1,247 results on '"BENCHMARK DATA"'
Search Results
2. Flame structure and reaction diagnostics for ammonia diffusion flame with hydrogen flame stabilizer
- Author
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Okumura, Yukihiko, Tsubota, Tomohiro, Matsuda, Naoya, Hori, Tsukasa, and Akamatsu, Fumiteru
- Published
- 2024
- Full Text
- View/download PDF
3. Generating synthetic gait patterns based on benchmark datasets for controlling prosthetic legs
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Minjae Kim and Levi J. Hargrove
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Generative adversarial network ,Benchmark data ,Impedance control ,Synthetic impedance parameters ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Abstract Background Prosthetic legs help individuals with an amputation regain locomotion. Recently, deep neural network (DNN)-based control methods, which take advantage of the end-to-end learning capability of the network, have been proposed. One prominent challenge for these learning-based approaches is obtaining data for the training, particularly for the training of a mid-level controller. In this study, we propose a method for generating synthetic gait patterns (vertical load and lower limb joint angles) using a generative adversarial network (GAN). This approach enables a mid-level controller to execute ambulation modes that are not included in the training datasets. Methods The conditional GAN is trained on benchmark datasets that contain the gait data of individuals without amputation; synthetic gait patterns are generated from the user input. Further, a DNN-based controller for the generation of impedance parameters is trained using the synthetic gait pattern and the corresponding synthetic stiffness and damping coefficients. Results The trained GAN generated synthetic gait patterns with a coefficient of determination of 0.97 and a structural similarity index of 0.94 relative to benchmark data that were not included in the training datasets. We trained a DNN-based controller using the GAN-generated synthetic gait patterns for level-ground walking, standing-to-sitting motion, and sitting-to-standing motion. Four individuals without amputation participated in bypass testing and demonstrated the ambulation modes. The model successfully generated control parameters for the knee and ankle based on thigh angle and vertical load. Conclusions This study demonstrates that synthetic gait patterns can be used to train DNN models for impedance control. We believe a conditional GAN trained on benchmark datasets can provide reliable gait data for ambulation modes that are not included in its training datasets. Thus, designing gait data using a conditional GAN could facilitate the efficient and effective training of controllers for prosthetic legs.
- Published
- 2023
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4. Recent and Future Advances in Water Electrolysis for Green Hydrogen Generation: Critical Analysis and Perspectives.
- Author
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Franco, Alessandro and Giovannini, Caterina
- Abstract
This paper delves into the pivotal role of water electrolysis (WE) in green hydrogen production, a process utilizing renewable energy sources through electrolysis. The term "green hydrogen" signifies its distinction from conventional "grey" or "brown" hydrogen produced from fossil fuels, emphasizing the importance of decarbonization in the hydrogen value chain. WE becomes a linchpin, balancing surplus green energy, stabilizing the grid, and addressing challenges in hard-to-abate sectors like long-haul transport and heavy industries. This paper navigates through electrolysis variants, technological challenges, and the crucial association between electrolytic hydrogen production and renewable energy sources (RESs). Energy consumption aspects are scrutinized, highlighting the need for optimization strategies to enhance efficiency. This paper systematically addresses electrolysis fundamentals, technologies, scaling issues, and the nexus with energy sources. It emphasizes the transformative potential of electrolytic hydrogen in the broader energy landscape, underscoring its role in shaping a sustainable future. Through a systematic analysis, this study bridges the gap between detailed technological insights and the larger energy system context, offering a holistic perspective. This paper concludes by summarizing key findings, showcasing the prospects, challenges, and opportunities associated with hydrogen production via water electrolysis for the energy transition. [ABSTRACT FROM AUTHOR]
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- 2023
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5. Generating synthetic gait patterns based on benchmark datasets for controlling prosthetic legs.
- Author
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Kim, Minjae and Hargrove, Levi J.
- Subjects
ARTIFICIAL legs ,ANKLE ,KNEE ,GENERATIVE adversarial networks ,IMPEDANCE control - Abstract
Background: Prosthetic legs help individuals with an amputation regain locomotion. Recently, deep neural network (DNN)-based control methods, which take advantage of the end-to-end learning capability of the network, have been proposed. One prominent challenge for these learning-based approaches is obtaining data for the training, particularly for the training of a mid-level controller. In this study, we propose a method for generating synthetic gait patterns (vertical load and lower limb joint angles) using a generative adversarial network (GAN). This approach enables a mid-level controller to execute ambulation modes that are not included in the training datasets. Methods: The conditional GAN is trained on benchmark datasets that contain the gait data of individuals without amputation; synthetic gait patterns are generated from the user input. Further, a DNN-based controller for the generation of impedance parameters is trained using the synthetic gait pattern and the corresponding synthetic stiffness and damping coefficients. Results: The trained GAN generated synthetic gait patterns with a coefficient of determination of 0.97 and a structural similarity index of 0.94 relative to benchmark data that were not included in the training datasets. We trained a DNN-based controller using the GAN-generated synthetic gait patterns for level-ground walking, standing-to-sitting motion, and sitting-to-standing motion. Four individuals without amputation participated in bypass testing and demonstrated the ambulation modes. The model successfully generated control parameters for the knee and ankle based on thigh angle and vertical load. Conclusions: This study demonstrates that synthetic gait patterns can be used to train DNN models for impedance control. We believe a conditional GAN trained on benchmark datasets can provide reliable gait data for ambulation modes that are not included in its training datasets. Thus, designing gait data using a conditional GAN could facilitate the efficient and effective training of controllers for prosthetic legs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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6. Measuring, Tracking, Observing, Scrutinizing and Reporting the Resilience and Sustainability Outcomes and Results
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Alibašić, Haris and Alibašić, Haris
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- 2022
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7. Experimental investigation of flexible filaments in fluid flow
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Silva Leon, Jorge, Filippone, Antonino, and Cioncolini, Andrea
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620.1 ,attachment angle ,vibrating rod ,hysteresis ,3D printing ,forced vibration ,angle of attack ,turbulence intensity ,SEM ,boundary layer ,crossflow ,hairs ,flexibility ,damping ratio ,TISEAN ,Strouhal number ,grid-generated turbulence ,Reynolds number ,membranes ,Buoyancy number ,VIV ,vortex-induced vibrations ,flapping ,flags ,linear time series analysis ,circular cylinders ,free-end effects ,Cauchy number ,bent cylinders ,autocorrelation function ,Scruton number ,benchmark data ,experiments ,coherence ,aspect ratio ,coverage area ,Matlab ,IIE ,free vibration ,MIE ,flexible filament ,string ,flow-induced vibration ,yawed cylinders ,turbulent buffeting ,integral lengthscale ,turbulence ,hairy coating ,wind tunnel testing ,smoke-wire visualization ,reconfiguration ,inclined cylinders ,vortex shedding ,cilia ,filaments ,EIE ,fluid-structure interaction ,high speed video ,flow-structure interaction ,flutter ,instability-induced excitation ,three-dimensional motion ,externally-induced excitation ,movement-induced excitation ,piezoelectric energy ,solar energy ,independence principle ,inverted flag ,nuclear reactor ,attractor ,limit cycle oscillation ,nonlinear time series analysis ,image processing ,chaos ,energy harvesting ,stereoscopic video ,hot-wire anemometry - Abstract
In recent years there has been an increased interest on flexible fluid-structure interaction problems with applications to flow control (reduction of drag and lift fluctuations) and energy harvesting. Particularly, studies have suggested that a hairy coating (poroelastic coating) may help reduce drag and lift fluctuations of a bluff body (cylinder) by around 15% and 40%, respectively. However, these studies have focused on two-dimensional setups, therefore real effects such as three-dimensional vortex shedding in the wake of a cylinder have not been considered. For instance, preliminary experiments carried out in a wind tunnel revealed that the motions of a single filament in the wake of a cylinder are complex due to the influence of the cylinder wake flow and the outer crossflow impinging on the hanging filament (sagged due to gravity). For this reason, this work was set to study experimentally the fundamental behaviour of filaments alone, hanging from a vertical support tube (i.e. not attached to a bluff body). This simple configuration is ideal to analyse the fundamental dynamics of flexible filaments in flow and provide insights for future investigations of hairy coatings. Noteworthy, the filaments hanging in crossflow were free to move in three dimensions, in contrast to the previously existent studies which come from two-dimensional studies, and thus provides unprecedented data valuable for validating fluid-structure interaction simulation codes. At low wind speeds the filaments bent and remained in static equilibrium, similar to the reconfiguration of plants. Beyond this condition, at a certain wind speed, the filaments started to vibrate and in certain cases entered into large-amplitude three-dimensional flutter motions which became more complicated as the wind speed was further increased. Through the use of stereoscopic non-contact high-speed imaging, hotwire anemometry, smoke visualizations and the recourse to linear and nonlinear time-series analysis techniques, the full range of filament behaviours were studied in detail. In particular, the results from this research provided unprecedented data and empirical correlations for the filament static reconfiguration and fluid loading at previously unexplored conditions. Also, the fluid mechanisms responsible for the onset of filament motion were investigated. Additionally, the vortex shedding from reconfigured filaments was for the first time experimentally studied and characterized. This work also provided the first documentation of the three-dimensional flutter motions of filaments, and the effects of turbulence intensity and filament attachment angle on the filaments flapping motions dynamics. Finally, the experimental methodologies (data acquisition, image processing and time-series analyses of motion) developed during this research were also applied for studying other fluid-structure interactions problems: the flow-induced vibration of cantilever rods in axial flow for nuclear reactor applications, and the dynamics of inverted flags for energy harvesting applications.
- Published
- 2019
8. A gait phase prediction model trained on benchmark datasets for evaluating a controller for prosthetic legs.
- Author
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Minjae Kim and Hargrove, Levi J.
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ARTIFICIAL legs ,KNEE ,ANKLE ,PREDICTION models ,ASSISTIVE technology - Abstract
Powered lower-limb assistive devices, such as prostheses and exoskeletons, are a promising option for helping mobility-impaired individuals regain functional gait. Gait phase prediction plays an important role in controlling these devices and evaluating whether the device generates a gait similar to that of individuals with intact limbs. This study proposes a gait phase prediction method based on a deep neural network (DNN). The long short-term memory (LSTM)-based model predicts a continuous gait phase from the 250 ms history of the vertical load, thigh angle, knee angle, and ankle angle, commonly available on powered lower-limb assistive devices. One unified model was trained using publicly available benchmark datasets containing intact limb gaits for level-ground walking (LGW) and ascending stairs (SA). A phase prediction error of 1.28% for all benchmark datasets was obtained. The model was subsequently applied to a state machine-controlled powered prosthetic leg dataset collected fromfour individuals with unilateral transfemoral amputation. The gait phase prediction results (a phase prediction error of 5.70%) indicate that the model trained on benchmark data can be used for a system not included in the training dataset with no post-processing, such as model adaptation. Furthermore, it provided information regarding evaluation of the controller: whether the prosthetic leg generated normal gait. In conclusion, the proposed gait phase predictionmodel will facilitate efficient gait prediction and evaluation of controllers for powered lower-limb assistive devices. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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9. A gait phase prediction model trained on benchmark datasets for evaluating a controller for prosthetic legs.
- Author
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Kim, Minjae and Hargrove, Levi J.
- Subjects
ARTIFICIAL legs ,KNEE ,ANKLE ,PREDICTION models ,ASSISTIVE technology - Abstract
Powered lower-limb assistive devices, such as prostheses and exoskeletons, are a promising option for helping mobility-impaired individuals regain functional gait. Gait phase prediction plays an important role in controlling these devices and evaluating whether the device generates a gait similar to that of individuals with intact limbs. This study proposes a gait phase prediction method based on a deep neural network (DNN). The long short-term memory (LSTM)-based model predicts a continuous gait phase from the 250 ms history of the vertical load, thigh angle, knee angle, and ankle angle, commonly available on powered lower-limb assistive devices. One unified model was trained using publicly available benchmark datasets containing intact limb gaits for level-ground walking (LGW) and ascending stairs (SA). A phase prediction error of 1.28% for all benchmark datasets was obtained. The model was subsequently applied to a state machine-controlled powered prosthetic leg dataset collected fromfour individuals with unilateral transfemoral amputation. The gait phase prediction results (a phase prediction error of 5.70%) indicate that the model trained on benchmark data can be used for a system not included in the training dataset with no post-processing, such as model adaptation. Furthermore, it provided information regarding evaluation of the controller: whether the prosthetic leg generated normal gait. In conclusion, the proposed gait phase predictionmodel will facilitate effcient gait prediction and evaluation of controllers for powered lower-limb assistive devices. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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10. A framework for benchmarking clustering algorithms
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Marek Gagolewski
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Clustering ,Machine learning ,Benchmark data ,Noise points ,External cluster validity ,Partition similarity score ,Computer software ,QA76.75-76.765 - Abstract
The evaluation of clustering algorithms can involve running them on a variety of benchmark problems, and comparing their outputs to the reference, ground-truth groupings provided by experts. Unfortunately, many research papers and graduate theses consider only a small number of datasets. Also, the fact that there can be many equally valid ways to cluster a given problem set is rarely taken into account. In order to overcome these limitations, we have developed a framework whose aim is to introduce a consistent methodology for testing clustering algorithms. Furthermore, we have aggregated, polished, and standardised many clustering benchmark dataset collections referred to across the machine learning and data mining literature, and included new datasets of different dimensionalities, sizes, and cluster types. An interactive datasets explorer, the documentation of the Python API, a description of the ways to interact with the framework from other programming languages such as R or MATLAB, and other details are all provided at https://clustering-benchmarks.gagolewski.com.
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- 2022
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11. How to Improve the Reproducibility, Replicability, and Extensibility of Remote Sensing Research.
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Kedron, Peter and Frazier, Amy E.
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REMOTE sensing , *TECHNOLOGICAL innovations , *SCIENTIFIC community , *REPRODUCIBLE research - Abstract
The field of remote sensing has undergone a remarkable shift where vast amounts of imagery are now readily available to researchers. New technologies, such as uncrewed aircraft systems, make it possible for anyone with a moderate budget to gather their own remotely sensed data, and methodological innovations have added flexibility for processing and analyzing data. These changes create both the opportunity and need to reproduce, replicate, and compare remote sensing methods and results across spatial contexts, measurement systems, and computational infrastructures. Reproducing and replicating research is key to understanding the credibility of studies and extending recent advances into new discoveries. However, reproducibility and replicability (R&R) remain issues in remote sensing because many studies cannot be independently recreated and validated. Enhancing the R&R of remote sensing research will require significant time and effort by the research community. However, making remote sensing research reproducible and replicable does not need to be a burden. In this paper, we discuss R&R in the context of remote sensing and link the recent changes in the field to key barriers hindering R&R while discussing how researchers can overcome those barriers. We argue for the development of two research streams in the field: (1) the coordinated execution of organized sequences of forward-looking replications, and (2) the introduction of benchmark datasets that can be used to test the replicability of results and methods. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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12. Maths Inside from Teachers’ Perspectives
- Author
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Prescott, Anne, Coupland, Mary, Angelini, Marco, Schuck, Sandra, Prescott, Anne, Coupland, Mary, Angelini, Marco, and Schuck, Sandra
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- 2020
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13. Deep Learning for Biometric Face Recognition: Experimental Study on Benchmark Data Sets
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Selitskaya, Natalya, Sielicki, S., Jakaite, L., Schetinin, V., Evans, F., Conrad, M., Sant, P., Celebi, M. Emre, Series Editor, Jiang, Richard, editor, Li, Chang-Tsun, editor, Crookes, Danny, editor, Meng, Weizhi, editor, and Rosenberger, Christophe, editor
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- 2020
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14. DALES Objects: A Large Scale Benchmark Dataset for Instance Segmentation in Aerial Lidar
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Nina M. Singer and Vijayan K. Asari
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3D data set ,aerial vision ,airborne system ,ALS ,benchmark data ,data annotation ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
We present DALES Objects, a large-scale instance segmentation benchmark dataset for aerial lidar. DALES Objects contains close to half a billion hand-labeled points, including semantic and instance segmentation labels. DALES Objects is an extension of the DALES (Varney et al., 2020) dataset, adding additional intensity and instance segmentation annotation. This paper provides an overview of the data collection, preprocessing, hand-labeling strategy, and final data format. We propose relevant evaluation metrics and provide insights into potential challenges when evaluating this benchmark dataset. Finally, we provide information about how researchers can access the dataset for their use at go.udayton.edu/dales3d.
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- 2021
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15. Benchmarking differential expression, imputation and quantification methods for proteomics data.
- Author
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Lin, Miao-Hsia, Wu, Pei-Shan, Wong, Tzu-Hsuan, Lin, I-Ying, Lin, Johnathan, Cox, Jürgen, and Yu, Sung-Huan
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- *
PROTEOMICS , *RNA sequencing , *INTEGRATED software , *DATA analysis , *DROSOPHILA - Abstract
Data analysis is a critical part of quantitative proteomics studies in interpreting biological questions. Numerous computational tools for protein quantification, imputation and differential expression (DE) analysis were generated in the past decade and the search for optimal tools is still going on. Moreover, due to the rapid development of RNA sequencing (RNA-seq) technology, a vast number of DE analysis methods were created for that purpose. The applicability of these newly developed RNA-seq-oriented tools to proteomics data remains in doubt. In order to benchmark these analysis methods, a proteomics dataset consisting of proteins derived from humans, yeast and drosophila, in defined ratios, was generated in this study. Based on this dataset, DE analysis tools, including microarray- and RNA-seq-based ones, imputation algorithms and protein quantification methods were compared and benchmarked. Furthermore, applying these approaches to two public datasets showed that RNA-seq-based DE tools achieved higher accuracy (ACC) in identifying DEPs. This study provides useful guidelines for analyzing quantitative proteomics datasets. All the methods used in this study were integrated into the Perseus software, version 2.0.3.0, which is available at https://www.maxquant.org/perseus. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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16. A DLPNO‐CCSD(T) benchmarking study of intermolecular interactions of ionic liquids.
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Seeger, Zoe L. and Izgorodina, Ekaterina I.
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INTERMOLECULAR interactions , *IONIC interactions , *IONIC liquids , *INTERMOLECULAR forces , *NATURAL orbitals , *APROTIC solvents - Abstract
The accuracy of correlation energy recovered by coupled cluster single‐, double‐, and perturbative triple‐excitations, CCSD(T), has led to the method being considered the gold standard of computational chemistry. The application of CCSD(T) has been limited to medium‐sized molecular systems due to its steep scaling with molecular size. The recent development of alternative domain‐based local pair natural orbital coupled‐cluster method, DLPNO‐CCSD(T), has significantly broadened the range of chemical systems to which CCSD(T) level calculations can be applied. Condensed systems such as ionic liquids (ILs) have a large contribution from London dispersion forces of up to 150 kJ mol−1 in large‐scale clusters. Ionic liquids show appreciable charge transfer effects that result in the increased valence orbital delocalization over the entire ionic network, raising the question whether the application of methods based on localized orbitals is reliable for these semi‐Coulombic materials. Here the performance of DLPNO‐CCSD(T) is validated for the prediction of correlation interaction energies of two data sets incorporating single‐ion pairs of protic and aprotic ILs. DLPNO‐CCSD(T) produced results within chemical accuracy with tight parameter settings and a non‐iterative treatment of triple excitations. To achieve spectroscopic accuracy of 1 kJ mol−1, especially for hydrogen‐bonded ILs and those containing halides, the DLPNO settings had to be increased by two orders of magnitude and include the iterative treatment of triple excitations, resulting in a 2.5‐fold increase in computational cost. Two new sets of parameters are put forward to produce the performance of DLPNO‐CCSD(T) within chemical and spectroscopic accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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17. Automatic voxel-based 3D indoor reconstruction and room partitioning from triangle meshes.
- Author
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Hübner, Patrick, Weinmann, Martin, Wursthorn, Sven, and Hinz, Stefan
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BUILDING information modeling , *CURVED surfaces , *BUILT environment , *TRIANGLES - Abstract
With the gaining popularity and proliferation of building information modeling (BIM) techniques, a growing demand emerges for accurate, up-to-date and semantically-enriched digital representations of built environments. In this regard, current mobile indoor mapping systems like the Microsoft HoloLens or Matterport allow to efficiently acquire triangle meshes of indoor building environments. However, manually reconstructing digital models of building interiors on the basis of these triangle meshes is a cumbersome and time-consuming task. Consequently, in this work, we propose a fully automatic, voxel-based indoor reconstruction approach to derive semantically-enriched and geometrically completed indoor models in voxel representation from unstructured triangle meshes. The presented approach does not require room surfaces such as walls, ceilings or floors to be planar or aligned with the coordinate axes. Furthermore, it does not rely on a clear vertical subdivision in distinct floor levels and even allows for slanted floors such as ramps or stair flights. It thus can also be applied to challenging indoor environments featuring curved room surfaces and complex vertical room layouts. The proposed approach labels voxels as 'Ceiling', 'Floor', 'Wall', 'Wall Opening', 'Interior Object' and 'Empty Interior'. Room surfaces are geometrically completed in case of holes in the input triangle meshes caused by occlusion or incomplete mapping. Furthermore, the derived interior space is partitioned into rooms and connecting transition spaces. To demonstrate the performance of our approach, we conduct a thorough quantitative evaluation on four labeled benchmark datasets. To this aim, we present a novel and adequate, automatic evaluation method. The four datasets have been acquired with the Microsoft HoloLens and are available along with the manually modeled ground truth. We also release the code of our implementation of the voxel-based indoor reconstruction approach presented in this paper as well as the code for the automated evaluation against the ground truth data at https://github.com/huepat/voxir. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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18. RECENT ADDITIONS OF CRITICALITY SAFETY RELATED INTEGRAL BENCHMARK DATA TO THE ICSBEP AND IRPHEP HANDBOOKS
- Author
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Sartori, Enrico
- Published
- 2009
19. Benchmark datasets incorporating diverse tasks, sample sizes, material systems, and data heterogeneity for materials informatics
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Ashley N. Henderson, Steven K. Kauwe, and Taylor D. Sparks
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Machine learning ,Materials discovery ,Benchmark data ,Materials datasets ,Materials informatics ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Science (General) ,Q1-390 - Abstract
Materials discovery via machine learning has become an increasingly popular method due to its ability to rapidly predict materials properties in a time-efficient and low-cost manner. However, one limitation in this field is the lack of benchmark datasets, particularly those that encompass the size, tasks, material systems, and data modalities present in the materials informatics literature. This makes it difficult to identify optimal machine learning model choices including algorithm, model architecture, data splitting, and data featurization for a given task. Here, we attempt to address this lack of benchmark datasets by assembling a unique repository of 50 different datasets for materials properties. The data contains both experimental and computational data, data suited for regression as well as classification, sizes ranging from 12 to 6354 samples, and materials systems spanning the diversity of materials research. Data were extracted from 16 publications. In addition to cleaning the data where necessary, each dataset was split into train, validation, and test splits. For datasets with more than 100 values, train-val-test splits were created, either with a 5-fold or 10-fold cross-validation method, depending on what each respective paper did in their studies. Datasets with less than 100 values had train-test splits created using the Leave-One-Out cross-validation method. These benchmark data can serve as a basis for a more diverse benchmark dataset in the future to further improve their effectiveness in the comparison of machine learning models.
- Published
- 2021
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20. MEArec: A Fast and Customizable Testbench Simulator for Ground-truth Extracellular Spiking Activity.
- Author
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Buccino, Alessio Paolo and Einevoll, Gaute Tomas
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When recording neural activity from extracellular electrodes, both in vivo and in vitro, spike sorting is a required and very important processing step that allows for identification of single neurons' activity. Spike sorting is a complex algorithmic procedure, and in recent years many groups have attempted to tackle this problem, resulting in numerous methods and software packages. However, validation of spike sorting techniques is complicated. It is an inherently unsupervised problem and it is hard to find universal metrics to evaluate performance. Simultaneous recordings that combine extracellular and patch-clamp or juxtacellular techniques can provide ground-truth data to evaluate spike sorting methods. However, their utility is limited by the fact that only a few cells can be measured at the same time. Simulated ground-truth recordings can provide a powerful alternative mean to rank the performance of spike sorters. We present here MEArec, a Python-based software which permits flexible and fast simulation of extracellular recordings. MEArec allows users to generate extracellular signals on various customizable electrode designs and can replicate various problematic aspects for spike sorting, such as bursting, spatio-temporal overlapping events, and drifts. We expect MEArec will provide a common testbench for spike sorting development and evaluation, in which spike sorting developers can rapidly generate and evaluate the performance of their algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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21. Challenges in benchmarking stream learning algorithms with real-world data.
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Souza, Vinicius M. A., dos Reis, Denis M., Maletzke, André G., and Batista, Gustavo E. A. P. A.
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MACHINE learning ,DATA distribution ,FINANCIAL databases ,RIVERS ,DISEASE vectors ,OPTICAL sensors - Abstract
Streaming data are increasingly present in real-world applications such as sensor measurements, satellite data feed, stock market, and financial data. The main characteristics of these applications are the online arrival of data observations at high speed and the susceptibility to changes in the data distributions due to the dynamic nature of real environments. The data stream mining community still faces some primary challenges and difficulties related to the comparison and evaluation of new proposals, mainly due to the lack of publicly available high quality non-stationary real-world datasets. The comparison of stream algorithms proposed in the literature is not an easy task, as authors do not always follow the same recommendations, experimental evaluation procedures, datasets, and assumptions. In this paper, we mitigate problems related to the choice of datasets in the experimental evaluation of stream classifiers and drift detectors. To that end, we propose a new public data repository for benchmarking stream algorithms with real-world data. This repository contains the most popular datasets from literature and new datasets related to a highly relevant public health problem that involves the recognition of disease vector insects using optical sensors. The main advantage of these new datasets is the prior knowledge of their characteristics and patterns of changes to adequately evaluate new adaptive algorithms. We also present an in-depth discussion about the characteristics, reasons, and issues that lead to different types of changes in data distribution, as well as a critical review of common problems concerning the current benchmark datasets available in the literature. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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22. Resource-constrained multi-project scheduling: benchmark datasets and decoupled scheduling.
- Author
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Van Eynde, Rob and Vanhoucke, Mario
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SCHEDULING ,GENETIC algorithms - Abstract
In this paper, we propose a new dataset for the resource-constrained multi-project scheduling problem and evaluate the performance of multi-project extensions of the single-project schedule generation schemes. This manuscript contributes to the existing research in three ways. First, we provide an overview of existing benchmark datasets and classify the multi-project literature based on the type of datasets that are used in these studies. Furthermore, we evaluate the existing summary measures that are used to classify instances and provide adaptations to the data generation procedure of Browning and Yassine (J Scheduling 13(2):143-161, 2010a). With this adapted generator we propose a new dataset that is complimentary to the existing ones. Second, we propose decoupled versions of the single-project scheduling schemes, building on insights from the existing literature. A computational experiment shows that the decoupled variants outperform the existing priority rule heuristics and that the best priority rules differ for the two objective functions under study. Furthermore, we analyse the effect of the different parameters on the performance of the heuristics. Third, we implement a genetic algorithm that incorporates specific multi-project operators and test it on all datasets. The experiment shows that the new datasets are challenging and provide opportunities for future research. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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23. Spatio-temporal fusion for remote sensing data: an overview and new benchmark.
- Author
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Li, Jun, Li, Yunfei, He, Lin, Chen, Jin, and Plaza, Antonio
- Abstract
Spatio-temporal fusion (STF) aims at fusing (temporally dense) coarse resolution images and (temporally sparse) fine resolution images to generate image series with adequate temporal and spatial resolution. In the last decade, STF has drawn a lot of attention and many STF methods have been developed. However, to date the STF domain still lacks benchmark datasets, which is a pressing issue that needs to be addressed in order to foster the development of this field. In this review, we provide (for the first time in the literature) a robust benchmark STF dataset that includes three important characteristics: (1) diversity of regions, (2) long timespan, and (3) challenging scenarios. We also provide a survey of highly representative STF techniques, along with a detailed quantitative and qualitative comparison of their performance with our newly presented benchmark dataset. The proposed dataset is public and available online. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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24. Benchmark Data
- Author
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Volkmar, Fred R., editor
- Published
- 2021
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25. Multi-Dimensional Classification via Decomposed Label Encoding
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Min-Ling Zhang and Bin-Bin Jia
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Computer science ,business.industry ,Feature vector ,Pattern recognition ,Space (mathematics) ,Class (biology) ,Computer Science Applications ,Computational Theory and Mathematics ,Encoding (memory) ,Multi dimensional ,Decomposition (computer science) ,Artificial intelligence ,Benchmark data ,business ,Class variable ,Information Systems - Abstract
In multi-dimensional classification (MDC), a number of class variables are assumed in the output space with each of them specifying the class membership w.r.t. one heterogeneous class space. One major challenge in learning from MDC examples lies in the heterogeneity of class spaces, where the modeling outputs from different class spaces are not directly comparable. To tackle this problem, we propose a new strategy named decomposed label encoding which enables modeling alignment for MDC in an encoded label space derived from one-vs-one (OvO) decomposition. Specifically, the original MDC output space is transformed into a ternary encoded label space by conducting OvO decomposition w.r.t. each class space. Then, the manifold structure in the feature space is exploited to enrich the labeling information in the encoded label space. Finally, the predictive model is induced by fitting the metric-aligned modeling outputs with enriched labeling information. Extensive experiments over twenty benchmark data sets clearly show the superiority of the proposed MDC strategy against state-of-the-art approaches.
- Published
- 2023
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26. Validation of codes for modeling and simulation of nuclear power plants: A review.
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Moshkbar-Bakhshayesh, Khalil and Mohtashami, Soroush
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- *
ARTIFICIAL neural networks , *DISTRIBUTION (Probability theory) , *TESTING laboratories , *ARTIFICIAL intelligence , *NUCLEAR models , *DEEP learning - Abstract
The validation process is done to ensure the performance of nuclear codes compared to experimental results and to determine the degree of reliability of codes output. The development of nuclear power plants (NPPs) designs and the need for safer power plants has led to the increasing diversity/extension of nuclear codes and, as a result, the validation process has become more complicated. In this study, single physics validation including neutronic, core thermal-hydraulics (CTH), system thermal-hydraulics (STH), fuel performance, and multi-physics validation especially coupled neutronic and thermal-hydraulics (CNTH) are discussed. An international collective effort to provide benchmark data and test facilities including core test facility (CTF), separate effect test facility (SETF), and integral test facility (ITF) accompanied with addressing challenges related to scaling issues has been made. However, validation processes may suffer from some challenges. Non-quantifiable parameters cannot be given by experimental measurements. Moreover, for measurable parameters, faulty sensors can lead to incorrect results. Neural network, especially generative deep learning, with the ability to learn the probability distribution of training data and to generate unknown patterns may be a good candidate for the challenges mentioned above, e.g., detecting faulty sensors values and estimating non-quantifiable parameters based on quantifiable ones. Therefore, the application of artificial intelligence (AI) in the validation process may lead to a reduction of the volume of experimental measurements /construction of test facilities which alone is valuable. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Liquid metal MHD research at KIT: Fundamental phenomena and flows in complex blanket geometries.
- Author
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Bühler, L., Brinkmann, H.-J., Courtessole, C., Klüber, V., Koehly, C., Lyu, B., Mistrangelo, C., and Roth, J.
- Subjects
- *
TRITIUM , *LIQUID metals , *FUSION reactor blankets , *NON-uniform flows (Fluid dynamics) , *PRESSURE drop (Fluid dynamics) - Abstract
The present paper gives an overview of liquid metal research activities performed in recent years at the Karlsruhe Institute of Technology (KIT). The work is motivated by applications in liquid metal blankets for a DEMO fusion reactor where lead lithium (PbLi), which serves as a neutron multiplier and tritium breeder, interacts with the plasma-confining magnetic field as it flows in the blanket covering the inner walls of the reactor. Liquid metal magnetohydrodynamic (MHD) research at KIT supports blanket design activities through theoretical and experimental investigations. Predictive computational tools are developed and validated by empirical data obtained for fundamental problems, such as flows in non-uniform magnetic fields or magneto-convective heat transfer from submerged obstacles. In addition, technological developments like pressure drop reduction by insulating flow channel inserts are pursued both theoretically and experimentally. Two complementary experimental facilities (MEKKA and MaPLE) provide a unique and versatile platform for MHD investigations at fusion relevant parameters. Using NaK as a model fluid in MEKKA allows experiments to be conducted at high Hartmann numbers in large complex geometries, such as scaled blanket mock-ups of ITER test blanket modules. For magneto-convection and heat transfer studies, MaPLE is well suited since it enables experiments with the prototypical fluid PbLi in test sections inclined at various orientations with respect to gravity. Some recent results have been selected to illustrate the broad spectrum of MHD activities at KIT. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Methodology Based on Photogrammetry for Testing Ship-Block Resistance in Traditional Towing Tanks: Observations and Benchmark Data
- Author
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José Enrique Gutiérrez-Romero, Samuel Ruiz-Capel, Jerónimo Esteve-Pérez, Blas Zamora-Parra, and Juan Pedro Luna-Abad
- Subjects
paraffin wax blocks ,ship resistance ,photogrammetry ,uncertainties ,model-scale test ,benchmark data ,Naval architecture. Shipbuilding. Marine engineering ,VM1-989 ,Oceanography ,GC1-1581 - Abstract
The real resistance that a ship must face when it is navigating in ice floes is the key factor for knowing the necessary power and the required engine size. The aim of this work is to provide valuable data to help other research in which numerical frameworks will be developed to study ship navigation in broken ice. In this work, we used paraffin wax as an alternative to obtain affordable solutions, avoiding the high cost of ice tests. The experiments were carried out in a traditional basin facility and they consisted of towing tank tests with a ship model using different concentrations of blocks simulated by the use of paraffin wax. Photogrammetry was used as technique to determine the initial position of the ice blocks, which is important as starting data in the current development of numerical simulation code for studying the features of ship resistance in drift ice. These data are available for some ice concentrations in attached files. In addition, a procedure for testing in traditional towing facilities is presented and discussed. The results of the resistance obtained in the experiments in the presence of simulated floes are presented for three concentrations and three model speeds. Some findings may be applicable to ice sailing, under given circumstances.
- Published
- 2022
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29. Recent Advances in Dialogue Machine Translation
- Author
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Siyou Liu, Yuqi Sun, and Longyue Wang
- Subjects
dialogue ,neural machine translation ,discourse issue ,benchmark data ,existing approaches ,real-life applications ,Information technology ,T58.5-58.64 - Abstract
Recent years have seen a surge of interest in dialogue translation, which is a significant application task for machine translation (MT) technology. However, this has so far not been extensively explored due to its inherent characteristics including data limitation, discourse properties and personality traits. In this article, we give the first comprehensive review of dialogue MT, including well-defined problems (e.g., 4 perspectives), collected resources (e.g., 5 language pairs and 4 sub-domains), representative approaches (e.g., architecture, discourse phenomena and personality) and useful applications (e.g., hotel-booking chat system). After systematical investigation, we also build a state-of-the-art dialogue NMT system by leveraging a breadth of established approaches such as novel architectures, popular pre-training and advanced techniques. Encouragingly, we push the state-of-the-art performance up to 62.7 BLEU points on a commonly-used benchmark by using mBART pre-training. We hope that this survey paper could significantly promote the research in dialogue MT.
- Published
- 2021
- Full Text
- View/download PDF
30. Hierarchical data generator based on tree-structured stick breaking process for benchmarking clustering methods.
- Author
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Olech, Łukasz P., Spytkowski, Michał, Kwaśnicka, Halina, and Michalewicz, Zbigniew
- Subjects
- *
DATABASES , *HIERARCHICAL clustering (Cluster analysis) , *CLUSTER analysis (Statistics) , *MACHINE learning , *HIERARCHIES - Abstract
A new variant of Hierarchical Cluster Analysis is gaining interest in the field of Machine Learning, called Object Cluster Hierarchy. Being still at an early stage of development, the lack of tools for systematic analysis of Object Cluster Hierarchies inhibits further improvement of this concept. In this paper we address this issue by proposing a generator of synthetic hierarchical data that can be used for benchmarking Object Cluster Hierarchy generation methods. The article presents a thorough empirical and theoretical analysis of the generator and provides guidance on how to control its parameters. The conducted experiments show the usefulness of the data generator capable of producing a wide range of differently structured data. Furthermore, datasets that represent the most common types of hierarchies are generated and made available to the public for benchmarking, along with the developed generator (http://kio.pwr.edu.pl/?page_id=396). [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
31. Event-based MILP models for ridepooling applications
- Author
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Michael Stiglmayr, Kathrin Klamroth, and Daniela Gaul
- Subjects
Mathematical optimization ,Information Systems and Management ,General Computer Science ,Optimization algorithm ,Computer science ,Event (computing) ,Event based ,Management Science and Operations Research ,Flow network ,Industrial and Manufacturing Engineering ,Time windows ,Modeling and Simulation ,Spatial representation ,Benchmark data - Abstract
Ridepooling services require efficient optimization algorithms to simultaneously plan routes and pool users in shared rides. We consider a static dial-a-ride problem (DARP) where a series of origin-destination requests have to be assigned to routes of a fleet of vehicles. Thereby, all requests have associated time windows for pick-up and delivery, and may be denied if they can not be serviced in reasonable time or at reasonable cost. Rather than using a spatial representation of the transportation network we suggest an event-based formulation of the problem, resulting in significantly improved computational times. While the corresponding MILP formulations require more variables than standard models, they have the advantage that capacity, pairing and precedence constraints are handled implicitly. The approach is tested and validated using a standard IP-solver on benchmark data from the literature. Moreover, the impact of, and the trade-off between, different optimization goals is evaluated on a case study in the city of Wuppertal (Germany).
- Published
- 2022
- Full Text
- View/download PDF
32. Benchmarking airborne laser scanning tree segmentation algorithms in broadleaf forests shows high accuracy only for canopy trees
- Author
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Cao, Y., Ball, J.G.C., Coomes, D.A., Steinmeier, L., Knapp, Nikolai, Wilkes, P., Disney, M., Calders, K., Burt, A., Lin, Y., Jackson, T.D., Cao, Y., Ball, J.G.C., Coomes, D.A., Steinmeier, L., Knapp, Nikolai, Wilkes, P., Disney, M., Calders, K., Burt, A., Lin, Y., and Jackson, T.D.
- Abstract
Individual tree segmentation from airborne laser scanning data is a longstanding and important challenge in forest remote sensing. Tree segmentation algorithms are widely available, but robust intercomparison studies are rare due to the difficulty of obtaining reliable reference data. Here we provide a benchmark data set for temperate and tropical broadleaf forests generated from labelled terrestrial laser scanning data. We compared the performance of four widely used tree segmentation algorithms against this benchmark data set. All algorithms performed reasonably well on the canopy trees. The point cloud-based algorithm AMS3D (Adaptive Mean Shift 3D) had the highest overall accuracy, closely followed by the 2D raster based region growing algorithm Dalponte2016 +. However, all algorithms failed to accurately segment the understory trees. This result was consistent across both forest types. This study emphasises the need to assess tree segmentation algorithms directly using benchmark data, rather than comparing with forest indices such as biomass or the number and size distribution of trees. We provide the first openly available benchmark data set for tropical forests and we hope future studies will extend this work to other regions.
- Published
- 2023
33. Comparison of systematically derived software metrics thresholds for object-oriented programming languages.
- Author
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Beranič, Tina and Heričko, Marjan
- Abstract
Without reliable software metrics threshold values, the efficient quality evaluation of software could not be done. In order to derive reliable thresholds, we have to address several challenges, which impact the final result. For instance, software metrics implementations vary in various software metrics tools, including varying threshold values that result from different threshold derivation approaches. In addition, the programming language is also another important aspect. In this paper, we present the results of an empirical study aimed at comparing systematically obtained threshold values for nine software metrics in four object-oriented programming languages (i.e., lava, C++, C#, and Python). We addressed challenges in the threshold derivation domain within introduced adjustments of the benchmark- based threshold derivation approach. The data set was selected in a uniform way, allowing derivation repeatability, while input values were collected using a single software metric tool, enabling the comparison of derived thresholds among the chosen object-oriented programming languages. Within the performed empirical study, the comparison reveals that threshold values differ between different programming languages. [ABSTRACT FROM AUTHOR]
- Published
- 2020
34. Intuitionistic Fuzzy Decision Trees - A New Approach
- Author
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Bujnowski, Paweł, Szmidt, Eulalia, Kacprzyk, Janusz, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Kobsa, Alfred, editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Weikum, Gerhard, editor, Goebel, Randy, editor, Tanaka, Yuzuru, editor, Wahlster, Wolfgang, editor, Siekmann, Jörg, editor, Rutkowski, Leszek, editor, Korytkowski, Marcin, editor, Scherer, Rafał, editor, Tadeusiewicz, Ryszard, editor, Zadeh, Lotfi A., editor, and Zurada, Jacek M., editor
- Published
- 2014
- Full Text
- View/download PDF
35. Comparing What? The Sense and Nonsense of Development Benchmarks
- Author
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Girbig, Robert, Meifert, Matthias T., and Meifert, Matthias T., editor
- Published
- 2013
- Full Text
- View/download PDF
36. Microarray Data Analysis Pipelines
- Author
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Lamprecht, Anna-Lena, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, and Lamprecht, Anna-Lena, editor
- Published
- 2013
- Full Text
- View/download PDF
37. Practice pattern variation: treatment of pelvic organ prolapse in The Netherlands
- Author
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Stefan J H Haan, Hugo W F van Eijndhoven, Mèlanie N van IJsselmuiden, Rolf H. Bremmer, Rosa A Enklaar, Joanna IntHout, and Olivier G A M Rijssenbeek
- Subjects
medicine.medical_specialty ,Pelvic organ ,Hysterectomy ,Referral ,Obstetrics ,business.industry ,Urology ,medicine.medical_treatment ,Obstetrics and Gynecology ,Women's cancers Radboud Institute for Health Sciences [Radboudumc 17] ,Reconstructive and regenerative medicine Radboud Institute for Health Sciences [Radboudumc 10] ,Conservative treatment ,medicine ,Benchmark data ,Pop surgery ,business ,Healthcare analytics ,Cohort study - Abstract
Introduction and hypothesis Great variety in clinical management of pelvic organ prolapse (POP) has been described over the last years. Practice pattern variation (PPV) reflects differences in care that cannot be explained by the underlying condition. We aim to explore whether PPV in management of POP in The Netherlands has changed between 2011 and 2017. Methods We conducted a multicenter cohort study, using prospective routinely collected benchmark data from LOGEX, a healthcare analytics company (Amsterdam, The Netherlands). Data of patients with a diagnosis POP from 50 hospitals (16 teaching and 34 non-teaching hospitals) were collected for the years 2011 and 2017. All treatments were categorized into three groups: conservative treatment, uterus-preserving or uterus-removing surgery. Using meta-analysis, we evaluated whether the proportions of conducted treatments changed over time and estimated the between-center variation (Cochran’s Q), reflecting the PPV in 2011 and 2017. This variation was analyzed using F-tests. Results Compared to 2011, referral for POP in 2017 decreased by 16.2% (−4505 patients), and the percentage of hysterectomies decreased by 33.6% (p p = 0.0137) and of hysterectomies by 41.5% (p = 0.0316). Conclusions We found a decline in PPV for POP surgery between 2011 and 2017. Furthermore, the number of surgical interventions decreased, which was mostly due to a decline of hysterectomies. This indicates a shift toward more conservative therapy and uterus preservation. A further reduction of PPV would be beneficial for the quality of health care.
- Published
- 2022
- Full Text
- View/download PDF
38. A critique of the bounded fuzzy possibilistic method
- Author
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Marek Gagolewski
- Subjects
Artificial Intelligence ,Logic ,Bounded function ,Cluster (physics) ,Point (geometry) ,Benchmark data ,Algorithm ,Fuzzy logic ,Mathematics - Abstract
In a recent paper published in this very journal, the “Bounded fuzzy possibilistic method” (BFPM) was proposed. We point out that there are some critical flaws in the said algorithm, which makes the results presented therein highly questionable. In particular, the method does not generate meaningful cluster membership degrees and fails to converge when run on some well-known benchmark data sets.
- Published
- 2022
- Full Text
- View/download PDF
39. Acquisition and Analysis of DIA-Based Proteomic Data: A Comprehensive Survey in 2023.
- Author
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Lou R and Shui W
- Subjects
- Mass Spectrometry methods, Gene Library, Proteome analysis, Proteomics methods, Software
- Abstract
Data-independent acquisition (DIA) mass spectrometry (MS) has emerged as a powerful technology for high-throughput, accurate, and reproducible quantitative proteomics. This review provides a comprehensive overview of recent advances in both the experimental and computational methods for DIA proteomics, from data acquisition schemes to analysis strategies and software tools. DIA acquisition schemes are categorized based on the design of precursor isolation windows, highlighting wide-window, overlapping-window, narrow-window, scanning quadrupole-based, and parallel accumulation-serial fragmentation-enhanced DIA methods. For DIA data analysis, major strategies are classified into spectrum reconstruction, sequence-based search, library-based search, de novo sequencing, and sequencing-independent approaches. A wide array of software tools implementing these strategies are reviewed, with details on their overall workflows and scoring approaches at different steps. The generation and optimization of spectral libraries, which are critical resources for DIA analysis, are also discussed. Publicly available benchmark datasets covering global proteomics and phosphoproteomics are summarized to facilitate performance evaluation of various software tools and analysis workflows. Continued advances and synergistic developments of versatile components in DIA workflows are expected to further enhance the power of DIA-based proteomics., Competing Interests: Conflict of interest The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
40. Progress in DES for Wall-Modelled LES of Complex Internal Flows
- Author
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Mockett, Charles, Thiele, Frank, and Kuzmin, Alexander, editor
- Published
- 2011
- Full Text
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41. How to Scale an Elephant with PDQ
- Author
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Gunther, Neil J. and Gunther, Neil J.
- Published
- 2011
- Full Text
- View/download PDF
42. miRcomp-Shiny: Interactive assessment of qPCR-based microRNA quantification and quality control algorithms [version 1; referees: 3 approved with reservations]
- Author
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Lauren Kemperman and Matthew N. McCall
- Subjects
Software Tool Article ,Articles ,Bioinformatics ,Genomics ,microRNA ,miRcomp ,qPCR ,benchmark data - Abstract
The miRcomp-Shiny web application allows interactive performance assessments and comparisons of qPCR-based microRNA expression and quality estimation methods using a benchmark data set. This work is motivated by two distinct use cases: (1) selection of methodology and quality thresholds for use analyzing one's own data, and (2) comparison of novel expression estimation algorithms with currently-available methodology. The miRcomp-Shiny application is implemented in the R/Shiny language and can be installed on any operating system on which R can be installed. It is made freely available as part of the miRcomp package (version 1.3.3 and later) available through the Bioconductor project at: http://bioconductor.org/packages/miRcomp. The web application is hosted at https://laurenkemperman.shinyapps.io/mircomp/. A detailed description of how to use the web application is available at: http://lkemperm.github.io/miRcomp_shiny_app
- Published
- 2017
- Full Text
- View/download PDF
43. An enhanced online LS-SVM approach for classification problems.
- Author
-
Dilmen, Erdem and Beyhan, Selami
- Subjects
- *
SUPPORT vector machines , *CLASSIFICATION algorithms , *PROBLEM solving , *KERNEL functions , *PARAMETER estimation - Abstract
In this paper, two novel approaches are proposed to improve the performance of online least squares support vector machine for classification problem. First, the parameters of support vector classifier model including kernel width parameter are simultaneously updated when a new sample arrives. In that model, kernel width parameter is a nonlinear term which cannot be estimated via least squares solution. Therefore, unscented Kalman filter is adopted to train all the parameters where Karush-Kuhn-Tucker conditions are satisfied. Second, a variable-size moving window, which is updated by an intelligent strategy, is proposed to construct the support vector set. Thus, the proposed model captures the dynamics of data quickly while precluding itself to become clumsy due to big amount of useless data. In addition, adaptive support vector set provides a lower computational load especially for the large data sets. Simultaneous training of the model parameters by unscented Kalman filter and intelligent update of support vector set provides a superior classification performance compared to the online support vector classification approaches in the literature. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
44. Facial-Video-Based Physiological Signal Measurement: Recent advances and affective applications
- Author
-
Zitong Yu, Xiaobai Li, and Guoying Zhao
- Subjects
Signal processing ,Facial expression ,Modalities ,Computer science ,Applied Mathematics ,Speech recognition ,SIGNAL (programming language) ,020206 networking & telecommunications ,02 engineering and technology ,Field (computer science) ,Signal Processing ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering ,Benchmark data ,Affective computing ,Video based - Abstract
Monitoring physiological changes [e.g., heart rate (HR), respiration, and HR variability (HRV)] is important for measuring human emotions. Physiological responses are more reliable and harder to alter compared to explicit behaviors (such as facial expressions and speech), but they require special contact sensors to obtain. Research in the last decade has shown that photoplethysmography (PPG) signals can be remotely measured (rPPG) from facial videos under ambient light, from which physiological changes can be extracted. This promising finding has attracted much interest from researchers, and the field of rPPG measurement has been growing fast. In this article, we review current progress on intelligent signal processing approaches for rPPG measurement, including earlier works on unsupervised approaches and recently proposed supervised models, benchmark data sets, and performance evaluation. We also review studies on rPPG-based affective applications and compare them with other affective computing modalities. We conclude this article by emphasizing the current main challenges and highlighting future directions.
- Published
- 2021
- Full Text
- View/download PDF
45. Retail Format Usage: Pre-COVID-19 Benchmark Data, Pandemic Practice, and Emergent Influence
- Author
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Susan Miertschin, Carole E. Goodson, and Barbara L. Stewart
- Subjects
Coronavirus disease 2019 (COVID-19) ,Computer science ,Pandemic ,General Medicine ,Benchmark data ,Data science ,Consumer behaviour - Abstract
Background: COVID-19 brought revolutionary change in consumer retail format behavior. Pre-pandemic, multiple retail formats were available, and consumers showed evidence of preference for particular formats. Then, the disruptions caused by store closures and stay-at-home mandates altered consumer behavior substantially. Aims of the Study: The purpose of this work is to report the results of research on consumer preferences for retail formats as a benchmark for examination of changes in consumer usage of retail formats wrought by COVID-19 and projection of emergent post-pandemic behaviors. Pre-COVID-19, variety in retail formats proliferated. Methodology Employed: Survey methodology captured preferences, practices, and recommendations related to use of retail formats. Research questions included: a) Which retail formats do consumers prefer? b) Which digital tools do consumers use to make purchases? c) Does delivery mode and/or product type influence retail format preference? d) Does retail format influence impulse purchasing behavior? e) Do consumers mix retail formats when making product purchases? and f) What will be the implications of COVID-19 for retail format preference? Results: Consumers reported differences in preferences for online, in-store, catalogue, and phone retail formats. Product type influenced consumer retail format preferences. Retail format influenced impulse purchase behaviors. Consumers used smart phones, laptops, desktops, tablets, email, discussion boards, social media, and social networks as purchasing tools. Conclusions: This study investigated pre-pandemic consumer preferences and usage variables related to retail format. It provides benchmarks for examination of changes resultant from the massive retail disruptions of mandatory store closures and stay-at-home mandates. It further provides a framework for projections of emergent, post-pandemic behaviors. Recommendations: The authors recommend further investigation of consumer retail format use during and subsequent to the height of the pandemic. Comparison of consumer usage pre- and post-pandemic can provide valuable input to retail planning.
- Published
- 2021
- Full Text
- View/download PDF
46. Do Double-Hybrid Exchange–Correlation Functionals Provide Accurate Chemical Shifts? A Benchmark Assessment for Proton NMR
- Author
-
David J. D. Wilson, Cristina A. Barboza, Ataualpa A. C. Braga, Júlia M. A. Alves, and Marcelo T. de Oliveira
- Subjects
Set (abstract data type) ,Correlation ,RESSONÂNCIA MAGNÉTICA NUCLEAR ,Chemical shift ,Maximum deviation ,Benchmark (computing) ,Proton NMR ,Thermodynamics ,Density functional theory ,Physical and Theoretical Chemistry ,Benchmark data ,Computer Science Applications ,Mathematics - Abstract
A benchmark density functional theory (DFT) study of 1H NMR chemical shifts for data sets comprising 200 chemical shifts, including complex natural products, has been carried out to assess the performance of DFT methods. Two new benchmark data sets, NMRH33 and NMRH148, have been established. The meta-GGA revTPSS performs remarkably well against the NMRH33 benchmark set (mean absolute deviation (MAD), 0.10 ppm; maximum deviation (max), 0.26 ppm) with the smallest MAD of all evaluated functionals. The best-performing double-hybrid density functional (DHDF), revDSD-BLYP (MAD, 0.16 ppm; max, 0.35 ppm), performs similarly to hybrid-GGA methods (e.g., mPW1PW91/6-311G(d) (MAD, 0.15 ppm; max, 0.36 ppm)), but at a considerably higher computational cost. The results indicate that currently available double-hybrid DFT methods offer no benefit over GGA (including hybrid and meta) functionals in the calculation of 1H NMR chemical shifts.
- Published
- 2021
- Full Text
- View/download PDF
47. Progressive Mimic Learning: A new perspective to train lightweight CNN models
- Author
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Dongzhu Feng, Licheng Jiao, Shuyuan Yang, Luping Zhang, and Hongbin Ma
- Subjects
Multiple stages ,Landmark ,Computer science ,business.industry ,Process (engineering) ,Cognitive Neuroscience ,Perspective (graphical) ,Computer Science Applications ,Artificial Intelligence ,Train ,Artificial intelligence ,State (computer science) ,Benchmark data ,business ,Human learning - Abstract
Knowledge distillation (KD) builds a lightweight Student Model (SM) and trains it to approximate a large Teacher Model (TM) by exploring knowledge learned by the TM, which shows effectiveness to train lightweight CNN models. However, training a small SM to achieve better performance remains a challenging problem. Recent researches on human learning behaviors show that both the knowledge from teachers and the knowledge learning processes of teachers are significant for students. Inspired by this characteristic, in this paper, we propose a new perspective, called Progressive Mimic Learning (PML), to train lightweight CNN models by mimicking the learning trajectory of the TM. In order to obtain a more powerful SM, the useful hints in the learning process of the TM are explored. To start with, the TM learning process is divided into multiple stages, and the last state of the TM in each stage is recorded as a landmark. The learning trajectory of the TM is composed of these landmarks. Then, a landmark loss is defined to constrain the SM to progressively mimic the learning process of the TM, by employing landmarks in the learning trajectory as a training hint of the SM. Several experiments are conducted on four benchmark data sets, CIFAR-10, CIFAR-100, Fashion-MNIST, and ImageNet-10, to investigate the performance of the PML. The results show that the PML can make SMs generate more accurate predictions than SMs trained by its counterparts.
- Published
- 2021
- Full Text
- View/download PDF
48. A robust supervised subspace learning approach for output-relevant prediction and detection against outliers
- Author
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Wenqing Li and Yue Wang
- Subjects
Optimization problem ,Optimization algorithm ,Computer science ,business.industry ,Pattern recognition ,Linear subspace ,Industrial and Manufacturing Engineering ,Computer Science Applications ,Control and Systems Engineering ,Modeling and Simulation ,Outlier ,Orthogonal decomposition ,Joint problem ,Artificial intelligence ,Benchmark data ,business ,Subspace topology - Abstract
This paper proposes a novel robust supervised subspace learning (RSSL) method for output-relevant prediction and detection against outliers. RSSL learns the robust subspaces by optimizing a joint problem over both the prediction of output and the reconstruction of input. To this end, the learned subspaces/data representations are informative, i.e., they are encapsulated with the critic information related to both the input and output, and thus can benefit the following tasks of output-related modeling and detection. Besides, we separate sparse items from the raw measurements to suppress the effects of outliers. An efficient optimization algorithm is designed to solve the optimization problem of RSSL. We further conduct post orthogonal decomposition upon the subspaces provided by RSSL so that the trimmed subspaces are more suitable for output-related detection. The efficacy of the proposed method is extensively verified by synthesis data and benchmark data.
- Published
- 2021
- Full Text
- View/download PDF
49. Domain-Driven Local Exceptional Pattern Mining for Detecting Stock Price Manipulation
- Author
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Ou, Yuming, Cao, Longbing, Luo, Chao, Zhang, Chengqi, Carbonell, Jaime G., editor, Siekmann, Jörg, editor, Ho, Tu-Bao, editor, and Zhou, Zhi-Hua, editor
- Published
- 2008
- Full Text
- View/download PDF
50. Lees-Edwards boundary conditions for the multi-sphere discrete element method
- Author
-
Yonghao Zhang, Sina Haeri, and Nathan Berry
- Subjects
Computer science ,General Chemical Engineering ,non-spherical particles ,02 engineering and technology ,Particle based methods ,021001 nanoscience & nanotechnology ,Constitutive modelling ,Discrete element method ,Simple shear ,020401 chemical engineering ,Benchmark (computing) ,Particle ,Applied mathematics ,Boundary value problem ,0204 chemical engineering ,Benchmark data ,Rheology ,0210 nano-technology ,Multi-sphere discrete element method ,Order of magnitude - Abstract
A consistent implementation of Lees-Edwards boundary conditions is proposed for the Multi-Sphere Discrete Element Method, which can mitigate various unphysical effects at the bulk and micro-structural levels. These effects include non-linear velocity profiles and inhomogeneous particle distributions, which result in significant errors with respect to pressure and granular temperature. In order to allow for a fair assessment of different implementations, a novel compound sphere particle shape is devised for comparison to reliable benchmark data generated from systems of spherical particles. The Multi-Sphere Discrete Element Method is utilised to examine two implementations of these conditions. The commonly used Naive approach results in the aforementioned unphysical effects, which are numerical artefacts causing deviations from the benchmark results of up to one order of magnitude. Meanwhile, the proposed consistent implementation fulfils the fundamental requirements of Lees-Edwards boundary conditions and produces data which are in excellent agreement with the benchmark results, as well as the available literature. Comparing the aforementioned implementations, general principles are developed for implementing Lees-Edwards boundary conditions for the Multi-Sphere Discrete Element Method.
- Published
- 2021
- Full Text
- View/download PDF
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