Effect of viscosity on flow patterns of pumping-up of liquid generated by a cone rotating at the liquid surface has been experimentally studied with various concentrations of glycerol aqueous solution. We have previou...Effect of viscosity on flow patterns of pumping-up of liquid generated by a cone rotating at the liquid surface has been experimentally studied with various concentrations of glycerol aqueous solution. We have previously found that the higher viscous non-Newtonian fluid was lifted-up along the conical surface with a radial filament-wise pattern, which is quite different from the monotonic thin film-wise pattern observed for the lower viscous fluid such as water. In order to elucidate the pumping-up mechanism, a transition diagram indicating the critical rotation rate is obtained as a function of viscosity?of Newtonian fluid in this study, varying from the lower value of water (μ?=?0.890 mPa·s) to the higher one of glycerin (μ?= 910?mPa·s). It is found that there are three categories depending on the viscosity classified as?1) film-wise pumping-up region for the viscosity?μ?≤?134?mPa·s,?2) filament-wise pumping-up one for the viscosity?μ?≥?520?mPa·s, and?3) no pumping-up phenomenon occurs?for 134??μ??mPa·s.展开更多
The modified normal form approach presented by ZHANG Wei-yi, K Huseyin and CHEN Yu-shu is further extended and a different procedure is introduced which lends itself readily to symbolic calculations, like MAPLE. This ...The modified normal form approach presented by ZHANG Wei-yi, K Huseyin and CHEN Yu-shu is further extended and a different procedure is introduced which lends itself readily to symbolic calculations, like MAPLE. This provides a number of significant advantages over the previous approach, and facilitates the associated calculations. To illustrate the new approach, three examples are presented.展开更多
The processes of globalization, the consequences of which are evident in all comers and at all levels of the contemporary world are linked to an increasing homogenization. Disciplines of architecture and urban design ...The processes of globalization, the consequences of which are evident in all comers and at all levels of the contemporary world are linked to an increasing homogenization. Disciplines of architecture and urban design contribute to that process, which is affecting the very definitions of place and identity. A desire to maintain and （re）create local identity within the context of that increasingly global world is connected to reviving of the past or to various interpretations of history, and preservation of the built environment of the place. This paper identifies peculiar processes of creation and maintenance of identity of place in the precincts of Tokyo Yanaka, Nezu and Sendagi, known as Yanesen. The authors argue that in Yanesen innovation appears as the byproduct of complex and creative responses to the threats of globalization, within a perpetual interplay of persistence and change. The paper opens a number of questions of where and how innovation in built environment can contribute to persistence of place identity.展开更多
At the present time, ultrasonic motors have been developed for a variety of purposes such as linear motion drives and rotational drives. The elaboration of an ultrasonic motor is time-consuming, because it is develope...At the present time, ultrasonic motors have been developed for a variety of purposes such as linear motion drives and rotational drives. The elaboration of an ultrasonic motor is time-consuming, because it is developed adapting on its application. In this study, a new ultrasonic motor structure that combines a piezoelectric element and a metallic plate is elaborated. The driving principle of this motor is that the metal plate is bent to an inchworm shape and rotates the rotor when the piezoelectric element is stretched. The objective of this study is to verify the functioning of the new motor experimentally.展开更多
To address the challenge of achieving both high sensitivity and a high quality factor in quartz crystal microbalance(QCM)humidity sensors,a nanodiamond(ND)/Ti_(3)C_(2)MXene composite-coated QCM humidity sensor was fab...To address the challenge of achieving both high sensitivity and a high quality factor in quartz crystal microbalance(QCM)humidity sensors,a nanodiamond(ND)/Ti_(3)C_(2)MXene composite-coated QCM humidity sensor was fabricated.The material characteristics of ND,Ti_(3)C_(2)MXene,and ND/Ti_(3)C_(2)MXene composite were analyzed by transmission electron microscopy(TEM)and Fourier transform infrared(FTIR)spectroscopy.The experimental results demonstrated that the hydrophilic ND nanoparticles coated on Ti_(3)C_(2) MXene nanosheet prevented the self-stacking of Ti_(3)C_(2)MXene and enhanced the sensitivity of Ti_(3)C_(2) MXene-based QCM humidity sensor.Moreover,the high mechanical modulus of Ti_(3)C_(2) MXene material helped ND/Ti_(3)C_(2)MXene composite-coated QCM humidity sensor to achieve a high quality factor(>20,000).ND/Ti_(3)C_(2)MXene compositecoated QCM humidity sensor exhibited a sensitivity of 82.45 Hz/%RH,a humidity hysteresis of 1.1%RH,fast response/recovery times,acceptable repeatability,and good stability from 11.3%RH to 97.3%RH.The response mechanism of ND/Ti_(3)C_(2) MXene composite-coated QCM humidity sensor was analyzed in combination with a bi-exponential kinetic adsorption model.Finally,the potential application of ND/Ti_(3)C_(2)MXene composite-coated QCM humidity sensor was demonstrated through its frequency response to wooden blocks with different moisture contents.展开更多
A formal policy development framework, based on a system of systems （SOS） approach, is synthesized to systematically address, in an integrative and adaptive fashion, major global challenges, such as the current food...A formal policy development framework, based on a system of systems （SOS） approach, is synthesized to systematically address, in an integrative and adaptive fashion, major global challenges, such as the current food and fjnancial crises, and their interactions with other key natural, societal, and technological systems. A SoS approach seeks to respect the different value systems of multiple participants, to harness complexity through effective integration, and to engage the world of uncertainty and unpredictability with an adaptive response. Faced with the present global challenges, what is needed are strategic and operational methods which lead to ethical policies, enhance integrative and adaptive management practices, and are able to direct conflict resolution in a positive direction. Policy makers need tools to model and analyze complex systems which they are trying to responsibly govern, taking into account values and risks to design and evaluate different policies. A preliminary investigation into the global food system is undertaken to understand the SoS and to provide insights on how to carry out policy development using the proposed framework.展开更多
A dynamic hesitant fuzzy linguistic group decisionmaking(DHFLGDM) problem is studied from the perspective of information reliability based on the theory of hesitant fuzzy linguistic term sets(HFLTSs). First, an approa...A dynamic hesitant fuzzy linguistic group decisionmaking(DHFLGDM) problem is studied from the perspective of information reliability based on the theory of hesitant fuzzy linguistic term sets(HFLTSs). First, an approach is applied to transform the dynamic HFLTSs(DHFLTSs) into a set of proportional linguistic terms to eliminate the time dimension. Second, expert reliability is measured by considering both group similarity and degree of certainty, and an optimization method is employed to quantify the linguistic terms by maximizing the group similarity. Third, through computing the attribute stability as well as its reliability, a combination rule which considers both reliability and weight is proposed to aggregate the information, and then the aggregated grade values and degree of stability are used to make a selection. Finally,the application and feasibility of the proposed method are verified through a case study and method comparison.展开更多
During the multistep process of metastasis,cancer cells encounter various mechanical forces which make them deform drastically.Developing accurate in-silico models,capable of simulating the interactions between the me...During the multistep process of metastasis,cancer cells encounter various mechanical forces which make them deform drastically.Developing accurate in-silico models,capable of simulating the interactions between the mechanical forces and highly deformable cancer cells,can pave the way for the development of novel diagnostic and predictive methods for metastatic progression.Spring-network models of cancer cell,empowered by our recently proposed identification approach,promises a versatile numerical tool for developing experimentally validated models that can simulate complex interactions at cellular scale.Using this numerical tool,we presented spring-network models of breast cancer cells that can accurately replicate the experimental data of deformation behavior of the cells flowing in a fluidic domain and passing narrow constrictions comparable to microcapillary.First,using high-speed imaging,we experimentally studied the deformability of breast cancer cell lines with varying metastatic potential(MCF-7(less invasive),SKBR-3(medium-high invasive),and MDA-MB-231(highly invasive)in terms of their entry time to a constricted microfluidic channel.We observed that MDA-MB-231,that has the highest metastatic potential,is the most deformable cell among the three.Then,by focusing on this cell line,experimental measurements were expanded to two more constricted microchannel dimensions.The experimental deformability data in three constricted microchannel sizes for various cell sizes,enabled accurate identification of the unknown parameters of the spring-network model of the breast cancer cell line(MDA-MB-231).Our results show that the identifed parameters depend on the cell size,suggesting the need for a systematic procedure for identifying the size-dependent parameters of spring-network models of cells.As the numerical results show,the presented cell models can simulate the entry process of the cell into constricted channels with very good agreements with the measured experimental data.展开更多
Materials exhibiting auxetic properties have a negative Poisson’s ratio, which intrigued researchers to understand the behavior of auxetic structure. Several researchers focused on the different auxetic cell designs,...Materials exhibiting auxetic properties have a negative Poisson’s ratio, which intrigued researchers to understand the behavior of auxetic structure. Several researchers focused on the different auxetic cell designs, while others focused on the auxetic applications. With the advance of additive manufacturing methods, computer-aided design and finite element analysis in recent decades, auxetics have been explored. One of the interesting applications is in the field of biomedical devices or implants, especially for certain natural biomedical organs such as tissues, certain ligaments that have auxetic properties. This paper is an overview of auxetic design approaches and biomedical applications.展开更多
In this work,we introduce a novel Micro Circular Log-Periodic Antenna(MCLPA)optimized with an advanced Evolutionary Neural Network(ENN)algorithm,specifically designed to enhance terahertz(THz)radiation detection.By le...In this work,we introduce a novel Micro Circular Log-Periodic Antenna(MCLPA)optimized with an advanced Evolutionary Neural Network(ENN)algorithm,specifically designed to enhance terahertz(THz)radiation detection.By leveraging the adaptive capabilities of the ENN framework,the antenna design efficiency is significantly improved,enabling rapid prototyping and yielding highly optimized structures tailored for practical THz applications.Extensive characterization confirms that the proposed MCLPA achieves outstanding performance,including an ultra-broad operational bandwidth of 372 GHz(0.135-0.507 THz),a peak gain of 5.51 dBi,an optimal S-parameter(S11)of−13.68 dB,and a maximum radiation efficiency of 82.39%.In addition,the MCLPA exhibits superior sensitivity,low noise susceptibility,and fast response,which are key attributes for reliable and precise THz detection.When configured in array form,the design further enhances gain and directional responsiveness,demonstrating the scalability and deployment potential of the MCLPA.This ENN-driven MCLPA represents a significant breakthrough in THz antenna engineering,introducing a transformative design paradigm that synergistically integrates algorithmic intelligence with structural innovation.By substantially reducing design time and cost while achieving exceptional performance,the proposed ENN framework sets a new benchmark for the development of next-generation THz detection and communication systems,offering broad implications for future high-frequency technologies.展开更多
This paper presents a novel technique for low-power generation of frequency combs(FC)over a wide frequency range.It leverages modal interactions between electrical and mechanical resonators in electrostatic NEMS opera...This paper presents a novel technique for low-power generation of frequency combs(FC)over a wide frequency range.It leverages modal interactions between electrical and mechanical resonators in electrostatic NEMS operating in air to provide a simple architecture for FC generators.A biased voltage signal drives the electrical resonator at resonance which is set to match an integer submultiple of twice the mechanical resonator’s resonance.Experimental results demonstrate that the NEMS displacement exhibit more than 150 equidistant peaks in the case of a 2:1 modal interaction and more than 60 equidistant peaks in the case of a 1:1 modal interaction.In both cases,the Free Spectral Range(FSR)was equal to the mechanical resonance frequency.Comparison between the FCs generated by the 2:1 and 1:1 modal interactions demonstrate the superiority of the former in terms of bandwidth and stability.The superior phase coherence of the FC generated via the 2:1 modal interaction was demonstrated via time-domain analysis.Our technique has the flexibility to generate multiple frequency combs and to fine-tune their FSR depending on the number of mechanical modes accessible to and the order of the activated modal interaction.It can be integrated into portable devices and is well aligned with modern miniaturization technology.展开更多
Formal systems engineering approaches to modeling misperceptions and attitudes are employed within the framework of the graph model for conflict resolution to systematically study the War of 1812 between the United St...Formal systems engineering approaches to modeling misperceptions and attitudes are employed within the framework of the graph model for conflict resolution to systematically study the War of 1812 between the United States of America and Great Britain in order to provide enhanced insights into the causes of the war. More specifically, relational definitions for preferences, movements and stability concepts are defined for describing the attitudes and associated behavior of decision makers involved in a conflict. To capture misperceptions of decision makers in the War of 1812, attitudes are studied within the structure of a hypergame. Combining attitudes and misperceptions within the paradigm of the graph model furnishes the flexible analytical tool which demonstrates that misunderstanding of attitudes by Great Britain and the United States may have contributed to the outbreak of this nasty war.展开更多
A comparison of two decision analysis tools for the analysis of strategic conflicts, the Analytic Network Process （ANP） and the graph model for conflict resolution, is carried out by applying them to the China-US TV...A comparison of two decision analysis tools for the analysis of strategic conflicts, the Analytic Network Process （ANP） and the graph model for conflict resolution, is carried out by applying them to the China-US TV dumping conflict. Firstly, the graph model is introduced along with practical procedures for modeling and analyzing conflicts using the decision support software, GMCR Ⅱ. Next, ANP is explained, emphasizing structural features and procedures for synthesizing priorities. Then a framework for employing ANP to analyze strategic conflicts is designed and used to compare ANP to the graph model. The case study of the China-US TV dumping conflict provides a basis for the graph model and ANP to be compared; different features of the approaches are highlighted. The study shows that because of different theoretical backgrounds, ANP and the graph model for conflict analysis both provide useful information which can be combined to furnish a better understanding of a strategic conflict.展开更多
A novel approach for assessing the robustness of an equilibrium in conflict resolution is presented. Roughly, an equilibrium is robust if it is resilient, or resistant to deviation. Robustness assessment is based on a...A novel approach for assessing the robustness of an equilibrium in conflict resolution is presented. Roughly, an equilibrium is robust if it is resilient, or resistant to deviation. Robustness assessment is based on a new concept called Level of Freedom, which evaluates the relative freedom of a decision maker to escape an equilibrium. Resolutions of a conflict can be affected by changes in decision makers＇ preferences, which may destabilize an equilibrium, causing the conflict to evolve. Hence, a conflict may become long-term and thereby continue to evolve, even after reaching an equilibrium. The new robustness measure is used to rank equilibria based on robustness, to facilitate distinguishing equiiibria that are relatively sustainable. An absolutely robust equilibrium is a special case in which the level of freedom is at an absolute minimum for each individual stability definition.展开更多
The strategic decisions and resulting consequences surrounding the conflict between the United States of America (US) and Iran regarding the Iranian nuclear program are formally investigated using a flexible decision ...The strategic decisions and resulting consequences surrounding the conflict between the United States of America (US) and Iran regarding the Iranian nuclear program are formally investigated using a flexible decision methodology called the Graph Model for Conflict Resolution (GMCR). This highly controversial dispute caught the world's attention as concerns were growing that Iran would reach a position where it would be able to build nuclear weapons, thereby posing a risk to world security. While Iran insisted on its rights for the peaceful use of nuclear technology;the international community;led by the US, tried to discourage the nuclear activities of Iran to ensure its obligations to the non-proliferation of nuclear weapons. This led to an escalation of tension on both sides, with an extension of the nuclear program by Iran and an increase in sanctions by the US, before it was possible to arrive at a negotiated agreement. As demonstrated in this paper, a systematic GMCR investigation provides valuable strategic insights into this important conflict. Further, it illustrates ways in which the conflict could have evolved, as well as mechanisms for stopping an escalation like this in the future.展开更多
Dempster-Shafer Theory (DST) and the Analytic Hierarchy Process (AHP) are integrated in order to elicit preference information from experts regarding decision makers (DMs) involved in a regulatory conflict. More preci...Dempster-Shafer Theory (DST) and the Analytic Hierarchy Process (AHP) are integrated in order to elicit preference information from experts regarding decision makers (DMs) involved in a regulatory conflict. More precisely, DST is used for combining expert knowledge regarding preferences of a specific DM (the regulatory body), and AHP is employed for ranking feasible states in the conflict for this same DM. In order to illustrate how this preference elicitation proposal can be conveniently implemented in practice within the Graph Model for Conflict Resolution (GMCR), it is applied to a real construction dispute located in the city of Ipojuca, Brazil. The conflict is modeled with three DMs: support, opposition, and the regulatory body. Results show that the new preference methodology possesses many inherent advantages including high flexibility the ability to capture uncertainty or even ignorance about preferences, the possibility of combining expert knowledge with respect to missing preferences, and a substantial reduction in the number of pairwise comparisons of states required to express preference information.展开更多
The real-time model-based control of polymer electrolyte membrane(PEM)fuel cells requires a computationally efficient and sufficiently accurate model to predict the transient and long-term performance under various op...The real-time model-based control of polymer electrolyte membrane(PEM)fuel cells requires a computationally efficient and sufficiently accurate model to predict the transient and long-term performance under various operational conditions,involving the pressure,temperature,humidity,and stoichiometry ratio.In this article,recent progress on the development of PEM fuel cell models that can be used for real-time control is reviewed.The major operational principles of PEM fuel cells and the associated mathematical description of the transport and electrochemical phenomena are described.The reduced-dimensional physics-based models(pseudo-twodimensional,one-dimensional numerical and zero dimensional analytical models)and the non-physics-based models(zero-dimensional empirical and data-driven models)have been systematically examined,and the comparison of these models has been performed.It is found that the current trends for the real-time control models are(i)to couple the single cell model with balance of plants to investigate the system performance,(ii)to incorporate aging effects to enable long-term performance prediction,(iii)to increase the computational speed(especially for one-dimensional numerical models),and(iv)to develop data-driven models with artificial intelligence/machine learning algorithms.This review will be beneficial for the development of physics or nonphysics based models with sufficient accuracy and computational speed to ensure the real-time control of PEM fuel cells.展开更多
Sensitivity analyses based on an algebraic representation in the graph model for conflict resolution (GMCR) are generalized for ascertaining the robustness of stability results by varying decision makers' preferen...Sensitivity analyses based on an algebraic representation in the graph model for conflict resolution (GMCR) are generalized for ascertaining the robustness of stability results by varying decision makers' preference ranking.The ordinal preferences in GMCR are advantageous to carry out sensitivity analyses with respect to systematically identifying the influence of preference alterations upon the four basic stabilities consisting of Nash stability,general metarationality,symmetric metarationality and sequential stability.The proposed algebraic representation of the four basic stabilities is not only effective and convenient for computer implementation of sensitivity analysis,but also makes it easier to understand the meaning of the four stabilities when compared with the existing matrix representation.Further,these sensitivity analyses results are embedded into the latest version of the decision support system NUAAGMCR,which can be used to study real-world conflicts.To illustrate how these contributions to sensitivity analyses can be applied in practice and provide valuable strategic insights,they are used to investigate the civil war conflict in South Sudan.展开更多
In 1951 Professor Weimin Zheng returned to the People＇s Republic of China from the United Kingdom to assist in building his country into a modern nation. Rather than pursue a doctoral degree at the California Institu...In 1951 Professor Weimin Zheng returned to the People＇s Republic of China from the United Kingdom to assist in building his country into a modern nation. Rather than pursue a doctoral degree at the California Institute of Technology, or Caltech as it is popularly called, Professor Zheng, unselfishly and patriotically, decided that he would devote his many talents to providing a first-class education to Chinese students within a strong university system. In particular,展开更多
MEMS/NEMS resonant sensors hold promise for minute mass and force sensing.However,one major challenge is that conventional externally driven sensors inevitably encounter undesired intrinsic noise,which imposes a funda...MEMS/NEMS resonant sensors hold promise for minute mass and force sensing.However,one major challenge is that conventional externally driven sensors inevitably encounter undesired intrinsic noise,which imposes a fundamental limitation upon their signal-to-noise ratio(SNR)and,consequently,the resolution.Particularly,this restriction becomes increasingly pronounced as sensors shrink to the nanoscale.In this work,we propose a counterintuitive paradigm shift that turns intrinsic thermal noise from an impediment to a constituent of the sensor by harvesting it as the driving force,obviating the need for external actuation and realizing‘noise-driven’sensors.Those sensors employ the dynamically amplified response to thermal noise at resonances for stimulus detection.We demonstrate that lightly damped and highly compliant nano-structures with high aspect ratios are promising candidates for this class of sensors.To overcome the phase incoherence of the drive force,three noise-enabled quantitative sensing mechanisms are developed.We validated our sensor paradigm by experimental demonstrating noise-driven pressure and temperature sensors.Noise-driven sensors offer a new opportunity for delivering practical NEMS sensors that can function at room temperature and under ambient pressure,and a development that suggests a path to cheaper,simpler,and low-power-consumption sensors.展开更多
文摘Effect of viscosity on flow patterns of pumping-up of liquid generated by a cone rotating at the liquid surface has been experimentally studied with various concentrations of glycerol aqueous solution. We have previously found that the higher viscous non-Newtonian fluid was lifted-up along the conical surface with a radial filament-wise pattern, which is quite different from the monotonic thin film-wise pattern observed for the lower viscous fluid such as water. In order to elucidate the pumping-up mechanism, a transition diagram indicating the critical rotation rate is obtained as a function of viscosity?of Newtonian fluid in this study, varying from the lower value of water (μ?=?0.890 mPa·s) to the higher one of glycerin (μ?= 910?mPa·s). It is found that there are three categories depending on the viscosity classified as?1) film-wise pumping-up region for the viscosity?μ?≤?134?mPa·s,?2) filament-wise pumping-up one for the viscosity?μ?≥?520?mPa·s, and?3) no pumping-up phenomenon occurs?for 134??μ??mPa·s.
文摘The modified normal form approach presented by ZHANG Wei-yi, K Huseyin and CHEN Yu-shu is further extended and a different procedure is introduced which lends itself readily to symbolic calculations, like MAPLE. This provides a number of significant advantages over the previous approach, and facilitates the associated calculations. To illustrate the new approach, three examples are presented.
文摘The processes of globalization, the consequences of which are evident in all comers and at all levels of the contemporary world are linked to an increasing homogenization. Disciplines of architecture and urban design contribute to that process, which is affecting the very definitions of place and identity. A desire to maintain and （re）create local identity within the context of that increasingly global world is connected to reviving of the past or to various interpretations of history, and preservation of the built environment of the place. This paper identifies peculiar processes of creation and maintenance of identity of place in the precincts of Tokyo Yanaka, Nezu and Sendagi, known as Yanesen. The authors argue that in Yanesen innovation appears as the byproduct of complex and creative responses to the threats of globalization, within a perpetual interplay of persistence and change. The paper opens a number of questions of where and how innovation in built environment can contribute to persistence of place identity.
文摘At the present time, ultrasonic motors have been developed for a variety of purposes such as linear motion drives and rotational drives. The elaboration of an ultrasonic motor is time-consuming, because it is developed adapting on its application. In this study, a new ultrasonic motor structure that combines a piezoelectric element and a metallic plate is elaborated. The driving principle of this motor is that the metal plate is bent to an inchworm shape and rotates the rotor when the piezoelectric element is stretched. The objective of this study is to verify the functioning of the new motor experimentally.
基金financially supported by the Project funded by the National Natural Science Foundation of China(No.61401047)the China Postdoctoral Science Foundation(No.2018M633349)+1 种基金the Oversea Students Funding Project of the Department of Human Resources and Social Security of Sichuanthe Scientific Research Foundation of CUIT(No.KYQN202210)。
文摘To address the challenge of achieving both high sensitivity and a high quality factor in quartz crystal microbalance(QCM)humidity sensors,a nanodiamond(ND)/Ti_(3)C_(2)MXene composite-coated QCM humidity sensor was fabricated.The material characteristics of ND,Ti_(3)C_(2)MXene,and ND/Ti_(3)C_(2)MXene composite were analyzed by transmission electron microscopy(TEM)and Fourier transform infrared(FTIR)spectroscopy.The experimental results demonstrated that the hydrophilic ND nanoparticles coated on Ti_(3)C_(2) MXene nanosheet prevented the self-stacking of Ti_(3)C_(2)MXene and enhanced the sensitivity of Ti_(3)C_(2) MXene-based QCM humidity sensor.Moreover,the high mechanical modulus of Ti_(3)C_(2) MXene material helped ND/Ti_(3)C_(2)MXene composite-coated QCM humidity sensor to achieve a high quality factor(>20,000).ND/Ti_(3)C_(2)MXene compositecoated QCM humidity sensor exhibited a sensitivity of 82.45 Hz/%RH,a humidity hysteresis of 1.1%RH,fast response/recovery times,acceptable repeatability,and good stability from 11.3%RH to 97.3%RH.The response mechanism of ND/Ti_(3)C_(2) MXene composite-coated QCM humidity sensor was analyzed in combination with a bi-exponential kinetic adsorption model.Finally,the potential application of ND/Ti_(3)C_(2)MXene composite-coated QCM humidity sensor was demonstrated through its frequency response to wooden blocks with different moisture contents.
基金support received from a strategic grant entitled"Systems Engineering Approaches for Brownfield Redevelopment"from the Natural Sciences and Engineering Research Council(NSERC) of Canada,from the Centre for International Governance Innovation (CIGI),and from the Social Sciences and Humanities Research Council(SSHRC) of Canada
文摘A formal policy development framework, based on a system of systems （SOS） approach, is synthesized to systematically address, in an integrative and adaptive fashion, major global challenges, such as the current food and fjnancial crises, and their interactions with other key natural, societal, and technological systems. A SoS approach seeks to respect the different value systems of multiple participants, to harness complexity through effective integration, and to engage the world of uncertainty and unpredictability with an adaptive response. Faced with the present global challenges, what is needed are strategic and operational methods which lead to ethical policies, enhance integrative and adaptive management practices, and are able to direct conflict resolution in a positive direction. Policy makers need tools to model and analyze complex systems which they are trying to responsibly govern, taking into account values and risks to design and evaluate different policies. A preliminary investigation into the global food system is undertaken to understand the SoS and to provide insights on how to carry out policy development using the proposed framework.
基金supported by the National Natural Science Foundation of China(71171112 71502073+2 种基金 71601002)the Scientific Innovation Research of College Graduates in Jiangsu Province(KYZZ150094)the Anhui Provincial Natural Science Foundation(1708085MG168)
文摘A dynamic hesitant fuzzy linguistic group decisionmaking(DHFLGDM) problem is studied from the perspective of information reliability based on the theory of hesitant fuzzy linguistic term sets(HFLTSs). First, an approach is applied to transform the dynamic HFLTSs(DHFLTSs) into a set of proportional linguistic terms to eliminate the time dimension. Second, expert reliability is measured by considering both group similarity and degree of certainty, and an optimization method is employed to quantify the linguistic terms by maximizing the group similarity. Third, through computing the attribute stability as well as its reliability, a combination rule which considers both reliability and weight is proposed to aggregate the information, and then the aggregated grade values and degree of stability are used to make a selection. Finally,the application and feasibility of the proposed method are verified through a case study and method comparison.
基金supported by the Natural Sciences and Engineering Research Council of Canada(RGPIN-2020-05522&RGPIN-2020-00428).
文摘During the multistep process of metastasis,cancer cells encounter various mechanical forces which make them deform drastically.Developing accurate in-silico models,capable of simulating the interactions between the mechanical forces and highly deformable cancer cells,can pave the way for the development of novel diagnostic and predictive methods for metastatic progression.Spring-network models of cancer cell,empowered by our recently proposed identification approach,promises a versatile numerical tool for developing experimentally validated models that can simulate complex interactions at cellular scale.Using this numerical tool,we presented spring-network models of breast cancer cells that can accurately replicate the experimental data of deformation behavior of the cells flowing in a fluidic domain and passing narrow constrictions comparable to microcapillary.First,using high-speed imaging,we experimentally studied the deformability of breast cancer cell lines with varying metastatic potential(MCF-7(less invasive),SKBR-3(medium-high invasive),and MDA-MB-231(highly invasive)in terms of their entry time to a constricted microfluidic channel.We observed that MDA-MB-231,that has the highest metastatic potential,is the most deformable cell among the three.Then,by focusing on this cell line,experimental measurements were expanded to two more constricted microchannel dimensions.The experimental deformability data in three constricted microchannel sizes for various cell sizes,enabled accurate identification of the unknown parameters of the spring-network model of the breast cancer cell line(MDA-MB-231).Our results show that the identifed parameters depend on the cell size,suggesting the need for a systematic procedure for identifying the size-dependent parameters of spring-network models of cells.As the numerical results show,the presented cell models can simulate the entry process of the cell into constricted channels with very good agreements with the measured experimental data.
文摘Materials exhibiting auxetic properties have a negative Poisson’s ratio, which intrigued researchers to understand the behavior of auxetic structure. Several researchers focused on the different auxetic cell designs, while others focused on the auxetic applications. With the advance of additive manufacturing methods, computer-aided design and finite element analysis in recent decades, auxetics have been explored. One of the interesting applications is in the field of biomedical devices or implants, especially for certain natural biomedical organs such as tissues, certain ligaments that have auxetic properties. This paper is an overview of auxetic design approaches and biomedical applications.
基金support from the Natural Sciences and Engineering Research Council of Canada(NSERC)and the Micro-Nano Technology(MNT)program facilitated by CMC Microsystems.
文摘In this work,we introduce a novel Micro Circular Log-Periodic Antenna(MCLPA)optimized with an advanced Evolutionary Neural Network(ENN)algorithm,specifically designed to enhance terahertz(THz)radiation detection.By leveraging the adaptive capabilities of the ENN framework,the antenna design efficiency is significantly improved,enabling rapid prototyping and yielding highly optimized structures tailored for practical THz applications.Extensive characterization confirms that the proposed MCLPA achieves outstanding performance,including an ultra-broad operational bandwidth of 372 GHz(0.135-0.507 THz),a peak gain of 5.51 dBi,an optimal S-parameter(S11)of−13.68 dB,and a maximum radiation efficiency of 82.39%.In addition,the MCLPA exhibits superior sensitivity,low noise susceptibility,and fast response,which are key attributes for reliable and precise THz detection.When configured in array form,the design further enhances gain and directional responsiveness,demonstrating the scalability and deployment potential of the MCLPA.This ENN-driven MCLPA represents a significant breakthrough in THz antenna engineering,introducing a transformative design paradigm that synergistically integrates algorithmic intelligence with structural innovation.By substantially reducing design time and cost while achieving exceptional performance,the proposed ENN framework sets a new benchmark for the development of next-generation THz detection and communication systems,offering broad implications for future high-frequency technologies.
基金K.M.acknowledges funding from the Canada Foundation for Innovation John R.Evans Leaders Fund(Project 35552)Ontario Research Fund—Research Infrastructure(Project 35552),the Waterloo Institute for Nanotechnology(WIN-NRC seed grant),and a Mitacs Globalink Research Award.
文摘This paper presents a novel technique for low-power generation of frequency combs(FC)over a wide frequency range.It leverages modal interactions between electrical and mechanical resonators in electrostatic NEMS operating in air to provide a simple architecture for FC generators.A biased voltage signal drives the electrical resonator at resonance which is set to match an integer submultiple of twice the mechanical resonator’s resonance.Experimental results demonstrate that the NEMS displacement exhibit more than 150 equidistant peaks in the case of a 2:1 modal interaction and more than 60 equidistant peaks in the case of a 1:1 modal interaction.In both cases,the Free Spectral Range(FSR)was equal to the mechanical resonance frequency.Comparison between the FCs generated by the 2:1 and 1:1 modal interactions demonstrate the superiority of the former in terms of bandwidth and stability.The superior phase coherence of the FC generated via the 2:1 modal interaction was demonstrated via time-domain analysis.Our technique has the flexibility to generate multiple frequency combs and to fine-tune their FSR depending on the number of mechanical modes accessible to and the order of the activated modal interaction.It can be integrated into portable devices and is well aligned with modern miniaturization technology.
文摘Formal systems engineering approaches to modeling misperceptions and attitudes are employed within the framework of the graph model for conflict resolution to systematically study the War of 1812 between the United States of America and Great Britain in order to provide enhanced insights into the causes of the war. More specifically, relational definitions for preferences, movements and stability concepts are defined for describing the attitudes and associated behavior of decision makers involved in a conflict. To capture misperceptions of decision makers in the War of 1812, attitudes are studied within the structure of a hypergame. Combining attitudes and misperceptions within the paradigm of the graph model furnishes the flexible analytical tool which demonstrates that misunderstanding of attitudes by Great Britain and the United States may have contributed to the outbreak of this nasty war.
文摘A comparison of two decision analysis tools for the analysis of strategic conflicts, the Analytic Network Process （ANP） and the graph model for conflict resolution, is carried out by applying them to the China-US TV dumping conflict. Firstly, the graph model is introduced along with practical procedures for modeling and analyzing conflicts using the decision support software, GMCR Ⅱ. Next, ANP is explained, emphasizing structural features and procedures for synthesizing priorities. Then a framework for employing ANP to analyze strategic conflicts is designed and used to compare ANP to the graph model. The case study of the China-US TV dumping conflict provides a basis for the graph model and ANP to be compared; different features of the approaches are highlighted. The study shows that because of different theoretical backgrounds, ANP and the graph model for conflict analysis both provide useful information which can be combined to furnish a better understanding of a strategic conflict.
文摘A novel approach for assessing the robustness of an equilibrium in conflict resolution is presented. Roughly, an equilibrium is robust if it is resilient, or resistant to deviation. Robustness assessment is based on a new concept called Level of Freedom, which evaluates the relative freedom of a decision maker to escape an equilibrium. Resolutions of a conflict can be affected by changes in decision makers＇ preferences, which may destabilize an equilibrium, causing the conflict to evolve. Hence, a conflict may become long-term and thereby continue to evolve, even after reaching an equilibrium. The new robustness measure is used to rank equilibria based on robustness, to facilitate distinguishing equiiibria that are relatively sustainable. An absolutely robust equilibrium is a special case in which the level of freedom is at an absolute minimum for each individual stability definition.
文摘The strategic decisions and resulting consequences surrounding the conflict between the United States of America (US) and Iran regarding the Iranian nuclear program are formally investigated using a flexible decision methodology called the Graph Model for Conflict Resolution (GMCR). This highly controversial dispute caught the world's attention as concerns were growing that Iran would reach a position where it would be able to build nuclear weapons, thereby posing a risk to world security. While Iran insisted on its rights for the peaceful use of nuclear technology;the international community;led by the US, tried to discourage the nuclear activities of Iran to ensure its obligations to the non-proliferation of nuclear weapons. This led to an escalation of tension on both sides, with an extension of the nuclear program by Iran and an increase in sanctions by the US, before it was possible to arrive at a negotiated agreement. As demonstrated in this paper, a systematic GMCR investigation provides valuable strategic insights into this important conflict. Further, it illustrates ways in which the conflict could have evolved, as well as mechanisms for stopping an escalation like this in the future.
文摘Dempster-Shafer Theory (DST) and the Analytic Hierarchy Process (AHP) are integrated in order to elicit preference information from experts regarding decision makers (DMs) involved in a regulatory conflict. More precisely, DST is used for combining expert knowledge regarding preferences of a specific DM (the regulatory body), and AHP is employed for ranking feasible states in the conflict for this same DM. In order to illustrate how this preference elicitation proposal can be conveniently implemented in practice within the Graph Model for Conflict Resolution (GMCR), it is applied to a real construction dispute located in the city of Ipojuca, Brazil. The conflict is modeled with three DMs: support, opposition, and the regulatory body. Results show that the new preference methodology possesses many inherent advantages including high flexibility the ability to capture uncertainty or even ignorance about preferences, the possibility of combining expert knowledge with respect to missing preferences, and a substantial reduction in the number of pairwise comparisons of states required to express preference information.
基金This work received financial support from Toyota Motor Engineering&Manufacturing North America,Inc.,Toyota Motor Manufacturing Canada,and Natural Sciences and Engineering Research Council of Canada through a Collaborative Research and Development Grant with the project number of CRDPJ 543945-19.
文摘The real-time model-based control of polymer electrolyte membrane(PEM)fuel cells requires a computationally efficient and sufficiently accurate model to predict the transient and long-term performance under various operational conditions,involving the pressure,temperature,humidity,and stoichiometry ratio.In this article,recent progress on the development of PEM fuel cell models that can be used for real-time control is reviewed.The major operational principles of PEM fuel cells and the associated mathematical description of the transport and electrochemical phenomena are described.The reduced-dimensional physics-based models(pseudo-twodimensional,one-dimensional numerical and zero dimensional analytical models)and the non-physics-based models(zero-dimensional empirical and data-driven models)have been systematically examined,and the comparison of these models has been performed.It is found that the current trends for the real-time control models are(i)to couple the single cell model with balance of plants to investigate the system performance,(ii)to incorporate aging effects to enable long-term performance prediction,(iii)to increase the computational speed(especially for one-dimensional numerical models),and(iv)to develop data-driven models with artificial intelligence/machine learning algorithms.This review will be beneficial for the development of physics or nonphysics based models with sufficient accuracy and computational speed to ensure the real-time control of PEM fuel cells.
基金The authors would like to express their appreciation to the anonymous reviewers and Editor for their constructive comments which improved the quality of the paper. The authors are grateful for the financial support supplied by the National Natural Science Foundation of China (71471087, 71071076 and 61673209), a Discovery Grant from the National Sciences and Engineering Research Council of Canada,and the Ministry of Education Humanities and Social Science Planning Foundation of China (18YJA630128).
文摘Sensitivity analyses based on an algebraic representation in the graph model for conflict resolution (GMCR) are generalized for ascertaining the robustness of stability results by varying decision makers' preference ranking.The ordinal preferences in GMCR are advantageous to carry out sensitivity analyses with respect to systematically identifying the influence of preference alterations upon the four basic stabilities consisting of Nash stability,general metarationality,symmetric metarationality and sequential stability.The proposed algebraic representation of the four basic stabilities is not only effective and convenient for computer implementation of sensitivity analysis,but also makes it easier to understand the meaning of the four stabilities when compared with the existing matrix representation.Further,these sensitivity analyses results are embedded into the latest version of the decision support system NUAAGMCR,which can be used to study real-world conflicts.To illustrate how these contributions to sensitivity analyses can be applied in practice and provide valuable strategic insights,they are used to investigate the civil war conflict in South Sudan.
文摘In 1951 Professor Weimin Zheng returned to the People＇s Republic of China from the United Kingdom to assist in building his country into a modern nation. Rather than pursue a doctoral degree at the California Institute of Technology, or Caltech as it is popularly called, Professor Zheng, unselfishly and patriotically, decided that he would devote his many talents to providing a first-class education to Chinese students within a strong university system. In particular,
基金support of the National Natural Science Foundation of China(12032015,12202263)the Science and Technology Innovation Plan of Shanghai(21190760100)+1 种基金the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-02-E00030)the China Postdoctoral Science Foundation(2021TQ0201,2022M712069).
文摘MEMS/NEMS resonant sensors hold promise for minute mass and force sensing.However,one major challenge is that conventional externally driven sensors inevitably encounter undesired intrinsic noise,which imposes a fundamental limitation upon their signal-to-noise ratio(SNR)and,consequently,the resolution.Particularly,this restriction becomes increasingly pronounced as sensors shrink to the nanoscale.In this work,we propose a counterintuitive paradigm shift that turns intrinsic thermal noise from an impediment to a constituent of the sensor by harvesting it as the driving force,obviating the need for external actuation and realizing‘noise-driven’sensors.Those sensors employ the dynamically amplified response to thermal noise at resonances for stimulus detection.We demonstrate that lightly damped and highly compliant nano-structures with high aspect ratios are promising candidates for this class of sensors.To overcome the phase incoherence of the drive force,three noise-enabled quantitative sensing mechanisms are developed.We validated our sensor paradigm by experimental demonstrating noise-driven pressure and temperature sensors.Noise-driven sensors offer a new opportunity for delivering practical NEMS sensors that can function at room temperature and under ambient pressure,and a development that suggests a path to cheaper,simpler,and low-power-consumption sensors.
