Refine
Year of publication
- 2013 (59) (remove)
Document Type
- Conference Proceeding (59) (remove)
Conference Type
- Konferenzartikel (42)
- Konferenz-Abstract (10)
- Sonstiges (3)
- Konferenz-Poster (2)
- Konferenzband (2)
Keywords
- Energieversorgung (3)
- Herzkrankheit (3)
- Kommunikation (3)
- Konstruktion (3)
- Synchronisierung (3)
- Batterie (2)
- Brennstoffzelle (2)
- Messung (2)
- Mikroelektronik (2)
- Optik (2)
Institute
- Fakultät Elektrotechnik und Informationstechnik (E+I) (bis 03/2019) (43)
- Fakultät Maschinenbau und Verfahrenstechnik (M+V) (11)
- INES - Institut für nachhaltige Energiesysteme (6)
- Fakultät Wirtschaft (W) (4)
- Fakultät Medien und Informationswesen (M+I) (bis 21.04.2021) (3)
- IUAS - Institute for Unmanned Aerial Systems (2)
Open Access
- Open Access (32)
- Closed Access (26)
- Bronze (5)
- Closed (1)
In the dual membrane fuel cell (DM-Cell), protons formed at the anode and oxygen ions formed at the cathode migrate through their respective dense electrolytes to react and form water in a porous composite layer called dual membrane (DM). The DM-Cell concept was experimentally proven (as detailed in Part I of this paper). To describe the electrochemical processes occurring in this novel fuel cell, a mathematical model has been developed which focuses on the DM as the characteristic feature of the DM-Cell. In the model, the porous composite DM is treated as a continuum medium characterized by effective macro-homogeneous properties. To simulate the polarization behavior of the DM-Cell, the potential distribution in the DM is related to the flux of protons and oxygen ions in the conducting phases by introducing kinetic and transport equations into charge balances. Since water pressure may affect the overall formation rate, water mass balances across the DM and transport equations are also considered. The satisfactory comparison with available experimental results suggests that the model provides sound indications on the effects of key design parameters and operating conditions on cell behavior and performance.
The increased complexity and dynamics of the business environment and the problems of a young organization are treated extensively in the literature [Bleicher 2002, p. 34; Malik 1996, p. 86; Ulrich/Probst 1990, p. 23ff; Gomez 1999, p. 65]. This complexity is the core of the leadership role in a company [Malik 1996, p. 184]. STÜTTGEN (1999, p. 8) states in this regard: "A satisfactory answer to the question, according to which patterns complex social systems are to be designed to meet the proliferating environmental complexity facing an adequate intrinsic complexity of the company can be, in this context, a critical success factor for management." How can young SMEs solve strategic problems with service engineering in their companies?
A 2002 study on corporate planning of the top German companies measured by turnover found that of the surveyed large companies, 80 percent have carried out strategic planning and 90 percent have operational planning in place [Link/Orbán 2002, pp. 11]. The human and material costs of designing and implementing the strategic planning can be very high. Many SMEs do not have the necessary capacities to do this. To obtain a comprehensive overview, this chapter examines the existing studies and findings for young SMEs. Many of the studies reviewed and the following publications relate to SMEs as defined by the EU. This analysis also includes established SMEs and medium-sized enterprises.
The communication technologies for automatic meter reading (smart metering) and for energy production and distribution networks (smart grid) have the potential to be one of the first really highly scaled machine-to-machine-M2M-applications. During the last years, two very promising developments around the wireless part of the smart grid communication were initialized, which possibly could have an impact on the network architectures and the markets far beyond Germany and far beyond energy automation. Besides the specification of the OMS Group of a security extension to the Wireless M-Bus protocol (EN13757-4), the German Federal Office for Information Security (Bundesamt für Sicherheit in der Informationstechnik, BSI) has designed a Protection Profile (PP) and a Technical Directive (TR) for the communication unit of an intelligent measurement system (Smart Meter Gateway), which were released in March 2013. This design uses state of the art technologies and prescribes their implementation in real-life systems. At first, the proposed paper will present the most important characteristics of this architecture. It will then give an insight into the implementation of the OMS security protocols, which imply the usage of a mutually authenticated SSL protocol also in the Local Metrological Network. This is achieved with the help of an additional Authentication and Fragmentation Layer (AFL). This secure communication will be terminated in a BSI conformant secure smart meter gateway, which is developed in a different project and described in the second step. Finally, the contribution will discuss the integration of such a metering network into an overall telecommunication network and PKI infrastructure.
Automatic Meter Reading (AMR) is a major enabler for the upcoming smart grid. Potentially, it will be one of the first really large-scale M2M-communication solutions for sensor applications.
To date, the definition of the standardized communication stacks for Local Metrological Network (LMN) in AMR is still ongoing. This holds true both for ZigBee Smart Energy Profile and for Wireless M-Bus according to EN 13757. During this process, there is the necessity for flexible, albeit optimized solutions, which support the different existing and upcoming versions of the communication protocols. In the case of Wireless M-Bus, the major contender for European and possibly Asian installations, this is valid not only for the different operation modes (C-, N-, P-, Q-, R-, S-, and T-modes), which work in different frequencies (i.e. 868 MHz, 433 MHz, and 169 MHz) but also for the application layer, where additional bodies, like EN137575, Open Metering System (OMS) Group, or national bodies follow their approaches.
This contribution describes requirements, design techniques and experiences from the development of highly efficient Wireless M-Bus protocol stacks with support of good flexibility and portability between microcontroller platforms and RF-transceivers. The presented approach is not limited to the use of modern software engineering design processes, as such, but also includes essential additional features like testing or simulation, as well as tools for commissioning and monitoring.
The communication between objects, i.e. between cars (car-2-car, C2C), between cars and infrastructure (car-2-infrastructure, C2I) and between cars and vulnerable road users (car-2-VRU, C2VRU) is a major stepping stone towards traffic applications to enable efficient and safe traffic flow. However, these applications pose very high requirements to the communication protocols, which go beyond the capabilities of an available standardized solution.
This contribution shows how iterative design processes can help to fulfill these requirements, while re-using a maximum of elements from one level to the next and thus avoiding unrealistic overhead. In especially, the added value of simulation and emulation in this iterative process is elaborated.