Sungkyunkwan University

About: Sungkyunkwan University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Thin film & Graphene. The organization has 28229 authors who have published 56428 publications receiving 1352733 citations. The organization is also known as: 성균관대학교.

An acceptance model for smart watches: Implications for the adoption of future wearable technology

Abstract: Purpose – The purpose of this paper is to identify the key psychological determinants of smart watch adoption (i.e. affective quality (AQ), relative advantage (RA), mobility (MB), availability (AV), subcultural appeal) and develops an extended technology acceptance model (TAM) that integrates the findings into the original TAM constructs. Design/methodology/approach – An online survey assessed the proposed psychological determinants of smart watch adoption. Confirmatory factor analysis (CFA) and structural equation modeling (SEM) were conducted on collected data (n=363) using the AMOS 22 statistical software. The reliability and validity of the measurement assessing the proposed factor structure were examined via CFA, while the strength and direction of the hypothesized causal paths among the constructs were analyzed via SEM. Findings – The AQ and RA of smart watches were found to be associated with perceived usefulness, while the sense of MB and AV induced by smart watches led to a greater perceived ease...

Modeling and Applications of Electrochemical Impedance Spectroscopy (EIS) for Lithium-ion Batteries

Abstract: As research on secondary batteries becomes important, interest in analytical methods to examine the condition of secondary batteries is also increasing. Among these methods, the electrochemical impedance spectroscopy (EIS) method is one of the most attractive diagnostic techniques due to its convenience, quickness, accuracy, and low cost. However, since the obtained spectra are complicated signals representing several impedance elements, it is necessary to understand the whole electrochemical environment for a meaningful analysis. Based on the understanding of the whole system, the circuit elements constituting the cell can be obtained through construction of a physically sound circuit model. Therefore, this mini-review will explain how to construct a physically sound circuit model according to the characteristics of the battery cell system and then introduce the relationship between the obtained resistances of the bulk (Rb), charge transfer reaction (Rct), interface layer (RSEI), diffusion process (W) and battery characteristics, such as the state of charge (SOC), temperature, and state of health (SOH).

Insulin modulates gluconeogenesis by inhibition of the coactivator TORC2.

Abstract: During feeding, increases in circulating pancreatic insulin inhibit hepatic glucose output through the activation of the Ser/Thr kinase AKT and subsequent phosphorylation of the forkhead transcription factor FOXO1 (refs 1-3). Under fasting conditions, FOXO1 increases gluconeogenic gene expression in concert with the cAMP responsive coactivator TORC2 (refs 4-8). In response to pancreatic glucagon, TORC2 is de-phosphorylated at Ser 171 and transported to the nucleus, in which it stimulates the gluconeogenic programme by binding to CREB. Here we show in mice that insulin inhibits gluconeogenic gene expression during re-feeding by promoting the phosphorylation and ubiquitin-dependent degradation of TORC2. Insulin disrupts TORC2 activity by induction of the Ser/Thr kinase SIK2, which we show here undergoes AKT2-mediated phosphorylation at Ser 358. Activated SIK2 in turn stimulated the Ser 171 phosphorylation and cytoplasmic translocation of TORC2. Phosphorylated TORC2 was degraded by the 26S proteasome during re-feeding through an association with COP1, a substrate receptor for an E3 ligase complex that promoted TORC2 ubiquitination at Lys 628. Because TORC2 protein levels and activity were increased in diabetes owing to a block in TORC2 phosphorylation, our results point to an important role for this pathway in the maintenance of glucose homeostasis.

Enhancement of Donor–Acceptor Polymer Bulk Heterojunction Solar Cell Power Conversion Efficiencies by Addition of Au Nanoparticles

Abstract: This research was supported by Future-based Technology Development Program (Nano Fields, 2010-0029321) and the WCU (World Class University) program (R32-2008-000-10142-0) through the NRF of Korea funded by the MEST. J. H. Park acknowledges the support from NRF of Korea funded by the MEST (NRF-2009- C1AAA001-2009-0094157, 2011-0006268). Research at UCSB was supported by the US Army General Technical Services (LLC/GTS-S- 09-1-196) and by the Department of Energy (BES-DOE- ER46535).

Stability of Quantum Dots, Quantum Dot Films, and Quantum Dot Light-Emitting Diodes for Display Applications

Abstract: Quantum dots (QDs) are being highlighted in display applications for their excellent optical properties, including tunable bandgaps, narrow emission bandwidth, and high efficiency. However, issues with their stability must be overcome to achieve the next level of development. QDs are utilized in display applications for their photoluminescence (PL) and electroluminescence. The PL characteristics of QDs are applied to display or lighting applications in the form of color-conversion QD films, and the electroluminescence of QDs is utilized in quantum dot light-emitting diodes (QLEDs). Studies on the stability of QDs and QD devices in display applications are reviewed herein. QDs can be degraded by oxygen, water, thermal heating, and UV exposure. Various approaches have been developed to protect QDs from degradation by controlling the composition of their shells and ligands. Phosphorescent QDs have been protected by bulky ligands, physical incorporation in polymer matrices, and covalent bonding with polymer matrices. The stability of electroluminescent QLEDs can be enhanced by using inorganic charge transport layers and by improving charge balance. As understanding of the degradation mechanisms of QDs increases and more stable QDs and display devices are developed, QDs are expected to play critical roles in advanced display applications.