Nonlinear profile monitoring using spline functions

[[abstract]]In this study, two new integrated control charts, named T2-MAE chart and MS-MAE chart, are introduced for monitoring the quality of a process when the mathematical form of nonlinear profile model for quality measure is complicated and unable to be specified. The T2-MAE chart is composed of two memoryless-type control charts and the MS-MAE chart is composed of one memory-type and one memoryless-type control charts. The normality assumption of error terms in the nonlinear profile model for both proposed control charts are extended to a generalized model. An intensive simulation study is conducted to evaluate the performance of the T2-MAE and MS-MAE charts. Simulation results show that the MS-MAE chart outperforms the T2-MAE chart with less false alarms during the Phase I monitoring. Moreover, the MS-MAE chart is sensitive to different shifts on the model parameters and profile shape during the Phase II monitoring. An example about the vertical density profile is used for illustration.[[notice]]補正完

Development of Traffic Live Load Models for Bridge Superstructure Rating with RBDO and Best Selection Approach

Reliability-based design optimization (RBDO) is frequently used to determine optimal structural geometry and material characteristics that can best meet performance goals while considering uncertainties. In this study, the effectiveness of RBDO to develop a rating load model for a set of bridge structures is explored, as well as the use of an alternate Best Selection procedure that requires substantially less computational effort. The specific problem investigated is the development of a vehicular load model for use in bridge rating, where the objective of the optimization is to minimize the variation in reliability index across different girder types and bridge geometries. Moment and shear limit states are considered, where girder resistance and load random variables are included in the reliability analysis. It was found that the proposed Best Selection approach could be used to develop rating model as nearly as effective as an ideal RBDO solution but with significantly less computational effort. Both approaches significantly reduced the range and coefficient of variation of reliability index among the bridge cases considered

Pushing the limits of Marangoni-driven patterning

Marangoni-driven patterning (MDP) is a relatively new technique that harnesses surface tension-driven flows to create topography in thin polymer films with potential uses in generating flexible electronics, metamaterials, and functional coatings for light capture, adhesive, and antibiofouling applications. To determine which applications MDP is best suited for, it is important to understand the fundamental limits of achievable pattern pitch and aspect ratio. To date, the maximum reported aspect ratio for MDP is roughly 0.05 and the minimum reported feature pitch is roughly 1.5 μm. To determine how much these metrics could be improved, we perform a numerical analysis to predict the maximum aspect ratio and minimum feature pitch for MDP. Our analysis shows that the maximum aspect ratio is roughly 0.5, which is roughly ten times better than what has been demonstrated to date. We also show that the pattern pitch is fundamentally limited by light-imaging capabilities and engineering constraints. One issue facing MDP is the leftover residual layer that blocks access to the substrate and necessitates a breakthrough etch for subsequent patterning. To avoid this extra processing step, we investigate the possibility of inducing a dewetting event during MDP, which could expose the underlying substrate during the annealing step and even improve the aspect ratio of the resulting pattern. Through modelling and simulation, we predict the conditions necessary to induce a dewetting event in MDP. Another issue in MDP is pattern control. When generating two-dimensional shapes like squares, simulations show that the corners and edges of the shape are significantly rounded. To improve pattern quality, we implement an algorithm to optimize the initial exposure to generate more favorable flow patterns and sharper topography. We also experimentally validate this work using a polystyrene polymer system. Finally, we investigate the root cause of unexpected bias reversal in spin-coated, conformal polymer films. Our model and simulation results show that Marangoni-driven flow could be responsible for this observation.Chemical Engineerin

Progress Report No. 24

Progress report of the Biomedical Computer Laboratory, covering period 1 July 1987 to 30 June 1988

Design and Implementation of Stewart Platform Robot for Robotics Course Laboratory

A Stewart Platform robot was designed, constructed, and programmed for use in Cal Poly’s ME 423 Robotics: Fundamentals and Applications laboratory section. A Stewart Platform is a parallel manipulator robot with six prismatic joints that has six degrees of freedom, able to be defined in both position and orientation. Its purpose is to supplement parallel robot material covered in lecture. Learning objectives include applying and verifying the Stewart Platform inverse kinematics and investigating the Stewart Platform’s operation, range of motion, and limitations. The Stewart Platform geometry and inverse kinematics were modeled and animated using MATLAB. The platform was then built using linear actuators, magnetic spherical bearings, and acrylic plates. Control of the Stewart Platform is achieved using an Arduino Due and a custom HexaMoto shield. Users interact with the system using a GUI created with MATLAB’s App Designer

MEMS Technology for Biomedical Imaging Applications

Biomedical imaging is the key technique and process to create informative images of the human body or other organic structures for clinical purposes or medical science. Micro-electro-mechanical systems (MEMS) technology has demonstrated enormous potential in biomedical imaging applications due to its outstanding advantages of, for instance, miniaturization, high speed, higher resolution, and convenience of batch fabrication. There are many advancements and breakthroughs developing in the academic community, and there are a few challenges raised accordingly upon the designs, structures, fabrication, integration, and applications of MEMS for all kinds of biomedical imaging. This Special Issue aims to collate and showcase research papers, short commutations, perspectives, and insightful review articles from esteemed colleagues that demonstrate: (1) original works on the topic of MEMS components or devices based on various kinds of mechanisms for biomedical imaging; and (2) new developments and potentials of applying MEMS technology of any kind in biomedical imaging. The objective of this special session is to provide insightful information regarding the technological advancements for the researchers in the community