Dear Editor,In this letter,we focus on the algebraic relationship between the coefficient matrices and the solution of the stochastic algebraic Riccati equation.It is revealed that,if the coefficient matrices are in a...Dear Editor,In this letter,we focus on the algebraic relationship between the coefficient matrices and the solution of the stochastic algebraic Riccati equation.It is revealed that,if the coefficient matrices are in an algebra,then the solution(and also the control gain in many cases)is also in the same algebra.The main result is verified by a numerical simulation.展开更多
Existing Internet of Things(IoT)systems that rely on Amazon Web Services(AWS)often encounter inefficiencies in data retrieval and high operational costs,especially when using DynamoDB for large-scale sensor data.These...Existing Internet of Things(IoT)systems that rely on Amazon Web Services(AWS)often encounter inefficiencies in data retrieval and high operational costs,especially when using DynamoDB for large-scale sensor data.These limitations hinder the scalability and responsiveness of applications such as remote energy monitoring systems.This research focuses on designing and developing an Arduino-based IoT system aimed at optimizing data transmission costs by concentrating on these services.The proposed method employs AWS Lambda functions with Amazon Relational Database Service(RDS)to facilitate the transmission of data collected from temperature and humidity sensors to the RDS database.In contrast,the conventional method utilizes AmazonDynamoDB for storing the same sensor data.Data were collected from 01 April 2022,to 26 August 2022,in Tokyo,Japan,focusing on temperature and relative humiditywitha resolutionof oneminute.The efficiency of the twomethods—conventional andproposed—was assessed in terms of both time and cost metrics,with a particular focus on data retrieval.The conventional method exhibited linear time complexity,leading to longer data retrieval times as the dataset grew,mainly due to DynamoDB’s pagination requirements and the parsing of payload data during the reading process.In contrast,the proposed method significantly reduced retrieval times for larger datasets by parsing payload data before writing it to the RDS database.Cost analysis revealed a savings of$1.56 per month with the adoption of the proposed approach for a 20-gigabyte database.展开更多
Aggregation-induced emission luminogens(AIEgens)exhibit viscosity-responsive behavior resembling those of molecular rotors;however,their response mechanisms are more complex and cannot be adequately described using si...Aggregation-induced emission luminogens(AIEgens)exhibit viscosity-responsive behavior resembling those of molecular rotors;however,their response mechanisms are more complex and cannot be adequately described using simple rotational models.AIEgens demonstrate intricate dynamics that are highly dependent on their molecular structures.In this study,we synthesized water-soluble derivatives of representative AIEgens,including tetraphenylethene(TPE),bis(N,N-dialkylamino)anthracene(BDAA),and bridged stilbene,and systematically investigated the dependence of their photophysical properties in water/glycerol mixed solvents on temperature and viscosity.To elucidate the origin of their viscosity responsiveness,quantum chemical calculations were conducted to analyze their potential energy surfaces(PESs).The results revealed that compared to typical molecular rotors,these AIEgens exhibit significantly higher sensitivity to viscosity in low-viscosity regions.Notably,for TPE and BDAA derivatives,the viscosity responsiveness was found to be governed not by the activation energy barrier(ΔE_(a))based on the PES,but rather by the viscosity-dependent constraints on molecular structural changes.Furthermore,molecules possessing multiple aromatic rings or large,flexible,rotatable moieties were found to exhibit enhanced sensitivity to viscosity due to increased frictional interactions in solutions.This study provides critical insights into the mechanistic origins of the viscosity responsiveness of AIEgens,thereby advancing the fundamental understanding of their behavior and expanding their potential application as viscositysensitive probes.展开更多
In order to verify the synthesis pathway of linoleic acid(LA)to generate arachidonic acid(ARA),the functions ofΔ6 FAD and Elovl 5 in Apostichopus japonicus were tested by heterologous expression in Pichia pastoris.A ...In order to verify the synthesis pathway of linoleic acid(LA)to generate arachidonic acid(ARA),the functions ofΔ6 FAD and Elovl 5 in Apostichopus japonicus were tested by heterologous expression in Pichia pastoris.A 60-day feeding experiment was conducted to evaluate the effects of dietary LA and ARA on growth,polyunsaturated fatty acids(PUFA)biosynthesis and im-mune function of A.japonicus.Seven diets containing graded levels of LA or ARA were formulated,and one diet without PUFA was applied as a control.The results confirmed thatΔ6 FAD from A.japonicus has a double desaturation ability ofΔ6 andΔ5 for PUFA,and it works together with Elovl 5 enzyme play important roles in biosynthesis of ARA from LA.With increasing dietary LA from 4.9 to 12.1 g/kg,the expressions ofΔ6 FAD and Elovl 5,levels of LA,ARA and EPA in tissues increased,and the activities of ACP,AKP and CAT enzymes in intestine initially increased and then decreased.Additionally,by increasing dietary ARA from 0.7 to 3.8 g/kg,the contents of ALA,EPA and DHA decreased,while theΔ6 FAD expression and the activities of ACP,AKP and CAT in intes-tine increased significantly.Therefore,appropriate dietary levels of LA(12.1 g/kg)or ARA(3.8 g/kg)build a reasonable composi-tion of n-3/n-6 PUFA in A.japonicus,and improved its growth,antioxidant capacity and immunological defenses.展开更多
The coercivity of Sm-Fe-N/Zn magnets is strongly influenced by the composition and distribution of grain boundary phases.In this study,a Zn layer was uniformly deposited onto the surface of Sm-Fe-N powders via an inno...The coercivity of Sm-Fe-N/Zn magnets is strongly influenced by the composition and distribution of grain boundary phases.In this study,a Zn layer was uniformly deposited onto the surface of Sm-Fe-N powders via an innovative electrodeposition method,followed by a twostep thermal treatment process(hot-pressing+annealing)to precisely control the formation of theГ-FeZn phase and the grain boundary structure.The results indicate that annealing at 430℃promotes the uniform distribution of theΓ-FeZn phase along the grain boundaries,achieving a coercivity of 14.60 kOe—nearly three times higher than that of the untreated sample.Transmission electron microscopy(TEM)analysis reveals that increasing the annealing temperature enhances Zn mobility and diffusion at the grain boundaries,which facilitates the gradual formation of a continuous T-FeZn phase encapsulating the magnetic particles.This structure effectively suppresses exchange coupling between grains,thereby significantly enhancing coercivity.However,when the temperature exceeds 450℃,excessive Zn diffusion leads to the formation of a Sm-Fe(Zn)-N intermediate phase,which weakens the anisotropy field and causes a reduction in coercivity.Unlike previous studies that primarily focused on the presence of the T-FeZn phase,the present work achieves synergistic optimization via electrodeposition and temperature regulation,providing a deeper understanding of the intrinsic relationship among Zn diffusion,grain boundary evolution,and magnetic properties.These findings present a novel strategy and theoretical basis for the design of high-performance Sm-Fe-N magnets.展开更多
This study explores the combination of ultrasound technology with a detection algorithm to categorize flow regimes in bubble columns used for aeration in aquaculture.An ultrasonic velocity profiler is used to obtain t...This study explores the combination of ultrasound technology with a detection algorithm to categorize flow regimes in bubble columns used for aeration in aquaculture.An ultrasonic velocity profiler is used to obtain the standard deviation of the bubble velocity distributed throughout the column.The bubble velocity data for three known flow regimes were used to develop a probability density function(PDF)classification model.The experimental apparatus consisted of a circular tank equipped with a bubble generator and gas hold-up monitoring systems.The flow regimes of the experimental fluid were determined,and the classification was conducted via the PDF method.The results demonstrate that the classification accuracy is not lower than that of traditional machine learning methods.展开更多
Traumatic spinal cord injury(SCI)is a devastating central nervous system(CNS)disorder characterized by significant neurological dysfunction and sensory loss,and effective therapies that prevent neuronal loss and funct...Traumatic spinal cord injury(SCI)is a devastating central nervous system(CNS)disorder characterized by significant neurological dysfunction and sensory loss,and effective therapies that prevent neuronal loss and functional recovery remain elusive.After SCI,lesions are surrounded by neuroprotective borders formed by newly proliferated reactive astrocytes.Astrocyte proliferation and activation mediate the formation and function of the glial scar and influence the balance between protection and inflammation.展开更多
Traffic at urban intersections frequently encounters unexpected obstructions,resulting in congestion due to uncooperative and priority-based driving behavior.This paper presents an optimal right-turn coordination syst...Traffic at urban intersections frequently encounters unexpected obstructions,resulting in congestion due to uncooperative and priority-based driving behavior.This paper presents an optimal right-turn coordination system for Connected and Automated Vehicles(CAVs)at single-lane intersections,particularly in the context of left-hand side driving on roads.The goal is to facilitate smooth right turns for certain vehicles without creating bottlenecks.We consider that all approaching vehicles share relevant information through vehicular communications.The Intersection Coordination Unit(ICU)processes this information and communicates the optimal crossing or turning times to the vehicles.The primary objective of this coordination is to minimize overall traffic delays,which also helps improve the fuel consumption of vehicles.By considering information from upcoming vehicles at the intersection,the coordination system solves an optimization problem to determine the best timing for executing right turns,ultimately minimizing the total delay for all vehicles.The proposed coordination system is evaluated at a typical urban intersection,and its performance is compared to traditional traffic systems.Numerical simulation results indicate that the proposed coordination system significantly enhances the average traffic speed and fuel consumption compared to the traditional traffic system in various scenarios.展开更多
Graph Neural Networks(GNNs)have proven highly effective for graph classification across diverse fields such as social networks,bioinformatics,and finance,due to their capability to learn complex graph structures.Howev...Graph Neural Networks(GNNs)have proven highly effective for graph classification across diverse fields such as social networks,bioinformatics,and finance,due to their capability to learn complex graph structures.However,despite their success,GNNs remain vulnerable to adversarial attacks that can significantly degrade their classification accuracy.Existing adversarial attack strategies primarily rely on label information to guide the attacks,which limits their applicability in scenarios where such information is scarce or unavailable.This paper introduces an innovative unsupervised attack method for graph classification,which operates without relying on label information,thereby enhancing its applicability in a broad range of scenarios.Specifically,our method first leverages a graph contrastive learning loss to learn high-quality graph embeddings by comparing different stochastic augmented views of the graphs.To effectively perturb the graphs,we then introduce an implicit estimator that measures the impact of various modifications on graph structures.The proposed strategy identifies and flips edges with the top-K highest scores,determined by the estimator,to maximize the degradation of the model’s performance.In addition,to defend against such attack,we propose a lightweight regularization-based defense mechanism that is specifically tailored to mitigate the structural perturbations introduced by our attack strategy.It enhances model robustness by enforcing embedding consistency and edge-level smoothness during training.We conduct experiments on six public TU graph classification datasets:NCI1,NCI109,Mutagenicity,ENZYMES,COLLAB,and DBLP_v1,to evaluate the effectiveness of our attack and defense strategies.Under an attack budget of 3,the maximum reduction in model accuracy reaches 6.67%on the Graph Convolutional Network(GCN)and 11.67%on the Graph Attention Network(GAT)across different datasets,indicating that our unsupervised method induces degradation comparable to state-of-the-art supervised attacks.Meanwhile,our defense achieves the highest accuracy recovery of 3.89%(GCN)and 5.00%(GAT),demonstrating improved robustness against structural perturbations.展开更多
As a closed-loop learning control method,repetitive control has been widely used in a variety of areas from appliances to aviation.A repetitive control system features perfect reference tracking and disturbance reject...As a closed-loop learning control method,repetitive control has been widely used in a variety of areas from appliances to aviation.A repetitive control system features perfect reference tracking and disturbance rejection in the steady state for periodic signals with a fixed period.This characteristic is important not only for conventional technologies and conventional industries but also for advanced technologies and emerging industries.This paper first explains the concept of repetitive control from its original idea.Next,it describes the structure of a repetitive controller as an internal model and shows the respective points of continuous-and discrete-time repetitive control.It presents a categorized list of practical applications of repetitive control.Moreover,two concrete applications,namely the control of a robotic manipulator and a rotating system,demonstrate the validity of the method with experimental results.Several current studies in this field are also reviewed,and some challenges and future studies for repetitive control are provided.展开更多
Wide-bandgap two-dimensional (2D) β-TeO_(2) has been reported as a high-mobility p-type transparent semiconductor [Nat. Electron. 4 277 (2021)], attracting significant attention. This "breakthrough" not onl...Wide-bandgap two-dimensional (2D) β-TeO_(2) has been reported as a high-mobility p-type transparent semiconductor [Nat. Electron. 4 277 (2021)], attracting significant attention. This "breakthrough" not only challenges the conventional characterization of TeO_(2) as an insulator but also conflicts with the anticipated difficulty in hole doping of TeO_(2) by established chemical trends. Notably, the reported Fermi level of 0.9 eV above the valence band maximum actually suggests that the material is an insulator, contradicting the high hole density obtained by Hall effect measurement. Furthermore, the detected residual Se and the possible reduced elemental Te in the 2D β-TeO_(2) samples introduces complexity, considering that elemental Se, Te, and Te_(1−x)Se_(x) themselves are high-mobility p-type semiconductors. Therefore, doubts regarding the true cause of the p-type conductivity observed in the 2D β-TeO_(2) samples arise. In this Letter, we employ density functional theory calculations to illustrate that TeO_(2), whether in its bulk forms of α-, β-, or γ-TeO_(2), or in the 2D β-TeO_(2) nanosheets, inherently exhibits insulating properties and poses challenges in carrier doping due to its shallow conduction band minimum and deep valence band maximum. Our findings shed light on the insulating properties and doping difficulty of TeO_(2), contrasting with the claimed p-type conductivity in the 2D β-TeO_(2) samples, prompting inquiries into the true origin of the p-type conductivity.展开更多
Purpose: In super-aging societies, prosthodontists will have a growing role and will need to improve their nutrition knowledge. This study aimed to evaluate the effectiveness of a workshop-based model for increasing d...Purpose: In super-aging societies, prosthodontists will have a growing role and will need to improve their nutrition knowledge. This study aimed to evaluate the effectiveness of a workshop-based model for increasing dysphagia diet awareness among prosthodontists working with head and neck cancer patients. Methods: The study had a post-intervention design and included 10 maxillofacial prosthetic educators from eight countries who participated in a 120-minute workshop focused on theoretical and practical training in nutrition support for patients with dysphagia. Sessions were held in a specialized restaurant in Tokyo and included lectures, observation of Japanese cooking techniques, hands-on preparation of dysphagia-friendly foods, and cross-cultural comparisons. Knowledge, confidence, and practical application were assessed using a post-workshop questionnaire. Descriptive statistics and thematic analysis were used to evaluate outcomes. Results: Seven of the 10 prosthodontists completed the post-intervention questionnaire. All respondents reported overall satisfaction with the workshop. Session content was regarded as easy to understand by 57.14%, appropriate by 28.57%, and easy by 14.29%. Most respondents (85.71%) were “very satisfied” with the instructors’ explanations, and 100% were “very satisfied” with the workshop’s length and structure;71.42% felt they could apply the knowledge in clinical practice, while 28.58% anticipated challenges. The respondents appreciated the workshop’s focus on dysphagia, particularly in elderly patients, and valued the insights into Japanese dysphagia diets and culture. Conclusions: Workshops on nutrition provide an interactive platform for prosthodontists to enhance their knowledge and improve comprehensive patient care, highlighting the importance for prosthodontists to stay updated on developments in nutrition, particularly in dysphagia.展开更多
Methanation of CO_(2)in biogas offers an efficient and sustainable pathway compared to the carbon sources from carbon capture and utilization/storage(CCU/CCS)technologies,as it avoids a separate CO_(2)capture step.Mor...Methanation of CO_(2)in biogas offers an efficient and sustainable pathway compared to the carbon sources from carbon capture and utilization/storage(CCU/CCS)technologies,as it avoids a separate CO_(2)capture step.Moreover,CO_(2)from biogas combustion does not need to be recycled,owing to the carbon-neutral nature of biogas as a renewable energy source.Herein,we report biogas methanation using plasma catalysis for the first time in a packed-bed dielectric barrier discharge(DBD)reactor over 6 wt%-Ni/γ-Al_(2)O_(3).The total gas flow rate reached up to 3000 mL min^(-1)(CH_(4)/CO_(2)=60/40,CO_(2)/H_(2)=1/4),representing a large-scale study.The respective contributions of nonthermal plasma and methanation reaction heat were clarified.We observed that plasma-generated reactive species—vibrationally excited CO_(2)and plasma-derived atomic hydrogen(PDAH)—play a crucial role.These species enhance CH_(4)yield at low temperature and decrease reaction onset temperature(T_(on))compared to thermal catalysis.Also,pseudo-autonomous operation was confirmed at a total gas flow of 3000 mL min^(-1)and DBD power of 11 W with CO_(2)conversion of 77%,CH_(4)selectivity>98%,and energy efficiency of 75%.Moreover,pulsed CH_(4)injection experiments demonstrated that they endow the reaction system with the ability to withstand external disturbances,such as fluctuation of CH_(4)content in biogas.These results demonstrate the feasibility and high efficiency of plasma-catalyzed biogas methanation.Moreover,a high flexibility of DBD makes it particularly suitable for upgrading decentralized or stranded biogas resources.展开更多
Parallel robotic mechanisms have emerged as a vital subfield in robotics science and engineering over the past few decades,receiving widespread attention and undergoing significant advancements.Despite extensive resea...Parallel robotic mechanisms have emerged as a vital subfield in robotics science and engineering over the past few decades,receiving widespread attention and undergoing significant advancements.Despite extensive research encompassing type synthesis,dimension optimization,control theory,design principles,manufacturing techniques,and others,comprehensive reviews on the motion–force-related performance of parallel robotic mechanisms and their applications to real-world problems are still lacking.This review aims to fill this gap by analyzing and summarizing significant studies on the motion–force interaction performance of parallel robotic mechanisms.Examining the historical development of theoretical paradigms,the research of parallel robotic mechanisms began relatively late compared with their serial counterparts.Initially,approaches for parallel mechanisms were inherited or adopted from serial mechanisms.However,many cases have demonstrated that parallel robotic mechanisms possess unique characteristics,making it infeasible to directly transfer the theories developed for serial mechanisms to parallel mechanisms.Therefore,new methodologies are needed to properly analyze and evaluate the intrinsic properties of parallel robotic mechanisms,where the interaction between motion and force plays a crucial role.This paper offers an extensive and systematic review of the existing journal literature that analyzes and evaluates motion–force interaction performance of parallel robotics mechanisms,also known as motion/force transmission and constraint performance,providing a broad and detailed bibliography that will serve as a reference for the research community.The work examines research strategies,evaluation methods,performance indices,and real-world applications concerning the motion–force interaction performance of parallel robotic mechanisms,offering a foundation to stimulate future research and innovation.展开更多
The field of soft robotics has witnessed impressive progress in recent decades,driven by the necessity to develop robotic systems that are more adaptable,flexible,and user-friendly.Biomimetic soft robotics,inspired by...The field of soft robotics has witnessed impressive progress in recent decades,driven by the necessity to develop robotic systems that are more adaptable,flexible,and user-friendly.Biomimetic soft robotics,inspired by nature and biological principles,has brought numerous benefits across various applications,ranging from industrial automation to underwater exploration.Advances in actuation mechanisms,sensing technology,and control systems have expanded the potential of these robots,enabling them to navigate complex,unstructured environments with unparalleled adaptability.This special issue on“Biomimetic soft robotics:actuation,sensing,and integration”includes seven research articles.展开更多
The paper introduces a microreactor with high thermal insulation properties,which has been developed forintegration with standard planar-type solid oxide fuel cells(SOFCs)in portable power generation applications.Whil...The paper introduces a microreactor with high thermal insulation properties,which has been developed forintegration with standard planar-type solid oxide fuel cells(SOFCs)in portable power generation applications.Whileplanar SOFCs offer high efficiency and energy density,their use has been largely limited to stationary applications dueto challenges in thermal management and slow start-up times.Our microreactor overcomes these barriers byproviding an effective thermal insulation system,allowing SOFCs to operate efficiently in a compact,portable format.We designed a cantilevered structure using yttria-stabilized zirconia(YSZ)to minimize thermal conduction andcombined it with a multilayer insulation(MLI)system to suppress thermal radiation loss.This flexible cantileveredstructure prevents cracking under thermal stress and maintains high temperatures up to 700℃,ensuring reliableoperation.Additionally,the MLI system features an inherent safety mechanism:when the insulation structure isdamaged by a drill,the loss of thermal insulation causes a rapid temperature drop,bringing the system below thehydrogen explosion threshold temperature within 5 minutes,thus preventing potential hazards.Our prototypesuccessfully demonstrated handheld power generation using a button-type metal-supported SOFC,achieving a rapidstart-up time of just 5 minutes and driving a motor.This breakthrough offers a new platform for miniaturized SOFCtechnology,bridging the gap between stationary and portable energy solutions.展开更多
We read with great interest the article by Sijberden et al.,published in a recent issue of Annals of Surgery(1).The authors compared the perioperative outcomes of robotic liver surgery(RLS)and laparoscopic liver surge...We read with great interest the article by Sijberden et al.,published in a recent issue of Annals of Surgery(1).The authors compared the perioperative outcomes of robotic liver surgery(RLS)and laparoscopic liver surgery(LLS)in an international retrospective cohort study.Over the past two decades,minimally invasive liver surgery(MILS)has significantly grown in adoption,with the efficacy of LLS evaluated in both observational and randomized studies.The use of RLS is increasing owing to its visualization,surgical precision,greater institutional availability,and dexterity in MILS(2).However,evidence supporting its implementation remains relatively scarce,and the associated costs are generally higher than those of LLS(3).展开更多
Shape memory alloys(SMAs)can recover their original shape after deformation when heated above a specifc transformation temperature.This study investigates the induction of the two-way shape memory efect(TWSME)in SMA f...Shape memory alloys(SMAs)can recover their original shape after deformation when heated above a specifc transformation temperature.This study investigates the induction of the two-way shape memory efect(TWSME)in SMA flms through laser surface treatment.Ti50Ni40Cu10 SMA flms with thicknesses of 20–40μm were fabricated using the melt-spinning method and subjected to laser irradiation under varying conditions.The efects of flm thickness and laser parameters on actuation characteristics and crystalline structure were evaluated.The results demonstrate the successful induction of TWSME in the laser-treated SMA flms,with actuation capability depending on the balance between the modifed and unmodifed layers through the thickness.X-ray difraction analysis reveals the presence of residual martensitic phase in the laser-treated specimens,contributing to the TWSME.Optimal actuation is achieved with a relatively thick modifed layer while maintaining sufcient unmodifed material for recovery to the memorized shape.This study provides insights into the laser-induced TWSME in SMA flms and its potential applications in microactuators,where bidirectional actuation without external preloading is desirable.展开更多
Next-generation power electronics require efficient heat dissipation management,and molecular design guidelines are needed to develop polymers with high thermal conductivity.Polymer materials have considerably lower t...Next-generation power electronics require efficient heat dissipation management,and molecular design guidelines are needed to develop polymers with high thermal conductivity.Polymer materials have considerably lower thermal conductivity than metals and ceramics due to phonon scattering in the amorphous region.The spontaneous orientation of the molecular chains of liquid crystalline polymers could potentially give rise to high thermal conductivity,but the molecular design of such polymers remains largely empirical.In this study,wedeveloped amachine learningmodel that predicts with more than 96%accuracy whether liquid crystalline states will form based on the chemical structure of the polymer.By exploring the inverse mapping of this model,we identified a comprehensive set of chemical structures for liquid crystalline polyimides.The polymers were then experimentally synthesized,and the results confirmed that they form liquid crystalline phases,with all polymers exhibiting calculated thermal conductivities within the range of 0.722–1.26Wm^(−1)K^(−1).展开更多
We developed a time-of-flight(TOF)detector with a thin foil for mass measurements of unstable nuclei using the Rare-RI Ring at the RIKEN RI beam factory.Compared to the previous design,the developed TOF detector emplo...We developed a time-of-flight(TOF)detector with a thin foil for mass measurements of unstable nuclei using the Rare-RI Ring at the RIKEN RI beam factory.Compared to the previous design,the developed TOF detector employed modified electrodes,and its static electric and magnetic fields were reduced.We improved the detection efficiency and stability of operation.Its specification and design were finally fixed for mass measurements.We also developed a position-sensitive detector based on the principles of the TOF detector.This study utilized larger microchannel plate(MCP)detectors than those of the prototype.By improving acceptance,we demonstrated the performance of the position-sensitive detector with very low material thickness.展开更多
文摘Dear Editor,In this letter,we focus on the algebraic relationship between the coefficient matrices and the solution of the stochastic algebraic Riccati equation.It is revealed that,if the coefficient matrices are in an algebra,then the solution(and also the control gain in many cases)is also in the same algebra.The main result is verified by a numerical simulation.
文摘Existing Internet of Things(IoT)systems that rely on Amazon Web Services(AWS)often encounter inefficiencies in data retrieval and high operational costs,especially when using DynamoDB for large-scale sensor data.These limitations hinder the scalability and responsiveness of applications such as remote energy monitoring systems.This research focuses on designing and developing an Arduino-based IoT system aimed at optimizing data transmission costs by concentrating on these services.The proposed method employs AWS Lambda functions with Amazon Relational Database Service(RDS)to facilitate the transmission of data collected from temperature and humidity sensors to the RDS database.In contrast,the conventional method utilizes AmazonDynamoDB for storing the same sensor data.Data were collected from 01 April 2022,to 26 August 2022,in Tokyo,Japan,focusing on temperature and relative humiditywitha resolutionof oneminute.The efficiency of the twomethods—conventional andproposed—was assessed in terms of both time and cost metrics,with a particular focus on data retrieval.The conventional method exhibited linear time complexity,leading to longer data retrieval times as the dataset grew,mainly due to DynamoDB’s pagination requirements and the parsing of payload data during the reading process.In contrast,the proposed method significantly reduced retrieval times for larger datasets by parsing payload data before writing it to the RDS database.Cost analysis revealed a savings of$1.56 per month with the adoption of the proposed approach for a 20-gigabyte database.
基金JSPS Research Fellowships for Young Scientistssupported in part by JST SPRING,Japan(Nos.JPMJSP2106 and JPMJSP2180,Takuya Tanaka.and Yuki Sawatari.)+1 种基金MEXT/JSPS KAKENHI grants(No.23H02036,Gen-ichi Konishi)Murata Science and Education Foundation(Gen-ichi Konishi)。
文摘Aggregation-induced emission luminogens(AIEgens)exhibit viscosity-responsive behavior resembling those of molecular rotors;however,their response mechanisms are more complex and cannot be adequately described using simple rotational models.AIEgens demonstrate intricate dynamics that are highly dependent on their molecular structures.In this study,we synthesized water-soluble derivatives of representative AIEgens,including tetraphenylethene(TPE),bis(N,N-dialkylamino)anthracene(BDAA),and bridged stilbene,and systematically investigated the dependence of their photophysical properties in water/glycerol mixed solvents on temperature and viscosity.To elucidate the origin of their viscosity responsiveness,quantum chemical calculations were conducted to analyze their potential energy surfaces(PESs).The results revealed that compared to typical molecular rotors,these AIEgens exhibit significantly higher sensitivity to viscosity in low-viscosity regions.Notably,for TPE and BDAA derivatives,the viscosity responsiveness was found to be governed not by the activation energy barrier(ΔE_(a))based on the PES,but rather by the viscosity-dependent constraints on molecular structural changes.Furthermore,molecules possessing multiple aromatic rings or large,flexible,rotatable moieties were found to exhibit enhanced sensitivity to viscosity due to increased frictional interactions in solutions.This study provides critical insights into the mechanistic origins of the viscosity responsiveness of AIEgens,thereby advancing the fundamental understanding of their behavior and expanding their potential application as viscositysensitive probes.
基金supported by the Natural Sci-ence Foundation of Shandong(Nos.ZR2022MC086 and ZR2023MC162).
文摘In order to verify the synthesis pathway of linoleic acid(LA)to generate arachidonic acid(ARA),the functions ofΔ6 FAD and Elovl 5 in Apostichopus japonicus were tested by heterologous expression in Pichia pastoris.A 60-day feeding experiment was conducted to evaluate the effects of dietary LA and ARA on growth,polyunsaturated fatty acids(PUFA)biosynthesis and im-mune function of A.japonicus.Seven diets containing graded levels of LA or ARA were formulated,and one diet without PUFA was applied as a control.The results confirmed thatΔ6 FAD from A.japonicus has a double desaturation ability ofΔ6 andΔ5 for PUFA,and it works together with Elovl 5 enzyme play important roles in biosynthesis of ARA from LA.With increasing dietary LA from 4.9 to 12.1 g/kg,the expressions ofΔ6 FAD and Elovl 5,levels of LA,ARA and EPA in tissues increased,and the activities of ACP,AKP and CAT enzymes in intestine initially increased and then decreased.Additionally,by increasing dietary ARA from 0.7 to 3.8 g/kg,the contents of ALA,EPA and DHA decreased,while theΔ6 FAD expression and the activities of ACP,AKP and CAT in intes-tine increased significantly.Therefore,appropriate dietary levels of LA(12.1 g/kg)or ARA(3.8 g/kg)build a reasonable composi-tion of n-3/n-6 PUFA in A.japonicus,and improved its growth,antioxidant capacity and immunological defenses.
基金financially supported by the National Natural Science Foundation of China(No.52101235)the Basic public welfare research program of Zhejiang Province(No.LGG22E010010)+2 种基金the Key R&D Project of Zhejiang Provincial Department Science and Technology(No.2024C01146)the Intergovernmental International Science,Technology and Innovation Cooperation Key Project of the National Key R&D Programme(No.2022YFE0109800)the National Key Research and Development Program of China(No.2021YFB3500203)
文摘The coercivity of Sm-Fe-N/Zn magnets is strongly influenced by the composition and distribution of grain boundary phases.In this study,a Zn layer was uniformly deposited onto the surface of Sm-Fe-N powders via an innovative electrodeposition method,followed by a twostep thermal treatment process(hot-pressing+annealing)to precisely control the formation of theГ-FeZn phase and the grain boundary structure.The results indicate that annealing at 430℃promotes the uniform distribution of theΓ-FeZn phase along the grain boundaries,achieving a coercivity of 14.60 kOe—nearly three times higher than that of the untreated sample.Transmission electron microscopy(TEM)analysis reveals that increasing the annealing temperature enhances Zn mobility and diffusion at the grain boundaries,which facilitates the gradual formation of a continuous T-FeZn phase encapsulating the magnetic particles.This structure effectively suppresses exchange coupling between grains,thereby significantly enhancing coercivity.However,when the temperature exceeds 450℃,excessive Zn diffusion leads to the formation of a Sm-Fe(Zn)-N intermediate phase,which weakens the anisotropy field and causes a reduction in coercivity.Unlike previous studies that primarily focused on the presence of the T-FeZn phase,the present work achieves synergistic optimization via electrodeposition and temperature regulation,providing a deeper understanding of the intrinsic relationship among Zn diffusion,grain boundary evolution,and magnetic properties.These findings present a novel strategy and theoretical basis for the design of high-performance Sm-Fe-N magnets.
基金supported by the Center of Excellence on Instru-mentation Technology and Automation(CEITA),Department of Instru-mentation and Electronics Engineering,Faculty of Engineering,King Mongkut’s University of Technology North Bangkok,Thailand。
文摘This study explores the combination of ultrasound technology with a detection algorithm to categorize flow regimes in bubble columns used for aeration in aquaculture.An ultrasonic velocity profiler is used to obtain the standard deviation of the bubble velocity distributed throughout the column.The bubble velocity data for three known flow regimes were used to develop a probability density function(PDF)classification model.The experimental apparatus consisted of a circular tank equipped with a bubble generator and gas hold-up monitoring systems.The flow regimes of the experimental fluid were determined,and the classification was conducted via the PDF method.The results demonstrate that the classification accuracy is not lower than that of traditional machine learning methods.
基金supported by a Grant-in-Aid of AMED under Grant Numbers(JP22gm1510009)to RM.
文摘Traumatic spinal cord injury(SCI)is a devastating central nervous system(CNS)disorder characterized by significant neurological dysfunction and sensory loss,and effective therapies that prevent neuronal loss and functional recovery remain elusive.After SCI,lesions are surrounded by neuroprotective borders formed by newly proliferated reactive astrocytes.Astrocyte proliferation and activation mediate the formation and function of the glial scar and influence the balance between protection and inflammation.
基金supported by the Japan Society for the Promotion of Science(JSPS)Grants-in-Aid for Scientific Research(C)23K03898.
文摘Traffic at urban intersections frequently encounters unexpected obstructions,resulting in congestion due to uncooperative and priority-based driving behavior.This paper presents an optimal right-turn coordination system for Connected and Automated Vehicles(CAVs)at single-lane intersections,particularly in the context of left-hand side driving on roads.The goal is to facilitate smooth right turns for certain vehicles without creating bottlenecks.We consider that all approaching vehicles share relevant information through vehicular communications.The Intersection Coordination Unit(ICU)processes this information and communicates the optimal crossing or turning times to the vehicles.The primary objective of this coordination is to minimize overall traffic delays,which also helps improve the fuel consumption of vehicles.By considering information from upcoming vehicles at the intersection,the coordination system solves an optimization problem to determine the best timing for executing right turns,ultimately minimizing the total delay for all vehicles.The proposed coordination system is evaluated at a typical urban intersection,and its performance is compared to traditional traffic systems.Numerical simulation results indicate that the proposed coordination system significantly enhances the average traffic speed and fuel consumption compared to the traditional traffic system in various scenarios.
基金funded by the National Key Research and Development Program of China(Grant No.2024YFE0209000)the NSFC(Grant No.U23B2019).
文摘Graph Neural Networks(GNNs)have proven highly effective for graph classification across diverse fields such as social networks,bioinformatics,and finance,due to their capability to learn complex graph structures.However,despite their success,GNNs remain vulnerable to adversarial attacks that can significantly degrade their classification accuracy.Existing adversarial attack strategies primarily rely on label information to guide the attacks,which limits their applicability in scenarios where such information is scarce or unavailable.This paper introduces an innovative unsupervised attack method for graph classification,which operates without relying on label information,thereby enhancing its applicability in a broad range of scenarios.Specifically,our method first leverages a graph contrastive learning loss to learn high-quality graph embeddings by comparing different stochastic augmented views of the graphs.To effectively perturb the graphs,we then introduce an implicit estimator that measures the impact of various modifications on graph structures.The proposed strategy identifies and flips edges with the top-K highest scores,determined by the estimator,to maximize the degradation of the model’s performance.In addition,to defend against such attack,we propose a lightweight regularization-based defense mechanism that is specifically tailored to mitigate the structural perturbations introduced by our attack strategy.It enhances model robustness by enforcing embedding consistency and edge-level smoothness during training.We conduct experiments on six public TU graph classification datasets:NCI1,NCI109,Mutagenicity,ENZYMES,COLLAB,and DBLP_v1,to evaluate the effectiveness of our attack and defense strategies.Under an attack budget of 3,the maximum reduction in model accuracy reaches 6.67%on the Graph Convolutional Network(GCN)and 11.67%on the Graph Attention Network(GAT)across different datasets,indicating that our unsupervised method induces degradation comparable to state-of-the-art supervised attacks.Meanwhile,our defense achieves the highest accuracy recovery of 3.89%(GCN)and 5.00%(GAT),demonstrating improved robustness against structural perturbations.
基金supported in part by the Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research(B)(23K25252,24K03325)the National Natural Science Foundation of China(61873348)the Natural Science Foundation of Hubei Province,China(2020CFA031)。
文摘As a closed-loop learning control method,repetitive control has been widely used in a variety of areas from appliances to aviation.A repetitive control system features perfect reference tracking and disturbance rejection in the steady state for periodic signals with a fixed period.This characteristic is important not only for conventional technologies and conventional industries but also for advanced technologies and emerging industries.This paper first explains the concept of repetitive control from its original idea.Next,it describes the structure of a repetitive controller as an internal model and shows the respective points of continuous-and discrete-time repetitive control.It presents a categorized list of practical applications of repetitive control.Moreover,two concrete applications,namely the control of a robotic manipulator and a rotating system,demonstrate the validity of the method with experimental results.Several current studies in this field are also reviewed,and some challenges and future studies for repetitive control are provided.
基金supported by the National Natural Science Foundation of China(Grant Nos.52372150,12088101,and 11991060)the National Key R&D Program of China(Grant No.2022YFB4200305)。
文摘Wide-bandgap two-dimensional (2D) β-TeO_(2) has been reported as a high-mobility p-type transparent semiconductor [Nat. Electron. 4 277 (2021)], attracting significant attention. This "breakthrough" not only challenges the conventional characterization of TeO_(2) as an insulator but also conflicts with the anticipated difficulty in hole doping of TeO_(2) by established chemical trends. Notably, the reported Fermi level of 0.9 eV above the valence band maximum actually suggests that the material is an insulator, contradicting the high hole density obtained by Hall effect measurement. Furthermore, the detected residual Se and the possible reduced elemental Te in the 2D β-TeO_(2) samples introduces complexity, considering that elemental Se, Te, and Te_(1−x)Se_(x) themselves are high-mobility p-type semiconductors. Therefore, doubts regarding the true cause of the p-type conductivity observed in the 2D β-TeO_(2) samples arise. In this Letter, we employ density functional theory calculations to illustrate that TeO_(2), whether in its bulk forms of α-, β-, or γ-TeO_(2), or in the 2D β-TeO_(2) nanosheets, inherently exhibits insulating properties and poses challenges in carrier doping due to its shallow conduction band minimum and deep valence band maximum. Our findings shed light on the insulating properties and doping difficulty of TeO_(2), contrasting with the claimed p-type conductivity in the 2D β-TeO_(2) samples, prompting inquiries into the true origin of the p-type conductivity.
文摘Purpose: In super-aging societies, prosthodontists will have a growing role and will need to improve their nutrition knowledge. This study aimed to evaluate the effectiveness of a workshop-based model for increasing dysphagia diet awareness among prosthodontists working with head and neck cancer patients. Methods: The study had a post-intervention design and included 10 maxillofacial prosthetic educators from eight countries who participated in a 120-minute workshop focused on theoretical and practical training in nutrition support for patients with dysphagia. Sessions were held in a specialized restaurant in Tokyo and included lectures, observation of Japanese cooking techniques, hands-on preparation of dysphagia-friendly foods, and cross-cultural comparisons. Knowledge, confidence, and practical application were assessed using a post-workshop questionnaire. Descriptive statistics and thematic analysis were used to evaluate outcomes. Results: Seven of the 10 prosthodontists completed the post-intervention questionnaire. All respondents reported overall satisfaction with the workshop. Session content was regarded as easy to understand by 57.14%, appropriate by 28.57%, and easy by 14.29%. Most respondents (85.71%) were “very satisfied” with the instructors’ explanations, and 100% were “very satisfied” with the workshop’s length and structure;71.42% felt they could apply the knowledge in clinical practice, while 28.58% anticipated challenges. The respondents appreciated the workshop’s focus on dysphagia, particularly in elderly patients, and valued the insights into Japanese dysphagia diets and culture. Conclusions: Workshops on nutrition provide an interactive platform for prosthodontists to enhance their knowledge and improve comprehensive patient care, highlighting the importance for prosthodontists to stay updated on developments in nutrition, particularly in dysphagia.
文摘Methanation of CO_(2)in biogas offers an efficient and sustainable pathway compared to the carbon sources from carbon capture and utilization/storage(CCU/CCS)technologies,as it avoids a separate CO_(2)capture step.Moreover,CO_(2)from biogas combustion does not need to be recycled,owing to the carbon-neutral nature of biogas as a renewable energy source.Herein,we report biogas methanation using plasma catalysis for the first time in a packed-bed dielectric barrier discharge(DBD)reactor over 6 wt%-Ni/γ-Al_(2)O_(3).The total gas flow rate reached up to 3000 mL min^(-1)(CH_(4)/CO_(2)=60/40,CO_(2)/H_(2)=1/4),representing a large-scale study.The respective contributions of nonthermal plasma and methanation reaction heat were clarified.We observed that plasma-generated reactive species—vibrationally excited CO_(2)and plasma-derived atomic hydrogen(PDAH)—play a crucial role.These species enhance CH_(4)yield at low temperature and decrease reaction onset temperature(T_(on))compared to thermal catalysis.Also,pseudo-autonomous operation was confirmed at a total gas flow of 3000 mL min^(-1)and DBD power of 11 W with CO_(2)conversion of 77%,CH_(4)selectivity>98%,and energy efficiency of 75%.Moreover,pulsed CH_(4)injection experiments demonstrated that they endow the reaction system with the ability to withstand external disturbances,such as fluctuation of CH_(4)content in biogas.These results demonstrate the feasibility and high efficiency of plasma-catalyzed biogas methanation.Moreover,a high flexibility of DBD makes it particularly suitable for upgrading decentralized or stranded biogas resources.
基金supported by the National Natural Science Foundation of China(Grant No.52105026).
文摘Parallel robotic mechanisms have emerged as a vital subfield in robotics science and engineering over the past few decades,receiving widespread attention and undergoing significant advancements.Despite extensive research encompassing type synthesis,dimension optimization,control theory,design principles,manufacturing techniques,and others,comprehensive reviews on the motion–force-related performance of parallel robotic mechanisms and their applications to real-world problems are still lacking.This review aims to fill this gap by analyzing and summarizing significant studies on the motion–force interaction performance of parallel robotic mechanisms.Examining the historical development of theoretical paradigms,the research of parallel robotic mechanisms began relatively late compared with their serial counterparts.Initially,approaches for parallel mechanisms were inherited or adopted from serial mechanisms.However,many cases have demonstrated that parallel robotic mechanisms possess unique characteristics,making it infeasible to directly transfer the theories developed for serial mechanisms to parallel mechanisms.Therefore,new methodologies are needed to properly analyze and evaluate the intrinsic properties of parallel robotic mechanisms,where the interaction between motion and force plays a crucial role.This paper offers an extensive and systematic review of the existing journal literature that analyzes and evaluates motion–force interaction performance of parallel robotics mechanisms,also known as motion/force transmission and constraint performance,providing a broad and detailed bibliography that will serve as a reference for the research community.The work examines research strategies,evaluation methods,performance indices,and real-world applications concerning the motion–force interaction performance of parallel robotic mechanisms,offering a foundation to stimulate future research and innovation.
文摘The field of soft robotics has witnessed impressive progress in recent decades,driven by the necessity to develop robotic systems that are more adaptable,flexible,and user-friendly.Biomimetic soft robotics,inspired by nature and biological principles,has brought numerous benefits across various applications,ranging from industrial automation to underwater exploration.Advances in actuation mechanisms,sensing technology,and control systems have expanded the potential of these robots,enabling them to navigate complex,unstructured environments with unparalleled adaptability.This special issue on“Biomimetic soft robotics:actuation,sensing,and integration”includes seven research articles.
基金supported by the following funding sources:JSPS KAKENHI Grant-in-Aid for Scientific Research(B),Grant Numbers 23K26749 and 23K21047the NEDO Project for the Promotion of Young Researchers in Industry-Academia-Government Collaboration+1 种基金and the ERCA Innovative Research and Development Program(Young Researcher Category)supported by joint research funds from Futaba Industrial Co.,Ltd.and TAIYO YUDEN Co.,Ltd.
文摘The paper introduces a microreactor with high thermal insulation properties,which has been developed forintegration with standard planar-type solid oxide fuel cells(SOFCs)in portable power generation applications.Whileplanar SOFCs offer high efficiency and energy density,their use has been largely limited to stationary applications dueto challenges in thermal management and slow start-up times.Our microreactor overcomes these barriers byproviding an effective thermal insulation system,allowing SOFCs to operate efficiently in a compact,portable format.We designed a cantilevered structure using yttria-stabilized zirconia(YSZ)to minimize thermal conduction andcombined it with a multilayer insulation(MLI)system to suppress thermal radiation loss.This flexible cantileveredstructure prevents cracking under thermal stress and maintains high temperatures up to 700℃,ensuring reliableoperation.Additionally,the MLI system features an inherent safety mechanism:when the insulation structure isdamaged by a drill,the loss of thermal insulation causes a rapid temperature drop,bringing the system below thehydrogen explosion threshold temperature within 5 minutes,thus preventing potential hazards.Our prototypesuccessfully demonstrated handheld power generation using a button-type metal-supported SOFC,achieving a rapidstart-up time of just 5 minutes and driving a motor.This breakthrough offers a new platform for miniaturized SOFCtechnology,bridging the gap between stationary and portable energy solutions.
文摘We read with great interest the article by Sijberden et al.,published in a recent issue of Annals of Surgery(1).The authors compared the perioperative outcomes of robotic liver surgery(RLS)and laparoscopic liver surgery(LLS)in an international retrospective cohort study.Over the past two decades,minimally invasive liver surgery(MILS)has significantly grown in adoption,with the efficacy of LLS evaluated in both observational and randomized studies.The use of RLS is increasing owing to its visualization,surgical precision,greater institutional availability,and dexterity in MILS(2).However,evidence supporting its implementation remains relatively scarce,and the associated costs are generally higher than those of LLS(3).
文摘Shape memory alloys(SMAs)can recover their original shape after deformation when heated above a specifc transformation temperature.This study investigates the induction of the two-way shape memory efect(TWSME)in SMA flms through laser surface treatment.Ti50Ni40Cu10 SMA flms with thicknesses of 20–40μm were fabricated using the melt-spinning method and subjected to laser irradiation under varying conditions.The efects of flm thickness and laser parameters on actuation characteristics and crystalline structure were evaluated.The results demonstrate the successful induction of TWSME in the laser-treated SMA flms,with actuation capability depending on the balance between the modifed and unmodifed layers through the thickness.X-ray difraction analysis reveals the presence of residual martensitic phase in the laser-treated specimens,contributing to the TWSME.Optimal actuation is achieved with a relatively thick modifed layer while maintaining sufcient unmodifed material for recovery to the memorized shape.This study provides insights into the laser-induced TWSME in SMA flms and its potential applications in microactuators,where bidirectional actuation without external preloading is desirable.
基金The synchrotron radiation experiments were performed at the BL40B2 beamline of SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal No. 2022B1131), with support from Dr. Noboru Ohta (JASRI) and Prof. Tomoyasu Hirai (Osaka Institute of Technology)This work was supported by the Japan Science and Technology Agency (JST) under the CREST program (Grant Number JPMJCR19I3) (J.M., T.H., R.Y., M.T., R.M.)+2 种基金Additionally, we acknowledge the Japan Society for the Promotion of Science (JSPS) for their support through the KAKENHI program (Grant Number 21K04828) (Y.N.)the Ministry of Education, Culture, Sports, Science and Technology for “Program for Promoting Researches on the Supercomputer Fugaku” (project ID: hp210264) (R.Y.)HM and RM were supported by JST SPRING (Grant No. JPMJSP2106).
文摘Next-generation power electronics require efficient heat dissipation management,and molecular design guidelines are needed to develop polymers with high thermal conductivity.Polymer materials have considerably lower thermal conductivity than metals and ceramics due to phonon scattering in the amorphous region.The spontaneous orientation of the molecular chains of liquid crystalline polymers could potentially give rise to high thermal conductivity,but the molecular design of such polymers remains largely empirical.In this study,wedeveloped amachine learningmodel that predicts with more than 96%accuracy whether liquid crystalline states will form based on the chemical structure of the polymer.By exploring the inverse mapping of this model,we identified a comprehensive set of chemical structures for liquid crystalline polyimides.The polymers were then experimentally synthesized,and the results confirmed that they form liquid crystalline phases,with all polymers exhibiting calculated thermal conductivities within the range of 0.722–1.26Wm^(−1)K^(−1).
基金Supported by the Research Project with Heavy Ions at QST-HIMAC(21H296)JSPS KAKENHI(JP18H03695,JP19K14730,JP21H04461)。
文摘We developed a time-of-flight(TOF)detector with a thin foil for mass measurements of unstable nuclei using the Rare-RI Ring at the RIKEN RI beam factory.Compared to the previous design,the developed TOF detector employed modified electrodes,and its static electric and magnetic fields were reduced.We improved the detection efficiency and stability of operation.Its specification and design were finally fixed for mass measurements.We also developed a position-sensitive detector based on the principles of the TOF detector.This study utilized larger microchannel plate(MCP)detectors than those of the prototype.By improving acceptance,we demonstrated the performance of the position-sensitive detector with very low material thickness.
