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91.
Bogdan M. Leu Hasan Yavaş Innokenty Kantor Vitali B. Prakapenka 《Journal of the American Oil Chemists' Society》2010,87(12):1517-1520
We measured the velocity of sound in olive oil under pressure with the Brillouin light scattering technique. Using the values
for the density and the thermal conductivity that have only recently been reported, we calculated the adiabatic compressibility
and the isobaric specific heat up to 356 MPa and the thermal diffusivity up to 200 MPa. The specific heat displays a maximum
at 124 MPa, suggesting a possible phase transition around this pressure. Apart from the theoretical and practical importance
of these results for the food industry and beyond, this work shows that Brillouin light scattering and macroscopic methods
are complementary and can be employed to measure thermophysical parameters of food liquids under pressure. 相似文献
92.
Maria Waqas Muhammad Khurram S. M. Rezaul Hasan 《Analog Integrated Circuits and Signal Processing》2017,91(2):329-342
Reducing transmit power is the most straightforward way towards more energy-efficient communications, but it results in lower SNRs at the receiver which can add a performance and/or complexity cost. At low SNRs, synchronization and channel estimation errors erode much of the gains achieved through powerful turbo and LDPC codes. Further expanding the turbo concept through an iterative receiver—which brings synchronization and equalization modules inside the loop—can help, but this solution is prohibitively complex and it is not clear what can and what cannot be a part of the iterative structure. This paper fills two important gaps in this field: (1) as compared to previous research which either focuses on a subset of the problem assuming perfect remaining parameters or is computationally too complex, we propose a proper partitioning of algorithm blocks in the iterative receiver for manageable delay and complexity, and (2) to the best of our knowledge, this is the first physical demonstration of an iterative receiver based on experimental radio hardware. We have found that for such a receiver to work, (1) iterative timing synchronization is impractical, iterative carrier synchronization can be avoided by using our proposed approach, while iterative channel estimation is essential, and (2) the SNR gains claimed in previous publications are validated in indoor channels. Finally, we propose a heuristic algorithm for simplifying the carrier phase synchronization in an iterative receiver such that computations of the log likelihood ratios of the parity bits can be avoided to strike a tradeoff between complexity and performance. 相似文献
93.
A new minimum mean square error (MMSE) estimator for discrete cosine transform (DCT) domain speech enhancement considering the two state possibilities of signal and noise DCT coefficients, the constructive and destructive interference, is proposed. Given proper identification of these events are possible, an optimum non-linear MMSE estimator can be derived considering the conditional events. Compared to the previously reported dual-gain multiplicative filters, the proposed estimator demonstrates superior theoretical and experimental performance with respect to mean square error (MSE) improvement and other objective quality measures. 相似文献
94.
Wi-Fi Direct has become vastly popular in the last few years. Due to its fast network setup and the provision of high transmission rates, it is expected to be the piggyback technology for high speed device-to-device communications in smart cities. The increasing demand on Wi-Fi Direct networks and its co-location in the same band with other Wi-Fi ad-hoc and infrastructure networks have entailed the need for developing new adaptive techniques to utilize the wireless spectrum efficiently. In this paper, we introduce, analyze and implement a self-organizing algorithm designed specifically for pop-up Wi-Fi Direct networks. The algorithm dynamically changes the operating channels of pop-up Wi-Fi Direct networks according to their performance in a non-cooperative manner. It utilizes the spectrum efficiently, reduces congestion and enhances performance. Moreover, the modified Wi-Fi Direct network running the proposed algorithm is interoperable with all other Wi-Fi network modes and setups and does not affect their functionalities. On the contrary, it enhances their performance implicitly. We implement the algorithm using the driver of RTL8188CUS chipset in a Linux environment and conduct experiments to evaluate its performance. The obtained results illustrate the benefits of using the proposed algorithm. 相似文献
95.
Bemgba B.Nyakuma Aliyu Jauro Segun A.Akinyemi Hasan M.Faizal Mohammed B.Nasirudeen Muhammad Ariff H.M.Fuad Olagoke Oladokun 《国际煤炭科学技术学报(英文)》2021,8(4):697-716
In this study,the physicochemical,microstructural,mineralogical,thermal,and kinetic properties of three newly discovered coals from Akunza (AKZ),Ome (OME),and S... 相似文献
96.
Mahdi N. Mahyari Hasan Karimi Hasan Naseh Mehran Mirshams 《Journal of Mechanical Science and Technology》2010,24(10):1997-2006
The focus of the present study is to investigate the effectiveness of installing vortex breakers at the outlet of launch vehicle
tanks on postponing vortex formation and decreasing the critical height of propellants while discharging. Analytical results
in the absence of a vortex breaker show that the effects of the Weber and Reynolds numbers in the flow field can be ignored
for values greater than 720 and 1.1 × 105, respectively; and critical height can be considered as a function of Froude number under aforementioned conditions. The
analytical criteria are verified by two-dimensional, axis symmetrical, transient and two-phase numerical model. Eventually,
some experiments are conducted to examine the effectiveness of the applied vortex breakers in reduction of the critical height
of propellant. Experimental results show that a 30% decrease can be achieved in critical height by using a particular type
of vortex breaker. Additionally, the carried out simulations for an existing two-stage launch vehicle indicate a 13% increase
in orbital altitude, which in turn proves the considerable improvement in launch vehicle mass/energetic capabilities. 相似文献
97.
Canjie Wu Li Han Hasan Riaz Shujuan Wang Kailai Cai Liguo Yang 《Food chemistry》2013,136(3-4):1122-1129
β-Cryptoxanthin, a provitaminic carotenoid, present in many fruits and vegetables, has been associated with decreased risk of chronic diseases, including cancer. The influence of β-cryptoxanthin derived from mandarin on the proliferation of the stomach tumor cell line BGC-823 was tested using MTT and cell count assay at 72 h and dose–response (from 0.01 to 20 μM). β-Cryptoxanthin suppressed the cell migration by the scratch assay. Furthermore, β-cryptoxanthin induced an accumulation of cells in the G1/G0 phase of the cell cycle (as detected by flow cytometry), which was in accordance with an increased expression of p21 and down regulations of cyclin D1 and cyclin E, detected by Western blot analysis, and β-cryptoxanthin increased the mRNA levels of retinoic acid receptor β (RARβ) with the treatment at 10 μM for 24 h. Collectively, the above findings suggest that β-cryptoxanthin could be therapeutic in the treatment of stomach cancer cell in vitro. 相似文献
98.
SPARCL: an effective and efficient algorithm for mining arbitrary shape-based clusters 总被引:3,自引:3,他引:0
Vineet Chaoji Mohammad Al Hasan Saeed Salem Mohammed J. Zaki 《Knowledge and Information Systems》2009,21(2):201-229
Clustering is one of the fundamental data mining tasks. Many different clustering paradigms have been developed over the years,
which include partitional, hierarchical, mixture model based, density-based, spectral, subspace, and so on. The focus of this
paper is on full-dimensional, arbitrary shaped clusters. Existing methods for this problem suffer either in terms of the memory
or time complexity (quadratic or even cubic). This shortcoming has restricted these algorithms to datasets of moderate sizes.
In this paper we propose SPARCL, a simple and scalable algorithm for finding clusters with arbitrary shapes and sizes, and
it has linear space and time complexity. SPARCL consists of two stages—the first stage runs a carefully initialized version
of the Kmeans algorithm to generate many small seed clusters. The second stage iteratively merges the generated clusters to
obtain the final shape-based clusters. Experiments were conducted on a variety of datasets to highlight the effectiveness,
efficiency, and scalability of our approach. On the large datasets SPARCL is an order of magnitude faster than the best existing
approaches. 相似文献
99.
Ahmad Feyz Dizaji Hossein Ali Sepiani Farzad Ebrahimi Akbar Allahverdizadeh Hasan Ali Sepiani 《Journal of Mechanical Science and Technology》2009,23(8):2299-2307
An initial-boundary value problem that is Duffing’s oscillator with time varying coefficients will be studied. Using Banach’s
fixed-point theorem, the existence of periodic solution of the equation will be predicted. The method applied in this paper
is the Schauder second fixed point theorem, which includes the response of structures under vibratory force systems. As an
example, the dynamics of nonlinear simply supported rectangular thin plate under influence of a relatively moving mass is
studied. By expansion of the solution as a series of mode functions, the governing equations of motion are reduced to an ordinary
differential equation for time development vibration amplitude, which is Duffing’s oscillator. Finally, a parametric study
is developed, after that some numerical examples are solved, and the validity of the present analysis is clearly shown.
This paper was recommended for publication in revised form by Associate Editor Maenghyo Cho
Hossein Ali Sepiani received his B.S. degree in Mechanical Engineering from University of Kashan, Iran, in 2003. He then received his M.S. degree
from University of Tehran, in 2006. Currently, Hossein is continuing his research at University of Tehran. His research interests
include new materials (FGMs, Nano-materials, SMAs, SMPs, etc), Composites (Woven Fabrics and Fiber Metal Laminates), Smart
Materials (Shape Memory Alloy, Magnet/Electro-rheological and Piezoelectric Sensors and Actuators), Intelligent structures
(Structures integrated with smart materials), Vibration and control of Intelligent Structures and their application.
Ahmad Feyz Dizaji got his B.S. degree from University of Tehran, Iran, in 1970. Then he continued his study in U.S. and received his PhD. degree
from Michigan State University in 1983, in Applied Mathematics under the supervision of Professor Shui-ni Chow and Professor
J. Mallet-Paret. Since then he has been a member of the Faculty of Engineering in University of Tehran, teaching mathematics
in both undergraduate and graduate levels. 相似文献
100.
Hasan Yalcin Ismet ?zt��rk Eray Tuluk?u Osman Sa?dic 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2011,6(2):197-202
Sar? 85 (Linum usitatissimum L.) linseed variety was used in this study. Linseed was cultivated at 2008 (LS-08) and 2009 (LS-09) without fertilizer. In addition, at 2009 diammonium phosphate [(NH4)2HPO4] and ammonium nitrate (NH4NO3) were applied (LSF-09). The linseeds were analyzed for protein, ash and oil contents and fatty acid compositions. There were differences among harvesting years for oil, protein and ash contents of the seeds. The greater oil and protein contents were obtained during LS-08 compared with LS-09. There were no significant difference in protein and ash content between LS-09 and LSF-09 while a significant difference was observed in oil content. Seed protein, oil and ash contents were significantly affected by the harvesting year, but only oil content was affected by the fertilizer treatment. There are significant differences in palmitic, stearic, oleic, ??-linolenic and arachidic acid between LS-08 and LS-09. While palmitic, stearic, oleic acid decreased, ??-linolenic and arachidic acid increased during 2009 harvesting year. LSF-09 has the highest amount of ??-linolenic acid. The fertilizing treatment seems to have an increasing effect on the amount of ??-linolenic acid, while it has a decreasing effect on the oleic acid content. 相似文献