• 천문학회보
• /
• 제44권1호
• /
• pp.36.3-36.3
• /
• 2019

Feedback process is one of the most important topics in the study of AGNs since it plays a key role in linking the SMBHs and their host galaxies. In order to further understand the co-evolution of SMBHs and their host galaxies, we probe the feedback process in local type-2 AGNs with a series of integral-field-spectroscopy observations. In the first part of my talk, I will introduce our GMOS observations of luminous type-2 AGNs at z < 0.1, which are selected using the integrated [O III] kinematics. Based on the dedicated emission-line diagnostics and kinematic studies, we identify the signatures of AGN-driven outflows and quantify the outflow size in the targets with extreme [O III] kinematics. For the targets without extreme [O III] kinematics, we find the presence of weak AGN-driven outflows, which are indicated by the significant differences between the kinematics of gas and stars. Then, I will present our recent study of 40 type-2 AGNs based on the SNIFS IFU. By comparing the radial profile of velocity dispersion of gas and stars, we measure the size of AGN-driven outflows in these targets and extend the outflow size-AGN luminosity relation in our previous GMOS studies. We also discuss the feedback effect of AGN-driven outflows by connecting the outflow velocity and host galaxy properties. These results highlight the importance of spatially-resolved observation in investigating gas kinematics and identifying the signatures of AGN-driven outflows.

• 패션비즈니스
• /
• 제25권1호
• /
• pp.51-64
• /
• 2021

The purpose of this study was to develop smart bags that combining fashion-specific trends and smart information technologies such as light-emitting diodes(LED) and optic fibers by grafting marquage techniques that have recently become popular as part of eco-fashion. We applied e-textiles by designing leather tote bags that could show off LED luminescence. A total of two tote bags, a white-colored peacock design and a black-colored paisley design, divided the LED's light-emitting method into two types, incremental lighting and random light-emission to suit each design, and the locations of the optical fibers were also reversed depending upon the design. The production of circuits for the LEDs and optical fibers was based on the design, and a flexible conductive fabric was laser-cut instead of wire line and attached to the circuit-line location. A separate connector was underwent three-dimensional(3D)-modeling and was connected to high-luminosity LEDs and optic fiber bundles. The optical fiber logo part expressed a subtle image using a white-colored LED, which did not offset the LED's sharp luminous effects, suggesting that using LEDs with fiber optics allowed for the expression of each in harmony without being heterogeneous. Overall, the LEDs and fiber optic fabric were well-harmonized in the fashion bag using marquage techniques, and there was no sense of it being a mechanical device. Also, the circuit part was made of conductive fabric, which is an e-textile product that feels the same as a thin, flexible fabric. The study confirmed that the bag was developed as a smart wearable product that could be used in everyday life.

• 한국인터넷방송통신학회논문지
• /
• 제22권2호
• /
• pp.15-20
• /
• 2022

색채는 크게 세 가지 속성인 색상, 명도, 채도로 구성되어 있으나 색채를 시감적으로 인지하는데 있어서 각 속성을 구분하여 독립적으로 인지하지 않는다. 채도와 밝기 관련 기존 선행된 연구들은 채도 속성의 순도 정도에 따라 밝기 속성이 다르게 느껴진다는 결과를 유의미하게 얻을 수 있었으나 정신물리학적 실험 대부분이 감산 혼합을 활용한 사례이기에 디스플레이 기반의 색채 인지 기초 연구가 필요하다. 본 연구에서는 자체 발광 시스템을 보유한 디스플레이 기반에서 채도와 밝기 관련 시각적 특성을 알아보고자 정신물리학적 실험을 진행하고 이를 분석하였다. 가산 혼합 형태의 디스플레이에서 일정한 밝기를 선정한 후 주요 색상의 채도를 조정하여 실험을 진행하였다. 본 연구에서는 진행된 실험 결과를 분석하여 감산 혼합과 동일한 결과가 산출되는지 알아보고 색채 인지 특성에 대한 연구 자료로써 유의미 여부를 정의한 후 향후 연구방향을 제시한다.

• 접착 및 계면
• /
• 제23권2호
• /
• pp.39-43
• /
• 2022

디스플레이, 태양전지와 같이 전기를 빛으로, 또는 빛을 전기로 변환시켜주는 광전자소자는 효율 향상을 위하여 빛의 거동 제어가 매우 중요하다. 즉, OLED의 경우 내부 빛 제어를 통해 더 많은 빛이 외부로 나갈 수 있도록 유도해 줄 때 발광효율을 향상시킬 수 있으며, 외부 빛 제어를 통해 광흡수층에서의 광경로를 증대시킬 경우 태양전지의 에너지 변환효율을 증가시킬 수 있다. 본 연구에서는 이러한 광거동 제어가 가능한 구조로서 주름구조에 대한 연구를 진행하였으며 응력 해소 시간을 제어하여 구조의 주기와 높이를 독립적으로 제어하고자 하였다. 주기와 높이의 변화가 광거동에 어떠한 영향을 미치는지 살펴보기 위하여 일정한 주기에서 높이 변화 및 유사한 높이에서 주기 변화에 따른 자외선/가시광선 분광분석(UV/Vis spectroscopy)을 실시하였으며 구조의 종횡비가 클수록 직진광의 비율이 낮고 분산광의 비율이 높음을 확인하였다. 이를 통해 광경로 변화 및 광경로 증가를 위하여 큰 종횡비의 주름구조가 요구됨을 확인할 수 있었다.

• 한국전기전자재료학회논문지
• /
• 제36권5호
• /
• pp.531-535
• /
• 2023

Mechanoluminescence (ML) is a phenomenon where the application of mechanical force to ML materials generates an electric field and produces light, holding significant promise as an eco-friendly technology. However, challenges in commercializing ML technology has arisen due to its low brightness and short luminous lifetime. To address this, in this work, we enhance ML efficiency by mixing carbon nanotubes (CNTs) into a ZnS: Cu embedded in a polydimethylsiloxane composite ML device. The inclusion of CNTs boosts ML intensity by 98% compared to devices without CNTs, as the increasing CNT fraction elevates conductivity, thereby amplifying ML intensity. However, this increase in CNT fraction also leads to enhanced light absorption within the device. Consequently, we observe a trend where ML intensity rises initially but declines beyond a CNT fraction of 0.0015 wt%. Based on these findings, we anticipate that our research will make valuable contributions to the advancement of electrical powerless mechanoluminescent technology.

• 한국표면공학회지
• /
• 제56권2호
• /
• pp.152-159
• /
• 2023

The night visibility of pavement is being considered as a global issue in the field of traffic safety. Although the spreading glass beads on the lane paints has been mainly used to secure night-visibility by utilizing the effect of retroreflection, obvious shortcoming of this method is that retroflection does not occur in the range where the headlights do not reach the glass beads. The use of functional paints including phosphorescent constituents could be a solution for overcoming fore-mentioned problem. SrAl₂O₄ based chemicals have not only good phosphorescent property, but also are chemically stable compared to existing ZnS based materials. However, this chemicals also need the improvement due to slightly reduced luminous effect in time. Herein, we developed novel paints showing enhanced phosphorescent properties by putting rare earth elements such as Eu, Dy and Y into SrAl₂O₄. These prepared phosphorescent pigments have displayed improved properties in terms of durability and long afterglow. For instance, the property of afterglow has been persisted after 5 hours with luminace of 20.6 mcd/m².

• 천문학회보
• /
• 제44권2호
• /
• pp.37.3-37.3
• /
• 2019

We study the stellar populations of the brightest group galaxies (BGGs) in groups whose halos have different dynamical states, using observational data from the GAMA survey. The two independent indicators to probe the dynamical state of the halo are the magnitude gap between two most luminous galaxies (∆M12) and offset between BGG and the luminosity center (Doffset) of the group. Such indicators complement each other in identifying relaxed and unrelaxed galaxy groups in our samples. We find that the BGGs of unrelaxed groups have significantly bluer NUV-r colours than in relaxed groups. This is also true at fixed sersic index. We find the bluer colours cannot be explained away by differing dust fraction, suggesting there are real differences in their stellar populations. SFRs derived from SED-fitting tend to be higher in unrelaxed systems. This could be partly because there is a greater fraction of BGGs with non-elliptical morphology, but also because unrelaxed systems are expected to have larger numbers of mergers, some of which may bring fuel for star formation. The SED-fitted stellar metallicities of BGGs in unrelaxed systems also tend to be higher, perhaps because the building blocks of the unrelaxed systems were more massive and had more time to enrich themselves. We find that the ∆M12 parameter is the most important parameter behind the observed differences in the relaxed/unrelaxed groups. We also find that groups selected to be unrelaxed using our criteria tend to have higher velocity offsets between the BGG and their group.

• 천문학회보
• /
• 제45권1호
• /
• pp.36.1-36.1
• /
• 2020

The progenitor of Type Ia supernovae (SNe Ia) is mainly believed to be a carbon/oxygen white dwarf (WD) with non-degenerate (single degenerate) or another WD companion (double degenerate). However, there is little observational evidence of their progenitor system. Recent studies suggest that shock-breakout cooling emission after the explosion can constrain the size of the progenitor system. To do so, we obtained a optical/Near-IR light curve of SN 2019ein, a normal but slightly sub-luminous type Ia supernova, from the very early phase using our high-cadence observation of Intensive Monitoring Survey of Nearby Galaxies (IMSNG). Assuming the expanding fireball model, the simple power-law fitting of the early part of the light curve gives power indices of 1.91 (B) and 2.09 (R) implying radioactive decay of 56Ni is the dominant energy source. By comparison with the expected light curve of the cooling emission, the early observation provides us an upper limit of the companion size of R∗≤1R⊙. This result suggests that we can exclude a large companion such as red giants, which is consistent with the previous study.

• 복식문화연구
• /
• 제32권3호
• /
• pp.398-418
• /
• 2024

This study aims to examine how the body and clothing of Jesus Christ are represented in the Russian Transfiguration of Christ icons of the 15th and 16th centuries and why it is considered to have established a distinct Russian iconography free from Byzantine influence. The study analyzes the Russian icons comparing them with their Byzantine prototypes to identify the distinctive 'Russianness' of the representation. The research methods comprise a qualitative analysis of the literature on Russian Orthodoxy, Russian icons, Christian theology, and Christ's clothing and an empirical analysis of the icons. The scope of the study is limited to Russian icons from the 15th and 16th centuries and Byzantine icons from the 9th century onwards. The study found that, compared to Byzantine icons, the Russian icons exhibit a more elongated body, darker facial features, and lighter clothing. A statistical analysis using the Mann-Whitney U test further revealed that the Russian icons feature a stiffer, simpler form, more opaque material, and more defined clothing boundaries. These stylistic differences suggest that the 'Russianness' in the expression of Christ's body and clothing in the Transfiguration of Christ icons derives from creativity, abstractness, and tradition. Rather than a simple recreation of the historical Christ or adherence to the Byzantine tradition, the Russian iconographic representation emphasizes Christ's transfiguration into a luminous form, as described in the Bible, accentuating his divine nature over his human aspects.

• 한국안광학회지
• /
• 제19권2호
• /
• pp.217-224
• /
• 2014

목적: 본 연구는 일상생활 속에서 흔히 접할 수 있는 근거리 시각매체의 재질과 글자크기에 따른 조절시스템(조절반응과 조절래그)을 비교 분석하고자 하였다. 방법: 특별한 안질환 및 굴절교정 수술경험이 없는 20~30세 성인 남녀 40명을 대상으로 시각매체의 재질(프린트용지, 신문용지, 잡지용지, 스마트폰, LCD 모니터)과 글자크기(6, 8, 10, 12)에 따른 조절반응을 양안 개방형 자동굴절계를 사용하여 측정 후 비교하였다. 결과: 실제 조절자극 유효굴절력은 $2.28{\pm}0.11D$이고 실제 조절반응 유효굴절력은 $1.66{\pm}0.30D$로 그 차이인 조절래그는 $0.62{\pm}0.28D$였다. 시각매체의 재질에 따른 조절반응은 LCD 모니터를 사용한 경우 $1.35{\pm}0.26D$(p=0.00), 스마트폰을 사용한 경우 $1.55{\pm}0.25D$(p=0.04)로서 통계적으로 유의하게 낮은 조절반응을 보였고 조절래그는 LCD 모니터를 사용한 경우 $0.93{\pm}0.24D$(p=0.00), 스마트폰을 사용한 경우 $0.73{\pm}0.25D$(p=0.04)로서 통계적으로 유의하게 큰 조절래그를 보였다. 글자크기에 따른 조절반응과 조절래그는 통계적으로 유의한 차이를 보이지 않았다(p>0.05). 결론: 근거리작업 시 조절시스템은 시각매체의 글자크기보다는 시각매체의 재질에 따라 더 큰 영향을 받으며, 특히 비발광체 재질의 시각매체(프린트용지, 신문용지, 잡지용지)는 발광체 재질의 시각매체(스마트폰, LCD 모니터)보다 조절시스템의 관점에서 눈에 부담을 더 적게 주는 것으로 사료된다.