• Title/Summary/Keyword: POSTECH

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Survey on Top-k Related Pair Search Method Using Cosine Similarity (코사인 유사도 기법을 이용한 top-k 관련쌍 검색 방법 조사)

  • Kim, Sungchul;Kim, Jeong-Hwan;Kim, Na-Yeong;Kim, Taehoon;Yu, Hwanjo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.04a
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    • pp.808-809
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    • 2017
  • 유사도 검색은 전통적으로 데이터베이스 그리고 웹검색 분야의 핵심이었으나, 대용량 데이터의 등장으로 검색의 정확도뿐만이 아니라 효율성 측면에서의 요구가 증가하며 여전히 다양한 분야에서 활발히 연구되고 있다. 아이템간의 유사도를 측정하기 위한 방법론 중 코사인 유사도 방법론은 고차원공간에서의 활용이 유리하다는 이점 때문에 가장 널리 활용되고 있는 방법론으로, 정보검색, 장바구니 분석, 생물정보학 등 다양한 분야에서 활용되고 있다. 본 논문에서는 코사인 유사도를 소개하고, 연관성 분석 측면에서 코사인 유사도를 사용한 기존의 연구들을 소개한다.

Graph Compression by Identifying Recurring Subgraphs

  • Ahmed, Muhammad Ejaz;Lee, JeongHoon;Na, Inhyuk;Son, Sam;Han, Wook-Shin
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.04a
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    • pp.816-819
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    • 2017
  • Current graph mining algorithms suffers from performance issues when querying patterns are in increasingly massive network graphs. However, from our observation most data graphs inherently contains recurring semantic subgraphs/substructures. Most graph mining algorithms treat them as independent subgraphs and perform computations on them redundantly, which result in performance degradation when processing massive graphs. In this paper, we propose an algorithm which exploits these inherent recurring subgraphs/substructures to reduce graph sizes so that redundant computations performed by the traditional graph mining algorithms are reduced. Experimental results show that our graph compression approach achieve up to 69% reduction in graph sizes over the real datasets. Moreover, required time to construct the compressed graphs is also reasonably reduced.

Developing of SMS Mobile System for the PAL Control System (가속기 제어시스템의 SMS 모바일 시스템 구현)

  • Yoon, J.C.;Park, B.R.;Oho, M.H.;Kang, H.S.;Choi, J.
    • Proceedings of the KIEE Conference
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    • 2006.07d
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    • pp.1913-1914
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    • 2006
  • Modem Industrial control systems tend to adopt a variety of intelligent wireless device controllers to interface front-end computers with active components of the industrial device. Some of the intelligent control systems come equipped with a wireless SMS(Simple Message Service) interface giving an opportunity to use fault alarm Interlock system. Immediately send warning or alert messages to Mobile devices or remote users. Real time monitoring the SMS systems by Mobile devices. Control systems remotely by mobile devices in emergency situation. In order to provide against system fault, SMS Mobile System will enable system administrator to promptly access, monitor and control the system whenever users want and wherever users are, by utilizing wireless Internet and mobile devices. This paper presents the Mobile SMS system for PAL Control System.

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High Temperature Size Exclusion Chromatography for High Throughput Analysis

  • Chang, Tai-Hyun;Park, Soo-Jin;Cho, Hee-Sook;Kim, Young-Tak;Ihm, Kyu-Hyun
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.202-202
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    • 2006
  • With a modern size exclusion chromatography (SEC) column, molecular weight analysis of a polymer sample takes about 10 min. However, it is desirable to reduce the analysis time further, in particular, for high throughput measurements required in combinatorial analyses or 2D-HPLC analyses. We implemented the high temperature SEC for the purpose. By inserting a narrow bore tubing between the column and the detector, a sufficient backpressure can be maintained to prevent the mobile phase from boiling and the effluent is cooled down enough when it reaches the detector. Therefore, a normal SEC detector can be used without any modification. The SEC resolution is greatly improved at the elevated temperature at high flow rate which allows high speed operation.

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Advanced Analysis Techniques for Oxide Cathodes

  • Je, Jung-Ho;Kim, In-Woo;Seol, Seung-Kwon;Kwon, Yong-Bum;Cho, Chang-Sik;Weon, Byung-Mook;Park, Gong-Seog;Hwang, Cheol-Ho;Hwu, Yeukuang;Tsai, Wen-Li
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.1155-1156
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    • 2003
  • The advanced analysis techniques such as high resolution X-ray absorption spectroscopy (XAS), X-ray scattering, and photoelectron emission microscope (PEEM) using synchrotron radiation are probably able to open new opportunities for improving the performances of oxide cathodes with more clear and deep understanding.

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EMI Issues in Pseudo-Differential Signaling for SDRAM Interface

  • Jang, Young-Jae;Yi, Il-Min;Kim, Byungsub;Sim, Jae-Yoon;Park, Hong-June
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.5
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    • pp.455-462
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    • 2015
  • H-field EMI measurements have been performed for the single-ended, the differential, and the pseudo-differential signaling on a 11" FR4 microstrip line. The pseudo-differential signaling reduces EMI by more than 10 dB compared to the single-ended signaling if the delay mismatch is lower than 5% of a period for a 3 GHz clock signal. Empirical H-field equations for both differential and single-ended signaling showed fair agreements with measurements.

Evaluation of COBALT-J/K, Japanese to Korean Machine Translation System (일한 기계번역 시스템 COBALT-J/K의 성능 평가)

  • Jeong, Jung-Rak;Kim, Jung-In;Moon, Kyong-Hi;Lee, Jong-Hyeok;Lee, Guen-Bae
    • Annual Conference on Human and Language Technology
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    • 1996.10a
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    • pp.338-345
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    • 1996
  • 일본어 특허 문서를 번역하기 위해 개발이 시작된 COBALT-J/K(COllocation - BAsed Language Translator from Japanese to Korea)는 현재 그 번역 대상을 모든 일본어 문서로 확장해 곧, 상용 시스템으로 전환을 바라보고 있다. 이런 시점에서 일반 문서를 대상으로 하는 범용 기계 번역 시스템의 관점에서 시스템을 평가하여 문제점을 찾고, COBALT-J/K가 우선적으로 해결하고자 한 문제들이 올바르게 해결되었는지를 살피고자 한다. 이를 위한 평가 방법으로 문형별로 분류된 다수의 일본어 문장에 대하여 실제 번역을 하여 한국어 번역문과 일본어 원문을 비교하는 방식으로 분석하였으며, 현재 시판되고 있는 J-Seoul에 대해서도 같은 방법으로 실험한 결과를 얻은 후, 이 결과는 평가의 보조 자료로 삼았다.

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Study on the high precision output of full-bride high-voltage inverter (Full-bridge 고전압 인버터의 출력전압 정밀제어에 관한연구)

  • Son, Y.G.;Kwon, S.J.;Jang, S.D.;Suh, J.H.;Oh, J.S.
    • Proceedings of the KIEE Conference
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    • 2005.11a
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    • pp.214-216
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    • 2005
  • The PAL (Pohang Accelerator Laboratory) is persuading to construct a SASE-XFEL facility (PAL XFEL) that supplies coherent X-rays. The bright and stable electron beam is essential for the PAL XEL. The electron beams has to have an emittance of 1.0 mm-mrad, a peak current of 3 kA, and a low energy spread of 1.0 MeV. In order to provide reasonably stable SASE output, the RF stability of 0.02% rms is required for both RF phase and amplitude. This is a technologically challenging issue for PAL XFEL. An inverter technology is to be applied to charge the PFN of a new modulator. Therefore, a new inverter system should provide very stable charging performances. This paper presents the development of an ultra stable klystron-modulator with an inverter power supply.

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Pre-processing Algorithm for Detection of Slab Information on Steel Process using Robust Feature Points extraction (강건한 특징점 추출을 이용한 철강제품 정보 검출을 위한 전처리 알고리즘)

  • Choi, Jong-Hyun;Yun, Jong-Pil;Choi, Sung-Hoo;Koo, Keun-Hwi;Kim, Sang-Woo
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1819-1820
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    • 2008
  • Steel slabs are marked with slab management numbers (SMNs). To increase efficiency, automated identification of SMNs from digital images is desirable. Automatic extraction of SMNs is a prerequisite for automatic character segmentation and recognition. The images include complex background, and the position of the text region of the slabs is variable. This paper describes an pre-processing algorithm for detection of slab information using robust feature points extraction. Using SIFT(Scale Invariant Feature Transform) algorithm, we can reduce the search region for extraction of SMNs from the slab image.

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