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Auflistung nach Autor:in "Johann, Timo"

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  • Konferenzbeitrag
    Environmental Informatics Prize for Students: Towards more Transparency in Supporting a Green Web
    (EnviroInfo Dessau 2012, Part 1: Core Application Areas, 2012) Kern, Eva; Heinz, Kai Benjamin; Hiller, Tim; Johann, Timo
    The resource and power consumption of Information and Communication Technologies (ICT) increased rapidly in the last years and is still increasing. One big player regarding the energy consumption within the ICT is represented by the World Wide Web. Since it gains soaring importance in nearly every branch of industry the number of servers is also growing. This has sufficient influences on our environment. On the one hand there are the greenhouse gases (GHG) produced in the process of production of these servers and on the other hand there are greenhouse gases produced while operating the devices. In this case we have to have a look at the energy that is used to run the server. When there is no label displayed on a website we surf on, we do not know which quality of energy is used. Is it atomic, renewable or any other kind of energy? Because of this it is important to achieve some transparency. This is interesting for every stakeholder but particularly for the end user. Hence, we developed the Green Power Indicator (GPI), that visualizes this information for web users. Our tool displays the class of energy the data center, hosting the current website, is powered by. We distinguish between three classes of energy, which are described in detail below. In addition, we will go into the technical details of the extension and introduce some further developments in this context. The Add-on is also able to show the status of a website before you surf on the specific website. With this opportunity the user can decide whether to click on a green link or not. We will also inform about other approaches towards a greener web including Green Web Initiatives and other Addons. Furthermore we will give a short introduction in Eco Labels and present research results. After describing the GPI, which is based on the extension introduced in (Naumann/Gresk/Schäfer 2008), we will give some background information including the development of the tool and, in order to get an impression of the student work behind the development of the Add-ons, we will also give a description of the students’ projects on the Environmental Campus Birkenfeld.
  • Konferenzbeitrag
    Green Web Engineering - Measurements and Findings
    (EnviroInfo Dessau 2012, Part 2: Open Data and Industrial Ecological Management, 2012) Dick, Markus; Kern, Eva; Johann, Timo; Naumann, Stefan; Gülden, Christian
    The power consumption of Information and Communication Technology (ICT) is still increasing. In order to handle this problem, we can hereby distinguish between two directions: Green IT and Green by IT. Green IT means, how ICT itself can be more energy efficient. Green by IT means how we can improve energy efficiency in other fields with the help of ICT. In our paper we describe an approach regarding Green IT: How software and especially websites can be improved on the server side regarding their energy consumption. For example, caching and compression technologies, as well as decreased sizes of pictures can significantly reduce the network traffic. Here we give some suggestions and we present concrete measurement results, which show the differences in the induced energy consumption.
  • Konferenzbeitrag
    Measurement and Rating of Software-induced Energy Consumption of Desktop PCs and Servers
    (Innovations in Sharing Environmental Observations and Information, 2011) Dick, Markus; Kern, Eva; Drangmeister, Jakob; Naumann, Stefan; Johann, Timo
    Up to now, the power consumption of ICT is still increasing. However, it is not clear whether or not energy savings through ICT overcompensate this increasing energy consumption. There are manifold efforts of Green IT addressing energy efficiency of computer hardware, but there is a lack of models, descriptions, or realizations in the field of computer software. In our paper, we present a method to measure and rate software-induced energy consumption of stand-alone applications on desktop computers as well as interactive transaction-based applications on servers. In both cases, realistic workloads are applied. Our test rig contains the tested system, an appropriate power meter, a workload generator, and a data evaluation system. Our measurement method is intended to support software developers, purchasers, administrators, and users in making informed decisions on software architecture and implementation as well as on software products they use or plan to use. As a proof of concept, we will describe two exemplary measurements that show the influence of software use on power consumption.