• 제목/요약/키워드: SAMI

검색결과 129건 처리시간 0.021초

Neural Network Active Control of Structures with Earthquake Excitation

  • Cho Hyun Cheol;Fadali M. Sami;Saiidi M. Saiid;Lee Kwon Soon
    • International Journal of Control, Automation, and Systems
    • /
    • 제3권2호
    • /
    • pp.202-210
    • /
    • 2005
  • This paper presents a new neural network control for nonlinear bridge systems with earthquake excitation. We design multi-layer neural network controllers with a single hidden layer. The selection of an optimal number of neurons in the hidden layer is an important design step for control performance. To select an optimal number of hidden neurons, we progressively add one hidden neuron and observe the change in a performance measure given by the weighted sum of the system error and the control force. The number of hidden neurons which minimizes the performance measure is selected for implementation. A neural network was trained for mitigating vibrations of bridge systems caused by El Centro earthquake. We applied the proposed control approach to a single-degree-of-freedom (SDOF) and a two-degree-of-freedom (TDOF) bridge system. We assessed the robustness of the control system using randomly generated earthquake excitations which were not used in training the neural network. Our results show that the neural network controller drastically mitigates the effect of the disturbance.

Comparison between reinforced concrete designs based on the ACI 318 and BS 8110 codes

  • Tabsh, Sami W.
    • Structural Engineering and Mechanics
    • /
    • 제48권4호
    • /
    • pp.467-477
    • /
    • 2013
  • Municipalities in the United Arab Emirates approve reinforced concrete design of building structures to follow either the ACI 318 or the BS 8110 code. Since the requirements of these codes are different from each, there is a need to compare the structural demand in the two codes. The main objective of this study is to compare the design requirements of the ACI 318 code with the BS 8110 code for the flexural, shear and axial compression limit states. The load factors and load combinations in the two codes are also compared. To do so, a large number of cross-sections with different geometries, material properties, and reinforcement ratios are analyzed following the procedures in the two codes. The relevant factored load combinations in the two codes are also investigated for a wide range of live-to-dead load ratios and for various wind-to-dead load ratios. The study showed that the differences between the design capacities in the ACI 318 and BS 8110 codes are minor for flexure, moderate for axial compression, and major for shear. Furthermore, the factored load combinations for dead load, live load and wind in the two codes yield minor-to-moderate differences, depending on the live-to-dead load ratio and intensity of wind.

Financial Stability of GCC Banks in the COVID-19 Crisis: A Simulation Approach

  • AL-KHARUSI, Sami;MURTHY, Sree Rama
    • The Journal of Asian Finance, Economics and Business
    • /
    • 제7권12호
    • /
    • pp.337-344
    • /
    • 2020
  • Stability and sustainability of the biggest banks in any country are extremely important. When big banks become unstable and vulnerable, they typically stop lending. The resulting credit squeeze pushes the economy into recession or a slow growth path. The present study examines the financial stability and sustainability of the 30 large banks operating in the six Gulf Cooperation Council countries. These banks represent 70% of the GCC banking market. Monte Carlo simulation was attempted assuming that key drivers can vary randomly by twenty percent on either side of the current values. The conclusions are drawn based on 300 simulation trails of the five-year forecast balance and income statement of each bank. Year 2020 is not favorable for the GCC countries because of the COVID-19 pandemic and low oil prices, though the future years may be better. The study identifies several banks, which may become financially unsustainable because the simulations indicate the possibility of negative profitability, unacceptably low capital ratios and potential for heavy credit losses during periods of economic turbulence, which is the current situation due to the COVID-19 pandemic. Through simulation the paper is able to throw light on which factors lead to bank instability and weakness.

Enhancement of Return Routability Mechanism for Optimized-NEMO Using Correspondent Firewall

  • Hasan, Samer Sami;Hassan, Rosilah
    • ETRI Journal
    • /
    • 제35권1호
    • /
    • pp.41-50
    • /
    • 2013
  • Network Mobility (NEMO) handles mobility of multiple nodes in an aggregate manner as a mobile network. The standard NEMO suffers from a number of limitations, such as inefficient routing and increased handoff latency. Most previous studies attempting to solve such problems have imposed an extra signaling load and/or modified the functionalities of the main entities. In this paper, we propose a more secure and lightweight route optimization (RO) mechanism based on exploiting the firewall in performing the RO services on behalf of the correspondent nodes (CNs). The proposed mechanism provides secure communications by making an authorized decision about the mobile router (MR) home of address, MR care of address, and the complete mobile network prefixes underneath the MR. In addition, it reduces the total signaling required for NEMO handoffs, especially when the number of mobile network nodes and/or CNs is increased. Moreover, our proposed mechanism can be easily deployed without modifying the mobility protocol stack of CNs. A thorough analytical model and network simulator (Ns-2) are used for evaluating the performance of the proposed mechanism compared with NEMO basic support protocol and state-of-the-art RO schemes. Numerical and simulation results demonstrate that our proposed mechanism outperforms other RO schemes in terms of handoff latency and total signaling load on wired and wireless links.

Carbon rich fly ash and their nanostructures

  • Salah, Numan;Habib, Sami S.;Khan, Zishan H.;Alshahrie, Ahmed;Memic, Adnan;Al-ghamdi, Attieh A.
    • Carbon letters
    • /
    • 제19권
    • /
    • pp.23-31
    • /
    • 2016
  • Carbon rich fly ash was recently reported to have compositions that are ideal for use as a precursor and catalyst for carbon nanotube growth. This fly ash powder is mostly composed of pure carbon, predominantly present as sp2. In this work, the effect of sonication time on the morphology and structural properties of carbon rich fly ash particles is reported. The obtained results show that ultrasound treatment is an effective tool for producing ultrafine particles/fragments with higher porosity, which might be suitable for the adsorption of gasses. Moreover, carbon nanoparticles (CNPs) of this fly ash were produced in parallel using the ball milling technique, and were evaluated as reinforcements for epoxy based composites. These CNPs have almost spherical shapes with particle sizes of around 30 nm. They were found to have strong C=O carbonyl group bonds, which might be generated during the ball milling process. The tensile testing results of a fly ash CNP reinforced epoxy composite showed significant improvements in the mechanical properties, mainly in the stiffness of the polymer. The stiffness value was increased by around 23% of that of neat epoxy. These CNPs with chemically active groups might also be useful for other applications.

A New IgG Immunoblot Kit for Diagnosis of Toxoplasmosis in Pregnant Women

  • Khammari, Imen;Saghrouni, Fatma;Lakhal, Sami;Bouratbine, Aida;Said, Moncef Ben;Boukadida, Jalel
    • Parasites, Hosts and Diseases
    • /
    • 제52권5호
    • /
    • pp.493-499
    • /
    • 2014
  • The determination of the accurate immune status of pregnant women is crucial in order to prevent congenital toxoplasmosis. Equivocal results with conventional serological techniques are not uncommon when IgG titers are close to the cut-off value of the test, so that a confirmatory technique is needed. For this purpose, we developed a homemade immunoblot (IB) using soluble extract of Toxoplasma gondii tachyzoites and assessed it by testing 154 positive, 100 negative, and 123 equivocal sera obtained from pregnant women. In order to select the more valuable bands in terms of sensitivity and specificity, we used the Youden Index (YI). The highest YIs were those given by the 32, 36, 98, 21, and 33 bands. The simultaneous presence on the same blot of at least 3 bands showed a much higher YI (0.964) and was adapted as the positivity criterion. The analysis of results showed that our homemade IB correlated well with the commercial LDBIO Toxo II $IgG^{(R)}$ kit recently recommended as a confirmatory test (96.7% of concordance).

First Molecular Characterization of Hypoderma actaeon in Cattle and Red Deer (Cervus elaphus) in Portugal

  • Ahmed, Haroon;Sousa, Sergio Ramalho;Simsek, Sami;Anastacio, Sofia;Kilinc, Seyma Gunyakti
    • Parasites, Hosts and Diseases
    • /
    • 제55권6호
    • /
    • pp.653-658
    • /
    • 2017
  • Hypoderma spp. larvae cause subcutaneous myiasis in several animal species. The objective of the present investigation was to identify and characterize morphologically and molecularly the larvae of Hypoderma spp. collected from cattle (Bos taurus taurus) and red deer (Cervus elaphus) in the district of Castelo Branco, Portugal. For this purpose, a total of 8 larvae were collected from cattle (n=2) and red deer (n=6). After morphological identification of Hypoderma spp. larvae, molecular characterization was based on PCR-RFLP and mitochondrial CO1 gene sequence analysis. All larvae were morphologically characterized as the third instar larvae (L3) of H. actaeon. Two restriction enzymes were used for molecular identification of the larvae. TaqI restriction enzyme was not able to cut H. actaeon. However, MboII restriction enzyme differentiated Hypoderma species showing 210 and 450 bp bands in H. actaeon. Furthermore, according to the alignment of the mt-CO1 gene sequences of Hypoderma species and to PCR-RFLP findings, all the identified Hypoderma larvae were confirmed as H. actaeon. This is the first report of identification of Hypoderma spp. (Diptera; Oestridae) from cattle and red deer in Portugal, based on morphological and molecular analyses.

Age and Gender Differences in the Relation of Chronic Diseases to Activity of Daily Living (ADL) Disability for Elderly South Koreans: Based on Representative Data

  • Kim, Il-Ho
    • Journal of Preventive Medicine and Public Health
    • /
    • 제44권1호
    • /
    • pp.32-40
    • /
    • 2011
  • Objectives: This study investigated the gender and age differential effect of major chronic diseases on activity of daily living (ADL) disability. Methods: Surveyfreq and Surveylogistic regression analyses were employed on the 2005 Korean National Health and Nutrition Examination Survey (KNHANES) with a sample of 3,609 persons aged 65 - 89. Results: After adjusting for potential covariates, stroke, among elderly men more so than women, had a 2-3 times greater odds of engendering ADL disability in the 65-69 (p < 0.05) and 70-79 age groups (p < 0.01). In comparison to elderly women, cancer, diabetes, and incontinence in elderly men was associated with a higher risk of ADL disability in the 70 - 79 age group (p < 0.05), and this association was also observed for pulmonary disease in the 80-89 age group. Among elderly women, however, a significant association between incontinence and ADL disability was identified in all three age groups. In addition, this association was found in pulmonary disease and diabetes in elderly women aged 70 - 79 years. Significant gender differences were observed in the association between stroke in the 60 - 79 age group and cancer in the 70 - 79 age group. Conclusions: Age and gender differences were observed in the effect of chronic diseases on ADL disability.

Study of Social Network Site Interactivity to Identify and Avert Usability Flaws for Effective User's Experience

  • Abduljalil, Sami;Hwang, Gi-Hyun;Kang, Dae-Ki
    • Journal of information and communication convergence engineering
    • /
    • 제9권3호
    • /
    • pp.325-330
    • /
    • 2011
  • Due to the wide growth and popularity of social network website, large numbers of users discover these social network sites are a place where they can be able to spend their leisure time sharing interests, sharing ideas freely, sharing personal experience, and also to search for new friends or partners. These websites give an opportunity for its users to socialize with new people and to keep in touch or reconnect with current or old friends and families across disperse continents, which traditionally replace the common traditional methods. These social network websites need accurate and careful investigations and findings on the usability issues for effective interactivity and more usability. However, little research might have previously invested on the usability of these social network websites. Therefore, we propose a new framework to study and test the usability of these social network sites. We namely call our framework "Interactivity". This framework will enable developers to assess the usability of the social network sites. It will provide an overview of the user's behavior while interacting in these social network websites. Performance of the framework will be performed using Camtasia software. This software will entirely capture the interactivity of users including the screen and the movements, which the screen and the motion of the user action will undergo to analysis at the end of our research.

Distribution of Agrobacterium tumefaciens Biovars in Jordan and Variation of Virulence

  • Al-Momani, Fouad;Albasheer, Sami;Saadoun, Ismail
    • The Plant Pathology Journal
    • /
    • 제22권4호
    • /
    • pp.318-322
    • /
    • 2006
  • One hundred and nine Agrobacterium isolates were recovered from 68 samples(51 plant tumor and 17 soil) that were collected from different habitats in Northern Jordan. The isolated cultures were grouped into 3 biovars based on their biochemical characteristics and biovar I, II, and III comprised a total number of 46, 41, and 22 isolates, respectively. Isolates of biovar I were obtained primarily from the diseased peach, oak and rose plants, whereas isolates of biovar II and ill were obtained mostly from apple and grape plants, respectively. Twenty-nine isolates were found to be virulent to at least one of the tested hosts such as carrots, chickpeas, garden peas and tomato plants with a response of tumor formation or tumor with roots induction. Our result suggested that A. tumefaciens strains from tumor of various plants and soil of Jordan were diverse and they have a variation in their virulence.