BACKGROUND Early detection of esophageal squamous neoplasms(ESN)is essential for improving patient prognosis.Optical diagnosis of ESN remains challenging.Probebased confocal laser endomicroscopy(pCLE)enables accurate ...BACKGROUND Early detection of esophageal squamous neoplasms(ESN)is essential for improving patient prognosis.Optical diagnosis of ESN remains challenging.Probebased confocal laser endomicroscopy(pCLE)enables accurate in vivo histological observation and optical biopsy of ESN.However,interpretation of pCLE images requires histopathological expertise and extensive training.Artificial intelligence(AI)has been widely applied in digestive endoscopy;however,AI for pCLE diagnosis of ESN has not been reported.AIM To develop a pCLE computer-aided diagnostic system for ESN and assess its diagnostic performance and assistant efficiency for nonexpert endoscopists.METHODS The intelligent confocal laser endomicroscopy(iCLE)system consists of image recognition(based on inception-ResNet V2),video diagnosis,and quality judgment modules.This system was developed using pCLE images and videos and evaluated through image and prospective video recognition tests.Patients between June 2020 and January 2023 were prospectively enrolled.Expert and nonexpert endoscopists and the iCLE independently performed diagnoses for pCLE videos,with histopathology as the gold standard.Thereafter,the non-expert endoscopists performed a second assessment with iCLE assistance.RESULTS A total of 25056 images from 2803 patients were selected for iCLE training and validation.Another 2442 images from 226 patients were used for testing.iCLE achieved a high accuracy of 98.3%,sensitivity of 95.3%and specificity of 98.8%for diagnosing ESN images.A total of 2581 patients underwent upper gastrointestinal pCLE examination and were prospectively screened;54 patients with suspected ESN were enrolled.Overall,187 videos from 67 lesions were assessed by iCLE,three nonexpert and three expert endoscopists.iCLE achieved a high accuracy,sensitivity and specificity of 90.9%,92.0%,and 90.2%,respectively.Compared to experts,iCLE showed significantly higher sensitivity(92.0%vs 80.4%;P<0.001)and negative predictive value(94.4%vs 87.7%;P=0.003).With iCLE assistance,nonexpert endoscopists showed significant improvements in accuracy(from 83.6%to 88.6%)and sensitivity(from 76.0%to 89.8%).CONCLUSION iCLE system demonstrated high diagnostic performance for ESN.It can assist nonexpert endoscopists in improving the diagnostic efficiency of pCLE for ESN and has the potential for reducing unnecessary biopsies.展开更多
Terrain Aided Navigation(TAN)technology has become increasingly important due to its effectiveness in environments where Global Positioning System(GPS)is unavailable.In recent years,TAN systems have been extensively r...Terrain Aided Navigation(TAN)technology has become increasingly important due to its effectiveness in environments where Global Positioning System(GPS)is unavailable.In recent years,TAN systems have been extensively researched for both aerial and underwater navigation applications.However,many TAN systems that rely on recursive Unmanned Aerial Vehicle(UAV)position estimation methods,such as Extended Kalman Filters(EKF),often face challenges with divergence and instability,particularly in highly non-linear systems.To address these issues,this paper proposes and investigates a hybrid two-stage TAN positioning system for UAVs that utilizes Particle Filter.To enhance the system’s robustness against uncertainties caused by noise and to estimate additional system states,a Fuzzy Particle Filter(FPF)is employed in the first stage.This approach introduces a novel terrain composite feature that enables a fuzzy expert system to analyze terrain non-linearities and dynamically adjust the number of particles in real-time.This design allows the UAV to be efficiently localized in GPS-denied environments while also reducing the computational complexity of the particle filter in real-time applications.In the second stage,an Error State Kalman Filter(ESKF)is implemented to estimate the UAV’s altitude.The ESKF is chosen over the conventional EKF method because it is more suitable for non-linear systems.Simulation results demonstrate that the proposed fuzzy-based terrain composite method achieves high positional accuracy while reducing computational time and memory usage.展开更多
In the heart of Addis Ababa,where tradition meets modern ambition,a gleaming structure of steel and glass is quietly reshaping Africa’s future.The new Africa Centres for Disease Control and Prevention(Africa CDC)Head...In the heart of Addis Ababa,where tradition meets modern ambition,a gleaming structure of steel and glass is quietly reshaping Africa’s future.The new Africa Centres for Disease Control and Prevention(Africa CDC)Headquarters is more than just a building-it’s a bold statement of partnership,progress,and a shared commitment to advancing public health across the continent.展开更多
Unmanned Aerial Vehicle(UAV)-aided communication,prized for its network reconfigurability,operational flexibility,and cost-effectiveness,is a key enabler of the low-altitude economy.However,the high possibilities of l...Unmanned Aerial Vehicle(UAV)-aided communication,prized for its network reconfigurability,operational flexibility,and cost-effectiveness,is a key enabler of the low-altitude economy.However,the high possibilities of line-of-sight links and the broadcast nature of air-ground UAV communications make it vulnerable and prone to eavesdropping by malicious nodes.展开更多
Unmanned Aerial Vehicle(UAV)-aided communication holds great potential to enhance the transmission performance.However,the information security remains a fundamental requirement due to the high possibilities of line-o...Unmanned Aerial Vehicle(UAV)-aided communication holds great potential to enhance the transmission performance.However,the information security remains a fundamental requirement due to the high possibilities of line-of-sight links and the broadcast nature.展开更多
Porcine Contagious Pleuropneumonia(PCP)is a respiratory infectious disease of pigs caused by Actinobacillus pleuropneumoniae.The disease has been prevalent in pig farms since it was first identified in 1957(Pattison e...Porcine Contagious Pleuropneumonia(PCP)is a respiratory infectious disease of pigs caused by Actinobacillus pleuropneumoniae.The disease has been prevalent in pig farms since it was first identified in 1957(Pattison et al.1957).展开更多
Design of internal combustion engine (ICE) components is one of the earliest and also the most active areas in which computer aided modeling techniques are applied. Computer aided modeling techniques could provide req...Design of internal combustion engine (ICE) components is one of the earliest and also the most active areas in which computer aided modeling techniques are applied. Computer aided modeling techniques could provide requisite information for follow up designing segments such as structural analysis, design of technological process and manufacturing etc, and thereby lead to the reduction of product design period and the quality and reliability improvement of ICE components. So the developing situations of ICE components' 2 D drafting, 3 D modeling of ICE, overall CAD of ICE as well as component design expert system etc. are surveyed, which are the typical applications of computer aided modeling techniques in ICE component design process, and some existent problems and tasks are pointed out so as to make some references for the further research work.展开更多
The importance and complexity of prioritizing construction projects (PCP) in urban road network planning lead to the necessity to develop an aided decision making program (ADMP). Cost benefit ratio model and stage rol...The importance and complexity of prioritizing construction projects (PCP) in urban road network planning lead to the necessity to develop an aided decision making program (ADMP). Cost benefit ratio model and stage rolled method are chosen as the theoretical foundations of the program, and then benefit model is improved to accord with the actuality of urban traffic in China. Consequently, program flows, module functions and data structures are designed, and particularly an original data structure of road ...展开更多
Today the development of information technology changes people's daily life in many aspects, including the translationmarket. The application of computer aided translation(CAT) greatly improves the efficiency and ...Today the development of information technology changes people's daily life in many aspects, including the translationmarket. The application of computer aided translation(CAT) greatly improves the efficiency and quality of translation work. Thispaper tries to introduce the development of CAT technology and the application of CAT on the Internet and gives some suggestionson CAT teaching.展开更多
It is well-known that grain refiners can tailor the microstructure and enhance the mechanical properties of titanium alloys fabricated by additive manufacturing(AM). However, the intrinsic mechanisms of Ni addition on...It is well-known that grain refiners can tailor the microstructure and enhance the mechanical properties of titanium alloys fabricated by additive manufacturing(AM). However, the intrinsic mechanisms of Ni addition on AM-built Ti–6Al–4V alloy is not well established. This limits its industrial applications. This work systematically investigated the influence of Ni additive on Ti–6Al–4V alloy fabricated by laser aided additive manufacturing(LAAM). The results showed that Ni addition yields three key effects on the microstructural evolution of LAAM-built Ti–6Al–4V alloy.(a) Ni additive remarkably refines the prior-β grains, which is due to the widened solidification range. As the Ni addition increased from 0 to 2.5 wt. %, the major-axis length and aspect ratio of the prior-β grains reduced from over 1500 μm and 7 to 97.7 μm and1.46, respectively.(b) Ni additive can discernibly induce the formation of globular α phase,which is attributed to the enhanced concentration gradient between the β and α phases. This is the driving force of globularization according to the termination mass transfer theory. The aspect ratio of the α laths decreased from 4.14 to 2.79 as the Ni addition increased from 0 to2.5 wt. %.(c) Ni as a well-known β-stabilizer and it can remarkably increase the volume fraction of β phase. Room-temperature tensile results demonstrated an increase in mechanical strength and an almost linearly decreasing elongation with increasing Ni addition. A modified mathematical model was used to quantitatively analyze the strengthening mechanism. It was evident from the results that the α lath phase and the solid solutes contribute the most to the overall yield strength of the LAAM-built Ti–6Al–4V–x Ni alloys in this work. Furthermore, the decrease in elongation with increasing Ni addition is due to the deterioration in deformability of the β phase caused by a large amount of solid-solution Ni atoms. These findings can accelerate the development of additively manufactured titanium alloys.展开更多
Compared with other kinds of airbags, curtain airbag（CAB） has more complex structures and larger coverage area. The product development process depends on many module tests, sled tests and full size vehicle tests. C...Compared with other kinds of airbags, curtain airbag（CAB） has more complex structures and larger coverage area. The product development process depends on many module tests, sled tests and full size vehicle tests. Computer aided engineering（CAE） technology can replace tests to a great extent, also save test costs and product development time. This paper introduces the way of setting up simulation models and application of static deployment tests and free motion headform（FMH） tests to verify simulation models. In the CAB simulation, uniform pressure airbag models and computational fluid dynamics（CFD） models are all used. The uniform pressure airbag models are not able to simulate the pressure difference among different parts inside the cushion during inflating process. CFD-based CAB models are used to help the curtain airbag optimization design. Based on effective CAE simulation, the optimization analyses related to diffuser tube parameters, inflator mass flow rate and cushion folding patterns are discussed and performed in different cases. The optimization result shows that the proposed techniques are helpful to the parametric optimization design of side curtain airbag module in curtain airbag development process.展开更多
Artificial bone with porous structure is crucial for tissue scaffold and clinic implants.Scaffold provides structure support for cells and guides tissues regeneration for final tissue structure.A computational aided p...Artificial bone with porous structure is crucial for tissue scaffold and clinic implants.Scaffold provides structure support for cells and guides tissues regeneration for final tissue structure.A computational aided process of porous bone modeling was developed which described the design and fabrication of tissue scaffolds by considering intricate architecture,porosity and pore size.To simulate intricate bone structure,different constructive units were presented.In modeling process,bone contour was gotten from computed tomography(CT)images and was divided into two levels.Each level was represented by relatively reconstructive process.Pore size distribution was controlled by using mesh generation.The whole hexahedral mesh was reduced by unit structure,when a 3D mesh with various hexahedral elements was provided.The simulation results show that constructive structure of porous scaffold can meet the needs of clinic implants in accurate and controlled way.展开更多
West Nile virus(WNV)causes West Nile fever and West Nile encephalitis.Because infection by WNV creates serious public health problems,its simple,rapid,and visual detection is very important in clinical practice,especi...West Nile virus(WNV)causes West Nile fever and West Nile encephalitis.Because infection by WNV creates serious public health problems,its simple,rapid,and visual detection is very important in clinical practice,especially in resource-limited laboratories.We have developed a rapid,specific,and highly sensitive internally controlled reverse transcription recombinase-aided amplification(RTRAA)assay to detect WNV,using both real-timefluoresce nee and the lateral flow dipstick(LFD)at39.0°C for 30 min.The analytical sensitivity of theRT-RAA assay was 10 plasmid copies and 1.6 pfu perreacti on with real-time fluoresce nee,and 1,000plasmid copies per reaction with the LFD.No crossreactionwith other control viruses was observed.Compared with the RT-qPCR assay,the RT-RAA assaydemonstrated 100%sensitivity and 100%specificityfor WNV.展开更多
To detect high frequency （HF） first-order sea echo spectra contaminated with ships, ionosphere interference, and other, a new characteristic-knowledge-aided detection method is proposed. With 2-D image features in r...To detect high frequency （HF） first-order sea echo spectra contaminated with ships, ionosphere interference, and other, a new characteristic-knowledge-aided detection method is proposed. With 2-D image features in range-Doppler spectrum, the trend of first-order sea echoes is extracted as indicative information by a multi-scale filter. Detection rules for both single and splitting first-order sea echoes are given based on the characteristic knowledge combining the indicative information with the global characteristics such as amplitude, symmetry, continuity, etc. Compared with the classical algorithms, the proposed method can detect and locate the first-order sea echo in the HF band more accurately especially in the environment with targets/clutters smearing. Experiments with real data verify the validity of the algorithm.展开更多
Laser aided additive manufacturing(LAAM)was used to fabricate bulk Fe_(49.5)Mn_(30)Co_(10)Cr_(10)C_(0.5)interstitial multicomponent alloy using pre-alloyed powder.The room temperature yield strength(σ_y),ultimate ten...Laser aided additive manufacturing(LAAM)was used to fabricate bulk Fe_(49.5)Mn_(30)Co_(10)Cr_(10)C_(0.5)interstitial multicomponent alloy using pre-alloyed powder.The room temperature yield strength(σ_y),ultimate tensile strength(σ_(UTS))and elongation(ε_(UTS))were 645 MPa,917 MPa and 27.0%respectively.The asbuilt sample consisted of equiaxed and dendritic cellular structures formed by elemental segregation.These cellular structures together with oxide particle inclusions were deemed to strengthen the material.The other contributing components include dislocation strengthening,friction stress and grain boundary strengthening.The highε_(UTS)was attributed to dislocation motion and activation of both twinning and transformation-induced plasticity(TWIP and TRIP).Tensile tests performed at-40℃and-130℃demonstrated superior tensile strength of 1041 MPa and 1267 MPa respectively.However,almost no twinning was observed in the fractured sample tested at-40℃and-130℃.Instead,higher fraction of strain-induced hexagonal close-packed(HCP)εphase transformation of 21.2%were observed for fractured sample tested at-40℃,compared with 6.3%in fractured room temperature sample.展开更多
This paper studies a multiple unmanned aerial vehicle(UAV)relaying communication system,where multiple UAV re-lays assist the blocked communication between a group of ground users(GUs)and a base station(BS).Since the ...This paper studies a multiple unmanned aerial vehicle(UAV)relaying communication system,where multiple UAV re-lays assist the blocked communication between a group of ground users(GUs)and a base station(BS).Since the UAVs only have limited-energy in practice,our design aims to maximize the energy efficiency(EE)through jointly designing the communica-tion scheduling,the transmit power allocation,as well as UAV trajectory under the buffer constraint over a given flight period.Actually,the formulated fractional optimization problem is diffi-cult to be solved in general because of non-convexity.To re-solve this difficulty,an efficient iterative algorithm is proposed based on the block coordinate descent(BCD)and successive convex approximation(SCA)techniques,as well as the Dinkel-bach’s algorithm.Specifically,the optimization variables of the formulated problem are divided into three blocks and we alter-nately optimize each block of the variables over iteration.Numeri-cal results verify the convergence of the proposed iterative al-gorithm and show that the proposed designs achieve significant EE gain,which outperform other benchmark schemes.展开更多
The purpose of this study is to develop a standard methodology for measuring the surface free energy (SFE),and its component parts of bamboo fiber materials.The current methods was reviewed to determine the surface te...The purpose of this study is to develop a standard methodology for measuring the surface free energy (SFE),and its component parts of bamboo fiber materials.The current methods was reviewed to determine the surface tension of natural fibers and the disadvantages of techniques used were discussed.Although numerous techniques have been employed to characterize surface tension of natural fibers,it seems that the credibility of results obtained may often be dubious.In this paper,critical surface tension estimates were obtained from computer aided machine vision based measurement.Data were then analyzed by the least squares method to estimate the components of SFE.SFE was estimated by least squares analysis and also by Schultz' method.By using the Fowkes method the polar and disperse fractions of the surface free energy of bamboo fiber materials can be obtained.Strictly speaking,this method is based on a combination of the knowledge of Fowkes theory. SFE is desirable when adhesion is required,and it avoids some of the limitations of existing studies which has been proposed.The calculation steps described in this research are only intended to explain the methods.The results show that the method that only determines SFE as a single parameter may be unable to differentiate adequately between bamboo fiber materials,but it is feasible and very efficient.In order to obtain the maximum performance from the computer aided machine vision based measurement instruments,this measurement should be recommended and kept available for reference.展开更多
In this paper, we review some mathematical models in medical image processing. Due to the superiority in modeling and computation, variational methods have been proven to be powerful techniques, which have been extrem...In this paper, we review some mathematical models in medical image processing. Due to the superiority in modeling and computation, variational methods have been proven to be powerful techniques, which have been extremely popular and dramatically improved in the past two decades. On one hand, many models have been proposed for nearly all kinds of applications. On the other hand, a lot of models can be globally optimized and also many computation tools have been introduced. Under the variational framework, we focus on two basic problems in medical imaging： image restoration and segmentation, which are core components for kinds of specific tasks. For image restoration, we discuss some models on both additive and multiplicative noises. For image segmentation, we review some models on both whole image segmentation and specific target delineation, with the later being a key step in computer aided surgery. Additionally, we present some models on liver delineation and give their applications to living donor liver transplantation.展开更多
Objective To establish a sensitive,simple and rapid detection method for African swine fever virus(ASFV)B646L gene.Methods A recombinase-aided amplification-lateral flow dipstick(RAA-LFD)assay was developed in this st...Objective To establish a sensitive,simple and rapid detection method for African swine fever virus(ASFV)B646L gene.Methods A recombinase-aided amplification-lateral flow dipstick(RAA-LFD)assay was developed in this study.Recombinase-aided amplification(RAA)is used to amplify template DNA,and lateral flow dipstick(LFD)is used to interpret the results after the amplification is completed.The lower limits of detection and specificity of the RAA assay were verified using recombinant plasmid and pathogenic nucleic acid.In addition,30 clinical samples were tested to evaluate the performance of the RAA assay.Results The RAA-LFD assay was completed within 15 min at 37°C,including 10 min for nucleic acid amplification and 5 minutes for LFD reading results.The detection limit of this assay was found to be 200 copies per reaction.And there was no cross-reactivity with other swine viruses.Conclusion A highly sensitive,specific,and simple RAA-LFD method was developed for the rapid detection of the ASFV.展开更多
We have carried out clinical observations on 34 patients with peripheral facial paralysis treatedby acupuncture therapy prescribed according to selection of treatment regimen on the basis of fa-cial thermogram and tem...We have carried out clinical observations on 34 patients with peripheral facial paralysis treatedby acupuncture therapy prescribed according to selection of treatment regimen on the basis of fa-cial thermogram and temperature.A comparison was made with a control group of 97 patientswho received conventional acupuncture therapy only.It was found that 1)The cure rate in thegroup of selecting acupoints by thermorgram(hereinafter referred to as the thermography-aidedtreatment group)was 67.65%,with a marked improvement rate of 26.40%;while the cure rateof the conventional acupuncture treatment group(hereinafter called the conventional treatmentgroup)was 46.39%,the marked improvement rate being 29.90%,indicating a significant differ-ence in therapeutic efficacy between the two groups(P【0.02).2)The average duration ofacupuncture therapy for the thermography aided treatment group was 6.02 weeks,whereas thatfor the conventional treatment group,24 weeks.There was also a significant difference betweenthe two groups(P【0.01).And 3)During the entire therapeutic course,25.2 sessions of treatmentwere given on the average in the thermography-aided treatment group,and 78.8 sessions in theconventional treatment group,showing a very significant difference(P【0.001).The present thermography-aided method exhibits advantages over the conventional one in en-hancing the cure rate and shortening the duration of treatment,which is worthy to be popularizedin clinical practice.And it is also of certain significance in standardization and-scientification ofacupuncture therapy.展开更多
基金Supported by the National Key Research and Development Program of China,No.2023YFC2413800the Taishan Scholars Program of Shandong Province,No.tsqn202306344the National Natural Science Foundation of China,No.82270580 and No.82070552.
文摘BACKGROUND Early detection of esophageal squamous neoplasms(ESN)is essential for improving patient prognosis.Optical diagnosis of ESN remains challenging.Probebased confocal laser endomicroscopy(pCLE)enables accurate in vivo histological observation and optical biopsy of ESN.However,interpretation of pCLE images requires histopathological expertise and extensive training.Artificial intelligence(AI)has been widely applied in digestive endoscopy;however,AI for pCLE diagnosis of ESN has not been reported.AIM To develop a pCLE computer-aided diagnostic system for ESN and assess its diagnostic performance and assistant efficiency for nonexpert endoscopists.METHODS The intelligent confocal laser endomicroscopy(iCLE)system consists of image recognition(based on inception-ResNet V2),video diagnosis,and quality judgment modules.This system was developed using pCLE images and videos and evaluated through image and prospective video recognition tests.Patients between June 2020 and January 2023 were prospectively enrolled.Expert and nonexpert endoscopists and the iCLE independently performed diagnoses for pCLE videos,with histopathology as the gold standard.Thereafter,the non-expert endoscopists performed a second assessment with iCLE assistance.RESULTS A total of 25056 images from 2803 patients were selected for iCLE training and validation.Another 2442 images from 226 patients were used for testing.iCLE achieved a high accuracy of 98.3%,sensitivity of 95.3%and specificity of 98.8%for diagnosing ESN images.A total of 2581 patients underwent upper gastrointestinal pCLE examination and were prospectively screened;54 patients with suspected ESN were enrolled.Overall,187 videos from 67 lesions were assessed by iCLE,three nonexpert and three expert endoscopists.iCLE achieved a high accuracy,sensitivity and specificity of 90.9%,92.0%,and 90.2%,respectively.Compared to experts,iCLE showed significantly higher sensitivity(92.0%vs 80.4%;P<0.001)and negative predictive value(94.4%vs 87.7%;P=0.003).With iCLE assistance,nonexpert endoscopists showed significant improvements in accuracy(from 83.6%to 88.6%)and sensitivity(from 76.0%to 89.8%).CONCLUSION iCLE system demonstrated high diagnostic performance for ESN.It can assist nonexpert endoscopists in improving the diagnostic efficiency of pCLE for ESN and has the potential for reducing unnecessary biopsies.
文摘Terrain Aided Navigation(TAN)technology has become increasingly important due to its effectiveness in environments where Global Positioning System(GPS)is unavailable.In recent years,TAN systems have been extensively researched for both aerial and underwater navigation applications.However,many TAN systems that rely on recursive Unmanned Aerial Vehicle(UAV)position estimation methods,such as Extended Kalman Filters(EKF),often face challenges with divergence and instability,particularly in highly non-linear systems.To address these issues,this paper proposes and investigates a hybrid two-stage TAN positioning system for UAVs that utilizes Particle Filter.To enhance the system’s robustness against uncertainties caused by noise and to estimate additional system states,a Fuzzy Particle Filter(FPF)is employed in the first stage.This approach introduces a novel terrain composite feature that enables a fuzzy expert system to analyze terrain non-linearities and dynamically adjust the number of particles in real-time.This design allows the UAV to be efficiently localized in GPS-denied environments while also reducing the computational complexity of the particle filter in real-time applications.In the second stage,an Error State Kalman Filter(ESKF)is implemented to estimate the UAV’s altitude.The ESKF is chosen over the conventional EKF method because it is more suitable for non-linear systems.Simulation results demonstrate that the proposed fuzzy-based terrain composite method achieves high positional accuracy while reducing computational time and memory usage.
文摘In the heart of Addis Ababa,where tradition meets modern ambition,a gleaming structure of steel and glass is quietly reshaping Africa’s future.The new Africa Centres for Disease Control and Prevention(Africa CDC)Headquarters is more than just a building-it’s a bold statement of partnership,progress,and a shared commitment to advancing public health across the continent.
文摘Unmanned Aerial Vehicle(UAV)-aided communication,prized for its network reconfigurability,operational flexibility,and cost-effectiveness,is a key enabler of the low-altitude economy.However,the high possibilities of line-of-sight links and the broadcast nature of air-ground UAV communications make it vulnerable and prone to eavesdropping by malicious nodes.
文摘Unmanned Aerial Vehicle(UAV)-aided communication holds great potential to enhance the transmission performance.However,the information security remains a fundamental requirement due to the high possibilities of line-of-sight links and the broadcast nature.
基金supported by the University-Industry Col aborative Education Program,China(220904860093831)。
文摘Porcine Contagious Pleuropneumonia(PCP)is a respiratory infectious disease of pigs caused by Actinobacillus pleuropneumoniae.The disease has been prevalent in pig farms since it was first identified in 1957(Pattison et al.1957).
文摘Design of internal combustion engine (ICE) components is one of the earliest and also the most active areas in which computer aided modeling techniques are applied. Computer aided modeling techniques could provide requisite information for follow up designing segments such as structural analysis, design of technological process and manufacturing etc, and thereby lead to the reduction of product design period and the quality and reliability improvement of ICE components. So the developing situations of ICE components' 2 D drafting, 3 D modeling of ICE, overall CAD of ICE as well as component design expert system etc. are surveyed, which are the typical applications of computer aided modeling techniques in ICE component design process, and some existent problems and tasks are pointed out so as to make some references for the further research work.
文摘The importance and complexity of prioritizing construction projects (PCP) in urban road network planning lead to the necessity to develop an aided decision making program (ADMP). Cost benefit ratio model and stage rolled method are chosen as the theoretical foundations of the program, and then benefit model is improved to accord with the actuality of urban traffic in China. Consequently, program flows, module functions and data structures are designed, and particularly an original data structure of road ...
文摘Today the development of information technology changes people's daily life in many aspects, including the translationmarket. The application of computer aided translation(CAT) greatly improves the efficiency and quality of translation work. Thispaper tries to introduce the development of CAT technology and the application of CAT on the Internet and gives some suggestionson CAT teaching.
基金supported by the Agency for Science,Technology and Research(A*Star),Republic of Singapore under the IAF-PP program‘Integrated large format hybrid manufacturing using wire-fed and powder-blown technology for LAAM process’,Grant No.A1893a0031the Academy of Sciences Project of Guangdong Province,Grant No.2016GDASRC-0105。
文摘It is well-known that grain refiners can tailor the microstructure and enhance the mechanical properties of titanium alloys fabricated by additive manufacturing(AM). However, the intrinsic mechanisms of Ni addition on AM-built Ti–6Al–4V alloy is not well established. This limits its industrial applications. This work systematically investigated the influence of Ni additive on Ti–6Al–4V alloy fabricated by laser aided additive manufacturing(LAAM). The results showed that Ni addition yields three key effects on the microstructural evolution of LAAM-built Ti–6Al–4V alloy.(a) Ni additive remarkably refines the prior-β grains, which is due to the widened solidification range. As the Ni addition increased from 0 to 2.5 wt. %, the major-axis length and aspect ratio of the prior-β grains reduced from over 1500 μm and 7 to 97.7 μm and1.46, respectively.(b) Ni additive can discernibly induce the formation of globular α phase,which is attributed to the enhanced concentration gradient between the β and α phases. This is the driving force of globularization according to the termination mass transfer theory. The aspect ratio of the α laths decreased from 4.14 to 2.79 as the Ni addition increased from 0 to2.5 wt. %.(c) Ni as a well-known β-stabilizer and it can remarkably increase the volume fraction of β phase. Room-temperature tensile results demonstrated an increase in mechanical strength and an almost linearly decreasing elongation with increasing Ni addition. A modified mathematical model was used to quantitatively analyze the strengthening mechanism. It was evident from the results that the α lath phase and the solid solutes contribute the most to the overall yield strength of the LAAM-built Ti–6Al–4V–x Ni alloys in this work. Furthermore, the decrease in elongation with increasing Ni addition is due to the deterioration in deformability of the β phase caused by a large amount of solid-solution Ni atoms. These findings can accelerate the development of additively manufactured titanium alloys.
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2006AA110102)
文摘Compared with other kinds of airbags, curtain airbag（CAB） has more complex structures and larger coverage area. The product development process depends on many module tests, sled tests and full size vehicle tests. Computer aided engineering（CAE） technology can replace tests to a great extent, also save test costs and product development time. This paper introduces the way of setting up simulation models and application of static deployment tests and free motion headform（FMH） tests to verify simulation models. In the CAB simulation, uniform pressure airbag models and computational fluid dynamics（CFD） models are all used. The uniform pressure airbag models are not able to simulate the pressure difference among different parts inside the cushion during inflating process. CFD-based CAB models are used to help the curtain airbag optimization design. Based on effective CAE simulation, the optimization analyses related to diffuser tube parameters, inflator mass flow rate and cushion folding patterns are discussed and performed in different cases. The optimization result shows that the proposed techniques are helpful to the parametric optimization design of side curtain airbag module in curtain airbag development process.
基金Project(2011DFB70230)supported by State International Cooperation Program of ChinaProject(N110403003)supported by Basic Research Foundation of Education Ministry of China
文摘Artificial bone with porous structure is crucial for tissue scaffold and clinic implants.Scaffold provides structure support for cells and guides tissues regeneration for final tissue structure.A computational aided process of porous bone modeling was developed which described the design and fabrication of tissue scaffolds by considering intricate architecture,porosity and pore size.To simulate intricate bone structure,different constructive units were presented.In modeling process,bone contour was gotten from computed tomography(CT)images and was divided into two levels.Each level was represented by relatively reconstructive process.Pore size distribution was controlled by using mesh generation.The whole hexahedral mesh was reduced by unit structure,when a 3D mesh with various hexahedral elements was provided.The simulation results show that constructive structure of porous scaffold can meet the needs of clinic implants in accurate and controlled way.
基金supported by grants from the China Mega-Projects for Infectious Disease [2017ZX10302301-004-002,2018ZX10711001,2017ZX10104001,2018ZX10713-002]IVDC [2019HYDQNJJ03]
文摘West Nile virus(WNV)causes West Nile fever and West Nile encephalitis.Because infection by WNV creates serious public health problems,its simple,rapid,and visual detection is very important in clinical practice,especially in resource-limited laboratories.We have developed a rapid,specific,and highly sensitive internally controlled reverse transcription recombinase-aided amplification(RTRAA)assay to detect WNV,using both real-timefluoresce nee and the lateral flow dipstick(LFD)at39.0°C for 30 min.The analytical sensitivity of theRT-RAA assay was 10 plasmid copies and 1.6 pfu perreacti on with real-time fluoresce nee,and 1,000plasmid copies per reaction with the LFD.No crossreactionwith other control viruses was observed.Compared with the RT-qPCR assay,the RT-RAA assaydemonstrated 100%sensitivity and 100%specificityfor WNV.
文摘To detect high frequency （HF） first-order sea echo spectra contaminated with ships, ionosphere interference, and other, a new characteristic-knowledge-aided detection method is proposed. With 2-D image features in range-Doppler spectrum, the trend of first-order sea echoes is extracted as indicative information by a multi-scale filter. Detection rules for both single and splitting first-order sea echoes are given based on the characteristic knowledge combining the indicative information with the global characteristics such as amplitude, symmetry, continuity, etc. Compared with the classical algorithms, the proposed method can detect and locate the first-order sea echo in the HF band more accurately especially in the environment with targets/clutters smearing. Experiments with real data verify the validity of the algorithm.
基金Agency for Science,Technology and Research(A*Star),Republic of Singapore,under the IAF-PP program“Integrated large format hybrid manufacturing using wire-fed and powder-blown technology for LAAM process”,Grant No:A1893a0031。
文摘Laser aided additive manufacturing(LAAM)was used to fabricate bulk Fe_(49.5)Mn_(30)Co_(10)Cr_(10)C_(0.5)interstitial multicomponent alloy using pre-alloyed powder.The room temperature yield strength(σ_y),ultimate tensile strength(σ_(UTS))and elongation(ε_(UTS))were 645 MPa,917 MPa and 27.0%respectively.The asbuilt sample consisted of equiaxed and dendritic cellular structures formed by elemental segregation.These cellular structures together with oxide particle inclusions were deemed to strengthen the material.The other contributing components include dislocation strengthening,friction stress and grain boundary strengthening.The highε_(UTS)was attributed to dislocation motion and activation of both twinning and transformation-induced plasticity(TWIP and TRIP).Tensile tests performed at-40℃and-130℃demonstrated superior tensile strength of 1041 MPa and 1267 MPa respectively.However,almost no twinning was observed in the fractured sample tested at-40℃and-130℃.Instead,higher fraction of strain-induced hexagonal close-packed(HCP)εphase transformation of 21.2%were observed for fractured sample tested at-40℃,compared with 6.3%in fractured room temperature sample.
基金supported by the National Natural Science Foundation of China(61671474).
文摘This paper studies a multiple unmanned aerial vehicle(UAV)relaying communication system,where multiple UAV re-lays assist the blocked communication between a group of ground users(GUs)and a base station(BS).Since the UAVs only have limited-energy in practice,our design aims to maximize the energy efficiency(EE)through jointly designing the communica-tion scheduling,the transmit power allocation,as well as UAV trajectory under the buffer constraint over a given flight period.Actually,the formulated fractional optimization problem is diffi-cult to be solved in general because of non-convexity.To re-solve this difficulty,an efficient iterative algorithm is proposed based on the block coordinate descent(BCD)and successive convex approximation(SCA)techniques,as well as the Dinkel-bach’s algorithm.Specifically,the optimization variables of the formulated problem are divided into three blocks and we alter-nately optimize each block of the variables over iteration.Numeri-cal results verify the convergence of the proposed iterative al-gorithm and show that the proposed designs achieve significant EE gain,which outperform other benchmark schemes.
基金the National Natural Science Foundation of China(No.31101085)the Scientific Research and Development Foundation for Start-up Projects of Zhejiang Agriculture and Forestry University (No.2034020044)
文摘The purpose of this study is to develop a standard methodology for measuring the surface free energy (SFE),and its component parts of bamboo fiber materials.The current methods was reviewed to determine the surface tension of natural fibers and the disadvantages of techniques used were discussed.Although numerous techniques have been employed to characterize surface tension of natural fibers,it seems that the credibility of results obtained may often be dubious.In this paper,critical surface tension estimates were obtained from computer aided machine vision based measurement.Data were then analyzed by the least squares method to estimate the components of SFE.SFE was estimated by least squares analysis and also by Schultz' method.By using the Fowkes method the polar and disperse fractions of the surface free energy of bamboo fiber materials can be obtained.Strictly speaking,this method is based on a combination of the knowledge of Fowkes theory. SFE is desirable when adhesion is required,and it avoids some of the limitations of existing studies which has been proposed.The calculation steps described in this research are only intended to explain the methods.The results show that the method that only determines SFE as a single parameter may be unable to differentiate adequately between bamboo fiber materials,but it is feasible and very efficient.In order to obtain the maximum performance from the computer aided machine vision based measurement instruments,this measurement should be recommended and kept available for reference.
基金Supported by the National Natural Science Foundation of China (11101365)a National Science and Technology Project during the twelfth five-year plan of China (2012BAI10B04)
文摘In this paper, we review some mathematical models in medical image processing. Due to the superiority in modeling and computation, variational methods have been proven to be powerful techniques, which have been extremely popular and dramatically improved in the past two decades. On one hand, many models have been proposed for nearly all kinds of applications. On the other hand, a lot of models can be globally optimized and also many computation tools have been introduced. Under the variational framework, we focus on two basic problems in medical imaging： image restoration and segmentation, which are core components for kinds of specific tasks. For image restoration, we discuss some models on both additive and multiplicative noises. For image segmentation, we review some models on both whole image segmentation and specific target delineation, with the later being a key step in computer aided surgery. Additionally, we present some models on liver delineation and give their applications to living donor liver transplantation.
基金supported by National Key R&D Program of China[2017YFC200503]National Natural Science Foundation of China[No.42077399].
文摘Objective To establish a sensitive,simple and rapid detection method for African swine fever virus(ASFV)B646L gene.Methods A recombinase-aided amplification-lateral flow dipstick(RAA-LFD)assay was developed in this study.Recombinase-aided amplification(RAA)is used to amplify template DNA,and lateral flow dipstick(LFD)is used to interpret the results after the amplification is completed.The lower limits of detection and specificity of the RAA assay were verified using recombinant plasmid and pathogenic nucleic acid.In addition,30 clinical samples were tested to evaluate the performance of the RAA assay.Results The RAA-LFD assay was completed within 15 min at 37°C,including 10 min for nucleic acid amplification and 5 minutes for LFD reading results.The detection limit of this assay was found to be 200 copies per reaction.And there was no cross-reactivity with other swine viruses.Conclusion A highly sensitive,specific,and simple RAA-LFD method was developed for the rapid detection of the ASFV.
文摘We have carried out clinical observations on 34 patients with peripheral facial paralysis treatedby acupuncture therapy prescribed according to selection of treatment regimen on the basis of fa-cial thermogram and temperature.A comparison was made with a control group of 97 patientswho received conventional acupuncture therapy only.It was found that 1)The cure rate in thegroup of selecting acupoints by thermorgram(hereinafter referred to as the thermography-aidedtreatment group)was 67.65%,with a marked improvement rate of 26.40%;while the cure rateof the conventional acupuncture treatment group(hereinafter called the conventional treatmentgroup)was 46.39%,the marked improvement rate being 29.90%,indicating a significant differ-ence in therapeutic efficacy between the two groups(P【0.02).2)The average duration ofacupuncture therapy for the thermography aided treatment group was 6.02 weeks,whereas thatfor the conventional treatment group,24 weeks.There was also a significant difference betweenthe two groups(P【0.01).And 3)During the entire therapeutic course,25.2 sessions of treatmentwere given on the average in the thermography-aided treatment group,and 78.8 sessions in theconventional treatment group,showing a very significant difference(P【0.001).The present thermography-aided method exhibits advantages over the conventional one in en-hancing the cure rate and shortening the duration of treatment,which is worthy to be popularizedin clinical practice.And it is also of certain significance in standardization and-scientification ofacupuncture therapy.
