bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of Cone Beam Computed Tomographic Imaging in a Paediatric Dentistry Department
Authors: Henein Claudy , Bhatia Shannu K , Drage Nicholas
Published: March 2021

Cone beam computed tomography (CBCT) is an emerging radiographic imaging modality. The diagnostic benefit must exceed the individual detriment that its generally higher radiation exposure may cause. Since limited studies exist on the use and impact of CBCT in paediatric dentistry, a service evaluation was carried out to explore the reasons for CBCT referral and to identify its impact on the treatment plan and/or management in a paediatric dentistry department. Clinical records for all paediatric patients who underwent a CBCT were reviewed, to identify the reason for referral and its influence on diagnosis or management, by comparing the provisional treatment plan with the definitive treatment plan, post-CBCT. A total of 130 paediatric patients underwent CBCT in a 12-month period, of which 52 satisfied the inclusion criteria. CBCTs were most commonly requested for the localisation of unerupted/impacted teeth 14/52 (27%), assessment of supernumerary teeth 12/52 (23%), and to investigate root resorption 9/52 (17%). All CBCTs provided additional information that assisted treatment planning, diagnosis, or management and, most significantly, 16/52 (31%) of treatment plans were changed based on CBCT findings. All CBCTs requested in this study were justified and confirmed or influenced the management of paediatric patients, ultimately reducing the risk of complications and further treatment.
Potent Antiviral Activity against HSV-1 and SARS-CoV-2 by Antimicrobial Peptoids
Authors: Diamond Gill , Molchanova Natalia , Herlan Claudine , Fortkort John , Lin Jennifer , Figgins Erika , Bopp Nathen , Ryan Lisa , Chung Donghoon , Adcock Robert , Sherman Michael , Barron Annelise
Published: March 2021

Viral infections, such as those caused by Herpes Simplex Virus-1 (HSV-1) and SARS-CoV-2, affect millions of people each year. However, there are few antiviral drugs that can effectively treat these infections. The standard approach in the development of antiviral drugs involves the identification of a unique viral target, followed by the design of an agent that addresses that target. Antimicrobial peptides (AMPs) represent a novel source of potential antiviral drugs. AMPs have been shown to inactivate numerous different enveloped viruses through the disruption of their viral envelopes. However, the clinical development of AMPs as antimicrobial therapeutics has been hampered by a number of factors, especially their enzymatically labile structure as peptides. We have examined the antiviral potential of peptoid mimics of AMPs (sequence-specific N-substituted glycine oligomers). These peptoids have the distinct advantage of being insensitive to proteases, and also exhibit increased bioavailability and stability. Our results demonstrate that several peptoids exhibit potent in vitro antiviral activity against both HSV-1 and SARS-CoV-2 when incubated prior to infection. In other words, they have a direct effect on the viral structure, which appears to render the viral particles non-infective. Visualization by cryo-EM shows viral envelope disruption similar to what has been observed with AMP activity against other viruses. Furthermore, we observed no cytotoxicity against primary cultures of oral epithelial cells. These results suggest a common or biomimetic mechanism, possibly due to the differences between the phospholipid head group makeup of viral envelopes and host cell membranes, thus underscoring the potential of this class of molecules as safe and effective broad-spectrum antiviral agents. We discuss how and why differing molecular features between 10 peptoid candidates may affect both antiviral activity and selectivity.
Increasing the Quality Factor (Q) of 1D Photonic Crystal Cavity with an End Loop-Mirror
Authors: Haron Mohamad Hazwan , Yeop Majlis Burhanuddin , Zain Ahmad Rifqi Md
Published: March 2021

Increasing the quality factor (Q-factor) of an optical resonator device has been a research focus utilized in various applications. Higher Q-factor means light is confined in a longer time which will produce a sharper peak and higher transmission. In this paper, we introduce a novel technique to further increase the Q-factor of a one-dimensional photonic crystal (1D PhC) cavity device by using an end loop-mirror (ELM). The technique utilizes and recycles the transmitted light from the conventional 1D PhC cavity design. The design has been proven to work by using the 2.5D FDTD simulation with Lumerical FDTD and MODE software. By using the ELM technique, the Q-factor of a 1D PhC design has been shown to increase up to 79.53% from the initial Q value without the ELM. The experimental result shows that the device is measurable by adding a Y-branch component to the one-port structure and able to get a high Q result. This novel design technique can be combined with any high Q-factor and very high Q-factor designs to increase more Q-factor values of photonic crystal cavity devices or any other suitable optical resonator devices.
High-Peak-Power Long-Wave Infrared Lasers with CO2 Amplifiers
Authors: Polyanskiy Mikhail , Pogorelsky Igor , Babzien Marcus , Kupfer Rotem , Vafaei-Najafabadi Navid , Palmer Mark
Published: March 2021

Long-wave infrared (LWIR) picosecond pulses with multi-terawatt peak power have recently become available for advanced high-energy physics and material research. Multi-joule pulse energy is achieved in an LWIR laser system via amplification of a microjoule seed pulse with high-pressure, mixed-isotope CO2 amplifiers. A chirped-pulse amplification (CPA) scheme is employed in such a laser to reduce the nonlinear interaction between the optical field and the transmissive elements of the system. Presently, a research and development effort is underway towards an even higher LWIR peak power that is required, for instance, for promising particle acceleration schemes. The required boost of the peak power can be achieved by reducing the pulse duration to fractions of a picosecond. For this purpose, the possibility of reducing the gain narrowing in the laser amplifiers and post-compression techniques are being studied. Another direction in research is aimed at the increased throughput (i.e., repetition rate), efficiency, and reliability of LWIR laser systems. The transition from a traditional electric-discharge pumping to an optical pumping scheme for CO2 amplifiers is expected to improve the robustness of high-peak-power LWIR lasers, making them suitable for broad implementation in scientific laboratory, industrial, and clinical environments.
Citrus Cell Suspension Culture Establishment, Maintenance, Efficient Transformation and Regeneration to Complete Transgenic Plant
Authors: Moniruzzaman M. , Zhong Yun , Huang Zhifeng , Yan Huaxue , Yuanda Lv , Jiang Bo , Zhong Guangyan
Published: March 2021

Agrobacterium-mediated transformation of epicotyl segment has been used in Citrus transgenic studies. The approach suffers, however, from limitations such as occasionally seed unavailability, the low transformation efficiency of juvenile tissues and the high frequency of chimeric plants. Therefore, a suspension cell culture system was established and used to generate transgenic plants in this study to overcome the shortcomings. The embryonic calli were successfully developed from undeveloped ovules of the three cultivars used in this study, “Sweet orange”-Egyptian cultivar (Citrus sinensis), “Shatangju” (Citrus reticulata) and “W. Murcott” (Citrus reticulata), on three different solid media. Effects of media, genotypes and ages of ovules on the induction of embryonic calli were also investigated. The result showed that the ovules’ age interferes with the callus production more significantly than media and genotypes. The 8 to 10 week-old ovules were found to be the best materials. A cell suspension culture system was established in an H+H liquid medium. Transgenic plants were obtained from Agrobacterium-mediated transformation of cell suspension as long as eight weeks subculture intervals. A high transformation rate (~35%) was achieved by using our systems, confirming BASTA selection and later on by PCR confirmation. The results demonstrated that transformation of cell suspension should be more useful for the generation of non-chimeric transgenic Citrus plants. It was also shown that our cell suspension culture procedure was efficient in maintaining the vigor and regeneration potential of the cells.
Assessment of the Origin and Diversity of Croatian Common Bean Germplasm Using Phaseolin Type, SSR and SNP Markers and Morphological Traits
Authors: Vidak Monika , Šatović Zlatko , Liber Zlatko , Grdiša Martina , Gunjača Jerko , Kilian Andrzej , Carović-Stanko Klaudija
Published: March 2021

Landraces represent valuable genetic resources for breeding programmes to produce high-yielding varieties adapted to stressful environmental conditions. Although the common bean (Phaseolus vulgaris L.) is an economically important food legume for direct human consumption worldwide, common bean production in Croatia is based almost exclusively on landraces and there is no common bean breeding program. Information on phaseolin type and results of population structure and genetic diversity obtained by analysis of SSR and SNP markers, in combination with the morphological characterization of 174 accessions of 10 common bean landraces (morphotypes), enabled thorough classification of accessions. The accessions were classified into phaseolin type H1 (“S”) of Mesoamerican origin and phaseolin types H2 (“H” or “C”) and H3 (“T”) of Andean origin. By applying distance- and model-based clustering methods to SSR markers, the accessions were classified into two clusters at K = 2 separating the accessions according to the centres of origin, while at K = 3, the accessions of Andean origin were further classified into two clusters of accessions that differed in phaseolin type (H2 and H3). Using SNP markers, model-based analysis of population structure was performed, the results of which were consistent with those of SSR markers. In addition, 122 accessions were assigned to 14 newly formed true-type morphogenetic groups derived from three different domestication events: (1) Mesoamerican (H1A) (“Biser”, “Kukuruzar”, “Tetovac”, “Trešnjevac”), (2) Andean—indeterminate type (H2B1) (“Dan noć”, “Sivi”, “Puter”, ”Sivi prošarani”, “Trešnjevac”) and (3) Andean—determinate type (H3B2) (“Bijeli”, “Dan noć”, “Puter”, “Trešnjevac”, “Zelenčec”). The rest of the accessions could represent putative hybrids between morphogenetic groups. The differences between the true-type groups of accessions were further analysed based on nine quantitative traits, and the subsets of traits that best distinguish among centres of origin (A: Mesoamerican, B: Andean) and genetic groups (H1A, H2B1, H3B2) were proposed.
Chemical Profiles, Anticancer, and Anti-Aging Activities of Essential Oils of Pluchea dioscoridis (L.) DC. and Erigeron bonariensis L.
Authors: Elgamal Abdelbaset M. , Ahmed Rania F. , Abd-ElGawad Ahmed M. , El Gendy Abd El-Nasser G. , Elshamy Abdelsamed I. , Nassar Mahmoud I.
Published: March 2021

Plants belonging to the Asteraceae family are widely used as traditional medicinal herbs around the world for the treatment of numerous diseases. In this work, the chemical profiles of essential oils (EOs) of the above-ground parts of Pluchea dioscoridis (L.) DC. and Erigeron bonariensis (L.) were studied in addition to their cytotoxic and anti-aging activities. The extracted EOs from the two plants via hydrodistillation were analyzed by gas chromatography-mass spectroscopy (GC-MS). GC-MS of EO of P. dioscoridis revealed the identification of 29 compounds representing 96.91% of the total oil. While 35 compounds were characterized from EO of E. bonariensis representing 98.21%. The terpenoids were found the main constituents of both plants with a relative concentration of 93.59% and 97.66%, respectively, including mainly sesquiterpenes (93.40% and 81.06%). α-Maaliene (18.84%), berkheyaradulen (13.99%), dehydro-cyclolongifolene oxide (10.35%), aromadendrene oxide-2 (8.81%), β-muurolene (8.09%), and α-eudesmol (6.79%), represented the preponderance compounds of EO of P. dioscoridis. While, trans-α-farnesene (25.03%), O-ocimene (12.58%), isolongifolene-5-ol (5.53%), α-maaliene (6.64%), berkheyaradulen (4.82%), and α-muurolene (3.99%), represented the major compounds EO of E. bonariensis. A comparative study of our results with the previously described data was constructed based upon principal component analysis (PCA) and agglomerative hierarchical clustering (AHC), where the results revealed a substantial variation of the present studied species than other reported ecospecies. EO of P. dioscoridis exhibited significant cytotoxicity against the two cancer cells, MCF-7 and A-549 with IC50 of 37.3 and 22.3 μM, respectively. While the EO of the E. bonariensis showed strong cytotoxicity against HepG2 with IC50 of 25.6 μM. The EOs of P. dioscoridis, E. bonariensis, and their mixture (1:1) exhibited significant inhibitory activity of the collagenase, elastase, hyaluronidase, and tyrosinase comparing with epigallocatechin gallate (EGCG) as a reference. The results of anti-aging showed that the activity of mixture (1:1) > P. dioscoridis > E. bonariensis against the four enzymes.
Morphological Characterization, Variability and Diversity among Vegetable Soybean (Glycine max L.) Genotypes
Authors: Shilpashree Nagaraju , Devi Sarojinikunjamma Nirmala , Manjunathagowda Dalasanuru Chandregowda , Muddappa Anjanappa , Abdelmohsen Shaimaa A. M. , Tamam Nissren , Elansary Hosam O. , El-Abedin Tarek K. Zin , Abdelbacki Ashraf M. M. , Janhavi Veerabhadregowda
Published: March 2021

Vegetable soybean production is dependent on the development of vegetable type varieties that would be achieved by the use of germplasm to evolve new agronomically superior yielding vegetable type with beneficial biochemical traits. This can be accomplished by a better understanding of genetics, which is why the research was conducted to reveal the quantitative genetics of vegetable soybean genotypes. Genetic variability of main morphological traits in vegetable soybean genotypes and their divergence was estimated, as a result of the magnitude of genotypic variation (GV), and phenotypic variation (PV) of traits varied among the genotypes. All traits showed high heritability (h2) associated with high genetic advance percentage mean (GAM). Therefore, these variable traits are potential for genetic improvement of vegetable type soybean. Genetic diversity is the prime need for breeding, and the magnitude of genetic diversity values were maximized among specific genotypes. Eight clusters were found for all genotypes; cluster VIII and cluster I were considered to have the most diversity. Cluster VIII consisted of two genotypes (GM-6 and GM-27), based on the mean outcomes of the high yield attributing traits. Hence, these two (GM-6, GM-27) genotypes can be advanced for commercial cultivation; furthermore, other genotypes can be used as source of breeding lines for genetic improvement of vegetable soybean.
Disentangling Species Delineation and Guiding Conservation of Endangered Magnolias in Veracruz, Mexico
Authors: Aldaba Núñez Fabián Augusto , Veltjen Emily , Martínez Salas Esteban Manuel , Samain Marie-Stéphanie
Published: March 2021

The Mexican state of Veracruz has suffered very high deforestation rates in the last few decades, and despite the establishment of protected areas and conservation projects, primary forest is now mainly persisting in mostly small, scattered, fragmented remnants. New species of Magnolia section Talauma in this state have been described with little to no reference to the already existing ones, potentially resulting in over-splitting, obscuring their taxonomic delineation and conservation status, and consequently conservation programs. To study the conservation units and their genetic diversity, we here employ 15 microsatellite markers on a highly representative sampling of 254 individuals of what are presumed to be five Magnolia species. The results support at least three species and maximum five main conservation units. We propose downgrading the latter to four, given morphological, ecological, demographical, and geographical considerations. Two out of the three sympatrically occurring species in the rainforest in the Los Tuxtlas volcanic area have weak genetic evidence to be considered separate species. Similarly, the individuals in the Sierra de Zongolica in central Veracruz, who bear a very high morphological and genetic similarity to Magnolia mexicana, have weak genetic evidence to be recognised as a separate species. Nonetheless, the individuals could be identified as Magnolia decastroi based on morphology, and further research including the full range of this species is recommended.
New Vegetable Oils with Different Fatty Acids on Natural Rubber Composite Properties
Authors: Boonrasri Siwarote , Sae-Oui Pongdhorn , Reungsang Alissara , Rachtanapun Pornchai
Published: March 2021

Owing to the toxicity of polycyclic aromatic (PCA) oils, much attention has been paid to the replacement of PCA oils by other nontoxic oils. This paper reports comparative study of the effects of new vegetable oils, i.e., Moringa oil (MO) and Niger oil (NO), on rheological, physical and dynamic properties of silica–filled natural rubber composite (NRC), in comparison with petroleum–based naphthenic oil (NTO). The results reveal that MO and NO exhibit higher thermal stability and better processability than NTO. Cure characteristics of the rubber compounds are not significantly affected by the oil type. It is also found that the NRCs containing MO or NO have better tensile strength and lower dynamic energy loss than the NRCs containing NTO. This may be because both MO and NO improve filler dispersion to a greater extent than NTO as supported by storage modulus and scanning electron microscopy results. Consequently, the present study suggests that MO and NO could be used as the alternative non–toxic oils for NRC without any loss of the properties evaluated.
Effects of Water Jet Height and End Dipping on the Cooling Rate and Hardenability in the Jominy End Quench Test
Authors: Hwang Joong-Ki
Published: March 2021

The effects of water jet height and end dipping on cooling rate and hardenability in the Jominy end quench test were investigated to understand the Jominy test in more detail. Experimental tests were conducted under end dipping cooling condition as well as for specific water jet heights of 35, 65, and 100 mm. The thermal behavior and mechanical properties of the Jominy specimen with region were evaluated using thermocouples and hardness measurements, respectively. The effect of the water jet height on the thermal and hardness behaviors was not large; especially, the influence of water jet height was negligible when the water jet height was over 50 mm. These observations indicate that the uncertainty of the water jet height is not important during the standard Jominy end quench test. Meanwhile, during the standard Jominy test, we cannot neglect the heat flow along the radial direction of the specimen because the temperature difference between the center and surface area was not small; the maximum temperature difference was approximately 50 °C. Based on the comparative study between the standard Jominy cooling and the end dipping cooling processes, the thermal gradient along the radial direction of the specimen can be reduced with the more stable cooling condition on the Jominy end. However, the effect of temperature deviation along the radial direction of the Jominy specimen on the hardness distribution along the longitudinal direction was not large, which shows the high reliability of the Jominy end quench test.
Insight into the Liquid–Liquid Extraction System AuCl4−/HCl/A327H+Cl− Ionic Liquid/Toluene
Authors: Alguacil Francisco J. , Lopez Félix A.
Published: March 2021

The ionic liquid A327H+Cl− is generated by reaction of the tertiary amine A327 (industrial mixture of tri-octyl and tri-decyl amines) and hydrochloric acid solutions. In this study, the extraction of Au(III) by A327H+Cl− ionic liquid under various variables, including metal and ionic liquid concentrations, was investigated. Results indicate that A327H+AuCl4− is formed by an exothermic (ΔH° = −3 kJ/mol) reaction in the organic solution. Aqueous ionic strength influences the formation constant values, and the specific interaction theory (SIT) was used to estimate the interaction coefficient between AuCl4− and H+. Gold (III) was stripped using thiocyanate media, and from the strip solutions, gold was precipitated as gold nanoparticles.
Application of Alum Sludge in Wastewater Treatment Processes: “Science” of Reuse and Reclamation Pathways
Authors: Zhao Wei , Xie Huina , Li Jie , Zhang Lihong , Zhao Yaqian
Published: March 2021

Alum sludge (AlS) refers to the inevitable by-product generated during the drinking water purification process, where Al-salt is used as a coagulant in the water industry. It has long been treated as “waste”, while landfill is its major final disposal destination. In fact, AlS is an underutilized material with huge potential for beneficial reuse as a raw material in various wastewater treatment processes. In the last two decades, intensive studies have been conducted worldwide to explore the “science” and practical application of AlS. This paper focuses on the recent developments in the use of AlS that show its strong potential for reuse in wastewater treatment processes. In particular, the review covers the key “science” of the nature and mechanisms of AlS, revealing why AlS has the potential to be a value-added material. In addition, the future focus of research towards the widespread application of AlS as a raw material/product in commercial markets is suggested, which expands the scope for AlS research and development.
Open Research Data and Open Peer Review: Perceptions of a Medical and Health Sciences Community in Greece
Authors: Delikoura Eirini , Kouis Dimitrios
Published: March 2021

Recently significant initiatives have been launched for the dissemination of Open Access as part of the Open Science movement. Nevertheless, two other major pillars of Open Science such as Open Research Data (ORD) and Open Peer Review (OPR) are still in an early stage of development among the communities of researchers and stakeholders. The present study sought to unveil the perceptions of a medical and health sciences community about these issues. Through the investigation of researchers‘ attitudes, valuable conclusions can be drawn, especially in the field of medicine and health sciences, where an explosive growth of scientific publishing exists. A quantitative survey was conducted based on a structured questionnaire, with 179 valid responses. The participants in the survey agreed with the Open Peer Review principles. However, they ignored basic terms like FAIR (Findable, Accessible, Interoperable, and Reusable) and appeared incentivized to permit the exploitation of their data. Regarding Open Peer Review (OPR), participants expressed their agreement, implying their support for a trustworthy evaluation system. Conclusively, researchers need to receive proper training for both Open Research Data principles and Open Peer Review processes which combined with a reformed evaluation system will enable them to take full advantage of the opportunities that arise from the new scholarly publishing and communication landscape.
The Filipino Business Leader in the Time of the (COVID-19) Pandemic within the Lens of the Catholic Social Teachings
Authors: Pabalan Joanne Marie Grace P. , Macaraan Willard Enrique R.
Published: March 2021

The COVID-19 pandemic is not only a global health problem—its ramifications are complex and extensive. From social routines to religious gatherings, as well as economic conditions, have all been significantly affected. The global economy has entered into a recession and local establishments, especially small and medium enterprises, have not been spared. Most of these businesses have laid-off workers and closed shops and stores. Within this chaos of business restructuring and systemic changes are complications and implications to the meaning of ethical business leadership and the value of work. This paper looks at these shifts and turns taking place in enterprises and workplaces in light of Catholic Social Thought (CST) and explores how these data and narratives from the ground could have contributed to a renewed or reshaped ethical identity of a Filipino business leader in the time of the (COVID-19) pandemic.
Household’s Overindebtedness during the COVID-19 Crisis: The Role of Debt and Financial Literacy
Authors: Kurowski Łukasz
Published: March 2021

The COVID-19 pandemic has shown how important it is to prepare one’s own financial budget for the unexpected loss of income. In this dimension, the financial education of the society plays an invaluable role. It allows us to account for events that may adversely affect personal finances in our budget management decisions. Therefore, the aim of the article is to check whether households with a higher level of financial and debt literacy have better management skills from the perspective of a household’s budget, which in the face of a crisis reduces the risk of individuals not paying their liabilities. Thus, at the turn of June and July 2020, we conducted surveys among 1300 Polish citizens. Using the multinomial logistic regression, we show that people with a higher financial and debt literacy are less affected by overindebtedness. During the crisis, people who have a higher debt literacy are better prepared to manage credit liabilities; in this situation, financial literacy is less important. In addition, the type of credit experience turned out to be significant. Respondents who have experience with consumer loans (potentially high-margin products) are more likely to have debt repayment problems than those with mortgage loans experiences.
Robust Maritime Target Detector in Short Dwell Time
Authors: Lee Myung-Jun , Kim Ji-Eun , Ryu Bo-Hyun , Kim Kyung-Tae
Published: March 2021

Detection of small-sized maritime targets is an important task for a marine surveillance radar. Recently, with the emergence of a marine surveillance radar system that has a narrow azimuth beamwidth and rapidly rotating antennas, the available dwell time for detecting a maritime target is usually very short. This short dwell time considerably degrades the performance of conventional detectors, especially those focusing on small-sized targets. In this paper, we propose an efficient detector for small-sized maritime targets to provide a reliable detection performance, even in short dwell times. The proposed scheme is based on a new joint metric, which results from the product of the magnitude and difference features in the Doppler spectra. We discriminate the target bins from sea clutter bins using a statistical discriminator based on the joint metric, whose probability density function follows the product distribution of standard gamma distributions. Compared to conventional detectors, the proposed scheme can provide a robust performance in terms of the average signal-to-clutter ratio as well as the detection rate, especially in shorter dwell times.
Secure LoRa Firmware Update with Adaptive Data Rate Techniques
Authors: Heeger Derek , Garigan Maeve , Eleni Tsiropoulou Eirini , Plusquellic Jim
Published: March 2021

Internet of Things (IoT) devices rely upon remote firmware updates to fix bugs, update embedded algorithms, and make security enhancements. Remote firmware updates are a significant burden to wireless IoT devices that operate using low-power wide-area network (LPWAN) technologies due to slow data rates. One LPWAN technology, Long Range (LoRa), has the ability to increase the data rate at the expense of range and noise immunity. The optimization of communications for maximum speed is known as adaptive data rate (ADR) techniques, which can be applied to accelerate the firmware update process for any LoRa-enabled IoT device. In this paper, we investigate ADR techniques in an application that provides remote monitoring of cattle using small, battery-powered devices that transmit data on cattle location and health using LoRa. In addition to issues related to firmware update speed, there are significant concerns regarding reliability and security when updating firmware on mobile, energy-constrained devices. A malicious actor could attempt to steal the firmware to gain access to embedded algorithms or enable faulty behavior by injecting their own code into the device. A firmware update could be subverted due to cattle moving out of the LPWAN range or the device battery not being sufficiently charged to complete the update process. To address these concerns, we propose a secure and reliable firmware update process using ADR techniques that is applicable to any mobile or energy-constrained LoRa device. The proposed system is simulated and then implemented to evaluate its performance and security properties.
Fringe Projection Profilometry in Production Metrology: A Multi-Scale Comparison in Sheet-Bulk Metal Forming
Authors: Hinz Lennart , Metzner Sebastian , Müller Philipp , Schulte Robert , Besserer Hans-Bernward , Wackenrohr Steffen , Sauer Christopher , Kästner Markus , Hausotte Tino , Hübner Sven , Nürnberger Florian , Schleich Benjamin , Behrens Bernd-Arno , Wartzack Sandro , Merklein Marion , Reithmeier Eduard
Published: March 2021

Fringe projection profilometry in combination with other optical measuring technologies has established itself over the last decades as an essential complement to conventional, tactile measuring devices. The non-contact, holistic reconstruction of complex geometries within fractions of a second in conjunction with the lightweight and transportable sensor design open up many fields of application in production metrology. Furthermore, triangulation-based measuring principles feature good scalability, which has led to 3D scanners for various scale ranges. Innovative and modern production processes, such as sheet-bulk metal forming, thus, utilize fringe projection profilometry in many respects to monitor the process, quantify possible wear and improve production technology. Therefore, it is essential to identify the appropriate 3D scanner for each application and to properly evaluate the acquired data. Through precise knowledge of the measurement volume and the relative uncertainty with respect to the specimen and scanner position, adapted measurement strategies and integrated production concepts can be realized. Although there are extensive industrial standards and guidelines for the quantification of sensor performance, evaluation and tolerancing is mainly global and can, therefore, neither provide assistance in the correct, application-specific positioning and alignment of the sensor nor reflect the local characteristics within the measuring volume. Therefore, this article compares fringe projection systems across various scale ranges by positioning and scanning a calibrated sphere in a high resolution grid.
Ground Moving Target Imaging via SDAP-ISAR Processing: Review and New Trends
Authors: Martorella Marco , Gelli Samuele , Bacci Alessio
Published: March 2021

Ground moving target imaging finds its main applications in both military and homeland security applications, with examples in operations of intelligence, surveillance and reconnaissance (ISR) as well as border surveillance. When such an operation is performed from the air looking down towards the ground, the clutter return may be comparable or even stronger than the target’s, making the latter hard to be detected and imaged. In order to solve this problem, multichannel radar systems are used that are able to remove the ground clutter and effectively detect and image moving targets. In this feature paper, the latest findings in the area of Ground Moving Target Imaging are revisited that see the joint application of Space-Time Adaptive Processing and Inverse Synthetic Aperture Radar Imaging. The theoretical aspects analysed in this paper are supported by practical evidence and followed by application-oriented discussions.
Analysis of Cooperative Perception in Ant Traffic and Its Effects on Transportation System by Using a Congestion-Free Ant-Trail Model
Authors: Kasture Prafull , Nishimura Hidekazu
Published: March 2021

We investigated agent-based model simulations that mimic an ant transportation system to analyze the cooperative perception and communication in the system. On a trail, ants use cooperative perception through chemotaxis to maintain a constant average velocity irrespective of their density, thereby avoiding traffic jams. Using model simulations and approximate mathematical representations, we analyzed various aspects of the communication system and their effects on cooperative perception in ant traffic. Based on the analysis, insights about the cooperative perception of ants which facilitate decentralized self-organization is presented. We also present values of communication-parameters in ant traffic, where the system conveys traffic conditions to individual ants, which ants use to self-organize and avoid traffic-jams. The mathematical analysis also verifies our findings and provides a better understanding of various model parameters leading to model improvements.
Generating Artificial Sensor Data for the Comparison of Unsupervised Machine Learning Methods
Authors: Zimmering Bernd , Niggemann Oliver , Hasterok Constanze , Pfannstiel Erik , Ramming Dario , Pfrommer Julius
Published: March 2021

In the field of Cyber-Physical Systems (CPS), there is a large number of machine learning methods, and their intrinsic hyper-parameters are hugely varied. Since no agreed-on datasets for CPS exist, developers of new algorithms are forced to define their own benchmarks. This leads to a large number of algorithms each claiming benefits over other approaches but lacking a fair comparison. To tackle this problem, this paper defines a novel model for a generation process of data, similar to that found in CPS. The model is based on well-understood system theory and allows many datasets with different characteristics in terms of complexity to be generated. The data will pave the way for a comparison of selected machine learning methods in the exemplary field of unsupervised learning. Based on the synthetic CPS data, the data generation process is evaluated by analyzing the performance of the methods of the Self-Organizing Map, One-Class Support Vector Machine and Long Short-Term Memory Neural Net in anomaly detection.
Phacoemulsification and IOL-Implantation without Using Viscoelastics: Combined Modeling of Thermo Fluid Dynamics, Clinical Outcomes, and Endothelial Cell Density
Authors: Goles Nikola , Nerancic Marko , Konjik Sanja , Pajic-Eggspuehler Brigitte , Pajic Bojan , Cvejic Zeljka
Published: March 2021

Phacoemulsification is a widely used surgical method in cataract surgery with a high energy ultrasound source. The viscoelastic is considered to be tissue protective. The aim of this study is to investigate during surgery the impact of using viscoelastic versus no viscoelastic on clinical outcomes, potential complications and effect on endothelial cell density. The study group included 64 patients, who were subjected to phacoemulsification using balanced salt solution (BSS). Control group consisted of 62 patients, who underwent phacoemulsification using Hyaloronic acid 1% Healon 1%. Student’s t-test was applied for statistical analysis. The simulations of temperature changes during phacoemulsification were performed by COMSOL Multiphysics software. In the BSS group, a mean endothelial cell loss (ECL) of 4.5% was measured one month postoperatively, while in the Healon group ECL was 5.3%. Data analysis showed no significant difference in ECL between the groups (Student’s t-test, p = 0.8). No significant difference was observed in endothelial cell morphology and IOP between the two groups pre- and postoperatively (all p > 0.05). The modeling of thermo fluid dynamics showed that the heating of the cornea is slightly less when Healon was used as irrigation fluid. The phacoemulsification technique can be performed by an experienced surgeon with viscoelastics or continuous anterior chamber (AC) irrigation on the same level of safety regarding endothelial cell damage, providing equally satisfying clinical outcomes.
Monitoring of Torque Induced Strain in Composite Shafts with Embedded and Surface-Mounted Optical Fiber Bragg Gratings
Authors: Konstantaki Maria , Violakis Georgios , Pappas Georgios A. , Geernaert Thomas , Korakas Nikos , Tiriakidis Nikos , Tiriakidi Thomai , Tiriakidis Kosmas , Thienpont Hugo , Berghmans Francis , Botsis John , Pissadakis Stavros
Published: March 2021

In this study, silica glass, optical fiber Bragg gratings (FBGs) are used for torque-induced strain monitoring in carbon fiber reinforced polymer (CFRP) hollow shafts toward the development of a methodology for structural load monitoring. Optical fibers with gratings are embedded during shaft manufacturing, by an industrial filament winding process, along different orientations with respect to its central axis and surface mounted after production. Experimental results are supported by numerical modeling of the shaft with appropriate boundary conditions and homogenized material properties. For an applied torque up to 800 Nm, the strain sensitivity of an embedded grating positioned along the reinforcing fibers’ direction winded under 55° is in the order of 3.6 pm/Nm, while this value is more than 4× times higher than the other examined orientations. The study also shows that surface-mounted optical fiber Bragg gratings along the reinforcing carbon fibers’ direction perform equally well in monitoring strains in composite shafts under torque.
Identification and Analysis of Weather-Sensitive Roads Based on Smartphone Sensor Data: A Case Study in Jakarta
Authors: Yang Chao-Lung , Sutrisno Hendri , Chan Arnold Samuel , Tampubolon Hendrik , Wibowo Budhi Sholeh
Published: March 2021

Weather change such as raining is a crucial factor to cause traffic congestion, especially in metropolises with the limited sewer system infrastructures. Identifying the roads which are sensitive to weather changes, defined as weather-sensitive roads (WSR), can facilitate the infrastructure development. In the literature, little research focused on studying weather factors of developing countries that might have deficient infrastructures. In this research, to fill the gap, the real-world data associating with Jakarta, Indonesia, was studied to identify WSR based on smartphone sensor data, real-time weather information, and road characteristics datasets. A spatial-temporal congestion speed matrix (STC) was proposed to illustrate traffic speed changes over time. Under the proposed STC, a sequential clustering and classification framework was applied to identify the WSR in terms of traffic speed. In this work, the causes of WSR were evaluated based on the variables’ importance of the classification method. The experimental results show that the proposed method can cluster the roads according to the pattern changes in the traffic speed caused by weather change. Based on the results, we found that the distances to shopping malls, mosques, schools, and the roads’ altitude, length, width, and the number of lanes are highly correlated to WSR in Jakarta.
Spectrum Sensing for Cognitive Radio: Recent Advances and Future Challenge
Authors: Nasser Abbass , Al Haj Hassan Hussein , Abou Chaaya Jad , Mansour Ali , Yao Koffi-Clément
Published: March 2021

Spectrum Sensing (SS) plays an essential role in Cognitive Radio (CR) networks to diagnose the availability of frequency resources. In this paper, we aim to provide an in-depth survey on the most recent advances in SS for CR. We start by explaining the Half-Duplex and Full-Duplex paradigms, while focusing on the operating modes in the Full-Duplex. A thorough discussion of Full-Duplex operation modes from collision and throughput points of view is presented. Then, we discuss the use of learning techniques in enhancing the SS performance considering both local and cooperative sensing scenarios. In addition, recent SS applications for CR-based Internet of Things and Wireless Sensors Networks are presented. Furthermore, we survey the latest achievements in Spectrum Sensing as a Service, where the Internet of Things or the Wireless Sensor Networks may play an essential role in providing the CR network with the SS data. We also discuss the utilisation of CR for the 5th Generation and Beyond and its possible role in frequency allocation. With the advancement of telecommunication technologies, additional features should be ensured by SS such as the ability to explore different available channels and free space for transmission. As such, we highlight important future research axes and challenging points in SS for CR based on the current and emerging techniques in wireless communications.
Self-Detecting Traffic Interference Control for Multi-Zone Services under 5G-Based Cellular Networks
Authors: Lee Chongdeuk
Published: March 2021

In this paper, we propose a multi-zone service control scheme to maximize the performance of each service zone when a large number of cellular service zones and Device-to-Device (D2D) service zones are composed into the 5G cellular network. This paper also improves performance of service zone by dividing traffic into real-time traffic and non-real-time traffic in order to minimize traffic interference. Real-time traffic and non-real-time traffic have a significant impact on communication performance. We propose a new self-detection traffic interference control technique to improve the Quality of Service (QoS) and throughput of D2D and Cellular-to-Device (C2D) communication in a cellular network, Self-detecting Traffic Interference Control Scheme (STICS). The proposed STICS mechanism distinguishes between short-term traffic congestion process and long-term traffic congestion process according to traffic characteristics to detect and control traffic. When the proposed scheme is applied to the 5G-based cellular network environment, it is expected that the traffic type will be efficiently classified by self-detecting the traffic according to the flow. Such classified traffic is less sensitive to communication between the D2D and C2D links, thereby reducing traffic overload. We evaluate the performance of the proposed scheme through simulation and show that the proposed scheme is more efficient than other comparison schemes.
Intelligent Fault Diagnosis of Rotary Machinery by Convolutional Neural Network with Automatic Hyper-Parameters Tuning Using Bayesian Optimization
Authors: Kolar Davor , Lisjak Dragutin , Pająk Michał , Gudlin Mihael
Published: March 2021

Intelligent fault diagnosis can be related to applications of machine learning theories to machine fault diagnosis. Although there is a large number of successful examples, there is a gap in the optimization of the hyper-parameters of the machine learning model, which ultimately has a major impact on the performance of the model. Machine learning experts are required to configure a set of hyper-parameter values manually. This work presents a convolutional neural network based data-driven intelligent fault diagnosis technique for rotary machinery which uses model with optimized hyper-parameters and network structure. The proposed technique input raw three axes accelerometer signal as high definition 1-D data into deep learning layers with optimized hyper-parameters. Input is consisted of wide 12,800 × 1 × 3 vibration signal matrix. Model learning phase includes Bayesian optimization that optimizes hyper-parameters of the convolutional neural network. Finally, by using a Convolutional Neural Network (CNN) model with optimized hyper-parameters, classification in one of the 8 different machine states and 2 rotational speeds can be performed. This study accomplished the effective classification of different rotary machinery states in different rotational speeds using optimized convolutional artificial neural network for classification of raw three axis accelerometer signal input. Overall classification accuracy of 99.94% on evaluation set is obtained with the CNN model based on 19 layers. Additionally, more data are collected on the same machine with altered bearings to test the model for overfitting. Result of classification accuracy of 100% on second evaluation set has been achieved, proving the potential of using the proposed technique.
Language as a Trigger for Racism: Language Barriers at Healthcare Institutions in Slovenia
Authors: Lipovec Čebron Uršula
Published: March 2021

The article analyzes the impact of language barriers on the medical treatment of foreign-speaking patients and illustrates that the absence of systemic, institutional responses to language barriers in healthcare facilities exacerbates racist attitudes toward migrants and ethnic groups. The article is based on 201 interviews with healthcare workers, employees of public or non-governmental institutions as well as users of healthcare services that were conducted between 2018 and 2019 in twelve local communities in Slovenia. Following the methodological and conceptual framework, the first part of the article highlights the various negative consequences of language barriers experienced by healthcare workers and foreign-speaking patients. The second part shows that in the absence of an accessible network of professional intercultural mediators or interpreters, healthcare workers are left to their own devices with respect to overcoming language barriers. Finally, the last part of the article shows that many interlocutors are increasingly searching for the culprit for this situation. Some healthcare workers attribute the responsibility to the abstract concept of the “system”, while others attribute the responsibility exclusively to migrants, thus perpetuating key elements of the culture of racism present in Slovenia. In this culture of racism, knowledge of Slovene language becomes one of the most important criteria that distinguishes deserving from undeserving migrants. The latter are a privileged object of racist responses at the level of cultural, institutional and personal racism, which is proving to be mutually toxic.
Exercise-Induced Changes in Tumor Growth via Tumor Immunity
Authors: Spiliopoulou Polyxeni , Gavriatopoulou Maria , Kastritis Efstathios , Dimopoulos Meletios , Terzis Gerasimos
Published: March 2021

Immunity in the tumor microenvironment plays a central role in tumor development. Cytotoxic immune cells act against tumors, while tumors manage to trigger immunosuppressive mechanisms for defense. One bout of physical exercise acutely regulates the immune system inducing short-term redistribution of immune cells among body organs. Repeated acute immune cell mobilization with continuing exercise training results in long-term adaptations. These long-term exercise-induced changes in the immune system arise both in healthy and in diseased populations, including cancer patients. Recent preclinical studies indicate that physical exercise may have a positive impact on intra-tumoral immune cell processes, resulting in tumor suppression. This short narrative review describes the effect of physical exercise on tumor growth as detected via changes in tumor immunity. Research evidence shows that exercise may improve tumor-suppressive functions and may reduce tumor-progressive responses and mechanisms of immune cells, controlling tumor development. Specifically, it seems that exercise in rodents triggers shifts in tumor infiltration of macrophages, neutrophils, natural killer cells, cytotoxic and regulatory T lymphocytes, resulting in tumor suppression. These recent promising data suggest that physical exercise could be combined with anticancer immunotherapies, although exercise parameters like intensity, duration, and frequency need to be evaluated in more detail. More research is needed to investigate the effect of exercise in other immune cell subtypes and their possible connection with tumor growth, whilst information from human tumors is also required.