• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.3
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• pp.165-170
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• 2018

In this study, double-layered TCO (transparent conductive oxide) films were produced by depositing two distinct TCO materials: $SnO_2$ works as an n-type layer and ITO (indium-doped tin oxide) serves as a transparent conductor. Both transparent conductive oxide-films were sequentially deposited by sputtering. The electrical and optical properties of single-layered TCO films ($SnO_2$) and double-layered TCO ($ITO/SnO_2$) films were investigated. A TCO-embedding photodetector was realized through the formation of an $ITO/SnO_2/p-Si/Al$ layered structure. The remarkably high rectifying ratio of 400.64 was achieved with the double-layered TCO device, compared to 1.72 with the single-layered TCO device. This result was attributed to the enhanced electrical properties of the double-layered TCO device. With respect to the photoresponses, the photocurrent of the double-layered TCO photodetector was significantly improved: 1,500% of that of the single-layered TCO device. This study suggests that, due to the electrical and optical benefits, double-layered TCO films are effective for enhancing the photoresponses of TCO photodetectors. This provides a useful approach for the design of photoelectric devices, including solar cells and photosensors.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.8
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• pp.975-982
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• 2007

The single-phase switched reluctance motor(SRM) drive requires DC source which is generally supplied through a rectifier connected with a commercial source. The rectifier is consist of a diode full bridge and a filter circuit. Usually the filter circuit uses capacitor with large value capacitance to reduce ripple component of DC power. Although the peak torque ripple of SRM is small, the short charge and discharge current of the filter capacitor draws the low power factor and system efficiency. A modified single phase SRM drive system is presented in this paper, which includes drive circuit realizing reduction of torque ripple and improvement of power factor. In the proposed drive circuit, one switching part and diode which can separate the output of AC/DC rectifier from the filter capacitor is added. Also, a upper switch of drive circuit is exchanged a diode in order to reduce power switching device. Therefore the number of power switch device is not changed, two diodes are only added in the SRM drive. To verify the proposed system, some simulation and experimental results are presented.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.97-97
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• 2010

We demonstrate the hybrid polymer-quantum dot based multi-functional device (Organic bistable devices, Light-emitting diode, and Photovoltaic cell) with a single active-layer structure consisting of CdSe/ZnS semiconductor quantum-dots (QDs) dispersed in a poly N-vinylcarbazole (PVK) and 1,3,5-tirs- (N-phenylbenzimidazol-2-yl) benzene (TPBi) fabricated on indium-tin-oxide (ITO)/glass substrate by using a simple spin coating technique. The multi-functionality of the device as Organic bistable device (OBD), Light Emitting Diode (LED), and Photovoltaic cell can be successfully achieved by adding an electron transport layer (ETL) TPBi to OBD for attaining the functions of LED and Photovoltaic cell in which the lowest unoccupied molecular orbital (LUMO) level of TPBi is positioned at the energy level between the conduction band of CdSe/ZnS and LiF/Al electrode (band-gap engineering). Through transmission electron microscopy (TEM) study, the active layer of the device has a p-i-n structure of a consolidated core-shell structure in which semiconductor QDs are uniformly and isotropically adsorbed on the surface of a p-type polymer core and the n-type small molecular organic materials surround the semiconductor QDs.

• Journal of the HCI Society of Korea
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• v.13 no.1
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• pp.21-28
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• 2018

The rapid increase of Sinlge-person household and the increase in the use of smart devices necessitate the context analysis of Sinlge-person household and specific design direction for Sinlge-person household products. Previous studies have analyzed the overall context of smart devices without distinguishing between Sinlge-person household and a household. However, since the number of family members, age distribution, and residential space are different in the case of Sinlge-person household, it is necessary to analyze the different behaviors of smart devices. Therefore, this study limits the use environment of smart device of Single-person household to the scope of investigation, and based on the theoretical background, defines the existing comprehensive context based on user's situation that lasts for a certain interval. For the concrete and empirical research results, Consolidated Flow Model was constructed through Contextual Task through user research. This shows the interaction characteristics such as the guarantee of physical space, efficiency, lifestyle reflection, and safety assurance of Single-person household.

• International Journal of Computer Science & Network Security
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• v.21 no.11
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• pp.354-362
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• 2021

The device to device (D2D) communication is an important and emerging area for future cellular networks. It is concerned about all aspect of secure data transmission between end devices along with originality of the data. In this paradigm, the major concerns are about how keys are delivered between the devices when the devices require the cryptographic keys. Another major concern is how effectively the receiver device verifies the data sent by the sender device which means that the receiver checks the originality of the data. In order to fulfill these requirements, the proposed system able to derive a cryptographic key using a single secret key and these derived keys are securely transmitted to the intended receiver with procedure called mutual authentication. Initially, derived keys are computed by applying robust procedure so that any adversary feel difficulties for cracking the keys. The experimental results shows that both sender and receiver can identify themselves and receiver device will decrypt the data only after verifying the originality of the data. Only the devices which are mutually authenticated each other can interchange the data so that entry of the intruder node at any stage is not possible.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1103-1107
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• 2005

Single-crystal silicon thin films on glass (SOG) and on fused-quartz (SOQ) were prepared using wafer bonding and hydrogen-induced layer transfer. Thinfilm transistors (TFTs) were subsequently fabricated. The high-temperature processed SOQ TFTs show better device performance than the low-temperature processed SOG TFTs. Tensile and compressive strain was measured respectively on SOQ and SOG. Consistent with the tensile strain, enhanced electron effective mobility was measured on the SOQ TFTs.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.805-806
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• 2006

Single phase switched reluctance motor has a merit in practical use because it has simple operating drives and control systems, very high energy density per unit volume comparing with three phase SRM. But it must have a starting device. This paper presents a single phase SRM model with a stepped rotor pole, so as to reduce the torque ripple. Also it is simulated the designed prototype model by FEM for the prediction of characteristics.

• ETRI Journal
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• v.29 no.1
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• pp.124-126
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• 2007

In this letter, we study the impact of single event upsets (SEUs) in space or defense electronic systems which use memory devices such as EEPROM, and SRAM. We built a microcontroller test board to measure the effects of protons on electronic devices at various radiation levels. We tested radiation hardening at beam current, and energy levels, measured the phenomenon of SEUs, and addressed possible reasons for SEUs.

• Journal of Electrical Engineering and Technology
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• v.2 no.2
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• pp.216-220
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• 2007

This paper deals with the characteristic analysis of the single phase switched reluctance motor based on the converter coupled FE analysis. The converter comprises a rectifier, LC filter and switching power device. A computational technique for the converter coupled FE analysis is introduced and its validity is proven by the experiment.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.67-69
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• 2005

Single phase switched reluctance motor lias a merit in practical use because it has simple operating drives and control systems, very high energy density per unit volume comparing with three Phase SRM. But it must have a starting device. This paper presents a single phase SRM model with a stepped rotor pole, so as to reduce the torque ripple. Also it is simulated the designed prototype model by FEM for the prediction of characteristics