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Utility and influence mechanism of densification modulation on grain boundary diffusion in NdFeB magnets 被引量:1
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作者 San'gen Luo Munan Yang +4 位作者 Shuwei Zhong Sajjad Ur Rehman Jiajie Li Xiaoqiang Yu Bin Yang 《Journal of Rare Earths》 2025年第3期569-577,I0006,共10页
Grain boundary diffusion technology is pivotal in the preparation of high-performance NdFeB magnets.This study investigates the factors that affect the efficiency of grain boundary diffusion,starting from the properti... Grain boundary diffusion technology is pivotal in the preparation of high-performance NdFeB magnets.This study investigates the factors that affect the efficiency of grain boundary diffusion,starting from the properties of the diffusion matrix.Through the adjustment of the sintering process,we effectively prepared magnets with varied densities that serve as the matrix for grain boundary diffusion with TbH,diffusion.The mobility characteristics of the Nd-rich phase during the densification stage are leveraged to ensure a more extensive distribution of heavy rare earth elements within the magnets.According to the experimental results,the increase in coercivity of low-density magnets after diffusion is significantly greater than that of relatively high-density magnets.The coercivity values measured are 805.32 kA/m for low-density magnets and 470.3 kA/m for high-density magnets.Additionally,grain boundary diffusion notably enhances the density of initial low-density magnets,addressing the issue of low density during the sintering stage.Before the diffusion treatment,the Nd-rich phases primarily concentrate at the triangular grain boundaries,resulting in an increased number of cavity defects in the magnets.These cavity defects contain atoms in a higher energy state,making them more prone to transition.Consequently,the diffusion activation energy at the void defects is lower than the intracrystalline diffusion activation energy,accelerating atom diffusion.The presence of larger cavities also provides more space for atom migration,thereby promoting the diffusion process.After the diffusion treatment,the proportion of bulk Nd-rich phases significantly decreases,and they infiltrate between the grains to fill the cavity defects,forming continuous fine grain boundaries.Based on these observations,the study aims to explore how to utilize this information to develop an efficient technique for grain boundary diffusion. 展开更多
关键词 NdFeB magnets DENSITY Grain boundary diffusion Defect utility Rare earths
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Utility-Driven Edge Caching Optimization with Deep Reinforcement Learning under Uncertain Content Popularity
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作者 Mingoo Kwon Kyeongmin Kim Minseok Song 《Computers, Materials & Continua》 2025年第10期519-537,共19页
Efficient edge caching is essential for maximizing utility in video streaming systems,especially under constraints such as limited storage capacity and dynamically fluctuating content popularity.Utility,defined as the... Efficient edge caching is essential for maximizing utility in video streaming systems,especially under constraints such as limited storage capacity and dynamically fluctuating content popularity.Utility,defined as the benefit obtained per unit of cache bandwidth usage,degrades when static or greedy caching strategies fail to adapt to changing demand patterns.To address this,we propose a deep reinforcement learning(DRL)-based caching framework built upon the proximal policy optimization(PPO)algorithm.Our approach formulates edge caching as a sequential decision-making problem and introduces a reward model that balances cache hit performance and utility by prioritizing high-demand,high-quality content while penalizing degraded quality delivery.We construct a realistic synthetic dataset that captures both temporal variations and shifting content popularity to validate our model.Experimental results demonstrate that our proposed method improves utility by up to 135.9%and achieves an average improvement of 22.6%compared to traditional greedy algorithms and long short-term memory(LSTM)-based prediction models.Moreover,our method consistently performs well across a variety of utility functions,workload distributions,and storage limitations,underscoring its adaptability and robustness in dynamic video caching environments. 展开更多
关键词 Edge caching video-on-demand reinforcement learning utility optimization
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Personalized fund recommendation with dynamic utility learning
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作者 Jiaxin Wei Jia Liu 《Financial Innovation》 2025年第1期1558-1584,共27页
This study introduces a fund recommendation system based on the ε-greedy algorithm and an incremental learning framework.This model simulates the interaction process when customers browse the web-pages of fund produc... This study introduces a fund recommendation system based on the ε-greedy algorithm and an incremental learning framework.This model simulates the interaction process when customers browse the web-pages of fund products.Customers click on their preferred fund products when visiting a fund recommendation web-page.The system collects customer click sequences to continually estimate and update their utility function.The system generates product lists using the ε-greedy algorithm,where each product on the list has the probability of 1-ε of being selected as an exploitation strategy,and the probability of ε is chosen as the exploration strategy.We perform a series of numerical tests to evaluate the estimation performance with different values of ε. 展开更多
关键词 Personalized fund recommendation ε-greedy algorithm Dynamic utility learning
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Empowering Underground Utility Tunnel Operation and Maintenance with Data Intelligence:Risk Factors,Prospects,and Challenges
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作者 Jie Zou Ping Wu +2 位作者 Jianwei Chen Weijie Fan Yidong Xu 《Structural Durability & Health Monitoring》 2025年第3期441-471,共31页
As an essential part of the urban infrastructure,underground utility tunnels have a long service life,complex structural performance evolution and dynamic changes both inside and outside the tunnel.These combined fact... As an essential part of the urban infrastructure,underground utility tunnels have a long service life,complex structural performance evolution and dynamic changes both inside and outside the tunnel.These combined factors result in a wide variety of disaster risks during the operation and maintenance phase,which make risk management and control particularly challenging.This work first reviews three common representative disaster factors during the operation and maintenance period:settlement,earthquakes,and explosions.It summarizes the causes of disasters,key technologies,and research methods.Then,it delves into the research on the intelligent operation and maintenance architecture for utility tunnels.Additionally,it explores the data challenges,monitoring technologies,and management platform architectures faced during the operation and maintenance process.This work provides new research perspectives for the long-term,healthy,and sustainable development of utility tunnels,which serve as the underground arteries of cities. 展开更多
关键词 Integrated utility tunnels operational hazards critical technologies intelligent maintenance smart platforms
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Patterns of utilization of antipsychotic drugs and direct medical costs among patients with schizophrenia in a tertiary care hospital
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作者 Aqeel Haider Lekha Saha Debashish Basu 《World Journal of Psychiatry》 2026年第1期125-135,共11页
BACKGROUND Drug utilization research has an important role in assisting the healthcare administration to know,compute,and refine the prescription whose principal objective is to enable the rational use of drugs.Resear... BACKGROUND Drug utilization research has an important role in assisting the healthcare administration to know,compute,and refine the prescription whose principal objective is to enable the rational use of drugs.Research in developing nations relating to the cost of treatment is scarce when compared with developed countries.Thus,the drug utilization research studies from developing nations are most needed,and their number has been growing.AIM To evaluate patterns of utilization of antipsychotic drugs and direct medical cost analysis in patients newly diagnosed with schizophrenia.METHODS The present study was observational in type and based on a retrospective cohort to evaluate patterns of utilization of antipsychotic drugs using World Health Organization(WHO)core prescribing indicators and anatomical therapeutic chemical/defined daily dose indicators.We also calculated direct medical costs for a period of 6 months.RESULTS This study has found that atypical antipsychotics are the mainstay of treatment for schizophrenia in every age group and subcategories of schizophrenia.The evaluation based on WHO prescribing indicators showed a low average number of drugs per prescription and low prescribing frequency of antipsychotics from the National List of Essential Medicines 2015 and the WHO Essential Medicines List 2019.The total mean drug cost of our study was 1396 Indian rupees.The total mean cost due to the investigation in our study was 1017.34 Indian rupees.Therefore,the total mean direct medical cost incurred on patients in our study was 4337.28 Indian rupees.CONCLUSION The information from the present study can be used for reviewing and updating treatment policy at the institutional level. 展开更多
关键词 Patterns of utilization Antipsychotic drugs Direct medical cost SCHIZOPHRENIA DRUGS
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Analyzing our educational resource deployment of compulsory education by marginal utility
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作者 高丽 程宝良 《陕西师范大学学报(哲学社会科学版)》 CSSCI 北大核心 2006年第S1期353-356,共4页
In the base of utility and marginal utility,the article put forwardthe concept of utility and marginal utilityof educational outlay and the theory of them,and analyzed the actuality of educational resource deployment ... In the base of utility and marginal utility,the article put forwardthe concept of utility and marginal utilityof educational outlay and the theory of them,and analyzed the actuality of educational resource deployment in ourcountry,gave some advice about howtoi mprove our educational resource deployment of compulsory education. 展开更多
关键词 marginal utility educational resource compulsory education
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Neural network approach to predicting mercury emission from utility boiler
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作者 杨宏旻 周波 《Journal of Southeast University(English Edition)》 EI CAS 2008年第1期55-58,共4页
The feasibility of using an ANN method to predict the mercury emission and speciation in the flue gas of a power station under un-tested combustion/operational conditions is evaluated. Based on existing field testing ... The feasibility of using an ANN method to predict the mercury emission and speciation in the flue gas of a power station under un-tested combustion/operational conditions is evaluated. Based on existing field testing datasets for the emissions of three utility boilers, a 3-layer back-propagation network is applied to predict the mercury speciation at the stack. The whole prediction procedure includes: collection of data, structuring an artificial neural network (ANN) model, training process and error evaluation. A total of 59 parameters of coal and ash analyses and power plant operating conditions are treated as input variables, and the actual mercury emissions and their speciation data are used to supervise the training process and verify the performance of prediction modeling. The precision of model prediction ( root- mean-square error is 0. 8 μg/Nm3 for elemental mercury and 0. 9 μg/Nm3 for total mercury) is acceptable since the spikes of semi- mercury continuous emission monitor (SCEM) with wet conversion modules are taken into consideration. 展开更多
关键词 mercury speciations electric utility boiler PREDICTION artificial neural network
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EOS Utility软件在摄影理论可视化教学中的应用
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作者 张廷琦 《电脑知识与技术》 2023年第13期171-173,共3页
可视化的理论知识更容易被识记、理解,而在摄影理论教学中,运用静态的图形图像,并不能理想地将复杂理论知识及其相互间的关系表征、可视化。运用EOS Utility软件进行摄影理论知识的辅助教学,可将各知识点内涵及其相互间的关系进行动态... 可视化的理论知识更容易被识记、理解,而在摄影理论教学中,运用静态的图形图像,并不能理想地将复杂理论知识及其相互间的关系表征、可视化。运用EOS Utility软件进行摄影理论知识的辅助教学,可将各知识点内涵及其相互间的关系进行动态地表征,实现摄影参数可视化、摄影过程可视化、摄影效果可视化,使摄影知识点及其相互间的关系更容易被识记、理解,提高教学效率。 展开更多
关键词 可视化 摄影 知识 教学 EOS utility软件
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Optimal consumption-leisure, portfolio and retirement selection based on α-maxmin expected CES utility with ambiguity 被引量:23
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作者 FEI Wei-yin 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2012年第4期435-454,共20页
This article studies optimal consumption-leisure, portfolio and retirement selection of an infinitely lived investor whose preference is formulated by a-maxmin expected CES utility which is to differentiate ambiguity ... This article studies optimal consumption-leisure, portfolio and retirement selection of an infinitely lived investor whose preference is formulated by a-maxmin expected CES utility which is to differentiate ambiguity and ambiguity attitude. Adopting the recursive multiple- priors utility and the technique of backward stochastic differential equations (BSDEs), we transform the (^-maxmin expected CES utility into a classical expected CES utility under a new probability measure related to the degree of an investor's uncertainty. Our model investi- gates the optimal consumption-leisure-work selection, the optimal portfolio selection, and the optimal stopping problem. In this model, the investor is able to adjust her supply of labor flex- ibly above a certain minimum work-hour along with a retirement option. The problem can be analytically solved by using a variational inequality. And the optimal retirement time is given as the first time when her wealth exceeds a certain critical level. The optimal consumption-leisure and portfolio strategies before and after retirement are provided in closed forms. Finally, the distinctions of optimal consumption-leisure, portfolio and critical wealth level under ambiguity from those with no vagueness are discussed. 展开更多
关键词 α-maxmin expected CES utility stochastic control BSDEs optimization of utility variationalinequality optimal consumption-leisure-portfolio and retirement.
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Seismic response of underground utility tunnels: shaking table testing and FEM analysis 被引量:38
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作者 Jiang Luzhen Chen Jun Li Jie 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第4期555-567,共13页
Underground utility tunnels are widely used in urban areas throughout the world for lifeline networks due to their easy maintenance and environmental protection capabilities. However, knowledge about their seismic per... Underground utility tunnels are widely used in urban areas throughout the world for lifeline networks due to their easy maintenance and environmental protection capabilities. However, knowledge about their seismic performance is still quite limited and seismic design procedures are not included in current design codes. This paper describes a series of shaking table tests the authors performed on a scaled utility tunnel model to explore its performance under earthquake excitation. Details of the experimental setup are first presented focusing on aspects such as the design of the soil container, scaled structural model, sensor array arrangement and test procedure. The main observations from the test program, including structural response, soil response, soil-structure interaction and earth pressure, are summarized and discussed. Further, a finite element model (FEM) of the test utility tunnel is established where the nonlinear soil properties are modeled by the Drucker- Prager constitutive model; the master-slave surface mechanism is employed to simulate the soil-structure dynamic interaction; and the confining effect of the laminar shear box to soil is considered by proper boundary modeling. The results from the numerical model are compared with experiment measurements in terms of displacement, acceleration and amplification factor of the structural model and the soil. The comparison shows that the numerical results match the experimental measurements quite well. The validated numerical model can be adopted for further analysis. 展开更多
关键词 lifeline system utility tunnel shaking table test finite element method soil-structure interaction
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Dynamic response of utility tunnel during the passage of Rayleigh waves 被引量:10
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作者 Jie Li Qingxia Yue Jun Chen 《Earthquake Science》 CSCD 2010年第1期13-24,共12页
The modeling methodologies and calculation of dynamic response of underground structure under Rayleigh waves is investigated in this paper. First the free field responses under Rayleigh waves are analyzed and the nume... The modeling methodologies and calculation of dynamic response of underground structure under Rayleigh waves is investigated in this paper. First the free field responses under Rayleigh waves are analyzed and the numerical results agree well with the theoretical results. Then, the approximate Rayleigh waves are put forward based on the preliminary re- search, and Rayleigh wave field is obtained through fast Fourier transform technique. Taking a utility tunnel as an example, its dynamic responses under Rayleigh waves is calculated by ABAQUS. The results demonstrate that bending deformation is the main component of structural deformation and the deformation at the top of the structure is about twice as much as that at bottom of the structure. The effect of soil-structure interface and the buried depth of underground structure are also investi- gated via parameter analysis. For the shallow buffed underground structures, Rayleigh waves can be the key factor to control the responses and damage of the structure. 展开更多
关键词 utility tunnel Rayleigh wave dynamic response fast Fourier transform
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Cooperative adaptive bidirectional control of a train platoon for efficient utility and string stability 被引量:8
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作者 高士根 董海荣 +3 位作者 宁滨 Roberts Clive 陈磊 孙绪彬 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第9期161-170,共10页
This paper proposes cooperative adaptive control schemes for a train platoon to improve efficient utility and guarantee string stability. The control schemes are developed based on a bidirectional strategy, i.e., the ... This paper proposes cooperative adaptive control schemes for a train platoon to improve efficient utility and guarantee string stability. The control schemes are developed based on a bidirectional strategy, i.e., the information of proximal(preceding and following) trains is used in the controller design. Based on available proximal information(prox-info) of location, speed, and acceleration, a direct adaptive control is designed to maintain the tracking interval at the minimum safe distance. Based on available prox-info of location, an observer-based adaptive control is designed to achieve the same target, which alleviates the requirements of equipped sensors to measure prox-info of speed and acceleration. The developed schemes are capable of on-line estimating of the unknown system parameters and stabilizing the closed-loop system, the string stability of train platoon is guaranteed on the basis of Lyapunov stability theorem. Numerical simulation results are presented to verify the effectiveness of the proposed control laws. 展开更多
关键词 train platoon string stability cooperative adaptive control efficient utility
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UMR: A utility-maximizing routing algorithm for delay-sensitive service in LEO satellite networks 被引量:5
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作者 Lu Yong Zhang Jun Zhang Tao 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2015年第2期499-507,共9页
This paper develops a routing algorithm for delay-sensitive packet transmission in a low earth orbit multi-hop satellite network consists of micro-satellites. The micro-satellite low earth orbit (MS-LEO) network end... This paper develops a routing algorithm for delay-sensitive packet transmission in a low earth orbit multi-hop satellite network consists of micro-satellites. The micro-satellite low earth orbit (MS-LEO) network endures unstable link connection and frequent link congestion due to the uneven user distribution and the link capacity variations. The proposed routing algorithm, referred to as the utility maximizing routing (UMR) algorithm, improve the network utility of the MS-LEO network for carrying flows with strict end-to-end delay bound requirement. In UMR, first, a link state parameter is defined to capture the link reliability on continuing to keep the end-to-end delay into constraint; then, on the basis of this parameter, a routing metric is for- mulated and a routing scheme is designed for balancing the reliability in delay bound guarantee among paths and building a path maximizing the network utility expectation. While the UMR algo- rithm has many advantages, it may result in a higher blocking rate of new calls. This phenomenon is discussed and a weight factor is introduced into UMR to provide a flexible performance option for network operator. A set of simulations are conducted to verify the good performance of UMR, in terms of balancing the traffic distribution on inter-satellite links, reducing the flow interruption rate, and improving the network utility. 展开更多
关键词 Delay bound LEO satellite networks MICRO-SATELLITE Network utility QoS routing
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Low-income and overweight in China:Evidence from a life-course utility model 被引量:3
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作者 REN Yan-jun Bente Castro Campos +1 位作者 Jens-Peter Loy Stephan Brosig 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第8期1753-1767,共15页
Previous literature has demonstrated that low-income people are more likely to settle for poor health choices in developed countries. By using income as a budget constraint and signal for future wellbeing in a life-co... Previous literature has demonstrated that low-income people are more likely to settle for poor health choices in developed countries. By using income as a budget constraint and signal for future wellbeing in a life-course utility model, we examine the association amongst income and overweight. The data used for this study are from the China Health and Nutrition Survey(CHNS). Estimations are conducted for overweight initiation, cessation, and participation mirroring a decision to begin and a past decision to not terminate. Our findings propose that body weight and the likelihood of overweight commencement rise with additional income but at a diminishing degree, representing a concave relation;while the likelihood of overweight discontinuance declines with additional income but at an accelerating degree, suggesting a convex relation.We presume that, as opposed to developed countries, low-income people are less inclined to be overweight in China, a country in transition. This could be explained by an income constraint for unhealthy foodstuff. Nevertheless, it will switch when income surpasses the critical threshold of the concave or inverted U-shape curve indicating that low-income people appear to receive not as much utility from future health. Specifically, this adjustment seems to occur earlier for females and inhabitants of urban areas. 展开更多
关键词 LOW-INCOME OVERWEIGHT LIFE-COURSE utility China
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Utility function based fair data scheduling algorithm for OFDM wireless network 被引量:3
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作者 Guo Kunqi Sun Lixin Jia Shilou 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第4期731-738,共8页
A system model is formulated as the maximization of a total utility function to achieve fair downlink data scheduling in multiuser orthogonal frequency division multiplexing (OFDM) wireless networks. A dynamic subca... A system model is formulated as the maximization of a total utility function to achieve fair downlink data scheduling in multiuser orthogonal frequency division multiplexing (OFDM) wireless networks. A dynamic subcarrier allocation algorithm (DSAA) is proposed, to optimize the system model. The subcarrier allocation decision is made by the proposed DSAA according to the maximum value of total utility function with respect to the queue mean waiting time. Simulation results demonstrate that compared to the conventional algorithms, the proposed algorithm has better delay performance and can provide fairness under different loads by using different utility functions. 展开更多
关键词 OFDM SCHEDULING ALGORITHM utility function.
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Large scale shaking table model test and analysis on seismic response of utility tunnel in non-homogeneous soil 被引量:12
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作者 Cho Mya Darli Tang Aiping +1 位作者 Huang Delong Zhang Jiqiang 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2021年第2期505-515,共11页
Underground utility tunnels are the most fundamental and reliable lifeline network in urban cities,and are widely constructed throughout the world.In urban areas,most utility tunnels usually encounter the non-homogene... Underground utility tunnels are the most fundamental and reliable lifeline network in urban cities,and are widely constructed throughout the world.In urban areas,most utility tunnels usually encounter the non-homogeneity of subsoil condition due to various construction effects.Studies have shown that the damage mechanism of shallow underground structures mainly depends on the inhomogeneity of the subsoil conditions.This would become a considerable factor for the stability of the underground utility tunnel structures.However,this type of research still needs to establish the vulnerable seismic design.In this study,a series of shaking table tests were conducted on non-homogenous soils to investigate the performance of seismic interaction between utility tunnels,surrounding soils and interior pipelines.The dynamic responses measured from the test account for the boundary condition of non-homogeneous soils,the internal forces,displacement of tunnel joints,the dynamic characteristics on interior pipelines and the reasonable spring stiffness with damping in the seismically isolated gas pipeline model inside the tunnel.The vulnerability of underground utility tunnel in non-homogeneous soil zone and the mechanism of the stability of interior facilities are the main topics discussed in this paper. 展开更多
关键词 utility tunnel non-homogeneous soil shaking table
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Study on information utility 被引量:1
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作者 张东戈 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第3期579-582,644,共5页
Information has two aspects. One aspect is the objective one; another aspect is the subjective one. Shannon has discussed the objective aspect of information in information theory. But the subjective aspect of informa... Information has two aspects. One aspect is the objective one; another aspect is the subjective one. Shannon has discussed the objective aspect of information in information theory. But the subjective aspect of information has not been fully discussed. Someone use “Bayesian approaches” to evaluate the value of information. But in some cases it does not meet the information user's need. This paper is focus on the subjective aspect of objectively measurable information and gives formal definitions for information, information utility, and marginal information utility, normalized calculation of information utility. The information discussed in the paper has interdisciplinary nature. This work can be the foundation of many application areas. 展开更多
关键词 analysis definition of information analysis definition of information utility analysis definition of marginal information utility normalized calculation of information utility mic^nomics analysis expression of information utility information utility functions C^4ISR system evaluation.
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Blast resistance evaluation of urban utility tunnel reinforced with BFRP bars 被引量:9
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作者 Qiang Zhou Hu-guang He +10 位作者 San-feng Liu Xiao-shuo Chen Ze-xun Tang Yang Liu Zhen-yu Qiu Sen-sen Li He Wang Yin-zhi Zhou Jian-nan Zhou Hua-lin Fan Feng-nian Jin 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第2期512-530,共19页
To improve corrosion-resistance of shallow-buried concrete urban utility tunnels(UUTs),basalt fiber reinforced polymer(BFRP)bars are applied to reinforce UUTs.As the UUT must have excellent survival capability under a... To improve corrosion-resistance of shallow-buried concrete urban utility tunnels(UUTs),basalt fiber reinforced polymer(BFRP)bars are applied to reinforce UUTs.As the UUT must have excellent survival capability under accidental explosions,a shallow-buried BFRP bars reinforced UUT(BBRU)was designed and constructed.Repetitive blast experiments were carried out on this BBRU.Dynamic responses,damage evolutions and failure styles of the BBRU under repetitive explosions were revealed.The tunnel roof is the most vulnerable component and longitudinal cracks develop along the tunnel.When the scaled distance is larger than 1.10 m/kg1/3,no cracks are observed in the experiments.When the BBRU is severely damaged,there are five cracks forming and developing along the roof.The roof is simplified as a clamped-supported one-way slab,proved by the observation that the maximum strain of the transverse bar is much larger than that of the longitudinal bar.Dynamic responses of the roof slab are predicted by dynamic Euler beam theory,which can consistently predict the roof displacement under large-scaleddistance explosion.Compared with the UUT reinforced with steel bars,the BBRU has advantages in blast resistance with smaller deflections and more evenly-distributed cracks when the scaled distance is smaller than 1.260 m/kg1/3 and the steel bars enter plastic state.Longer elastic defamation of the BFRP bars endows the UUT more excellent blast resistance under small-scaled-distance explosions. 展开更多
关键词 utility tunnel BFRP bars Explosion Dynamic response CRACK Dynamic theory
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Optimization of the Dressing Parameters in Cylindrical Grinding Based on a Generalized Utility Function 被引量:2
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作者 ALEKSANDROVA Irina 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第1期63-73,共11页
The existing studies, concerning the dressing process, focus on the major influence of the dressing conditions on the grinding response variables. However, the choice of the dressing conditions is often made, based on... The existing studies, concerning the dressing process, focus on the major influence of the dressing conditions on the grinding response variables. However, the choice of the dressing conditions is often made, based on the experience of the qualified staff or using data from reference books. The optimal dressing parameters, which are only valid for the particular methods and dressing and grinding conditions, are also used. The paper presents a methodology for optimization of the dressing parameters in cylindrical grinding. The generalized utility function has been chosen as an optimization parameter. It is a complex indicator determining the economic, dynamic and manufacturing characteristics of the grinding process. The developed methodology is implemented for the dressing of aluminium oxide grinding wheels by using experimental diamond roller dressers with different grit sizes made of medium- and high-strength synthetic diamonds type AC32 and AC80. To solve the optimization problem, a model of the generalized utility function is created which reflects the complex impact of dressing parameters. The model is built based on the results from the conducted complex study and modeling of the grinding wheel lifetime, cutting ability, production rate and cutting forces during grinding. They are closely related to the dressing conditions (dressing speed ratio, radial in-feed of the diamond roller dresser and dress-out time), the diamond roller dresser grit size/grinding wheel grit size ratio, the type of synthetic diamonds and the direction of dressing. Some dressing parameters are determined for which the generalized utility fimction has a maximum and which guarantee an optimum combination of the following: the lifetime and cutting ability of the abrasive wheels, the tangential cutting force magnitude and the production rate of the grinding process. The results obtained prove the possibility of control and optimization of grinding by selecting particular dressing parameters. 展开更多
关键词 dressing conditions cylindrical grinding diamond roller dresser generalized utility function based optimization
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On Utility Maximization with Random Interval Payoffs 被引量:2
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作者 YOU Su-rong PENG Yu-zheng ZHAO Fei-fei 《Chinese Quarterly Journal of Mathematics》 CSCD 2012年第3期424-431,共8页
This article discusses the problem of utility maximization in a market with random-interval payoffs without short-selling prohibition. A novel expected utility model is given to measure an investor's subjective vi... This article discusses the problem of utility maximization in a market with random-interval payoffs without short-selling prohibition. A novel expected utility model is given to measure an investor's subjective view toward random interval wealth. Some techniques are proposed to transfer a complex programming involving interval numbers into a simple non-linear programming. Under the existence of the optimal strategy, relations between the optimal strategy and assets' prices are discussed. Some properties of the maximal utility function with respect to the endowment are given. 展开更多
关键词 random interval payoff acceptable state price vector expected utility optimal strategy
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