http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Kim, Hyun-seung,Kim, Jaekwang,Kim, Hyosung,Kim, Youngjin,Ryu, Ji Heon,Oh, Seung M.,Yoon, Songhun Elsevier 2018 Journal of Electroanalytical Chemistry Vol.808 No.-
<P><B>Abstract</B></P> <P>A hydrothermally synthesized tin (IV) sulfide electrode was examined for use as a negative electrode in sodium-ion batteries. Using ex-situ XRD and electrochemical analysis, the sodiation mechanism of tin (IV) sulfide was clarified, which revealed that the typical conversion reaction-coupled alloying reaction happened during sodiation with a high reversible capacity (~640mAhg<SUP>−1</SUP>). Also, the improved cycleability was observed in the tin (IV) sulfide electrode when compared with tin metal electrode. From comparison of quasi-open-circuit voltages at the 20th de-sodiated electrode, it was revealed that sodium trapping was considerably suppressed by sulfide formation with tin.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hydrothermally-synthesized tin (IV) sulfide (SnS<SUB>2</SUB>) is applied as negative electrode for sodium-ion batteries. </LI> <LI> Hydrothermally-synthesized SnS<SUB>2</SUB> shows stable cycleability. </LI> <LI> The dead particle generation is very suppressed at SnS<SUB>2</SUB> negative electrode. </LI> </UL> </P>
Kim, Kiyoung,Kim, Song-Hee,Kim, Jaekwang,Kim, Heuijong,Yim, Jeongbin American Society for Biochemistry and Molecular Bi 2012 The Journal of biological chemistry Vol.287 No.9
<▼1><P><B>Background:</B> Glutathione <I>S</I>-transferase Omega has been shown to be associated with Parkinson disease.</P><P><B>Results:</B><I>Drosophila</I> GSTO1 regulates mitochondrial ATP synthase activity in <I>parkin</I> mutants.</P><P><B>Conclusion:</B><I>Drosophila</I> GSTO1 plays a protective role in a <I>Drosophila</I> model of Parkinson disease.</P><P><B>Significance:</B> These findings may lead to a better understanding of the molecular mechanism of neuroprotection due to GSTO in Parkinson disease.</P></▼1><▼2><P>A loss-of-function mutation in the gene <I>parkin</I> causes a common neurodegenerative disease that may be caused by mitochondrial dysfunction. Glutathione <I>S</I>-transferase Omega (GSTO) is involved in cell defense mechanisms, but little is known about the role of GSTO in the progression of Parkinson disease. Here, we report that restoration of <I>Drosophila</I> GSTO1 (DmGSTO1), which is down-regulated in <I>parkin</I> mutants, alleviates some of the <I>parkin</I> pathogenic phenotypes and that the loss of <I>DmGSTO1</I> function enhances <I>parkin</I> mutant phenotypes. We further identified the ATP synthase β subunit as a novel <I>in vivo</I> target of DmGSTO1. We found that glutathionylation of the ATP synthase β subunit is rescued by DmGSTO1 and that the expression of DmGSTO1 partially restores the activity and assembly of the mitochondrial F<SUB>1</SUB>F<SUB>0</SUB>-ATP synthase in <I>parkin</I> mutants. Our results suggest a novel mechanism for the protective role of DmGSTO1 in <I>parkin</I> mutants, through the regulation of ATP synthase activity, and provide insight into potential therapies for Parkinson disease neurodegeneration.</P></▼2>
A novel recommendation approach based on chronological cohesive units in content consuming logs
Kim, Jaekwang,Lee, Jee-Hyong Elsevier science 2019 Information sciences Vol.470 No.-
<P><B>Abstract</B></P> <P>We propose a novel recommendation approach based on chronological cohesive units (CCUs) of content consuming logs. Chronological cohesive units are defined as sub-sequences of logs in which items are highly related to each other. We first generate rules for splitting consuming logs into CCUs. We select features which are effective for splitting of consuming logs and combine them into a binary decision tree to generate splitting rules with genetic programming. With the rules, we split content consuming logs into CCUs, and identify strongly associated items in the CCUs. Next items are recommended with an association rule-based approach. The proposed method is evaluated using two-real datasets: web page navigation logs and movie consuming logs. The experiments confirm that the proposed approach is superior to the existing methods in various aspects such as hit ratio, click-soon ratio, sparsity, diversity and serendipity.</P>
Novel estimation method of operating life in lithium-ion pouch cells
Kim, Hyosung,Kim, Jaekwang,Kim, Nayeong,Lee, Ilbok,Hwang, Keebum,Bae, Joongho,Yoon, Songhun THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.67 No.-
<P><B>Abstract</B></P> <P>Herein, a novel operating life (OL) test method was evaluated with 200mAh pouch-type lithium-ion batteries. By combining the calendar life (CL) test with intermediate pulse power cycling, more realistic life prediction was possible, which encompassed real operation of batteries accompanying with thermal acceleration. Larger capacity decrease and resistance increase of pouch cell were observed in the OL test, which was well explained using the SEI film growth model. After dissemble of pouch cell, capacity loss and resistance increase mostly occurred within anode, reflecting that SEI film growth on anode surface was highly attributable to cell degradation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Suggestion of novel operating life prediction. </LI> <LI> Intermediate pulse power cycling to simulate vehicle operation. </LI> <LI> Combination of pulse power cycling and thermal degradation by calendar life prediction. </LI> <LI> Surface film growth model to explain capacity and resistance change. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Jaekwang Kim,김다은,이일복,심혜원,이진우,손형빈,이동현,윤성훈 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.2
Hexagonally ordered mesoporous carbon materials were prepared and used as electrode materials in an electric double-layer capacitor. Using this electrode, the change of electrolyte resistance within the mesopores was investigated according to the bulk electrolyte concentration. Using three different electrochemical transient experiments—imaginary capacitance analysis, chronoamperometry, and chronopotentiometry—the time constant associated with electrolyte transport was determined, which was then used to obtain the electrolyte resistance within the mesopores. With decreasing electrolyte concentration, the increase in electrolyte resistance was smaller than the increase in the resistivity of the bulk electrolyte, which is indicative of a different environment for ionic transport within the mesopores. On using the confinement effect within the mesopores, the predicted higher concentration within mesopore probably results in lower electrolyte resistance, especially under low bulk concentrations.
Kim, Hyun-seung,Kim, Jaekwang,Jang, Jihyun,Kim, Nayeong,Ryu, Ji Heon,Yoon, Songhun,Oh, Seung M. Elsevier 2017 Solid state ionics Vol.311 No.-
<P><B>Abstract</B></P> <P>In this study, polarization behavior during initial lithiation step was comparatively investigated using a tungsten oxide (WO<SUB>3</SUB>) and its reduced one (WO<SUB>3− <I>x</I> </SUB>). Ex-situ X-ray diffraction revealed that the overall lithiation process in WO<SUB>3</SUB> was mostly similar to that of WO<SUB>3− <I>x</I> </SUB>, which was associated with the typical conversion reaction of transition-metal oxide. In the WO<SUB>3− <I>x</I> </SUB> anode, however, insertional lithiation was initiated above 2V vs. Li/Li<SUP>+</SUP> and a following conversion reaction was observed, which was different charging behavior from WO<SUB>3</SUB> electrode. The severe polarization related with the conversion reaction was alleviated owing to the high electrical conductivity in the mixed-valance state of WO<SUB>3− <I>x</I> </SUB>. Furthermore, the different initial polarization in WO<SUB>3− <I>x</I> </SUB> anode resulted in the improvement of cycle performance and efficiency.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Kim, Hyun-seung,Kim, Jongjung,Lee, Jae Gil,Ryu, Ji Heon,Kim, Jaekwang,Oh, Seung M.,Yoon, Songhun Elsevier 2018 Solid state ionics Vol.314 No.-
<P><B>Abstract</B></P> <P>A cheap Si powder byproduct from solar cell production was applied as a negative electrode for lithium-ion batteries. To improve the cycle and rate performances, the as-obtained Si powder was composited with tungsten oxide and coated with carbon, in sequence. After preparing the composite material, its electrochemical performance is evaluated, which exhibits a high reversible capacity of 975mAhg<SUP>−1</SUP> with improved cycleability. Especially, the rate capability is significantly improved to 390mAhg<SUP>−1</SUP> under 1000mAg<SUP>−1</SUP> applied current. This advanced electrochemical performance is attributed to the matrix effect of the formed Li<SUB>2</SUB>O and W metal with carbon coating, as identified using ex-situ X-ray diffraction experiments, and associated with the low polarization resistance observed in the galvanostatic charge intermittent technique.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Preparation of composite between Si powder with tungsten oxide and carbon </LI> <LI> Improved capacity and cycleability due to buffer phase of W and Li<SUB>2</SUB>O </LI> <LI> High rate capability of prepared composite from low polarization of electrode </LI> </UL> </P>