Measure Of Information Content Research Articles

The information content of conflict, social unrest and policy uncertainty measures for macroeconomic forecasting

It is widely accepted that episodes of social unrest, conflict, political tensions and policy uncertainty affect the economy. Nevertheless, the real-time dimension of such relationships is less studied, and it remains unclear how to incorporate them in a forecasting framework. This can be partly explained by a certain divide between the economic and political science contributions in this area, as well as the traditional lack of availability of timely high-frequency indicators measuring such phenomena. The latter constraint, though, is becoming less of a limiting factor through the production of text-based indicators. In this paper we assemble a dataset of such monthly measures of what we call “institutional instability”, for three representative emerging market economies: Brazil, Colombia and Mexico. We then forecast quarterly GDP by adding these new variables to a standard macro-forecasting model using different methods. Our results strongly suggest that capturing institutional instability above a broad set of standard high-frequency indicators is useful when forecasting quarterly GDP. We also analyse relative strengths and weaknesses of the approach.

Robust inference of causality in high-dimensional dynamical processes from the Information Imbalance of distance ranks

We introduce an approach which allows detecting causal relationships between variables for which the time evolution is available. Causality is assessed by a variational scheme based on the Information Imbalance of distance ranks, a statistical test capable of inferring the relative information content of different distance measures. We test whether the predictability of a putative driven system Y can be improved by incorporating information from a potential driver system X, without explicitly modeling the underlying dynamics and without the need to compute probability densities of the dynamic variables. This framework makes causality detection possible even between high-dimensional systems where only few of the variables are known or measured. Benchmark tests on coupled chaotic dynamical systems demonstrate that our approach outperforms other model-free causality detection methods, successfully handling both unidirectional and bidirectional couplings. We also show that the method can be used to robustly detect causality in human electroencephalography data.

Illumination pattern optimization in tomography based on the Kalman estimation filter and optimal experiment design

Tomography is widely used in medical imaging or industrial non-destructive testing applications. One costly and time consuming operation in any form of tomography is the process of data acquisition where a large number of measurements are made and collected data is used for image reconstruction. Data acquisition can slow down tomography to the point that the scanner cannot catch up with the speed of changes in the medium under test. By optimizing the information content of each measurement, we can reduce the number of measurements needed to achieve the target precision. Development of algorithms to optimize the information content of tomography measurements is the main goal of this article. Here, the dynamics of the medium and tomography measurements are formulated in the form of a Kalman estimation filter. A mathematical algorithm is developed to compute the optimal measurement matrix which minimizes the uncertainty left in the estimation of the distribution the tomography scanner is reconstructing. Results, as presented in the paper, show noticeable improvement is the quality of generated images when the medium is scanned by optimal measurements instead of traditional raster or random scanning protocols.

Sparse reconstruction in spin systems. I: iid spins

AbstractFor a sequence of Boolean functions $${f_n}:{\{ - 1,1\} ^{{V_n}}} \to \{ - 1,1\} $$ f n : { − 1 , 1 } V n → { − 1 , 1 } , defined on increasing configuration spaces of random inputs, we say that there is sparse reconstruction if there is a sequence of subsets Un ⊆ Vn of the coordinates satisfying ∣Un∣ = o(∣Vn∣) such that knowing the coordinates in Un gives us a non-vanishing amount of information about the value of fn.We first show that, if the underlying measure is a product measure, then no sparse reconstruction is possible for any sequence of transitive functions. We discuss the question in different frameworks, measuring information content in L2 and with entropy. We also highlight some interesting connections with cooperative game theory. Beyond transitive functions, we show that the left-right crossing event for critical planar percolation on the square lattice does not admit sparse reconstruction either. Some of these results answer questions posed by Itai Benjamini.

Information and disinformation in hydrological data across space: The case of streamflow predictions using machine learning

Study regionA total of 461 watersheds across the USA.Study Focus:This study aimed to assess the usefulness of data from donor watersheds to predict streamflow in parent watersheds. For this purpose, Long Short-Term Memory network (LSTM) was used as an information extraction algorithm because of its state-of-the art performance in terms of predicting streamflow. Out of the 461 watersheds used in this study, 57 watersheds were selected as the parent watersheds. The quantity ‘optimal number of donor watersheds (NT)’ and ‘changes in NSE’ were used as a practical measures of information content in donor watersheds. Several LSTM models were developed by using the data from different number of donor watersheds, varying from 1 to 128, to train the models.New Hydrological Insights for the Region:Increasing the number of donor watersheds beyond some optimal NT resulted in a statistically insignificant and, in several cases, hydrologically irrelevant gain in accuracy. In some cases, the Nash-Sutcliff Efficiency (NSE) slightly decreased when NT was increased beyond the optimal value. In several watersheds using a large number of donor watersheds might result in excessively rainfall sensitive LSTM models. Further, data from donor watersheds do not seem to provide information for low flow predictions. Thus, this study offers a nuanced and sobering perspective on the usefulness of data from multiple donor watersheds in terms of streamflow predictions in any given watershed.

Multimode vibrational dynamics and orientational effects in fluorescence-encoded infrared spectroscopy. I. Response function theory.

Fluorescence-encoded infrared (FEIR) spectroscopy is an emerging technique for performing vibrational spectroscopy in solution with detection sensitivity down to single molecules. FEIR experiments use ultrashort pulses to excite a fluorescent molecule's vibrational and electronic transitions in a sequential, time-resolved manner, and are therefore sensitive to intervening vibrational dynamics on the ground state, vibronic coupling, and the relative orientation of vibrational and electronic transition dipole moments. This series of papers presents a theoretical treatment of FEIR spectroscopy that describes these phenomena and examines their manifestation in experimental data. This first paper develops a nonlinear response function description of Fourier-transform FEIR experiments for a two-level electronic system coupled to multiple vibrations, which is then applied to interpret experimental measurements in the second paper [L. Whaley-Mayda et al., J. Chem. Phys. 159, 194202 (2023)]. Vibrational coherence between pairs of modes produce oscillatory features that interfere with the vibrations' population response in a manner dependent on the relative signs of their respective Franck-Condon wavefunction overlaps, leading to time-dependent distortions in FEIR spectra. The orientational response of population and coherence contributions are analyzed and the ability of polarization-dependent experiments to extract relative transition dipole angles is discussed. Overall, this work presents a framework for understanding the full spectroscopic information content of FEIR measurements to aid data interpretation and inform optimal experimental design.

Mutual-information based optimal experimental design for hyperpolarized ^{13}C-pyruvate MRI

A key parameter of interest recovered from hyperpolarized (HP) MRI measurements is the apparent pyruvate-to-lactate exchange rate, k_{{textrm PL}}, for measuring tumor metabolism. This manuscript presents an information-theory-based optimal experimental design approach that minimizes the uncertainty in the rate parameter, k_{{textrm PL}}, recovered from HP-MRI measurements. Mutual information is employed to measure the information content of the HP measurements with respect to the first-order exchange kinetics of the pyruvate conversion to lactate. Flip angles of the pulse sequence acquisition are optimized with respect to the mutual information. A time-varying flip angle scheme leads to a higher parameter optimization that can further improve the quantitative value of mutual information over a constant flip angle scheme. However, the constant flip angle scheme, 35 and 28 degrees for pyruvate and lactate measurements, leads to an accuracy and precision comparable to the variable flip angle schemes obtained from our method. Combining the comparable performance and practical implementation, optimized pyruvate and lactate flip angles of 35 and 28 degrees, respectively, are recommended.

The information content of alternative performance measures in the European context

The information content of alternative performance measures in the European context

A Conceptual Graph-Based Method to Compute Information Content

This research uses the computing of conceptual distance to measure information content in Wikipedia categories. The proposed metric, generality, relates information content to conceptual distance by determining the ratio of the information that a concept provides to others compared to the information that it receives. The DIS-C algorithm calculates generality values for each concept, considering each relationship’s conceptual distance and distance weight. The findings of this study are compared to current methods in the field and found to be comparable to results obtained using the WordNet corpus. This method offers a new approach to measuring information content applied to any relationship or topology in conceptualization.

Beware of Extreme Investor Sentiments! Indian Evidence on the Performance of Neuro-specific Options Volatility Trading Strategies on the Facets of COVID-19

This study investigates the dynamic relationship between noise trader sentiment and excessive volatility in the Indian financial market during the COVID-19 outbreak. It proposes novel options trading strategies to ensure profitability in times of irrational exuberance and to satisfy diverse investment requirements of volatility traders, which arise from the varying levels of stimulating neurotransmitters, namely dopamine and serotonin in the human body. Empirical results show that the incremental information content of sentiment measures is vital in forecasting future volatility and the proposed options trading strategies effectively accomplish the neuro-specific intentions of the traders during extreme volatility in the Indian equity market. JEL Codes: G12, G13

Measures of Information Content during Anesthesia and Emergence in the Caenorhabditis elegans Nervous System.

Suppression of behavioral and physical responses defines the anesthetized state. This is accompanied, in humans, by characteristic changes in electroencephalogram patterns. However, these measures reveal little about the neuron or circuit-level physiologic action of anesthetics nor how information is trafficked between neurons. This study assessed whether entropy-based metrics can differentiate between the awake and anesthetized state in Caenorhabditis elegans and characterize emergence from anesthesia at the level of interneuronal communication. Volumetric fluorescence imaging measured neuronal activity across a large portion of the C. elegans nervous system at cellular resolution during distinct states of isoflurane anesthesia, as well as during emergence from the anesthetized state. Using a generalized model of interneuronal communication, new entropy metrics were empirically derived that can distinguish the awake and anesthetized states. This study derived three new entropy-based metrics that distinguish between stable awake and anesthetized states (isoflurane, n = 10) while possessing plausible physiologic interpretations. State decoupling is elevated in the anesthetized state (0%: 48.8 ± 3.50%; 4%: 66.9 ± 6.08%; 8%: 65.1 ± 5.16%; 0% vs. 4%, P < 0.001; 0% vs. 8%, P < 0.001), while internal predictability (0%: 46.0 ± 2.94%; 4%: 27.7 ± 5.13%; 8%: 30.5 ± 4.56%; 0% vs. 4%, P < 0.001; 0% vs. 8%, P < 0.001), and system consistency (0%: 2.64 ± 1.27%; 4%: 0.97 ± 1.38%; 8%: 1.14 ± 0.47%; 0% vs. 4%, P = 0.006; 0% vs. 8%, P = 0.015) are suppressed. These new metrics also resolve to baseline during gradual emergence of C. elegans from moderate levels of anesthesia to the awake state (n = 8). The results of this study show that early emergence from isoflurane anesthesia in C. elegans is characterized by the rapid resolution of an elevation in high frequency activity (n = 8, P = 0.032). The entropy-based metrics mutual information and transfer entropy, however, did not differentiate well between the awake and anesthetized states. Novel empirically derived entropy metrics better distinguish the awake and anesthetized states compared to extant metrics and reveal meaningful differences in information transfer characteristics between states.

Do Machine-Learning Atomic Descriptors and Order Parameters Tell the Same Story? The Case of Liquid Water.

Machine-learning (ML) has become a key workhorse in molecular simulations. Building an ML model in this context involves encoding the information on chemical environments using local atomic descriptors. In this work, we focus on the Smooth Overlap of Atomic Positions (SOAP) and their application in studying the properties of liquid water both in the bulk and at the hydrophobic air-water interface. By using a statistical test aimed at assessing the relative information content of different distance measures defined on the same data space, we investigate if these descriptors provide the same information as some of the common order parameters that are used to characterize local water structure such as hydrogen bonding, density, or tetrahedrality to name a few. Our analysis suggests that the ML description and the standard order parameters of the local water structure are not equivalent. In particular, a combination of these order parameters probing local water environments can predict SOAP similarity only approximately, and vice versa, the environments that are similar according to SOAP are not necessarily similar according to the standard order parameters. We also elucidate the role of some of the metaparameters in the SOAP definition in encoding chemical information.

Collaborative contracting for Manufacturing-as-a-Service (MaaS) by information content measurement and decision tree learning

Product realization through Manufacturing-as-a-Service (MaaS) has observed as an emerging trend towards Industry 4.0. It offers new opportunities for reaching external partner’s knowledge and resources while allowing companies to focus on their core competencies. This paper envisions the importance of collaborative contracting for MaaS fulfillments, in which tournament-based crowdsourcing entails evaluation and selection of manufacturing service providers as a best-matching problem of multi-criteria decision making. MaaS collaborative contracting involves numerous evaluation criteria related to not only technical capabilities of the fulfilling agents, but also their business performance involved with MaaS operations in the past history. This paper develops a contracting analysis and evaluation methodology for selection of appropriate MaaS agent selection. The proposed evaluation mechanism utilizes information content measure and decision tree learning for better matching of fulfilling agents to maximize customer satisfaction and effectiveness of multiple stakeholders of MaaS operations. The multi-attribute utility theory is integrated with decision tree learning within a coherent predictive analytics framework to not only synthesize pre-defined functional and cost requirements for customers, but also leverage upon historical data of business performance. A case study of orthodontic brace mass customization through MaaS is reported to illustrate the feasibility and potential of collaborative contracting in MaaS.

EEG Entropy in REM Sleep as a Physiologic Biomarker in Early Clinical Stages of Alzheimer's Disease.

Alzheimer's disease (AD) is associated with EEG changes across the sleep-wake cycle. As the brain is a non-linear system, non-linear EEG features across behavioral states may provide an informative physiologic biomarker of AD. Multiscale fluctuation dispersion entropy (MFDE) provides a sensitive non-linear measure of EEG information content across a range of biologically relevant time-scales. To evaluate MFDE in awake and sleep EEGs as a potential biomarker for AD. We analyzed overnight scalp EEGs from 35 cognitively normal healthy controls, 23 participants with mild cognitive impairment (MCI), and 19 participants with mild dementia due to AD. We examined measures of entropy in wake and sleep states, including a slow-to-fast-activity ratio of entropy (SFAR-entropy). We compared SFAR-entropy to linear EEG measures including a slow-to-fast-activity ratio of power spectral density (SFAR-PSD) and relative alpha power, as well as to cognitive function. SFAR-entropy differentiated dementia from MCI and controls. This effect was greatest in REM sleep, a state associated with high cholinergic activity. Differentiation was evident in the whole brain EEG and was most prominent in temporal and occipital regions. Five minutes of REM sleep was sufficient to distinguish dementia from MCI and controls. Higher SFAR-entropy during REM sleep was associated with worse performance on the Montreal Cognitive Assessment. Classifiers based on REM sleep SFAR-entropy distinguished dementia from MCI and controls with high accuracy, and outperformed classifiers based on SFAR-PSD and relative alpha power. SFAR-entropy measured in REM sleep robustly discriminates dementia in AD from MCI and healthy controls.

Informativeness across Interpreting Types: Implications for Language Shifts under Cognitive Load

Previous quantitative studies discussing interpreting types have focused on various features of linguistic forms in outputs. However, none of them has examined their informativeness. Entropy, as a measure of the average information content and the uniformity of the probability distribution of language units, has been applied to quantitative linguistic research on different types of language texts. In the present study, entropy and repeat rate were used to investigate the difference of overall informativeness and concentration of output texts between simultaneous interpreting and consecutive interpreting. We intend to figure out the frequency distribution patterns of word and word category in two types of interpreting texts. Analyses of linear mixed-effects models showed that entropy and repeat rate can distinguish the informativeness of consecutive and simultaneous interpreting outputs, and consecutive interpreting outputs entail a higher word entropy value and a lower word repeat rate than simultaneous interpreting outputs. We propose that consecutive interpreting is a cognitive process which reaches an equilibrium between production economy for interpreters and comprehension sufficiency for listeners, especially in the case where input speeches are more complex. Our findings also shed lights on the selection of interpreting types in application scenarios. The current research is the first of its kind in examining informativeness across interpreting types, demonstrating a dynamic adaptation of language users to extreme cognitive load.

A new statistical thermodynamic mechanism for quantum mechanics

A new quantum mechanics mechanism theory based on statistical mechanics is introduced. This theory is based on corresponding changes in the number of states with associated energy changes at the observer and observed occurring at observer 1) reset and 2) observation. It is shown that a) the change in the number of states has different consequences than determining the “value” obtained at observation, where each state is a possible interaction between the system and the environment. The number of bits, as a measure of information content, is determined in discrete cell size increments. Two experiments are proposed to validate the introduced mechanism. The first experiment is to determine the spatial and temporal characteristics of energy changes and how they are related to the observer and observed during the entire measurement process. The second experiment is designed to determine timing between changes in the number of states in the system at observer reset. It is anticipated that these experiments will demonstrate no time delay, an entangled process, and, hence, explain delayed choice observations. Moreover, they would demonstrate that bits not stored in the system are transferred to the environment at observer reset, so when the number of inputs is greater than the number of outputs, an energy change occurs and interference is observed (wave characteristics). Conversely, if the number of inputs equals the number of outputs, no energy change occurs and no interference is observed (particle characteristics). It is envisioned that upon validating this mechanism theory, it will further the understanding of the measurement process and entanglement’s involvement in that process.

White Matter Correlates of Spoken Discourse in Cerebrovascular Disease

AbstractBackgroundSpoken discourse (language beyond single words or sentences) performance can be used to detect cognitive impairment in cerebrovascular disease (CVD) [Roberts A, et al. (2021). Top Lang Disord 41(1):73‐98]. However, the neurological basis for altered spoken discourse in CVD is poorly defined. This study examined the association between spoken discourse and indicators of white matter microstructural integrity provided by diffusion tensor imaging (DTI) to better define the link between CVD‐related neurodegeneration and altered spoken discourse.MethodSpoken discourse and 3T DTI data (30‐32 directions, b=1000) were obtained from the CVD cohort of the Ontario Neurodegenerative Disease Research Initiative (n=133). Spoken discourse analyses were completed previously [Roberts, 2021]. A DTI analysis pipeline [Hassan SMH, et al. (2019) PLoS One 14(12):e0226715] was used to generate brain maps of fractional anisotropy (FA) and mean diffusivity (MD) and calculate mean FA and MD values for the inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus – parietal (SLFp) and temporal (SLFt) endings, and uncinate fasciculi (UNC) in each hemisphere. Canonical correlation analyses examined associations between DTI metrics and 10 spoken discourse measures separately for FA in left hemisphere, MD in left hemisphere, FA in right hemisphere, MD in right hemisphere.ResultCanonical correlations were significant in the left hemisphere (FA: r=0.47, p&lt;0.05; MD: r=0.51, p&lt;0.01) but not the right (FA: r=0.34, p=0.90; MD: r=0.40, p=0.15)(Figure 1). Among the white matter tracts, the strongest canonical loadings were seen for the SLFp (FA: 0.81; MD: ‐0.59) and SLFt (FA: 0.71; MD: ‐0.40) compared to the ILF (FA: 0.44; MD: 0.03) and UNC (FA: ‐0.34; MD: 0.10). Higher FA in the SLFp and SLFt was associated with better performance on measures of fluency and information content. Lower MD in these tracts was associated with better performance on measures of fluency, information content, and syntax.ConclusionSpoken discourse performance was associated with white matter microstructural integrity in the left hemisphere of the brain. Of the white matter tracts investigated in this study, impaired spoken discourse performance in CVD was most strongly linked to altered tissue microstructure in the parietal and temporal endings of the superior longitudinal fasciculus.

White Matter Correlates of Spoken Discourse in Cerebrovascular Disease

AbstractBackgroundSpoken discourse (language beyond single words or sentences) performance can be used to detect cognitive impairment in cerebrovascular disease (CVD) [Roberts A, et al. (2021). Top Lang Disord 41(1):73‐98]. However, the neurological basis for altered spoken discourse in CVD is poorly defined. This study examined the association between spoken discourse and indicators of white matter microstructural integrity provided by diffusion tensor imaging (DTI) to better define the link between CVD‐related neurodegeneration and altered spoken discourse.MethodSpoken discourse and 3T DTI data (30‐32 directions, b=1000) were obtained from the CVD cohort of the Ontario Neurodegenerative Disease Research Initiative (n=133). Spoken discourse analyses were completed previously [Roberts, 2021]. A DTI analysis pipeline [Hassan SMH, et al. (2019) PLoS One 14(12):e0226715] was used to generate brain maps of fractional anisotropy (FA) and mean diffusivity (MD) and calculate mean FA and MD values for the inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus – parietal (SLFp) and temporal (SLFt) endings, and uncinate fasciculi (UNC) in each hemisphere. Canonical correlation analyses examined associations between DTI metrics and 10 spoken discourse measures separately for FA in left hemisphere, MD in left hemisphere, FA in right hemisphere, MD in right hemisphere.ResultCanonical correlations were significant in the left hemisphere (FA: r=0.47, p&lt;0.05; MD: r=0.51, p&lt;0.01) but not the right (FA: r=0.34, p=0.90; MD: r=0.40, p=0.15)(Figure 1). Among the white matter tracts, the strongest canonical loadings were seen for the SLFp (FA: 0.81; MD: ‐0.59) and SLFt (FA: 0.71; MD: ‐0.40) compared to the ILF (FA: 0.44; MD: 0.03) and UNC (FA: ‐0.34; MD: 0.10). Higher FA in the SLFp and SLFt was associated with better performance on measures of fluency and information content. Lower MD in these tracts was associated with better performance on measures of fluency, information content, and syntax.ConclusionSpoken discourse performance was associated with white matter microstructural integrity in the left hemisphere of the brain. Of the white matter tracts investigated in this study, impaired spoken discourse performance in CVD was most strongly linked to altered tissue microstructure in the parietal and temporal endings of the superior longitudinal fasciculus.

Economic value-added (EVA) myths and realities: evidence from the Indian manufacturing sector

PurposeThe main aim of this paper is to examine the claim that economic value added (EVA) advocates its superiority over the traditional accounting-based financial performance measures, i.e. profit after tax (PAT), earnings per share (EPS), return on assets (ROA), return on equity (ROE) and return on investment (ROI) in the Indian manufacturing sector and at the same time, give empirical facts. It also tests and examines the information content of various performance measures and their relationship with stock returns.Design/methodology/approachThe paper uses the sample of 534 Indian manufacturing companies from the Bombay Stock Exchange (BSE) during the period 2000–2018. Multiple regression models are applied to examine the information content of EVA and traditional performance measures in explaining shareholders’ returns.FindingsRelative information content tests revealed that traditional accounting-based measures such as EPS, ROE and ROA performed better than EVA in explaining the returns of Indian manufacturing companies. Incremental information content of EVA adds little contribution to information content above traditional performance measures. The claim of superiority of EVA over accounting-based measures in association with shareholder returns is proved invalid in Indian manufacturing companies.Originality/valueThis study concludes that EVA has no superiority over traditional accounting-based financial performance measures in explaining stock returns of Indian manufacturing companies. To achieve heftiness in outcomes, panel data are tested by using Breusch–Pagan–Godfrey (BPG) test for heteroskedasticity, Hausman’s test for fixed and random effect, variance inflation factor (VIF) test for multicollinearity and Durbin–Watson test for autocorrelation.

Application of Multiple Length Cross-linkers to the Characterization of Gaseous Protein Structure.

The speed, sensitivity, and tolerance of heterogeneity, as well as the kinetic trapping of solution-like states during electrospray, make native mass spectrometry an attractive method to study protein structure. Increases in the resolution of ion mobility measurements and in mass resolving power and range are leading to the increase of the information content of intact protein measurements and an expanded role of mass spectrometry in structural biology. Herein, a suite of different length noncovalent (sulfonate to positively charged side chain) cross-linkers was introduced via gas-phase ion/ion chemistry and used to determine distance restraints of kinetically trapped gas-phase structures of native-like cytochrome c ions. Electron capture dissociation allowed for the identification of cross-linked sites. Different length linkers resulted in distinct pairs of side chains being linked, supporting the ability of gas-phase cross-linking to be structurally specific. The gas-phase lengths of the cross-linkers were determined by conformational searches and density functional theory, allowing for the interpretation of the cross-links as distance restraints. These distance restraints were used to model gas-phase structures with molecular dynamics simulations, revealing a mixture of structures with similar overall shape/size but distinct features, thereby illustrating the kinetic trapping of multiple native-like solution structures in the gas phase.