It remains a big challenge to develop solid-state stimuli-responsive materials for time-dependent information encryption and inkless erasable printing with long retention times.Herein,a 2D Cu_(2)I_(2)-based MOF with p...It remains a big challenge to develop solid-state stimuli-responsive materials for time-dependent information encryption and inkless erasable printing with long retention times.Herein,a 2D Cu_(2)I_(2)-based MOF with photoresponsive spiropyran(SP)groups orderly installed on its skeleton is developed.The structural isomerization from SP to colored merocyanine(MC)form can be triggered by removing the CH_(3)CN guests.Besides,the degree of structural isomerization and the retention time can be adjusted by controlling the amount of CH_(3)CN guests,exhibiting dynamic photochromic behavior with multicolor states and tunable retention time.Based on these advantages,time-dependent information encryption is successfully achieved.Furthermore,the long retention time(>72 h)of the MC form under daylight conditions in the CH_(3)CN-removed Cu_(2)I_(2)-based MOF and good repeatability make it promising in various applications,such as temporary calendars,price-cards,billboards,and reusable identity cards.This work provides a novel design strategy to fabricate multi-functional MOF-based smart materials for challenging applications of time-dependent information encryption and inkless erasable printing.展开更多
A method was developed to estimate EEPROM device life based on the consistency for break- down charge, QBD, for constant voltage time dependent dielectric breakdown （TDDB） and constant current TDDB stress tests. Alt...A method was developed to estimate EEPROM device life based on the consistency for break- down charge, QBD, for constant voltage time dependent dielectric breakdown （TDDB） and constant current TDDB stress tests. Although an EEPROM works with a constant voltage, QBD for the tunnel oxide can be extracted using a constant current TDDB. Once the charge through the tunnel oxide, △QFG, is measured, the lower limit of the EEPROM life can be related to QBD/△QFG. The method is reached by erase/write cycle tests on an EEPROM.展开更多
A 512-bit EEPROM IP was designed by using just logic process based devices.To limit the voltages of the devices within 5.5 V,EEPROM core circuits,control gate(CG) and tunnel gate(TG) driving circuits,DC-DC converters:...A 512-bit EEPROM IP was designed by using just logic process based devices.To limit the voltages of the devices within 5.5 V,EEPROM core circuits,control gate(CG) and tunnel gate(TG) driving circuits,DC-DC converters:positive pumping voltage(VPP=4.75 V) ,negative pumping voltage(VNN=4.75 V) ,and VNNL(=VNN/2) generation circuit were proposed.In addition,switching powers CG high voltage(CG_HV) ,CG low voltage(CG_LV) ,TG high voltage(TG_HV) ,TG low voltage(TG_LV) ,VNNL_CG and VNNL_TG switching circuit were supplied for the CG and TG driving circuit.Furthermore,a sequential pumping scheme and a new ring oscillator with a dual oscillation period were proposed.To reduce a power consumption of EEPROM in the write mode,the reference voltages VREF_VPP for VPP and VREE_VNN for VNN were used by dividing VDD(1.2 V) supply voltage supplied from the analog block in stead of removing the reference voltage generators.A voltage level detector using a capacitive divider as a low-power DC-DC converter design technique was proposed.The result shows that the power dissipation is 0.34μW in the read mode,13.76μW in the program mode,and 13.66μW in the erase mode.展开更多
The task of mining erasable patterns(EPs)is a data mining problem that can help factory managers come up with the best product plans for the future.This problem has been studied by many scientists in recent times,and ...The task of mining erasable patterns(EPs)is a data mining problem that can help factory managers come up with the best product plans for the future.This problem has been studied by many scientists in recent times,and many approaches for mining EPs have been proposed.Erasable closed patterns(ECPs)are an abbreviated representation of EPs and can be con-sidered condensed representations of EPs without information loss.Current methods of mining ECPs identify huge numbers of such patterns,whereas intelligent systems only need a small number.A ranking process therefore needs to be applied prior to use,which causes a reduction in efficiency.To overcome this limitation,this study presents a robust method for mining top-rank-k ECPs in which the mining and ranking phases are combined into a single step.First,we propose a virtual-threshold-based pruning strategy to improve the mining speed.Based on this strategy and dPidset structure,we then develop a fast algorithm for mining top-rank-k ECPs,which we call TRK-ECP.Finally,we carry out experiments to compare the runtime of our TRK-ECP algorithm with two algorithms modified from dVM and TEPUS(Top-rank-k Erasable Pattern mining Using the Subsume concept),which are state-of-the-art algorithms for mining top-rank-k EPs.The results for the running time confirm that TRK-ECP outperforms the other experimental approaches in terms of mining the top-rank-k ECPs.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21825106,92061201,22105175)Postdoctoral Research Grant in Henan Province(No.202102001)。
文摘It remains a big challenge to develop solid-state stimuli-responsive materials for time-dependent information encryption and inkless erasable printing with long retention times.Herein,a 2D Cu_(2)I_(2)-based MOF with photoresponsive spiropyran(SP)groups orderly installed on its skeleton is developed.The structural isomerization from SP to colored merocyanine(MC)form can be triggered by removing the CH_(3)CN guests.Besides,the degree of structural isomerization and the retention time can be adjusted by controlling the amount of CH_(3)CN guests,exhibiting dynamic photochromic behavior with multicolor states and tunable retention time.Based on these advantages,time-dependent information encryption is successfully achieved.Furthermore,the long retention time(>72 h)of the MC form under daylight conditions in the CH_(3)CN-removed Cu_(2)I_(2)-based MOF and good repeatability make it promising in various applications,such as temporary calendars,price-cards,billboards,and reusable identity cards.This work provides a novel design strategy to fabricate multi-functional MOF-based smart materials for challenging applications of time-dependent information encryption and inkless erasable printing.
基金Supported the State Important Sci-Tech Special Projects(2009ZX02306-04)
文摘A method was developed to estimate EEPROM device life based on the consistency for break- down charge, QBD, for constant voltage time dependent dielectric breakdown （TDDB） and constant current TDDB stress tests. Although an EEPROM works with a constant voltage, QBD for the tunnel oxide can be extracted using a constant current TDDB. Once the charge through the tunnel oxide, △QFG, is measured, the lower limit of the EEPROM life can be related to QBD/△QFG. The method is reached by erase/write cycle tests on an EEPROM.
基金Project supported by the Second Stage of Brain Korea 21
文摘A 512-bit EEPROM IP was designed by using just logic process based devices.To limit the voltages of the devices within 5.5 V,EEPROM core circuits,control gate(CG) and tunnel gate(TG) driving circuits,DC-DC converters:positive pumping voltage(VPP=4.75 V) ,negative pumping voltage(VNN=4.75 V) ,and VNNL(=VNN/2) generation circuit were proposed.In addition,switching powers CG high voltage(CG_HV) ,CG low voltage(CG_LV) ,TG high voltage(TG_HV) ,TG low voltage(TG_LV) ,VNNL_CG and VNNL_TG switching circuit were supplied for the CG and TG driving circuit.Furthermore,a sequential pumping scheme and a new ring oscillator with a dual oscillation period were proposed.To reduce a power consumption of EEPROM in the write mode,the reference voltages VREF_VPP for VPP and VREE_VNN for VNN were used by dividing VDD(1.2 V) supply voltage supplied from the analog block in stead of removing the reference voltage generators.A voltage level detector using a capacitive divider as a low-power DC-DC converter design technique was proposed.The result shows that the power dissipation is 0.34μW in the read mode,13.76μW in the program mode,and 13.66μW in the erase mode.
文摘The task of mining erasable patterns(EPs)is a data mining problem that can help factory managers come up with the best product plans for the future.This problem has been studied by many scientists in recent times,and many approaches for mining EPs have been proposed.Erasable closed patterns(ECPs)are an abbreviated representation of EPs and can be con-sidered condensed representations of EPs without information loss.Current methods of mining ECPs identify huge numbers of such patterns,whereas intelligent systems only need a small number.A ranking process therefore needs to be applied prior to use,which causes a reduction in efficiency.To overcome this limitation,this study presents a robust method for mining top-rank-k ECPs in which the mining and ranking phases are combined into a single step.First,we propose a virtual-threshold-based pruning strategy to improve the mining speed.Based on this strategy and dPidset structure,we then develop a fast algorithm for mining top-rank-k ECPs,which we call TRK-ECP.Finally,we carry out experiments to compare the runtime of our TRK-ECP algorithm with two algorithms modified from dVM and TEPUS(Top-rank-k Erasable Pattern mining Using the Subsume concept),which are state-of-the-art algorithms for mining top-rank-k EPs.The results for the running time confirm that TRK-ECP outperforms the other experimental approaches in terms of mining the top-rank-k ECPs.
