On the Complexity of Computing Two Nonlinearity Measures

We study the computational complexity of two Boolean nonlinearity measures: the nonlinearity and the multiplicative complexity. We show that if one-way functions exist, no algorithm can compute the multiplicative complexity in time $2^{O(n)}$ given the truth table of length $2^n$, in fact under the same assumption it is impossible to approximate the multiplicative complexity within a factor of $(2-\epsilon)^{n/2}$. When given a circuit, the problem of determining the multiplicative complexity is in the second level of the polynomial hierarchy. For nonlinearity, we show that it is #P hard to compute given a function represented by a circuit

The Frequent Items Problem in Online Streaming under Various Performance Measures

In this paper, we strengthen the competitive analysis results obtained for a fundamental online streaming problem, the Frequent Items Problem. Additionally, we contribute with a more detailed analysis of this problem, using alternative performance measures, supplementing the insight gained from competitive analysis. The results also contribute to the general study of performance measures for online algorithms. It has long been known that competitive analysis suffers from drawbacks in certain situations, and many alternative measures have been proposed. However, more systematic comparative studies of performance measures have been initiated recently, and we continue this work, using competitive analysis, relative interval analysis, and relative worst order analysis on the Frequent Items Problem.Comment: IMADA-preprint-c

From Shaq to Serena Williams: An Analysis of Celebrity SPACs

Special Purpose Acquisition Companies (SPACs) surged in popularity in 2020 and 2021. For the first time in U.S. history, more SPAC IPOs occurred in a particular year than traditional IPOs and direct listings. Amidst the increase in SPAC IPOs, an expanding number of celebrities became involved with these investment vehicles. This thesis investigates the trend of celebrity backed SPACs by examining how celebrity involvement or association with a SPAC may affect the performance of these equities in the market. This study examines the SPAC period returns, deSPAC period returns, IPO sizes, deal lengths, and PIPE financing amounts of 339 SPAC deals that closed between November 30, 2017, to March 17, 2022. SPAC period returns are annualized and measured as of the date of business combination. The deSPAC period returns are measured at the following intervals: one day, three months, and one year following a business combination. I find that there is not a significant difference in the common share performance between celebrity-backed and non-celebrity-backed SPACs at the 90% confidence level at any of the four intervals analyzed. Moreover, IPO sizes, PIPE financing amounts, and deal length are not found to have a significant effect on SPAC or deSPAC period performance. Given that the celebrity-backing of SPACs is a recent phenomenon, future studies should investigate whether there is a celebrity effect on common share performance past the one-year deSPAC interval

Reflection, Interrupted: Material Mirror Work in the Confessio Amantis

The Confessio Amantis concludes with a revelatory scene in which Venus holds up a mirror to Amans, allowing him to recognize John Gower the poet— a moment that is often read as a mimetic and healing counterpoint to the Confessio’s sickness and self-questioning. My intention in this paper is to very slightly modify certain aspects of this narrative, to consider how the materiality of the mirror can inform its metaphoric deployments in the Confessio. I organize my discussion around two seemingly contrasting moments in the poem in which the self is seen and in different ways recognized through a reflective surface: the “Tale of Narcissus,” and the concluding moment in which Amans looks into the mirror to see, eventually, John Gower. Drawing in particular on the production and dissemination of mirrors in the Middle Ages, as well as basic properties of reflection, I point to certain challenges facing the medieval mirror: the hazy reflective properties of the lead mirror, and the impurities of the precariously made, limitedly accessible glass mirror. I ultimately suggest that, more than a revelation through reflective recognition, the Confessio’s ending would have proven most resonant for its portrayal of seeing through a complicated medium

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Taha Toros Arşivi, Dosya No: 118-Ali Sami Boyar. Not: Gazetenin "Sanat Hatıraları" köşesinde yayımlanmıştır.Unutma İstanbul projesi İstanbul Kalkınma Ajansı'nın 2016 yılı "Yenilikçi ve Yaratıcı İstanbul Mali Destek Programı" kapsamında desteklenmiştir. Proje No: TR10/16/YNY/010