• ETRI Journal
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• 제32권4호
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• pp.626-629
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• 2010

In this letter, we present an enhanced block-based adaptive loop filter (E-BALF) with multiple filter symmetric structures. The E-BALF adapts various filter symmetric structures in a rate-distortion optimization sense, reflecting the statistical properties of each image in a video sequence. Experimental results show that the proposed method achieves a reduction in the Bj${\phi}$ntegaard delta (BD)-bitrate by an average of 9.60% compared with Joint Model 11.0 of H.264/AVC. Compared to the state-of-the-art BALF, a reduction of up to 1.13% in BD-bitrate is achieved.

• ETRI Journal
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• 제43권5호
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• pp.891-899
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• 2021

We propose a stray inductance extraction method on power modules of the few-kilovolts/several-hundred-amperes class using only low voltages and low currents. The method incorporates a double-pulse generator, a level shifter, a switching device, and a load inductor. The conventional approach generally requires a high voltage of more than half the power module's rated voltage and a high current of around half the rated current. In contrast, the proposed method requires a low voltage and low current environment regardless of the power module's rated voltage because the module is measured in a turn-off state. Both theoretical and experimental results are provided. A physical circuit board was fabricated, and the method was applied to three commercial power modules with EconoDUAL3 cases. The obtained stray inductance values differed from the manufacturer-provided values by less than 1.65 nH, thus demonstrating the method's accuracy. The greatest advantage of the proposed approach is that high voltages or high currents are not required.

• 기술혁신학회지
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• 제18권4호
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• pp.693-718
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• 2015

본 연구는 국가과학기술연구회(구, 기초기술연구회 및 산업기술연구회) 산하 출연연 24개 기관이 출연금과 정부수탁과제로 집행한 최근 3개년간(2011~2013)의 연구과제중 국가과학기술표준분류의 중 분류 기준으로 2개 이상의 기술을 연구하는 융합기술 연구과제를 사회연결망분석 기법을 활용하여 기술간에 어떠한 네트워크 구조를 가지고 있는지를 분석해 보았다. 분석결과 출연연의 융합연구는 국가연구개발사업의 전체 융합연구와 비교할 때 더 활발하고, 다양한 기술분야에서 수행되고 있음을 확인할 수 있었다. 또한 외부기관과 공동연구에 의한 융합연구보다 내부에서 더 활발히 융합연구가 이루어지고 있음을 확인하였다. 그리고 융합기술의 네트워크 중심성을 파악하여 융합연구의 중심역할을 하는 기술이 내부중심형 기술과 외부중심형 기술로 분류된다는 것을 확인하였다. 융합연구는 단순히 기술간의 융합만을 뜻하는 것은 아니다. 출연연은 융합연구 활성화를 위해서 단순히 다기술 연구만을 수행하지 말고, 신기술, 신산업을 창출할 수 있는 융합연구 영역도 창출해야 할 것이다. 이러한 관점에서 본 논문은 출연연의 융합연구 현황 및 네트워크 분석을 통해 출연연의 융합연구를 활성화를 위한 역할에 대한 정책적 시사점을 제시하고 있다.

• ETRI Journal
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• 제39권4호
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• pp.467-479
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• 2017

This study examines how the characteristics of cooperative research and development (R&D) projects in the public domain impact information and communication technology (ICT) convergence. Based on the analysis of 416 cooperative R&D projects under the ICT-based industry convergence R&D program in Korea, the study finds that the characteristics of cooperative R&D projects significantly impact ICT convergence. Moreover, the participation of public research institutes and universities is critical for ICT convergence compared with that of firms. However, in firm-to-firm cooperation, the participation of small and medium enterprises contributes to cross-sectional convergence, while the participation of large firms leads to overall and longitudinal convergence. R&D inputs such as the number of partners and government subsidies exhibit an inverted U-shaped relationship (negative quadratic effect) with technology convergence. Project duration and homogeneous partners are also critical factors for ICT convergence. The results indicate several implications and guidelines on how to effectively organize cooperative R&D projects to facilitate technology convergence.

• ETRI Journal
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• 제45권3호
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• pp.543-550
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• 2023

Electrostatic discharge (ESD) testing for human body model tests is an essential part of the reliability evaluation of electronic/electrical devices and components. However, global environmental concerns have called for the need to replace the mercury-wetted relay switches, which have been used in ESD testers. Therefore, herein, we propose an ESD tester using metal oxide semiconductor-controlled thyristor (MCT) devices with a significantly higher rising rate of anode current (di/dt) characteristics. These MCTs, which have a breakdown voltage beyond 3000 V, were developed through an in-house foundry. As a replacement for the existing mercury relays, the proposed ESD tester with the developed MCT satisfies all the requirements stipulated in the JS-001 standard for conditions at or below 2000 V. Moreover, unlike traditional relays, the proposed ESD tester does not generate resonance; therefore, no additional circuitry is required for resonant removal. To the best of our knowledge, the proposed ESD tester is the first study to meet the JS-001 specification by applying a new switch instead of an existing mercury-wetted relay.

• 한국전기전자재료학회논문지
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• 제35권3호
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• pp.292-296
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• 2022

(La_0.5Nd_0.2Sr_0.3)MnO₃ specimens were prepared by a solid-state reaction. In all specimens, X-ray diffraction patterns of an orthorhombic structure were shown. The fracture surfaces of (La_0.5Nd_0.2Sr_0.3)MnO₃ specimens showed a transgranular fracture pattern be possibly due to La ions (0.122 nm) as a perovskite A-site dopant substituting for Nd ions (0.115 nm) having a small ionic radius. The full-width at half maximum (FWHM) of the Mn 2p XPS spectra showed a value greater than that [8] of the single valence state, which is believed to be due to the overlapping of Mn²⁺, Mn³⁺, and Mn⁴⁺ ions. The dependence of Mn 2p spectra on the Mn³⁺/Mn⁴⁺ ratio according to sintering time was not observed. Electrical resistivity resulted in the minimum value of 100.7 Ω-cm for the specimen sintered for 9 hours. All specimens show a typical negative temperature coefficient of resistance (NTCR) characteristics. In the 9-hour sintered specimen, TCR, activation energy, and B25/65-value were -1.24%/℃, 0.19 eV, and 2,445 K, respectively.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.1390-1392
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• 2015

최근 다양한 웨어러블 기기의 등장으로 인해, 이종의 라이프로그 정보로부터 개인별 맞춤형 건강관리 서비스를 제공할 수 있는 분석 솔루션의 중요성이 대두되고 있다. 본 연구에서는 이기종의 웨어러블 기기를 통해 수집된 라이프로그 정보를 근간으로 개인의 건강상태를 모니터링하고 분석할 수 있는 웰니스 인포메틱스엔진에 대한 프레임워크를 소개한다. 또한 개발된 인포메틱스엔진의 효과성은 실증시범서비스 기간 동안에 수집된 다양한 라이프로그 정보를 활용하여, 2가지 벤치마크 방법들과의 예측능력을 비교함으로써 그 효과성을 제시한다.

• Molecules and Cells
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• 제47권3호
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• pp.100009.1-100009.3
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• 2024

• Molecules and Cells
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• 제46권12호
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• pp.743-745
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• 2023

• 한국생산제조학회지
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• 제22권3호
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• pp.414-420
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• 2013

Research on decreasing the weight of composite sandwich panels is in progress. This paper reports the experimental results for the mechanical behavior of a composite sandwich panel. The skins of sandwich panels were made of glass fiber sheets and plywood matrix composites. Their interior layers consisted of glass fiber pultrusion pipes and gold foam. Experimental tests were performed to obtain the mechanical properties and complex mechanical behavior. Before fatigue tests, tensile tests and 3-point bending tests were carried out to obtain the optimal design and determine their strength and failure mechanisms in the flat-wise position. After the static test, a fatigue test were conducted at a load frequency of 5 Hz, stress ratio (R) of 0.1, and endurance limit for the S-N curve. It showed that the failure modes were related to both the core design and skin failure.