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Lightweight design of an electric bus body structure with analytical target cascading

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0718-y

摘要: Lightweight designs of new-energy vehicles can reduce energy consumption, thereby improving driving mileage. In this study, a lightweight design of a newly developed multi-material electric bus body structure is examined in combination with analytical target cascading (ATC). By proposing an ATC-based two-level optimization strategy, the original lightweight design problem is decomposed into the system level and three subsystem levels. The system-level optimization model is related to mass minimization with all the structural modal frequency constraints, while each subsystem-level optimization model is related to the sub-structural performance objective with sub-structure mass constraints. To enhance the interaction between two-level systems, each subsystem-level objective is reformulated as a penalty-based function coordinated with the system-level objective. To guarantee the accuracy of the model-based analysis, a finite element model is validated through experimental modal test. A sequential quadratic programming algorithm is used to address the defined optimization problem for effective convergence. Compared with the initial design, the total mass is reduced by 49 kg, and the torsional stiffness is increased by 17.5%. In addition, the obtained design is also validated through strength analysis.

关键词: electric vehicle     body in white (BIW)     lightweight     analytical target cascading (ATC)    

Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distribution

L. RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

《能源前沿(英文)》 2012年 第6卷 第1期   页码 47-56 doi: 10.1007/s11708-011-0159-5

摘要: The advancement in power distribution system poses a great challenge to power engineering researchers on how to best monitor and estimate the state of the distribution network. This paper is executed in two stage processes. The first stage is to identify the optimal location for installation of monitoring instrument with minimal investment cost. The second stage is to estimate the bus voltage magnitude, where real time measurement is conducted and measured through identified meter location which is more essential for decision making in distribution supervisory control and data acquisition system (DSCADA). The hybrid intelligent technique is applied to execute the above two algorithms. The algorithms are tested with institute of electrical and electronics engineers (IEEE) and Tamil Nadu electricity board (TNEB) benchmark systems. The simulated results proves that the swarm tuned artificial neural network (ANN) estimator is best suited for accurate estimation of voltage with different noise levels.

关键词: artificial intelligence     power distribution control     state estimation    

Fracture resistance on aggregate bridging crack in concrete

ZHANG Xiufang, XU Shilang

《结构与土木工程前沿(英文)》 2007年 第1卷 第1期   页码 63-70 doi: 10.1007/s11709-007-0006-2

摘要: Fracture toughening exhibited in quasi-brittle materials such as concrete is often mainly related to the action of aggregate bridging, which leads to the presence of a fracture process zone ahead of stress-free cracks in such materials. In this investigation, the fracture resistance induced by aggregate bridging, denoted by GI-bridging, is the primary focus. In order to quantitatively determine it, a general analytical formula is firstly developed, based on the definition of fracture energy by Hillerborg. After this, we further present the calculated procedures of determining this fracture resistance from the recorded load vs. crack opening displacement curve. Then, both numerical simulations and fracture experiments are performed on concrete three-point bending beams. Utilizing the obtained load against crack opening displacement curve, the value of G at any crack extension as well as the change of G with the crack extension is examined. It is found that G will firstly increase with the development of crack and then stay constant once the initial crack tip opening displacement reaches the characteristic crack opening displacement w0. The effects of material strength and specimen depth on this fracture resistance are also investigated. The results reveal that the values of G of different specimens at any crack propagation are strongly associated with the values of fracture energy of specimens. If the values of fracture energy between different specimens are comparable, the differences between G are ignored. Instead, if values of fracture energy are different, the G will be different. This shows that for specimens with different strengths, G will change greatly whereas for specimens that are different in depth, whether GI-bridging exhibits size effect depends on whether the fracture energy of specimens considered in the calculation of G is assumed to be a size-dependent material parameter.

Urban constructed wetlands: Assessing ecosystem services and disservices for safe, resilient, and sustainable

《工程管理前沿(英文)》   页码 582-596 doi: 10.1007/s42524-023-0268-y

摘要: Climate change and rapid urbanization are pressing environmental and social concerns, with approximately 56% of the global population living in urban areas. This number is expected to rise to 68% by 2050, leading to the expansion of cities and encroachment upon natural areas, including wetlands, causing their degradation and fragmentation. To mitigate these challenges, green and blue infrastructures (GBIs), such as constructed wetlands, have been proposed to emulate and replace the functions of natural wetlands. This study evaluates the potential of eight constructed wetlands near Beijing, China, focusing on their ecosystem services (ESs), cost savings related to human health, growing/maintenance expenses, and disservices using an emergy-based assessment procedure. The results indicate that all constructed wetlands effectively purify wastewater, reducing nutrient concentrations (e.g., total nitrogen, total phosphorus, and total suspended solids). Among the studied wetlands, the integrated vertical subsurface flow constructed wetland (CW-4) demonstrates the highest wastewater purification capability (1.63E+14 sej/m2/yr) compared to other types (6.78E+13 and 2.08E+13 sej/m2/yr). Additionally, constructed wetlands contribute to flood mitigation, groundwater recharge, wildlife habitat protection, and carbon sequestration, resembling the functions of natural wetlands. However, the implementation of constructed wetlands in cities is not without challenges, including greenhouse gas emissions, green waste management, mosquito issues, and disturbances in the surrounding urban areas, negatively impacting residents. The ternary phase diagram reveals that all constructed wetlands provide more benefits than costs and impacts. CW-4 shows the highest benefit‒cost ratio, reaching 50%, while free water surface constructed wetland (CW-3) exhibits the lowest benefits (approximately 38%), higher impacts (approximately 25%), and lower costs (approximately 37%) compared to other wetlands. The study advocates the use of an emergy approach as a reliable method to assess the quality of constructed wetlands, providing valuable insights for policymakers in selecting suitable constructed wetlands for effective urban ecological management.

关键词: constructed wetland     emergy     ecosystem services     disservices     ternary diagram    

Project management maturity in construction consulting services: Case of Expo in China

Yongkui LI, Qing YANG, Yan ZHANG

《工程管理前沿(英文)》 2020年 第7卷 第3期   页码 384-395 doi: 10.1007/s42524-019-0070-z

摘要: For many years, project management maturity models (PMMM) derived from the software industry have brought immeasurable benefits. However, the adoption and investigation of PMMM in the construction field have been weak and insufficient, particularly in construction consulting services (CCS). Moreover, professionals have gradually realized the importance of non-process factors (e.g., teamwork, culture, leadership) in the evaluation of PMMM. This study describes the construction of PMMM for CCS that considers non-process factors and combines them with CCS-specific process factors. To verify the effectiveness of the proposed model, we conduct a case study on the overall project management consultancy for China’s 2010 Winter Expo. The results would fill in the PMMM research gap in CCS and provide practitioners with ideas to improve their performance.

关键词: construction consulting services     project management maturity model     non-process factors     Expo    

全生命周期成本分析框架下的电动公交充电器部署和车队管理 Article

曾子凌, 王帅安, 曲小波

《工程(英文)》 2023年 第21卷 第2期   页码 45-60 doi: 10.1016/j.eng.2022.07.019

摘要:

尽管城市交通电气化快速发展,但电池电动公交车(EB)车队的系统规划和管理进展却较为落后。本研究首先综述了影响电池电动系统的基本问题,包括充电站部署、电池尺寸、公交车调度和生命周期分析。目前,EB系统的规划和运行是按顺序进行的,公交车调度是在公交车队和基础设施部署完毕后进行的,这导致了资源利用率低和资源浪费。对此,本文提出了混合整数规划模型整合充电站部署和公交车队管理,以尽可能低的生命周期成本(LCC),包括所有权、运营、维护和排放费用,缩小最佳规划与运营之间的差距。引入了分支定价算法,以减少寻找最佳解决方案所需的计算工作量。本研究还通过分析真实案
例,与目前的公交运营策略和充电站布局相比,一条公交线路的LCC优化后可显著降低30.4%。提出的方法不仅可以进行生命周期分析,还可以为交通部门和运营商提供可靠的充电桩部署及单线和多线的公交调度计划,这两者都是未来具有高电气化普及率的交通系统中决策支持的关键要求,此研究也有助于推动可持续交通的发展。

关键词: 电动公交车     充电站部署     电池尺寸     公交车调度     生命周期分析    

Family planning technical services in China

Shang-Chun WU

《医学前沿(英文)》 2010年 第4卷 第3期   页码 285-289 doi: 10.1007/s11684-010-0097-3

摘要: Family planning is a basic state policy in China. Its aim is to control population growth and to enhance population quality. Technical services are the key measures for implementing the family planning policy. In order to ensure that people use safe, effective, and appropriate contraceptive methods based on the government’s commitment, China has established countrywide family planning service networks down to the township level. The people can access various and convenient contraceptive services. In urban areas, all contraceptive services are free. The contraceptive prevalence rate in 2007 was 84.6%, the percentage of intrauterine device (IUD) was 52.3%, that of female sterilization was 32.3%, and that of vasectomy was 6.1%. This means that more than 90% of married childbearing couples were using long-term contraceptives. At the same time, the government gives priority to supporting research on contraceptive technology. Studies’ results have provided scientific evidence for development, introduction, and expansion of contraceptive methods, and also for establishment and revision of the technical guidelines. Great efforts have been made in promoting “human-oriented and client-centered” services during the recent ten years. Remarkable success has been achieved in improving the quality of technical services.

关键词: family planning     contraceptive method     service delivery    

基于CAN总线的TT-FPS调度算法研究及其性能分析

吕伟杰,刘鲁源,王毅新

《中国工程科学》 2006年 第8卷 第5期   页码 45-48

摘要:

针对CAN总线中消息在固定优先级调度(FPS)算法下传输不可预知、低优先级消息容易被阻塞的问题,提出了一种基于时间触发机制的固定优先级调度(TT-FPS)算法,给出了最糟糕响应时间的计算方法。然后以纯电动汽车消息系统为例进行了TT-FPS的性能分析,验证了TT-FPS 较FPS有更好的性能。

关键词: CAN总线     TT-FPS     最糟糕响应时间    

Review of self-referenced measurement algorithms: Bridging lateral shearing interferometry and multi-probe

Dede ZHAI, Shanyong CHEN, Ziqiang YIN, Shengyi LI

《机械工程前沿(英文)》 2017年 第12卷 第2期   页码 143-157 doi: 10.1007/s11465-017-0432-3

摘要:

With the development of new materials and ultra-precision processing technology, the sizes of measured objects increase, and the requirements for machining accuracy and surface quality become more exacting. The traditional measurement method based on reference datum is inadequate for measuring a high-precision object when the quality of the reference datum is approximately within the same order as that of the object. Self-referenced measurement techniques provide an effective means when the direct reference-based method cannot satisfy the required measurement or calibration accuracy. This paper discusses the reconstruction algorithms for self-referenced measurement and connects lateral shearing interferometry and multi-probe error separation. In lateral shearing interferometry, the reconstruction algorithms are generally categorized into modal or zonal methods. The multi-probe error separation techniques for straightness measurement are broadly divided into two-point and three-point methods. The common features of the lateral shearing interferometry method and the multi-probe error separation method are identified. We conclude that the reconstruction principle in lateral shearing interferometry is similar to the two-point method in error separation on the condition that no yaw error exists. This similarity may provide a basis or inspiration for the development of both classes of methods.

关键词: self-referenced measurement     lateral shearing interferometry     multi-probe error separation     surface metrology    

Optimization of urban bus operation frequency under common route condition with rail transit

Bin YU, Sijia REN, Enze WU, Yifan ZHOU, Yunpeng WANG

《工程管理前沿(英文)》 2017年 第4卷 第4期   页码 451-462 doi: 10.15302/J-FEM-2017036

摘要: The overlap of bus and rail transit routes is common in China. This overlap provides passengers multiple choices for one trip. However, the availability of multiple options would cause uncertainty in the travel distribution of passengers. Given that buses and rail transits are becoming increasingly common, this paper aims to present the overlapped operation condition of bus and rail transit using a bi-level model from the perspective of bus operators. Frequency optimization model is established in the upper-level model. A heuristic algorithm called shuffled complex evolution (SCE-UA) method is used to solve the established frequency optimization model, and three other heuristic methods are compared with SCE-UA. A lower-level Logit model based on Agent simulation is set for traffic mode split. Data on the transit system in Dalian city are chosen as an example to test the feasibility of the model and the algorithm. Results show that as the overlapped optimization of bus route and rail transit routes changed primary bus frequency, the use of SCE-UA to solve such problems has evident advantages and feasibility; furthermore, changed bus frequency would improve bus operations.

关键词: common route     bus operation frequency     bi-level model     Agent simulation     SCE-UA algorithm    

Investigating the effect of online and offline reputation on the provision of online counseling services

《工程管理前沿(英文)》   页码 563-576 doi: 10.1007/s42524-022-0198-0

摘要: The sustainable development of Internet hospitals and e-health platforms relies on the participation of patients and physicians, especially on the provision of health counseling services by physicians. The objective of our study is to explore the factors motivating Chinese physicians to provide online health counseling services from the perspectives of their online and offline reputation. We collect the data of 141029 physicians from 6173 offline hospitals located in 350 cities in China. Based on the reputation theory and previous studies, we incorporate patients’ feedback as physicians’ online reputation and incorporate physicians’ offline professional status as physicians’ offline reputation. Results show that physicians’ online reputation significantly and positively influence their online counseling behaviors, whereas physicians’ offline reputation significantly and negatively influence their online counseling behaviors. We conclude that physician’s online and offline reputations show a competitive and substitute relationship rather than a complementary relationship in influencing physicians to provide online counseling services in Internet hospitals. One possible explanation for the substitute relationship could be the constraints of limited time and effort of physicians.

关键词: Internet hospitals     physicians’ online counseling     online reputation     offline reputation    

Organophosphate esters in sediment from Taihu Lake, China: Bridging the gap between riverine sources

《环境科学与工程前沿(英文)》 2022年 第16卷 第3期 doi: 10.1007/s11783-021-1464-9

摘要:

• Eleven OPEs were detected in river sediment and lake sediment in Taihu Lake.

关键词: Organophosphate esters     Partition     Vertical distribution     Composition profile     Positive matrix factorization    

Socialized care services for the aged population: System construction and support measures

《工程管理前沿(英文)》 2023年 第10卷 第2期   页码 339-353 doi: 10.1007/s42524-022-0208-2

摘要: Given the aging society, an increase in social demand, information- and communication technology-driven culture, and government policy support emerges to enable the development of the socialized care services system for the aged (SCSSA). The development of the SCSSA would be a significant step toward addressing China’s aging population. However, the construction of the SCSSA challenges the theories and methods of traditional elderly care service system construction. Specifically, the implementation path for such elderly care service policies is unclear, the necessary technological support is insufficient, and the mechanism for integrating intelligent information technology remains underexplored. Thus, this paper focuses on the needs of the elderly, grounded in the context of the changing elderly care service policies in China, and proposes a research paradigm that integrates system construction and support measure embedding. We then construct the original SCSSA, which includes “material + spirit + medical treatment + healthcare” and propose a method of optimization and iteration. Finally, we build the research framework of systematic support measures from the perspectives of policy reconstruction, institutional embeddedness, and technical support. Our work provides theoretical support and practical guidance for the construction and dynamic optimization of the SCSSA, thus making a significant contribution that will help China effectively cope with its aging society.

关键词: socialized     care service for the elderly     system construction     support measure    

Lignin-based polymer with high phenolic hydroxyl group content prepared by the alkyl chain bridging method

《化学科学与工程前沿(英文)》 2023年 第17卷 第8期   页码 1075-1084 doi: 10.1007/s11705-022-2272-x

摘要: Inspired by the importance of the phenolic group to the electron transporting property of hole transport materials, phenolic hydroxyl groups were introduced in lignosulfonate (LS) via the alkyl chain bridging method to prepare phenolated-lignosulfonate (PLS). The results showed that the phenolic group was boosted from 0.81 mmol∙g–1 of LS to 1.19 mmol∙g–1 of PLS. The electrochemical property results showed two oxidation peaks in the cyclic voltammogram (CV) curve of PLS, and the oxidation potential of the PLS-modified electrode decreased by 0.5 eV compared with that of LS. This result indicates that PLS is more easily oxidized than LS. Based on the excellent electron transporting property of PLS, PLS was applied as a dopant in poly(3,4-ethylenedioxythiophene) (PEDOT, called PEDOT:PLSs). PLS showed excellent dispersion properties for PEDOT. Moreover, the transmittance measurement results showed that the transmittance of PEDOT:PLSs exceeded 85% in the range of 300–800 nm. The CV results showed that the energy levels of PEDOT:PLSs could be flexibly adjusted by PLS amounts. The results indicate that the phenolic hydroxyl group of lignin can be easily boosted by the alkyl chain bridging method, and phenolated lignin-based polymers may have promising potential as dopants of PEDOT to produce hole transporting materials for different organic photovoltaic devices.

关键词: lignosulfonate     phenolic group     PEDOT:PLS     hole extract layer     energy level    

State versus private sector provision of water services in Armenia

Naira HARUTYUNYAN

《环境科学与工程前沿(英文)》 2012年 第6卷 第5期   页码 620-630 doi: 10.1007/s11783-012-0425-8

摘要: Despite increasing advocacy and adaptation of public-private model of water governance worldwide since the 1990s, today only 5% of the world’s population is served by water utilities with private involvement. The present article examines the experience of the water sector in Armenia with private sector participation. The study describes the process of the introduction of public-private partnerships in the water sector and focuses on analyzing the impact of privatization on water utility performance. The analysis employs the partial indicator method for evaluating the impacts in relation to operational, finance, and environmental performance, done by drawing on the database for the five water companies in Armenia. The empirical evidence shows that private participation in general led to improved overall performance. In particular, private involvement resulted in increased operational efficiency in terms of labor productivity, water metering, continuity of service, and revenue collection efficiency. There were mixed improvements in the operating cost coverage ratio. As for environmental performance, there were gains in the reduction of residential water consumption, accompanied, however, by an increase in non-revenue water.

关键词: water governance     water privatization     public-private partnership     operational efficiency     Armenia     transition economy    

标题 作者 时间 类型 操作

Lightweight design of an electric bus body structure with analytical target cascading

期刊论文

Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distribution

L. RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

期刊论文

Fracture resistance on aggregate bridging crack in concrete

ZHANG Xiufang, XU Shilang

期刊论文

Urban constructed wetlands: Assessing ecosystem services and disservices for safe, resilient, and sustainable

期刊论文

Project management maturity in construction consulting services: Case of Expo in China

Yongkui LI, Qing YANG, Yan ZHANG

期刊论文

全生命周期成本分析框架下的电动公交充电器部署和车队管理

曾子凌, 王帅安, 曲小波

期刊论文

Family planning technical services in China

Shang-Chun WU

期刊论文

基于CAN总线的TT-FPS调度算法研究及其性能分析

吕伟杰,刘鲁源,王毅新

期刊论文

Review of self-referenced measurement algorithms: Bridging lateral shearing interferometry and multi-probe

Dede ZHAI, Shanyong CHEN, Ziqiang YIN, Shengyi LI

期刊论文

Optimization of urban bus operation frequency under common route condition with rail transit

Bin YU, Sijia REN, Enze WU, Yifan ZHOU, Yunpeng WANG

期刊论文

Investigating the effect of online and offline reputation on the provision of online counseling services

期刊论文

Organophosphate esters in sediment from Taihu Lake, China: Bridging the gap between riverine sources

期刊论文

Socialized care services for the aged population: System construction and support measures

期刊论文

Lignin-based polymer with high phenolic hydroxyl group content prepared by the alkyl chain bridging method

期刊论文

State versus private sector provision of water services in Armenia

Naira HARUTYUNYAN

期刊论文