Andreas Springer

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The water-soluble organic fractions of aerosol samples collected in Riverside, CA, in summer 2005 were analyzed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Elemental compositions of about 1000 molecular species were determined in the range m/z 220-420, and four series of organic compounds were(More)
Fulvic acids are one of the largest classes of dissolved organic matter, but they are poorly defined and of unclear origin. Three fulvic acid isolates of different origin were analyzed by size-exclusion chromatography coupled to electrospray ionization-Fourier-transform ion cyclotron resonance (FTICR)-mass spectrometry, and molecular formulas for 700-1900(More)
Synchronization is a key functionality in wireless networks, enabling a wide variety of services. We consider a Bayesian inference framework whereby network nodes can achieve phase and skew synchronization in a fully distributed way. In particular, under the assumption of Gaussian measurement noise, we derive two message passing methods (belief propagation(More)
Structure elucidation of naturally occurring linear and cyclic peptidic compounds can be complicated by rearrangement reactions induced upon collision activation (CA) when parts of the molecule migrate, suggesting incorrect substitution patterns. Such complex rearrangements are examined and discussed for two iron complexing compounds produced by the(More)
In this work we investigate the use of a known symbol sequence – a so-called unique word (UW) – instead of the well-known cyclic prefix (as it is used in OFDM (Orthogonal Frequency Division Multiplexing) systems) for a single carrier system with frequency domain equalization (SC/FDE). The considered SC/FDE system is similar to the one proposed in the IEEE(More)
We present a factor graph framework and a particle-based belief propagation algorithm for distributed cooperative simultaneous localization and synchronization (CoSLAS) in decentralized sensor networks. The proposed algorithm jointly estimates the locations and clock parameters of the network nodes in a fully decentralized fashion. This estimation is based(More)
In this paper, we propose to use spatial modulation (SM) and the generalized spatial modulation (GSM) MIMO schemes in indoor line-of-sight (LOS) millimeter-wave (mmWave) communication at 60 GHz. SM/GSM are known but only at low-GHz frequencies where the channels are typically rich scattered and characterized by Rayleigh or Rician distribution. However, 60(More)
In this paper, we show by simulations that the interference generated by the synchronization channel (SCH) and common pilot channel (CPICH) has considerable impact on the throughput of the high-speed physical downlink shared channel (HS-PDSCH) in UMTS. First, the simulation model for high speed downlink packet access (HSDPA) in UMTS is described. The(More)