Negative / Null Result ReportOpen accessComputer Science
Jaroslaw Kornowicz · 2024 · arXiv
This study empirically examines the "Evaluative AI" framework, which aims to enhance the decision-making process for AI users by transitioning from a recommendation-based approach to a hypothesis-driven one. Rather than offering direct recommendations, this framework presents users pro and con evidence for hypotheses to support more informed decisions. However, findings from the current behavioral experiment reveal no significant improvement in decision-making performance and limited user engagement with the evidence provided, resulting in cognitive processes similar to those observed in tradi
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Agnès Ferté, Kevin Hong · 2023 · arXiv
We highlight the role of weak lensing measurements from current and upcoming stage-IV imaging surveys in the search for cosmic inflation, specifically in measuring the scalar spectral index $n_s$. To do so, we combine the Dark Energy Survey 3 years of observation weak lensing and clustering data with BICEP/Keck, Planck and Sloan Digital Sky Survey data in $rΛ$CDM where $r$ is the tensor-to-scalar ratio. While there is no significant improvement in constraining power, we obtain a 1$σ$ shift on $n_s$. Additionally, we forecast a weak lensing and clustering data vector from the 10-year Legacy Sur
View details →Negative / Null Result ReportOpen accessComputer Science
Karam Ahmed, Sherif Abuelenin, Heba Soliman et al. · 2015 · arXiv
V-BLAST detection method suffers large computational complexity due to its successive detection of symbols. In this paper, we propose a modified V-BLAST algorithm to decrease the computational complexity by reducing the number of detection iterations required in MIMO communication systems. We begin by showing the existence of a maximum number of iterations, beyond which, no significant improvement is obtained. We establish a criterion for the number of maximum effective iterations. We propose a modified algorithm that uses the measured SNR to dynamically set the number of iterations to achieve
View details →Negative / Null Result ReportOpen accessComputer Science
Alp Atici · 2003 · arXiv
It is an established fact that for many of the interesting problems quantum algorithms based on queries of the standard oracle bring no significant improvement in comparison to known classical algorithms. It is conceivable that there are other oracles of algorithmic importance acting in a less intuitive fashion to which such limitations do not apply. Thus motivated this article suggests a broader understanding towards what a general quantum oracle is. We propose a general definition of a quantum oracle and give a classification of quantum oracles based on the behavior of the eigenvalues and ei
View details →Negative / Null Result ReportOpen accessComputer Science
James Large, Paul Southam, Anthony Bagnall · 2018 · arXiv
tl;dr: no, it cannot, at least not on average on the standard archive problems. We assess whether using six smoothing algorithms (moving average, exponential smoothing, Gaussian filter, Savitzky-Golay filter, Fourier approximation and a recursive median sieve) could be automatically applied to time series classification problems as a preprocessing step to improve the performance of three benchmark classifiers (1-Nearest Neighbour with Euclidean and Dynamic Time Warping distances, and Rotation Forest). We found no significant improvement over unsmoothed data even when we set the smoothing param
View details →Negative / Null Result ReportOpen accessEconomics, Econometrics and Finance
Dimitrios Exadaktylos, Massimo Riccaboni, Armando Rungi · 2020 · arXiv
In this paper, we test the contribution of foreign management on firms' competitiveness. We use a novel dataset on the careers of 165,084 managers employed by 13,106 companies in the United Kingdom in the period 2009-2017. We find that domestic manufacturing firms become, on average, between 7% and 12% more productive after hiring the first foreign managers, whereas foreign-owned firms register no significant improvement. In particular, we test that previous industry-specific experience is the primary driver of productivity gains in domestic firms (15.6%), in a way that allows the latter to ca
View details →Negative / Null Result ReportOpen accessPhysics
F. M. Brunbauer, R. Aleksan, Y. Angelis et al. · 2026 · arXiv
The combination of a Cherenkov radiator with a semi-transparent photocathode and a Micromegas based amplification stage allows PICOSEC Micromegas detectors to achieve a time resolution of better than 15ps. While tileable prototypes with 10x10 channels feature 1x1 cm^2 readout pads, finer readout granularity can be used to improve the spatial resolution. We report on the study of high readout granularity PICOSEC Micromegas prototypes which achieve around 0.5mm spatial resolution with 3.5mm large pads. No significant improvement was found when readout pad size was further reduced to 2.2mm. The t
View details →Negative / Null Result ReportOpen accessComputer Science
J. Bouchez · 2000 · arXiv
We show that the unified method recently proposed by Feldman and Cousins to put confidence intervals on bounded parameters cannot avoid the possibility of getting null results. A modified bayesian approach is also proposed (although not advocated) which ensures no null results and proper coverage.
View details →Negative / Null Result ReportOpen accessComputer Science
Hao Guo, Han Wang, Di Zhu et al. · 2025 · arXiv
Modeling spatial heterogeneity in the data generation process is essential for understanding and predicting geographical phenomena. Despite their prevalence in geospatial tasks, neural network models usually assume spatial stationarity, which could limit their performance in the presence of spatial process heterogeneity. By allowing model parameters to vary over space, several approaches have been proposed to incorporate spatial heterogeneity into neural networks. However, current geographically weighting approaches are ineffective on graph neural networks, yielding no significant improvement
View details →Negative / Null Result ReportOpen accessPhysics
Filip K. Malinowski, Frederico Martins, Peter D. Nissen et al. · 2017 · arXiv
We operate a resonant exchange qubit in a highly symmetric triple-dot configuration using IQ-modulated RF pulses. At the resulting three-dimensional sweet spot the qubit splitting is an order of magnitude less sensitive to all relevant control voltages, compared to the conventional operating point, but we observe no significant improvement in the quality of Rabi oscillations. For weak driving this is consistent with Overhauser field fluctuations modulating the qubit splitting. For strong driving we infer that effective voltage noise modulates the coupling strength between RF drive and the qubi
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Guoliang Shang, Lukas Maiwald, Hagen Renner et al. · 2018 · arXiv
Non-iridescent structural colors based on disordered arrangement of monodisperse spherical particles, also called photonic glass, show low color saturation due to gradual transition in reflectivity. No significant improvement is usually expected from particles optimization, as the Mie resonances are broad for small dielectric particles with moderate refractive index. Moreover, the short range order of a photonic glass alone is also insufficient to cause sharp spectral features. We show here, that the combination of a well-chosen particle geometry with the short range order of a photonic glass
View details →Negative / Null Result ReportOpen accessComputer Science
Hoyeon Chang, Jinho Park, Seonghyeon Ye et al. · 2024 · arXiv
Despite the recent observation that large language models (LLMs) can store substantial factual knowledge, there is a limited understanding of the mechanisms of how they acquire factual knowledge through pretraining. This work addresses this gap by studying how LLMs acquire factual knowledge during pretraining. The findings reveal several important insights into the dynamics of factual knowledge acquisition during pretraining. First, counterintuitively, we observe that pretraining on more data shows no significant improvement in the model's capability to acquire and maintain factual knowledge.
View details →Negative / Null Result ReportOpen accessEngineering
Junwei Yang, Xiao-Xin Li, Feihong Liu et al. · 2021 · arXiv
Recent studies on T1-assisted MRI reconstruction for under-sampled images of other modalities have demonstrated the potential of further accelerating MRI acquisition of other modalities. Most of the state-of-the-art approaches have achieved improvement through the development of network architectures for fixed under-sampling patterns, without fully exploiting the complementary information between modalities. Although existing under-sampling pattern learning algorithms can be simply modified to allow the fully-sampled T1-weighted MR image to assist the pattern learning, no significant improveme
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· 2022 · The Brown University Psychopharmacology Update
Eight infusions of ketamine administered over 4 weeks did not significantly improve symptoms of post‐traumatic stress disorder (PTSD) in a group of veterans and active‐duty military who had failed on prior antidepressant treatment, a…
View details →Negative / Null Result ReportOpen accessComputer Science
Ivan Silajev, Niels Victor, Phillip Mortimer · 2022 · arXiv
This paper presents an application of the LayoutLMv3 model for semantic table detection on financial documents from the IIIT-AR-13K dataset. The motivation behind this paper's experiment was that LayoutLMv3's official paper had no results for table detection using semantic information. We concluded that our approach did not improve the model's table detection capabilities, for which we can give several possible reasons. Either the model's weights were unsuitable for our purpose, or we needed to invest more time in optimising the model's hyperparameters. It is also possible that semantic inform
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Anam Zahra, Pierre-Etienne Martin · 2021 · arXiv
This paper presents a table tennis stroke detection method from videos. The method relies on a two-stream Convolutional Neural Network processing in parallel the RGB Stream and its computed optical flow. The method has been developed as part of the MediaEval 2021 benchmark for the Sport task. Our contribution did not outperform the provided baseline on the test set but has performed the best among the other participants with regard to the mAP metric.
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Bob de Ruiter · 2021 · arXiv
The goal of this study was to improve the post-processing of precipitation forecasts using convolutional neural networks (CNNs). Instead of post-processing forecasts on a per-pixel basis, as is usually done when employing machine learning in meteorological post-processing, input forecast images were combined and transformed into probabilistic output forecast images using fully convolutional neural networks. CNNs did not outperform regularized logistic regression. Additionally, an ablation analysis was performed. Combining input forecasts from a global low-resolution weather model and a regiona
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Arvid Frydenlund · 2024 · arXiv
The recently introduced path-star task is a minimal task designed to exemplify limitations to the abilities of language models (Bachmann and Nagarajan, 2024). It involves a path-star graph where multiple arms radiate from a single starting node and each node is unique. Given the start node and a specified target node that ends an arm, the task is to generate the arm containing that target node. This is straightforward for a human but surprisingly difficult for language models, which did not outperform the random baseline. The authors hypothesized this is due to a deficiency in teacher-forcing
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Haresh Rengaraj Rajamohan, Yuxuan Chen, Kyunghyun Cho et al. · 2026 · arXiv
This study assesses whether self-supervised learning (SSL) improves knee osteoarthritis (OA) modeling for diagnosis and prognosis relative to ImageNet-pretrained initialization. We compared (i) image-only SSL pretrained on knee radiographs from the OAI, MOST, and NYU cohorts, and (ii) multimodal image-text SSL pretrained on hospital knee radiographs paired with radiologist impressions. For diagnostic Kellgren-Lawrence (KL) grade prediction, SSL yielded mixed results. While image-only SSL improved accuracy during linear probing (frozen encoder), it did not outperform ImageNet pretraining during
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Alexander Sagomonyan · 2022 · ISTORIYA
The little-known aspects of a problem long discussed in historiography are highlighted: why Spain did not enter the Second World War. On the eve of his suicide, Hitler called his two fatal mistakes: the attack on the USSR, as well as the…
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Ilkka Kantola, Taru Kantola · 2021 · Journal of Hypertension
Objective: To clarify if a difference is noticed in quality of life between Finnish drug-treated hypertensive patients who reached target daytime systolic and diastolic blood pressure (below 140/90 mmHg) compared to those who did not.…
View details →Negative / Null Result ReportOpen accessPhysics
Mykola Malygin, Dmytro Iakubovskyi · 2010 · arXiv
In this work, we perform the detailed analysis of absorption features in spectra of magnetar candidates observed by XMM-Newton satellite. No significant line-like feature has been found. This negative result may indicate the possible presence of smoothing out the absorption features mechanisms.
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Brandon W. Langley, Garrett Vanacore, Philip W. Phillips · 2015 · arXiv
We compute conductivities of strongly-interacting and non-uniform charge densities dual to inhomogeneous anti-de Sitter--black hole spacetimes. Backreacting bulk scalars with periodic boundary profiles, we construct generalizations of Reissner-Nordström-AdS that interpolate between those used in two previous studies --- one that reports power-law scaling for the boundary optical conductivity and one that does not. We find no evidence for power-law scaling of the conductivity, thereby corroborating the previous negative result that gravitational crystals are insufficient to generate the power-l
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R. Foot · 2004 · arXiv
We examine the recent CDMS II results in the context of the mirror matter interpretation of the DAMA/NaI experiment.We find that the favoured mirror matter interpretation of the DAMA/NaI experiment -- a $He'/H'$ dominated halo with a small $O'$ component is fully consistent with the null results reported by CDMS II. While the CDMS II experiment is quite sensitive to a heavy $Fe'$ component, and may yet find a positive result, a more decisive test of mirror matter-type dark matter would require a lower threshold experiment using light target elements.
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Cheongho Han · 1994 · arXiv
Spin vectors of 60 galaxies in the ``Ursa Major Filament'' are obtained from CCD images and spectroscopic determinations of the directions of rotation. These data are used to remove the four-fold degeneracy introduced by the project ed images of galaxies, making possible the complete reconstruction of the galaxy spin vectors. Several possible organizations of spin vectors are investigated by means of statistical analyses of the three-dimensional spin vector maps. The results indicate that there exists no significant alignment of galaxy spin vectors with respect to the supergalactic plane, the
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C. Giunti · 1998 · arXiv
Several possible statistical interpretations of the null result of the KARMEN 2 neutrino oscillation experiment are discussed with the aim of clarifying the implications of the fact that KARMEN 2 did not observe any of the expected background events. The formalism that allows to take into account the error of the expected mean background in a Poisson process with background is presented and applied to the statistical analysis of the KARMEN 2 null result. The possibility of ignoring the expected mean background calculated for the KARMEN 2 experiment is discussed and it is shown that the resulti
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Zhi-zhong Xing, Zhen-hua Zhao, Ye-Ling Zhou · 2015 · arXiv
The Majorana nature of massive neutrinos will be crucially probed in the next-generation experiments of the neutrinoless double-beta ($0ν2β$) decay. The effective mass term of this process, $\langle m\rangle^{}_{ee}$, may be contaminated by new physics. So how to interpret a discovery or null result of the $0ν2β$ decay in the foreseeable future is highly nontrivial. In this paper we introduce a novel three-dimensional description of $|\langle m\rangle_{ee}^{}|$, which allows us to see its sensitivity to the lightest neutrino mass and two Majorana phases in a transparent way. We take a look at
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Luke D. Conlin, Eric Kuo, Nicole R. Hallinen · 2018 · arXiv
A central aim of physics education research is to understand the processes of learning and use that understanding to inform instruction. To this end, researchers often conduct studies to measure the effect of classroom interventions on student learning outcomes. Many of these intervention studies have provided an empirical foundation of reformed teaching techniques, such as active engagement. However, many times there is not sufficient evidence to conclude that the intervention had the intended effect, and these null results often end up in the file drawer. In this paper, we argue that null re
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Daniel Angerhausen, Amedeo Balbi, Andjelka B. Kovačević et al. · 2025 · arXiv
Future telescopes will survey temperate, terrestrial exoplanets to estimate the frequency of habitable ($η_{\text{Hab}}$) or inhabited ($η_{\text{Life}}$) planets. This study aims to determine the minimum number of planets ($N$) required to draw statistically significant conclusions, particularly in the case of a null result (i.e., no detections). Using a Bayesian framework, we analyzed surveys of up to $N=100$ planets to infer the frequency of a binary observable feature ($η_{\text{obs}}$) after null results. Posterior best fits and upper limits were derived for various survey sizes and compa
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J. E. Ottoni, A. P. Baeta Scarpelli, Marcos Sampaio et al. · 2006 · arXiv
We apply Implicit regularization in the calculation of the one-loop graviton and gravitino corrections to the anomalous magnetic moment of the lepton in unbroken supergravity, which is known to be an important test for any regularization method. We find a null result as it is expected from supersymmetry. We compare our results with the ones obtained by using Differential Regularization and Dimensional Reduction, which are known to preserve supersymmetry at one-loop order.
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