Search results

This case is based on a project carried out in a tertiary care hospital of the Northeastern region of India for a period of eight months and is written by Dr Ankit Singh, Dr Meenal Kulkarni and Mr Avinash Poojari. The case was developed with the help of the hospital’s management team, disguised on request as Mr Raghugopal Ramalinga (Chief Hospital Administrator), Mr Suresh Kumar (Chief Engineer), Ms Linney Krubah (Chief Nursing Superintendent), Dr Premanand Ale (Chief Medical Superintendent) and Mr Srikrishna Shukla (Chief Finance Officer).

This case is about Trident Hospital, which faces issues pertaining to oxygen supply. Oxygen supply at Trident Hospitals is through three options as highlighted in the case, but due to the lack of preventive maintenance and no risk assessment done for the crucial medical oxygen, interruptions and additional work for the staff became a common phenomenon. The existing situation can lead to patient harm or death and can attract medico-negligence suit against the hospital, threatening the overall existence of the hospital. The hospital administrator is currently viewing the problem from only the cost perspective, which is a high-risk and a short-term approach.

Students pursuing full time/part time/diploma programme in health-care management, hospital administration/hospital operations; and undergraduate and post-graduate level students.

THE general purpose of the test trolley is to replace the operating and control mechanics in the cockpit so that each engine can be tested before being mounted in position on the aircraft. The advantage as compared with the method previously employed is that if any auxiliary components are not working properly (or are wrongly connected) they can be found and adjusted before the engine is installed; this greatly reduces the risk of having to waste time on dismantling the engine again and makes sure that a properly functioning engine unit is installed.

The purpose of this paper is to discuss the design and manufacture of an intake system for a 600cc Formula Society of Automotive Engineers engine. Owing to the inherent geometric limitations imposed by the existing manufacturing process (bending and welding of aluminum), it is difficult to design and fabricate an intake manifold system in which pressure losses are kept to a minimum and equal charge is provided to each cylinder. The aim is to develop a fabrication process that circumvents these limitations.

Fused deposition modeling (FDM) is used to create an intake system (consisting of a plenum, plenum elbow, and cylinder runners) that is then later covered in layers of carbon fiber composite fabric through vacuum bagging. FDM allows for geometric design freedom, while the layup of a composite material (and its associated high‐temperature resin) provide the strength and heat‐resistivity necessary for this application.

As a result of this approach, a functional intake manifold is created that survived the high temperatures and pressures of the turbo‐charged engine. The process allowed the geometry of the intake to be redesigned, resulting in reduced weight (due to lower material density and lack of welds, hose clamps, and silicon couples), improved charge distribution, and increased torque through a wide RPM range when compared to its traditionally manufactured aluminum counterpart.

The approach described in this paper shows that a functional, end‐use intake manifold can be produced by the combination of FDM method and subsequent lamination of a carbon‐fiber composite material. The approach enables the geometric freedom to improve manifold design, resulting in improved vehicle performance.

This case study presents a low‐cost manner of directly manufacturing functional parts through the combination of FDM and composite material layup.

This paper reports some investigative results obtained through the application of differential geometry to the array manifold of a direction finding (DF) sensor array. It emphasises the crucial but so far disregarded role of the array manifold in the performance of subspace‐based direction finding (DF) algorithms and then proceeds to a compact mathematical analysis of the array manifold using the tools of differential geometry. The results thus obtained are used to quantify the effects of the array manifold properties on the performance of a DF system and to design superresolution sensor arrays.

It is often observed in practice that the essential behavior of mathematical models involving many variables can be captured by a much smaller model involving only a few variables. Further, the simpler model very often displays oscillatory behavior of some sort, especially when critical problem parameters are varied in certain ranges. This paper attempts to supply arguments from the theory of dynamical systems for why oscillatory behavior is so frequently observed and to show how such behavior emerges as a natural consequence of focusing attention upon so‐called “essential” variables in the process of model simplification. The relationship of model simplification and oscillatory behavior is shown to be inextricably intertwined with the problems of bifurcation and catastrophe in that the oscillations emerge when critical system parameters, i.e. those retained in the simple model, pass through critical regions. The importance of the simplification, oscillation and bifurcation pattern is demonstrated here by consideration of several examples from the environmental, economic and urban areas.

SUMMARY This report describes briefly the problem of fuel boiling in reheat manifolds and the special tests which were carried out to investigate it. In order to analyse the test results the concept of a fuel manifold flow number was used. During these tests the two common types of aviation turbine fuels were used and the conditions at the onset of boiling were established.

This paper aims to establish a multi-input equilibrium manifold expansion (EME) model for gas turbine (GT). It proposes that the extension of model input dimension is realized based on similarity theory and affine structure in the framework of single-input EME model. The study aims to expand the scope of application of the EME model so that it can be used for the control or fault diagnosis of GTs.

In this paper, the concepts of corrected equilibrium manifold expansion (CEME) model and multi-cell equilibrium manifold expansion (MEME) model are first proposed. This paper uses theoretical analysis and simulation experiments to demonstrate the effectiveness of the bilayer equilibrium manifold expansion (BEME) model, which is a combination of the CEME and the MEME models. Simulation experiments include confirmatory experiments and comparative experiments.

The paper provides a new sight into building a multiple-input EME (MI-EME) model for GTs. The proposed method can build an accurate and robust MI-EME model that has superior performance compared with widely used nonlinear models including Wiener model (WM), Hammerstein model (HM), Hammerstein–Wiener model (HWM) and nonlinear autoregressive with exogenous inputs (NARX) network model. In terms of accuracy, the maximum error percentage of the proposed model is just 1.309%, far less than WM, HM and HWM. In terms of the stability of model calculation, the range of the mean error percentage of the proposed model is just a quarter of that of NARX network model.

The paper fulfills the construction of a novel multi-input nonlinear model, which has laid a foundation for the follow-up research of model-based GT fault detection and isolation or GT control.

With the increasing demand for surveillance and smart transportation, drone technology has become the center of attraction for robotics researchers. This study aims to introduce a new path planning approach to drone navigation based on topology in an uncertain environment. The main objective of this study is to use the Ricci flow evolution equation of metric and curvature tensor over angular Riemannian metric, and manifold for achieving navigational goals such as path length optimization at the minimum required time, collision-free obstacle avoidance in static and dynamic environments and reaching to the static and dynamic goals. The proposed navigational controller performs linearly and nonlinearly both with reduced error-based objective function by Riemannian metric and scalar curvature, respectively.

Topology and manifolds application-based methodology establishes the resultant drone. The trajectory planning and its optimization are controlled by the system of evolution equation over Ricci flow entropy. The navigation follows the Riemannian metric-based optimal path with an angular trajectory in the range from 0° to 360°. The obstacle avoidance in static and dynamic environments is controlled by the metric tensor and curvature tensor, respectively. The in-house drone is developed and coded using C++. For comparison of the real-time results and simulation results in static and dynamic environments, the simulation study has been conducted using MATLAB software. The proposed controller follows the topological programming constituted with manifold-based objective function and Riemannian metric, and scalar curvature-based constraints for linear and nonlinear navigation, respectively.

This proposed study demonstrates the possibility to develop the new topology-based efficient path planning approach for navigation of drone and provides a unique way to develop an innovative system having characteristics of static and dynamic obstacle avoidance and moving goal chasing in an uncertain environment. From the results obtained in the simulation and real-time environments, satisfactory agreements have been seen in terms of navigational parameters with the minimum error that justifies the significant working of the proposed controller. Additionally, the comparison of the proposed navigational controller with the other artificial intelligent controllers reveals performance improvement.

In this study, a new topological controller has been proposed for drone navigation. The topological drone navigation comprises the effective speed control and collision-free decisions corresponding to the Ricci flow equation and Ricci curvature over the Riemannian metric, respectively.

The purpose of this study is to investigate the feasibility of using additive manufacturing (AM) technique to produce an efficient valve manifold for hydraulic actuator by redesigning valve blocks produced by conventional methods.

A priori, a computational fluid dynamics (CFD) analysis was carried out using the software ANSYS Fluent to determine the optimal flow path that results in least pressure drop, highest average velocity and least energy losses. Fluid–structure interaction (FSI) simulations, processed with imported pressure distribution from the CFD, were conducted to determine the resulting loading and deformations of the manifold assembly.

The new design offers a 23 per cent reduction of oil volume in the circuit, while weighing 84 per cent less. When using the new design, a decrease of pressure drop by nearly 25 per cent and an increase in the average velocity by 2.5 per cent is achieved. A good agreement, within 16 per cent, is found in terms of the pressure drop between the experiment and computational model.

It is possible to build an efficient hydraulic manifold design by iterative refinement for adequate production via selective laser melting (SLM) and minimize used material to circumventing building support structures in non-machinable features of the manifold.

The purpose of this paper is to develop a superconvergent trajectory optimization method for the design of low-thrust transfer trajectories from parking orbit to libration point orbits near the collinear libration points.

The optimization method is developed by merging the concept of Lyapunov feedback control law with the manifold dynamics. First, the whole transfer trajectory is divided into two segments, raising segment and coast segment. Then, the trajectories of each segment are described in different coordinate frames, and designed with Lyapunov feedback control law and the manifold dynamics, respectively. The Poincaré section is used as an effective tool to search the compatible patching point between these two segments on the manifold. Finally, the transfer trajectory is optimized using sequential quadratic programming.

In the numerical simulation, the proposed optimization method does not have any convergence problem. It is a fast and effective method for the very sensitive trajectory optimization problem.

The nonlinear constraints in the original trajectory optimization problem are satisfied by using the Lyapunov feedback control law; hence, the problem is transformed into a nonconstrained parameter optimization problem. The convergence problem of the sensitive optimization problem is solved thoroughly.