Design of a second life product family from the perspective of the remanufacturing agent

This thesis presents a method of solving a newly posed Second Life Product Family Design problem. This is unique in that the architecture of the product is not speci ed to be identical to one of the recaptured products, rather it is determined through optimization. The problem is framed using Conjoint Analysis and the Multi Nomial Logit Model, formatted with respect to components available for inclusion in the nal products and then solved using an implementation of Genetic Algorithms. The solution method is also encapsulated in a software module which can be disseminated to industrial users without a background in optimization or familiarity with Genetic Algorithms. A case study is performed to determine the e ectiveness of the proposed solution method, and analyze the in uences di erent market conditions and component similarities can have on the optimal design. It is concluded that the proposed method converges to an optimal Second Life Product Family Design

ARE CATTLE ON FEED REPORT REVISIONS RANDOM AND DOES INDUSTRY ANTICIPATE THEM?

Cattle on Feed (COF) reports are an important source of beef supply information. This study investigates whether COF report revisions are unbiased, random, and anticipated. Initial COF reports are biased, but the bias is economically small. Revisions to COF estimates are not random. Market analysts do not correctly anticipate revisions.Livestock Production/Industries,

Crossover to Potential Energy Landscape Dominated Dynamics in a Model Glass-forming Liquid

An equilibrated model glass-forming liquid is studied by mapping successive configurations produced by molecular dynamics simulation onto a time series of inherent structures (local minima in the potential energy). Using this ``inherent dynamics'' approach we find direct numerical evidence for the long held view that below a crossover temperature, $T_x$, the liquid's dynamics can be separated into (i) vibrations around inherent structures and (ii) transitions between inherent structures (M. Goldstein, J. Chem. Phys. {\bf 51}, 3728 (1969)), i.e., the dynamics become ``dominated'' by the potential energy landscape. In agreement with previous proposals, we find that $T_x$ is within the vicinity of the mode-coupling critical temperature $T_c$. We further find that at the lowest temperature simulated (close to $T_x$), transitions between inherent structures involve cooperative, string like rearrangements of groups of particles moving distances substantially smaller than the average interparticle distance.Comment: Expanded from 4 to 7 page

Electromagnetic cascade in high energy electron, positron, and photon interactions with intense laser pulses

The interaction of high energy electrons, positrons, and photons with intense laser pulses is studied in head-on collision geometry. It is shown that electrons and/or positrons undergo a cascade-type process involving multiple emissions of photons. These photons can consequently convert into electron-positron pairs. As a result charged particles quickly lose their energy developing an exponentially decaying energy distribution, which suppresses the emission of high energy photons, thus reducing the number of electron-positron pairs being generated. Therefore, this type of interaction suppresses the development of the electromagnetic avalanche-type discharge, i.e., the exponential growth of the number of electrons, positrons, and photons does not occur in the course of interaction. The suppression will occur when 3D effects can be neglected in the transverse particle orbits, i.e., for sufficiently broad laser pulses with intensities that are not too extreme. The final distributions of electrons, positrons, and photons are calculated for the case of a high energy e-beam interacting with a counter-streaming, short intense laser pulse. The energy loss of the e-beam, which requires a self-consistent quantum description, plays an important role in this process, as well as provides a clear experimental observable for the transition from the classical to quantum regime of interaction.Comment: 13 pages, 7 figure

Solution of nonlinear algebraic equations characteristic of filter circuits Summary technical report

Digital computer program developed for solving nonlinear algebraic equations characteristic of filter circuit

Hopping in Disordered Media: A Model Glass Former and A Hopping Model

Two models involving particles moving by ``hopping'' in disordered media are investigated: I) A model glass-forming liquid is investigated by molecular dynamics under (pseudo-) equilibrium conditions. ``Standard'' results such as mean square displacements, intermediate scattering functions, etc. are reported. At low temperatures hopping is present in the system as indicated by a secondary peak in the distribution of particle displacements during a time interval 't'. The dynamics of the model is analyzed in terms of its potential energy landscape (potential energy as function of the 3N particle coordinates), and we present direct numerical evidence for a 30 years old picture of the dynamics at sufficiently low temperatures. Transitions between local potential energy minima in configuration space are found to involve particles moving in a cooperative string-like manner. II) In the symmetric hopping model particles are moving on a lattice by doing thermally activated hopping over energy barriers connecting nearest neighbor sites. This model is analyzed in the extreme disorder limit (i.e. low temperatures) using the Velocity Auto Correlation (VAC) method. The VAC method is developed in this thesis and has the advantage over previous methods, that it can calculate a diffusive regime in finite samples using periodic boundary conditions. Numerical results using the VAC method are compared to three analytical approximations, including the Diffusion Cluster Approximation (DCA), which is found to give excellent agrement with the numerical results.Comment: Ph.D. thesis, 101 pages, 52 figure