• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 26
  • 14
  • 4
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 57
  • 57
  • 18
  • 15
  • 12
  • 7
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Τεχνικές σχεδιασμού εφαρμογών και υπηρεσιών ηλεκτρονικής διακυβέρνησης

Σουρλά, Ευφροσύνη 22 September 2009 (has links)
Η εποχή της παγκοσμιοποίησης και του ψηφιακού κόσμου έχει δημιουργήσει ένα νέο είδος κοινωνίας της πληροφορίας και οικονομίας βασισμένης στη γνώση, τα οποία αλλάζουν την ανθρώπινη συμπεριφορά. Αυτό επιδρά σε πολλούς τομείς όπως στην πολιτική, στα οικονομικά και στην κοινωνία. Η τεχνολογία της πληροφορίας και της επικοινωνίας (Information and Communication Technology, ICT), θεωρείται ένα πανίσχυρο εργαλείο που παίζει βασικό ρόλο σ’ αυτές τις αλλαγές. Παρέχει έναν εναλλακτικό τρόπο επικοινωνίας μεταξύ κυβέρνησης και πολιτών μέσω ηλεκτρονικών υπηρεσιών. Αυτές οι υπηρεσίες μπορούν να οδηγήσουν στη διαφάνεια της κυβερνητικής διαχείρισης στο δημοκρατικό κόσμο. Ο όρος Ηλεκτρονική Διακυβέρνηση (Electronic Government, επίσης γνωστός και ως e-gov) αναφέρεται στη χρήση των τεχνολογιών της πληροφορικής και των υπολογιστών ως πλατφόρμα για την ανταλλαγή πληροφοριών, παροχή υπηρεσιών και πραγματοποίηση συναλλαγών με πολίτες, επιχειρήσεις και άλλα σκέλη της κυβέρνησης. Επίσης, η ευρεία χρήση του Διαδικτύου έχει οδηγήσει στην ανάδειξη μιας ποικιλίας ηλεκτρονικών υπηρεσιών, γνωστών ως “e-services”. Τα Ηλεκτρονικά Εισιτήρια, ή αλλιώς “e-Tickets”, αποτελούν παράδειγμα ηλεκτρονικών υπηρεσιών. Γενικά μιλώντας, τα ηλεκτρονικά εισιτήρια είναι αντίστοιχα με τα έντυπα εισιτήρια και αποδεικνύουν ότι ο κάτοχός τους έχει πληρώσει ή δικαιούται μια υπηρεσία, όπως παραδείγματος χάριν είσοδο σε μέρος διασκέδασης, αναβάθμιση λογισμικού μέσω internet, χρήση κάποιου μέσου μαζικής μεταφοράς. Τα έντυπα και τα ηλεκτρονικά εισιτήρια εμφανίζονται επίσης σε συστήματα διαχείρισης ροής πελατών για ιδιωτικούς ή δημόσιους οργανισμούς και επιχειρήσεις που αντιμετωπίζουν το πρόβλημα των μεγάλων ουρών και χρόνων αναμονής. Τέτοιες περιπτώσεις είναι τράπεζες, φαρμακεία, ταχυδρομεία, νοσοκομεία, εμπορικά κέντρα, αστυνομικές υπηρεσίες και υπηρεσίες ευρέσεως εργασίας. Στις περιπτώσεις αυτές, ο πελάτης εισέρχεται στο χώρο υποδοχής, λαμβάνει ένα εισιτήριο και μπαίνει σε μια ουρά αναμονής μέχρι να έρθει η ώρα εξυπηρέτησής του οπότε και ειδοποιείται να προσέλθει στο χώρο εξυπηρέτησης. Τα συστήματα αυτά, παρά τα πλεονεκτήματα που έχουν, παρουσιάζουν κάποιες ελλείψεις οι οποίες μπορούν να συνοψιστούν στις εξής: Ο πελάτης πρέπει να προσέλθει στο χώρο υποδοχής για να λάβει το εισιτήριο, δεν υπάρχει δηλαδή κάποιο σύστημα παραγωγής ηλεκτρονικών εισιτηρίων ώστε ο πελάτης να λαμβάνει ηλεκτρονικά εισιτήρια πριν μεταβεί στους χώρους του οργανισμού ή της επιχείρησης. Επίσης, ο πελάτης πρέπει να περιμένει μέχρι να εξυπηρετηθεί στους χώρους αναμονής του οργανισμού ή της επιχείρησης μιας και δεν υπάρχει σύστημα με το οποίο να ενημερώνεται όποια στιγμή το θελήσει για τον ανανεωμένο χρόνο αναμονής του. Στον τομέα των τραπεζών, οι τραπεζικοί οργανισμοί παρέχουν ένα ευρύ σύνολο ηλεκτρονικών υπηρεσιών που περιλαμβάνουν διαδικτυακές υπηρεσίες και υπηρεσίες μέσω κινητών συσκευών και αφορούν οικονομικές συναλλαγές και υπηρεσίες πληροφόρησης. Στις ηλεκτρονικές υπηρεσίες τους δεν περιλαμβάνονται ωστόσο υπηρεσίες για ηλεκτρονική κράτηση θέσης, μέσω ηλεκτρονικών εισιτηρίων, στις ουρές αναμονής των υποκαταστημάτων τους, για τους πελάτες που θέλουν να εξυπηρετηθούν με αυτόν τον τρόπο. Επίσης δεν υπάρχουν υπηρεσίες που να ενημερώνουν τον κάτοχο ενός ηλεκτρονικού εισιτηρίου όποια στιγμή το θελήσει για τον ανανεωμένο χρόνο αναμονής του. Στα πλαίσια της παρούσας διπλωματικής εργασίας, αναπτύχθηκε ένα ολοκληρωμένο σύστημα εφαρμογών για παραγωγή και εξυπηρέτηση Ηλεκτρονικών Εισιτηρίων. Το ηλεκτρονικό αυτό σύστημα επιτρέπει τη δημιουργία ηλεκτρονικών εισιτηρίων αναμονής και την εξυπηρέτηση των κατόχων τους σε ένα σύστημα εικονικών τραπεζών. Βασικές λειτουργίες του συστήματος είναι η δυνατότητα που δίνει στους χρήστες να αιτούνται ηλεκτρονικά εισιτήρια πριν μεταβούν στους χώρους εξυπηρέτησης μέσω διαδικτυακών εφαρμογών και εφαρμογών για φορητές συσκευές χειρός, όπως επίσης και η δυνατότητα που δίνει στους κατόχους των ηλεκτρονικών εισιτηρίων να ενημερώνονται οποιαδήποτε στιγμή θελήσουν, για τον τρέχοντα χρόνο αναμονής που αντιστοιχεί στο εισιτήριό τους. Το σύστημα αυτό αποτελεί μια από τις πρώτες προσπάθειες όχι μόνο στον τομέα των τραπεζικών οργανισμών αλλά στον ευρύτερο τομέα διαχείρισης ηλεκτρονικών εισιτηρίων για ουρές αναμονής. Η δομή της παρούσας διπλωματικής εργασίας έχει ως εξής: Στο πρώτο κεφάλαιο γίνεται μια εισαγωγή και παρουσίαση της έννοιας της Ηλεκτρονικής Διακυβέρνησης και των διαστάσεών της. Στο δεύτερο κεφάλαιο γίνεται εκτενής αναφορά στις πολιτικές που εφαρμόζονται σε εθνικό και ευρωπαϊκό επίπεδο για την Ηλεκτρονική Διακυβέρνηση. Σε ευρωπαϊκό επίπεδο γίνεται αναφορά στη στρατηγική i2010 και στην πρωτοβουλία e-Europe, ενώ σε εθνικό επίπεδο παρουσιάζεται το πρόγραμμα της Κοινωνίας της Πληροφορίας και η αναπτυξιακή στρατηγική της χώρας μας για το διάστημα 2007 – 2013. Στο κεφάλαιο αυτό παρουσιάζονται και κάποια παραδείγματα από το διεθνή χώρο, βέλτιστων πρακτικών Ηλεκτρονικής Διακυβέρνησης. Στο τρίτο κεφάλαιο δίνεται έμφαση στην κατάσταση που επικρατεί στη χώρα μας σχετικά με την Ηλεκτρονική Διακυβέρνηση. Παρουσιάζεται το «Ελληνικό Πλαίσιο Παροχής Υπηρεσιών Ηλεκτρονικής Διακυβέρνησης και Πρότυπα Διαλειτουργικότητας» και συγκεκριμένα η αρχιτεκτονική του πλαισίου και τα συστατικά του μέρη, καθώς και η έκθεση του World Economic Forum 2007 – 2008. Στο τέταρτο κεφάλαιο γίνεται παρουσίαση της έννοιας των Ηλεκτρονικών Εισιτηρίων και των τομέων εφαρμογής τους. Πιο αναλυτικά παρουσιάζεται ο τομέας εφαρμογής που αφορά στη διαχείριση της ροής των πελατών, με παρουσίαση των δυο πιο γνωστών συστημάτων διεθνώς. Στη συνέχεια γίνεται αναφορά στις υπηρεσίες που παρέχουν σήμερα οι τραπεζικοί οργανισμοί και δίνεται έμφαση στις κατηγορίες ηλεκτρονικών υπηρεσιών, οι οποίες και παρουσιάζονται αναλυτικά. Στο τέλος του κεφαλαίου περιγράφεται η σημερινή κατάσταση στην Ελλάδα στον τομέα των ηλεκτρονικών τραπεζικών συναλλαγών. Στο πέμπτο κεφάλαιο παρουσιάζεται το Ολοκληρωμένο Σύστημα Εφαρμογών για Παραγωγή και Εξυπηρέτηση Ηλεκτρονικών Εισιτηρίων που υλοποιήθηκε στα πλαίσια της παρούσας διπλωματικής εργασίας. Πιο αναλυτικά, παρουσιάζεται η αρχιτεκτονική του συστήματος και τα συστατικά του μέρη: η Βάση Δεδομένων, οι Μηχανισμοί Υπολογισμού Μέσου Χρόνου Αναμονής και Μέσου Χρόνου Εξυπηρέτησης, ο Διαδικτυακός Τόπος, η Τοπική Εφαρμογή PDA, οι Διαδικτυακές Υπηρεσίες εξυπηρέτησης αιτήσεων Διαδικτυακού Τόπου και Τοπικής Εφαρμογής PDA, η Τοπική Εφαρμογή Προσομοίωσης Τραπεζών και η Διαδικτυακή Υπηρεσία εξυπηρέτησης αιτήσεων Τοπικής Εφαρμογής Προσομοίωσης Τραπεζών. Τέλος γίνεται μια σύνοψη των πλεονεκτημάτων του συστήματος και παρουσιάζονται προτάσεις μελλοντικής βελτίωσης. Στο έκτο κεφάλαιο παρουσιάζονται οι τεχνολογίες που χρησιμοποιήθηκαν για την ανάπτυξη του Ολοκληρωμένου Συστήματος Εφαρμογών για Παραγωγή και Εξυπηρέτηση Ηλεκτρονικών Εισιτηρίων. Στο έβδομο κεφάλαιο παρουσιάζεται η βιβλιογραφία στην οποία βασίστηκε η συγγραφή της διπλωματικής εργασίας. / The era of globalization or digital world has created a new kind of information society and knowledge-based economy, which change our human behavior. This has effects on many aspects such as politics, economic, and society. Information and Communication Technology (ICT) is claimed as the powerful tool which plays an important role on those changes. It provides an alternative channel for government and citizens’ communication of new services, e.g. providing information source, collaboration between stakeholders. Such e-Services could lead to transparency of government administration in democracy world. The term Electronic Government (e-Government) refers to the use of information and communication technology to provide and improve government services, transactions and interactions with citizens, businesses, and other arms of government. The widespread use of Internet has recently led to the emergence of a variety of electronic services, also known as “e-services”. Electronic tickets, or e-tickets, are an example of such a class of e-services. Generally speaking, e-tickets are the Internet counterpart of real-world tickets, and give evidence that the holder has paid or is entitled to some service (e.g., entering a place of entertainment, upgrading a software from the Internet). Paper and Electronic Tickets also appear in customer flow management systems for private and public organizations or enterprises, which face the problem of big queues and waiting times. Such cases include banks, pharmacies, post offices, hospitals, shopping malls, police stations, employment services. In these cases, customers enter the reception area, get a ticket and enter a waiting queue until their time to be served arrives. That time, they are informed to enter the service area. These systems, despite their advantages, have a few deficiencies which are summarized below: Customers have to enter the reception area in order to get a ticket. There exists no electronic tickets production system for customers to receive e-tickets before they arrive at the building. Moreover, customers have to wait somewhere in the facilities of the organization or enterprise until they will be served, as there exists no system to inform them whenever they want about their refreshed waiting time. In regard of the banks sector, bank organizations provide a wide variety of e-services which include internet services and services for mobile devices. These services involve financial transactions and information services. However, banks e-services don’t include services for electronic reservations in waiting queues using e-tickets, for customers who want to be served in bank branches. Moreover, banks e-services don’t include services with which e-ticket holders can be informed whenever they want about their refreshed waiting time. In this thesis, an Applications Integrated System for Creating and Servicing e-Tickets was developed. The integrated system allows e-tickets creation and their holders’ service from a set of virtual banks. The system’s basic functionality includes e-tickets creation, via internet applications and applications for mobile devices, before customers reach the servicing area, as well as informing e-ticket holders, whenever they want, about their refreshed waiting time. The integrated system constitutes one of the first attempts, not only in the bank organizations sector, but in the wider sector of managing e-tickets for waiting queues. The thesis structure is organized as follows: The first chapter introduces and presents the concept of e-Government and its aspects. The second chapter includes a comprehensive reference to the European and National policies for e-Government. The European policies include the strategy i2010 and the e-Europe initiative, while the national policies include the Operational Program of Information Society and developmental strategy for years 2007 – 2013. This chapter also includes best practices of e-Government in the international arena. The third chapter revolves around the current situation in our country regarding e-Government. The “Greek Framework for e-Government Services Provision and Interoperability Templates” is presented and distinctly, the architecture and the various components of the framework, as well as the exhibition of the World Economic Forum 2007-2008. The fourth chapter presents the concept of e-ticket and its application domain. Namely, the application sector concerning customer flow management is described, followed by the two most important systems worldwide. Next, the services provided by banks are reported, laying emphasis on the categories of e-services, which are presented thoroughly. In the end of the chapter, the current status in the domain of electronic bank transactions in Greece is presented. The fifth chapter presents the Integrated System for Creating and Servicing e-Tickets which was developed for this thesis. More explicitly, the chapter presents the system architecture and all of its components: the Database, the Mean Waiting Time and Servicing Time Computing Mechanisms, the Web Site, the PDA Local Application, the Web Services for servicing requests made by the Web Site and the PDA Local Application, the Banks Simulation Local Application, the Web Service for servicing requests made by the Banks Simulation Local Application. In the end, the chapter summarizes the Integrated System’s advantages and presents proposals for future improvements. The sixth chapter presents the technologies being used for the development of the Integrated System for Creating and Servicing e-Tickets. The seventh chapter presents the bibliography in which the composition of this thesis was based.
52

Différenciation et intégration des systèmes comptables : Une étude typologique / Differentiation and integration of accounting systems : a typological study

Orf, Lazhar El 25 October 2012 (has links)
L’objectif de notre thèse est de comprendre et d’expliquer les modes d’intégration des systèmes comptables des entreprises à partir de quatre cas (deux grandes entreprises et deux entreprises moyennes). Nous nous sommes appuyés sur la théorie de la différenciation-intégration de Lawrence et Lorsch (1967) pour interpréter les situations d’intégration étudiées. Cette théorie montre que les entreprises ayant des structures très différenciées disposent des mécanismes d’intégration sophistiqués tandis que celles dont les structures sont peu différenciées ont des mécanismes de coordination rudimentaires. Nous avons également mobilisé l’approche événementielle et multidimensionnelle de Sorter (1969) qui propose un cadre théorique de l’intégration informatico-comptable. Les progiciels ERP constituent une application très concrète de cette approche. Notre analyse qualitative de quatre cas en termes de similitudes et de différences, appuyée sur la théorie de la différenciation-intégration, a permis d’expliquer les situations d’intégration des sous-systèmes comptables observées mais aussi de montrer la pertinence de l’approche événementielle, comme cadre de conception du système d’information de structures diversifiées et différenciées. Nos résultats montrent, à l’instar de Lawrence et Lorsch, qu’il existe des modes différents d’intégration des systèmes comptables adaptés à des contextes différents. Nous avons ébauché une typologie de quatre configurations types des systèmes comptables (quatre situations d’intégration-différenciation) : (1) Système classique bidimensionnel, (2) Système quasi-intégré centralisé, (3) Système intégré, (4) Système multidimensionnel. La stratégie et la taille paraissent être, au-delà de toutes autres considérations, les principaux déterminants de l’intégration comptable ; viennent ensuite, l’environnement et certains autres éléments du contexte tels que la structure de gestion et le système de contrôle. Cependant, l’impact de la taille diffère d’une entreprise à l’autre. Lorsque la taille est combinée à une stratégie de diversification (et par extension à des environnements variés et dynamiques) son effet différenciateur sur l’organisation (et le système comptable) est très important, ce qui nécessite des mécanismes compensateurs d’intégration développés. Les deux entreprises diversifiées (POULINA et MEDDEB) ont mis en place un système comptable intégré voire multidimensionnel pour maitriser leurs sous-systèmes différenciés. Lorsque la taille est la conséquence d’un simple développement d’une activité unique (monoactivité) son effet différenciateur-intégrateur sur l’organisation et le système comptable est moins important. Les deux entreprises ayant des activités et des structures homogènes (SONEDE et SME) se sont contentées d’un système comptable peu intégré voire bidimensionnel. / The objective of this thesis is to understand and explain the modes of integration of accounting systems of companies from four cases (two big and two medium-sized enterprises). We relied on the theory of differentiation-integration of Lawrence and Lorsch (1967) to interpret the studied integration situations. This theory shows that companies with very different structures have sophisticated mechanisms for integration while those whose structures are poorly differentiated have rudimentary coordination mechanisms. We have also mobilized the event and multidimensional approach of Sorter (1969) who proposes a theoretical framework for the accountant integration. The ERP is a highly practical application of this approach.Our qualitative analysis of four cases study in terms of similarities and differences, supported on the theory of the differentiation-integration, helped to explain the observed situations of integration of accounting subsystems but also to show the relevance of the event-based approach, as part of system design information structures diversified and differentiated. Our results show, like Lawrence and Lorsch, that there are different modes of integration of accounting systems tailored to different contexts. We have developed a typology consisting of four configurations of accounting systems (four situations integration-differentiation): (1) Conventional two-dimensional system, (2) Quasi-integrated centralized system, (3) Integrated system,(4),Multidimensional,system.Strategy and size appear to be, beyond all other considerations, the main determinants of the accounting, followed, environment and other elements of the context of the accounting system such as the management structure and system management control. However, the impact of the size differs from one company to another. When the size is combined with a strategy of diversification (and by extension to various and dynamic environments) its differentiating effect on the organization (and the accounting system) is very important, requiring developed integration compensatory mechanisms. Both diversified firms (POULINA and MEDDEB) have implemented an integrated accounting system to unify their subsystems differentiated. When the size is the result of a simple development of a single activity (monoactivity) its integrator-differentiator effect on the organization and the accounting system is less important. Companies with activities and homogeneous structures (SONEDE and SME) have been content to a poorly integrated accounting system or two-dimensional.
53

A inteligência competitiva organizacional e os sistemas integrados de gestão ERP: um estudo nas indústrias calçadistas de Jaú

Rodrigues, Rodrigo [UNESP] 31 July 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-07-31Bitstream added on 2014-06-13T20:55:10Z : No. of bitstreams: 1 rodrigues_r_me_mar.pdf: 689285 bytes, checksum: d38aa83282f6a5f21ac969d3baab7454 (MD5) / Universidade Estadual Paulista (UNESP) / No mundo globalizado as informações têm papel extremamente importante, visto que a internacionalização da economia exige excelência em relação aos sistemas de informação e documentação, por isso mesmo as informações se tornaram um recurso de gestão extremamente importante, mas nem sempre são valorizadas corretamente por parte das organizações. Nos ambientes organizacionais é absolutamente necessária a utilização de recursos tecnológicos para mediar o acesso e uso da informação pelo usuário, bem como para apoiar as distintas atividades organizacionais, desde as atividades cotidianas, o processo decisório, até o planejamento de ações estratégicas. O foco do problema de pesquisa refere-se aos fluxos informacionais em âmbito organizacional, mais especificamente os fluxos informacionais vinculados ao processo de inteligência competitiva organizacional (ICO). O objetivo deste estudo visava a analisar a contribuição das tecnologias de informação e comunicação (TICs), através dos sistemas integrados de gestão, mais especificamente o Enterprise Resource Planning (ERP), aplicado ao processo de inteligência competitiva organizacional nas indústrias associadas ao Sindicato Calçadista da cidade de Jaú/SP. Estudou-se os conceitos, definições, métodos e técnicas relacionados ao processo de ICO e às TICs, mais especificamente o ERP, por meio da análise da literatura nacional e internacional, assim como identificou-se e analisou-se no universo pesquisado as indústrias que possuem e aplicam o sistema ERP ou outro sistema semelhante, visando a analisar a relação do uso desse tipo de sistema para a competitividade organizacional. Da mesma forma, verificou-se a ocorrência do uso de métodos e técnicas aplicados ao processo de inteligência competitiva organizacional, desde que baseados em sistemas ERP. A pesquisa é descritiva exploratória... / In the world globalized the information have seen, extremely important role that to economy and requires excellence regarding the information and documentation systems, by that even the information became a resource of extremely important management, but do not always be valued correctly on the part of organizations. In organizational environments is absolutely necessary the utilization of technological resources for mediate the access and use of information by the user, as well like for support the distinct organizational activities, since the routine activities, the decision making process, until the planning of strategic actions. The focus of problem of research refers to the information flows in organizational scope, more specifically the information flows linked to the organizational competitive intelligence process (OCI). The objective of this study aims analyze the contribution of information and communication technologies (ICTs), through the management integrated systems, more specifically the Enterprise Resource Planning (ERP), applied to the organizational competitive intelligence process in the associated industries to the Footwear Syndicate of Jaú/SP city. Intends to study the concepts, definitions, approaches and techniques related to the OCI process and ICTs, more specifically the ERP, through the analysis the international and national literature, as well as intends identify and analyze in universe researched the industries that possess and apply the system ERP or another similar system, aiming at analyze the relation of the use of that system kind for the organizational competitiveness. Similarly, intends to verify the occurrence of use of approaches and techniques applied to the organizational competitive intelligence process, since based in ERP systems. The research is descriptive exploratory, of qualitative nature, analyzes data and information collected... (Complete abstract click electronic access below)
54

Contribuição para os usuários de sistemas CAD/CAM/CNC em operação de fresamento de topo em aço para moldes e matrizes / Contribution to the users of systems CAD/CAM/CNC in end milling operation in steel for molds and dies

Costa, Gustavo Guilherme dos Santos 16 June 2011 (has links)
The increased in the demand for plastic products and the need for reduction manufacturing times, and the growing dependence of man on the computer in present day, especially in manufacturing activities, has resulted in constant research of technological developments in order to supply these needs. In dies and molds manufacturing industry for plastic injection requiring machining operations such as (milling, drilling and polishing, among others), is increasing dependence by computer systems, such as CAD/CAM. This technology helps in the manufacturing steps, provides fast and high accuracy in the manufacturing of complex geometries. Therefore, to understand and to use efficiently these resources that aided in manufacturing are of enormous importance for the optimization of a production process. In this context, this work presents a study on the use of resources programming CAD/CAM in milling operation of cavities steel VP50 with inserts cemented carbide with ball nose. The influence of two types of interpolation (linear and circular) and tolerances bands (0.05 mm and 0.1 mm) that define the tool path for machining of a cavity that has a similar form the a mold of a battery cover cell phone. As output variables evaluated were machining time, the number of lines of the program, the parameters of surface roughness (Ra, Rq, Rz) of parts, the radius of curvature, form deviation of any line profile and the tool wear. The results showed that, from the statistical point of view (ANOVA), none of the conditions of interpolation and tolerance employed significantly influenced the values of surface roughness in form deviation of any line and tool wear. Linear interpolation with tolerance of 0.1 mm was most viable for the production of such cavity in the conditions investigated because the produced good finish, low tool wear and machining time is shorter. / O aumento pela demanda por produtos plásticos e a necessidade de redução nos tempos de fabricação, além da crescente dependência do homem pelo computador em dias atuais, especialmente nas atividades de fabricação, tem implicado na busca por constantes desenvolvimentos tecnológicos a fim de suprir estas necessidades. Na indústria de fabricação de matrizes como também de moldes para injeção de plásticos (que necessitam de operações de usinagem tais como fresamento, furação e polimento, dentre outros), é cada vez maior a dependência pelos sistemas computacionais, como o sistema CAD/CAM. Essa tecnologia auxilia nas etapas de fabricação, oferece rapidez e alta exatidão na fabricação de geometrias complexas. Portanto, entender e saber utilizar de forma eficiente estes recursos que auxiliam na manufatura são de enorme importância para a otimização de um processo produtivo. Neste contexto, este trabalho apresenta um estudo sobre a utilização de recursos de programação CAD/CAM em fresamento de cavidades de aço VP50 com insertos de metal duro ponta de esférica. Foi investigada a influência de dois tipos de interpolações (linear e circular) e tolerâncias (0,05mm e 0,1 mm) que definem o percurso da ferramenta na usinagem de uma cavidade que possui forma semelhante a um molde da tampa da bateria do aparelho celular. Como variáveis de saída foram avaliadas o tempo de usinagem, o número de linhas do programa, os parâmetros de rugosidade superficial (Ra, Rq, Rz) das cavidades, o raio de curvatura, o desvio de forma de uma linha qualquer e o desgaste das ferramentas. Dos resultados obtidos, constatou-se que, sob o ponto de vista estatístico (ANOVA), nenhuma das condições de interpolação e tolerância empregadas influenciou significativamente nos valores de rugosidade da superfície, no desvio de forma de uma linha qualquer e desgaste das ferramentas. A interpolação linear com tolerância de 0,1mm mostrou-se a mais viável para a produção de tal cavidade nas condições investigadas devido a bom acabamento produzido, pequeno desgaste e tempo de usinagem mais curto. / Mestre em Engenharia Mecânica
55

Hodnota firmy Modos spol. s r. o. / The valuation of the company Modos spol. s r.o.

Šindlerová, Veronika January 2008 (has links)
The aim of this thesis is to find out the financial gain of the integrated system of management quality, human safety and environment by the valuation of the company. My thesis includes the evaluation of the efficiency of integrated system of management quality, human safety and environment and after that there is included the valuation of the company in two versions. The first version reflects the real situation, the company has implemented the integrated system of management quality, human safety and environment. The second version reflects the hypothetical situation, in this settings the company wouldn't have the integrated system. The difference between these two valuation is the financial gain of this system.
56

Concentrator photovoltaics combined with reverse osmosis and membrane distillation for high-efficiency desalination and electricity production / Koncentrerade solceller i kombination med omvänd osmos och membrandestillation för högeffektiv avsaltning och elproduktion

Hou, Novalie, Jiang, Sofie January 2020 (has links)
This project is a bachelor thesis and aims to study the integration of concentrator photovoltaics (CPV), reverse osmosis (RO) and membrane distillation (MD) for water desalination and purification. In this report, an introduction of the need for efficient water desalination is presented. Following the introduction, relevant literature has been reviewed to build up the fundamental understanding of CPV, RO and MD. A general classification of CPV subsequently introduced. In order to acquire a more comprehensive understanding of CPVs, two case studies were performed with two different types of CPV/T. The cost efficiency of each type of CPV was analysed when integrated with RO and MD systems. The result turns out to be that it was not economically beneficial to have MD in the integrated system. The reason behind is the extensive thermal energy demand of MD. Other affecting parameters, such as location and system types were also discussed. Lastly, improvements and suggestions for further studies were considered. / Detta projekt är en kandidatuppsats och syftar till att studera ett integrerande system bestående av koncentrerade solceller (CPV), omvänd osmos (RO) och membrandestillation (MD) för vattenavsaltning och rening. Rapporten börjar med en introduktion om behovet av effektiv avsaltning av vatten. Relevant litteratur har granskats för att bygga upp den grundläggande förståelsen för CPV, RO och MD. Därefter gjordes en klassificering av CPV. För att få en mer omfattande förståelse av CPV valdes två olika typer av CPV /T för en djupare undersökning. Kostnadseffektiviteten för varje CPV analyserades, när dessa var integrerade med RO- och MD-system. Resultatet visar sig att det tyvärr inte var ekonomiskt fördelaktigt att ha med MD i det integrerade systemet. Anledningen bakom detta var det omfattande termiska energibehovet för MD. Andra avgörande faktorer, såsom plats och systemtyp diskuterades tillika. Slutligen avslutades rapporten med förslag på förbättringar och områden för vidare studier.
57

Towards an Integrated Water Quality Monitoring System Using Low Cost Electrochemical Sensors

Alam, Arif Ul January 2019 (has links)
The monitoring of pharmaceuticals, heavy metal, pH and free chlorine concentration in drinking water is important for public health and the environment. However, conventional laboratory-based analytical methods are labor-intensive, expensive, and time consuming. This thesis focuses on developing an integrated, highly sensitive, easy-to-use, and low-cost pharmaceuticals, heavy metal, pH and free chlorine sensing system for drinking water quality monitoring. A low-temperature, solution-processed modification of multi-walled carbon nanotubes (MWCNT) with β-cyclodextrin (βCD) on glassy carbon electrode is developed for detecting low levels of acetaminophen. The adsorption properties of βCD are combined with the high surface area of carbon nanotubes towards enhanced electrochemical sensing of acetaminophen with a limit of detection of 11 nM and linear range from 0.05-300 μM. Also, a systematic investigation is carried out using four types of modified MWCNT-βCD. A novel, one-step approach called Steglich esterification modified MWCNT-βCD results in large effective surface area, and fast electron transfer towards sensitive detection of acetaminophen and 17β-estradiol (E2, primary female sex hormone) in the range of 0.005–20 and 0.01–15 μM, with low detection limits of 3.3 and 2.5 nM, respectively. The similar MWCNT-βCD modified electrodes can also detect heavy metal ion (lead, Pb2+) with a limit of detection of <10 ppb. Low frequency noise behavior of these sensors are studied. A spin-coated Pd/PdO based pH sensor, and amine-modified carbon electrode-based free chlorine sensor are fabricated on a common substrate together with the pharmaceuticals and heavy metal sensors. A Wheatstone-bridge temperature sensor is fabricated based on silicon and PEDOT:PSS on another substrate. All the sensors are connected to an Arduino microcontroller based data acquisition system with a smartphone application interface. The integrated sensing system is easy-to-use, low-cost, and can provide accurate monitoring data with real drinking water samples. / Dissertation / Doctor of Philosophy (PhD) / Low-cost, easy-to-use, and sensitive monitoring system for pharmaceuticals, heavy metal, pH and free chlorine in drinking water is crucial for public health safety. In this thesis, we develop solution-based synthesis of multi-walled carbon nanotubes modified by β-cyclodextrin for electrochemical sensing of pharmaceuticals and heavy metal. The modification approaches are compared and characterized to analyze their electrochemical behavior and sensing performances. The developed sensors are highly sensitive toward the detection of acetaminophen (a widely used pain-killer) and estrogen hormone in drinking water. We also develop a modified spin-coating technique to deposit palladium/palladium oxide films for potentiometric pH sensor, a calibration-free free chlorine sensor based on modified carbon electrode, and a resistive temperature sensor. The developed pH, free chlorine and temperature sensors are highly sensitive, and stable with fast response time. All the sensors are integrated and interfaced with a custom-made and smartphone-controlled electronic readout system for accurate and on-site drinking water quality monitoring at low cost.

Page generated in 0.0551 seconds