A single-machine scheduling with preventive periodic maintenance activities in a remanufacturing system including resumable and non-resumable jobs is studied.The objective is to find a schedule to minimize the makespa...A single-machine scheduling with preventive periodic maintenance activities in a remanufacturing system including resumable and non-resumable jobs is studied.The objective is to find a schedule to minimize the makespan and an LPT-LS algorithm is proposed.Non-resumable jobs are first scheduled in a machine by the longest processing time（LPT） rule,and then resumable jobs are scheduled by the list scheduling（LS） rule.And the worst-case ratios of this algorithm in three different cases in terms of the value of the total processing time of the resumable jobs（denoted as S2） are discussed.When S2 is longer than the spare time of the machine after the non-resumable jobs are assigned by the LPT rule,it is equal to 1.When S2 falls in between the spare time of the machine by the LPT rule and the optimal schedule rule,it is less than 2.When S2 is less than the spare time of the machine by the optimal schedule rule,it is less than 2.Finally,numerical examples are presented for verification.展开更多
The Western Carpathians are located out of world main natural hazardous zones. Human casualties are related more to snow avalanches in connection with mountain hiking, some individuals yearly by flooding and rarely by...The Western Carpathians are located out of world main natural hazardous zones. Human casualties are related more to snow avalanches in connection with mountain hiking, some individuals yearly by flooding and rarely by forest fires. Economic lost about 0.1 to 0.2 %, exceptionally up to 0.8 % of the gross domestic product (GDP) proportionally to the Carpathian regions of particular countries. Natural disasters are linked, except of the above mentioned events, to infrequent small and medium scale earthquakes, landslides, and erosion. Records of the most harmful natural events are found in archives since the 16th century. Their systematic study and factor analysis started from the end of the 19th century, and protective measures and organization of impact mitigation developed during the 20th century to minimize the risk.展开更多
U disk is the most conveuient external memory, it is simple and easy to carry, but at the same time it is best tools to bring the virus. Limiting the use of USB interface effectively not only can limit the circulation...U disk is the most conveuient external memory, it is simple and easy to carry, but at the same time it is best tools to bring the virus. Limiting the use of USB interface effectively not only can limit the circulation of the virus, but also can play a part in safety precautions. In fact ,the easiest way of restricting USB interface is to modify the registry,but for many users, dealing with Registry keys is a boring job,for ordinary users, the application is the best way to solve this problem. This article describes a software development process, focusing on how to use C # to modify the registry key and password protection settings, to provide some reference for computer enthusiasts.展开更多
Ionic skins that demonstrate great advantages in the mechanical properties and multiple sensory capabilities are regarded as an attractive candidate to mimic functions of human skin.However,human skin is vulnerable to...Ionic skins that demonstrate great advantages in the mechanical properties and multiple sensory capabilities are regarded as an attractive candidate to mimic functions of human skin.However,human skin is vulnerable to be damaged under long-time sunlight irradiation,and most of the current ionic skins also lack a protection against harmful ultraviolet and infrared lights.Herein,this work develops a multifunctional ionic skin based on ionic conductive and light-managing hydrogels via a facile one-step locally confined polymerization.It is mechanically adaptable,able to modulate light in the broadband solar spectrum,and protect human skin from the harmful ultraviolet and infrared lights.Moreover,without complicated processing,the ionic skin enables human-machine interactions via wireless and optical camouflaged Morse codes.We believe this work will promote the development of smart wearable devices with multiple customizable functions.展开更多
基金The National Natural Science Foundation of China (No.70971022,71271054)the Scientific Research Innovation Project for College Graduates in Jiangsu Province(No.CXLX_0157)the Scientific Research Foundation of the Education Department of Anhui Province(No.2011sk123)
文摘A single-machine scheduling with preventive periodic maintenance activities in a remanufacturing system including resumable and non-resumable jobs is studied.The objective is to find a schedule to minimize the makespan and an LPT-LS algorithm is proposed.Non-resumable jobs are first scheduled in a machine by the longest processing time（LPT） rule,and then resumable jobs are scheduled by the list scheduling（LS） rule.And the worst-case ratios of this algorithm in three different cases in terms of the value of the total processing time of the resumable jobs（denoted as S2） are discussed.When S2 is longer than the spare time of the machine after the non-resumable jobs are assigned by the LPT rule,it is equal to 1.When S2 falls in between the spare time of the machine by the LPT rule and the optimal schedule rule,it is less than 2.When S2 is less than the spare time of the machine by the optimal schedule rule,it is less than 2.Finally,numerical examples are presented for verification.
文摘The Western Carpathians are located out of world main natural hazardous zones. Human casualties are related more to snow avalanches in connection with mountain hiking, some individuals yearly by flooding and rarely by forest fires. Economic lost about 0.1 to 0.2 %, exceptionally up to 0.8 % of the gross domestic product (GDP) proportionally to the Carpathian regions of particular countries. Natural disasters are linked, except of the above mentioned events, to infrequent small and medium scale earthquakes, landslides, and erosion. Records of the most harmful natural events are found in archives since the 16th century. Their systematic study and factor analysis started from the end of the 19th century, and protective measures and organization of impact mitigation developed during the 20th century to minimize the risk.
文摘U disk is the most conveuient external memory, it is simple and easy to carry, but at the same time it is best tools to bring the virus. Limiting the use of USB interface effectively not only can limit the circulation of the virus, but also can play a part in safety precautions. In fact ,the easiest way of restricting USB interface is to modify the registry,but for many users, dealing with Registry keys is a boring job,for ordinary users, the application is the best way to solve this problem. This article describes a software development process, focusing on how to use C # to modify the registry key and password protection settings, to provide some reference for computer enthusiasts.
基金supported by the National Natural Science Foundation of China(51973035 and 51733003)。
文摘Ionic skins that demonstrate great advantages in the mechanical properties and multiple sensory capabilities are regarded as an attractive candidate to mimic functions of human skin.However,human skin is vulnerable to be damaged under long-time sunlight irradiation,and most of the current ionic skins also lack a protection against harmful ultraviolet and infrared lights.Herein,this work develops a multifunctional ionic skin based on ionic conductive and light-managing hydrogels via a facile one-step locally confined polymerization.It is mechanically adaptable,able to modulate light in the broadband solar spectrum,and protect human skin from the harmful ultraviolet and infrared lights.Moreover,without complicated processing,the ionic skin enables human-machine interactions via wireless and optical camouflaged Morse codes.We believe this work will promote the development of smart wearable devices with multiple customizable functions.
