Inferring Size-Based Functional Responses From the Physical Properties of the Medium

First derivations of the functional response were mechanistic, but subsequent uses of these functions tended to be phenomenological. Further understanding of the mechanisms underpinning predator-prey relationships might lead to novel insights into functional response in natural systems. Because recent consideration of the physical properties of the environment has improved our understanding of predator-prey interactions, we advocate the use of physics-based approaches for the derivation of the functional response from first principles. These physical factors affect the functional response by constraining the ability of both predators and prey to move according to their size. A physics-based derivation of the functional response should thus consider the movement of organisms in relation to their physical environment. One recent article presents a model along these criteria. As an initial validation of our claim, we use a slightly modified version of this model to derive the classical parameters of the functional response (i.e., attack rate and handling time) of aquatic organisms, as affected by body size, buoyancy, water density and viscosity. We compared the predictions to relevant data. Our model provided good fit for most parameters, but failed to predict handling time. Remarkably, this is the only parameter whose derivation did not rely on physical principles. Parameters in the model were not estimated from observational data. Hence, systematic discrepancies between predictions and real data point immediately to errors in the model. An added benefit to functional response derivation from physical principles is thus to provide easy ways to validate or falsify hypotheses about predator-prey relationships.

Motorcycle Accident Reconstruction

Accident reconstruction utilizes principles of physics and empirical data to analyze the physical, electronic, video, audio, and testimonial evidence from a crash, to determine how and why the crash occurred, how the crash could have been avoided, or to determine whose description of the crash is most accurate. This process draws together aspects of mathematics, physics, engineering, materials science, human factors, and psychology, and combines analytical models with empirical test data. Different types of crashes produce different types of evidence and call for different analysis methods. Still, the basic philosophical approach of the reconstructionist is the same from crash type to crash type, as are the physical principles that are brought to bear on the analysis. This book covers a basic approach to accident reconstruction, including the underlying physical principles that are used, then details how this approach and the principles are applied when reconstructing motorcycle crashes. This second edition of Motorcycle Accident Reconstruction presents a thorough, systematic, and scientific overview of the available methods for reconstructing motorcycle crashes. This new edition contains: Additional theoretical models, examples, case studies, and test data. An updated bibliography incorporating the newest studies in the field. Expanded coverage of the braking capabilities of motorcyclists. Updated, refined, and expanded discussion of the decelerations of motorcycles sliding on the ground. A thoroughly rewritten and expanded discussion of motorcycle impacts with passenger vehicles. Updated coefficients of restitution for collisions between motorcycles and cars. A new and expanded discussion of using passenger car EDR data in motorcycle accident reconstruction. A new section covering recently published research on post-collision frozen speedometer readings on motorcycles. A new section on motorcycle interactions with potholes, roadway deterioration, and debris and expanded coverage of motorcycle falls. This second edition of Motorcycle Accident Reconstruction is a must-have title for accident reconstructionists, forensic engineers, and all interested in understanding why and how motorcycle crashes occur.

PR_29 Photon-Pair Generation using Coupled Silicon Microring Resonators (1201308-PO)

The physical principles of entangled photon-pair generation in coupled silicon microring resonators were studied theoretically and experimentally. Summary of a Project Outcomes report of research funded by the National Science Foundation under Project Number 1201308.

Withdrawing a non-Newtonian fluid by a moving inclined plate with account for the near-wall split effect

A fluid withdrawn by a moving inclined surface with account for the near-wall slip effect is analyzed theoretically. A non-Newtonian fluid task is stated in general form. The solving of this task enables revealing the basic physical principles and mechanisms of the process over the entire withdrawal velocity range realized in practice. The case of withdrawing a finite yield stress viscoplastic fluid is considered.

Analysis and forecasting of fog over Bangalore airport

The fog over Bangalore airport has been analysed. The different favourable conditions on the previous night of the fog day has been studied. Attempts have been made to forecast the fog using different techniques. The Composite method is a new objective method which provides a better technique both in terms of physical principles and statistics. The accuracy of different methods have been calculated for the purpose of comparison. The most important result of the analysis is that the frequency of duration and intensity of fog have gradually increased from the decade of 80s to the decade of 90s which may be due to the increase in pollution of air, other factors remaining unchanged.

Model and method development for determining the completeness of information for remote detection of landmarks for autonomous mobile robots

The object of research is the completeness of information for making a navigation decision by an autonomous mobile robot when it performs a task in an unfamiliar area without GPS. It is difficult to identify a landmark in the absence and abundance of information. One of the most problematic places is the mathematical description of the criterion according to which an autonomous robot makes a decision about the completeness of information. The paper substantiates a model and method for determining the completeness of information by a robot equipped with several landmarks detection tools operating on different physical principles. It is shown that the implementation of the method requires a priori information on the probability of detecting various landmarks by passive and active means against a continuous and discontinuous background at different illumination of objects, in day and night conditions under different weather conditions. The values of the probability of detecting a specific type of landmark obtained in such studies serve as the basis for constructing an information cadastre for a job performing tasks on the ground. Three formulas are proposed for determining the coefficient of completeness of information, taking into account a priori and a posteriori inventories, and recommended areas of application. The value of this coefficient depends on the threshold level of the probability of detecting a landmark. The reliability of a decision made by a robot is greatest when it is made under conditions of a certain level of completeness of information. The proposed method can be used for other technical objects from which the measurement information is received. Compared with the known methods, it expands the boundaries of application and reveals the possibility of assessing the completeness of information in constantly changing conditions. Along with a change in these conditions, the characteristics of the completeness of information also change. The coefficient of completeness of information can approach unity even in the absence of separate means of detecting landmarks, and then the method makes it possible to assess the need for their use in the given conditions.

Modern laser-technologies and nanotechnologies - next-generation on new physical principles

In the paper we discuss new tendencies and trends in laser/nanotechnologies based on topological material-science with spatial structures of necessary types induced by laser radiation on solid surface. Review of the current state of research on this issue, main directions and scientific advantages are presented. In our study we used originally manufactured the multibeam laser-technological automated complex for thermal hardening of the surface of different products with variable elemental composition. The database for several functional characteristics, varied under processing by laser radiation the surface of materials, is given.

MULTIFUNCTIONAL SENSOR BASED ON A PLANAR CAPACITOR FOR REMOTE SENSING

The article deals with the issues related to the technical implementation of environmental sensing using capacitive sensors. It proposes a design of a capacitive sensor of a planar type, and studies physical principles of its operation. The operation of the sensor in two main modes is analyzed: 1) determination of the distance to the object at known electrophysical characteristics of the object; 2) determination of the electrophysical characteristics of the object at a known distance to it. The article provides data of direct measurements of the sensor capacitance and its output signal level under various conditions.