Underwater monocular SLAM is a challenging problem with applications from autonomous underwater vehicles to marine archaeology. However, existing underwater SLAM methods struggle to produce maps with high-fidelity rendering. In this paper, we propose WaterSplat-SLAM, a novel monocular underwater SLAM system that achieves robust pose estimation and photorealistic dense mapping. Specifically, we couple semantic medium filtering into two-view 3D reconstruction prior to enable underwater-adapted camera tracking and depth estimation. Furthermore, we present a semantic-guided rendering and adaptive map management strategy with an online medium-aware Gaussian map, modeling underwater environment in a photorealistic and compact manner. Experiments on multiple underwater datasets demonstrate that WaterSplat-SLAM achieves robust camera tracking and high-fidelity rendering in underwater environments.
This paper describes the work of the UniBuc Archaeology team for CLPsych's 2024 Shared Task, which involved finding evidence within the text supporting the assigned suicide risk level. Two types of evidence were required: highlights (extracting relevant spans within the text) and summaries (aggregating evidence into a synthesis). Our work focuses on evaluating Large Language Models (LLM) as opposed to an alternative method that is much more memory and resource efficient. The first approach employs a good old-fashioned machine learning (GOML) pipeline consisting of a tf-idf vectorizer with a logistic regression classifier, whose representative features are used to extract relevant highlights. The second, more resource intensive, uses an LLM for generating the summaries and is guided by chain-of-thought to provide sequences of text indicating clinical markers.
Human cultural complexity did not arise in a vacuum. Scholars in the humanities and social sciences have long debated how ecological factors, such as climate and resource availability, enabled early hunter-gatherers to allocate time and energy beyond basic subsistence tasks. This paper presents a formal, interdisciplinary approach that integrates theoretical modeling with computational methods to examine whether conditions that allow lower spoilage of stored food, often associated with colder climates and abundant large fauna, could indirectly foster the emergence of cultural complexity. Our contribution is twofold. First, we propose a mathematical framework that relates spoilage rates, yield levels, resource management skills, and cultural activities. Under this framework, we prove that lower spoilage and adequate yields reduce the frequency of hunting, thus freeing substantial time for cultural pursuits. Second, we implement a reinforcement learning simulation, inspired by engineering optimization techniques, to validate the theoretical predictions. By training agents in different $(Y,p)$ environments, where $Y$ is yield and $p$ is the probability of daily spoilage, we observe patterns consistent with the theoretical model: stable conditions with lower spoilage strongly correlate with increased cultural complexity. While we do not claim to replicate prehistoric social realities directly, our results suggest that ecologically stable niches provided a milieu in which cultural forms could germinate and evolve. This study, therefore, offers an integrative perspective that unites humanistic inquiries into the origins of culture with the formal rigor and exploratory power of computational modeling.
Chintan Vedpathak, Archana Das, S.P. Prizomwala
et al.
The fluvio-marine archives have been widely used to assess the imprints of land-sea interaction during the Holocene period, which has been enigmatic in terms of changes in environmental conditions. To comprehend the fluvial-marine interactions during the Holocene period in response to relative sea level changes, a sedimentary record has been studied from the mouth of the Sabarmati river at the Gulf of Khambhat (western India), which has also hosted mighty Harappan cultural centres during Holocene period. We employed a suite of multiproxy technique (sedimentology, OSL dating, geochemistry and foraminiferal content) from a terrace sequence at the Sabarmati River mouth (i.e. Vadgam). Based on an optical dating, the studied terrace sequence spans from 11 ± 1 ka to 1.3 ± 0.3 ka (11300–1300 year BP) covering almost entire Holocene period. The multiproxy investigation identified three distinct depositional zones at the site, namely zone 1 (11300–5300 year BP), which is characterised by a predominantly fluvial to marginal marine environment, zone 2 (5300–3700 year BP), which indicates a change to a marginal marine to predominantly marine environment, and zone 3 (3700–1300 year BP), which demonstrates a change to an again mixed environment. A present analogue to the palaeoenvironments in the area is provided by the deposition that is still occurring at the mouth of the Sabarmati River under the estuarine tidal environment. The variations in the rate of sedimentation and the source of the sediments are consistent with the environmental change, which will be driven by the changes in climatic circumstances in connection with the rapid sedimentation near the mouth of the Sabarmati River.
Adomas Butrimas, Tomas Rimkus, Marius Iršėnas
et al.
DaktariÅ¡kÄ 5 is a hunterÂgatherer site with organic preservation in western Lithuania. It is located on a former island of Lake Biržulis, where most finds were obtained in the lacustrine environment. The excavations revealed various osseous tools, such as axes and adzes, projectile points, barbed points, gouges and chisels, dating from the 6th to the 3rd millennium cal BC. Despite the abundance of finds in the vicinity of Lake Biržulis, including those at the DaktariÅ¡kÄ 5 site, many remain unexplored in terms of presenting their typological diversity, technology and direct AMS 14C dating. In this paper, we focus on a single case and present a study of a fully preserved socketed toggle harpoon head manufactured from antler. We provide the latest data on its technological assessments, direct AMS 14C dating, species identification by ZooMS, and archaeological and ethnographic parallels. The latter suggest that such type of implement in northern latitudes was designed for hunting large aquatic mammals. Archaeozoological evidence of large freshwater fish, beavers and otters from Lake Biržulis suggests that this tool could have been adapted to the local environment. Consequently, we discuss the origin and possible use of the toggle harpoon head in the Lake Biržulis environment.
Weihan Wang, Bharat Joshi, Nathaniel Burgdorfer
et al.
This paper addresses real-time dense 3D reconstruction for a resource-constrained Autonomous Underwater Vehicle (AUV). Underwater vision-guided operations are among the most challenging as they combine 3D motion in the presence of external forces, limited visibility, and absence of global positioning. Obstacle avoidance and effective path planning require online dense reconstructions of the environment. Autonomous operation is central to environmental monitoring, marine archaeology, resource utilization, and underwater cave exploration. To address this problem, we propose to use SVIn2, a robust VIO method, together with a real-time 3D reconstruction pipeline. We provide extensive evaluation on four challenging underwater datasets. Our pipeline produces comparable reconstruction with that of COLMAP, the state-of-the-art offline 3D reconstruction method, at high frame rates on a single CPU.
The recent NASA TESS mission has the potential to increase the available asteroseismic sample dramatically, but its precision and accuracy have yet to be confirmed. To date, NASA's Kepler mission has been considered the gold standard for asteroseismic samples, despite data only being available for a small portion of the sky. TESS's observations cover the whole sky, and previous work has identified 158,000 potential red giant oscillators. Using APOGEE, which is calibrated to the asteroseismic scale of the Kepler data, we show that seismology from TESS is calibrated to the Kepler scale to better than 5% for about 90% of red giants, and has only slight trends with mass, metallicity, and surface gravity. We therefore conclude that current TESS seismic results can already be used for galactic archaeology, and future results are likely to be highly transformational to our understanding.
More than two thousand years ago the first hydrostatic balance with a rudimentary structure was invented by the Greek sage “Archimedes.” Iranian scholars would later develop balances that were used not only for weighing but also for determining the density and titration of alloys.To appraise the path of evolution of these balances as well as their potentials, an experimental research program was undertaken by the Iranian Research Organisation for Science and Technology (IROST). Therefore, five different balances were selected, ranging from the oldest known in the history of science, the Archimedes balance, to the most sophisticated one, the balance of wisdom by Al-Khazini, which are separated by a lapse of time of about fourteen hundred years. Balances designed by Abu Rayhan Al-Biruni, Zakariya Al-Razi, and Omar Khayyam were the other three. In the course of the research, replicas of the selected balances were designed and fabricated according to the remaining design details in the related literature. The article covers the detailed design of each balance, their construction and functional test details as well as a comparison of their functions and their precision in densitometry and titration.
As a less known region with respect to Islamic pottery, Khusf County was surveyed in 2014 to record itshistorical relics. The intervening years have seen the publication of a lot of archaeological information on thedocumented relics, but the corpus of Islamic pottery from the region remains virtually unpublished. Its richdiversity in motif and decoration types and attribution to several different Islamic centuries as well as the fact thatthere were few published studies from South Khorasan province in general regarding regional Islamic ceramicswarranted an independent study. Thus, the present study has the potential to not only shed light on the archeologyof Khusf but also contribute to the studies of the related Islamic pottery from the province. With these in mind,the major questions addressed here concern the chronology of the pottery corpus in question and the centersfrom which comparanda could be drawn. This paper embarks on a comparative analysis of the Islamic potteryassemblages from Khusf County to establish a comparative chronology. The data for this descriptive-comparativestudy comes from both field and library researches. The findings suggest that the Islamic pottery from the countyspans at least the 10th to the 19th century AD. In types of motifs and decoration, the pottery finds parallels over abroad swathe of eastern and southern Iran, and for the most part represents potential imports from such regions orcenters as Nishapur, Mashhad, and Kerman.
James W. Johnson, Charlie Conroy, Benjamin D. Johnson
et al.
We model the stellar abundances and ages of two disrupted dwarf galaxies in the Milky Way stellar halo: Gaia-Sausage Enceladus (GSE) and Wukong/LMS-1. Using a statistically robust likelihood function, we fit one-zone models of galactic chemical evolution with exponential infall histories to both systems, deriving e-folding timescales of $τ_\text{in} = 1.01 \pm 0.13$ Gyr for GSE and $τ_\text{in} = 3.08^{+3.19}_{-1.16}$ Gyr for Wukong/LMS-1. GSE formed stars for $τ_\text{tot} = 5.40^{+0.32}_{-0.31}$ Gyr, sustaining star formation for $\sim$$1.5 - 2$ Gyr after its first infall into the Milky Way $\sim$10 Gyr ago. Our fit suggests that star formation lasted for $τ_\text{tot} = 3.36^{+0.55}_{-0.47}$ Gyr in Wukong/LMS-1, though our sample does not contain any age measurements. The differences in evolutionary parameters between the two are qualitatively consistent with trends with stellar mass $M_\star$ predicted by simulations and semi-analytic models of galaxy formation. Our fitting method is based only on poisson sampling from an evolutionary track and requires no binning of the data. We demonstrate its accuracy by testing against mock data, showing that it accurately recovers the input model across a broad range of sample sizes ($20 \leq N \leq 2000$) and measurement uncertainties ($0.01 \leq σ_\text{[$α$/Fe]}, σ_\text{[Fe/H]} \leq 0.5$; $0.02 \leq σ_{\log_{10}(\text{age})} \leq 1$). Our inferred values of the outflow mass-loading factor reasonably match $η\propto M_\star^{-1/3}$ as predicted by galactic wind models. Due to the generic nature of our derivation, this likelihood function should be applicable to one-zone models of any parametrization and easily extensible to other astrophysical models which predict tracks in some observed space.
Ghost imaging is a remarkable technique where light that never interacts with an object is detected with a camera and still the image of the object is recorded. The method relies on the use of correlated light and an additional bucket detector. Ghost imaging has been used in archaeology, bio-medicine, for seeing through turbid media, and promises X-ray imaging improvements, amongst many other applications. However, the advantage of ghost imaging over regular imaging can be difficult to quantify. For classical ghost imaging of a single pixel aperture (the object), we find a closed analytic expression for the signal-to-noise ratio using basic statistics. We find that this signal-to-noise ratio can exceed that of regular imaging with the same exposure of the aperture when the detectors are sufficiently noisy, illustrating a simple and quantifiable advantage. Numerical simulation confirms the theoretical analysis.
The Aras and other rivers running across the Moghan region played an important role in the formation of prehistoric sites. The Moghan plain has not so far received the scholarly attention it deserves. While extensive scientific activities have covered the Lake Urmia Basin, this plain has for the most part remained neglected. Yatag Tepesi, a prehistoric site in Germi, Moghan, was subjected to a systematic investigation. The main objective of this paper is to introduce the pottery traditions and to determine the chronological sequence of the site. To gain a more detailed understanding of cultural interactions with other regions and to ascertain the chronological sequence of the site in the Chalcolithic period, the following questions were raised: To which cultural period(s) does YatagTepesi date based on the recovered cultural evidence, including the pottery? The main hypothesis is that the site relates to the Middle Chalcolithic (LC1) and Late Chalcolithic (LC2‒3). Judging from the available evidence, to which regions does the site exhibit the closet links? Our analyses indicate contacts and affinities with other parts of northwest Iran, most notably the Qaradagh region and the Lake Urmia Basin, and South Caucasia. The paper adopts a descriptive-analytical approach. The results of the study suggest that in light of the pottery and other lines of evidence, Yatag Tepesi maintained interactions with other centers of northwest Iran, and flourished between 3700/3600‒4500 BCE.
La pandemia de Covid-19 como hecho histórico marca un antes y un después. Durante el año 2020 y 2021, el distanciamiento social afectó radicalmente nuestro trabajo sobre el patrimonio, la arqueología y el turismo. Estas medidas limitaron mucho la comunicación entre nuestro equipo de investigación y la comunidad de Tapso (El Alto, Catamarca). Desde nuestra perspectiva del patrimonio, sin el trabajo colaborativo con las co- munidades es imposible abordar nuestros objetivos. Este trabajo apunta a comunicar los avances y formatos de la re-vinculación investigadores-comunidad. Durante estos últimos dos años, y luego de intentar elaborar una línea de trabajo a nivel virtual sin éxito, nos abocamos a la reconexión con presencia en el territorio. En consecuencia, a través de entrevistas, actividades en la escuela y el museo, prospección y relevamiento de sitios con la comunidad, hemos fortalecido el vínculo deteriorado por el distanciamiento social producto de la pandemia.
El Valle del Côa fue inscrito por la UNESCO como Patrimonio de la Humanidad en 1998 y está considerado como «el sitio de arte rupestre al aire libre más importante del Paleolítico». El estudio del arte rupestre del Valle del Côa ha revelado que su cronología abarca desde el Paleolítico Superior hasta el siglo XX.
El presente trabajo se desarrolló en el marco del proyecto RARAA, financiado por la Fundação para a Ciência e Tecnologia (FCT) «COA / OVD / 0097 / 2019- Rock Art Open Access Repository», con el objetivo de estudiar el arte rupestre de la Edad de Hierro en el Valle del Côa y compartir en acceso abierto tanto la estructura de datos como los datos y metadatos del proyecto, imágenes, modelos 3D, descriptores y vocabularios. Con la publicación de la metodología de registro y los descriptores utilizados, pretendemos contribuir a mejorar el uso y la reutilización de los datos, así como el desarrollo de Linked Open Data, para que sean localizables y accesibles, utilizando los principios FAIR (Hollander et al., 2018), y potenciando la interoperabilidad con plataformas nacionales e internacionales.
Bone tools have a long archaeological history, and have recently been shown to retain use-traces distinctive of different perishable crafting practices. When examined in a controlled way, these diagnostic use-traces can serve as proxies for the crafted forms the bone tools were used to produce (e.g., baskets, leather goods, etc.). However, a number of methodological stumbling-blocks have hindered the sharing of bone tool use-wear results in a consistent standardized format. We suggest the application of Reflectance Transformation Imaging (RTI), and provide details for how to construct an RTI system which resolves most problems related to reproducibility in use-trace analysis.
The X-ray polarization properties of the reflection nebulae in the Galactic center inform us about the direction of the illuminating source (through the polarization angle) and the cloud position along the line of sight (through the polarization degree). However, the detected polarization degree is expected to be lowered because the polarized emission of the clouds is mixed with the unpolarized diffuse emission that permeates the Galactic center region. In a real observation, also the morphological smearing of the source due to the point spread function and the unpolarized instrumental background contribute in diluting the polarization degree. So far, these effects have never been included in the estimation of the dilution. We evaluate the detectability of the X-ray polarization predicted for the MC2, Bridge-B2, G0.11-0.11, Sgr B2, Sgr C1, Sgr C2, and Sgr C3 molecular clouds with modern X-ray imaging polarimeters such as the Imaging X-ray Polarimetry Explorer (IXPE) and the Enhanced X-ray Timing and Polarimetry mission (eXTP). We perform realistic simulations of X-ray polarimetric observations considering (with the aid of Chandra maps and spectra) the spatial, spectral, and polarization properties of all the diffuse emission and background components in each region of interest. We find that in the 4.0-8.0 keV band, where the emission of the molecular clouds outshines the other components, the dilution of the polarization degree, including the contribution due to the morphological smearing of the source, ranges between $\sim$19\% and $\sim$55\%. We conclude that for some distance values reported in the literature, the diluted polarization degree of G0.11-0.11, Sgr B2, Bridge-B2, Bridge-E, Sgr C1, and Sgr C3 may be detectable in a 2 Ms long IXPE observations. The enhanced capabilities of eXTP may allow detecting the 4.0-8.0 keV of all the targets considered here.
The nucleosynthetic site of the rapid ($r$) neutron-capture process is currently being debated. The direct detection of the neutron star merger GW170817, through gravitational waves and electromagnetic radiation, has confirmed such events as important sources of the $r$-process elements. However, chemical evolution models are not able to reproduce the observed chemical abundances in the Milky Way when neutron star mergers are assumed to be the only $r$-process site and realistic time distributions of such events are taken into account. Now for the first time, we combine all the available observational evidence of the Milky Way and its dwarf galaxy satellites to show that the data can only be explained if there are (at least) two distinct $r$-process sites: a quick source with timescales comparable to core-collapse supernovae, $t_{quick}\lesssim10^8$ yr, and a delayed source with characteristic timescales $t_{delayed}\gtrsim4$ Gyr. The delayed $r$-process source most probably originates in neutron star mergers, as the timescale fits well with that estimated for GW170817. Given the short timescales of the quick source, it is likely associated with massive stars, though a specific fast-track channel for compact object mergers cannot be excluded at this point. Our approach demonstrates that only by looking at all the available data will we be able to solve the puzzle that is the $r$-process.
Shape correspondence is a fundamental problem in computer graphics and vision, with applications in various problems including animation, texture mapping, robotic vision, medical imaging, archaeology and many more. In settings where the shapes are allowed to undergo non-rigid deformations and only partial views are available, the problem becomes very challenging. To this end, we present a non-rigid multi-part shape matching algorithm. We assume to be given a reference shape and its multiple parts undergoing a non-rigid deformation. Each of these query parts can be additionally contaminated by clutter, may overlap with other parts, and there might be missing parts or redundant ones. Our method simultaneously solves for the segmentation of the reference model, and for a dense correspondence to (subsets of) the parts. Experimental results on synthetic as well as real scans demonstrate the effectiveness of our method in dealing with this challenging matching scenario.