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71.
Mehmet Önder Efe 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2009,13(1):23-29
This paper presents an approach to improve the performance of intelligent sliding model control achieved by the use of a fundamental
constituent of soft computing, named Adaptive Linear Element (ADALINE). The proposed scheme is based on the fractional calculus.
A previously considered tuning scheme is revised according to the rules of fractional order differintegration. After a comparison
with the integer order counterpart, it is seen that the control system with the proposed adaptation scheme provides (1) better
tracking performance, (2) suppression of undesired drifts in parameter evolution and (3) a very high degree of robustness
and insensitivity to disturbances. The claims are justified through some simulations utilizing the dynamic model of a two
degrees of freedom (DOF) direct drive robot arm and overall, the contribution of the paper is to introduce the fractional
order calculus into a robust and nonlinear control problem with some outperforming features that are absent when the integer
order differintegration operators are adopted. 相似文献
72.
Summary The polymerization of methyl methacrylate (MMA), ethyl acrylate (EA), styrene (St) and 2-vinyl pyridine (VP) is initiated upon irradiation at >350 nm of dichloromethane solutions containing N-ethoxy-2-methylpyridinium hexafluorophosphate (EMP+PF6
-) and anthracene or thioxanthone. Initiation mechanisms involving the formation of ethoxyl radicals during the decomposition of EMP+ ions via electron transfer are proposed. 相似文献
73.
K Oette G Kühn A R?mer R Niemann KJ Gundermann R Schumacher 《Canadian Metallurgical Quarterly》1995,45(8):875-879
Essentiale and Lipostabil contain "essential" phospholipids from the soybean, mainly 1,2-dilinoleoyl-phosphatidylcholine (CAS 998-06-1, DLPC) which is considered as the main active ingredient. A single oral dose of d15-DLPC loaded with deuterium 9 times in the choline and 6 times in the linoleic acid of the 1-position was given to volunteers. Sera from 11 blood samples taken within 48 h after application were examined by means of mass spectrometry with regard to d9-choline and d6-linoleic acid in the 1- and 2-position of serum phosphatidylcholines (PC) as well as in the serum triglycerides. d9-choline, i.e. the total of d15-PC and d9-PC, showed maximum values of 5.6% of the total serum PC concentration. Normally, about 1.3% of PC in the human serum is DLPC. Serum 1-linoleoyl-PC was increased by 32-40% after oral application of d15-DLPC. A minor uptake of d6-linoleic acid into the 2-position of serum PC, which is rich in linoleic acid, and into the serum triglycerides was observed with peak values of 2.3% and 6.1%, resp. The uptake of polyunsaturated PC species like DLPC and 1-linoleoyl-PC into the liver after oral application of drugs containing such species in high amounts like "essential" phospholipids with about 50% of DLPC let expect therapeutic effects on membranes into which this special species is incorporated. 相似文献
74.
Emrah Öncü Rasit Tutgun Emre Aktas 《International Journal of Satellite Communications and Networking》2023,41(6):589-598
Conventional solid-state power amplifier (SSPA) design approach isolates radio frequency (RF) design from communication theory. In this paper, a unified SSPA design approach is proposed, which optimizes SSPA parameters (bias voltage and input RF signal power) to minimize total DC power consumption while satisfying received SNR constraint specified by the link budget. The effect of SSPA nonlinearity is quantified by the error vector magnitude measured at its output and the corresponding received SNR degradation is analyzed. Using the quantitative metrics for received SNR, it is possible to evaluate highly nonlinear SSPA classes such as Class-B or deep-Class AB, which are normally not considered in conventional SSPA design approach to be used in satellite communication applications. 相似文献
75.
This article aims to explore the impact of the integration of risk factors into delayed milestones for construction projects. A simulation model was developed to determine the impact of schedule variability on cost estimation. To generate random scenarios a Monte Carlo Simulation (MCS) technique was applied. The developed model computes the cost impact of delayed milestone in the expected budget. Using a risk integration approach revealed the critical time frame that may lead to a budget deficit for a project. As a result, a number of cost-sensitive risk factors and schedule delays were identified for the critical time period where the risk of budget deficit increases. The method of integration proposed in this article highlights the priority of risk factors and schedule delays for construction contracts involving Payments at Event Occurrences (PEO). Consequently, the developed method can be useful for practitioners in anticipation of potential increase of costs, hence, prevention of failure due to budget deficit. 相似文献
76.
A Review of Metal Fabricated with Laser‐ and Powder‐Bed Based Additive Manufacturing Techniques: Process,Nomenclature, Materials,Achievable Properties,and its Utilization in the Medical Sector
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77.
Ümit Işıkdağ Aycan Hepsağ Süreyya İmre Bıyıklı Derya Öz Gebrail Bekdaş Zong Woo Geem 《计算机、材料和连续体(英文)》2023,74(1):113-129
Construction Industry operates relying on various key economic indicators. One of these indicators is material prices. On the other hand, cost is a key concern in all operations of the construction industry. In the uncertain conditions, reliable cost forecasts become an important source of information. Material cost is one of the key components of the overall cost of construction. In addition, cost overrun is a common problem in the construction industry, where nine out of ten construction projects face cost overrun. In order to carry out a successful cost management strategy and prevent cost overruns, it is very important to find reliable methods for the estimation of construction material prices. Material prices have a time dependent nature. In order to increase the foreseeability of the costs of construction materials, this study focuses on estimation of construction material indices through time series analysis. Two different types of analysis are implemented for estimation of the future values of construction material indices. The first method implemented was Autoregressive Integrated Moving Average (ARIMA), which is known to be successful in estimation of time series having a linear nature. The second method implemented was Non-Linear Autoregressive Neural Network (NARNET) which is known to be successful in modeling and estimating of series with non-linear components. The results have shown that depending on the nature of the series, both these methods can successfully and accurately estimate the future values of the indices. In addition, we found out that Optimal NARNET architectures which provide better accuracy in estimation of the series can be identified/discovered as result of grid search on NARNET hyperparameters. 相似文献
78.
H. Böcük B. A. Albiss İ Ercan H. Özkan N. Gasanly 《Journal of Low Temperature Physics》1996,105(3-4):975-980
Voltage-current characteristics of YBCO superconductor was studied under magnetic field up to 0.4 T at different temperatures below Tc. The critical temperature decreases and the transition width broadens under magnetic field. V-I data below Tc were fitted to a power law expression V I(T,B) in which (T,B) is found to decrease with increase of magnetic field and temperature, gradually approaching unity as T approaches Tc, being independent of magnetic field. Similarly, (T,B) approaches unity as magnetic field increases being independent of temperature. 相似文献
79.
Local feature-based approaches mainly aim to achieve robustness to variations in facial images by assuming that only some
parts of the facial images may be affected. However, such approaches may lose spatial information. In this study, a compromise
feature extraction scheme is studied which extracts local features while preserving spatial information. The proposed scheme
exploits an ensemble of classifiers where each member is constructed using randomly selected design parameters including the
size, number and location of sub-images for local feature extraction. Experiments conducted on FERET and ORL databases have
shown that proposed scheme surpasses the local feature-based reference systems which focus on either local information or
preserving spatial information. 相似文献
80.
Yakup Kara Melek Acar Boyacioglu Ömer Kaan Baykan 《Expert systems with applications》2011,38(5):5311-5319
Prediction of stock price index movement is regarded as a challenging task of financial time series prediction. An accurate prediction of stock price movement may yield profits for investors. Due to the complexity of stock market data, development of efficient models for predicting is very difficult. This study attempted to develop two efficient models and compared their performances in predicting the direction of movement in the daily Istanbul Stock Exchange (ISE) National 100 Index. The models are based on two classification techniques, artificial neural networks (ANN) and support vector machines (SVM). Ten technical indicators were selected as inputs of the proposed models. Two comprehensive parameter setting experiments for both models were performed to improve their prediction performances. Experimental results showed that average performance of ANN model (75.74%) was found significantly better than that of SVM model (71.52%). 相似文献