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11.
Yahya H. Zweiri 《国际自动化与计算杂志》2008,5(2):185-192
Parameter identification is a key requirement in the field of automated control of unmanned excavators (UEs). Furthermore, the UE operates in unstructured, often hazardous environments, and requires a robust parameter identification scheme for field applications. This paper presents the results of a research study on parameter identification for UE. Three identification methods, the Newton-Raphson method, the generalized Newton method, and the least squares method are used and compared for prediction accuracy, robustness to noise and computational speed. The techniques are used to identify the link parameters (mass, inertia, and length) and friction coefficients of the full-scale UE. Using experimental data from a full-scale field UE, the values of link parameters and the friction coefficient are identified. Some of the identified parameters are compared with measured physical values. Furthermore, the joint torques and positions computed by the proposed model using the identified parameters are validated against measured data. The comparison shows that both the Newton-Raphson method and the generalized Newton method are better in terms of prediction accuracy. The Newton-Raphson method is computationally efficient and has potential for real time application, but the generalized Newton method is slightly more robust to measurement noise. The experimental data were obtained in collaboration with QinetiQ Ltd. 相似文献
12.
SATCHMORE was introduced as a mechanism to integrate relevancy testing with the model-generation theorem prover SATCHMO. This
made it possible to avoid invoking some clauses that appear in no refutation, which was a major drawback of the SATCHMO approach.
SATCHMORE relevancy, however, is driven by the entire set of negative clauses and no distinction is accorded to the query
negation. Under unfavorable circumstances, such as in the presence of large amounts of negative data, this can reduce the
efficiency of SATCHMORE. In this paper we introduce a further refinement of SATCHMO called SATCHMOREBID: SATCHMORE with BIDirectional
relevancy. SATCHMOREBID uses only the negation of the query for relevancy determination at the start. Other negative clauses
are introduced on demand and only if a refutation is not possible using the current set of negative clauses. The search for
the relevant negative clauses is performed in a forward chaining mode as opposed to relevancy propagation in SATCHMORE which
is based on backward chaining. SATCHMOREBID is shown to be refutationally sound and complete. Experiments on a prototype SATCHMOREBID
implementation point to its potential to enhance the efficiency of the query answering process in disjunctive databases.
Donald Loveland, Ph.D.: He is Emeritus Professor of Computer Science at Duke University. He received his Ph.D. in mathematics from New York University
and taught at NYU and CMU prior to joining Duke in 1973. His research in automated deduction includes defining the model elimination
proof procedure and the notion of linear resolution. He is author of one book and editor/co-editor of two other books on automated
theorem proving. He has done research in the areas of algorithms, complexity, expert systems and logic programming. He is
an AAAI Fellow, ACM Fellow and winner of the Herbrand Award in Automated Reasoning.
Adnan H. Yahya, Ph.D.: He is an associate professor at the Department of Electrical Engineering, Birzeit University, Palestine. He received his
Diploma and PhD degrees from St. Petersburg Electrotechnical University and Nothwestern University in 1979 and 1984 respectively.
His research interests are in Artificial Intelligence in general and in the areas of Deductive Databases, Logic Programming
and Nonmonotonic Reasoning in particular. He had several visiting appointments at universities and research labs in the US,
Germany, France and the UK. Adnan Yahya is a member of the ACM, IEEE and IEEE Computer Society. 相似文献
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15.
S. Shamsuddin S. N. Supardan Abdel-Baset M. A. Ibrahim A. K. Yahya 《Journal of Superconductivity and Novel Magnetism》2014,27(5):1229-1234
Sr doping in the charge-ordered compound Nd0.3La0.2Ca0.5?x Sr x MnO3 has been systematically studied to examine its effect on ultrasonic velocity and elastic moduli as well as magnetic and electrical transport properties. DC electrical resistivity, ρ and AC susceptibility, χ′ measurements showed all samples exhibit metal-insulator (MI) behavior accompanied by ferromagnetic-paramagnetic (FM-PM) transition where the MI transition temperature, T MI and FM-PM transition temperature, T C increased with Sr content indicating the enhancement of double-exchange mechanism. Analysis of the resistivity change with respect to temperature, dlnρ/dT ?1 versus T indicates onset of charge-ordering (CO) state where its CO transition temperature, T CO decreased with Sr content indicating weakening of the CO state. On the other hand, both absolute longitudinal and shear velocities as well as elastic moduli measured at 80 K increased significantly with Sr doping indicating improvement in elastic properties, which is suggested to be due to the increase in formation of ferromagnetic domains. A longitudinal velocity anomaly characterized by a slope change around the vicinity of T CO was observed for all samples. The longitudinal elastic anomaly is attributed to the Jahn–Teller (JT) effect of Mn3+ ions where analysis of the anomaly using the mean-field theory suggests involvement of the JT effect in the samples, which transforms from dynamic to static type with decreasing temperature. The elastic anomaly shifted down from 222 K (x=0) to 205 K (x=0.05) indicating that the static JT effect was weakened with Sr content. 相似文献
16.
Zakaria Maamar Noura Faci Mohamed Sellami Khouloud Boukadi Fadwa Yahya Ahmed Barnawi Sherif Sakr 《Service Oriented Computing and Applications》2017,11(2):203-215
This paper presents an approach for monitoring the execution progress of business processes. The monitoring focuses on the exceptions that could arise during this execution and, hence, could make the processes fail if not handled properly and timely. The approach relies on three flows known as control, communication, and navigation. The control flow connects tasks together with respect to a certain business logic. The communication flow captures the messages exchanged between persons/machines when they perform tasks of processes. Finally, the navigation flow captures the interactions between specialized networks that offer solutions to exceptions. These networks are built upon relations between tasks, between persons, and between machines. The coordination of control, communication, and navigation flows focuses on both the actions that are taken and the messages that are exchanged when handling exceptions. A system demonstrating flow development and coordination is, also, presented in the paper. 相似文献
17.
Mohamed Abdin Yahya Saud Hamed Hafiz Muhammad Saleem Akhtar Dan Chen Shanza Mukhtar Peng Wan Asad Riaz Xiaoxiong Zeng 《International Journal of Food Science & Technology》2019,54(6):2084-2093
The objectives of this study were to determine the optimal extraction conditions of polyphenols from Syzygium cumini seeds by response surface methodology and investigate their antioxidant activity and inhibition on α-amylase and pancreatic lipase. As results, the optimal extraction conditions in the ultrasonic extraction process which maximised total polyphenols content, minimised the IC50 values of α-amylase and pancreatic lipase were determined as follows: extraction time 60 min, ethanol concentration 63% and solvent/solid ratio 44 mL g−1. The main phenolic compounds in partially purified fraction of Syzygium cumini seeds were catechin, epicatechin, kaempferol, gallic, 5-caffeoylquinic, caffeic and ferulic acids. In addition, the partially purified fraction inhibited 87.66 ± 5.55 and 86.61 ± 3.15% of α-amylase and pancreatic lipase, respectively. The results suggested that Syzygium cumini seeds could be explored as a natural antioxidant and could be used as a source of highly antidiabetic and anti-obesity bioactive compounds. 相似文献
18.
Nourédine Yahya Bey 《Signal, Image and Video Processing》2018,12(7):1279-1283
A highly accurate frequency estimation providing suppression of windowing effects, denoising performances and frequency resolutions in excess of Gabor–Heisenberg limit, is proposed for brief duration signals. It is shown that unbiased frequency estimation with vanishing frequency variances is achieved far below Cramer–Rao lower bound when signal-to-noise ratio reaches vicinity of threshold values. Observed performances provide novel and valuable perspectives for efficient and accurate frequency estimation for brief duration signals in noise. 相似文献
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20.
The effect of nano-sized PbO (10–30 nm) addition on the transport critical current density, Jc of (Bi1.6Pb0.4)Sr2Ca2Cu3O10 (PbO)x (x=0–0.15 wt%) was investigated. Jc of PbO added pellet samples showed the maximal value at x=0.05 wt%. Using this result, Ag-sheathed (Bi1.6Pb0.4)Sr2Ca2Cu3O10 (PbO)x/Ag tapes (x=0 and 0.05 wt %) were fabricated by the powder-in-tube (PIT) method. The tapes were sintered for 50 h and 100 h at 845 °C. The temperature dependence of Jc for the non-added and PbO added tapes in applied field was investigated. Jc of the non-added tapes was 4510 A/cm2 at 40 K and 949 A/cm2 at 77 K. Jc of (Bi1.6Pb0.4)Sr2Ca2Cu3O10 (PbO)0.05/Ag tape sintered for 100 h was 26,800 A/cm2 at 40 K and 10,700 A/cm2 at 40 K, which was higher than the tapes sintered for 50 h (8590 A/cm2 at 40 K and 1880 A/cm2 at 77 K). Nano-sized PbO added tapes sintered for 100 h showed a higher Jc (more than 10 times) under magnetic field (0–0.75 T) compared with the non-added tape. A combined effect of enhanced flux pinning and improved microstructure led to the significant increase in Jc of the nano-sized PbO added tapes. 相似文献