• Current Photovoltaic Research
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• v.1 no.1
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• pp.59-62
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• 2013

We investigated the effects of ZnO thin film deposition methods on the performance of inverted polymer solar cells with a structure of ITO/ZnO/P3HT:PCBM/MoO3/Al. The ZnO thin films were deposited by various methods (spin coating of nanoparticles, sol-gel process, atomic layer deposition) and their morphology was analyzed by atomic force microscopy (AFM). The device with ZnO nanoparticle thin films showed the highest power conversion efficiency of 3 % with low series resistance and high shunt resistance. The superior performance of the device with the ZnO nanoparticle layer is attributed to better electron extraction capability.

• ETRI Journal
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• v.31 no.5
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• pp.616-618
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• 2009

In this letter, a novel hybrid planar inverted-F antenna (PIFA) with a T-shaped slot on the ground plane is proposed. The loop structure formed by the feed line and shorting pin can be operated as a series and shunt inductance for the PIFA and the T-shaped slot antenna, respectively. The PIFA operates at a frequency of 1.75 GHz, while the T-shaped slot on the ground plane operates at 2.4 GHz by the same voltage feeding source. The height of the PIFA is 6.5 mm, and the size of an upper patch is designed to be 30 mm${\times}$16 mm. The measured relative impedance bandwidth of the PIFA and the T-shaped slot are about 12% and 21%, respectively. In addition, good antenna performance was achieved.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.1023-1026
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• 2007

Highly efficient inverted bottom emission organic light emitting device (IBOLED) with a structure of ITO/EIL/Alq3/NPB/WO3/Al was investigated. To enhance electron injection from ITO cathode to Alq3 EML layer, we introduced ultra thin Al layer and Liq layer between ITO and Alq3. The device characteristics showed tune on voltage of 4.5V, the maximum luminance of 21100 Cd/m2 and current efficiencies of 3.56 Cd/A.

• Korean Journal of Plant Taxonomy
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• v.53 no.3
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• pp.230-236
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• 2023

Rhododendron caucasicum Pall. is a shrub distributed in the mountainous areas of the Caucasus from northeastern Türkiye towards the Caspian Sea. This study reports the first complete chloroplast genome sequence of R. caucasicum. The plastome is 199,487 base pairs (bp) long and exhibits a typical quadripartite structure comprising a large single-copy region of 107,645 bp, a small single-copy region of 2,598 bp, and a pair of identical inverted repeat regions of 44,622 bp each. It contains 143 genes, comprising 93 protein-coding genes, 42 tRNA genes, and eight rRNA genes. The large chloroplast genome size is likely due to the expansion of inverted repeats. A phylogenetic analysis of chloroplast genomes with other Rhododendron species supports previously recognized infrageneric relationship.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.4
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• pp.17-22
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• 2009

Two different organic-inorganic hybrid thin film transistors (OITFTs) with the structures of glass/ITO/ZnO/PMMA/Al (staggered structure) and glass/ITO/PMMA/ZnO/Al (inverted staggered structure), were fabricated and their electrical and structural properties were compared. The ZnO thin films used as active channel layers were deposited by the atomic layer deposition (ALD) method at a temperature of $100^{\circ}C$. To investigate the effect of the substrates on their properties, the ZnO films were deposited on bare glass, PMMA/glass and ITO/glass substrates and their crystal properties and surface morphologies were analyzed. The structural properties of the ZnO films varied with the substrate conditions. The ZnO film deposited on the ITO/glass substrate showed better crystallinity and morphologies, such as a higher preferred c-axis orientation, lower FWHM value and larger particle size compared with the one deposited on the PMMA/glass substrate. The field effect mobility ($\mu$), threshold voltage ($V_T$) and $I_{on/off}$ switching ratio for the OITFT with the staggered structure were about $0.61\;cm^2/V{\cdot}s$, 5.5 V and $10^2$, whereas those of the OITFT with the inverted staggered structure were found to be $0.31\;cm^2/V{\cdot}s$, 6.8 V and 10, respectively. The improved electrical properties for the staggered OITFTs may originate from the improved crystal properties and larger particle size of the ZnO active layer.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.12
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• pp.1337-1344
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• 2007

It is shown that inverted ${\pi}$ feeder affects the gain improvement for the internal antenna of mobile phone. Generation of current on the inverted ${\pi}$ feeder, by the modification of conventional feeding structure for the PIFA and IFA, can apply T matching theory to the new feeder. Therefore, inverted ${\pi}$ feeder based on the T matching theory makes higher radiation resistance, and also increases the gain. To verify inverted ${\pi}$ feeding effect, feeder is applied to GSM/DCS dual band conventional PIFA, and measured return loss and patterns. By measurement, it's shown that this new feeding antenna has $0.23{\sim}0.84$ dB higher average gain for GSM band and $0.01{\sim}1.74$ dB higher average gain for DCS band than conventional fed PIFA without resonant frequency change.

• Structural Engineering and Mechanics
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• v.44 no.2
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• pp.239-255
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• 2012

This work presents a contribution to understand the inverted trussed beams behavior. The system has a main beam and struts with rectangular cross section associated to a wire rope enlaced to the main beam. It is an unpublished system with the advantage of easy positioning of the wire rope, once it is a continuous and connected by turnbuckles. It is a system that can be used as support for concrete formworks or for rehabilitation wooden beams proposal. The enlacement of the cable demands a small notch at the top of the cross section and a cross pin at the bottom. Six inverted trussed beams were tested, with spans of 180 cm with cables diameter of 1/4". Additionally, four simple beams without any external steel cable were also tested with material from the same lot of wood, allowing a comparison in rupture. The results showed capacity gain of around 60% compared to a simple beam. Once the wire rope characteristics and anchoring are very important for structure response, some improvement suggestions for the efficiency of the cables are also presented.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.8
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• pp.835-841
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• 2014

In this paper we propose a swing-up strategy for a single inverted pendulum. The proposed method has a feature whereby can handle the input and output constraint of a pendulum in a systematic way. For the swing-up of a pendulum, we adopt a 2-DOF control structure that combines the feedforward and feedback control. In order to generate the swing-up feedforward trajectories that satisfy the input and output constraint, we formulate the problem of generating feedforward trajectories as a nonlinear optimal control problem subject to constraints. We illustrate that the proposed method is more flexible than the existing method and provides great freedom in choosing the actuator of the inverted pendulum. Through an experiment, we show that the proposed method can swing a pendulum upward effectively while satisfying all the imposed constraints.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.228-236
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• 2012

In this paper, a controller for two wheeled inverted pendulum robot is designed to have more stable balancing capability than conventional controller. Fuzzy control structure is chosen for the two wheeled inverted pendulum robot, and fuzzy membership function factors for the controller are obtained for specified 3 users' weights using trial-and-error method. Next a neural network is employed to generate fuzzy membership function factors for more stable control performance when the user's weight is arbitrarily selected. Through the simulation study we find that the designed fuzzy controller using the neural network is superior to the conventional fuzzy controller.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.291-298
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• 2018

In this paper, we propose an antenna that improves narrow band characteristics which is a disadvantage of inverted-F type antenna and utilizes the structural advantages of small size and low profile by modifying the inverted-F type antenna structure and applying CPW feeding method. Experimental results show that the broadband characteristic of about 40% at the center frequency of 3 GHz is seen, and it is found that the narrow band characteristic which is a disadvantage of the conventional inverted F antenna can be improved. The radiation pattern showed almost omnidirectional characteristics and the maximum gain was about 2.0dBi.