Modern out-of-order CPUs heavily rely on speculative execution for performance optimization, with branch prediction serving as a cornerstone to minimize stalls and maximize efficiency. Whenever shared branch prediction resources lack proper isolation and sanitization methods, they may originate security vulnerabilities that expose sensitive data across different software contexts. This paper examines the fundamental components of modern Branch Prediction Units (BPUs) and investigates how resource sharing and contention affect two widely implemented but underdocumented features: Bias-Free Branch Prediction and Branch History Speculation. Our analysis demonstrates that these BPU features, while designed to enhance speculative execution efficiency through more accurate branch histories, can also introduce significant security risks. We show that these features can inadvertently modify the Branch History Buffer (BHB) update behavior and create new primitives that trigger malicious mis-speculations. This discovery exposes previously unknown cross-privilege attack surfaces for Branch History Injection (BHI). Based on these findings, we present three novel attack primitives: two Spectre attacks, namely Spectre-BSE and Spectre-BHS, and a cross-privilege control flow side-channel attack called BiasScope. Our research identifies corresponding patterns of vulnerable control flows and demonstrates exploitation on multiple processors. Finally, Chimera is presented: an attack demonstrator based on eBPF for a variant of Spectre-BHS that is capable of leaking kernel memory contents at 24,628 bit/s.
Nishit Patel, Hoang-Ha Nguyen, Jet van de Geest
et al.
Physical inactivity significantly contributes to obesity and other non-communicable diseases, yet efforts to increase population-wide physical activity levels have met with limited success. The built environment plays a pivotal role in encouraging active behaviors like walking. Walkability indices, which aggregate various environmental features, provide a valuable tool for promoting healthy, walkable environments. However, a standardized, high-resolution walkability index for Europe has been lacking. This study addresses that gap by developing a standardized, high-resolution walkability index for the entire European region. Seven core components were selected to define walkability: walkable street length, intersection density, green spaces, slope, public transport access, land use mix, and 15-minute walking isochrones. These were derived from harmonized, high-resolution datasets such as Sentinel-2, NASA's elevation models, OpenStreetMap, and CORINE Land Cover. A 100 m x 100 m hierarchical grid system and advanced geospatial methods, like network buffers and distance decay, were used at scale to efficiently model real-world density and proximity effects. The resulting index was weighted by population and analyzed at different spatial levels using visual mapping, spatial clustering, and correlation analysis. Findings revealed a distinct urban-to-rural gradient, with high walkability scores concentrated in compact urban centers rich in street connectivity and land use diversity. The index highlighted cities like Barcelona, Berlin, Munich, Paris, and Warsaw as walkability leaders. This standardized, high-resolution walkability index serves as a practical tool for researchers, planners, and policymakers aiming to support active living and public health across diverse European contexts.
Jan von der Velde kjøpte i 1741 offentlige rettigheter i Sunnfjord av den dansk-norske kongen, som retten til å utnevne dommer på det tidligere Svanøygodset og tienden av korn og fisk. Samlingen av rettigheter ble kalt Svanøy birks herligheter. Artikkelens første hovedtema er omfanget av dem. De gikk over til etterkommerne i et sameie i 1755. Dette bestod til den siste rettigheten ble innløst ved lov i 1903. Det andre hovedtemaet er om sameiet var et fideikommiss.
Through analysis of 50 autoethnographies I interpret international students’ imaginaries of Italy-Florence (South Europe), Finland-Helsinki (North Europe) and what can be called “the cosmopolitan elsewhere”. International students’ imaginary of Finland-Helsinki is very slight; that of Italy-Florence is richer and variously articulated: media images and narratives shape students’ expectations before their arrival in the host country. The Finland-Helsinki country profile is instead associated with a vague idea of Northern Europe and often confused with Scandinavia. The respective autoethnographic passages can be synthetically interpreted as past (Italy) vs. present (Finland). On one side Italy-Florence’s image is almost embedded in a cultural past, on the other Finland-Helsinki’s image is almost severed from its history and is seen more as a geographical entity: the deep and mysterious north. Analysis of secondary sources connected with studying abroad reveals the absence of a clear-cut narrative of what it means to be an international student. Nevertheless, there is a glimpse of a vague cosmopolitan narrative. This story, constructed on a global scale by different actors and institutions upholds the generic validity of studying abroad for both instrumental and expressive reasons, and sees it as an institutionalized rite of passage towards global citizenship.
Muhammad Shihab Rashid, Jannat Ara Meem, Vagelis Hristidis
Open Retrieval Conversational Question Answering (OrConvQA) answers a question given a conversation as context and a document collection. A typical OrConvQA pipeline consists of three modules: a Retriever to retrieve relevant documents from the collection, a Reranker to rerank them given the question and the context, and a Reader to extract an answer span. The conversational turns can provide valuable context to answer the final query. State-of-the-art OrConvQA systems use the same history modeling for all three modules of the pipeline. We hypothesize this as suboptimal. Specifically, we argue that a broader context is needed in the first modules of the pipeline to not miss relevant documents, while a narrower context is needed in the last modules to identify the exact answer span. We propose NORMY, the first unsupervised non-uniform history modeling pipeline which generates the best conversational history for each module. We further propose a novel Retriever for NORMY, which employs keyphrase extraction on the conversation history, and leverages passages retrieved in previous turns as additional context. We also created a new dataset for OrConvQA, by expanding the doc2dial dataset. We implemented various state-of-the-art history modeling techniques and comprehensively evaluated them separately for each module of the pipeline on three datasets: OR-QUAC, our doc2dial extension, and ConvMix. Our extensive experiments show that NORMY outperforms the state-of-the-art in the individual modules and in the end-to-end system.
Annet Konings, Mariia Marinichenko, Oleksii Mikulenko
et al.
Primordial gravitational waves propagate almost unimpeded from the moment they are generated to the present epoch. Nevertheless, they are subject to convolution with a non-trivial transfer function. Within the standard thermal history, shifts in the temperature-redshift relation combine with damping effects by free streaming neutrinos to non-trivially process different wavelengths during radiation domination, with subsequently negligible effects at later times. Presuming a nearly scale invariant primordial spectrum, one obtains a characteristic late time spectrum, deviations from which would indicate departures from the standard thermal history. Given the paucity of probes of the early universe physics before nucleosynthesis, it is useful to classify how deviations from the standard thermal history of the early universe can be constrained from observations of the late time stochastic background. The late time spectral density has a plateau at high frequencies that can in principle be significantly enhanced or suppressed relative to the standard thermal history depending on the equation of state of the epoch intervening reheating and the terminal phase of radiation domination, imprinting additional features from bursts of entropy production, and additional damping at intermediate scales via anisotropic stress production. In this paper, we survey phenomenologically motivated scenarios of early matter domination, kination, and late time decaying particles as representative non-standard thermal histories, elaborate on their late time stochastic background, and discuss constraints on different model scenarios.
Large Language Models (LLMs) such as ChatGPT and Llama have become prevalent in real-world applications, exhibiting impressive text generation performance. LLMs are fundamentally developed from a scenario where the input data remains static and unstructured. To behave interactively, LLM-based chat systems must integrate prior chat history as context into their inputs, following a pre-defined structure. However, LLMs cannot separate user inputs from context, enabling chat history tampering. This paper introduces a systematic methodology to inject user-supplied history into LLM conversations without any prior knowledge of the target model. The key is to utilize prompt templates that can well organize the messages to be injected, leading the target LLM to interpret them as genuine chat history. To automatically search for effective templates in a WebUI black-box setting, we propose the LLM-Guided Genetic Algorithm (LLMGA) that leverages an LLM to generate and iteratively optimize the templates. We apply the proposed method to popular real-world LLMs including ChatGPT and Llama-2/3. The results show that chat history tampering can enhance the malleability of the model's behavior over time and greatly influence the model output. For example, it can improve the success rate of disallowed response elicitation up to 97% on ChatGPT. Our findings provide insights into the challenges associated with the real-world deployment of interactive LLMs.
Åse Marie Søisdal, Anne Mette Seines, May-Brith Ohman Nielsen
Sammendrag Artikkelen diskuterer norsk historisk rovdyrfellingsstatistikk med utgangspunkt i en rekke nasjonale og lokale arkiver fra det sydlige Norge. Den nasjonale statistikken har bygget på utbetalte og innrapporterte skuddpremier for ulike arter. Skuddpremiene var ledd i de nasjonale utryddingskampanjene for rovdyr mellom 1845 og 1976. Arkivstudiene våre viser at ikke alle dyr som ble drept for dusør, havnet i denne nasjonale samlestatistikken, at det var en betydelig andel giftdrepte dyr i dette premiematerialet, og at begrepet «skuddpremier» derfor er misvisende. Artikkelen diskuterer ulike sider ved de historiske skuddpremiepraksisene, skuddpremieregistreringer og skuddpremiestatistikken. Den avdekker også at store deler av det historiske kildematerialet som var underlag for statistikken, ser ut til å ha forsvunnet fra lokale arkiver i forbindelse med utarbeidelsen av statistikken, og at det ikke kan gjenfinnes i Arkivverket. Dette er problematisk for forskning på norsk natur- og miljøhistorie så vel som for forskning på lokalhistorie, kulturhistorie og gifthistorie. Oppsummert kan vi konstatere at norsk fauna var langt rikere, utryddingskampanjene var mer omfattende og metodene mer problematiske enn kunnskapsstatus basert på eksisterende nasjonal statistikk vitner om.
We present Grantecan 10 m telescope (GTC) spectroscopic confirmations of 55 faint Planetary Nebulae (PNe) candidates discovered largely in the INT Photometric H$_α$ Survey of the Northern Galactic Plane (IPHAS) by our pro-am collaboration. We confirm 46 of them as 'True' (T), 4 as 'Likely' (L) and 5 as 'Possible' (P) PNe and including 5 new PNe central star (CSPN) discoveries. This was from observations of 62 new candidates yielding a maximum PN discovery success rate of 89%. The sensitivity and longer wavelength coverage of IPHAS allows PNe to be found in regions of greater extinction and at these lower Galactic latitudes, including PNe in a more advanced evolutionary state and at larger distances compared to previously known Galactic PNe. We use an holistic set of observed characteristics and optical emission-line diagnostics to confirm candidates. Plasma properties have been determined in a self-consistent way using PyNeb. This work is facilitated by the functionality of our powerful, multi-wavelength database 'HASH' (Hong Kong, Australian Astronomical Observatory, Strasbourg Observatory H-alpha Planetary Nebula catalogue) that federates known imaging, spectroscopy and other pertinent data for all Galactic T, L, P PNe and the significant numbers of mimics. Reddenings, corrected radial velocities and PNe electron density and temperature estimates are provided for these new PNe where possible.
Siteng Fan, Sandrine Guerlet, François Forget
et al.
Thermal tides in the Martian atmosphere are analyzed using temperature profiles retrieved from nadir observations obtained by the TIRVIM Fourier-spectrometer, part of the Atmospheric Chemistry Suite (ACS) onboard the ExoMars Trace Gas Orbiter (TGO). The data is selected near the northern summer solstice at solar longitude (LS) 75°-105° of Martian Year (MY) 35. The observations have a full local time coverage, which enables analyses of daily temperature anomalies. The observed zonal mean temperature is lower by 4-6K at ~100Pa, but higher towards the summer pole, compared to the LMD Mars General Circulation Model (GCM). Wave mode decomposition shows dominant diurnal tide and important semi-diurnal tide and diurnal Kelvin wave, with maximal amplitudes of 5K, 3K, and 2.5K, respectively, from tens to hundreds of Pa. The results generally agree well with the LMD Mars GCM, but with noticeable earlier phases of diurnal (~1h) and semi-diurnal (~3h) tides.
Imad Pasha, Deborah Lokhorst, Pieter G. van Dokkum
et al.
We identify a $\sim$600 pc-wide region of active star formation located within a tidal streamer of M82 via $Hα$ emission ($F_{Hα}\sim 6.5\times10^{-14}$ erg s$^{-1}$ cm$^{-2}$), using a pathfinder instrument based on the Dragonfly Telephoto Array. The object is kinematically decoupled from the disk of M82 as confirmed via Keck / LRIS spectroscopy, and is spatially and kinematically coincident with an overdensity of HI and molecular hydrogen within the "northern HI streamer" induced by the passage of M81 several hundred Myr ago. From HI data, we estimate that $\sim5\times10^7$ M$_{\odot}$ of gas is present in the specific overdensity coincident with the $Hα$ source. The object's derived metallicity (12+$\log(O/H)\simeq 8.6$), position within a gas-rich tidal feature, and morphology (600 pc diameter with multiple star forming clumps), indicate that it is likely a tidal dwarf galaxy in the earliest stages of formation.
Additive manufacturing parameters of high-performance polymers greatly affect the thermal history and consequently quality of the end-part. For fused deposition modeling (FDM), this may include printing speed, filament size, nozzle, and chamber temperatures, as well as build plate temperature. In this study, the effect of thermal convection inside a commercial 3D printer on thermal history and crystalline morphology of polyetheretherketone (PEEK) was investigated using a combined experimental and numerical approach. Using digital scanning calorimetry (DSC) and polarized optical microscopy (POM), crystallinity of PEEK samples was studied as a function of thermal history. In addition, using finite element (FE) simulations of heat transfer, which were calibrated using thermocouple measurements, thermal history of parts during virtual 3D printing was evaluated. By correlating the experimental and numerical results, the effect of printing parameters and convection on thermal history and PEEK crystalline morphology was established. It was found that the high melting temperature of PEEK, results in fast melt cooling rates followed by short annealing times during printing, leading to relatively low degree of crystallinity (DOC) and small crystalline morphology.
Jatin Ganhotra, Samuel Thomas, Hong-Kwang J. Kuo
et al.
End-to-end spoken language understanding (SLU) systems that process human-human or human-computer interactions are often context independent and process each turn of a conversation independently. Spoken conversations on the other hand, are very much context dependent, and dialog history contains useful information that can improve the processing of each conversational turn. In this paper, we investigate the importance of dialog history and how it can be effectively integrated into end-to-end SLU systems. While processing a spoken utterance, our proposed RNN transducer (RNN-T) based SLU model has access to its dialog history in the form of decoded transcripts and SLU labels of previous turns. We encode the dialog history as BERT embeddings, and use them as an additional input to the SLU model along with the speech features for the current utterance. We evaluate our approach on a recently released spoken dialog data set, the HarperValleyBank corpus. We observe significant improvements: 8% for dialog action and 30% for caller intent recognition tasks, in comparison to a competitive context independent end-to-end baseline system.
Sammendrag
Det førmoderne samfunnet var preget av rettspluralisme, og enkelte
samfunnsgrupper kunne være underlagt flere parallelle rettssystemer.
Da Larvik grevskap ble organisert som eget jurisdiksjonsområde på
slutten av 1600-tallet, kom arbeiderne ved grevskapets jernverk
til å være underlagt både bergjurisdiksjonen i Norge og grevens
birkejurisdiksjon i tillegg til den overordnede kongelige jurisdiksjonen.
Rettsordningen ved Fritzøe jernverk ble således uryddig og uklar.
Derfor ble rettsapparatet i grevskapet omorganisert før midten av
1700-tallet, en omorganisering som førte til en fastere og tydeligere
struktur der forholdet mellom grevens jurisdiksjon og bergretten,
ble avklart. Grevens juridiske maktområde ble styrket på den måten
at han i siste del av århundret, gjennom sin lokale administrasjon, kunne
utøve en tilnærmet ubeskåret birkejurisdiksjon over sine undersåtter
ved jernverket. I denne prosessen spilte byfogden en sentral rolle.
We establish sharp asymptotically optimal strategies for the problem of online prediction with history dependent experts. The prediction problem is played (in part) over a discrete graph called the $d$ dimensional de Bruijn graph, where $d$ is the number of days of history used by the experts. Previous work [11] established $O(\varepsilon)$ optimal strategies for $n=2$ experts and $d\leq 4$ days of history, while [10] established $O(\varepsilon^{1/3})$ optimal strategies for all $n\geq 2$ and all $d\geq 1$, where the game is played for $N$ steps and $\varepsilon=N^{-1/2}$. In this paper, we show that the optimality conditions over the de Bruijn graph correspond to a graph Poisson equation, and we establish $O(\varepsilon)$ optimal strategies for all values of $n$ and $d$.
We have investigated the possible evolutional history of the water ocean on Venus, adopting the one dimensional radiative-convective model,including the parameters as albedo and relative humidity. Under this model, it has the possibility that the habitable zone could include Venus. It could continue for $\sim 1$ Gy in faint young solar flux increasing, with modest parameters such as albedo = 0.3, relative humidity (RH=1), and $p_{n0}=10^5 $Pa. If we relax parameters considering the 3-Dimensional calculations, the ocean could exist there longer than $\sim$ 4.6 Gy. In such cases, we have to consider the cause of runaway other than just solar luminosity increasing. It is important to investigate Venus history for the coming future of Earth and observations of exoplanets for their historical habitable zones.