Physics in the Garden

The Final Design Review (FDR) report explains the initial research, design process, finalized design, manufacturing and assembly methods, and testing done by the senior project group in Mechanical Engineering Department at California Polytechnic State University, San Luis Obispo. For this project, the San Luis Obispo Botanical Garden would like to develop an educational and interactive exhibit that conveys a lesson in physics. The Botanical Garden envisions an exciting feature to educate children on physical science and broaden the appeal of the garden. This document captures the problem’s scope, requirements, initial concept, design research, target demographic, ideation, evaluation processes, and project timeline. The evaluation process includes Weighted Decision Matrices, which led to the final concept design. The final design and justifications for each component explains why each material and design were chosen. The manufacturing plan describes how each component and assembly will be produced. The design verification plan shows various tests to ensure safety, ease of maintenance, and longevity. Our team’s final design is a gearbox, which demonstrates how gear size and ratio affect gear speed, along with how gears are commonly used in everyday objects. The included project Gantt Chart displays major milestones that were met throughout this project

Over-Fit: Noisy-Label Detection based on the Overfitted Model Property

Due to the increasing need to handle the noisy label problem in a massive dataset, learning with noisy labels has received much attention in recent years. As a promising approach, there have been recent studies to select clean training data by finding small-loss instances before a deep neural network overfits the noisy-label data. However, it is challenging to prevent overfitting. In this paper, we propose a novel noisy-label detection algorithm by employing the property of overfitting on individual data points. To this end, we present two novel criteria that statistically measure how much each training sample abnormally affects the model and clean validation data. Using the criteria, our iterative algorithm removes noisy-label samples and retrains the model alternately until no further performance improvement is made. In experiments on multiple benchmark datasets, we demonstrate the validity of our algorithm and show that our algorithm outperforms the state-of-the-art methods when the exact noise rates are not given. Furthermore, we show that our method can not only be expanded to a real-world video dataset but also can be viewed as a regularization method to solve problems caused by overfitting.Comment: 10 pages, 7 figure

Particulate counter electrode system for enhanced light harvesting in dye-sensitized solar cells

A particulate counter electrode with photo scattering and redox catalytic properties is applied to dye sensitized solar cells (DSSCs) in order to improve photo conversion efficiency and simplify the assembly process. Our particulate counter electrode acts as both a photo reflecting layer and a catalyst for reduction of electrolyte. The reflective and catalytic properties of the electrode are investigated through optical and electrochemical analysis, respectively. A short circuit current density enhancement is observed in the DSSCs without the need to add an additional reflecting layer to the electrode. This leads to a simplified assembly process. (C) 2013 Optical Society of Americ

Performance of a lead rubber damper under cyclic shear loading and its applicability to a full-scale structure

In this paper, we investigate the performance of a new lead rubber damper (LRD) and its applicability to a full-scale structure. This device is more advanced than existing lead-rubber based isolation devices. In contrast to the existing devices, multiple lead cores are installed in the LRD in order to enhance the performance of the laminated rubber and lead. It is able to perform effectively under the application of shear force. An experiment was performed to investigate its dependency on the level of shear strain and frequency. The applicability of this new device to a full-scale structure is also examined by performing a vibration test on a five floor modal-test tower

The Effects of Discrimination Experience on Life Satisfaction of North Korean Refugees:Mediating Effect of Stress

Objective This study investigated the mediation effect of stress between the experience of discrimination and life satisfaction among North Korean refugees who resettled in South Korea. The findings of the current study provide empirical evidence for the need of social interventions to mitigate adverse effects of stress on North Korean refugees who are subject to social discrimination on a daily basis. Methods In this study, we included 500 subjects among 2,138 North Korean refugees who took refuge in South Korea in 2007. The interview started from April 6th 2009 and finished on May 25th 2009. We conducted moderator effect analysis with Path analysis was conducted because we confirm the experience of discrimination was affected by life satisfaction and stress can affected life satisfaction as a moderator. Results The experience of discrimination significantly affects stress and stress significantly affects life satisfaction. However, the experience of discrimination was not directly related to life satisfaction. The more stress the study respondents experienced, the lower the life satisfaction they reported. Conclusion The present finding suggests that the effects of discriminating experiences on the life satisfaction of North Korean refugees in South Korea were mediated by their own perceived stress