http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Choi, Juhyung,Seong, Kwang-dong,Kang, Jeongmin,Hwang, Minsik,Kim, Jong Min,Jin, Xuanzhen,Piao, Yuanzhe Elsevier 2018 ELECTROCHIMICA ACTA Vol.279 No.-
<P><B>Abstract</B></P> <P>A one-pot facile hydrothermal synthesis of fluorine-doped CoFe<SUB>2</SUB>O<SUB>4</SUB> sphere (FS-CoFe<SUB>2</SUB>O<SUB>4</SUB>)/graphene sheet (GS) composites, based on the Ostwald ripening mechanism, is presented in this work. Incorporation of fluorine in CoFe<SUB>2</SUB>O<SUB>4</SUB>/GS improves ion diffusion by forming a highly porous structure that serves as an electrolyte reservoir during the redox reactions and facilitates charge transfer in the electrode material. The influence of the fluorine concentration on the relationship between structure and electrochemical performance of CoFe<SUB>2</SUB>O<SUB>4</SUB>/GS is also studied. The FS-CoFe<SUB>2</SUB>O<SUB>4</SUB>/GS composite exhibits a high specific capacity of 288 C g<SUP>−1</SUP> at a current density of 1 A g<SUP>−1</SUP>, along with an excellent rate capability of 80% (230 C g<SUP>−1</SUP> at a current density of 10 A g<SUP>−1</SUP>). Moreover, the FS-CoFe<SUB>2</SUB>O<SUB>4</SUB>/GS composite is used to assemble a hybrid supercapacitor, which exhibits a high operating voltage of 1.6 V and delivers a high energy density of 28.4 Wh kg<SUP>−1</SUP> at a power density of 0.9 kW kg<SUP>−1</SUP>, as well as an outstanding cycling performance (90% capacity retention after 20,000 cycles, in which the GSs support FS-CoFe<SUB>2</SUB>O<SUB>4</SUB> for the whole duration of the cycling tests). The present study can open up a new avenue for exploiting fluorine as a dopant in high-performance hybrid supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fluorine-doped CoFe<SUB>2</SUB>O<SUB>4</SUB>/Graphene sheet composites were prepared by one-pot facile hydrothermal synthesis. </LI> <LI> The nanocomposite exhibits a high specific capacity of 288 C g<SUP>−1</SUP> at 1 A g<SUP>−1</SUP> in a three-electrode system. </LI> <LI> The influence of the fluorine concentration of CoFe<SUB>2</SUB>O<SUB>4</SUB>/GS is studied. </LI> <LI> A hybrid supercapacitor using the nanocomposite exhibits excellent rate capability and cycling stability. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The paper reported Fluorine-doped CoFe<SUB>2</SUB>O<SUB>4</SUB>/Graphene sheet composites through one-pot facile hydrothermal synthesis. A hybrid supercapacitor using incorporation of fluorine in CoFe<SUB>2</SUB>O<SUB>4</SUB>/GS composites exhibits excellent rate capability and cycling stability.</P> <P>[DISPLAY OMISSION]</P>
Jihyun Won,Juhyung Kang,Wonyoung Park,José C. J. M. D. S. Menezes,Marc Diederich,Eunyoung Kim,Wonku Kang 한국분석과학회 2023 분석과학 Vol.36 No.1
2’-Hydroxy-3’,4’-methylenedioxy-3,4,5-trimethoxychalcone (HMTC) is a newly synthesized chalcone that affects proliferation, cytotoxic potential and apoptosis in human leukemia cells. However, no validated determination method has been described so far for HMTC in biological samples. Thus, we developed a liquid chromatographic method using a tandem mass spectrometry to determine HMTC in rat plasma. Liquid-liquid extraction with ethyl acetate was used for the clean-up procedure. The analyte was separated on a reversedphase column with mobile phase of distilled water and acetonitrile (2:8, v/v, including 0.1 % formic acid). The ion transition of the precursor to the product ion was principally deprotonated ions [M-H]− at m/z 356.8 → 327.2 for HMTC. This analytical method was successfully applied in pharmacokinetic study of HMTC after intravenous administration in rats.
소프트웨어 도용 방지를 위한 클래스 분할 기반 워터마킹
강병섭 ( Byengseup Kang ),고석향 ( Seokhyang Go ),김주형 ( Juhyung Kim ),박희완 ( Heewan Park ) 한국정보처리학회 2016 한국정보처리학회 학술대회논문집 Vol.23 No.1
최근 모바일 내비게이션 시장의 양대 강자인 ‘T맵’과 ‘김기사’가 송사에 휘말려서 사회적인 이슈가 되었다. 이 사건을 통해서 소프트웨어의 불법 복제 방지 및 개발자의 저작권을 식별하기 위한 워터마킹 기법이 부각되었다. 본 논문에서는 안드로이드 앱의 클래스를 여러개의 클래스로 분할하여 저작권 정보를 삽입하는 클래스 분할 워터마킹 기법을 제안한다. 본 논문에서 제안하는 워터마킹 기법은 소프트웨어 코드가 도용되었을 때 원저작자의 정보를 확인할 수 있도록 하여 불법 복제 시도를 사전에 예방할 수 있으며, 불법 복제가 의심되었을 때 근거 자료로 사용될 수 있다.
Machine learning-based self-powered acoustic sensor for speaker recognition
Han, Jae Hyun,Bae, Kang Min,Hong, Seong Kwang,Park, Hyunsin,Kwak, Jun-Hyuk,Wang, Hee Seung,Joe, Daniel Juhyung,Park, Jung Hwan,Jung, Young Hoon,Hur, Shin,Yoo, Chang D.,Lee, Keon Jae Elsevier 2018 Nano energy Vol.53 No.-
<P><B>Abstract</B></P> <P>Herein, we report a new platform of machine learning-based speaker recognition via the flexible piezoelectric acoustic sensor (f-PAS) with a highly sensitive multi-resonant frequency band. The resonant self-powered f-PAS was fabricated by mimicking the operating mechanism of the basilar membrane in the human cochlear. The f-PAS acquired abundant voice information from the multi-channel sound inputs. The standard TIDIGITS dataset were recorded by the f-PAS and converted to frequency components by using a Fast Fourier Transform (FFT) and a Short-Time Fourier Transform (STFT). The machine learning based Gaussian Mixture Model (GMM) was designed by utilizing the most highest and second highest sensitivity data among multi-channel outputs, exhibiting outstanding speaker recognition rate of 97.5% with error rate reduction of 75% compared to that of the reference MEMS microphone.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new platform of machine learning-based speaker recognition system was realized. </LI> <LI> The resonant self-powered f-PAS was fabricated by mimicking the human cochlear. </LI> <LI> Using the machine learning algorithm, f-PAS exhibited high speaker recognition rate. </LI> </UL> </P>
Chae, Jongchul,Cho, Kyuhyoun,Kang, Juhyung,Lee, Kyoung-Sun,Kwak, Hannah,Lim, Eun-Kyung The Korean Astronomical Society 2021 Journal of The Korean Astronomical Society Vol.54 No.5
We present an updated version of the multilayer spectral inversion (MLSI) recently proposed as a technique to infer the physical parameters of plasmas in the solar chromosphere from a strong absorption line. In the original MLSI, the absorption profile was constant over each layer of the chromosphere, whereas the source function was allowed to vary with optical depth. In our updated MLSI, the absorption profile is allowed to vary with optical depth in each layer and kept continuous at the interface of two adjacent layers. We also propose a new set of physical requirements for the parameters useful in the constrained model fitting. We apply this updated MLSI to two sets of Hα and Ca II line spectral data taken by the Fast Imaging Solar Spectrograph (FISS) from a quiet region and an active region, respectively. We find that the new version of the MLSI satisfactorily fits most of the observed line profiles of various features, including a network feature, an internetwork feature, a mottle feature in a quiet region, and a plage feature, a superpenumbral fibril, an umbral feature, and a fast downflow feature in an active region. The MLSI can also yield physically reasonable estimates of hydrogen temperature and nonthermal speed as well as Doppler velocities at different atmospheric levels. We conclude that the MLSI is a very useful tool to analyze the Hα line and the Ca II 8542 line spectral daya, and will promote the investigation of physical processes occurring in the solar photosphere and chromosphere.