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排序方式: 共有852条查询结果,搜索用时 15 毫秒
1.
A parallel version of quicksort on a CRCW PRAM is developed. The algorithm uses n processors and a linear space to sort n keys in the expected time O(log n) with large probability. 相似文献
2.
aneta Polkowska Jacek Namienik Jacek Czerwiski & Bogdan Zygmunt 《International Journal of Food Science & Technology》1996,31(5):387-395
Applicability of thin-layer headspace (TLHS) procedure giving an aqueous concentrate and also classical purge and trap (PT) in off-line mode to isolate and enrich volatile organohalogen compounds in common beverages was tested. Both enrichment tech-niques were used in combination with gas chromatography – electron capture detection (GC-ECD). TLHS, combined with direct aqueous injection (DAI)-GC-ECD, proved applicable in the determination of volatile organohalogen compounds in all studied beverages, while the PT in a version with no preliminary sample pre-treatment was of limited applicability. Detection limits of the TLHS-based procedure were in the order of 1 ppt. Content of volatile organohalogen compounds in a number of beverages available on the Polish market including mineral waters, beers, juices, carbonated and non-carbonated soft drinks, etc. was determined by means of TLHS-DAI-GC-ECD. 相似文献
3.
The various complex mathematical transformations previously proposed for eliminating methodological errors of multicolor radiation pyrometry are mainly reduced to the determination of such combinations of wavelengths or corrections of registered brightness for the spectral distribution of the radiating capacity of the object being thermometered at which its equivalent radiating capacity is equal to unity. Mathematical formulas of the determining parameters of multicolor pyrometry of radiation have been obtained. Engineering techniques for calculating the critical values of the determining and adjustable parameters at which the application of multicolor optical thermometry is excluded because of large errors have been developed. Algorithms of a priori and a posteriori calibration systems of multicolor pyrometry of radiation of objects with practically any spectral distribution of the radiating capacity are proposed. 相似文献
4.
Benjamin Zeiss Andras Kovacs Nikolay Pakulin Bogdan Stanca-Kaposta 《International Journal on Software Tools for Technology Transfer (STTT)》2014,16(3):285-294
With more than 10 years of maturing through industrial use and standardization, the Testing and Test Control Notation (TTCN-3) has become a widely used technology that many businesses depend upon for ensuring their product quality. With the rising number of supporters and tools, the demand for a means to assess the standards compliance of TTCN-3 tools has increased. In this article, we describe the motivation, approach, methodology, and results of the still ongoing project to develop a standardized conformance test suite for TTCN-3 tools. We discuss the challenges involved in creating such a test suite, the way to deal with imposed resource limitations of the project, and where we think the effort is heading. 相似文献
5.
Bogdan C. Simionescu Silvia Ioan Aurora Chiriac Cristofor I. Simionescu 《Polymer Bulletin》1987,17(5):439-443
Summary Temperature dependence of viscosity data was investigated on poly(butyl methacrylate) fractions in dilute solution. A discontinuity in intrinsic viscosity was observed in the 25°C–35°C temperature range. Sharp changes of unperturbed dimensions were visualized from this behaviour. The phenomenon can be accounted for by assuming conformational changes of the chain in different solvents. 相似文献
6.
Paper introduces a 3-D shape representation scheme for automatic face analysis and identification, and demonstrates its invariance to facial expression. The core of this scheme lies on the combination of statistical shape modelling and non-rigid deformation matching. While the former matches 3-D faces with facial expression, the latter provides a low-dimensional feature vector that controls the deformation of model for matching the shape of new input, thereby enabling robust identification of 3-D faces. The proposed scheme is also able to handle the pose variation without large part of missing data. To assist the establishment of dense point correspondences, a modified free-form-deformation based on B-spline warping is applied with the help of extracted landmarks. The hybrid iterative closest point method is introduced for matching the models and new data. The feasibility and effectiveness of the proposed method was investigated using standard publicly available Gavab and BU-3DFE datasets, which contain faces with expression and pose changes. The performance of the system was compared with that of nine benchmark approaches. The experimental results demonstrate that the proposed scheme provides a competitive solution for face recognition. 相似文献
7.
Bogdan Branowski Leszek Pacholski Michał Rychlik Marek Zabłocki Piotr Pohl 《人机工程学与制造业中的人性因素》2013,23(4):255-266
The article presents a new concept of combining the three dimensions (3D) of a person's manipulation space. The data concern information about the reach of the arms and biomechanical data about limiting the load of a disabled person sitting in a wheelchair. Measurement data were acquired empirically, on original measuring station. The data included, respectively, arms' reach (static and dynamic) or, alternatively, measurements of limiting forces. The obtained data were processed into virtual 3D surfaces of arms' reach and forces. These surfaces provide the required graphic model of anthropotechnical and biomechanical data. Developed model was utilized to perform a virtual analysis of the accessibility of a disabled person to technical means: in a market sale space and in the ergonomic analysis into the space of a personal car. The presented method of 3D graphic modeling of anthropometrical and biomechanical data can be universally applied in ergonomic designing of work stations not only for disabled persons. © 2011 Wiley Periodicals, Inc. 相似文献
8.
The microscopic character of melting for quasi–two dimensional N
2
adlayers on graphite is examined for surface densities 0.2 1, where the upper limit corresponds to a complete monolayer. A Monte Carlo method, with the multiple histogram procedure, is employed to determine various thermodynamic quantities. Using the calculated specific heats and selected order parameters, determined at various surface densities, the mechanism for melting is shown to be vacancy mediated. The somewhat unusual behavior of the melting temperature versus density is shown to be entirely due to the vacancy concentration and their topology. Because this is determined by the free energy, our analysis should be general. Preliminary results for Xe on graphite supports this claim. 相似文献
9.
Smolic-Rocak N. Bogdan S. Kovacic Z. Petrovic T. 《Automation Science and Engineering, IEEE Transactions on》2010,7(1):151-155
This paper presents a dynamic routing method for supervisory control of multiple automated guided vehicles (AGVs) that are traveling within a layout of a given warehouse. In dynamic routing a calculated path particularly depends on the number of currently active AGVs' missions and their priorities. In order to solve the shortest path problem dynamically, the proposed routing method uses time windows in a vector form. For each mission requested by the supervisor, predefined candidate paths are checked if they are feasible. The feasibility of a particular path is evaluated by insertion of appropriate time windows and by performing the windows overlapping tests. The use of time windows makes the algorithm apt for other scheduling and routing problems. Presented simulation results demonstrate efficiency of the proposed dynamic routing. The proposed method has been successfully implemented in the industrial environment in a form of a multiple AGV control system. 相似文献
10.
We consider deterministic distributed broadcasting on multiple access channels in the framework of adversarial queuing. Packets
are injected dynamically by an adversary that is constrained by the injection rate and the number of packets that may be injected
simultaneously; the latter we call burstiness. A protocol is stable when the number of packets in queues at the stations stays
bounded. The maximum injection rate that a protocol can handle in a stable manner is called the throughput of the protocol.
We consider adversaries of injection rate 1, that is, of one packet per round, to address the question if the maximum throughput
1 can be achieved, and if so then with what quality of service. We develop a protocol that achieves throughput 1 for any number
of stations against leaky-bucket adversaries. The protocol has
O(n2+\textburstiness){\mathcal{O}(n^2+\text{burstiness})} packets queued simultaneously at any time, where n is the number of stations; this upper bound is proved to be best possible. A protocol is called fair when each packet is
eventually broadcast. We show that no protocol can be both stable and fair for a system of at least two stations against leaky-bucket adversaries. We study in detail small systems of exactly
two and three stations against window adversaries to exhibit differences in quality of broadcast among classes of protocols.
A protocol is said to have fair latency if the waiting time of packets is
O(\textburstiness){\mathcal{O}(\text{burstiness})}. For two stations, we show that fair latency can be achieved by a full sensing protocol, while there is no stable acknowledgment
based protocol. For three stations, we show that fair latency can be achieved by a general protocol, while no full sensing
protocol can be stable. Finally, we show that protocols that either are fair or do not have the queue sizes affect the order
of transmissions cannot be stable in systems of at least four stations against window adversaries. 相似文献