Academic literature on the topic 'Human Simulations'

Human Body Communication (HBC) is a novel communication method between devices which use human body as a transmission medium. This idea is mostly based on the concept of wireless biomedical monitoring system. The on-body sensor nodes can monitor vital signs of a human body and use the body as a transmission medium. This technology is convenient for long durations of clinical monitoring with the option of more mobility and freedom for the user. In this thesis, IEEE 802.15.6-2012 physical (PHY) layer for the HBC was simulated. Simulation model is following the standard’s requirements and processes. The human body was taken as a transmission medium and simulations, which follow the HBC standard, have been carried out. For the purpose of simulations, MATLAB is used as a platform to test and run the simulations. The constants and variables used in the simulations are taken from the IEEE 802.15 working group for wireless personal area networks (WPANs). The transmitter model and the receiver model have been taken from the standard, with changes done in it for performing the simulations on the PHY layer only. The simulations were done keeping in mind the dielectric properties of the outer layer of a human body, i.e., the dielectric values for human skin are noted and their corresponding values were used in the mathematical calculations. The work done here presents a transmitter and receiver architecture for the human body communication. The minimum data rate being 164 kbps and the transmitter being designed around the 21 MHz center frequency has achieved some outputs which are worth looking. The channel models used in this simulator are HBC channel and AWGN (additive white Gaussian noise) channel. It was observed that when signal was passed through AWGN channel, noise was added uniformly over the signal, while in the HBC channel signal strength is directly proportional to the transceiver ground sizes. In conclusion, the size of the ground terminals plays a critical role for the signal quality in the HBC simulator. The results in this thesis show that pathloss has certain linearity with the distance. The pathloss is calculated for different parts of the body with higher loss for structure with higher amount of bone, and vice versa. It is observed that in the HBC channel there are four factors with high impact on the system. These are the distances between the transceiver in air and on body while the other two are the sizes of the transceiver grounds. The size of the transmitter ground has been deemed very significant for the HBC from the simulations results. The four factors show high impact on the HBC channel. The signal strength is highly effected with the change in these four characteristics. From the simulation results it is evident that the HBC channel show a 15 to 20 dB deviation when compared to AWGN channel. The Eb⁄N0 for BER level at 10^(-3) for AWGN channel is 10 to 11 dB while for HBC it is around 27 dB showing a significant difference in the results.

<p>The purpose of this master thesis was to investigate the psychological and computational basis for human behavior representation (HBR) in military simulations and identify problem areas of existent software agent frameworks that provide computer generated forces (CGF) with human like cognitive abilities. The master thesis identifies psychological properties that influence human cognition in an operational environment through a theoretical study of operational and cognitive psychology. The psychological properties of human cognition are then connected to artificial intelligence through a theoretical study of agents and multi-agent systems and form the foundation for identifying general HBR properties. The HBR properties are used as evaluation markers that constitute the basis for constructing an evaluation of relevant agent frameworks thereby visualizing their strengths and weaknesses. The problem areas of incorporating artificial intelligence into CGF are further concretized by the development of a demonstrator that interacts with a synthetic environment. The demonstrator is an implementation of a tank platoon in the agent framework Jadex. The synthetic environment is provided by VR-Forces which is a product by MÄK technologies. The thesis makes a distinction between the conceptual structure of agent frameworks and their actual implementation. According to this master thesis it is the output of the agent framework that is the most important feature not how the output came into being. Producing the correct output requires the selection of the correct tools for the job. The selection of an agent framework should be taken on the background of an evaluation of the simulation requirements. A large portion of the development time is consumed by the development of application and communication interfaces. The problem is a result of lacking standardization and that most cognitive agent frameworks are experimental in nature. In addition the artificial intelligence (AI) in such simulations is often dived into levels, where the synthetic environment takes care of low-level AI and the agent framework the high-level AI. Tight synchronization between low and high-level AI is important if one wishes to create sensible behavior. The purpose of an agent framework in conjunction with CGF is thereby ensuring rapid development and testing of behavior models.</p>

Approved for public release; distribution is unlimited.<br>Search and Target Acquisition (STA) in military simulations is the process of first identifying targets in a particular setting, then determining the probability of detection. This study will focus on the search aspect in STA, particularly with unaided vision. Current algorithms in combat models use an antiquated windshield wiper search pattern when conducting search. The studies used to determine these patterns used aided vision, such as binoculars or night vision devices. Very little research has been conducted for unaided vision and particularly not in urban environments. This study will use a data set taken from an earlier study in Fort Benning, GA, which captured the fixation points of 27 participants in simulated urban environments. This study achieved strong results showing that search is driven by salient scene information and is not random, using a series of nonparametric tests. The proposed algorithm, using points of interest (POIs) for the salient scene information, showed promising results for predicting the initial direction of search from the empirical data. However, the best results were realized when breaking the field of regard (FOR) into a small number of fields of view (FOVs).

Human behavior plays an important role in infectious disease epidemics. The choice of preventive actions taken by individuals can completely change the epidemic outcome. Computational epidemiologists usually employ large-scale agent-based simulations of human populations to study disease outbreaks and assess intervention strategies. Such simulations rarely take into account the decision-making process of human beings when it comes to preventive behaviors. Absence of realistic agent behavior can undermine the reliability of insights generated by such simulations and might make them ill-suited for informing public health policies. In this thesis, we address this problem by developing a methodology to create and calibrate an agent decision-making model for a large multi-agent simulation, in a data driven way. Our method optimizes a cost vector associated with the various behaviors to match the behavior distributions observed in a detailed survey of human behaviors during influenza outbreaks. Our approach is a data-driven way of incorporating decision making for agents in large-scale epidemic simulations.<br>Master of Science<br>In the real world, individuals can decide to adopt certain behaviors that reduce their chances of contracting a disease. For example, using hand sanitizers can reduce an individual‘s chances of getting infected by influenza. These behavioral decisions, when taken by many individuals in the population, can completely change the course of the disease. Such behavioral decision-making is generally not considered during in-silico simulations of infectious diseases. In this thesis, we address this problem by developing a methodology to create and calibrate a decision making model that can be used by agents (i.e., synthetic representations of humans in simulations) in a data driven way. Our method also finds a cost associated with such behaviors and matches the distribution of behavior observed in the real world with that observed in a survey. Our approach is a data-driven way of incorporating decision making for agents in large-scale epidemic simulations.

<p>Study of physical phenomena by means of mathematical models is common in various branches of engineering and science. In biomechanics, modelling often involves studying human motion by treating the body as a mechanical system made of interconnected rigid links. Robotics deals with similar cases as robots are often designed to imitate human behavior. Modelling human movements is a complicated task and, therefore, requires several simplifications and assumptions. Available computational resources often dictate the nature and the complexity of the models. In spite of all these factors, several meaningful results are still obtained from the simulations.</p><p>One common problem form encountered in real life is the movement between known initial and final states in a pre-specified time. This presents a problem of dynamic redundancy as several different trajectories are possible to achieve the target state. Movements are mathematically described by differential equations. So modelling a movement involves solving these differential equations, along with optimization to find a cost effective trajectory and forces or moments required for this purpose.</p><p>In this study, an algorithm developed in Matlab is used to study dynamics of several common human movements. The main underlying idea is based upon temporal finite element discretization, together with optimization. The algorithm can deal with mechanical formulations of varying degrees of complexity and allows precise definitions of initial and target states and constraints. Optimization is carried out using different cost functions related to both kinematic and kinetic variables.</p><p>Simulations show that generally different optimization criteria give different results. To arrive on a definite conclusion on which criterion is superior over others it is necessary to include more detailed features in the models and incorporate more advanced anatomical and physiological knowledge. Nevertheless, the algorithm and the simplified models present a platform that can be built upon to study more complex and reliable models.</p>

This report covers the effect of safety factors on the time taken for humans to escape a building where fire has initiated. Monte Carlo simulation is used to determine the probability of failure to escape in a given fire scenario. The simulations indicate that the safety factor is very influential upon the probability of failure to escape. The major effects upon egress are ranked in this order of significance; time taken for the occupant to decide to leave the building after hearing the alarm, the time until conditions are too hostile for human survival, and the time until the fire is detected. The occupant's travel speed to leave the building has such a low level of significance that it should be treated deterministically in future studies of this type. Where a safety factor of two is applied there is a reasonable probability of failure.

Dissertation (Ph.D. in Modeling, Virtual Environments and Simulation (MOVES))--Naval Postgraduate School, June 2009.<br>Dissertation Advisor(s): Darken, Christian J. "June 2009." Description based on title screen as viewed on July 10, 2009. DTIC Identifiers: Human visual perception, visual attention, eye tracking, human behavior modeling, visual search, semantic relevance, relevance mapa. Author(s) subject terms: Human Visual Perception, Visual Attention, Eye Movements, Eye Tracking, Human Behavior Modeling, Target Detection, Visual Search, Semantic Relevance, Relevance Map. Includes bibliographical references (p. 145-149). Also available in print.

Molecular dynamics (MD) simulations provide a very useful tool for investigating the function of membrane transporters and understanding their transport mechanism at the atomic level. In this thesis, we use MD simulations to study human glucose and glutamate transporters. Glucose transport in humans is mostly mediated by the facilitative glucose transporters, GLUTs. The crystallisation of GLUT3 has opened the way for performing MD simulations to study the transporter. However, it has been shown that most of the popular force fields underestimate the solvation free energy of simple carbohydrates. This could cause inaccuracies in MD simulations, leading to unreliable results. Therefore, we optimised the GLYCAM06 parameters for glucose by boosting the oxygen charges and showed that these new parameters perform well in MD simulations and allow for an accurate calculation of the binding free energy of glucose to GLUT3. Human glutamate transporters, EAATs, clear excess glutamate from the extracellular space. The determination of the crystal structure for EAAT1 has allowed the computational study of this transporter. We performed MD simulations with the crystal structure but we believe that the many mutations in this structure had an impact on the structure. Therefore, we constructed a homology model of WT EAAT1 and with this model we showed that both Na+/Na+ and K+/Na+ co-binding states are feasible, proposing a new transport mechanism where K+ and Na+ exchange in the binding pocket to allow the K+ to escape. Also, we found that the binding mode for aspartate is identical to the one found in a previous study and in agreement with experimental evidence, and we showed that the protonation of Glu406 is necessary for substrate binding. Finally, we studied the effect of two mutations that cause episodic ataxia and found that both mutants were able to bind the first Na+ ion, however, both failed in maintaining the co-binding state.