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Search Results: 1 - 10 of 2103 matches for " Mohsen Shiva "
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Decision-Directed Recursive Least Squares MIMO Channels Tracking
Mohsen Shiva
EURASIP Journal on Wireless Communications and Networking , 2006,
Abstract: A new approach for joint data estimation and channel tracking for multiple-input multiple-output (MIMO) channels is proposed based on the decision-directed recursive least squares (DD-RLS) algorithm. RLS algorithm is commonly used for equalization and its application in channel estimation is a novel idea. In this paper, after defining the weighted least squares cost function it is minimized and eventually the RLS MIMO channel estimation algorithm is derived. The proposed algorithm combined with the decision-directed algorithm (DDA) is then extended for the blind mode operation. From the computational complexity point of view being O3 versus the number of transmitter and receiver antennas, the proposed algorithm is very efficient. Through various simulations, the mean square error (MSE) of the tracking of the proposed algorithm for different joint detection algorithms is compared with Kalman filtering approach which is one of the most well-known channel tracking algorithms. It is shown that the performance of the proposed algorithm is very close to Kalman estimator and that in the blind mode operation it presents a better performance with much lower complexity irrespective of the need to know the channel model.
Decision-Directed Recursive Least Squares MIMO Channels Tracking
Karami Ebrahim,Shiva Mohsen
EURASIP Journal on Wireless Communications and Networking , 2006,
Abstract: A new approach for joint data estimation and channel tracking for multiple-input multiple-output (MIMO) channels is proposed based on the decision-directed recursive least squares (DD-RLS) algorithm. RLS algorithm is commonly used for equalization and its application in channel estimation is a novel idea. In this paper, after defining the weighted least squares cost function it is minimized and eventually the RLS MIMO channel estimation algorithm is derived. The proposed algorithm combined with the decision-directed algorithm (DDA) is then extended for the blind mode operation. From the computational complexity point of view being versus the number of transmitter and receiver antennas, the proposed algorithm is very efficient. Through various simulations, the mean square error (MSE) of the tracking of the proposed algorithm for different joint detection algorithms is compared with Kalman filtering approach which is one of the most well-known channel tracking algorithms. It is shown that the performance of the proposed algorithm is very close to Kalman estimator and that in the blind mode operation it presents a better performance with much lower complexity irrespective of the need to know the channel model.
Preparation, characterization and evaluation of moisturizing and UV protecting effects of topical solid lipid nanoparticles
Shiva Golmohammadzadeh,Mohsen Mokhtari,Mahmoud Reza Jaafari
Brazilian Journal of Pharmaceutical Sciences , 2012,
Abstract: Solid lipid nanoparticles (SLN) were recently proposed as carriers for various pharmaceutical and cosmetic actives. These lipid nanoparticles can act as moisturizers and physical sunscreens on their own. Therefore, the full potential of these carriers has yet to be determined. The present study was aimed to determine and compare moisturizing and UV-protecting effects of different solid lipid nanoparticles (SLN) prepared by different solid lipids including Glyceryl monostearate (GMS), Precirol (P) and cetyl palmitate (CP) as carrier systems of moisturizers and sunscreens. The influence of the size and matrix crystallinity of the solid lipids on the occlusive factor, skin hydration and UV-protection were evaluated by in vitro and in vivo methods. The SLN were prepared by high-shear homogenization and ultrasound methods. Size, zeta potential and morphological characteristics of the samples were assessed by transmission electron microscopy (TEM) and thermotropic properties with differential scanning calorimetry (DSC) technique. Results of the assessments showed that SLN-CP significantly increases skin hydration and UV-protection, compared to SLN-GMS and SLN-P. It was demonstrated that the size of SLN, crystallinity index of solid lipid in SLN and probably other mechanisms besides the occlusive factor can influence skin hydration and UV-protection indices. Furthermore, findings of the assessments demonstrated significant difference between in vitro and in vivo assessments regarding occlusive factor and moisturizing effects. Findings of the present study indicate that the SLN-CP could be a promising carrier for sunscreens and moisturizers. Nanopartículas lipídicas sólidas (NLS) foram, recentemente, propostas como carreadores de vários ativos cosméticos e farmacêuticos. Essas nanopartículas lipídicas podem atuar como hidratantes e protetores solares físicos por si só. Assim sendo, determinou-se o potencial desses carreadores. Os objetivos do presente estudo foram determinar e comparar os efeitos hidratantes e protetores contra UV das diferentes partículas lipídicas sólidas (NLS) preparadas com diferentes lipídios sólidos, incluindo o monoestearato de gligerila (MSG), Precirol (P) e palmitato de cetila (PC) como sistemas carreadores de hidratantes e de protetores solares. A influência do tamanho e da cristalinidade da matriz dos lipídios sólidos no fator oclusivo, na hidrata o da pele e na prote o ao UV foi avaliada por métodos in vitro e in vivo. As NLS foram preparadas por homogeneiza o por alto corte e métodos de ultrassom. Tamanho, potencial zeta e car
The Impact of Tea Crop Insurance in the Development of Tea Industry (Case study: Otagvar, Langrood)
Maysam Musai,Mohsen Mehrara,Shiva Parvaei Haredasht,Hojat Sharifi
International Journal of Academic Research in Business and Social Sciences , 2013,
Abstract: The Agricultural Insurance Fund has covered tea crop since (2003). Due to undisputable effect of tea industry in the livelihood and the economy of Northern cities and people of the region, the Fund’s performance gains its importance. So in this paper, we investigate the impact of tea crop insurance in development of tea industry and factors effective on this impact. Our main question to be answered is that whether, in the present situation, tea crop insurance has been able to wield its role in the development of tea industry. To provide an answer to the question above, we employed variety of qualitative and quantitative methods of research. Quantitative method has been done as survey and our instrument was a questionnaire the questions of which were answered by 200 farmers in Otagvar, Langrood. To achieve a better sample population, we have used the random and cluster methods of sampling. Qualitative method has used the discussion groups with insurance agents in Amlash and Kumleh and interview with experts of Organization for Rural Cooperation and Agricultural Insurance Fund.
Public and Private Cultural Expenditure on the Economic Growth in Iran
Maysam Musai,Mohsen Mehrara,Rabab Aalami,Shiva Parvaei Haredasht
International Journal of Academic Research in Business and Social Sciences , 2013,
Abstract: This paper try to find the effect of public and private cultural expenditure on the economic growth in Iran and determine the most important factor. Statical analysis and econometrics was performed for investigation of public and private cultural expenditure roles on economic growth using Kab-Daglus productional function and calculated according to Statistical Center of Iran and Central Bank of the Islamic Republic of Iran data. The results showed that labours, capital and cultural expenditure has positive effect on economic develoment, however the production tendency of labours has fist ranking between entities, it means that manpower is the most effective factor on the economic growth. Capital is the second factor and the cultural expenditure is the last effective factor. In fact, the production tendecy of Public and private sectors of culture is less than production tendecy of capital and labours. And the production tendecy of private sector is larger than public one. It means the effect of cultur expenditure of families on economic growth is more than the government cultural expenditure.
Urinary Prognostic Biomarkers and Classification of IgA Nephropathy by High Resolution Mass Spectrometry Coupled with Liquid Chromatography
Shiva Kalantari, Dorothea Rutishauser, Shiva Samavat, Mohsen Nafar, Leyla Mahmudieh, Mostafa Rezaei-Tavirani, Roman A. Zubarev
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0080830
Abstract: IgA nephropathy is the most common cause of primary glomerulonephritis. There are different pathologic biopsy-based scoring systems in use, but there is no consensus among nephrologists yet regarding the best classification method. Our aim was to test urine proteomics as a non-invasive method for classification of IgA nephropathy. This aim was pursued by discovering novel prognostic protein biomarkers in urine, and linking them to pathogenesis of the disease through known signaling and metabolic pathways. 13 urine samples of the patients with biopsy-proven IgA nephropathy were analyzed via two proteomics approaches: nanoflow LC-MS/MS and GeLC-MS/MS. The results of label-free quantification were subjected to multivariate statistical analysis, which could classify patients into two groups, broadly corresponding to the primary and advance stages. The proteome classification correlated well with biopsy-based scoring systems, especially endocapillary hypercellularity score of the Oxford’s classification. Differentially excreted candidate proteins were found as potential prognostic biomarkers: afamin, leucine-rich alpha-2-glycoprotein, ceruloplasmin, alpha-1-microgolbulin, hemopexin, apolipoprotein A-I, complement C3, vitamin D-binding protein, beta-2-microglobulin, and retinol-binding protein 4. Pathway analysis suggested impairment of Extra Cellular Matrix (ECM)-Receptor Interaction pathways as well as activation of complement and coagulation pathway in progression of IgA nephropathy.
Choices of health care financing schemes for resource poor country: An analysis of Nepal’s experiences  [PDF]
Shiva Raj Adhikari
Health (Health) , 2013, DOI: 10.4236/health.2013.58176
Abstract:

An appropriate health care financing scheme can improve the efficient, equitable, and effective use of health care resources; however, each popular health care financing scheme has some advantages and disadvantages. The designing of health care financing strategy to fit with the country specific features is not straightforward. In resource poor country, allocation of resources for health care services are always critical and frequently unstable due to nuances annual budget process, small fiscal space, uncertainties in contributions of external development partners. Considerable quantities of country specific researches require for the choice of an appropriate health care financing scheme. The paper illustrates possible better options for the government to pursue the goal of ensuring that the poor receive more benefits. The paper compares the benefit incidences and cost of services with different options purposed for primary health care services by utilizing recently collected data from different hospitals in Nepal. The paper offers an alternative policy such as a universal free care below the district level services; but in the district level which is top level of primary care, “extended targeted free health care” may be an efficient, fair, and relatively simple approach.

On a Generic Security Game Model  [PDF]
Vivek Shandilya, Sajjan Shiva
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2017, DOI: 10.4236/ijcns.2017.107008
Abstract: To protect the systems exposed to the Internet against attacks, a security system with the capability to engage with the attacker is needed. There have been attempts to model the engagement/interactions between users, both benign and malicious, and network administrators as games. Building on such works, we present a game model which is generic enough to capture various modes of such interactions. The model facilitates stochastic games with imperfect information. The information is imperfect due to erroneous sensors leading to incorrect perception of the current state by the players. To model this error in perception distributed over other multiple states, we use Euclidean distances between the outputs of the sensors. We build a 5-state game to represent the interaction of the administrator with the user. The states correspond to 1) the user being out of the system in the Internet, and after logging in to the system; 2) having low privileges; 3) having high privileges; 4) when he successfully attacks and 5) gets trapped in a honeypot by the administrator. Each state has its own action set. We present the game with a distinct perceived action set corresponding to each distinct information set of these states. The model facilitates stochastic games with imperfect information. The imperfect information is due to erroneous sensors leading to incorrect perception of the current state by the players. To model this error in perception distributed over the states, we use Euclidean distances between outputs of the sensors. A numerical simulation of an example game is presented to show the evaluation of rewards to the players and the preferred strategies. We also present the conditions for formulating the strategies when dealing with more than one attacker and making collaborations.
Multiple Periodic Solutions for Some Classes of First-Order Hamiltonian Systems  [PDF]
Mohsen Timoumi
Applied Mathematics (AM) , 2011, DOI: 10.4236/am.2011.27114
Abstract: Considering a decomposition R2N=A⊕B of R2N , we prove in this work, the existence of at least (1+dimA) geometrically distinct periodic solutions for the first-order Hamiltonian system Jx'(t)+H'(t,x(t))+e(t)=0 when the Hamiltonian H(t,u+v) is periodic in (t,u) and its growth at infinity in v is at most like or faster than |v|a, 0≤a<1 , and e is a forcing term. For the proof, we use the Least Action Principle and a Generalized Saddle Point Theorem.
Corrosion effect on the flexural strength & micro-hardness of ips e-max ceramics  [PDF]
Cherif Mohsen
Open Journal of Stomatology (OJST) , 2011, DOI: 10.4236/ojst.2011.12006
Abstract: Objectives: The effect of ceramics construction (press- able, machinable) and corrosion on flexural strength and micro-hardness was studied. Materials & Methods: Two types of ceramics were tested: IPS e-max Press and IPS e-max CAD. Forty samples were constructed and divided into 2 groups according to the type of ceramics. Each group was then subdivided into 2 subgroups. Subgroups 1 were not subjected to corrosion while subgroups 2 were subjected to corro-sion test. Finally each subgroup was divided into 2 classes according to the type of test: biaxial flexural strength, micro-hardness. Results: There was a sig-nificant difference between the two tested ceramics as regard weight loss as IPS e-max CAD recorded less weight loss than IPS e-max Press. As regard the flex-ural strength, IPS e-max CAD recorded significant higher strength than IPS e-max Press. Corroded sam- ples recorded significant lower flexural strength than non-corroded samples for the two tested ceramics. As regard the Vickers micro-hardness test, the results showed significant difference between the two tested ceramics. IPS e-max CAD recorded higher mi-cro-hardness values than IPS e-max Press. The results also showed that the corroded samples recorded no significant micro-hardness values than non- corroded samples for the two tested ceramics. Conclusions: IPS e-max CAD recorded less weight loss weight loss after being subjected to corrosion test than IPS e-max Press. The method of fabrication affected the flexural strength µ-hardness of ceramic as machinable ceramic (e-max CAD) recorded significant higher data than pressable ceramic (e-mas Press). Corrosion decreased the flexural strength of both tested ceramics but had no effect on micro- hardness.
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