• KIEAE Journal
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• v.7 no.6
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• pp.53-64
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• 2007

The idea that city culture can be employed as a driver for urban development has become part of the new orthodoxy by which cities seek to enhance their competitive position. Such development reflect not only the rise to prominence of the cultural sphere in the city development, but also how the meaning of culture has been refined to include new uses in order to meet the main objectives of sustainable development. This study focuses on the procedure how the cultural infrastructure and historical context can be applied for urban regeneration strategy. Two successful cases (Bilbao, Spain and Yokohama, Japan) were selected for analysis of strategies as a whole, background, main characteristics of culture-led urban regeneration strategies and their effect for urban regeneration have been analyzed in detail. In conclusion, lessons for the future development were suggested in terms of resources, planning and linking strategies.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.12
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• pp.13-18
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• 2005

In this paper, we fabricated a pixel array in which each pixel was consisted of Organic Thin Film Transistor (OTFT) serially connected with Organic Light Emitting Diode (OLED) on Poly-ethylene-terephthalate (PET) substrate and the number of pixels was 64 x 64. As a gate insulator of OTFT, the thermally cross-linked PVP was used and the organic semiconductor, Pentacene, is deposited for an active layer of OTFT considering the compatibility with PET substrate. The mobility of OTFT is $1.0\;cm^2/V{\cdot}sec$ as a discrete device, but it was reduced to $0.1\~0.2\;cm^2/V{\codt}sec$ in the array. We analyzed the operation of the array and confirmed the current driving ability of OTFTs for the OLEDs.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.214-219
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• 2013

This study was conducted to examine the effect of LED light quality and treatment time on the growth and flowering in potted plants of Impatiens (Impatiens hawkerihybrid). Plant height of Impatiens was enhanced under Blue light, regardless of treatment time. Root length and stem diameter of Impatiens were enhanced by Red light or Blue light. The number of internodes was not influenced by LED light quality. The number of branches of Impatiens was increased under Blue light, but treatment time did not result in statistically significant differences. Leaf area was increased by all LED lights in Impatiens. The number of flower buds and open flowers was decreased by LED light, but days to flowering were reduced by Red light in Impatiens. Chlorophyll and anthocyanin content were not significantly affected by LED light, but anthocyanin content tended to increase by Blue light for 4 h after sunset. Fresh and dry weights were enhanced by Blue light in Impatiens.

• The Magazine for Energy Service Companies
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• s.70
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• pp.64-65
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• 2011

지난 3월 9일부터 11일까지 태국 방콕 더 웨스틴 호텔에서 한-태국 에너지효율 컨퍼런스가 성황리에 개최되었다. 이 행사는 에너지효율 분야에서 양국 공공기관, 기업간 협력 채널을 구축하고 협력사업을 촉진하기 위하여 마련된 행사로 한국과 태국의 정부관계자 및 업계 관계자들이 모여 양국의 에너지절약정책, 에너지진단 및 ESCO산업과 LED산업, 에너지라벨링 프로그램 등 관련내용을 교차 발표하는 형식으로 이루어졌다.

• Journal of Fashion Business
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• v.25 no.1
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• pp.51-64
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• 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.

• KIEAE Journal
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• v.15 no.2
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• pp.117-122
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• 2015

Purpose: Generally, 30% of the total energy consumption in office building is used for artificial indoor lightings, and almost 75-85% of electric power in fluorescent and Light-Emitting Diode (LED) lightings can be dissipated as a form of heat into indoor environment. The heat generated by indoor lightings can cause the increase of cooling load in office buildings. Thus, it its important to consider indoor lightings as a heat and light source, simultaneously. Method: In this study, we installed two kinds of indoor lightings including fluorescent and LED lightings and measured surface temperature of both indoor lightings. In addition, we obtained ambient temperature of indoor space and finally calculated total heat dissipated from plenum area and surface of lightings. Result: Total indoor heat gain was 87.17Wh and 201.36Wh in cases of six 40W-LED lightings and 64W-fluorescent lightings, respectively.

• Korean Journal of Materials Research
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• v.20 no.2
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• pp.60-64
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• 2010

This study looked at high performance copper-based alloys as LED lead frame materials with higher electrical-conductivity and the maintenance of superior tensile strength. This study investigated the effects on the tensile strength, electrical conductivity, thermal softening, size and distribution of the precipitation phases when Cr was added in Cu-Fe alloy in order to satisfy characteristics for LED Lead Frame material. Strips of the alloys were produced by casting and then properly treated to achieve a thickness of 0.25 mm by hot-rolling, scalping, and cold-rolling; mechanical properties such as tensile strength, hardness and electrical-conductivity were determined and compared. To determine precipitates in alloy that affect hardness and electrical-conductivity, electron microscope testing was also performed. Cr showed the effect of precipitation hardened with a $Cr_3Si$ precipitation phase. As a result of this experiment, appropriate aging temperature and time have been determined and we have developed a copper-based alloy with high tensile strength and electrical-conductivity. This alloy has the possibility for use as a substitution material for the LED Lead Frame of Cu alloy.

• Science of Emotion and Sensibility
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• v.21 no.4
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• pp.37-42
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• 2018

This study was conducted to evaluate the effects of LED illumination and task difficulty on a person's long-term memory. Illumination levels of 400 lx and 1,000 lx were employed in this study, and task difficulty was set at learning 4 words (easy task) and 7 words (difficult task). The person's retention rate of the learned task was designated as a dependent variable. A total of 64 subjects participated in this study, and 16 participants assigned to each of the four sets of conditions. The results indicated that the retention rate for the difficult task under relatively dark 400 lx conditions was 68.49%, while and the retention rate was higher than 56.03% for 1,000 lx conditions. In addition, for the easy task, the retention rate was 67.97% and 56.55% for the 400 1x and the 1,000 1x conditions, respectively. However, the interaction between illumination and task difficulty was not statistically significant. The study results further suggested that long-term memory can be effective in relatively dark conditions and indirectly suggests that long-term memory may not follow the Yokers-Dodson law.

• Journal of Ginseng Research
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• v.36 no.2
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• pp.198-204
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• 2012

An light-emitting diode (LED)-based light source was used as a monochromatic light source to determine the responses of raw ginseng roots (Panax ginseng Meyer) to specific emission spectra with respect to the production of ginsenosides. The ginsenoside content in the ginseng roots changed in response to the LED light treatments at $25^{\circ}C$ relative to the levels in the control roots that were treated in the dark or at $4^{\circ}C$ for 7 d. Ginseng roots were exposed to LEDs with four different peak emission wavelengths, 380, 450, 470, and 660 nm, in closed compartments. Compared with the control $4^{\circ}C$-treated roots, roots that were treated with 450 and 470 nm light showed a significantly increased production of ginsenosides (p<0.05), with increases of 64.9% and 74.1%, respectively. The contents of the ginsenosides $Rb_2$, Rc, and $Rg_1$ were significantly higher (p<0.05) in the 450 and 470 nm-treated root samples. The ratio of protopanaxadiol ginsenosides ($Rb_1$, $Rb_2$, Rc, and Rd) to protopanaxatriol ginsenosides ($Rb_1$, $Rb_2$, Re, and Rf) was significantly higher (p<0.05) in the 450 and 470 nm-treated root samples than in the control $4^{\circ}C$-treated roots. This is the first report that demonstrates the increase and conversion of ginsenosides in raw ginseng roots in response to exposure to LED light.

• Journal of the Optical Society of Korea
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• v.16 no.4
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• pp.349-353
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• 2012

Uniform spreading of injection current in light-emitting diodes (LEDs) is one of the crucial requirements for better device performances. It is reported that non-uniform current spreading leads to low output power, high current crowding, heating, and reliability degradation of the LED device. This paper reports on the effects of different surface and electrode geometries in the LEDs. To increase the output power of LEDs and reduce the series resistance, a rectangular-type LED (RT-LED) with a centered island cathode has been fabricated and investigated by comparison with a conventional LED (CV-LED). The performances of RT-LEDs were prominently enhanced via uniform current spreading and low current crowding. Performances in terms of increased output power and lower forward voltage of simulated RT-LEDs are much superior to those of CV-LEDs. Based on these results, we investigated the correlation between device geometries and optical characteristics through the fabricated CV and RT-LEDs. The measured output power and forward voltage of the RT-LEDs at 100 mA are 64.7% higher and 8% smaller compared with those of the CV-LEDs.