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1.
The Ozone Monitoring Instrument (OMI) operates onboard the National Aeronautics and Space Administration's Earth Observing System Aura satellite, which was launched in July 2004. Like its sister spacecraft Terra and Aqua, Aura's capabilities include direct broadcast (DB), i.e., the ability to broadcast data at the same time as they are being measured and stored in the spacecraft's memory for later transmission to Earth. The Finnish Meteorological Institute's Satellite Data Centre at Sodankyla/spl uml/ in Finnish Lapland is exploiting this capability to receive OMI data while Aura is in sight of the receiver, which enables nearly immediate production of OMI data products for a region that includes a large part of Europe, stretching from the North Pole to the Italian Alps. The current OMI Very Fast Delivery (VFD) products include maps of surface UV-B, ozone columns, and cloud coverage.  相似文献   
2.
We describe a novel quadrotor Micro Air Vehicle (MAV) system that is designed to use computer vision algorithms within the flight control loop. The main contribution is a MAV system that is able to run both the vision-based flight control and stereo-vision-based obstacle detection parallelly on an embedded computer onboard the MAV. The system design features the integration of a powerful onboard computer and the synchronization of IMU-Vision measurements by hardware timestamping which allows tight integration of IMU measurements into the computer vision pipeline. We evaluate the accuracy of marker-based visual pose estimation for flight control and demonstrate marker-based autonomous flight including obstacle detection using stereo vision. We also show the benefits of our IMU-Vision synchronization for egomotion estimation in additional experiments where we use the synchronized measurements for pose estimation using the 2pt+gravity formulation of the PnP problem.  相似文献   
3.
Cellulose is abundantly available in the form of forestry and agricultural lignocellulosic residues. These residues offer the most potential source for the production of cellulosic glucose, which is a prerequisite for the sustainable production of glucose-based fuels and chemicals. Acid catalysis is one path to lignocellulosic glucose and further to its dehydration end products. Furthermore, many studied lignocellulose pretreatment methods for enzymatic hydrolysis are carried out in acidic conditions, in which the unwanted release of hemicellulose-based glucose and its further reactions to harmful end products are possible. Thus, in order to maximize glucose production from non-food cellulosic raw materials, data on the kinetics of cellulose decomposition and formation rates of end products are required. Glucose decomposition is a complex reaction system that has often been modelled with empirical, simplified models. In this study, a kinetic model was developed for glucose decomposition in formic acid solution. The experimentation was carried out in batch reactors at 180-220 °C in 5-20% (w/w) formic acid. The model developed relies on a mechanistic step through an unknown substance and gives excellent correspondence to the experimental data despite the pseudo-elementary nature of the model structure.  相似文献   
4.
On Design of Parallel Memory Access Schemes for Video Coding   总被引:3,自引:0,他引:3  
Some of the modern powerful digital signal processors (DSPs) have byte-addressable internal data memory. This property is valuable especially in computationally demanding inter frame video encoding, where data accesses are typically unaligned according to word boundaries. The byte-addressable memory allows load or store command to start accessing from any byte-address, providing at most as many successive bytes from subsequent addresses as data bus can handle in parallel. Maybe the simplest way to construct such a byte-addressable memory is to use N 8-bit memory modules or banks to be accessed in parallel, when N is data bus width in bytes. However, in addition to byte-addressable subsequent bytes, memory consisting of parallel memory modules can provide much more versatile addressing capabilities with reasonable implementation cost. Versatile access formats can significantly reduce the need for data reordering in the register file. At first, we provide motivation for using parallel memory architecture with versatile access formats as an internal on-chip data memory of modern DSP. After this, notations are described and general view of parallel memory design is given. We propose some example parallel data memory architecture designs with data access formats especially helpful in H.263 encoding and MPEG-4 core profile motion and texture encoding. The examples are given for different data bus widths (16, 32, 64, and 128 bits). Finally, performance is shortly compared to other memory architectures and area, delay, and power figures are estimated.Jarno K. Tanskanen was born in Joensuu, Finland in 1975. He studied analog and digital electronics in the Department of Electrical Engineering, and computer architecture in the Department of Information Technology at Tampere University of Technology, where he received his M.Sc. degree in 1999. He is currently working as a research scientist in the Institute of Digital and Computer Systems at TUT. His Dr.Tech. research concerns parallel processing of video compression. jarno.tanskanen@tut.fiReiner Creutzburg received his Diploma in Mathematics in 1976 and attained his Ph.D. in Mathematics in 1984 from the Rostock University, Germany. Prof. Creutzburg has published 3 books, filed 2 patents, and produced approximately 100 articles, preprint, and conference papers. Professional Experience: Since 2000—Part-time Professor for Multimedia technology, Tampere University of Technology, Finland. Since 1992—Full-time Professor of Computer Science, Fachhochschule Brandenburg-University of Applied Sciences, Brandenburg, Germany. 1990 to 1992—Assistant Professor, University of Karlsruhe, Institute of Algorithms and Cognitive Systems, Germany. 1987 to 1989—Head of the Research Section Image Processing. 1986 to 1989—Founder and Head of the International Base Laboratory of Image Processing and Computer Graphics for East European countries at the Central Institute of Cybernetics and Information Processes of the Academy of Sciences (Berlin), Germany. 1976 to 1989—Researcher and Assistant Professor in various Universities and the Academy of Sciences, Central Institute of Cybernetics and Information, Berlin. creutzburg@fh-brandenburg.deJarkko T. Niittylahti was born in Orivesi, Finland, in 1962. He received the M.Sc, Lic.Tech, and Dr.Tech degrees at Tampere University of Technology (TUT) in 1988, 1992, and 1995, respectively. From 1987 to 1992, he was a researcher at TUT. In 1992–93, he was a researcher at CERN in Geneva, Switzerland. In 1993–95, he was with Nokia Consumer Electronics, Bochum, Germany, and in 1995–97 with Nokia Research Center, Tampere, Finland. In 1997–2000, he was a Professor at Signal Processing Laboratory, TUT, and in 2000–2002 at Institute of Digital and Computer Systems, TUT. Currently, he is a Docent of Digital Techniques at TUT and the managing director of Staselog Ltd. He is also a co-founder and President of Atostek Ltd. He is interested in designing digital systems and architectures. jarkko.niittylahti@tut.fi  相似文献   
5.
Propagation of long terminal repeat (LTR)-bearing retrotransposons and retroviruses requires integrase (IN, EC 2.7.7.-), encoded by the retroelements themselves, which mediates the insertion of cDNA copies back into the genome. An active retrotransposon family, BARE-1, comprises approximately 7% of the barley (Hordeum vulgare subsp. vulgare) genome. We have generated models for the secondary and tertiary structure of BARE-1 IN and demonstrate their similarity to structures for human immunodeficiency virus 1 and avian sarcoma virus INs. The IN core domains were compared for 80 clones from 28 Hordeum accessions representative of the diversity of the genus. Based on the structural model, variations in the predicted, aligned translations from these clones would have minimal structural and functional effects on the encoded enzymes. This indicates that Hordeum retrotransposon IN has been under purifying selection to maintain a structure typical of retroviral INs. These represent the first such analyses for plant INs.  相似文献   
6.
Twenty-three experimental cattle, mainly calves, were each inoculated 1-3 times with one of ten Finnish Borrelia burgdorferi sensu lato strains. All three genospecies were represented. Borreliae were administered mainly by both intravenous (about 10(6) to 10(9) spirochaetes) and intradermal (10(4)) routes, and on six occasions subcutaneously (10(3)) only. For infectivity control and comparison purposes mice and rabbits were inoculated simultaneously. Immune responses in cattle were monitored both with whole-cell sonicate enzyme-linked immunosorbent assay (IgG-ELISA) and indirect immunofluorescent assay (IgM-IgG-IFA). Five Finnish strains and the American strain B31 were used as antigens. No clinical signs of borreliosis were observed. Of the strains, 7/10 were interpreted by the immune responses to have caused relatively short-term subclinical infections of varying intensity. Borreliae could not be isolated from blood or other organ specimens of cattle. A rough estimate of the mean infectious dose in the conditions of experiments is 10(6) to 10(7) organisms. In conclusion, the overall result appears to argue a low susceptibility of cattle to clinical borreliosis, at least when infected by Finnish strains of the agent. Significant antigen-specific differences were observed both by ELISA and IFA in detection and quantification of immune responses. As a rule, the homologous antigen was found to be the most sensitive. Genospecies differences were mostly distinct. Antigens of two Borrelia garinii isolates proved practically equal in sensitivity, whereas major differences were displayed between two Borrelia afzelii antigens. In an IFA study, an American (B31) and a Finnish B. burgdorferi sensu stricto strain proved equally sensitive as antigens. In two relatively strong primary immune responses the antigen-specific measurement differences were such that diagnostically in a cross-sectional study only the homologous antigen or an antigen of the same genospecies would have been sufficiently sensitive to show a positive result.  相似文献   
7.
The Ozone Monitoring Instrument (OMI) onboard the NASA Earth Observing System (EOS) Aura spacecraft is a nadir-viewing spectrometer that measures solar reflected and backscattered light in a selected range of the ultraviolet and visible spectrum. The instrument has a 2600-km-wide viewing swath, and it is capable of daily, global contiguous mapping. We developed and implemented a surface ultraviolet (UV) irradiance algorithm for OMI that produces noontime surface spectral UV irradiance estimates at four wavelengths (305, 310, 324, and 380 nm). Additionally, noontime erythemal dose rate and the erythemal daily dose are estimated. The OMI surface UV algorithm inherits from the surface UV algorithm developed by NASA Goddard Space Flight Center for the Total Ozone Mapping Spectrometer (TOMS). The OMI surface UV irradiance products are produced and archived in HDF5-EOS format by Finnish Meteorological Institute. The accuracy of the surface UV estimates depend on UV wavelength and atmospheric and other geolocation specific conditions ranging from 7% to 30%. A postprocessing aerosol correction can be applied at sites with additional ground-based measurements of the aerosol absorption optical thickness. The current OMI surface UV product validation plan is presented.  相似文献   
8.
Propionibacterium freudenreichii is used as a ripening culture in Swiss cheese manufacture. This study investigates the molecular diversity and the population structure of this bacterium via multilocus sequence typing (MLST). Internal fragments of seven genes sequenced for 113 strains of different subspecies and origins allowed the resolution of 46 sequence types (STs) with occurrence frequencies ranging from 1 to 11. The core genome of the species harbours a low level of nucleotide polymorphism. In our data, single nucleotide polymorphisms account for only 2.28% of the concatenated sequences, and the average polymorphism rate in pairwise comparisons is 0.46%. The analyses reveal quantitatively comparable contributions of recombination and mutation in nucleotide changes at core genome loci along cell lineages. Remarkably, the STs exhibit little if any dairy biotope specialization. Phenotypic characterisation of the strains, based on their aptitude to use lactose and nitrate, shows that the two previously identified subspecies (freudenreichii and shermani) do not reflect the ancestral relationships in the P. freudenreichii population. The considerable phenotypic heterogeneity, found even at the ST level, suggests instead a history of recurrent switches between phenotypes.  相似文献   
9.
In this study, the feasibility of utilizing pure component saturated vapour pressure Pisat in representing the temperature-dependency of physisorption of vapours on zeolites is examined. Adsorption data of water, alcohols and aromatic compounds both on hydrophilic on and hydrophobic zeolites has been collected from the literature and represented as a function of P/Pisat. It is found that the temperature-dependency of adsorption of a component can be described by the saturated vapour pressure, especially for water adsorption on zeolites. For systems where chemisorption also plays an important role, such as aromatics adsorption on zeolites, Pisat alone is not capable of predicting the temperature-dependency accurately enough. It is also observed that contrary to common practice, the maximum adsorption loading qisat on zeolite should be considered independent of temperature. The proposed approach can be used in the modelling and design of industrial processes exploiting adsorption, such as in zeolite membrane systems, where separation is based on both adsorption and diffusion phenomena.  相似文献   
10.
Fiber-Optic Transceiver Module for High-Speed Intrasatellite Networks   总被引:1,自引:0,他引:1  
High-speed intrasatellite networks are needed to interconnect units such as synthetic aperture radars, high-resolution cameras, and fast image-compression processors that produce data beyond gigabits per second. We have developed a fiber-optic link, named SpaceFibre, which operates up to 3.125 Gb/s and is compatible with the existing SpaceWire network. The link provides symmetrical, bidirectional, full-duplex, and point-to-point communication. It employs 850-nm vertical-cavity surface emitting lasers, radiation-hardened laser-optimized 50/125 mum graded-index fibers, and GaAs p-i-n photo diodes. The transceiver electronics is realized using a multilayer-ceramic-substrate technology that enables the passive alignment of optical fibers to active devices. The SpaceFibre link demonstrator was tested to transfer data at 2.5 Gb/s over 100 m with a bit error rate of less than 1.3middot10-14. Fiber-pigtailed modules were stressed with temperature variations from -40degC to +85degC, vibrations up to 30 g, and mechanical shocks up to 3900 g. The test results of 20 modules show that the SpaceFibre link is a promising candidate for the upcoming high-speed intrasatellite networks  相似文献   
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