• 한국세라믹학회지
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• 제53권5호
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• pp.489-493
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• 2016

Scandia ($Sc2O_3$)-stabilized zirconia (ScSZ) electrolyte-supported symmetrical solid oxide electrolyzer cells (SOECs), in which lanthanum strontium cobalt ferrite (LSCF)-gadolinia ($Gd_2O_3$)-doped ceria (GDC) composite materials are used as both the cathode and anode, were fabricated and their high temperature steam electrolysis (HTSE) performance was investigated. Current density-voltage curves were obtained for cells operated in 10% $H_2O$/90% Ar at 750, 800, and $850^{\circ}C$. It was possible to determine the ohmic, cathodic, and anodic contributions to the total overpotential using the three-electrode technique. The HTSE performance was significantly improved in the symmetrical cell with LSCF-GDC electrodes compared to the cell consisting of an Ni-YSZ cathode and LSCF-GDC anode. It was found that the overpotential due to the LSCF-GDC cathode largely decreased and, at a given current density, the total cell voltage decreased, which resulted in the enhanced hydrogen production rate in the symmetrical cell.

• Transactions on Electrical and Electronic Materials
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• 제10권2호
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• pp.44-48
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• 2009

A simulation study of a 10-bit two-stage DAC was done by using a conventional current switch cell. The DAC adopts the segmented architecture in order to reduce the circuit complexity and the die area. The 10-bit CMOS DAC was designed in 2 blocks, a unary cell matrix for 6 MSBs and a binary weighted array for 4 LSBs, for fabrication in a 0.35-${\mu}m$ CMOS process. To cancel the accumulation of errors in each current cell, a symmetrical switching sequence is applied in the unary cell matrix for 6 MSBs. To ensure high-speed operation, a decoding circuit with one stage latch and a cascode current source were developed. Simulations show that the maximum power consumption of the 10-bit DAC is 74 mW with a sampling frequency of 100 MHz.

• Applied Microscopy
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• 제8권1호
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• pp.53-66
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• 1978

An attempt has been made to discriminate the synapses in the striatum consisting caudate nucleus, putamen and fundus striati of the cat with emphasis on the characteristic structures of axon terminals and postsynaptic profiles. The differentiation is based on the size and shape of vesicle in the bouton terminal, and the symmetrical or asymmetrical thickening the pre- and postsynaptic membrane. Four types of synapses could be differentiated: Type I: the bontons with asymmetrical,synaptic thickenings contain round 45 nm diameter vesicles and contact cell soma, dendritic shafts and dendritic spines (74%). Type II : the boutons contain round 45nm diameter vesicles and are associated with symmetrical membrane thickenings. These synapses are formed on the soma and dendritic shafts (6%). Type III: the boutons with symmetrical membrane thickenings contain 50-60 nm diameter pleomorphic vesicles, and contact soma and dendritic shafts (18%). Type IV: the terminals contain flattened vesicles ($25{\times}45 nm$) and are associated with symmetrical membrane thickenings. These synapses are found in contact with soma and dendritic shafts. Additionally, the bouton en passant, which is expanded from myelinated or unmyelinated axons containing round vesicles (45nm diameter) contacts the dendritic shaft or dendritic spine with asymmetrical membrane thickenings. Two unusual types of synapses, axo-axonic and dendro-dendritic, are found occasionally.

• 전기학회논문지
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• 제58권8호
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• pp.1512-1518
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• 2009

Recently, new dispersed power sources such as photovoltaics, wind power, fuel cell etc. are energetically interconnected and operated in the distribution systems, as one of the national projects for alternative energy. This paper deals with the optimal countermeasures for the mal-function of protective devices at primary feeder in distribution systems when new power sources like photovoltaic (PV) systems are interconnected, based on the symmetrical components of short circuit studies. When new power sources are considered to be interconnected to distribution systems, bi-directional power flow and interconnection transformer connection of new power sources may cause the operation problems of protective devices (mainly re-closer), since new power sources can change typical characteristics of distribution systems. Therefore, this paper shows an analysis skill of the mal-functional mechanism of protective relay and proposes the optimal solution for the mal-function problem using the symmetrical components of fault analysis. And, this paper also shows the effectiveness of proposed method by the simulation at the field distribution systems.

• 한국광물학회지
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• 제22권4호
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• pp.325-330
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• 2009

합성 FeOOH-괴타이트 분말시료에 대한 고압실험을 압축성을 검증하기 위해 상온에서 시행하였다. 방사광이용 실험장치에서 대칭다이아몬드 앤빌기기를 각분산회절방법으로 배열하여 실험을 하였다. $K_{T'}$ 값을 4.0으로 가정하였을 때, 체적탄성률은 222.8 GPa로 계산되었다. 이 값은 천연산 괴타이트로부터 얻은 기존의 값과 비교하여 볼 때 매우 높은 값으로, 시료의 생성조건에 따라 나타나는 물질의 압력에 대한 이상 거동에 대해 고찰하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.232-232
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• 2010

Simulation Program (AFORS-HET 2.4.1) was used, include the basic structure of crystalline silicon thin film as above, under the intrinsic a-Si:H films bonded symmetrical structure (Symmetrical structure) were used. The structure of ITO, a-Si p-type, intrinsic a-Si, c-Si, intrinsic a-Si, a-Si n-type, metal (Al) layer has one of the seven. When thickness for each layer was given the change, the changes of a-Si p-type layer and the intrinsic a-Si layer on top had an impact on efficiency. Efficiency ratio of p-type a-Si:H layer thickness was sensitive to, especially a-Si: H layer thickness is increased in a rapid decrease in Jsc and FF, and efficiency was also decreased.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.366-366
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• 2010

Simulation Program (AFORS-HET 2.4.1) was used, include the basic structure of crystalline silicon thin film as above, below Intrinsic a-Si:H films bonded symmetrical structure (Symmetrical structure) were used. Efficiency with variation of the concentration was grown by the a-Si p-type with increasing concentrations of Na, efficiency with increasing a-Si n-type of Nd Concentrations was not changed, was decreased rapidly when concentrations were decreased. Efficiency was increased when c-Si n-type of Nd concentration was increased, otherwise efficiency was decreased when concentration was decreased.

• 센서학회지
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• 제26권3호
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• pp.173-178
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• 2017

In this paper, we newly developed an omnidirectional receiver for visible light communication (VLC). The omnidirectional receiver was composed of a flexible solar cell attached on a cylindrical surface with its axis in vertical direction. The solar cell surface was symmetrical and showed an almost uniform receiving pattern in a horizontal plane. The maximum difference in a receiving pattern was within 7% of its peak value in a horizontal plane. This configuration is very easy to fabricate and useful in constructing wireless sensor networks in which one receiver needs to detect multiple LED signals in different directions.

• Annals of Clinical Neurophysiology
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• 제17권1호
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• pp.31-34
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• 2015

We report a case with squamous cell lung cancer with concomitant Guillain-Barre syndrome (GBS) as a paraneoplastic syndrome. A 67-year-old patient who was previously diagnosed as metastatic squamous cell lung cancer developed mild symmetrical weakness, paresthesia and sensory ataxia. Nerve conduction study showed sensorimotor polyneuropathy. Analysis of cerebrospinal fluid showed high tilter for monospecific anti-GD1b IgG antibody without onconeuronal antibodies. After treatment with intravenous immunoglobulin, the patient's symptoms improved.

• 전력전자학회논문지
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• 제20권2호
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• pp.160-166
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• 2015

This study proposes an improved cell balancing circuit for fast equalization among lithium-ion (Li-ion) batteries. A simple voltage sensorless charge balancing circuit has been proposed in the past. This cell balancing circuit automatically transfers energy from high-to low-voltage battery cells. However, the circuit requires a switch with low on-resistance because the balancing speed is limited by the on-resistance of the switch. Balancing speed decreases as the voltage difference among the battery cells decrease. In this study, the balancing speed of the cell balancing circuit is enhanced by using the auxiliary circuit, which boosts the balancing current. The charging current is determined by the nominal battery cell voltage and thus, the balancing speed is almost constant despite the very small voltage differences among the batteries. Simulation results are provided to verify the validity of the proposed cell balancing circuit.