Shape matching and clustering in design

Generalising knowledge and matching patterns is a basic human trait in re-using past experiences. We often cluster (group) knowledge of similar attributes as a process of learning and or aid to manage the complexity and re-use of experiential knowledge [1, 2]. In conceptual design, an ill-defined shape may be recognised as more than one type. Resulting in shapes possibly being classified differently when different criteria are applied. This paper outlines the work being carried out to develop a new technique for shape clustering. It highlights the current methods for analysing shapes found in computer aided sketching systems, before a method is proposed that addresses shape clustering and pattern matching. Clustering for vague geometric models and multiple viewpoint support are explored

Illumination uniformity in endoscopic imaging

Standardised endoscopic digital images were taken and analysed using an image analysis software (National Instruments Vision Assistant version 7.1.1). The luminance plane was extracted and the pixel intensity distribution was determined along a horizontal line at the position of highest average intensity (centroid). The data was exported to MS Excel and the pixel intensity (y-axis) was plotted against pixel position (x-axis). A trendline using a 2nd order polynomial curve was fitted to each data set. The resultant equation for each curve was compared with equations obtained from other images taken under various illumination conditions and settings

Cavity optoelectromechanical regenerative amplification

Cavity optoelectromechanical regenerative amplification is demonstrated. An optical cavity enhances mechanical transduction, allowing sensitive measurement even for heavy oscillators. A 27.3 MHz mechanical mode of a microtoroid was linewidth narrowed to 6.6\pm1.4 mHz, 30 times smaller than previously achieved with radiation pressure driving in such a system. These results may have applications in areas such as ultrasensitive optomechanical mass spectroscopy

Positron annihilation induced Auger electron spectroscopy

Recently, Weiss et al. have demonstrated that it is possible to excite Auger transitions by annihilating core electrons using a low energy (less than 30eV) beam of positrons. This mechanism makes possible a new electron spectroscopy, Positron annihilation induced Auger Electron Spectroscopy (PAES). The probability of exciting an Auger transition is proportional to the overlap of the positron wavefunction with atomic core levels. Since the Auger electron energy provides a signature of the atomic species making the transition, PAES makes it possible to determine the overlap of the positron wavefunction with a particular element. PAES may therefore provide a means of detecting positron-atom complexes. Measurements of PAES intensities from clean and adsorbate covered Cu surfaces are presented which indicate that approx. 5 percent of positrons injected into CU at 25eV produce core annihilations that result in Auger transitions

Scalable Spatial Super-Resolution using Entangled Photons

N00N states -- maximally path-entangled states of N photons -- exhibit spatial interference patterns sharper than any classical interference pattern. This is known as super-resolution. However, even with perfectly efficient number-resolving detectors, the detection efficiency of all previously demonstrated methods to measure such interference decreases exponentially with the number of photons in the N00N state, often leading to the conclusion that N00N states are unsuitable for spatial measurements. Here, we create spatial super-resolution fringes with two-, three-, and four-photon N00N states, and demonstrate a scalable implementation of the so-called ``optical centroid measurement'' which provides an in-principle perfect detection efficiency. Moreover, we compare the N00N-state interference to the corresponding classical super-resolution interference. Although both provide the same increase in spatial frequency, the visibility of the classical fringes decreases exponentially with the number of detected photons, while the visibility of our experimentally measured N00N-state super-resolution fringes remains approximately constant with N. Our implementation of the optical centroid measurement is a scalable method to measure high photon-number quantum interference, an essential step forward for quantum-enhanced measurements, overcoming what was believed to be a fundamental challenge to quantum metrology

The Meme Stock Frenzy: Origins and Implications

In 2021, several publicly traded companies, such as GameStop and AMC, became “meme stocks,” experiencing a sharp rise in their stock prices through a dramatic influx of retail investors into their shareholder base. Analyses of the meme stock surge and its implications for corporate governance have focused on the idiosyncratic creation of online communities around particular stocks during the COVID-19 pandemic. In this Article, we argue that the emergence of meme stocks is part of longer-running digital transformations in trading, investing, and governance. On the trading front, the sudden abolition of commissions by major online brokerages in 2019 reduced entry costs for retail investors. Zero-commission trading represents a modification of the payment for order flow (PFOF) system, which is itself a product of technological disruptions in the financial markets in the 1980s. With respect to investing, the emergence of social media communication amplified retail investors’ pre-existing dependence on social networks to make decisions regarding stock market entry and portfolio construction. It also allowed them to coordinate their investing activities and affect the market price while expressing their non-financial interests. Finally, while some startups have attempted to bring the shareholder experience into the digital age and help retail investors participate in governance, these developments have been relatively modest. After tracing the meme stock phenomenon, we sketch a research agenda for law and finance scholars to explore the concrete effects of meme investing on corporate governance outcomes. First, we ask whether retail traders can transform into enthusiastic retail shareholders engaged in corporate governance. Second, we propose a broader metric for “meme-ness”: future scholarship can use modern advances in data science to better identify which companies are vulnerable to meme surges and social media-driven investing unrelated to their financial fundamentals

Meme Corporate Governance

Can retail investors revolutionize corporate governance and make public companies more responsive to social concerns? The U.S. stock market offered an unusual experiment to test the impact of retail investors in 2021, when there was a dramatic influx of retail investors into the shareholder base of companies such as GameStop and AMC. The meme surge phenomenon elicited a variety of reactions from scholars and practitioners. While some worried that affected companies’ share prices were becoming disjointed from their financial fundamentals, others predicted that retail shareholders will reduce the power of large institutional investors and democratize corporate governance. This Article presents the first empirical analysis of the impact of retail investors on the governance of companies affected by the “meme stock surge.” The Article presents three principal findings. First, we show how the “meme stock” frenzy was affected by the introduction of the commission-free trading platform, such as Robinhood, in 2019. We show that the meme stock companies experienced higher abnormal stock returns when commission-free trading was widely introduced, and saw elevated trading volumes afterward. Second, we examine how the influx of retail shareholders has directly affected the governance outcomes at the meme stock companies. Notwithstanding the promise of a more active retail shareholder base, we show that meme stock companies have experienced a significant decrease in participation by their shareholders with respect to voting. Shareholder proposals under Rule 14a-8 have also been extremely limited, with most meme firms seeing no proposals brought after the rapid increase in retail ownership. Third, we examine whether the increase in retail shareholder base had any indirect effect on corporate governance and performance. While board gender diversity at these firms is broadly unchanged, their ESG scores have gotten worse subsequent to the meme surge. Examining meme firms’ use of corporate funds, we find decreases in research and development and capital expenditures after the meme surge. Collectively, our findings suggest that the influx of retail shareholders at these companies have not translated into more “democratic” governance regimes or reduced agency costs, even at firms the scholarly and popular commentary had highlighted as the cynosure of the retail investor storm

Meme Corporate Governance

Can retail investors revolutionize corporate governance and make public companies more responsive to social concerns? Beginning in 2021, there was a dramatic influx of retail investors into the shareholder base of “meme” stock companies such as GameStop, AMC, and Bed Bath & Beyond. Observing the unprecedented, coordinated trading among retail investors, scholars and practitioners predicted that the influx of retail investors would reduce the power of large institutional investors and democratize corporate governance. These predictions were driven by three factors: generational, with assumptions that millennial and Gen Z investors would challenge corporate management; societal, reflecting growing discontent with slow progress on issues such as sustainability and boardroom diversity; and technological, with the advent of easily accessible and user-friendly mobile apps allowing investors to directly intervene in corporate governance. While plausible, these predictions have so far not been tested. This Article empirically analyzes the impact of retail investors on corporate governance, particularly at meme stock companies. We provide new quantitative evidence regarding the origins of meme investing and conclude that—despite their coordinated trading behavior in the market—meme investors have not democratized corporate governance or advanced social issues. The Article presents three principal findings. First, we show how the “meme stock” frenzy was affected by the abolition of trading commissions by major brokerages in 2019. Meme stock companies experienced positive abnormal stock returns when commission-free trading was widely introduced and saw elevated trading volumes afterward. Second, we find that despite the promise of a more active retail shareholder base, meme stock companies experienced a significant decrease in shareholder voting. Shareholder proposals have also been very limited, with most meme stock companies seeing no proposals after the rapid rise in retail ownership. Third, we do not find any improvement in meme stock companies’ corporate governance, financial performance, and social responsibility, as represented by director independence, board gender diversity, ESG scores, and capital and R&D expenditures. Collectively, our findings suggest that the influx of retail shareholders has not translated into more “democratic” governance regimes or encouraged shareholder participation in corporate governance at companies most affected by the meme investor storm