The major drawbacks of traditional approaches to product costing include lack of manufacturing knowledge, reliance on the detailed design description, poor cost function approximation and inability to update estimatio...The major drawbacks of traditional approaches to product costing include lack of manufacturing knowledge, reliance on the detailed design description, poor cost function approximation and inability to update estimation algorithms by using actual cost data. Adopting the Activity-Based Costing (ABC) concept and based on estimated processing time, this paper proposes a pragmatic approach to product costing. The approach involves two stages, namely the preparatory stage and the estimation stage. A case study conducted in a refrigerator company is reported.展开更多
This paper reports on the time and frequency standard system for the Five-hundred meter Aperture Spherical radio Telescope(FAST),including the system design,stability measurements and pulsar timing observations.The st...This paper reports on the time and frequency standard system for the Five-hundred meter Aperture Spherical radio Telescope(FAST),including the system design,stability measurements and pulsar timing observations.The stability and drift rate of the frequency standard are calculated using 1-year monitoring data.The UTC-NIM Disciplined Oscillator(NIMDO)system improves the system time accuracy and stability to the level of 5 ns.Pulsar timing observations were carried out for several months.The weighted RMS of timing residuals reaches the level of less than 3.0μs.展开更多
This paper focuses on studying the Noether symmetry and the conserved quantity with non-standard Lagrangians, namely exponential Lagrangians and power-law Lagrangians on time scales. Firstly, for each case, the Hamilt...This paper focuses on studying the Noether symmetry and the conserved quantity with non-standard Lagrangians, namely exponential Lagrangians and power-law Lagrangians on time scales. Firstly, for each case, the Hamilton prin- ciple based on the action with non-standard Lagrangians on time scales is established, with which the corresponding Euler-Lagrange equation is given. Secondly, according to the invariance of the Hamilton action under the infinitesimal transformation, the Noether theorem for the dynamical system with non-standard Lagrangians on time scales is established. The proof of the theorem consists of two steps. First, it is proved under the infinitesimal transformations of a special one-parameter group without transforming time. Second, utilizing the technique of time-re-parameterization, the Noether theorem in a general form is obtained. The Noether-type conserved quantities with non-standard Lagrangians in both clas- sical and discrete cases are given. Finally, an example in Friedmann-Robertson-Walker spacetime and an example about second order Duffing equation are given to illustrate the application of the results.展开更多
A clustering algorithm and a probability statistics method were applied to different phases of a flight to analyze operation time during aircraft ground taxiing and airborne flight.And the clustering pattern,distribut...A clustering algorithm and a probability statistics method were applied to different phases of a flight to analyze operation time during aircraft ground taxiing and airborne flight.And the clustering pattern,distribution characteristics and dynamically changing rules of the two phases were identified.Further,an estimate method was established to measure operation time of flight legs,with creative steps of calculating individual segment separately and then integrating them accordingly.The method can both objectively and dynamically measure operation time,and accurately reflect real situation.It helps to better utilize airport slot resources and provides a strong support for air traffic flow management when scheduling flight plan in strategic and pre-tactic phases.展开更多
Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be...Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be sensitive to the loading sequence encountered. In order to take account of the loading sequence effect, fatigue life prediction should be based on fatigue crack propagation（FCP） theory rather than the currently used cumulative fatigue damage（CFD） theory. A unified fatigue life prediction（UFLP） method for marine structures has been proposed by the authors＇ group. In order to apply the UFLP method for newly designed structures, authorities such as the classification societies should provide a standardized load-time history（SLH） such as the TWIST and FALSTAFF sequences for transport and fighter aircraft. This paper mainly aims at proposing a procedure to generate the SLHs for marine structures based on a short-term loading sample and to provide an illustration on how to use the presented SLH to a typical tubular T-joint in an offshore platform based on the UFLP method.展开更多
Background: Hypoxia is a primary cause of mountain sickness and a common pathological condition in patients with heart failure, shock, stroke, and chronic obstructive pulmonary disease(COPD). Thus far, little advancem...Background: Hypoxia is a primary cause of mountain sickness and a common pathological condition in patients with heart failure, shock, stroke, and chronic obstructive pulmonary disease(COPD). Thus far, little advancement in countering hypoxic damage has been achieved, and one of the main reasons is the absence of an ideal algorithm or calculation method to normalize hypoxia tolerance scores when evaluating an animal model. In this study, we improved a traditional calculation formula for assessment of hypoxia tolerance.Methods: We used a sealed bottle model in which the oxygen is gradually consumed by a mouse inside. To evaluate the hypoxia tolerance of mice, the survival time(ST) of the mouse is recorded and was used to calculate standard hypoxia tolerance time(STT) and adjusted standard hypoxia tolerance time(ASTT). Mice administered with methazolamide and saline were used as positive and negative controls, respectively.Results: Since mice were grouped according to either body weight(BW) or bottle volume, we found a strongly negative correlation between STT and BW instead of between STT and bottle volume, suggesting that different BWs could cause false positive or negative errors in the STT results. Furthermore, both false positive and negative errors could be rectified when ASTT was used as the evaluation index. Screening for anti-hypoxic medicines by using mice as the experimental subjects would provide more credible results with the improved ASTT method than with the STT method.Conclusions: ASTT could be a better index than STT for the evaluation of hypoxia tolerance abilities as it could eliminate the impact of animal BW.展开更多
Effects of storage time on some properties of jatropha biodiesel were investigated over the storage time of 0 to 8 weeks at the temperature of 25℃. Such properties as water content and density were found to increase ...Effects of storage time on some properties of jatropha biodiesel were investigated over the storage time of 0 to 8 weeks at the temperature of 25℃. Such properties as water content and density were found to increase at the rates of 5 ppm and 14 kg/m3 per week respectively. These rates translate into property values which compare closely with the standard properties of fossil-diesel and properties of quality biodiesel. As a result, the jatropha biodiesel can be used as alternative fuel to fossil-diesel in compression ignition engines within 8 weeks of its production. However, the calorific value and flash point of the biodiesel decreased at the rate of 1.4℃ and 2.5 MJ/kg per week respectively. Although the flash point was within the acceptable level for quality biodiesel, the calorific values were abnormally higher than the values for quality biodiesel of about 38.7 MJ/kg. With the exception of the calorific values, the other properties were not reasonably affected.展开更多
On February 28th, 2005, AQSIQ (the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China), and SAC (the Standardization Administration of P. R. China)jointly ho...On February 28th, 2005, AQSIQ (the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China), and SAC (the Standardization Administration of P. R. China)jointly hosted the press conference on seven items of national standards on nano-materials in Beijing. The seven items of national standards were approved on Sept. 29th and Dec. 27th, 2004 respectively by SAC, and publicized in Jan. 2005. They will be formally put into practice from April 1st, 2005.展开更多
Motion time study is employed by manufacturing industries to determine operation time.An accurate estimate of operation time is crucial for effective process improvement and production planning.Traditional motion time...Motion time study is employed by manufacturing industries to determine operation time.An accurate estimate of operation time is crucial for effective process improvement and production planning.Traditional motion time study is conducted by human analysts with stopwatches,which may be exposed to human errors.In this paper,an automated time study model based on computer vision is proposed.The model integrates a convolutional neural network,which analyzes a video of a manual operation to classify work elements in each video frame,with a time study model that automatically estimates the work element times.An experiment is conducted using a grayscale video and a color video of a manual assembly operation.The work element times from the model are statistically compared to the reference work element time values.The result shows no statistical difference among the time data,which clearly demonstrates the effectiveness of the proposed model.展开更多
基金National 863High-Tech Scheme of China and Kelong Electronics Ltd( No.863-51 1 -984 5-0 0 9863- 51 1 -91 0 -4 0 2 )
文摘The major drawbacks of traditional approaches to product costing include lack of manufacturing knowledge, reliance on the detailed design description, poor cost function approximation and inability to update estimation algorithms by using actual cost data. Adopting the Activity-Based Costing (ABC) concept and based on estimated processing time, this paper proposes a pragmatic approach to product costing. The approach involves two stages, namely the preparatory stage and the estimation stage. A case study conducted in a refrigerator company is reported.
基金supported by the Joint Research Fund in Astronomy(Grant Nos.U1931129,U1631115 and U1831117)under cooperative agreement between NSFC and Chinese Academy of Sciences(CAS)NSFC-STINT Grant 11611130023(CH2015-6360)the National Natural Science Foundation of China(NSFC,Grant No.11403054)
文摘This paper reports on the time and frequency standard system for the Five-hundred meter Aperture Spherical radio Telescope(FAST),including the system design,stability measurements and pulsar timing observations.The stability and drift rate of the frequency standard are calculated using 1-year monitoring data.The UTC-NIM Disciplined Oscillator(NIMDO)system improves the system time accuracy and stability to the level of 5 ns.Pulsar timing observations were carried out for several months.The weighted RMS of timing residuals reaches the level of less than 3.0μs.
基金supported by the National Natural Science Foundation of China(Grant Nos.11572212 and 11272227)the Innovation Program of Suzhou University of Science and Technology,China(Grant No.SKYCX16 012)
文摘This paper focuses on studying the Noether symmetry and the conserved quantity with non-standard Lagrangians, namely exponential Lagrangians and power-law Lagrangians on time scales. Firstly, for each case, the Hamilton prin- ciple based on the action with non-standard Lagrangians on time scales is established, with which the corresponding Euler-Lagrange equation is given. Secondly, according to the invariance of the Hamilton action under the infinitesimal transformation, the Noether theorem for the dynamical system with non-standard Lagrangians on time scales is established. The proof of the theorem consists of two steps. First, it is proved under the infinitesimal transformations of a special one-parameter group without transforming time. Second, utilizing the technique of time-re-parameterization, the Noether theorem in a general form is obtained. The Noether-type conserved quantities with non-standard Lagrangians in both clas- sical and discrete cases are given. Finally, an example in Friedmann-Robertson-Walker spacetime and an example about second order Duffing equation are given to illustrate the application of the results.
基金supported by the National Natural Science Foundation of China(No.U1333202)
文摘A clustering algorithm and a probability statistics method were applied to different phases of a flight to analyze operation time during aircraft ground taxiing and airborne flight.And the clustering pattern,distribution characteristics and dynamically changing rules of the two phases were identified.Further,an estimate method was established to measure operation time of flight legs,with creative steps of calculating individual segment separately and then integrating them accordingly.The method can both objectively and dynamically measure operation time,and accurately reflect real situation.It helps to better utilize airport slot resources and provides a strong support for air traffic flow management when scheduling flight plan in strategic and pre-tactic phases.
基金financially supported by the Fourth Term of"333 Engineering"Program of Jiangsu Province(Grant No.BRA2011116)Youth Foundation of Jiangsu Province(Grant No.BK2012095)Special Program for Hadal Science and Technology of Shanghai Ocean University(Grant No.HAST-T-2013-01)
文摘Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be sensitive to the loading sequence encountered. In order to take account of the loading sequence effect, fatigue life prediction should be based on fatigue crack propagation（FCP） theory rather than the currently used cumulative fatigue damage（CFD） theory. A unified fatigue life prediction（UFLP） method for marine structures has been proposed by the authors＇ group. In order to apply the UFLP method for newly designed structures, authorities such as the classification societies should provide a standardized load-time history（SLH） such as the TWIST and FALSTAFF sequences for transport and fighter aircraft. This paper mainly aims at proposing a procedure to generate the SLHs for marine structures based on a short-term loading sample and to provide an illustration on how to use the presented SLH to a typical tubular T-joint in an offshore platform based on the UFLP method.
基金supported by the grants from the Natural Science Foundation of China(No.81071610 and No.81471814)Consultative Project of Transformation Medicine in Southwest Hospital of the Third Military Medical University(SWH2014ZH05)
文摘Background: Hypoxia is a primary cause of mountain sickness and a common pathological condition in patients with heart failure, shock, stroke, and chronic obstructive pulmonary disease(COPD). Thus far, little advancement in countering hypoxic damage has been achieved, and one of the main reasons is the absence of an ideal algorithm or calculation method to normalize hypoxia tolerance scores when evaluating an animal model. In this study, we improved a traditional calculation formula for assessment of hypoxia tolerance.Methods: We used a sealed bottle model in which the oxygen is gradually consumed by a mouse inside. To evaluate the hypoxia tolerance of mice, the survival time(ST) of the mouse is recorded and was used to calculate standard hypoxia tolerance time(STT) and adjusted standard hypoxia tolerance time(ASTT). Mice administered with methazolamide and saline were used as positive and negative controls, respectively.Results: Since mice were grouped according to either body weight(BW) or bottle volume, we found a strongly negative correlation between STT and BW instead of between STT and bottle volume, suggesting that different BWs could cause false positive or negative errors in the STT results. Furthermore, both false positive and negative errors could be rectified when ASTT was used as the evaluation index. Screening for anti-hypoxic medicines by using mice as the experimental subjects would provide more credible results with the improved ASTT method than with the STT method.Conclusions: ASTT could be a better index than STT for the evaluation of hypoxia tolerance abilities as it could eliminate the impact of animal BW.
文摘Effects of storage time on some properties of jatropha biodiesel were investigated over the storage time of 0 to 8 weeks at the temperature of 25℃. Such properties as water content and density were found to increase at the rates of 5 ppm and 14 kg/m3 per week respectively. These rates translate into property values which compare closely with the standard properties of fossil-diesel and properties of quality biodiesel. As a result, the jatropha biodiesel can be used as alternative fuel to fossil-diesel in compression ignition engines within 8 weeks of its production. However, the calorific value and flash point of the biodiesel decreased at the rate of 1.4℃ and 2.5 MJ/kg per week respectively. Although the flash point was within the acceptable level for quality biodiesel, the calorific values were abnormally higher than the values for quality biodiesel of about 38.7 MJ/kg. With the exception of the calorific values, the other properties were not reasonably affected.
文摘On February 28th, 2005, AQSIQ (the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China), and SAC (the Standardization Administration of P. R. China)jointly hosted the press conference on seven items of national standards on nano-materials in Beijing. The seven items of national standards were approved on Sept. 29th and Dec. 27th, 2004 respectively by SAC, and publicized in Jan. 2005. They will be formally put into practice from April 1st, 2005.
基金This work is jointly supported by the SIIT Young Researcher Grant,under a Contract No.SIIT 2019-YRG-WP01the Excellent Research Graduate Scholarship,under a Contract No.MOU-CO-2562-8675.
文摘Motion time study is employed by manufacturing industries to determine operation time.An accurate estimate of operation time is crucial for effective process improvement and production planning.Traditional motion time study is conducted by human analysts with stopwatches,which may be exposed to human errors.In this paper,an automated time study model based on computer vision is proposed.The model integrates a convolutional neural network,which analyzes a video of a manual operation to classify work elements in each video frame,with a time study model that automatically estimates the work element times.An experiment is conducted using a grayscale video and a color video of a manual assembly operation.The work element times from the model are statistically compared to the reference work element time values.The result shows no statistical difference among the time data,which clearly demonstrates the effectiveness of the proposed model.
