No description available.

Σκοπός αυτής της διπλωματικής εργασίας είναι η μελέτη της μεταβατικής συμπεριφοράς ενός υποσταθμού υψηλής τάσης. Πιο συγκεκριμένα, με τη χρήση του προγράμματος εξομοίωσης EMTP μετρώνται τα δυναμικά σε ορισμένα σημεία του πλέγματος γείωσης του υποσταθμού όταν κεραυνός πλήττει τον πυλώνα του υποσταθμού και όταν εμφανίζεται ρεύμα βραχυκύκλωσης στον μετασχηματιστή. Πιο αναλυτικά, σε αυτή την εργασία περιλαμβάνονται τα εξής: Στο κεφάλαιο 1 περιγράφονται τα χαρακτηριστικά του κεραυνού και ο μηχανισμός δημιουργίας του ενώ αναλύονται τα είδη των υπερτάσεων που προκαλούνται από τα κεραυνικά πλήγματα. Στο κεφάλαιο 2 περιγράφονται τα είδη και οι μορφές των γειώσεων ενώ γίνεται αναφορά και στα συστήματα γειώσεων που χρησιμοποιούνται. Στο κεφάλαιο 3 αναλύεται το φαινόμενο ιονισμού του εδάφους το οποίο λάβαμε υπόψιν στην προσομοίωση του πλέγματος γείωσης του υποσταθμού. Περιγράφεται ο μηχανισμός διάσπασης του εδάφους και αναλύονται τα διάφορα μοντέλα που έχουν προταθεί για τη περιγραφή της διαδικασίας του ιονισμού. Στο κεφάλαιο 4 γίνεται μια αναλυτική περιγραφή των διαφόρων μοντέλων που έχουν αναπτυχθεί για τη μελέτη της μεταβατικής συμπεριφοράς των συστημάτων γείωσης. Από τα μοντέλα αυτά επιλέγεται το κατάλληλο που θα χρησιμοποιηθεί για την προσομοίωση του πλέγματος γείωσης του υποσταθμού. Στο κεφάλαιο 5 περιγράφεται το πρόγραμμα ανάλυσης ηλεκτρομαγνητικών φαινομένων που χρησιμοποιήθηκε για την προσομοίωση του υποσταθμού. Στο κεφάλαιο 6 δίνονται τα στοιχεία για το πλέγμα γείωσης του υποσταθμού και γίνεται η επιλογή του μοντέλου προσομοίωσης για το πλέγμα ενώ παρουσιάζεται και η μορφή του πλέγματος γείωσης που σχεδιάστηκε στο EMTP. Επίσης, αναλύεται η διαδικασία της εξομοίωσης που περιλαμβάνει μελέτη της μεταβατικής συμπεριφοράς του υποσταθμού σε πλήγμα κεραυνού στον πύργο των 150 kV και σε ενδεχόμενη εμφάνιση ρεύματος βραχυκύκλωσης στον μετασχηματιστή. Επίσης, μελετάμε και την περίπτωση όπου προσθέτουμε επιπλέον κατακόρυφες ράβδους γείωσης. Στο κεφάλαιο 7 παρουσιάζονται τα αποτελέσματα της εξομοίωσης. Δίνονται αναλυτικά όλα τα γραφήματα των δυναμικών που μετρήθηκαν καθώς και συγκεντρωτικά γραφήματα ενώ παρατίθενται και τα συμπεράσματα της προσομοίωσης. Έτσι, καταλήγουμε στο ότι οι μεγαλύτερες τιμές των δυναμικών εμφανίζονται στους κόμβους που εγχέουμε το ρεύμα κεραυνού και το ρεύμα βραχυκύκλωσης ενώ με την προσθήκη των επιπλέον κατακόρυφων ράβδων οι τιμές των δυναμικών μειώνονται. / The aim of this diploma thesis is the study of the transient behavior of a high voltage substation. First, basic senses such as the grounding and the lightning are analyzed. Sesondly, the bibliography related to the phenomenon of soil ionization of the ground and the transient behavior simulation models is presented while there is an analytical description of the simulation program that is used, EMTP-ATP. Moreover, the appropriate model for the simulation of the grounding grid is selected, including the phenomenon of the soil ionization, and the process of the simulation is explained. Finally, the simulation results are presented as well as the conclusions.

La calotte polaire antarctique représente le plus gros contributeur potentiel à l'élévation future du niveau des mers. On estime que 80 % du volume de glace déchargée de la calotte vers l'océan transite par les vastes plateformes flottantes qui bordent près de 45 % de la côte du continent. En vertu du principe d'Archimède, la contribution de la glace au niveau des mers est comptabilisée aussitôt que celle-ci franchit la ligne d'échouage qui marque la limite au delà de laquelle la glace posée sur le socle se met à flotter sur l'océan. Par conséquent, une modélisation réaliste de la dynamique de la ligne d'échouage est capitale pour obtenir des projections de l'évolution future du niveau des mers dignes de confiance. Cette dynamique est affectée par un certain nombre de processus physiques mal représentés dans les modèles d'écoulement glaciaire actuels. Cette thèse s'intéresse à deux de ces processus : l'endommagement de la glace d'une part et le frottement basal en lien avec l'hydrologie sous-glaciaire d'autre part.L'endommagement caractérise la dégradation des propriétés mécaniques de la glace due à la présence de fractures et crevasses telles qu'on les observe communément à la surface des glaciers. Cet endommagement rétroagit sur l'écoulement en réduisant la viscosité de la glace. La loi d'évolution de l'endommagement fait intervenir une équation d'advection pure dont la résolution numérique nécessite l'adoption de méthodes de stabilisation. Nous montrons que, pour des maillages associés à des temps de calcul acceptables, la dynamique de la ligne d'échouage est sensible au choix de cette méthode, ce qui complique nettement la modélisation des processus d'endommagement.Le frottement basal est représenté au sein des modèles par l'intermédiaire de lois de frottement qui visent à expliciter le lien entre vitesses basales et contraintes de cisaillement basales. Différentes formulations de ces lois ont été proposées au cours des dernières décennies sur la base d'arguments théoriques. Certaines d'entre elles intègrent explicitement l'effet de la pression de l'eau présente au sein du réseau de drainage sous-glaciaire, connue pour favoriser le mouvement basal. Malheureusement, les échelles spatiales et temporelles mises en jeu en glaciologie empêchent la validation in situ de ces différentes formulations et les modèles grande échelle optent habituellement pour la plus simple d'entre elles, la loi de Weertman. L'effet de la pression de l'eau sous-glaciaire sur le frottement basal est alors pris en compte de manière implicite via un coefficient de frottement dont la distribution est évaluée à l'aide de méthodes inverses. Faute de contrainte sur l'évolution temporelle de cette distribution, celle-ci est généralement maintenue stationnaire et une discontinuité peu réaliste du frottement apparaît à la ligne d'échouage dès lors qu'elle recule. Dans un premier temps, nous montrons que la dynamique de la ligne d'échouage modélisée est sensible à la manière dont cette discontinuité est traitée numériquement. Dans un second temps, nous mettons en évidence sur un cas synthétique que la prise en compte explicite de l'action de la pression de l'eau sous-glaciaire sur le frottement basal conduit à un phénomène de rétroactions positives qui induit des pertes de masse accrues. Enfin, nous étendons ces conclusions à un cas réel, le bassin d'Amundsen en Antarctique de l'Ouest, en montrant une sensibilité importante de la dynamique de la ligne d'échouage au choix de la loi de frottement ainsi qu'aux valeurs attribuées à certains paramètres intervenant au sein des lois testées. / The Antartic ice sheet represents the world's largest potential contributor to sea level rise. Over 80 % of Antarctica's grounded ice drains through its fringing ice shelves which surround close to 45 % of the continent's shore. Because of Archimède' principle, the contribution of the ice to sea level is accounted for as soon as it flows through the grounding line, which defines the limit beyond which ice grounded on the bedrock starts floating on the ocean. Therefore, realistic modelling of grounding line dynamics is crucial to produce trustworthy projections of future sea level rise. This dynamics is affected by a number of physical processes, some of which are not properly represented in current ice flow models. This PhD thesis focuses on two of these processes: damage of ice on the one hand and basal friction related to basal hydrology on the other hand.Damage accounts for the degradation of ice mechanical properties due to the presence of fractures and crevasses, commonly observed at the surface of glaciers. Damage affects ice flow by lowering ice viscosity. The evolution of damage is governed by a pure advection equation, the numerical resolution of which requires stabilisation methods. We show that, for numerical resolutions associated to acceptable calculation times, grounding line dynamics is sensitive to the choice of this method, which seriously complicates the modelling of damage processes.Ice flow models account for basal friction through the use of friction laws, i.e. the mathematical relationship between basal drag and sliding velocities. Several formulations of these laws have been proposed over the last decades based on theoretical arguments. Some of these formulations explicitly include the effect of basal water which is present in the subglacial drainage system and the pressure of which eases basal motion. Unfortunately, the temporal and spatial scales at stake in glaciology make it impossible to validate these different formulations in situ and large-scale ice flow models usually make use of the simplest one, the Weertman law. The effect of basal water pressure is then accounted for in an implicit fashion via a friction coefficient, the spatial distribution of which is inferred through the use of inverse methods. Because the temporal evolution of this coefficient is poorly constrained, it is usual to keep it stationary. This lead to an unphysical discontinuity of friction at the grounding line when the latter retreats. First of all, we show that grounding line dynamics is sensitive to the way this discontinuity is treated numerically. Then, we demonstrate on a synthetic case that the fact of explicitly accounting for the effect of basal water pressure on basal friction leads to positive feedback phenomeno which implies larger ice losses. Finally, these conclusions are extended to a real case, the Amundsen basin in West Antarctica, by showing a significant sensitivity of grounding line dynamics to the chosen friction law as well as to the values given to some of the parameters involved in the tested friction laws.

Spegling, härbärgering och grundning - En studie av tre begrepp i det terapeutiska rummet, av Elin Nygren, är en uppsats inom ramen för Magisterprogrammet i musikpedagogik med inriktning musikterapi vid Kungl. Musikhögskolan i Stockholm. Syftet med uppsatsen har varit att i litteraturstudier samt i intervjuer undersöka begreppen spegling, härbärgering och grundning. Intervjuerna har haft i fokus att utforska hur fyra terapeuter kliniskt använder begreppen och hur musik kan utveckla dessa. Uppsatsen grundar sig i de utvecklingspsykologiska teorierna och i Wigrams teorier om musikterapeutiska improvisationstekniker. Resultatdelen i uppsatsen är en sammanställning av intervjuerna efter att de bearbetats enligt modellen Tematisk analys. I denna del redovisas hur terapeuterna beskriver det metodiska användandet av begreppen anpassat efter de olika målgrupper som de arbetar med. Vid sammanställning av intervjuerna blev det tydligt att de fyra terapeuterna har en överensstämmande syn kring de tre begreppens funktion för terapeuten och en överensstämmelse i sina definitioner av dem. Det framkom också att musik i många delar är analogt med Sterns vitalitetsaffekter och kompatibelt med hur vi människor kommunicerar. / Reflecting, containing and grounding – A study of three concepts used in therapy, by Elin Nygren is a study carried out within the context of Master Program in Music Education, with orientation Music Therapy at The Royal College of Music in Stockholm. The purpose with this paper has been to look into the concepts reflecting, containing and grounding in literature and in interviews. The main focus of these interviews has been to explore how four therapists in therapy uses the concepts and how music can develop these. The paper is based on the developmental psychology theories and Wigram’s theories of improvisation techniques in music therapy. The result of this paper is a compilation of the interviews, after being processed according to the model of Thematic Analysis. In the result it is reported how the therapists describes the methodological use of the concepts adapted to the different audiences they work with. In the compilation it was clear that the four therapists have equivalent perspectives about the three concepts function for the therapist and an equivalent definition of them. It also appeared that music is analogue to Sterns dynamic forms of vitality and compatible with how humans communicate.

Made available in DSpace on 2014-06-11T19:24:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-07Bitstream added on 2014-06-13T18:52:40Z : No. of bitstreams: 1 santanna_cj_me_bauru.pdf: 665147 bytes, checksum: 6306cdfa87c4bda06d03c808dedff5fd (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho possui como linha mestra a apresentação de proposições técnicas para as instalações de baixa e média tensão na incidência de descargas atmosféricas, visando diminuir danos nos equipamentos elétricos dos consumidores. Para a realização dessas proposições foram estudados e analisados diversos casos relacionados ao sistema de aterramento recomendados pelas normas e publicações técnicas. A diretriz metodológica adotada nesta pesquisa incorporou estudos correlatos já consolidados, experimentos e também simulações computacionais. Os resultados obtidos foram analisados levando-se em conta a influência dos sistemas de aterramento e seus componentes, tais como: tipos de eletrodos, solo, tipo de condutor de descida e dispositivos de proteção contra surtos. / The master line of this present study consists of the presentation of technical propositions related to low and medium tension installations in the incidence lightning, aiming to decrease damages on consumer's electrical equipment. For the accomplishment of those propositions, several cases related to the earthing systems recommended standards and publications have been studied and analyzed. The methodological directive adopted in the present research has been incorporated already consolidated correlate studies consolidated, experiments, as well as digital simulations. The results obtained have been analyzed taking into account the influence of the earthing systems and their components, such as: electrodes, soil, descending conductors and protection devices.

AssociaÃÃo TÃcnico-CientÃfica Eng. Paulo de Frontin / This paper presents the study and development of a voltage impulse generator using a cascaded boost converter topology operating in Discontinuous Conduction Mode (DCM) which will be used for the inspection of grounding systems used by electric power companies. The output voltage of the converter is applied to the grounding system which behaves as a load. The signal applied to the ground was measured by the data acquisition system and analyzed by an intelligent algorithms software. The voltage has the characteristics of a double exponential waveform which is a mathematical model used for study of lightning. Furthermore, the impulse generator has the option to produce a square waveform output voltage. Unlike, the traditional impulse generator with spark gaps, which was disadvantages of poor lifetime and the need of external system to operating the same, the developed generator uses only semiconductor devices in its construction. A theoretical study was carried out through qualitative and quantitative analyzes moreover, the switching process and the losses in the converter components were studied. In this work was performed the design of a cascaded boost converter for evaluating grounding systems with approximated 156 W, input voltage of 110 Vac rms and an output peak voltage of approximately 880 VDC, which correspond to the sum each voltage capacitor of the boost converter, when they are connected in series. A prototype with the indicated specifications was implemented and experimentally tested in the laboratory and real conditions using four grounding systems configurations. Tests were performed considering that the grounding impedance is resistive. The obtained experimental and simulation results are used to validate the theoretical analysis and the designed converter. / Este trabalho apresenta o estudo e desenvolvimento de um gerador de impulsos de tensÃo usando a topologia de um conversor boost em cascata operando em Modo de ConduÃÃo DescontÃnua (MCD) que serà utilizado para inspeÃÃo de sistemas de aterramentos usados pelas concessionÃrias de energia elÃtrica. A tensÃo obtida na saÃda do conversor à aplicada ao sistema de aterramento que se comporta como uma carga. O sinal aplicado ao aterramento à medido pelo sistema de aquisiÃÃo de dados e analisado pelo software por algoritmos inteligentes. A tensÃo aplicada tem as caracterÃsticas de uma onda tipo dupla exponencial que à um modelo matemÃtico para estudo de descargas atmosfÃricas. AlÃm disso, o gerador poderà gerar tensÃes com caracterÃsticas de uma onda quadrada. O gerador de impulsos desenvolvido utiliza apenas dispositivos semicondutores na sua construÃÃo que apresentam as vantagens de possuir uma longa vida Ãtil, podem operar em altas frequÃncias, sÃo acionados com baixa tensÃo e possuem uma baixa queda de tensÃo ao contrÃrio dos tradicionais geradores de impulsos que utilizam os spark gaps para chaveamento que apresentam como desvantagens a baixa vida Ãtil e a necessidade de um sistema externo para funcionamento da mesma. Um estudo teÃrico foi realizado atravÃs das anÃlises qualitativa e quantitativa, alÃm das anÃlises do processo de comutaÃÃo e das perdas nos componentes do conversor. Neste trabalho foi realizado o projeto do conversor boost em cascata para inspeÃÃo de sistemas de aterramento com uma potÃncia aproximada de 156 W, tensÃo de entrada eficaz de 110 Vca e tensÃo de pico de aproximadamente 880 Vcc que corresponde à soma da tensÃo dos capacitores do conversor boost quando estÃo dispostos em sÃrie. Um protÃtipo com as especificaÃÃes indicadas foi construÃdo e testado experimentalmente em laboratÃrio e em campo utilizando quatro topologias de sistemas de aterramento. Foram realizados testes considerando que a impedÃncia de aterramento era puramente resistiva. Os resultados de simulaÃÃo e experimentais obtidos sÃo utilizados para validar a anÃlise teÃrica e o projeto realizado.

Le bâtiment quel qu'il soit (industrie, tertiaire, domestique), s'électrifie toujours plus pour répondre entre autre au besoin de l'efficacité énergétique. Ainsi de nombreux équipements, en particulier d'électronique de puissance ou encore d'actionneurs sont présents et produisent des perturbations électromagnétiques tant conduites que rayonnées véhiculées ou propagées par les câblages électriques et dispositifs de protection, dimensionnés pour 50Hz et non les hautes fréquences. Ceci est à l’origine de la problématique CEM dans le bâtiment. La méthodologie de modélisation proposée consiste à chercher un schéma équivalent pour chaque constituant ou composant d’une installation. L’accès aux paramètres localisés de chacun est un des points fort de la méthode, tout en permettant l’association avec d’autres composants (couplages). Les modèles ainsi générés sont implantés automatiquement dans un logiciel circuit, en l’occurrence Spice, permettant la résolution et l’association d’autres équipements électriques complexes. La modélisation des différents composants, principalement le circuit de mise à la terre, permet la simulation et l’analyse de plusieurs configurations qui devraient nous permettre de dicter des règles de conception pour rendre plus robuste le bâtiment moderne fortement électrifié. / In order to answer the need for energy efficiency, building, whatever it is (industrial, commercial, domestic), still electrifies more and more. Hence many equipment, in particular power electronic or actuators are introduced and produce conducted and radiated electromagnetic disturbances. They propagate via cabling and protection devices which have been sized for 50Hz and not for high frequencies generated by the equipment. This constitutes the EMC problematic for building.The proposed modeling methodology is to evaluate an electrical equivalent circuit for each installation’s component. Access to lumped parameters of each component is one of the highlights of this method, allowing the other components association (couplings). The generated models are implemented in a circuit software such as Spice, enabling the resolution and the association of other electrical components.The modeling of the components, mainly the grounding circuit, allows the simulation of different configurations. The analysis of several configurations should help the elaboration of design rules to make today buildings more efficient.

Regarding the ground electrical connection in trucks and buses, the requirements of earthing in heavy-duty vehicles were gathered and evaluated. The most important problems in the state-of-the-art grounding devices are corrosion, electrical resistance and uncertainty in the mounting process, altogether with depreciation over time. The goal is to come up with new concepts that can give a more reliable and better ground connection into the frame with faster, easier and safer manufacturing operations. Several methods for attaching different ground connectors to the steel frame are going to be investigated, including bolted connections, press devices, soldering, brazing and local plating spots. It will be shown that the welding operation gives the best electrical results, while lowering mounting costs, time and variability. Two welded connectors are then going to be proposed as the best alternatives and a parallel investigation with both of them is going to be carried out. These new concepts, filed for patent protection, are going to be labelled as “SRM Welded ground stud” and “SRM Welded grounding nut”. The first of them consists of a plated steel threaded stud (M8 or M10) with a ring shaped contact surface built in one of the ends, where the Ø12 mm weld is to be performed onto the uncoated frame. The second concept comprises a stainless steel M10 round nut welded over a punched hole. The optimization will also cover different alternatives for plating metals, contact aid compounds and masking caps for both devices. The risk of mechanical weakening of the frame because of the new welded concepts is going to be tested for the case of the SRM Welded ground stud. The results will show an increase in fatigue resistance of at least 20% compared to the current ground screw. Furthermore, the strength of the welded interface will show higher proof load than the stud itself. The welded nuts, tested with torque loading, will show a sufficient performance as well. The electrical tests present an expected decrease in ground resistance of 40% for the welded stud and an increase of 28% for the welded nuts, compared with the current ground screw. The conclusion of this Master Thesis states the recommendation of the implementation of a new grounding method through the SRM Welded ground stud. Although, some modifications in the transportation process of the frames might be needed because of the new protruding parts, pointing an estimated distance of 20mm from the frame surface. / När det gäller jordad elanslutning i lastbilar och bussar, har kraven på jordning i tunga fordon samlats och utvärderats. De största problemen i de mest avancerade jordade enheterna är korrosion, elektriskt motstånd och osäkerhet i monteringsprocessen, sammantaget med avskrivning över tiden. Målet är att utveckla nya koncept som kan ge en bättre och mer tillförlitlig jordanslutning i ramen med snabbare, enklare och säkrare tillverkning. Flera metoder för att fästa olika mark kontakter till stålramen kommer att undersökas, bland annat skruvförband, pressanordning, lödning, hårdlödning och lokala pläteringsfläckar. Det kommer att visa att svetsning ger den bästa elektriska resultatet, samtidigt som monteringskostnader, tid och variabilitet minskar. Två svetsade kontakter kommer sedan att föreslås som de bästa alternativen och en parallell undersökning med dem båda kommer att genomföras. Dessa nya koncept, för vilka patentskydd har ansökts, kommer att märkas som “SRM Svetsade marktapp” och “SRM Svetsade jordmutter”. Den första av dem består av en pläterad stålgängad tapp med en ringformad kontaktyta byggt i en av ändarna, där svetsen skall utföras på den obelagda ramen. Det andra konceptet består av en rostfri rund mutter svetsad över ett stansat hål. Optimeringen kommer även att omfatta olika alternativ för pläterade metaller, kontaktstöds föreningar och maskeringslock för de båda enheterna. Risken för mekanisk försvagning av ramen på grund av det nya svetsade konceptet kommer att testas med avseende på fallet med SRM Svetsad bottenreglar. Resultaten visar en ökad utmattningshållfasthet på minst 20% jämfört med den nuvarande jordskruven. Dessutom kommer styrkan av den svetsade gränsytan uppvisa en högre provbelastning än tappen själv. De svetsade muttrarna, testade med momentbelastning, kommer också uppvisa en tillräcklig prestanda. De elektriska testerna presenterade en förväntad minskning av markmotståndet på 40% för svetsade tappar och en ökning med 28% för svetsade muttrar, jämfört med den nuvarande jordskruven. Slutsatsen av detta examensarbete anger en rekommendation av genomförandet av en ny jordningsmetod genom en SRM Svetsad marktapp. Trots detta kan vissa ändringar behövas i transportprocessen av ramarna på grund av de nya utskjutande delarna, vilka pekar från ramens yta med ett uppskattat avstånd av 20 mm.

Yes / The Stream X-Machine (SXM) testing method provides strong and repeatable guarantees of functional correctness, up to a specification. These qualities make the method attractive for software certification, especially in the domain of brokered cloud services, where arbitrage seeks to substitute functionally equivalent services from alternative providers. However, practical obstacles include: the difficulty in providing a correct specification, the translation of abstract paths into feasible concrete tests, and the large size of generated test suites. We describe a novel SXM verification and testing method, which automatically checks specifications for completeness and determinism, prior to generating complete test suites with full grounding information. Three optimisation steps achieve up to a ten-fold reduction in the size of the test suite, removing infeasible and redundant tests. The method is backed by a set of tools to validate and verify the SXM specification, generate technology-agnostic test suites and ground these in SOAP, REST or rich-client service implementations. The method was initially validated using seven specifications, three cloud platforms and five grounding strategies. / European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 328392, the Broker@Cloud project [11].

Syftet med studien är att presentera ett designkoncept för publika diskussioner på nätet med målet att uppnå djupare diskussioner och minska mängden information overload. Arbetet använder metoden Concept Driven Interaction Design (CDID) som går ut på att skapa ett designkoncept utifrån flera olika teorier som appliceras genom interaktionsdesign. Ett designkoncept innehåller tre delar: ett namn, ett syfte och huvudprinciper. CDID innehåller sju steg som arbetet är utformat efter: 1.      Concept Generation – Summeras i en tabell som jämför diskussioner i forum (med flera antagande) och diskussioner med hjälp av metoden Philosophy for Children (P4C), samt annan teori. 2.      Concept Exploration – Åtta olika designaspekter identifieras utifrån jämförelsetabellen. 3.      Internal Concept Critique – Designaspekterna jämförs med två snarlika diskussionsformat. 4.      Design of Artifacts – Designkoncept version 1 skapas. 5.      External Design Critique – Intervjuer utförs för att undersöka intervjupersonerna generella erfarenheter av online diskussioner, testar antagandena från jämförelsetabellen och ge direkt feedback på första versionen av designkonceptet. 6.      Concept Revisited – Ändringar görs baserat på intervjumaterial och direkt feedback. 7.      Concept Contextualization – Designkonceptet kopplas tillbaka till litteraturen. Studien resulterar i ett designkoncept kallat CoFramer och stödjer dessa huvudprinciper som ställs i kontrast till material som identifierats genom intervjuerna: Tabell 1: CoFramers huvudprinciper och faktorer från intervjuer om diskussioner på forum. CoFramers huvudprinciper | Från intervjuer om diskussioner på forum Strukturerad början och slut | Diskussion utan tydligt slut Begränsat antal deltagare | Stor mängd deltagare Minimum antal deltagare | Många inaktiva åskådare Explicita deltagare | Lite information om deltagare Gemensamma förutsättningar | Otydlighet kring deltagares förutsättningar Begränsad informationstäthet per inlägg | Långa inlägg och/eller snabba inlägg Den röda tråden och parallella trådar | Oftast parallella trådar Aktiv samtalsledare | Outredda missförstånd Studien indikerar på att CoFramer bör resultera i mer strukturerade diskussioner och som utsätter användaren för en lägre mängd information overload och mindre grounding cost jämfört med vad som vanligtvis uppstår i publika diskussioner online. / The focus of this essay is to develop a design concept for online public discussions with deep discussions and low information overload. The method used is Concept Driven Interaction Design (CDID) which involves constructing a design concept by applying a variety of theories in tangible interaction design. A design concept has three basic parts: a name, high-level goals and outlines generic principles. CDID includes seven steps which is used in this work: 1.      Concept Generation – Formatted into a table that compare forum discussion (with several hypothesis) compared to discussions with the method Philosophy for Children (P4C) and other theories. 2.      Concept Exploration – Eight distinct design aspects are identified from the comparison table. 3.      Internal Concept Critique – The design aspects are compared to three similar discussion formats. 4.      Design of Artifacts – Design concept version 1 is created. 5.      External Design Critique – Interviews are conducted to explore their general experience of online discussions, investigate the hypothesis from the comparison table and to seek direct feedback on the first draft of the design concept. 6.      Concept Revisited – Changes are made to the design concept based on the interview material and the direct feedback. 7.      Concept Contextualization – The design concept is related to the original literature. The result of the study is a design concept named CoFramer. CoFramer’s generic principles are summarized and contrasted against factors identified from the interview material in this table: Tabell 2: CoFramer’s generic principles and interviews about online discussions. CoFramer’s generic principles | From interview material on forum discussion Organized start and ending | Discussions without clear ending Limited number of participants | Large number of participants Minimum number of participants | Large number of inactive spectators Explicit participants | Low information about participants Common conditions | Vagueness in participants conditions Limited information density per post | Long posts and/or fast posts The red thread and parallel threads | Often parallel threads Active facilitator | Unresolved misunderstandings The study indicates that CoFramer would create more structured discussions with a lower amount of information overload and less grounding cost compared what normally arise in public online discussions.