• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.271-273
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• 2005

많은 글로벌 기업들이 비용절감 및 효율성 증대를 위하여 RFID 시스템을 도입하거나 도입을 적극 검토 중에 있다. RFID 시스템으로부터 획득된 수많은 정보들이 기업의 업무효율을 증대시킬 수 있도록 하기 위해서는 상위 응용 서비스에서 RFID 데이터를 효율적으로 사용할 수 있도록 리더와 응용 서비스 간의 중계 역할을 할 수 있는 RFID 미들웨어의 역할이 매우 중요하다. 이러한 요구사항에 맞춰 최근 EPCglobal에서는 RFID 미들웨어인 ALE(Application Level Event)를 제시하고 있다. ALE는 RFID 리더에 의해 읽혀진 EPC 이벤트 데이터를 실시간으로 수집하여 원본 데이터의 오류를 보정한 후에 사용자와 응용 서비스의 요구에 따라 특정 이벤트 데이터를 필터링하여 보고하는 역할을 한다. 본 논문에서는 ALE의 실시간 EPC 이벤트 데이터 처리를 위한 EMS(Event Management System) 컴포넌트를 제시하며 EMS에 대한 요구사항을 분석하고 설계하였다. EMS 컴포넌트는 RFID 리더를 통해서 끊임없이 들어오는 스트링 형태의 EPC 이벤트 데이터를 블록킹 없이 수집하는 역할을 한다. 또한, RFID 리더에서 수집한 데이터의 보정 및 필요 데이터 추출을 위한 다양한 필터링 기능을 제공함으로써 수집된 데이터의 정확성을 높이며 신속한 데이터 제공을 가능하게 한다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.422-425
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• 2006

본 연구는 도체주변에 감겨진 광섬유 코일에 따라 선형편광축이 자기장에 의해 회전하는 Faraday Effect를 이용한 GIS(Gas Insulated Switchgear,이하 GIS) 용 광 전류센서의 구성과 DAQ(Data Acquisition,이하 DAQ)보드를 장착한 PC를 이용하여 실시간 데이터 취득, 분석 그리고 저장을 동시에 수행하였다 광원은 1310[nm]의 레이저 다이오드를 이용하였다. 센서부는 GIS에 맞게 원형으로 제작하였고 $9/125[{\mu}m]$규격 단일모드의 일반 통신용 광섬유를 지름 31[cm]의 센서부 코어에 20[회] 감아 설치하였다. PC기반의 실시간 데이터 분석 프로그래밍은 NI사의 Labview를 이용하여 코딩하였으며 PD(Photo Diode,이하 PD)의 전기적인 신호는 터미널 블록을 거쳐 NI사의 16bit DAQ M시리즈를 이용하여 수집되어진다. 직접 코딩한 프로그램을 이용하여 $700A\sim1400A$ 측정한 출력값 선형적인 증가추세를 보여주었다. 또한 OCS(Oscilloscope,이하 OCS)를 이용한 측정시스템과의 출력신호 및 정밀도를 비교 검토하였다. 그리고 Labview에서 지원하는 Web Tool기능을 이용하여 Web기반의 원거리 측정에서도 안정된 출력을 보여주었다.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.9
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• pp.483-490
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• 2005

Recently, flash memory is widely used in embedded applications since it has strong points: non-volatility, fast access speed, shock resistance, and low power consumption. However, due to its hardware characteristics, it requires a software layer called FTL(flash translation layer). The main functionality of FTL is to convert logical addresses from the host to physical addresses of flash memory We present a new FTL algorithm called STAFF(State Transition Applied Fast Flash Translation Layer). Compared to the previous FTL algorithms, STAFF shows five times higher performance than basic block mapping scheme and requires less memory. We provide performance results based on our implementation of STAFF and previous FTL algorithms.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.840-843
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• 2019

IoT 산업이 발전하면서 기존 토이와 IoT 기술을 결합한 스마트토이가 각광 받고 있다. 스마트토이는 수동적인 방식의 기존토이와는 다르게 토이 간 인터렉션이 가능하며 전자 센서들을 사용하여 토이를 사용하는 어린아이들에 코딩을 활용한 콘텐츠를 제공가능하다. 기존 스마트토이는 처음에는 호기심을 자극하지만, 익숙해지면 흥미가 떨어지는 현상을 보인다. 이에 본 논문에서는 기존 스마트토이가 갖는 재미요소 증가와 다양한 콘텐츠의 개발을 위해서 스마트 토이에 Artificial Intelligence(AI) 기능을 접목한 AI 카메라블록을 사용하여 새로운 콘텐츠를 개발하였다.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.4
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• pp.306-316
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• 2018

Monolithic zirconia has been widely used in fixed partial dentures due to high strength and fracture toughness. Nevertheless, the usage of monolithic zirconia in anterior restoration was limited because of opacity. Recently, esthetic monolithic zirconia blocks are developed by improving translucency and using various shading systems. Manufacturer introduces 3M $Lava^{TM}$ Esthetic with increased cubic phase and fluorescent ingredients is more esthetic than previous monolithic zirconia. This case report describes favorable anterior restorations using translucent monolithic zirconia.

• Journal of IKEEE
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• v.23 no.3
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• pp.925-933
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• 2019

In this paper, we implement ZYNQ SoC-based post-processing system that utilizes partial reconfiguration to remove blocking artifacts generated by compression algorithm. Hardware implementation of the deblocking filter in a Field Programmable Gate Array (FPGA) provides high computational capability and can be partially reconfigured to process 1080p images in real time. Partially reconfigurable areas in FPGA can be utilized to use hardware more efficiently in highly resource-constrained embedded systems. Experimental results of the proposed system show improvement of visual quality both objectively and subjectively with 0.6dB higher PSNR after deblocking filtering process. The measured power consumption of the deblocking filter during run-time is 68.33mW.

• Journal of Broadcast Engineering
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• v.24 no.3
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• pp.485-494
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• 2019

A software-driven real-time frequency de-modulator is implemented with the aid of universal-serial-bus (USB) type software defined radio dongle. An analog stereo frequency modulation (FM) broadcast signal is down-converted to the basedband analog signal then converted to digital bit streams in the USB dongle. Computer software such as Matlab, Python, and GNU Radio manipulates the incoming bit streams with the technique of digital signal processing. Low pass filtering, band pass filtering, decimation, frequency discriminator, double sideband amplitude demodulation, phase locked loop, and deemphasis function blocks are implemented using such computer languages. Especially, GNU Radion is employed to realize the real-time demodulator.

• The Journal of the Acoustical Society of Korea
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• v.26 no.6
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• pp.227-234
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• 2007

This paper describes a transmission method based on a single carrier with frequency domain equalization (SC-FDE) scheme with cyclic prefix(CP). The SC-FDE has similar features with orthogonal frequency division multiplexing(OFDM). Similar to OFDM, a SC-FDE system is computationally efficient since equalization is reformed on a block of data in the frequency domain. Especially, it has the advantage of low sensitivity to nonlinear distortion compared to OFDM. In this paper, we design a SC-FDE receiver using decision-directed method, and present simulation results.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.318-324
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• 2015

Purpose: This study compared shear bond strengths of five self-adhesive cements with phosphate monomer to zirconium oxide ceramic with and without airborn particle abrasion. Materials and methods: One hundred zirconia samples were air-abraded ($50{\mu}mAl_2O_3$). One hundred composite resin cylinders were fabricated. Composite cylinders were bonded to the zirconia samples with either Permacem 2.0 (P), $Clearfil^{TM}$ SA Luting (C), $Multilink^{(R)}$ Speed (M), $RelyX^{TM}$ U200 Automix (R), G-Cem $LinkAce^{TM}$ (G). All bonded specimens were stored in distilled water ($37^{\circ}C$) for 24 h and half of them were additionally aged by thermocycling ($5^{\circ}C$, $55^{\circ}C$, 5,000 times). The bonded specimens were loaded in shear force until fracture (1 mm/min) by using Universal Testing Machine (Model 4201, Instron Co, Canton, MA, USA). The failure sites were inspected under field-emission scanning electron microscopy. The data was analyzed with ANOVA, Tukey HSD post-hoc test and paired samples t-test ($\alpha$=.05). Results: Before and after thermocycling, $Multilink^{(R)}$ Speed (M) revealed higher shear-bond strength than the other cements. G-Cem $LinkAce^{TM}$ (G) showed significantly lower bond strengths after thermocycling than before treatment (P<.05), but the other groups were not significantly different (P>.05). Conclusion: Most self-adhesive cements with phosphate monomer showed high shear bond strength with zirconia ceramic and weren't influenced by thermocycling, so they seem to valuable to zirconia ceramic bonding.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.324-334
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• 2017

The simulators for a plant unit master control (UMC) developed by domestic or overseas researchers have been developed for operator-training purposes. UMC simulators normally constructed at the end of the plant construction, despite the UMC logics, should be simulated to pre-check many signal interfaces within the power generation systems. Because of the differences in construction schedule, it is difficult for logic designers or commissioning engineers to simulate the UMC logic during the design or commissioning stage. In this background, this paper proposes a simulation method that can be used easily by plant logic designers or operators in the MATLAB Simulink programming environment. The core of the UMC is realized with a unique simulation algorithm based on mathematical analysis and functional blocks combination. In addition, an integer-based configuration was proposed to realize the plant target value control for the equipment in the logic. With these simulation methods, functions, e.g., load distribution, high-low limitations, frequency compensation, etc. were simulated. The results showed that the plant UMC logic can be simulated in Simulink without a plant simulator. The various functions proposed in this paper can provide useful information about Simulink-based simulation design for plant logic designers or commissioning engineers during the power plant construction period.