The problem of vibration isolation by rectangular open trenches in a plane strain context is numerically studied using a finite element code, PLAXIS. The soil media is assumed to be linear elastic, isotropic, and homo...The problem of vibration isolation by rectangular open trenches in a plane strain context is numerically studied using a finite element code, PLAXIS. The soil media is assumed to be linear elastic, isotropic, and homogeneous subjected to a vertical harmonic load producing steady-state vibration. The present model is validated by comparing it with previously published works. The key geometrical features of a trench, i.e., its depth, width, and distance from the source of excitation, are normalized with respect to the Rayleigh wavelength. The attenuation of vertical and horizontal components of vibration is studied for various trench dimensions against trench locations varied from an active to a passive case. Results are depicted in non-dimensional forms and conclusions are drawn regarding the effects of geometrical parameters in attenuating vertical and horizontal vibration components. The screening efficiency is primarily governed by the normalized depth of the barrier. The effect of width has little significance except in some specific cases. Simplified regression models are developed to estimate average amplitude reduction factors. The models applicable to vertical vibration cases are found to be in excellent agreement with previously published results.展开更多
Objective:This study aimed to investigate the nurses’perspectives on open family visitation and its barriers and facilitators in neonatal intensive care units(NICUs).Methods:This is a descriptive,cross-sectional stud...Objective:This study aimed to investigate the nurses’perspectives on open family visitation and its barriers and facilitators in neonatal intensive care units(NICUs).Methods:This is a descriptive,cross-sectional study.A total of 113 nurses employed in 3 main NICUs of Tabriz participated in the study through the census sampling method.Nurses’perspectives on open visitation and its facilitators and barriers were assessed and analyzed using the Beliefs and Attitudes toward Visitation in NICU Questionnaire(BAVNIQ)and descriptive and analytical statistics,respectively.Results:Approximately 74%of the nurses who participating in the study had a moderate perspective on open visitation.From the nurses’viewpoint,“Parents’low awareness of sensitivity and hygienic principles of the NICU”was the first(90.3%)barrier,and the 2 factors,namely,“physical structure of the ward/lack of sufficient space”and“far distance between family’s residence and the hospital/having another child,”were the second(86.8%)barrier with an equal percentage.Among the facilitating factors,“Supporting employed parents during the neonate’s hospitalization”and“providing facilities for family accommodation in the hospital”were the first(82.3%)and the second(79.6%)facilitators,respectively,for open visitation.Conclusions:The majority of NICU nurses had a moderate perspective on the family open visitation.This reluctance seems to be originated mainly from the factors inhibiting open visitation,making its implementation challenging for nurses.The perspective of the frontline staff in caring for vulnerable infants on facilitators and barriers to open visitation may help policymakers,managers,and relevant officials in decision-making and implementing new visiting policies in the NICUs.展开更多
Too high energy consumption is widely recognized to be a critical problem in large-scale parallel computing systems.The LogP-based energy-saving model and the frequency scaling method were proposed to reduce energy co...Too high energy consumption is widely recognized to be a critical problem in large-scale parallel computing systems.The LogP-based energy-saving model and the frequency scaling method were proposed to reduce energy consumption analytically and systematically for other two representative barrier algorithms:tournament barrier and central counter barrier.Furthermore,energy optimization methods of these two barrier algorithms were implemented on parallel computing platform.The experimental results validate the effectiveness of the energy optimization methods.67.12% and 70.95% energy savings are obtained respectively for tournament barrier and central counter barrier on platforms with 2048 processes with 1.55%?8.80% performance loss.Furthermore,LogP-based energy-saving analytical model for these two barrier algorithms is highly accurate as the predicted energy savings are within 9.67% of the results obtained by simulation.展开更多
文摘The problem of vibration isolation by rectangular open trenches in a plane strain context is numerically studied using a finite element code, PLAXIS. The soil media is assumed to be linear elastic, isotropic, and homogeneous subjected to a vertical harmonic load producing steady-state vibration. The present model is validated by comparing it with previously published works. The key geometrical features of a trench, i.e., its depth, width, and distance from the source of excitation, are normalized with respect to the Rayleigh wavelength. The attenuation of vertical and horizontal components of vibration is studied for various trench dimensions against trench locations varied from an active to a passive case. Results are depicted in non-dimensional forms and conclusions are drawn regarding the effects of geometrical parameters in attenuating vertical and horizontal vibration components. The screening efficiency is primarily governed by the normalized depth of the barrier. The effect of width has little significance except in some specific cases. Simplified regression models are developed to estimate average amplitude reduction factors. The models applicable to vertical vibration cases are found to be in excellent agreement with previously published results.
基金supported by Pediatric Health Research Center,Tabriz University of Medical Sciences(Grant number:IR.TBZMED.REC.1398.585).
文摘Objective:This study aimed to investigate the nurses’perspectives on open family visitation and its barriers and facilitators in neonatal intensive care units(NICUs).Methods:This is a descriptive,cross-sectional study.A total of 113 nurses employed in 3 main NICUs of Tabriz participated in the study through the census sampling method.Nurses’perspectives on open visitation and its facilitators and barriers were assessed and analyzed using the Beliefs and Attitudes toward Visitation in NICU Questionnaire(BAVNIQ)and descriptive and analytical statistics,respectively.Results:Approximately 74%of the nurses who participating in the study had a moderate perspective on open visitation.From the nurses’viewpoint,“Parents’low awareness of sensitivity and hygienic principles of the NICU”was the first(90.3%)barrier,and the 2 factors,namely,“physical structure of the ward/lack of sufficient space”and“far distance between family’s residence and the hospital/having another child,”were the second(86.8%)barrier with an equal percentage.Among the facilitating factors,“Supporting employed parents during the neonate’s hospitalization”and“providing facilities for family accommodation in the hospital”were the first(82.3%)and the second(79.6%)facilitators,respectively,for open visitation.Conclusions:The majority of NICU nurses had a moderate perspective on the family open visitation.This reluctance seems to be originated mainly from the factors inhibiting open visitation,making its implementation challenging for nurses.The perspective of the frontline staff in caring for vulnerable infants on facilitators and barriers to open visitation may help policymakers,managers,and relevant officials in decision-making and implementing new visiting policies in the NICUs.
基金Projects(60903044,61170049) supported by National Natural Science Foundation of China
文摘Too high energy consumption is widely recognized to be a critical problem in large-scale parallel computing systems.The LogP-based energy-saving model and the frequency scaling method were proposed to reduce energy consumption analytically and systematically for other two representative barrier algorithms:tournament barrier and central counter barrier.Furthermore,energy optimization methods of these two barrier algorithms were implemented on parallel computing platform.The experimental results validate the effectiveness of the energy optimization methods.67.12% and 70.95% energy savings are obtained respectively for tournament barrier and central counter barrier on platforms with 2048 processes with 1.55%?8.80% performance loss.Furthermore,LogP-based energy-saving analytical model for these two barrier algorithms is highly accurate as the predicted energy savings are within 9.67% of the results obtained by simulation.
