Wyniki wyszukiwania - BazTech

1

Investigation, analysis and comparison of current-voltage characteristics for Au/Ni/GaN Schottky structure using I-V-T simulation

Sadoun A., Mansouri S., Chellali M., Lakhdar N., Hima A., Benamara Z.

Materials Science Poland

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2019

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Vol. 37, No. 3

496--502

EN

In this work, we have presented a theoretical study of Au/Ni/GaN Schottky diode based on current-voltage (I-V) measurement for temperature range of 120 K to 400 K. The electrical parameters of Au/Ni/GaN, such as barrier height (Φb), ideality factor and series resistance have been calculated employing the conventional current-voltage (I-V), Cheung and Chattopadhyay method. Also, the variation of Gaussian distribution (P (Φb)) as a function of barrier height (Φb) has been studied. Therefore, the modified [formula] relation has been extracted from (I-V) characteristics, where the values of ΦB0 and A+Simul have been found in different temperature ranges. The obtained results have been compared to the existing experimental data and a good agreement was found.

2

Detection of valvular heart diseases using impedance cardiography ICG

Chabchoub S., Mansouri S., Ben Salah R.

Biocybernetics and Biomedical Engineering

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2018

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Vol. 38, no. 2

251--261

EN

Impedance cardiography (ICG) is a simple, non-invasive and cost effective tool for monitor-ing hemodynamic parameters. It has been successfully used to diagnose several cardiovas-cular diseases, like the heart failure and myocardial infarction. In particular, valvular heart disease (VHD) is characterized by the affection of one or more heart valves: mitral, aortic, tricuspid or pulmonary valves and it is usually diagnosed using the Doppler echocardiogra- phy. However, this technique is rather expensive, requires qualified expertise, discontinu- ous, and often not necessary to make just a simple diagnosis. In this paper, a new computer aided diagnosis system is proposed to detect VHD using the ICG signals. Six types of ICG heartbeats are analyzed and classified: normal heartbeats (N), mitral insufficiency heart-beats (MI), aortic insufficiency heartbeats (AI), mitral stenosis heartbeats (MS), aortic steno-sis heartbeats (AS), and pulmonary stenosis heartbeats (PS). The proposed methodology is validated on 120 ICG recordings. Firstly, ICG signal is denoised using the Daubechies wavelet family with order eight (db8). Then, these signals are segmented into several heartbeats and, later, subjected to the linear prediction LP and discrete wavelet transform DWT approaches to extract temporal and time–frequency features, respectively. In order to reduce the number of features and select the most relevant ones among them, the Student's t-test is applied. Therefore, a total of 16 features are selected (3 temporal features and 13 time– frequency features). For the classification step, the support vector machine SVM and k-nearest neighbors KNN classifiers are used. Different combinations between extracted features and classifiers are proposed. Hence, experimental results showed that the combi-nation between temporal features, time–frequency features and SVM classifier achieved the highest classification performance in classifying the N, MI, MS, AI, AS and PS heartbeats with 98.94% of overall accuracy.

3

Inter-region planning and analysis of water resources by using WEAP model Seybouse (Annaba) and Coastal East of Constantine (El-Taref)

Mansouri S., Ouerdachi L., Remaoun M.

Journal of Water and Land Development

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2017

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no. 33

115--122

EN

Water is seen as key factor for development. Its scarcity raises concerns at all scales. In regards to water resources, Annaba and El-Taref are intimately connected, the different activities (groundwater and superficial), focused on increasing supply, have been considered as a response to water demand. The actual system use of water resources is not able to sustain water needs that are more and more growing in different expansion sectors. Consequently, a strategy should therefore be sought to integrate the various sectoral needs in available water resources in order to reach the economic and ecological sustainability. We will try to respond to this problem by use of Water Evaluation and Planning (WEAP) model. This study is the first attempt to estimate water demand and analysis of multiple and competing uses of hydro-system in Seybouse’s Wadi basin and to make comparison with proposed water storage estimates. This model was applied according to five different scenarios which reflect the best and worst conditions of the supply and demand, not only to evaluate water demand deficit, but also to help planners to the alternative management. The model stimulation showed that the area study is sensitive to a serious water scarcity by 2030. It is possible to observe an improvement with integration of other management strategies for a best operating system.

PL

Woda jest uznawana za kluczowy czynnik rozwoju. Jej brak rodzi problemy w wielu wymiarach. W odniesieniu do zasobów wodnych prowincje Annaba i El-Taref są ściśle powiązane. W odpowiedzi na rosnące potrzeby rozważane są różne działania (w stosunku do wód podziemnych i powierzchniowych) zmierzające do zwiększenia zasilania. Istniejące systemowe użytkowanie zasobów wodnych nie jest w stanie zaspokoić potrzeb wodnych, które ciągle rosną w rozwijających się sektorach gospodarki. Należy więc poszukiwać strategii integrowania różnych branżowych potrzeb celem osiągnięcia równowagi gospodarczej i środowiskowej. Autorzy podjęli próbę rozwiązania tego problemu, stosując model oceny i planowania zasobów wodnych (WEAP – ang. Water Evaluation and Planning). Te badania są pierwszą próbą oszacowania potrzeb wodnych oraz analizy rozlicznych i konkurujących ze sobą użytkowników zlewni rzeki Seybouse oraz próbą porównania ich z przeprowadzonym szacunkiem zasobów. Modelowanie realizowano według pięciu różnych scenariuszy, które odzwierciedlają najlepsze i najgorsze warunki dostawy i zapotrzebowania nie tylko na potrzeby oceny deficytu wody, ale także, by wspierać planistów w alternatywnych formach zarządzania. Symulacja modelu wykazała, że obszar badań będzie podatny na poważne niedobory wody do roku 2030. Można zaobserwować poprawę wynikającą z integracji innych strategii zarządzania w celu osiągnięcia najlepszego systemu operacyjnego.