The increase in capacity of displacement piles with time after installation is typically known as soil/pile set-up. A full-scale field test is carried out to observe the set-up effect for open-ended concrete pipe pile...The increase in capacity of displacement piles with time after installation is typically known as soil/pile set-up. A full-scale field test is carried out to observe the set-up effect for open-ended concrete pipe piles jacked into mixed soils. Both the total capacity and the average unit shaft resistance increase approximately linearly with logarithmic time. The average increase rate for unit shaft resistance is 44% per log cycle, while the average increase for total capacity is approximately 21%. A review on case histories for long-term set-up indicates an average set-up rate of approximately 40%. Based on this, the mechanism of pile set-up is discussed in detail and a three-phase model is suggested.展开更多
Based on the time dependent mild slope equation including the effect of wave energy dissipation, an expression for the energy dissipation factor is derived in conjunction with the wave energy balance equation, and the...Based on the time dependent mild slope equation including the effect of wave energy dissipation, an expression for the energy dissipation factor is derived in conjunction with the wave energy balance equation, and then a practical method for the simulation of wave height and wave set- up in nearshore regions is presented. The variation of the complex wave amplitude is numerically simulated by use of the parabolic mild slope equation including the effect of wave energy dissipation due to wave breaking. The components of wave radiation stress are calculated subsequently by new expressions for them according to the obtained complex wave amplitude, and then the depth-averaged equation is applied to the calculation of wave set-up due to wave breaking. Numerical results are in good agreement with experimental data, showing that the expression for the energy dissipation factor is reasonable and that the new method is effective for the simulation of wave set-up due to wave breaking in nearshore regions.展开更多
Storm surge along the China＇s Zhe-Min coast is addressed using the tightly coupled surge model ofADCIRC＋SWAN. In this study, we primarily focus on the effects of surge-tide interaction and waveset-up/set-down. And t...Storm surge along the China＇s Zhe-Min coast is addressed using the tightly coupled surge model ofADCIRC＋SWAN. In this study, we primarily focus on the effects of surge-tide interaction and waveset-up/set-down. And the influences of intensity and landing moment of tropical cyclone （TC） arealso presented. The results show that： water elevation without considering tide-surge interactiontends to be underestimated/overestimated when TC lands during astronomical low/high tide;tide-surge coupling effect is more pronounced north of TC track （more than 0.7 m in our cases）;irrelevant to TC＇s intensity, wave set-up south of TC track is negligible because the depth-relatedwave breaking doesn＇t occur in water body blown towards open seas.展开更多
In this study, we investigated wave transformation and wave set-up between a submerged permeable breakwater and a seawall. Modified time-dependent mild-slope equations, which involve parameters of the porous medium, w...In this study, we investigated wave transformation and wave set-up between a submerged permeable breakwater and a seawall. Modified time-dependent mild-slope equations, which involve parameters of the porous medium, were used to calculate the wave height transformation and the mean water level change around a submerged breakwater. The numerical solution is verified with experimental data. The simulated results show that modulations of the wave profile and wave set-up are clearly observed between the submerged breakwater and the seawall. In contrast to cases without a seawall, the node or pseudo-node of wave height evolution can be found between the submerged breakwater and the seawall. Higher wave set-up occurs if the nodal or pseudo-nodal point appears near the submerged breakwater. We also examined the influence of the porosity and friction factor of the submerged permeable breakwater on wave transformation and set-up.展开更多
A new high frequency short pulse electrochemical machining(HSPECM) set-up was developed, including mechanical machine set-up, pulse power, drive system, interelectrode gap detection unit and controlling system. Accord...A new high frequency short pulse electrochemical machining(HSPECM) set-up was developed, including mechanical machine set-up, pulse power, drive system, interelectrode gap detection unit and controlling system. According to the present investigation, using a group of optimal parameters, an experiment replicating complex shape workpiece was made. From the photograph of the machined jobs, it can be seen that it has clear contour and smooth end surface. And the machining rate increases largely and the effective utilization of HSPECM in the micromachining field will be further strengthened.展开更多
This paper proposes an equation to calculate breaking wave induced wave set-up and set-down along reef flat. The mathematical equation was derived based on the theory of radiation stress and the conservation of wave e...This paper proposes an equation to calculate breaking wave induced wave set-up and set-down along reef flat. The mathematical equation was derived based on the theory of radiation stress and the conservation of wave energy. The equation is primarily determined by several physical variables including the breaking wave index, the stable wave index, the attenuation coefficient of wave energy flux, and the flow velocity in the re-stabilization zone. A series of laboratory experiments were carried out to calibrate the theoretical equations. Specifically, the breaking wave index,the stable wave index, and the velocity over the reef flat were measured in the laboratory. The attenuation coefficient of wave energy flux in our theoretical equation was determined by calibration by comparing with the laboratory measured wave height. Furthermore, it has been put forward that the velocity based on cnoidal wave theory could be used to determine the velocity over the reef flat if there is no velocity measurement available. Overall, the proposed equation can provide satisfactory prediction of wave set-up and set-down along the reef flat.展开更多
We study the scheduling on an unbounded parallel-batch machine with jobs having set-up times to minimize a regular objective function which is either of the sumform or of the max-form.As we know,in the existing litera...We study the scheduling on an unbounded parallel-batch machine with jobs having set-up times to minimize a regular objective function which is either of the sumform or of the max-form.As we know,in the existing literature,the research about parallel-batch scheduling does not consider the set-up times of jobs.However,the set-up times of jobs are widely presented in practical applications.Each job considered in this paper has a set-up time.The set-up time of each batch is equal to the maximum set-up time of all jobs contained in the batch,and the processing time of each batch is equal to the longest processing time of the jobs contained in the batch.Depending on the different definitions of the completion time of a job,we consider two types of jobs:batch jobs and drop-line jobs.For batch jobs,the completion time of a job is given by the completion time of the batch containing this job.For drop-line jobs,the completion time of a job is given by the starting time of the batch containing this job plus the processing time of this job.In this paper,we give pseudo-polynomial time algorithms for the above scheduling problems in which the jobs have agreeable processing times and set-up times.In addition,when the objective functions are the total weighted completion time,the maximum lateness,and the maximum cost,we present a polynomial time algorithm,respectively.展开更多
This study aims to evaluate inter-fractional set-up errors in patients treated with distinct immobilization equipment (thermoplastic mask, knee-fix and feet-fix, wing board and vac-lok) for four anatomical regions inc...This study aims to evaluate inter-fractional set-up errors in patients treated with distinct immobilization equipment (thermoplastic mask, knee-fix and feet-fix, wing board and vac-lok) for four anatomical regions including brain, head and neck (HN), thorax and pelvis. Data of randomly selected 140 patients who were treated for four anatomical regions were obtained using Hi-Art Helical Tomotherapy (HT) system. Pre-treatment planning was based on automatic registration readings of computed tomography (CT) and mega-voltage computed tomography (MVCT) on a daily basis. Distinct immobilization equipment was used for varying anatomical regions. Individual mean set-up error (M), systematic error (Σ), and random error (σ) values were calculated through daily translational and rotational deviation values. The size of translational, systematic and random error was 1.31 - 4.93 mm for brain, 2.28 - 4.88 mm for HN, 4.04 - 9.90 mm for thorax, and 6.34 - 14.68 mm for pelvis. Rotational values were as follows: 0.06° - 0.73° for brain, 0.42° - 0.6° for HN, 0.48° - 1.14° for thorax and 0.65° - 1.05° for pelvis. The highest translational, systematic and random error value was obtained from the pelvic regional. The highest standard and random error value in pitch and roll was produced in the rotational direction of the pelvis (0.05° and 0.71°), while the highest error value in yaw was (1.14°) produced from thorax. Inter-fractional set-up errors were most commonly produced in the pelvis, followed by thorax. Our study results suggest that the highest systematic and random errors are found for thorax and pelvis. Distinct immobilization equipment was important in these results. Safety margins around the clinical target volume (CTV) are changeable for different anatomical regions. A future work could be developed to new equipment for immobilization because of the reduced margins CTV.展开更多
In vitro experimental set-up is an important tool for investigating abdominal aortic aneurysm (AAA). Accurate reproduction of the physiological pulsatile flow waveform in the abdominal aorta at various anatomic locati...In vitro experimental set-up is an important tool for investigating abdominal aortic aneurysm (AAA). Accurate reproduction of the physiological pulsatile flow waveform in the abdominal aorta at various anatomic locations is an important component of these experimental methods. The objective of this study is to establish an experimental set-up to generate a physiological pulsatile flow for in vitro simulations of the abdominal aorta. The physiological flow was established by a computer-controlled peristaltic pump and the flow field in a circular straight pipe is measured under pulsatile flow conditions by a 2-dimensional particle image velocimetry system (2D-PIV). Experimental results show that the in vitro experimental set-up provides a flow with a period of 2 s, a reasonable cross-sectional velocity distribution and an approximate inlet velocity profile that is close to the human abdominal aorta.展开更多
According to the National Meeting on Power Construction and Cost Control held in Beijing on 26th August 1996, the target for power construction in the period of 9th Five- year Plan is set-up as follows:
Presents the fin-propeller test set-up to solve the problem of roll stabilization with ships in full speed range, withwhich, tests were run in water rank for acquisition of data, and concludes from data acquired that ...Presents the fin-propeller test set-up to solve the problem of roll stabilization with ships in full speed range, withwhich, tests were run in water rank for acquisition of data, and concludes from data acquired that the fin-propeller test set-up produces more lift than simple fin, and provides lateral thrust as well, and it is therefore an effective roll stabilization devicefor ships in full speed range.展开更多
A new heuristic for preemptive parallel machine scheduling with batch set up time is provided by modifying some recent algorithms, we prove that it has a better asymptotic performance in some sence.
背景与目的:乳腺癌保乳术后单周超大分割全乳放疗能在保证疗效和安全性的同时缩短疗程,是目前可选的全乳放疗方案。超大分割放疗要求患者每日接受图像引导,但其对位置误差的影响尚不明确。在每日锥形束计算机断层扫描(cone-beam compute...背景与目的:乳腺癌保乳术后单周超大分割全乳放疗能在保证疗效和安全性的同时缩短疗程,是目前可选的全乳放疗方案。超大分割放疗要求患者每日接受图像引导,但其对位置误差的影响尚不明确。在每日锥形束计算机断层扫描(cone-beam computed tomography,CBCT)引导下,本研究旨在探索单周超大分割全乳放疗的位置误差及其影响因素,并计算临床靶体积(clinical target volume,CTV)外扩至计划靶体积(planning target volume,PTV)的三维边界。方法:纳入2021年2月-10月于上海瑞金医院入组乳腺癌术后单周超大分割全乳放疗前瞻性研究(NCT04926766)连续入组的患者的临床资料[(2020)临伦审第(352)号]。所有患者每日治疗前摆位后行CBCT1,根据CBCT1纠正误差后再行CBCT2,当次治疗结束后行CBCT3。CBCT1、CBCT2与定位CT的三维位置误差分别为初始、残余分次间误差。CBCT2与CBCT3间的三维位置误差为分次内误差。根据每次治疗的分次间及分次内误差,基于van Herk公式计算CTV外扩至PTV三维边界。结果:本研究共入组患者34例,收集CBCT图像510例次。每日治疗前CBCT在线位置纠正显著减少三维位置误差(初始分次间误差vs残余分次间误差:前后2.8 mm vs 0.4 mm;头脚1.6 mm vs 0.5 mm;左右1.8 mm vs 0.3 mm;P均<0.001)。对于残余分次间误差,CTV体积较大患者(>402.5 cm^(3)vs≤402.5 cm^(3))在前后方向(0.5 mm vs 0.3 mm,P=0.023)和头脚方向(0.6 mm vs 0.5 mm,P=0.037)更大。对于分次内误差,CTV较大患者(>402.5 cm^(3)vs≤402.5 cm^(3))在前后方向更大(0.5 mm vs 0.2 mm,P=0.001);身体质量指数(body mass index,BMI)较高患者(>23.2 kg/m^(2)vs≤23.2 kg/m^(2))在前后方向更大(0.7 mm vs 0.2 mm,P<0.001);体重更大患者(> 60.0 kg vs≤60.0 kg)在前后方向更大(0.5 mm vs 0.2 mm,P=0.033)。每日CBCT引导下CTV外扩至PTV边界推荐为:前后2.3 mm,头脚2.8 mm,左右2.0mm。但CTV>402.5 cm^(3)和BMI>23.2 kg/m^(2)的患者需要更大的头脚方向外扩边界,分别为3.1和3.4 mm。结论:每日CBCT图像引导下,对大部分患者将全乳放疗CTV外扩至PTV的三维边界限制在3 mm内是可行的,而BMI较高和CTV较大患者需在头脚方向适度增大外扩边界。展开更多
基金Project supported by the National Natural Science Foundation of China (No. 51078330)the Natural Science Foundation of Zhejiang Province (No. Y1090610),China
文摘The increase in capacity of displacement piles with time after installation is typically known as soil/pile set-up. A full-scale field test is carried out to observe the set-up effect for open-ended concrete pipe piles jacked into mixed soils. Both the total capacity and the average unit shaft resistance increase approximately linearly with logarithmic time. The average increase rate for unit shaft resistance is 44% per log cycle, while the average increase for total capacity is approximately 21%. A review on case histories for long-term set-up indicates an average set-up rate of approximately 40%. Based on this, the mechanism of pile set-up is discussed in detail and a three-phase model is suggested.
基金This subject was financially supported by the National Natural Science Foundation of China (Grant No. 59839330 and No. 59979025)
文摘Based on the time dependent mild slope equation including the effect of wave energy dissipation, an expression for the energy dissipation factor is derived in conjunction with the wave energy balance equation, and then a practical method for the simulation of wave height and wave set- up in nearshore regions is presented. The variation of the complex wave amplitude is numerically simulated by use of the parabolic mild slope equation including the effect of wave energy dissipation due to wave breaking. The components of wave radiation stress are calculated subsequently by new expressions for them according to the obtained complex wave amplitude, and then the depth-averaged equation is applied to the calculation of wave set-up due to wave breaking. Numerical results are in good agreement with experimental data, showing that the expression for the energy dissipation factor is reasonable and that the new method is effective for the simulation of wave set-up due to wave breaking in nearshore regions.
基金the support of National Natural Science Foundation of China (11772339)the Strategic Priority Research Programs (Category B) of the Chinese Academy of Sciences (XDB22040203)
文摘Storm surge along the China＇s Zhe-Min coast is addressed using the tightly coupled surge model ofADCIRC＋SWAN. In this study, we primarily focus on the effects of surge-tide interaction and waveset-up/set-down. And the influences of intensity and landing moment of tropical cyclone （TC） arealso presented. The results show that： water elevation without considering tide-surge interactiontends to be underestimated/overestimated when TC lands during astronomical low/high tide;tide-surge coupling effect is more pronounced north of TC track （more than 0.7 m in our cases）;irrelevant to TC＇s intensity, wave set-up south of TC track is negligible because the depth-relatedwave breaking doesn＇t occur in water body blown towards open seas.
基金supported by The Science Council of Taiwan under Grant No. 95-2221-E-005-154
文摘In this study, we investigated wave transformation and wave set-up between a submerged permeable breakwater and a seawall. Modified time-dependent mild-slope equations, which involve parameters of the porous medium, were used to calculate the wave height transformation and the mean water level change around a submerged breakwater. The numerical solution is verified with experimental data. The simulated results show that modulations of the wave profile and wave set-up are clearly observed between the submerged breakwater and the seawall. In contrast to cases without a seawall, the node or pseudo-node of wave height evolution can be found between the submerged breakwater and the seawall. Higher wave set-up occurs if the nodal or pseudo-nodal point appears near the submerged breakwater. We also examined the influence of the porosity and friction factor of the submerged permeable breakwater on wave transformation and set-up.
文摘A new high frequency short pulse electrochemical machining(HSPECM) set-up was developed, including mechanical machine set-up, pulse power, drive system, interelectrode gap detection unit and controlling system. According to the present investigation, using a group of optimal parameters, an experiment replicating complex shape workpiece was made. From the photograph of the machined jobs, it can be seen that it has clear contour and smooth end surface. And the machining rate increases largely and the effective utilization of HSPECM in the micromachining field will be further strengthened.
基金jointly supported by the National Key R&D Program of China (Grant No. 2018YFC0407503)the National Natural Science Foundation of China (Grant No. 51779149)+2 种基金the Scientific Research Project of Yangtze-to-Huaihe Water Diversion Project (Grant No. YJJHYJJC-ZX-20191106220)the Nanjing Hydraulic Research Institute Special Fund for Basic Scientific Research of Central Public Research Institutes(Grant Nos. Y220002, Y219012 and Y220013)the Water Conservancy Science and Technology Project of Jiangsu Province (Grant No. 2019009)。
文摘This paper proposes an equation to calculate breaking wave induced wave set-up and set-down along reef flat. The mathematical equation was derived based on the theory of radiation stress and the conservation of wave energy. The equation is primarily determined by several physical variables including the breaking wave index, the stable wave index, the attenuation coefficient of wave energy flux, and the flow velocity in the re-stabilization zone. A series of laboratory experiments were carried out to calibrate the theoretical equations. Specifically, the breaking wave index,the stable wave index, and the velocity over the reef flat were measured in the laboratory. The attenuation coefficient of wave energy flux in our theoretical equation was determined by calibration by comparing with the laboratory measured wave height. Furthermore, it has been put forward that the velocity based on cnoidal wave theory could be used to determine the velocity over the reef flat if there is no velocity measurement available. Overall, the proposed equation can provide satisfactory prediction of wave set-up and set-down along the reef flat.
基金Supported by National Natural Science Foundation of China(Grant No.11901539)。
文摘We study the scheduling on an unbounded parallel-batch machine with jobs having set-up times to minimize a regular objective function which is either of the sumform or of the max-form.As we know,in the existing literature,the research about parallel-batch scheduling does not consider the set-up times of jobs.However,the set-up times of jobs are widely presented in practical applications.Each job considered in this paper has a set-up time.The set-up time of each batch is equal to the maximum set-up time of all jobs contained in the batch,and the processing time of each batch is equal to the longest processing time of the jobs contained in the batch.Depending on the different definitions of the completion time of a job,we consider two types of jobs:batch jobs and drop-line jobs.For batch jobs,the completion time of a job is given by the completion time of the batch containing this job.For drop-line jobs,the completion time of a job is given by the starting time of the batch containing this job plus the processing time of this job.In this paper,we give pseudo-polynomial time algorithms for the above scheduling problems in which the jobs have agreeable processing times and set-up times.In addition,when the objective functions are the total weighted completion time,the maximum lateness,and the maximum cost,we present a polynomial time algorithm,respectively.
文摘This study aims to evaluate inter-fractional set-up errors in patients treated with distinct immobilization equipment (thermoplastic mask, knee-fix and feet-fix, wing board and vac-lok) for four anatomical regions including brain, head and neck (HN), thorax and pelvis. Data of randomly selected 140 patients who were treated for four anatomical regions were obtained using Hi-Art Helical Tomotherapy (HT) system. Pre-treatment planning was based on automatic registration readings of computed tomography (CT) and mega-voltage computed tomography (MVCT) on a daily basis. Distinct immobilization equipment was used for varying anatomical regions. Individual mean set-up error (M), systematic error (Σ), and random error (σ) values were calculated through daily translational and rotational deviation values. The size of translational, systematic and random error was 1.31 - 4.93 mm for brain, 2.28 - 4.88 mm for HN, 4.04 - 9.90 mm for thorax, and 6.34 - 14.68 mm for pelvis. Rotational values were as follows: 0.06° - 0.73° for brain, 0.42° - 0.6° for HN, 0.48° - 1.14° for thorax and 0.65° - 1.05° for pelvis. The highest translational, systematic and random error value was obtained from the pelvic regional. The highest standard and random error value in pitch and roll was produced in the rotational direction of the pelvis (0.05° and 0.71°), while the highest error value in yaw was (1.14°) produced from thorax. Inter-fractional set-up errors were most commonly produced in the pelvis, followed by thorax. Our study results suggest that the highest systematic and random errors are found for thorax and pelvis. Distinct immobilization equipment was important in these results. Safety margins around the clinical target volume (CTV) are changeable for different anatomical regions. A future work could be developed to new equipment for immobilization because of the reduced margins CTV.
文摘In vitro experimental set-up is an important tool for investigating abdominal aortic aneurysm (AAA). Accurate reproduction of the physiological pulsatile flow waveform in the abdominal aorta at various anatomic locations is an important component of these experimental methods. The objective of this study is to establish an experimental set-up to generate a physiological pulsatile flow for in vitro simulations of the abdominal aorta. The physiological flow was established by a computer-controlled peristaltic pump and the flow field in a circular straight pipe is measured under pulsatile flow conditions by a 2-dimensional particle image velocimetry system (2D-PIV). Experimental results show that the in vitro experimental set-up provides a flow with a period of 2 s, a reasonable cross-sectional velocity distribution and an approximate inlet velocity profile that is close to the human abdominal aorta.
文摘According to the National Meeting on Power Construction and Cost Control held in Beijing on 26th August 1996, the target for power construction in the period of 9th Five- year Plan is set-up as follows:
文摘Presents the fin-propeller test set-up to solve the problem of roll stabilization with ships in full speed range, withwhich, tests were run in water rank for acquisition of data, and concludes from data acquired that the fin-propeller test set-up produces more lift than simple fin, and provides lateral thrust as well, and it is therefore an effective roll stabilization devicefor ships in full speed range.
文摘A new heuristic for preemptive parallel machine scheduling with batch set up time is provided by modifying some recent algorithms, we prove that it has a better asymptotic performance in some sence.
文摘背景与目的:乳腺癌保乳术后单周超大分割全乳放疗能在保证疗效和安全性的同时缩短疗程,是目前可选的全乳放疗方案。超大分割放疗要求患者每日接受图像引导,但其对位置误差的影响尚不明确。在每日锥形束计算机断层扫描(cone-beam computed tomography,CBCT)引导下,本研究旨在探索单周超大分割全乳放疗的位置误差及其影响因素,并计算临床靶体积(clinical target volume,CTV)外扩至计划靶体积(planning target volume,PTV)的三维边界。方法:纳入2021年2月-10月于上海瑞金医院入组乳腺癌术后单周超大分割全乳放疗前瞻性研究(NCT04926766)连续入组的患者的临床资料[(2020)临伦审第(352)号]。所有患者每日治疗前摆位后行CBCT1,根据CBCT1纠正误差后再行CBCT2,当次治疗结束后行CBCT3。CBCT1、CBCT2与定位CT的三维位置误差分别为初始、残余分次间误差。CBCT2与CBCT3间的三维位置误差为分次内误差。根据每次治疗的分次间及分次内误差,基于van Herk公式计算CTV外扩至PTV三维边界。结果:本研究共入组患者34例,收集CBCT图像510例次。每日治疗前CBCT在线位置纠正显著减少三维位置误差(初始分次间误差vs残余分次间误差:前后2.8 mm vs 0.4 mm;头脚1.6 mm vs 0.5 mm;左右1.8 mm vs 0.3 mm;P均<0.001)。对于残余分次间误差,CTV体积较大患者(>402.5 cm^(3)vs≤402.5 cm^(3))在前后方向(0.5 mm vs 0.3 mm,P=0.023)和头脚方向(0.6 mm vs 0.5 mm,P=0.037)更大。对于分次内误差,CTV较大患者(>402.5 cm^(3)vs≤402.5 cm^(3))在前后方向更大(0.5 mm vs 0.2 mm,P=0.001);身体质量指数(body mass index,BMI)较高患者(>23.2 kg/m^(2)vs≤23.2 kg/m^(2))在前后方向更大(0.7 mm vs 0.2 mm,P<0.001);体重更大患者(> 60.0 kg vs≤60.0 kg)在前后方向更大(0.5 mm vs 0.2 mm,P=0.033)。每日CBCT引导下CTV外扩至PTV边界推荐为:前后2.3 mm,头脚2.8 mm,左右2.0mm。但CTV>402.5 cm^(3)和BMI>23.2 kg/m^(2)的患者需要更大的头脚方向外扩边界,分别为3.1和3.4 mm。结论:每日CBCT图像引导下,对大部分患者将全乳放疗CTV外扩至PTV的三维边界限制在3 mm内是可行的,而BMI较高和CTV较大患者需在头脚方向适度增大外扩边界。
