentanglement of science from social and ethical values. This chapter argues that there is something to the first idea—that there is an important conceptual difference between normative and descriptive claims, but because of their logical structures, normative claims cannot provide sole support for descriptive claims, and vice versa. It argues that the second idea is crucially incomplete—that although there are distinctive epistemic values in science, they cannot decisively guide inference. And, finally, it argues that the third idea is inadequate as well—that we need a more complex understanding of why we grant science general epistemic authority, with multiple bases supporting that authority.
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Mao, Youdong. "Structure, Dynamics and Function of the 26S Proteasome". En Subcellular Biochemistry, 1–151. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-58971-4_1.
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AbstractThe 26S proteasome is the most complex ATP-dependent protease machinery, of ~2.5 MDa mass, ubiquitously found in all eukaryotes. It selectively degrades ubiquitin-conjugated proteins and plays fundamentally indispensable roles in regulating almost all major aspects of cellular activities. To serve as the sole terminal “processor” for myriad ubiquitylation pathways, the proteasome evolved exceptional adaptability in dynamically organizing a large network of proteins, including ubiquitin receptors, shuttle factors, deubiquitinases, AAA-ATPase unfoldases, and ubiquitin ligases, to enable substrate selectivity and processing efficiency and to achieve regulation precision of a vast diversity of substrates. The inner working of the 26S proteasome is among the most sophisticated, enigmatic mechanisms of enzyme machinery in eukaryotic cells. Recent breakthroughs in three-dimensional atomic-level visualization of the 26S proteasome dynamics during polyubiquitylated substrate degradation elucidated an extensively detailed picture of its functional mechanisms, owing to progressive methodological advances associated with cryogenic electron microscopy (cryo-EM). Multiple sites of ubiquitin binding in the proteasome revealed a canonical mode of ubiquitin-dependent substrate engagement. The proteasome conformation in the act of substrate deubiquitylation provided insights into how the deubiquitylating activity of RPN11 is enhanced in the holoenzyme and is coupled to substrate translocation. Intriguingly, three principal modes of coordinated ATP hydrolysis in the heterohexameric AAA-ATPase motor were discovered to regulate intermediate functional steps of the proteasome, including ubiquitin-substrate engagement, deubiquitylation, initiation of substrate translocation and processive substrate degradation. The atomic dissection of the innermost working of the 26S proteasome opens up a new era in our understanding of the ubiquitin-proteasome system and has far-reaching implications in health and disease.
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Manninger, Sandra y Matias del Campo. "Deep Mining Authorship". En Computational Design and Robotic Fabrication, 3–10. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-8405-3_1.
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AbstractConsidering the emerging field of architecture and artificial intelligence, it might be necessary to contemplate the remodeling of the concept of authorship entirely. The invention of authorship is a complex historical process that can be traced back to the emergence of print culture in Europe in the 15th century. Prior to this period, most literary and artistic works were created anonymously or attributed to collective or anonymous sources, such as folklore or religious traditions. However, with the rise of printing, texts became more easily reproducible and marketable, and there emerged a need for individual authors to take credit for their works. The notion of authorship was closely tied to the idea of originality and ownership, as authors sought to assert their exclusive rights to their works and to distinguish themselves from other writers. This was supported by the development of copyright law, which granted legal protection to authors and their works, and helped to establish a market for literary and artistic works. The idea of the author as a singular, autonomous figure gained further prominence in the 18th and 19th centuries, with the emergence of romanticism and the cult of the individual. This period saw the rise of the idea of the artist as a genius, whose works were the product of their own unique creativity and imagination. This idea was further reinforced by the rise of literary criticism, which focused on the interpretation and analysis of individual works and their authors. However, as Michel Foucault and other scholars have argued, the notion of authorship is not a universal or timeless concept, but rather a historically contingent and culturally specific one. Different societies ad cultures have different understandings of authorship, and these have shifted over time in response to changes in technology, culture, and social values. As it stands now, authorship in its traditional form can hardly be applied in a context where automated collaborations provide more than 50% of the generated material. This is true for multiple art fields. Visual Arts (Mario Klingemann, Sofia Crespo, Memo Atken, Ooouch, etc.), Music (Dadabots, YACHT, Holly Herndon), Literature, etc. Very soon this will also be true for Architecture. The consequence is also an entire rethinking of the concept of the sole genius. This notion, developed by German Romanticists in the early 19th century, is, in the current context of AI-assisted creativity, completely obsolete, as we are drawing from the genius of hundreds of thousands of artists and artworks in order to interrogate the latent space for unseen artistic opportunities. More akin to an archeological dig leading to the discovery of a next-generation jet fighter plane.
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Zahedi, Sanam, Jillian M. McLaughlin y Linda G. Phillips. "Gluteal Flap for Pressure Sores". En Operative Plastic Surgery, editado por Gregory R. D. Evans, 747–52. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780190499075.003.0070.
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Pressure sores usually occur over bony prominences. Based on the distribution of pressure, sacral pressure sores are more common in supine patients, and ischial pressure sores are more common in sitting patients. Patients in acute care settings, in nursing homes, or with spinal cord injuries are among the most commonly affected populations. Pressure sores are a recurrent problem with multiple risk factors including direct pressure, friction, shearing forces, immobility, and moisture. Malnutrition, anemia, and chronic illness can also contribute to their formation by the impairment of blood supply and delayed wound healing. This chapter reviews the operative technique for using different types of gluteal flaps as coverage for sacral pressure sores. It highlights essential components of preoperative, operative, and postoperative decision-making and common postoperative complications encountered.
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Davies, David. "Non-Platonist Ontologies of Multiples". En An Ontology of Multiple Artworks, 154–71. Oxford University PressOxford, 2024. http://dx.doi.org/10.1093/oso/9780192848864.003.0009.
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Abstract A non-Platonist realism about multiple artworks must offer a principled way of selecting from the range of concrete particulars that enter into our artistic practices some element(s) that can plausibly be taken to play the roles ascribed to works in such practices. This chapter considers at length two materialist forms of non-Platonist realism: (1) perdurantism, defended by Caplan and Matheson, where musical works are fusions of those temporal stages that are their performances, and (2) endurantism, as defended by Rohrbaugh, where multiple artworks are enduring essentially historical individuals dependent upon their occurrences. It is argued that each account faces difficulties accounting for some central explananda. Cray and Matheson’s ‘sophisticated idealism’, according to which musical compositions are completed ideas for musical manifestation, is then considered. Unlike traditional idealist theories, the ‘systems’ conception of ideas they employ makes such compositions in principle public and shareable entities. They argue that sophisticated idealism accounts for four definitive features of musical compositions, whereas type theories and materialist theories fail to account for at least one of these features. Some problems for sophisticated idealism are discussed. First, it does not address the issue of variability. Second, it seems crucial to the idealist status of sophisticated idealism that musical compositions exist primarily in the minds of composers and those who mentally entertain an idea with the same content, and are only contingently externalized. But this raises problems concerning compositions whose contents are too complex for an artist to hold entirely in her mind.
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Friedman, Jeffrey D. y Eric S. Ruff. "Soleus Flap for Lower Leg Reconstruction". En Operative Plastic Surgery, editado por Gregory R. D. Evans, 873–80. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780190499075.003.0086.
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Open wounds in the middle third of the lower leg often require soft tissue reconstruction to allow for primary wound healing. The soleus muscle flap is uniquely suited for this purpose and is used primarily as a muscle flap without the accompanying overlying skin. This muscle has a blood supply that is segmental in nature, arising from multiple perforators from the posterior tibial vessels. Given that that this blood supply is primarily located in the proximal third of the leg, the soleus muscle flap is generally based proximally to allow for coverage of middle-third defects. While the muscle has a clear intermuscular septum which separates the medial head from the lateral segment, the use of a so-called hemi-soleus flap is less reliable and thus used on an infrequent basis. The soleus muscle flap can also be based distally in the leg for small distal-third defects; however, this flap can often be unreliable due to a paucity of sufficient perforators located in this area.
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McCrindle, Brian W. "Kawasaki’s disease". En Oxford Textbook of Medicine, 3698–704. Oxford University Press, 2010. http://dx.doi.org/10.1093/med/9780199204854.003.191108_update_001.
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Kawasaki’s disease is an acute, self-limited, inflammatory vasculitis of unknown aetiology, with a peak incidence under 5 years of age. Clinical features—the diagnosis is made in the presence of persistent fever for 5 days or more and at least four of the following five clinical signs: (1) nonpurulent conjunctivitis, (2) oropharyngeal inflammation, (3) cervical lymphadenopathy, (4) polymorphous exanthem, and (5) erythema of the palms and soles with subsequent desquamation. Incomplete presentations occur in approximately 25% of patients. The primary complications are cardiac, with coronary artery dilation and aneurysms evident in approximately 15 to 25% of untreated patients....
Actas de conferencias sobre el tema "Four à soles multiples"
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DeBeer, D., E. Usadi y S. R. Hartmann. "Ultrafast modulations in time-delayed four-wave mixing experiments". En OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1988. http://dx.doi.org/10.1364/oam.1988.me5.
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Two transient time-delayed four-wave mixing experiments have been performed on the Na D doublet and modulations of 1.9 ps and 980 as have been observed. These periods correspond to the difference and sum frequencies of the two Na D lines. Both experiments were performed using 7-ns pulses of light with frequency components at each of the D-line transitions. The effects of superimposition-state modulations are observed in the integrated TDFWM signal as a function of the time delay. As the time delay is varied, the lowest diffraction order mixing signal is modulated. Higher diffraction order mixing signals contain modulation components at integral multiples of the beat frequency.
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Bousbiat, Sana, Michel Y. Jaffrin y Imen Assadi. "Factors Influencing the Measurement and Reproducibility of Foot-to-Foot in Body Fat Analysers". En ASME 2012 11th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/esda2012-82076.
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Body fat analysers use four plantar electrodes integrated in a body scale to measure the foot-to-foot resistance and estimate body fat by using a proprietary equation. The variation of this resistance with the contact area between feet and electrodes has been investigated by using a podoscope permitting to photograph feet soles and electrodes. This resistance was found to decrease when current electrode area increased. The reproducibility of the electronics was excellent (< 2Ω) in measurements repeated without changing feet position, but the mean standard deviation was 3.5 to 4 Ω when the subject stepped down at each measurement due to feet position changes.
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Zhao, Wenzhong y Shapour Azarm. "A Cross-Sectional Shape Multiplier Method for Two-Level Optimum Design of Frames". En ASME 1990 Design Technical Conferences. American Society of Mechanical Engineers, 1990. http://dx.doi.org/10.1115/detc1990-0068.
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Abstract In this paper, a new method for optimum design of frame structures is presented. The method is based on a hierarchical decomposition of the structure into two-levels, namely, the bottom- and the top-level. The bottom-level consists of several subproblems each dealing with the cross-sectional sizing of a given frame-element. The top-level consists of one subproblem which is formulated for configuration design of the frame structure. Since there may be a large number of frame elements, a new shape multiplier method has been developed to simplify the formulation of the bottom-level subproblems. Furthermore, a two-level solution procedure has been developed which first solves the bottom-level subproblems based on their monotonicity analysis. It then solves the top-level subproblem as it coordinates, based on a linear approximation, the solutions to the bottom-level subproblems. Three examples with increasing degree of difficulty are presented to demonstrate the effectiveness of the method.
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Catapane, G. "Labyrinth quarter-wavelength tubes array for the reduction of machinery noise". En Aeronautics and Astronautics. Materials Research Forum LLC, 2023. http://dx.doi.org/10.21741/9781644902813-158.
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Abstract. Anthropogenic noise from navigation is a major contributor to the disturbance of the acoustic soundscape in underwater environments. The noise generated by ship’s machinery exhibits energetic tonal harmonic peaks at multiples of the rotating and firing frequency, that occur in the 20-200 Hz frequency range and difficult to control with classical soundproofing materials. Quarter wavelength tubes (QWT) can be a concrete solution since their absorption peaks are harmonic odd integers of the first resonance frequency. The main issue of QWT is their tuning length, which equals 1.43 m for a 60 Hz resonator. The problem is solved by coiling the tube into a labyrinth. Three labyrinth quarter wavelength tubes are tuned respectively at 60, 90 and 120 Hz. Samples are printed with filament 3D additive manufacturing techniques using PLA and tested with a square impedance tube designed for low-frequency measurements. Measurement results are in good agreement with analytical and numerical predictions. An array including four 60 Hz, four 90 Hz and four 120 Hz labyrinths QWTs is finally tested.
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Kramer, M. "Intracavity Sub-G Hz-Mod illation of Nanosecond Laser Pulses via Resonator enhanced Four Wave Mixing". En The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/cleo_europe.1996.cmg4.
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The temporal shape of laser pulses emitted from an unstable laser resonator was investigated [1, 2]. The resonator was Q-switched by means of stimulated Brillouin scattering (SBS) in a cell filled with acetone. Besides a change in pulse length from 40 ns to 2-3 ns by a variation of the resonator configuration, sub-GHz-modulations of the 40 ns-pulses were observed (fig. 1a)-c)). In a set of 150 laser shots 28 were strongly modulated, which were taken for analysis in fig.2. Only modulation frequencies which are harmonic multiples of the resonator roundtrip frequency (100 MHz) appeared whereas frequencies of 400 MHz and above 600 MHz were missing. It is remarkable, that the measured frequencies belong to a subharmonic of the Brillouin shift (in acetone 3000 MHz at 1064 nm), whereas the missing frequencies are no subhamtonics of the Brillouin shift. It turns out, that the modulations are caused by a not too low Q-value before the Q-switching of the laser, which enables prelasing. Based on long prelasing pulses a spontaneaous mode locking takes place, which is responsible for the statistical behavior of the modulation frequencies. If the modulation frequency of this mode locking is matched to the Brillouin shift, a four wave mixing process is initiated in the SBS-cell causing a Q-switch of the resonator. In analogy to Brillouin enhanced four wave mixing (BEFWM) this process may be called resonator enhanced four wave mixing (REFWM).
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Johnson, Benjamin V. y David J. Cappelleri. "Modeling, Control and Planning for Multiple Mobile Microrobots". En ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/detc2019-98392.
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Abstract We present the modeling, control and planning for multiple magnetic mobile microrobots actuated on a planar array of coils that generates local magnetic fields. The system is capable of actuating multiple microrobots independently. Such systems have a future in micromanufacturing and biomedical applications. The coils are modeled extensively to understand the forces generated by various coil combinations of the array, and solutions for different actuation force directions are discovered. The path planning problem is formulated as a Markov decision process that solves a policy to reach a goal from any location in the workspace. The presence of multiple robots in the workspace can interfere with their motion. Hence, the coil models are used concurrently with models of interaction force between multiple magnetic robots to plan efficient paths to reach a goal in the workspace in the presence of other robots.
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Liang, Yi y Ho-Hoon Lee. "Avoidance of Multiple Obstacles for a Mobile Robot With Nonholonomic Constraints". En ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-81744.
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In this study, a decoupled controller, consisting of a force controller and a torque controller, is designed to achieve a smooth translational and rotational motion control of a group of nonholonomic mobile robots. The proposed controller also solves the problem of obstacle avoidance, where obstacles with arbitrary boundary shapes are taken into account. Since the tangential direction of obstacle boundary is adopted as the guiding direction of a robot, the proposed controller allows a mobile robot to escape from a concave obstacle, while the robot could be trapped with most of the conventional obstacle avoidance algorithms.
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Chen, J. P. y W. R. Briley. "A Parallel Flow Solver for Unsteady Multiple Blade Row Turbomachinery Simulations". En ASME Turbo Expo 2001: Power for Land, Sea, and Air. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/2001-gt-0348.
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A parallel flow solver has been developed to provide a turbomachinery flow simulation tool that extends the capabilities of a previous single–processor production code (TURBO) for unsteady turbomachinery flow analysis. The code solves the unsteady Reynolds-averaged Navier-Stokes equations with a k–ε turbulence model. The parallel code now includes most features of the serial production code, but is implemented in a portable, scalable form for distributed–memory parallel computers using MPI message passing. The parallel implementation employs domain decomposition and supports general multiblock grids with arbitrary grid–block connectivity. The solution algorithm is an iterative implicit time–accurate scheme with characteristics–based finite–volume spatial discretization. The Newton subiterations are solved using a concurrent block–Jacobi symmetric Gauss–Seidel (BJ–SGS) relaxation scheme. Unsteady blade–row interaction is treated either by simulating full or periodic sectors of blade–rows, or by solving within a single passage for each row using phase–lag and wake–blade interaction approximations at boundaries. A scalable dynamic sliding–interface algorithm is developed here, with an efficient parallel data communication between blade rows in relative motion. Parallel computations are given here for flat plate, single blade row (Rotor 67) and single stage (Stage 37) test cases, and these results are validated by comparison with corresponding results from the previously validated serial production code. Good speedup performance is demonstrated for the single–stage case with a relatively small grid of 600,000 points.
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Drabik, Timothy J. y Sing H. Lee. "Parallel algorithms for matrix algebra problems on shift-connected digital optical single-instruction multiple-data arrays". En OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1986. http://dx.doi.org/10.1364/oam.1986.ml3.
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Shift-connected digital optical single-instruction multiple-data (SIMD) arrays1 comprise a 2-D (N × N) array of 1-bit logic/arithmetic elements with optical inputs and outputs, a memory that stores binary images, and hardware to perform arbitrary, programmable space-invariant shifts on data images as they are brought from memory to the logic array. Results of logic operations are returned to the memory in parallel. Such a shift-connected array can efficiently perform multiples of dense matrices or of sparse matrices possessing a multidiagonal structure from which algorithms for matrix inversion, partial differential equations, and eigenvalue problems can be assembled. Multiplication of an N vector by an N × N dense matrix requires computation time proportional to K2, where K is the number of bits of precision desired, and memory proportional to K. Multiplication of an N 2 vector by an N2 × N2 sparse matrix with multidiagonal structure corresponds to accumulating weighted, shifted versions of an N × N array of numbers. Computation time required is proportional to DK2, where D is the number of nonzero diagonals. Memory required also depends linearly on D. Because shifts across multiple processing elements are available, 2-D shift-connected arrays can easily be programmed to have 3-D or 4-D topologies as well.1 Multiples by sparse matrices arising from the discretization of continuous problems in two to four dimensions can be optimally performed on a processor array with the same dimensionality. The case of implementing these algorithms derives from the 2-D parallelism and global data movement capability of optical systems.
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Shelby, R. M. y Marc D. Levenson. "Bistability, nondegenerate four-wave mixing and squeezed state generation in a single-mode fiber ring resonator". En OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1985. http://dx.doi.org/10.1364/oam.1985.wj16.
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In optical fibers, nonlinear dispersion due to the same third-order susceptibility as that responsible for parametric mixing significantly alters the squeezing behavior in a traveling wave geometry, giving the squeezed quadrature an intensity dependent phase and reducing the overall squeezing. Phase noise is not squeezed at all. In the case of a fiber ring resonator, the nonlinear susceptibility will also lead to dispersive optical bistability and the squeezing will be strongly dependent on pump and sideband detuning. Yurke1 has analyzed squeezing due to backward four-wave mixing in a cavity, but the pump wave did not circulate in the cavity, and bistability was not dealt with. We have developed a theory of the resonant fiber ring interferometer, where the pump wave is near resonance with an interferometer mode and the circulating power is thereby enhanced. For perfect pump resonance and for frequencies corresponding to sideband resonance, the overall enhancement of the squeezing in the output mode compared to the traveling wave case is proportional to the square of the resonator finesse. The best squeezing in the output mode is always found for this condition of sideband resonance. The phase of the minimum noise quadrature is quite sensitive to both pump and sideband detuning. This feature may provide a means for avoiding excess thermal phase noise due to guided acoustic wave Brillouin scattering in the fiber itself. At the critical points for dispersive optical bistability in such a resonator and for sideband resonance (i.e., noise frequencies which are multiples of the resonator free spectral range), perfect squeezing of the output light is predicted. This result was also obtained previously for the case of degenerate mixing in a resonant cavity by Collett and Walls.2 Our current theory does not account for the reduction in squeezing due to the loss present in such a resonator.2 Since the loss is also enhanced by a factor of the resonator finesse, this is of some concern and will limit the maximum useful finesse for quantum noise squeezing. The major source of loss is the single-mode directional coupler, which for currently available technology is of the order of a few percent.
Informes sobre el tema "Four à soles multiples"
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Morrison, Mark y Joshuah Miron. Molecular-Based Analysis of Cellulose Binding Proteins Involved with Adherence to Cellulose by Ruminococcus albus. United States Department of Agriculture, noviembre de 2000. http://dx.doi.org/10.32747/2000.7695844.bard.
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At the beginning of this project, it was clear that R. albus adhered tightly to cellulose and its efficient degradation of this polysaccharide was dependent on micromolar concentrations of phenylacetic acid (PAA) and phenylpropionic acid (PPA). The objectives for our research were: i) to identify how many different kinds of cellulose binding proteins are produced by Ruminococcus albus; ii) to isolate and clone the genes encoding some of these proteins from the same bacterium; iii) to determine where these various proteins were located and; iv) quantify the relative importance of these proteins in affecting the rate and extent to which the bacterium becomes attached to cellulose. BARD support has facilitated a number of breakthroughs relevant to our fundamental understanding of the adhesion process. First, R. albus possesses multiple mechanisms for adhesion to cellulose. The P.I.'s laboratory has discovered a novel cellulose-binding protein (CbpC) that belongs to the Pil-protein family, and in particular, the type 4 fimbrial proteins. We have also obtained genetic and biochemical evidence demonstrating that, in addition to CbpC-mediated adhesion, R. albus also produces a cellulosome-like complex for adhesion. These breakthroughs resulted from the isolation (in Israel and the US) of spontaneously arising mutants of R. albus strains SY3 and 8, which were completely or partially defective in adhesion to cellulose, respectively. While the SY3 mutant strain was incapable of growth with cellulose as the sole carbon source, the strain 8 mutants showed varying abilities to degrade and grow with cellulose. Biochemical and gene cloning experiments have been used in Israel and the US, respectively, to identify what are believed to be key components of a cellulosome. This combination of cellulose adhesion mechanisms has not been identified previously in any bacterium. Second, differential display, reverse transcription polymerase chain reaction (DD RT-PCR) has been developed for use with R. albus. A major limitation to cellulose research has been the intractability of cellulolytic bacteria to genetic manipulation by techniques such as transposon mutagenesis and gene displacement. The P.I.'s successfully developed DD RT- PCR, which expanded the scope of our research beyond the original objectives of the project, and a subset of the transcripts conditionally expressed in response to PAA and PPA have been identified and characterized. Third, proteins immunochemically related to the CbpC protein of R. albus 8 are present in other R. albus strains and F. intestinalis, Western immunoblots have been used to examine additional strains of R. albus, as well as other cellulolytic bacteria of ruminant origin, for production of proteins immunochemically related to the CbpC protein. The results of these experiments showed that R. albus strains SY3, 7 and B199 all possess a protein of ~25 kDa which cross-reacts with polyclonal anti-CbpC antiserum. Several strains of Butyrivibrio fibrisolvens, Ruminococcus flavefaciens strains C- 94 and FD-1, and Fibrobacter succinogenes S85 produced no proteins that cross-react with the same antiserum. Surprisingly though, F. intestinalis strain DR7 does possess a protein(s) of relatively large molecular mass (~200 kDa) that was strongly cross-reactive with the anti- CbpC antiserum. Scientifically, our studies have helped expand the scope of our fundamental understanding of adhesion mechanisms in cellulose-degrading bacteria, and validated the use of RNA-based techniques to examine physiological responses in bacteria that are nor amenable to genetic manipulations. Because efficient fiber hydrolysis by many anaerobic bacteria requires both tight adhesion to substrate and a stable cellulosome, we believe our findings are also the first step in providing the resources needed to achieve our long-term goal of increasing fiber digestibility in animals.
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Jones, David, Roy Cook, John Sovell, Matt Ley, Hannah Shepler, David Weinzimmer y Carlos Linares. Natural resource condition assessment: Lincoln Boyhood National Memorial. National Park Service, 2024. http://dx.doi.org/10.36967/2301822.
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The National Park Service (NPS) Natural Resource Condition Assessment (NRCA) Program administered by the NPS Water Resources Division evaluates current conditions for important natural resources and resource indicators using primarily existing information and data. NRCAs also report on trends in resource condition, when possible, identify critical data gaps, and characterize a general level of confidence for study findings. This NRCA complements previous scientific endeavors, is multi-disciplinary in scope, employs a hierarchical indicator framework, identifies and develops reference conditions/values for comparison against current conditions, and emphasizes spatial evaluation of conditions where possible. Lincoln Boyhood National Memorial (LIBO) was authorized by an act of Congress on February 19, 1962, (Public Law 87-407) to preserve the site associated with the boyhood and family of President Abraham Lincoln, including a portion of the original Tom Lincoln farm and the nearby gravesite of Nancy Hanks Lincoln. The 200-acre memorial commemorates the pioneer farm where Abraham Lincoln lived from the age of 7 to 21. The NRCA for LIBO employed a scoping process involving Colorado State University, LIBO and other NPS staffs to establish the NRCA framework, identify important park resources, and gather existing information and data. Indicators and measures for each resource were then identified and evaluated. Data and information were analyzed and synthesized to provide summaries and address condition, trend and confidence using a standardized but flexible framework. A total of nine focal resources were examined: four addressing system and human dimensions, one addressing chemical and physical attributes, and four addressing biological attributes. The quality and currentness of data used for the evaluation varied by resource. Landscape context ? system and human dimensions included land cover and land use, natural night skies, soundscape, and climate change. Climate change and land cover/land use were not assigned a condition or trend?they provide important context to the memorial and many natural resources and can be stressors. Some of the land cover and land use-related stressors at LIBO and in the larger region are related to the development of rural land and increases in population/housing over time. The trend in land development, coupled with the lack of significantly sized and linked protected areas, presents significant challenges to the conservation of natural resources of LIBO to also include natural night skies, natural sounds and scenery. Climate change is happening and is affecting resources, but is not considered good or bad per se. The information synthesized in that section is useful in examining potential trends in the vulnerability of sensitive resources and broad habitat types such as forests. Night skies and soundscapes, significantly altered by disturbance due to traffic, development and urbanization, warrant significant and moderate concern, respectively, and appear to be in decline. Air quality was the sole resource supporting chemical and physical environment at the memorial. The condition of air quality can affect human dimensions of the park such as visibility and scenery as well as biological components such as the effect of ozone levels on vegetation health. Air quality warrants significant concern and is largely impacted by historical and current land uses outside the memorial boundary. The floral biological component was examined by assessing native species composition, Mean Coefficient of Conservation, Floristic Quality Assessment Index, invasive exotic plants, forest pests and disease, and forest vulnerability to climate change. Vegetation resources at LIBO have been influenced by historical land uses that have changed the species composition and age structure of these communities. Although large tracts of forests can be found surrounding the park, the majority of forested areas are fragmented, and few areas within and around LIBO exhibit late-successional or old-growth characteristics. Vegetation communities at LIBO have a long history of being impacted by a variety of stressors and threats including noxious and invasive weeds, diseases and insect pests; compounding effects of climate change, air pollution, acid rain/atmospheric chemistry, and past land uses; and impacts associated with overabundant white-tail deer populations. These stressors and threats have collectively shaped and continue to impact plant community condition and ecological succession. The sole metric in good condition was native species composition, while all other indicators and metrics warranted either moderate or significant concern. The faunal biological components examined included birds, herptiles, and mammals. Birds (unchanging trend) and herptiles (no trend determined) warrant moderate concern, while mammal populations warrant significant concern (no trend determined). The confidence of both herptiles and mammals was low due to length of time since data were last collected. Current forest structure within and surrounding LIBO generally reflects the historical overstory composition but changes in the hardwood forest at LIBO and the surrounding area have resulted in declines in the avian fauna of the region since the 1970s. The decline in woodland bird populations has been caused by multiple factors including the conversion of hardwood forest to other land cover types, habitat fragmentation, and increasing human population growth. The identification of data gaps during the course of the assessment is an important NRCA outcome. Resource-specific details are presented in each resource section. In some cases, significant data gaps contributed to the resource not being evaluated or low confidence in the condition or trend being assigned to a resource. Primary data gaps and uncertainties encountered were lack of recent survey data, uncertainties regarding reference conditions, availability of consistent long-term data, and the need for more robust or sensitive sampling designs. Impacts associated with development outside the park will continue to stress some resources. Regionally, the direct and indirect effects of climate change are likely but specific outcomes are uncertain. Nonetheless, within the past several decades, some progress has been made toward restoring the quality of natural resources within the park, most notably the forested environments. Regional and park-specific mitigation and adaptation strategies are needed to maintain or improve the condition of some resources over time. Success will require acknowledging a ?dynamic change context? that manages widespread and volatile problems while confronting uncertainties, managing natural and cultural resources simultaneously and interdependently, developing disciplinary and interdisciplinary knowledge, and establishing connectivity across broad landscapes beyond park borders.
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Fait, Aaron, Grant Cramer y Avichai Perl. Towards improved grape nutrition and defense: The regulation of stilbene metabolism under drought. United States Department of Agriculture, mayo de 2014. http://dx.doi.org/10.32747/2014.7594398.bard.
Texto completoResumen
The goals of the present research proposal were to elucidate the physiological and molecular basis of the regulation of stilbene metabolism in grape, against the background of (i) grape metabolic network behavior in response to drought and of (ii) varietal diversity. The specific objectives included the study of the physiology of the response of different grape cultivars to continuous WD; the characterization of the differences and commonalities of gene network topology associated with WD in berry skin across varieties; the study of the metabolic response of developing berries to continuous WD with specific attention to the stilbene compounds; the integration analysis of the omics data generated; the study of isolated drought-associated stress factors on the regulation of stilbene biosynthesis in plantaand in vitro. Background to the topic Grape quality has a complex relationship with water input. Regulated water deficit (WD) is known to improve wine grapes by reducing the vine growth (without affecting fruit yield) and boosting sugar content (Keller et al. 2008). On the other hand, irregular rainfall during the summer can lead to drought-associated damage of fruit developmental process and alter fruit metabolism (Downey et al., 2006; Tarara et al., 2008; Chalmers et al., 792). In areas undergoing desertification, WD is associated with high temperatures. This WD/high temperature synergism can limit the areas of grape cultivation and can damage yields and fruit quality. Grapes and wine are the major source of stilbenes in human nutrition, and multiple stilbene-derived compounds, including isomers, polymers and glycosylated forms, have also been characterized in grapes (Jeandet et al., 2002; Halls and Yu, 2008). Heterologous expression of stilbenesynthase (STS) in a variety of plants has led to an enhanced resistance to pathogens, but in others the association has not been proven (Kobayashi et al., 2000; Soleas et al., 1995). Tomato transgenic plants harboring a grape STS had increased levels of resveratrol, ascorbate, and glutathione at the expense of the anthocyanin pathways (Giovinazzo et al. 2005), further emphasizing the intermingled relation among secondary metabolic pathways. Stilbenes are are induced in green and fleshy parts of the berries by biotic and abiotic elicitors (Chong et al., 2009). As is the case for other classes of secondary metabolites, the biosynthesis of stilbenes is not very well understood, but it is known to be under tight spatial and temporal control, which limits the availability of these compounds from plant sources. Only very few studies have attempted to analyze the effects of different environmental components on stilbene accumulation (Jeandet et al., 1995; Martinez-Ortega et al., 2000). Targeted analyses have generally shown higher levels of resveratrol in the grape skin (induced), in seeded varieties, in varieties of wine grapes, and in dark-skinned varieties (Gatto et al., 2008; summarized by Bavaresco et al., 2009). Yet, the effect of the grape variety and the rootstock on stilbene metabolism has not yet been thoroughly investigated (Bavaresco et al., 2009). The study identified a link between vine hydraulic behavior and physiology of stress with the leaf metabolism, which the PIs believe can eventually lead to the modifications identified in the developing berries that interested the polyphenol metabolism and its regulation during development and under stress. Implications are discussed below.