bluuebunny/crossref_metadata_2025 huggingface dataset:
Indígenas, Borbones y enclaves coloniales. Las relaciones interétnicas en el fuerte San José durante su primera década de funcionamiento (Chubut, 1779-1789)
Authors: Buscaglia Silvana
Published: July 2015

A fines del siglo XVIII la Corona española pone en práctica el plan de colonización de la costa atlántica patagónica. Como parte del mismo fueron creados el fuerte Nuestra Señora del Carmen (provincia de Buenos Aires), la Nueva Colonia y fuerte de Floridablanca (provincia de Santa Cruz) y el fuerte San José (provincia de Chubut). En este trabajo me centraré puntualmente en el análisis de las relaciones interétnicas en el fuerte San José. En particular, me interesa contextualizar estas relaciones y discutirlas en función de las características inherentes a un contexto fundacional así como de las políticas indígenas y borbónicas respecto al contacto, durante la primera década de funcionamiento del fuerte. Los resultados obtenidos hasta el momento indican una estructuración particular de las relaciones interétnicas en el escenario del fuerte San José, manifestando una faceta predominantemente conflictiva, en comparación a los otros dos poblados.
Deslizándose en las fisuras de la utopía: los Toba en las fronteras del Estado Nación argentino
Authors: Salamanca Carlos
Published: July 2015

Realizada en el Chaco argentino, en esta tesis analizamos las relaciones entre espacio, relaciones sociales y acción política. Para esto nos centramos en la relación entre los toba y el Estado-Nación argentino. El espacio ha sido abordado en esta tesis reconociendo su condición heterogénea, constituida a partir de la existencia sincrónica de múltiples sociedades y espacios diferentes. Develando la fuerza del pensamiento utópico en la consolidación del Estado-nación y en los fundamentos de todas las relaciones que éste ha establecido con los indígenas, analizamos el proceso de constitución de la Nación argentina en el Chaco y sus características de utopía de carácter universalista. El análisis de la construcción del Estado Nación y del devenir histórico de los toba ha sido realizado sobrepasando la idea de la existencia de un estado a-histórico de los indígenas y los estudios centrados en la oposiciones disciplina/trasgresión, espacio natural dado/ espacio social construido y hegemonía/resistencia. Centrándonos en sus formas de acción política, argumentamos que los toba develan las fisuras de la utopía nacionalista. Sostenemos la tesis de que en sus relaciones con la Nación los toba ‘mariscan’ en los espacios de acción política y proceden a la fabricación de sus identidades colectivas a través de la subjetivación de los universalismos. Tales universalismos son inherentes a la ciudadanía, el indigenismo, el evangelismo, y los movimientos político-sociales convocados a partir de la clase social, siendo todos estos ‘dispositivos políticos relacionales’ en los que los toba se juegan la acción política contemporánea.
Négoce et transfert culturel. Dimitrios Bikélas et le réseau intellectuel franco-grec dans la seconde moitié du xixe siècle
Authors: Mitsou Marie-Élisabeth
Published: July 2015

Figure plurielle, étroitement liée aux spécificités de l’histoire politique et culturelle de la Grèce moderne, l’intellectuel grec du xixe siècle est loin d’obtenir son autonomie sociale. Souvent il tire son origine des riches familles de commerçants de la diaspora grecque en Méditerranée orientale. Polyglotte, cosmopolite, voyageur, il déploie ses réseaux d’Alexandrie à Marseille et de la Mer Noire à Amsterdam. Par sa vie et son œuvre, Dimitrios Bikélas (1835-1908) illustre ce passage du monde transnational du négoce à l’univers intellectuel des transferts culturels entre la France, l’Angleterre et la Grèce dans la seconde moitié du xixe siècle.
Intellectuels et originalité au cours du XIXe siècle grec
Authors: Matthaiou Sophia
Published: July 2015

Après la fondation de l’État grec, la production des philologues comprend peu d’études qui pourraient recevoir l’épithète d’originales : il s’agit surtout de livres de grammaire (d’ordinaire traductions ou adaptations d’ouvrages étrangers) ou de chrestomathies (anthologies de textes anciens), de manuels destinés à l’enseignement, de dictionnaires (souvent des adaptations d’originaux étrangers). La première génération des philologues doit donc composer avec les priorités urgentes d’un nouvel État dont elle doit couvrir les besoins élémentaires. Le désir d’inventorier la réalité grecque apparaît constant. Ce phénomène peut être interprété par la prise en compte des circonstances présidant à la formation de l’État grec qui, outre les nécessités pratiques, doit affronter le problème de l’homogénéisation nationale des populations comprises dans ses frontières.
L’émergence de l’intellectuel en tant que réformateur politique et culturel : l’exemple de Jean Psichari (1854-1929)
Authors: Patéridou Géorgia
Published: July 2015

Il est connu que l’intellectuel en tant que figure publique a émergé dans le monde moderne en France à l’époque de l’affaire Dreyfus, bien qu’un des premiers usages du terme, paru dans les écrits d’Ernest Renan (Cahiers de jeunesse, 1945), suggère que l’invention de l’intellectuel moderne n’est pas sans rapport avec les révolutions de 1848. Quelques figures importantes, impliquées dans l’affaire Dreyfus, étaient aussi les agents actifs dans les vastes réformes politiques et culturelles qui ont eu lieu à la fin du XIXe siècle. Yannis Psycharis (ou Jean Psichari comme il était connu en France) était une telle figure. Il appartenait à deux contextes politiques et culturels différents et il les avait marqués tous les deux. Le présent article suit sa trajectoire, en apportant des informations importantes sur son activité et ses écrits, ce qui explique sa contribution aux combats idéologiques de son époque. Le cas exemplaire de Jean Psichari éclaire sur le rôle et la fonction de l’intellectuel dans le monde cosmopolite et multiforme du XIXe siècle en Méditerranée.
Être un intellectuel en Espagne (1898-1936)
Authors: Aubert Paul
Published: July 2015

Après avoir critiqué le régime de la Restauration, les intellectuels espagnols constituent, à partir du milieu des années vingt, une opposition démocratique et républicaine puisque la monarchie a lié son sort à la dictature. Il s’agit d’expliquer ce phénomène, d’en évaluer l’enjeu, de préciser les modalités, les étapes et la portée d’un tel engagement dans le contexte historique espagnol et dans le cadre européen. On accuse souvent l’intellectuel soit de faire de la politique sans le contrepoids des actes réels soit d’imaginer une démocratie sans le peuple, ou de renoncer à ce rôle critique qu’on attend de lui et qu’on lui reproche tout à la fois.
Cornelius Castoriadis : parcours d’un Eros
Authors: Dosse François
Published: July 2015

Cette contribution vise à restituer la cohérence du parcours d’un grand intellectuel méditerranéen, grec et français, Cornelius Castoriadis (1922-1997). Jeune résistant grec révolutionnaire menacé de mort par les staliniens, il arrive en France à l’âge de 23 ans, alors que l’engouement pour l’URSS est à son zénith. Il contribue alors à créer, avec Claude Lefort l’une des branches les plus vivaces de la gauche radicale, « Socialisme ou Barbarie », qui deviendra ensuite une revue mythique, notamment par sa critique de gauche des régimes dits « communistes ». Économiste, philosophe, psychanalyste, militant politique, Castoriadis est l’auteur d’une œuvre essentielle pour quiconque s’intéresse à la question de l’institution hors du cadre de l’État, notamment avec ce qu’on peut considérer comme l’un des maîtres ouvrages du XXe siècle, L’Institution imaginaire de la société (1975). Il n’a en effet cessé, en croisant l’analyse historienne et l’approche psychanalytique, de s’attacher à penser la conquête de l’autonomie comme condition de l’approfondissement démocratique.
Has IFRS Improved Comparability Regarding Earnings Management in Latin America?
Authors: Rathke Alex Augusto Timm , Santana Verônica de Fátima
Published: July 2015

The adoption of IFRS as a unique set of accounting standards is claimed to have the potential to enhance cross-border financial statements comparability, due to a reduction of information costs and information asymmetry. IFRS is a recent issue in Latin America and there is a lack of knowledge about its application in the region, with countries beginning to completely converge to international accounting standards around 2010. This chapter compares the level of earnings management in the first three Latin American IFRS adopters, Brazil, Chile and Peru, considering the periods before and after IFRS adoption. The results show that firms from each country evidence different levels of earnings management before IFRS adoption, and that those differences no longer remain after the adoption of IFRS. The results indicate that IFRS has made financial information more homogeneous and, therefore, enhanced information comparability in Latin America.
Do IFRS Matter in Emerging Countries?
Authors: Lourenço Isabel , Branco Manuel Castelo , Curto José Dias
Published: July 2015

This study analyzes the impact of the process of IFRS adoption on earnings management in the emerging country that is probably the most important in the world economy that has adopted in full the IFRS, Brazil. We examine earnings distributions for discontinuities around thresholds before and after IFRS adoption for a sample of Brazilian listed firms for the period 2004-2011. The findings of this study reveal that discontinuities exist, both before and after IFRS implementation, and that there is a decrease in discontinuity. The results of our study suggest that mandatory adoption of IFRS by Brazilian companies is associated with a decrease in earnings management, in particular during the period of full adoption of IFRS (post-2010).
The Impact of the Mandatory Adoption of IFRS in the Fees of Auditing in Companies of BM&FBovespa
Authors: Murro Eduardo Vinícius Bassi , Munhoz Tayrine Rodrigues , Teixeira Guilherme Bittencourt , Lourenço Isabel
Published: July 2015

This study aims to investigate if the mandatory adoption of the IFRS by the Brazilian companies listed in BM&FBovespa has made an impact on the audit fees. The final sample was made by 151 companies, between 2009 and 2012. To restrict the relations, other control variables of the size of the companies, of the turnover of auditing companies and of the quality level of the published financial statements were listed. The results made evident that the mandatory adoption of the IFRS represented a significant increase of 20.71% in the auditing fees. It has also been noticed that a positive relation between the auditing fees charged by the services and the size of the companies. However, the rotation of the auditing companies has generated a negative impact, reducing the fees paid to the independent auditors. Related to the quality of the financial statements, it was not verified a statistically significant relation.
Difficulties in the Adoption of IFRS on Small and Medium Enterprises (SMEs) in Brazil
Authors: Carvalho João Conrado de Amorim
Published: July 2015

In this chapter are showed how cultural factors influence accounting practices in different countries of the world, due to culture after the adoption of IFRS by SMEs in Brazil. It is based on a sample of 120 SMEs located in the state of Maranhão, Brazil. The SMEs were selected from a group that has been receiving accounting and financial advice since 2008. These companies are from a range of different sectors, but have in common the need to arrange bank financing in order to expand their activities. The results suggest that cultural impacts continue to prevail, such as the subordination to tax rules, but the disinterest of stakeholders in financial reporting provides a strong case to postpone the IFRS adoption process.
A Tale of Two Newsrooms
Authors: Ferrucci Patrick , Tandoc Jr. Edson C.
Published: July 2015

This chapter describes the results of a study that compared a strongly market-oriented newsroom and a less market-oriented newsroom in terms of how they used web analytics in news work. Using ethnographic methods, the study finds that web analytics influenced editorial decisions in both newsrooms. However, the two newsrooms differed in the extent to which they used analytics and in their reasons for doing so. These differences are examined using the framework of market theory in news construction.
Data-Driven Information Consumption
Authors: McKendrick Joseph E.
Published: July 2015

Things are changing dramatically within the publishing industry. However, news media itself isn't on the wane, as many pundits are stating. In this chapter, the author explores how the business model for media organizations is shifting away from print, and away from the “gateway” approach to journalism and content development, in which a few select articles are presented to audience by editors, writers and reporters. In its place, the new digital media model is creating a plethora of content from many different sources, oftentimes first-hand accounts, original sources, or commentary. In the process, rather than resulting in a dearth of news content, audiences have access to an often dizzying, overwhelming and potentially contradictory content. This is creating potentially new roles for news and publishing organizations, serving as sources of validation and aggregation of content. At the same time, the rise of digital media is providing consumers a far wider range of choices pushing media organizations to provide content more tailored to their audiences.
Modeling the Kinetics of Lignocellulosic Biomass Pyrolysis
Authors: Rueda-Ordóñez Yesid Javier , Baroni Érico de Godois , Tinoco-Navarro Lizeth Katerine , Tannous Katia
Published: July 2015

The study of the kinetics involved in lignocellulosic biomass pyrolysis has received great attention in the last decades and different mathematical models have been derived. In this chapter, a literature review was performed in order to summarize the existing models that use thermogravimetric data to estimate the kinetic parameters, which are important to improve and optimize the process. Additionally, a case study was presented exemplifying the application of kinetic modeling for the residue of one Brazilian species (Brazil nut woody shell). The isoconversional models of Ozawa-Flynn-Wall, modified Coats-Redfern, and Friedman were applied, as well as three and four independent parallel reactions models. The four reactions model presented the best fit between experimental and theoretical data, providing a better representation of the biomass pyrolysis reaction.
Technical and Marketing Criteria for the Development of Fast Pyrolysis Technologies
Authors: Mesa-Pérez Juan Miguel , Felfli Felix Fonseca
Published: July 2015

The management of projects regarding the use of biomass requires human resources with specific technical knowledge and tools to assess the real potential of raw materials within one or several production chains. Storage and transportation logistics, conservation and handling of the biomass, available technologies of transformation, and consumer market for the products are critical stages in the management process. The following chapter will present the technical, financial, and market criteria for managing production chains that use biomass as raw material in processes of fast pyrolysis.
Modeling Energy Portfolio Scoring
Authors: Diaz Rafael , Behr Joshua G. , Landaeta Rafael , Longo Francesco , Nicoletti Letizia
Published: July 2015

U.S. regions are expected to follow the national trend towards investment in renewable energy as part of their electricity portfolio. The progress of energy portfolios that typically involves traditional methods, such as centralized nuclear and coal-fired generation, and towards cleaner- and renewable-source generation will impact economic growth and public health. Renewable electricity production must strike a balance among cost, reliability, and compatibility. The economic and health benefits obtained from developing an efficient energy portfolio make renewable energy alternatives an important consideration for regions endowed with natural resources. A portfolio mix of production method that considers the economic benefits while limiting adverse health and environmental impacts is attractive. This research proposes a System Dynamics simulation framework to support policy-making efforts in assessing the impact of energy portfolios. The authors demonstrate the utility of the framework by means of analyzing data that pertain to the U.S. Hampton Roads - Peninsula Region.
A Systematic Approach for Business Data Analytics with a Real Case Study
Authors: Liu Kaibo , Shi Jianjun
Published: July 2015

Business data analytics is a process of utilizing analytic techniques for resolving business issues based on business performance data. While the avalanche of business data creates unprecedented opportunity, it also poses three fundamental challenges for analytics: (1) Business data often encounters quality issues and needs substantial cleaning efforts; (2) Business data is large in overall size but cannot be fully shared due to the concern of data security; and (3) Business data often needs to be cross-referenced with public databases to reveal more information and knowledge. Due to these challenges, the leading obstacle at many organizations is the lack of a systematic approach to understanding how to leverage the business data analytics techniques to transfer from data-rich into decision-smart. To answer this question, this article proposes a systematic step-by-step procedure for business data analytics. This proposed framework is illustrated and validated by a real case study that involves choosing an optimal location for opening of a new retail site.
The Study of Influential Adaptation of Information Technology between Buyers and Suppliers
Authors: Jitpaiboon Thawatchai , Gu Qiannong , Patel Pankaj C.
Published: July 2015

This research explores the mechanism by which the buyers and suppliers adopt different information technologies (IT) as they enter into buyer-supplier relationships. It further studies how buyers' technology choices influence suppliers' technology adaptation in an Influential Adaptation model. Using empirical data collected from the Society of Manufacturing Engineer's executives, a confirmatory factor analysis was used to improve measurement rigors including convergent validity, discriminant validity, and reliability. The Planning IT use sub-construct is developed for this study. The structural model results show that suppliers' adoption of IT use is largely influenced by buyers' level of IT use; however, there is no clear relationship pattern relating to suppliers' IT use.
Improve Intelligence of E-CRM Applications and Customer Behavior in Online Shopping
Authors: Ahmed Bashar Shahir , Ben Maati Mohammed Larbi , Al Mohajir Badreddine
Published: July 2015

The advent of internet has led to the application of electronic services in enhancing the customer relationship management. E-CRM integrates IT in internal organization in executing the marketing strategies. The current issue facing the E-CRM is determining the number of customers that are responsive to the e-commerce application. Furthermore, a huge number of customers are continuously becoming frustrated when using the E-CRM application. The application, thus becomes redundant making it difficult in meeting the set targets of customer service. The purposive study thus seeks to understand the customer responsiveness to e-CRM. The intelligence of online shopping using E-CRM cannot be underestimated. The research study made use of both qualitative and quantitative methodologies in coming up with the necessary data. Qualitative approach examined the overall effectiveness of E-CRM in influencing positive customer relationships.
The Performance Mining Method
Authors: Pachidi Stella , Spruit Marco
Published: July 2015

Software Performance is a critical aspect for all software products. In terms of Software Operation Knowledge, it concerns knowledge about the software product's performance when it is used by the end-users. In this paper the authors suggest data mining techniques that can be used to analyze software operation data in order to extract knowledge about the performance of a software product when it operates in the field. Focusing on Software-as-a-Service applications, the authors present the Performance Mining Method to guide the process of performance monitoring (in terms of device demands and responsiveness) and analysis (finding the causes of the identified performance anomalies). The method has been evaluated through a prototype which was implemented for an online financial management application in the Netherlands.
A Study on a Combined Model in Business Intelligence for Improving Electronic Insurance
Authors: Bazargani Mahdi , Namazi Elnaz
Published: July 2015

Business intelligence is one of the tools of IT in business and Information systems for management have been just developed theoretically, and have never fulfilled the demands of organizations, practically. The establishment and marketing of electronic insurance demands the readiness of tools and the foundation of IT. Business intelligence provides the managers with a collection of tools, techniques and methods in order to help them in better understanding of business state. Business intelligence techniques are applied by an optimized pattern in electronic insurance industry which its basis is merging two significant models in this field known as Kano Model and Model of Quality Function Deployment (QFD). Kano Model tool is a questionnaire filled by customers which they should answer to the questions with two positive and negative alternatives. These answers will lead to understanding quality demands of customers and considering basic demands, practical demands as well as motivational ones.
Page Ranking Validation using Cellular Automata in Cloud
Authors: Mitra Arnab , Kundu Anirban
Published: July 2015

Usage of search engine is considered as effective practice for information retrieval. Importance of “page rank” has been recognized for information retrieval. Relevant clouds are indexed by search engines for necessary information. Thus importance has been realized to validate the page rank for clouds. In the authors' design, page rank has been considered to be in a range of values for its normal behaviour. Each change in page rank has to be scrutinized. Cellular Automata (CA) has been considered for proposed system design as CA is a dynamic mathematical model for designing complex systems and capability of easy deployment at minimal cost, such as using D-type flip-flops. Usage of Null Boundary CA has been emphasized in this work. Dynamics computation of CA rules based on Langton's ?-parameter has been shown for enhanced study of proposed model. Results obtained in experiments have been compared with traffic data collected from Alexa Tool by “Amazon.com”. Comparison results have ensured effectiveness of proposed design.
Food Porn and the Invitation to Gaze
Authors: Ibrahim Yasmin
Published: July 2015

In the digital world, notions of intimacy, communion and sharing are increasingly enacted through new media technologies and social practices which emerge around them. These technologies with the ability to upload, download and disseminate content to select audiences or to a wider public provide opportunities for the creation of new forms of rituals which authenticate and diarise everyday experiences. Consumption cultures in many ways celebrate the notion of the exhibit and the spectacle inviting gaze through everyday objects and rituals. Food as a vital part of culture, identity, belonging, and meaning making celebrates both the everyday and the invitation to renew connections through food as a universal subject of appeal. Food imagery as a form of transacted materiality online offers familiarity, comfort, co-presence but above all a common elemental literacy where food transcends cultural barriers, offering a universal pull towards a commodity which is ephemeral yet preserved through the click economy. Food is symbolic of human solidarity, sociality and sharing and equally of difference creating a spectacle and platform for conversations, conventions, connections, and vicarious consumption. Food images symbolise connection at a distance through everyday material culture and practices.
Hunger Hurts
Authors: Howarth Anita
Published: July 2015

Austerity food blogs have become prominent as household food budgets have become tighter, government finances constrained, and an ideology of austerity has become dominant. The British version of austerity privileges reducing government spending by cutting welfare benefits, and legitimizes this through individual failure explanations of poverty and stereotypes of benefit claimants. Austerity food blogs, written by those forced to live hand to mouth, are a hybrid form of digital culture that merges narratives of lived experience, food practices and political commentary in ways that challenge the dominant views on poverty. The popular blog A Girl Called Jack disrupts the austerity hegemony by breaking the silence that the stigma of poverty imposes on the impoverished and by personalizing poverty through Jack Monroe's narratives of her lived experience of it, inviting the reader's pity and refuting reductionist explanations of the causes of poverty. Monroe also challenges austerity through practices derived through her personal knowledge gained during her struggle to survive and eat healthily on £10-a-week food budget. This combination of narrative and survival practices written evocatively and eloquently resonate powerfully with readers; however the response to Monroe's blog highlights a deep uneasiness in British society over growing levels of poverty, and deep divisions over who is responsible for addressing it; and more fundamentally, over identifying and defining the modern poor and modern poverty.
Politicization of the Low-Carb High-Fat Diet in Sweden, Promoted On Social Media by Non-Conventional Experts
Authors: Holmberg Christopher
Published: July 2015

The low-carb high fat (LCHF) diet, a buzz diet in Sweden, is stirring dogmatic conflict between dieters and representatives from the National Food Agency (NFA), even gaining international reputation. After gathering materials from social media and press reports covering the popular diet, a thematic analysis has been conducted. The aim of this study was to investigate how three non-conventional experts and influential promoters of the LCHF movement transact their criticisms of current nutrition authorities, and how they utilize social media for their purpose. The diet has been highly politicized, creating distrust against the established scientific community. Findings indicate that events on the national level led to an increased public awareness of the LCHF diet, providing the supporters with invaluable opportunities to criticize the established nutritional community. This enabled certain prominent advocates of the diet to gain momentum while using features of social media to further the diet's believability.
The Creation of a Theoretical Framework for Avatar Creation and Revision
Authors: Beck Dennis , Murphy Cheryl
Published: July 2015

Multi-User Virtual Environments (MUVE) are increasingly being used in education and provide environments where users can manipulate minute details of their avatar's appearance including those traditionally associated with gender and race identification. The ability to choose racial and gender characteristics differs from real-world educational environments and raises interesting questions regarding the applicability of previous racial and gender research findings. Specifically, do racial and gender categorizations found in traditional classroom research convey to virtual worlds where gender and race are controllable? To explore this issue research related to racial and gender characteristics in traditional and MUVEs environments is considered. Additionally, the theories of classification and mental categorization, media equation theory, equalization hypothesis, and Social Identification Model of Deindividuation Effects are examined as potential foundations of understanding. Results of two pilot studies conducted to determine associations of avatar appearance with gender and racial classifications are discussed in relation to the development of a theoretical framework. Implications for future investigations are discussed.
Classroom Orchestration
Authors: Hämäläinen Raija , Laine Kati
Published: July 2015

The nature of vocational education needs has changed. In authentic vocational classroom contexts, there is a rising need to develop new ways to integrate ongoing and overlapping processes of students' personal learning environments and collaborative knowledge construction. However, there is currently very little knowledge about how teachers integrate these two approaches in arranging learning. This creates new challenges for teachers when creating instructional activities, especially regarding teacher-student interactions. This case study illuminates teachers' instructional activities in empowering the students' knowledge construction in a technology-enhanced learning setting. The results showed six main teacher-student interactions related to orchestrating learning. In addition, this study illustrates how vocational education teachers enhance students' learning in ways that meet working life needs (e.g., by selectively restructuring knowledge from the viewpoint of work settings).
Overview of the Technology of Bionic Surface Drag Reduction
Authors: Gu Yun Qing , Dai Dong Shun , Mou Jie Gang , Zheng Shui Hua , Wu Deng Hao , Wang Evan
Published: July 2015

With the development of economy, the energy problem is becoming more and more seriously, which is closely related to resistance, and drag reduction means to save energy. Research on the technology of drag reduction plays an important role in the area of energy saving and its utilization rate enhancing. Using the method of bionic surface drag reduction to reduce the surface friction drag in a fluid medium has become a hot topic in the research area of drag reduction. Furthermore, through analyzing approaches of bionic surface drag reduction on the necessary of energy saving, energy utilization rate enhancing and drag reduction theory system improving, the research progress of the dynamic bionic non-smooth surfaces and bionic jet surface drag reduction technology are summarized in detail, the main trend of non-smooth drag reduction technology research and jet drag reduction technology is reviewed.
Grey Relational Analysis Based Taguchi Method for Optimization Design of the Drilling Parameters in PCB Drilling Process
Authors: Bogale Teshome Mulatie , Shiou Fang Jung , Tang Geo Ry
Published: July 2015

The purpose of this paper is to study the multiple performance optimizations of printed circuit board (PCB) drilling parameters. The major characteristics indexes for performance selected to evaluate the processes are flank wear area of microdrill and diameter of the PCB through-hole, and the corresponding drilling parameters are spindle speed, infeed, and backfeed rate. Thus, the grey relational analysis based Taguchi method has been employed to determine the optimal combination of drilling parameters. The results of confirmation experiments reveal that the average values of grey relational grade fall within the 95% confidence interval, hence the multiple performance optimizations of PCB drilling parameters using grey relational analysis based Taguchi method is proven to be reliable and effective.
A Study of Cutting Temperatures in Turning Carbon-Fiber-Reinforced-Plastic (CRFP) Composites with Nose Radius Tools
Authors: Chang Chung Shin
Published: July 2015

Nine kinds of chamfered main cutting edge nose radius tools were used in turning of high-strength carbon-fiber-reinforced-plastics (CFRP) materials to study the cutting temperature of tip's surface. A new cutting temperature model using the variations of shear and friction plane areas occurring in tool nose situations are presented in this paper. The frictional forces and heat generated in the cutting process are calculated by using the measured cutting forces and the theoretical cutting analysis. The heat partition factor between the tip and chip is solved by using the inverse heat transfer analysis, which utilizes temperature on the K type carbide tip’s surface measured by infrared as the input. The tip’s carbide surface temperature is determined by finite element analysis (FEA) and compared with temperatures obtained from experimental measurements. Good agreement demonstrates the proposed model.
An Intelligent and Confident System for Automatic Surface Defect Quantification in 3D
Authors: Tailor Mitul , Petzing Jon , Jackson Michael
Published: July 2015

Automatic surface defect inspection within mass production of high-precision components is growing in demand and requires better measurement and automated analysis systems. Many manufacturing industries may reject manufactured parts that exhibit even minor defects, because a defect might result in an operational failure at a later stage. Defect quantification (depth, area and volume) is a key element in quality assurance in order to determine the pass or failure criterion of manufactured parts. Existing human visual analysis of surface defects is qualitative and subjective to varying interpretation. Non-contact and three dimensional (3D) analyses should provide a robust and systematic quantitative approach for defect analysis. Various 3D measuring instruments generate point cloud data as an output, although they work on different physical principles. Instrument’s native software processing of point cloud data is often subject to issues of repeatability and may be non-traceable causing significant concern with data confidence.This work reports the development of novel traceable surface defect artefacts produced using the Rockwell hardness test equipment on flat metal plate, and the development of a novel, traceable, repeatable, mathematical solution for automatic defect detection and quantification in 3D. Moreover, in order to build-up the confidence in automatic defect analysis system and generated data, mathematical simulated defect artefacts (soft-artefact) have been created. This is then extended to a surface defect on a piston crown that is measured and quantified using a parallel optical coherence tomography instrument integrated with 6 axis robot. The results show that surface defect quantification using implemented solution is efficient, robust and more repeatable than current alternative approaches.
A Study of Micro-Grinding and Inspection for Aspheric Glass Lens
Authors: Lin Shou Yee , Ghiang Han Min
Published: July 2015

This study discussed abrasive machining of aspheric glass lens, with the aim to increase the aspheric lens machining efficiency and reduce the back-end polishing process. The discussions covered "optical lens design", "Taguchi method optimization", "grinding force measurement", and "on-line real-time inspection". A window interface was designed by using Borland C++ Builder for optical glass design. The aspheric design parameters were substituted in it to obtain the machining path. In terms of Taguchi method optimization, the performance of electroformed grinding rod was compared with that of resin grinding rod. Taguchi method was used to look for optimization, and the quality characteristic was surface roughness. After experimental analysis, the optimization results were: using a resin binder grinding rod, the optimum parameter of 50,000 (rpm), forward grinding, feeding at 10 mm/min, grinding depth at 0.02mm, and aspheric lens surface roughness of 0.03μm. In terms of grinding force measurement, an eight-ring strain gage dynamometer was designed to measure the optimum grinding force. The measurement result showed that the grinding force in vertical direction was 3.2kg, and that in horizontal direction is 4kg. In terms of visual inspection, a CCD camera was mounted on the machine, which takes the image of workpiece immediately after it is machined. The form was inspected, and the dismounting error was reduced.
Characterization of Second-Phase Inclusion in Silicon Carbide Powders
Authors: Hsiao Ta Ching , Tsao Shen , Nagalyuk Sergey , Mokhov Evgeny
Published: July 2015

A specific transition metal is used as a dopant element in silicon carbide powders to create the compensation effect. According to ab-initio simulation, vanadium, chromium, and manganese-induced compensation decrease the lifetime of the acceptor carrier and cause higher resistance when boron is the main impurity. Since the silicon carbide lattice has low solubility, excess metal precipitates on the surface of powders, particularly on the grain boundaries. The compositions of matrix and precipitation in the powders reveal obvious differences between the two areas. The X-ray diffraction (XRD) pattern shows the structure of VSi2, which indicates the existence of a second phase. Dual-beam focused ion beam (DBFIB) is used to further analyze the geography inside the powders. A cross-section view by DBFIB shows a second phase in the grains with a composition similar to that in the grain boundary. Metal-doped silicon carbide powders are used as starting materials to conduct crystal growth with better dopant element distribution.
Effect of Various Crucibles for High Quality AIN Crystal Growth on SiC Seed by PVT Method
Authors: Lee Hee Jun , Lee Hee Tae , Shin Hee Won , Park Mi Seon , Jang Yeon Suk , Lee Won Jae , Kim Dong Yeob , Hong Soon Ku , Kim Jung Gon
Published: July 2015

Aluminum nitride (AlN) bulk crystals, approximately 50.8mm in diameter and up to 5mm thickness, were grown by a physical vapor transport (PVT) method in a tantalum crucible. To investigate the effect of crucible materials, various crucible materials, a graphite and TaC-coated graphite and tantalum crucible were used for the AlN growth. XRD pattern of AlN crystal grown on SiC seed in the Ta-crucible exhibited only (00l) peaks, indicating that AlN single crystal was successfully grown on SiC seed. The interface structure between AlN and SiC crystals was observed by a high resolution TEM.
Synchrotron X-Ray Study on Crack Prevention in AlN Crystals Grown on Gradually Decomposing SiC Substrates
Authors: Argunova Tatiana S. , Gutkin Mikhail Yu. , Kazarova Olga P. , Mokhov E.N. , Nagalyuk Sergey , Je Jung H.
Published: July 2015

We report on the growth method and the structural characterization of freestanding AlN crystals. An AlN layer is grown on a gradually decomposing SiC substrate yielding a freestanding crack free 2H single crystal with dislocation density 5×104 cm–2 and without grain boundaries as confirmed by synchrotron radiation phase contrast imaging and topography data. Wafers of 600–1000 μm thick and up to 15 mm in diameter are obtained. The thermal stress distribution in a conventional AlN/SiC structure is discussed. Theoretical estimates show that cracking of AlN layers is a natural result of their growth on undecomposed SiC substrates.
High-Speed and Long-Length SiC Growth Using High-Temperature Gas Source Method
Authors: Kojima Jun , Makino Emi , Tokuda Yuichiro , Sugiyama Naohiro , Hoshino Norihiro , Tsuchida Hidekazu
Published: July 2015

This article gives the results of crystal growth by a High-Temperature Gas Source Method such as HTCVD. It was reported that clusters were formed and were an important factor of the growth in HTCVDs, and some influences of them were investigated. The difference between the model with and without clustering was compared. The experimental growth rates corresponded to the cluster model, and this indicated that clusters affect the crystal growth. Relations between the experimental growth rate and the growth temperature as a function of gas flow ratio were investigated. The gas flow ratio was defined: (SiH4+C3H8) / (SiH4+C3H8+H2). Maximum growth rate was 2.3mm/h under high source gas ratio. At present, a Φ75mm×54mm sized ingot has been developed.
Ge Addition during 4H-SiC Epitaxial Growth by CVD: Mechanism of Incorporation
Authors: Soulière Véronique , Alassaad Kassem , Cauwet François , Peyre Hervé , Kups Thomas , Pezoldt Joerg , Kwasnicki Pawel , Ferro Gabriel
Published: July 2015

In this paper, we will describe a detailed experimental study on the behavior of Ge incorporation into 4H-SiC during its homoepitaxial growth by CVD. Addition of GeH4 precursor to the standard chemical system SiH4 + C3H8 was investigated as a function of various growth parameters. Its effect on surface morphology, layer quality and purity was followed. All these results will allow proposing an exhaustive picture of Ge incorporation mechanism into 4H-SiC with the possible benefits of such impurity incorporation in the silicon carbide lattice.
Cleaning Process for Using Chlorine Trifluoride Gas Silicon Carbide Chemical Vapor Deposition Reactor
Authors: Habuka Hitoshi , Fukumoto Yusuke , Mizuno Kosuke , Ishida Yuuki , Ohno Toshiyuki
Published: July 2015

The silicon carbide CVD reactor cleaning process was studied by means of detaching silicon carbide particles, which was formed on the silicon carbide coated carbon susceptor surface during the silicon carbide film deposition. The contact points between the particles and the susceptor surface were etched using chlorine trifluoride gas at temperatures lower than 290 °C for 120 min. During this process, the carbon susceptor covered with the silicon carbide coating film suffered from little damage while achieving cleaning.
Study of SiC Epitaxial Growth Using Tetrafluorosilane and Dichlorosilane in Vertical Hotwall CVD Furnace
Authors: Balachandran Anusha , Song Hai Zheng , Sudarshan T.S. , Shetu Shamaita S. , Chandrashekhar M.V.S.
Published: July 2015

This paper presents one of the first comparative studies of distinctive results obtained using halogenated silicon precursors, dichlorosilane (SiH2Cl2, DCS) and tetrafluorosilane (SiF4, TFS) for SiC homo epitaxial growth. Both TFS and DCS possess very distinct properties that show specific influence on SiC growth. SiC epitaxial growth using TFS greatly suppresses parasitic deposition in the gas delivery system. Growth using TFS shows carbon mediated growth regime, and exhibits controlled doping concentration of the epilayer by an order of magnitude lower than that in the growth using DCS at the same C/Si ratio. Studies of epilayer surface morphology show that the epilayers from TFS growth have a specular surface in a wide C/Si range whereas in the growth using DCS, the epilayer surface roughness is strongly dependent on the C/Si ratio.
Change in Surface Morphology by Addition of Impurity Elements in 4H-SiC Solution Growth with Si Solvent
Authors: Komatsu Naoyoshi , Mitani Takeshi , Takahashi Tetsuo , Kato Tomohisa , Kurashige Kazuhisa , Matsumoto Yuji , Ujihara Toru , Okumura Hajime
Published: July 2015

In solution growth of 4H-SiC, we have investigated changes in macrostep height with addition of the Group III (B, Al, Ga), Group IV (Ge, Sn), Group V (N) elements, and transition metals (Ti, V, Cr, Ni) to Si solvents, in order to find additives improving severe step bunching which often occurs during growth. The addition of Al, B, Sn, N, and V decreased the average macrostep height compared with the crystal grown with Si solvents. The addition of Al, B, Sn, N, and V suppressed the generation of trench-shaped surface defects in long-term growth of 10 hours. This result demonstrated that the addition of Al, B, Sn, N, and V has an advantage to achieve high quality bulk crystal growth from solution.
Influence of Site Competition Effects on Dopant Incorporation during Chemical Vapor Deposition of 4H-SiC Epitaxial Layers
Authors: Arvinte Roxana , Zielinski Marcin , Chassagne Thierry , Portail Marc , Michon Adrien , Kwasnicki Pawel , Juillaguet Sandrine , Peyre Hervé
Published: July 2015

An exhaustive experimental study of the influence of C/Si ratio on voluntary incorporation of nitrogen (N) and aluminum (Al) in 4H-SiC thin films is presented. The films were grown by chemical vapor deposition (CVD) in a horizontal, hot wall CVD reactor on Si- and C-face substrates, under Si-rich and C-rich conditions. Under some conditions the observed variation of dopant incorporation with C/Si ratio could be clearly attributed to the site competition effects, while in several cases other mechanisms have to be taken into account.
150 mm 4H-SiC Epitaxial Layer Growth in a Warm-Wall Planetary Reactor
Authors: Sun Yong Qiang , Feng Gan , Lv Li Ping , Qian Wei Ning , Li Yi Yang , Luo Jin Yun , Zhang Jian Hui
Published: July 2015

Homo-epitaxial growth of 4H-SiC on 4o off-axis 150 mm diameter substrates has been performed in a commercial warm-wall multi-wafer planetary reactor. Based on our well developed 100 mm 4H-SiC epitaxial growth process, which can achieve excellent thickness and doping uniformities (δ/mean) of <1% and <5%, respectively, the growth process and hardware were further fine-tuned and improved for 150 mm 4H-SiC homoepitaxy. After the improvement, the 6 to7 μm thick epilayer uniformity has reached 1.1% with a 5mm edge exclusion while the doping uniformity has improved to 16.5% (<10%) with an edge exclusion of 5 mm (10mm), respectively. Surface roughness of the as-grown 150 mm 4H-SiC epitaxial layer has an RMS value of 0.12 nm scanned by AFM on 20×20 μm2 areas. Homo-epitaxial growth on C-face 150 mm 4H-SiC substrates has also been carried out. Other than the doping concentration and uniformity, the other results are very close to the epi-growth on Si-face.
Progress of SiC Epitaxy on 150mm Substrates
Authors: Zhang Jie , Thomas Bernd , Moeggenborg Kevin , Torres Victor M. , Hansen Darren
Published: July 2015

This paper presents the current performance of 150mm SiC epitaxy on state-of-the-art 150mm substrates. Excellent on-wafer uniformity has been achieved with mean thickness uniformity at 1.8% and mean doping uniformity at 5.4%. The epilayer surface is smooth across wafer diameter with a typical defect density below 1 cm-2. Within a run, wafer-to-wafer variation of 0.7 % for thickness and 5% for doping is demonstrated. The mean values of warp and bow after epitaxy are 35 um 15 μm, respectively. The above metrics are critical to enable cost effective production of 150mm SiC epiwafers suited for device fabrication.
SiC Epitaxial Growth in a 7x100mm/3x150mm Horizontal Hot-Wall Batch Reactor
Authors: Höchbauer Tobias , Leitner Mario , Kern Ronny , Künle Matthias
Published: July 2015

We present results on the homo-epitaxial growth on the Si face of 100 mm and 150 mm (0001)-oriented (4° off-orientation) 4H SiC wafers utilizing the horizontal hot-wall batch reactor Probus-SiCTM from Tokyo Electron Limited. Standard epitaxial growth processes show very high levels of intra-wafer, intra-run wafer-to-wafer, and run-to-run uniformities in the layer thickness as well as in the n-type doping concentration. N-type background doping levels less that 5e13 /cm3 have been reached. AFM measurements reveal a surface roughness of 0.2nm (rms). The density of epitaxy related defects such as triangular defects, carrots, and ingrown particles due to downfall are very low, as confirmed by high blocking yields.
Low Pressure Homoepitaxial Growth of 4H-SiC on 4°off-Axis Substrates
Authors: Hu Ji Chao , Zhang Yu Ming , Jia Ren Xu , Wang Yue Hu , Xin Bin
Published: July 2015

Step-bunching and triangular defects are significant problems in achieving higher growth rate 4H-SiC epilayers in a horizontal hot wall CVD reactor using a standard non-chlorinated chemistry of silane-propane-hydrogen on 4°off-axis substrates. In this work, the impact of growth pressure on generation of step-bunching and triangular defects and the correlations between the surface roughness and the formation of defects were investigated. It has been found that the impact of growth pressure on concentration of the triangle defects and surface roughness is obviously different. An overall reduction of defects was observed with decreasing growth pressure while the surface roughness increased. The increased adatom surface mobility in low pressure range and minimization of surface free energy are the main reasons for the phenomenon above. High Resolution X-Ray Diffraction (HRXRD) indicated that the structural quality of 4H-SiC epilayers performed at low pressure was higher than that obtained at high pressure.