• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5253-5270
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• 2016

With device-to-device (D2D) communications, an inactive user terminal can be utilized as a relay node to support multi-hop communication so that connective experience of the cell-edge user as well as the capacity of the whole system can be significantly improved. In this paper, we investigate the spectrum sharing for a cooperative relay assisted D2D communication underlying a cellular network. We formulate a joint relay selection and channel assignment problem to maximize the throughput of the system while guaranteeing the quality of service (QoS) requirements of cellular users (CUs) and D2D users (DUs). By exploiting coalition formation game theory, we propose two algorithms to solve the problem. The first algorithm is designed based on merge and split rules while the second one is developed based on single user's movement. Both of them are proved to be stable and convergent. Simulation results are presented to show the effectiveness of the proposed algorithms.

• Advances in nano research
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• v.10 no.1
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• pp.91-99
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• 2021

Silicene is an emerging two-dimensional (2D) semiconductor material which has been envisaged to be compatible with conventional silicon technology. This paper presents a theoretical study of uniformly doped silicene with aluminium (AlSi3) Field-Effect Transistor (FET) along with the benchmark of device performance metrics with other 2D materials. The simulations are carried out by employing nearest neighbour tight-binding approach and top-of-the-barrier ballistic nanotransistor model. Further investigations on the effects of the operating temperature and oxide thickness to the device performance metrics of AlSi3 FET are also discussed. The simulation results demonstrate that the proposed AlSi3 FET can achieve on-to-off current ratio up to the order of seven and subthreshold swing of 67.6 mV/dec within the ballistic performance limit at room temperature. The simulation results of AlSi3 FET are benchmarked with FETs based on other competitive 2D materials such as silicene, graphene, phosphorene and molybdenum disulphide.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.312-312
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• 2011

All ship's ballast water should be inspected by administration after enter into force IMO BWM Convention. The purpose of the sampling device is to concentrate large amount of samples and to improve return rate of samples. It is composed of Concentration and Rinsing Part and optimized by the variety of tests. it is fully automated and therefore efficiently operated in ships.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1361-1363
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• 2005

In this paper, we report on the performance stability of solution processible OTFT devices with Au/Ti and ITO source-drain (S/D) electrodes. It appears that the contact resistance of the S/D electrode strongly affects the stability of OTFT devices. Interestingly, the devices with the Au/Ti electrode showed lower mobility than those with the ITO (S/D) devices. The field effect mobilities of the devices with the Au/Ti and ITO electrodes were 0.06, and $0.44cm^2/Vs$, respectively. However, the mobility of the device with the Au/Ti electrode was increased up to $0.26cm^2/Vs$ after 2 weeks, while the mobility of the device with ITO electrode was slightly decreased down to $0.41cm^2/Vs$. The experimental data show us that ITO could be used as the S/D electrode for low-cost OTFT devices.

• Proceedings of the KIEE Conference
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• 1984.07a
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• pp.226-229
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• 1984

A novel high intensity charging device has been developed for the control of the submicron particles, such as the diesel soot particulates, which are very hard to charge highly by any means of the conventional charging device. Having new corona electrodes of a multineedle disk with the corona field-control electrodes in the outer-cylinder electrode, extremely intense and stable coronas on there sharp points expanding both radially and axially are established in the corona charging region between the multi-corona -needles and an outer-cylinder electrode. As a result, the maximum corona field intensity and current density of the charging device of the standard one on soot load in laboratory tests have been 8.5KV/cm(E=$2V_m$/D(1nD/d)) and $6.5{\mu}A/cm^2$ which enhance greatly the charging of soot particles about several 100 times higher than those obtained in conventional cylinder precipitators.

• Journal of Korea Multimedia Society
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• v.15 no.10
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• pp.1264-1272
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• 2012

Three-dimensional volume rendering method which shows the inside of human body is widely used in medical imaging area. Existing medical imaging system using a volume rendering method already has provided a variety of three-dimensional results. Recently existing results in the medical imaging among physicians and patients to facilitate communication have been studied since smart device which has advantage of portability applied in the medical imaging. In this paper, we propose 3D volume visualization system for a relatively low spec portable smart devices by using 2D textures and we also implements 2D diagnostic images of portable medical imaging visualization system.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.6
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• pp.98-106
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• 1994

To realize high accuracy and high speed we developed a new self compensation scheme and applied it to a 10-bit D/A converter. This circuit can compensate the device mismatch without interrupting the D/A converter operation. With the compensation circuit,INA decreased down to 0.22LSB from 0.47LSB. The device was fabricated using a 0.8$\mu$m CMOS process. The area of the D/A converter core is 3.2mm$^{2}$ and the area of the compensation part is 0.64mm$^{2}$.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1091-1094
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• 2004

High-luminous efficiency full-color emissions in photoluminescence (PL) were obtained in $GdVO_4$ phosphor thin films co-doped with various amounts of Eu, Er and/or Tm and postannealed at approximately 1000$^{\circ}C$. The $GdVO_4$:Eu,Er,Tm phosphor thin films were deposited on thick $BaTiO_3$ ceramic sheets by r.f. magnetron sputtering using powder targets and postannealed in an air atmosphere. The rare earth (RE) content (RE/(Gd+V+RE) atomic ratio) in the oxide phosphor thin films was varied in the range from 0.1 to 2 at.%. It was found that the excitation of $GdVO_4$:Eu.Er,Tm thin films is attributed to band-to-band transition. A white PL emission was obtained in a $GdVO_4$:Eu,Er,Tm thin film with Eu, Er and Tm contents of 0.2, 0.7 and 1 at.%, respectively: CIE chromaticity color coordinates. (X=0.352 and Y=0.351). In addition, a white emission was obtained in a thin-film electroluminescent (TFEL) device made with this thin film.

• Korean Journal of Optics and Photonics
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• v.33 no.4
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• pp.137-145
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• 2022

A directional coupler device, one of the fundamental components of photonic integrated circuits, distributes optical power by evanescent field coupling between two adjacent optical waveguides. In this paper, the design process for manufacturing a directional coupler device is reviewed, and the accuracy of the design results, as seen from the characteristics of the actual fabricated device, is confirmed. When designing a directional coupler device through a two-dimensional (2D) beam-propagation-method (BPM) simulation, an optical structure is converted to a two-dimensional planar structure through the effective index method. After fabricating the directional coupler device array, the characteristics are measured. To supplement the 2D-BPM results that are different from the experimental results, a 3D-BPM simulation is performed. Although 3D-BPM simulation requires more computational resources, the simulation result is closer to the experimental results. Furthermore, the waveguide core refractive index used in 3D-BPM is adjusted to produce a simulation result consistent with the experimental results. The proposed design procedure enables accurate design of directional coupler devices, predicting the experimental results based on 3D-BPM.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.224-227
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• 2007

The reconstruction characteristics of MgO (111) textured protective layer by over-frequency accelerated discharge in AC-PDP were investigated and correlated to the variations of electronic structures. The reconstruction process and exaggerated grain growth (EGG) were explained by defect-assisted 2-D nucleation and growth mechanism combined with charged cluster model.