Results 1 - 10 of 12177
Results 1 - 10 of 12177. Search took: 0.029 seconds
|Sort by: date | relevance|
[en] Reverse engineering is an important technique means of product imitation and new product development. Its core technology -- surface reconstruction is the current research for scholars. In the various algorithms of surface reconstruction, using axis reconstruction is a kind of important method. For the various reconstruction, using medial axis algorithm was summarized, pointed out the problems existed in various methods, as well as the place needs to be improved. Also discussed the later surface reconstruction and development of axial direction. (paper)
[en] It would be useful to have the best possible estimate of this mean life-time of our new klystrons based on the most recent, available operating experience. A simple formula is given for this best estimate, based on the maximum likelihood method. This method also provides an indication of the reliability of the estimated lifetime. The results given here apply uniquely to a uniform klystron population for which we can assume that deaths occur randomly, and independently of the previous history (operating time) of any one klystron
[en] Anthropomorphic robots are designed a human environment operates: buildings and structures, cabs and etc. The movement of these robots is carried out by walking which provides high throughput to overcome natural and manmade obstacles. The article presents some algorithm results for dynamic walking on the anthropomorphic robot AR601 example. The work is performed according to the Russian Government Program of Competitive Growth of Kazan Federal University. (paper)
[en] A simple, fast and accurate amplitude estimation algorithm of sinusoidal signals for DSP based instrumentation is proposed. It is shown that eight samples, used in two steps, are sufficient. A practical analytical formula for amplitude estimation is obtained. Numerical results are presented. Simulations have been performed when the sampled signal is affected by white Gaussian noise and when the samples are quantized on a given number of bits.
[en] This paper presents an energy-bounding approach for robustly stable bilateral teleoperation over a communication channel with severe variable time delays and packet drops. We extend the energy-bounding algorithm (EBA) for haptic interaction with virtual environments to bilateral teleoperation with remote environments by using an analogy between haptic interaction and teleoperation controls. Robust stability is achieved by both restricting the extra energy that is generated by the sample-and-hold to within the consumable energy in the master device or slave robot and passifying the communication network. Theoretical analyses of transparency are performed for both position and force tracking aspects. Comprehensive test results for various free and contact motions subsequently show that the proposed bilateral EBA can ensure robust stability against fairy large constant/variable round trip time delays (tested for up to 5 sec for free motion and 600 msec for contact motion within the device workspace) as well as for packet losses of up to 90 % during data transmission
[en] This paper presents firstly a dynamic grouping maintenance strategy for multi-component systems with positive economic dependence, which implies that combining maintenance activities is cheaper than performing maintenance on components separately. Preventive maintenance durations and multiple occurrences of maintenance activities within scheduling horizon are considered. Moreover, in a dynamic context, maintenance opportunities, defined as inactivity periods of the systems at which several maintenance activities could be executed with reduced maintenance costs, may randomly occur with time. The second objective of the paper is to propose a new algorithm to optimally update online the grouped maintenance planning by taking into account the maintenance opportunities. A numerical example of a five components system is finally introduced to illustrate the proposed dynamic grouping maintenance strategy
[en] Modern engineered products are becoming increasingly complicated and most consumers prefer compact designs. Layout design plays an important role in many engineered products. The objective of this study is to suggest a method to apply the simulated annealing method to the arbitrarily shaped three-dimensional component layout design problem. The suggested method not only optimizes the packing density but also satisfies constraint conditions among the components. The algorithm and its implementation as suggested in this paper are extendable to other research objectives
[en] A split-spectrum processing technique for an ultrasonic flaw detection system has been developed, which improves the flaw-to-grain echo ratio in large-grained materials. The enhancement is achieved by partitioning a wide-band received spectrum to obtain frequency shifted bands, which are then processed to suppress the grain echoes with respect to the flaw echo, using a novel signal minimization algorithm. A technique for suppression of grain echoes has also been devised which takes advantage of the fact that the grain echo amplitude changes with the frequency of the incident ultrasound whereas the flaw echo amplitude does not. The combination of this technique and the new flaw detection system greatly improve the capabilities of ultrasonic evaluation of large grain materials
[en] Because most networks are intrinsically directed, the directed shortest path problem has been one of the fundamental issues in network optimization. In this paper, a novel algorithm for finding the shortest path in directed networks is proposed. It extends a bio-inspired path finding model of Physarum polycephalum, which is designed only for undirected networks, by adopting analog circuit analysis. Illustrative examples are given to show the effectiveness of the proposed algorithm in finding the directed shortest path. (paper)
[en] Highlights: • Developed a fully automated Levenberg–Marquardt optimization algorithm with novel adaptive merit function switching process. • The method was successfully applied on three test examples, alongside practical modifications to their original designs. • The proposed automated optimization can replace traditional manual tuning methods, greatly accelerating spectrometer development and enhancing operational usability. - Abstract: In the current study, we demonstrate an automated optimization method based on the Levenberg–Marquardt algorithm for electron-optical systems, incorporating an adaptive merit function switching process that enhances minimization convergence. The algorithm is successfully applied to three energy spectrometer designs—a radial mirror analyzer, a parallel radial mirror analyzer, and a parallel magnetic sector analyzer—by first implementing practical modifications to the device geometries. We then optimize the key design parameters to yield good focusing optics. The robustness of the method towards starting configuration is also demonstrated. The procedure can greatly enhance efficiency in the design process of electron-optical systems.