bluuebunny/crossref_metadata_2025 huggingface dataset:
Atomic Receiver by Utilizing Multiple Radio-Frequency Coupling at Rydberg States of Rubidium
Authors: Zou Haiyang , Song Zhenfei , Mu Huihui , Feng Zhigang , Qu Jifeng , Wang Qilong
Published: February 2020

Rydberg atoms have been extensively utilized in microwave measurement with high sensitivity, which has great potential in the field of communication. In this study, we discuss the digital communication based on a Rydberg atomic receiver under simultaneously coupling by resonant and near detuning microwaves. In addition, we verify the feasibility of the Rydberg atom-based frequency division multiplexing (FDM) in microwave communication. We demonstrate the principle and performance of the atom-based FDM receiver by applying amplitude modulation (AM) and frequency modulation (FM), respectively. To demonstrate the actual communication performance at different data transfer rates, we consider monochromatic images as an example. The experimental results show that the maximum acceptable data transfer rate of both AM and FM is about 200 kbps, whereas their maximum bit error rates (BER) is less than 5%. When compared with the traditional electronic receiver, this atomic receiver, which is compatible with FDM, has numerous advantages, such as small size, low power consumption, and high sensitivity. Furthermore, this receiver has a strong ability of anti-electromagnetic interference, and the signals transmitted do not interfere with each other in different channels.
Velocity-Aware Handover Self-Optimization Management for Next Generation Networks
Authors: Alhammadi Abdulraqeb , Roslee Mardeni , Alias Mohamad Yusoff , Shayea Ibraheem , Alquhali Abdullah
Published: February 2020

The fifth generation (5G) network is an upcoming standard for wireless communications that coexists with the current 4G network to increase the throughput. The deployment of ultra-dense small cells (UDSC) over a macro-cell layer yields multi-tier networks, which are known as heterogeneous networks (HetNets). HetNets play a key role in the cellular network to provide services to numerous users. However, the number of handovers (HOs) and radio link failure (RLF) greatly increase due to the increase in the UDSC in the network. Therefore, mobility management becomes a very important function in a self-organizing network to improve the system performance. In this paper, we propose a velocity-based self-optimization algorithm to adjust the HO control parameters in 4G/5G networks. The proposed algorithm utilizes the user’s received power and speed to adjust the HO margin and the time to trigger during the user’s mobility in the network. Simulation results demonstrate that the proposed algorithm achieves a remarkable reduction in the rate of ping-pong HOs and RLF compared with other existing algorithms, thereby outperforming such algorithms by an average of more than 70% for all HO performance metrics.
Oxy-Fuel Combustion Characteristics of Pulverized Coal under O2/Recirculated Flue Gas Atmospheres
Authors: Hou Shuhn-Shyurng , Chiang Chiao-Yu , Lin Ta-Hui
Published: February 2020

Oxy-fuel combustion is an effective technology for carbon capture and storage (CCS). Oxy-combustion for coal-fired power stations is a promising technology by which to diminish CO2 emissions. Unfortunately, little attention has been paid to the oxy-combustion characteristics affected by the combustion atmosphere. This paper is aimed at investigating the oxy-fuel combustion characteristics of Australian coal in a 0.3 MWth furnace. In particular, the influences of various oxygen flow rates and recirculated flue gas (RFG) on heating performance and pollutant emissions are examined in O2/RFG environments. The results show that with increases in the secondary RFG flow rate, the temperatures in the radiative and convective sections decrease and increase, respectively. At a lower oxygen flow rate, burning Australian coal emits lower residual oxygen and NO concentrations. In the flue gas, a high CO2 concentration of up to 94.8% can be achieved. Compared to air combustion, NO emissions are dramatically reduced up to 74% for Australian coal under oxy-combustion. Note that the high CO2 concentrations in the flue gas under oxy-coal combustions suggest great potential for reducing CO2 emissions through carbon capture and storage.
Deep Learning for Computational Mode Decomposition in Optical Fibers
Authors: Rothe Stefan , Zhang Qian , Koukourakis Nektarios , Czarske Jürgen W.
Published: February 2020

Multimode fibers are regarded as the key technology for the steady increase in data rates in optical communication. However, light propagation in multimode fibers is complex and can lead to distortions in the transmission of information. Therefore, strategies to control the propagation of light should be developed. These strategies include the measurement of the amplitude and phase of the light field after propagation through the fiber. This is usually done with holographic approaches. In this paper, we discuss the use of a deep neural network to determine the amplitude and phase information from simple intensity-only camera images. A new type of training was developed, which is much more robust and precise than conventional training data designs. We show that the performance of the deep neural network is comparable to digital holography, but requires significantly smaller efforts. The fast characterization of multimode fibers is particularly suitable for high-performance applications like cyberphysical systems in the internet of things.
Spinal Cord Segmentation in Ultrasound Medical Imagery
Authors: Benjdira Bilel , Ouni Kais , Al Rahhal Mohamad M. , Albakr Abdulrahman , Al-Habib Amro , Mahrous Emad
Published: February 2020

In this paper, we study and evaluate the task of semantic segmentation of the spinal cord in ultrasound medical imagery. This task is useful for neurosurgeons to analyze the spinal cord movement during and after the laminectomy surgical operation. Laminectomy is performed on patients that suffer from an abnormal pressure made on the spinal cord. The surgeon operates by cutting the bones of the laminae and the intervening ligaments to relieve this pressure. During the surgery, ultrasound waves can pass through the laminectomy area to give real-time exploitable images of the spinal cord. The surgeon uses them to confirm spinal cord decompression or, occasionally, to assess a tumor adjacent to the spinal cord. The Freely pulsating spinal cord is a sign of adequate decompression. To evaluate the semantic segmentation approaches chosen in this study, we constructed two datasets using images collected from 10 different patients performing the laminectomy surgery. We found that the best solution for this task is Fully Convolutional DenseNets if the spinal cord is already in the train set. If the spinal cord does not exist in the train set, U-Net is the best. We also studied the effect of integrating inside both models some deep learning components like Atrous Spatial Pyramid Pooling (ASPP) and Depthwise Separable Convolution (DSC). We added a post-processing step and detailed the configurations to set for both models.
The Effect of Different Filament Arrangements on Thermal and Optical Performances of LED Bulbs
Authors: Wang Wei , Zou Jun , Zheng Qiaoyu , Li Yuefeng , Yang Bobo , Shi Mingming , Li Yang , Li Xinyu , Zhang Canyun , Li Cao , Chen Difei
Published: February 2020

The influences on thermal and optical performances of light emitting diode (LED) bulbs with three different filament arrangements are investigated in detail. The average junction temperature, temperature of the surface of the bulb, and luminous flux of three samples all increased with increasing power. The thermal performance test results show that between the average junction, temperature and power were linear. The junction temperatures of the three samples at a power of 3.5 W were 102.48, 98.46, and 88.88 °C. The optical performance test results revealed that the luminous flux and efficiency in the two vertical filament arrangements were closely related to each other and higher than that of the horizontal filament arrangement. A numerical model of LED filament bulbs was established by the Floefd 17.2 software for analyzing the temperature distribution of the cross section and the gas flow path inside the bulb. The simulation results illustrated that the average temperatures of three samples were 105.88, 101.83, and 96.12 °C. Additionally, the gas flow inside the bulb of the two vertical filament arrangements was subject to forming a thermal cycle during operation work more than that of the horizontal filament arrangement. As a result, the flexible spiral LED filament bulb is feasible as a new light source.
Atomic Data for Calculation of the Intensities of Stark Components of Excited Hydrogen Atoms in Fusion Plasmas
Authors: Marchuk Oleksandr , Schultz David , Ralchenko Yuri
Published: February 2020

Motional Stark effect (MSE) spectroscopy represents a unique diagnostic tool capable of determining the magnitude of the magnetic field and its direction in the core of fusion plasmas. The primary excitation channel for fast hydrogen atoms in injected neutral beams, with energy in the range of 25–1000 keV, is due to collisions with protons and impurity ions (e.g., He 2 + and heavier impurities). As a result of such excitation, at the particle density of 10 13 –10 14 cm − 3 , the line intensities of the Stark multiplets do not follow statistical expectations (i.e., the populations of fine-structure levels within the same principal quantum number n are not proportional to their statistical weights). Hence, any realistic modeling of MSE spectra has to include the relevant collisional atomic data. In this paper we provide a general expression for the excitation cross sections in parabolic states within n = 3 for an arbitrary orientation between the direction of the motion-induced electric field and the proton-atom collisional axis. The calculations make use of the density matrix obtained with the atomic orbital close coupling method and the method can be applied to other collisional systems (e.g., He 2 + , Be 4 + , C 6 + , etc.). The resulting cross sections are given as simple fits that can be directly applied to spectral modeling. For illustration we note that the asymmetry detected in the first classical cathode ray experiments between the red- and blue-shifted spectral components can be quantitatively studied using the proposed approach.
Inhomogeneous Temperature Distribution Affecting the Cyclic Aging of Li-Ion Cells. Part I: Experimental Investigation
Authors: Werner Daniel , Paarmann Sabine , Wiebelt Achim , Wetzel Thomas
Published: February 2020

Alongside electrical loads, it is known that temperature has a strong influence on battery behavior and lifetime. Investigations have mainly been performed at homogeneous temperatures and non-homogeneous conditions in single cells have at best been simulated. This publication presents the development of a methodology and experimental setup to investigate the influence of thermal boundary conditions during the operation of lithium-ion cells. In particular, spatially inhomogeneous and transient thermal boundary conditions and periodical electrical cycles were superimposed in different combinations. This required a thorough design of the thermal boundary conditions applied to the cells. Unlike in other contributions that rely on placing cells in a climatic chamber to control ambient air temperature, here the cell surfaces and tabs were directly connected to individual cooling and heating plates. This improves the control of the cells’ internal temperature, even with high currents accompanied by strong internal heat dissipation. The aging process over a large number of electrical cycles is presented by means of discharge capacity and impedance spectra determined in repeated intermediate characterizations. The influence of spatial temperature gradients and temporal temperature changes on the cyclic degradation is revealed. It appears that the overall temperature level is indeed a decisive parameter for capacity fade during cyclic aging, while the intensity of a temperature gradient is not as essential. Furthermore, temperature changes can have a substantial impact and potentially lead to stronger degradation than spatial inhomogeneities.
Recapitulating the Vasculature Using Organ-On-Chip Technology
Authors: Pollet Andreas M.A.O. , den Toonder Jaap M.J.
Published: February 2020

The development of Vasculature-on-Chip has progressed rapidly over the last decade and recently, a wealth of fabrication possibilities has emerged that can be used for engineering vessels on a chip. All these fabrication methods have their own advantages and disadvantages but, more importantly, the capability of recapitulating the in vivo vasculature differs greatly between them. The first part of this review discusses the biological background of the in vivo vasculature and all the associated processes. We then evaluate the biological relevance of different fabrication methods proposed for Vasculature-on-Chip, we indicate their possibilities and limitations, and we assess which fabrication methods are capable of recapitulating the intrinsic complexity of the vasculature. This review illustrates the complexity involved in developing in vitro vasculature and provides an overview of fabrication methods for Vasculature-on-Chip in relation to the biological relevance of such methods.
Morphological Features of the Anther Development in Tomato Plants with Non-Specific Male Sterility
Authors: Chaban Inna A. , Kononenko Neonila V. , Gulevich Alexander A. , Bogoutdinova Liliya R. , Khaliluev Marat R. , Baranova Ekaterina N.
Published: February 2020

The study was devoted to morphological and cytoembryological analysis of disorders in the anther and pollen development of transgenic tomato plants with a normal and abnormal phenotype, which is characterized by the impaired development of generative organs. Various abnormalities in the structural organization of anthers and microspores were revealed. Such abnormalities in microspores lead to the blocking of asymmetric cell division and, accordingly, the male gametophyte formation. Some of the non-degenerated microspores accumulate a large number of storage inclusions, forming sterile mononuclear pseudo-pollen, which is similar in size and appearance to fertile pollen grain (looks like pollen grain). It was discussed that the growth of tapetal cells in abnormal anthers by increasing the size and ploidy level of nuclei contributes to this process. It has been shown that in transgenic plants with a normal phenotype, individual disturbances are also observed in the development of both male and female gametophytes. The reason for the developmental arrest of some ovules was the death of endosperm at different stages of the globular embryo. At the same time, noticeable hypertrophy of endothelial cells performing a secretory function was observed. In the ovules of transgenic plants with abnormalities, the endothelium forms a pseudo-embryo instead of the embryo sac, stimulating the development of parthenocarpic fruits. The data obtained in this study can be useful for a better understanding of the genetic and molecular mechanisms of cytoplasmic male sterility and parthenocarpic fruit development in tomatoes.
Extracellular Traps: An Ancient Weapon of Multiple Kingdoms
Authors: Neumann Ariane , Brogden Graham , von Köckritz-Blickwede Maren
Published: February 2020

The discovery, in 2004, of extracellular traps released by neutrophils has extended our understanding of the mode of action of various innate immune cells. This fascinating discovery demonstrated the extracellular trapping and killing of various pathogens by neutrophils. During the last decade, evidence has accumulated showing that extracellular traps play a crucial role in the defence mechanisms of various cell types present in vertebrates, invertebrates, and plants. The aim of this review is to summarise the relevant literature on the evolutionary history of extracellular traps used as a weapon in various kingdoms of life.
Detection of the Ovarian Cancer Biomarker Lysophosphatidic Acid in Serum
Authors: De La Franier Brian , Thompson Michael
Published: February 2020

Lysophosphatidic acid (LPA) is present during the medical condition of ovarian cancer at all stages of the disease, and, therefore possesses considerable potential as a biomarker for screening its presence in female patients. Unfortunately, there is currently no clinically employable assay for this biomarker. In the present work, we introduce a test based on the duel protein system of actin and gelsolin that could allow the quantitative measurement of LPA in serum samples in a biosensing format. In order to evaluate this possibility, actin protein was dye-modified and complexed with gelsolin protein, followed by surface deposition onto silica nanoparticles. This solid-phase system was exposed to serum samples containing various concentrations of LPA and analyzed by fluorescence microscopy. Measurements conducted for the LPA-containing serum samples were higher after exposure to the developed test than samples without LPA. Early results suggest a limit of detection of 5 μM LPA in serum. The eventual goal is to employ the chemistry described here in a biosensor configuration for the large population-scale, rapid screening of women for the potential occurrence of ovarian cancer.
Towards Sustainable Heritage Tourism: A Space Syntax-Based Analysis Method to Improve Tourists’ Spatial Cognition in Chinese Historic Districts
Authors: Xu Yabing , Rollo John , Jones David S. , Esteban Yolanda , Tong Hui , Mu Qipeng
Published: February 2020

Historical and cultural blocks in Chinese historic districts are important components of sustainable heritage tourism. In towns along the Grand Canal, historical and cultural blocks are generally integrated with modern commerce, forming a complex space characterized by multi-elements, multi-cultures, and multi-functions. The understanding of tourists’ spatial cognition thus becomes extremely important to support heritage conservation and encourage sustainable heritage tourism. This study proposes a space syntax-based methodology to help inform heritage consultants and urban designers in understanding the tourists’ spatial cognition of canal town cultural blocks, and thereby assists designers and managers in identifying where cognitive experiences can be improved. The proposed method is applied to Nanyang, which is a canal town currently in decline in Shandong Province, and is contrasted with the ancient town of Wuzhen in Zhejiang Province, China, a highly successful tourist town. By using this proposed method, the relationship between street networks and tourists’ spatial cognition has been explored. The results of the analysis were evaluated in order to inform a range of design concepts that could enhance the sustainable heritage tourism experience of these two towns.
Photocatalytic BiOX Mortars under Visible Light Irradiation: Compatibility, NOx Efficiency and Nitrate Selectivity
Authors: Nava-Núñez Magaly Y. , Jimenez-Relinque Eva , Grande Maria , Martínez-de la Cruz Azael , Castellote Marta
Published: February 2020

The use of new photocatalysts active under visible light in cement-based building materials represents one interesting alternative to improve the air quality in the urban areas. This work undertakes the feasibility of using BiOX (X = Cl and I) as an addition on mortars for visible-light-driven NOx removal. The interaction between BiOX photocatalysts and cement matrix, and the influence of their addition on the inherent properties of the cement-based materials was studied. The NO removal by the samples ranking as follows BiOCl-cem > BiOI-cem > TiO2-cem. The higher efficiency under visible light of BiOCl-cem might be ascribed to the presence of oxygen vacancies together with a strong oxidation potential. BiOI-cem suffers a phase transformation of BiOI in alkaline media to an I-deficient bismuth oxide compound with poor visible light absorbance capability. However, BiOI-cem showed considerably higher nitrate selectivity that resulted in the highest NOx global removal efficiency. These results can make its use more environmentally sustainable than TiO2 and BiOCl cement composites.
Biodiesel Production Using Solid Acid Catalysts Based on Metal Oxides
Authors: Vasić Katja , Hojnik Podrepšek Gordana , Knez Željko , Leitgeb Maja
Published: February 2020

The development of solid acid catalysts, especially based on metal oxides and different magnetic nanoparticles, gained much awareness recently as a result of the development of different nano-based materials. Solid acid catalysts based on metal oxides are promising for the (trans)esterification reactions of different oils and waste materials for biodiesel production. This review gives a brief overview of recent developments in various solid acid catalysts based on different metal oxides, such as zirconia, zinc, titanium, iron, tungsten, and magnetic materials, where the catalysts are optimized for various reaction parameters, such as the amount of catalyst, molar ratio of oil to alcohol, reaction time, and temperature. Furthermore, yields and conversions for biodiesel production are compared. Such metal-oxide-based solid acid catalysts provide more sustainable, green, and easy-separation synthesis routes with high catalytic activity and reusability than traditionally used catalysts.
Co-Supported CeO2Nanoparticles for CO Catalytic Oxidation: Effects of Different Synthesis Methods on Catalytic Performance
Authors: Sui Chao , Xing LeHong , Cai Xue , Wang Yang , Zhou Qi , Li Minghao
Published: February 2020

Hydrothermal and co-precipitation methods were studied as two different methods for the synthesis of CeO2nanocatalysts. Co/CeO2 catalysts supported by 2, 4, 6, or 8wt% Co were further synthesized through impregnation and the performance of the catalytic oxidation of CO has been investigated. The highest specific surface area and the best catalytic performance was obtained by the catalyst 4wt% Co/CeO2 with the CeO2 support synthesized by the hydrothermal method (4% Co/CeO2-h), which yielded 100% CO conversion at 130 °C. The formation of CeO2 nanoparticles was confirmed by TEM analysis. XRD and SEM-EDX mapping analyses indicated that CoOx is highly dispersed on the 4% Co/CeO2-h catalyst surface. H2-TPR and O2-TPD results showed that 4% Co/CeO2-h possesses the best redox properties and the highest amount of chemically adsorbed oxygen on its surface among all tested catalysts. Raman and XPS spectra showed strong interactions between highly dispersed Co2+ active sites and exposed Ce3+ on the surface of the CeO2 support, resulting in the formation of the strong redox cycle Ce4+ + Co2+↔ Ce3+ + Co3+.This may explain that 4% Co/CeO2-h exhibited the best catalytic activity among all tested catalysts.
Influence of a Biocompatible Hydrophilic Needle Surface Coating on a Puncture Biopsy Process for Biomedical Applications
Authors: Gao Fan , Song Qinghua , Liu Zhanqiang , Jiang Yonghang , Hao Xiuqing
Published: February 2020

A puncture biopsy is a widely used, minimally invasive surgery process. During the needle insertion process, the needle body is always in direct contact with a biological soft tissue. Tissue adhesion and different degrees of tissue damage occur frequently. Optimization of the needle surface, and especially the lubrication of the needle surface, can deal with these problems efficiently. Therefore, in this paper, a biocompatible hydrophilic coating was applied onto the surface of a needle to improve the surface quality of the needle surface. Further, a simplified finite element model of insertion was established, and extracorporeal insertion experiments were used to verify the accuracy of the model. Then, by analyzing a simulation model of a coated needle and a conventional needle, the influence of the application of the coated needle on the insertion process was obtained. It can be seen from the results that the coating application relieved the force on the needle and the soft tissue during the insertion process and could significantly reduce friction during the insertion process. At the same time, the deformation of biological soft tissue was reduced, and the adhesion situation between the needle and tissue improved, which optimized the puncture needle.
Iron-Doped Titanium Dioxide Nanoparticles As Potential Scaffold for Hydrazine Chemical Sensor Applications
Authors: Umar Ahmad , Harraz Farid A. , Ibrahim Ahmed A. , Almas Tubia , Kumar Rajesh , Al-Assiri M. S. , Baskoutas Sotirios
Published: February 2020

Herein, we report the fabrication of a modified glassy carbon electrode (GCE) with high-performance hydrazine sensor based on Fe-doped TiO2 nanoparticles prepared via a facile and low-cost hydrothermal method. The structural morphology, crystalline, crystallite size, vibrational and scattering properties were examined through different characterization techniques, including FESEM, XRD, FTIR, UV–Vis, Raman and photoluminescence spectroscopy. FESEM analysis revealed the high-density synthesis of Fe-doped TiO2 nanoparticles with the average diameter of 25 ± 5 nm. The average crystallite size of the synthesized nanoparticles was found to be around 14 nm. As-fabricated hydrazine chemical sensors exhibited 1.44 μA µM−1 cm−2 and 0.236 µM sensitivity and limit of detection (LOD), respectively. Linear dynamic ranged from 0.2 to 30 µM concentrations. Furthermore, the Fe-doped TiO2 modified GCE showed a negligible inference behavior towards ascorbic acid, uric acid, glucose, SO42−, NO3−, Pb2+ and Ca2+ ions on the hydrazine sensing performance. Thus, Fe-doped TiO2 modified GCE can be efficiently used as an economical, easy to fabricate and selective sensing of hydrazine and its derivatives.
Uniform Spheres of α-NaYF4:RE3+ (RE=Eu, Tb, Ce, Er, and Tm): Template-Free Synthesis, Multi-Color Photoluminescence, and Their Application in Cellular Imaging
Authors: Fan Xiaofeng , Gu Laiqin , Hu Yiling , Zhu Qi
Published: February 2020

Uniformly dispersed luminescent probes with a high brightness and high resolution are desired in bio imaging fields. Here, ~100 nm sized and well-dispersed spheres of RE3+ doped α-NaYF4 (rare earth (RE) = Eu, Tb, Ce, Er, and Tm) have been facile synthesized through hydrothermal processing in the absence of a template, followed by a proper annealing. The processing window of the cubic structured spheres is wide, because the hydrothermal products are independent of the processing conditions, including reaction time and temperature. The original morphology and crystal structure can be well retained with a calcination temperature up to 600 °C. However, calcination gives rise to a reduction of particle sizes, as a result of the crystallite growth and densification. Under ultraviolet radiation, α-NaYF4:RE3+ spheres show characteristic f-f emissions of RE3+ (RE = Eu, Tb, Ce, Er, and Tm), and exhibit orange red, green, ultraviolet (UV), blue green, and blue emissions, respectively. Mainly because of the near-infrared emission at ~697 nm (5D0→7F4 transitions of Eu3+), the successful imaging of macrophages was achieved by NH2-NaYF4:Eu3+ probes, indicating their excellent imaging capacity for cells in vitro.
3D Numerical Analysis of the Asymmetric Three-Phase Line of Floating Zone for Silicon Crystal Growth
Authors: Han Xue-Feng , Liu Xin , Nakano Satoshi , Harada Hirofumi , Miyamura Yoshiji , Kakimoto Koichi
Published: February 2020

A numerical simulation has been carried out to study the asymmetric heat transfer, fluid flow, and three-phase line to explain the phenomenon of the spillage of the melt in floating zone (FZ) silicon growth. A three-dimensional high-frequency electromagnetic (EM) field is coupled with the heat transfer in the melt and crystal calculation domains. The current density along the three-phase line is investigated to demonstrate the inhomogeneous heating along the three-phase line. The asymmetric heating is found to affect the flow pattern and temperature distribution of the melt. The three-dimensional solid–liquid interface results show that, below the current supplies, the interface is deflected due to strong heating below the current supplies. The calculated asymmetric three-phase line shows a similar trend as the experimentally observed results. The results indicate that the re-melting and spillage phenomenon could occur below the current supplies.
Symmetry-Adapted Finite Strain Landau Theory Applied to KMnF3
Authors: Tröster Andreas , Schranz Wilfried , Ehsan Sohaib , Belbase Kamal , Blaha Peter
Published: February 2020

In recent years, finite strain Landau theory has been gradually developed as both a conceptual as well as a quantitative framework to study high pressure phase transitions of the group-subgroup type. In the current paper, we introduce a new version of this approach which is based on symmetry-adapted finite strains. This results in a substantial simplification of the original formulation. Moreover, it allows for replacing the clumsy use of truncated Taylor expansions by a convenient functional parametrization. Both the weaknesses of the traditional Landau approach based on infinitesimal strains as well as the major improvements made possible by our new parametrization are illustrated in great detail in an application to the ambient temperature high pressure transition of the perovskite KMnF 3 .
Combination of Two Rapid Ophthalmic Test Kits for Improved Diagnosis in Cases of Severe Binocular Conjunctivitis
Authors: Kodama Asako , Kobayashi Fumitaka , Yang Hao Yung , Fukagawa Kazumi , Yazu Hiroyuki , Fujishima Hiroshi
Published: February 2020

Introduction: Diagnosis of conjunctivitis can be sometimes difficult, especially in cases of severe conjunctivitis and those involving both eyes. In this study, we performed commercial tests for adenovirus (Capilia Adeno Eye®) and total tear IgE (Allerwatch®) in a single visit in patients with bilateral conjunctivitis to examine if, and by how much, the combination of these two tests would improve the diagnostic accuracy of conjunctivitis. Methods: The study included sixty patients with relatively severe conjunctivitis in both eyes within a week of consulting our clinic and who had no previous treatment. Capilia Adeno Eye® and Allerwatch® tests were performed. Results: A significantly higher number of cases (55/60) were diagnosed when both tests were evaluated than with either test (Capilia Adeno Eye® (12/60; p < 0.001) or Allerwatch® (44/60; p < 0.005)) alone. The positivity rate of Allerwatch® was significantly higher than that of Capilia Adeno Eye® (p < 0.001). The diagnosis rate of atopic keratoconjunctivitis was 100% in patients with allergic conjunctivitis, but there was no significant difference in positivity compared with other types of allergic conjunctivitis. Conclusions: Testing patients with both Capilia Adeno Eye® and Allerwatch® improves the diagnostic accuracy for conjunctivitis and can diagnose more than 90% of cases. Detection of adenovirus antigen and IgE in tears, using these simple and rapid methods, will be useful for early diagnosis and prevention of adenoviral conjunctivitis.
CD163+ Foamy Macrophages Are Associated with the Morphogenesis of Oral Verruciform Xanthoma through Angiogenesis by VEGF Expression: An Immunohistochemical Study
Authors: Shigeoka Manabu , Koma Yu-ichiro , Kodama Takayuki , Nishio Mari , Akashi Masaya , Yokozaki Hiroshi
Published: February 2020

Oral verruciform xanthoma (OVX) is an uncommon benign lesion that is characterized histologically by the accumulation of several foamy macrophages in the lamina propria papillae. The pathogenesis of OVX has not been completely elucidated, although the significance of macrophage polarization (M1, tumor suppression; and M2, tumor promotion) and the contribution of M2 macrophages to angiogenesis are well established. This study investigated the role of foamy macrophages in OVX, with a focus on angiogenesis. Four patients who underwent surgical excision or total excisional biopsy for OVXs were enrolled in this study. We evaluated the expression of the macrophage markers CD68 (broad) and CD163 (M2) and the CD34-positive microvessel density (MVD) of OVXs. The foamy macrophages of all patients exhibited positivity to CD68 and CD163. We evaluated the MVD and the expression of the vascular endothelial growth factor (VEGF) based on histological architecture. The MVD of all OVX cases was significantly higher than that of the corresponding normal epithelia. Interestingly, the MVD of verrucous-type OVX cases was higher than that of the other type. VEGF was expressed on foamy macrophages in all cases. Overall, the foamy macrophages expressing CD163 were associated with the morphogenesis of OVX through the process of angiogenesis by VEGF expression.
Bioinformatics-Based Adaptive System towards Real-Time Dynamic E-learning Content Personalization
Authors: Mwambe Othmar Othmar , Tan Phan Xuan , Kamioka Eiji
Published: February 2020

Adaptive Educational Hypermedia Systems (AEHS) play a crucial role in supporting adaptive learning and immensely outperform learner-control based systems. AEHS’ page indexing and hyperspace rely mostly on navigation supports which provide the learners with a user-friendly interactive learning environment. Such AEHS features provide the systems with a unique ability to adapt learners’ preferences. However, obtaining timely and accurate information for their adaptive decision-making process is still a challenge due to the dynamic understanding of individual learner. This causes a spontaneous changing of learners’ learning styles that makes hard for system developers to integrate learning objects with learning styles on real-time basis. Thus, in previous research studies, multiple levels navigation supports have been applied to solve this problem. However, this approach destroys their learning motivation because of imposing time and work overload on learners. To address such a challenge, this study proposes a bioinformatics-based adaptive navigation support that was initiated by the alternation of learners’ motivation states on a real-time basis. EyeTracking sensor and adaptive time-locked Learning Objects (LOs) were used. Hence, learners’ pupil size dilation and reading and reaction time were used for the adaption process and evaluation. The results show that the proposed approach improved the AEHS adaptive process and increased learners’ performance up to 78%.
Exploring Issues and Challenges of Leadership among Early Career Doctors in Nigeria Using a Mixed-Method Approach: CHARTING Study
Authors: Isibor Efosa , Kanmodi Kehinde , Adebayo Oladimeji , Olaopa Olusegun , Igbokwe Martin , Adufe Iyanu , Oduyemi Ibiyemi , Adeniyi Makinde Adebayo , Oiwoh Sebastine Oseghae , Omololu Ayanfe , Egbuchulem Ifeanyichukwu Kelvin , Kpuduwei Selekeowei Peter Kespi , Efuntoye Oluwafemi , Egwu Onuwabuchi , Ogunsuji Oluwaseyi , Grillo Elizabeth O. , Rereloluwa Babalola
Published: February 2020

(1) Background: leadership behaviour is a poorly explored phenomenon among early-career doctors (ECDs). Good leadership is vital in maximising the effective management of patients in a clinical setting. While a good number of studies, though with small sample surveys, have researched the role of leadership in clinical setting quantitatively, qualitative investigations are yet to be done in Nigeria. This study aims to explore the attitudes, skills, and experience of ECDs in Nigeria on issues pertaining to leadership in a medical setting, using a mixed-method approach. (2) Methods: we conducted two sessions of key informant focus group discussion (FGD) that involved 14 ECD leaders in Nigeria, exploring their leadership experience in a clinical setting. Furthermore, we used a self-administered questionnaire to quantitatively survey 474 ECDs from seven Nigerian teaching hospitals to explore their attitudes, skills, and experience on issues pertaining to medical leadership. (3) Results: taking on leadership roles is a common phenomenon (52.7%) among the surveyed ECDs; however, the medical leadership position can be very challenging for ECDs in Nigeria. Despite the fact that many (91.1%) of the surveyed ECDs perceived leadership skills as essential skills needed by a doctr, many (44.1%) of them were yet to be formally trained on medical leadership. About three out of every 10 (23.6%) of surveyed ECDs that have ever held leadership positions in a medical setting experienced major leadership challenges while in such office due to their lack of training on leadership skills. Leadership skill acquisition programmes are highly recommended to become an integral part of medical training programmes in Nigeria. (4) Conclusion: there is a need for a structured leadership skill acquisition programme for ECDs in Nigeria. This programme will help in the robust delivery of highly effective healthcare services in Nigeria, as effective leadership is crucial to patient care services.
Gate Current and Snapback of 4H-SiC Thyristors on N+ Substrate for Power-Switching Applications
Authors: Lee Hojun , Seok Ogyun , Kim Taeeun , Ha Min-Woo
Published: February 2020

High-power switching applications, such as thyristor valves in a high-voltage direct current converter, can use 4H-SiC. The numerical simulation of the 4H-SiC devices requires specialized models and parameters. Here, we present a numerical simulation of the 4H-SiC thyristor on an N+ substrate gate current during the turn-on process. The base-emitter current of the PNP bipolar junction transistor (BJT) flow by adjusting the gate potential. This current eventually activated a regenerative action of the thyristor. The increase of the gate current from P+ anode to N+ gate also decreased the snapback voltage and forward voltage drop (Vf). When the doping concentration of the P-drift region increased, Vf decreased due to the reduced resistance of a low P-drift doping. An increase in the P buffer doping concentration increased Vf owing to enhanced recombination at the base of the NPN BJT. There is a tradeoff between the breakdown voltage and forward characteristics. The breakdown voltage is increased with a decrease in concentration, and an increase in drift layer thickness occurs due to the extended depletion region and reduced peak electric field.
Radio Network Planning towards 5G mmWave Standalone Small-Cell Architectures
Authors: Athanasiadou Georgia E. , Fytampanis Panagiotis , Zarbouti Dimitra A. , Tsoulos George V. , Gkonis Panagiotis K. , Kaklamani Dimitra I.
Published: February 2020

The 5G radio networks have introduced major changes in terms of service requirements and bandwidth allocation compared to cellular networks to date and hence, they have made the fundamental radio planning problem even more complex. In this work, the focus is on providing a generic analysis for this problem with the help of a proper multi-objective optimization algorithm that considers the main constraints of coverage, capacity and cost for high-capacity scenarios that range from dense to ultra-dense mmWave 5G standalone small-cell network deployments. The results produced based on the above analysis demonstrate that the denser the small-cell deployment, the higher the area throughput, and that a sectored microcell configuration can double the throughput for ultra-dense networks compared to dense networks. Furthermore, dense 5G networks can actually have cell radii below 400 m and down to 120 m for the ultra-dense sectored network that also reached spectral efficiency 9.5 bps/Hz/Km2 with no MIMO or beamforming.
Novel Design and Adaptive Fuzzy Control of a Lower-Limb Elderly Rehabilitation
Authors: Zhang Xin , Li Jiehao , Ovur Salih Ertug , Chen Ziyang , Li Xiangnan , Hu Zhenhuan , Hu Yingbai
Published: February 2020

Design and control of a lower-limb exoskeleton rehabilitation of the elderly are the main challenge for health care in the past decades. In order to satisfy the requirements of the elderly or disabled users, this paper presents a novel design and adaptive fuzzy control of lower-limb empowered rehabilitation, namely MOVING UP. Different from other rehabilitation devices, this article considers active rehabilitation training devices. Firstly, a novel product design method based on user experience is proposed for the lower-limb elderly exoskeleton rehabilitation. At the same time, in order to achieve a stable operation control for the assistant rehabilitation system, an adaptive fuzzy control scheme is discussed. Finally, the feasibility of the design and control method is validated with a detailed simulation study and the human-interaction test. With the booming demand in the global market for the assistive lower-limb exoskeleton, the methodology developed in this paper will bring more research and manufacturing interests.
Experimental Investigation of Finite Aspect Ratio Cylindrical Bodies for Accelerated Wind Applications
Authors: Parker Michael , Bohl Douglas
Published: February 2020

The placement of a cylindrical body in a flow alters the velocity and pressure fields resulting in a local increase in the flow speed near the body. This interaction is of interest as wind turbine rotor blades could be placed in the area of increased wind speed to enhance energy harvesting. In this work the aerodynamic performance of two short aspect ratio (AR = 0.93) cylindrical bodies was evaluated for potential use in “accelerated wind” applications. The first cylinder was smooth with a constant diameter. The diameter of the second cylinder varied periodically along the span forming channels, or corrugations, where wind turbine blades could be placed. Experiments were performed for Reynolds numbers ranging from 1 × 105 to 9 × 105. Pressure distributions showed that the smooth cylinder had lower minimum pressure coefficients and delayed separation compared to the corrugated cylinder. Velocity profiles showed that the corrugated cylinder had lower peak speeds, a less uniform profile, and lower kinetic energy flux when compared to the smooth cylinder. It was concluded that the smooth cylinder had significantly better potential performance in accelerated wind applications than the corrugated cylinder.
Reef Mapping Using Different Seabed Automatic Classification Tools
Authors: Menandro Pedro S. , Bastos Alex C. , Boni Geandré , Ferreira Lucas C. , Vieira Fernanda V. , Lavagnino Ana Carolina , Moura Rodrigo L. , Diesing Markus
Published: February 2020

There is a great demand to develop new acoustic techniques to efficiently map the seabed and automate the interpretation of acoustic, sedimentological, and imaging data sets, eliminating subjectivity. Here, we evaluate the potential, limitations and complementariety of distinct supervised and automatic classification techniques in the mapping of reefs by comparing these results with a reference map. The study was carried out in the Abrolhos Continental Shelf (Eastern Brazilian Continental Margin) using a multibeam echosounder and side scan sonar (SSS) dataset. Two automatic supervised techniques were applied. A reference map was derived by detailed manual interpretation carried out by three experts. The two supervised classification techniques were: benthic terrain modeler (BTM), a morphometric classification with focus on spatial analyses of the bathymetric grid derivatives, and object-based image analysis (OBIA), a segmentation applied to the backscatter data from the SSS mosaic. Both automatic techniques obtained similar values of reef coverage area, but overestimated the reef area when compared with the reference map. The agreement between BTM and OBIA results and the reference map was 69% and 67%, respectively. Disagreement was mainly due to quantity of reef (both methods over-estimated reef), while the disagreement in spatial allocation was relatively low, it indicates that both methods are reasonable representation of the spatial patterns of reef. Efficient mapping of reef in the wider area of the Abrolhos Continental Shelf will be best achieved by a further development of automatic methods tested against reference maps obained from representative areas of the seabed. By combining the results of the two automatic methods, it was possible to create an ensemble map, which achieved better agreement with the reference dataset.
Digitalization of the Marketing Activities of Enterprises: Case Study
Authors: Shpak Nestor , Kuzmin Oleh , Dvulit Zoriana , Onysenko Tetiana , Sroka Włodzimierz
Published: February 2020

The pace and scale of the digitalization of today’s global information society open up new opportunities for business. At the same time, they set new challenges for business owners and managers in the field of marketing. Given this fact, the purpose of the study was to present the impact of digitalization on the marketing activity of the enterprise in the field of services by promoting the use of online sales via electronic distribution channels, social networks, and mobile applications. A comparative system of estimating the parameters of the influence of digitalization on the marketing activity of the enterprise was proposed as a confirmation of this impact. Based on the developed “tree of goals,” the dynamics of the digitalization of services were projected and the prospects of development of this sphere of activity were outlined. For testing the proposed methodology, the railway passenger transportation company (JSC “Ukrzaliznytsia”) was chosen as the object of the research. Research methods used in the study include: (1) statistical; (2) SWOT analysis; (3) systematization, comparative, and structural-dynamic analysis; and (4) an expert survey. As a result of revealing the impact of individual elements of digitalization on the level of marketing activity, the number of recommendations regarding the development of digitalization of electronic ticket sales services and their accounting for enterprises dealing with railway passenger transportation were proposed.
Digital Image Watermarking Techniques: A Review
Authors: Begum Mahbuba , Uddin Mohammad Shorif
Published: February 2020

Digital image authentication is an extremely significant concern for the digital revolution, as it is easy to tamper with any image. In the last few decades, it has been an urgent concern for researchers to ensure the authenticity of digital images. Based on the desired applications, several suitable watermarking techniques have been developed to mitigate this concern. However, it is tough to achieve a watermarking system that is simultaneously robust and secure. This paper gives details of standard watermarking system frameworks and lists some standard requirements that are used in designing watermarking techniques for several distinct applications. The current trends of digital image watermarking techniques are also reviewed in order to find the state-of-the-art methods and their limitations. Some conventional attacks are discussed, and future research directions are given.
An ECDSA Approach to Access Control in Knowledge Management Systems Using Blockchain
Authors: Nyame Gabriel , Qin Zhiguang , Obour Agyekum Kwame Opuni-Boachie , Sifah Emmanuel Boateng
Published: February 2020

Access control has become problematic in several organizations because of the difficulty in establishing security and preventing malicious users from mimicking roles. Moreover, there is no flexibility among users in the participation in their roles, and even controlling them. Several role-based access control (RBAC) mechanisms have been proposed to alleviate these problems, but the security has not been fully realized. In this work, however, we present an RBAC model based on blockchain technology to enhance user authentication before knowledge is accessed and utilized in a knowledge management system (KMS). Our blockchain-based system model and the smart contract ensure that transparency and knowledge resource immutability are achieved. We also present smart contract algorithms and discussions about the model. As an essential part of RBAC model applied to KMS environment, trust is ensured in the network. Evaluation results show that our system is efficient.