Under the background of social and economic stable development, the number of construction projects is not only improved, but also the scale is expanding, which is an important part of the high form construction, beca...Under the background of social and economic stable development, the number of construction projects is not only improved, but also the scale is expanding, which is an important part of the high form construction, because the content involved is relatively more, and they have a certain degree of professionalism, leading to the construction process is often restricted by a variety of factors. Therefore, in order to fully ensure the high efficiency of the application of high support form construction, it is necessary to have a sufficient understanding of the current status of construction projects, formulate targeted construction plans, strengthen the importance of technology application, and urge the staff to attach importance to their responsibilities. Based on this, this paper mainly analyzes the application of high-support formwork construction technology in construction engineering, and expounds the relevant suggestions.展开更多
Roadway instability has been a major concern in the fields of mining engineering. This paper aims to provide practical and efficient strategy to support the roadways under high in-situ stress. A case study on the stab...Roadway instability has been a major concern in the fields of mining engineering. This paper aims to provide practical and efficient strategy to support the roadways under high in-situ stress. A case study on the stability of deep roadways was carried out in an underground mine in Gansu province, China. Currently,the surrounding rock strata is extremely fractured, which results in a series of engineering disasters, such as side wall collapse and severe floor heave in the past decades. Aiming to solve these problems, an improved support method was proposed, which includes optimal bolt parameters and arrangement, floor beam layout by grooving, and full length grouting. Based on the modeling results by FLAC3D, the new support method is much better than the current one in terms of preventing the large deformation of surrounding rock and restricting the development of plastic zones. For implementation and verification, field experiments, along with deformation monitoring, were conducted in the 958 level roadway of Mining II areas. The results show that the improved support can significantly reduce surrounding rock deformation, avoid frequent repair, and maintain the long-term stability of the roadway. Compared to the original support, the new support method can greatly save investment of mines, and has good application value and popularization value.展开更多
Roof falls in longwall headgate can occur when weak roof and high horizontal stress are present. To prevent roof falls in the headgate under high horizontal stress, it is important to understand the ground response to...Roof falls in longwall headgate can occur when weak roof and high horizontal stress are present. To prevent roof falls in the headgate under high horizontal stress, it is important to understand the ground response to high horizontal stress in the longwall headgate and the requirements for supplemental roof support. In this study, a longwall headgate under high horizontal stress was instrumented to monitor stress change in the pillars, deformations in the roof, and load in the cable bolts. The conditions in the headgate were monitored for about six months as the longwall face passed by the instrumented site.The roof behavior in the headgate near the face was carefully observed during longwall retreat.Numerical modeling was performed to correlate the modeling results with underground observation and instrumentation data and to quantify the effect of high horizontal stress on roof stability in the longwall headgate. This paper discusses roof support requirements in the longwall headgate under high horizontal stress in regard to the pattern of supplemental cable bolts and the critical locations where additional supplemental support is necessary.展开更多
A rationally designed support for deep roadways excavated in broken soft rock under high stress was investigated. The deformation and failure characteristics and the mechanism of ''yielding support'' w...A rationally designed support for deep roadways excavated in broken soft rock under high stress was investigated. The deformation and failure characteristics and the mechanism of ''yielding support'' was studied for anchor bolts and cables. The rail roadway of the 2-501 working face in the Liyazhuang Mine of the Huozhou coal area located in Shanxi province was used for field trials. The geological conditions used there were used during the design phase. The new ''highly resistant, yielding'' support system has a core of high strength, yielding bolts and anchor cables. The field tests show that this support system adapts well to the deformation and pressure in the deep broken soft rock. The support system effectively controls damage to the roadway and ensures the long term stability of the wall rock and safe production in the coal mine. This provides a remarkable economic and social benefit and has broad prospects for fur- ther application.展开更多
Abstract Accurate aerodynamic models are the basis of flight simulation and control law design. Mathematically modeling unsteady aerodynamics at high angles of attack bears great difficulties in model structure determ...Abstract Accurate aerodynamic models are the basis of flight simulation and control law design. Mathematically modeling unsteady aerodynamics at high angles of attack bears great difficulties in model structure determination and parameter estimation due to little understanding of the flow mechanism. Support vector machines （SVMs） based on statistical learning theory provide a novel tool for nonlinear system modeling. The work presented here examines the feasibility of applying SVMs to high angle.-of-attack unsteady aerodynamic modeling field. Mainly, after a review of SVMs, several issues associated with unsteady aerodynamic modeling by use of SVMs are discussed in detail, such as sele, ction of input variables, selection of output variables and determination of SVM parameters. The least squares SVM （LS-SVM） models are set up from certain dynamic wind tunnel test data of a delta wing and an aircraft configuration, and then used to predict the aerodynamic responses in other tests. The predictions are in good agreement with the test data, which indicates the satisfving learning and generalization performance of LS-SVMs.展开更多
In Tokomak, the support of the ELM coil, which is close to the plasma and subject to high radiation level, high temperature and high magnetic field, is used to transport and bear the thermal load due to thermal expans...In Tokomak, the support of the ELM coil, which is close to the plasma and subject to high radiation level, high temperature and high magnetic field, is used to transport and bear the thermal load due to thermal expansion and the alternating electromagnetic force generated by high magnetic field and AC current in the coil. According to the feature of ITER ELM coil, the mechanical performance of rigid and flexible supports under different high nuclear heat levels is studied. Results show that flexible supports have more excellent performance in high nuclear heat condition than rigid supports. Concerning thermal and electromagnetic （EM） loads, optimized results further prove that flexible supports have better mechanical performance than rigid ones. Through these studies, reasonable support design can be provided for the ELM coils or similar coils in Tokamak based on the nuclear heat level.展开更多
AIM: To assess the safety, efficacy and predictability of the AcrySof phakic angle-supported intraocular lens (IOL) (Alcon Inc., U.S.A.) for correction of high-to-extremely high myopia in adults. METHODS: In this pros...AIM: To assess the safety, efficacy and predictability of the AcrySof phakic angle-supported intraocular lens (IOL) (Alcon Inc., U.S.A.) for correction of high-to-extremely high myopia in adults. METHODS: In this prospective study performed in Tianjin Medical University Eye Center & College of Optometry, Tianjin, China, 25 eyes of 13 patients were implanted with AcrySof phakic angle-supported IOLs and followed for 1 year postoperatively. Preoperative manifest refractive sphere was (-12.08 +/- 2.44) diopters (D) and cylinder was (-1.35 +/- 0.62)D. Visual acuity, predictability and stability of manifest refraction spherical equivalent (MRSE), adverse events, and endothelial cell density were analyzed during 1-year of follow-up. RESULTS: After 1 year of follow-up, no eyes lost 1 line (best spectacle-corrected visual acuity)BSCVA; an uncorrected visual acuity (UCVA) of 20/20 or better was achieved in 60% of eyes; 100% had an UCVA of 20/40 or better; a BSCVA of 20/30 or better was achieved by 100% of eyes; 84% had a BSCVA of 20/20 or better. The overall mean percentage change in endothelial cell density 1 year after surgery was (-0.27 +/- 3.60)%. Two eyes (8%) had increased intraocular pressure (IOP) on the day of surgery. No pupil ovalization, pupillary block, or retinal detachment events were observed. CONCLUSION: After 1 year of follow-up, the implantation of AcrySof phakic angle-supported IOL is proved to be safe, effective and predictable with minimal complications in patients with high-to-extremely high myopia. Due to the limitation of visiting time, long-term of clinical investigation is necessary to verify the safety and efficacy of this IOL.展开更多
Because the oilfields in eastern China are in the very high water cut development stage, accurate forecast of oilfield development indices is important for exploiting the oilfields efficiently. Regarding the problems ...Because the oilfields in eastern China are in the very high water cut development stage, accurate forecast of oilfield development indices is important for exploiting the oilfields efficiently. Regarding the problems of the small number of samples collected for oilfield development indices, a new support vector regression prediction method for development indices is proposed in this paper. This method uses the principle of functional simulation to determine the input-output of a support vector machine prediction system based on historical oilfield development data. It chooses the kernel function of the support vector machine by analyzing time series characteristics of the development index; trains and tests the support vector machine network with historical data to construct the support vector regression prediction model of oilfield development indices; and predicts the development index. The case study shows that the proposed method is feasible, and predicted development indices agree well with the development performance of very high water cut oilfields.展开更多
In this paper, a classification method based on Support Vector Machine (SVM) is given in the digital modulation signal classification. The second, fourth and sixth order cumulants of the received signals are used as c...In this paper, a classification method based on Support Vector Machine (SVM) is given in the digital modulation signal classification. The second, fourth and sixth order cumulants of the received signals are used as classification vectors firstly, then the kernel thought is used to map the feature vector to the high dimensional feature space and the optimum separating hyperplane is constructed in space to realize signal recognition. In order to build an effective and robust SVM classifier, the radial basis kernel function is selected, one against one or one against rest of multi-class classifier is designed, and method of parameter selection using cross- validation grid is adopted. Through the experiments it can be concluded that the classifier based on SVM has high performance and is more robust.展开更多
Aim: The present study aimed to investigate problems relating to education, past situations and treatments in high school students with attention-deficit/ hyperactivity disorder (ADHD) and to discuss appropriate consi...Aim: The present study aimed to investigate problems relating to education, past situations and treatments in high school students with attention-deficit/ hyperactivity disorder (ADHD) and to discuss appropriate considerations. Methods: Participants were 6 students who were diagnosed with ADHD according to Diagnostic and Statistical Manual of Mental Disorders IV, Text Revision (DSM-IV-TR) criteria. Results: In total, 6 cases of high-school students with ADHD showed dominantly inattention features. They had notably not been diagnosed with ADHD or received appropriate special support education until they were of high-school age, although they had clearly shown characteristic features of the disorder from childhood. As a result, they had decreased motivation to study and showed indolence, and suffered from low self-esteem. Conclusion: This case report suggests that early diagnosis of ADHD and early intervention with special support education are of great importance. To support these students, better educational and medical support systems are warranted.展开更多
According to statistic data,machinery faults contribute to largest proportion of High-voltage circuit breaker failures,and traditional maintenance methods exist some disadvantages for that issue.Therefore,based on the...According to statistic data,machinery faults contribute to largest proportion of High-voltage circuit breaker failures,and traditional maintenance methods exist some disadvantages for that issue.Therefore,based on the wavelet packet decomposition approach and support vector machines,a new diagnosis model is proposed for such fault diagnoses in this study.The vibration eigenvalue extraction is analyzed through wavelet packet decomposition,and a four-layer support vector machine is constituted as a fault classifier.The Gaussian radial basis function is employed as the kernel function for the classifier.The penalty parameter c and kernel parameterδof the support vector machine are vital for the diagnostic accuracy,and these parameters must be carefully predetermined.Thus,a particle swarm optimizationsupport vector machine model is developed in which the optimal parameters c andδfor the support vector machine in each layer are determined by the particle swarm algorithm.The validity of this fault diagnosis model is determined with a real dataset from the operation experiment.Moreover,comparative investigations of fault diagnosis experiments with a normal support vector machine and a particle swarm optimization back-propagation neural network are also implemented.The results indicate that the proposed fault diagnosis model yields better accuracy and e-ciency than these other models.展开更多
This study addresses sustainable transportation in the Texas Urban Triangle at the regional scale. Its aim is to determine the most suitable corridor for new transport infrastructure by employing a spatial decision su...This study addresses sustainable transportation in the Texas Urban Triangle at the regional scale. Its aim is to determine the most suitable corridor for new transport infrastructure by employing a spatial decision support system proposed in this project. The system is being tested through its application to a prototype corridor parallel to Interstate 35 between San Antonio and Austin. The basic research questions asked are spatial in nature, so accordingly the geographic information system is the primary method of data analysis. The overall modeling approach is devoted to answering the following questions: What are the considerations to support sustainable growth? What scale or type of infrastructure is necessary? And how to adequately model the transportation corridors to meet the demands and to sustain the living environment at the same time?展开更多
Aiming at reducing the deficiency of the traditional fire pre-warning algorithms and the intelligent fire pre-warning algorithms such as artificial neural network,and then to improve the accuracy of fire prewarning fo...Aiming at reducing the deficiency of the traditional fire pre-warning algorithms and the intelligent fire pre-warning algorithms such as artificial neural network,and then to improve the accuracy of fire prewarning for high-rise buildings,a composite fire pre-warning controller is designed according to the characteristic（ nonlinear,less historical data,many influence factors）,also a high-rise building fire pre-warning model is set up based on the support vector regression（ SV R）. Then the wood fire standard history data is applied to make empirical analysis. The research results can provide a reliable decision support framework for high-rise building fire pre-warning.展开更多
文摘Under the background of social and economic stable development, the number of construction projects is not only improved, but also the scale is expanding, which is an important part of the high form construction, because the content involved is relatively more, and they have a certain degree of professionalism, leading to the construction process is often restricted by a variety of factors. Therefore, in order to fully ensure the high efficiency of the application of high support form construction, it is necessary to have a sufficient understanding of the current status of construction projects, formulate targeted construction plans, strengthen the importance of technology application, and urge the staff to attach importance to their responsibilities. Based on this, this paper mainly analyzes the application of high-support formwork construction technology in construction engineering, and expounds the relevant suggestions.
基金Financial supports for this work, provided by the Major Program of the National Natural Science Foundation of China (Nos. 51174228 and 51474249)the Program for New Century Excellent Talents in University the Open Project of State Key Laboratory of Coal resources and Safe Mining, China University of Mining and Technology
文摘Roadway instability has been a major concern in the fields of mining engineering. This paper aims to provide practical and efficient strategy to support the roadways under high in-situ stress. A case study on the stability of deep roadways was carried out in an underground mine in Gansu province, China. Currently,the surrounding rock strata is extremely fractured, which results in a series of engineering disasters, such as side wall collapse and severe floor heave in the past decades. Aiming to solve these problems, an improved support method was proposed, which includes optimal bolt parameters and arrangement, floor beam layout by grooving, and full length grouting. Based on the modeling results by FLAC3D, the new support method is much better than the current one in terms of preventing the large deformation of surrounding rock and restricting the development of plastic zones. For implementation and verification, field experiments, along with deformation monitoring, were conducted in the 958 level roadway of Mining II areas. The results show that the improved support can significantly reduce surrounding rock deformation, avoid frequent repair, and maintain the long-term stability of the roadway. Compared to the original support, the new support method can greatly save investment of mines, and has good application value and popularization value.
文摘Roof falls in longwall headgate can occur when weak roof and high horizontal stress are present. To prevent roof falls in the headgate under high horizontal stress, it is important to understand the ground response to high horizontal stress in the longwall headgate and the requirements for supplemental roof support. In this study, a longwall headgate under high horizontal stress was instrumented to monitor stress change in the pillars, deformations in the roof, and load in the cable bolts. The conditions in the headgate were monitored for about six months as the longwall face passed by the instrumented site.The roof behavior in the headgate near the face was carefully observed during longwall retreat.Numerical modeling was performed to correlate the modeling results with underground observation and instrumentation data and to quantify the effect of high horizontal stress on roof stability in the longwall headgate. This paper discusses roof support requirements in the longwall headgate under high horizontal stress in regard to the pattern of supplemental cable bolts and the critical locations where additional supplemental support is necessary.
基金supported by the National Natural Science Foundation of China (No. 50874103)the National Basic Research Program of China (No. 2010CB226805)+1 种基金the Natural Science Foundation of Jiangsu Province (No. BK2008135)as well as by the Open Foundation of State Key Laboratory of Geomechanics and Deep Underground Engineering (No. SKLGDUEK0905)
文摘A rationally designed support for deep roadways excavated in broken soft rock under high stress was investigated. The deformation and failure characteristics and the mechanism of ''yielding support'' was studied for anchor bolts and cables. The rail roadway of the 2-501 working face in the Liyazhuang Mine of the Huozhou coal area located in Shanxi province was used for field trials. The geological conditions used there were used during the design phase. The new ''highly resistant, yielding'' support system has a core of high strength, yielding bolts and anchor cables. The field tests show that this support system adapts well to the deformation and pressure in the deep broken soft rock. The support system effectively controls damage to the roadway and ensures the long term stability of the wall rock and safe production in the coal mine. This provides a remarkable economic and social benefit and has broad prospects for fur- ther application.
文摘Abstract Accurate aerodynamic models are the basis of flight simulation and control law design. Mathematically modeling unsteady aerodynamics at high angles of attack bears great difficulties in model structure determination and parameter estimation due to little understanding of the flow mechanism. Support vector machines （SVMs） based on statistical learning theory provide a novel tool for nonlinear system modeling. The work presented here examines the feasibility of applying SVMs to high angle.-of-attack unsteady aerodynamic modeling field. Mainly, after a review of SVMs, several issues associated with unsteady aerodynamic modeling by use of SVMs are discussed in detail, such as sele, ction of input variables, selection of output variables and determination of SVM parameters. The least squares SVM （LS-SVM） models are set up from certain dynamic wind tunnel test data of a delta wing and an aircraft configuration, and then used to predict the aerodynamic responses in other tests. The predictions are in good agreement with the test data, which indicates the satisfving learning and generalization performance of LS-SVMs.
文摘In Tokomak, the support of the ELM coil, which is close to the plasma and subject to high radiation level, high temperature and high magnetic field, is used to transport and bear the thermal load due to thermal expansion and the alternating electromagnetic force generated by high magnetic field and AC current in the coil. According to the feature of ITER ELM coil, the mechanical performance of rigid and flexible supports under different high nuclear heat levels is studied. Results show that flexible supports have more excellent performance in high nuclear heat condition than rigid supports. Concerning thermal and electromagnetic （EM） loads, optimized results further prove that flexible supports have better mechanical performance than rigid ones. Through these studies, reasonable support design can be provided for the ELM coils or similar coils in Tokamak based on the nuclear heat level.
文摘AIM: To assess the safety, efficacy and predictability of the AcrySof phakic angle-supported intraocular lens (IOL) (Alcon Inc., U.S.A.) for correction of high-to-extremely high myopia in adults. METHODS: In this prospective study performed in Tianjin Medical University Eye Center & College of Optometry, Tianjin, China, 25 eyes of 13 patients were implanted with AcrySof phakic angle-supported IOLs and followed for 1 year postoperatively. Preoperative manifest refractive sphere was (-12.08 +/- 2.44) diopters (D) and cylinder was (-1.35 +/- 0.62)D. Visual acuity, predictability and stability of manifest refraction spherical equivalent (MRSE), adverse events, and endothelial cell density were analyzed during 1-year of follow-up. RESULTS: After 1 year of follow-up, no eyes lost 1 line (best spectacle-corrected visual acuity)BSCVA; an uncorrected visual acuity (UCVA) of 20/20 or better was achieved in 60% of eyes; 100% had an UCVA of 20/40 or better; a BSCVA of 20/30 or better was achieved by 100% of eyes; 84% had a BSCVA of 20/20 or better. The overall mean percentage change in endothelial cell density 1 year after surgery was (-0.27 +/- 3.60)%. Two eyes (8%) had increased intraocular pressure (IOP) on the day of surgery. No pupil ovalization, pupillary block, or retinal detachment events were observed. CONCLUSION: After 1 year of follow-up, the implantation of AcrySof phakic angle-supported IOL is proved to be safe, effective and predictable with minimal complications in patients with high-to-extremely high myopia. Due to the limitation of visiting time, long-term of clinical investigation is necessary to verify the safety and efficacy of this IOL.
基金support from Scientific Research Fund of Sichuan Provincial Education Department, P. R. China (No. 07za143)
文摘Because the oilfields in eastern China are in the very high water cut development stage, accurate forecast of oilfield development indices is important for exploiting the oilfields efficiently. Regarding the problems of the small number of samples collected for oilfield development indices, a new support vector regression prediction method for development indices is proposed in this paper. This method uses the principle of functional simulation to determine the input-output of a support vector machine prediction system based on historical oilfield development data. It chooses the kernel function of the support vector machine by analyzing time series characteristics of the development index; trains and tests the support vector machine network with historical data to construct the support vector regression prediction model of oilfield development indices; and predicts the development index. The case study shows that the proposed method is feasible, and predicted development indices agree well with the development performance of very high water cut oilfields.
文摘In this paper, a classification method based on Support Vector Machine (SVM) is given in the digital modulation signal classification. The second, fourth and sixth order cumulants of the received signals are used as classification vectors firstly, then the kernel thought is used to map the feature vector to the high dimensional feature space and the optimum separating hyperplane is constructed in space to realize signal recognition. In order to build an effective and robust SVM classifier, the radial basis kernel function is selected, one against one or one against rest of multi-class classifier is designed, and method of parameter selection using cross- validation grid is adopted. Through the experiments it can be concluded that the classifier based on SVM has high performance and is more robust.
文摘Aim: The present study aimed to investigate problems relating to education, past situations and treatments in high school students with attention-deficit/ hyperactivity disorder (ADHD) and to discuss appropriate considerations. Methods: Participants were 6 students who were diagnosed with ADHD according to Diagnostic and Statistical Manual of Mental Disorders IV, Text Revision (DSM-IV-TR) criteria. Results: In total, 6 cases of high-school students with ADHD showed dominantly inattention features. They had notably not been diagnosed with ADHD or received appropriate special support education until they were of high-school age, although they had clearly shown characteristic features of the disorder from childhood. As a result, they had decreased motivation to study and showed indolence, and suffered from low self-esteem. Conclusion: This case report suggests that early diagnosis of ADHD and early intervention with special support education are of great importance. To support these students, better educational and medical support systems are warranted.
基金Supported by National Natural Science Foundation of China(Grant No.51705372)National Science and Technology Project of the Power Grid of China(Grant No.5211DS16002L).
文摘According to statistic data,machinery faults contribute to largest proportion of High-voltage circuit breaker failures,and traditional maintenance methods exist some disadvantages for that issue.Therefore,based on the wavelet packet decomposition approach and support vector machines,a new diagnosis model is proposed for such fault diagnoses in this study.The vibration eigenvalue extraction is analyzed through wavelet packet decomposition,and a four-layer support vector machine is constituted as a fault classifier.The Gaussian radial basis function is employed as the kernel function for the classifier.The penalty parameter c and kernel parameterδof the support vector machine are vital for the diagnostic accuracy,and these parameters must be carefully predetermined.Thus,a particle swarm optimizationsupport vector machine model is developed in which the optimal parameters c andδfor the support vector machine in each layer are determined by the particle swarm algorithm.The validity of this fault diagnosis model is determined with a real dataset from the operation experiment.Moreover,comparative investigations of fault diagnosis experiments with a normal support vector machine and a particle swarm optimization back-propagation neural network are also implemented.The results indicate that the proposed fault diagnosis model yields better accuracy and e-ciency than these other models.
文摘This study addresses sustainable transportation in the Texas Urban Triangle at the regional scale. Its aim is to determine the most suitable corridor for new transport infrastructure by employing a spatial decision support system proposed in this project. The system is being tested through its application to a prototype corridor parallel to Interstate 35 between San Antonio and Austin. The basic research questions asked are spatial in nature, so accordingly the geographic information system is the primary method of data analysis. The overall modeling approach is devoted to answering the following questions: What are the considerations to support sustainable growth? What scale or type of infrastructure is necessary? And how to adequately model the transportation corridors to meet the demands and to sustain the living environment at the same time?
基金Supported by the National Natural Science Foundation of China(11072035)
文摘Aiming at reducing the deficiency of the traditional fire pre-warning algorithms and the intelligent fire pre-warning algorithms such as artificial neural network,and then to improve the accuracy of fire prewarning for high-rise buildings,a composite fire pre-warning controller is designed according to the characteristic（ nonlinear,less historical data,many influence factors）,also a high-rise building fire pre-warning model is set up based on the support vector regression（ SV R）. Then the wood fire standard history data is applied to make empirical analysis. The research results can provide a reliable decision support framework for high-rise building fire pre-warning.
