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  • 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.
91

Analýza činnosti dopravního operátora / An analysis of a transport operator´s job description

HOUZIMOVÁ, Jana January 2008 (has links)
An analysis of a transport operator´s job description My degree work is centred on the problems of a transport operator´s job in a forwarding agency. The introduction provides an explanation of a term of "dispatch service" and explains why logistics is so important in transport. Then there is a description of the transport development after 1990 and the changes transport had to undergo in the time of globalization. The main part of the work deals with the operator´s working procedure from an offer to a demand, an order and other actions to the final realization. A model example is given to represent an actual transporting process. The work also states conditions under which transport is executed, for example payment terms and terms of delivery. Next chapters outline the way of calculation, give a detailed description of collecting service (which is implemented within the bounds of CS Expres system) and of storing problems including the introduction of bar codes in stores and possibilities of logistic service extension. The conclusion is focused on the firm developing strategy.
92

CoreLB: uma proposta de balanceamento de carga na rede com Openflow e SNMP

Dossa, Clebio Gavioli 18 August 2016 (has links)
Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-11-01T15:35:45Z No. of bitstreams: 1 Clebio Dossa_.pdf: 1252617 bytes, checksum: 784b95c29ee09e2a922686b26cb7aa51 (MD5) / Made available in DSpace on 2016-11-01T15:35:45Z (GMT). No. of bitstreams: 1 Clebio Dossa_.pdf: 1252617 bytes, checksum: 784b95c29ee09e2a922686b26cb7aa51 (MD5) Previous issue date: 2016-08-18 / Nenhuma / Atualmente, muitos serviços distribuem a carga entre diversos nós computacionais direcionando as conexões com alguma estratégia de balanceamento para divisão da carga. O advento do uso de redes definidas por software (SDN) está mudando paradigmas da administração de redes, absorvendo serviços especializados, automatizando processos e gerando inteligência para regras estáticas com uma grande variedade de opções de implementação. O balanceamento de carga é um dos serviços especializados que pode usufruir dos conceitos de SDN, sem definições e processos estáticos como ocorre muitas vezes nos atuais modelos usados de balanceamento de carga. A definição dos protocolos que suportam SDN usualmente permitem soluções alternativas e eficientes para este problema, desta forma, neste trabalho, é apresentada uma proposta de metodologia para balanceamento de carga entre distintos servidores de um pool com a troca do destino de tráfego realizada pela rede. Esta solução é chamada Core-based load balance (CoreLB), pois o serviço especializado de balanceamento de carga é realizado pela rede onde a administração de pacotes é nativamente realizada. A metodologia faz uso do protocolo SNMP para análise de recursos dos servidores com o objetivo de avaliar a situação de carga de cada nó computacional e de estatísticas de consumo de rede através do protocolo OpenFlow. Este trabalho avaliou o balanceamento de carga em serviços Web e a união de estatísticas de rede e da carga dos servidores, para a tomada de decisão de balanceamento, mostra-se uma metodologia eficiente e com melhores tempos de resposta ao usuário comparado com outras metodologias de avaliadas. Também melhorou a distribuição de consumo de recursos entre os servidores. / Currently, most services balance the load between distinct hosts forwarding connections with a load balance strategy in front. Usually, a dedicated appliance is responsible to performthe balance and may be a fault point and become expensive. The new concepts of computer network architecture with Software-Defined Networking (SND) are changing the network management, absorving specialist services, automating process and building intelligence to statics rules with loads of delivery options. The load balance is a specialized service that can enjoy in a positive way of SDN concepts, with low costs, in a flexible way as per the process needs instead of a plastered process definitions that occurs in many actual models. The OpenFlow protocol definition allow us to use a new solution to address this issue. This work shows a load balance purpose between distinct hosts with the destination change of connections made by the network core. It calls Core-based load balance (CoreLB) because the specialized load balance service move to the network core where the package forwarding is naturally made. This solution intend to use the SNMP protocol to analyse the hosts resources to evaluate server’s load. Using the network forwarding statistics and OS load informations, an efficient solution of load balance, the metodology proved to be efficient with better users’ response times average of 19% than no balanced scenario as well as around 9% better than others load balance strategies and a properly balance consumption of resources from hosts side. This process can be inhered in distinct models, however, this research intend to evaluate Web Services.
93

Relay Selection for Geographical Forwarding in Sleep-Wake Cycling Wireless Sensor Networks

Naveen, K P January 2013 (has links) (PDF)
Advances in wireless communication and microelectronics have led to the development of low-power compact sensor nodes (popularly called motes) that are capable of sensing, computing, and communication. A large number of these nodes can be deployed over some area of interest to form a multi-hop network, commonly referred to as a wireless sensor network (WSN). Typical applications of WSNs include, environment and process monitoring in industrial installations, forest fire detection, structural health monitoring, etc. In such applications where the variables to be measured are slowly varying, or the events to be monitored are rare, continuous sensing is unnecessary. Instead, the nodes, in order to conserve their battery power, can sleep-wake cycle whereby each node is allowed to independently alternate between an ON state and a low power OFF state. Sleep-wake cycling, while increasing the network lifetime, renders the network disconnected a large fraction of the time; however, connectivity can be established over time by transporting packets in a store-and-forward manner, whereby packets are held by a forwarding node until a suitable node wakes up in its neighborhood that can serve to forward the packet towards the destination. We are concerned with sleep-wake cycling multi-hop wireless networks whose main task is to carry sporadic alarms packets from sensing nodes to a sink node. Our objective is to design simple local-information based routing solutions for such networks. With this in mind, we propose a relay selection problem that arises at a forwarding node (which is currently holding the alarm packet) while choosing a next-hop relay node. The forwarder, as and when the relays wake-up, evaluating the goodness of a relay based on a “reward” metric (e.g., a function of the relay’s progress towards sink, and the power required to get the packet across), has to decide whether to forward to this relay or to wait for future ones (i.e., to stop or continue). The forwarder’s objective is to choose a relay so as to minimize a combination of the average delay incurred and the average reward achieved. A basic version of our relay selection problem is equivalent to the basic asset selling problem studied in the operations research literature. After reviewing the solution to the basic problem we will proceed to study a model with full information, referred to as the completely observable (CO) model, where the number of relays is exactly known to the forwarder. Formulating the problem as a Markov decision process (MDP) we will characterize the solution to the CO model in terms of recursively-computable threshold functions. Next, we consider the partially observable (PO) model where only a belief (probability mass function) on the number of relays is known. Hence, the PO model falls within the realm of partially observable MDPs. After incorporating our model into this framework we will characterize the solution in terms of stopping sets, which is the set of all belief states where it is optimal to stop. Our main contribution here is to obtain inner and outer bounds for the stopping sets. We next propose a variant where the relays, upon waking up, do not reveal their rewards immediately, but instead the forwarder can choose to probe the relay to know its reward, incurring a probing cost. Thus, to the existing set of stop and continue actions, we have added a new probe action. This model is motivated by the efforts required to learn the channel gains (by probing) in a wireless system. A key result we prove here is that the solution is characterized in terms of stage independent thresholds. Finally, we study a model comprising two forwarders which are competing against each other to choose a next-hop relay (one for each). Here, a relay is allowed to offer possibly different reward to each forwarder. We will first consider a complete information case where the reward pair of a relay is known to both the forwarders. Using stochastic game theory we will characterize the solution to this model in terms of Nash equilibrium policy pairs (NEPPs). We obtain results illustrating the structure of NEPPs. Next, we study a partial information model where each forwarder gets to observe only its reward value. Towards obtaining the solution for this model, we will first formulate a Bayesian game which is effectively played by both the forwarders at each stage. Next, for this Bayesian game we prove the existence of Nash equilibrium strategies within the class of threshold strategies. This result will enable us to construct NEPPs for the partial information model. Although our primary contribution from the thesis is the theoretical study of the above mentioned variants of the basic relay selection model, we have also conducted extensive simulations to study the end-to-end performance obtained by applying the solution to these models at each hop en-route to the sink in a sleep-wake cycling WSN.
94

Srovnání právní úpravy obchodních závazkových vztahů v Spolkové republice Německo a v České republice / Comparison of legal regulation of the trade relationships of obligation in Germany and the Czech Republic

Přecechtělová, Jana January 2008 (has links)
This Master thesis deals with the comparison of trade relationships of obligation in Germany and the Czech Republic. In order to introduce and analyse the topic thoroughly at first the main legal acts connected with relationships of obligation and trade relationships of obligations in both compared countries are being introduced. The main stress is put on the content of these legal acts, on their historical development, their application methods as well as on their mutual relationship. The next part of this Master thesis then explains the term trade relationship of obligation with respect to the definitions obtained in both compared legal systems. After the theoretical introduction the general legal regulation of the trade relationships of obligation is being characterised. Since the general legal regulation of the trade relationships of obligation is based on the general legal regulation of the relationships of obligation at first the differences between these two legal regulations in Germany are explained. After that the German general legal regulation of trade relationships of obligation is being compared with the Czech general legal regulation of this area. After the characterisation of the general legal regulation of the trade relationships of obligation the individual types of German trade relationships of obligation are being compared with their equivalents in the Czech legal system. The specific trade relationships of obligation that are being analysed and compared in both legal systems are namely contract with a commission agent, contract of consignment, forwarding contract and storage contract.

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