• Korean Institute of Interior Design Journal
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• v.24 no.4
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• pp.91-98
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• 2015

Double skin façade is known that several features affected the building energy and daylighting performance. That is why the envelope is able to consist of all architectural materials such as glass, aluminum, wood and insulation for vision of residents and workers in buildings. Its specifications is very diverse according to the building designers and building owners. In recent times, visual environment became a major focus and resulted in the development of cutting edge engineering of diverse glazing systems and shading devices by growing interests of friendly environment. Thus this research has evaluated the fluctuations of interior lighting and atmospheric conditions based on double skin facade systems. Especially in terms of daylighting environment as dependent on solar variations, this research provides quantitative analysis of interior lighting conditions and how it affects the living conditions as well as improve the design of interior spaces.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.1
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• pp.70-75
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• 2011

We introduced nanoscale interfacial layers between the PV layer and the cathode in poly (3-hexylthiophene):methanofullerene bulk-heterojunction polymer photovoltaic (PV) cells. The nanoscale double interfacial layers were made of ultrathin poly (oxyethylenetridecylether) surfactant and low-work-function alloy-metal of Al:Li layers. It was found that the nanoscale interfacial layers increase the photovoltaic performance, i.e., increasing short-circuit current density and fill factor with improved device stability. For PV cells with the nanoscale double interfacial layers, an increase in power conversion efficiency of $4.18{\pm}0.24%$ was achieved, compared to that of the control devices ($3.89{\pm}0.08%$) without the double interfacial layers.

• Korean Journal of Optics and Photonics
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• v.18 no.3
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• pp.226-231
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• 2007

In this paper, we analyze the characteristics of various curved waveguides composed of double metal strips using finite difference method (FDM). Our investigation reveals that the bending loss of the double metal strip waveguide can be improved with less degradation of the straight waveguide's propagation loss compared to the single metal strip structure. Optimization of the double metal strip waveguide structure has been conducted considering bending and propagation losses.

• KIEAE Journal
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• v.2 no.3
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• pp.39-45
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• 2002

Double facades are built to allow natural ventilation in high rise buildings and buildings with high outside noise level. In high rise Buildings the gains in summer can be reduced by sufficient sun protection devices placed outside the rooms in the ventilated space between the inner and outer facade. To evaluate the energetic performance, three buildings with double facade were monitored for at least one year (Siemens Building in Dortmund/Germany, Victoria Insurance Company in Duesseldorf/Germany and RWE Tower in Essen/Germany). The results document the indoor climate, the boundary conditions for further planning and the possibilities for high rise buildings without or with little cooling facilities.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.97-98
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• 2006

High current behaviors of the grounded gate extended drain N-type metal-oxide-semiconductor field effects transistor (GG_EDNMOS) electro-static discharge (ESD) protection devices are analyzed. Simulation based contour analyses reveal that combination of BJT operation and deep electron channeling induced by high electron injection gives rise to the 2-nd on-state. Thus, the deep electron channel formation needs to be prevented in order to realize stable and robust ESD protection performance. Based on our analyses, general methodology to avoid the double snapback and to realize stable ESD protection is to be discussed.

• ETRI Journal
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• v.44 no.1
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• pp.147-154
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• 2022

We demonstrate a new double-layer structure for stretchable interconnects, where the top surface of a serpentine polyimide support is coated with a thin eutectic gallium-indium liquid metal layer. Because the liquid metal layer is constantly fixed on the solid serpentine body in this liquid-on-solid structure, the overall stretching is accomplished by widening the solid frame itself, with little variation in the total length and cross-sectional area of the current path. Therefore, we can achieve both invariant resistance and infinite fatigue life by combining the stretchable configuration of the underlying body with the freely deformable nature of the top liquid conductor. Further, we fabricated various types of double-layer interconnects as narrow as 10 ㎛ using the roll-painting and lift-off patterning technique based on conventional photolithography and quantitatively validated their beneficial properties. The new interconnecting structure is expected to be widely used in applications requiring high-performance and high-density stretchable circuits owing to its superior reliability and capability to be monolithically integrated with thin-film devices.

• Journal of the Korean Vacuum Society
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• v.5 no.3
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• pp.175-180
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• 1996

Double conductance method is proposed as an effectvie way to measure real outgassing rates of materials regardless of their adsorbing power. The real outgassing rate and the sticking coefficient of the CFC (carbon fiber composite) which is used widely as the material for armor plates infusion experiment devices were obtained by adopting this method. At $40^{\circ}C$ the real ougassing rate was $Pa, m^3/s.m^2$(in $N_2$ equivalent), which was higher than 5 times the measured one, and the sticking coefficient was about 0.018($H_2O\; and \;H_2$ were the main residual gases).

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.460-463
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• 1999

A new multi-step voltage source inverter is proposed in this paper. The proposed scheme is composed of the double-connected 12-step inverter with an auxiliary circuit. The auxiliary circuit includes two voltage dividing capacitors, two switching devices and a low KVA autotransformer. The resultant system is shown to be a 24-step inverter suitable for large scale SVC applications in which the PWM method can not be employed. The design parameters are derived from the analysis of voltages and currents by means of switching functions. The simulation results verify the proposed concept.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.10a
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• pp.157-161
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• 1993

Optical devices and electronic equipments used in the laboratory of the synchrotron light source building of the accelerator have stringent vibration limits. In order to control the vibration of the building structure and HVAC systems which are main vibration sources are evaluated using experimental modal analysis. Double anti-vibration system is used for the HVAC system and results show that the double anti-vibration system reduces the vibrations of the building to acceptable levels.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.278-278
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• 2016

Solution-processed metal-oxide semiconductors have been considered as the next generation semiconducting materials for transparent and flexible electronics due to their high electrical performance. Moreover, since the oxide semiconductors show high sensitivity to light illumination and possess persistent photoconductivity (PPC), these properties can be utilized in realizing optical memory devices, which can transport information much faster than the electrons. In previous works, metal-oxide semiconductors are utilized as a memory device by using the light (i.e. illumination does the "writing", no-gate bias recovery the "reading" operations) [1]. The key issues for realizing the optical memory devices is to have high photoconductivity and a long life time of free electrons in the oxide semiconductors. However, mono-layered indium-zinc-oxide (IZO) and mono-layered indium-gallium-zinc-oxide (IGZO) have limited photoconductivity and relaxation time of 570 nA, 122 sec, 190 nA and 53 sec, respectively. Here, we boosted up the photoconductivity and relaxation time using a double-layered IZO/IGZO active layer structure. Solution-processed IZO (top) and IGZO (bottom) layers are prepared on a Si/SiO2 wafer and we utilized the conventional thermal annealing method. To investigate the photoconductivity and relaxation time, we exposed 9 mW/cm2 intensity light for 30 sec and the decaying behaviors were evaluated. It was found that the double-layered IZO/IGZO showed high photoconductivity and relaxation time of 28 uA and 1048 sec.