Eliminating the effects of gravity and designing nonlinear energy sinks(NESs)that suppress vibration in the vertical direction is a challenging task with numerous damping requirements.In this paper,the dynamic design ...Eliminating the effects of gravity and designing nonlinear energy sinks(NESs)that suppress vibration in the vertical direction is a challenging task with numerous damping requirements.In this paper,the dynamic design of a vertical track nonlinear energy sink(VTNES)with zero linear stiffness in the vertical direction is proposed and realized for the first time.The motion differential equations of the VTNES coupled with a linear oscillator(LO)are established.With the strong nonlinearity considered of the VTNES,the steady-state response of the system is analyzed with the harmonic balance method(HBM),and the accuracy of the HBM is verified numerically.On this basis,the VTNES prototype is manufactured,and its nonlinear stiffness is identified.The damping effect and dynamic characteristics of the VTNES are studied theoretically and experimentally.The results show that the VTNES has better damping effects when strong modulation responses(SMRs)occur.Moreover,even for small-amplitude vibration,the VTNES also has a good vibration suppression effect.To sum up,in order to suppress the vertical vibration,an NES is designed and developed,which can suppress the vertical vibration within certain ranges of the resonance frequency and the vibration intensity.展开更多
The purpose of this study was to assess the effectiveness of interventions based on health promotion theories in changing the recycling behavior of the targeted population. The study focused on the development and eva...The purpose of this study was to assess the effectiveness of interventions based on health promotion theories in changing the recycling behavior of the targeted population. The study focused on the development and evaluation of innovative recycling education programs that address energy recovery, recycling, and waste management. The study applied Health Belief Model-(HBM) as an approach to motivate recycling behaviors and to evaluate the impact of the applied approaches on recycling set-out rates and participation. A total of 102 households from a Midwestern city participated in this study. The study was conducted over a period of six months. A Likert scale questionnaire was used to collect data on recycling and environmental knowledge, skills, behavior, and attitudes. The other set of data was the weight of recyclables that was obtained at each participant’s curb four times over the six months period of interventions. Results indicated a significant increase in average set out rates of recyclables among HBM participants (21.34 lbs. pre-test to 59.3 lbs. post-test). It was concluded that HBM educational approaches can be effective in motivating recycling. This study signifies the need for renewed effort in motivating individuals, households or businesses to recycle. Not every community or city significantly participates in recycling. Innovative strategies as well the application of approaches in the theories of behavioral change can positively influence recycling and overall waste reduction behaviors.展开更多
采用常规的人体模型(Human Body Model,HBM)进行静电释放(Electro-Static Discharge,ESD)测试时往往容易受到寄生参数的影响,使得电源芯片抗静电能力测量值与实际抗静电能力存在偏差,导致劣质产品通过HBM ESD测试,影响电源芯片产品良品...采用常规的人体模型(Human Body Model,HBM)进行静电释放(Electro-Static Discharge,ESD)测试时往往容易受到寄生参数的影响,使得电源芯片抗静电能力测量值与实际抗静电能力存在偏差,导致劣质产品通过HBM ESD测试,影响电源芯片产品良品率的提升。为此,提出了一种RC-HBM模型,通过引入RC并联支路,校正因寄生参数引起的静电放电电流的偏差,满足电源芯片静电可靠性测试的要求。首先阐述了静电对电源芯片的损坏机理。其次,分析了寄生参数对ESD电流的影响,阐述了常规HBM ESD测试的局限性。并提出了一种新型的RC-HBM模型,给出了RC并联支路参数的设计依据。最后,通过批量实验验证了所提RC-HBM模型的准确性和合理性。展开更多
The coupling vibration of a hydraulic pipe system consisting of two pipes is studied.The pipes are installed in parallel and fixed at their ends,and are restrained by clips to one bracket at their middle points.The pi...The coupling vibration of a hydraulic pipe system consisting of two pipes is studied.The pipes are installed in parallel and fixed at their ends,and are restrained by clips to one bracket at their middle points.The pipe subjected to the basement excitation at the left end is named as the active pipe,while the pipe without excitation is called the passive pipe.The clips between the two pipes are the bridge for the vibration energy.The adjacent natural frequencies will enhance the vibration coupling.The governing equation of the coupled system is deduced by the generalized Hamilton principle,and is discretized to the modal space.The modal correction is used during the discretization.The investigation on the natural characters indicates that the adjacent natural frequencies can be adjusted by the stiffness of the two clips and bracket.The harmonic balance method(HBM)is used to study the responses in the adjacent natural frequency region.The results show that the vibration energy transmits from the active pipe to the passive pipe swimmingly via the clips together with a flexible bracket,while the locations of them are not node points.The adjacent natural frequencies may arouse wide resonance curves with two peaks for both pipes.The stiffness of the clip and bracket can release the vibration coupling.It is suggested that the stiffness of the clip on the passive pipe should be weak and the bracket should be strong enough.In this way,the vibration energy is reflected by the almost rigid bracket,and is hard to transfer to the passive pipe via a soft clip.The best choice is to set the clips at the pipe node points.The current work gives some suggestions for weakening the coupled vibration during the dynamic design of a coupled hydraulic pipe system.展开更多
In this study,a coupling model of fluid-conveying pipes made of functionally graded materials(FGMs)with NiTiNOL-steel(NiTi-ST)for vibration absorption is investigated.The vibration responses of the FGM fluid-conveying...In this study,a coupling model of fluid-conveying pipes made of functionally graded materials(FGMs)with NiTiNOL-steel(NiTi-ST)for vibration absorption is investigated.The vibration responses of the FGM fluid-conveying pipe with NiTi-ST are studied by the Galerkin truncation method(GTM)and harmonic balance method(HBM).The harmonic balance solutions and the numerical results are consistent.Also,the linearized stability of the structure is determined.The effects of the structure parameters on the absorption performance are also studied.The results show that the NiTi-ST is an effective means of vibration absorption.Furthermore,in studying the effect of the NiTi-ST,a closed detached response(CDR)is first observed.It is noteworthy that the CDR may dramatically change the vibration amplitude and that the parameters of the NiTi-ST may determine the emergence or disappearance of the CDR.This vibration absorption device can be extended to offer more general vibration control in engineering applications.展开更多
The harmonic balance method(HBM)is one of the most widely used methods in solving nonlinear vibration problems,and its accuracy and computational efficiency largely depend on the number of the harmonics selected.The a...The harmonic balance method(HBM)is one of the most widely used methods in solving nonlinear vibration problems,and its accuracy and computational efficiency largely depend on the number of the harmonics selected.The adaptive harmonic balance(AHB)method is an improved HBM method.This paper presents a modified AHB method with the asymptotic harmonic selection(AHS)procedure.This new harmonic selection procedure selects harmonics from the frequency spectra of nonlinear terms instead of estimating the contribution of each harmonic to the whole nonlinear response,by which the additional calculation is avoided.A modified continuation method is proposed to deal with the variable size of nonlinear algebraic equations at different values of path parameters,and then all solution branches of the amplitude-frequency response are obtained.Numerical experiments are carried out to verify the performance of the AHB-AHS method.Five typical nonlinear dynamic equations with different types of nonlinearities and excitations are chosen as the illustrative examples.Compared with the classical HBM and Runge-Kutta methods,the proposed AHB-AHS method is of higher accuracy and better convergence.The AHB-AHS method proposed in this paper has the potential to investigate the nonlinear vibrations of complex high-dimensional nonlinear systems.展开更多
Using an original public opinion survey, we study public attitudes and behaviors toward air pollution in Almaty, Kazakhstan. In the Health Belief Model (HBM) framework previously used to understand an individual’s he...Using an original public opinion survey, we study public attitudes and behaviors toward air pollution in Almaty, Kazakhstan. In the Health Belief Model (HBM) framework previously used to understand an individual’s health decision-making, we evaluate citizens’ awareness of the poor air quality, their perception of risk, and their willingness to devote time and resources to reduce their air pollution exposure. We find that although citizens are aware of the gravity and general harms of air pollution, they significantly underestimate their individual health risks, and, as a result, often engage in daily routines that exacerbate their exposure to pollution. We find that behaviors increasing the risk of pollution exposure are related to the underlying beliefs about personal health risks, self-efficacy, and material and economic limitations. This means that treating pollution as an individual health problem rather than social issue in public discourse may promote behaviors reducing exposure and improving personal and public health outcomes.展开更多
随着摩尔定律的放缓,通过制程微缩来提高芯片性能越来越难,基于芯粒集成的先进封装方案的重要性随之日益显现。尤其是在一些高算力芯片产品的设计上,采用芯粒集成已逐渐成为设计者们一个绕不开的性能提高手段。在2.5D先进封装方案中,CoW...随着摩尔定律的放缓,通过制程微缩来提高芯片性能越来越难,基于芯粒集成的先进封装方案的重要性随之日益显现。尤其是在一些高算力芯片产品的设计上,采用芯粒集成已逐渐成为设计者们一个绕不开的性能提高手段。在2.5D先进封装方案中,CoWoS-S(chip on wafer on substrate)封装因其高带宽、低延迟及丰富的成功量产案例而被广泛应用于片上系统芯片(SoC-system on chip)与高带宽内存(HBM-high bandwidth memory)的互连。然而,在CoWoS-S技术的硅中介层设计过程中,设计人员将面临严苛的信号完整性与电源完整性的综合挑战。为了解决这些挑战,Cadence作为EDA领域的创新者和领导者,开发了完整的EDA解决方案,以协助设计人员完成硅中介层的设计及签核任务。本文将介绍如何利用Cadence EDA解决方案来高效率地实现CoWoS-S硅中介层的设计与签核,内容聚焦于大电流区域的电源完整性设计以及HBM互连区域的信号完整性设计。展开更多
基金the China National Funds for Distinguished Young Scholars(No.12025204)。
文摘Eliminating the effects of gravity and designing nonlinear energy sinks(NESs)that suppress vibration in the vertical direction is a challenging task with numerous damping requirements.In this paper,the dynamic design of a vertical track nonlinear energy sink(VTNES)with zero linear stiffness in the vertical direction is proposed and realized for the first time.The motion differential equations of the VTNES coupled with a linear oscillator(LO)are established.With the strong nonlinearity considered of the VTNES,the steady-state response of the system is analyzed with the harmonic balance method(HBM),and the accuracy of the HBM is verified numerically.On this basis,the VTNES prototype is manufactured,and its nonlinear stiffness is identified.The damping effect and dynamic characteristics of the VTNES are studied theoretically and experimentally.The results show that the VTNES has better damping effects when strong modulation responses(SMRs)occur.Moreover,even for small-amplitude vibration,the VTNES also has a good vibration suppression effect.To sum up,in order to suppress the vertical vibration,an NES is designed and developed,which can suppress the vertical vibration within certain ranges of the resonance frequency and the vibration intensity.
文摘The purpose of this study was to assess the effectiveness of interventions based on health promotion theories in changing the recycling behavior of the targeted population. The study focused on the development and evaluation of innovative recycling education programs that address energy recovery, recycling, and waste management. The study applied Health Belief Model-(HBM) as an approach to motivate recycling behaviors and to evaluate the impact of the applied approaches on recycling set-out rates and participation. A total of 102 households from a Midwestern city participated in this study. The study was conducted over a period of six months. A Likert scale questionnaire was used to collect data on recycling and environmental knowledge, skills, behavior, and attitudes. The other set of data was the weight of recyclables that was obtained at each participant’s curb four times over the six months period of interventions. Results indicated a significant increase in average set out rates of recyclables among HBM participants (21.34 lbs. pre-test to 59.3 lbs. post-test). It was concluded that HBM educational approaches can be effective in motivating recycling. This study signifies the need for renewed effort in motivating individuals, households or businesses to recycle. Not every community or city significantly participates in recycling. Innovative strategies as well the application of approaches in the theories of behavioral change can positively influence recycling and overall waste reduction behaviors.
基金Project supported by the National Natural Science Foundation of China(No.12002195)the Pujiang Project of Shanghai Science and Technology Commission of China(No.20PJ1404000)。
文摘The coupling vibration of a hydraulic pipe system consisting of two pipes is studied.The pipes are installed in parallel and fixed at their ends,and are restrained by clips to one bracket at their middle points.The pipe subjected to the basement excitation at the left end is named as the active pipe,while the pipe without excitation is called the passive pipe.The clips between the two pipes are the bridge for the vibration energy.The adjacent natural frequencies will enhance the vibration coupling.The governing equation of the coupled system is deduced by the generalized Hamilton principle,and is discretized to the modal space.The modal correction is used during the discretization.The investigation on the natural characters indicates that the adjacent natural frequencies can be adjusted by the stiffness of the two clips and bracket.The harmonic balance method(HBM)is used to study the responses in the adjacent natural frequency region.The results show that the vibration energy transmits from the active pipe to the passive pipe swimmingly via the clips together with a flexible bracket,while the locations of them are not node points.The adjacent natural frequencies may arouse wide resonance curves with two peaks for both pipes.The stiffness of the clip and bracket can release the vibration coupling.It is suggested that the stiffness of the clip on the passive pipe should be weak and the bracket should be strong enough.In this way,the vibration energy is reflected by the almost rigid bracket,and is hard to transfer to the passive pipe via a soft clip.The best choice is to set the clips at the pipe node points.The current work gives some suggestions for weakening the coupled vibration during the dynamic design of a coupled hydraulic pipe system.
基金Project supported by the National Natural Science Foundation of China(Nos.12272240 and12022213)。
文摘In this study,a coupling model of fluid-conveying pipes made of functionally graded materials(FGMs)with NiTiNOL-steel(NiTi-ST)for vibration absorption is investigated.The vibration responses of the FGM fluid-conveying pipe with NiTi-ST are studied by the Galerkin truncation method(GTM)and harmonic balance method(HBM).The harmonic balance solutions and the numerical results are consistent.Also,the linearized stability of the structure is determined.The effects of the structure parameters on the absorption performance are also studied.The results show that the NiTi-ST is an effective means of vibration absorption.Furthermore,in studying the effect of the NiTi-ST,a closed detached response(CDR)is first observed.It is noteworthy that the CDR may dramatically change the vibration amplitude and that the parameters of the NiTi-ST may determine the emergence or disappearance of the CDR.This vibration absorption device can be extended to offer more general vibration control in engineering applications.
基金Project supported by the National Natural Science Foundation of China(Nos.11972129 and12372008)the National Major Science and Technology Projects of China(No.2017-IV-0008-0045)+3 种基金the Natural Science Foundation of Heilongjiang Province of China(No.YQ2022A008)the Fundamental Research Funds for the Central Universities of China(No.HIT.OCEF.2023006)the Polish National Science Centre of Poland under the OPUS 18 grant(No.2019/35/B/ST8/00980)the Tianjin University Independent Innovation Foundation of China(No.2023XJS-0038)。
文摘The harmonic balance method(HBM)is one of the most widely used methods in solving nonlinear vibration problems,and its accuracy and computational efficiency largely depend on the number of the harmonics selected.The adaptive harmonic balance(AHB)method is an improved HBM method.This paper presents a modified AHB method with the asymptotic harmonic selection(AHS)procedure.This new harmonic selection procedure selects harmonics from the frequency spectra of nonlinear terms instead of estimating the contribution of each harmonic to the whole nonlinear response,by which the additional calculation is avoided.A modified continuation method is proposed to deal with the variable size of nonlinear algebraic equations at different values of path parameters,and then all solution branches of the amplitude-frequency response are obtained.Numerical experiments are carried out to verify the performance of the AHB-AHS method.Five typical nonlinear dynamic equations with different types of nonlinearities and excitations are chosen as the illustrative examples.Compared with the classical HBM and Runge-Kutta methods,the proposed AHB-AHS method is of higher accuracy and better convergence.The AHB-AHS method proposed in this paper has the potential to investigate the nonlinear vibrations of complex high-dimensional nonlinear systems.
文摘Using an original public opinion survey, we study public attitudes and behaviors toward air pollution in Almaty, Kazakhstan. In the Health Belief Model (HBM) framework previously used to understand an individual’s health decision-making, we evaluate citizens’ awareness of the poor air quality, their perception of risk, and their willingness to devote time and resources to reduce their air pollution exposure. We find that although citizens are aware of the gravity and general harms of air pollution, they significantly underestimate their individual health risks, and, as a result, often engage in daily routines that exacerbate their exposure to pollution. We find that behaviors increasing the risk of pollution exposure are related to the underlying beliefs about personal health risks, self-efficacy, and material and economic limitations. This means that treating pollution as an individual health problem rather than social issue in public discourse may promote behaviors reducing exposure and improving personal and public health outcomes.
文摘随着摩尔定律的放缓,通过制程微缩来提高芯片性能越来越难,基于芯粒集成的先进封装方案的重要性随之日益显现。尤其是在一些高算力芯片产品的设计上,采用芯粒集成已逐渐成为设计者们一个绕不开的性能提高手段。在2.5D先进封装方案中,CoWoS-S(chip on wafer on substrate)封装因其高带宽、低延迟及丰富的成功量产案例而被广泛应用于片上系统芯片(SoC-system on chip)与高带宽内存(HBM-high bandwidth memory)的互连。然而,在CoWoS-S技术的硅中介层设计过程中,设计人员将面临严苛的信号完整性与电源完整性的综合挑战。为了解决这些挑战,Cadence作为EDA领域的创新者和领导者,开发了完整的EDA解决方案,以协助设计人员完成硅中介层的设计及签核任务。本文将介绍如何利用Cadence EDA解决方案来高效率地实现CoWoS-S硅中介层的设计与签核,内容聚焦于大电流区域的电源完整性设计以及HBM互连区域的信号完整性设计。
