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Shishir Ram Shetty,Saad Wahby Al Bayatti,Hesham Marei,Raghavendra Shetty,Hossam Abdelatty Abdelmagyd,Alexander Maniangat Luke 대한구강악안면외과학회 2021 대한구강악안면외과학회지 Vol.47 No.1
Objectives: The purpose of the study was to assess the occurrence, location, and dimensions of the intraosseous vascular canal in the lateral wall of the maxillary antrum using cone-beam computed tomography (CBCT). Materials and Methods: In this retrospective study, we examined 400 CBCT scans from our archive of patients who had earlier reported to a dental teaching hospital in the United Arab Emirates. The prevalence, location, and dimensions of the lateral antral intraosseous canal (LAIC) in the maxillary antrum were evaluated by 2 examiners using standardised methods. A third examiner was consulted in cases of disagreement. Results: The prevalence of LAIC was 62.3% (249 maxillary antra) among the study population. The mean distance between the most inferior point of the alveolar bone and the inferior border of the LAIC in the posterior maxillary region was 19.83±3.12 mm. There was a significant difference (P=0.05) between the maxillary molar and premolar regions in mean distance from the most inferior point of the alveolar bone and the inferior border of the LAIC. There was no statistically significant difference in mean distance between the most inferior point of the alveolar bone and the inferior border of the LAIC between dentulous and edentulous areas (P=0.1). The G3-intrasinusal type canal less than 1mm in diameter was the most common type of LAIC. Conclusion: This study established the approximate location of the LAIC in a United Arab Emirates cohort, which will assist the oral surgeon in selecting the appropriate site for sinus lift procedures with reduced risk of surgical hemorrhage.
Optimal Location of SVC Considering Critical Contingency and Varying Load
Shishir Dixit,Laxmi Srivastava,Ganga Agnihotri 사단법인 인문사회과학기술융합학회 2013 예술인문사회융합멀티미디어논문지 Vol.3 No.2
The flexible Alternating Current transmission system (FACTS) may play a vital role in solving various problems of modern restructured power system networks, which have to operate under highly stressed conditions because of ever increasing demand of electric power. However, due to huge capital investment, an intensive investigation is required at planning stage to select optimal location and size of these devices to acquire maximum benefit of it. In this paper, Continuous Genetic Algorithm (CGA) based method is proposed for placement of Static Var Compensator (SVC) for minimizing real power loss, load bus voltage deviations and size of SVC. As a first step, contingency ranking is performed to determine the most severe line outages by evaluating voltage performance index (VPI) for both cases i.e. for base load condition and when load is varied randomly. Thereafter, Continuous Genetic Algorithm (CGA) has been applied to solve mixed continuous-discrete optimization problem. The optimization is carried out to find optimal location and size of SVC to minimize real power loss, load voltage deviation and rating SVC. The effectiveness of the proposed methodology is demonstrated on a standard IEEE 30-bus system.
Shishir Dixit,Laxmi Srivastava,Ankita Singh,Ganga Agnihotri 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.6
Flexible Alternating Current Transmission Systems (FACTS) represents a vast development in the area of power system operation and control. As we know that under heavily loaded conditions our power system is at high risks of consequent voltage instability problem. This paper gives an overview about application of series connected Flexible alternating current transmission system (FACTS) for improvement of power system performance like transfer stability, secure voltage profile and reduce the system losses etc. FACTS devices require huge capital investment. Therefore, heuristic techniques are used for optimal location and sizing of series FACTS controllers like Genetic Algorithm (GA), Particle Swarm Optimization (PSO) etc. These techniques are used to solve the optimization problem. This paper gives details of optimal placement and sizing of FACTS devices based on different evolutionary techniques which is used for minimization of transmission loss, enhancement of stability of power system. In this study one of the FACTS devices is used as a scheme for enhancement of power system stability.Proper installation of FACTS devices also results in significant reduction of transmission loss. In this review,TCSC is selected as the compensation device.
BER Analysis of Receive Diversity Using Multiple Antenna System and MRC
Shishir Sapkota 한국디지털융합학회 2017 IJICTDC Vol.2 No.1
In this work, the performance analysis of a wireless communication is done by modeling a wireless communication system and analysing its bit error rate (BER). The BER of any communication system is helpful for it performance analysis. So, the consequences of multiple antenna system on BER at receiver end is analysed and maximal ratio combining (MRC) is also estimated between signal and noise. Therefore, the BER is attempted to reduce in the wireless communication system which can affect to receive the pure signal in the receiver.
Hygrothermal effects on buckling of composite shell-experimental and FEM results
Shishir Kr. Sahu,Madhusmita Biswal,A.V. Asha,Namita Nanda 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.22 No.6
The effects of moisture and temperature on buckling of laminated composite cylindrical shell panels are investigated both numerically and experimentally. A quadratic isoparametric eight-noded shell element is used in the present analysis. First order shear deformation theory is used in the present finite element formulation for buckling analysis of shell panels subjected to hygrothermal loading. A program is developed using MATLAB for parametric study on the buckling of shell panels under hygrothermal field. Benchmark results on the critical loads of hygrothermally treated woven fiber glass/epoxy laminated composite cylindrical shell panels are obtained experimentally by using universal testing machine INSTRON 8862. The effects of curvature, lamination sequences, number of layers and aspect ratios on buckling of laminated composite cylindrical curved panels subjected to hygrothermal loading are considered. The results are presented showing the reduction in buckling load of laminated composite shells with the increase in temperature and moisture concentrations.
Scattering of torsional surface waves in a three layered model structure
Shishir Gupta,Prasenjit Pati,Anand Mandi,Santimoy Kundu 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.4
In this article, a comparative study has been made to investigate the scattering behaviour of three layered structure model on torsional surface wave. For such model intermediate layer is taken as fiber reinforced composite, resting over a dry sandy Gibson substratum and underlying by different anelastic media. We consider two distinct mediums for topmost layer. In the first case, topmost layer has been taken as fluid saturated homogeneous porous layer, while in the second case the fluid saturated porous layer has been replaced by a transversely isotropic layer. Simple form expression for the secular equation of torsional surface wave has been worked out in both the cases by executing specific boundary conditions, which comprises Whittaker’s function and its derivative, for imminent result that have been elaborated asymptotically. Some special cases have been constituted which are in excellent compliance with recorded literatures. For the sake of comparative study, numerical estimation and graphical illustration have been accomplished to identify the effects of the width ratio of the layers, Biot’s gravity parameter, sandy parameter, porosity parameter and other heterogeneity parameters corresponding to the layers and half spaces, horizontal compressive and tensile initial stress on the phase velocity of torsional surface wave.