16,072 research outputs found
Rhodobacter veldkampii, a new species of phototrophic purple nonsulfur bacteria
We describe a new species of purple nonsulfur bacteria, which has the ability to grow under photoautotrophic growth conditions with sulfide as an electron donor and shows the characteristic properties of Rhodobacter species (i.e., ovoid to rod-shaped cells, vesicular internal photosynthetic membranes, bacteriochlorophyll a and carotenoids of the spheroidene series as photosynthetic pigments). In its physiological properties this new species is particularly similar to the recently described species Rhodobacter adriaticus, but it shows enough differences compared with R. adriaticus and the other Rhodobacter species to be recognized as a separate species. In honor of Hans Veldkamp, a Dutch microbiologist, the name Rhodobacter veldkampii sp. nov. is proposed
On properties of modeling control software for embedded control applications with CSP/CT framework
This PROGRESS project (TES.5224) traces a design framework for implementing embedded real-time software for control applications by exploiting its natural concurrency. The paper illustrates the stage of yielded automation in the process of structuring complex control software architectures, modeling controlled mechatronic systems and designing corresponding control laws, simulating them, generating control code out of simulated control strategy and implementing the software system on a (embedded) computer. The gap between the development of control strategies and the procedures of implementing them on chosen hardware targets is going to be overcome
CAN Fieldbus Communication in the CSP-based CT Library
In closed-loop control systems several realworld entities are simultaneously communicated to through a multitude of spatially distributed sensors and actuators. This intrinsic parallelism and complexity motivates implementing control software in the form of concurrent processes deployed on distributed hardware architectures. A CSP based occam-like architecture seems to be the most convenient for such a purpose. Many, often conflicting, requirements make design and implementation of distributed real-time control systems an extremely difficult task. The scope of this paper is limited to achieving safe and real-time communication over a CAN fieldbus for an\ud
existing CSP-based framework
Entropy of unimodular Lattice Triangulations
Triangulations are important objects of study in combinatorics, finite
element simulations and quantum gravity, where its entropy is crucial for many
physical properties. Due to their inherent complex topological structure even
the number of possible triangulations is unknown for large systems. We present
a novel algorithm for an approximate enumeration which is based on calculations
of the density of states using the Wang-Landau flat histogram sampling. For
triangulations on two-dimensional integer lattices we achive excellent
agreement with known exact numbers of small triangulations as well as an
improvement of analytical calculated asymptotics. The entropy density is
consistent with rigorous upper and lower bounds. The presented
numerical scheme can easily be applied to other counting and optimization
problems.Comment: 6 pages, 7 figure
Thue-Morse at Multiples of an Integer
Let (t_n) be the classical Thue-Morse sequence defined by t_n = s_2(n) (mod
2), where s_2 is the sum of the bits in the binary representation of n. It is
well known that for any integer k>=1 the frequency of the letter "1" in the
subsequence t_0, t_k, t_{2k}, ... is asymptotically 1/2. Here we prove that for
any k there is a n<=k+4 such that t_{kn}=1. Moreover, we show that n can be
chosen to have Hamming weight <=3. This is best in a twofold sense. First,
there are infinitely many k such that t_{kn}=1 implies that n has Hamming
weight >=3. Second, we characterize all k where the minimal n equals k, k+1,
k+2, k+3, or k+4. Finally, we present some results and conjectures for the
generalized problem, where s_2 is replaced by s_b for an arbitrary base b>=2.Comment: 14 page
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