Zugl.: Ilmenau, Techn. Univ., Diss., 2006 u.d.T.: Petsch, Mathias: Integrative Betrachtung der Offenheit von Multiagentensystemen unter technischen, systemischen, sozialen und organisatorischen Aspekten

Bachelor-Arbeit Univ. St. Gallen, 2005.

Bachelor-Arbeit Univ. St. Gallen, 2006.

This master thesis is a part of digitization project at NIBE AB, Markaryd, Sweden.Nowadays, the demand for digitization is increasing. One of the main goals ofdigitization is to build smart houses and industries to offer better lifestyles.NIBE is a company which produces heat pumps, water heaters, district waterheaters, digital stoves and etc. NIBE AB is planning to launch their new products witha communication module which helps users to control NIBE AB’s products remotelythrough their personal devices such as mobile phones, remote control devices and etc.The main objective of this thesis project is to improve these communicationmodules by improving their antenna with better design or replacing them with otherkinds of antennas for efficient communication and also accordingly design impedancematching networks for the system.This work presents the integrated results of an antenna for NIBE AB, tuned tocover 2.45 GHz ISM band which will implemented on a communication module. Wedesigned and simulated four types of different Printed Circuit Board (PCB) antennasand we got the better simulation results of Gain, Reflection Coefficient, VSWR andBand Width from these designs.Also, we used different types of substrates in the simulation to get goodresults and design the impedance matching networks accordingly. If we compare theresults with the current monopole antenna and its parameters, we have goodcharacteristic results in most of the aspects.

When transmitting data from an aircraft being prepared at the apron (the area in front of the hangar) telemetry data is transmitted to ground personnel. The transmitted data is subject to severe distortion due to multipath propagation created by the surroundings, resulting in erroneous detection. By equalizing the signal using the Constant Modulus Algorithm a significant increase in detection performance has been observed, both in simulations and tests on collected data. The most sufficient parameters were chosen after testing a set of different parameter combinations on simulations with single delays. These parameters were then used to equalize simulated multipath as well as collected data. The results show that short delays with low power can be resolved without any equalizer. Longer delays with relatively low power can be resolved using the proposed equalizer but long delays with high power cannot be resolved by the equalizer at all. The thesis shows that it is worth investigating implementation of the equalizer.

No description available.

Advances in communication technologies continue to increase information sharing among the people.~Short-range wireless networking technologies such as Bluetooth or ZigBee, which are mainly used for data transfer over short range, will, however, suffer from network congestion, high power consumption and security issues in the future. The body-coupled communication (BCC), a futuristic short-range wireless technology, uses the human body as a transmission medium. In BBC channel, a small electric field is induced onto the human body which enables the propagation of a signal between communication devices that are in the proximity or direct contact with the human body. The direct baseband transmission and simple architecture make BCC an attractive candidate for a future short-range wireless communication technology in particular applications such as body area network. The main focus of this thesis is on the design and implementation of digital baseband transmitter and receiver for the body-coupled communication. The physical layer (PHY) implementation of the digital baseband transmitter and receiver is inspired from the IEEE 802.3 Ethernet transmission protocol. The digital design is implemented at RTL level using hardware description language (VHDL). The functionality of the digital baseband transmitter and receiver is demonstrated by developing data transfer application layers.

As increased demand of cloud computing leads to increased electricity costs for cloud providers, there is an incentive to investigate in new methods to lower electricity costs in data centers. Electricity price markets suffer from sudden price spikes as well as irregularities between different geographical electricity markets. This thesis investigates in whether it is possible to leverage these volatilities and irregularities between different electricity price markets, to offload or move storage in order to reduce electricity price costs for data storage. By forecasting four different electricity price markets it was possible to predict sudden price spikes and leverage these forecasts in a simple optimization model to offload storage of data in data centers and successfully reduce electricity costs for data storage.

Kommunikation är viktigt i alla arbetssituationer som involverar mer än en individ. Vi tror teknologin hos tillverkarna av aktiva hörselkåpor har kommit ikapp med kraven som ställs på dom men helt enkelt glömts bort av industrin. Syftet med det här experimentet är att testa om de aktiva hörselkåporna kan skilja på allt bakgrundsljud som finns i ett maskinrum och samtalsljud från en annan människa. Experiementet tar plats först i ett maskinrum ombord på Calmare Nyckel för att mäta upp referensvärden sedan därefter i maskinsimulatorn. Testerna ombord på Calmare Nyckel och i simulatorn fick liknande resultat vilket bevisar att det inte spelar någon roll om ljudet kommer från en maskin eller en högtalare. Resultatet av experimentet visade att det inte spelar roll om ljudet kommer från en högtalare eller en maskin eftersom frekvensen vi pratar på var starkt representerad i båda fallen. Alla deltagare i experiment sa att dom inte kände någon märkbar förbättring av förståelsen genom medhörningen. Om något var hörselkåporna bara tyngre och större att ha på huvudet vilket uppfattas något negativt.

Many emerging applications based on wireless networks involve distributed control. This implies high requirements on reliability, but also on predictable maximum delay. Further, for applications, it is vital to use off-the-shelf components, both due to cost constraints and requirements on interoperability with existing networks. This, in turn, implies that concurrent transmissions and multiuser detection are seldom possible. Instead, half-duplex time-division multiple access (TDMA) is typically used. Aiming to reduce the packet error rate given a deadline (a set of TDMA time-slots), this thesis proposes a relaying scheme, which can be implemented on top of off-the-shelf components. The relaying scheme selects the best sequence of relayers, given the number of time-slots allowed by the deadline, such that the resulting error probability is minimized at the targeted receiver(s). The scheme differs from existing work in that it considers both unicast as well as broadcast and assumes that all nodes can overhear each other, as opposed to separating source nodes, relay nodes and destination nodes into three disjoint sets. A full analysis of the resulting error probability is provided and complementary numerical results show that the proposed relay sequencing strategy significantly improves reliability given a certain maximum delay, or alternatively, reduces the delay, given a certain target reliability requirement. To illustrate the performance improvements of relay sequencing, it is incorporated in a platooning application. If the decision regarding which relayer to assign in each time-slot can be taken online, just before the transmission, much can be gained. To this end, a low-complexity algorithm is developed, which is shown to be highly likely to find the optimal combination of relaying nodes that minimizes the resulting error probability at the targeted receiver(s). Data packets in wireless automation networks is typically small. To enable timely and reliable all-to-all broadcast in such systems, relay sequencing using packet aggregation is proposed. The strategy assigns relayers to time slots, as well as determines which packets to aggregate in each slot, using the proposed low-complexity algorithm. To further increase the reliability, a clustering scheme is proposed. When a relayer in the sequence fails to overhear a correct copy, a backup relayer in the cluster takes over. This work thereby enables ultra-reliable communications with maintained end-toend delay using low-complexity techniques and off-the-shelf components.