Secrecy in the American Revolution

This paper analyzes how the use of various cryptographic and cryptanalytic techniques affected the American Revolution. By examining specific instances of and each country\u27s general approaches to cryptography and cryptanalysis, it is determined that America\u27s use of these techniques provided the rising nation with a critical advantage over Great Britain that assisted in its victory

Comparación de la dinámica e impactos de los choques financieros y de términos del intercambio en América Latina en el período 1980-2006

Incluye BibliografíaResumenEn el período 1960-2006, en los países de América Latina se observa un aumento de la frecuencia y la amplitud de los ciclos económicos. Entre 1960 y 1995 la región registró, en promedio, una aceleración (desaceleración); cada cuatro años, frecuencia que pasó a dos años a partir de 1995. Asimismo, la amplitud promedio de los ciclos del PIBprácticamente se duplicó a partir de 1995.La dinámica del ciclo económico ha estado históricamente ligada a las fluctuaciones de los términos del intercambio y los flujos financieros. La importancia relativa de aquellas ha variado con el tiempo: el coeficiente de correlación entre el ciclo del producto interno bruto regional y las fluctuaciones financieras aumentó significativamente en la década de 1990. Las fluctuaciones de los términos del intercambio tuvieron una importancia relativa mayor entre 1960 y 1980 y entre 2002-2006.Dada la importancia de las fluctuaciones de los términos del intercambio y de los flujos financieros en los ciclos económicos, el documento identifica y describe la dinámica de las fluctuaciones más extremas (es decir, los choques); de los términos del intercambio y los flujos financieros de América Latina en el período 1980-2006 evaluando su impacto sobre el crecimiento económico.Se identifican los choques de acuerdo con una metodología estadística que separa los componentes de tendencia y ciclo de la serie. Luego, sobre la base de la construcción de distribuciones de probabilidad empíricas y los respectivos intervalos de confianza, se definen los años de choques financieros y de términos del intercambio

Why Industry Professionals Should Care About Fandom

A fandom is a community of people who share a common interest and interact with each other on the basis of that common interest. When a fandom comes together on the basis of a creative work, it allows a mutually beneficial relationship to form in which the fandom will eagerly consume existing content, allowing new content to be produced for their consumption. Thus, professionals in industries such as publishing, theater, and television and film should be aware of the integral role fandoms play in the consumption of their content and how to nurture fandoms through the means discussed in this article

Homosexuality During the Transition from Weimar Republic to Third Reich

Homosexual communities successfully formed prominent subcultures during the Weimar Republic for a multitude of reasons: scientific research and educational outreach to the public about the inborn nature of homosexuality, less strict media censorship laws, and a vague anti-sodomy law that was difficult to enforce led police to often prefer tolerance over prosecution. The Third Reich brought about a deep cultural shift that would prove incredibly harmful to the homosexual communities. While at first, homosexuals had not been a targeted group largely thanks to Hitler’s personal friendship with a gay Nazi named Ernst Röhm, the latter’s sexuality became the center of a targeted media attack against the Nazis and Röhm was eventually killed. After that, it became convenient for the Nazis to scapegoat homosexuals and use their prosecution and persecution to appease the Nazis’ morally conservative supporters. Furthermore, Heinrich Himmler’s personal agenda against homosexuals aligned with Hitler’s vision of a homogenous society

Optimal Testing of Generalized Reed-Muller Codes in Fewer Queries

A local tester for an error correcting code $C\subseteq \Sigma^{n}$ is a tester that makes $Q$ oracle queries to a given word $w\in \Sigma^n$ and decides to accept or reject the word $w$. An optimal local tester is a local tester that has the additional properties of completeness and optimal soundness. By completeness, we mean that the tester must accept with probability $1$ if $w\in C$. By optimal soundness, we mean that if the tester accepts with probability at least $1-\epsilon$ (where $\epsilon$ is small), then it must be the case that $w$ is $O(\epsilon/Q)$-close to some codeword $c\in C$ in Hamming distance. We show that Generalized Reed-Muller codes admit optimal testers with $Q = (3q)^{\lceil{ \frac{d+1}{q-1}\rceil}+O(1)}$ queries. Here, for a prime power $q = p^{k}$, the Generalized Reed-Muller code, RM[n,q,d], consists of the evaluations of all $n$-variate degree $d$ polynomials over $\mathbb{F}_q$. Previously, no tester achieving this query complexity was known, and the best known testers due to Haramaty, Shpilka and Sudan(which is optimal) and due to Ron-Zewi and Sudan(which was not known to be optimal) both required $q^{\lceil{\frac{d+1}{q-q/p} \rceil}}$ queries. Our tester achieves query complexity which is polynomially better than by a power of $p/(p-1)$, which is nearly the best query complexity possible for generalized Reed-Muller codes. The tester we analyze is due to Ron-Zewi and Sudan, and we show that their basic tester is in fact optimal. Our methods are more general and also allow us to prove that a wide class of testers, which follow the form of the Ron-Zewi and Sudan tester, are optimal. This result applies to testers for all affine-invariant codes (which are not necessarily generalized Reed-Muller codes).Comment: 42 pages, 8 page appendi

Characterizing Direct Product Testing via Coboundary Expansion

A $d$-dimensional simplicial complex $X$ is said to support a direct product tester if any locally consistent function defined on its $k$-faces (where $k\ll d$) necessarily come from a function over its vertices. More precisely, a direct product tester has a distribution $\mu$ over pairs of $k$-faces $(A,A')$, and given query access to $F\colon X(k)\to\{0,1\}^k$ it samples $(A,A')\sim \mu$ and checks that $F[A]|_{A\cap A'} = F[A']|_{A\cap A'}$. The tester should have (1) the ``completeness property'', meaning that any assignment $F$ which is a direct product assignment passes the test with probability $1$, and (2) the ``soundness property'', meaning that if $F$ passes the test with probability $s$, then $F$ must be correlated with a direct product function. Dinur and Kaufman showed that a sufficiently good spectral expanding complex $X$ admits a direct product tester in the ``high soundness'' regime where $s$ is close to $1$. They asked whether there are high dimensional expanders that support direct product tests in the ``low soundness'', when $s$ is close to $0$. We give a characterization of high-dimensional expanders that support a direct product tester in the low soundness regime. We show that spectral expansion is insufficient, and the complex must additionally satisfy a variant of coboundary expansion, which we refer to as \emph{Unique-Games coboundary expanders}. Conversely, we show that this property is also sufficient to get direct product testers. This property can be seen as a high-dimensional generalization of the standard notion of coboundary expansion over non-Abelian groups for 2-dimensional complexes. It asserts that any locally consistent Unique-Games instance obtained using the low-level faces of the complex, must admit a good global solution

Near Optimal Alphabet-Soundness Tradeoff PCPs

We show that for all $\varepsilon>0$, for sufficiently large prime power $q$, for all $\delta>0$, it is NP-hard to distinguish whether a 2-Prover-1-Round projection game with alphabet size $q$ has value at least $1-\delta$, or value at most $1/q^{(1-\epsilon)}$. This establishes a nearly optimal alphabet-to-soundness tradeoff for 2-query PCPs with alphabet size $q$, improving upon a result of [Chan 2016]. Our result has the following implications: 1) Near optimal hardness for Quadratic Programming: it is NP-hard to approximate the value of a given Boolean Quadratic Program within factor $(\log n)^{(1 - o(1))}$ under quasi-polynomial time reductions. This result improves a result of [Khot-Safra 2013] and nearly matches the performance of the best known approximation algorithm [Megrestki 2001, Nemirovski-Roos-Terlaky 1999 Charikar-Wirth 2004] that achieves a factor of $O(\log n)$. 2) Bounded degree 2-CSP's: under randomized reductions, for sufficiently large $d>0$, it is NP-hard to approximate the value of 2-CSPs in which each variable appears in at most d constraints within factor $(1-o(1))d/2$ improving upon a recent result of [Lee-Manurangsi 2023]. 3) Improved hardness results for connectivity problems: using results of [Laekhanukit 2014] and [Manurangsi 2019], we deduce improved hardness results for the Rooted $k$-Connectivity Problem, the Vertex-Connectivity Survivable Network Design Problem and the Vertex-Connectivity $k$-Route Cut Problem.Comment: STOC 2024, 91 page