This paper proposes modifications to the tradional Ceiling Bounce Model and uses it to characterize diffuse indoor optical wireless channel by analyzing the effect of transceiver position on signal propagation propert...This paper proposes modifications to the tradional Ceiling Bounce Model and uses it to characterize diffuse indoor optical wireless channel by analyzing the effect of transceiver position on signal propagation properties. The modified approach uses a combination of the tradional ceiling bounce method and a statistical approach. The effects of different transmitter-receiver separations and height of the ceiling on path loss and delay spread are studied in detail.展开更多
This paper presents an image-based mobile robot guidance system in an indoor space with installed artificial ceiling landmarks. The overall system, including an omni-directional mobile robot motion control, landmark i...This paper presents an image-based mobile robot guidance system in an indoor space with installed artificial ceiling landmarks. The overall system, including an omni-directional mobile robot motion control, landmark image processing and image recognition, is implemented on a single FPGA chip with one CMOS image sensor. The proposed feature representation of the artificial ceiling landmarks is invariant with respect to rotation and translation. One unique feature of the proposed ceiling landmark recognition system is that the feature points of landmarks are determined by topological information from both the foreground and background. To enhance recognition accuracy, landmark classification is performed after the mobile robot is moved to a position such that the ceiling landmark is located in the upright- top corner position of the robot’s camera image. The accuracy of the proposed artificial ceiling landmark recognition system using the nearest neighbor classification is 100% in our experiments.展开更多
This work focuses on the estimation of a duty cycle of a radiant ceiling heating system with a panel surface temperature of 35℃and a heat flux of 65 W/m2 that corresponds to a thermal comfort for sedentary occupants....This work focuses on the estimation of a duty cycle of a radiant ceiling heating system with a panel surface temperature of 35℃and a heat flux of 65 W/m2 that corresponds to a thermal comfort for sedentary occupants.The results obtained are based on the theoretical heat transfer equations that govern the radiant and natural convection heat exchange mechanisms,and experimental heat transfer coefficients available in the literature.The results of the examined radiant heating system with specific conditions showed that a duty cycle of 6.46 min alternated by 13.36 min in shutting-down position is required to assure an acceptable thermal comfort for the enclosure space occupants.In addition,the study showed that for extremely cold-temperature conditions the heating system requires a daily operating load of about 61.2%which clearly proves the efficiency of these radiant heating systems in terms of energy consumption.展开更多
After the decoupling of the US dollar from gold in 1971,US Treasuries replaced gold as the value benchmark of the international monetary system and acquired an exorbitant privilege.Subsequently,the total amount of US ...After the decoupling of the US dollar from gold in 1971,US Treasuries replaced gold as the value benchmark of the international monetary system and acquired an exorbitant privilege.Subsequently,the total amount of US debt exhibited an exponential expansion trend,unbound by any substantial constraints.The so-called debt ceiling is a partisan game rather than a rigid fiscal constraint on the United States.As long as there are no fundamental changes in the global monetary system,the international credit of US Treasuries will stay stable,and their trend of infinite expansion will be sustained.Massive quantitative easing policies have failed to significantly shake this stability,and the notion of global investors offloading US Treasuries is more an illusion than a fact.The exorbitant privilege of US Treasuries grants its federal government the“freedom to borrow,”shielding the American financial sector from due penalties during global financial crises and securing excessive returns in global capital cycles.In the old days when running“twin surpluses”on capital and current accounts,China kept the value of Renminbi low to support its export manufacturing sector along the southeast coast.As a result,China accumulated huge foreign exchange reserves,mainly US Treasuries.Nowadays,this practice is no longer necessary,yielding low returns and posing significant security risks.展开更多
Severe damage to suspended ceilings of metal grids and lay-in panels was observed in public buildings during the 2013 M7.0 Lushan earthquake in China. Over the past several years, suspended ceilings have been widely u...Severe damage to suspended ceilings of metal grids and lay-in panels was observed in public buildings during the 2013 M7.0 Lushan earthquake in China. Over the past several years, suspended ceilings have been widely used practice in public buildings throughout China, including government offices, schools and hospitals. To investigate the damage mechanism of suspended ceilings, a series of three-dimensional shake table tests was conducted to reproduce the observed damage. A full-scale reinforced concrete frame was constructed as the testing frame for the ceiling, which was single-story and infilled with brick masonry walls to represent the local construction of low-rise buildings. In general, the ceiling in the tests exhibited similar damage phenomena as the field observations, such as higher vulnerability of perimeter elements and extensive damage to the cross runners. However, it exhibited lower fragility in terms of peak ground/roof accelerations at the initiation of damage. Further investigations are needed to clarify the reasons for this behavior.展开更多
The architectural?complexes?of Hasan Basha Tahir?were suffering from many damages and deformation in different elements as load bearing walls, arches and wooden ceiling. Ground water, salt weathering, air pollution, b...The architectural?complexes?of Hasan Basha Tahir?were suffering from many damages and deformation in different elements as load bearing walls, arches and wooden ceiling. Ground water, salt weathering, air pollution, biological colonization and environmental aspects were the main degradation factors which caused a lot of damage and deterioration phenomena in the complexes. Horizontal and vertical cracks, salts, loss of decorations, and featured dark of the stone surface were noticed at the complexes elements. In addition, the celling of the complex was in a very bad condition;?it had lost a lot of decoration elements, cracking, soot deposition, insects’ holes, and fungi growth. This research will discuss the various deterioration phenomena that?have?effect on the main building materials and cause the damages and discuss the general scientific methodology of the architectural and structural conservation project which was?carried out.展开更多
A recent draft setting a mortality ceiling on Chinese hospitals as one of the criteria to assess their medical services has provoked widespread controversy among the public. Issued by the National Health and Family Pl...A recent draft setting a mortality ceiling on Chinese hospitals as one of the criteria to assess their medical services has provoked widespread controversy among the public. Issued by the National Health and Family Planning Commission （NHFPC） in late July, the draft stipulates that there should be no more than eight deaths per every 1,000 inpatients and no more than 1.4 deaths per every 1,000 inpatient operations in China＇s Class-3 genera hospitals. While for Class-2 general hospitals, the figures should remain less than four and 0.28 respectively.展开更多
The advent of biologics and small molecules in inflammatory bowel disease(IBD)has marked a significant turning point in the prognosis of IBD,decreasing the rates of corticosteroid dependence,hospitalizations and impro...The advent of biologics and small molecules in inflammatory bowel disease(IBD)has marked a significant turning point in the prognosis of IBD,decreasing the rates of corticosteroid dependence,hospitalizations and improving overall quality of life.The introduction of biosimilars has also increased affordability and enhanced access to these otherwise costly targeted therapies.Biologics do not yet represent a complete panacea:A subset of patients do not respond to first-line anti-tumor necrosis factor(TNF)-alpha agents or may subsequently demonstrate a secondary loss of response.Patients who fail to respond to anti-TNF agents typically have a poorer response rate to second-line biologics.It is uncertain which patient would benefit from a different sequencing of biologics or even a combination of biologic agents.The introduction of newer classes of biologics and small molecules may provide alternative therapeutic targets for patients with refractory disease.This review examines the therapeutic ceiling in current treatment strategies of IBD and the potential paradigm shifts in the future.展开更多
文摘This paper proposes modifications to the tradional Ceiling Bounce Model and uses it to characterize diffuse indoor optical wireless channel by analyzing the effect of transceiver position on signal propagation properties. The modified approach uses a combination of the tradional ceiling bounce method and a statistical approach. The effects of different transmitter-receiver separations and height of the ceiling on path loss and delay spread are studied in detail.
文摘This paper presents an image-based mobile robot guidance system in an indoor space with installed artificial ceiling landmarks. The overall system, including an omni-directional mobile robot motion control, landmark image processing and image recognition, is implemented on a single FPGA chip with one CMOS image sensor. The proposed feature representation of the artificial ceiling landmarks is invariant with respect to rotation and translation. One unique feature of the proposed ceiling landmark recognition system is that the feature points of landmarks are determined by topological information from both the foreground and background. To enhance recognition accuracy, landmark classification is performed after the mobile robot is moved to a position such that the ceiling landmark is located in the upright- top corner position of the robot’s camera image. The accuracy of the proposed artificial ceiling landmark recognition system using the nearest neighbor classification is 100% in our experiments.
文摘This work focuses on the estimation of a duty cycle of a radiant ceiling heating system with a panel surface temperature of 35℃and a heat flux of 65 W/m2 that corresponds to a thermal comfort for sedentary occupants.The results obtained are based on the theoretical heat transfer equations that govern the radiant and natural convection heat exchange mechanisms,and experimental heat transfer coefficients available in the literature.The results of the examined radiant heating system with specific conditions showed that a duty cycle of 6.46 min alternated by 13.36 min in shutting-down position is required to assure an acceptable thermal comfort for the enclosure space occupants.In addition,the study showed that for extremely cold-temperature conditions the heating system requires a daily operating load of about 61.2%which clearly proves the efficiency of these radiant heating systems in terms of energy consumption.
文摘After the decoupling of the US dollar from gold in 1971,US Treasuries replaced gold as the value benchmark of the international monetary system and acquired an exorbitant privilege.Subsequently,the total amount of US debt exhibited an exponential expansion trend,unbound by any substantial constraints.The so-called debt ceiling is a partisan game rather than a rigid fiscal constraint on the United States.As long as there are no fundamental changes in the global monetary system,the international credit of US Treasuries will stay stable,and their trend of infinite expansion will be sustained.Massive quantitative easing policies have failed to significantly shake this stability,and the notion of global investors offloading US Treasuries is more an illusion than a fact.The exorbitant privilege of US Treasuries grants its federal government the“freedom to borrow,”shielding the American financial sector from due penalties during global financial crises and securing excessive returns in global capital cycles.In the old days when running“twin surpluses”on capital and current accounts,China kept the value of Renminbi low to support its export manufacturing sector along the southeast coast.As a result,China accumulated huge foreign exchange reserves,mainly US Treasuries.Nowadays,this practice is no longer necessary,yielding low returns and posing significant security risks.
基金Research fund for earthquake engineering of China Earthquake Administration(201508023)a project of the National Science&Technology Support Program during the Twelfth Five-year Plan Period of China(2015BAK17B03)a general program of National Natural Science Foundation of China(51578515)
文摘Severe damage to suspended ceilings of metal grids and lay-in panels was observed in public buildings during the 2013 M7.0 Lushan earthquake in China. Over the past several years, suspended ceilings have been widely used practice in public buildings throughout China, including government offices, schools and hospitals. To investigate the damage mechanism of suspended ceilings, a series of three-dimensional shake table tests was conducted to reproduce the observed damage. A full-scale reinforced concrete frame was constructed as the testing frame for the ceiling, which was single-story and infilled with brick masonry walls to represent the local construction of low-rise buildings. In general, the ceiling in the tests exhibited similar damage phenomena as the field observations, such as higher vulnerability of perimeter elements and extensive damage to the cross runners. However, it exhibited lower fragility in terms of peak ground/roof accelerations at the initiation of damage. Further investigations are needed to clarify the reasons for this behavior.
文摘The architectural?complexes?of Hasan Basha Tahir?were suffering from many damages and deformation in different elements as load bearing walls, arches and wooden ceiling. Ground water, salt weathering, air pollution, biological colonization and environmental aspects were the main degradation factors which caused a lot of damage and deterioration phenomena in the complexes. Horizontal and vertical cracks, salts, loss of decorations, and featured dark of the stone surface were noticed at the complexes elements. In addition, the celling of the complex was in a very bad condition;?it had lost a lot of decoration elements, cracking, soot deposition, insects’ holes, and fungi growth. This research will discuss the various deterioration phenomena that?have?effect on the main building materials and cause the damages and discuss the general scientific methodology of the architectural and structural conservation project which was?carried out.
文摘A recent draft setting a mortality ceiling on Chinese hospitals as one of the criteria to assess their medical services has provoked widespread controversy among the public. Issued by the National Health and Family Planning Commission （NHFPC） in late July, the draft stipulates that there should be no more than eight deaths per every 1,000 inpatients and no more than 1.4 deaths per every 1,000 inpatient operations in China＇s Class-3 genera hospitals. While for Class-2 general hospitals, the figures should remain less than four and 0.28 respectively.
文摘The advent of biologics and small molecules in inflammatory bowel disease(IBD)has marked a significant turning point in the prognosis of IBD,decreasing the rates of corticosteroid dependence,hospitalizations and improving overall quality of life.The introduction of biosimilars has also increased affordability and enhanced access to these otherwise costly targeted therapies.Biologics do not yet represent a complete panacea:A subset of patients do not respond to first-line anti-tumor necrosis factor(TNF)-alpha agents or may subsequently demonstrate a secondary loss of response.Patients who fail to respond to anti-TNF agents typically have a poorer response rate to second-line biologics.It is uncertain which patient would benefit from a different sequencing of biologics or even a combination of biologic agents.The introduction of newer classes of biologics and small molecules may provide alternative therapeutic targets for patients with refractory disease.This review examines the therapeutic ceiling in current treatment strategies of IBD and the potential paradigm shifts in the future.
