Anton Hadar

Methods for Multiscale Modeling of Membranes

Multiscale modeling is a recent approach to simulating molecular systems, such as membranes and liposomes, in which different levels of detail are combined. By using distinct models, it is often possible to speed up or enrich the sampling of a given system. Examples are the use in molecular dynamics simulations of both coarse-grained and fine-grained representations, either simultaneously or alternating in time or space domains. Another possible example is the combination of Monte Carlo and molecular dynamics simulations. This chapter reviews the existing proposed methods of multiscale modeling and simulation and also presents new insights into this fascinating new trend.

Improved OpenMM algorithms for CUDA and OpenCL using new stochastic dynamics and the Berendsen thermostat

The simulations done in molecular dynamics (MD) are used to learn about the behavior of macromolecular systems. While analyzing large macromolecular systems, the computation can last long, many times for days, weeks and months, due to which the need of parallelization occurs for shortening the time. The graphics processing unit (GPU) yields to multithread computational capacity by the use of CUDA high-level language which suits the molecular dynamics algorithms. The OpenCL platform allows its reckoning kernels to run without difficulty on GPUs, as well as on multicore computers. We developed a new thermostat that combines Langevin dynamics with the global Berendsen thermostat which is parallelized in CUDA, as well as in OpenCL. The GPU parallelization is presented in this paper by applying stochastic dynamics, respectively the Langevin integrator, together with the Berendsen thermostat. A system of atoms is tested by taking into consideration the friction coefficient and the coupling parameter.

Advanced Engineering in Orthopedic Surgery Applications

The paper reports the use of advanced engineering tools, techniques and manufacturing process for the preoperative planning, visualization and simulation of complex osteotomy of a diabetic foot (Charcot osteoarthropathy). Two case studies focused on the same clinical data are illustrating the use of medical modeling techniques, reverse engineering and Additive Manufacturing technology in the development of 3D printed anatomical model and customized surgical cutting guides, as well as the use of Augmented Reality (AR) tools for enhancing the communication and information exchange between surgeons, and between surgeons and engineers. A good and accurate communication surgeon-engineer in identifying and selecting anatomical landmarks and supporting surfaces, in establishing the resections trajectories and K-wires positions proved mandatory for the guides’ design process. The importance of using both 3D virtual models, AR models and physical models as collaboration tools is also discussed.

How to design and additive manufacture individualized surgical guides for hand osteotomy

The paper focuses on the design and additive manufacturing of patient-specific surgical guides, in particular for hand osteotomy. The use of these guides allows the surgeon to better orient during surgery, improves intervention accuracy, reduces surgery time and cost and decreases X-ray exposure. They can be used for routine activities or for new and complicated surgical procedures. The processes of design and manufacturing these guides involve tight collaboration between surgeon and engineer for correctly transferring medical requirements into technical specification, which can be a difficult task due to professional language barrier, specific constraints, etc. Therefore, starting from the approach used so far in practice, the paper fundaments the need and presents the current status of implementation of an intelligent online platform, as a modern solution to overcome miscommunication problems and to ensure a degree of automation to a workflow which otherwise has to be resumed for each patient/clinical case.

Improvement of the Dynamic Behavior of a Fan Using Finite Element Method

The first part of this article presents a dynamic analysis of the fan of a generator connected by rigid coupling to a diesel engine. The purpose of this analysis is to correlate the main components of the fan’s frequency response spectrum with the ones of the excitation source, i.e., the diesel engine. The second part describes a finite element analysis of the fan in order to find the best design solution.Copyright