A novel integrated circuit for driving LED lighting has been proposed, designed and fabricated. Besides the typical parts of LED driver, an integral part was added at the output terminal of error amplifier in the driv...A novel integrated circuit for driving LED lighting has been proposed, designed and fabricated. Besides the typical parts of LED driver, an integral part was added at the output terminal of error amplifier in the driver. In this way, a novel average current mode can be set up to take the place ordinary peak current control mode. In addition, a BUCK low-level topology was adopted, too. It can be used to drive up to eight 1 W HB LED lights with 350 mA constant current. In this way, the LED driver displays high performance, in which output current with less 1% error and total efficiency as high as 96%. The feasibility of the design has been verified by actual measurement on the fabricated chip.展开更多
Through-silicon-via （TSV） to TSV crosstalk noise is one of the key factors affecting the signal integrity of three- dimensional integrated circuits （3D ICs）. Based on the frequency dependent equivalent electrical ...Through-silicon-via （TSV） to TSV crosstalk noise is one of the key factors affecting the signal integrity of three- dimensional integrated circuits （3D ICs）. Based on the frequency dependent equivalent electrical parameters for the TSV channel, an analytical crosstalk noise model is established to capture the TSV induced crosstalk noise. The impact of various design parameters including insulation dielectric, via pitch, via height, silicon conductivity, and terminal impedance on the crosstalk noise is analyzed with the proposed model. Two approaches are proposed to alleviate the TSV noise, namely, driver sizing and via shielding, and the SPICE results show 241 rnV and 379 mV reductions in the peak noise voltage, respectively.展开更多
The Integrated Agricultural Systems workgroup is examining agricultural systems of the US to determine fundamental principles that underlie successful production systems. Our hypothesis is that principles are applicab...The Integrated Agricultural Systems workgroup is examining agricultural systems of the US to determine fundamental principles that underlie successful production systems. Our hypothesis is that principles are applicable across regions, but key drivers interact to influence producer decisions and create distinct production systems. We interviewed agricultural producers to examine the underlying rationale for producer decisions and discern primary factors influencing production and marketing practices. While drivers are common among regions, interactions between drivers and influences on decision-makers vary substantially to create unique production systems. The internal social driver that values farming lifestyle is the principal factor that leads people to farming. The type of farming is partly a lifestyle choice and is influenced by other factors. Economic drivers and marketing options are primary drivers influencing production systems and management choices, as farmers provide an economic foundation for their families. While all producers employed strategies to manage production and marketing risks, these varied with different marketing channels. Identification of key drivers and principles can be used by producers, scientists and policy makers to direct agricultural production and agricultural research. New management systems can be developed that are flexible enough to respond to changing societal demands, and are environmentally and economically sustainable.展开更多
The pursuit of human needs and demands is placing more pressure on land resources than ever before. The challenge of feeding 7 billion people is increasingly competing with rising demands for materials and biofuels. D...The pursuit of human needs and demands is placing more pressure on land resources than ever before. The challenge of feeding 7 billion people is increasingly competing with rising demands for materials and biofuels. Deforestation and land degradation are among the pressing outcomes of these trends. Drivers of environmental change—including population growth, economic activity, consumption, urbanization, trade, conflict, and governance—clearly play a role in aggravating or mitigating these pressures on land. Despite advances in understanding causality in complex systems, navigating the interactions between these drivers remains a major challenge. This paper analyzes and visualizes the relationships between multiple, interacting drivers of environmental change and specific pressures on land-based ecosystems. Drawing on experience from the development of the Drivers and Land chapters of the UN Environment Programme’s Fifth Global Environment Outlook report (GEO-5), we use a series of Kiviat diagrams to illustrate the relative influence of key drivers on selected pressures on land. When individual diagrams are overlaid, patterns of influence emerge that can provide insight into where policy responses might best be targeted. We propose that, subject to some limitations, the Kiviat exercise can provide an accessible and potentially valuable “knowledge-intermediary” tool to help link science-based information to policy action.展开更多
近年来,清洁低碳的电-气综合能源系统(electricity-gas integrated energy system,EGIES)受到了广泛关注。然而,EGIES涉及不同能源形式的设备量测与信息传输,数据误差的产生因素复杂且不确定性突出,导致确定性的点状态估计可信度不足,...近年来,清洁低碳的电-气综合能源系统(electricity-gas integrated energy system,EGIES)受到了广泛关注。然而,EGIES涉及不同能源形式的设备量测与信息传输,数据误差的产生因素复杂且不确定性突出,导致确定性的点状态估计可信度不足,为系统安全稳定运行带来严峻挑战。针对此问题,提出基于模型-数据联合驱动的EGIES区间状态估计方法。建立EGIES加权最小二乘(weighted least square,WLS)点状态估计模型,并利用人工鱼群算法(artificial fish swarms algorithm,AFSA)求解;考虑估计结果置信水平,利用核密度估计(kernel density estimation,KDE)构造点状态估计误差区间,进而得到区间状态估计结果;基于量测量样本与区间状态估计结果样本,训练长短期记忆(long short term memory,LSTM)神经网络得到EGIES快速区间状态估计模型。以30节点电力系统与14节点天然气系统耦合的EGIES进行算例分析,结果表明,所提区间状态估计方法的区间覆盖概率均保持在置信度水平之上。同时所提方法测试集在线估计时间仅为13.97s,相比于WLS-NR-KDE方法与WLS-AFSA-KDE方法分别降低76.44%与94.00%。展开更多
A p-type low-temperature poly-Si thin film transistors（LTPS TFTs） integrated gate driver using 2 nonoverlapped clocks is proposed.This gate driver features charge-sharing structure to turn off buffer TFT and suppres...A p-type low-temperature poly-Si thin film transistors（LTPS TFTs） integrated gate driver using 2 nonoverlapped clocks is proposed.This gate driver features charge-sharing structure to turn off buffer TFT and suppresses voltage feed-through effects.It is analyzed that the conventional gate driver suffers from waveform distortions due to voltage uncertainty of internal nodes for the initial period.The proposed charge-sharing structure also helps to suppress the unexpected pulses during the initialization phases.The proposed gate driver shows a simple circuit,as only 6 TFTs and 1 capacitor are used for single-stage,and the buffer TFT is used for both pulling-down and pulling-up of output electrode.Feasibility of the proposed gate driver is proven through detailed analyses.Investigations show that voltage bootrapping can be maintained once the bootrapping capacitance is larger than0.8 pF,and pulse of gate driver outputs can be reduced to 5μs.The proposed gate driver can still function properly with positive V（TH）shift within 0.4 V and negative V（TH） shift within-1.2 V and it is robust and promising for high-resolution display.展开更多
文摘A novel integrated circuit for driving LED lighting has been proposed, designed and fabricated. Besides the typical parts of LED driver, an integral part was added at the output terminal of error amplifier in the driver. In this way, a novel average current mode can be set up to take the place ordinary peak current control mode. In addition, a BUCK low-level topology was adopted, too. It can be used to drive up to eight 1 W HB LED lights with 350 mA constant current. In this way, the LED driver displays high performance, in which output current with less 1% error and total efficiency as high as 96%. The feasibility of the design has been verified by actual measurement on the fabricated chip.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61131001,61322405,61204044,61376039,and 61334003)
文摘Through-silicon-via （TSV） to TSV crosstalk noise is one of the key factors affecting the signal integrity of three- dimensional integrated circuits （3D ICs）. Based on the frequency dependent equivalent electrical parameters for the TSV channel, an analytical crosstalk noise model is established to capture the TSV induced crosstalk noise. The impact of various design parameters including insulation dielectric, via pitch, via height, silicon conductivity, and terminal impedance on the crosstalk noise is analyzed with the proposed model. Two approaches are proposed to alleviate the TSV noise, namely, driver sizing and via shielding, and the SPICE results show 241 rnV and 379 mV reductions in the peak noise voltage, respectively.
文摘The Integrated Agricultural Systems workgroup is examining agricultural systems of the US to determine fundamental principles that underlie successful production systems. Our hypothesis is that principles are applicable across regions, but key drivers interact to influence producer decisions and create distinct production systems. We interviewed agricultural producers to examine the underlying rationale for producer decisions and discern primary factors influencing production and marketing practices. While drivers are common among regions, interactions between drivers and influences on decision-makers vary substantially to create unique production systems. The internal social driver that values farming lifestyle is the principal factor that leads people to farming. The type of farming is partly a lifestyle choice and is influenced by other factors. Economic drivers and marketing options are primary drivers influencing production systems and management choices, as farmers provide an economic foundation for their families. While all producers employed strategies to manage production and marketing risks, these varied with different marketing channels. Identification of key drivers and principles can be used by producers, scientists and policy makers to direct agricultural production and agricultural research. New management systems can be developed that are flexible enough to respond to changing societal demands, and are environmentally and economically sustainable.
文摘The pursuit of human needs and demands is placing more pressure on land resources than ever before. The challenge of feeding 7 billion people is increasingly competing with rising demands for materials and biofuels. Deforestation and land degradation are among the pressing outcomes of these trends. Drivers of environmental change—including population growth, economic activity, consumption, urbanization, trade, conflict, and governance—clearly play a role in aggravating or mitigating these pressures on land. Despite advances in understanding causality in complex systems, navigating the interactions between these drivers remains a major challenge. This paper analyzes and visualizes the relationships between multiple, interacting drivers of environmental change and specific pressures on land-based ecosystems. Drawing on experience from the development of the Drivers and Land chapters of the UN Environment Programme’s Fifth Global Environment Outlook report (GEO-5), we use a series of Kiviat diagrams to illustrate the relative influence of key drivers on selected pressures on land. When individual diagrams are overlaid, patterns of influence emerge that can provide insight into where policy responses might best be targeted. We propose that, subject to some limitations, the Kiviat exercise can provide an accessible and potentially valuable “knowledge-intermediary” tool to help link science-based information to policy action.
文摘近年来,清洁低碳的电-气综合能源系统(electricity-gas integrated energy system,EGIES)受到了广泛关注。然而,EGIES涉及不同能源形式的设备量测与信息传输,数据误差的产生因素复杂且不确定性突出,导致确定性的点状态估计可信度不足,为系统安全稳定运行带来严峻挑战。针对此问题,提出基于模型-数据联合驱动的EGIES区间状态估计方法。建立EGIES加权最小二乘(weighted least square,WLS)点状态估计模型,并利用人工鱼群算法(artificial fish swarms algorithm,AFSA)求解;考虑估计结果置信水平,利用核密度估计(kernel density estimation,KDE)构造点状态估计误差区间,进而得到区间状态估计结果;基于量测量样本与区间状态估计结果样本,训练长短期记忆(long short term memory,LSTM)神经网络得到EGIES快速区间状态估计模型。以30节点电力系统与14节点天然气系统耦合的EGIES进行算例分析,结果表明,所提区间状态估计方法的区间覆盖概率均保持在置信度水平之上。同时所提方法测试集在线估计时间仅为13.97s,相比于WLS-NR-KDE方法与WLS-AFSA-KDE方法分别降低76.44%与94.00%。
基金Project supported by the Science and Technology Project of Hunan Province,China(No.2015JC3401)
文摘A p-type low-temperature poly-Si thin film transistors（LTPS TFTs） integrated gate driver using 2 nonoverlapped clocks is proposed.This gate driver features charge-sharing structure to turn off buffer TFT and suppresses voltage feed-through effects.It is analyzed that the conventional gate driver suffers from waveform distortions due to voltage uncertainty of internal nodes for the initial period.The proposed charge-sharing structure also helps to suppress the unexpected pulses during the initialization phases.The proposed gate driver shows a simple circuit,as only 6 TFTs and 1 capacitor are used for single-stage,and the buffer TFT is used for both pulling-down and pulling-up of output electrode.Feasibility of the proposed gate driver is proven through detailed analyses.Investigations show that voltage bootrapping can be maintained once the bootrapping capacitance is larger than0.8 pF,and pulse of gate driver outputs can be reduced to 5μs.The proposed gate driver can still function properly with positive V（TH）shift within 0.4 V and negative V（TH） shift within-1.2 V and it is robust and promising for high-resolution display.
