bluuebunny/crossref_metadata_2025 huggingface dataset:
Generating Up-to-Date Crop Maps Optimized for Sentinel-2 Imagery in Israel
Authors: Goldberg Keren , Herrmann Ittai , Hochberg Uri , Rozenstein Offer
Published: September 2021

The overarching aim of this research was to develop a method for deriving crop maps from a time series of Sentinel-2 images between 2017 and 2018 to address global challenges in agriculture and food security. This study is the first step towards improving crop mapping based on phenological features retrieved from an object-based time series on a national scale. Five main crops in Israel were classified: wheat, barley, cotton, carrot, and chickpea. To optimize the object-based classification process, different characteristics and inputs of the mean shift segmentation algorithm were tested, including vegetation indices, three-band combinations, and high/low emphasis on the spatial and spectral characteristics. Four known vegetation indices (VIs)-based time series were tested. Additionally, we compared two widely used machine learning methods for crop classification, support vector machine (SVM) and random forest (RF), in addition to a newer classifier, extreme gradient boosting (XGBoost). Lastly, we examined two accuracy measures—overall accuracy (OA) and area under the curve (AUC)—in order to optimally estimate the accuracy in the case of imbalanced class representation. Mean shift best performed when emphasizing both the spectral and spatial characteristics while using the green, red, and near-infrared (NIR) bands as input. Both accuracy measures showed that RF and XGBoost classified different types of crops with significantly greater success than achieved by SVM. Nevertheless, AUC was better able to represent the significant differences between the classification algorithms than OA was. None of the VIs showed a significantly higher contribution to the classification. However, normalized difference infrared index (NDII) with XGBoost classifier showed the highest AUC results (88%). This study demonstrates that the short-wave infrared (SWIR) band with XGBoost improves crop type classification results. Furthermore, the study emphasizes the importance of addressing imbalanced classification datasets by using a proper accuracy measure. Since object-based classification and phenological features derived from a VI-based time series are widely used to produce crop maps, the current study is also relevant for operational agricultural management and informatics at large scales.
An Improved Method for Automatic Identification and Assessment of Potential Geohazards Based on MT-InSAR Measurements
Authors: Luo Shuran , Feng Guangcai , Xiong Zhiqiang , Wang Haiyan , Zhao Yinggang , Li Kaifeng , Deng Kailiang , Wang Yuexin
Published: September 2021

Multi-temporal Interferometric Synthetic Aperture Radar (MT-InSAR) has been widely used for ground motion identification and monitoring over large-scale areas, due to its large spatial coverage and high accuracy. However, automatically locating and assessing the state of the ground motion from the massive Interferometric Synthetic Aperture Radar (InSAR) measurements is not easy. Utilizing the spatial-temporal characteristics of surface deformation on the basis of the Small Baseline Subsets InSAR (SBAS-InSAR) measurements, this study develops an improved method to locate potential unstable or dangerous regions, using the spatial velocity gradation and the temporal evolution trend of surface displacements in large-scale areas. This method is applied to identify the potential geohazard areas in a mountainous region in northwest China (Lajia Town in Qinghai province) using 73 and 71 Sentinel-1 images from the ascending and descending orbits, respectively, and an urban area (Dongguan City in Guangdong province) in south China using 32 Sentinel-1 images from the ascending orbit. In the mountainous area, 23 regions with potential landslide hazards have been identified, most of which have high to very high instability levels. In addition, the instability is the highest at the center and decreases gradually outward. In the urban area, 221 potential hazards have been identified. The moderate to high instability level areas account for the largest proportion, and they are concentrated in the farmland irrigation areas, and construction areas. The experiment results show that the improved method can quickly identify and evaluate geohazards on a large scale. It can be used for disaster prevention and mitigation.
Time-Variable Gravity Field from the Combination of HLSST and SLR
Authors: Zhong Luping , Sośnica Krzysztof , Weigelt Matthias , Liu Bingshi , Zou Xiancai
Published: September 2021

The Earth’s time-variable gravity field is of great significance to study mass change within the Earth’s system. Since 2002, the NASA-DLR Gravity Recovery and Climate Experiment (GRACE) and its successor GRACE follow-on mission provide observations of monthly changes in the Earth gravity field with unprecedented accuracy and resolution by employing low-low satellite-to-satellite tracking (LLSST) measurements. In addition to LLSST, monthly gravity field models can be acquired from satellite laser ranging (SLR) and high-low satellite-to-satellite tracking (HLSST). The monthly gravity field solutions HLSST+SLR were derived by combining HLSST observations of low earth orbiting (LEO) satellites with SLR observations of geodetic satellites. Bandpass filtering was applied to the harmonic coefficients of HLSST+SLR solutions to reduce noise. In this study, we analyzed the performance of the monthly HLSST+SLR solutions in the spectral and spatial domains. The results show that: (1) the accuracies of HLSST+SLR solutions are comparable to those from GRACE for coefficients below degree 10, and significantly improved compared to those of SLR-only and HLSST-only solutions; (2) the effective spatial resolution could reach 1000 km, corresponding to the spherical harmonic coefficient degree 20, which is higher than that of the HLSST-only solutions. Compared with the GRACE solutions, the global mass redistribution features and magnitudes can be well identified from HLSST+SLR solutions at the spatial resolution of 1000 km, although with much noise. In the applications of regional mass recovery, the seasonal variations over the Amazon Basin and the long-term trend over Greenland derived from HLSST+SLR solutions truncated to degree 20 agree well with those from GRACE solutions without truncation, and the RMS of mass variations is 282 Gt over the Amazon Basin and 192 Gt in Greenland. We conclude that HLSST+SLR can be an alternative option to estimate temporal changes in the Earth gravity field, although with far less spatial resolution and lower accuracy than that offered by GRACE. This approach can monitor the large-scale mass transport during the data gaps between the GRACE and the GRACE follow-on missions.
Study on Collaborative Emission Reduction in Green-House and Pollutant Gas Due to COVID-19 Lockdown in China
Authors: Zhang Haowei , Ma Xin , Han Ge , Xu Hao , Shi Tianqi , Zhong Wanqin , Gong Wei
Published: September 2021

In recent years, as China’s peaking carbon dioxide emissions and air pollution control projects have converged, scholars have begun to focus on the synergistic mechanisms of greenhouse gas and pollution gas reduction. In 2020, the unprecedented coronavirus pandemic, which led to severe nationwide blockade measures, unexpectedly provided a valuable opportunity to study the synergistic reduction in greenhouse gases and polluting gases. This paper uses a combination of NO2, O3, and CO2 column concentration products from different satellites and surface concentrations from ground-based stations to investigate potential correlations between these monitoring indicators in four Chinese representative cities. We found that XCO2 decreased in March to varying degrees in different cities. It was witnessed that the largest decrease in CO2, −1.12 ppm, occurred in Wuhan, i.e., the first epicenter of COVID-19. We also analyzed the effects of NO2 and O3 concentrations on changes in XCO2. First, in 2020, we used a top-down approach to obtain the conclusion that the change amplitude of NO2 concentration in Beijing, Shanghai, Guangzhou, and Wuhan were −24%, −18%, −4%, and −39%, respectively. Furthermore, the O3 concentration increments were 5%, 14%, 12%, and 14%. Second, we used a bottom-up approach to obtain the conclusion that the monthly averaged NO2 concentrations in Beijing, Shanghai, and Wuhan in March had the largest changes, changing to −39%, −40%, and −61%, respectively. The corresponding amounts of changes in monthly averaged O3 concentrations were −14%, −2%, and 9%. However, the largest amount of change in monthly averaged NO2 concentration in Guangzhou was found in December 2020, with a value of −40%. The change in O3 concentration was −12% in December. Finally, we analyzed the relationship of NO2 and O3 concentrations with XCO2. Moreover, the results show that the effect of NO2 concentration on XCO2 is positively correlated from the point of the satellite (R = 0.4912) and the point of the ground monitoring stations (R = 0.3928). Surprisingly, we found a positive (in satellite observations and R = 0.2391) and negative correlation (in ground monitoring stations and R = 0.3333) between XCO2 and the O3 concentrations. During the epidemic period, some scholars based on model analysis found that Wuhan’s carbon emissions decreased by 16.2% on average. Combined with satellite data, we estimate that Wuhan’s XCO2 fell by about 1.12 ppm in February. At last, the government should consider reducing XCO2 and NO2 concentration at the same time to make a synergistic reduction.
Real-Time Action Recognition System for Elderly People Using Stereo Depth Camera
Authors: Zin Thi Thi , Htet Ye , Akagi Yuya , Tamura Hiroki , Kondo Kazuhiro , Araki Sanae , Chosa Etsuo
Published: September 2021

Smart technologies are necessary for ambient assisted living (AAL) to help family members, caregivers, and health-care professionals in providing care for elderly people independently. Among these technologies, the current work is proposed as a computer vision-based solution that can monitor the elderly by recognizing actions using a stereo depth camera. In this work, we introduce a system that fuses together feature extraction methods from previous works in a novel combination of action recognition. Using depth frame sequences provided by the depth camera, the system localizes people by extracting different regions of interest (ROI) from UV-disparity maps. As for feature vectors, the spatial-temporal features of two action representation maps (depth motion appearance (DMA) and depth motion history (DMH) with a histogram of oriented gradients (HOG) descriptor) are used in combination with the distance-based features, and fused together with the automatic rounding method for action recognition of continuous long frame sequences. The experimental results are tested using random frame sequences from a dataset that was collected at an elder care center, demonstrating that the proposed system can detect various actions in real-time with reasonable recognition rates, regardless of the length of the image sequences.
A Bivariate Volterra Series Model for the Design of Power Amplifier Digital Predistorters
Authors: Crespo-Cadenas Carlos , Madero-Ayora María J. , Becerra Juan A.
Published: September 2021

The operation of the power amplifier (PA) in wireless transmitters presents a trade-off between linearity and power efficiency, being more efficient when the device exhibits the highest nonlinearity. Its modeling and linearization performance depend on the quality of the underlying Volterra models that are characterized by the presence of relevant terms amongst the enormous amount of regressors that these models generate. The presence of PA mechanisms that generate an internal state variable motivates the adoption of a bivariate Volterra series perspective with the aim of enhancing modeling capabilities through the inclussion of beneficial terms. In this paper, the conventional Volterra-based models are enhanced by the addition of terms, including cross products of the input signal and the new internal variable. The bivariate versions of the general full Volterra (FV) model and one of its pruned versions, referred to as the circuit-knowledge based Volterra (CKV) model, are derived by considering the signal envelope as the internal variable and applying the proposed methodology to the univariate models. A comparative assessment of the bivariate models versus their conventional counterparts is experimentally performed for the modeling of two PAs driven by a 30 MHz 5G New Radio signal: a class AB PA and a class J PA. The results for the digital predistortion of the class AB PA under a direct learning architecture reveal the benefits in linearization performance produced by the bivariate CKV model structure compared to that of the univariate CKV model.
Provisioning, Authentication and Secure Communications for IoT Devices on FIWARE
Authors: Sousa Patrícia , Magalhães Luís , Resende João , Martins Rolando , Antunes Luís
Published: September 2021

The increasing pervasiveness of the Internet of Things is resulting in a steady increase of cyberattacks in all of its facets. One of the most predominant attack vectors is related to its identity management, as it grants the ability to impersonate and circumvent current trust mechanisms. Given that identity is paramount to every security mechanism, such as authentication and access control, any vulnerable identity management mechanism undermines any attempt to build secure systems. While digital certificates are one of the most prevalent ways to establish identity and perform authentication, their provision at scale remains open. This provisioning process is usually an arduous task that encompasses device configuration, including identity and key provisioning. Human configuration errors are often the source of many security and privacy issues, so this task should be semi-autonomous to minimize erroneous configurations during this process. In this paper, we propose an identity management (IdM) and authentication method called YubiAuthIoT. The overall provisioning has an average runtime of 1137.8 ms ±65.11+δ. We integrate this method with the FIWARE platform, as a way to provision and authenticate IoT devices.
The Effect of Cleat Position on Running Using Acceleration-Derived Data in the Context of Triathlon
Authors: Evans Stuart , James Daniel , Rowlands David , Lee James
Published: September 2021

Appropriate cycling cleat adjustment could improve triathlon performance in both cycling and running. Prior recommendations regarding cleat adjustment have comprised aligning the first metatarsal head above the pedal spindle or somewhat forward. However, contemporary research has questioned this approach in triathlons due to the need to run immediately after cycling. Subsequently, moving the pedal cleat posteriorly could be more appropriate. This study evaluated the effectiveness of a triaxial accelerometer to determine acceleration magnitudes of the trunk in outdoor cycling in two different bicycle cleat positions and the consequential impact on trunk acceleration during running. Seven recreational triathletes performed a 20 km cycle and a 5 km run using their own triathlon bicycle complete with aerodynamic bars and gearing. Interpretation of data was evaluated based on cadence changes whilst triathletes cycled in an aerodynamic position in two cleat positions immediately followed by a self-paced overground run. The evaluation of accelerometer-derived data within a characteristic overground setting suggests a significant increase in total trunk acceleration magnitude during cycling with a posterior cleat with significant increases to longitudinal acceleration (p = 0.04) despite a small effect (d = 0.2) to the ratings of perceived exertion (RPE). Cycling with a posterior cleat significantly reduced longitudinal trunk acceleration in running and overall acceleration magnitudes (p < 0.0001) with a large effect size (d = 0.9) and a significant reduction in RPE (p = 0.02). In addition, running after cycling in a posterior cleat was faster compared to running after cycling in a standard cleat location. Practically, the magnitude of trunk acceleration during cycling in a posterior cleat position as well as running after posterior cleat cycling differed from that when cycling in the fore-aft position followed by running. Therefore, the notion that running varies after cycling is not merely an individual athlete’s perception, but a valid observation that can be modified when cleat position is altered. Training specifically with a posterior cleat in cycling might improve running performance when trunk accelerations are analysed.
Distributed Fibre Optic Sensing (DFOS) for Deformation Assessment of Composite Collectors and Pipelines
Authors: Bednarz Bartosz , Popielski Paweł , Sieńko Rafał , Howiacki Tomasz , Bednarski Łukasz
Published: September 2021

Due to the low costs of distributed optical fibre sensors (DFOS) and the possibility of their direct integration within layered composite members, DFOS technology has considerable potential in structural health monitoring of linear underground infrastructures. Often, it is challenging to truly simulate the actual ground conditions at all construction stages. Thus, reliable measurements are required to adjust the model and verify theoretical calculations. The article presents a new approach to monitor displacements and strains in Glass Fiber Reinforced Polymer (GFRP) collectors and pipelines using DFOS. The research verifies the effectiveness of the proposed monitoring solution for health monitoring of composite pipelines. Optical fibres were installed over the circumference of a composite tubular pipe, both on the internal and external surfaces, while loaded externally. Analysis of strain profiles allowed for calculating the actual displacements (shape) of the pipe within its cross-section plane using the Trapezoidal method. The accuracy of proposed approach was positively verified both with reference spot displacement transducer as well as numerical simulations using finite element method (FEM). DFOS could obtain a comprehensive view of structural deformations, including both strains and displacements under externally applied load. The knowledge gained during research will be ultimately used for renovating existing collectors.
An Optimized Approach to Channel Modeling and Impact of Deteriorating Factors on Wireless Communication in Underground Mines
Authors: Javaid Fawad , Wang Anyi , Sana Muhammad Usman , Husain Asif , Ashraf Imran
Published: September 2021

The environment of underground coal mines has challenging properties that makes this zone inadaptable for a stable communication system. Additionally, various deteriorating physical parameters strongly affect the performance of wireless networks, which leads to limited network coverage and poor quality of data communication. This study investigates the communication capability in underground coal mines by optimizing the wireless link to develop a stable network for an underground hazardous environment. A hybrid channel-modeling scheme is proposed to characterize the environment of underground mines for wireless communication by classifying the area of a mine into the main gallery and sub-galleries. The complex segments of mine are evaluated by categorizing the wireless links for the line-of-sight (LOS) zones and hybrid modeling is employed to examine the characteristics of electromagnetic signal propagation. For hybrid channel modeling, the multimode waveguide model and geometrical optic (GO) model are used for developing an optimal framework that improves the accessibility of the network in the critical time-varying environment of mines. Moreover, the influence of various deteriorating factors is analyzed using 2.4 GHz to 5 GHz frequency band to study its relationship with the vital constraints of an underground mine. The critical factors such as path loss, roughness loss, delay spread, and shadow fading are examined under detailed analysis with variation in link structure for the mine.
A nanotechnológia múltja, jelene és jövője
Authors: B. Nagy János
Published: September 2021

Már az ókori, mezopotámiai, egyiptomi, illetve a középkori művészek alkotásai, a különböző színű ablaküvegek is csodálatra késztetnek, melyeket fémnanorészecskék segítségével állítottak elő. A cikk röviden ismerteti a zeolitokat, a nanorészecskéket és a szénnanocsöveket. Ez utóbbiakat részletesen kifejtjük, mivel megalapítottunk egy Nanocyl nevű céget, mely szénnanocsöveket árul, és a legjobb európai cég lett. Egy szénnanocső 100000-szer vékonyabb, mint egy hajszál, nagyon könnyű – kétszer könnyebb, mint az alumínium –, nagy az ellenálló képessége – sokkal nagyobb, mint az acélé –, és vezeti az áramot, sokkal jobban, mint a fémes vezetők. A szénnanocsövek alkalmazása nagyon fontos a nanotechnológiában. Például csavaros nanocsövek segítségével sikerült megmérni egyetlen nanorészecske súlyát, ami egy femtogramm (10–15 gramm). Szénnanocsöveket használnak az autófestékben, mellyel megszüntetik a statikus elektromosságot. Szénnanocsövek segítségével le lehet csökkenteni a tűz terjedésének sebességét, ha kompozit anyagokba bevisszük. Veszélyes gázok érzékelésére szenzornak is nagyon jók a szénnanocsövek. Jelen cikkben az alkalmazási területét mutatjuk be. A nanotechnológia jövőjét a nanogépek jellemzik; szó lesz a Föld és a Hold közötti liftről, a grafénről (egyetlen atomsíkból álló grafitlemez) és a valószínűleg a szénnanocsövek alkalmazására alapuló eljárásról, mely segít tengervízből ivóvizet gyártani és vizet tisztítani.
Scientific Associations as Communities of Practice for Fostering Collaborative Knowledge Building: Case Study of IAKM
Authors: Handzic Meliha , Bratianu Constantin , Bolisani Ettore
Published: September 2021

Knowledge building is a social process that is driven by the willingness of people to share their expertise and create new knowledge. Scientific Communities of Practice (CoPs) are communities of professors and researchers whose aim is to foster scientific knowledge generation. In the KM literature, research concerning this kind of CoPs has been substantially neglected so far. The present research analyses the case study of the International Association for Knowledge Management (IAKM) seen as a scientific CoP where members are mostly academics with research interests in developing and promoting knowledge management. Based on a collection of quantitative and qualitative data about member collaborations and scientific production, the study investigates the structure of interactions and the collaborative processes of IAKM members and the specific mechanisms of knowledge building within this CoP, seen as a paradigmatic example of scientific community. Members were asked to respond to a survey regarding their collaborative activities carried out with other IAKM members in the period of 2011 – 2020. The descriptive analysis revealed the kind of collaborations, the distribution of interactions across the community, and the dynamic patterns over time. A follow-up social network analysis was used to provide deeper insight into the community structure and dynamics. The research found that a CoP can really be useful for progress in a scientific field because it can provide a platform for trust and mutual acquaintance that reduces barriers to collaboration and knowledge building across different universities, professional roles, countries, and cultures, which is increasingly important for the progress of science. Most importantly, IAKM exhibited a cohesive and active core membership with pivotal roles played by a number of active members, which contributed significantly to the growth of the Association and, in general, to the advancements in the field of KM through collaborative knowledge building.
Fracturas expuestas: clasificación y abordaje.
Authors: Orozco Montoya Abdy , Morales Brenes Natalia , Serrano Calvo Josué
Published: September 2021

Las fracturas expuestas se caracterizan por una disminución de la continuidad ósea, con exposición al exterior, debido a esto, son frágiles a complicaciones como situaciones infecciosas. Muchas de éstas, son debidas a traumas de alta energía. Su clasificación se basa según el mecanismo de producción, la lesión de los tejidos blandos, la conformación de la fractura y la contaminación. La prioridad del tratamiento oportuno es conseguir una adecuada prevención de la infección, así como también, la estabilización y consolidación de la fractura, así mismo se debe tratar de obtener una restauración en la función del miembro afectado con un manejo adecuado.
A MODEL AND METHOD OF MULTI-CONNECTIVITY FOR ULTRA-RELIABLE 5G CONNECTIONS
Authors: КАШКАРОВ Д.В. , ПАРАМОНОВ А.И. , КУЧЕРЯВЫЙ А.Е.
Published: September 2021

Представлен анализ, модель и метод решения задачи обеспечения требований по надежности доставки данных при организации сверхнадежных соединений с ультрамалыми задержками ( URLLC - Ultra Reliable Low Latency Communications) в сетях 5G. Рассматривается подход, основанный на организации множественных соединений (multi-connectivity) и дублировании передаваемых данных. Приведена аналитическая модель для оценки вероятности отказа, учитывающая интенсивность трафика, вероятность отказа элементов и количество используемых соединений. Предложен метод повышения надежности доставки данных путем оптимизации числа соединений.

The paper presents an analysis, model, and method of solving the problem of ensuring the reliability of data delivery when organizing ultra-reliable and low latency connections (URLLC) in 5G networks. An approach based on the organization of multiple connections (multi-connectivity) and duplication of transmitted data is considered. An analytical model is presented for assessing the probability of failure, taking into account the traffic intensity, the probability of failure of elements, and the number of used connections. A method for increasing the reliability of data delivery by optimizing the number of connections is proposed.
CURRENT VIEWS ON HISTOPHYSIOLOGY OF BRONCHIOLAR EXOCRINE CELLS
Authors: Горячкина В. Л. , Цомартова Д. А. , Черешнева Е. В. , Иванова М. Ю. , Кузнецов С. Л.
Published: September 2021

В обзоре приводятся новые данные о структуре и функции бронхиолярных экзокриноцитов. Впервые нереснитчатые клетки в бронхиолах были описаны ещё А. фон Кёлликером в 1881 г. Детальное изучение этих клеток в бронхиолах человека и кроликов было проведено М. Клара в 1937 г., в честь которого они были названы. В обзоре обсуждаются следующие функции клеток Клара (КК), или бронхиолярных экзокриноцитов: защитная функция, обусловленная секрецией специфических белков, а также жидкого субстрата, располагающегося на поверхности слизистой оболочки; участие в восстановлении повреждённых реснитчатых клеток в качестве своеобразных стволовых (прогениторных) клеток; функция детоксикации вредных веществ, попадающих в лёгкие, а именно: метаболизация ксенобиотиков и канцерогенных веществ; участие в развитии многих форм рака лёгких, источником формирования которых являются бронхиолярные экзокриноциты, включая аденокарциному - наиболее часто диагностируемую опухоль лёгкого.

This review provides new data on the structure and function of bronchiolar exocrine cells. The nonciliary cells in the bronchioles were first described by Kolliker as early as in 1881. The detailed study of these cells in human and rabbit bronchioles was carried out by M. Clara in 1973, and the cells were named after him. The review discusses the following functions of Clara cells or bronchiolar exocrine cells: a protective function due to the secretion of specific proteins, as well as a liquid substrate located on the surface of the mucous membrane; participation in the restoration of damaged ciliary cells as a kind of stem (progenitor) cells; the function of detoxification of harmful substances that enter the lungs, namely: the metabolism of xenobiotics and carcinogens; participation in the development of many forms of lung cancer, the source of the formation of which are bronchiolar exocrine cells, including adenocarcinoma, the most commonly diagnosed lung tumor.
POSSIBILITIES FOR PREDICTING OF CARDIAC ARRHYTHMIAS AND CONDUCTIVITY DISORDERS IN FORMER ATHLETES
Authors: Крысюк О. Б. , Обрезан А. Г. , Задворьев С. Ф. , Яковлев А. А.
Published: September 2021

Для выявления характера взаимосвязи спортивного анамнеза лиц, практиковавших в прошлом интенcивные физические нагрузки, и выявленных у них нарушений ритма сердца и внутрисердечной проводимости был проведен ретроспективный анализ медицинских документов 39 мужчинветеранов спорта (средний возраст - 61,6±11,3 года, средняя длительность постспортивного периода - 23,9±17,3 года, средний стаж соревновательной деятельности - 20,1±9,9 года), имеющих установленные сердечно-сосудистые заболевания. Проведено скрининговое обследование на предмет нарушений ритма и проводимости сердца, эхокардиографическое исследование. Выявлено, что распространенность устойчивых пароксизмов фибрилляции предсердий составила 42% в совокупной выборке, увеличиваясь с повышением уровня спортивной квалификации. Желудочковые нарушения ритма высокой градации выявлены у 14% обследованных. Лишь три параметра были достоверно связаны с риском нарушений ритма у ветеранов спорта: уровень спортивной квалификации, наличие генерализованного атеросклероза (антириск-фактор), возраст. Риск нарушений ритма у ветеранов спорта на 43% определяется указанными факторами. Был предложен алгоритм скрининга нарушений ритма у ветеранов спорта на основе клинических данных. Необходимы дальнейшие проспективные наблюдения для валидации алгоритма.

In order to analyze the relationship between the athletic qualiﬁcation and syndrome of cardiac rhythm and conductivity disturbances in former athletes, a retrospective analysis of medical records of 39 male former athletes with cardiovascular complaints (mean age 61,6±11,3 years, mean duration of career in sports 23,9±17,3 years, mean duration of post-athletic period 20,1±9,9 years) was carried out. The patients were screened for cardiac arrhythmias and underwent echocardiography. The overall prevalence of sustained paroxysms of atrial ﬁbrillation was 42%, increasing with the athletic qualiﬁcation. Ryan grade 4 b -5 premature ventricular contractions were found in 14% of patients. 3 parameters were found to be the independent predictors of arrhythmias in former athletes, i. e. athletic qualiﬁcation, multifocal atherosclerosis (as an anti-risk factor), and age. The coefﬁcient of determinance for the created prognostic model reached 43%. Further prospective studies are needed to validate an algorithm.
Derin Öğrenme ile Optik Koherens Tomografi Görüntülerinin Sınıflandırılması
Authors: GÜLDEMİR Numan Halit , ALKAN Ahmet
Published: September 2021

Bu makalede, dünyada görme bozukluklarının %8.7’sinin sebebi olan yaşa bağlı makula dejenerasyonu hastalığının tespit edilmesi için otomatik bir sistem sunulmuştur. Hastalığın teşhisi için, son zamanlarda görüntüden özellik tanısı çıkarma işlemlerinde sıklıkla kullanılan evrişimsel sinir ağı mimarisinden faydalanılmıştır. Çalışmada, yaşa bağlı makula dejenerasyonu hastalığının sınıflandırılması için evrişimsel sinir ağı, etiketli 28031 adet OCT görüntüsü ile eğitilmiştir. Eğitilen evrişimsel sinir ağı 6900 adet OCT görüntüsü ile test edilmiştir. Eğitim ve test için Xception, VGG16, InceptionV3 ve Resnet50 derin öğrenme ağları kullanılmıştır. Eğitilen ağlar karşılaştırılıp OCT veri seti için ağların performansları değerlendirilmiştir. Derin öğrenme ağlarının test edilmesi sonucunda Resnet50 ağı 0.95, VGG16 ağı 0.95, InceptionV3 ağı 0.97 ve Xception ağı 0.98 doğruluk oranı OCT veri setini sınıflandırmıştır. 0.96 değerindeki F1 skoruyla Xception ağı kullanılan OCT veri seti üzerindeki en başarılı sınıflandırmayı elde etmiştir.
Genealogías de devenires feministas en África
Authors: Cejas Mónica Inés , Riley Emily Jenan
Published: September 2021

Este dossier presenta diversas expresiones contra-hegemónicas que dan cuenta de las disputas de poder y develan historias únicas del relato oficial y académico dominante sobre las condiciones y agencia social de las mujeres en África. En contrapartida se hacen evidentes las historias de las mujeres y las mujeres -y sus ausencias- en la(s) Historia(s) de África. También se ponen sobre la mesa las múltiples expresiones de la(s) violencia(as) contra las mujeres -incluida la epistémica- desde y en contextos africanos en las voces, experiencias y reflexiones de las mismas africanas.
Investigation of Thermomechanical Processing of Nb Microalloyed Steel Produced by Powder Metallurgy
Authors: TAŞTEMÜR Demet , GÜNDÜZ Süleyman , ERDEN Mehmet Akif
Published: September 2021

One of the most important properties of microalloyed steels is the different microstructures which are obtained by changing the thermomechanical processing parameters and steel composition. The control of microstructure such as grain size, precipitates, dislocation structure and inclusions are highly effective to determine the mechanical properties of microalloyed steels. The strengthening of mechanical properties can be done by thermomechanical processesing due to increase of nucleation sides via maximizing the austenite boundary and density of the deformation band. In this study, the unalloyed steel and microalloyed steel containing 0.15% Nb were produced by powder metallurgy and hot deformed to reduce the thickness by 40% and 75%. EDX analyzes, density, hardness and grain size measurements were also performed on specimens. According to the SEM microstructure results, the grain size gradually decreased with respect to the deformation rate in both steels. It was observed that small grains occurred due to a complete recrystallization process at 75% deformation rate which were supported by grain size analysis. The density and hardness values increased by the increase in deformation rate. While the density and hardness of microalloy steel under sintered conditions was 89.46% and 75 Hv, respectively, 75% deformed condition was 98.51 % and 231 Hv.
Covid-19 Sürecinde Yükselen Sosyal Belediyecilik: Ankara Büyükşehir Belediyesi Örneği
Authors: ÖNER Şerif , ÇAM Barış
Published: September 2021

Bütün olarak tüm toplumları sosyo-ekonomik, siyasal, kültürel vb. pek çok açıdan etkisi altına alan distopik bir süreç olarak Covid-19 pandemisi kurumsal yapılara mevcut durum analizi yapma fırsatı tanımıştır. Bu kurumlardan biri de genel olarak yerel nitelikli hizmetlerle odaklanan belediye yönetimleridir. Covid-19 sürecinde ülkemizde belediye yönetimleri bir kez daha hemşehrilere/insana dokunma özelliğini test etme, mevcut potansiyelini sahaya yansıtma fırsatı yakalamışlardır. Sürecin kısa bir özeti olacak biçimde korku ve panik eşliğinde ortaya konulan izolasyon tedbirlerinin kent hizmetlerinin sunumu açısından hemşehriler arasında ortaya çıkardığı yoksunluklar ve erişim yetersizlikleri sosyal belediyecilik olgusunu yeniden güçlü biçimde gündeme getirmiştir. Refah devleti anlayışının yerel ölçekteki yansıması olarak görülen sosyal belediyecilik anlayışının neo-liberal politika araçları ve devasa etkileri açısından küreselleşme olgusunun tazyikleri altında kaybettiği ilgi Covid-19 süreci ile yeniden bu defa “daha güçlü şekilde” gündeme gelmiştir. Sosyal belediyecilik anlayışının gelişimini analiz ettiğimiz çalışmamızın örnek alanı olarak “Covid-19 sürecinde sosyal belediyecilik açısından örnek teşkil edecek çalışmaları ile kamuoyunun dikkatini çekmiş olması nedeniyle” Ankara Büyükşehir Belediyesi (ABB) seçilmiştir. Çalışmamızın içeriğinde; salgın sürecinde ABB yönetimi ile merkezi idare arasında yaşanan siyasi ve idari çekişmelerin etkisi altında gerçekleştirilen başta halk sağlığı olmak üzere sosyal belediyecilik girişimleri, sosyal yardım ve destek projelerine yer verilecek; ABB’nin sosyal belediyecilik girişimlerinin değerlendirilmesi çerçevesinde elde edilen sonuçlar ele alınacaktır. Literatür incelemesine dayalı tarama yöntemiyle gerçekleştirilen çalışmamızda post-Covid’e ilişkin sosyal belediyecilik olgusunun olası seyri üzerinde projeksiyon ortaya konulacaktır.
Designing Problem Based STAD Learning Models to Improve Students’ Writing Skill
Authors: Rianti Wida , Ayu Citra , Asilestari Putri
Published: September 2021

This research was conducted to develop a learning model by using the ADDIE model. The problem-Based STAD learning model was designed by Analysis, Design, Development or Production, Implementation or Delivery, and Evaluations. This research was done in the English Language Education Study Program of the University of Pahlawan Tuanku Tambusai in Writing II. Based on the result of data analysis, it can be concluded that 1) The Problem-based STAD Type Learning Model has been produced through the ADDIE development model. 2) Problem-based STAD Type Learning Model that has met the criteria of validity. 3) The model is valid with the characteristics of the suitability of the research model development with the ADDIE procedure. English teachers can use this model to improve students’ skills in writing and motivate the students in writing English text.
Origen y migración de las neuronas GnRH en el bovino (Bos taurus)
Authors:   , Soto Andrés Telésforo
Published: September 2021

La hormona liberadora de gonadotrofinas (GnRH) es liberada por células neurosecretoras ubicadas en el hipotálamo y regula la secreción de las hormonas gonadotróficas hipofisiarias, foliculoestimulante (FSH) y luteinizante (LH), es imprescindibles en los procesos de esteroidogénesis y gametogénesis gonadal. Mediante la aplicación de técnicas de inmunohistoquímica con la utilización del anticuerpo monoclonal LRH13 y del anticuerpo policlonal cII 675 se caracterizaron los tipos, la migración y distribución de la población de neuronas y fibras GnRH en fetos (4ta a 22da semana de edad gestacional) y ejemplares prepúberes de bovinos (Bos taurus). No se hallaron inmunomarcaciones positivas al anticuerpo cII 675. La migración naso-encefálica de las neuronas GnRHir ocurrió en la 8ta semana del desarrollo fetal. Las células tipo neuroblásticas fueron detectadas en el epitelio de la cavidad nasal y del órgano vomeronasal. Estas células migran por rutas definidas por los nervios vomeronasales y nervio terminal atravesando la lámina cribada del etmoides y penetran por la intersección naso-encefálica, para ubicarse en el prosencéfalo, principalmente en el área presuntiva del POA. Durante este período las células GnRHir sufrieron cambios significativos en su morfometría. Si bien, las células y fibras GnRHir post-migración naso-encefálica se ubicaron mayoritariamente en el hipotálamo rostral, la distribución y ubicación definitiva se alcanzó en la 21-22da semana del desarrollo fetal, momento en que se considerá que culminó la migración encefálica. Las neuronas GnRHir se distribuyeron principalmente en el área septal, POA, SON y AHA y en menor medida en la región periarcuata y ARC, tanto en fetos como en los terneros. Las neuronas GnRHir fueron mayoritariamente bipolares. Se encontraron variaciones significativas en el tamaño de las neuronas fetales, y entre estas y las neuronas GnRHir de los terneros.
Розробка та дослідження генетичного методу для медичного діагностування цукрового діабету
Authors: Федорченко Є. М. , Олійник А. О. , Корнієнко С. К. , Степаненко О. О. , Саман М. В.
Published: September 2021

У результаті дослідження розроблено інтелектуальну систему підтримки прийняття рішень для діагностування цукрового діабету, яка базується на моделях машинного навчання. Розроблено модифікований генетичний метод оптимізації параметрів нейронної мережі. Модифікація простого генетичного алгоритму, яку реалізовано в рамках виконання проєкту, дозволяє пришвидшити виконання підбору параметрів навчання нейронних мереж і підвищити результуючий показник точності порівняно з базовою версією простого генетичного алгоритму, за рахунок модифікації оператора мутації, а також, зміненого підходу до вибору особин для схрещення. Розроблена модель призначена для застосування у сфері медичного обслуговування та дозволяє з певною точністю визначати наявність ризику захворюваності пацієн-та на цукровий діабет за клінічними показниками стану здоров’я. Результатом застосування даної моделі є зменшення ймовірності по-милки лікаря, підвищення впевненості лікаря в прийнятому рішенні при постановці діагнозу та більша кількість врятованих життів за рахунок постановки вірного та своєчасного діагнозу.
Experiences of Instructors in Online Teaching: A Phenomenological Study
Authors: Baluyos Genelyn , Clarin Ariel R.
Published: September 2021

The abrupt shift to online distance education as a result of COVID-19 pademic resulted to the diversification of teaching modalities and pedagogies. This study explored the lived experiences of instructors in online teaching during the SY 2020-2021 using Van Manen's hermeneutic phenomenological design. Purposive sampling was used to select the twenty-five participants for the study. In-depth face-to-face interviews were conducted with all the participants to gather information from the teachers. Data analysis was employed using the six components of hermeneutic phenomenological design and with the aid of NVivo software. Results revealed that the instructors’ experiences in online teaching were identified in five themes: preparation of learning materials, realization of learning outcomes, stability of internet connection, availability of technological resources, and difficulty in the conduct of assessment activities. The instructors encountered positive and negative experiences in online teaching. Online teaching enhancement program is recommended in this study.
PENERAPAN MODEL ALTMAN Z-SCORE DALAM MENGUKUR POTENSI KEBANGKRUTAN (STUDI KASUS PADA PERUSAHAAN PERBANKAN BUMN YANG TERDAFTAR DI BURSA EFEK INDONESIA TAHUN 2018 & 2019)
Authors: Rofinus Leki Rofinus Leki
Published: September 2021

Abstract: This   research   is   a   sustainability   research,   which   uses   the   same   non- manufacturing Altman Z-Score model, with the aim of re-examining the financial health sustainability of the four BUMN banks that the author has studied in 2017 and in 2019. The four BUMN banks are Bank Negara Indonesia (Persero) Tbk PT, Bank Rakyat Indonesia (Persero) Tbk. PT, Bank Tabungan Negara (Persero) Tbk PT,  Bank  Mandiri  (Persero)  Tbk  PT.  The  results  showed  that  PT.  Bank  BTN (Persero) Tbk has a Z-score that has improved in 2018 and 2019, compared to previous years, namely in 2014, 2015, 2016, and 2017. Currently PT. Bank BTN (Persero) Tbk., has moved from the potential financial distress into a "gray area" (improving). Meanwhile, the other three BUMN banks are consistently in the gray area category with a Z-score above 1.2 but below a Z-score of 2.9. The results of this study also show that there is a significant financial performance improvement in every BUMN banking company, but has decreased somewhat in

2019  at Bank BNI (Persero), Tbk. PT and Bank BRI (Persero) Tbk.PT. Be expected is   that   with   the   continuous   and   consistent   improvement   in   financial performance, the financial health position of BUMN Banking (Persero) Tbk can immediately move to the "safe zone".

 

Keywords: Financial Health of BUMN Banks, Altman Z-Score Model
Narrativas emergentes sobre la construcción de paz indígena en Colombia: la resistencia sentipensante del pueblo Nasa Wes’x-Tolima
Authors: Sandoval Forero Eduardo Andrés , Capera Figueroa José Javier
Published: September 2021

Las diferentes violencias que afectan de forma directa e indirecta la armonía y equilibro de los pueblos indígenas en sus territorios, representan fenómenos de índole estructural y sistémico que son motivo de reflexión de los estudios de paz en perspectiva decolonizadora. Por ende, la finalidad del siguiente artículo de investigación consiste en describir las narrativas emergentes de carácter decolonial que influyen en la construcción de paz indígena en Colombia, teniendo en cuenta la experiencia de resistencia decolonial y subalterna del pueblo Nasa Wes´x – Tolima. La metodología utilizada, es la teoría fundamentada en articulación con las narrativas, voces y experiencias comunitarias provenientes del discurso oral y praxis ética liberadora del sujeto ontológico indígena (Escobar, 2016). Asimismo, la asociación de la investigación colaborativa, análisis crítico del discurso y el diálogo intersubjetivo en el marco horizontal entre el investigador y los grupos sociales. Teniendo en cuenta las propuestas teóricas-conceptuales de construcción de paz intercultural provenientes de Alonso (2010); Fontan (2013); Márquez Fernández (2018) y Sandoval & Capera (2020a), orientadas a la cosmovisión/cosmogonía de las comunidades indígenas frente a la configuración de paces, equilibrio y armonización en los territorios ancestrales al ser principios identitarios de resistencia colectiva, pacifica, no-violenta y de convivencia restaurativa-territorial (Sandoval, 2021). Uno de los resultados más importantes es la construcción de narrativas de resistencia pacífica desde la visión decolonizadora en función de las luchas, demandas, proyectos y propuestas desde abajo de orden emergentes en articulación con las luchas socioculturales, pacíficas y democráticas populares de los pueblos indios en contravía del proyecto de guerra abierta, exterminio étnico y prácticas recolonizadoras de violencia sistémica que afecta de forma radical su condición humana y de existencia indígena.
¿Citan las mujeres investigadoras más a las otras mujeres que a los hombres?
Authors: Dinu Nicoleta-Roxana
Published: September 2021

El objetivo de la investigación presentada en este artículo es analizar posibles sesgos de citación entre artículos científicos debidos al género de los autores. Diversos investigadores, como Maliniak, Powers y Walter (2013); Beaudry y Larivière (2016); Ghiasi et al. (2018); Huang et al. (2019); Potthoff y Zimmermann (2017); y Thelwall (2020), han puesto de relieve la brecha de género existente en las carreras universitarias, y también en la publicación científica, reflejo de lo que ocurre en la Sociedad en general. La hipótesis de partida de esta investigación es que debido a la discriminación de que son objeto, las mujeres podrían reaccionar citando más a otras autoras. La metodología usada ha sido 1) la realización de una búsqueda bibliográfica sobre el tema. Los resultados de la búsqueda, que expresan situaciones negativas para las mujeres, sirven como preámbulo del razonamiento que se lleva a cabo sobre posibles reacciones de las mujeres ante tales situaciones, y del planteamiento de esta investigación, preguntándonos si de forma consciente o por sensibilidad y afinidad las mujeres tienen alguna tendencia a citar más los trabajos de sus congéneres que los de los colegas masculinos. 2) Se han seleccionado los artículos de dos números completos de cuatro revistas, y se han contabilizado las citas de hombres a hombres, hombres a mujeres, mujeres a mujeres y mujeres a hombres. Los resultados obtenidos muestran una diferencia de comportamiento según el género: las mujeres son más equilibradas: citan un 40% a mujeres y un 60% a hombres. En cambio, los hombres demuestran más homofilia enviando solo un 25% de citas a las mujeres y un 75% a sus congéneres. Se concluye que perdura la brecha de género y que continúa una situación perjudicial para las mujeres que, al no recibir la merecida acreditación por sus trabajos, no consiguen alcanzar los niveles superiores de las carreras académicas.