nils-herrmann/clean_scirepeval huggingface dataset:
Performance and Cramer Rao Bounds for DoA/RSS Estimation and Transmitter Localization Using Sectorized Antennas
Venue: IEEE Transactions on Vehicular Technology

Using collaborative sensors or other observing devices equipped with sectorized antennas provides a practical and low cost solution to direction of arrival (DoA) and received signal strength (RSS) estimation, as well as noncooperative transmitter (TX) localization. In this paper, we study the performance and theoretical bounds of DoA/RSS estimation and localization using sectorized antennas. We first show that the sector power measurements at an individual sensor form a sufficient statistic for DoA/RSS estimation and TX localization. Motivated by that, we then derive the Cramer Rao bound (CRB) on DoA/RSS estimation based on sector powers and study its asymptotic behavior. Moreover, we derive an analytical expression for the mean square error (MSE) of a practical sectorized antenna based DoA estimator, compare its performance to the derived CRB, and study its asymptotic properties. Next, we derive the CRB for localization based on sector powers. The resulting CRB is a lower bound for a localization system where the DoA/RSS estimates, obtained from sector powers at individual sensors, are fused together into a location estimate. Moreover, the CRB also covers the more general case of a localization system where the sector powers from individual nodes are directly fused together, without an intermediate DoA/RSS estimation step. We compare the obtained CRB to a localization approach employing an intermediate DoA/RSS estimation step and observe that skipping this intermediate processing step may result in a substantially improved localization performance. Finally, we study the influence of various important system parameters, such as the number of sensors, sectors, and measurement samples, on the achievable estimation and localization performance. Overall, this paper demonstrates and quantifies the achievable DoA/RSS estimation and localization performance of sectorized antennas and provides comprehensive design guidelines for sector power based low complexity localization systems.
Improved allometric equations for tree aboveground biomass estimation in tropical dipterocarp forests of Kalimantan, Indonesia
Venue: Forest Ecosystems

BackgroundCurrently, the common and feasible way to estimate the most accurate forest biomass requires ground measurements and allometric models. Previous studies have been conducted on allometric equations development for estimating tree aboveground biomass (AGB) of tropical dipterocarp forests (TDFs) in Kalimantan (Indonesian Borneo) However, before the use of existing equations, a validation for the selection of the best allometric equation is required to assess the model bias and precision. This study aims at evaluating the validity of local and pantropical equations; developing new allometric equations for estimating tree AGB in TDFs of Kalimantan; and validating the new equations using independent datasets.MethodsWe used 108 tree samples from destructive sampling to develop the allometric equations, with maximum tree diameter of 175 cm and another 109 samples from previous studies for validating our equations. We performed ordinary least squares linear regression to explore the relationship between the AGB and the predictor variables in the natural logarithmic form.ResultsThis study found that most of the existing local equations tended to be biased and imprecise, with mean relative error and mean absolute relative error more than 0.1 and 0.3, respectively. We developed new allometric equations for tree AGB estimation in the TDFs of Kalimantan. Through a validation using an independent dataset, we found that our equations were reliable in estimating tree AGB in TDF. The pantropical equation, which includes tree diameter, wood density and total height as predictor variables performed only slightly worse than our new models.ConclusionsOur equations improve the precision and reduce the bias of AGB estimates of TDFs. Local models developed from small samples tend to systematically bias. A validation of existing AGB models is essential before the use of the models.
Re evaluation of individual diameter height allometric models to improve biomass estimation of tropical trees.
Venue: Ecological applications a publication of the Ecological Society of America

Accurate estimation of tree biomass is necessary to provide realistic values of the carbon stored in the terrestrial biosphere. A recognized source of errors in tree aboveground biomass (AGB) estimation is introduced when individual tree height values (H) are not directly measured but estimated from diameter at breast height (DBH) using allometric equations. In this paper, we evaluate the performance of 12 alternative DBH H equations and compare their effects on AGB estimation for three tropical forests that occur in contrasting climatic and altitudinal zones. We found that fitting a three parameter Weibull function using data collected locally generated the lowest errors and bias in H estimation, and that equations fitted to these data were more accurate than equations with parameters derived from the literature. For computing AGB, the introduced error values differed notably among DBH H allometric equations, and in most cases showed a clear bias that resulted in either over or under estimation of AGB. Fitting the three parameter Weibull function minimized errors in AGB estimates in our study and we recommend its widespread adoption for carbon stock estimation. We conclude that many previous studies are likely to present biased estimates of AGB due to the method of H estimation.
Allometric Equations for Estimating Tree Aboveground Biomass in Tropical Dipterocarp Forests of Vietnam

There are few allometric equations available for dipterocarp forests, despite the fact that this forest type covers extensive areas in tropical Southeast Asia. This study aims to develop a set of equations to estimate tree aboveground biomass (AGB) in dipterocarp forests in Vietnam and to validate and compare their predictive performance with allometric equations used for dipterocarps in Indonesia and pantropical areas. Diameter at breast height (DBH) total tree height (H) and wood density (WD) were used as input variables of the nonlinear weighted least square models. Akaike information criterion (AIC) and residual plots were used to select the best models; while percent bias, root mean square percentage error, and mean absolute percent error were used to compare their performance to published models. For mixed species, the best equation was AGB 0.06203 x DBH 2.26430 x H 0.51415 x WD 0.79456 When applied to a random independent validation dataset, the predicted values from the generic equations and the dipterocarp equations in Indonesia overestimated the AGB for different sites, indicating the need for region specific equations. At the genus level, the selected equations were AGB 0.03713 x DBH 2.73813 and AGB 0.07483 x DBH 2.54496 for two genera, Dipterocarpus and Shorea, respectively, in Vietnam. Compared to the mixed species equations, the genus specific equations improved the accuracy of the AGB estimates. Additionally, the genus specific equations showed no significant differences in predictive performance in different regions (e.g. Indonesia, Vietnam) of Southeast Asia.
Improving quantitative structure activity relationship models using Artificial Neural Networks trained with dropout
Venue: Journal of Computer Aided Molecular Design

training technique that has been shown to improve ANN performance across canonical machine learning (ML) datasets. Quantitative Structure Activity Relationship (QSAR) datasets used to relate chemical structure to biological activity in Ligand Based Computer Aided Drug Discovery pose unique challenges for ML techniques, such as heavily biased dataset composition, and relatively large number of descriptors relative to the number of actives. To test the hypothesis that dropout also improves QSAR ANNs, we conduct a benchmark on nine large QSAR datasets. Use of dropout improved both enrichment false positive rate and log scaled area under the receiver operating characteristic curve (logAUC) by 22 46 over conventional ANN implementations. Optimal dropout rates are found to be a function of the signal to noise ratio of the descriptor set, and relatively independent of the dataset. Dropout ANNs with 2D and 3D autocorrelation descriptors outperform conventional ANNs as well as optimized fingerprint similarity search methods.
Improving Neural Network Generalization by Combining Parallel Circuits with Dropout
Venue: ICONIP

In an attempt to solve the lengthy training times of neural networks, we proposed Parallel Circuits (PCs) a biologically inspired architecture. Previous work has shown that this approach fails to maintain generalization performance in spite of achieving sharp speed gains. To address this issue, and motivated by the way Dropout prevents node co adaption, in this paper, we suggest an improvement by extending Dropout to the PC architecture. The paper provides multiple insights into this combination, including a variety of fusion approaches. Experiments show promising results in which improved error rates are achieved in most cases, whilst maintaining the speed advantage of the PC approach.
Revisiting rodent models: Octodon degus as Alzheimer's disease model?
Venue: Acta neuropathologica communications

Alzheimer's disease primarily occurs as sporadic disease and is accompanied with vast socio economic problems. The mandatory basic research relies on robust and reliable disease models to overcome increasing incidence and emerging social challenges. Rodent models are most efficient, versatile, and predominantly used in research. However, only highly artificial and mostly genetically modified models are available. As these 'engineered' models reproduce only isolated features, researchers demand more suitable models of sporadic neurodegenerative diseases. One very promising animal model was the South American rodent Octodon degus, which was repeatedly described as natural 'sporadic Alzheimer's disease model' with 'Alzheimer's disease like neuropathology' To unveil advantages over the 'artificial' mouse models, we re evaluated the age dependent, neurohistological changes in young and aged Octodon degus (1 to 5 years old) bred in a wild type colony in Germany. In our hands, extensive neuropathological analyses of young and aged animals revealed normal age related cortical changes without obvious signs for extensive degeneration as seen in patients with dementia. Neither significant neuronal loss nor enhanced microglial activation were observed in aged animals. Silver impregnation methods, conventional, and immunohistological stains as well as biochemical fractionations revealed neither amyloid accumulation nor tangle formation. Phosphoepitope specific antibodies against tau species displayed similar intraneuronal reactivity in both, young and aged Octodon degus.In contrast to previous results, our study suggests that Octodon degus born and bred in captivity do not inevitably develop cortical amyloidosis, tangle formation or neuronal loss as seen in Alzheimer's disease patients or transgenic disease models.
Virtual Reality Smart City Based on WebVRGIS
Venue: IEEE Internet of Things Journal

A network virtual reality (VR) engine for interactive analysis and smart city immersive visualization which integrates several latest information technologies, i.e. Web virtual reality (WebVR) Internet of Things (IoT) and three dimensional (3 D) geographical information system (3 DGIS) with peer to peer (P2P) network, has been proposed in this study. It can be used in big spatial data (e.g. remote sensing data) organization and presentation while achieving the online sharing by hash based P2P networks. In the P2P network, a map, which contains the real geographic space users and the virtual scene user avatar with prep the virtual network nodes, has been made. Moreover, it can also support the following integrated functions of VRGIS: 3 D spatial analysis function, 3 D visualization for spatial information process, and Web engine for 3 D globe and smart big city. To evaluate WebVRGIS system, a user study had been conducted by comparing it with virtual community system. The performance evaluation results had confirmed the higher usability and user satisfaction of the proposed WebVRGIS system.
Multiscale musculoskeletal modelling, data model fusion and electromyography informed modelling
Venue: Interface Focus

This paper proposes methods and technologies that advance the state of the art for modelling the musculoskeletal system across the spatial and temporal scales; and storing these using efficient ontologies and tools. We present population based modelling as an efficient method to rapidly generate individual morphology from only a few measurements and to learn from the ever increasing supply of imaging data available. We present multiscale methods for continuum muscle and bone models; and efficient mechanostatistical methods, both continuum and particle based, to bridge the scales. Finally, we examine both the importance that muscles play in bone remodelling stimuli and the latest muscle force prediction methods that use electromyography assisted modelling techniques to compute musculoskeletal forces that best reflect the underlying neuromuscular activity. Our proposal is that, in order to have a clinically relevant virtual physiological human, (i) bone and muscle mechanics must be considered together; (ii) models should be trained on population data to permit rapid generation and use underlying principal modes that describe both muscle patterns and morphology; and (iii) these tools need to be available in an open source repository so that the scientific community may use, personalize and contribute to the database of models.
A novel automated phasor measurement system for validated and traceable EMC/EMI near field analysis
Venue: IEEE Electromagnetic Compatibility Magazine

Traceable high precision EMC/EMI measurements will simplify product specifications and reduce the liability of OEMs. A novel automated near field testbed for system to chip level EMC/ EMI in the RF domain based on photonic phasor probes is presented. The scanning system combines a large scanning volume with micrometer resolution. An optical surface reconstruction system allows the surface structure of the device under test (DUT) to be measured with better than 20 mm uncertainty, allowing scans at a precisely known distance above arbitrary electronic components. Miniaturized active electro optical time domain ultra wideband Eand H field sensors for the frequency range from 0.01 to 6 GHz combined with a high speed vector signal analyzer are applied to measure the EM phasor field distribution with a dynamic range of >120 dB. The fully isolated probes eliminate perturbations of the EM fields generated by the DUT compared to electrically connected probes and offer up to 60 dB better sensitivity than passive 42 2016 IEEE Electromagnetic Compatibility Magazine Volume 5 Quarter 2 electro optical probes. The testbed enables high precision broadband near field 3D scans for EMC/EMI analysis to be performed and excellent inter laboratory repeatability to be achieved. In the near future, it will be possible to reconstruct emission data from the near field to the far field.
Russian Language in the Intercultural Communication Space: Modern Problem Paradigm

A special role belongs to cross cultural communication in the modern world. An attempt to limit the problem of the Russian language in Russia just with linguistic aspects, and only to culturological and political ones in the post Soviet Union space is deeply wrong because of the whole complex of factors, relevant to the current state of the language, including both its fundamental character for the Russian culture preservation and transference and its enduring role in preservation of Russia's and neighbouring states' information and national security. A problem of the link between generations is especially topical for Russia, as the Russian society and nation are disoriented in language as a field of meanings and styles, in axiological and ethical coordinates of the world picture. Detailed investigation of the factors affecting the development of the Russian language in the cross cultural communication space is becoming strategically important in the aspect of ensuring national security of Russia and its national unity.
Sharing Linked Open Data over Peer to Peer Distributed File Systems: The Case of IPFS
Venue: MTSR

Linked Open Data (LOD) is a method of publishing machine readable open data so that it can be interlinked and become more useful through semantic querying. The decentralized nature of the current LOD cloud relies on location specific services, which is known to result in problems of availability and broken links. Current approaches to peer to peer (P2P) decentralized file systems could be used to support better availability and performance and provide permanent data, while preserving LOD principles. Applications would also benefit from mechanisms that ensure that LOD entities are permanent and immutable, independently of their original publishers. This paper outlines a first prototype design of LOD over the Interplanetary File System (IPFS) a P2P system based on Merkel DAGs and a content addressed block storage model. The fundamental ideas on that implementation are discussed and an example implementation on the early version of IPFS is described, showing the feasibility of such approach and its main differentiating features.
The Paradoxes of Time Travel

T IME travel, I maintain, is possible. The paradoxes of time travel are oddities, not impossibilities. They prove only this much, which few would have doubted: that a possible world where time travel took place would be a most strange world, different in fundamental ways from the world we think is ours. I shall be concerned here with the sort of time travel that is recounted in science fiction. Not all science fiction writers are clear headed, to be sure, and inconsistent time travel stories have often been written. But some writers have thought the problems through with great care, and their stories are perfectly consistent. 1 If I can defend the consistency of some science fiction stories of time travel, then I suppose parallel defenses might be given of some controversial physical hypotheses such as the hypothesis that time is circular or the hypothesis that there are particles that travel faster than light. But I shall not explore these parallels here. What is time travel? Inevitably, it involves a discrepancy between time and time. Any traveler departs and then arrives at his destination; the time elapsed from departure to arrival (positive, or perhaps zero) is the duration of the journey. But if he is a time traveler, the separation in time between departure and arrival does not equal the duration of his journey. He departs; he travels for an hour, let us say; then he arrives. The time he reaches is not the time one hour after his departure. It is later, if he has traveled toward the future; earlier, if he has traveled toward the past. If he has traveled far toward the past, it is earlier even than his departure. How can it be that the same two events, his departure and his arrival, are separated by two unequal amounts of time? It is tempting to reply that there must be two independent time dimensions; that for time travel to be possible time must be not a line but a plane. 2 Then a pair of events may have two unequal separations if they are separated more in one of the time dimensions than in the other. The lives of common people occupy straight diagonal lines across the plane of time, sloping at a rate of exactly one hour of time 1 per hour of time 2. The life of the time traveler occupies a bent
Mental Time Travel: Episodic Memory and Our Knowledge of the Personal Past

Kourken Michaelian describes his book Mental Time Travel: Episodic Memory and Our Knowledge of the Personal Past chapter 1 the author sets out the three core questions addressed by the book. For a psychological audience, the restatement of these core questions found in the final chapter is more relevant because it succinctly sets out the relationship between psychology and the philosophical inquiry pursued in this book:
Decreased mental time travel to the past correlates with default mode network disintegration under lysergic acid diethylamide
Venue: Journal of psychopharmacology

This paper reports on the effects of LSD on mental time travel during spontaneous mentation. Twenty healthy volunteers participated in a placebo controlled crossover study, incorporating intravenous administration of LSD (75 mg) and placebo (saline) prior to functional magnetic resonance imaging (fMRI) Six independent, blind judges analysed mentation reports acquired during structured interviews performed shortly after the functional magnetic resonance imaging (fMRI) scans (approximately 2.5 h post administration) Within each report, specific linguistic references to mental spaces for the past, present and future were identified. Results revealed significantly fewer mental spaces for the past under LSD and this effect correlated with the general intensity of the drug's subjective effects. No differences in the number of mental spaces for the present or future were observed. Consistent with the previously proposed role of the default mode network (DMN) in autobiographical memory recollection and ruminative thought, decreased resting state functional connectivity (RSFC) within the DMN correlated with decreased mental time travel to the past. These results are discussed in relation to potential therapeutic applications of LSD and related psychedelics, e.g. in the treatment of depression, for which excessive reflection on one's past, likely mediated by DMN functioning, is symptomatic.
Do future thoughts reflect personal goals? Current concerns and mental time travel into the past and future
Venue: Quarterly journal of experimental psychology

Our overriding hypothesis was that future thinking would be linked with goals to a greater extent than memories; conceptualizing goals as current concerns (i.e. uncompleted personal goals) We also hypothesized that current concern related events would differ from non current concern related events on a set of phenomenological characteristics. We report novel data from a study examining involuntary and voluntary mental time travel using an adapted laboratory paradigm. Specifically, after autobiographical memories or future thoughts were elicited (between participants) in an involuntary and voluntary retrieval mode (within participants) participants self generated five current concerns and decided whether each event was relevant or not to their current concerns. Consistent with our hypothesis, compared with memories, a larger percentage of involuntary and voluntary future thoughts reflected current concerns. Furthermore, events related to current concerns differed from non concern related events on a range of cognitive, representational, and affective phenomenological measures. These effects were consistent across temporal direction. In general, our results agree with the proposition that involuntary and voluntary future thinking is important for goal directed cognition and behaviour.