bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Injection Strategy on the Flow Structure and Performance of Water Ramjet Engine using Magnesium Powder
Authors: Hu Yu-Peng , Zhou Ben-Quan , Zhang Gang , Xue Rui , Wu Yun-Kai , Liu Jun-Li
Published: April 2023

Different inlet structures have a significant impact on the internal flow characteristics of a solid-magnesium powder water ramjet engine. Based on the magnesium-water reaction model, a computational fluid dynamics (CFD) method is applied to establish a numerical simulation method for the internal flow field of the engine, and the internal flow characteristics of the engine under different inlet structure conditions are studied. The simulation results show that high-temperature gas can effectively promote the ignition of magnesium powder at the top of the combustion chamber, while accelerating the evaporation of the first inlet water and increasing the combustion rate of magnesium powder. The secondary inlet has the most significant effect on the temperature inside the combustion chamber. When the secondary inlet flow rate increases towards the top of the combustion chamber, it increases the amount of heat absorbed by the evaporating water at the top of the chamber, thereby reducing the temperature at the top of the combustion chamber. However, when the flow rate is low, it results in insufficient oxidizer at the top of the combustion chamber, which is unfavorable for the combustion of magnesium powder.
The Impact of Investment in University Campus Open Spaces on the Student Experience : An Assessment of Universities in the UK and USA
Authors: Gabr Mohammed , Elkadi Hisham
Published: April 2023

As universities increasingly compete to improve students’ experience through investment in their campuses, well-designed Campus Open Spaces (COSs) become a major feature as well as a marketing tool. Well-designed and managed COSs are increasingly attractive to students and increase the number of public visits to university campuses (footfall). Current literature does not provide planners with evidence of what makes a COS add value to the student experiences. As such, this paper aims to find the nexus between the value/cost of COS and the attractiveness to - and enhanced experience of - students. This aim is approached via a three-phase integrative framework and results in a validated assessment model with a ‘COS Exp score’ that quantifies the most used/vital, best used/engaging, and most valued/beneficial COS. The data was gathered from in-depth analysis of 21 universities in the UK & USA. The conclusion offers valuable insights into improving experience-based outdoor space developments.
Numerical Simulation of the Lubricant-Solid Interface Using the Multigrid Method
Authors: Patel Ruchita , Khan Zulfiqar Ahmad , Bakolas Vasilios , Saeed Adil
Published: April 2023

Solid asperity interactions are common and inevitable under severe loading conditions for any lubricated contact. Heavy-duty machine components (gear, bearings etc.) generally operate under Mixed Lubrication, where uneven surface features contact each other when generated fluid pressure is not enough to support the external load. The Reynolds equation is commonly used to simulate smooth lubricated contacts numerically. In rough lubricated interfaces where opposite surface asperities make contact, the Reynolds equation alone cannot accurately predict pressure using the traditional numerical simulation method. In this paper, Lubrication-Contact interface conditions (LCICs) have been implemented and extended to solve the multiple asperity contact problem using the full-multigrid approach. The developed novel algorithm has significantly accelerated the solution process and improved the accuracy and efficiency of pressure calculation for fluid-solid sub-interactions that can occur under ML regions. The Finite Difference Method (FDM) results have been compared with Computational Fluid Dynamics (CFD) simulation to validate the newly developed model. Hence, the proposed optimized solution method will provide valuable insight to researchers and industry engineers interested in simulating the ML problem where the effect of the fluid-solid interface can be captured effectively to improve reliability in the calculation of the life expectancy of the lubricated parts.
Analysis of Flow Characteristics of a Debris Filter in a Condenser Tube Cleaning System
Authors: Jung Da Woon , Lim Young-Chan , Seo Chung-Won , Kim Dong Sun , Lee Seung Yul , Suh Hyun Kyu
Published: April 2023

In a power plant that uses seawater as a coolant, a debris filter is required to remove foreign substances from the seawater, and differential pressure leads to a decrease in the coolant flow rate, leading to a decrease in power generation efficiency. In this study, analysis was performed under different initial flow velocity conditions of 1.5m/s, 2.0m/s, and 2.5m/s for a debris filter used in a power plant to understand flow characteristics in CTCS. The flow and differential pressure characteristics of a CTCS with an installed debris filter were considered in a comparative analysis of velocity, pressure, and turbulent kinetic energy distribution. The results confirmed that a vortex was generated in the pipe with the debris filter, apparently due to the collision of the flow with the bracket of the debris filter. As the flow rate increased, the range of the vortex increased, causing a loss in flow.
Comparison of Uni- and Multimodal Interfaces for Spatial Human-Robot Interaction
Authors: Chojecki Paul , Strazdas Dominykas , Przewozny David , Gard Niklas , Runde Detlef , Hoerner Niklas , Al-Hamadi Ayoub , Eisert Peter , Bosse Sebastian
Published: April 2023

Multimodal user interfaces hold the promise to enable natural and intuitive means of human-machine interaction. But is the effort of using many sensors rewarded by the users - or is a single modality sufficient? For an industrial use case of a weld seam inspection workstation we study three independent interfaces (augmented spatial button interaction on (1) a workpiece or (2) a worktable and through (3) speech commands) and their combination (4). While users preferred the interaction on the augmented worktable when comparing single modalities, they used all three in multimodal user interface. From the isolated test of an input modality it is not possible to infer its use in a complex system. Therefore, the effort implementing and using multiple input modalities is reasonable.
Reconfiguration Analysis and Characteristics of a Novel 8-link Variable-DOF Planar Mechanism with Five Motion Modes
Authors: Kong Xianwen , Wang Jieyu
Published: April 2023

Variable-DOF (or kinematotropic) mechanisms are a class of reconfigurable mechanisms. The number of variable-DOF multi-loop planar mechanisms proposed so far is very limited. This paper proposes a novel 8-link variable-DOF planar mechanism with five motion modes. Firstly, a description of the 8-link variable-DOF planar mechanism is presented. Reconfiguration analysis of the 8-link mechanism is then carried out using an elimination and algebraic geometry hybrid approach. The analysis shows that the 8-link mechanism has one 2-DOF motion mode and four 1-DOF motion modes and can switch among three motion modes at four transition configurations and between two motion modes at the remaining four transition configurations. Geometric characteristics of the mechanism in different motion modes are also revealed. Unlike the variable-DOF planar mechanisms found in literature, the proposed 8-link mechanism has two inactive joints in one of its 1-DOF motion modes, and both 4R kinematic sub-chains of the mechanism must appear as parallelograms in a pair or anti-parallelograms in a pair in the same motion mode. As a by-product, a method for factoring trigonometric functions in two angles is proposed.
Effect of Temperature on Salmonella enterica subsp. enterica ser. Javiana, Listeria monocytogenes, and Listeria innocua Persistence in Hydroponic Nutrient Solution
Authors: Dhulappanavar Gayatri Rajashekhar , Gibson Kristen Elizabeth
Published: April 2023

This study aimed to determine the persistence of Salmonella Javiana, Listeria monocytogenes, and Listeria innocua in hydroponic nutrient solution (NS) at 15, 25, 30, and 37°C over a 21-day period to mimic time from seedling to mature lettuce. Bacteria were inoculated in modified Hoagland's NS at 106 CFU/ml and maintained at 15, 25, 30, and 37°C. Samples were collected at various time points and quantified. Data were analyzed using a mixed effect model to compare mean log CFU/ml obtained from each sampling point for all three bacteria at four different temperatures. Least mean squares were calculated to compare mean log CFU/ml. Tukey-Kramer honest significant difference test was used to compare mean values. At all temperatures, S. Javiana persisted in NS throughout the 21-day study period, compared to L. innocua and L. monocytogenes where persistence was limited to d 5 to d 14 and d 1 to d 14, respectively. Similarly, decimal reduction values (D-values) of S. Javiana indicated longer persistence in nutrient solution than L. innocua and L. monocytogenes at most temperatures. For instance, at 15°C and 25°C D-values for S. Javiana were estimated at 82 and 26 d, respectively, compared to D-values of 3.6 and ~3 d for L. monocytogenes. Data indicate that temperature has minimal effect on S. Javiana and thus may pose a greater risk during hydroponic production of leafy greens due to longer survival in NS when compared to Listeria spp. This study furthers the understanding of potential food safety risks associated with hydroponic systems and may aid in developing management strategies to reduce foodborne outbreaks, fresh produce recalls, and economic losses.
Optimization of Magnetohydrodynamic Parameters in Two- Dimensional Incompressible Fluid Flow on a Porous Channel
Authors: Onyancha Carolyne , Kerongo Joash , Bulinda Vincent
Published: April 2023

Optimization of Magnetohydrodynamics parameters on the velocity profile and temperature distribution of incompressible fluid flow on a porous channel was evaluated. The fluid flow was considered to be unsteady, incompressible and flowing in 2-D in porous channel. The effects of magnetic parameter, Darcy’s number and fluid pressure on velocity profiles, and the effect of variable viscosity and Eckert number on temperature distribution in incompressible fluid flow were determined. The flow was considered to be in a channel running along the x-axis on which the magnetic field exist and finally along the y-axis on the porous part of the channel. The resulting model equations were solved by Finite Difference Method (FDM) in MATLAB software. Analysis of results indicated that increasing Darcy’s number and fluid pressure leads to increase in fluid velocity profile, while increasing magnetic parameter decreases fluid velocity profile. Also, it was observed that increase in both Eckert number and fluid viscosity lead to increase in temperature distribution. Optimization in temperature was achieved by increasing the magnetic field while viscosity was optimized by increasing the length of the porous part of the channel. This study will helpful to contribute alternative equations and methodology to engineering and in factories where getting the MHD parameters optimally is the main objective, particularly on temperature, velocity and pressure.
Characteristics of Corrosion Products of Friction-type High-Strength Bolted Joints of Steel Bridge: A Case Study
Authors: Xu Gangnian , Xu Wenpeng , Dong Xu , Fan Shengwei , Wang Xianggang
Published: April 2023

This paper analyzed the main diseases of the friction high-strength bolt (FHSB) joints in order to study the characteristics of the corrosion products of the joints in steel bridge and the influence factors. Seven representative FHSB connection pairs and eight steel plate samples were selected from the Dongying Shengli Yellow River Bridge, which has been in operation for 33 years. Then Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and X-Ray Diffraction (XRD) were used to analyze the microscopic morphology and chemical composition of the corroded surface of the samples. Finally, this paper discussed the relationship between the corroded sample surface and the environmental corrosion. The research results showed that construction quality problems, such as non-standard hole expansion, segmental slab joint dislocation and contact surface pollution, accelerated corrosion of the contact surface. With the increase of corrosion degree of joints, the contact surface of aluminum spraying layer gradually changed from a rugged and dense state to a smooth and porous powder state. With the corrosion of the steel plate substrate, the contact surface gradually changed from a fluffy stratified state to a surface bonding state. It was inferred that the friction coefficient of the FHSB connection node on the corroded aluminum sprayed contact surface first decreased and then increased. The corroded node samples detected not only a large number of S and Cl elements, but also the oxides of Mn, Si and other elements as well as FeS. It was speculated that node corrosion was also related to atmospheric (acid rain) and industrial dust and other corrosive environments. Almost all samples detected the component SiO2 of the Yellow River soil, as well as Mg, Ca, K, Na and other elements at the same time, which is basically consistent with the component elements of the Yellow River soil. Therefore, it was inferred that it was related to the inclusion of the Yellow River soil.
Evaluation of Antibiotic Prescribing Pattern Using WHO Access, Watch and Reserve Classification in Kinshasa, Democratic Republic of Congo
Authors: Kakumba Jocelyn Mankulu , Kindenge Jeremie Mbinze , Kapepula Paulin Mutwale , Iyamba Jean Marie Liesse , Mashi Murielle Longokolo , Mulwahali Jose Wambale , Kialengila Didi Mana
Published: April 2023

Background: The AWaRe tool was set up by the World Health Organization (WHO) to promote the rational use of antimicrobials. Indeed, this tool classifies antibiotics into four groups, Access, Watch, Reserve and not-recommended antibiotics. In Republic Democratic of Congo, data on antibiotic dispensing (prescribing) by health professionals according to the AWaRe classification are scarce. In this research work, we aimed to explore antibiotic dispensing pattern from health professionals according to the WHO AWaRe classification to strengthen the national antimicrobial resistance plan.
Methods: For this purpose, a survey was conducted from July to December 2022 in the district of Tshangu in Kinshasa. From randomly selected drugstores, drug-sellers were interviewed and randomly selected customers attending those drugstores were included in the study for medical prescriptions collection. The prescribed antibiotics were classified into the Access, Watch, Reserve and not recommended antibiotics group and by antibiotics number by prescription among pharmacies surveyed.
Results: Of 400 medical prescriptions collected, 301 (75.25%) contained antibiotics. Of 301 prescriptions containing antibiotics, 164 (164/301; 54.5%) contained one antibiotic, 117 (117/301; 38.9%) two antibiotics, 15 (15/301; 5%) three antibiotics and 5 (5/301; 1.6%) 4 antibiotics. Out of the total of 463 antibiotics prescribed, 169 (169/463; 36.5%) were from the Access group, 200 (200/463; 43.2%) from the Watch group and 94 (94/463; 20.3%) from not recommended antibiotics group, respectively. Based on the anatomical, therapeutic and chemical (ATC) classification, it can be seen that third generation cephalosporins contained 34.33% of the prescribed antibiotics, followed by penicillins 17.17%, macrolides 7.63%, aminoglycosides 7. 36% and Imidazoles 7.36%, thus accounting approximately for 74% of the classes of antibiotics prescribed. Of the 463 antibiotics prescribed, the most frequently prescribed antibiotics were Ceftriaxone (21.38%), Amoxicillin (11.01%), Gentamycin (5.61%), Amoxicillin-clavulanic acid (5 .61%), Azithromycin (4.97%) and Metronidazole (4.75%), thus accounting for approximately 54% of all antibiotics prescribed.
Conclusion: These results highlight the importance of strict implementation of the national plan to combat antimicrobial resistance and the need to train health workers in the correct application of the WHO AWaRe classification.
Current Therapies for Cholestatic Diseases
Authors: Méndez-Sánchez Nahum , Coronel-Castillo Carlos E. , Ordoñez-Vázquez Ana L
Published: April 2023

Cholestasis is a condition defined as an abnormal decrease of bile flow due to progressive pathological states or cholestatic liver diseases that affect the biliary tree at intrahepatic and extrahepatic level. It induces complications such as cirrhosis, liver failure, malignancies, pruritus, fatigue, bone disease and nutritional deficiencies that merit close follow-up and specific interventions to improve quality of life. Furthermore, cholestasis can progress to end-stage liver disease and represents an entity with high morbidity and mortality; and economic burden, Therefore, it is important that clinicians understand the treatment options for cholestatic liver diseases. This review addresses the pathophysiology of cholangiopathies, a general view of current treatments and their molecular targets, and a specific review of those groups of drugs. The objective is to provide clinicians with an overview of the current treatment of cholangiopathies based on evidence on its efficacy and safety.
The Future of Fisheries Co-Management in The Context of Sustainable Blue Economy and Green Deal: There Is No Green Without Blue !
Authors: Kyvelou Stella Sofia , Ierapetritis Dimitrios G. , Chiotinis Michalis
Published: April 2023

Appropriate governance structures, among other factors, are extremely important for the fishery dependent communities to develop integrated territorial development and adaptive capacity to change, including the climate one. This paper intends to assess to what extent fisheries co-management schemes (e.g Fisheries LAGs, being regional/local governance instruments in fishing communities on a pan-European scale) are strengthening sustainability, i.e improving energy efficiency, promoting RES, coping with climate crisis, minimizing environmental impacts, and promoting sustainable blue economy. Since blue growth potential is mostly produced in coastal, marine and insular spaces, the research lens focuses on the Greek FLAGs and their capacity of aligning climate adaptation, blue economy and Green Deal targets. Therefore, a co-development process with FLAG managers is used to map their efficiency in pursuing Green Deal objectives. The findings reveal the scarcity of sustainability and blue economy related strategies. The paper concludes that transition to a post-carbon blue economy on a local level, requires the understanding of the evolutionary character both of fishery dependent local communities, due also to their bonding with marine ecosystems, and of fisheries co-management schemes. The latter as coherent, multi-sectoral schemes dedicated to their region’s integrated territorial development, may boost dialogue and cooperation towards an effective Maritime Spatial Planning, promoting harmonization between local development strategies and EU policies. MSP as an evolutionary governance process itself, can be a driver for making FLAGs evolve, towards strengthening commonization and blue justice and equity for fishers.
Resilient Security Framework Using TNN and Blockchain for IoMT
Authors: Alsemmeari Rayan A. , Dahab Mohamed Yehia , Alsulami Abdulaziz A. , Alturki Badraddin , Algarni Sultan
Published: April 2023

The growth in the Internet of Things (IoT) devices in the healthcare sector enables the new era of the Internet of Medical Things (IoMT). However, IoT devices are susceptible to diverse cybersecurity attacks and threats that lead to negative consequences. Cyberattacks can harm not just the IoMT devices being used but also human life. Currently, several security solutions are proposed to enhance the security of the IoMT, which uses machine learning (ML) and blockchain. ML can be used to develop detection and classification methods to identify cyberattacks targeting IoMT devices in the healthcare sector. In addition, blockchain technology enables a decentralized approach to the healthcare system and eliminates some disadvantages of a centralized system, such as a single point of failure. This paper proposes a resilient security framework integrating a Tri-layered Neural Network (TNN) and blockchain technology in the healthcare domain. The TNN detects anomalies in data measured by medical sensors to find fraudulent data. Therefore, cyberattacks are detected and discarded from the IoMT system before data is processed at the fog layer. In addition, a blockchain network is used in the fog layer to ensure that the data is not altered, boosting the integrity and privacy of the medical data. The experimental results show that the TNN and blockchain models produce the expected result. Furthermore, the accuracy of the TNN model reached 99.99% on the F1-score accuracy metric.
Intrapulse Correlated Dynamics of Self-Phase Modulation and Spontaneous Raman Scattering in Synthetic Diamond Excited and Probed by Positively Chirped Ultrashort Laser Pulses
Authors: Kudryashov Sergey. , Danilov Pavel , Chen Jiajun
Published: April 2023

In synthetic diamond plate, the intrapulse correlated dynamics of self-phase modulation and spontaneous Raman scattering by optical phonons were for the first time directly investigated for tightly focused (focusing numerical aperture NA = 0.25) positively-chirped visible-range ultrashort laser pulses with variable durations (0.3-9.5 ps) and energies, transmitted through the sample. The observed modulation of the transmitted light spectra and Stokes Raman scattering spectra for the different pulse durations were related to nonthermal excitation of nonlinear phonon polarization and its eventual picosecond-scale suppression due to thermal decay of optical phonons on the timescale of electron-phonon thermalization in the material.
Cognitive Impairments, Neuroinflammation and Blood Brain Barrier Permeability in Mice Exposed to Chronic Sleep Fragmentation During the Daylight Period.
Authors: Puech Clementine , Badran Mohammad , Runion Alexandra R , Barrow Max B , Cataldo Kylie , Gozal David
Published: April 2023

Obstructive sleep apnea (OSA) is a chronic condition characterized by intermittent hypoxia (IH) and sleep fragmentation (SF). In murine models, chronic SF can impair endothelial function and induce cognitive declines. These deficits are likely mediated, at least in part, by alterations in Blood-Brain Barrier (BBB) integrity. Male C57Bl/6J mice were randomly assigned to SF or sleep control (SC) conditions for 4 or 9 weeks, and in a subset 2 or 6 weeks of normal sleep recovery. Presence of inflammation and microglia activation were evaluated. Explicit memory function was assessed with the novel object recognition (NOR) test, while BBB permeability was determined by systemic dextran-4kDA-FITC injection and Claudin 5 expression. SF exposures resulted in decreased NOR performance and in increased inflammatory markers and microglial activation as well as enhanced BBB permeability. Explicit memory and BBB permeability were significantly associated. BBB permeability remained elevated after 2 weeks of sleep recovery (p<0.01) and returned to baseline values only after 6 weeks. Chronic SF exposures mimicking the fragmentation of sleep that characterizes patient with OSA elicits evidence of inflammation in brain regions and explicit memory impairments in mice. Similarly, SF is also associated with increased BBB permeability, the magnitude of which is closely associated with cognitive functional losses. Despite normalization of sleep patterns, BBB functional recovery is a protracted process that merits further investigation.
SGLT -2 Inhibitors and the Inflammasome: What's next in the 21st century?
Authors: Kounatidis Dimitris , Vallianou Natalia , Evangelopoulos Angelos , Vlachodimitris Ioannis , Grivakou Eugenia , Kotsi Evangelia , Dimitriou Krystalia , Skourtis Alexandros , Mourouzis Iordanis
Published: April 2023

Nucleotide-binding domain like receptor protein 3 (NLRP3) inflammasome in the kidney and the heart is increasingly being suggested to play a key role in mediating inflammation. In the kidney, NLRP3 activation has been associated with the progression of diabetic kidney disease. In the heart, activation of the NLRP3 inflammasome has been related to enhanced release of interleukin-1β (IL-1β) and the subsequent induction of atherosclerosis and heart failure. Apart from their glucose-lowering effects, SGLT-2 Inhibitors have been documented to attenuate activation of the NLRP3, thus, resulting in the constellation of an anti-inflammatory milieu. In this review, we will focus on the interplay between SGLT-2 Inhibitors and the inflammasome in the kidney, the heart and the neurons in the context of diabetes mellitus and its complications.
Pedestrian Avoidance Method Considering Passenger Comfort for Autonomous Personal Mobility Vehicles
Authors: Yoshitake Hiroshi , Isono Yosuke , Shino Motoki
Published: April 2023

During the autonomous navigation of personal mobility vehicles (PMVs) in pedestrian spaces, avoiding collisions with pedestrians walking nearby is necessary. The avoidance paths of PMVs are affected by the behaviors of the pedestrians, which may also affect passenger comfort. Herein, a local path-planning method that considers passenger comfort to realize comfortable pedestrian avoidance during the autonomous navigation of PMVs in pedestrian spaces is proposed. First, the avoidance path and pedestrian behavior parameters affecting passenger comfort are investigated by evaluating passenger comfort in scenarios with different avoidance paths and pedestrian behaviors. Next, the requirements of a pedestrian avoidance method that considers passenger comfort are set based on the parameters affecting passenger comfort. Finally, a novel path-planning method that satisfies the requirements is proposed. The method is shown to generate comfortable paths in pedestrian spaces via a numerical simulation and participant experiment.
Study on Control for Prevention of Collision Caused by Failure of Localization for Map-Based Automated Driving Vehicle
Authors: Nishimura Shun , Omae Manabu
Published: April 2023

In demonstration experiments of automated driving vehicles, lane departures and collisions with roadside structures due to poor vehicle positioning and self-localization have been reported. In this study, we propose a promising method to prevent such departures and collisions, and then validate the proposed method by applying it to an actual automated driving vehicle. The proposed method monitors the target steering angles computed by the automated driving control and limits them before commanded the actuator when there is a risk of colliding with obstacles. As the above-mentioned control is lower-level, it can prevent an automated driving vehicle from colliding with obstacles without complicating upper-level controls. Experiments on an actual automated driving vehicle showed that the steering control structure of the proposed method could prevent an automated driving vehicle from colliding with obstacles by limiting its target steering angle. In addition, the method does not impose excessive limits on the steering angle when the automated driving vehicle follows a normal path and no risk of collision exists.
MGV Obstacle Avoidance Trajectory Generation Considering Vehicle Shape
Authors: Arai Yoshihide , Sago Takashi , Ueyama Yuki , Harada Masanori
Published: April 2023

This study investigates the application of obstacle avoidance trajectory generation considering the vehicle shape of a micro ground vehicle by successive convexification and state-triggered constraints. The avoidance trajectory is generated by numerical computation and path-following experiments are conducted to assess the generated trajectory. The numerical computation results indicate that the trajectory obtained by the algorithm successfully avoids obstacles considering the vehicle shape and satisfies the constraints. The experiment includes the model predictive control to follow the generated trajectory. Numerical computations and experiments confirm the usefulness of the trajectory generation algorithm.
Gesture Interface and Transfer Method for AMR by Using Recognition of Pointing Direction and Object Recognition
Authors: Ikeda Takahiro , Noda Naoki , Ueki Satoshi , Yamada Hironao
Published: April 2023

This paper describes a gesture interface for a factory transfer robot. Our proposed interface used gesture recognition to recognize the pointing direction, instead of estimating the point as in conventional pointing gesture estimation. When the autonomous mobile robot (AMR) recognized the pointing direction, it performed position control based on the object recognition. The AMR traveled along our unique path to ensure that its camera detected the object to be referenced for position control. The experimental results confirmed that the position and angular errors of the AMR controlled with our interface were 0.058 m and 4.7° averaged over five subjects and two conditions, which were sufficiently accurate for transportation. A questionnaire showed that our interface was user-friendly compared with manual operation with a commercially available controller.
Continuous-Time Receding-Horizon Estimation via Primal-Dual Dynamics on Vehicle Path-Following Control
Authors: Sato Kaito , Sawada Kenji
Published: April 2023

In vehicle control, state estimation is essential even as the sensor accuracy improves with technological development. One of the vehicle estimation methods is receding-horizon estimation (RHE), which uses a past series of the measured state and input of the plant, and determines the estimated states based on linear or quadratic programming. It is known that RHE can estimate the vehicular state to which the extended Kalman filter cannot be applied owing to modeling errors. This study proposes a new computational form of the RHE based on primal-dual dynamics. The proposed form is expressed by a dynamic system; therefore, we can consider the computational stability based on the dynamic system theory. In this study, we propose a continuous-time representation of the RHE algorithm and redundant filters to improve the convergence performance of the estimation and demonstrate its effectiveness through a vehicle path-following control problem.
Speed Control of Mobile Robots Using Vibration Stimuli from Bumpy Road Surface
Authors: Mizoguchi Ryosuke , Minami Yuki , Ishikawa Masato
Published: April 2023

Speed bumps and rumble strips have been introduced into the traffic infrastructure to improve traffic safety. When a vehicle travels on a road where speed bumps and rumble strips are installed, vibration stimuli are transmitted to the driver to encourage control of the speed and position of the vehicle. In this letter, speed bumps are applied to an automated driving system. More precisely, this letter considers the speed control of a mobile robot using vibration stimuli from bumpy road surfaces. We formulated a design problem for a speed control law for a mobile robot and proposed a controller that can adjust the speed according to road surface geometry. The performance of the proposed method was verified via simulation using Unity.
Turning at Intersections Using Virtual LiDAR Signals Obtained from a Segmentation Result
Authors: Adachi Miho , Honda Kazufumi , Miyamoto Ryusuke
Published: April 2023

We implemented a novel visual navigation method for autonomous mobile robots, which is based on the results of semantic segmentation. The novelty of this method lies in its control strategy used for a robot during road-following: the robot moves toward a target point determined through semantic information. Previous implementations of the method sometimes failed to turn at an intersection owing to a fixed value of the turning angle. To address this issue, this study proposes a novel method for turning at an intersection using a control method based on a target point, which was originally developed for road-following. Here, an intersection is modeled as consisting of multiple straight roads. Evaluation using the CARLA simulator showed that the proposed method could accurately estimate the parameters representing a virtual road composing an intersection. In addition, run experiments conducted at the Ikuta Campus of Meiji University using an actual robot confirmed that the proposed method could appropriately make turns at intersections.
Localization System for Vehicle Navigation Based on GNSS/IMU Using Time-Series Optimization with Road Gradient Constrain
Authors: Takanose Aoki , Kondo Kaito , Hoda Yuta , Meguro Junichi , Takeda Kazuya
Published: April 2023

In this paper, we propose a GNSS/IMU localization system for mobile robots when wheel speed sensors cannot be attached. Highly accurate location information is required for autonomous navigation of mobile robots. A typical method of acquiring location information is to use a Kalman filter for position estimation. The Kalman filter is a maximum-likelihood estimation method that assumes normally distributed noise. However, non-normally distributed GNSS multipath noise that frequently occurs in urban environments causes the Kalman filter to break down, and degrades the estimation performance. Other GNSS/IMU localization methods capable of lane-level estimation in urban environments use wheel speed sensors, which are unsuitable for the present situation. In this study, we aim to improve the performance of lane-level localization by adding a vehicle speed estimation function to adapt the method to those requiring wheel speed sensors. The proposed method optimizes time-series data to accurately compensate for accelerometer bias errors and reduce GNSS multipath noise. The evaluation confirmed the effectiveness of the proposed method, with improved velocity and position estimation performance compared with the Kalman filter method.
Detection and Localization of Thin Vertical Board for UAV Perching
Authors: Kominami Takamasa , Paul Hannibal , Shimonomura Kazuhiro
Published: April 2023

An autonomous vision-based landing system with a passively driven perching mechanism for a UAV is described in this paper. In our previous research, we developed a passively driven perching mechanism that can land on various shapes. The goal of this study was to achieve automatic perching on a thin vertical board using the passive mechanism. For autonomous perching, an RGB-D camera was used to detect and track a perching target and automatically control the flight of the UAV to the target position. The combination of RGB-D tracking system for thin vertical board and self-position estimation from another tracking camera mounted on the UAV enabled automatic perching. The results of the experiment using the passively driven perching mechanism and autonomous system verified that it is possible to land on objects such as road signs at heights, by using the integrated system for object detection and UAV control. In the experiment, the UAV was controlled to fly autonomously to the vicinity of the target and then perched on a 2 mm thick board.
Aerodynamic Drag of a Tilt-Rotor UAV During Forward Flight in Rotary-Wing Mode
Authors: Urakubo Takateru , Wada Koki , Sabe Kohtaro , Hirai Shinji , Miwa Masafumi
Published: April 2023

This paper examines the aerodynamic drag force acting on a tilt-rotor UAV that has three mini fans and a main rotor with a tilt mechanism. The mini fans are embedded in the nose and the left and right wings. The main rotor is located near the center of the vehicle, and its front half is surrounded by the trailing edge of the nose in rotary-wing mode. The downward airflow from the fans and the main rotor generates an aerodynamic drag force called momentum drag, which is linearly proportional to the airspeed of UAV. To verify the existence of momentum drag, parameter identification of drag coefficients is performed from experimental data where the UAV flies forward in rotary-wing mode. The drag force is also investigated using computational fluid dynamics simulations. These experimental and numerical results are consistent with theoretical results based on momentum theory.
Application and Mechanical Evaluation of Polyarylate Fiber Rope in Wire Drive Mechanism of Robotic Surgical Instruments
Authors: Nojima Kanta , Tadano Kotaro , Haraguchi Daisuke
Published: April 2023

In this study, a polyarylate fiber rope, which is a high-strength synthetic fiber rope, is used in the wire drive mechanism of a multi-degree of freedom (DOF) robotic forceps to evaluate its mechanical practicability. Using a nonconducting material for the drive wire, different from typical use of metallic wires made of stainless steel and tungsten, a technology is developed to simplify the insulation structure significantly, decrease the diameter of the robotic surgical instrument, and lower its cost. In this study, first, a prototype of the multi-DOF robotic forceps equipped with a polyetheretherketone (PEEK) resin flexible wrist joint part with an external diameter of 5 mm is manufactured. The prototype is used to evaluate the assembling of a polyarylate fiber rope with a diameter of 0.34 mm in a multi-DOF mechanism and examine the endurance of the rope to mechanical motions under a single-use assumption. As fastening structures to assemble the rope – a crimp terminal using a hollow pipe and a thread knot – are examined individually by assembling them in the prototype robotic forceps and conducting strength tests of the tension generated by the drive. The test results show that the thread knot method exerts a stabler fastening strength than the hollow pipe method. However, a problem of the former is that the wire may break because of its strong contact with the edge of the hole of the wire guide. Subsequently, to evaluate the endurance of the rope to single-use operation motion, operation tests are conducted by implementing reciprocating bending motions of the flexible wrist joint part of the robotic forceps 1,000 times. The assembled rope endures the sliding within the flexible wrist joint part and the contact loading with the guide part and the fixed structure within the cartridge repeatedly. The endurance operation test results confirm that the drive transmission of the polyarylate fiber rope has sufficient mechanical endurance to 1,000 reciprocating bending motions of the PEEK flexible wrist joint part.
Investigation of Obstacle Prediction Network for Improving Home-Care Robot Navigation Performance
Authors: Yani Mohamad , Saputra Azhar Aulia , Chin Wei Hong , Kubota Naoyuki
Published: April 2023

Home-care manipulation robot requires exploring and performing the navigation task safely to reach the grasping target and ensure human safety in the home environment. An indoor home environment has complex obstacles such as chairs, tables, and sports equipment, which make it difficult for robots that rely on 2D laser rangefinders to detect. On the other hand, the conventional approaches overcome the problem by using 3D LiDAR, RGB-D camera, or fusing sensor data. The convolutional neural network has shown promising results in dealing with unseen obstacles in navigation by predicting the unseen obstacle from 2D grid maps to perform collision avoidance using 2D laser rangefinders only. Thus, this paper investigated the predicted grid map from the obstacle prediction network result for improving indoor navigation performance using only 2D LiDAR measurement. This work was evaluated by combining the configuration of the various local planners, type of static obstacles, raw map, and predicted map. Our investigation demonstrated that using the predicted grid map enabled all the local planners to achieve a better collision-free path by using the 2D laser rangefinders only rather than the RGB-D camera with 2D laser rangefinders with a raw map. This advanced investigation considers that the predicted map is potentially helpful for future work in the learning-based local navigation system.
The development of local plants e-module based on mobile learning for the subjects of botany and plant morphology
Authors: Masing Feliksitas Angel , Sila Vinsensia Ulia Rita
Published: April 2023

This research aims to know: 1) develop a local plant e module from Timor Tengah Utara Regency based on android mobile, 2) test the feasibility of a local plant e module from Timor Tengah Utara Regency based on android mobile on the aspect of substance/material and aspects of learning media. This type of research is development research using the Design and Development Research (DDR) method at the Validity stage which includes development, internal validation by material experts and learning media experts and external validation by third semester students of Biology Education Study Program, University of Timor as test participants. The results of this study are; 1) development of local plant modules from Timor Tengah Utara Regency based on mobile android in accordance with the Design and Development Research (DDR) development model at the Validity stage which includes development, internal validation, and external validation, 2) local plant modules from Timor Tengah Utara Regency based on android mobile is feasible to use in terms of substance/material and learning media. Based on the assessments of material experts and learning media experts, this module is in the "good" category, while the assessment by students as trial participants is in the "very good" category. The content of the E module is local plants originating from Timor Tengah Utara Regency which consists of several plants such as Santalum album, Pinus merkusii, Piper majusculum Blume, Coffea arabica, Arenga pinnata, Aleurites moluccana, Rhizophora apiculata, and so on. Each plant presented in the e module is equipped with its classification and morphology so that it is very useful for Biology students at the University of Timor in studying plant botany and morphology courses.
Advantages of Posterior Indirect Decompression Surgery in Thoracolumbar Burst Fractures with Neurologic Symptoms
Authors: Lim Jung Won , Park Jin Hoon , Shin Hong Kyung , Joo Jeong Kyun , Lee Jung Jae
Published: April 2023

Objective: Approximately 90% of spinal fractures occur at the thoracolumbar (T-L) junction and may be accompanied by neurological symptoms, in which decompression and post-fixation are generally performed. However, decompression surgery can aggravate patients’ symptoms due to adverse incidents, such as developing postoperative hematomas or iatrogenic spinal cord injury. This study compared the surgical and radiographic outcomes of patients with T-L junction burst fractures and neurological deficits who underwent direct or indirect decompression.Methods: We retrospectively reviewed all patients who had undergone posterior surgical treatment for T-L junction burst fractures with neurologic deficits. Patients were classified according to the procedure: indirect decompression (group 1) or spinal decompression through laminectomy and facetectomy (group 2). Clinical results and radiologic findings were compared between the two groups for 2 years.Results: Among 57 patients who met the inclusion criteria, 29 were categorized into group 1, and 28 were categorized into group 2. Group 1 had a statistically significantly lower Oswestry Disability Index score than group 2 at the final follow-up visit (p=0.03). In group 1, both the T-L junction angle and wedge angle of the injured vertebrae improved significantly, both immediately after surgery (p=0.02 and p=0.01, respectively) and at the final follow-up visit (p=0.01 and p=0.01, respectively). In group 2, the difference between the pelvic incidence and lumbar lordosis was significantly greater than in group 1 at the final follow-up visit (p=0.02).Conclusion: This study confirmed that symptoms could be sufficiently improved with indirect decompression, which should be kept in mind for cases where it is difficult to perform direct decompression,
A study on the regulation of Non-indictment in accusation case: Focusing on the review of cases
Authors:   Korean Association of Public Safety and Criminal Justice, Shin Kwan Woo
Published: April 2023

The purpose of this study is to present a reasonable control plan for the prosecution discretion of prosecutors who protect the safety of the social system as a representative of the public interest, Examining the institutional background of the prosecution's non-indictment. After processing and reviewing cases of non-prosecution dispositions in accusation cases, the direction of control of non-indictment was sought.
Prosecutors may institute prosecution or non-indictment by investigating cases in which complaints and accusations are forwarded by judicial police officers or cases in which direct complaints and accusations are prescribed by Acts and subordinate statutes. The control system for non-indictment by prosecutors is divided into internal control and external control. For dissatisfaction with the non-indictment of the accusation case, internal control measures are being prepared through ‘notice of the purpose and reason for the non-indictment’ and ‘appeal to the prosecution (reappeal)’.
In this study, the following matters were reviewed through the progress of cases of non-indictment and review of legal principles. For the first time, While acknowledging the fact of the actor's act, we discussed the wrong interpretation of the law that may not admit the establishment of a crime by changing the interpretation of the law. Also, In the discretionary judgment of suspension of indictment, additional factors for judgment on the possibility of blame related to the responsibility derived from the legal status of actors were examined. And, Once the prosecution appeal (reappeal) procedure, which is an internal control method for non-indictment recognized by the accuser, is completed, there is no longer any means of dissatisfaction in criminal procedures.
The direction of control sought through the review of non-indictment cases is as follows. First, the target cases should be expanded so that all accusation cases can be Application for Adjudication. Second, the standard and scope of the prosecutor's prosecution should be stipulated at the level of the law and order, and notified to the general public. Third, public procedures should be established so that the general public can read and copy the reason for non-indictment, which is a quasi-judicial judgment at the end of the investigation process.
This study lacks a discussion in connection with the appeal limit system for the judicial police officer's non-transfer decision in accusation cases. therefore. It should be supplemented from a macroscopic point of view of criminal justice procedures through future research.