bluuebunny/crossref_metadata_2025 huggingface dataset:
Gradient-wise search strategy for blind image deblurring
Authors: Wang Yunhong , Liu Dan
Published: January 2022

Blind image deblurring is a long-standing challenging problem to improve the sharpness of an image as a prerequisite step. Many iterative methods are widely used for the deblurring image, but care must be taken to ensure that the methods have fast convergence and accuracy solutions. To address these problems, we propose a gradient-wise step size search strategy for iterative methods to achieve robustness and accelerate the deblurring process. We further modify the conjugate gradient method with the proposed strategy to solve the bling image deblurring problem. The gradient-wise step size aims to update gradient for each pixel individually, instead of updating step size by the fixed factor. The modified conjugate gradient method improves the convergence performance computation speed with a gradient-wise step size. Experimental results show that our method effectively estimates the sharp image for both motion blur images and defocused images. The results of synthetic datasets and natural images are better than what is achieved with other state-of-the-art blind image deblurring methods.
Real-time recognition of weld defects based on visible spectral image and machine learning
Authors: Zhang Sujie , Deng Ming , Xie Xiaoyuan
Published: January 2022

The quality of Tungsten Inert Gas welding is dependent on human supervision, which can’t suitable for automation. This study designed a model for assessing the tungsten inert gas welding quality with the potential of application in real-time. The model used the K-Nearest Neighborhood (KNN) algorithm, paired with images in the visible spectrum formed by high dynamic range camera. Firstly, projecting the image of weld defects in the training set into a two-dimensional space using multidimensional scaling (MDS), so similar weld defects was aggregated into blocks and distributed in hash, and among different weld defects has overlap. Secondly, establishing models including the KNN, CNN, SVM, CART and NB classification, to classify and recognize the weld defect images. The results show that the KNN model is the best, which has the recognition accuracy of 98%, and the average time of recognizing a single image of 33ms, and suitable for common hardware devices. It can be applied to the image recognition system of automatic welding robot to improve the intelligent level of welding robot.
Research on dynamic routing algorithm based on gaussian mixture model
Authors: Huang Yuzhan
Published: January 2022

In this paper, based on the method of environmental sound detection, a neural network model based on capsule network and Gaussian mixture model is proposed. The model proposed in this paper mainly aims at the disadvantages of dynamic routing algorithm in the capsule network, and proposes a dynamic routing algorithm based on Gaussian mixture model. The improved dynamic routing algorithm assumes that the characteristics of the data conform to the multi-dimensional Gaussian distribution, so the model can learn the distribution of data features by building distribution functions of different classes. The information entropy is used as the activation value of the salient degree of the feature. Through experiments, the accuracy of the proposed algorithm on Urbansound8K data set is more than 92%, which is 4.8% higher than the original algorithm.
Acceleration-critical density time-delay model for crowd stability analysis based on Lyapunov theory
Authors: Zhao Rongyong , Jia Ping , Wang Yan , Li Cuiling , Ma Yunlong , Zhang Zhishu
Published: January 2022

Crowd stability analysis is one of research hotspots to alleviate the severe situation of stampede accidents worldwide. Different from the conventional analysis models for crowd stability based on pedestrian density, this study analyses the characteristics of external disturbances and internal obstacle disturbance based on Lyapunov's theory. The critical range of crowd acceleration in crowd evacuation is obtained, a crowd merging acceleration-critical density time delay model is established, and a stability criterion of acceleration vector based on Lyapunov is obtained based on Lyapunov stability analysis. This provides new information for ensuring the stability of crowd movement in public places, assessing the stability of the crowd in the area, and taking reasonable protection and guidance measures prior to instability of a crowd flow.
Automatic body region localization in 3D-CT images based on the improved YOLO model
Authors: Du Linghao , Wang Rui , Cui Lin , Min Xiaolin , Liu Qingyi , Ren Yande , Huang Kai , Bai Peirui
Published: January 2022

Automatic body region localization in medical three-dimensional (3D)-CT images is a critical step of computerized body-wide Automatic Anatomy Recognition (AAR) system, which can be applied for radiotherapy planning and interest slices retrieving. Currently, the complex internal structure of human body and time consuming computation are the main challenges for the localization. Therefore, this paper introduces and improves the YOLO-v3 model into the body region localization for these problems. First, seven categories of body regions in a CT volume image I are defined based on the modification version of our previous work. Second, an improved YOLO-v3 model is trained to classify each axial slice into one of the seven categories. Then, the effectiveness of the proposed method is evaluated on 3D-CT images that collected from 220 subjects. The experimental results demonstrate that the slice localizing error is less than 3 NoS (Number of slices), which is competitive to the state-of-the-art methods. Beyond this, our method is simple and computationally efficient owing to its less training time, and the average computational time for localizing a volume CT images is about 3 second, which shows potential for a further application.
Research prospect of autonomous driving decision technology under complex traffic scenarios
Authors: Cao Yaoguang , Chen Yuyi , Liu Lu
Published: January 2022

Decision-making system is the essential part of the autonomous vehicle “brain”, which determines the safety and stability of vehicles, and is also the key to reflect the intelligent level of autonomous vehicles. Compared with simple scenarios such as expressway, urban traffic scenarios have the characteristics of complex and frequent interaction between traffic participants. Carrying out in-depth research on complex traffic scenarios and optimizing autonomous decision-making algorithms are the key methods for the purpose of promoting the application of autonomous driving technologies. In the future, we can further combine the artificial intelligence methods such as cognitive or knowledge map, behaviour prediction of traffic participants, and humanoid intelligence, so as to enhance the intelligent level of autonomous driving.
Research on artificial intelligence safety prediction and intervention model based on ship driving habits
Authors: Liu Runnan , Liu Guangze , He Pengfei , Lin Xingzhi
Published: January 2022

Based on the analysis of the causes of ship accidents, the development prospect and development direction of ship intelligent safe driving, the artificial intelligence safety prediction and intervention model is put forward. This model solves the problem of ship intelligent safety prediction by using intelligent analysis technology and network technology, and promotes the development of ship intelligence and ship safety navigation technology. Additionally, it expands the channels of obtaining information, connects the ship's mechanical and electrical equipment, collects, stores and analyzes the data reasonably, and constructs the intelligent analysis and processing platform of ship small-world data processing to implement intelligent intervention. What is impressive is that it makes ship navigation safer, more economical, more reasonable and optimized, and accelerates the development of ship artificial intelligence safe navigation.
Fault identification of double-circuit transmission lines on the same pole based on EEMD energy ratio
Authors: Liu Yicen , Chen Ying , Fan Songhai , Gong Yiyu , Zou Xi
Published: January 2022

In order to improve the sensitivity and reliability of traveling wave protection, on the basis of analyzing the relationship of the anti-traveling wave current amplitude in the window after the internal/external failure of the double circuit line on the same tower, a fault identification method based on EEMD energy ratio is proposed. Use EEMD decomposition to decompose the anti-traveling wave current in a time window after the fault into 7 scales, and extracts the EEMD energy ratio at each scale at both ends to form a feature vector. Then it is sent to the particle swarm optimization support vector machine (PSO-SVM) for training and testing, and the internal and external faults are identified. Experiments show that the algorithm has good fault identification ability, the fault accuracy is 95% and the method sensitivity is high.
Distributed AI embedded cluster for real-time video analysis systems with edge computing
Authors: Li Wei , Han Zhiyuan , Shen Jian , Luo Dandan , Gao Bo , Xie Jin
Published: January 2022

Herein, on the basis of a distributed AI cluster, a real-time video analysis system is proposed for edge computing. With ARM cluster server as the hardware platform, a distributed software platform is constructed. The system is characterized by flexible expansion, flexible deployment, data security, and network bandwidth efficiency, which makes it suited to edge computing scenarios. According to the measurement data, the system is effective in increasing the speed of AI calculation by over 20 times in comparison with the embedded single board and achieving the calculation effect that matches GPU. Therefore, it is considered suited to the application in heavy computing power such as real-time AI computing.
Analysis of the characteristics of computer certification test suitable for higher vocational colleges
Authors: Song Dixin , Jiao Shufeng , Xu Yan , Du Shaojie
Published: January 2022

With the popularization of computer application, there is a craze for computer certification in the society. Faced with a wide variety of examinations, how to choose a suitable examination is the concern of every examinee. This paper analyzes the current popular examinations from the aspects of examination organization departments, suitable people, examination methods and examination contents. It also puts forward some suggestions on the reform of computer examination.
Research on high-speed synchronous motor direct torque control
Authors: Cui Hong , Gao Youqing
Published: January 2022

High-speed motor is increasingly used in ultra-high precision machining and high-performance machinery. It is necessary to achieve closed-loop control of high-speed motor in order to realize high-performance motor control. The high-frequency and high-speed characteristics of high-speed motor have brought great difficulties for its realization of closed-loop control. The performance of the hexagonal flux direct torque control (DTC) method that can reduce the switching frequency of power devices is researched for high-speed synchronous motor in this paper. After adopting this control method, the harmonics in the motor current and torque can be suppressed by adopting an appropriate filtering method. The same effect as the conventional DTC can still be achieved. It provides a basis for the application realization of the high-speed synchronous motor control system.
Research on network security technology of industrial control system
Authors: Jin Kai , Niu Zhanji , Liu Jieping , Bai Jinxue , Zhang Lei
Published: January 2022

The relationship between industrial control system and Internet is becoming closer and closer, and its network security has attracted much attention. Penetration testing is an active network intrusion detection technology, which plays an indispensable role in protecting the security of the system. This paper mainly introduces the principle of penetration testing, summarizes the current cutting-edge penetration testing technology, and looks forward to its development.
Dynamics of a stochastic population model with Allee effect and jumps
Authors: Liu Rong , Liu Guirong
Published: January 2022

This paper is concerned with a stochastic population model with Allee effect and jumps. First, we show the global existence of almost surely positive solution to the model. Next, exponential extinction and persistence in mean are discussed. Then, we investigated the global attractivity and stability in distribution. At last, some numerical results are given. The results show that if attack rate a is in the intermediate range or very large, the population will go extinct. Under the premise that attack rate a is less than growth rate r, if the noise intensity or jump is relatively large, the population will become extinct; on the contrary, the population will be persistent in mean. The results in this paper generalize and improve the previous related results.
Establishing local diagnostic reference levels for adult computed tomography in Morocco
Authors: El Mansouri M. , Talbi M. , Choukri A. , Nhila O. , Aabid M.
Published: January 2022

In Morocco, the radiation doses received by adult patients are increasing due to the number of CT examinations performed and the larger number of computed tomography (CT) scanners installed. The aim of this study was to evaluate the radiation doses received by patients for the most common adult CT examinations in order to establish local diagnostic reference levels (DRLs). Data from 1016 adult patients were collected during 3 months from four Moroccan hospitals. Dose length product (DLP) and volumetric computed tomography dose index (CTDIvol) were evaluated by determining the 75th percentile as diagnostic reference levels for the most common examinations including head, chest and abdomen. The DRL for each examination was compared with other studies. The established DRLs in Morocco in terms of CTDIvol were 57.4, 12.3 and 10.9 for CT examinations of the head, chest, abdomen, respectively. For DLP, they were 1020, 632 and 714, respectively. These established DRLs for CTDIvol were almost similar to the UK DRLs at all examinations, higher than the Egyptian DRLs and lower than the Japanese DRLs at the head CT examination, lower than the DRLs from Egypt and Japan at the CT abdomen examination. In terms of DLP, the DRLs were higher than those of the British studies, lower than those of the Egyptian and Japanese studies at the head CT examination were higher at chest CT and lower at abdominal CT than those of all selected studies. The higher level of established DRLs in our study demonstrates the requirement of an optimization process while keeping a good image quality for a reliable diagnosis.
Evaluation of the radiological risk in cargo scanning by comparison with known biological consequences
Authors: Pelegrineli S.Q. , Silva A.X. , Filho W.S.S. , Oliveira L.S.R. , Stenders R.M. , Junior J.P.R. , Pereira W.S. , Ramos de Andrade E.
Published: January 2022

This study proposes a quick, easy, and low-cost method that can be used to assess the radiological safety of an irradiation line used for cargo and container inspection facilities. The radiation-emitting equipment used was a Smiths Heimam particle accelerator model HCVP4029 operating at 4.5 MeV. The radiation dose measurements were performed using a personal radiation monitor Ultra Radac mod MRAD 111 (Geiger–Muller). The ambient equivalent dose H*(10) was estimated for two facilities: A (real) (1.12E-03 mSv per scan) and B (fictitious) (3.25E-03 mSv per scan). The dimensionless factor R, which represents a ratio between two specific scanning (Ss) quantities regarding the facilities A and B, is introduced as a reference for assessing the level of radiological safety. This study compares facilities A and B by using a simple alternative safety assessment based on the R factor. The dimensionless R-value appears to be able to facilitate both the personnel’s and the general public’s perception of risk levels, even with no fixed scale.
New preference violation indices for the condition of order preservation
Authors: Mazurek Jiří
Published: January 2022

Consistency of pairwise comparisons is one particular aspect that is studied thoroughly in the recent decades. However, since the introduction of the concept of the condition of the order preservation in 2008, there is no inconsistency measure based on the aforementioned condition. Therefore, the aim of this paper is to fill this gap and propose new preference violation indices for measuring violation of the condition of the order preservation. Further, an axiomatic system for the proposed measures is discussed, and it is shown that the proposed indices satisfy uniqueness, invariance under permutation, invariance under inversion of preferences and continuity axioms.
Mobilisation auf Intensivstationen: Intensivpflegezimmer und Medizintechnik können helfen
Authors: Grunow Julius J. , Nydahl Peter , Schaller Stefan J.
Published: January 2022

(Früh-)Mobilisation ist ein wichtiges Element auf der Intensivstation – es dient der Prävention und Therapie der durch eine kritische Erkrankung verursachten Einschränkungen der körperlichen Funktion. Aufgrund diverser Barrieren werden die aktuellen Leitlinien-Ziele aber nicht immer erreicht. In diesem Beitrag geht es um die Integration des Intensivpflegezimmers und moderner Medizintechnik in die Frühmobilisation zur Überwindung dieser Barrieren.
Letaler Hitzeschock mit disseminierter intravasaler Koagulopathie
Authors: Herpertz Gerrit U. , Nykamp Lukas , Radke Oliver C.
Published: January 2022

Das Thema hitzebedingter Erkrankungen ist in den letzten Jahren mit überaus heißen Sommern und häufigen Hitzewellen immer relevanter geworden. Epidemiologisch lassen sich solche Erkrankungen nur schwer fassen, da sie saisonal vorkommen und überwiegend besonders exponierte Patienten betreffen. Fatale Verläufe wie der im Beitrag beschriebene sind äußerst selten 1.
Bettina lebt – Kälberdurchfall in der
homöopathischen Praxis
Authors: Gerke Stephan
Published: January 2022

Anhand eines Falles von Kälberdurchfall wird die Arzneimittelfindung
mithilfe eines Repertorisationsprogramms und des Symptomenlexikons dargestellt.
Hierbei wird Secale cornutum als am besten indiziertes Arzneimittel gefunden.
Die Anwendung von Secale cornutum bei Kälberdurchfall wird
diskutiert.
Endoscopic retrograde appendicitis therapy versus laparoscopic appendectomy for uncomplicated acute appendicitis
Authors: Yang Baohong , Kong Lingjian , Ullah Saif , Zhao Lixia , Liu Dan , Li Deliang , Shi Xuezhong , Jia Xiaocan , Dalal Paras , Liu Bingrong
Published: January 2022

Background Endoscopic retrograde appendicitis therapy (ERAT) is a new and minimally invasive technique for the treatment of acute appendicitis. This study aimed to assess the efficacy and clinical outcomes of ERAT versus laparoscopic appendectomy for patients with uncomplicated acute appendicitis.

Methods We adopted propensity score matching (1:1) to compare ERAT and laparoscopic appendectomy in patients with uncomplicated acute appendicitis between April 2017 and March 2020. We reviewed 2880 patients with suspected acute appendicitis, of whom 422 patients with uncomplicated acute appendicitis met the matching criteria (ERAT 79; laparoscopic appendectomy 343), yielding 78 pairs of patients.

Results The rate of curative treatment within 1 year after ERAT was 92.1 % (95 % confidence interval [CI] 83.8 % to 96.3 %). The percentage of patients recording visual analog scale values of  ≤ 3 for pain at 6 hours after treatment was 94.7 % (95 %CI 87.2 % to 97.9 %) in the ERAT group, which was significantly higher than that in the laparoscopic appendectomy group (83.3 %; 95 %CI 73.5 % to 90.0 %). Median procedure time and median hospital length of stay were significantly lower in the ERAT group compared with the laparoscopic appendectomy group. At 1 year, the median recurrence time was 50 days (interquartile range 25–127) in the ERAT group. The overall adverse event rate was 24.4 % (95 %CI 14.8 % to 33.9 %) in the laparoscopic appendectomy group and 18.4 % (95 %CI 9.7 % to 27.1 %) in the ERAT group, with no significant difference between the two groups.

Conclusion ERAT was a technically feasible method of treating uncomplicated acute appendicitis compared with laparoscopic appendectomy.
Effectiveness of Clinical Decision Support Systems on the Appropriate Use of Imaging for Central Nervous System Injuries: A Systematic Review
Authors: Zare Sahar , Mobarak Zohre , Meidani Zahra , Nabovati Ehsan , Nazemi Zahra
Published: January 2022

Background One of the best practices for timely and efficient diagnoses of central nervous system (CNS) trauma and complex diseases is imaging. However, rates of imaging for CNS are high and impose a lot of costs to health care facilities in addition to exposing patients with negative impact of ionizing radiation.

Objectives This study aimed to systematically review the effects and features of clinical decision support systems (CDSSs) for the appropriate use of imaging for CNS injuries.

Method We searched MEDLINE, SCOPUS, Web of Science, and Cochrane without time period restriction. We included experimental and quasiexperimental studies that assessed the effectiveness of CDSSs designed for the appropriate use of imaging for CNS injuries in any clinical setting, including primary, emergency, and specialist care. The outcomes were categorized based on imaging-related, physician-related, and patient-related groups.

Result A total of 3,223 records were identified through the online literature search. Of the 55 potential papers for the full-text review, 11 eligible studies were included. Reduction of CNS imaging proportion varied from 2.6 to 40% among the included studies. Physician-related outcomes, including guideline adherence, diagnostic yield, and knowledge, were reported in five studies, and all demonstrated positive impact of CDSSs. Four studies had addressed patient-related outcomes, including missed or delayed diagnosis, as well as length of stay. These studies reported a very low rate of missed diagnosis due to the cancellation of computed tomography (CT) examine according to the CDSS recommendations.

Conclusion This systematic review reports that CDSSs decrease the utilization of CNS CT scan, while increasing physicians' adherence to the rules. However, the possible harm of CDSSs to patients was not well addressed by the included studies and needs additional investigation. The actual effect of CDSSs on appropriate imaging would be realized when the saved cost of examinations is compared with the cost of missed diagnosis.
Gastrointestinal Bleeding in Congenital Bleeding Disorders
Authors: Samii Amir , Norouzi Mahshaad , Ahmadi Abbas , Dorgalaleh Akbar
Published: January 2022

Gastrointestinal bleeding (GIB) is serious, intractable, and potentially life-threatening condition. There is considerable heterogeneity in GIB phenotypes among congenital bleeding disorders (CBDs), making GIB difficult to manage. Although GIB is rarely encountered in CBDs, its severity in some patients makes the need for a comprehensive and precise assessment of underlying factors and management approaches imperative. Initial evaluation of GIB begins with assessment of hematological status; GIB should be ruled out in patients with chronic anemia, and in presentations that include hematemesis, hematochezia, or melena. High-risk patients with recurrent GIB require urgent interventions such as replacement therapy for treatment of coagulation factor deficiency (CFD). However, the best management strategy for CFD-related bleeding remains controversial. While several investigations have identified CBDs as potential risk factors for GIB, research has focused on assessing the risks for individual factor deficiencies and other CBDs. This review highlights recent findings on the prevalence, management strategies, and alternative therapies of GIB related to CFDs, and platelet disorders.
Interaction between Antiphospholipid Antibodies and Protein C Anticoagulant Pathway: A Narrative Review
Authors: Pengo Vittorio
Published: January 2022

Thrombotic antiphospholipid syndrome (APS) is a condition in which thrombosis in venous, arterial, and/or small vessels is ascribed to the presence of antiphospholipid antibodies (aPL). Among the various proposed pathogenic theories to explain thrombotic APS, those involving the interaction between aPL and the protein C system have gained much consensus. Indeed, robust data show an acquired activated protein C resistance (APC-R) in these patients. The role of aPL in this impairment is clear, but the mechanism of action is uncertain, as the type of aPL and to what extent aPL are involved remains a gray area. Lupus anticoagulant (LA) is often associated with APC-R, but antibodies generating LA comprise those directed to β2-glycoprotein I and antiphosphatidylserine/prothrombin. Moreover, the induction of APC-R by aPL requires the presence of phospholipids and is suppressed by the presence of an excess of phospholipids. How phospholipids exposed on the cell membranes work in the system in vivo is unknown. Interestingly, acquired APC-R due to aPL might explain the clinical phenotypes of thrombotic APS. Indeed, the literature reports cases of both venous and arterial thromboembolism as well as skin necrosis, the latter observed in the severe form of protein C deficiency and in catastrophic APS.
Transcranial Color Coded Duplex Sonography Findings in Stroke Patients Undergoing Rehabilitation: An Observational Study
Authors: Venkatakrishnan Srikant , Khanna Meeka , Gupta Anupam
Published: January 2022

Background Transcranial color-coded duplex sonography (TCCD) provides information on intracranial blood flow status in stroke patients and can predict rehabilitation outcomes.

Objective This study aimed to assess middle cerebral artery (MCA) parameters using TCCD in MCA territory stroke patients admitted for rehabilitation and correlate with clinical outcome measures.

Materials and Methods Patients aged 18 to 65 years with a first MCA territory stroke, within 6 months of onset were recruited. The clinical outcome scales and TCCD parameters were assessed at both admission and discharge. The scales used were the Scandinavian stroke scale (SSS), Barthel Index (BI), modified Rankin Scale (mRS), Fugl–Meyer upper extremity scale (FMA-UE), modified motor assessment scale (mMAS) scores. TCCD parameters measured were MCA peak systolic, end diastolic, mean flow velocities (MFV), and index of symmetry (SI) and were correlated with clinical scores.

Results Fourteen patients were recruited with median age of 56.5 years, median duration of stroke was 42.5 days. Mean flow velocities of affected and unaffected MCA were 46.2 and 50.7 cm/s, respectively. Flow velocities and SI did not change between the two assessments. There was significant improvement in clinical outcome scores at discharge. Significant correlation was observed for patient group with SI > 0.9 at admission with FMA-UE, SSS, and BI scores at discharge (p < 0.05).

Conclusion Flow velocity parameters did not change during in-patient rehabilitation. Patients with symmetric flow at admission had improved clinical outcomes measure scores at discharge. Thus SI can predict rehabilitation outcomes in stroke survivors.
How does successive inpatriation contribute to subsidiary capability building and subsidiary evolution? An organizational knowledge creation perspective
Authors: Kim Heejin , Reiche B. Sebastian , Harzing Anne-Wil
Published: January 2022

Intra-company knowledge transfer is a key source of competitive advantage for multinational companies (MNCs) and this knowledge is usually embedded in individuals. Drawing on organizational knowledge creation theory, we explore how inpatriation contributes to knowledge transfer and, in turn, subsidiary performance. Inpatriation involves the international assignment of employees from an MNC’s foreign subsidiary to its headquarters. Despite increasing attention to the role of inpatriation, we lack a clear understanding of whether and how inpatriates provide value to their subsidiaries after returning from headquarters. Through a qualitative case study of Japanese MNCs, we demonstrate the process through which inpatriates’ knowledge transfer contributes to subsidiary capability building and subsidiary evolution over time, and explain why successive inpatriation is thus critical to enhance subsidiary performance. Our theoretical model highlights the value of inpatriates as knowledge agents, reveals the process through which inpatriates transfer knowledge between HQ and subsidiaries, and provides a more nuanced understanding of the micro-foundations of intra-MNC knowledge transfer processes. Based on these findings, we argue that inpatriation is not merely a staffing method that is complementary to expatriation, but a key practice in its own right to support subsidiaries’ growth and performance.
Comparison of enhancement techniques based on neural networks for attenuated voice signal captured by flexible vibration sensors on throats
Authors: Gao Shenghan , Zheng Changyan , Zhao Yicong , Wu Ziyue , Li Jiao , Huang Xian
Published: January 2022

Wearable flexible sensors attached on the neck have been developed to measure the vibration of vocal cords during speech. However, high-frequency attenuation caused by the frequency response of the flexible sensors and absorption of high-frequency sound by the skin are obstacles to the practical application of these sensors in speech capture based on bone conduction. In this paper, speech enhancement techniques for enhancing the intelligibility of sensor signals are developed and compared. Four kinds of speech enhancement algorithms based on a fully connected neural network (FCNN), a long short-term memory (LSTM), a bidirectional long short-term memory (BLSTM), and a convolutional-recurrent neural network (CRNN) are adopted to enhance the sensor signals, and their performance after deployment on four kinds of edge and cloud platforms is also investigated. Experimental results show that the BLSTM performs best in improving speech quality, but is poorest with regard to hardware deployment. It improves short-time objective intelligibility (STOI) by 0.18 to nearly 0.80, which corresponds to a good intelligibility level, but it introduces latency as well as being a large model. The CRNN, which improves STOI to about 0.75, ranks second among the four neural networks. It is also the only model that is able to achieves real-time processing with all four hardware platforms, demonstrating its great potential for deployment on mobile platforms. To the best of our knowledge, this is one of the first trials to systematically and specifically develop processing techniques for bone-conduction speed signals captured by flexible sensors. The results demonstrate the possibility of realizing a wearable lightweight speech collection system based on flexible vibration sensors and real-time speech enhancement to compensate for high-frequency attenuation.
Flexible and stretchable bioelectronics inform cardiac health
Authors: Piccone Ashley
Published: January 2022

Using rigid electronics in soft tissue poses problems, but soft devices can study the heart in unique ways.
Stickiness of snow investigated with ice particle experiment
Authors: Johnson-Groh Mara
Published: January 2022

Using tiny ice particles, researchers studied variables that affect how snow sticks together.
Simulating stochastic adsorption of diluted solute molecules at interfaces
Authors: Chen Jixin
Published: January 2022

This report uses Monte Carlo simulations to connect stochastic single-molecule and ensemble surface adsorption of molecules from dilute solutions. Monte Carlo simulations often use a fundamental time resolution to simulate each discrete step for each molecule. The adsorption rate obtained from such a simulation surprisingly contains an error compared to the results obtained from the traditional method. Simulating adsorption kinetics is interesting in many processes, such as mass transportation within cells, the kinetics of drug–receptor interactions, membrane filtration, and other general reaction kinetics in diluted solutions. Thus, it is important to understand the origin of the disagreement and find a way to correct the results. This report reviews the traditional model, explains the single-molecule simulations, and introduces a method to correct the results of adsorption rate. For example, one can bin finer time steps into time steps of interest to simulate the fractal diffusion or simply introduce a correction factor for the simulations. Then two model systems, self-assembled monolayer (SAM) and biosensing on the patterned surface, are simulated to check the accuracy of the equations. It is found that the adsorption rate of SAM is highly dependent on the conditions and the uncertainty is large. However, the biosensing system is relatively accurate. This is because the concentration gradient near the interface varies significantly with reaction conditions for SAMs while relatively stable for the biosensing system.
Evidence of thermionic emission in forward biased β-Ga2O3 Schottky diodes at Boltzmann doping limit
Authors: Mukhopadhyay Swarnav , Lyle Luke A. M. , Pal Hridibrata , Das Kalyan K. , Porter Lisa M. , Sarkar Biplab
Published: January 2022

A near-ideal and homogeneous β-Ga2O3 Schottky diode with Co contact for a doping level of ∼4.2 × 1017 cm−3 in the drift layer where the Boltzmann approximation is valid is reported. Unlike Si or GaN, thermionic emission is shown to be the dominant current conduction mechanism in the β-Ga2O3 Schottky diode at this doping level. A wide depletion region appended with a large built-in potential is observed to limit the thermionic field emission current, which is otherwise evident in narrower bandgap semiconductor (such as Si or GaN) Schottky diodes having a similar carrier concentration in the drift region. The results shown in this study can be used to identify the theoretical limits of drift layer doping beyond which the ideality factor and reverse leakage current should start deteriorating in ultra-wide bandgap semiconductor based Schottky diodes.
Mixed-lubrication analysis of misaligned journal bearing considering turbulence and cavitation
Authors: Song Xintao , Wu Wei , Yuan Shihua
Published: January 2022

By integrating the average flow equation and Ng–Pan turbulence model using the boundary condition of mass conserving [Jakobsson-Floberg-Olsson (JFO)], a mixed lubrication model for misaligned bearing was established considering the effects of turbulence and cavitation. The numerical solution was obtained using a finite difference scheme. The results indicate that the frictional force and moment calculated using the JFO boundary condition are greater than those calculated using the Reynolds boundary condition under the constant external load. In high speed conditions, the turbulence begins to play a role, which makes the maximum oil film pressure and moment decrease and the minimum oil film thickness, cavitation zone, and friction coefficient increase. The boundary condition and turbulence have important effects on the equilibrium position of the axis. The misalignment leads to an obvious increase in the friction of the mixed lubrication area and a slight decrease in that of the hydrodynamic lubrication area.
Collapse of partially and fully submerged granular column generating impulse waves: An empirical law of maximum wave amplitude based on coupled multiphase fluid–particle modeling results
Authors: Nguyen Nhu H. T.
Published: January 2022

In this study, impulse waves generated by partially and fully submerged granular collapse are investigated using a modeling method coupling the volume of fluid and discrete element method. Of particular focus is the effects of geometrical and material parameters of granular samples on wave generation mechanisms, thereby determining the controlling factors of maximum wave amplitude, which were unclear or inconsistently reported in previous experimental studies. It is found that the relative submerged depth (i.e., the ratio of initial granular sample height to water depth) is the main geometrical parameter governing the maximum wave amplitude generated by partially and fully submerged granular collapse. The inter-particle friction of granular materials also influences the maximum wave amplitude via altering the material mobility and momentum transferred from particles to water during the collapse process. The density of the granular material, on the other hand, has a negligible effect on impulse wave generation. Based on numerical characterization, an empirical model of the maximum wave amplitude is proposed and validated against experimental data. Its practical application to estimate the maximum wave amplitude generated by partially submerged landslide events is also demonstrated, suggesting its potential for the hazard assessment of landslide-generated tsunamis.
Isomerization of hydrogen cyanide and hydrogen isocyanide in a cluster environment: quantum chemical study
Authors: Zamir Alon , Stein Tamar
Published: January 2022

Hydrogen cyanide (HCN) and its isomer hydrogen isocyanide (HNC) are omnipresent in the interstellar medium (ISM). The ratio between the two isomers serves as an indicator of the physical conditions in different areas of the ISM. As such, the isomerization process between the two isomers has been extensively studied on the neutral potential energy surface. Moreover, HCN and HNC are thought to be precursors of important organic molecules, such as adenine. Here, we use quantum chemistry calculations and ab initio molecular dynamics simulations to focus on the chemistry that occurs upon ionization of pure HNC clusters. We demonstrate that upon ionization of HNC clusters, a distonic ion CN⋯HCNH+ is formed, and this formation is accompanied by HNC-to-HCN isomerization. Moreover, we show that the cluster environment and the network of hydrogen bonds are crucial for the isomerization process to occur and for the stabilization of the clusters. We demonstrate that, in contrast to HNC clusters, isomerization of ionized HCN clusters can occur only for the larger clusters. In addition, we discuss the formation of aminonitrile cation in the clusters and propose a barrierless route for diaminonitrile, a known precursor of amino acids and nucleobases, to form.
The observation of spin Seebeck effect in opposite spin Hall angle materials of polycrystalline bulk-Fe3O4/(Co/Fe) systems
Authors: Bavontaweepanya Ruchipas , Infahsaeng Yingyot , Pongophas Ekkarat , Maiaugree Wasan , Piyasin Piyawat , Palaporn Dulyawich , Wannasen Likkhasit , Pinitsoontorn Supree , Pattanakul Rungrueang , Ramamoorthy Harihara , Somphonsane Ratchanok , Khayaiwong Paowarin , Wongjom Poramed
Published: January 2022

In this study, we report on the observation of spin current in opposite spin Hall angle materials of polycrystalline bulk-Fe3O4/Co and polycrystalline bulk-Fe3O4/Fe spin Seebeck effect (SSE) devices. In contrast to prior works, a facile and low-cost hot-pressing powder metallurgy process was employed to manufacture the polycrystalline bulk-Fe3O4 samples. The crystal structure, magnetization properties, and electrical resistivity characterizations of the fabricated bulk-Fe3O4, which were performed using x-ray diffraction, vibration sample microscope, and four-point probe, respectively, revealed excellent agreement with those of conventional Fe3O4. By taking advantage of the fact that the SSE signal in our devices is typically contaminated with the anomalous Nernst effect (ANE), we show that the total thermo-voltage obtained from our devices can be enhanced by the significant ANE signals exhibited by the Co and Fe spin detectors. Importantly, the ANE contributions could be filtered out from the main signal by independent measurements of the ANE voltage in SiO2/Co and SiO2/Fe systems, thereby allowing the approximate extraction of the SSE voltage. Our experiments reveal that the polarity of the measured ANE (and pure SSE voltages) are opposite to each other in the bulk-Fe3O4/Co and bulk-Fe3O4/Fe structures, thus proving the opposite spin-hall angles character of these materials. The findings of this work provide a pathway for further exploration of methods through which the thermo-voltage output in future spin-Hall thermopile devices may be improved using materials manufactured via a facile, low-cost, and easily scalable process.
Study on insulating properties of polyethylene terephthalate/montmorillonite nanocomposites
Authors: Wang Qian , Hou Yicheng , Ma Shuyue , Wang Tao , Zhang Jiawei , Qin Sichen , Li Tingting , Bai Zhili
Published: January 2022

Photovoltaic (PV) power is one of the most effective green energies, which has attracted extensive attention from the industry and the international community. Polyethylene terephthalate (PET) is the main material of the PV backsheet, providing insulation protection for PV modules. Although PET has excellent optical properties, weather resistance, and chemical resistance, its relatively weak insulation properties restrict its application in engineering plastic. In this paper, the insulating properties of PET/montmorillonite (MMT) are studied. PET/MMT nanocomposites with an MMT content of 1%, 3%, and 5% are prepared by the melt blending method, and their insulating properties are tested. The results show that the addition of MMT can change the distribution of the electric field inside PET, thus, increasing the breakdown voltage. Furthermore, it can reduce the number of times of partial discharge (PD) and weaken the intensity of PD in PET/MMT composites to some extent. When the MMT content is 3%, PET/MMT composites have the best insulation performance. This study can provide a reference for the application of nanocomposites in the field of green energy.
Single and double toroid formation during oil droplet impact on an air–water interface at low Reynolds number
Authors: Chaudhuri Joydip , Mandal Tapas Kumar , Bandyopadhyay Dipankar
Published: January 2022

The impact of an oil droplet on an air–water interface is explored for low to moderate impact velocities. A computational fluid dynamic framework has been employed with appropriate boundary conditions to uncover the finer features of post-impact dynamics of such ternary systems. Simulations reveal that the impacting oil droplet opens up a “crater” on the water surface, which initially expands and then collapses during the evolution. Simultaneously, the oil droplet flattens, spreads, stretches, immerses, or dewets on the crater surface to manifest interesting metastable or unstable flow morphologies. At lower impact velocities, we observe the formation of oil droplets or air bubbles entrapped in water, oil lens, oil toroids, and compound droplets to name a few. The interfacial tension, density and viscosity contrasts across the interface play key roles in the formation of such flow morphologies. Energy analysis of the droplet impact reveals that a part of the kinetic energy of the droplet gets converted into surface energy, which, in turn, facilitates the interfacial deformation, formation of new interfaces, and metastable flow morphologies, such as single or twin toroids. All the different flow morphologies are categorized into eight fundamental regimes, which are mapped with the variation of Reynolds number and capillary number. The results provide insight into the complex physics associated with ternary phase drop impacts, and the different flow morphologies shown in the present study can be of significance in the production of double or Janus emulsions, as well as the development of next-generation microfluidic devices for bio-analysis, drug delivery, and multiphase reactions.
Theoretical and applied considerations in depth-integrated currents for third-generation wave models
Authors: Calvino Clément , Dabrowski Tomasz , Dias Frederic
Published: January 2022

A new derivation of ray equations is proposed in the framework of a current uniform with depth, differentiating the contributions from the current-induced wave phase speed and wave group velocity. It is useful when substituting higher order expressions for those quantities that account for a sheared current. The new formulation is easy to implement in third-generation spectral wave models even if this task is not performed in the present paper. The numerical vertical integration of the current profile evaluating the current-induced corrections is also studied. We show that a large numerical error can potentially be induced if one uses the vertical resolution normally encountered in ocean modeling. We offer a simple solution to reduce this error and demonstrate its impact on the computation of the current-induced phase speed and wave group corrections using both theoretical and realistic profiles. Discrepancies can induce changes up to 40% of the current-induced speed. We observe these strong discrepancies for large wavenumbers, associated with wind waves, when current effects are the most prevalent.
Photocatalytic properties of annealed TiO2 films with controlled structure fabricated using oxygen-ion-assisted reactive evaporation with glancing angle deposition technique
Authors: Yasuda Yoji , Kobayashi Shin-ichi , Hoshi Yoichi
Published: January 2022

Titanium dioxide (TiO2) has been an attractive material for applications such as in photocatalytic reactions, water purification, and cancer treatment. However, issues with the deposition methods have affected the performance of TiO2 films. Herein, we have developed a method to deposit TiO2 at room temperature using oxygen-ion-assisted reactive evaporation combined with glancing angle deposition. Furthermore, we investigated the effect of the incident angle and air annealing temperature range of 450–650 °C on the crystallinity, morphology, and photocatalytic properties of the deposited films. The physical microstructures were investigated via the θ–2θ x-ray diffraction method and field-emission scanning electron microscopy. The hydrophilicity was evaluated by measuring the contact angle of pure water on the film surface. The organic decomposition characteristics were evaluated by following decomposition of methylene blue under ultraviolet light irradiation. We found that as the annealing temperature increased, the grain size increased. A highly porous structure was formed at a higher incident angle of 80°, increasing the effective surface area of the TiO2 films. Furthermore, good organic decomposition capability was achieved using the TiO2 films deposited at the incident angle of 80° and annealed at 650 °C. We have demonstrated a method to deposit TiO2 films with improved properties, such as morphology, hydrophilicity, and specific surface area, which led to the improvement of the photocatalytic characteristics.
Epistatic models predict mutable sites in SARS-CoV-2 proteins and epitopes
Authors: Rodriguez-Rivas Juan , Croce Giancarlo , Muscat Maureen , Weigt Martin
Published: January 2022

Significance

During the COVID pandemic, new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants emerge and spread, some being of major concern due to their increased infectivity or capacity to reduce vaccine efficiency. Anticipating mutations, which might give rise to new variants, would be of great interest. We construct sequence models predicting how mutable SARS-CoV-2 positions are, using a single SARS-CoV-2 sequence and databases of other coronaviruses. Predictions are tested against available mutagenesis data and the observed variability of SARS-CoV-2 proteins. Interestingly, predictions agree increasingly with observations, as more SARS-CoV-2 sequences become available. Combining predictions with immunological data, we find an overrepresentation of mutations in current variants of concern. The approach may become relevant for potential outbreaks of future viral diseases.