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Value and governance of high-speed railway

Xiaoyan LIN, Zehua ZHANG, Meng WANG

《工程管理前沿（英文）》 2017年第4卷第4期页码 463-482 doi: 10.15302/J-FEM-2017054

摘要： This paper considers multiple perspectives to explore the concept of high-speed railway (HSR), rationally abstract its value formation mechanism, and quantitatively measure its actual performance. This paper analyzes the governance potential of major countries in the high-speed railway value chain and studies the feasible ways and development strategies to enhance the high-speed railway governance in China. Findings of this paper are as follows. First, the government, as the early manager of high-speed railway governance, has given way to Siemens and other integrated enterprises. Second, the high-speed railway standard output has become the core competitiveness that embodies high-speed railway. Third, the global high-speed railway market presents a hierarchical high-speed railway governance model and changes to a modular approach to governance.

关键词： high-speed railway value communication value high-speed railway value governance governance path upgrade

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卫星移动通信的现状与发展

张乃通,张中兆,初海彬,刘会杰

《中国工程科学》 2002年第4卷第10期页码 11-16

摘要：

介绍了国际上出现的三种星座通信系统，重点分析了几个具有代表性系统的组成、结构、功能及其存在的问题。探讨了卫星移动通信系统的发展趋势，并对发展卫星移动通信做了几点思考。

关键词：卫星移动通信星座通信系统宽带业务

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第三代移动通信——现代无线技术面向IP的应用

邬贺铨

《中国工程科学》 2000年第2卷第8期页码 69-75

摘要：

文章首先回顾了第一代（模拟）移动通信和第二代（数字）移动通信技术的演进，预测今后10年是移动通信大发展时期，它的用户将超过固定电话用户数。随着因特网的发展，移动通信业务将从话音扩展到数据，移动通信技术也将从电路模式发展到分组模式。文章在简介即将投入应用的第二代半移动通信技术之后，引出面向宽带多媒体应用的第三代移动通信（3GM），重点介绍了被选作3GM国际无线传输技术标准的几种主流方案及其关键技术，特别对其中由我国提交的TD-SCDMA方案的技术特点作了说明，最后展望了网络如何从第二代移动通信过渡到第三代移动通信及3GM核心网发展趋势。

关键词：移动通信第三代移动通信码分多址时分同步码分多址

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Special issue on 5G wireless communication systems and technologies Editorial

Ping ZHANG

《信息与电子工程前沿（英文）》 2017年第18卷第6期页码 751-752 doi: 10.1631/FITEE.1720000

摘要： None

关键词： None

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军事通信抗干扰工程发展策略研究及建议

姚富强

《中国工程科学》 2005年第7卷第5期页码 24-29

摘要：

在阐述军事通信抗干扰装备的覆盖范围和分析外军通信抗干扰发展趋势的基础上，结合我军正在进行的新军事变革和信息化建设，重点研究了我军通信抗干扰工程发展策略的有关问题，并提出了一些初步的建议。

关键词：军事通信抗干扰电子防御

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Value Engineering/Value Management Model and Application of Aerospace Projects

Wan-hua Qiu,Han-peng Zhang,Ze-Shui Xu,De-Sheng Wu

《工程管理前沿（英文）》 2015年第2卷第4期页码 373-377 doi: 10.15302/J-FEM-2015056

摘要： This paper presents a new space model developed by general value engineering/value management model. The authors take the function analysis, function optimization and function realization of the development object as the basic point, to get the final optimization structure by value evaluation, so as to improve the project quality and reduce the project cost. The final case shows that the application of this model can save about 18% of the time and considerable cost of the usually planned projects under the condition of quality assurance.

关键词： aerospace project value engineering value optimization value stream design structure matrix

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Higher heating value prediction of torrefaction char produced from non-woody biomass

Nitipong SOPONPONGPIPAT,Dussadeeporn SITTIKUL,Unchana SAE-UENG

《能源前沿（英文）》 2015年第9卷第4期页码 461-471 doi: 10.1007/s11708-015-0377-3

摘要： The higher heating value of five types of non-woody biomass and their torrefaction char was predicted and compared with the experimental data obtained in this paper. The correlation proposed in this paper and the ones suggested by previous researches were used for prediction. For prediction using proximate analysis data, the mass fraction of fixed carbon and volatile matter had a strong effect on the higher heating value prediction of torrefaction char of non-woody biomass. The high ash fraction found in torrefied char resulted in a decrease in prediction accuracy. However, the prediction could be improved by taking into account the effect of ash fraction. The correlation developed in this paper gave a better prediction than the ones suggested by previous researches, and had an absolute average error (AAE) of 2.74% and an absolute bias error (ABE) of 0.52%. For prediction using elemental analysis data, the mass fraction of carbon, hydrogen, and oxygen had a strong effect on the higher heating value, while no relationship between the higher heating value and mass fractions of nitrogen and sulfur was discovered. The best correlation gave an AAE of 2.28% and an ABE of 1.36%.

关键词： higher heating value correlation biomass proximate analysis ultimate analysis

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现代通信技术的发展趋势

毕厚杰

《中国工程科学》 2000年第2卷第8期页码 31-34

摘要：

文章综合分析了通信网络、通信终端技术的发展趋势，着重指出我国加强通信软件产业化及发展EDA技术，以迎接入关（WTO）。

关键词：电信网分组化多媒体化移动化通信终端

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Modeling and simulating the impact of forgetting and communication errors on delays in civil infrastructure

Zhe SUN, Cheng ZHANG, Pingbo TANG

《工程管理前沿（英文）》 2021年第8卷第1期页码 109-121 doi: 10.1007/s42524-019-0084-6

摘要： Handoff processes during civil infrastructure operations are transitions between sequential tasks. Typical handoffs constantly involve cognitive and communication activities among operations personnel, as well as traveling activities. Large civil infrastructures, such as nuclear power plants (NPPs), provide critical services to modern cities but require regular or unexpected shutdowns (i.e., outage) for maintenance. Handoffs during such an outage contain interwoven workflows and communication activities that pose challenges to the cognitive and communication skills of handoff participants and constantly result in delays. Traveling time and changing field conditions bring additional challenges to effective coordination among multiple groups of people. Historical NPP records studied in this research indicate that even meticulous planning that takes six months before each outage could hardly guarantee sufficient back-up plans for handling various unexpected events. Consequently, delays frequently occur in NPP outages and bring significant socioeconomic losses. A synthesis of previous studies on the delay analysis of accelerated maintenance schedules revealed the importance and challenges of handoff modeling. However, existing schedule representation methods could hardly represent the interwoven communication, cognitive, traveling, and working processes of multiple participants collaborating on completing scheduled tasks. Moreover, the lack of formal models that capture how cognitive, waiting, traveling, and communication issues affect outage workflows force managers to rely on personal experiences in diagnosing delays and coordinating multiple teams involved in outages. This study aims to establish formal models through agent-based simulation to support the analytical assessment of outage schedules with full consideration of cognitive and communication factors involved in handoffs within the NPP outage workflows. Simulation results indicate that the proposed handoff modeling can help predict the impact of cognitive and communication issues on delays propagating throughout outage schedules. Moreover, various activities are fully considered, including traveling between workspaces and waiting. Such delay prediction capability paves the path toward predictive and resilience outage control of NPPs.

关键词： NPP outage human error team cognition handoff modeling

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The value of epigenetic markers in esophageal cancer

Xiao-Mei ZHANG, Ming-Zhou GUO,

《医学前沿（英文）》 2010年第4卷第4期页码 378-384 doi: 10.1007/s11684-010-0230-3

摘要： Developing esophageal cancer is a multi-step process that begins with the accumulation of genetic and epigenetic alterations, and leads to the activation of oncogenes and the inactivation or loss of tumor suppressor genes (TSG). In addition to genetic alteration, epigenetic modifications, and in particular DNA methylation, are recognized as a common molecular alteration in human tumors. In esophageal cancer, aberrant methylation of promoter regions occurs not only in advanced cancer, but also in premalignant lesions. DNA methylation is related to survival time and sensitivity of chemoradiotherapy. This review is mainly focused on epigenetic changes in esophageal cancer and the value of early detection for patient prognosis, treatment choices, and potential targeting therapy.

关键词： epigenetics DNA methylation esophageal cancer dysplasia

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Soil health—useful terminology for communication or meaningless concept? Or both?

David S. POWLSON

《农业科学与工程前沿（英文）》 2020年第7卷第3期页码 246-250 doi: 10.15302/J-FASE-2020326

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On the added value of multi-scale modeling of concrete

《结构与土木工程前沿（英文）》 2022年第16卷第1期页码 1-23 doi: 10.1007/s11709-021-0790-0

摘要： This review of the added value of multi-scale modeling of concrete is based on three representative examples. The first one is concerned with the analysis of experimental data, taken from four high-dynamic tests. The structural nature of the high-dynamic strength increase can be explained by using a multi-scale model. It accounts for the microstructure of the specimens. The second example refers to multi-scale thermoelastic analysis of concrete pavements, subjected to solar heating. A sensitivity analysis with respect to the internal relative humidity (RH) of concrete has underlined the great importance of the RH for an assessment of the risk of microcracking of concrete. The third example deals with multi-scale structural analysis of a real-scale test of a segmental tunnel ring. It has turned out that multi-scale modeling of concrete enables more reliable predictions of crack opening displacements in tunnel segments than macroscopic models taken from codes of practice. Overall, it is concluded that multi-scale models have indeed a significant added value. However, its degree varies with these examples. In any case, it can be assessed by means of a comparison of the results from three sources, namely, multi-scale structural analysis, conventional structural analysis, and experiments.

关键词： experiments multi-scale analysis conventional structural analysis concrete reinforced concrete

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Observer design for induction motor: an approach based on the mean value theorem

Mohamed Yacine HAMMOUDI,Abdelkarim ALLAG,Mohamed BECHERIF,Mohamed BENBOUZID,Hamza ALLOUI

《能源前沿（英文）》 2014年第8卷第4期页码 426-433 doi: 10.1007/s11708-014-0314-x

摘要： In this paper, observer design for an induction motor has been investigated. The peculiarity of this paper is the synthesis of a mono-Luenberger observer for highly coupled system. To transform the nonlinear error dynamics for the induction motor into the linear parametric varying (LPV) system, the differential mean value theorem combined with the sector nonlinearity transformation has been used. Stability conditions based on the Lyapunov function lead to solvability of a set of linear matrix inequalities. The proposed observer guarantees the global exponential convergence to zero of the estimation error. Finally, the simulation results are given to show the performance of the observer design.

关键词： observer design differential mean value theorem (DMVT) sector nonlinearity transformation linear matrix inequalities (LMI) induction motor

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The Building of Papermaking Enterprise’s Recycling Economy Evaluation Index System Based on Value Flow

Zhi-fang Zhou,Jing Ou,Sha-sha Wang,Xiao-hong Chen

《工程管理前沿（英文）》 2016年第3卷第1期页码 9-17 doi: 10.15302/J-FEM-2016009

摘要： At present, the research on circular economy has made a lot of substantive results both at home and abroad. But for the papermaking enterprise, which is the representative of the light industry, few studies have analyzed the evaluation index system of circular economy. Since the current material flow analyses have limitations that the researchers cannot calculate materials with different units. The authors take advantage of the intrinsic correlation between the basic principle of value flow analysis and circular economy, and then analyze the dynamic changes of material flow and value flow through enterprises internal production process. Considering the resource output, the authors set up the layered structure of the evaluation index system, and then preliminarily determine the index form. Next, the authors use the frequency statistics analysis method to adjust indicators, forming a preliminary index system. After that, the principal component analysis and independent analysis are applied for screening. Finally, the authors build a circular economy evaluation index system for papermaking enterprise to provide scientific guidance for the process of circular economy.

关键词： circular economy the papermaking enterprise material flow analysis value flow analysis evaluation index system

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Does oil price affect the value of firms? Evidence from Tunisian listed firms

Kaouther ZAABOUTI,Ezzeddine BEN MOHAMED,Abdelfettah BOURI

《能源前沿（英文）》 2016年第10卷第1期页码 1-13 doi: 10.1007/s11708-016-0396-8

摘要： A new debate on the potential impact of oil price changes on the value of firms was initiated in this paper. Using a stochastic frontier approach, an attempt was made to derive the optimal value * of firms and calculate the value observed. Then the shortfall ( *– ) which represents the inefficiency term was explained. Starting from 19 industrial Tunisian firms listed on the Tunis Stock Exchange between 2007 and 2011, the fact that variation of oil prices can largely explain distortions in the value of firms was empirically demonstrated.

关键词： industrial Tunisian firms oil price value of firm stochastic frontier approach