• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1027-1029
• /
• 2004

In this paper, we have fabricated pentacene thin film transistors (TFTs) using polyvinylphenol (PVP) copolymer and cross-linked PVP as gate insulator on glass and plastic (PET) substrate. Depending on the density of PVP and cross-link material the performance has been changed. We obtained the best device performance with the mobility of 0.32cm2/V${\cdot}$sec and the on/off current ratio of 1.19${\times}$106 for the case of 10wt% PVP copolymer mixed with 5wt% poly (melamine-co-formaldehyde). Additionally using pentacene TFTs with the above PVP gate insulator, we fabricated the integrated circuits including inverter which produced the gain of 9.7.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.356-358
• /
• 2004

In this paper we fabricated and succeeded to demonstrate a test panel for AMOLED on 2" glass and PET substrate. The test panel consisted of an array of 64 x 64 pixels in which OLEDs was driven by pentacene TFT. OTFTs were made of the inverted staggered structure and employed polyvinylphenol as the gate insulator and pentacene thin film as the active layer, producing the filed effect mobility of 0.3$cm^2$/V.sec and on/off current ratio of $10^5$. OLEDs were composed of TPD for HTL and Alq3 for EML with 35nm thick each, generating green monochrome light.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2005.11a
• /
• pp.63-68
• /
• 2005

In this paper, Coplanar Waveguide(CPW) low-pass filter with the spurious-reduced is designed by using Defected Ground Structures(DGS). Two different LPF unit cells and DGS pattern are combined to reduce the spurious. In comparison to a conventional step impedance LPF, the size of proposed LPF as 17.2mm*6.8mm is several times smaller. The simulation and measurements confirm that spurious characteristics is presented less than -30dB($S_{21}$) to three times cut off frequency.

• Progress in Superconductivity and Cryogenics
• /
• v.5 no.3
• /
• pp.38-42
• /
• 2003

HTS transformer is promising one of HTS power applications to be commercialized in the near future. To realize the applications, insulation technology in the coolant, liquid nitrogen, should be established. So breakdown characteristics should be considered at insulation components; turn-to-turn, layer-to-layer, winding-to-winding, were investigated. Firstly breakdown strengths of Kapton films were compared with Kraft paper these are as turn insulator. And next the characteristics of surface flashover on FRP were measured and the influence on breakdown strength of bubble generated with joule heat was discussed with the shape of cooling channel between layers. Finally barrier effect at winding-to-winding was discussed.

• Proceedings of the Korean Information Science Society Conference
• /
• 2010.11a
• /
• pp.147-148
• /
• 2010

최근 IT 산업 전반에 걸쳐 모바일에 대한 중요도가 높아짐에 따라 인터넷 브라우저의 성능이 중요하게 되었다. 자바스크립트 언어의 수행은 인터넷 브라우저의 사용에 있어 상당히 비중이 높다. 이 논문에서는 자바스크립트 언어를 수행하는 엔진 중 하나인 TraceMonkey엔진이 트레이스를 하는 과정에서 생기는 오버헤드를 줄이는 최적화를 구현, 적용하고 이를 실험하여 평가한다.

• Journal of Korea Multimedia Society
• /
• v.13 no.12
• /
• pp.1748-1759
• /
• 2010

We extend the octree subdivision process from Cartesian coordinates to spherical coordinates to develop more efficient space-partitioning structure for surface models. As an application of the proposed structure, we apply the octree subdivision in spherical coordinates ("S-Octree") to geometry compression in progressive mesh coding. Most previous researches on geometry-driven progressive mesh compression are devoted to improve predictability of geometry information. Unlike this, we focus on the efficient information storage for the space-partitioning structure. By eliminating void space at initial stage and aligning the R axis for the important components in geometry information, the S-Octree improves the efficiency in geometry information coding. Several meshes are tested in the progressive mesh coding based on the S-Octree and the results for performance parameters are presented.

• Proceedings of the Acoustical Society of Korea Conference
• /
• autumn
• /
• pp.541-544
• /
• 2004

본 논문에서는 서라운드 패닝알고리즘에서의 음색보정필터 설계기법에 대한 것으로 기존 패닝알고리즘에 음색보정필터를 추가하여 가상음원의 음색왜곡을 보정하는 알고리즘을 제안한 다. 가상음상과 실제 라우드 스피커의 머리전달함수 분석을 통해 기존 일정파워패닝알고리즘의 음색왜곡 문제점을 지적하고 이를 완화시키기 위한 새로운 패닝알고리즘을 제안한다.

• Proceedings of the Acoustical Society of Korea Conference
• /
• autumn
• /
• pp.279-282
• /
• 2004

산조 가야금의 경우 몸체의 뒷판에 세 개의 구멍(공명혈)이 있다. 이 구멍은, 몸체를 일정한 부피를 가진 용기로 보았을 때, 그 용기의 입구의 단면적, 다시 말해, 헬름홀츠 공진기 (Helmholtz Resonator) 입구의 단면적과 같다. 본 논문에서는 이 공명혈의 역할을 알아보기 위해, 1) 우선 기성의 산조 가야금 몸체의 세 공명혈을 모두 막은 상태, 일부만 막은 상태, 열려있는 상태에서의 몸체의 충격응답 전달함수를 측정, 분석하여 개략적으로 알아보았고, 이어서 2) 뒷판에 구멍이 전혀 없는 실험용의 산조 가야금 몸체의 제작을 의뢰하여, 뒷판 중앙에 구멍을 점차적으로 넓게 뚫어가면서, 각 단계별로 몸체의 충격응답을 측정하여, 구멍의 크기와 몸체의 충격응답 전달특성 변화 간의 상관관계를 분석 해보았다.

• ETRI Journal
• /
• v.32 no.5
• /
• pp.676-686
• /
• 2010

Mining sequential patterns is an important research issue in data mining and knowledge discovery with broad applications. However, the existing sequential pattern mining approaches consider only binary frequency values of items in sequences and equal importance/significance values of distinct items. Therefore, they are not applicable to actually represent many real-world scenarios. In this paper, we propose a novel framework for mining high-utility sequential patterns for more real-life applicable information extraction from sequence databases with non-binary frequency values of items in sequences and different importance/significance values for distinct items. Moreover, for mining high-utility sequential patterns, we propose two new algorithms: UtilityLevel is a high-utility sequential pattern mining with a level-wise candidate generation approach, and UtilitySpan is a high-utility sequential pattern mining with a pattern growth approach. Extensive performance analyses show that our algorithms are very efficient and scalable for mining high-utility sequential patterns.

• Proceedings of the Korean Information Science Society Conference
• /
• 2008.06b
• /
• pp.460-463
• /
• 2008

현재의 스토리지 시스템 및 백업 시스템에서 중복된 데이터의 증가로 인한 문제가 점점 대두되고 있다. 이러한 중복 데이터를 검사하거나 파일의 유사성을 검사하는 데에는 BSW알고리즘이 많이 사용되고 있으며 이 BSW알고리즘 내에서 해시 값을 구하는데에는 Rabin's Fingerprint알고리즘이 일반적으로 사용되고 있다. 본 논문에서는 Rabin's Fingerprint알고리즘에 비해 보다 빠르고 간단한 Modulo-K알고리즘을 제안하며 BSW알고리즘에서 Rabin's Fingerprint를 대체함으로써 최종적으로 BSW알고리즘의 속도를 향상 시킬 수 있는 Modulo-K알고리즘을 제안한다.