Background Total knee arthroplasty （TKA） is an important therapy for the treatment of various late-stage knee diseases. However, it has been observed that patients have lower hemoglobin （HB） counts postoperatively...Background Total knee arthroplasty （TKA） is an important therapy for the treatment of various late-stage knee diseases. However, it has been observed that patients have lower hemoglobin （HB） counts postoperatively, which are significantly inconsistent with the measured blood loss. Although the concept of hidden blood loss has been presented in 2000, very little clinical attention has been paid since then. In this study, we investigated the characteristics and influential factor of hidden blood loss after TKA in treating knee osteoarthritis.展开更多
A large number of hydraulic concrete structures have hidden defects such as cracks, erosion, freeze and thaw, thermal fatigue, carbonization. These hidden defects seriously affect the strength, stability and durabilit...A large number of hydraulic concrete structures have hidden defects such as cracks, erosion, freeze and thaw, thermal fatigue, carbonization. These hidden defects seriously affect the strength, stability and durability of structures. These problems are studied mainly by single monitoring or diagnosis methods at present. The integration of multiple monitoring and diagnosis methods is not applied widely. Besides, the analysis theory on these problems is not developed very well. The systemic study on the aging mechanism of hydraulic concrete structures, time- variation model and health diagnosis is still not enough. The support for engineering practice is limited. Aimed at these major scientific and technological problems and combined with specific projects, study on detection of hidden defects and health diagnosis of hydraulic concrete structure has been carried out. This study includes the following content: field non-destructive examination of hidden defects of hydraulic concrete structures, seepage detection, the construction of in-situ sensing system, the combination of field detection and in-situ monitoring, the mechanism of crack, freeze and thaw, erosion and carbonization of hydraulic concrete structure, mechanism of combination aging; time-variation model of hydraulic concrete structure, theories and methods for health diagnosis of hydraulic concrete structures.展开更多
Traditionally, SQL query language is used to search the data in databases. However, it is inappropriate for end-users, since it is complex and hard to learn. It is the need of end-user, searching in databases with key...Traditionally, SQL query language is used to search the data in databases. However, it is inappropriate for end-users, since it is complex and hard to learn. It is the need of end-user, searching in databases with keywords, like in web search engines. This paper presents a survey of work on keyword search in databases. It also includes a brief introduction to the SEEKER system which has been developed.展开更多
Background The aim of this study was to determine the relationship between prosthesis coverage and postoperative hidden blood loss （HBL） in primary total knee arthroplasty （TKA）.Methods A total of 120 patients who...Background The aim of this study was to determine the relationship between prosthesis coverage and postoperative hidden blood loss （HBL） in primary total knee arthroplasty （TKA）.Methods A total of 120 patients who had undergone unilateral TKA from August 2012 to May 2013 were retrospectively studied.The Gross formula was used to calculate the amount of HBL.Routine standard anteroposterior （AP） and lateral x-ray films of the knee joint were taken postoperatively and used to measure the percentages of coronal femoral and of coronal and sagittal tibial prosthetic coverage.Then Pearson＇s correlation analysis was performed to assess the correlations between the percentages of prosthetic coverage for each AP and lateral position and HBL on the first and third postoperative days.Results The volumes of HBL on the first and third postoperative days after TKA were （786.5±191.6） ml and （1 256.6±205.1） ml,respectively,and lateral x-ray film measurements of percentages of coronal femoral,tibial coronal,and sagittal prosthetic coverage were （87.9±2.5）％,（88.5±2.2）％,and （89.1±2.3）％,respectively.Pearson＇s correlation analysis showed statistically significant correlations between percentages of total knee prosthetic coverage for each AP and lateral position and volumes of HBL on the first and third postoperative days （P ＜0.05）.Conclusions HBL after TKA correlates with degree of prosthetic coverage.To some extent,the size of the surfaces exposed by osteotomy determines the amount of HBL.Choice of the appropriate prosthesis can significantly reduce postoperative HBL.Designing individualized prostheses would be a worthwhile development in joint replacement surgery.展开更多
Based on the regularity nature of lower-limb motion,an intent pattern recognition approach for above-knee prosthesis is proposed in this paper. To remedy the defects of recognizer based on electromyogram(EMG), we deve...Based on the regularity nature of lower-limb motion,an intent pattern recognition approach for above-knee prosthesis is proposed in this paper. To remedy the defects of recognizer based on electromyogram(EMG), we develop a pure mechanical sensor architecture for intent pattern recognition of lower-limb motion. The sensor system is composed of an accelerometer, a gyroscope mounted on the prosthetic socket, and two pressure sensors mounted under the sole. To compensate the delay in the control of prosthesis, the signals in the stance phase are used to predict the terrain and speed in the swing phase. Specifically, the intent pattern recognizer utilizes intraclass correlation coefficient(ICC) according to the Cartesian product of walking speed and terrain. Moreover, the sensor data are fused via DempsterShafer's theory. And hidden Markov model(HMM) is used to recognize the realtime motion state with the reference of the prior step. The proposed method can infer the prosthesis user's intent of walking on different terrain, which includes level ground,stair ascent, stair descent, up and down ramp. The experiments demonstrate that the intent pattern recognizer is capable of identifying five typical terrain-modes with the rate of 95.8%. The outcome of this investigation is expected to substantially improve the control performance of powered above-knee prosthesis.展开更多
Once in the hands of end users, such durable equipment as spacecraft, aircraft, ships,automobiles, computers, etc. are in a state of debugging, working or storage. In either state, availability, reliability and super-...Once in the hands of end users, such durable equipment as spacecraft, aircraft, ships,automobiles, computers, etc. are in a state of debugging, working or storage. In either state, availability, reliability and super-efficiency are the ultimate goals, which have been achieved through constant monitoring as well as regular, preventive, routine and corrective maintenance. Although some advanced instruments can visualize certain invisible malfunctioning phenomena into visible ones, deeply hidden troubles cannot be found unless monitoring and testing data are addressed using tools that process the data statistically, analytically and mathematically. Some state-of-theart trouble-shooting and life-predicting techniques and approaches are introduced in this paper.展开更多
We propose a model structure with a double-layer hidden Markov model (HMM) to recognise driving intention and predict driving behaviour. The upper-layer multi-dimensional discrete HMM (MDHMM) in the double-layer HMM r...We propose a model structure with a double-layer hidden Markov model (HMM) to recognise driving intention and predict driving behaviour. The upper-layer multi-dimensional discrete HMM (MDHMM) in the double-layer HMM represents driving intention in a combined working case, constructed according to the driving behaviours in certain single working cases in the lower-layer multi-dimensional Gaussian HMM (MGHMM). The driving behaviours are recognised by manoeuvring the signals of the driver and vehicle state information, and the recognised results are sent to the upper-layer HMM to recognise driving intentions. Also, driving behaviours in the near future are predicted using the likelihood-maximum method. A real-time driving simulator test on the combined working cases showed that the double-layer HMM can recognise driving intention and predict driving behaviour accurately and efficiently. As a result, the model provides the basis for pre-warning and intervention of danger and improving comfort performance.展开更多
文摘Background Total knee arthroplasty （TKA） is an important therapy for the treatment of various late-stage knee diseases. However, it has been observed that patients have lower hemoglobin （HB） counts postoperatively, which are significantly inconsistent with the measured blood loss. Although the concept of hidden blood loss has been presented in 2000, very little clinical attention has been paid since then. In this study, we investigated the characteristics and influential factor of hidden blood loss after TKA in treating knee osteoarthritis.
基金Supported by the Key Project of Chinese National Programs for Fundamental Research and Development (Grant No. 2002CB412707) Key Project of NNSF and Yalongjiang Hydroelectric Development Joint Research Fund (50539110, 50539030)+2 种基金 Science and Technology Support Plan (20006BAC14B03) National Natural Science Foundation Major Project (50539010)National Natural Science Foundation of China (Grant No. 50579010)
文摘A large number of hydraulic concrete structures have hidden defects such as cracks, erosion, freeze and thaw, thermal fatigue, carbonization. These hidden defects seriously affect the strength, stability and durability of structures. These problems are studied mainly by single monitoring or diagnosis methods at present. The integration of multiple monitoring and diagnosis methods is not applied widely. Besides, the analysis theory on these problems is not developed very well. The systemic study on the aging mechanism of hydraulic concrete structures, time- variation model and health diagnosis is still not enough. The support for engineering practice is limited. Aimed at these major scientific and technological problems and combined with specific projects, study on detection of hidden defects and health diagnosis of hydraulic concrete structure has been carried out. This study includes the following content: field non-destructive examination of hidden defects of hydraulic concrete structures, seepage detection, the construction of in-situ sensing system, the combination of field detection and in-situ monitoring, the mechanism of crack, freeze and thaw, erosion and carbonization of hydraulic concrete structure, mechanism of combination aging; time-variation model of hydraulic concrete structure, theories and methods for health diagnosis of hydraulic concrete structures.
文摘Traditionally, SQL query language is used to search the data in databases. However, it is inappropriate for end-users, since it is complex and hard to learn. It is the need of end-user, searching in databases with keywords, like in web search engines. This paper presents a survey of work on keyword search in databases. It also includes a brief introduction to the SEEKER system which has been developed.
基金This project was partially supported by a grant from the National Natural Science Foundation of China （No.81273972）.
文摘Background The aim of this study was to determine the relationship between prosthesis coverage and postoperative hidden blood loss （HBL） in primary total knee arthroplasty （TKA）.Methods A total of 120 patients who had undergone unilateral TKA from August 2012 to May 2013 were retrospectively studied.The Gross formula was used to calculate the amount of HBL.Routine standard anteroposterior （AP） and lateral x-ray films of the knee joint were taken postoperatively and used to measure the percentages of coronal femoral and of coronal and sagittal tibial prosthetic coverage.Then Pearson＇s correlation analysis was performed to assess the correlations between the percentages of prosthetic coverage for each AP and lateral position and HBL on the first and third postoperative days.Results The volumes of HBL on the first and third postoperative days after TKA were （786.5±191.6） ml and （1 256.6±205.1） ml,respectively,and lateral x-ray film measurements of percentages of coronal femoral,tibial coronal,and sagittal prosthetic coverage were （87.9±2.5）％,（88.5±2.2）％,and （89.1±2.3）％,respectively.Pearson＇s correlation analysis showed statistically significant correlations between percentages of total knee prosthetic coverage for each AP and lateral position and volumes of HBL on the first and third postoperative days （P ＜0.05）.Conclusions HBL after TKA correlates with degree of prosthetic coverage.To some extent,the size of the surfaces exposed by osteotomy determines the amount of HBL.Choice of the appropriate prosthesis can significantly reduce postoperative HBL.Designing individualized prostheses would be a worthwhile development in joint replacement surgery.
基金supported in part by the National Nature Science Fundation(61174009,61203323)Youth Foundation of Hebei Province(F2016202327)+3 种基金the Colleges and Universities in Hebei Province Science and Technology Research Project(ZC2016020)supported in part by Key Project of NSFC(61533009)111 Project(B08015)Research Project(JCYJ20150403161923519)
文摘Based on the regularity nature of lower-limb motion,an intent pattern recognition approach for above-knee prosthesis is proposed in this paper. To remedy the defects of recognizer based on electromyogram(EMG), we develop a pure mechanical sensor architecture for intent pattern recognition of lower-limb motion. The sensor system is composed of an accelerometer, a gyroscope mounted on the prosthetic socket, and two pressure sensors mounted under the sole. To compensate the delay in the control of prosthesis, the signals in the stance phase are used to predict the terrain and speed in the swing phase. Specifically, the intent pattern recognizer utilizes intraclass correlation coefficient(ICC) according to the Cartesian product of walking speed and terrain. Moreover, the sensor data are fused via DempsterShafer's theory. And hidden Markov model(HMM) is used to recognize the realtime motion state with the reference of the prior step. The proposed method can infer the prosthesis user's intent of walking on different terrain, which includes level ground,stair ascent, stair descent, up and down ramp. The experiments demonstrate that the intent pattern recognizer is capable of identifying five typical terrain-modes with the rate of 95.8%. The outcome of this investigation is expected to substantially improve the control performance of powered above-knee prosthesis.
基金co-supported by the National Natural Science Fundation for Distinguished Young Scholar of China(No.61025014)the National Natural Science Foundation of China(Nos.61174030,61104223,61374126,61374120,61004069 and 61370031)
文摘Once in the hands of end users, such durable equipment as spacecraft, aircraft, ships,automobiles, computers, etc. are in a state of debugging, working or storage. In either state, availability, reliability and super-efficiency are the ultimate goals, which have been achieved through constant monitoring as well as regular, preventive, routine and corrective maintenance. Although some advanced instruments can visualize certain invisible malfunctioning phenomena into visible ones, deeply hidden troubles cannot be found unless monitoring and testing data are addressed using tools that process the data statistically, analytically and mathematically. Some state-of-theart trouble-shooting and life-predicting techniques and approaches are introduced in this paper.
基金Project (Nos. 50775096 and 51075176) supported by the National Natural Science Foundation of China
文摘We propose a model structure with a double-layer hidden Markov model (HMM) to recognise driving intention and predict driving behaviour. The upper-layer multi-dimensional discrete HMM (MDHMM) in the double-layer HMM represents driving intention in a combined working case, constructed according to the driving behaviours in certain single working cases in the lower-layer multi-dimensional Gaussian HMM (MGHMM). The driving behaviours are recognised by manoeuvring the signals of the driver and vehicle state information, and the recognised results are sent to the upper-layer HMM to recognise driving intentions. Also, driving behaviours in the near future are predicted using the likelihood-maximum method. A real-time driving simulator test on the combined working cases showed that the double-layer HMM can recognise driving intention and predict driving behaviour accurately and efficiently. As a result, the model provides the basis for pre-warning and intervention of danger and improving comfort performance.
