Minimum-risk path finding by an adaptive amoebal network

When two food sources are presented to the slime mold Physarum in the dark, a thick tube for absorbing nutrients is formed that connects the food sources through the shortest route. When the light-avoiding organism is partially illuminated, however, the tube connecting the food sources follows a different route. Defining risk as the experimentally measurable rate of light-avoiding movement, the minimum-risk path is exhibited by the organism, determined by integrating along the path. A model for an adaptive-tube network is presented that is in good agreement with the experimental observations.     

Multidentate Europium Chelates as Luminoionophores for Anion Recognition: Impact of Ligand Design on Sensitivity and Selectivity,and Applicability to Enzymatic Assays

The design of photoluminescent molecular probes for the selective recognition of anions is a major challenge for the development of optical chemical sensors. The reversible binding of anions to lanthanide centers is one promising option for the realization of anion sensors, because it leads in some cases to a strong luminescence increase by the replacement of quenching water molecules. Yet, it is an open problem to gain control of the sensitivity and selectivity of the luminescence response. Primarily, the selective detection of (poly)phosphate species such as nucleotides has emerged as a demanding task, because they are involved in many biological processes and enzymatic reactions. We designed a series of pyridyl‐based multidentate europium complexes (seven‐, six‐, and five‐dentate) including sensitizing chromophores and studied their luminescence intensity and lifetime responses to different (poly)phosphates (adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), cyclic adenosine monophosphate (cAMP), pyrophosphate, and phosphate anions), and carboxyanions (citrate, malate, oxalacetate, succinate, α‐ketoglutarate, pyruvate, oxalate, carbonate). The results reveal that the number of free coordination sites has a significant impact on the sensitivity and selectivity of the response. Because of its reversibility, the lanthanide probes can be applied to monitor the activity of ATP‐consuming enzymes such ATPases and apyrases, which is demonstrated by means of the five‐dentate complex.     

Scalable Architecture for SoC Video Encoders

Evolving video coding standards demand functional flexibility for implementations, not only at design time but also after fabrication. This paper presents a System-on-Chip design approach with a feasible combination of performance, scalability, programmability, area efficiency, and design time effort for a video encoder. The encoder is based on a homogeneous master-slave processor architecture. Each slave encodes a part of the frame in the Single Program Multiple Data (SPMD) data parallel model. Both shared and distributed memory architectures are presented. Design effort is reduced by identical program codes, automated assembly of software and hardware modules independent of the number and type of processors, as well as our flexible on-chip communication network called Heterogeneous IP Block Interconnection (HIBI). A case study implementation with two to ten simple ARM7 processors, 32-bit HIBI bus and non-optimized processor-independent software gives the performance from 6 to 53 fps for QCIF. The whole encoder area ranges from 173 to 770 kgates excluding the memories. The relation scales reasonably well to systems with more powerful processors and optimized code. The optimization of the communication network shows that with more than six slaves even a serial HIBI connection with 100 MHz speed is feasible. HIBI and the parallelization approach allow exploration and optimization of the communication both at the application and architecture layers. Tero Kangas, MSc ’01, Tampere University of Technology (TUT). Since 1999 he has been working as a research scientist in the Institute of Digital and Computer Systems (DCS) at TUT. Currently he is working towards his PhD degree and his main research topics are system architectures and SoC design methodologies in multimedia applications. Kimmo Kuusilinna, PhD ’01, TUT. His main research interests include system-level design and verification, interconnection networks, and parallel memories. Currently he is working as a senior research engineer at the Nokia Research Center. Timo D. H?m?l?inen, MSc ’93, PhD ’97, TUT. He acted as a senior research scientist and project manager at TUT in 1997-2001. He was nominated to full professor at TUT/Institute of Digital and Computer Systems in 2001. He heads the DACI research group that focuses on three main lines: wireless local area networking and wireless sensor networks, high-performance DSP/HW based video encoding, and interconnection networks with design flow tools for heterogeneous SoC platforms.     

On robust identification in the square and king grids

Fault diagnosis of multiprocessor systems gives the motivation for robust identifying codes. We provide robust identifying codes for the square and king grids. Often we are able to find optimal such codes.     

Decidability of the binary infinite Post Correspondence Problem

We shall show that it is decidable for binary instances of the Post Correspondence Problem whether the instance has an infinite solution. In this context, a binary instance (h,g) consists of two morphisms h and g with a common two element domain alphabet. An infinite solution ω is an infinite word ω=a₁a₂… such that h(ω)=g(ω). This problem is known to be undecidable for the unrestricted instances of the Post Correspondence Problem.     

Synthesis and thermal behavior of Janus dendrimers,part 1

Eight Janus-type dendrimers up to the second generation were synthesized, and their thermal properties were evaluated. Compounds consist of the dendritic bisMPA based polyester moieties, and either 3,4-dihexyloxybenzoic acid or 3,4-dihexadecyloxybenzoic acid moieties, attached to opposite sides of the pentaerythritol core. The structures of the molecules were verified with ¹H NMR, ¹³C NMR, ESI TOF mass spectrometry and elemental analysis. The thermal stability was evaluated by thermogravimetric analysis, displaying onset decomposition temperatures (T_d) ranging from 241 to 308 °C. Phase transitions were studied by differential scanning calorimetry. Based on the performed studies it was confirmed that OH terminated dendrimers 2, 4, 6 and 8 exhibited liquid crystalline phases. Also, the X-ray powder diffraction measurements were accomplished for the dendrimers having terminal hydroxyl groups.     

New octahedral Ta(V) hydrazido-substituted compounds for atomic layer deposition: Syntheses,X-ray diffraction structures of TaCl(NMe2)3[N(TMS)NMe2] and Ta(NMe2)4[N(TMS)NMe2], and fluxional behavior of the amido and hydrazido ligands in solution

The synthesis and structural characterization of new tantalum(V) compounds containing a single hydrazido(I) ligand are reported. Hydrazinolysis of TaCl(NMe₂)₄ using trimethylsilyl(dimethyl)hydrazine affords the compound TaCl(NMe₂)₃[N(TMS)NMe₂] in essentially quantitative yield. Metathetical replacement of the chloride ligand in TaCl(NMe₂)₃[N(TMS)NMe₂] by LiNMe₂ gives the all-nitrogen coordinated compound Ta(NMe₂)₄[N(TMS)NMe₂]. VT ¹H NMR studies support the existence of low-energy pathways involving rotation about the Ta–N bonds of the ancillary amido and hydrazido ligands in both hydrazido-substituted compounds. X-ray crystallographic analyses confirm the octahedral disposition about the tantalum metal in TaCl(NMe₂)₃[N(TMS)NMe₂] and Ta(NMe₂)₄[N(TMS)NMe₂] and the presence of an η²-hydrazido(I) ligand. Preliminary data using Ta(NMe₂)₄[N(TMS)NMe₂] as an ALD precursor for the preparation of tantalum nitride and tantalum oxide thin films are presented.     

Locating–dominating codes in paths

Bertrand, Charon, Hudry and Lobstein studied, in their paper in 2004 [1], r-locating–dominating codes in paths P_n. They conjectured that if r≥2 is a fixed integer, then the smallest cardinality of an r-locating–dominating code in P_n, denoted by , satisfies for infinitely many values of n. We prove that this conjecture holds. In fact, we show a stronger result saying that for any r≥3 we have for all n≥n_r when n_r is large enough. In addition, we solve a conjecture on location–domination with segments of even length in the infinite path.     

L, C and X band integrated synthetic aperture radar (SAR) receiver

An integrated receiver consisting of RF front ends, analog baseband (BB) chain with an analog to digital converter (ADC) for a synthetic aperture radar (SAR) implemented in 130 nm CMOS technology is presented in this paper. The circuits are integrated on a single chip with a size of 10.88 mm². The RF front end consists of three parallel signal channel intended for L, C and X-band of the SAR receiver. The BB is selectable between 50 and 160 MHz bandwidths through switches. The ADC has selectable modes of 5, 6, 7 and 8 bits via control switches. The receiver has a nominal gain of 40 and 37 dB and noise figure of 11 and 13.5 dB for 160 MHz BB filter at room temperature for L-band and C-band, respectively. The circuits, which use a 1.2 V supply voltage, dissipate maximum power of 650 mW with 50 MHz BB and 8 bit mode ADC, and maximum power of 800 mW with 160 MHz BB and 8 bit mode ADC.