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Hybrid genetic algorithm for bi-objective resource-constrained project scheduling

Fikri KUCUKSAYACIGIL, Gündüz ULUSOY

《工程管理前沿（英文）》 2020年 第7卷 第3期   页码 426-446 doi: 10.1007/s42524-020-0100-x

摘要： In this study, we considered a bi-objective, multi-project, multi-mode resource-constrained project scheduling problem. We adopted three objective pairs as combinations of the net present value (NPV) as a financial performance measure with one of the time-based performance measures, namely, makespan ( ), mean completion time (MCT), and mean flow time (MFT) (i.e., min /max , min /max , and min /max ). We developed a hybrid non-dominated sorting genetic algorithm II (hybrid-NSGA-II) as a solution method by introducing a backward–forward pass (BFP) procedure and an injection procedure into NSGA-II. The BFP was proposed for new population generation and post-processing. Then, an injection procedure was introduced to increase diversity. The BFP and injection procedures led to improved objective functional values. The injection procedure generated a significantly high number of non-dominated solutions, thereby resulting in great diversity. An extensive computational study was performed. Results showed that hybrid-NSGA-II surpassed NSGA-II in terms of the performance metrics hypervolume, maximum spread, and the number of non-dominated solutions. Solutions were obtained for the objective pairs using hybrid-NSGA-II and three different test problem sets with specific properties. Further analysis was performed by employing cash balance, which was another financial performance measure of practical importance. Several managerial insights and extensions for further research were presented.

关键词： backward–forward scheduling     hybrid bi-objective genetic algorithm     injection procedure     maximum cash balance     multi-objective multi-project multi-mode resource-constrained project scheduling problem    

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Systematic screening procedure and innovative energy-saving design for ionic liquid-based extractive

《化学科学与工程前沿（英文）》 2023年 第17卷 第1期   页码 34-45 doi: 10.1007/s11705-022-2234-3

摘要： In the traditional extractive distillation process, organic solvents are often used as entrainers. However, environmental influence and high energy-consumption are significant problems in industrial application. In this study, a systematic screening strategy and innovative energy-saving design for ionic liquid-based extractive distillation process was proposed. The innovative energy-saving design focused on the binary minimum azeotrope mixtures isopropanol and water. Miscibility, environmental impact and physical properties (e.g., melting point and viscosity) of 30 ionic liquids were investigated. 1-Ethyl-3-methyl-imidazolium dicyanamide and 1-butyl-3-methyl-imidazolium dicyanamide were selected as candidate entrainers. Feasibility analysis of these two ionic liquids was further performed via residue curve maps, isovolatility line and temperature profiles. An innovative ionic liquid-based extractive distillation process combining distillation column and stripping column was designed and optimized with the objective function of minimizing the total annualized cost. The results demonstrate that the total annualized cost was reduced by 19.9% with 1-ethyl-3-methyl-imidazolium dicyanamide as the entrainer and by 24.3% with 1-butyl-3-methyl-imidazolium dicyanamide, compared with that of dimethyl sulfoxide. The method proposed in this study is conducive to the green and sustainable development of extractive distillation process.

关键词： ionic liquid     entrainer screening     feasibility analysis     extractive distillation    

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Effects of combined procedure and devascularization alone on hyperdynamics of the portal venous system

HUA Rong, SUN Yongwei, WU Zhiyong

《医学前沿（英文）》 2008年 第2卷 第3期   页码 244-247 doi: 10.1007/s11684-008-0046-6

摘要： Shunts and devascularizations have totally different effects on the hemodynamics of the portal venous system. The actual results of pericardial devascularization (PCDV) alone and conventional splenorenal shunt combined with pericardial devascularization (combined procedure, CP) should be determined by more clinical observations. This study aimed to evaluate effects on hemodynamics in the portal venous system after CP and PCDV only. In 20 patients who received CP and 18 who received PCDV, hemodynamic parameters of the portal venous system were studied by magnetic resonance angiography 1 week before and 2 weeks after operation. Free portal pressure (FPP) was continuously detected by a transducer during the operations. Compared to the preoperative data, a decreased flow in the portal vein (PVF) [(563.12 ± 206.42) mL/min (1080.63 ± 352.85) mL/min, < 0.05], a decreased portal vein diameter (PVD) [(1.20 ± 0.11) cm (1.30 ± 0.16) cm, < 0.01], a decreased FPP [(21.50 ± 2.67) mmHg (29.88 ± 2.30) mmHg, < 0.01] and an increased flow in the superior mesenteric vein (SMVF) [(1105.45 ± 309.03) mL/min (569.13 ± 178.46) mL/min, < 0.05] were found in the CP group after operation; a decreased PVD [(1.27 ± 0.16) cm (1.40 ± 0.23) cm, < 0.05], a decreased PVF [(684.60 ± 165.73) mL/min (1175.64 ± 415.09) mL/min, < 0.05], a decreased FPP [(24.40 ± 3.78) mmHg (28.80 ± 3.56) mmHg, < 0.05] and an increased SMVF [(697.91 ± 121.83) mL/min (521.30 ± 115.82) mL/min, < 0.05] were observed in the PCDV group. After operation, PVF in the CP group [(563.12 ± 206.42) mL/min (684.60 ± 165.73) mL/min, > 0.05] had no significant decrease, while FPP [(21.50 ± 2.67) mmHg (24.40 ± 3.78) mmHg, < 0.01] had a significant decrease as compared with that in the PCDV group. PVF and FPP could be decreased by both surgical procedures, but the effect of decreasing FPP was much better in the combined procedure than in PCDV alone. Further, there was no significant difference in PVF between the two groups. It is suggested that the combined surgical procedure could integrate the advantages of shunting with those of devascularization, as well as maintaining the normal anatomic structure of hepatic portal system, thus it should be one of the best choices for patients with portal hypertension when surgical interventions are considered.
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Three-dimensional numerical simulation for plastic injection-compression molding

Yun ZHANG, Wenjie YU, Junjie LIANG, Jianlin LANG, Dequn LI

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 74-84 doi: 10.1007/s11465-018-0490-1

摘要：

Compared with conventional injection molding, injection-compression molding can mold optical parts with higher precision and lower flow residual stress. However, the melt flow process in a closed cavity becomes more complex because of the moving cavity boundary during compression and the nonlinear problems caused by non-Newtonian polymer melt. In this study, a 3D simulation method was developed for injection-compression molding. In this method, arbitrary Lagrangian-Eulerian was introduced to model the moving-boundary flow problem in the compression stage. The non-Newtonian characteristics and compressibility of the polymer melt were considered. The melt flow and pressure distribution in the cavity were investigated by using the proposed simulation method and compared with those of injection molding. Results reveal that the fountain flow effect becomes significant when the cavity thickness increases during compression. The back flow also plays an important role in the flow pattern and redistribution of cavity pressure. The discrepancy in pressures at different points along the flow path is complicated rather than monotonically decreased in injection molding.

关键词： injection-compression molding     simulation     injection molding     melt flow     cavity pressure    

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density measurement for plastic injection molding via ultrasonic technology

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0714-2

摘要： Density variation during the injection molding process directly reflects the state of plastic melt and contains valuable information for process monitoring and optimization. Therefore, in-situ density measurement is of great interest and has significant application value. The existing methods, such as pressure−volume−temperature (PVT) method, have the shortages of time-delay and high cost of sensors. This study is the first to propose an in-situ density measurement method using ultrasonic technology. The analyses of the time-domain and frequency-domain signals are combined in the proposed method. The ultrasonic velocity is obtained from the time-domain signals, and the acoustic impedance is computed through a full-spectral analysis of the frequency-domain signals. Experiments with different process conditions are conducted, including different melt temperature, injection speed, material, and mold structure. Results show that the proposed method has good agreement with the PVT method. The proposed method has the advantages of in-situ measurement, non-destructive, high accuracy, low cost, and is of great application value for the injection molding industry.

关键词： ultrasonic measurement     melt density     in-situ measurement     injection molding    

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凝析气藏的经济开采模式

刘廷元

《中国工程科学》 2001年 第3卷 第3期   页码 85-91

摘要：

液态凝析油是凝析气藏的重要产品，它的开采应该是有效而经济的。介绍了国外近20 a来在凝析气藏开采技术领域的各种经济模式，包括回注φd=75%干气、自流回注、注N2、注水、水气交替注和注CO2等开采模式。研究结果表明，这些开采模式同传统的降压开采方法相比，能够有效地适应地面-地下的各种复杂情况。

关键词： 凝析气藏     开采模式     注气     注氮     注水     注二氧化碳     经济    

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A dynamic procedure based on the scale-similarity hypotheses for large-eddy simulation

ZHOU Bing, CUI Guixiang, CHEN Naixiang

《能源前沿（英文）》 2007年 第1卷 第4期   页码 468-472 doi: 10.1007/s11708-007-0069-z

摘要： Current dynamic procedures in large-eddy simulation treat the two subgrid-scale stresses in the Germano identity with the same subgrid base model. Thus to get the base model coefficient, the coefficient must be assumed to be consta

关键词： large-eddy simulation     Germano identity     coefficient     subgrid-scale    

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Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 171-175 doi: 10.1007/s11465-009-0091-0

摘要： Trend prediction technology is the key technology to achieve condition-based maintenance of mechanical equipment. Large-sized water injection units are key equipment in oilfields. The traditional preventive maintenance is not economical and cannot completely avoid vicious accidents. To ensure the normal operation of units and save maintenance costs, trend prediction technology is studied to achieve condition-based maintenance for water injection units. The main methods of the technology are given, the trend prediction method based on neural network is put forward, and the expert system based on the knowledge is developed. The industrial site verification shows that the proposed trend prediction technology can reflect the operating condition trend change of the water injection units and provide technical means to achieve condition-based predictive maintenance.

关键词： water injection units     condition-based maintenance     trend prediction    

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新建有岩爆倾向硬岩矿床采矿技术研究工作程序

郭然,于润沧

《中国工程科学》 2002年 第4卷 第7期   页码 51-55

摘要：

目前矿山的岩爆研究工作大都是围绕着如何预报和防治岩爆展开的，针对如何开展新建或尚未发生过岩爆矿山的岩爆研究工作不多。文章重点探讨了新建有岩爆倾向硬岩矿床开采技术研究工作程序，为建立有岩爆倾向深赋硬岩矿床采矿理论体系奠定了基础。

关键词： 岩爆     采矿技术     工作程序    

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过程神经元网络的若干理论问题

何新贵,梁久祯

《中国工程科学》 2000年 第2卷 第12期   页码 40-44

摘要：

文章提出一种过程神经元模型，其输人为与时间有关的函数或过程，它是传统人工神经元模型在时间域上的扩展。基于这种过程神经元模型，给出了一种仅含一个隐层的前馈型过程神经网络模型，即基展开过程神经元网络模型。证明了相应的连续性定理，逼近定理，计算能力定理等。

关键词： 过程神经元网络     函数逼近能力     计算能力     连续性    

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Intelligent methods for the process parameter determination of plastic injection molding

Huang GAO, Yun ZHANG, Xundao ZHOU, Dequn LI

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 85-95 doi: 10.1007/s11465-018-0491-0

摘要：

Injection molding is one of the most widely used material processing methods in producing plastic products with complex geometries and high precision. The determination of process parameters is important in obtaining qualified products and maintaining product quality. This article reviews the recent studies and developments of the intelligent methods applied in the process parameter determination of injection molding. These intelligent methods are classified into three categories: Case-based reasoning methods, expert system-based methods, and data fitting and optimization methods. A framework of process parameter determination is proposed after comprehensive discussions. Finally, the conclusions and future research topics are discussed.

关键词： injection molding     intelligent methods     process parameters     optimization    

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三峡升船机船厢室施工程序研究

曾明

《中国工程科学》 2013年 第15卷 第9期   页码 40-44

摘要：

针对三峡升船机船厢室平衡重和船厢荷载的施加顺序对塔柱埋件结构部位变形的影响，对船厢室的施工顺序和设备安装顺序方案进行了研究，解决了船厢和平衡重荷载的施加顺序对螺母柱、齿条和纵向导向变位影响的施工技术难题。根据对塔柱结构进行的仿真计算结果，分析了船厢与平衡重荷载施加顺序分别对螺母柱、齿条、纵向导向部位横河向、顺河向和竖向变形的影响，通过对施工程序优化提出了合理的升船机船厢室的施工程序以及施工总进度计划安排。该施工程序能够使螺母柱、齿条、纵向导向、船厢结构与塔柱在各工况下的位移满足安全要求，并且基于该施工程序的施工进度满足升船机试运行要求。工程实践证明了本文所建立的三峡升船机船厢室施工程序的合理性与科学性，确保了三峡升船机船厢室的顺利施工，保障了升船机的安全运行，可为类似升船机船厢室的施工提供参考。

关键词： 施工程序     船厢室     升船机     三峡工程    

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New concept and procedure for reliability assessment of an IEC 61850 based substation and distribution

Hosein HAYATI,Amir AHADI,Seyed Mohsen MIRYOUSEFI AVAL

《能源前沿（英文）》 2015年 第9卷 第4期   页码 387-398 doi: 10.1007/s11708-015-0382-6

摘要： Smart grid is a power grid consists of extensive monitoring systems which deal with the monitoring of attributes such as current, voltage, power, and energy at distribution transformers, substations transformers, distribution switching devices and smart meters. Smart grid with advanced communication technologies can be used for several purposes such as efficiency and reliability improvement. IEC 61850 is the core standard in the smart grid domain for distribution and substation automation. This paper introduces a vision of modern substation and distribution systems using the IEC 61850. Network operators mainly assume that the modern substation and distribution systems based on the IEC 61850 are reliable for a long-time of operation. However, similar to any other systems, the implemented IEC 61850 might fail because of the operational failures or aging failures. This paper proposes a novel method for reliability evaluation of modern substation and distribution systems. A typical IEC 61850 based distribution and substation system is developed and analyzed using the proposed method. The fault tree analysis (FTA) is used to quantify the reliability of the system. The technique is implemented and demonstrated on the Roy Billinton test system (RBTS). The analysis is further extended on a 400/63 kV substation with a breaker- and-a-half configuration. In addition, the technique proves to be robust under different operations. The results verify the feasibility and applicability of the proposed method.

关键词： IEC 61850     reliability assessment     fault tree analysis    

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methodology for regulating fuel stratification and improving fuel economy of GCI mode via double main-injection

《能源前沿（英文）》 2023年 第17卷 第5期   页码 678-691 doi: 10.1007/s11708-022-0859-z

摘要： Gasoline compression ignition (GCI) combustion faces problems such as high maximum pressure rise rate (MPRR) and combustion deterioration at high loads. This paper aims to improve the engine performance of the GCI mode by regulating concentration stratification and promoting fuel-gas mixing by utilizing the double main-injection (DMI) strategy. Two direct injectors simultaneously injected gasoline with an octane number of 82.7 to investigate the energy ratio between the two main-injection and exhaust gas recirculation (EGR) on combustion and emissions. High-load experiments were conducted using the DMI strategy and compared with the single main-injection (SMI) strategy and conventional diesel combustion. The results indicate that the DMI strategy have a great potential to reduce the MPRR and improve the fuel economy of the GCI mode. At a 10 bar indicated mean effective pressure, increasing the main-injection-2 ratio (Rm-2) shortens the injection duration and increases the mean mixing time. Optimized Rm-2 could moderate the trade-off between the MPRR and the indicated specific fuel consumption with both reductions. An appropriate EGR should be adopted considering combustion and emissions. The DMI strategy achieves a highly efficient and stable combustion at high loads, with an indicated thermal efficiency (ITE) greater than 48%, CO and THC emissions at low levels, and MPRR within a reasonable range. Compared with the SMI strategy, the maximum improvement of the ITE is 1.5%, and the maximum reduction of MPRR is 1.5 bar/°CA.

关键词： gasoline compression ignition     injection strategy     fuel stratification     high efficiency     high load    

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CO, N, and CO/N mixed gas injection for enhanced shale gas recovery and CO geological storage

《能源前沿（英文）》 2023年 第17卷 第3期   页码 428-445 doi: 10.1007/s11708-023-0865-9

摘要： In this work, using fractured shale cores, isothermal adsorption experiments and core flooding tests were conducted to investigate the performance of injecting different gases to enhance shale gas recovery and CO2 geological storage efficiency under real reservoir conditions. The adsorption process of shale to different gases was in agreement with the extended-Langmuir model, and the adsorption capacity of CO2 was the largest, followed by CH4, and that of N2 was the smallest of the three pure gases. In addition, when the CO2 concentration in the mixed gas exceeded 50%, the adsorption capacity of the mixed gas was greater than that of CH4, and had a strong competitive adsorption effect. For the core flooding tests, pure gas injection showed that the breakthrough time of CO2 was longer than that of N2, and the CH4 recovery factor at the breakthrough time (RCH4) was also higher than that of N2. The RCH4 of CO2 gas injection was approximately 44.09%, while the RCH4 of N2 was only 31.63%. For CO2/N2 mixed gas injection, with the increase of CO2 concentration, the RCH4 increased, and the RCH4 for mixed gas CO2/N2 = 8:2 was close to that of pure CO2, about 40.24%. Moreover, the breakthrough time of N2 in mixed gas was not much different from that when pure N2 was injected, while the breakthrough time of CO2 was prolonged, which indicated that with the increase of N2 concentration in the mixed gas, the breakthrough time of CO2 could be extended. Furthermore, an abnormal surge of N2 concentration in the produced gas was observed after N2 breakthrough. In regards to CO2 storage efficiency (Sstorage-CO2), as the CO2 concentration increased, Sstorage-CO2 also increased. The Sstorage-CO2 of the pure CO2 gas injection was about 35.96%, while for mixed gas CO2/N2 = 8:2, Sstorage-CO2 was about 32.28%.

关键词： shale gas     gas injection     competitive adsorption     enhanced shale gas recovery     CO2 geological storage    

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标题 作者 时间 类型 操作

Hybrid genetic algorithm for bi-objective resource-constrained project scheduling

Fikri KUCUKSAYACIGIL, Gündüz ULUSOY

期刊论文

Systematic screening procedure and innovative energy-saving design for ionic liquid-based extractive

期刊论文

Effects of combined procedure and devascularization alone on hyperdynamics of the portal venous system

HUA Rong, SUN Yongwei, WU Zhiyong

期刊论文

Three-dimensional numerical simulation for plastic injection-compression molding

Yun ZHANG, Wenjie YU, Junjie LIANG, Jianlin LANG, Dequn LI

期刊论文

density measurement for plastic injection molding via ultrasonic technology

期刊论文

凝析气藏的经济开采模式

刘廷元

期刊论文

A dynamic procedure based on the scale-similarity hypotheses for large-eddy simulation

ZHOU Bing, CUI Guixiang, CHEN Naixiang

期刊论文

Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

期刊论文

新建有岩爆倾向硬岩矿床采矿技术研究工作程序

郭然,于润沧

期刊论文

过程神经元网络的若干理论问题

何新贵,梁久祯

期刊论文

Intelligent methods for the process parameter determination of plastic injection molding

Huang GAO, Yun ZHANG, Xundao ZHOU, Dequn LI

期刊论文

三峡升船机船厢室施工程序研究

曾明

期刊论文

New concept and procedure for reliability assessment of an IEC 61850 based substation and distribution

Hosein HAYATI,Amir AHADI,Seyed Mohsen MIRYOUSEFI AVAL

期刊论文

methodology for regulating fuel stratification and improving fuel economy of GCI mode via double main-injection

期刊论文

CO, N, and CO/N mixed gas injection for enhanced shale gas recovery and CO geological storage

期刊论文