http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Mahdi Motamedi (검색결과 3 건)
- 무료
- 기관 내 무료
- 유료
-
PSNR Enhancement in Image Streaming over Cognitive Radio Sensor Networks
Mahdi Bahaghighat,Seyed Ahmad Motamedi 한국전자통신연구원 2017 ETRI Journal Vol.39 No.5
Several studies have focused on multimedia transmission over wireless sensor networks (WSNs). In this paper, we propose a comprehensive and robust model to transmit images over cognitive radio WSNs (CRWSNs). We estimate the spectrum sensing frequency and evaluate its impact on the peak signal-to-noise ratio (PSNR). To enhance the PSNR, we attempt to maximize the number of pixels delivered to the receiver. To increase the probability of successful image transmission within the maximum allowed time, we minimize the average number of packets remaining in the send buffer. We use both single- and multi-channel transmissions by focusing on critical transmission events, namely hand-off (HO), No-HO, and timeout events. We deploy our advanced updating method, the dynamic parameter updating procedure, to guarantee the dynamic adaptation of model parameters to the events. In addition, we introduce our ranking method, named minimum remaining packet best channel selection, to enable us to rank and select the best channel to improve the system performance. Finally, we show the capability of our proposed image scrambling and filtering approach to achieve noticeable PSNR improvement.
-
A Study on UCS of Stabilized Peat with Natural Filler: A Computational Estimation Approach
Ali Dehghanbanadaki,Mahdy Khari,Ali Arefnia,Kamarudin Ahmad,Shervin Motamedi 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.4
This study applied two feed-forward type computational methods to estimate the Unconfined Compression Strength (UCS) of stabilized peat soil with natural filler and cement. For this purpose, experimental data was obtained via testing of 271 samples at different natural filler and cement mixture dosages. The input parameters for the developed UCS (output) model were: 1) binder dosage, 2) coefficient of compressibility, 3) filler dosage, and 4) curing time. The model estimated the UCS through two types of feed-forward Artificial Neural Network (ANN) models that were trained with Particle Swarm Optimization (ANN-PSO) and Back Propagation (ANN-BP) learning algorithms. As a means to validate the precision of the model two performance indices i.e., coefficient of correlation (R2) and Mean Square Error (MSE) were examined. Sensitivity analyses was also performed to investigate the influence of each input parameters and their contribution on estimating the output. Overall, the results showed that MSE(PSO) < MSE(BP) while R2 (PSO) > R2 (BP); suggesting that the ANN-PSO model better estimates the UCS compared to ANN-BP. In addition, on the account of sensitivity analysis, it is found that the binder and filler content were the two most influential factors whilst curing period was the least effective factor in predicting UCS.
-
Mohammad Maleki,Mahdi Motamedi,Mahsa Sedighi,Seyed Morteza Zamir,Farzaneh Vahabzadeh 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.1
In the present study, phenol-adapted cells ofRalstonia eutropha were used to degrade p-nitrophenol(PNP) in the presence of phenol. PNP at initial concentrationsranging from 5 to 15 mg/L was degraded almost completelyby free cells of R. eutropha. The use of loofa-immobilizedcells increased the complete removal of PNP up to 30 mg/L. Kinetic data for PNP biodegradation by immobilized cellsof R. eutropha best fitted the Haldane model. The kineticparameters were ks = 0.0006 (mg PNP/mg biomass.h), Ks =8.83 (mg/L) and Ki = 30.77 (mg/L). The degradation pathwaysof PNP through the metabolites, 4-nitro-catechol (4-NC)and hydroquinone (HQ), were investigated using HPLC.
ScienceON연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
