Abstract-Because of shrinking structure sizes and operating voltages, computing hardware exhibits an increasing susceptibility against transient hardware faults: Issues previously only known from avionics systems, such as bit flips caused by cosmic radiation, nowadays also affect automotive and other cost-sensitive "ground-level" control systems. For such cost-sensitive systems, many software-based measures have been suggested to harden applications against transient effects. However, all these measures assume that the underlying operating system works reliably in all cases. We present software-based concepts for constructing an operating system that provides a reliable computing base even on unreliable hardware. Our design is based on two pillars: First, strict fault avoidance by static tailoring and elimination of susceptible indirections. Second, reliable fault detection by finegrained arithmetic encoding of the complete kernel execution path. Compared to an industry-grade off-the-shelf RTOS, our resulting dOSEK kernel thereby achieves a robustness improvement by four orders of magnitude. Our results are based on extensive fault-injection campaigns that cover the entire space of single-bit faults in random-access memory and registers.

Despite intensive research in the field of mote-class Wireless Sensor Networks in recent years, real-life deployments are still challenging and systems are prone to failures. This can typically be attributed to fragile hardware or misbehaving software. Issues caused by software, often induced by the inherent constraints of resources, can be countered using simulations. However the simulation results often do not reflect those of the specific deployment.We suggest analyzing the actual environment conditions of a deployed network and map them to a simulator. Then, based on simulations, software and parameters can be tailored to the specific deployment.We developed two tool chains, RealSim and DryRun, and compared results from simulation runs to those acquired from two different testbeds using Tmote Sky nodes. This was done in two campaigns, each altering 2 configuration parameters from the hardware to the application layer. The presented data is based on over 1100 experiments, respectively over 270 h, on real hardware and almost 7000 simulations. The close relation of simulation and real measurements shows that our DrySim approach is feasible.

Toluene as a replacement for common N-benzylating agents, such as benzyl bromide, can be an atom-efficient alternative reagent. Under nickel catalysis and mildly oxidative conditions, it is possible to activate toluene efficiently and use it directly for the benzylation of different 2-aminopyridines. The transformation is not restricted to simple toluene, but also substituted derivatives give the desired product in good yields. Effective cleavage of the pyridine moiety is presented.

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The ability to construct C(sp3)–C(sp3) bonds from easily accessible reagents is a crucial, yet challenging endeavor for synthetic organic chemists. Herein, we report the realization of such a cross-coupling reaction, which combines N-sulfonyl hydrazones and C(sp3)–H donors through a diarylketone-enabled photocatalytic Hydrogen Atom Transfer and a subsequent fragmentation of the obtained alkylated hydrazide. This mild and metal-free protocol was employed to prepare a wide array of alkyl-alkyl cross-coupled products and is tolerant of a variety of functional groups. The application of this chemistry further provides a preparatively useful route to various medicinally-relevant compounds, such as homobenzylic ethers, aryl ethyl amines, β-amino acids and other moieties which are commonly encountered in approved pharmaceuticals, agrochemicals and natural products.