bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaporative and Wicking Functionalities at Hot Airflows of Laser Nano-/Microstructured Ti-6Al-4V Material
Authors: Fang Ranran , Pan Zhonglin , Zheng Jiangen , Wang Xiaofa , Li Rui , Yang Chen , Deng Lianrui , Vorobyev Anatoliy Y.
Published: January 2023

A novel multifunctional material with efficient wicking and evaporative functionalities was fabricated using hierarchical surface nano-/microstructuring by femtosecond laser micromachining. The created material exhibits excellent multifunctional performance. Our experiments in a wind tunnel demonstrate its good wicking and evaporative functionalities under the conditions of high-temperature airflows. An important finding of this work is the significantly enhanced evaporation rate of the created material compared with the free water surface. The obtained results provide a platform for the practical implementation of Maisotsenko-cycle cooling technologies for substantially increasing efficiency in power generation, thermal management, and other evaporation-based technologies. The developed multifunctional material demonstrates long-lasting wicking and evaporative functionalities that are resistant to degradation under high-temperature airflows, indicating its suitability for practical applications.
Multi-Mode Lanthanide-Doped Ratiometric Luminescent Nanothermometer for Near-Infrared Imaging within Biological Windows
Authors: Li Hao , Heydari Esmaeil , Li Yinyan , Xu Hui , Xu Shiqing , Chen Liang , Bai Gongxun
Published: January 2023

Owing to its high reliability and accuracy, the ratiometric luminescent thermometer can provide non-contact and fast temperature measurements. In particular, the nanomaterials doped with lanthanide ions can achieve multi-mode luminescence and temperature measurement by modifying the type of doped ions and excitation light source. The better penetration of the near-infrared (NIR) photons can assist bio-imaging and replace thermal vision cameras for photothermal imaging. In this work, we prepared core–shell cubic phase nanomaterials doped with lanthanide ions, with Ba2LuF7 doped with Er3+/Yb3+/Nd3+ as the core and Ba2LaF7 as the coating shell. The nanoparticles were designed according to the passivation layer to reduce the surface energy loss and enhance the emission intensity. Green upconversion luminescence can be observed under both 980 nm and 808 nm excitation. A single and strong emission band can be obtained under 980 nm excitation, while abundant and weak emission bands appear under 808 nm excitation. Meanwhile, multi-mode ratiometric optical thermometers were achieved by selecting different emission peaks in the NIR window under 808 nm excitation for non-contact temperature measurement at different tissue depths. The results suggest that our core–shell NIR nanoparticles can be used to assist bio-imaging and record temperature for biomedicine.
Design of LTE/Sub-6 GHz Dual-Band Transparent Antenna Using Frame-Structured Metal Mesh Conductive Film
Authors: Lin Yu-Ming , Wu Hung-Wei , Chang Shoou-Jinn
Published: January 2023

This paper proposes a dual-band transparent antenna using frame-structured metal mesh conductive film (MMCF). The frame-structured metal mesh conductive film is based on the conductive-coated thin film and forms a narrow strip surrounding the edge of the antenna. The frame-structured metal mesh conductive film can resist considerable current leakage on the edge of the conductive strip to improve the antenna’s efficiency by 51% at 2.1 GHz and 53% at 3.6 GHz. As a result, the transparent dual-band antenna has an operating bandwidth of 1.9–2.4 GHz and 3.2–4.1 GHz with a high transparency of 80%, which make it valuable to the applications of biomedical electronic components, wearable devices, and automobile vehicles.
Solvent Influence on the Magnetization and Phase of Fe-Ni Alloy Nanoparticles Generated by Laser Ablation in Liquids
Authors: Khairani Inna Y. , Lin Qiyuan , Landers Joachim , Salamon Soma , Doñate-Buendía Carlos , Karapetrova Evguenia , Wende Heiko , Zangari Giovanni , Gökce Bilal
Published: January 2023

The synthesis of bimetallic iron-nickel nanoparticles with control over the synthesized phases, particle size, surface chemistry, and oxidation level remains a challenge that limits the application of these nanoparticles. Pulsed laser ablation in liquid allows the properties tuning of the generated nanoparticles by changing the ablation solvent. Organic solvents such as acetone can minimize nanoparticle oxidation. Yet, economical laboratory and technical grade solvents that allow cost-effective production of FeNi nanoparticles contain water impurities, which are a potential source of oxidation. Here, we investigated the influence of water impurities in acetone on the properties of FeNi nanoparticles generated by pulsed laser ablation in liquids. To remove water impurities and produce “dried acetone”, cost-effective and reusable molecular sieves (3 Å) are employed. The results show that the Fe50Ni50 nanoparticles’ properties are influenced by the water content of the solvent. The metastable HCP FeNi phase is found in NPs prepared in acetone, while only the FCC phase is observed in NPs formed in water. Mössbauer spectroscopy revealed that the FeNi nanoparticles oxidation in dried acetone is reduced by 8% compared to acetone. The high-field magnetization of Fe50Ni50 nanoparticles in water is the highest, 68 Am2/kg, followed by the nanoparticles obtained after ablation in acetone without water impurities, 59 Am2/kg, and acetone, 52 Am2/kg. The core-shell structures formed in these three liquids are also distinctive, demonstrating that a core-shell structure with an outer oxide layer is formed in water, while carbon external layers are obtained in acetone without water impurity. The results confirm that the size, structure, phase, and oxidation of FeNi nanoparticles produced by pulsed laser ablation in liquids can be modified by changing the solvent or just reducing the water impurities in the organic solvent.
Metamaterial Based Ku-Band Antenna for Low Earth Orbit Nanosatellite Payload System
Authors: Alam Touhidul , Islam Mohammad Tariqul , Hakim Mohammad Lutful , Alharbi Khalid H. , Singh Mandeep Singh Jit , Sheikh Muntasir M. , Aldhaheri Rabah W. , Islam Md. Shabiul , Soliman Mohamed S.
Published: January 2023

The concept of nanosatellite technology becomes a viable platform for earth and space observation research to minimize cost and build time for the payload. The communication approach is the essential fundamental attribute of a satellite, of which the antenna is a crucial component for forming a communication link between the nanosatellite and the earth. The nanosatellite antenna must comply with some special requirements like compact size, lightweight, and high gain with a space-compatible structure. This paper proposes a compact metamaterial-based Ku-band antenna with circular polarization for the nanosatellite communication system. The designed antenna obtained an impedance bandwidth of 2.275 GHz with a realized gain of 6.74 dBi and 3 dB axial beamwidth of 165° at 12.10 GHz. The overall antenna size of the designed is 0.51λ × 0.51λ × 0.17λ, which is fabricated on Rogers 5880 substrate material. The antenna results performance has been examined with a 1 U nanosatellite structure and found suitable to integrate with metallic and nonmetallic surfaces of any miniature nanosatellite structure.
Oh So Sweet: A Comparative Investigation of Retail Market Composition of Sweetened and Flavoured Beverages in Singapore and Australia
Authors: Anastasiou Kim , Brooker Paige G. , Cleanthous Xenia , Tan Rebecca , Smith Benjamin P. C. , Riley Malcolm
Published: January 2023

The consumption of sugar and non-nutritive sweeteners has been associated with poor health outcomes. The aim of this paper was to provide a comparison of the range of sweetened or flavoured beverages between two high-income countries in the Asia-Pacific region: Australia and Singapore. Following the FoodTrackTM methodology, nutrition, labelling, and price data were collected from major Australian and Singaporean supermarket chains and convenience stores. The nutrient profiles of products were tested for differences using Kruskal–Wallis and Mann–Whitney U tests. The greatest number of products collected in Australia were from the ‘carbonated beverages’ category (n = 215, 40%), and in Singapore the greatest number of products were from the ‘tea and coffee ready-to-drink’ category (n = 182, 35%). There were more calorically sweetened beverages in Singapore compared with Australia (n = 462/517 vs. n = 374/531, p < 0.001). For calorically sweetened products, the median energy of Singaporean products was significantly higher than Australian products (134 kJ vs. 120 kJ per 100 mL, p = 0.009). In Australia, 52% of sweetened or flavoured beverages displayed a front-of-pack nutrient signposting logo, compared with 34% of sweetened or flavoured beverages in Singapore. These findings also indicate that the consumption of just one serving of calorically sweetened carbonated beverages or energy drinks would exceed the WHO maximum daily free sugar recommendations.
Effects of Initial Combinations of Gemigliptin Plus Metformin Compared with Glimepiride Plus Metformin on Gut Microbiota and Glucose Regulation in Obese Patients with Type 2 Diabetes: The INTESTINE Study
Authors: Lim Soo , Sohn Minji , Florez Jose C. , Nauck Michael A. , Ahn Jiyoung
Published: January 2023

The efficacy and safety of medications can be affected by alterations in gut microbiota in human beings. Among antidiabetic medications, incretin-based therapy such as dipeptidyl peptidase 4 inhibitors might affect gut microbiomes, which are related to glucose metabolism. This was a randomized, controlled, active-competitor study that aimed to compare the effects of combinations of gemigliptin–metformin vs. glimepiride–metformin as initial therapies on gut microbiota and glucose homeostasis in drug-naïve patients with type 2 diabetes. Seventy drug-naïve patients with type 2 diabetes (mean age, 52.2 years) with a glycated hemoglobin (HbA1c) level ≥7.5% were assigned to either gemigliptin–metformin or glimepiride–metformin combination therapies for 24 weeks. Changes in gut microbiota, biomarkers linked to glucose regulation, body composition, and amino acid blood levels were investigated. Although both treatments decreased the HbA1c levels significantly, the gemigliptin–metformin group achieved HbA1c ≤ 7.0% without hypoglycemia or weight gain more effectively than did the glimepiride–metformin group (59% vs. 24%; p < 0.05). At the phylum level, the Firmicutes/Bacteroidetes ratio tended to decrease after gemigliptin–metformin therapy (p = 0.065), with a notable depletion of taxa belonging to Firmicutes, including Lactobacillus, Ruminococcus torques, and Streptococcus (all p < 0.05). However, regardless of the treatment modality, a distinct difference in the overall gut microbiome composition was noted between patients who reached the HbA1c target goal and those who did not (p < 0.001). Treatment with gemigliptin–metformin resulted in a higher achievement of the glycemic target without hypoglycemia or weight gain, better than with glimepiride–metformin; these improvements might be related to beneficial changes in gut microbiota.
Adding Walnuts to the Usual Diet Can Improve Diet Quality in the United States: Diet Modeling Study Based on NHANES 2015–2018
Authors: Spence Lisa A , Henschel Beate , Li Rui , Tekwe Carmen D , Thiagarajah Krisha
Published: January 2023

Background: The under-consumption of calcium, potassium, fiber, and vitamin D is considered a U.S. public health concern. Shifts in eating patterns that increase the consumption of vegetables, fruits, whole grains, nuts/seeds, and dairy products can help achieve the recommended intakes of these nutrients, leading to healthier diets. Objective: We assessed the impact of adding 1 ounce (28.35 g) of walnuts to usual diets on diet quality and nutrients of concern, including magnesium, fiber, and potassium. Methods: We utilized 24 h dietary recalls obtained from the What We Eat in America, National Health and Nutrition Examination Survey (NHANES) and modeled the addition of 1 ounce (28.35 g) of walnuts to the usual diets of no-nut consumers. No-nut consumers aged ≥4 years (n = 7757) from the 2015–2018 NHANES study were included. Population percentages with intakes below the estimated average requirement (EAR) values for calcium, magnesium, folate, and vitamin E and above the adequate intake (AI) values for potassium and fiber were examined. Diet quality was assessed using the Healthy Eating Index-2015 (HEI-2015). The National Cancer Institute method was used to estimate the usual and modeled intakes. Significant differences between usual (current) and modeled intakes were determined using non-overlapping 95% confidence intervals. All analyses included sample weights to account for the NHANES survey design. Results: Adding 1 ounce (28.35 g) of walnuts to the usual diet resulted in significant reductions in the percentages of adults with intakes below the EAR for magnesium and folate (69.6% vs. 52.0%; 49.2% vs. 40.6%, respectively), and increased the percentage of adults above the AI for potassium (22.8% vs. 26.5%). A similar trend was observed among children (4–18 years). HEI scores improved significantly from 49.1 (95% CI: 48.0–50.4) to 58.5 (95% CI: 57.5–59.6) in children and from 52.4 (95% CI: 51.0–53.8) to 59.2 (95% CI: 58.0–60.5) in adults. Conclusions: Adding 1 ounce (28.35 g) of walnuts to the usual diet of no-nut consumers improved the diet quality and adequacy of some under-consumed nutrients.
Comparative Analysis of Tick-Borne Relapsing Fever Spirochaetes from Ethiopia and Nigeria
Authors: Bankole Adefolake A. , Kumsa Bersissa , Mamo Gezahegne , Ogo Ndudim I. , Elelu Nusirat , Morgan Winston , Cutler Sally J.
Published: January 2023

Despite increasing reports of tick-borne diseases in Africa, remarkably, reports of tick-borne relapsing fever (TBRF) in Nigeria are lacking. Ornithodoros savignyi from Nigeria have been reported with the relapsing fever Candidatus Borrelia kalaharica. Conversely, in Ethiopia, the agent of relapsing fever is the louse-borne relapsing fever (LBRF) spirochaete Borrelia recurrentis with no TBRF reported to occur. A total of 389 Ornithodoros ticks, Ethiopia (N = 312) and Nigeria (N = 77), were sampled, together with 350 cattle, and 200 goat sera were collected from Nigeria. Samples were screened for Borrelia spp. by RT-PCR. Reactive samples were confirmed, then sequenced using flagellin B, 16S rRNA, and 16S–23S intergenic spacer region. The prevalence of Borrelia spp. in livestock was 3.8% (21/550) and 14% (3/21) after final molecular confirmation. Of 312 ticks from Ethiopia, 3.5% (11/312) were positive for Borrelia, with 36% (4/11) by conventional PCR. Sequencing revealed that the borreliae in soft ticks was C. B. kalaharica, whilst that found in animals was Borrelia theileri. Soft ticks were confirmed by sequencing 7% (22/312) and 12% (9/77) of the Ethiopian and Nigerian ticks, respectively. Phylogenetic analysis revealed that these were Ornithodoros savignyi. This is the first evidence of C. B. kalaharica in Ethiopia and demonstrates the co-existence of TBRF in a country endemic to LBRF. Important, this might cause a diagnostic challenge given that LBRF is predominantly diagnosed by microscopy, which cannot differentiate these two spirochaetes. Furthermore, we report B. theileri in ruminants in Nigeria, which may also be of veterinary and economic importance.
Risk Factors for Exposure of Wild Birds to West Nile Virus in A Gradient of Wildlife-Livestock Interaction
Authors: Casades-Martí Laia , Holgado-Martín Rocío , Aguilera-Sepúlveda Pilar , Llorente Francisco , Pérez-Ramírez Elisa , Jiménez-Clavero Miguel Ángel , Ruiz-Fons Francisco
Published: January 2023

West Nile virus (WNV) transmission rate is shaped by the interaction between virus reservoirs and vectors, which may be maximized in farm environments. Based on this hypothesis, we screened for WNV in wild birds in three scenarios with decreasing gradient of interaction with horses: (i) the farm (A1); (ii) the neighborhood (A2); and (iii) a wild area (A3). We captured wild birds and analyzed their sera for WNV antibodies by blocking ELISA and micro-virus neutralization test. Flavivirus infections were tested with generic and specific PCR protocols. We parameterized linear mixed models with predictors (bird abundance and diversity, vector abundance, vector host abundance, and weather quantities) to identify Flavivirus spp. and WNV exposure risk factors. We detected a low rate of Flavivirus infections by PCR (0.8%) and 6.9% of the birds were seropositive by ELISA. Exposure to Flavivirus spp. was higher in A1 (9%) than in A2 and A3 (5.6% and 5.8%, respectively). Bird diversity was the most relevant predictor of exposure risk and passerines dominated the on-farm bird community. Our results suggest that measures deterring the use of the farm by passerines should be implemented because the environmental favorability of continental Mediterranean environments for WNV is increasing and more outbreaks are expected.
Fluorescence Quantum Yields and Lifetimes of Aqueous Natural Dye Extracted from Tradescantia pallida purpurea at Different Hydrogen Potentials
Authors: De Lima Sthanley R. , Lourenço Larissa R. , Thomaz Marina , Messias Djalmir N. , Andrade Acácio A. , Pilla Viviane
Published: January 2023

In this work, we monitored the fluorescence quantum efficiency (η) and the fluorescence lifetime (τ) of natural dye extracts from the leaves of Tradescantia pallida purpurea. The natural dye was extracted from leaves in aqueous solutions as a function of the potential of hydrogen (pH). The η was determined from conical diffraction (CD) pattern measurements due to thermally-driven self-phase modulation. The fluorescence spectra and time-resolved fluorescence measurements corroborate the CD results, and the average η ≈ 0.28 and τ ≈ 3.1 ns values were obtained in the pH range 3.96–8.02. In addition, the extracted natural dye was tested as a possible colorimetric and/or fluorometric pH indicator in milk.
Proteogenomic Approaches to Understand Gene Mutations and Protein Structural Alterations in Colon Cancer
Authors: Sarkar Soumyadev
Published: January 2023

With colon cancer being one of the deadliest and most common cancers, understanding the mechanisms behind colon cancer is crucial in improving therapies. One of the newest approaches in cancer research is the concept of proteogenomics. While genomic data is not sufficient to understand cancer, the integration of multi-omics data including proteomics in conjugation with protein modeling has a better potential to elucidate protein structural alterations and characterize tumors. This enables a more efficient diagnosis of cancer and improves remedial strategies. In this review, we aim to discuss the linkage between gene mutations and protein structural alterations that lead to colon cancer. Topics include alterations in the glycoproteome and structures of proteases that impact colon cancer development. Additionally, we highlight the importance of precision oncology with an emphasis on proteogenomic approaches, protein modeling, and the potential impact on colon cancer therapy.
Secondary Metabolites from Aspergillus sparsus NBERC_28952 and Their Herbicidal Activities
Authors: Wu Zhaoyuan , Liu Fang , Ke Shaoyong , Zhang Zhigang , Hu Hongtao , Fang Wei , Xiao Shaoyujia , Zhang Yani , Wang Yueying , Wang Kaimei
Published: January 2023

Fungi have been used in the production of a wide range of biologically active metabolites, including potent herbicides. In the search for pesticides of natural origin, Aspergillus sparsus NBERC_28952, a fungal strain with herbicidal activity, was obtained. Chemical study of secondary metabolites from NBERC_28952 resulted in the isolation of three new asperugin analogues, named Aspersparin A–C (2–4), and a new azaphilone derivative, named Aspersparin D (5), together with two known compounds, Asperugin B (1) and sydonic acid (6). The structures of these compounds were elucidated based on extensive spectroscopic data and single-crystal X-ray diffraction analysis. All of the isolated compounds were evaluated for their herbicidal activities on seedlings of Echinochloa crusgalli and Amaranthus retroflexus through Petri dish bioassays. Among them, compounds 5 and 6 exhibited moderate inhibitory activities against the growth of the roots and shoots of E. crusgalli seedlings in a dose-dependent manner, while 6 showed obvious inhibitory effect on seedlings of A. retroflexus, with an inhibitory rate of 78.34% at a concentration of 200 μg/mL. These herbicidal metabolites represent a new source of compounds to control weeds.
Direct Powder Forging—A New Approach for near Net Shape Processing of Titanium Powders
Authors: Germain Careau Sébastien , Ulate-Kolitsky Elena , Tougas Bernard
Published: January 2023

This study investigates direct powder forging (DPF) as a new approach for near-net-shape processing of titanium alloys using a coarse particle size distribution (PSD) between 90 and 250 μm. This route was utilised to takes advantage of DPF’s enclosed nature to make near-net-shape components with conventional forging equipment, making it attractive and viable even for reactive powder such as titanium. In this study, the uncompacted Ti-6Al-4V ELI powder was sealed under vacuum in a stainless-steel canister and hot forged in air to produce a fully dense titanium femoral stem. After the final forging stage, the excess material in the flash region was cut, which efficiently released the canister, revealing the forged part with minimal surface contamination. The as-forged microstructure comprises coarse β grains with a martensitic structure. The subsequent annealing was able to generate a fine and homogenous lamellar microstructure with mechanical properties that respects the surgical implant standard, showing that DPF offers significant potential for forged titanium parts. Therefore, the DPF process provides a suitable alternative to produce titanium components using basic equipment, making it more available to the industry.
Terpenoids as Natural Agents against Food-Borne Bacteria—Evaluation of Biofilm Biomass versus Viability Reduction
Authors: Fink Rok
Published: January 2023

This study aimed to analyse the antibacterial potential of limonene, terpineol, and eugenol for the biofilm reduction of food-borne E. coli, S. aureus and S. typhimurium. A microdilution test with resazurin application was used for the minimum inhibitory concentration and a colony plate count was used for the minimum bactericidal concentration. Biofilm biomass was quantified using the crystal violet assay, while biofilm viability was determined using the plate count method. The results show the highest antibacterial potential among terpenoids for eugenol, followed by terpineol and limonene. Both biomass reduction and viability are strongly dependent on the concentration of all terpenoids tested (p < 0.05). Moreover, eugenol reduced biofilm biomass most effectively (67% for E. coli), while viability was reduced most by terpineol (3.8 log CFU cm−2 for E. coli and S. aureus). The correlation coefficient for the reduction in biomass and viability was highest for eugenol (0.9) and chlorhexidine for all bacteria tested, while the lowest correlation was found for limonene (0.6). Results also demonstrate that tested terpenoids are effective as standard antimicrobial agent chlorhexidine. This suggests that eugenol has potential against food-borne biofilms as it simultaneously reduces both biomass and viability of biofilms.
Gross National Happiness in Bhutan: Is Buddhist Constitutionalism Legitimate in the Age of Secularism? A Post-Colonial View
Authors: van Norren Dorine Eva
Published: January 2023

Bhutan’s current constitution draws upon the historical dual system of religious-civil governance under the monarchy (previously Abbot-king) embodying the Mahayana Buddhist concept of Boddhisatva-leadership. Bhutan’s democracy includes an executive-military and pluralist religious custodian role for the King who can be abdicated by parliament. It includes Gross National Happiness as spiritual core, which is non-binding law, incorporating many human rights and human values like compassion. The ban on proselytization in the secular constitution should be viewed from a geopolitical post-colonial perspective of the Christian civilization mission and India/China annexation-politics, and Asian definitions of secularism (Royal patronage of religious pluralism). Christians do experience restrictions on congregation. Hindu Nepalese-origin migrants experience(d) citizenship issues due to geopolitical context but can express religion fully. GNH-policy also has certain implementation difficulties and the GNH index indicates declining community values and spirituality in the face of modernist development. Bhutan’s constitution does not fall within the definition of theocracy. The clergy is excluded from the electoral process. The King’s authority is mainly based on moral leadership, popular uncertainty about imported democracy, and is non-absolute but larger than conventional constitutional monarchies. The constitution is more secular than Buddhist in its binding provisions and offers space for non-GNH oriented governments, also in recent practice. Preserving identity and stability is Bhutan’s aim and secularism needs to look at a group approach, apart from individualist approaches. Human rights traditions could acknowledge the cultural-religious roots that inspired them and keep human dignity alive, instead of wanting to remove it from the state altogether and making human rights the new religion.
Evaluation of MODIS DT, DB, and MAIAC Aerosol Products over Different Land Cover Types in the Yangtze River Delta of China
Authors: Jiang Jie , Liu Jiaxin , Jiao Donglai , Zha Yong , Cao Shusheng
Published: January 2023

The Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) has been widely used in atmospheric environment and climate change research. Based on data of the Aerosol Robotic Network and Sun–Sky Radiometer Observation Network in the Yangtze River Delta, the retrieval accuracies of MODIS C6.1 Dark Target (DT), Deep Blue (DB), and C6.0 Multi-angle Implementation of Atmospheric Correction (MAIAC) products under different land cover types, aerosol types, and observation geometries were analyzed. About 65.64% of MAIAC AOD is within the expected error (Within EE), which is significantly higher than 41.43% for DT and 56.98% for DB. The DT product accuracy varies most obviously with the seasons, and the Within EE in winter is more than three times that in spring. The DB and MAIAC products have low accuracy in summer but high in other seasons. The accuracy of the DT product gradually decreases with the increase in urban and water land-cover proportion. After being corrected by bias and mean relative error, the DT accuracy is significantly improved, and the Within EE increases by 24.12% and 32.33%, respectively. The observation geometries and aerosol types were also examined to investigate their effects on AOD retrieval.
False Detections Revising Algorithm for Millimeter Wave Radar SLAM in Tunnel
Authors: Li Yang , Wei Yonghui , Wang Yanping , Lin Yun , Shen Wenjie , Jiang Wen
Published: January 2023

Millimeter wave (MMW) radar simultaneous localization and mapping (SLAM) technology is an emerging technology in a tunnel vehicle accident rescue scene. It is a powerful tool for statistic-trapped vehicle detection with limited vision caused by darkness, heat, and smoke. A variety of SLAM frameworks have been proven to be able to obtain 3-degree-of-freedom (3-dof) pose estimation results using 2-dimention (2D) MMW radar in open space. In the application of millimeter wave radar for pose estimation and mapping in a closed environment, closed space structures and artificial targets together constitute high-intensity multi-path scattering measurement data, leading to radar false detections. Radar false detections caused by multi-path scattering are generally considered to be detrimental to radar applications, such as multi-target tracking. However, few studies analyze the mechanism of multi-path effects on radar SLAM, especially in closed spaces. In order to address the problem, this paper first presents a radar multi-path scattering theory to study the generation mechanism difference of false and radar true detection and their influences on radar SLAM 2D pose estimation and mapping in tunnel. According to the scattering mechanism differences on SLAM, a radar azimuth scattering angle signature is proposed, which allows distinguishing radar false detections from real ones. This is useful in avoiding using unreliable radar false detections to solve a radar SLAM problem. In addition, two different radar false detection revising methods combined with the CSM (correlative scan matching) algorithm are proposed in this paper. The HTMR-CSM (hard-threshold-multi-path-revised correlative scan matching) algorithm only depends on a hard threshold of radar azimuth scattering angle signature to eliminate all radar false detections as much as possible before CSM. Another idea is the STMR-CSM (soft-threshold-multi-path-revised correlative scan matching) algorithm. All the radar false detections are classified according to the distribution model of radar azimuth accuracy, and part of more reliable radar false detections are retained to estimate a more accurate pose. All the ideas in this paper are validated by using an MMW 2D radar mounted on a rail-guided robot in a tunnel. Two cars on fire were set as the targets. The experimental results show that the STMR-CSM algorithm that keeps the reliable radar false detections improves the positioning accuracy by 20% compared with CSM.
High-Resolution Observation of Ionospheric E-Layer Irregularities Using Multi-Frequency Range Imaging Technology
Authors: Chen Bo , Liu Yi , Feng Jian , Zhang Yuqiang , Zhou Yufeng , Zhou Chen , Zhao Zhengyu
Published: January 2023

E-region field-aligned irregularities (FAIs) are a hot topic in space research, since electromagnetic signal propagation through ionospheric irregularities can undergo sporadic enhancements and fading known as ionospheric scintillation, which could severely affect communication, navigation, and radar systems. However, the range resolution of very-high-frequency (VHF) radars, which is widely used to observe E-region FAIs, is limited due to its bandwidth. As a technology that is widely used in atmosphere radars to improve the range resolution of pulsed radars by transmitting multiple frequencies, this paper employed the multifrequency radar imaging (RIM) technique in a Wuhan VHF radar. The results showed that the range resolution of E-region FAIs greatly improved when compared with the results in traditional single-frequency mode, and that finer structures of E-region FAIs can be obtained. Specifically, the imaging results in multifrequency mode show that E-region FAIs demonstrate an overall descending trend at night, and it could be related to the tides or gravity waves due to their downward phase velocities or even driven by downwind shear. In addition, typical quasi-periodic (QP) echoes with a time period of around 10 min could be clearly seen using the RIM technique, and the features of the echoes suggest that they could be modulated by gravity waves. Furthermore, the RIM technique can be used to obtain the fine structure of irregularities within a short time period, and the hierarchical structure of E-region FAIs can be easily found. Therefore, the multifrequency imaging RIM technique is suitable for observing E-region FAIs and their evolution, as well as for identifying the different layers of E-region FAIs. Combined with the RIM technique, a VHF radar provides an effective and promising way to observe the structure of E-region FAIs in more detail to study the physical mechanism behind the formation and evolution of ionospheric E-region irregularities.
Ongoing Development of the Bass Strait GNSS/INS Buoy System for Altimetry Validation in Preparation for SWOT
Authors: Zhou Boye , Watson Christopher , Legresy Benoit , King Matt A. , Beardsley Jack
Published: January 2023

GNSS equipped buoys remain an important tool in altimetry validation. Progressive advances in altimetry missions require associated development in such validation tools. In this paper, we enhanced an existing buoy approach and gained further understanding of the buoy dynamics based on in situ observations. First, we implemented the capability to separate the ambiguity fixing strategy for different constellations in the processing software TRACK. A comparison between GPS and GNSS solutions suggested up to 3 cm reduction in the root mean square of the buoy minus co-located mooring SSH residuals over the selected sidereal periods. Then, comparison between double differencing and precise point positioning solutions suggested a possible common mode error external to GNSS processing. To assess buoy performance in different ocean conditions and sea states, GNSS and INS observations were used during periods where external forcings (waves, current and wind) were not interacting substantially. For the deployments investigated, no significant relationship was found, noting the maximum significant wave height and current velocity was ~2.3 m and ~0.3 m/s, respectively. In the lead up to the validation required for the SWOT mission, these results place important bounds on the performance of the buoy design under real operating conditions.
Pore and Microfracture Characterization in Tight Gas Sandstone Reservoirs with a New Rock-Physics-Based Seismic Attribute
Authors: Guo Zhiqi , Qin Xiaoying , Liu Cai
Published: January 2023

Pores and microfractures provide storage spaces and migration pathways for gas accumulation in tight sandstones with low porosity and permeability, acting as one of the controlling factors of gas production. The development of a rational rock physics model is essential for better understanding the elastic responses of tight sandstone with complex pore structures. Accordingly, seismic characterization of pores and microfractures based on the rock physics model provides valuable information in predicting high-quality tight gas sandstone reservoirs. This paper proposes a rock-physics-based approach to compute the pore–microfracture indicator (PMI) from elastic properties for pore structure evaluation in tight sandstones. The PMI is achieved based on the axis rotation of the elastic parameter space using well-log data. The rotation angle is determined by finding the maximum correlation between the linearized combination of the elastic parameters and the introduced factor associated with total porosity and microfracture porosity. The microfracture porosity is then estimated with an inversion scheme based on the double-porosity model. Finally, the optimized rotation angle is employed to compute the PMI with seismic data. The obtained results are of great benefit in predicting the permeable zones, providing valuable information for sweet spot characterization in tight gas sandstone reservoirs.
Vision-Based Efficient Robotic Manipulation with a Dual-Streaming Compact Convolutional Transformer
Authors: Guo Hao , Song Meichao , Ding Zhen , Yi Chunzhi , Jiang Feng
Published: January 2023

Learning from visual observation for efficient robotic manipulation is a hitherto significant challenge in Reinforcement Learning (RL). Although the collocation of RL policies and convolution neural network (CNN) visual encoder achieves high efficiency and success rate, the method general performance for multi-tasks is still limited to the efficacy of the encoder. Meanwhile, the increasing cost of the encoder optimization for general performance could debilitate the efficiency advantage of the original policy. Building on the attention mechanism, we design a robotic manipulation method that significantly improves the policy general performance among multitasks with the lite Transformer based visual encoder, unsupervised learning, and data augmentation. The encoder of our method could achieve the performance of the original Transformer with much less data, ensuring efficiency in the training process and intensifying the general multi-task performances. Furthermore, we experimentally demonstrate that the master view outperforms the other alternative third-person views in the general robotic manipulation tasks when combining the third-person and egocentric views to assimilate global and local visual information. After extensively experimenting with the tasks from the OpenAI Gym Fetch environment, especially in the Push task, our method succeeds in 92% versus baselines that of 65%, 78% for the CNN encoder, 81% for the ViT encoder, and with fewer training steps.
A Self-Collision Detection Algorithm of a Dual-Manipulator System Based on GJK and Deep Learning
Authors: Wu Di , Yu Zhi , Adili Alimasi , Zhao Fanchen
Published: January 2023

Self-collision detection is fundamental to the safe operation of multi-manipulator systems, especially when cooperating in highly dynamic working environments. Existing methods still face the problem that detection efficiency and accuracy cannot be achieved at the same time. In this paper, we introduce artificial intelligence technology into the control system. Based on the Gilbert-Johnson-Keerthi (GJK) algorithm, we generated a dataset and trained a deep neural network (DLNet) to improve the detection efficiency. By combining DLNet and the GJK algorithm, we propose a two-level self-collision detection algorithm (DLGJK algorithm) to solve real-time self-collision detection problems in a dual-manipulator system with fast-continuous and high-precision properties. First, the proposed algorithm uses DLNet to determine whether the current working state of the system has a risk of self-collision; since most of the working states in a system workspace do not have a self-collision risk, DLNet can effectively reduce the number of unnecessary detections and improve the detection efficiency. Then, for the working states with a risk of self-collision, we modeled precise colliders and applied the GJK algorithm for fine self-collision detection, which achieved detection accuracy. The experimental results showed that compared to that with the global use of the GJK algorithm for self-collision detection, the DLGJK algorithm can reduce the time expectation of a single detection in a system workspace by 97.7%. In the path planning of the manipulators, it could effectively reduce the number of unnecessary detections, improve the detection efficiency, and reduce system overhead. The proposed algorithm also has good scalability for a multi-manipulator system that can be split into dual-manipulator systems.
Performance Analysis of Multihop Full-Duplex NOMA Systems with Imperfect Interference Cancellation and Near-Field Path-Loss
Authors: Tu Lam-Thanh , Phan Van-Duc , Nguyen Tan , Tran Phuong , Duy Tran , Nguyen Quang-Sang , Nguyen Nhat-Tien , Voznak Miroslav
Published: January 2023

Outage probability (OP) and potential throughput (PT) of multihop full-duplex (FD) nonorthogonal multiple access (NOMA) systems are addressed in the present paper. More precisely, two metrics are derived in the closed-form expressions under the impact of both imperfect successive interference cancellation (SIC) and imperfect self-interference cancellation. Moreover, to model short transmission distance from the transmit and receive antennae at relays, the near-field path-loss is taken into consideration. Additionally, the impact of the total transmit power on the performance of these metrics is rigorously derived. Furthermore, the mathematical framework of the baseline systems is provided too. Computer-based simulations via the Monte Carlo method are given to verify the accuracy of the proposed framework, confirm our findings, and highlight the benefits of the proposed systems compared with the baseline one.
An Intelligent Platform for Software Component Mining and Retrieval
Authors: Bibi Nazia , Rana Tauseef , Maqbool Ayesha , Afzal Farkhanda , Akgül Ali , De la Sen Manuel
Published: January 2023

The development of robotic applications necessitates the availability of useful, adaptable, and accessible programming frameworks. Robotic, IoT, and sensor-based systems open up new possibilities for the development of innovative applications, taking advantage of existing and new technologies. Despite much progress, the development of these applications remains a complex, time-consuming, and demanding activity. Development of these applications requires wide utilization of software components. In this paper, we propose a platform that efficiently searches and recommends code components for reuse. To locate and rank the source code snippets, our approach uses a machine learning approach to train the schema. Our platform uses trained schema to rank code snippets in the top k results. This platform facilitates the process of reuse by recommending suitable components for a given query. The platform provides a user-friendly interface where developers can enter queries (specifications) for code search. The evaluation shows that our platform effectively ranks the source code snippets and outperforms existing baselines. A survey is also conducted to affirm the viability of the proposed methodology.
Comparing State-of-the-Art Deep Learning Algorithms for the Automated Detection and Tracking of Black Cattle
Authors: Myat Noe Su , Zin Thi Thi , Tin Pyke , Kobayashi Ikuo
Published: January 2023

Effective livestock management is critical for cattle farms in today’s competitive era of smart modern farming. To ensure farm management solutions are efficient, affordable, and scalable, the manual identification and detection of cattle are not feasible in today’s farming systems. Fortunately, automatic tracking and identification systems have greatly improved in recent years. Moreover, correctly identifying individual cows is an integral part of predicting behavior during estrus. By doing so, we can monitor a cow’s behavior, and pinpoint the right time for artificial insemination. However, most previous techniques have relied on direct observation, increasing the human workload. To overcome this problem, this paper proposes the use of state-of-the-art deep learning-based Multi-Object Tracking (MOT) algorithms for a complete system that can automatically and continuously detect and track cattle using an RGB camera. This study compares state-of-the-art MOTs, such as Deep-SORT, Strong-SORT, and customized light-weight tracking algorithms. To improve the tracking accuracy of these deep learning methods, this paper presents an enhanced re-identification approach for a black cattle dataset in Strong-SORT. For evaluating MOT by detection, the system used the YOLO v5 and v7, as a comparison with the instance segmentation model Detectron-2, to detect and classify the cattle. The high cattle-tracking accuracy with a Multi-Object Tracking Accuracy (MOTA) was 96.88%. Using these methods, the findings demonstrate a highly accurate and robust cattle tracking system, which can be applied to innovative monitoring systems for agricultural applications. The effectiveness and efficiency of the proposed system were demonstrated by analyzing a sample of video footage. The proposed method was developed to balance the trade-off between costs and management, thereby improving the productivity and profitability of dairy farms; however, this method can be adapted to other domestic species.
Stress Estimation Using Biometric and Activity Indicators to Improve QoL of the Elderly
Authors: Matsumoto Kanta , Matsui Tomokazu , Suwa Hirohiko , Yasumoto Keiichi
Published: January 2023

It is essential to estimate the stress state of the elderly to improve their QoL. Stress states change every day and hour, depending on the activities performed and the duration/intensity. However, most existing studies estimate stress states using only biometric information or specific activities (e.g., sleep duration, exercise duration/amount, etc.) as explanatory variables and do not consider all daily living activities. It is necessary to link various daily living activities and biometric information in order to estimate the stress state more accurately. Specifically, we construct a stress estimation model using machine learning with the answers to a stress status questionnaire obtained every morning and evening as the ground truth and the biometric data during each of the performed activities and the new proposed indicator including biological and activity perspectives as the features. We used the following methods: Baseline Method 1, in which the RRI variance and Lorenz plot area for 4 h after waking and 24 h before the questionnaire were used as features; Baseline Method 2, in which sleep time was added as a feature to Baseline Method 1; the proposed method, in which the Lorenz plot area per activity and total time per activity were added. We compared the results with the proposed method, which added the new indicators as the features. The results of the evaluation experiments using the one-month data collected from five elderly households showed that the proposed method had an average estimation accuracy of 59%, 7% better than Baseline Method 1 (52%) and 4% better than Baseline Method 2 (55%).
Comparison of a Wearable Accelerometer/Gyroscopic, Portable Gait Analysis System (LEGSYS+TM) to the Laboratory Standard of Static Motion Capture Camera Analysis
Authors: Homes Ryan , Clark Devon , Moridzadeh Sina , Tosovic Danijel , Van den Hoorn Wolbert , Tucker Kylie , Midwinter Mark
Published: January 2023

Examination of gait patterns has been used to determine severity, intervention triage and prognostic measures for many health conditions. Methods that generate detailed gait data for clinical use are typically logistically constrained to a formal gait laboratory setting. This has led to an interest in portable analysis systems for near clinical or community-based assessments. The following study assessed with the wearable accelerometer/gyroscopic, gait analysis system (LEGSYS+TM) and the standard of static motion capture camera (MOCAP) analysis during a treadmill walk at three different walking speeds in healthy participants (n = 15). To compare each speed, 20 strides were selected from the MOCAP data and compared with the LEGSYS+ strides at the same time point. Both scatter and bland-Altman plots with accompanying linear regression analysis for each of the parameters. Each stride parameter showed minimal or a consistent difference between the LEGSYS+ and MOCAP, with the phase parameters showing inconsistencies between the systems. Overall, LEGSYS+ stride parameters can be used in the clinical setting, with the utility of phase parameters needing to be taken with caution.
Discussion on a Vehicle–Bridge Interaction System Identification in a Field Test
Authors: Shin Ryota , Okada Yukihiko , Yamamoto Kyosuke
Published: January 2023

For infrastructures to be sustainable, it is essential to improve maintenance and management efficiency. Vibration-based monitoring methods are being investigated to improve the efficiency of infrastructure maintenance and management. In this paper, signals from acceleration sensors attached to vehicles traveling on bridges are processed. Methods have been proposed to individually estimate the modal parameters of bridges and road unevenness from vehicle vibrations. This study proposes a method to simultaneously estimate the mechanical parameters of the vehicle, bridge, and road unevenness with only a few constraints. Numerical validation examined the effect of introducing the Kalman filter on the accuracy of estimating the mechanical parameters of vehicles and bridges. In field tests, vehicle vibration, bridge vibration, and road unevenness were measured and verified, respectively. The road surface irregularities estimated by the proposed method were compared with the measured values, which were somewhat smaller than the measured values. Future studies are needed to improve the efficiency of vehicle vibration preprocessing and optimization methods and to establish a methodology for evaluating accuracy.