Facing the challenges posed by exponentially increasing e-waste,the development of recyclable and tran-sient electronics has paved the way to an environmentally-friendly progression strategy,where electron-ics can dis...Facing the challenges posed by exponentially increasing e-waste,the development of recyclable and tran-sient electronics has paved the way to an environmentally-friendly progression strategy,where electron-ics can disintegrate and/or degrade into eco-friendly end products in a controlled way.Natural polymers possess cost and energy efficiency,easy modification,and fast degradation,all of which are ideal prop-erties for transient electronics.Gelatin is especially attractive due to its unique thermoreversible gelation processes,yet its huge potential as a multifunctional electronic material has not been well-researched due to its limited mechanical strength and low conductivity.Herein,we explored versatile applications of gelatin-based hydrogels through the assistance of multifunctional additives like carbon nanotubes to enhance their electromechanical performances.The optimized gelatin hydrogel displays not only a high conductivity of 0.93 S/m,electromagnetic shielding effectiveness of 39.6 dB,and tensile stress tolerance of 263 kPa,but also shows a negative permittivity phenomenon,which may find versatile applications in novel electronics.As a proof of concept,hydrogels were assembled as wearable sensors to sensitively de-tect static and dynamic pressures and strains generated by solids,liquids,and airflow,as well as diverse body movements.Furthermore,the recyclability,biocompatibility,and degradability of gelatin-based hy-drogels were well studied and analyzed.This work outlines a facile method to design multifunctional transient materials for wearable,sustainable,and eco-friendly electronics.展开更多
The recent advancements in sensor technology have made it possible to collect enormous amounts of data in real time.How to find out unusual pattern from time series data plays a very important role in data mining.In t...The recent advancements in sensor technology have made it possible to collect enormous amounts of data in real time.How to find out unusual pattern from time series data plays a very important role in data mining.In this paper,we focus on the abnormal subsequence detection.The original definition of discord subsequences is defective for some kind of time series,in this paper we give a more robust definition which is based on the k nearest neighbors.We also donate a novel method for time series representation,it has better performance than traditional methods(like PAA/SAX)to represent the characteristic of some special time series.To speed up the process of abnormal subsequence detection,we used the clustering method to optimize the outer loop ordering and early abandon subsequence which is impossible to be abnormal.The experiment results validate that the algorithm is correct and has a high efficiency.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(No.52073075)the Shenzhen Science and Technology Program(No.KQTD20170809110344233)the Initial Scientific Research Foundation of Overseas High-level Talents of Harbin Institute of Technology(Shenzhen)(No.DB11409008).
文摘Facing the challenges posed by exponentially increasing e-waste,the development of recyclable and tran-sient electronics has paved the way to an environmentally-friendly progression strategy,where electron-ics can disintegrate and/or degrade into eco-friendly end products in a controlled way.Natural polymers possess cost and energy efficiency,easy modification,and fast degradation,all of which are ideal prop-erties for transient electronics.Gelatin is especially attractive due to its unique thermoreversible gelation processes,yet its huge potential as a multifunctional electronic material has not been well-researched due to its limited mechanical strength and low conductivity.Herein,we explored versatile applications of gelatin-based hydrogels through the assistance of multifunctional additives like carbon nanotubes to enhance their electromechanical performances.The optimized gelatin hydrogel displays not only a high conductivity of 0.93 S/m,electromagnetic shielding effectiveness of 39.6 dB,and tensile stress tolerance of 263 kPa,but also shows a negative permittivity phenomenon,which may find versatile applications in novel electronics.As a proof of concept,hydrogels were assembled as wearable sensors to sensitively de-tect static and dynamic pressures and strains generated by solids,liquids,and airflow,as well as diverse body movements.Furthermore,the recyclability,biocompatibility,and degradability of gelatin-based hy-drogels were well studied and analyzed.This work outlines a facile method to design multifunctional transient materials for wearable,sustainable,and eco-friendly electronics.
文摘The recent advancements in sensor technology have made it possible to collect enormous amounts of data in real time.How to find out unusual pattern from time series data plays a very important role in data mining.In this paper,we focus on the abnormal subsequence detection.The original definition of discord subsequences is defective for some kind of time series,in this paper we give a more robust definition which is based on the k nearest neighbors.We also donate a novel method for time series representation,it has better performance than traditional methods(like PAA/SAX)to represent the characteristic of some special time series.To speed up the process of abnormal subsequence detection,we used the clustering method to optimize the outer loop ordering and early abandon subsequence which is impossible to be abnormal.The experiment results validate that the algorithm is correct and has a high efficiency.
