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Optimization design of anti-seismic engineering measures for intake tower based on non-dominated sorting genetic algorithm-II

《结构与土木工程前沿（英文）》   页码 1428-1441 doi: 10.1007/s11709-023-0998-2

摘要： High-rise intake towers in high-intensity seismic areas are prone to structural safety problems under vibration. Therefore, effective and low-cost anti-seismic engineering measures must be designed for protection. An intake tower in northwest China was considered the research object, and its natural vibration characteristics and dynamic response were first analyzed using the mode decomposition response spectrum method based on a three-dimensional finite element model. The non-dominated sorting genetic algorithm-II (NSGA-II) was adopted to optimize the anti-seismic scheme combination by comprehensively considering the dynamic tower response and variable project cost. Finally, the rationality of the original intake tower antiseismic design scheme was evaluated according to the obtained optimal solution set, and recommendations for improvement were proposed. The method adopted in this study may provide significant references for designing anti-seismic measures for high-rise structures such as intake towers located in high-intensity earthquake areas.

关键词： intake tower     NSGA-II     mode decomposition response spectrum method     anti-seismic engineering measures     optimization design     variable project cost    

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应用型工程造价专业人才培养模式的探索与实践——以天津理工大学为例

尹贻林,白 娟

《中国工程科学》 2015年 第17卷 第1期   页码 114-119

摘要：

咨询行业的跨越式发展对工程造价专业人才的供给提出了新的要求，培养适用于市场需求的应用型人才是工程专业人才培养的首要任务。本文以天津理工大学为例，剖析应用型工程专业人才的素质特征，从教学体系构建，团队的培养和建设两方面，对应用型工程造价专业人才培养模式进行的构建进行系统的阐述，旨在为应用型工程造价专业人才的培养提供借鉴。

关键词： 应用型人才；工程造价专业；人才培养模式    

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Performance of seven highway construction contracting methods analyzed by project size

Yuanxin ZHANG, Abdol CHINI, R. Edward MINCHIN Jr., Lourdes PTSCHELINZEW, Dev SHAH

《工程管理前沿（英文）》 2018年 第5卷 第2期   页码 240-250 doi: 10.15302/J-FEM-2018040

摘要： The conventional Design-Bid-Build (DBB) construction contracting method has had various drawbacks exposed in highway construction practice, including lack of communication, inefficient design, antagonizing relationships, and increased disputes. To mitigate the negative aspects of DBB, several alternative contracting methods and alternative project delivery systems have been devised and introduced to the industry over the past 30 years. Five such innovations were tested by a research team from the University of Florida under the sponsorship of the Florida Department of Transportation (FDOT). To perform a realistic assessment, this study categorized FDOT projects built between 2006 and 2015 into groups according to current contract amounts. Both absolute and relative metrics were defined and employed. For comparison purposes, a collective analysis on all gathered data was performed. Additionally, the influence of outliers on the results was examined. The results showed that analyses based on individual cost categories are more convincing because large projects tend to impose stronger influence on the analyses. In addition, outliers must be identified and screened to reach realistic and reliable conclusions. With regard to the actual performance of the contracting methods, each performs differently within different cost categories.

关键词： alternative contracting methods     time     cost     performance evaluation    

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Mechanical design, modeling, and identification for a novel antagonistic variable stiffness dexterous

《机械工程前沿（英文）》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0691-5

摘要： This study traces the development of dexterous hand research and proposes a novel antagonistic variable stiffness dexterous finger mechanism to improve the safety of dexterous hand in unpredictable environments, such as unstructured or man-made operational errors through comprehensive consideration of cost, accuracy, manufacturing, and application. Based on the concept of mechanical passive compliance, which is widely implemented in robots for interactions, a finger is dedicated to improving mechanical robustness. The finger mechanism not only achieves passive compliance against physical impacts, but also implements the variable stiffness actuator principle in a compact finger without adding supererogatory actuators. It achieves finger stiffness adjustability according to the biologically inspired stiffness variation principle of discarding some mobilities to adjust stiffness. The mechanical design of the finger and its stiffness adjusting methods are elaborated. The stiffness characteristics of the finger joint and the actuation unit are analyzed. Experimental results of the finger joint stiffness identification and finger impact tests under different finger stiffness presets are provided to verify the validity of the model. Fingers have been experimentally proven to be robust against physical impacts. Moreover, the experimental part verifies that fingers have good power, grasping, and manipulation performance.

关键词： multifingered hand     mechanism design     robot safety     variable stiffness actuator    

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Effect of variable heat capacities on performance of an irreversible Miller heat engine

Xingmei YE

《能源前沿（英文）》 2012年 第6卷 第3期   页码 280-284 doi: 10.1007/s11708-012-0203-0

摘要： Based on the variable heat capacities of the working fluid, the irreversibility coming from the compression and expansion processes, and the heat leak losses through the cylinder wall, an irreversible cycle model of the Miller heat engine was established, from which expressions for the efficiency and work output of the cycle were derived. The performance characteristic curves of the Miller heat engine were generated through numerical calculation, from which the optimal regions of some main parameters such as the work output, efficiency and pressure ratio were determined. Moreover, the influence of the compression and expansion efficiencies, the variable heat capacities and the heat leak losses on the performance of the cycle was discussed in detail, and consequently, some significant results were obtained.

关键词： Miller cycle     variable heat capacity     irreversibility     parametric optimization    

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Life-cycle cost analysis of optimal timing of pavement preservation

Zilong WANG,Hao WANG

《结构与土木工程前沿（英文）》 2017年 第11卷 第1期   页码 17-26 doi: 10.1007/s11709-016-0369-3

摘要： Optimal application of pavement preservation or preventive maintenance is critical for highway agencies to allocate the limited budget for different treatments. This study developed an integrated life-cycle cost analysis (LCCA) model to quantify the impact of pavement preservation on agency cost and vehicle operation cost (VOC) and analyzed the optimal timing of preservation treatments. The international roughness index (IRI) data were extracted from the long-term pavement performance (LTPP) program specific pavement studies 3 (SPS-3) to determine the long-term effectiveness of preservation treatments on IRI deterioration. The traffic loading and the initial IRI value significantly affects life extension and the benefit of agency cost caused by pavement preservation. The benefit in VOC is one to two orders greater in magnitude as compared to the benefit in agency cost. The optimal timing calculated based on VOC is always earlier than the optimal timing calculated based on agency cost. There are considerable differences among the optimal timing of three preservation treatments.

关键词： pavement preservation     life-cycle cost analysis     agency cost     vehicle operation cost    

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斜井全断面变径滑模新工艺——在三峡工程永久船闸地下输水系统斜井砼施工中的应用

周宇,钱兴喜,樊启祥,廖建新

《中国工程科学》 2002年 第4卷 第9期   页码 81-85

摘要：

文章简要介绍了斜井全断面变径滑模结构、工作原理和主要技术性能指标。针对三峡工程永久船闸地下输水系统斜井具有数量多、长度短、体型复杂、边墙高度逐渐变化等特点。混凝土施工采用全断面变径滑模新工艺，斜井直段一次浇筑成型，洞身高度变化在滑升过程中自动完成，并收到显著的经济效益和社会效益。

关键词： 三峡工程     斜井砼施工     全断面变径滑模    

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Comparative cost analysis of three different anesthesia methods in gynecological laparoscopic surgery

null

《医学前沿（英文）》 2012年 第6卷 第3期   页码 311-316 doi: 10.1007/s11684-012-0205-7

摘要：

In the current study, we assessed and evaluated the costs and benefits of three popular methods of general anesthesia practiced in our department for gynecological laparoscopic surgery in recent years. Sixty adult female patients who underwent elective gynecological laparoscopic surgery under general anesthesia were randomly divided into three groups: group V, group I and group C. In group V, anesthesia was induced intravenously with midazolam, remifentanil, propofol and vecuronium, and maintained with continuous infusion of propofol and remifentanil. In group I, anesthesia was intravenously induced with midazolam, fentanyl, propofol and vecuronium, and maintained with inhaled isoflurane and intravenous bonus of fentanyl. In group C, anesthesia was induced as in group I, but maintained with isoflurane inhalation combined with propofol-remifentanil infusion. All patients received vecuronium for muscle relaxation. Perioperative incidences of complications and total anesthesia costs for patients in all groups were recorded. In addition, postoperative satisfaction of the patients was also noted, and similar outcomes of the satisfaction were reported in all 60 patients. Although there was no statistical significance among groups, the incidence of postoperative nausea and vomiting were higher in group C, and the rates of shivering and the needs for analgesics were higher in group V. Anesthesia costs in group I were the lowest. Therefore, it is concluded that the costs of anesthesia induced with midazolam, fentanyl, propofol, vecuronium, and maintained with isoflurane, fentanyl and vecuronium are cheapest, and there is no significant difference in patients’ satisfaction and safety among the three above-mentioned methods of anesthesia in our department.

关键词： general anesthesia     economics     cost    

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A neural network-based production process modeling and variable importance analysis approach in corn

《化学科学与工程前沿（英文）》 2023年 第17卷 第3期   页码 358-371 doi: 10.1007/s11705-022-2190-y

摘要： Corn to sugar process has long faced the risks of high energy consumption and thin profits. However, it’s hard to upgrade or optimize the process based on mechanism unit operation models due to the high complexity of the related processes. Big data technology provides a promising solution as its ability to turn huge amounts of data into insights for operational decisions. In this paper, a neural network-based production process modeling and variable importance analysis approach is proposed for corn to sugar processes, which contains data preprocessing, dimensionality reduction, multilayer perceptron/convolutional neural network/recurrent neural network based modeling and extended weights connection method. In the established model, dextrose equivalent value is selected as the output, and 654 sites from the DCS system are selected as the inputs. LASSO analysis is first applied to reduce the data dimension to 155, then the inputs are dimensionalized to 50 by means of genetic algorithm optimization. Ultimately, variable importance analysis is carried out by the extended weight connection method, and 20 of the most important sites are selected for each neural network. The results indicate that the multilayer perceptron and recurrent neural network models have a relative error of less than 0.1%, which have a better prediction result than other models, and the 20 most important sites selected have better explicable performance. The major contributions derived from this work are of significant aid in process simulation model with high accuracy and process optimization based on the selected most important sites to maintain high quality and stable production for corn to sugar processes.

关键词： big data     corn to sugar factory     neural network     variable importance analysis    

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On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate

Hui Ching FAN, Hong Sen YAN

《机械工程前沿（英文）》 2012年 第7卷 第1期   页码 5-15 doi: 10.1007/s11465-012-0310-y

摘要：

Without modifying the cam contour, a cam mechanism with a variable input speed trajectory offers an alternative solution to flexibly achieve kinematic and dynamic characteristics, and then decrease the follower’s residual vibration. Firstly, the speed trajectory of cam is derived by employing Bezier curve, and motion continuity conditions are investigated. Then the motion characteristics between the plate cam and its roller follower are derived. To analyze the residual vibration, a single degree of freedom dynamic model of the elastic cam-follower system is introduced. Based on the motion equation derived from the dynamic model, the residual vibration of the follower is yielded. The design procedure to improve the kinematic and dynamic motion characteristics is presented and two design examples with discussions are provided. Finally, the simulations of the kinematic and dynamic models by ADAMS are carried out and verified that the design models as well as the performances of the mechanism are feasible.

关键词： cam mechanism     variable input speed     kinematic design     dynamic design     optimal design    

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Lifecycle carbon footprint and cost assessment for coal-to-liquid coupled with carbon capture, storage

《能源前沿（英文）》 2023年 第17卷 第3期   页码 412-427 doi: 10.1007/s11708-023-0879-3

摘要： The coal-to-liquid coupled with carbon capture, utilization, and storage technology has the potential to reduce CO2 emissions, but its carbon footprint and cost assessment are still insufficient. In this paper, coal mining to oil production is taken as a life cycle to evaluate the carbon footprint and levelized costs of direct-coal-to-liquid and indirect-coal-to-liquid coupled with the carbon capture utilization and storage technology under three scenarios: non capture, process capture, process and public capture throughout the life cycle. The results show that, first, the coupling carbon capture utilization and storage technology can reduce CO2 footprint by 28%–57% from 5.91 t CO2/t·oil of direct-coal-to-liquid and 24%–49% from 7.10 t CO2/t·oil of indirect-coal-to-liquid. Next, the levelized cost of direct-coal-to-liquid is 648–1027 $/t of oil, whereas that of indirect-coal-to-liquid is 653–1065 $/t of oil. When coupled with the carbon capture utilization and storage technology, the levelized cost of direct-coal-to-liquid is 285–1364 $/t of oil, compared to 1101–9793 $/t of oil for indirect-coal-to-liquid. Finally, sensitivity analysis shows that CO2 transportation distance has the greatest impact on carbon footprint, while coal price and initial investment cost significantly affect the levelized cost of coal-to-liquid.

关键词： coal-to-liquid     carbon capture     utilization and storage (CCUS)     carbon footprint     levelized cost of liquid     lifecycle assessment    

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Mechanical design and analysis of a novel variable stiffness actuator with symmetrical pivot adjustment

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 711-725 doi: 10.1007/s11465-021-0647-1

摘要： The safety of human–robot interaction is an essential requirement for designing collaborative robotics. Thus, this paper aims to design a novel variable stiffness actuator (VSA) that can provide safer physical human–robot interaction for collaborative robotics. VSA follows the idea of modular design, mainly including a variable stiffness module and a drive module. The variable stiffness module transmits the motion from the drive module in a roundabout manner, making the modularization of VSA possible. As the key component of the variable stiffness module, a stiffness adjustment mechanism with a symmetrical structure is applied to change the positions of a pair of pivots in two levers linearly and simultaneously, which can eliminate the additional bending moment caused by the asymmetric structure. The design of the double-deck grooves in the lever allows the pivot to move freely in the groove, avoiding the geometric constraint between the parts. Consequently, the VSA stiffness can change from zero to infinity as the pivot moves from one end of the groove to the other. To facilitate building a manipulator in the future, an expandable electrical system with a distributed structure is also proposed. Stiffness calibration and control experiments are performed to evaluate the physical performance of the designed VSA. Experiment results show that the VSA stiffness is close to the theoretical design stiffness. Furthermore, the VSA with a proportional–derivative feedback plus feedforward controller exhibits a fast response for stiffness regulation and a good performance for position tracking.

关键词： variable stiffness actuator     variable stiffness module     drive module     symmetrical structure     double-deck grooves     expandable electrical system    

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Floating production storage and offloading systems’ cost and motion performance: A systems thinking application

Rini NISHANTH, Andrew WHYTE, V. John KURIAN

《工程管理前沿（英文）》 2018年 第5卷 第3期   页码 357-368 doi: 10.15302/J-FEM-2018022

摘要：

Floating production storage and offloading (FPSO) units increasingly represent a practical and economic means for deep-water oil extraction and production. Systems thinking gives a unique opportunity to seek a balance between FPSO technical performance(s), with whole-cost; stakeholder decision-making is charged to align different fit-for-use design specification options’ that address technical-motion(s), with respective life-cycle cost analyses (LCCA). Soft system methodology allows situation based analyses over set periods-of-time by diagnosing the problem-at-hand; namely, assessing the antecedents of life-cycle cost relative to FPSO sub-component design alternatives. Alternative mooring- component comparisons for either new-build hulls or refurbished hulls represent an initial necessary consideration to facilitate extraction, production and storage of deep-water oil reserves. Coupled dynamic analysis has been performed to generate FPSO motion in six degrees of freedom using SESAM DeepC, while life-cycle cost analysis (LCAA) studies give net-present-value comparisons reflective of market conditions. A parametric study has been conducted by varying wave heights from 4 – 8 m to understand FPSO motion behavior in the presence of wind and current, as well as comparing the motions of turreted versus spread mooring design alternatives. LCCA data has been generated to compare the cost of such different mooring options/hull conditions over 10 and 25-year periods. Systems thinking has been used to explain the interaction of problem variables; resultantly this paper is able to identify explicit factors affecting the choice of FPSO configurations in terms of motion and whole-cost, toward assisting significantly with the front-end engineering design (FEED) phase of fit-for-purpose configured FPSOs, in waters off Malaysia and Australia.

关键词： FPSO     LCCA     spread/turret-mooring     DeepC     cost     motion     soft-systems    

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三参数区间数研究及其在决策分析中的应用

胡启洲,张卫华,于莉

《中国工程科学》 2007年 第9卷 第3期   页码 47-51

摘要：

在定义三参数区间数的基础上，给出了三参数区间数的运算关系；然后将权重为区间数的多指标决 策问题转化为指标取值为三参数区间数的多指标决策问题；在三参数区间数理想方案点定义的基础上，给出了 权重为三参数区间数的逼近理想点法；最后将其应用于某城市公交线网的优化调整中。结果表明，该法科学合理、切实可行。

关键词： 多指标决策     三参数区间数     逼近理想点法    

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Convective heat transfer in helical coils for constant-property and variable-property flows with high

Yufei MAO, Liejin GUO, Bofeng BAI, Ximin ZHANG

《能源前沿（英文）》 2010年 第4卷 第4期   页码 546-552 doi: 10.1007/s11708-010-0116-8

摘要： Forced convection heat transfer of single-phase water in helical coils was experimentally studied. The testing section was constructed from a stainless steel round tube with an inner diameter of 10 mm, coil diameter of 300 mm, and pitch of 50 mm. The experiments were conducted over a wide Reynolds number range of 40000 to 500000. Both constant-property flows at normal pressure and variable-property flows at supercritical pressure were investigated. The contribution of secondary flow in the helical coil to heat transfer was gradually suppressed with increasing Reynolds number. Hence, heat transfer coefficients of the helical tube were close to those of the straight tube under the same flow conditions when the Reynolds number is large enough. Based on the experimental data, heat transfer correlations for both incompressible flows and supercritical fluid flows through helical coils were proposed.

关键词： convective heat transfer     helical coils     high Reynolds number     supercritical pressure     variable property    

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标题 作者 时间 类型 操作

Optimization design of anti-seismic engineering measures for intake tower based on non-dominated sorting genetic algorithm-II

期刊论文

应用型工程造价专业人才培养模式的探索与实践——以天津理工大学为例

尹贻林,白 娟

期刊论文

Performance of seven highway construction contracting methods analyzed by project size

Yuanxin ZHANG, Abdol CHINI, R. Edward MINCHIN Jr., Lourdes PTSCHELINZEW, Dev SHAH

期刊论文

Mechanical design, modeling, and identification for a novel antagonistic variable stiffness dexterous

期刊论文

Effect of variable heat capacities on performance of an irreversible Miller heat engine

Xingmei YE

期刊论文

Life-cycle cost analysis of optimal timing of pavement preservation

Zilong WANG,Hao WANG

期刊论文

斜井全断面变径滑模新工艺——在三峡工程永久船闸地下输水系统斜井砼施工中的应用

周宇,钱兴喜,樊启祥,廖建新

期刊论文

Comparative cost analysis of three different anesthesia methods in gynecological laparoscopic surgery

null

期刊论文

A neural network-based production process modeling and variable importance analysis approach in corn

期刊论文

On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate

Hui Ching FAN, Hong Sen YAN

期刊论文

Lifecycle carbon footprint and cost assessment for coal-to-liquid coupled with carbon capture, storage

期刊论文

Mechanical design and analysis of a novel variable stiffness actuator with symmetrical pivot adjustment

期刊论文

Floating production storage and offloading systems’ cost and motion performance: A systems thinking application

Rini NISHANTH, Andrew WHYTE, V. John KURIAN

期刊论文

三参数区间数研究及其在决策分析中的应用

胡启洲,张卫华,于莉

期刊论文

Convective heat transfer in helical coils for constant-property and variable-property flows with high

Yufei MAO, Liejin GUO, Bofeng BAI, Ximin ZHANG

期刊论文