이수연 교수

The crack formation mechanism of O3-type Na_0.8Mg_0.2Fe_0.4Mn_0.4O₂ due to air-exposure is directly evidenced using <italic>in situ</italic> mass spectrometry and various atomic-scale analyses.

본 연구는 지방정부 지역사회 시민단체 등이 커뮤니티 비즈니스를 활용하여 지역발전을추구하는 정책과정을 협력적 거버넌스의 틀을 통해 분석하고 향후 커뮤니티 비즈니스제도화 과정에서 정책적 시사점을 얻고자 하는 것이 목적이다. 이를 위해 현재 커뮤니티비즈니스 조직이 설립되어 운영 중인 전북 완주군을 사례로 선정하여 분석하였다. 협력적거버넌스의 분석틀은 크게 일반적 맥락과 촉발요인 및 협력과정, 결과로 구분할 수 있다. 이러한 분석틀에 기반을 두어 커뮤니티 비즈니스를 추진하는 정책과정을 분석해 보면지역 문제의 새로운 해법을 추구하였던 지방자치단체장이 시민단체와 적극적으로 정책대안 개발에 나서면서 시민단체와 지방정부의 협력이 시작되었다. 또한 지역주민들이정책의 기반이 되는 장기 발전 계획 과정에 참여하면서 새로운 정책에 대한 지역사회의이해가 높아졌다. 또한 커뮤니티 비즈니스 사업을 집행하는 과정에서도 주민들이 커뮤니티 비즈니스에 대한 공감대를 형성하는 과정을 거쳤으며, 민관 파트너십 형태의 중

The industrial manufacturing process for Ni-rich layered oxides for Li-ion batteries includes a washing step to remove residual Li compounds, such as LiOH and Li 2 CO 3, from the oxide surface. However, Ni-rich layered oxides are deformed during a conventional water-based washing process, leading to the degradation of the oxide surface. In this regard, a significant challenge for Ni-rich layered oxides is to remove residual Li compounds without surface damage during a washing process. Herein, th

Over the years, nanostructures have been developed to enable to support enzyme usability to obtain highly selective and efficient biocatalysts for catalyzing processes under various conditions. This review summarizes recent developments in the nanostructures for enzyme supporters, typically those formed with various inorganic materials. To improve enzyme attachment, the surface of nanomaterials is properly modified to express specific functional groups. Various materials and nanostructures can b

Ni-rich layered oxides have received significant attention as promising cathode materials for Li-ion batteries due to their high reversible capacity. However, intergranular and intragranular cracks form at high state-of-charge (SOC) levels exceeding 4.2 V (vs. Li/Li + ), representing a prominent failure mechanism of Ni-rich layered oxides. The nanoscale crack formation at high SOC levels is attributed to a significant volume change resulting from a phase transition between the H2 and H3 phases.

We present a new type of torsional soft morphing actuator designed and fabricated by twisted shape memory alloy (SMA) wires embedded in polydimethylsiloxane matrix. The design and fabrication process of the proposed soft morphing actuator are presented with investigations of its working mechanism. Actuation performance was evaluated with respect to the temporal response, the maximum torsional deformation under an applied electric current, and various design parameters including the twist directi

Coupled nanoantennas as metamaterial unit elements possess peculiar spectral and radiational behaviors. We show that nanoantennas made of two identical plasmonic slot resonators can greatly enhance the quality factors of resonance spectra and control radiation patterns through the selective excitation of bright and dark coupled modes. We confirm experimentally the enhanced quality factor of a bright mode in coupled nanoantennas. Adding phase modulators to the coupled microwave antennas, we demon

A CMOS up-conversion mixer with an intermediate frequency (IF) amplifier and local oscillator (LO) buffer is presented for mobile 28-GHz-band 5G dual-conversion transceivers. A balun transformer with improved common-mode rejection ratio characteristics is proposed to improve the LO second-harmonic signal suppression, which is a problem in the up-conversion mixer of the 5G dual-conversion architecture. By applying the proposed balun transformer instead of the conventional one, a common-mode rejec

We clarify the nature of dynamic coupling in plasmonic resonators and determine the dynamic coupling coefficient using a simple analytic model. We show that plasmonic resonators, such as subwavelength holes in a metal film which can be treated as bound charge oscillators, couple to each other through the retarded interaction of oscillating screened charges. Our dynamic coupling model offers, for the first time, a quantitative analytic description of the fundamental symmetric and anti-symmetric m

In this study, the monoterpenes, α-pinene and geraniol, were biotransformed to synthesize monoterpene alcohol compounds. Polyporus brumalis which is classified as a white rot fungus was used as a biocatalyst. Consequently α-terpineol was synthesized from α-pinene by P. brumalis mycelium, after three days. Moreover, another substrate, the acyclic monoterpenoids geraniol was transformed into the cyclic compound, p-menthane-3, 8-diol (PMD). The main metabolites, i.e., α-terpineol and PMD, are known

Imaging spectral information of materials and analysis of its properties have become an intriguing tool for consumer electronics used for food inspection, beauty care, etc. Those sensory physical quantities are difficult to quantify. Hyperspectral imaging cameras, which capture the figure and spectral information simultaneously, can be a good candidate for nondestructive remote sensing. In this study, with the aid of a hyperspectral imaging system (HIS) and machine learning (ML) techniques, meat

A 24-GHz direct-conversion transmitter is proposed for in-cabin radar applications. The proposed RF transmitter consists of an I/Q up-conversion mixer, an I/Q local (LO) oscillator generator, and a power amplifier. To improve the linearity of the I/Q up-conversion mixer, an inverter transconductor with third-order intermodulation (IM3) distortion cancellation is proposed. To improve the I/Q balancing performance of the I/Q LO generator, a poly-phase filter, including parasitic line inductance, i

The sharp increase of smartphone malwares has become one of the most serious security problems. The most significant part of the growth is the variants of existing malwares. A legacy approach for malware, the signature matching, is efficient in temporal dimension, but it is not practical because of its lack of robustness against the variants. A counter approach, the behavior analysis to handle the variant issue, takes too much time and resources. We propose a variant detection mechanism using ru