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31.
Hume is a contemporary programming language oriented to systems with strong resource bounds, based on autonomous concurrent
“boxes” interacting across “wires”. Hume’s design reflects the explicit separation of coordination and computation aspects
of multi-process systems, which greatly eases establishing resource bounds for programs. However, coordination and computation
are necessarily tightly coupled in reasoning about Hume programs. Furthermore, in Hume, local changes to coordination or computation,
while preserving input/output correctness, can have profound and unforeseen effects on other aspects of programs such as timing
of events and scheduling of processes. Thus, traditional program calculi prove inappropriate as they tend to focus exclusively
either on the coordination of interacting processes or on computation within individual processes. 相似文献
32.
We introduce Process Overview, a situation awareness characterisation of the knowledge derived from monitoring process plants. Process Overview is based on observational studies of process control work in the literature. The characterisation is applied to develop a query-based measure called the Process Overview Measure. The goal of the measure is to improve coupling between situation and awareness according to process plant properties and operator cognitive work. A companion article presents the empirical evaluation of the Process Overview Measure in a realistic process control setting. The Process Overview Measure demonstrated sensitivity and validity by revealing significant effects of experimental manipulations that corroborated with other empirical results. The measure also demonstrated adequate inter-rater reliability and practicality for measuring SA based on data collected by process experts.
Practitioner Summary: The Process Overview Measure is a query-based measure for assessing operator situation awareness from monitoring process plants in representative settings. 相似文献
33.
In a buyer-supplier game, a special type of assignment game, a distinguished player, called the buyer, wishes to purchase some combinatorial structure. A set of players, called suppliers, offer various components of the structure for sale. Any combinatorial minimization problem can be transformed into a buyer-supplier game. While most previous work has been concerned with characterizing the core of buyer-supplier games, in this paper we study optimization over the set of core vectors. We give a polynomial time algorithm for optimizing over the core of any buyer-supplier game for which the underlying minimization problem is solvable in polynomial time. In addition, we show that it is hard to determine whether a given vector belongs to the core if the base minimization problem is not solvable in polynomial time. Finally, we introduce and study the concept of focus point price, which answers the question: If we are constrained to play in equilibrium, how much can we lose by playing the wrong equilibrium? 相似文献
34.
Laser-induced fluorescence (LIF) measurements have been performed for the first time in a low temperature (Te approximately 0.6 eV) Xe plasma using a tunable diode laser in the visible range of wavelengths. The transition in Xe II involved the (3P1)5d[3]7/2 metastable state and the excitation wavelength was found to be 680.570+/-0.001 nm (air). LIF measurements of I 2 in a room temperature iodine gas cell were used to monitor the wavelength of the laser during the measurements. 相似文献
35.
Unal G Yezzi A Soatto S Slabaugh G 《IEEE transactions on pattern analysis and machine intelligence》2007,29(8):1322-1338
This paper addresses the problem of calibrating camera parameters using variational methods. One problem addressed is the severe lens distortion in low-cost cameras. For many computer vision algorithms aiming at reconstructing reliable representations of 3D scenes, the camera distortion effects will lead to inaccurate 3D reconstructions and geometrical measurements if not accounted for. A second problem is the color calibration problem caused by variations in camera responses that result in different color measurements and affects the algorithms that depend on these measurements. We also address the extrinsic camera calibration that estimates relative poses and orientations of multiple cameras in the system and the intrinsic camera calibration that estimates focal lengths and the skew parameters of the cameras. To address these calibration problems, we present multiview stereo techniques based on variational methods that utilize partial and ordinary differential equations. Our approach can also be considered as a coordinated refinement of camera calibration parameters. To reduce computational complexity of such algorithms, we utilize prior knowledge on the calibration object, making a piecewise smooth surface assumption, and evolve the pose, orientation, and scale parameters of such a 3D model object without requiring a 2D feature extraction from camera views. We derive the evolution equations for the distortion coefficients, the color calibration parameters, the extrinsic and intrinsic parameters of the cameras, and present experimental results. 相似文献
36.
A Logic of Access Control 总被引:2,自引:0,他引:2
37.
38.
Annelise E. Gerbase José R. Gregório Márcia Martinelli Márcia C. Brasil Ana N. F. Mendes 《Journal of the American Oil Chemists' Society》2002,79(2):179-181
We studied the methyltrioxorhenium (MTO)-CH2Cl2/H2O2 biphasic system for epoxidizing soybean oil. The reactions were optimized (reactant ratio, time, and temperature), which
resulted in a better performance (higher conversion and selectivity) than those described in the literature. Total doublebond
conversion and 95% selectivity were obtained in 2 h at room temperature. Furthermore, it was possible to reach desired epoxidation
degrees by changing the oxidant and MTO amounts. The rhenium-epoxidized soybean oil remained stable in the absence of stabilizers
for up to 30 d when stored at mild conditions. 相似文献
39.
40.
GregGianforte 《数码世界》2003,2(10):45-46
当前采用软件服务供应商(ASP)之风再度复苏显然是事出有因:软件获取成本降低——通过取消购买和管理服务器硬件、操作系统、存储设备和其他一些支持设施,ASP托管能够减少50%,甚至更多的软件生命周期所有权成本。 相似文献