Robert E. Wernikoff. / "January 11, 1957." / Bibliography: p. 73. / Army Signal Corps Contract DA36-039-sc-64637. Dept. of the Army Task 3-99-06-108 and Project 3-99-00-100.

Η ομαδική τηλεσυνεργασία είναι ένας καινούργιος εναλλακτικός τρόπος εργασίας, ο οποίος έχει γνωρίσει σημαντική ανάπτυξη τα τελευταία χρόνια. Η ανάπτυξη και η εξέλιξή της οφείλεται στην βελτίωση της ποιότητας των υπολογιστών, στη μείωση κόστους των εφαρμογών και υλικού και στην εξέλιξη των τηλεπικοινωνιακών συστημάτων. Γενικά ο ορισμός ομαδικής τηλεσυνεργασία ή ομαδικής υποδομής δίνεται από την ITU ως: ένα αυτοματοποιημένο περιβάλλον επικεντρωμένο στις διαδράσεις μεταξύ ανθρώπου και Τερματικών Οντοτήτων (ΤΟ). Η Ομαδική Αρχιτεκτονική αποκαθιστά την υποδομή των συνεργατικών διεργασιών και των τηλεπικοινωνιών. Ενώ κατά ΙΕΕΕ ορίζεται ως εξής: Υπολογιστικά συστήματα τα οποία υποστηρίζουν ομάδες χρηστών που εμπλέκονται σε ένα κοινό έργο (ή στόχο) και τα οποία παρέχουν μία διεπαφή σε ένα διαμοιραζόμενο περιβάλλον. Η τηλεσυνεργασία εφαρμόζεται παντού στην οικονομία και σε διάφορους τομείς επαγγελματικής δραστηριότητας. Ο τραπεζικός και ασφαλιστικός τομέας ήταν οι πρώτοι που την χρησιμοποίησαν ευρέως, γεγονός που οφείλεται στην οικειότητα του προσωπικού τους με τον πληροφοριακό εξοπλισμό και στην συχνά πολύ αποκεντρωμένη οργάνωση τέτοιων εταιρειών (υποκαταστήματα, κινητό δυναμικό πώλησης, κλπ) Επιπλέον, μεγάλες εταιρείες (ειδικά στον τομέα της Πληροφορικής), ήταν από τις πρώτες που χρησιμοποίησαν την τηλε-απασχόληση Ο βασικός στόχος της παρούσας διατριβής αυτής είναι η δημιουργία μιας ενιαίας υποδομής για την υποστήριξη ομαδικής τηλε-εργασίας με την εισαγωγή πρωτοκόλλου τηλεματικής ειδικού σκοπού. Ειδικότερα πραγματοποιήθηκε η Μοντελοποίηση & Τυποποίηση Νέων Προδιαγραφών Υπηρεσιών Αντικειμένων Στοιχειολογισμικού του Ειδικού Πρωτοκόλλου στο Ενδιάμεσο Επίπεδο για την Υποστήριξη Ομαδικών Υπηρεσιών Τηλεματικής (Groupware) Η υποδομή αυτή οργανώθηκε έτσι ώστε να συνιστά μία Πλατφόρμα Υποστήριξης Ομαδικών Υπηρεσιών (ΠΥΟY). Η ΠΥΟΥ αυτή αποτελεί τη βάση για την ανάπτυξη σύνθετων εφαρμογών και υπηρεσιών Τηλε-εργασίας που αφορούν για παράδειγμα πιθανούς συνδρομητές και παροχείς υπηρεσιών Β2Β. Κατά το σχεδιασμό της ΠΥΟY ελήφθη υπ’ όψιν η αρχιτεκτονική των κατανεμημένων τεχνολογιών, όπως CORBA κτλ. με στόχο να της προσδώσουν αφ’ ενός μεν μεγάλη ανοχή στα σημεία κρίσης-καταστροφής έτσι ώστε να είναι διαρκώς διαθέσιμη, αφετέρου δε ικανότητα διαμοιρασμού των πόρων υπολογιστικής ισχύος σε όλους τους σταθμούς με στόχο την αύξηση της απόδοσης του συστήματος. Στα πλαίσια της παρούσας διατριβής, γίνεται επίσης αξιολόγηση της απόδοσης των οντοτήτων που απαρτίζουν την ΠΥΟΥ. Τα στοιχεία αξιολόγησης βασίζονται κατά κύριο λόγο σε μετρήσεις που βασίστηκαν σε εξομοιώσεις λειτουργίας της ΠΥΟΥ σε διάφορους τρόπους λειτουργίας καθώς και με τα αποτελέσματα που προέκυψαν από τις απαντήσεις στα ερωτηματολόγια εργαστηριακού προτύπου που μοιράστηκαν στους χρήστες τις πλατφόρμας. / Group-working is a new alternative way of work, which has known important growth the last years. The growth and its development are owed in the improvement of computers quality, in the reduction of applications and material costs, as well as of the telecommunications systems development. Generally the term Group-working is reported in any type of work, which can be executed far from the traditional labour space, as are the office, the factory or the company. Group-working is applied everywhere in the economy and in various sectors of professional activity. The banking and insurance sector were first that used Group-working widely, a fact that is owed in the personnel familiarity with the informative equipment and in the decentralised organisation of such companies (branch companies, mobile sale potential, etc). Moreover, big companies (specifically in the Information technology sector), were the first that used Group-working. The choice of suitable platform and tools for each Group-working application depends from the particular application. For this the reason an extensive study of application should take place first, in order to ensure that all the requirements are met. Based on the aforementioned requirements we will determine the suitable technical solution Of course for the final choice the cost it is taken under serious consideration and the. In the frames of this thesis the results of a big scale common project of are presented, aiming into the implementation of a Value Added Group-working Platform, capable to support Service Provider Companies in their plans. The novel Group-working Platform is the basis of a ready-to-be-applied multi-level pertinent Tele-Working Service and is planned to satisfy the demands of possible B2B providers and subscribers. An extensive presentation is also provided, for handling the Service by means of the Object Request Broker (ORB) technology approach. The Group-working Platform has been developed so as to manage fault tolerance and enable non-stop availability. By making use of idle processing power within the distributed system, the overall efficiency can be increased by ‘load balancing’ all the nodes. Synchronization across the Group-working Services system presents a management challenge that requires specialised technologies to be implemented; also, security enforcement can also be less than trivial to achieve The entities of both the platform and the major issues regarding the service are presented, along to an extensive evaluation procedure utilised in order to measure their performance by means of a period of their pilot implementation.

The epitaphs carved in marble and set up around the city of Rome by Damasus I (366- 384) have long been understood as important in the political and ecclesiastic history of the city and as crucial in the development of its Christian martyr-cult. I have applied principles of collective memory and material culture theories in order to discuss the role of the epitaphs as physical vehicles of cultural value and self-conception for the post- Constantinian Christian community at Rome. / Graduate

The increasing deployment of portable computers and mobile devices leads to an increasing demand for wireless connections. Infrared presentsseveral advantagesover radio for indoor wireless connectivity but infrared link quality is affected by ambient infrared noise and by low power transmission levels due to eye safety limitations. The Infrared Data Association (IrDA) has developed the widely used IrDA 1.x protocol standard for short range, narrow beam, point to point connections.IrDA addressedthe requirement for indoor multipoint connectivity with the development of the Advanced Infrared (AIr) protocol stack. This work analyses infrared link layer design based on IrDA proposals for addressing link layer topics and suggests implementation issues and protocol modifications that improve the operation of short range infrared connections. The performance of optical wireless links is measuredby the utilization, which can be drawn at the data link layer. A new mathematical model is developed that reaches a simple equation that calculates IrDA 1.x utilization. The model is validated by comparing its outcome with simulation results obtained using the OPNET modeler. The mathematical model is employed to study the effectiveness on utilization of physical and link layer parameters.The simple equation gives insights for the optimum control of the infrared link for maximum utilization. By differentiating the utilization equation, simple formulas are derived for optimum values of the window and frame size parameters. Analytical results indicate that significant utilization increase is observed if the optimum values are implemented, especially for high error rate links. A protocolimprovement that utilizes special Supervisory frames (S-frames) to pass transmission control is proposed to deal with delays introduced by F-timer expiration. Results indicate that employing the special S-frame highly improves utilization when optimum window and frame size values are implemented. The achieved practical utilization increase for optimum parameter implementation is confirmed by meansof simulation. AIr protocol trades speedfor range by employing Repetition Rate (RR) coding to achieve the increased transmission range required for wireless LAN connectivity. AIr employs the RTS/CTS medium reservation scheme to cope with hidden stations and CSMA/CA techniques with linear contention window (CW) adjustment for medium access. A mathematical model is developed for the AIr collision avoidance (CA) procedures and validated by comparing analysis with simulation results. The model is employed to examine the effectiveness of the CA parameters on utilization. By differentiating the utilization equation, the optimum CW size that maximises utilization as a function of the number of the transmitting stations is derived. The proposed linear CW adjustment is very effective in implementing CW values close to optimum and thus minimizing CA delays. AIr implements a Go-Back-N retransmission scheme at high or low level to cope with transmission errors. AIr optionally implements a Stop-and-Wait retransmission scheme to efficiently implement RR coding. Analytical models for the AIr retransmission schemes are developed and employed to compare protocol utilization for different link parametervalues. Finally, the effectiveness of the proposedRR coding on utilization for different retransmission schemes is explored.

A fines del siglo V y durante del siglo IV a.c. la medicina tuvo un momento cúlmine de valoración social y espiritual dentro de la cultura griega; cultura por sí misma orientada a la formación del cuerpo y del espíritu; el médico llegó a significar algo así como el representante de un conocimiento especial del más alto refinamiento metodológico, a la vez que personificaba la encarnación de una ética profesional de carácter práctico, supeditando su saber teórico al fin último del sentido de la vida humana. En la cultura moderna no llegará nunca a recobrar ese lugar. Sin embargo, es importante señalar que dicha medicina jamás habría llegado a convertirse en una ciencia sin las indagaciones de los primeros filósofos jónicos que buscaban una explicación “natural” a todos los fenómenos o sin esa tendencia a reducir todo efecto a una causa ni a descubrir en dicha relación (causa-efecto) la existencia de un orden general y necesario. Su fe inquebrantable en encontrar la clave de todos los misterios del mundo mediante la observación imparcial de las cosas y la fuerza del conocimiento racional fue un aporte sustancial. Sobre esa base, fueron los médicos griegos, disciplinados por aquel pensamiento normado por sus precursores filosóficos, los primeros que fueron capaces de crear un sistema teórico que pudiese servir de sustentación a un movimiento científico.

Despite interest from policymakers and the telecommunications sector to deliver superfast broadband to the whole of the UK, rural areas remain underserved, decreasing their ability to benefit from broadband-enabled services. Public intervention, primarily structured as national subsidies, is active across the UK to respond to this rural market failure. Complementing such practices are local-level strategies framed as community-led broadband initiatives. Their inclusion within wider superfast broadband installation strategies has not yet been examined. This doctoral research examines two of these initiatives, their structure and impact on the community to develop an understanding of their potential as replicable rural broadband delivery mechanisms. I analyse both the process of installing superfast broadband technology from community-led perspective and the subsequent engagement with superfast broadband through a qualitative longitudinal approach. A conceptual framework of 'social resilience' is developed as a contemporary analytical tool for examining these individual and community processes. The findings reveal an inherent complexity to rural community-led broadband provision. Community-led broadband reflects a 'localism' development approach, and this process has strengthened local rural identity. Following the adoption of superfast broadband, rural users experienced a growth in digital knowledge and individual resilience. However, the initiatives themselves are often discussed as 'separate from', or incompatible with, the telecommunications industry, as well as sitting outside the scope of current government interventions. In doing so, barriers to external networking and extra-local partnerships are built, limiting the opportunities for community-led broadband networks to become a substantive part of rural broadband delivery across the UK. Throughout the thesis, an understanding of these various tensions, impacting the success, use and replicability of rural community-led broadband, is developed and community-led broadband is shown to be another example of uneven rural development. I conclude by making recommendations for future digital policy interventions in the UK.

O propósito deste trabalho é determinar a natureza, especificidade e necessidade da categoria da política no pensamento maduro de Aristóteles, tendo por eixo central o exame de três obras capitais: Ética Nicomaquéia, A Constituição de Atenas e Política. Estabelecer, portanto, os nexos e laços históricos que uniram e animaram o pensamento político do estagirita, relacionando-os à realidade ateniense do século do IV a.C que influenciou, sobremaneira, a démarche ideológica do filósofo em tela. Trata-se de apontar os elos que motivaram concretamente o autor a encontrar na política e na ética instrumentos a moderar, a impor limites ao modo de vida grego (à comunidade política) e à individualidade, respectivamente. O ideário político-ético aristotélico brotou dos desafios incontornáveis de uma pólis grega declinante, com suas adstringências ingênitas, de apoucadas forças produtivas. Assim, foi levado, historicamente, a responder ao grande desafio de seu tempo: recompor, a partir de certa exeqüibilidade, o equilíbrio citadino perdido por décadas de guerras internas e externas. De modo que, política e ética foram compreendidas como mecanismos reguladores a dirimir conflitos e tensões em momento singular da vida pública grega, a saber, em uma pólis prestes a perder sua autonomia política para Filipe e Alexandre. Em síntese, visava, portanto, intermediar relações, limitar e equilibrar a comunidade e o indivíduo que dela participava, pois, do contrário, a ausência de limites acabaria (como de fato ocorreu) impondo a dissolução da vida in communitas. / The purpose of this work is to determine the nature, specificity and necessity of the politics category in Aristotle\'s mature thought, having as central axis the examination of his major works: Nichomachean Ethics, Constitution of Athens and Politics. To find, therefore, the historical nexus and ties that animate and link the Stagirite\'s political ideology to the 4th-century BC Athenian reality, which strongly influenced the philosopher\'s ideological démarche. The point is to establish the links that concretely motivated the philosopher of Stagira to find in Politics and in Ethics the instruments to moderate and impose limits to the Greek way of life (the political community) and to individuality, respectively. Thus, the Aristotelian political-ethical ideology rises from the unescapable challenges of a declining Greek polis, with its innate restrictions of scarce productive forces. Such a reflection finds in the Athenian decline the motivation for its birth, that is, the Stagirite is historically driven to respond to the great challenge of his time: to recompose, within a certain degree of possibility, the city-state balance lost through decades of internal and external wars. In this way, Politics and Ethics are understood as regulative mechanisms to settle conflicts and tensions in a singular moment of Greek public life, that is, in a polis about to lose its political autonomy to Philip and Alexander. In synthesis, the aim of the Stagirite\'s political-ethical ideology is to intermediate relations, to limit and to equilibrate the community and its participant individual because, otherwise, the absence of limits would eventually impose (as it actually occurred) the dissolution of life in communitas.

O propósito deste trabalho é determinar a natureza, especificidade e necessidade da categoria da política no pensamento maduro de Aristóteles, tendo por eixo central o exame de três obras capitais: Ética Nicomaquéia, A Constituição de Atenas e Política. Estabelecer, portanto, os nexos e laços históricos que uniram e animaram o pensamento político do estagirita, relacionando-os à realidade ateniense do século do IV a.C que influenciou, sobremaneira, a démarche ideológica do filósofo em tela. Trata-se de apontar os elos que motivaram concretamente o autor a encontrar na política e na ética instrumentos a moderar, a impor limites ao modo de vida grego (à comunidade política) e à individualidade, respectivamente. O ideário político-ético aristotélico brotou dos desafios incontornáveis de uma pólis grega declinante, com suas adstringências ingênitas, de apoucadas forças produtivas. Assim, foi levado, historicamente, a responder ao grande desafio de seu tempo: recompor, a partir de certa exeqüibilidade, o equilíbrio citadino perdido por décadas de guerras internas e externas. De modo que, política e ética foram compreendidas como mecanismos reguladores a dirimir conflitos e tensões em momento singular da vida pública grega, a saber, em uma pólis prestes a perder sua autonomia política para Filipe e Alexandre. Em síntese, visava, portanto, intermediar relações, limitar e equilibrar a comunidade e o indivíduo que dela participava, pois, do contrário, a ausência de limites acabaria (como de fato ocorreu) impondo a dissolução da vida in communitas. / The purpose of this work is to determine the nature, specificity and necessity of the politics category in Aristotle\'s mature thought, having as central axis the examination of his major works: Nichomachean Ethics, Constitution of Athens and Politics. To find, therefore, the historical nexus and ties that animate and link the Stagirite\'s political ideology to the 4th-century BC Athenian reality, which strongly influenced the philosopher\'s ideological démarche. The point is to establish the links that concretely motivated the philosopher of Stagira to find in Politics and in Ethics the instruments to moderate and impose limits to the Greek way of life (the political community) and to individuality, respectively. Thus, the Aristotelian political-ethical ideology rises from the unescapable challenges of a declining Greek polis, with its innate restrictions of scarce productive forces. Such a reflection finds in the Athenian decline the motivation for its birth, that is, the Stagirite is historically driven to respond to the great challenge of his time: to recompose, within a certain degree of possibility, the city-state balance lost through decades of internal and external wars. In this way, Politics and Ethics are understood as regulative mechanisms to settle conflicts and tensions in a singular moment of Greek public life, that is, in a polis about to lose its political autonomy to Philip and Alexander. In synthesis, the aim of the Stagirite\'s political-ethical ideology is to intermediate relations, to limit and to equilibrate the community and its participant individual because, otherwise, the absence of limits would eventually impose (as it actually occurred) the dissolution of life in communitas.

En la aproximación aristotélica al problema del aprendizaje de la virtud encontramos ya no solo una búsqueda comprometida con un saber práctico, sino principalmente el bosquejo de un método para la actualización de dicho conocimiento en el carácter del agente moral. La dimensión epistémica de la sabiduría práctica se amplía dentro de un modelo argumentativo complejo, en cuya estructura se van a articular principios generales, percepciones particulares y acciones concretas. Es decir, ya no solo se trata de saber en qué consiste la justicia, sino más bien en cómo soy justo en esta situación específica. / Tesis

Nuestro trabajo consiste en un análisis textual desde los presupuestos hermenéuticos de la unidad y la coherencia del pensamiento aristotélico sobre el alma y dios. Para tal fin se investigará, en primer lugar, cómo es que se habla del intelecto a lo largo del De anima, y si se menciona su separación; luego, en una segunda parte, se analizará la concepción de alma, según se presenta en el texto, en vista al problema del intelecto o alma humana; aquí mismo desarrollaremos la doble concepción de acto-potencia que Aristóteles desarrolla para aclarar lo que es el alma. En un tercer capítulo se verá en forma detallada cuál es la concepción del intelecto agente y cómo actúa este, a base de las metáforas del capítulo III.5; por último, analizaremos la concepción de dios según el libro doce de la metafísica y la relación que existe entre dios y el intelecto humano. / Tesis