Academic articles

Nano-sized wireless ad-hoc networks are expected to play a critical role in future medical, industrial quality control, environmental monitoring and military applications. The networking of nano-nodes will require an even more simple protocol stack, at least until manufacturing capabilities in nano-scales experience a major breakthrough. To this end, the present work introduces a simple physical layer which combines MAC, routing, beam forming and source location discovery capabilities.

The objective of this paper was to determine the effects of adding a healthcare provider in triage on average length of stay (LOS) and proportion of patients with >6 h LOS. The other goal was to assess the accuracy of computer simulation in predicting the magnitude of such effects on these metrics.

This paper presents a hybrid simulation model for the management of an eye condition called age-related macular degeneration, which particularly affects the elderly. The model represents not only the detailed clinical progression of disease in an individual, but also the organization of the hospital clinic in which patients with this condition are treated and the wider environment in which these patients live (and their social care needs, if any, are met). The model permits a ‘whole system’ societal view which captures the interactions between the health and social care systems

In mechanized tunneling a significant loss of performance resulting from weak spots in the supply chain or unforeseen geological conditions is a frequent and costly problem. Furthermore, disturbances of critical machine components can have such impact on the production that unforeseen modifications become necessary. Due to the sequential character the malfunction of one element might evoke cascading-effects which may result in a complete standstill of the tunneling progress. Transparent evaluation of applicable tunnel boring machine designs is essential in order to improve the productivity, avoid unplanned interruptions and to estimate the project duration in general. In order to meet these defiances, this paper presents a multimethod simulation model to investigate the advancement rate of tunnel boring machines. Processrelated disturbances can be considered easily within the presented simulation model. Simulation experiments demonstrate the purposive functionality of the model and visualize the significant influence of technical failure on the overall project performance

The share of renewable energy sources in energy production is growing steadily. Domestic homes can be equipped with solar panels, micro combined heat and power systems, batteries, and they can become adaptive consumers. They can also deliver energy to the grid and react to the energy supply. This paper presents a hybrid simulation approach for the analysis of a grid of domestic homes equipped with different technological options with respect to efficiency and costs. For energy storage and energy flows the system dynamics modeling paradigm is used whereas control decisions are modeled as statecharts. The highly intermittent solar irradiation and also the electric power and heat demands are implemented as stochastic models. The component-based design allows for quick creation of new case studies. As examples, different homes with batteries, micro combined heat and power systems, or energy carrier carbazole as energy storage are analyzed

Software development projects are difficult to manage due to the high uncertainty in their various phases. Simulation is one of the tools that has been used to help software project managers produce project plans. Research into software process simulation modeling (SPSM) shows the dominance of discrete-event simulation and system dynamics. This paper supports the use of ABS in SPSM. We propose a practical effort function to estimate developers’ behavior. The other contribution of this paper is to demonstrate how the ABS model can be developed, calibrated and validated using data readily available to many software development companies/departments. This paper focuses on the construction phase of a tailored Rational Unified Process used in a geographically distributed software development department at AVL. The results look promising but more work needs to be done to include ABS into one of the mainstream simulation paradigms in SPSM

In this paper two different possible machine allocation policies are studied for a production system consisting of MRP and kanban controlled materials. Performance measures are inventory costs, backorder costs and service level. In policy one, the production system is segmented into one segment for MRP planned materials and one for kanban controlled materials. Policy two implements common machine groups for both kinds of materials. A scalable production planning simulation model is applied which is set up by parameterization of the respective database without any model implementation work. For high set-up times and low number of items, we find that whenever utilization of the production system is high, the production system segmentation policy is preferable. However, for medium and low utilization values common machine groups perform best in all scenarios. The scalable simulation model for different kinds of production systems contributes to further research in this field

The Mosque prayer hall is perhaps the only architectural space designed for a large number of floorseated occupants. A critical issue in the design of mosques is determining the number and configuration of exit locations. This paper describes a discrete-event simulation model developed to assess the effect of mosque prayer hall configuration on the egress times of the occupants. The simulation model takes into consideration the behavioral aspects of the mosque occupants such as shoe placement and pickup, after prayer lingering, late egress of front rows, after prayers, and congregations inside and outside the mosque. Most of the various exit configurations possible in mosque design are modeled and assessed for total egress time as well as flow rates. It is shown that one-sided exit location out performs all other configurations. The study presents the first such analysis of mosque egress and the results should of great interest to architects and researchers alike

Product complexity in the aerospace industry has grown fast while design procedures and techniques did not keep pace. Product life cycle implications are largely neglected during the early design phase. Also, aerospace designers fail to optimize products for the intended operational environment. This study shows how a design, simulated within its anticipated operational environment, can inform about critical design parameters, thereby creating a more targeted design improving the chance of commercial success. An agent-based operational simulation for civil Unmanned Aerial Vehicles conducting maritime Search-andRescue missions is used to design and optimize aircrafts. Agent interactions with their environment over the product life-cycle are shown to lead to unexpected model outputs. Unique insights into the optimal design are gained by analysis of the operational performance of the aircraft within its simulated environment

Due to the ageing of the world population, the demand for technology innovations in healthcare is growing rapidly. All stakeholders (e.g., patients, healthcare providers and health industry) can take profit of innovative products, but the development degenerates often into a time consuming and cost-intensive process. Prospective Health Technology Assessment (ProHTA) is a new approach that combines the knowledge of an interdisciplinary team and uses simulation techniques to indicate the effects of new innovations early before the expensive and risky development phase begins. In this paper, we describe an approach with loosely coupled system dynamics and agent-based models within a hybrid simulation environment for ProHTA as well as a use-case scenario with an innovative stroke technology