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Search Results: 1 - 10 of 461953 matches for " A. Rahimian "
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Analytical Evaluation of Space-Time M-QAM Signaling and Time-Delay Estimation in Multipath Terrestrial Communications  [PDF]
Ardavan Rahimian
Journal of Computer and Communications (JCC) , 2013, DOI: 10.4236/jcc.2013.14003
Abstract:

This paper presents novel information-theoretic PHY layer performance improvement for combating the system fading effects in wireless terrestrial communication applications. Robust space-time system strategies in cooperation with the high performance unpunctured serially concatenated codes have been jointly employed. The wireless terrestrial system also uses M-ary quadrature amplitude modulation (QAM) signaling to develop a well-established system modeling for multiple-input single-output (MISO) and multiple-input multiple-output (MIMO) analysis. This research also undertakes the analytical evaluation of time delay estimation in the presence of additive white Gaussian noise (AWGN) in multipath areas. The objective of this investigation is to develop mathematically-oriented estimations intended for a suitable employment in terrestrial communications. This model considers the problem of overlapping the terrestrial signals arrival-times estimation from a noisy received waveform in order to develop a system model for terrestrial TDE.

The Effects of Erythropoietin in the Management of Anemia of Chronic Renal Failure in Patients on Hemodialysis
M Rahimian,A Hasan Zadeh,R Sami
Journal of Shahid Sadoughi University of Medical Sciences , 2005,
Abstract: Introdaction: The purpose of this study was to evaluate the therapeutic and side effects of erythropoietin in the management of anemia in chronic renal failure. In this study, 60 patients were given Erythropoietin subcutaneously three times/week for 2 months. Methods: Mean hemoglobin of patients was recorded before beginning Erythropoietin and also one weeks, one month and two months after treatment. Results: Mean hemoglobin value before treatment was 7.6 g/dl that increased to 9.08g/dl 2 months later. Hemoglobin levels were not dependent on the age and sex of the patient, but there was a meaningful difference between diabetics and nondiabetics. Conclusion: The side effects of Erythropoietin in this study in order of frequency were as follows: Hypertension, A.V fistula thrombosis, allergy and seizure.
Evaluation of Feezing Tolerance of Chickpea (Cicer arietinum L.) Genotypes under Controlled Conditions
A. Nezami,A. Bagheri,H. Rahimian,M. Kafi
Journal of Science and Technology of Agriculture and Natural Resources , 2007,
Abstract: The present experiment was aimed to evaluate the freezing tolerance of two cold tolerant (MCC426 and MCC252) and a cold susceptible (MCC505) chickpea genotypes. The study was carried out in a split-plot factorial design with three replications. Factorial arrangement of genotype and acclimation (acclimation and non acclimation) were imposed as main plot and temperatures (0, -4, -8, -12, 16, -20oC) as subplot. The effect of freezing temperature (FT) on plant survival was significantly different among genotypes (p
Effect of Rathayibacter tritici on Movement of Anguina tritici Larvae and Nematode Function as Vector of Ear Rot Bacterium
N. Sahebani,A. Kheiri,H. Rahimian,A. Sharifi Tehrani
Journal of Science and Technology of Agriculture and Natural Resources , 2007,
Abstract: The effect of Rathayibacter tritici on the movement of Anguina tritici larva and nematode function as vector of ear rot bacterium was conducted in the laboratory (Agarose plates) and greenhouse conditions. The results showed that the contact of nematode larva with high concentration of bacterium or long duration of nematode-bacteria contact can decrease the movement and the efficiency of nematode function as the vector of the disease, and in some cases it resulted in the mortality of the nematode. No differences were detected in the mobility of larva in the concentrations less than 102 CFU and less than 0.5 hour of nematode-bacteria contact times and their controls (exposed to water alone). Movement of the nematodes appeared to be random under these conditions. It can be concluded that Rathayibacter tritici did not act as an attractant to Anguina tritici larva. These results suggest that the attachment of a large number of bacteria to nematode (as an essential vector of the bacterium) would induce nematode weakness and mortality. So it is possible that ear rot bacterium can parasite ear cockle nematode, or the nematode is a host for this bacterium .
Minimal Actuator Placement with Bounds on Control Effort
V. Tzoumas,M. A. Rahimian,G. J. Pappas,A. Jadbabaie
Mathematics , 2014,
Abstract: We address the problem of minimal actuator placement in a linear system subject to an average control energy bound. First, following the recent work of Olshevsky, we prove that this is NP-hard. Then, we provide an efficient algorithm which, for a given range of problem parameters, approximates up to a multiplicative factor of O(logn), n being the network size, any optimal actuator set that meets the same energy criteria; this is the best approximation factor one can achieve in polynomial time, in the worst case. Moreover, the algorithm uses a perturbed version of the involved control energy metric, which we prove to be supermodular. Next, we focus on the related problem of cardinality-constrained actuator placement for minimum control effort, where the optimal actuator set is selected so that an average input energy metric is minimized. While this is also an NP-hard problem, we use our proposed algorithm to efficiently approximate its solutions as well. Finally, we run our algorithms over large random networks to illustrate their efficiency.
Seroprevalence of Neospora Spp. in Horses in North East of Iran
MH Hosseini,M Moraveji,Y Tahamtan,A Rahimian
Iranian Journal of Parasitology , 2011,
Abstract: Background: Neospora caninum, an obligate intracellular protozoan parasite, is recognized as a major cause of abortion in cattle, while limited information is presently available on the seropreva-lence of Neospora antibodies in horses' worldwide .The aim of the present study was to de-termine serologic prevalence of Neospora infection in horses in Iran.Methods: Sera from 150 horses from Mashhad suburb in Razavi Khorasan Province, northeast Iran were examined for antibodies to Neospora spp. using Neospora modified direct agglutina-tion test (N-MAT).Results: Antibodies to this parasite were detected in 45 (30%) of the examined serum samples. Thirty four percent of the samples had titer of 1:40 while then reduced to 30% when 1:80 serum dilution was applied as significant cut off titer.Conclusion: This study is the first investigation carried out on the Neospora in horses in Iran and indi-cates that horses in Iran are exposed to this parasite.
Assessment of Genetic Diversity of Navel Sweet Orange Cultivars Grown in Mazandaran Province Using RAPD Markers
A. Dehesdtani,S.K. Kazemitabar,H. Rahimian
Asian Journal of Plant Sciences , 2007,
Abstract: The genetic heterogeneity of navel sweet orange (Citrus sinensis, Navel ) trees grown in Mazandaran province was evaluated with RAPD markers. Fifty two navel orange leaf samples from trees bearing each of the three morphologically distinct fruit types, soft rind, rough rind (old line), semi-rough rind (nucellar), were employed. Four of the 21 random primers used produced reproducible polymorphic bands. Of 864 fragments 150 to 2100 bp in size, amplified by the four primers, 70.13% were polymorphic. A similarity matrix using Nei coefficient, was generated and the genotypes were clustered with the UPGMA method by POPGEN32. The nucellar lines appeared to be closely similar to the standard Washington navel line. The highest levels of heterogeneity were observed within the soft rind and the rough rind lines. The observed heterogeneity may have resulted from the occasional budsports occurred and the selection methods variously employed by the nurserymen. The nucellar lines, which are gaining popularity only recently, have not been propagated extensively and thus remained comparatively homogeneous. It appears from the results of the present study, that the cultivar locally known as Thomson navel is misnamed and would probably be regarded as Washington navel.
Study of Fire Blight Severity in Some Pear Cultivars with USDA Standard System
A. Davoodee,E. Majidi,H. Rahimian,M. Valizadeh
Journal of Science and Technology of Agriculture and Natural Resources , 2005,
Abstract: The fire blight with the bacterial causal agent, Erwinia amylovora (Burrill) winslow etal. is one of the most important diseases of the pome fruits that causes the economical losses to quince, pear and apple productions, respectively, in some parts of country. To determine the infection severity of the 43 raturally infected pear cultivars in collection of karaj horticulture research division and also for studing the reaction of these cultivars against disease, the evaluation was performed by the USDA standard system for these cultivars in collection. In this study, although the most of cultivars had been infected on the natural conditions, but disease severity was significantly different between them. By the USDA system, pear cultivars were divided in the 2 classes. Percentage of pear cultivars in very susceptible and moderately susceptible classes were 81.4 and 18.6 respectively. Also for dividing the pear cultivars, beside of USDA method, SPSS software and the cluster analysis were also by the UPGMA method and cultivars were divided into 3 clusters, but it seems that the classification of cluster analysis did not conform with USDA system. Correlation of I.V.S in the artificial tests and the disease severity by natural infection was very significant (r= -0.83).
Detection of Spiroplasma citri , the Causal Agent of Citrus Stubborn Disease in the Field Collected Leafhoppers in Southern Kerman Province
Z. Lori,A. Hosseini-Pour,H. Massumi,H. Rahimian
Journal of Science and Technology of Agriculture and Natural Resources , 2008,
Abstract: Citrus stubborn disease is caused by the helical mollicute Spiroplasma citri. The pathogen is naturally transmitted by sap feeding leafhopper vectors. In the present study attempts were made to detect S. citri in presumptive vectors. Leafhoppers were collected from various wild and cultivated plants in citrus growing areas in Jirfot. Fifteen leafhopper species were identified and 12 species were analyzed for the possibility of carrying S. citri with an antiserum prepared against a citrus strain of S. citri by indirect ELISA. S. citri was detected in leafhopper species by ELISA in Austroagallia sinuata, Psammotettix alienus, Circulifer haematoceps, Orosius albicinctus and Psamotettix striatus. However, S. citri was isolated only from the last three leafhopper species in LD10 medium. These leafhoppers were primarily captured from sesame fields. Therefore, these potential vectors and sesame farms may play a key role in the epidemiology of S. citri in the surveyed area.
Nodular posterior scleritis mimicking choroidal metastasis: a report of two cases
Hage R,Jean-Charles A,Guyomarch J,Rahimian O
Clinical Ophthalmology , 2011,
Abstract: Rabih Hage, Albert Jean-Charles, Jér me Guyomarch, Olivier Rahimian, Angélique Donnio, Harold MerleDepartment of Ophthalmology, University Hospital of Fort-de-France, Martinique, French West IndiesAbstract: Posterior scleritis is a rare underdiagnosed condition that can potentially cause blindness. Its varied presentations lead to delayed or incorrect treatment. We present here the cases of two patients with nodular posterior scleritis mimicking a choroidal metastasis. Two female patients presented with a sudden unilateral visual loss associated with ocular pain. Fundus examination revealed temporomacular choroidal masses with exudative detachments that, due to angiographic presentation, were suggestive of choroidal metastasis. Systemic examinations were unremarkable. In the two cases, a local or general anti-inflammatory treatment led to the complete recovery of the lesions, which were, thus, considered nodular posterior scleritis. The diagnosis of nodular posterior scleritis has to be evoked in all patients presenting with a choroidal mass in fundus examination. It represents the principal curable differential diagnosis of malignant choroidal tumor.Keywords: choroidal tumor, choroidal mass, visual loss, ocular pain, blindness, posterior scleritis
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