Case Report : Diagnostic Dilemma in an Unusual Case of Common Bile Duct Obstruction

( Nitin Sharma ),( Rajkumar Chejara ),( Vimal Bhandari ),( Mohit Singh ),( Hari Gopal Vyas ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2011 Gut and Liver Vol.5 No.2

Biliary obstructions are rarely caused by a foreign body and have received sparse attention. We present an unusual case with pruritis and abdominal pain caused by impacted full length surgical gauze within the common bile duct. The patient had previously undergone an open cholecystectomy. Radiological investigations were inconclusive and suggestive of either a calculus or a cholangiocarcinoma. Surgical exploration revealed full length surgical gauze within the common bile duct. Because imaging modalities are often non-determinant, the possibility of biliary tract obstruction from a foreign body should be borne in mind for patients with unusual presentations, especially those who have previously undergone surgery. (Gut Liver 2011;5:245-247)

Composite Differential Evolution Aided Channel Allocation in OFDMA Systems with Proportional Rate Constraints

Nitin Sharma,Alagan Anpalagan 한국통신학회 2014 Journal of communications and networks Vol.16 No.5

Orthogonal frequency divisionmultiple access (OFDMA)is a promising technique, which can provide high downlink capacityfor the future wireless systems. The total capacity of OFDMAcan be maximized by adaptively assigning subchannels to the userwith the best gain for that subchannel, with power subsequentlydistributed by water-filling. In this paper, we propose the use ofcomposite differential evolution (CoDE) algorithm to allocate thesubchannels. The CoDE algorithm is population-based where a setof potential solutions evolves to approach a near-optimal solutionfor the problem under study. CoDE uses three trial vector generationstrategies and three control parameter settings. It randomlycombines them to generate trial vectors. In CoDE, three trial vectorsare generated for each target vector unlike other differentialevolution (DE) techniques where only a single trial vector is generated. Then the best one enters the next generation if it is betterthan its target vector. It is shown that the proposed method obtainshigher sum capacities as compared to that obtained by previousworks, with comparable computational complexity.

Evaluation of vibroacoustic responses of laminated composite sandwich structure using higher-order finite-boundary element model

Nitin Sharma,Trupti R. Mahapatra,Subrata K. Panda,Kulmani Mehar 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.28 No.5

In this paper, the vibroacoustic responses of baffled laminated composite sandwich flat panel structure under the influence of harmonic excitation are studied numerically using a novel higher-order coupled finite-boundary element model. A numerical scheme for the vibrating plate has been developed in the frame work of the higher-order mid-plane kinematics and the eigen frequencies are obtained by employing suitable finite element steps. The acoustic responses are then computed by solving the Helmholtz wave equation using boundary element method coupled with the structural finite elements. The proposed scheme has been implemented via an own MATLAB base code to compute the desired responses. The validity of the present model is established from the conformance of the current natural frequencies and the radiated sound power with the available benchmark solutions. The model is further utilized to scrutinize the influence of core-to-face thickness ratio, modular ratio, lamination scheme and the support condition on the sound radiation characteristics of the vibrating sandwich flats panel. It can be concluded that the present scheme is not only accurate but also efficient and simple in providing solutions of the coupled vibroacoustic response of laminated composite sandwich plates.

Vibro-acoustic analysis of un-baffled curved composite panels with experimental validation

Nitin Sharma,Trupti R. Mahapatra,Subrata K. Panda 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.64 No.1

The article presents the vibration and acoustic responses of un-baffled doubly curved laminated composite panel structure under the excitation of a harmonic point load. The structural responses are obtained using a simulation model via ANSYS including the effect various geometries (cylindrical, elliptical, spherical and hyperboloid). Initially, the model has been established by solving adequate number of available examples to show the convergence and comparison behaviour of the natural frequencies. Further, the acoustic responses are obtained using an indirect boundary element approach for the coupled fluidstructure analysis in LMS Virtual.lab by importing the natural frequency values. Subsequently, the values for the sound power level are computed using the present numerical model and compared with that of the available published results and in-house experimentally obtained data. Further, the acoustic responses (mean-square velocity, radiation efficiency and sound power level) of the doubly curved layered structures are evaluated using the current simulation model via several numerical experimentations for different structural parameters and corresponding discussions are provided in detail.

Duplication with Task Assignment in Mesh Distributed System

Sharma, Rashmi,Nitin, Nitin Korea Information Processing Society 2014 Journal of information processing systems Vol.10 No.2

Load balancing is the major benefit of any distributed system. To facilitate this advantage, task duplication and migration methodologies are employed. As this paper deals with dependent tasks (DAG), we used duplication. Task duplication reduces the overall schedule length of DAG along-with load balancing. This paper proposes a new task duplication algorithm at the time of tasks assignment on various processors. With the intention of conducting proposed algorithm performance computation; simulation has been done on the Netbeans IDE. The mesh topology of a distributed system is simulated at this juncture. For task duplication, overall schedule length of DAG is the main parameter that decides the performance of a proposed duplication algorithm. After obtaining the results we compared our performance with arbitrary task assignment, CAWF and HEFT-TD algorithms. Additionally, we also compared the complexity of the proposed algorithm with the Duplication Based Bottom Up scheduling (DBUS) and Heterogeneous Earliest Finish Time with Task Duplication (HEFT-TD).

A Review of Mobile Robots: Applications and Future Prospect

Nitin Sharma,Jitendra Kumar Pandey,Surajit Mondal 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.9

Approximately eight decades ago, during World War II, the concept of intelligent robots capable of independent arm movement began to emerge as computer science and electronics merged with advancements in mechanical engineering. This marked the starting point of a thriving industry focused on research and development in mobile robotics. In recent years, there has been a growing association between robotics and artificial intelligence, aiming to enable robots to make autonomous decisions akin to human cognition. To achieve this objective, researchers are actively exploring the integration of artificial neural networks with mechatronic robots. These intelligent and self-decision-making robots possess the potential to revolutionize human capabilities and elevate our intelligence to unprecedented levels. In various physical service sectors such as cleaning, security, and other tasks that don't require creative or analytical thinking, these robots can efficiently carry out the assigned responsibilities. Moreover, robots have the potential to play a significant role in military operations, eliminating the need for human lives to be sacrificed in warfare. This review article aims to explore the advancements in mobile robotics since their inception nearly 80 years ago. It will delve into the detailed applications of these robots across different sectors and discuss their profound effects on contemporary human lives and industrial landscapes.

Mitigating Blackhole and Grayhole Attack in MANET using Enhanced AODV with TLTB Mechanism

Nitin Khanna,Priyanka Sharma 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.8

MANET is multi-hop network which is a decentralized and infrastructure-less network that includes collection of mobile nodes that are self configurable and co-operates with each other for transmission of data. It has dynamic nature in terms of topology. Due to this dynamic nature of topology and no fixed infrastructure in MANET, these nodes have to be dependent on each other for transmission of data and thus are prone to packet drop attacks like Blackhole, grayhole attack. These attacks hinder the smooth transmission of data between nodes and hampers effective communication. In this paper, a new mechanism Traffic Light Trust Based (TLTB) is proposed to detect both Blackhole attacks and Grayhole attacks. This mechanism works after modification in the standard AODV routing protocol and Watchdog mechanism. This mechanism uses color scheme to define trust level of a node or any path. Just like traffic light it includes three colors to depict the level of trust. AODV routing protocol packets are modified to include new fields for application of proposed trust mechanism. These Solutions are compared with Light-weight Trust Based (LTB) and EDRI mechanism for Normalized Control load, Packet Delivery Ratio, accuracy in Blackhole and Grayhole detection and reliability of paths.

Duplication with Task Assignment in Mesh Distributed System

( Rashmi Sharma ),( Nitin ) 한국정보처리학회 2014 Journal of information processing systems Vol.10 No.2

Load balancing is the major benefit of any distributed system. To facilitate this advantage, task duplication and migration methodologies are employed. As this paper deals with dependent tasks (DAG), we used duplication. Task duplication reduces the overall schedule length of DAG along-with load balancing. This paper proposes a new task duplication algorithm at the time of tasks assignment on various processors. With the intention of conducting proposed algorithm performance computation; simulation has been done on the Netbeans IDE. The mesh topology of a distributed system is simulated at this juncture. For task duplication, overall schedule length of DAG is the main parameter that decides the performance of a proposed duplication algorithm. After obtaining the results we compared our performance with arbitrary task assignment, CAWF and HEFT-TD algorithms. Additionally, we also compared the complexity of the proposed algorithm with the Duplication Based Bottom Up scheduling (DBUS) and Heterogeneous Earliest Finish Time with Task Duplication (HEFT-TD).

Acoustic responses of natural fibre reinforced nanocomposite structure using multiphysics approach and experimental validation

Satankar, Rajesh Kumar,Sharma, Nitin,Ramteke, Prashik Malhari,Panda, Subtra Kumar,Mahapatra, Siba Shankar Techno-Press 2020 Advances in nano research Vol.9 No.4

In this article, the acoustic responses of free vibrated natural fibre-reinforced polymer nanocomposite structure have been investigated first time with the help of commercial package (ANSYS) using the multiphysical modelling approach. The sound relevant data of the polymeric structure is obtained by varying weight fractions of the natural nanofibre within the composite. Firstly, the structural frequencies are obtained through a simulation model prepared in ANSYS and solved through the static structural analysis module. Further, the corresponding sound data within a certain range of frequencies are evaluated by modelling the medium through the boundary element steps with adequate coupling between structure and fluid via LMS Virtual Lab. The simulation model validity has been established by comparing the frequency and sound responses with published results. In addition, sets of experimentation are carried out for the eigenvalue and the sound pressure level for different weight fractions of natural fibre and compared with own simulation data. The experimental frequencies are obtained using own impact type vibration analyzer and recorded through LABVIEW support software. Similarly, the noise data due to the harmonically excited vibrating plate are recorded through the available Array microphone (40 PH and serial no: 190569). The numerical results and subsequent experimental comparison are indicating the comprehensiveness of the presently derived simulation model. Finally, the effects of structural design parameters (thickness ratio, aspect ratio and boundary conditions) on the acoustic behaviour of the natural-fibre reinforced nanocomposite are computed using the present multiphysical model and highlighted the inferences.

Numerical buckling temperature prediction of graded sandwich panel using higher order shear deformation theory under variable temperature loading

Brundaban Sahoo,Bamadev Sahoo,Nitin Sharma,Kulmani Mehar,Subrata Kumar Panda 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.26 No.5

The finite element solutions of thermal buckling load values of the graded sandwich curved shell structure are reported in this research using a higher-order kinematic model including the shear deformation effect. The numerical buckling temperature has been computed using an in-house specialized code (MATLAB environment) prepared in the framework of the current mathematical formulation. In addition, the mathematical model includes the excess structural distortion under the influence of elevated environment via Green-Lagrange nonlinear strain. The corresponding eigenvalue equation has been solved to predict the critical buckling temperature of the graded sandwich structure. The numerical stability and the accuracy of the current solution have been confirmed by comparing with the available published results. Thereafter, the model is extended to bring out the influences of structural parameters i.e. the curvature ratio, core-face thickness ratio, support conditions, power-law indices and sandwich types on the thermal buckling behavior of graded sandwich curved shell panels.