bluuebunny/crossref_metadata_2025 huggingface dataset:
Lamb Wave Line Sensing for Crack Detection in a Welded Stiffener
Authors: An Yun-Kyu , Kim Jae , Yim Hong
Published: July 2014

This paper proposes a novel Lamb wave line sensing technique for crack detection in a welded stiffener. The proposed technique overcomes one of the biggest technical challenges of Lamb wave crack detection for real structure applications: crack-induced Lamb waves are often mixed with multiple reflections from complex waveguides. In particular, crack detection in a welded joint, one of the structural hot spots due to stress concentration, is accompanied by reflections from the welded joint as well as a crack. Extracting and highlighting crack-induced Lamb wave modes from Lamb wave responses measured at multi-spatial points along a single line can be accomplished through a frequency-wavenumber domain analysis. The advantages of the proposed technique enable us not only to enhance the crack detectability in the welded joint but also to minimize false alarms caused by environmental and operational variations by avoiding the direct comparison with the baseline data previously accumulated from the pristine condition of a target structure. The proposed technique is experimentally and numerically validated in vertically stiffened metallic structures, revealing that it successfully identifies and localizes subsurface cracks, regardless of the coexistence with the vertical stiffener.
Automatic Fall Monitoring: A Review
Authors: Pannurat Natthapon , Thiemjarus Surapa , Nantajeewarawat Ekawit
Published: July 2014

Falls and fall-related injuries are major incidents, especially for elderly people, which often mark the onset of major deterioration of health. More than one-third of home-dwelling people aged 65 or above and two-thirds of those in residential care fall once or more each year. Reliable fall detection, as well as prevention, is an important research topic for monitoring elderly living alone in residential or hospital units. The aim of this study is to review the existing fall detection systems and some of the key research challenges faced by the research community in this field. We categorize the existing platforms into two groups: wearable and ambient devices; the classification methods are divided into rule-based and machine learning techniques. The relative merit and potential drawbacks are discussed, and we also outline some of the outstanding research challenges that emerging new platforms need to address.
Association Rule Extraction from XML Stream Data for Wireless Sensor Networks
Authors: Paik Juryon , Nam Junghyun , Kim Ung , Won Dongho
Published: July 2014

With the advances of wireless sensor networks, they yield massive volumes of disparate, dynamic and geographically-distributed and heterogeneous data. The data mining community has attempted to extract knowledge from the huge amount of data that they generate. However, previous mining work in WSNs has focused on supporting simple relational data structures, like one table per network, while there is a need for more complex data structures. This deficiency motivates XML, which is the current de facto format for the data exchange and modeling of a wide variety of data sources over the web, to be used in WSNs in order to encourage the interchangeability of heterogeneous types of sensors and systems. However, mining XML data for WSNs has two challenging issues: one is the endless data flow; and the other is the complex tree structure. In this paper, we present several new definitions and techniques related to association rule mining over XML data streams in WSNs. To the best of our knowledge, this work provides the first approach to mining XML stream data that generates frequent tree items without any redundancy.
Improving Stewardship of Marine Resources: Linking Strategy to Opportunity
Authors: Von Heland Franciska , Clifton Julian , Olsson Per
Published: July 2014

The need for improved stewardship of coastal and marine resources is evident worldwide. However, complex ecosystem dynamics, institutional inertia, and budgetary constraints impede such action. This study explores how networks of change-oriented individuals or “institutional entrepreneurs” can introduce new types of human-environment interaction. The focus is on investigating the interplay between the strategies of institutional entrepreneurs and broader system dynamics that shape the context in which they are working, and possible impacts of institutional entrepreneurship on marine governance. We explore these issues in the context of Wakatobi National Park in eastern Indonesia. We suggest that creating links between different social spheres, such as between marine resource management and spirituality or between marine resource management and education, may accelerate the development of a new ecosystem stewardship. We further suggest that the use of media has significant power to show alternative futures, but that media may also serve to objectify certain resource users and increase the complexity of marine resource management. In general, institutional entrepreneurs play an important role in capturing and managing opportunity to open up space for experimentation and novel ideas, for example by linking their ideas to broader political priorities. Yet, such strategies bear the risk of institutional capture. Finally, institutional entrepreneurs sometimes have vested interests in certain solutions that may forsake experimentation toward a sustainable future.
Mechanism of West Nile Virus Neuroinvasion: A Critical Appraisal
Authors: Suen Willy , Prow Natalie , Hall Roy , Bielefeldt-Ohmann Helle
Published: July 2014

West Nile virus (WNV) is an important emerging neurotropic virus, responsible for increasingly severe encephalitis outbreaks in humans and horses worldwide. However, the mechanism by which the virus gains entry to the brain (neuroinvasion) remains poorly understood. Hypotheses of hematogenous and transneural entry have been proposed for WNV neuroinvasion, which revolve mainly around the concepts of blood-brain barrier (BBB) disruption and retrograde axonal transport, respectively. However, an over‑representation of in vitro studies without adequate in vivo validation continues to obscure our understanding of the mechanism(s). Furthermore, WNV infection in the current rodent models does not generate a similar viremia and character of CNS infection, as seen in the common target hosts, humans and horses. These differences ultimately question the applicability of rodent models for pathogenesis investigations. Finally, the role of several barriers against CNS insults, such as the blood-cerebrospinal fluid (CSF), the CSF-brain and the blood-spinal cord barriers, remain largely unexplored, highlighting the infancy of this field. In this review, a systematic and critical appraisal of the current evidence relevant to the possible mechanism(s) of WNV neuroinvasion is conducted.
Lactobacillus rhamnosus GG suspected infection in a newborn with intrauterine growth restriction
Authors: Sadowska-Krawczenko I. , Paprzycka M. , Korbal P. , Wiatrzyk A. , Krysztopa-Grzybowska K. , Polak M. , Czajka U. , Lutyńska A.
Published: July 2014

A disseminated Lactobacillus rhamnosus GG ATCC 53103 infection was suspected in a 6 day-old newborn with intrauterine growth restriction (IUGR) symptoms, treated empirically with antibiotics and given L. rhamnosus GG with the aim of preventing antibiotic-associated gastrointestinal complications. The level of C-reactive protein on day 5 compared with day 2 was increased in spite of negative urine and cerebrospinal fluid cultures. The blood sampled on day 6 was found to be positive for lactobacilli, and the isolate was pre-identified as L. rhamnosus or Lactobacillus casei on day 11. The strain identity was then verified as L. rhamnosus GG through PCR and 16S rRNA sequencing. Genotyping with the rep-PCR and AFLP methods confirmed the 100% genetic similarity for both the strain isolated from patient blood and the probiotic product. The newborn became touch-sensitive, cried a lot, had worsening laboratory test results, and increased inflammation parameters, but no fever was observed. After a further 9 days of antibiotic therapy, blood cultures became negative, and laboratory tests improved on day 25. The patient was discharged from the hospital after 27 days. IUGR with a possible link to L. rhamnosus GG bacteraemia might be a new potential risk group, beside patients with organ failure, immunocompromised status and dysfunctional gut barrier mechanisms, for which safe use of probiotics needs careful attention. Universally accepted or improved guidelines for the safer administration of probiotics in risk groups are urgently needed. This report should not discourage the use of probiotics, but should highlight the need for their careful use in IUGR patients.
Predictive modelling of aflatoxin contamination to support maize chain management
Authors: Battilani P. , Leggieri M. Camardo
Published: July 2014

The aim of this work was to design the potential support given by predictive models to maize management in a chain vision aimed at minimising aflatoxin contamination and human and animal exposure. There are some predictive models available but only AFLA-maize, which is a mechanistic model, is suitable for aflatoxin risk prediction worldwide. Weather data are the mandatory input for aflatoxin risk prediction and the output depends strictly on data sources, thus being influenced by both the time and distance scale of meteorological data. A user friendly summary interface of output data from predictive models is represented by risk maps in which the spatial gradient of the risk is highlighted. Actual (day by day throughout the maize growing season), historical (collected in the past) and future (predicted) data can be considered from single weather stations, a network of weather stations or a data base to support a single farm, a group of farms or an area, respectively. Past scenarios are the output generated by historical data, predictions related to actual data describe the risk situation of the current growing season and future data support the prediction of future scenarios. Model predictions cannot really support operational decisions throughout the maize growing season, but they are useful approaching crop ripening, when it is suggested that early harvest is associated with high risk and a switch from contaminated grain to non-food/ feed use can be decided. Scenarios generated by historical data can support preseason decisions with more careful management in high risk areas, while climate change scenarios are mainly destined for strategic actions deputed to institutions and policy makers. Model predictions destined for all the actors in the chain (farmers, extension services, stakeholders, politicians, institutions and researchers) can further support crop management, being also useful as communication and risk management tools.
Intravitreal Bevacizumab and Aflibercept for the Treatment of Exudative Age-Related Macular Degeneration
Authors: Selid Paul D. , Jundt Michael C. , Fortney Aaron C. , Beal James R.
Published: July 2014

BACKGROUND AND OBJECTIVE:

To compare treatment of exudative age-related macular degeneration (AMD) with bevacizumab versus aflibercept in terms of central retinal thickness (CRT) and best corrected visual acuity (BCVA).

PATIENTS AND METHODS:

A retrospective cohort study examining changes in CRT and BCVA over 12 months of follow-up in 111 patients treated with bevacizumab and 91 treated with aflibercept for exudative AMD.

RESULTS:

Treatment with bevacizumab and aflibercept reduced CRT from baseline to 12 months. Aflibercept significantly reduced the mean change from baseline CRT at 12 months compared to bevacizumab. However, mean CRT at 12 months was not significantly different after aflibercept versus bevacizumab (271.6 ± 74.0 μm vs 257.9 ± 48.5 μm). BCVA was significantly better at 6 months in the aflibercept group. At baseline, 18.5% of bevacizumab and 26.4% of aflibercept patients had BCVA better than 20/40. At 12 months, 34.8% of bevacizumab and 38.9% of aflibercept patients had BCVA better than 20/40.

CONCLUSION:

CRT decreased and BCVA improved after treatment with bevacizumab and aflibercept for exudative AMD.

[
Ophthalmic Surg Lasers Imaging Retina
. 2014;45:275–281.]
Clinical Monitoring of Patients With Age-Related Macular Degeneration Treated With Intravitreal Bevacizumab or Ranibizumab
Authors: Kiss Szilárd , Liu Ying , Brown Joseph , Holekamp Nancy M. , Almony Arghavan , Campbell Joanna , Kowalski Jonathan W.
Published: July 2014

BACKGROUND AND OBJECTIVE:

Patients with neovascular age-related macular degeneration (AMD) require frequent follow-up and regular anti-VEGF injections for optimal outcomes. Although studies suggest that injection frequency is suboptimal in clinical practice, monitoring frequency in this setting is unclear. This study evaluates annual monitoring patterns between 2008 and 2011.

PATIENTS AND METHODS:

This retrospective claims analysis included newly diagnosed neovascular AMD patients with at least one intravitreal bevacizumab or ranibizumab injection (8,811 and 2,877 patients, respectively). Patient monitoring and treatment patterns were assessed at 12-month intervals.

RESULTS:

From 2008 to 2010, the mean number of injections increased. In the 2010 cohort, among bevacizumab- and ranibizumab-treated patients, respectively, less than 23% and less than 40% had at least 10 ophthalmologist visits, and less than 4% and less than 21% had at least 10 optical coherence tomography scans.

CONCLUSION:

Patients with neovascular AMD in clinical settings during 2008 to 2011 were monitored less frequently and received fewer anti-VEGF injections than patients in major clinical trials, which may affect outcomes.

[
Ophthalmic Surg Lasers Imaging Retina
. 2014;45:285–291.]
Ocriplasmin for Treatment of Stage 2 Macular Holes: Early Clinical Results
Authors: Miller John B. , Kim Leo A. , Wu David M. , Vavvas Demetrios G. , Eliott Dean , Husain Deeba
Published: July 2014

BACKGROUND AND OBJECTIVE:

To review clinical and structural outcomes of ocriplasmin for treatment of stage 2 macular holes.

PATIENTS AND METHODS:

A retrospective review of the first patients with stage 2 macular holes to be treated with ocriplasmin at Massachusetts Eye and Ear Infirmary. All patients were imaged with spectral-domain optical coherence tomography (SD-OCT).

RESULTS:

Eight patients with stage 2 macular holes received a single injection of 125 μg of ocriplasmin. One patient (12.5%) demonstrated macular hole closure. The posterior hyaloid separated from the macula in six eyes (75%). All seven holes that remained open showed enlargement in hole diameters (narrowest, apical, and basal) at 1 week and 1 month. All seven were successfully closed with surgery. Ellipsoid zone disruptions were observed by OCT in four eyes (50%) and persisted throughout follow-up (more than 6 months on average).

CONCLUSION:

In early clinical results, the authors found a lower macular hole closure rate with ocriplasmin than previously reported. Enlargement was observed in all holes that failed to close with ocriplasmin. The authors found ellipsoid zone disruptions that persisted through 6 months of follow-up after ocriplasmin injection. Further work is needed to investigate the cause for these ellipsoid zone changes.

[
Ophthalmic Surg Lasers Imaging Retina
. 2014;45:293–297.]
Rāšid et les Idrissides: l’histoire “originelle” du Maroc entre marginalisation et glorification
Authors: Benchekroun Chafik T.
Published: July 2014

[fr] Si les Idrissides sont aujourd’hui considérés comme la dynastie fondatrice de l’histoire musulmane du Maroc, seules les deux figures d’Idrīs I et d’Idrīs II monopolisent l’attention du grand public marocain (voire des spécialistes également). La figure de Rāšid est totalement marginalisée. Pourtant, c’est ce dernier qui conduisit le futur Idris I jusqu’à Volubilis (depuis La Mecque en passant notamment par l’Egypte), qui lui succéda au pouvoir pour régner presque trois fois plus longtemps que lui (environ douze années), qui frappa des monnaies à son nom (ainsi que l’a démontré une récente publication scientifique) aussi bien dans la capitale des Rustumides Tāhirt qu’il devait donc avoir temporairement conquise que dans la sienne Volubilis. La logique historique convainc mème du fait qu’il ait fondé Fès, vu que les plus anciennes monnaies (anonymes) frappées dans cette ville le furent sous son règne/régence… Autant de points qui méritent donc que l’on s’intéresse de plus près à cette figure mystérieuse qui pourrait bel et bien avoir eu un rôle de loin plus important que celui auquel l’a “cantonn” l’historiographie traditionnelle.
Dissimulation des opinions politiques sous contrôle: Le cas d’Ibn Ḥazm à Séville
Authors: Kaddouri Samir
Published: July 2014

[fr] Les historiens arabes classiques ont fait allusion au fait qu’al-Mutaḍid, roi de Séville, avait persécuté Ibn Ḥazm et aurait condamné ses livres au feu. Ces mêmes historiens ne disaient rien d’explicite qui pourra nous renseigner avec exactitude et détails sur les circonstances politiques qui ont donné lieu à ce drame. Nous avons étudié et reconstruit le contexte historique des événements tout en tirant un plus grand profit de quelques faits nouveaux qu’avait révélés notre récente étude consacrée à l’histoire du texte de Kitāb al-Faṣl.
Martirio político y censura religiosa en la Sicilia islámica: un caso de la época de Ibrāhīm II (261-289/875-902)
Authors: Mandalà Giuseppe
Published: July 2014

Al final del periodo islámico en Sicilia, la escuela jurídica mālikí estaba firmemente arraigada y documentada en la isla, pero, como ocurre con otros muchos aspectos de su vida cultural en época islámica, el proceso histórico que había llevado a esa situación todavía necesita ser aclarado. Este estudio tiene como objetivo proporcionar a suministrar un contexto histórico para entender un pasaje del Kitāb al-miḥan, obra de martirología islámica compuesta por Abūl-‘Arab Muḥammad al-Tamīmī (m. 333/945), pasaje al que hasta ahora no se ha prestado atención en los estudios antiguos y modernos sobre la Sicilia islámica. En él se relata cómo un juez que vivía y trabajaba en Sicilia, Aḥmad b. Muḥammad al-Ṭā’ī, conocido por Ibn al-Majjānī, fue hecho prisionero y torturado por orden de Ibrāhīm II (261-289/875-902), el gobernante aglabí al que los historiadores han prestado una atención especial. Además de establecer una fecha plausible para este acontecimiento (275/888-889), se analiza el papel histórico de lugares y personajes, situando el «martirio» de Ibn al-Maŷŷānī en el contexto de la represión política llevada a cabo por Ibrāhīm II tras el episodio de Ibn Ṭālib (m. 275/888-889) y la consiguiente censura religiosa impuesta por el emir aglabí sobre las elites malikíes en Ifrīqiya y también, tal vez, en la cercana wilāya de Sicilia.
La destrucción de libros por los tradicionistas
Authors: Melchert Christopher
Published: July 2014

Este artículo ofrece una panorámica de la destrucción de libros especialmente por parte de los tradicionistas (compiladores, transmisores, críticos del hadiz), especialmente en el siglo IX de la era cristiana y antes, que sirve como una adenda al estudio (en curso de publicación) de Omar Ali de Unzaga sobre la quema
de libros en el islam. La destrucción de libros a causa de la desconfianza hacia la transmisión escrita ha sido analizada en profundidad por Michael Cook. Lo que me interesa añadir a la investigación previa son algunos ejemplos adicionales, unas breves consideraciones sobre la destrucción de libros en pro de la ortodoxia, y una mejor presentación de las razones piadosas para destruir libros, razones que tenían mucho que ver con la desconfianza no tanto de poner escrito el hadiz, sino de enseñarlo, en tanto que tentación para caer en la vanidad y distracción de asuntos más importantes.
“A la más virtuossa de las mujeres”. La reina María de Aragón (1420-1445) como impulsora de las letras en la Corona de Castilla
Authors: Pelaz Flores Diana
Published: July 2014

Fruto del singular esfuerzo dialéctico que supone la Querella de las Mujeres, en el siglo XV se alcanza un elevado nivel cultural que se traduce en la producción de obras de gran calidad acerca de las relaciones entre varones y mujeres en el ámbito de la corte de Juan II y de su primera esposa, la reina María de Aragón. La dedicatoria hacia la reina que da inicio a las obras de Diego de Valera y Juan Rodríguez del Padrón invita al análisis de las mismas respecto a la concepción de la virtud femenina ejemplificada en la figura de la reina, con el fin de reconocer los rasgos que han de caracterizar a la esposa del rey, como modelo para el resto de la población femenina. Esto lleva a hablar de un concepto plural de autoría, en el que la reina también tomaría partido del proceso creador de la obra, aun quedando al margen del propio proceso de escritura, en tanto que motor que impulsa la confección del tratado a favor de las mujeres.
Antigua disciplina: el ejemplo romano en los tratados militares ibéricos, c. 1560-1600
Authors: Martínez Bermejo Saúl
Published: July 2014

La historia militar y la imagen imperial de Roma proporcionaron un marco de referencia fundamental para concebir el papel estratégico del ejército en las monarquías portuguesa y española de la Edad Moderna. Un elemento clave del pensamiento militar de este momento fue la disciplina. Este término refería tanto a la creciente profesionalización y estandarización de la práctica bélica (así como del propio entrenamiento disciplinado) como al desarrollo de un conjunto de saberes específicos sobre la guerra. Este artículo analiza la importancia de Roma en la configuración de la disciplina militar a través del análisis de las reflexiones, reclamaciones y propuestas de reforma de los numerosos autores militares ibéricos de la época. El objetivo que se persigue es doble: la identificación y análisis de un discurso romano particular y la contextualización del género literario de las artes militares como una manifestación cultural cuya importancia e influencia trasciende los límites de la historia militar.
El proyecto general para las fortificaciones de Alicante en 1721
Authors: Echarri Iribarren Víctor
Published: July 2014

El auge de la actividad portuaria en Alicante, y los acontecimientos bélicos que sufrió la ciudad durante la Guerra de Sucesión, despertaron el interés por modernizar su obsoleto recinto amurallado. Este artículo describe el proyecto general de 1721 para las fortificaciones de esta ciudad —hasta la fecha desconocido— y valora su calidad técnica. Fue sin duda el mejor proyecto que se realizó para la modernización de las fortificaciones de Alicante durante el siglo XVIII. No tenemos noticia de la memoria que debió de elaborarse, pero sí un plano de 1721 que se conserva en el Servicio Geográfico del Ejército, hasta el momento considerado anónimo. El hecho de que el Ingeniero General Jorge Próspero de Verboom visitara Alicante en esa fecha, además de otras valoraciones técnicas, permite atribuir su autoría a dicho ingeniero. Se describen también otros proyectos coetáneos de ingenieros militares elaborados por orden de Verboom.
La sombra de la percepción: las autoridades coloniales británicas y francesas y el Protectorado español en Marruecos (1912-1936)
Authors: La Porte Pablo
Published: July 2014

Este artículo explora elementos de percepción y falta de percepción en las relaciones internacionales en torno al Protectorado marroquí a comienzos del siglo XX. El artículo parte de la constatación de que estos elementos apenas han sido visitados por la historiografía del Protectorado español y arguye que su análisis clarifica algunos de sus extremos más enrevesados. Estas páginas afirman que existió en Marruecos un mundo variado de opiniones y percepciones, vivo y cambiante, sobre la colonización española, que afectó y se extendió a las autoridades coloniales de otros países europeos y cuya incidencia en las prioridades de política colonial de sus respectivas metrópolis resultó significativa, asícomo la mediación e influencia de estas últimas en la aplicación de las mismas. Estos niveles de análisis ofrecen la oportunidad de enriquecer el conocimiento sobre la dimensión internacional del Protectorado español y las dificultades y obstáculos a los que se enfrentó en el primer tercio del siglo XX. El artículo presenta cuatro dimensiones de la colonización española que se consideran fundamentales: su problemática legitimidad; las deficiencias y carencias del Ejército colonial de África; los vaivenes e indecisiones de la política colonial española, y el levantamiento de julio de 1936, que sirve de punto final al recorrido histórico que aquí se presenta. Se ha recogido información proveniente de archivos británicos y franceses para ilustrar los puntos de vista de sus representantes en Marruecos, así como las reacciones de sus respectivas metrópolis.
Guerreros y teólogos. Guerra santa y martirio fascista en la literatura de la cruzada del 36
Authors: Rodrigo Javier
Published: July 2014

Este artículo contribuye, desde el análisis de fuentes narrativas primarias, al estudio de los mecanismos de identificación con la causa sublevada en la retaguardia franquista en guerra civil. Desde una conceptualización amplia de la noción de Cruzada, observa los porqués de su aceptación generalizada. Y desde ella, señala algunas de las claves para comprender su éxito, en tanto que lenguaje para comprender, en un contexto de guerra total, al “nosotros” y al “ellos”.
Afghanistan Conflict
Authors: Ateş Haydar
Published: July 2014

Afghanistan is one of the key countries in Asia and natural bridge between Asia and Europe via the Caspian basin. Because of her strategic situation, she has been one of the main interest points of super powers in the world. Afghanistan has lived through many invasions, chaos, conflicts, and civil wars throughout her 5.000 - year history. It is not easy to understand and solve Afghanistan conflict and prevent chaos. It may take a long time to understand the main reasons of conflict and solutions on them. The Afghanistan conflict cannot be solved in international arena without understanding the native culture, life style, society structure, religious issues, tribal issues, chaos environment, the history, and main reasons of the conflicts. The purpose of this chapter is to give some facts and ideas about Afghanistan, historical reasons about conflicts, the current conditions, and some tips and points of view for the future solutions.
The Relationship between Education and Employment and Chaos
Authors: Çakır Rahman
Published: July 2014

Chaos theory conjectures can be found in most statistical data. Mentioned obscurities especially become important in consideration of educational data and related subjects. This chapter aims at explaining the relationship between education and employment in terms of chaos. In this context, education and employment data of Turkey and OECD countries of the year 2012 has been used. In employment of women, educational qualification is important and with the raise of educational qualification, the employment ratio is also rising which in turn reduces unemployment rate. Besides this, sensitive connectivity to initial situations, which is one of the important chaos theory conjectures, appears in obtained data. The low level of initial situation of Turkey compared to other OECD countries affects the speed and rate of progress in following years.
New Advances in Single Fiber Electromyography
Authors: Rodriguez-Falces Javier
Published: July 2014

The aim of this chapter is to present a general perspective of SFEMG together with a description of the anatomical, physiological, and technical aspects that are involved in the recording of single fibre action potentials (SFAPs). First, a simulation model that relates analytically the intracellular action potential (IAP) and SFAP mathematical expressions is described. Second, the most recent findings regarding the shape features of human SFAPs are outlined. Third, a description of how different types of needle electrodes affect the characteristics of the recorded potential is detailed. Fourth, an explanation of the most important effects of filtering on the SFAP characteristics is provided. Finally, a description of the principles of jitter estimation together with the most important sources of errors is presented.
Modeling the Human Elbow Joint Dynamics from Surface Electromyography
Authors: Ruiz-Olaya Andrés Felipe
Published: July 2014

Biomechanical modelling and analysis of human motion are main topics of interest for a number of disciplines, ranging from biomechanics to human movement science. There exist various experimental and theoretical techniques developed to model the biomechanics and human motor system. A classic way to characterize a system is done by perturbation analysis, through applying an external perturbation and the observation of changes in the dynamic of system. In literature, human joint dynamics has been studied mainly in relation to external perturbations. However, those perturbations interact with the natural human motor behaviour. This chapter describes an approximation for non-invasive biomechanical modelling of the elbow joint dynamics from electromyographic information. A case study presents results obtained aimed at deriving a relationship between the dynamic behaviour of the human elbow joint and Surface Electromyography (SEMG) information in postural control. A set of experiments were carried out to measure bioelectrical (SEMG) and biomechanics information from human elbow joint, during postural control (i.e. isometric contractions) and correlate them with mechanical impedance at elbow joint. Estimates of elbow impedance were obtained by applying torque perturbations to the forearm. The results demonstrate that it is possible to estimate human joint dynamics from SEMG. The obtained results can contribute to the field of human motor control and also to its application in robotics and other engineering applications through the definition, specification and characterization of properties associated with the human upper limb and strategies used by people to command it.
Design and Development of EMG Conditioning System and Hand Gesture Recognition Based on Principal Component Analysis Feature Reduction Technique
Authors: Geethanjali P.
Published: July 2014

This chapter discusses design and development of a surface Electromyogram (EMG) signal detection and conditioning system along with the issues of gratuitous spurious signals such as power line interference, artifacts, etc., which make signals plausible. In order to construe the recognition of hand gestures from EMG signals, Time Domain (TD) and well as Autoregressive (AR) coefficients features are extracted. The extracted features are diminished using the Principal Component Analysis (PCA) to alleviate the burden of the classifier. A four-channel continuous EMG signal conditioning system is developed and EMG signals are acquired from 10 able-bodied subjects to classify the 6 unique movements of hand and wrist. The reduced statistical TD and AR features are used to classify the signal patterns through k Nearest Neighbour (kNN) as well as Neural Network (NN) classifier. Further, EMG signals acquired from a transradial amputee using 8-channel systems for the 6 amenable motions are also classified. Statistical Analysis of Variance (ANOVA) results on classification performance of able-bodied subject divulge that the performance TD-PCA features are more significant than the AR-PCA features. Further, no significant difference in the performance of NN classifier and kNN classifier is construed with TD reduced features. Since the average classification error of kNN classifier with TD features is found to be less, kNN classifier is implemented in off-line using the TMS2407eZdsp digital signal controller to study the actuation of three low-power DC drives in the identification of intended motion with an able-bodied subject.
The Relationship between Anthropometric Variables and Features of Electromyography Signal for Human–Computer Interface
Authors: Phinyomark Angkoon , Quaine Franck , Laurillau Yann
Published: July 2014

Muscle-computer interfaces (MCIs) based on surface electromyography (EMG) pattern recognition have been developed based on two consecutive components: feature extraction and classification algorithms. Many features and classifiers are proposed and evaluated, which yield the high classification accuracy and the high number of discriminated motions under a single-session experimental condition. However, there are many limitations to use MCIs in the real-world contexts, such as the robustness over time, noise, or low-level EMG activities. Although the selection of the suitable robust features can solve such problems, EMG pattern recognition has to design and train for a particular individual user to reach high accuracy. Due to different body compositions across users, a feasibility to use anthropometric variables to calibrate EMG recognition system automatically/semi-automatically is proposed. This chapter presents the relationships between robust features extracted from actions associated with surface EMG signals and twelve related anthropometric variables. The strong and significant associations presented in this chapter could benefit a further design of the MCIs based on EMG pattern recognition.
The Impact of ICT in Educating Students with Learning Disabilities in Australian Schools
Authors: Adam Tas , Tatnall Arthur
Published: July 2014

The term “Learning Difficulties” (sometimes also referred to as Special Needs) is used in reference to students who have significant difficulties in the acquisition of literacy and numeracy skills and need extra assistance with schooling. This is a large heterogeneous group. Another more specific term is “Learning Disabilities” that refers to the small sub-group of students who exhibit severe and unexplained problems. This chapter presents a report on an investigation, framed by the use of actor-network theory, of how the use of Information and Communications Technologies can aid in improving the education of students with Learning Disabilities. The study involved case studies and participant observation of the use of ICT in two outer Melbourne suburban Special Schools and an investigation of the impact of Education Department policies on these school environments. Research at the two Special Schools revealed that use of Information and Communications Technologies can have a very beneficial impact on these students by improving their self-esteem and facilitating their acquisition of useful life skills.
A Fluid Metaphor to Theorize IT Artifacts
Authors: Naidoo Rennie , Leonard Awie
Published: July 2014

This chapter extends existing metaphors used to conceptualise the unique features of contemporary IT artifacts. Some of these artifacts are innately complex, and current conceptualisations dominated by a “black box” metaphor seem to be too limited to further advance theory and offer practical design prescriptions. Using empirical material drawn from a longitudinal case study of an Internet-based self-service technology implementation, this chapter analyses various aspects of an artifact's fluidity. Post-actor network theory concepts are used to analyse the artifact's varying identities, its vague boundaries, its unexpected usage patterns, and its resourceful designers. The successes and failures of the artifact, its complex and elusive relations, and the unintended ways user practices emerged, are also analysed. This chapter contributes by extending orthodox metaphors that overemphasise a stable and enduring IT artifact—metaphors that conceal the increasingly unpredictable and transitory nature of IT artifacts—with the distinctive characteristics of fluidity. Several prescriptions for the design and management of fluid IT artifacts are offered.
Actor-Network Theory
Authors: Carroll Noel
Published: July 2014

Public sector institutions continue to significantly invest in Information and Communication Technology (ICT) as a solution for many of their service provision challenges, for example, greater efficiency and quality of services. However, what has come to light is that there is a lack of research on understanding the contributory value or “success” of technological innovations. This chapter introduces a socio-technical view of public service innovation. The aim of this research is to extend on the notion of bureaucracy, which is traditionally focused on the politics of office environments. This socio-technical view extends this traditional view to include the politics of service networks, particularly within IT-enabled public service innovation. The chapter focuses on how service innovation is exploited to align specific interests through the process of translation and shifts the focus from value co-creation to value co-enactment. In essence, this chapter explains how public service technological innovations act as an agent of bureaucracy that alters the relational dynamics of power, risk, responsibility, and accountability. For demonstrative purposes, this chapter describes a case study that examines IT-enabled service innovation with an academic service environment.
E-Health in Australia and Germany
Authors: Zwicker Manuel , Seitz Juergen , Wickramasinghe Nilmini
Published: July 2014

This chapter focuses on two specific e-health solutions, the PCEHR in Australia and the German EHC. National e-health solutions are being developed by most if not all OECD countries, but few studies compare and contrast these solutions to uncover the true benefits and critical success criteria. The chapter provides an assessment of these two solutions, the possibility for any lessons learnt with regard to designing and implementing successful and appropriate e-health solutions, as well as understanding the major barriers and facilitators that must be addressed. Finally, ANT is used to provide a rich lens to investigate the key issues in these respective e-health solutions.
Achieving E-Health Success
Authors: Wickramasinghe Nilmini , Tatnall Arthur
Published: July 2014

Healthcare delivery continues to be challenged in all OECD countries. To address these challenges, most are turning their attention to e-health as the panacea. Indeed, it is true that in today's global and networked world, e-health should be the answer for ensuring pertinent information, relevant data, and germane knowledge anywhere anytime so that clinicians can deliver superior healthcare. Sadly, healthcare has yet to realize the full potential of e-health, which is in stark contrast to other e-business initiatives such as e-government and e-education, e-finance, or e-commerce. This chapter asserts that it is only by embracing a rich theoretical lens of analysis that the full potential of e-health can be harnessed, and thus, it proffers Actor-Network Theory (ANT) as such a lens.
Evolving Digital Communication
Authors: Singh Mohini , Kurian Jayan
Published: July 2014

This chapter analyses elements of social networking sites to establish how a combination of heterogeneous elements of technology, media, language, users, data, and information are networked together to provide this new communication media. Social networking sites are also referred to as social media sites, which can be explained using the Actor-Network Theory. Social networking sites have clearly achieved widespread adoption as a new means of communication in a very short time around the globe. An analysis of literature on social networking sites is included in this chapter to reflect the new social networking language and style, the content shared via this media, the mode of use, and the language used for communication, which is a combination of a number of technological and social entities. This chapter explains how the Actor-Network Theory (ANT) can be used to explain social networking and includes some issues for research on this topic.
Research on a Test Method of Dynamic Force of Jet Elements
Authors: Yang Zhong , Yao Xiao Xian , Zhang Dong Xu
Published: July 2014

According to the characteristics of the dynamic force of jet elements, a kind of simple pendulum test system was presented. The dynamic jet force value was obtained indirectly by the acceleration value of the jet element under its force. The mathematic model of the test system was established and the test errors of the amplitude and delay time were analyzed. A processing method of dynamic force test data was presented based on the test curve and the parameters of amplitude and delay time were obtained. The result indicates that the test method can satisfy the testing requirements of dynamic force and it has advantages of simple structure, low demands of testing condition and simple method of data processing.
Model and Simulate an Underwater Hexapod Based on Isolated Body Method
Authors: Wang Zheng
Published: July 2014

Deployment, operation and recovery of an underwater robot are time-consuming and expensive activities which involve a highly skilled team and a complex logistic. An accurate and comprehensive virtual environment is required in order to rapidly designing, developing, in-lab testing and evaluating the working of an underwater robot and to minimize the risks to lose expensive equipment during hazardous in field testing. We formulate the kinematics equations for a hexapod robot with Denavit-Hartenberg description and present the dynamics equations with free body diagram based on isolated body dynamical analysis so as to overcome the difficulties of modeling Lagrange dynamics. As for contact and hydrodynamics effects, we adopt some classic methods and empirical models to obtain realism. The simulation results combining computer graphics with dynamics prove our method valid.
Contact Stress FEM Analysis of Deep Groove Ball Bearing Based on ANSYS Workbench
Authors: Xin Hua Rong , Zhu Lin
Published: July 2014

The 3D nonlinear contact model of a deep groove ball bearing was established in ANSYS Workbench software. With the reasonable setting of the boundary conditions,the contact stress and deformation are calculated in Static Structural (ANSYS) by using the finite element method,and the contact stress and deformation of the inner ring, the outer ring and the rolling elements were obtained. Furthermore, the computational values are consistent with the Hertz values. The results show that solving the bearing contact problem with ANSYS Workbench software is feasible and it coincides with the stress and deformation of the actual situation. The FEM results provide reference for the design,optimization and failure analysis of rolling bearings and have practical engineering value.
Numerical Simulation of Insulation Layer Ablation in Solid Rocket Motor Based on Fluent
Authors: Li Jian , Zhang Mei , Zhang Jiang Tao
Published: July 2014

A two-dimensional axisymmetric model was constructed to predict the ablation of the insulation layer in an end burning rocket motor by using the Computational Fluid Dynamics (CFD) software Fluent. The insulation material of graphite was used in the model. The wall surface reactions and discrete phase erosion were applied to simulate the insulation layer ablation. The influence of the burning surface movement was analyzed by using the dynamic mesh method. Numerical results show that the erosion rate increase with the increasing of burning time. The maximum erosion rate occurs at the upstream of the nozzle throat. There has a high erosion rate closing to the burning surface, and it decreases gradually away from the burning surface and becomes zero near the nozzle. It’s found that solid particle deposition appears on the inner surface of combustor closing to the nozzle, and it increases with the increasing of time.
Relay Protection Setting Calculation and Analysis of Auxiliary Power System for Hydropower Plants
Authors: Fang Nian , Li Xian Shan , Xu Hao , Du Yu Long
Published: July 2014

The configuration and setting calculation of auxiliary power protection are directly related to the regular and safe operation of the equipments, thereby affecting the security and stability of the power plant. The system features are analyzed in depth according to the operational requirements of auxiliary power system protection in Xiangjiaba hydropower plant ,the system model is built on the basis of the actual project, and a variety of short-circuit current calculations are carried out. At last, the setting of the auxiliary power system relay protection is completed. This thesis also proposes solutions to the emerging problems in the process of protection setting. The results of the setting have been applied to the actual operation and no misoperation or maloperation caused by improper constant setting value has occurred so far in Xiangjiaba hydropower plant.
Mechanical Characterization of Tatanium-Based Gradient Bioceramic Composite by Laser Cladding
Authors: Zheng Min , Fang Ao , Duan Hong Yan , Fan Ding
Published: July 2014

The gradient calcium phosphate bioceramic coating was produced on titanium alloy substrate by laser cladding. The microstructure, microhardness, fracture toughness, and residual stress of the tatanium-based gradient bioceramic composite coating were investigated. The results show that the microhardness gradually decreases with further depth increasing cross-section. The highest microhardness of the coating and the transition layer is 1544HV and 1160HV, respectively. The fracture toughness KIC is 3.72±0.03 MPa·m1/2 of bioceramic coating and 4.55±0.02 MPa·m1/2 of the transition layer, which is closely resembles the human compact bone. Furthermore, the residual stress gradually decreases from the coating to substrate, which is 221MPa between ceramic layer and the transition layer and 108MPa between the transition layer and substrate. This distribution is conforms to gradient composition design, which reducing harm of the specimen deformation and cracking.
Processing and Microstructure Properties of 7055-Al Alloy Prepared by Low-Pressure Spray Forming
Authors: Si Chao Run , Zhang Xian Jie , Wang Jun Biao
Published: July 2014

Spray forming is a new developed advanced metal-forming process, of which the property benefits from rapid solidification. The porosity produced during the atomization progress can obviously decrease the material performance. In this paper, a self-designed Laval-type atomizer is used to improve atomization efficiency. The atomization results show that the atomizer can obtain well atomization effect at a relative lower atomization pressure, and the mass median diameter d50 is 63.5μm and 43.4μm when the atomization gas pressure P0=0.4 and 0.8MPa separately. The technological parameters are optimized by overall considering the atomized droplet size, gas consumption, deposition property, and the metal yield. By the designed atomizer, the as-deposited billet with lower porosity content can be obtained with the technological parameters of the melting temperature T=800°C, atomization pressure P0=0.6MPa, and spray distance h=500mm. Further test with the deposited billet show that the grain size of the spray formed 7055-Al alloy is mainly ranging 10~30μm, which is about one third of that of as-cast billet.
The Effects of Rare Earth Element on the Al-Ti-B Master Alloy Second Phase
Authors: Hu Hua , Hu Zhi Liu , Wei Liang Jie , Yin Jian Bao
Published: July 2014

Al-Ti-B-RE master alloy is an efficient long-term new refiner. Al-Ti-B-RE refiner was prepared by Al-Ti-B master alloy doped with LaF3, La-rich RE carbonate and Ce respectively. This paper studies the effect of different type and mass fraction of RE on the Second Phase Particles distributions and shape in Master Alloys. The addition of RE have a certain effect of refining TiAl3 and TiB2 intermediate phase. Moreover, it prevents aggregation of TiB2 intermediate phase. As the different type and addition of RE has an effect on the microstructure of master alloy, then the reasonable addition of RE is put forward.