Hasil untuk "History America"

Jacob Haqq-Misra

Evidence for fluvial features and standing liquid water indicate that Mars was a warmer and wetter place in its past; however, climate models have historically been unable to produce conditions to yield a warm early Mars under the faint young sun. Some models invoke thick greenhouse atmospheres to produce continuously warm conditions, but others have argued that available geologic evidence is more consistent with short-duration and transient warming events on an otherwise cold Mars. One possibility of harmonizing these perspectives is that early Mars experienced climate limit cycles that caused the climate to oscillate between short periods of warmth and prolonged periods of glaciation, due to modulation of greenhouse warming by the carbonate-silicate cycle. This study suggests that episodic limit cycling during the Noachian and Hesperian periods provides a hypothetical explanation for the timing and formation of fluvial features on Mars. A schematic time-forward trajectory of the full history of Mars is calculated using an energy balance climate model, which includes an active carbonate-silicate cycle, instellation changes due to the sun's main sequence evolution, variations in the obliquity of Mars, and supplemental warming from additional greenhouse gases beyond carbon dioxide alone. These calculations demonstrate the viability of a climate history for Mars involving episodic limit cycling to enable the formation of the valley networks at 4.1-3.5 Ga and delta features at 3.3-3.0 Ga, interspersed with cold stable climates and ending in the late Amazonian in a carbon dioxide condensation regime. This schematic climate trajectory provides a plausible narrative that remains consistent with available geologic data, and further exploration of warming mechanisms for the climate of Mars should consider the possibility of episodic transient events driven by carbonate-silicate limit cycling.

D. Bois.

Fernando Mino Gracia

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Fengran Mo, Abbas Ghaddar, Kelong Mao et al.

In this paper, we study how open-source large language models (LLMs) can be effectively deployed for improving query rewriting in conversational search, especially for ambiguous queries. We introduce CHIQ, a two-step method that leverages the capabilities of LLMs to resolve ambiguities in the conversation history before query rewriting. This approach contrasts with prior studies that predominantly use closed-source LLMs to directly generate search queries from conversation history. We demonstrate on five well-established benchmarks that CHIQ leads to state-of-the-art results across most settings, showing highly competitive performances with systems leveraging closed-source LLMs. Our study provides a first step towards leveraging open-source LLMs in conversational search, as a competitive alternative to the prevailing reliance on commercial LLMs. Data, models, and source code will be publicly available upon acceptance at https://github.com/fengranMark/CHIQ.

Xuemei Tang, Zekun Deng, Qi Su et al.

Natural Language Processing (NLP) plays a pivotal role in the realm of Digital Humanities (DH) and serves as the cornerstone for advancing the structural analysis of historical and cultural heritage texts. This is particularly true for the domains of named entity recognition (NER) and relation extraction (RE). In our commitment to expediting ancient history and culture, we present the ``Chinese Historical Information Extraction Corpus''(CHisIEC). CHisIEC is a meticulously curated dataset designed to develop and evaluate NER and RE tasks, offering a resource to facilitate research in the field. Spanning a remarkable historical timeline encompassing data from 13 dynasties spanning over 1830 years, CHisIEC epitomizes the extensive temporal range and text heterogeneity inherent in Chinese historical documents. The dataset encompasses four distinct entity types and twelve relation types, resulting in a meticulously labeled dataset comprising 14,194 entities and 8,609 relations. To establish the robustness and versatility of our dataset, we have undertaken comprehensive experimentation involving models of various sizes and paradigms. Additionally, we have evaluated the capabilities of Large Language Models (LLMs) in the context of tasks related to ancient Chinese history. The dataset and code are available at \url{https://github.com/tangxuemei1995/CHisIEC}.

Nick P. Petropoulos

Data are given, commentary is supplied and explanations are provided with regard to the technical, the organizational and, of course, the human history connected to the time of research, which resulted to the paper entitled "Soil sampling and Cs-137 analysis of the Chernobyl fallout in Greece", written by late Professor S.E. Simopoulos. This paper has been provided in Greek translation within an issued honorary volume (ISBN 978-960-254-714-4). Reasonably, the narration starts with the review of the political, the financial and the social situation of Greece around 1986. Subsequently, an analysis is given on the then available means, the persons involved, the methods used, the lessons learned and any other connection with the oral history of the NTUA's Nuclear Engineering Laboratory and other relevant Greek Laboratories. For this history, written proof is now scarce and the persons available to pass it on are growing less and less. N.P. Petropoulos, now Laboratory member and then student of Professor S.E. Simopoulos was in charge of preparation of this text.

Sebastián Nicolás Merayo

Durante sus primeros diez años, el Centro Español de Unión Republicana de Rosario, fundado en 1933, llevó a cabo un conjunto de prácticas políticas y culturales que pusieron de relieve la construcción de un espacio de sociabilidad antifascista de carácter liberal en la ciudad. En este artículo, planteamos estudiar aquellas prácticas a partir de un abordaje que contemple la dimensión transnacional y las estrategias de acción que desarrollaron sus integrantes. Se trata de una pesquisa sobre diversas publicaciones ligadas al Centro, a la prensa local y a voces opositoras que tensaron una disputa ideológica en la esfera pública local.

Huanqing Chen, Joshua Speagle, Keir K. Rogers

Understanding the entire history of the ionization state of the intergalactic medium (IGM) is at the frontier of astrophysics and cosmology. A promising method to achieve this is by extracting the damping wing signal from the neutral IGM. As hundreds of redshift $z>6$ quasars are observed, we anticipate determining the detailed time evolution of the ionization fraction with unprecedented fidelity. However, traditional approaches to parameter inference are not sufficiently accurate. We assess the performance of a simulation-based inference (SBI) method to infer the neutral fraction of the universe from quasar spectra. The SBI method adeptly exploits the shape information of the damping wing, enabling precise estimations of the neutral fraction $\left<x_{\rm HI}\right>_{\rm v}$ and the wing position $w_p$. Importantly, the SBI framework successfully breaks the degeneracy between these two parameters, offering unbiased estimates of both. This makes the SBI superior to the traditional method using a pseudo-likelihood function. We anticipate that SBI will be essential to determine robustly the ionization history of the Universe through joint inference from the hundreds of high-$z$ spectra we will observe.

Thiago do Amaral Biazotto

Este artigo investiga a relação entre animais humanos e não-humanos no pensamento de Aristóteles, tomando como fonte principal seus tratados de zoologia e, dentre eles, a História dos animais. O objetivo central é discutir em que medida é possível identificar traços incontornáveis de antropocentrismo em Aristóteles, e, em caso positivo, em quais termos esse antropocentrismo é expresso. A partir da leitura de passagens diversas, e da análise filológica de determinados verbos empregados pelo filósofo, argumento que o dado antropocêntrico dos escritos de Aristóteles, embora presente, pode ser nuançado, em especial quando algumas espécies – como a esponja do mar – são abordadas pelo estagirita. Assim, concluo que a retórica antropocêntrica de Aristóteles aparece com mais frequência quando os animais são abordados em conjunto do que como espécies isoladas.

Massimo Giovannini

According to the common wisdom, between a fraction of the mHz and few Hz the spectral energy density of the inflationary gravitons can be safely disregarded even assuming the most optimistic sensitivities of the space-borne detectors. In this analysis we show that this conclusion is evaded if, prior to nucleosynthesis, the post-inflationary evolution includes a sequence of stages expanding either faster or slower than radiation. As a consequence, contrary to the conventional lore, it is shown that below a fraction of the Hz the spectral energy density of the relic gravitons may exceed (even by eight orders of magnitude) the signal obtained under the hypothesis of radiation dominance throughout the whole expansion history prior to the formation of light nuclei. Since the slopes and the amplitudes of the spectra specifically reflect both the inflationary dynamics and the subsequent decelerated evolution, it is possible to disentangle the contribution of the relic gravitons from other (late-time) bursts of gravitational radiation associated, for instance, with a putative strongly first-order phase transition at the TeV scale. Hence, any limit on the spectral energy density of the relic gravitons in the mHz range simultaneously constrains the post-inflationary expansion history and the inflationary initial data.

R. Cook, Richard Hofstadter

Harold W. Cruse

Julio Cesar de Almeida Duarte

Inicialmente contextualizamos o termo ancestralidade como referência aos nossos ancestrais indígenas e africanos e a herança cultural que deles herdamos, enquanto o termo modernidade diz respeito ao tempo presente, ao modo como nos relacionamos em sociedade uns com os outros, como um reflexo das manifestações culturais transmitidas de geração em geração por nossos antepassados. Este artigo demonstra que a intolerância subsiste desde os tempos do Brasil colônia, através de uma abordagem histórica de como as práticas discriminatórias do estado português se enraizaram em nossa sociedade, beneficiando a cultura europeia e desqualificando os saberes indígenas e africanos. Apresentamos a ancestralidade indígena, suas lendas, mitos, e suas práticas de cura. Abordamos a miscigenação das raças – indígenas, africanos e europeus, bem como do sincretismo cultural desses povos, que deu origem às religiões brasileiras, tais como o Tambor de Mina, o Catimbó e a Umbanda, por exemplo. Por fim, mostramos a inércia do poder público em combater os atos violentos, intolerantes, discriminatórios, ilegais e preconceituosos contra indígenas, afrodescendentes e seguidores das religiões de matriz ameríndia e africana.

Yevgeny Tsodikovich, Xavier Venel, Anna Zseleva

We study zero-sum repeated games where the minimizing player has to pay a certain cost each time he changes his action. Our contribution is twofold. First, we show that the value of the game exists in stationary strategies, depending solely on the previous action of the minimizing player, not the entire history. We provide a full characterization of the value and the optimal strategies. The strategies exhibit a robustness property and typically do not change with a small perturbation of the switching costs. Second, we consider a case where the minimizing player is limited to playing simpler strategies that are completely history-independent. Here too, we provide a full characterization of the (minimax) value and the strategies for obtaining it. Moreover, we present several bounds on the loss due to this limitation.

Rachel C. Zhang, Bing Zhang

The redshift distribution of fast radio bursts (FRBs) is not well constrained. The association of the Galactic FRB 200428 with the young magnetar SGR 1935+2154 raises the working hypothesis that FRB sources track the star formation history of the universe. The discovery of FRB 20200120E in association with a globular cluster in the nearby galaxy M81, however, casts doubts on such an assumption. We apply the Monte Carlo method developed in a previous work to test different FRB redshift distribution models against the recently released first CHIME FRB catalog in terms of their distributions in specific fluence, external dispersion measure ($\rm DM_E$), and inferred isotropic energy. Our results clearly rule out the hypothesis that all FRBs track the star formation history of the universe. The hypothesis that all FRBs track the accumulated stars throughout history describes the data better but still cannot meet both the $\rm DM_E$ and the energy criteria. The data seem to be better modeled with either a redshift distribution model invoking a significant delay with respect to star formation or a hybrid model invoking both a dominant delayed population and a subdominant star formation population. We discuss the implications of this finding for FRB source models.

A. Kaplan, D. Pease

Mónica Bartolucci

In Argentina, the problema of violence has been adresseded, above all, in its relationship with politics and from various perspectives, among which the historical context, modernization processes, and the affiliation with revolutionary ideas. In this article, from that magazine directed by Juan Carlos Colombres, “Landrú, we will see the social and political violence, and even the crime and death, as a natural data of the argentine reality, taken in sneer, challenging through humor and the dramatic nature of the facts.

Roger Pita Pico

En el marco del Bicentenario de la Independencia de Colombia, este artículo tiene como mira analizar el armisticio de Trujillo firmado en 1820 y observar su implementación en las provincias del sur de Colombia. En medio de un ambiente generalizado de desconfianza e incertidumbre, surgieron inconsistencias en la toma de decisiones y vacíos normativos que generaron dilaciones, no solo en la notificación del acuerdo en cada una de las áreas en disputa, sino también en el proceso de fijación de límites. No obstante, aún con todos los tropiezos registrados, es indudable que el armisticio significó al menos un corto respiro en la frenética y cruda lucha militar; sentó las bases para la regularización de la guerra y les permitió a los republicanos contar con un tiempo valioso mientras el general Simón Bolívar lanzaba la campaña de liberación definitiva de estos territorios.

Yuxian Meng, Chun Fan, Zijun Sun et al.

Any prediction from a model is made by a combination of learning history and test stimuli. This provides significant insights for improving model interpretability: {\it because of which part(s) of which training example(s), the model attends to which part(s) of a test example}. Unfortunately, existing methods to interpret a model's predictions are only able to capture a single aspect of either test stimuli or learning history, and evidences from both are never combined or integrated. In this paper, we propose an efficient and differentiable approach to make it feasible to interpret a model's prediction by jointly examining training history and test stimuli. Test stimuli is first identified by gradient-based methods, signifying {\it the part of a test example that the model attends to}. The gradient-based saliency scores are then propagated to training examples using influence functions to identify {\it which part(s) of which training example(s)} make the model attends to the test stimuli. The system is differentiable and time efficient: the adoption of saliency scores from gradient-based methods allows us to efficiently trace a model's prediction through test stimuli, and then back to training examples through influence functions. We demonstrate that the proposed methodology offers clear explanations about neural model decisions, along with being useful for performing error analysis, crafting adversarial examples and fixing erroneously classified examples.

C. Degler