In clinic＇s appointment scheduling system no-shows have been a significant and confirmed issue with a bad influence on patient accessibility and clinic efficiency. The problem of walk-in has often been seen as the op...In clinic＇s appointment scheduling system no-shows have been a significant and confirmed issue with a bad influence on patient accessibility and clinic efficiency. The problem of walk-in has often been seen as the opposite of no-show problem. In this work we revisit a walk-in admitting based approach to mitigate the bad influence of no-show without overbooking. First we establish a model which utilizes marginal benefit objective function to balance the interests of the clinic, the patient and the doctor, we prove that no-show and walk-in cancels out each other straightly has a bad property. Then we propose a new rule which is an extension of the well-known Bailey - Welch rule, the simulation results show that our rule has an improvement comparing with the common rule that cancels them out straightly.展开更多
The trigger voltage walkin effect has been investigated by designing two different laterally diffused metal-oxide-semiconductor （LDMOS） transistors with an embedded silicon controlled rectifier （SCR）. By inserting...The trigger voltage walkin effect has been investigated by designing two different laterally diffused metal-oxide-semiconductor （LDMOS） transistors with an embedded silicon controlled rectifier （SCR）. By inserting a P＋ implant region along the outer and the inner boundary of the N＋ region at the drain side of a conventional LDMOS transistor, we fabricate the LDMOS-SCR and the SCR-LDMOS devices with a different triggering order in a 0.5/zm bipolar-CMOS-DMOS process, respectively. First, we perform transmission line pulse （TLP） and DC-voltage degradation tests on the LDMOS-SCR. Results show that the trigger voltage walk-in effect can be attributed to the gate oxide trap generation and charge trapping. Then, we perform TLP tests on the SCR-LDMOS. Results indicate that the trigger voltage walk-in effect is remarkably reduced. In the SCR-LDMOS, the embedded SCR is triggered earlier than the LDMOS, and the ESD current is mainly discharged by the parasitic SCR structure. The electric potential between the drain and the gate decreases significantly after snapback, leading to decreased impact ionization rates and thus reduced trap generation and charge trapping. Finally, the above explanation of the different trigger voltage walk-in behavior in LDMOS-SCR and SCR-LDMOS devices is confirmed by TCAD simulation.展开更多
角度随机游走(angle random walk,ARW)误差已成为制约长航时惯性导航系统精度的主要因素。为了减弱ARW对系统精度的影响,针对初始对准和长航时导航两个方面研究误差传播规律及抑制方法。仿真结果表明:ARW直接影响方位对准精度,在长航时...角度随机游走(angle random walk,ARW)误差已成为制约长航时惯性导航系统精度的主要因素。为了减弱ARW对系统精度的影响,针对初始对准和长航时导航两个方面研究误差传播规律及抑制方法。仿真结果表明:ARW直接影响方位对准精度,在长航时的导航中,游走系数N所产生的速度振荡幅值与60N的常值漂移大致相当,姿态振荡误差中的24 h周期因素更为关键,ARW产生的经度误差发散项均方差随时间的平方根增长;系统可采用卡尔曼滤波削弱ARW所造成的对准误差,通过水平阻尼方法可以消除由ARW引起的位置误差中的振荡项。展开更多
Objective:To demonstrate the versatility of the natural soil gas harvesting technique,coupled with a semi-dynamic injection algorithm,as an efficient and reliable source for continuous ^(222)Rn delivery to a large-vol...Objective:To demonstrate the versatility of the natural soil gas harvesting technique,coupled with a semi-dynamic injection algorithm,as an efficient and reliable source for continuous ^(222)Rn delivery to a large-volume calibration chamber across different soil conditions and climatic conditions.Methods:Long-term experiments were performed during three seasons of a year in a tropical monsoonal climatic region with high rainfall on the Southwest Coast of India.Soil gas extraction was performed using soil-gas probes,inserted to 1 m deep into the ground.Soil gas was harvested at a flow rate of 60 L/min,passed through a moisture trap,a ^(222)Rn progeny filter,and a delay volume and pumped into a ^(222)Rn calibration chamber of volume 22.7 m^(3).Continuous monitoring of ^(222)Rn concentration in the chamber was performed using ionization chamber-based reference monitors.To achieve and maintain the desired ^(222)Rn concentration values in the calibration chamber,the semi-dynamic injection method was adopted,in which the ^(222)Rn concentration in the soil gas was monitored periodically,and injection into the chamber was controlled using a well-defined pumping algorithm.Three ranges of ^(222)Rn concentration values were chosen as the target values to be maintained in the calibration chamber for long-term experiments(15 d):low concentration(500-1,000 Bq/m3),medium concentration(1,000-10,000 Bq/m^(3)),and high concentration(10,000-25,000 Bq/m^(3)).Results:The achieved ^(222)Rn concentration values were in good agreement with the target values,with deviations of 12%,8% and 5% for the low,medium and high concentration exposures,respectively,during the summer season.During the monsoon season,the deviations between the target and the achieved concentration values were 12%,10% and 5% for low,medium and high concentration exposures,respectively,and the corresponding deviations were 12%,4%,and 5% for the winter season.These deviations are well within the cumulative uncertainty associated with the measurements.Conclusions:The results of this study conclusively demonstrate that the soil gas harvesting method,when coupled with the semi-dynamic injection approach,is a reliable method for generating and maintaining the desired ^(222)Rn concentration in the large volume calibration chamber during different seasons and environmental conditions.展开更多
文摘In clinic＇s appointment scheduling system no-shows have been a significant and confirmed issue with a bad influence on patient accessibility and clinic efficiency. The problem of walk-in has often been seen as the opposite of no-show problem. In this work we revisit a walk-in admitting based approach to mitigate the bad influence of no-show without overbooking. First we establish a model which utilizes marginal benefit objective function to balance the interests of the clinic, the patient and the doctor, we prove that no-show and walk-in cancels out each other straightly has a bad property. Then we propose a new rule which is an extension of the well-known Bailey - Welch rule, the simulation results show that our rule has an improvement comparing with the common rule that cancels them out straightly.
基金Project supported by the National Natural Science Foundation of China(Nos.61171038,61150110485)the Natural Science Foundation of Jiangsu Province(No.BK20130156)+2 种基金the Fundamental Research Funds for the Central Universities(Nos.JUSRP51323B,JUDCF13032)the Summit of the Six Top Talents Program of Jiangsu Province(Nos.DZXX-053 and DZXX-027)the Graduate Student Innovation Program for Universities of Jiangsu Province(No.CXLX13_747)
文摘The trigger voltage walkin effect has been investigated by designing two different laterally diffused metal-oxide-semiconductor （LDMOS） transistors with an embedded silicon controlled rectifier （SCR）. By inserting a P＋ implant region along the outer and the inner boundary of the N＋ region at the drain side of a conventional LDMOS transistor, we fabricate the LDMOS-SCR and the SCR-LDMOS devices with a different triggering order in a 0.5/zm bipolar-CMOS-DMOS process, respectively. First, we perform transmission line pulse （TLP） and DC-voltage degradation tests on the LDMOS-SCR. Results show that the trigger voltage walk-in effect can be attributed to the gate oxide trap generation and charge trapping. Then, we perform TLP tests on the SCR-LDMOS. Results indicate that the trigger voltage walk-in effect is remarkably reduced. In the SCR-LDMOS, the embedded SCR is triggered earlier than the LDMOS, and the ESD current is mainly discharged by the parasitic SCR structure. The electric potential between the drain and the gate decreases significantly after snapback, leading to decreased impact ionization rates and thus reduced trap generation and charge trapping. Finally, the above explanation of the different trigger voltage walk-in behavior in LDMOS-SCR and SCR-LDMOS devices is confirmed by TCAD simulation.
文摘角度随机游走(angle random walk,ARW)误差已成为制约长航时惯性导航系统精度的主要因素。为了减弱ARW对系统精度的影响,针对初始对准和长航时导航两个方面研究误差传播规律及抑制方法。仿真结果表明:ARW直接影响方位对准精度,在长航时的导航中,游走系数N所产生的速度振荡幅值与60N的常值漂移大致相当,姿态振荡误差中的24 h周期因素更为关键,ARW产生的经度误差发散项均方差随时间的平方根增长;系统可采用卡尔曼滤波削弱ARW所造成的对准误差,通过水平阻尼方法可以消除由ARW引起的位置误差中的振荡项。
文摘Objective:To demonstrate the versatility of the natural soil gas harvesting technique,coupled with a semi-dynamic injection algorithm,as an efficient and reliable source for continuous ^(222)Rn delivery to a large-volume calibration chamber across different soil conditions and climatic conditions.Methods:Long-term experiments were performed during three seasons of a year in a tropical monsoonal climatic region with high rainfall on the Southwest Coast of India.Soil gas extraction was performed using soil-gas probes,inserted to 1 m deep into the ground.Soil gas was harvested at a flow rate of 60 L/min,passed through a moisture trap,a ^(222)Rn progeny filter,and a delay volume and pumped into a ^(222)Rn calibration chamber of volume 22.7 m^(3).Continuous monitoring of ^(222)Rn concentration in the chamber was performed using ionization chamber-based reference monitors.To achieve and maintain the desired ^(222)Rn concentration values in the calibration chamber,the semi-dynamic injection method was adopted,in which the ^(222)Rn concentration in the soil gas was monitored periodically,and injection into the chamber was controlled using a well-defined pumping algorithm.Three ranges of ^(222)Rn concentration values were chosen as the target values to be maintained in the calibration chamber for long-term experiments(15 d):low concentration(500-1,000 Bq/m3),medium concentration(1,000-10,000 Bq/m^(3)),and high concentration(10,000-25,000 Bq/m^(3)).Results:The achieved ^(222)Rn concentration values were in good agreement with the target values,with deviations of 12%,8% and 5% for the low,medium and high concentration exposures,respectively,during the summer season.During the monsoon season,the deviations between the target and the achieved concentration values were 12%,10% and 5% for low,medium and high concentration exposures,respectively,and the corresponding deviations were 12%,4%,and 5% for the winter season.These deviations are well within the cumulative uncertainty associated with the measurements.Conclusions:The results of this study conclusively demonstrate that the soil gas harvesting method,when coupled with the semi-dynamic injection approach,is a reliable method for generating and maintaining the desired ^(222)Rn concentration in the large volume calibration chamber during different seasons and environmental conditions.
