Journal articles: 'Features variability'

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ADGER, DAVID. "Combinatorial Variability." Journal of Linguistics 42, no. 3 (October 13, 2006): 503–30. http://dx.doi.org/10.1017/s002222670600418x.

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The purpose of this paper is to provide a plausibility argument for a new way of thinking about intra-personal morphosyntactic variation. The idea is embedded within the framework of the Minimalist Program, and makes use of notions of feature interpretability and feature checking. Specifically, I argue that underspecification of uninterpretable features in a matching relation with interpretable features allows us to model categoricality and variability within a single system. Unlike many current approaches to intra-personal variation (which involve multiple grammars or building stochastic weightings into the grammar itself), the system attempts to predict (rather than capture) frequencies of variants. It does this by combining an evaluation metric for the acquisition of uninterpretable features with the standard properties of features and syntactic operations in the Minimalist framework. The argument is made through a case study of was/were variation in a Scottish dialect.

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Onimisi Yahaya, Mohammed. "On the Problem of Features Variability in Sequence Learning Problems." International Journal of Future Computer and Communication 4, no. 2 (April 2015): 88–92. http://dx.doi.org/10.7763/ijfcc.2015.v4.362.

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Ni, Zhiqiang, Fangmin Sun, and Ye Li. "Heart Rate Variability-Based Subjective Physical Fatigue Assessment." Sensors 22, no. 9 (April 21, 2022): 3199. http://dx.doi.org/10.3390/s22093199.

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Accurate assessment of physical fatigue is crucial to preventing physical injury caused by excessive exercise, overtraining during daily exercise and professional sports training. However, as a subjective feeling of an individual, physical fatigue is difficult for others to objectively evaluate. Heart rate variability (HRV), which is derived from electrocardiograms (ECG) and controlled by the autonomic nervous system, has been demonstrated to be a promising indicator for physical fatigue estimation. In this paper, we propose a novel method for the automatic and objective classification of physical fatigue based on HRV. First, a total of 24 HRV features were calculated. Then, a feature selection method was proposed to remove useless features that have a low correlation with physical fatigue and redundant features that have a high correlation with the selected features. After feature selection, the best 11 features were selected and were finally used for physical fatigue classifying. Four machine learning algorithms were trained to classify fatigue using the selected features. The experimental results indicate that the model trained using the selected 11 features could classify physical fatigue with high accuracy. More importantly, these selected features could provide important information regarding the identification of physical fatigue.

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Yasyukevich, Anna. "Features of short-period variability of total electron content at high and middle latitudes." Solar-Terrestrial Physics 7, no. 4 (December 20, 2021): 71–78. http://dx.doi.org/10.12737/stp-74202107.

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The study presents the results of comparative analysis of features of a short-period (with periods of internal gravity waves) variability of total electron content (TEC) in the ionosphere at middle (Novosibirsk) and high (Norilsk) latitudes over a long period of time (2003–2020). The period analyzed makes it possible to estimate not only diurnal and seasonal variations in the variability, but also its changes within the solar activity cycle. The level of TEC variability is shown to experience pronounced seasonal variations with maxima in winter months. The difference between the level of variability in winter and summer is about two times for Novosibirsk and up to seven times for Norilsk. The variability features a distinct diurnal variation; however, the diurnal dependence at the mid- and high-latitude stations differs significantly. At high latitudes, the level of variability in the winter period strictly depends on solar activity. For the mid-latitude station, there is no clear dependence of variability level on solar activity; in the years of solar maximum, on the contrary, a slight decrease in the variability is observed. In summer, the level of variability at both middle and high latitudes remains practically unchanged and does not depend on solar activity. The main features in the dynamics of variability are shown to be similar at stations located at other longitudes, except for the East American sector. The result obtained suggests that the short-period TEC variability at high latitudes is primarily related to changes in solar activity, but regular variations in the variability at midlatitudes are probably not associated with heliophysical activity. The observed increase in the level of short-period variability in the winter mid-latitude ionosphere is assumed to be related to an increase in wave activity in the stratosphere.

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Ivanov, Aleksey V., and Sergey V. Vasilyev. "Australian Aborigines: geographical variability of craniological features." Вестник антропологии (Herald of Anthropology) 48, no. 4 (December 10, 2019): 243–51. http://dx.doi.org/10.33876/2311-0546/2019-48-4/243-251.

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This work is devoted to the study of craniological traits of Australian aborigines (male and female samples) and their geographical differentiation applying a special program of cranial traits. According to the craniological classification (Pestryakov, Grigorieva, 2004), native population of Australia belongs to the Tropid craniotype, i.e. is characterized by a relatively small size and long, narrow and relatively high form of the skull. The primary settlement of the Australian continent could only origin in the North. There are two contrasting craniotypes in Australia, which probably reflect the two main waves of the aboriginal migration across the continent. The skulls of the first migratory wave were larger and relatively low-vaulted. They are mostly characteristic of the aborigines of South Australia, who later also migrated to the north, to the arid zone of Central Australia. The second major wave is characterized by smaller high-vaulted skulls, which are now characteristic of the population of the north of the continent (Queensland and, especially, the Northern Territory and North-West Australia). The territory of the southeast of Australia (Victoria and New South Wales states) is the most favorable area for human living. The two main migratory waves mixed there, which led to the observed craniological heterosis. The craniological samples of western and northwestern Australia are also of mixed origin, but are more comparable to the Northern Territory groups. The Tasmanians are significantly different from the General Australian population in terms of craniology. This is especially true for the female sample. Perhaps the ancestors of the Tasmanians represented the very first settlement wave of the ancient Sahul continent, before the separation of the island from the mainland.

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Pestriyakov, Aleksandr P., Olga M. Grigorieva, and Yulia V. Pelenitsina. "Australian Aborigines: geographical variability of craniological features." Вестник антропологии (Herald of Anthropology) 48, no. 4 (December 10, 2019): 252–67. http://dx.doi.org/10.33876/2311-0546/2019-48-4/252-267.

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This work is devoted to the study of craniological traits of Australian aborigines (male and female samples) and their geographical differentiation applying a special program of cranial traits. According to the craniological classification (Pestryakov, Grigorieva, 2004), native population of Australia belongs to the Tropid craniotype, i.e. is characterized by a relatively small size and long, narrow and relatively high form of the skull. The primary settlement of the Australian continent could only origin in the North. There are two contrasting craniotypes in Australia, which probably reflect the two main waves of the aboriginal migration across the continent. The skulls of the first migratory wave were larger and relatively low-vaulted. They are mostly characteristic of the aborigines of South Australia, who later also migrated to the north, to the arid zone of Central Australia. The second major wave is characterized by smaller high-vaulted skulls, which are now characteristic of the population of the north of the continent (Queensland and, especially, the Northern Territory and North-West Australia). The territory of the southeast of Australia (Victoria and New South Wales states) is the most favorable area for human living. The two main migratory waves mixed there, which led to the observed craniological heterosis. The craniological samples of western and northwestern Australia are also of mixed origin, but are more comparable to the Northern Territory groups. The Tasmanians are significantly different from the General Australian population in terms of craniology. This is especially true for the female sample. Perhaps the ancestors of the Tasmanians represented the very first settlement wave of the ancient Sahul continent, before the separation of the island from the mainland

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7

Ibraheem, Sumaya, and Said Ghoul. "Software Evolution: A Features Variability Modeling Approach." Journal of Software Engineering 11, no. 1 (December 15, 2016): 12–21. http://dx.doi.org/10.3923/jse.2017.12.21.

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Fu, Zuntao, Liu Shi, Fenghua Xie, and Lin Piao. "Nonlinear features of Northern Annular Mode variability." Physica A: Statistical Mechanics and its Applications 449 (May 2016): 390–94. http://dx.doi.org/10.1016/j.physa.2016.01.014.

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Cunha, Â., R. Ferro, S. Guerra, M. Conceição, J. Correia, C. António, R. Nunes, and A. Simões Torres. "PULMONARY ALVEOLAR PROTEINOSIS: VARIABILITY IN CLINICAL FEATURES." Chest 157, no. 6 (June 2020): A158. http://dx.doi.org/10.1016/j.chest.2020.05.179.

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Sahidullah, Md, and Tomi Kinnunen. "Local spectral variability features for speaker verification." Digital Signal Processing 50 (March 2016): 1–11. http://dx.doi.org/10.1016/j.dsp.2015.10.011.

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11

HUDSON, RICHARD. "Inherent variability and Minimalism: Comments on Adger's ‘Combinatorial variability’." Journal of Linguistics 43, no. 3 (October 22, 2007): 683–94. http://dx.doi.org/10.1017/s002222670700480x.

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Adger (2006) claims that the Minimalist Program provides a suitable theoretical framework for analysing at least one example of inherent variability: the variation between was and were after you and we in the Scottish town of Buckie. Drawing on the feature analysis of pronouns and the assumption that lexical items normally have equal probabilities, his analysis provides two ‘routes’ to we/you was, but only one to we/you were, thereby explaining why the former is on average twice as common as the latter. This comment points out four serious flaws in his argument: it ignores important interactions among sex, age and subject pronoun; hardly any social groups actually show the predicted average 2:1 ratio; there is no general tendency for lexical items to have equal probability of being used; the effects of the subject may be better stated in terms of the lexemes you and we rather than as semantic features. The conclusion is that inherent variability supports a usage-based theory rather than Minimalism.

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Zeynally, Gulyaz. "Melodic Features of Cause and Result Clauses in Modern English in the Light of Experiments." International Journal of English Linguistics 7, no. 2 (January 20, 2017): 167. http://dx.doi.org/10.5539/ijel.v7n2p167.

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Variability of language units is the main feature of a language system and its activity. Variability has distinctive features providing processes like coding, decoding, maintaining and transforming the information from one generation to the other. One of the characteristic features of modern linguistics is the identification of invariants in every level of a language system. It helps us to say that an invariant is the factor that provides the unity of elements but a variant distinguishes different steps of this unity. Variability of language units is the main means providing the communicative function of the language, or “the possibility of variability of language units is the characteristic feature of the language nature”, as G. V. Stepanov says. (Stepanov, 1976, p. 223)Variability is the characteristic feature of the realization of the units of phonological, morphological and syntactic levels of the language in syntagmatics, in other words the units of these levels are represented in variants in the speech act. The study of variability of the sentence intonation can be a great contribution to the development of the variability problem. Our aim is to investigate melodic contour of adverbial clauses of cause and result, the direction of intonation contour, the interval between syntagms and their register.

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Andreieva, Iana, Olekсandr Tokarenko, and Dmitro Myrnyi. "Age features of heart rate variability in obesity." ScienceRise: Medical Science, no. 1 (21) (January 23, 2018): 25–28. http://dx.doi.org/10.15587/2519-4798.2018.121610.

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Kyono, A. "Compositional variability and crystal structural features of guanacoite." American Mineralogist 93, no. 4 (April 1, 2008): 501–7. http://dx.doi.org/10.2138/am.2008.2661.

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Maccarone, Thomas J. "Detection of Variability Features in Background Limited Data." Research Notes of the AAS 3, no. 8 (August 14, 2019): 116. http://dx.doi.org/10.3847/2515-5172/ab3a36.

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Moridani, M. K., Z. Mahabadi, and N. Javadi. "Heart rate variability features for different stress classification." Bratislava Medical Journal 121, no. 09 (2020): 619–27. http://dx.doi.org/10.4149/bll_2020_107.

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Mavliyev, Fanis, Andrew Nazarenko, and Nikolay Sosnov. "Typological features of variability of blood circulation parameters." Uchenye zapiski universiteta imeni P.F. Lesgafta, no. 91 (September 2012): 97–101. http://dx.doi.org/10.5930/issn.1994-4683.2012.09.91.p97-101.

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Guzik, Przemyslaw, Jaroslaw Piskorski, Tomasz Krauze, Krzysztof Narkiewicz, Andrzej Wykretowicz, and Henryk Wysocki. "Asymmetric features of short-term blood pressure variability." Hypertension Research 33, no. 11 (August 5, 2010): 1199–205. http://dx.doi.org/10.1038/hr.2010.138.

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Driessen, L. N., G. H. Janssen, C. G. Bassa, B. W. Stappers, and D. R. Stinebring. "Scattering features and variability of the Crab pulsar." Monthly Notices of the Royal Astronomical Society 483, no. 1 (November 27, 2018): 1224–32. http://dx.doi.org/10.1093/mnras/sty3192.

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Rymen, Daisy, Julia Winter, Peter M. Van Hasselt, Jaak Jaeken, Cigdem Kasapkara, Gulden Gokçay, Hanneke Haijes, et al. "Key features and clinical variability of COG6-CDG." Molecular Genetics and Metabolism 116, no. 3 (November 2015): 163–70. http://dx.doi.org/10.1016/j.ymgme.2015.07.003.

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Kustova, Yulia, Natalya Chelnokova, Nickolaj Yakovlev, Elena Anisimova, and Valery Konnov. "AGE-RELATED VARIABILITY OF SOMATOTYPE FEATURES IN FE." Archiv Euromedica 10, no. 3 (September 28, 2020): 33–36. http://dx.doi.org/10.35630/2199-885x/2020/10/3.7.

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Mackin, Dennis, Xenia Fave, Lifei Zhang, David Fried, Jinzhong Yang, Brian Taylor, Edgardo Rodriguez-Rivera, Cristina Dodge, Aaron Kyle Jones, and Laurence Court. "Measuring Computed Tomography Scanner Variability of Radiomics Features." Investigative Radiology 50, no. 11 (November 2015): 757–65. http://dx.doi.org/10.1097/rli.0000000000000180.

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Baran, R. "Physiological variability of nail features in healthy newborns." Journal of the European Academy of Dermatology and Venereology 31, no. 2 (January 27, 2017): 203. http://dx.doi.org/10.1111/jdv.14110.

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Mitchell, Drew, Samantha Buszek, Benjamin Tran, Maguy Farhat, Jodi Goldman, Lily Erickson, Brandon Curl, et al. "Managing the effect of magnetic resonance imaging pulse sequence on radiomic feature reproducibility in the study of brain metastases." F1000Research 11 (August 4, 2022): 892. http://dx.doi.org/10.12688/f1000research.122871.1.

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Background: Despite the promise of radiomics studies, their limited reproducibility has hindered meaningful clinical translation. Variability in study designs as well as image acquisition and processing contribute to unreproducible radiomic results. This work’s purpose was to (i) quantitatively compare variability of radiomic features extracted from 2-D spin echo (SE) and 3-D spoiled gradient echo (SPGR) T1-weighted post-contrast magnetic resonance (MR) images of brain metastases acquired within the same patient in a single imaging session, and (ii) provide a framework to inform data acquisition for reproducible radiomics studies. Methods: A retrospective cohort of 29 patients with pathologically-confirmed brain metastases and contrast-enhanced T1-weighted MR images acquired using 2-D SE and 3-D SPGR sequences within one exam was identified. Metastases were segmented twice by different physicians using semi-automated methods. Radiomic features were extracted using PyRadiomics for 264 preprocessing variable combinations. Lin’s concordance correlation coefficient (CCC) was computed between features extracted from images acquired by both pulse sequences and different tumor segmentations. Results: We provided general recommendations to improve MR-based radiomic feature reproducibility by clustering and identifying low-concordance features and processing variables. Median CCC between 2-D SE and 3-D SPGR (measuring feature agreement between pulse sequences) was greater for fixed bin count intensity discretization (0.76 versus 0.63) and specific high-concordance features (0.74 versus 0.53). Applying all recommendations improved median CCC from 0.51 to 0.79. Median CCC between contours (measuring feature sensitivity to inter-observer variability) was higher for 2-D SE (0.93 versus 0.86) but improved to 0.93 for 3-D SPGR after low-concordance feature exclusion. Conclusions: The following recommendations are proposed to improve reproducibility: 1) Fixed bin count intensity discretization for all studies, 2) for studies with 2-D and 3-D datasets, excluding high-variability features from downstream analyses, 3) when segmentation is manual or semi-automated, using only 2-D SE images or excluding features susceptible to segmentation variability.

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Grange, Thomas, Mélodie Aubart, Maud Langeois, Louise Benarroch, Pauline Arnaud, Olivier Milleron, Ludivine Eliahou, et al. "Quantifying the Genetic Basis of Marfan Syndrome Clinical Variability." Genes 11, no. 5 (May 20, 2020): 574. http://dx.doi.org/10.3390/genes11050574.

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Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder with considerable inter- and intra-familial clinical variability. The contribution of inherited modifiers to variability has not been quantified. We analyzed the distribution of 23 clinical features in 1306 well-phenotyped MFS patients carrying FBN1 mutations. We found strong correlations between features within the same system (i.e., ophthalmology vs. skeletal vs. cardiovascular) suggesting common underlying determinants, while features belonging to different systems were largely uncorrelated. We adapted a classical quantitative genetics model to estimate the heritability of each clinical feature from phenotypic correlations between relatives. Most clinical features showed strong familial aggregation and high heritability. We found a significant contribution by the major locus on the phenotypic variance only for ectopia lentis using a new strategy. Finally, we found evidence for the “Carter effect” in the MFS cardiovascular phenotype, which supports a polygenic model for MFS cardiovascular variability and indicates additional risk for children of MFS mothers with an aortic event. Our results demonstrate that an important part of the phenotypic variability in MFS is under the control of inherited modifiers, widely shared between features within the same system, but not among different systems. Further research must be performed to identify genetic modifiers of MFS severity.

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Matějka, K., J. Leugner, and V. Krpeš. "Phenotype features in juvenile populations of Picea abies and their growth." Journal of Forest Science 60, No. 3 (April 2, 2014): 96–108. http://dx.doi.org/10.17221/77/2013-jfs.

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The young populations of Norway spruce (Picea abies) can be evaluated in terms of both variability in the quantitative characteristics and share of different phenotypes according to the needle types. A set of two-years-old seedlings produced in the nursery and several populations of natural regeneration in the Krkono&scaron;e Mts. and the Kru&scaron;né hory Mts. were evaluated using the needle anatomy, size and colour. The tree height growth was measured simultaneously. The growth was related to some needle features. Four basic anatomical types of needles were distinguished in the mountain Norway spruce seedlings: flat needles, intermediate needles, inversion type and sclerotized needles. The growth of natural regeneration populations is mainly correlated with the needle width and the <br /> length/width ratio. The population variability according to growth can be related to the variability of some phenotype characteristics. This relationship differs in natural regeneration and planting.  

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Fajar, Ahmad Nurul, Eko K. Budiardjo, and Zainal A. Hasibuan. "BRIDGING GAP OF USER GOAL REQUIREMENTS AND IMPLEMENTED APPLICATIONS BASED ON FEATURE MODEL." Jurnal Sistem Informasi 8, no. 2 (October 23, 2013): 113. http://dx.doi.org/10.21609/jsi.v8i2.332.

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Feature modeling is a conceptual thinking for identifying and classification feature in order for support software product lines. However, there are lack of the user goal requirements. It related with a technique for managing of features commonalities and variability. It has a hierarchy of features with variability and the purpose is to organize features. In practice of implemented applications, the feature model development lack of goal user requirement. The goal of user requirement in Indonesian government has described in document regulations. It should be a fundamental concern to develop e-government applications. However, In order to capture degree of software feature importance, some of features compared with implemented e-government applications. We have extracted some of features which can be compared with the implemented e-government applications. Our technique is extracted are derived from document regulations to business process model and feature model also. We Choose SIPKD and SIMDA applications which has implemented in Indonesian local government which has variation from one and another. We use extended AHP and S-AHP to find the prioritization of software features. The results are 80 features in SIPKD and 90 features in SIMDA. There are 65 features common and 25 variant features .This make un-optimization usage applications.

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Chen, Yuhe, Simeng Ma, Xiaoyu Yang, Dujuan Liu, and Jun Yang. "Screening Children’s Intellectual Disabilities with Phonetic Features, Facial Phenotype and Craniofacial Variability Index." Brain Sciences 13, no. 1 (January 16, 2023): 155. http://dx.doi.org/10.3390/brainsci13010155.

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Background: Intellectual Disability (ID) is a kind of developmental deficiency syndrome caused by congenital diseases or postnatal events. This syndrome could be intervened as soon as possible if its early screening was efficient, which may improve the condition of patients and enhance their self-care ability. The early screening of ID is always achieved by clinical interview, which needs in-depth participation of medical professionals and related medical resources. Methods: A new method for screening ID has been proposed by analyzing the facial phenotype and phonetic characteristic of young subjects. First, the geometric features of subjects’ faces and phonetic features of subjects’ voice are extracted from interview videos, then craniofacial variability index (CVI) is calculated with the geometric features and the risk of ID is given with the measure of CVI. Furthermore, machine learning algorithms are utilized to establish a method for further screening ID based on facial features and phonetic features. Results: The proposed method using three feature sets, including geometric features, CVI features and phonetic features was evaluated. The best performance of accuracy was closer to 80%. Conclusions: The results using the three feature sets revealed that the proposed method may be applied in a clinical setting in the future after continuous improvement.

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Chapman, Christopher C., Bernadette M. Sloyan, Terence J. O’Kane, and Matthew A. Chamberlain. "Interannual Subtropical Indian Ocean Variability due to Long Baroclinic Planetary Waves." Journal of Climate 33, no. 16 (August 15, 2020): 6765–91. http://dx.doi.org/10.1175/jcli-d-19-0469.1.

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AbstractLow-frequency variability in the south Indian Ocean is studied by analyzing 200 years of output from a fully coupled climate model simulation. At time scales of 2–10 years, the variability is dominated by westward-propagating features that form on the eastern side of the basin. Using feature tracking and clustering, the spatiotemporal characteristics and preferred pathways of the propagating features are identified and studied in detail. By comparison of the phase speed and vertical structure of the propagating anomalies identified by the feature tracking with linear theory, we conclude that these features are likely mode 1 or 2 baroclinic planetary waves. The effects of this low-frequency variability on the climate system is investigated. By analysis of the mixed-layer temperature budget, it is shown that at particular geographic locations, the propagating features can substantially modify the near-surface ocean and induce significant fluxes of heat into the atmosphere. In turn, these heat fluxes can drive a coherent atmospheric response, although this response does not appear to feed back onto the ocean. Finally, we discuss the implications for the interannual climate predictability.

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Romano, Francesco Bryan. "Morphological variability in L2 Italian." ITL - International Journal of Applied Linguistics 168, no. 2 (December 30, 2017): 203–47. http://dx.doi.org/10.1075/itl.16010.rom.

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Abstract Key accounts of morphological variability in L2 acquisition posit either deficits in the representation of abstract morphosyntactic features or the mapping between morpho-phonological forms and syntactic features due to computational limitations. This study extends previous research to L2 Italian, a richly inflected language. The production and grammatical intuitions of suppletive and affixal verb inflection were elicited from a cross-section of instructed adult L2 learners with L1 Spanish and L1 English. Although a clear production-intuition gap was found, supporting computational views, a strong regularity in the degree of variability across test conditions, L1s, and proficiency levels was also attested, supporting representational accounts. The findings suggest morphological development in L2 Italian is consistent with structure-building models that assume no L1 transfer of functional features. Imperative verb forms in L2 Italian are proposed as defaults equivalent to the bare verb forms of L2 English and non-finite defaults of L2 French and German.

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Golz, Martin, Adolf Schenka, Florian Haselbeck, and Martin Patrick Pauli. "Inter-individual variability of EEG features during microsleep events." Current Directions in Biomedical Engineering 5, no. 1 (September 1, 2019): 13–16. http://dx.doi.org/10.1515/cdbme-2019-0004.

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AbstractThis paper examines the question of how strongly the spectral properties of the EEG during microsleep differ between individuals. For this purpose, 3859 microsleep examples were compared with 4044 counterexamples in which drivers were very drowsy but were able to perform the driving task. Two types of signal features were compared: logarithmic power spectral densities and entropy measures of wavelets coefficient series. Discriminant analyses were performed with the following machine learning methods: support-vector machines, gradient boosting, learning vector quantization. To the best of our knowledge, this is the first time that results of the leave-one-subject-out cross-validation (LOSO CV) for the detection of microsleep are presented. Error rates lower than 5.0 % resulted in 17 subjects and lower than 13 % in another 11 subjects. In 3 individuals, EEG features could not be explained by the pool of EEG features of all other individuals; for them, detection errors were 15.1 %, 17.1 %, and 27.0 %. In comparison, cross validation by means of repeated random subsampling, in which individuality is not considered, yielded mean error rates of 5.0 ± 0.5 %. A subsequent inspection of raw EEG data showed that in two individuals a bad signal quality due to poor electrode attachment could be the cause and in one individual a very unusual behavior, a high and long-lasting eyelid activity which interfered the recorded EEG in all channels.

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Shadlinskiy, V. B., A. B. Isaev, and K. Dzh Gulieva. "Features of Individual-Typological Variability of the Pterygomaxillary Fissure." Journal of Anatomy and Histopathology 6, no. 3 (2017): 82–85. http://dx.doi.org/10.18499/2225-7357-2017-6-3-82-85.

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Кузовов, Сергей, Sergey Kuzovov, Константин Макаренко, Konstantin Makarenko, Дмитрий Илюшкин, and Dmitriy Ilyushkin. "Features hot cracking under temperature variability pouring steel castings." Bulletin of Bryansk state technical university 2014, no. 3 (September 30, 2014): 38–41. http://dx.doi.org/10.12737/23202.

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Robinson, A. R., M. Golnaraghi, W. G. Leslie, A. Artegiani, A. Hecht, E. Lazzoni, A. Michelato, E. Sansone, A. Theocharis, and Ü. Ünlüata. "The eastern Mediterranean general circulation: features, structure and variability." Dynamics of Atmospheres and Oceans 15, no. 3-5 (April 1991): 215–40. http://dx.doi.org/10.1016/0377-0265(91)90021-7.

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Aboamer, Mohamed Abdelkader, Ahmad Taher Azar, Abdallah S. A. Mohamed, Karl-Jürgen Bär, Sandy Berger, and Khaled Wahba. "Nonlinear features of heart rate variability in paranoid schizophrenic." Neural Computing and Applications 25, no. 7-8 (June 3, 2014): 1535–55. http://dx.doi.org/10.1007/s00521-014-1621-1.

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Mukhtarova, Aziza E. "PSYCHOLOGICAL FEATURES OF PROFESSIONAL TRAINING OF TEACHER PSYCHOLOGISTS." American Journal Of Social Sciences And Humanity Research 02, no. 12 (December 1, 2022): 69–75. http://dx.doi.org/10.37547/ajsshr/volume02issue12-11.

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In the context of dynamic processes taking place in the economy of Uzbekistan, the current stage of development of society is characterized by a change in educational paradigms, a transition to new pedagogical technologies focused on variability, subjectivity, creative individuality, personal potential of specialists who are as ready as possible for practical activities, able to quickly engage in innovative processes and adjust their professional activities.

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Çelik, Gamze, Mustafa Yıldırım, Mahmut Ilhan, Özcan Karaman, Ertuğrul Taşan, Sadık Kara, and Şükrü Okkesim. "Comparison of Pulse Rate Variability and Heart Rate Variability for Hypoglycemia Syndrome." Methods of Information in Medicine 55, no. 03 (2016): 250–57. http://dx.doi.org/10.3414/me15-01-0088.

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SummaryBackground: Heart rate variability (HRV) is a signal obtained from RR intervals of electro -cardiography (ECG) signals to evaluate the balance between the sympathetic nervous system and the parasympathetic nervous system; not only HRV but also pulse rate va -riability (PRV) extracted from finger pulse plethysmography (PPG) can reflect irregularities that may occur in heart rate and control procedures.Objectives: The purpose of this study is to compare the HRV and PRV during hypogly -cemia in order to evaluate the features that computed from PRV that can be used in detection of hypoglycemia.Methods: To this end, PRV and HRV of 10 patients who required testing with insulininduced hypoglycemia (IIHT) in Clinics of Endocrinology and Metabolism Diseases of Bezm-i Alem University (Istanbul, Turkey), were obtained. The recordings were done at three stages: prior to IIHT, during the IIHT, and after the IIHT. We used Bland-Altman analysis for comparing the parameters and to evaluate the correlation between HRV and PRV if exists.Results: Significant correlation (r > 0.90, p < 0.05) and close agreement were found between HRV and PRV for mean intervals, the root-mean square of the difference of successive intervals, standard deviation of successive intervals and the ratio of the low-to-high frequency power.Conclusions: In conclusion, all the features computed from PRV and HRV have close agreement and correlation according to Bland-Altman analyses’ results and features computed from PRV can be used in detection of hypoglycemia.

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Sudjai, Narumol, Palanan Siriwanarangsun, Nittaya Lektrakul, Pairash Saiviroonporn, Sorranart Maungsomboon, Rapin Phimolsarnti, Apichat Asavamongkolkul, and Chandhanarat Chandhanayingyong. "Robustness of Radiomic Features: Two-Dimensional versus Three-Dimensional MRI-Based Feature Reproducibility in Lipomatous Soft-Tissue Tumors." Diagnostics 13, no. 2 (January 10, 2023): 258. http://dx.doi.org/10.3390/diagnostics13020258.

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This retrospective study aimed to compare the intra- and inter-observer manual-segmentation variability in the feature reproducibility between two-dimensional (2D) and three-dimensional (3D) magnetic-resonance imaging (MRI)-based radiomic features. The study included patients with lipomatous soft-tissue tumors that were diagnosed with histopathology and underwent MRI scans. Tumor segmentation based on the 2D and 3D MRI images was performed by two observers to assess the intra- and inter-observer variability. In both the 2D and the 3D segmentations, the radiomic features were extracted from the normalized images. Regarding the stability of the features, the intraclass correlation coefficient (ICC) was used to evaluate the intra- and inter-observer segmentation variability. Features with ICC > 0.75 were considered reproducible. The degree of feature robustness was classified as low, moderate, or high. Additionally, we compared the efficacy of 2D and 3D contour-focused segmentation in terms of the effects of the stable feature rate, sensitivity, specificity, and diagnostic accuracy of machine learning on the reproducible features. In total, 93 and 107 features were extracted from the 2D and 3D images, respectively. Only 35 features from the 2D images and 63 features from the 3D images were reproducible. The stable feature rate for the 3D segmentation was more significant than for the 2D segmentation (58.9% vs. 37.6%, p = 0.002). The majority of the features for the 3D segmentation had moderate-to-high robustness, while 40.9% of the features for the 2D segmentation had low robustness. The diagnostic accuracy of the machine-learning model for the 2D segmentation was close to that for the 3D segmentation (88% vs. 90%). In both the 2D and the 3D segmentation, the specificity values were equal to 100%. However, the sensitivity for the 2D segmentation was lower than for the 3D segmentation (75% vs. 83%). For the 2D + 3D radiomic features, the model achieved a diagnostic accuracy of 87% (sensitivity, 100%, and specificity, 80%). Both 2D and 3D MRI-based radiomic features of lipomatous soft-tissue tumors are reproducible. With a higher stable feature rate, 3D contour-focused segmentation should be selected for the feature-extraction process.

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Yasyukevich, Anna. "Features of short-period variability of total electron content at high and middle latitudes." Solnechno-Zemnaya Fizika 7, no. 4 (December 20, 2021): 75–83. http://dx.doi.org/10.12737/szf-74202107.

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The study presents the results of comparative analysis of features of a short-period (with periods of internal gravity waves) variability of total electron content (TEC) in the ionosphere at middle (Novosibirsk) and high (Norilsk) latitudes over a long period of time (2003–2020). The period analyzed makes it possible to estimate not only diurnal and seasonal variations in the variability, but also its changes within the solar activity cycle. The level of TEC variability is shown to experience pronounced seasonal variations with maxima in winter months. The difference between the level of variability in winter and summer is about two times for Novosibirsk and up to seven times for Norilsk. The variability features a distinct diurnal variation; however, the diurnal dependence at the mid- and high-latitude stations differs significantly. At high latitudes, the level of variability in the winter period strictly depends on solar activity. For the mid-latitude station, there is no clear dependence of variability level on solar activity; in the years of solar maximum, on the contrary, a slight decrease in the variability is observed. In summer, the level of variability at both middle and high latitudes remains practically unchanged and does not depend on solar activity. The main features in the dynamics of variability are shown to be similar at stations located at other longitudes, except for the East American sector. The result obtained suggests that the short-period TEC variability at high latitudes is primarily related to changes in solar activity, but regular variations in the variability at midlatitudes are probably not associated with heliophysical activity. The observed increase in the level of short-period variability in the winter mid-latitude ionosphere is assumed to be related to an increase in wave activity in the stratosphere.

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Xu, Jianbo, and Wenxi Chen. "Impact of Water Temperature on Heart Rate Variability during Bathing." Life 11, no. 5 (April 22, 2021): 378. http://dx.doi.org/10.3390/life11050378.

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Background: Heart rate variability (HRV) is affected by many factors. This paper aims to explore the impact of water temperature (WT) on HRV during bathing. Methods: The bathtub WT was preset at three conditions: i.e., low WT (36–38 °C), medium WT (38–40 °C), and high WT (40–42 °C), respectively. Ten subjects participated in the data collection. Each subject collected five electrocardiogram (ECG) recordings at each preset bathtub WT condition. Each recording was 18 min long with a sampling rate of 200 Hz. In total, 150 ECG recordings and 150 WT recordings were collected. Twenty HRV features were calculated using 1-min ECG segments each time. The k-means clustering analysis method was used to analyze the rough trends based on the preset WT. Analyses of the significant differences were performed using the multivariate analysis of variance of t-tests, and the mean and standard deviation (SD) of each HRV feature based on the WT were calculated. Results: The statistics show that with increasing WT, 11 HRV features are significantly (p < 0.05) and monotonously reduced, four HRV features are significantly (p < 0.05) and monotonously rising, two HRV features are rising first and then reduced, two HRV features (fuzzy and approximate entropy) are almost unchanged, and vLF power is rising. Conclusion: The WT has an important impact on HRV during bathing. The findings in the present work reveal an important physiological factor that affects the dynamic changes of HRV and contribute to better quantitative analyses of HRV in future research works.

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Kalpathy-Cramer, J., S. You, K. Keck, D. Erdogmus, M. F. Chiang, and E. Ataer-Cansizoglu. "Analysis of Underlying Causes of Inter-expert Disagreement in Retinopathy of Prematurity Diagnosis." Methods of Information in Medicine 54, no. 01 (2015): 93–102. http://dx.doi.org/10.3414/me13-01-0081.

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SummaryObjective: Inter-expert variability in image-based clinical diagnosis has been demonstrated in many diseases including retinopathy of prematurity (ROP), which is a disease affecting low birth weight infants and is a major cause of childhood blindness. In order to better understand the underlying causes of variability among experts, we propose a method to quantify the variability of expert decisions and analyze the relationship between expert diagnoses and features computed from the images. Identification of these features is relevant for development of computer-based decision support systems and educational systems in ROP, and these methods may be applicable to other diseases where inter-expert variability is observed.Methods: The experiments were carried out on a dataset of 34 retinal images, each with diagnoses provided independently by 22 experts. Analysis was performed using concepts of Mutual Information (MI) and Kernel Density Estimation. A large set of structural features (a total of 66) were extracted from retinal images. Feature selection was utilized to identify the most important features that correlated to actual clinical decisions by the 22 study experts. The best three features for each observer were selected by an exhaustive search on all possible feature subsets and considering joint MI as a relevance criterion. We also compared our results with the results of Cohen’s Kappa [36] as an inter-rater reliability measure.Results: The results demonstrate that a group of observers (17 among 22) decide consistently with each other. Mean and second central moment of arteriolar tortuosity is among the reasons of disagreement between this group and the rest of the observers, meaning that the group of experts consider amount of tortuosity as well as the variation of tortuosity in the image.Conclusion: Given a set of image-based features, the proposed analysis method can identify critical image-based features that lead to expert agreement and disagreement in diagnosis of ROP. Although tree-based features and various statistics such as central moment are not popular in the literature, our results suggest that they are important for diagnosis.

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Tripath, Kirti, Harsh Sohal, and Shruti Jain. "COMPUTER-AIDED DIAGNOSTIC SYSTEM FOR FEATURE-BASED CLASSIFICATION USING HEART RATE VARIABILITY." Biomedical Engineering: Applications, Basis and Communications 32, no. 02 (April 2020): 2050009. http://dx.doi.org/10.4015/s101623722050009x.

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This article proposes a computer-aided diagnostic system for feature-based selection classification (CAD-FSC) to detect arrhythmia, atrial fibrillation and normal sinus rhythm. The CAD-FSC methodology encompasses of ECG signal processing phases: ECG pre-processing, R-peak detection, feature extraction, feature selection and ECG classification. Digital filters are used to pre-process the ECG signal and the R-peak is detected by using the Pan-Tompkin’s algorithm. The heart rate variability (HRV) features are extracted in time and frequency domains. Among them, the prominent features are selected with analysis of variance (ANOVA) using Statistical Package for the Social Sciences (SPSS) tool. Cubic support vector machine (C-SVM), coarse Gaussian support vector machine (CG-SVM), cubic k-nearest neighbor (C-kNN) and weighted k-nearest neighbor (W-kNN) classifiers are utilized to validate the CAD-FSC system for three-stage classification. The C-SVM outperforms all other classifiers by giving higher overall accuracy of 98.4% after feature selection of time domain and frequency domain.

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Guy, Gregory R., and Charles Boberg. "Inherent variability and the obligatory contour principle." Language Variation and Change 9, no. 2 (July 1997): 149–64. http://dx.doi.org/10.1017/s095439450000185x.

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ABSTRACTEnglish coronal stop deletion is constrained by the preceding segment, so that stops and sibilants favor deletion more than liquids and nonsibilant fricatives. Previous explanations of this constraint (e.g., the sonority hierarchy) have failed to account for the details, but we show that it can be comprehensively treated as a consequence of the obligatory contour principle (OCP). The OCP, introduced to account for a variety of categorical constraints against adjacent identical tones, segments, and so forth, can be generalized as a universal disfavoring of sequences of like features: *[αF] [αF]. Therefore, coronal stop deletion, which targets the set of segments /t, d/ defined by the features [−son, −cont, +cor], is favored when the preceding segment shares any of these features. But this requires adopting the assumption of inherent variability and interpreting the OCP as a probabilistic constraint with cumulative effects (the more shared features, the greater likelihood of deletion). This suggests an attractive theoretical integration of categorical and variable processes in the grammar.

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Caswell, J. L., R. A. Vaile, and S. P. Ellingsen. "Variability of Methanol Masers." Publications of the Astronomical Society of Australia 12, no. 1 (April 1995): 37–53. http://dx.doi.org/10.1017/s1323358000020026.

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AbstractSites of recent star formation often radiate strong maser emission from methanol transitions near 6-6 and 12 GHz. We have studied many of these masers over several years and find that intensity variations are common on both transitions. We present observations which demonstrate marked variability in 48 sources. We explore the characteristics of the variability and find it to be typically quasi-periodic, on a timescale of between a month and several years. The amplitude of the variation is most commonly less than a factor of two, but can reach factors of ten. The variability of different features in a source is usually independent. Variability of features seen at both 6·6 and 12 GHz is sometimes correlated, with larger amplitudes usually seen at 12 GHz. A likely inference is that variations are occasionally due to a change in the pump rate throughout the masing region, but most are consistent with a change in the masing path length due to large-scale motions. In addition, it is likely that the majority of 6·6-GHz masers are saturated whereas the 12-GHz masers may be somewhat less saturated.

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Hasan, Muhammad A., Derek Abbott, Mathias Baumert, and Sridhar Krishnan. "Increased beat-to-beat T-wave variability in myocardial infarction patients." Biomedical Engineering / Biomedizinische Technik 63, no. 2 (March 28, 2018): 123–30. http://dx.doi.org/10.1515/bmt-2015-0186.

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AbstractThe purpose of this study was to investigate the beat-to-beat variability of T-waves (TWV) and to assess the diagnostic capabilities of T-wave-based features for myocardial infarction (MI). A total of 148 recordings of standard 12-lead electrocardiograms (ECGs) from 79 MI patients (22 females, mean age 63±12 years; 57 males, mean age 57±10 years) and 69 recordings from healthy subjects (HS) (17 females, 42±18 years; 52 males, 40±13 years) were studied. For the quantification of beat-to-beat QT intervals in ECG signal, a template-matching algorithm was applied. To study the T-waves beat-to-beat, we measured the angle between T-wave max and T-wave end with respect to Q-wave (∠α) and T-wave amplitudes. We computed the standard deviation (SD) of beat-to-beat T-wave features and QT intervals as markers of variability in T-waves and QT intervals, respectively, for both patients and HS. Moreover, we investigated the differences in the studied features based on gender and age for both groups. Significantly increased TWV and QT interval variability (QTV) were found in MI patients compared to HS (p<0.05). No significant differences were observed based on gender or age. TWV may have some diagnostic attributes that may facilitate identifying patients with MI. In addition, the proposed beat-to-beat angle variability was found to be independent of heart rate variations. Moreover, the proposed feature seems to have higher sensitivity than previously reported feature (QT interval and T-wave amplitude) variability for identifying patients with MI.

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A.A., BELOUS, SERMYAGIN A.A., TREBUNSKIKH E.A., and ZINOVIEVA N.A. "FODDER BEHAVIOR FEATURES OF LANDRAS BREED BOARS IN CONNECTION WITH PHENOTYPIC AND GENETIC FEATURES VARIABILITY." PIG-BREEDING, no. 6 (2021): 9–13. http://dx.doi.org/10.37925/0039-713x-2021-6-9-13.

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Currently, realization and improvement of genetic potential of purebred boars is an urgent task in the field of pig-breeding. To achieve the task, it is necessary to include new parameters for the selection of individuals for the reproduction of the herd. The purpose of this work was to calculate genetic and phenotype correlation of fodder behavior indicators, feed conversion and predicted residual feed intake in pigs of Landras breed. The obtained scores of EBV could be used to understand direction of selection work, including new parameters of quantative features.

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SOREL, ANTHONY, RICHARD KULPA, EMMANUEL BADIER, and FRANCK MULTON. "DEALING WITH VARIABILITY WHEN RECOGNIZING USER'S PERFORMANCE IN NATURAL 3D GESTURE INTERFACES." International Journal of Pattern Recognition and Artificial Intelligence 27, no. 08 (December 2013): 1350023. http://dx.doi.org/10.1142/s0218001413500237.

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Recognition of natural gestures is a key issue in many applications including videogames and other immersive applications. Whatever is the motion capture device, the key problem is to recognize a motion that could be performed by a range of different users, at an interactive frame rate. Hidden Markov Models (HMM) that are commonly used to recognize the performance of a user however rely on a motion representation that strongly affects the overall recognition rate of the system. In this paper, we propose to use a compact motion representation based on Morphology-Independent features and we evaluate its performance compared to classical representations. When dealing with 15 very similar upper limb motions, HMM based on Morphology-Independent features yield significantly higher recognition rate (84.9%) than classical Cartesian or angular data (70.4% and 55.0%, respectively). Moreover, when the unknown motions are performed by a large number of users who have never contributed to the learning process, the recognition rate of Morphology-Independent input feature only decreases slightly (down to 68.2% for a HMM trained with the motions of only one subject) compared to other features (25.3% for Cartesian features and 17.8% for angular features in the same conditions). The method is illustrated through an interactive demo in which three virtual humans have to interactively recognize and replay the performance of the user. Each virtual human is associated with a HMM recognizer based on the three different input features.

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Ara, Iffat. "Wavelet Transform Based Heart Rate Variability Analysis of ECG." International Journal of Recent Technology and Engineering (IJRTE) 11, no. 4 (November 30, 2022): 19–22. http://dx.doi.org/10.35940/ijrte.d7294.1111422.

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Electrocardiography (ECG) is recording of heart electrical activity. For analyzing and diagnosis of heart diseases ECG is very important. In graphical ECG which used for clinical diagnosis all features are not visible. Different types of signal processing methods are present which can be used for extracting ECG signal features. Wavelet transforms is one kind of signal processing tool which is used for analyzing ECG signal. For features extraction multi-resolution wavelet transform can be used. During recording of ECG different kind of noise are added with ECG. So noise should be removed from ECG, than R peaks were detected which amplitude is higher than the other peaks. Referring to R peaks the others peak as P, Q, S and T were detected. Then different feature of the ECG signal were detected. Time differences between R peaks were calculated and then heart rate calculated from mean RR interval. In ECG RR interval indicate the change between consecutive heart rate (HR). Heart rate variability (HRV) explored how RR interval varies over time. HRV is calculated from RR interval series obtained from ECG signal analysis. From the RR intervals time domain indices of HRV were determined by using MATLAB programming and MIT-BIH database signal were used as input. In the time domain method SDNN, RMSSD, and pNN50 etc were determined here.

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Henderson, C. Y., V. Mariotti, F. Santos, S. Villotte, and C. A. Wilczak. "The New Coimbra Method for Recording Entheseal Changes and the Effect of Age-at-Death." Bulletins et Mémoires de la Société d'Anthropologie de Paris 29, no. 3-4 (June 20, 2017): 140–49. http://dx.doi.org/10.1007/s13219-017-0185-x.

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Entheseal changes have been widely used in anthropology to study activity patterns, but there is an increasing awareness that ageing is associated with these changes. The aim of this study was to test each feature of the new Coimbra method for its variability, side asymmetry and its relationship with age. In addition to this, an overall relationship with age was tested for a larger sample. Males 16 and over from the Coimbra skeletal collection of historically identified individuals were recorded using the new method (N = 260). To reduce the impact of occupation, side variability in asymmetry and age were only tested in the labourers (N = 51). All occupation groups were included to test the overall relationship with age using a random forest test. The results show that scores lack variability for many of the features and entheses. Where there is side asymmetry this is typically in favour of higher scores in the right side, excepting the biceps brachii insertion. Most of the features scored show a relationship with ageing, but this is not uniform for all features or entheses. Some features are associated with an increase in age (bone formation and erosions), while others generally occur in younger individuals (fine porosity and textural change). Logistic regression showed that ageing explains at most 44% of the variability. This alongside the side asymmetry may indicate that biomechanics has an explanatory role.

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Oyen, Michelle L., and Ching-Chang Ko. "Indentation variability of natural nanocomposite materials." Journal of Materials Research 23, no. 3 (March 2008): 760–67. http://dx.doi.org/10.1557/jmr.2008.0103.

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Small-scale depth-sensing indentation (nanoindentation) is a popular technique for measuring the mechanical properties of a wide range of materials. Contact mechanics solutions used in data analysis are based on the indentation of a homogeneous half-space, but the experiments are frequently conducted on mineralized biological tissues—biocomposite materials with nanometer-scale features—such as bone and dentin. The current study examines the experimental indentation response of bone across orders of magnitude in contact dimension length-scale, from nanometers to micrometers. Scaling arguments are used to establish the need for nanoscale simulations of mineralized tissue indentation. A finite element model of an inhomogeneous contact problem is developed and used to interpret experimental indentation data on bone and dentin. Both experimental data and modeling results demonstrate a convergence in apparent elastic modulus at increasing contact length-scales. Models results are used to estimate a feature size associated with inhomogeneity of the indentation response; for experiments conducted here the characteristic feature size is found to be substantially larger for bone than for dentin, and in both cases larger than for individual nanometer-scale mineral platelets.

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Journal articles on the topic 'Features variability'

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