Large language models(LLMs)represent significant advancements in artificial intelligence.However,their increasing capabilities come with a serious challenge:misalignment,which refers to the deviation of model behavior...Large language models(LLMs)represent significant advancements in artificial intelligence.However,their increasing capabilities come with a serious challenge:misalignment,which refers to the deviation of model behavior from the designers’intentions and human values.This review aims to synthesize the current understanding of the LLM misalignment issue and provide researchers and practitioners with a comprehensive overview.We define the concept of misalignment and elaborate on its various manifestations,including generating harmful content,factual errors(hallucinations),propagating biases,failing to follow instructions,emerging deceptive behaviors,and emergent misalignment.We explore the multifaceted causes of misalignment,systematically analyzing factors from surface-level technical issues(e.g.,training data,objective function design,model scaling)to deeper fundamental challenges(e.g.,difficulties formalizing values,discrepancies between training signals and real intentions).This review covers existing and emerging techniques for detecting and evaluating the degree of misalignment,such as benchmark tests,red-teaming,and formal safety assessments.Subsequently,we examine strategies to mitigate misalignment,focusing on mainstream alignment techniques such as RLHF,Constitutional AI(CAI),instruction fine-tuning,and novel approaches that address scalability and robustness.In particular,we analyze recent advances in misalignment attack research,including system prompt modifications,supervised fine-tuning,self-supervised representation attacks,and model editing,which challenge the robustness of model alignment.We categorize and analyze the surveyed literature,highlighting major findings,persistent limitations,and current contentious points.Finally,we identify key open questions and propose several promising future research directions,including constructing high-quality alignment datasets,exploring novel alignment methods,coordinating diverse values,and delving into the deep philosophical aspects of alignment.This work underscores the complexity and multidimensionality of LLM misalignment issues,calling for interdisciplinary approaches to reliably align LLMs with human values.展开更多
Presetting tensile twins(TTs)can enhance the mechanical properties of magnesium(Mg)alloys.Two as-received(AR)sheets,as-received state-A(AR-A)with fiber texture and nonuniform grains and as-received state-B with basal ...Presetting tensile twins(TTs)can enhance the mechanical properties of magnesium(Mg)alloys.Two as-received(AR)sheets,as-received state-A(AR-A)with fiber texture and nonuniform grains and as-received state-B with basal texture and uniform equiaxial grains are selected to induce TTs via a novel method called corrugated wide limit alignment(CWLA),and the corresponding CWLA-processed sheets are denoted as CWLA-processed state-A(C-A)and CWLA-processed state-B(C-B).The results demonstrate that a larger initial average grain size correlates with a higher fraction of TTs induced in Mg sheets,thereby refining the grains and forming a new rolling direction(RD)tilted texture during CWLA.The ultimate tensile strength increases by 32%from AR-A to C-A,primarily due to refinement strengthening and twinning-induced strain hardening.The recrystallization mechanism of C-A is dominated by twinning-induced dynamic recrystallization(DRX),where DRX grains prefer to inherit the orientation of TTs,resulting in an enhanced RD-tilted texture and the formation of multi-modal texture.The recrystallization mechanism of C-B is mainly discontinuous DRX and continuous DRX,and the DRX grains prefer to inherit the orientation of matrix grains,ultimately forming a basal texture.In summary,the tensile mechanical behavior of pre-twinned Mg sheets significantly depends on the grain size and texture of the AR sheets,so they present similar changing trends during tensile deformation.展开更多
In this study,we present the fabrication of vertical SnO/β-Ga_(2)O_(3) heterojunction diode(HJD)via radio frequency(RF)reactive magnetron sputtering.The valence and conduction band offsets betweenβ-Ga_(2)O_(3) and S...In this study,we present the fabrication of vertical SnO/β-Ga_(2)O_(3) heterojunction diode(HJD)via radio frequency(RF)reactive magnetron sputtering.The valence and conduction band offsets betweenβ-Ga_(2)O_(3) and SnO are determined to be 2.65and 0.75 eV,respectively,through X-ray photoelectron spectroscopy,showing a type-Ⅱband alignment.Compared to its Schottky barrier diode(SBD)counterpart,the HJD presents a comparable specific ON-resistances(R_(on,sp))of 2.8 mΩ·cm^(2) and lower reverse leakage current(I_R),leading to an enhanced reverse blocking characteristics with breakdown voltage(BV)of 1675 V and power figure of merit(PFOM)of 1.0 GW/cm~2.This demonstrates the high quality of the SnO/β-Ga_(2)O_(3) heterojunction interface.Silvaco TCAD simulation further reveals that electric field crowding at the edge of anode for the SBD was greatly depressed by the introduction of SnO film,revealing the potential application of SnO/β-Ga_(2)O_(3) heterojunction in the futureβ-Ga_(2)O_(3)-based power devices.data mining,AI training,and similar technologies,are reserved.展开更多
BACKGROUND In an era leaning toward a personalized alignment of total knee arthroplasty,coronal plane alignment of the knee(CPAK)phenotypes for each population are studied;furthermore,other possible variables affectin...BACKGROUND In an era leaning toward a personalized alignment of total knee arthroplasty,coronal plane alignment of the knee(CPAK)phenotypes for each population are studied;furthermore,other possible variables affecting the alignment,such as ankle joint alignment,should be considered.AIM To determine CPAK distribution in the North African(Egyptian)population with knee osteoarthritis and to assess ankle joint line orientation(AJLO)adaptations across different CPAK types.METHODS A cross-sectional study was conducted on patients with primary knee osteoarthritis and normal ankle joints.Radiographic parameters included the mechanical lateral distal femoral angle,medial proximal tibial angle,and the derived calculations of joint line obliquity(JLO)and arithmetic hip-knee-ankle angle(aHKA).The tibial plafond horizontal angle(TPHA)was used for AJLO assessment,where 0°is neutral(type N),<0°is varus(type A),and>0°is valgus(type B).The nine CPAK types were further divided into 27 subtypes after incorporating the three AJLO types.RESULTS A total of 527 patients(1054 knees)were included for CPAK classification,and 435 patients(870 knees and ankles)for AJLO assessment.The mean age was 57.2±7.8 years,with 79.5%females.Most knees(76.4%)demonstrated varus alignment(mean aHKA was-5.51°±4.84°)and apex distal JLO(55.3%)(mean JLO was 176.43°±4.53°).CPAK types I(44.3%),IV(28.6%),and II(10%)were the most common.Regarding AJLO,70.2%of ankles exhibited varus orientation(mean TPHA was-5.21°±6.45°).The most frequent combined subtypes were CPAK type I-A(33.7%),IV-A(21.5%),and I-N(6.9%).A significant positive correlation was found between the TPHA and aHKA(r=0.40,P<0.001).CONCLUSION In this North African cohort,varus knee alignment with apex distal JLO and varus AJLO predominated.CPAK types I,IV,and II were the most common types,while subtypes I-A,IV-A,and I-N were commonly occurring after incorporating AJLO types;furthermore,the AJLO was significantly correlated to aHKA.展开更多
The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input mult...The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input multi-output,nonlinearity,and strong coupling presents significant challenges.The substantial internal force generated during the adjustment process can potentially damage the LAC and degrade the assembly quality.Hence,a workspace-based hybrid force position control scheme was developed to achieve high quality assembly with high-precision and lower internal force.Firstly,an offline workspace analysis with inherent geometric characteristics to form time-varying posture error constraint.Then,the posture error is integrated into the online position axis control to ensure tracking the ideal posture,while the force control axis compensates for posture deviation by minimizing internal force,thereby achieving high precision and low internal force.Finally,the effectiveness was demonstrated through experiments.The root mean square errors of orientation and position are 104 rad and 0.1 mm,respectively.A reduction in internal force can range from 10.96%to 57.4%compared to the traditional method.Key points'max position error is decreased from 0.32 mm to 0.18 mm,satisfying the 0.5 mm tolerance.Therefore,the proposed method will help promote the development of high-performance manufacturing.展开更多
Root rot is a prevalent soil-borne fungal disease in citrus.Citron C-05(Citrus medica)stands out as a germplasm within Citrus spp.due to its complete resistance to citrus canker and favorable characteristics such as s...Root rot is a prevalent soil-borne fungal disease in citrus.Citron C-05(Citrus medica)stands out as a germplasm within Citrus spp.due to its complete resistance to citrus canker and favorable characteristics such as single embryo and easy rooting.However,Citron C-05 was found to be highly susceptible to root rot during cultivation,with the specific pathogens previously unknown.In this study,four candidate fungal species were isolated from Citron C-05 roots.Sequence analysis of ITS,EF-1a,RPB1,and RPB2 identified two Fusarium solani strains,Rr-2 and Rr-4,as the candidates causing root rot in Citron C-05.Resistance tests showed these two pathogens increased root damage rate from 10.30%to 35.69%in Citron C-05,sour orange(Citrus aurantium),sweet orange(Citrus sinensis)and pummelo(Citrus grandis).F.solani exhibited the weak pathogenicity towards trifoliate orange(Poncirus trifoliata).DAB staining revealed none of reddish-brown precipitation in the four susceptible citrus germplasm after infection with F.solani,while trifoliate orange exhibited significant H2O2 accumulation.Trypan blue staining indicated increased cell death in the four susceptible citrus germplasm following infection with these two pathogens but not in trifoliate orange.These findings provide a comprehensive understanding of citrus root rot and support future research on the mechanisms of root rot resistance in citrus.展开更多
Objective:Deep learning is employed increasingly in Gastroenterology(GI)endoscopy computer-aided diagnostics for polyp segmentation and multi-class disease detection.In the real world,implementation requires high accu...Objective:Deep learning is employed increasingly in Gastroenterology(GI)endoscopy computer-aided diagnostics for polyp segmentation and multi-class disease detection.In the real world,implementation requires high accuracy,therapeutically relevant explanations,strong calibration,domain generalization,and efficiency.Current Convolutional Neural Network(CNN)and transformer models compromise border precision and global context,generate attention maps that fail to align with expert reasoning,deteriorate during cross-center changes,and exhibit inadequate calibration,hence diminishing clinical trust.Methods:HMA-DER is a hierarchical multi-attention architecture that uses dilation-enhanced residual blocks and an explainability-aware Cognitive Alignment Score(CAS)regularizer to directly align attribution maps with reasoning signals from experts.The framework has additions that make it more resilient and a way to test for accuracy,macro-averaged F1 score,Area Under the Receiver Operating Characteristic Curve(AUROC),calibration(Expected Calibration Error(ECE),Brier Score),explainability(CAS,insertion/deletion AUC),cross-dataset transfer,and throughput.Results:HMA-DER gets Dice Similarity Coefficient scores of 89.5%and 86.0%on Kvasir-SEG and CVC-ClinicDB,beating the strongest baseline by+1.9 and+1.7 points.It gets 86.4%and 85.3%macro-F1 and 94.0%and 93.4%AUROC on HyperKvasir and GastroVision,which is better than the baseline by+1.4/+1.6macro-F1 and+1.2/+1.1AUROC.Ablation study shows that hierarchical attention gives the highest(+3.0),followed by CAS regularization(+2–3),dilatation(+1.5–2.0),and residual connections(+2–3).Cross-dataset validation demonstrates competitive zero-shot transfer(e.g.,KS→CVC Dice 82.7%),whereas multi-dataset training diminishes the domain gap,yielding an 88.1%primary-metric average.HMA-DER’s mixed-precision inference can handle 155 pictures per second,which helps with calibration.Conclusion:HMA-DER strikes a compromise between accuracy,explainability,robustness,and efficiency for the use of reliable GI computer-aided diagnosis in real-world clinical settings.展开更多
To solve the problem that the standard Kalman filter cannot give the optimal solution when the system model and stochastic information are unknown accurately, single fading factor Kalman filter is suitable for simple ...To solve the problem that the standard Kalman filter cannot give the optimal solution when the system model and stochastic information are unknown accurately, single fading factor Kalman filter is suitable for simple systems. But for complex systems with multi-variable, it may not be sufficient to use single fading factor as a multiplier for the covariance matrices. In this paper, a new multiple fading factors Kalman filtering algorithm is presented. By calculating the unbiased estimate of the innovation sequence covariance using fenestration, the fading factor matrix is obtained. Adjusting the covariance matrix of prediction error Pk｜k-1 using fading factor matrix, the algorithm provides different rates of fading for different filter channels. The proposed algorithm is applied to strapdown inertial navigation system （SINS） initial alignment, and simulation and experimental results demonstrate that, the alignment accuracy can be upgraded dramatically when the actual system noise characteristics are different from the pre-set values. The new algorithm is less sensitive to uncertainty noise and has better estimation effect of the parameters. Therefore, it is of significant value in practical applications.展开更多
Considering gravity change from ground alignment to space applications, a fuzzy proportional-integral-differential(PID)control strategy is proposed to make the space manipulator track the desired trajectories in diffe...Considering gravity change from ground alignment to space applications, a fuzzy proportional-integral-differential(PID)control strategy is proposed to make the space manipulator track the desired trajectories in different gravity environments. The fuzzy PID controller is developed by combining the fuzzy approach with the PID control method, and the parameters of the PID controller can be adjusted on line based on the ability of the fuzzy controller. Simulations using the dynamic model of the space manipulator have shown the effectiveness of the algorithm in the trajectory tracking problem. Compared with the results of conventional PID control,the control performance of the fuzzy PID is more effective for manipulator trajectory control.展开更多
We develop a general approach to the fabrication of films with unidirectional grooves, such as silicon nitride, silicon dioxide and aluminium oxide, in which the surface is not required to be treated. Super-aligned ca...We develop a general approach to the fabrication of films with unidirectional grooves, such as silicon nitride, silicon dioxide and aluminium oxide, in which the surface is not required to be treated. Super-aligned carbon nanotube （SACNT） film may be used as a template and as sacrificial layer, which is subsequently removed by heating in an atmosphere of air. The unidirectional morphology of the SACNT film turns into a desired film, which is found to possess the ability to align liquid crystal molecules. This approach also features high efficiency, low cost and easy scaling-up for mass production.展开更多
Orientation control of anisotropic one-dimensional(1D)and two-dimensional(2D)materials in solutions is of great importance in many fields ranging from structural materials design,the thermal management,to energy stora...Orientation control of anisotropic one-dimensional(1D)and two-dimensional(2D)materials in solutions is of great importance in many fields ranging from structural materials design,the thermal management,to energy storage.Achieving fine control of vertical alignment of anisotropic fillers(such as graphene,boron nitride(BN),and carbon fiber)remains challenging.This work presents a universal and scalable method for constructing vertically aligned structures of anisotropic fillers in composites assisted by the expansion flow(using2D BN platelets as a proof-of-concept).BN platelets in the silicone gel strip are oriented in a curved shape that includes vertical alignment in the central area and horizontal alignment close to strip surfaces.Due to the vertical orientation of BN in the central area of strips,a throughplane thermal conductivity as high as 5.65 W m^(-1) K^(-1) was obtained,which can be further improved to 6.54 W m^(-1) K^(-1) by combining BN and pitch-based carbon fibers.The expansion-flow-assisted alignment can be extended to the manufacture of a variety of polymer composites filled with 1D and 2D materials,which can find wide applications in batteries,electronics,and energy storage devices.展开更多
Knee osteoarthritis(OA) is a progressive joint disease hallmarked by cartilage and bone breakdown and associated with changes to all of the tissues in the joint,ultimately causing pain,stiffness,deformity and disabili...Knee osteoarthritis(OA) is a progressive joint disease hallmarked by cartilage and bone breakdown and associated with changes to all of the tissues in the joint,ultimately causing pain,stiffness,deformity and disability in many people.Radiographs are commonly used for the clinical assessment of knee OA incidence and progression,and to assess for risk factors.One risk factor for the incidence and progression of knee OA is malalignment of the lower extremities(LE).The hipknee-ankle(HKA) angle,assessed from a full-length LE radiograph,is ideally used to assess LE alignment.Careful attention to LE positioning is necessary to obtain the most accurate measurement of the HKA angle.Since full-length LE radiographs are not always available,the femoral shaft-tibial shaft(FS-TS) angle may be calculated from a knee radiograph instead.However,the FS-TS angle is more variable than the HKA angle and it should be used with caution.Knee radiographs are used to assess the severity of knee OA and its progression.There are three types of ordinal grading scales for knee OA:global,composite and individual feature scales.Each grade on a global scale describes one or more features of knee OA.The entire description must be met for a specific grade to be assigned.The KellgrenLawrence scale is the most commonly-used global scale.Composite scales grade several features of knee OA individually and sum the grades to create a total score.One example is the compartmental grading scale for knee OA.Composite scales can respond to change in a variety of presentations of knee OA.Individual feature scales assess one or more OA features individually and do not calculate a total score.They are most often used to monitor change in one OA feature,commonly joint space narrowing.The most commonly-used individual feature scale is the OA Research Society International atlas.Each type of scale has its advantages;however,composite scales may offer greater content validity.Responsiveness to change is unknown for most scales and deserves further evaluation.展开更多
An important point for computer systems is the identification of users for authentication. One of these identification methods is keystroke dynamics. The keystroke dynamics is a biometric measurement in terms of keyst...An important point for computer systems is the identification of users for authentication. One of these identification methods is keystroke dynamics. The keystroke dynamics is a biometric measurement in terms of keystroke press duration and keystroke latency. However, several problems are arisen like the similarity between users and identification accuracy. In this paper, we propose innovative model that can help to solve the problem of similar user by classifying user’s data based on a membership function. Next, we employ sequence alignment as a way of pattern discovery from the user’s typing behaviour. Experiments were conducted to evaluate accuracy of the proposed model. The results show high performance compared to standard classifiers in terms of accuracy and precision.展开更多
Silicon nitride(Si_(3)N_(4))based ceramics are one of the most attractive advanced engineering materials,which have been widely used under high-speed rotational operation or for mechanical contacts across a curved sur...Silicon nitride(Si_(3)N_(4))based ceramics are one of the most attractive advanced engineering materials,which have been widely used under high-speed rotational operation or for mechanical contacts across a curved surface.In the present study,rotationally symmetric texturing of Si_(3)N_(4),with radial grain align-ment,was obtained by centripetal sinter-forging(CSF)of a partially sintered sample.The average values of the included angles between the c-axis of the local Si_(3)N_(4)grain and radial direction were approxi-mately 16.4°and 11.0°,on the section plane perpendicular to the pressing direction,and parallel to both the pressing and radial directions,respectively.The compressive strain in the pressing direction forced the ceramic body to flow towards the central axis,resulting in compressive strain in the tangential di-rection and tensile strain in the radial direction.A fundamental physical model was created to simulate the grain rotation during the 3-dimentional strain reorientation,which revealed the rod-like grain would preferentially rotate toward the center of the sample under the CSF process.In addition,due to the fric-tion between the sample surface and the pressing punch,the increased shear strain could enhance the Si_(3)N_(4)grain alignment.Consequently,ceramics with rod-like grains perpendicular to the curved side sur-face could be anticipated by applying the centripetal forming concept in a controlled manner.展开更多
In this paper , the principle of H∞ filtering is discussed and H_∞ filter is constructed, which is used in the initial alignment of the strapdown inertial navigation systems(SINS). The error model of SINS is derived...In this paper , the principle of H∞ filtering is discussed and H_∞ filter is constructed, which is used in the initial alignment of the strapdown inertial navigation systems(SINS). The error model of SINS is derived. By utilizing constructed H∞ filter, the filtering calculation to that system has been conducted. The simulation results of the misalignment angle are given under the condition of unknown noises. The results show that the process of alignment with H∞ filter is much faster and with excellent robustness.展开更多
基金supported by National Natural Science Foundation of China(62462019,62172350)Guangdong Basic and Applied Basic Research Foundation(2023A1515012846)+6 种基金Guangxi Science and Technology Major Program(AA24263010)The Key Research and Development Program of Guangxi(AB24010085)Key Laboratory of Equipment Data Security and Guarantee Technology,Ministry of Education(GDZB2024060500)2024 Higher Education Scientific Research Planning Project(No.24NL0419)Nantong Science and Technology Project(No.JC2023070)the Open Fund of Advanced Cryptography and System Security Key Laboratory of Sichuan Province(GrantNo.SKLACSS-202407)sponsored by the Cultivation of Young andMiddle-aged Academic Leaders in the“Qing Lan Project”of Jiangsu Province and the 2025 Outstanding Teaching Team in the“Qing Lan Project”of Jiangsu Province.
文摘Large language models(LLMs)represent significant advancements in artificial intelligence.However,their increasing capabilities come with a serious challenge:misalignment,which refers to the deviation of model behavior from the designers’intentions and human values.This review aims to synthesize the current understanding of the LLM misalignment issue and provide researchers and practitioners with a comprehensive overview.We define the concept of misalignment and elaborate on its various manifestations,including generating harmful content,factual errors(hallucinations),propagating biases,failing to follow instructions,emerging deceptive behaviors,and emergent misalignment.We explore the multifaceted causes of misalignment,systematically analyzing factors from surface-level technical issues(e.g.,training data,objective function design,model scaling)to deeper fundamental challenges(e.g.,difficulties formalizing values,discrepancies between training signals and real intentions).This review covers existing and emerging techniques for detecting and evaluating the degree of misalignment,such as benchmark tests,red-teaming,and formal safety assessments.Subsequently,we examine strategies to mitigate misalignment,focusing on mainstream alignment techniques such as RLHF,Constitutional AI(CAI),instruction fine-tuning,and novel approaches that address scalability and robustness.In particular,we analyze recent advances in misalignment attack research,including system prompt modifications,supervised fine-tuning,self-supervised representation attacks,and model editing,which challenge the robustness of model alignment.We categorize and analyze the surveyed literature,highlighting major findings,persistent limitations,and current contentious points.Finally,we identify key open questions and propose several promising future research directions,including constructing high-quality alignment datasets,exploring novel alignment methods,coordinating diverse values,and delving into the deep philosophical aspects of alignment.This work underscores the complexity and multidimensionality of LLM misalignment issues,calling for interdisciplinary approaches to reliably align LLMs with human values.
基金supported by the National Natural Science Foundation of China(No.52005362)the Fundamental Research Program of Shanxi Province(Nos.202303021221005 and 202303021211045)+1 种基金the Patent Commercialization Program of Shanxi Province(No.202402003)the Key Research and Development Plan of Xinzhou City.
文摘Presetting tensile twins(TTs)can enhance the mechanical properties of magnesium(Mg)alloys.Two as-received(AR)sheets,as-received state-A(AR-A)with fiber texture and nonuniform grains and as-received state-B with basal texture and uniform equiaxial grains are selected to induce TTs via a novel method called corrugated wide limit alignment(CWLA),and the corresponding CWLA-processed sheets are denoted as CWLA-processed state-A(C-A)and CWLA-processed state-B(C-B).The results demonstrate that a larger initial average grain size correlates with a higher fraction of TTs induced in Mg sheets,thereby refining the grains and forming a new rolling direction(RD)tilted texture during CWLA.The ultimate tensile strength increases by 32%from AR-A to C-A,primarily due to refinement strengthening and twinning-induced strain hardening.The recrystallization mechanism of C-A is dominated by twinning-induced dynamic recrystallization(DRX),where DRX grains prefer to inherit the orientation of TTs,resulting in an enhanced RD-tilted texture and the formation of multi-modal texture.The recrystallization mechanism of C-B is mainly discontinuous DRX and continuous DRX,and the DRX grains prefer to inherit the orientation of matrix grains,ultimately forming a basal texture.In summary,the tensile mechanical behavior of pre-twinned Mg sheets significantly depends on the grain size and texture of the AR sheets,so they present similar changing trends during tensile deformation.
基金supported by the National Natural Science Foundation of China(NSFC,No.62074048)the Key Research and Development Plan of Anhui Province(No.2022f04020007)the Natural Science Foundation of Anhui Province(No.2208085MF177)。
文摘In this study,we present the fabrication of vertical SnO/β-Ga_(2)O_(3) heterojunction diode(HJD)via radio frequency(RF)reactive magnetron sputtering.The valence and conduction band offsets betweenβ-Ga_(2)O_(3) and SnO are determined to be 2.65and 0.75 eV,respectively,through X-ray photoelectron spectroscopy,showing a type-Ⅱband alignment.Compared to its Schottky barrier diode(SBD)counterpart,the HJD presents a comparable specific ON-resistances(R_(on,sp))of 2.8 mΩ·cm^(2) and lower reverse leakage current(I_R),leading to an enhanced reverse blocking characteristics with breakdown voltage(BV)of 1675 V and power figure of merit(PFOM)of 1.0 GW/cm~2.This demonstrates the high quality of the SnO/β-Ga_(2)O_(3) heterojunction interface.Silvaco TCAD simulation further reveals that electric field crowding at the edge of anode for the SBD was greatly depressed by the introduction of SnO film,revealing the potential application of SnO/β-Ga_(2)O_(3) heterojunction in the futureβ-Ga_(2)O_(3)-based power devices.data mining,AI training,and similar technologies,are reserved.
基金approved by Institutional Review Board of Faculty of Medicine in Assiut University,No.04-2024-300470.
文摘BACKGROUND In an era leaning toward a personalized alignment of total knee arthroplasty,coronal plane alignment of the knee(CPAK)phenotypes for each population are studied;furthermore,other possible variables affecting the alignment,such as ankle joint alignment,should be considered.AIM To determine CPAK distribution in the North African(Egyptian)population with knee osteoarthritis and to assess ankle joint line orientation(AJLO)adaptations across different CPAK types.METHODS A cross-sectional study was conducted on patients with primary knee osteoarthritis and normal ankle joints.Radiographic parameters included the mechanical lateral distal femoral angle,medial proximal tibial angle,and the derived calculations of joint line obliquity(JLO)and arithmetic hip-knee-ankle angle(aHKA).The tibial plafond horizontal angle(TPHA)was used for AJLO assessment,where 0°is neutral(type N),<0°is varus(type A),and>0°is valgus(type B).The nine CPAK types were further divided into 27 subtypes after incorporating the three AJLO types.RESULTS A total of 527 patients(1054 knees)were included for CPAK classification,and 435 patients(870 knees and ankles)for AJLO assessment.The mean age was 57.2±7.8 years,with 79.5%females.Most knees(76.4%)demonstrated varus alignment(mean aHKA was-5.51°±4.84°)and apex distal JLO(55.3%)(mean JLO was 176.43°±4.53°).CPAK types I(44.3%),IV(28.6%),and II(10%)were the most common.Regarding AJLO,70.2%of ankles exhibited varus orientation(mean TPHA was-5.21°±6.45°).The most frequent combined subtypes were CPAK type I-A(33.7%),IV-A(21.5%),and I-N(6.9%).A significant positive correlation was found between the TPHA and aHKA(r=0.40,P<0.001).CONCLUSION In this North African cohort,varus knee alignment with apex distal JLO and varus AJLO predominated.CPAK types I,IV,and II were the most common types,while subtypes I-A,IV-A,and I-N were commonly occurring after incorporating AJLO types;furthermore,the AJLO was significantly correlated to aHKA.
基金co-supported by the National Natural Science Foundation of China(No.52125504)the Liaoning Revitalization Talents Program(No.XLYC2202017)Dalian Support Policy Project for Innovation of Technological Talents(No.2023RG001)。
文摘The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input multi-output,nonlinearity,and strong coupling presents significant challenges.The substantial internal force generated during the adjustment process can potentially damage the LAC and degrade the assembly quality.Hence,a workspace-based hybrid force position control scheme was developed to achieve high quality assembly with high-precision and lower internal force.Firstly,an offline workspace analysis with inherent geometric characteristics to form time-varying posture error constraint.Then,the posture error is integrated into the online position axis control to ensure tracking the ideal posture,while the force control axis compensates for posture deviation by minimizing internal force,thereby achieving high precision and low internal force.Finally,the effectiveness was demonstrated through experiments.The root mean square errors of orientation and position are 104 rad and 0.1 mm,respectively.A reduction in internal force can range from 10.96%to 57.4%compared to the traditional method.Key points'max position error is decreased from 0.32 mm to 0.18 mm,satisfying the 0.5 mm tolerance.Therefore,the proposed method will help promote the development of high-performance manufacturing.
基金supported by Joint Funds of the National Natural Science Foundation of China(Grant No.U21A20228).
文摘Root rot is a prevalent soil-borne fungal disease in citrus.Citron C-05(Citrus medica)stands out as a germplasm within Citrus spp.due to its complete resistance to citrus canker and favorable characteristics such as single embryo and easy rooting.However,Citron C-05 was found to be highly susceptible to root rot during cultivation,with the specific pathogens previously unknown.In this study,four candidate fungal species were isolated from Citron C-05 roots.Sequence analysis of ITS,EF-1a,RPB1,and RPB2 identified two Fusarium solani strains,Rr-2 and Rr-4,as the candidates causing root rot in Citron C-05.Resistance tests showed these two pathogens increased root damage rate from 10.30%to 35.69%in Citron C-05,sour orange(Citrus aurantium),sweet orange(Citrus sinensis)and pummelo(Citrus grandis).F.solani exhibited the weak pathogenicity towards trifoliate orange(Poncirus trifoliata).DAB staining revealed none of reddish-brown precipitation in the four susceptible citrus germplasm after infection with F.solani,while trifoliate orange exhibited significant H2O2 accumulation.Trypan blue staining indicated increased cell death in the four susceptible citrus germplasm following infection with these two pathogens but not in trifoliate orange.These findings provide a comprehensive understanding of citrus root rot and support future research on the mechanisms of root rot resistance in citrus.
文摘Objective:Deep learning is employed increasingly in Gastroenterology(GI)endoscopy computer-aided diagnostics for polyp segmentation and multi-class disease detection.In the real world,implementation requires high accuracy,therapeutically relevant explanations,strong calibration,domain generalization,and efficiency.Current Convolutional Neural Network(CNN)and transformer models compromise border precision and global context,generate attention maps that fail to align with expert reasoning,deteriorate during cross-center changes,and exhibit inadequate calibration,hence diminishing clinical trust.Methods:HMA-DER is a hierarchical multi-attention architecture that uses dilation-enhanced residual blocks and an explainability-aware Cognitive Alignment Score(CAS)regularizer to directly align attribution maps with reasoning signals from experts.The framework has additions that make it more resilient and a way to test for accuracy,macro-averaged F1 score,Area Under the Receiver Operating Characteristic Curve(AUROC),calibration(Expected Calibration Error(ECE),Brier Score),explainability(CAS,insertion/deletion AUC),cross-dataset transfer,and throughput.Results:HMA-DER gets Dice Similarity Coefficient scores of 89.5%and 86.0%on Kvasir-SEG and CVC-ClinicDB,beating the strongest baseline by+1.9 and+1.7 points.It gets 86.4%and 85.3%macro-F1 and 94.0%and 93.4%AUROC on HyperKvasir and GastroVision,which is better than the baseline by+1.4/+1.6macro-F1 and+1.2/+1.1AUROC.Ablation study shows that hierarchical attention gives the highest(+3.0),followed by CAS regularization(+2–3),dilatation(+1.5–2.0),and residual connections(+2–3).Cross-dataset validation demonstrates competitive zero-shot transfer(e.g.,KS→CVC Dice 82.7%),whereas multi-dataset training diminishes the domain gap,yielding an 88.1%primary-metric average.HMA-DER’s mixed-precision inference can handle 155 pictures per second,which helps with calibration.Conclusion:HMA-DER strikes a compromise between accuracy,explainability,robustness,and efficiency for the use of reliable GI computer-aided diagnosis in real-world clinical settings.
基金Pre-research Foundation of PLA General Armaments Department （51309010602） National Natural Science Foundation of China （60774002）
文摘To solve the problem that the standard Kalman filter cannot give the optimal solution when the system model and stochastic information are unknown accurately, single fading factor Kalman filter is suitable for simple systems. But for complex systems with multi-variable, it may not be sufficient to use single fading factor as a multiplier for the covariance matrices. In this paper, a new multiple fading factors Kalman filtering algorithm is presented. By calculating the unbiased estimate of the innovation sequence covariance using fenestration, the fading factor matrix is obtained. Adjusting the covariance matrix of prediction error Pk｜k-1 using fading factor matrix, the algorithm provides different rates of fading for different filter channels. The proposed algorithm is applied to strapdown inertial navigation system （SINS） initial alignment, and simulation and experimental results demonstrate that, the alignment accuracy can be upgraded dramatically when the actual system noise characteristics are different from the pre-set values. The new algorithm is less sensitive to uncertainty noise and has better estimation effect of the parameters. Therefore, it is of significant value in practical applications.
基金supported by National High Technology Research and Development Program of China(863 Program)(No.2011AA)
文摘Considering gravity change from ground alignment to space applications, a fuzzy proportional-integral-differential(PID)control strategy is proposed to make the space manipulator track the desired trajectories in different gravity environments. The fuzzy PID controller is developed by combining the fuzzy approach with the PID control method, and the parameters of the PID controller can be adjusted on line based on the ability of the fuzzy controller. Simulations using the dynamic model of the space manipulator have shown the effectiveness of the algorithm in the trajectory tracking problem. Compared with the results of conventional PID control,the control performance of the fuzzy PID is more effective for manipulator trajectory control.
基金Project supported by the National Basic Research Program of China(Grant Nos.2005CB623606 and 2007CB935301)the National Natural Science Foundation of China(Gang Nos.10704044,50825201,and 10721404)
文摘We develop a general approach to the fabrication of films with unidirectional grooves, such as silicon nitride, silicon dioxide and aluminium oxide, in which the surface is not required to be treated. Super-aligned carbon nanotube （SACNT） film may be used as a template and as sacrificial layer, which is subsequently removed by heating in an atmosphere of air. The unidirectional morphology of the SACNT film turns into a desired film, which is found to possess the ability to align liquid crystal molecules. This approach also features high efficiency, low cost and easy scaling-up for mass production.
基金supported by The National Key Research and Development Program of China(2020YFA0210704)。
文摘Orientation control of anisotropic one-dimensional(1D)and two-dimensional(2D)materials in solutions is of great importance in many fields ranging from structural materials design,the thermal management,to energy storage.Achieving fine control of vertical alignment of anisotropic fillers(such as graphene,boron nitride(BN),and carbon fiber)remains challenging.This work presents a universal and scalable method for constructing vertically aligned structures of anisotropic fillers in composites assisted by the expansion flow(using2D BN platelets as a proof-of-concept).BN platelets in the silicone gel strip are oriented in a curved shape that includes vertical alignment in the central area and horizontal alignment close to strip surfaces.Due to the vertical orientation of BN in the central area of strips,a throughplane thermal conductivity as high as 5.65 W m^(-1) K^(-1) was obtained,which can be further improved to 6.54 W m^(-1) K^(-1) by combining BN and pitch-based carbon fibers.The expansion-flow-assisted alignment can be extended to the manufacture of a variety of polymer composites filled with 1D and 2D materials,which can find wide applications in batteries,electronics,and energy storage devices.
文摘Knee osteoarthritis(OA) is a progressive joint disease hallmarked by cartilage and bone breakdown and associated with changes to all of the tissues in the joint,ultimately causing pain,stiffness,deformity and disability in many people.Radiographs are commonly used for the clinical assessment of knee OA incidence and progression,and to assess for risk factors.One risk factor for the incidence and progression of knee OA is malalignment of the lower extremities(LE).The hipknee-ankle(HKA) angle,assessed from a full-length LE radiograph,is ideally used to assess LE alignment.Careful attention to LE positioning is necessary to obtain the most accurate measurement of the HKA angle.Since full-length LE radiographs are not always available,the femoral shaft-tibial shaft(FS-TS) angle may be calculated from a knee radiograph instead.However,the FS-TS angle is more variable than the HKA angle and it should be used with caution.Knee radiographs are used to assess the severity of knee OA and its progression.There are three types of ordinal grading scales for knee OA:global,composite and individual feature scales.Each grade on a global scale describes one or more features of knee OA.The entire description must be met for a specific grade to be assigned.The KellgrenLawrence scale is the most commonly-used global scale.Composite scales grade several features of knee OA individually and sum the grades to create a total score.One example is the compartmental grading scale for knee OA.Composite scales can respond to change in a variety of presentations of knee OA.Individual feature scales assess one or more OA features individually and do not calculate a total score.They are most often used to monitor change in one OA feature,commonly joint space narrowing.The most commonly-used individual feature scale is the OA Research Society International atlas.Each type of scale has its advantages;however,composite scales may offer greater content validity.Responsiveness to change is unknown for most scales and deserves further evaluation.
文摘An important point for computer systems is the identification of users for authentication. One of these identification methods is keystroke dynamics. The keystroke dynamics is a biometric measurement in terms of keystroke press duration and keystroke latency. However, several problems are arisen like the similarity between users and identification accuracy. In this paper, we propose innovative model that can help to solve the problem of similar user by classifying user’s data based on a membership function. Next, we employ sequence alignment as a way of pattern discovery from the user’s typing behaviour. Experiments were conducted to evaluate accuracy of the proposed model. The results show high performance compared to standard classifiers in terms of accuracy and precision.
基金supported by the Shandong Provincial Key Research and Development Program(No.2019JZZY010330)National Natural Science Foundation of China(Nos.52172066,52172064,52072077 and51832002)JWRI International Joint Research Collaborators(No.JIJReC)program.
文摘Silicon nitride(Si_(3)N_(4))based ceramics are one of the most attractive advanced engineering materials,which have been widely used under high-speed rotational operation or for mechanical contacts across a curved surface.In the present study,rotationally symmetric texturing of Si_(3)N_(4),with radial grain align-ment,was obtained by centripetal sinter-forging(CSF)of a partially sintered sample.The average values of the included angles between the c-axis of the local Si_(3)N_(4)grain and radial direction were approxi-mately 16.4°and 11.0°,on the section plane perpendicular to the pressing direction,and parallel to both the pressing and radial directions,respectively.The compressive strain in the pressing direction forced the ceramic body to flow towards the central axis,resulting in compressive strain in the tangential di-rection and tensile strain in the radial direction.A fundamental physical model was created to simulate the grain rotation during the 3-dimentional strain reorientation,which revealed the rod-like grain would preferentially rotate toward the center of the sample under the CSF process.In addition,due to the fric-tion between the sample surface and the pressing punch,the increased shear strain could enhance the Si_(3)N_(4)grain alignment.Consequently,ceramics with rod-like grains perpendicular to the curved side sur-face could be anticipated by applying the centripetal forming concept in a controlled manner.
文摘In this paper , the principle of H∞ filtering is discussed and H_∞ filter is constructed, which is used in the initial alignment of the strapdown inertial navigation systems(SINS). The error model of SINS is derived. By utilizing constructed H∞ filter, the filtering calculation to that system has been conducted. The simulation results of the misalignment angle are given under the condition of unknown noises. The results show that the process of alignment with H∞ filter is much faster and with excellent robustness.
