425 research outputs found

    Key factors influencing the sustained growth of high-tech SMEs in South Korea - the perspectives of founder owner-managers

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    Purpose This paper explores key factors influencing high performing, sustained growth, high-tech small and medium-sized enterprises (SMEs) in South Korea. Design/methodology/approach A qualitative study is adopted to explore seventeen founder owner-managers of high-tech SMEs who sustained consistent employment growth, greater than the industry average, for 7 years. Within the sample, those with higher (10% or over) employment Compound Annual Growth Rates over this period are also compared to those with lower rates. Findings The study suggests that proactive approaches, such as flexible organization, risk manage-ment, fast decision making, and international market entry, are seen as important contrib-uting factors to sustained growth. These findings contribute to a better theoretical and empir-ical understanding of sustained high-tech SME growth, in a country with a strong entrepre-neurial and internationally competitive Information Technology sector. Also, collaboration across the SME was perceived as making an important contribution to staff growth, con-sistent with stewardship theory. Research limitations/implications The sample is based on successful high-tech SMEs, so there are limitations in extrapolating results to other types of firms, sectors or countries. Practical implications Key factors identified in this study can be considered by entrepreneurs seeking to achieve sustainable business. These also provide improved understanding for policy makers into the complexity of factors related to sustained and high growth of technology-based SMEs, which many countries are keen to foster to aid national economic growth. Originality/value The research provides new evidence exploring the diverse perspectives of founder owner-managers, on the sustained growth and failure in South Korean high-tech SMEs, and how these have changed since the inception of their business

    CROSS-LAYER DESIGN, OPTIMIZATION AND PROTOTYPING OF NoCs FOR THE NEXT GENERATION OF HOMOGENEOUS MANY-CORE SYSTEMS

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    This thesis provides a whole set of design methods to enable and manage the runtime heterogeneity of features-rich industry-ready Tile-Based Networkon- Chips at different abstraction layers (Architecture Design, Network Assembling, Testing of NoC, Runtime Operation). The key idea is to maintain the functionalities of the original layers, and to improve the performance of architectures by allowing, joint optimization and layer coordinations. In general purpose systems, we address the microarchitectural challenges by codesigning and co-optimizing feature-rich architectures. In application-specific NoCs, we emphasize the event notification, so that the platform is continuously under control. At the network assembly level, this thesis proposes a Hold Time Robustness technique, to tackle the hold time issue in synchronous NoCs. At the network architectural level, the choice of a suitable synchronization paradigm requires a boost of synthesis flow as well as the coexistence with the DVFS. On one hand this implies the coexistence of mesochronous synchronizers in the network with dual-clock FIFOs at network boundaries. On the other hand, dual-clock FIFOs may be placed across inter-switch links hence removing the need for mesochronous synchronizers. This thesis will study the implications of the above approaches both on the design flow and on the performance and power quality metrics of the network. Once the manycore system is composed together, the issue of testing it arises. This thesis takes on this challenge and engineers various testing infrastructures. At the upper abstraction layer, the thesis addresses the issue of managing the fully operational system and proposes a congestion management technique named HACS. Moreover, some of the ideas of this thesis will undergo an FPGA prototyping. Finally, we provide some features for emerging technology by characterizing the power consumption of Optical NoC Interfaces

    Teoria de jogos para utilização efetiva dos recursos em aplicações para 5G

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    Doutoramento em Engenharia Eletrotécnica - TelecomunicaçõesEsta tese tem como objetivo fornecer afirmações conclusivas em relação a utilização eficiente de recursos para redes e aplicações de 5G (5a geração) com recurso a teoria dos jogos. Neste contexto, investigamos dois cenários principais, um relativo a comunicações móveis e um outro relativo a redes inteligentes. Uma métrica importante para o desenho das redes móveis emergentes é a eficiência energética, com particular ênfase no lado do dispositivo móvel, onde as tecnologias das baterias são ainda limitadas. Alguns trabalhos de investigação relacionados têm demonstrado que a cooperação pode ser um paradigma útil no sentido de resolver o problema do défice energético. Contudo, pretendemos ir mais além, ao definir a cooperação e os utilizadores móveis como um grupo de jogadores racionais, que podem atuar sobre estratégias e utilidades, por forma a escolher a retransmissão mais apropriada para poupança de energia. Esta interpretação presta-se à aplicação da teoria dos jogos, e recorremos assim aos jogos coalicionais para solucionar conflitos de interesse entre dispositivos cooperantes, empregando Programação Linear (LP) para resolver o problema da selecção da retransmissão e derivar a principal solução do jogo. Os resultados mostram que a escolha do jogo de retransmissão coalicional proposto pode potencialmente duplicar a duração da bateria, numa era em que a próxima geração de dispositivos móveis necessitará de cada vez mais energia para suportar serviços e aplicações cada vez mais sofisticados. O segundo cenário investiga a resposta da procura em aplicações smart grid, que está a ganhar interesse sob a égide do 5G e que é considerada uma abordagem promissora, incentivando os utilizadores a consumir electricidade de forma mais uniforme em horas de vazio. Recorremos novamente à teoria dos jogos, imaginando as interacções estratégicas entre a empresa fornecedora de energia eléctrica e os potenciais utilizadores finais como um jogo de forma extensiva. São abordados dois programas em tempo real de resposta à procura: Day-Ahead Pricing (DAP) e Convex Pricing Tariffs. A resposta dos consumidores residenciais conscientes dos preços destas tarifas, é formulada como um problema de Mixed Integer Linear Programming (MILP) ou Quadratic Programming (QP), nos quais as soluções potenciais são o agendamento dos seus electrodomésticos inteligentes de modo a minimizar os seus gastos diários de electricidade, satisfazendo as suas necessidades diárias de energia e níveis de conforto. Os resultados demonstram que implementar o programa DAP pode reduzir a razão Peak-to-Average (PAR) at e 71% e as faturas de consumo das casas inteligentes at e 32%. Para além disso, a aplicação de tarifas convexas em tempo real pode melhorar ainda mais estas métricas de desempenho, alcançando uma redução de 80% do PAR e uma economia de mais de 50% na faturação da energia residencial.This research thesis aims to provide conclusive statements towards effective resource utilization for 5G (5th Generation) mobile networks and applications using game theory. In this context, we investigate two key scenarios pertaining to mobile communications and smart grids. A pivotal design driver for the upcoming era of mobile communications is energy efficiency, with particular emphasis on the mobile side where battery technology is still limited. Related works have shown that cooperation can be a useful engineering paradigm to take a step towards solving the energy deficit. However, we go beyond by envisaging cooperation and mobile users as a game of rational players, that can act on strategies and utilities in order to choose the most appropriate relay for energy saving. This interpretation lends itself to the application of game theory, and we look at coalitional games to settle conflicts of interest among cooperating user equipments, and employ Linear Programming (LP) to solve the relay selection problem and to derive the core solution of the game. The results reveal that adopting the proposed coalitional relaying game can potentially double battery lifetime, in an era where the next wave of next generation handsets will be more energy demanding supporting sophisticated services and applications. The second scenario investigates demand response in smart grid applications, which is also gaining momentum under the umbrella of 5G, which is a promising approach urging end-users to consume electricity more evenly during nonpeak hours of the day. Again, we resort to game theory and picture the strategic interactions between the electric utility company and the potential end-users as an extensive form game. Two real-time demand response programmes are addressed, namely Day-Ahead Pricing (DAP) and convex pricing tariffs. The response of price-aware residential consumers to these programmes is formulated as Mixed Integer Linear Programming (MILP) or Quadratic Programming (QP) problem, which optimally schedule their smart home appliances so as to minimise their daily electricity expenses while satisfying their daily energy needs and comfort levels. The results demonstrate that implementing the DAP programme can reduce the Peakto- Average Ratio (PAR) of demand by up to 71% and cut smart households bill by 32%. Moreover, applying real-time convex pricing tariffs can push these performance metrics even further, achieving 80% PAR reduction and more than 50% saving on the household electricity bill

    Augmented reality device for first response scenarios

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    A prototype of a wearable computer system is proposed and implemented using commercial off-shelf components. The system is designed to allow the user to access location-specific information about an environment, and to provide capability for user tracking. Areas of applicability include primarily first response scenarios, with possible applications in maintenance or construction of buildings and other structures. Necessary preparation of the target environment prior to system\u27s deployment is limited to noninvasive labeling using optical fiducial markers. The system relies on computational vision methods for registration of labels and user position. With the system the user has access to on-demand information relevant to a particular real-world location. Team collaboration is assisted by user tracking and real-time visualizations of team member positions within the environment. The user interface and display methods are inspired by Augmented Reality1 (AR) techniques, incorporating a video-see-through Head Mounted Display (HMD) and fingerbending sensor glove.*. 1Augmented reality (AR) is a field of computer research which deals with the combination of real world and computer generated data. At present, most AR research is concerned with the use of live video imagery which is digitally processed and augmented by the addition of computer generated graphics. Advanced research includes the use of motion tracking data, fiducial marker recognition using machine vision, and the construction of controlled environments containing any number of sensors and actuators. (Source: Wikipedia) *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Adobe Acrobat; Microsoft Office; Windows MediaPlayer or RealPlayer

    Creation of value with open source software in the telecommunications field

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    Tese de doutoramento. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 200

    Mobile Robots

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    The objective of this book is to cover advances of mobile robotics and related technologies applied for multi robot systems' design and development. Design of control system is a complex issue, requiring the application of information technologies to link the robots into a single network. Human robot interface becomes a demanding task, especially when we try to use sophisticated methods for brain signal processing. Generated electrophysiological signals can be used to command different devices, such as cars, wheelchair or even video games. A number of developments in navigation and path planning, including parallel programming, can be observed. Cooperative path planning, formation control of multi robotic agents, communication and distance measurement between agents are shown. Training of the mobile robot operators is very difficult task also because of several factors related to different task execution. The presented improvement is related to environment model generation based on autonomous mobile robot observations

    A Trust Evaluation Framework in Vehicular Ad-Hoc Networks

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    Vehicular Ad-Hoc Networks (VANET) is a novel cutting-edge technology which provides connectivity to millions of vehicles around the world. It is the future of Intelligent Transportation System (ITS) and plays a significant role in the success of emerging smart cities and Internet of Things (IoT). VANET provides a unique platform for vehicles to intelligently exchange critical information, such as collision avoidance or steep-curve warnings. It is, therefore, paramount that this information remains reliable and authentic, i.e., originated from a legitimate and trusted vehicle. Due to sensitive nature of the messages in VANET, a secure, attack-free and trusted network is imperative for the propagation of reliable, accurate and authentic information. In case of VANET, ensuring such network is extremely difficult due to its large-scale and open nature, making it susceptible to diverse range of attacks including man-in-the-middle (MITM), replay, jamming and eavesdropping. Trust establishment among vehicles can increase network security by identifying dishonest vehicles and revoking messages with malicious content. For this purpose, several trust models (TMs) have been proposed but, currently, there is no effective way to compare how they would behave in practice under adversary conditions. Further, the proposed TMs are mostly context-dependent. Due to randomly distributed and highly mobile vehicles, context changes very frequently in VANET. Ideally the TMs should perform in every context of VANET. Therefore, it is important to have a common framework for the validation and evaluation of TMs. In this thesis, we proposed a novel Trust Evaluation And Management (TEAM) framework, which serves as a unique paradigm for the design, management and evaluation of TMs in various contexts and in presence of malicious vehicles. Our framework incorporates an asset-based threat model and ISO-based risk assessment for the identification of attacks against critical risks. TEAM has been built using VEINS, an open source simulation environment which incorporates SUMO traffic simulator and OMNET++ discrete event simulator. The framework created has been tested with the implementation of three types of TM (data-oriented, entity-oriented and hybrid) under four different contexts of VANET based on the mobility of both honest and malicious vehicles. Results indicate that TEAM is effective to simulate a wide range of TMs, where the efficiency is evaluated against different Quality of Service (QoS) and security-related criteria. Such framework may be instrumental for planning smart cities and for car manufacturers.University of Derb

    Differentiator factors in the implementation of social network sites

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    Estágio realizado na Business Analyst da Documento Crítico - Desenvolvimento de Software, S. A. (Cardmobili) e orientado pelo Eng.ª Catarina MaiaTese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 200

    Applications in Electronics Pervading Industry, Environment and Society

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    This book features the manuscripts accepted for the Special Issue “Applications in Electronics Pervading Industry, Environment and Society—Sensing Systems and Pervasive Intelligence” of the MDPI journal Sensors. Most of the papers come from a selection of the best papers of the 2019 edition of the “Applications in Electronics Pervading Industry, Environment and Society” (APPLEPIES) Conference, which was held in November 2019. All these papers have been significantly enhanced with novel experimental results. The papers give an overview of the trends in research and development activities concerning the pervasive application of electronics in industry, the environment, and society. The focus of these papers is on cyber physical systems (CPS), with research proposals for new sensor acquisition and ADC (analog to digital converter) methods, high-speed communication systems, cybersecurity, big data management, and data processing including emerging machine learning techniques. Physical implementation aspects are discussed as well as the trade-off found between functional performance and hardware/system costs
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