• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.19-21
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• 2005

EPCglobal은 RFID와 관련된 다양한 분야의 표준화를 주도하고 있으며 응용 표준으로써 Tag 정보의 운용을 위한 미들웨어 표준인 ALE Specification을 제시하였다. ALE의 ECSpec은 애플리케이션이 미들웨어에 등록하는 이벤트 필터링을 위한 스펙으로써 일정 시간동안 반복적으로 수행되는 연속 질의와 유사한 특성을 가진다. ECSpec을 연속질의로 변환할 때 해당질의의 WHERE절이 가지는 Predicate는 매우 긴 길이를 가지는 Long Interval이 된다. 이러한 특성은 기존의 질의 색인들의 삽입과 검색 성능을 저하시키는 문제점을 가진다. 이 논문에서는 ECSpec을 연속 질의의 형태로 변환하고 해당 질의가 기지는 Predicate인 2D Interval의 특성을 반영한 새로운 질의 색인 구조로써 TLC-Index를 제안한다. 색인 구조는 그리드 방식의 큰 크기를 가지는 셀 분할 구조와 선분 모양의 가상 분할 구조를 병행하는 하이브리드 구조이다. 색인에서 Long Interval의 정의는 셀 분할 구조의 길이보다. 크거나 같은 길이를 가지는 interval이다. 제안하는 색인은 Long Interval을 큰 크기를 가지는 셀 분할 구조로 분할 삽입함으로써 저장 공간의 소모를 줄이고 삽입 성능을 향상시킨다. 또한 Short Interval들을 짧은 길이를 가지는 가상 분할 구조들로 분할 삽입함으로써 그리드 방식이 가질 수 있는 부분적 겹침을 제거하여 검색 성능을 향상시킨다.

• Annual Conference on Human and Language Technology
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• 1993.10a
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• pp.119-130
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• 1993

우리말의 표준말에서는 모음의 장단이 낱말의 뜻을 가르는 음운론적 기능을 갖는다. 그러나, 소리의 길이는 음운론적인 장단 뿐 아니라 앞뒤의 소리, 초점, 소리의 위치, 말의 속도 등과 같은 여러 음성언어학적 요소에 의해 결정되어 그 언어의 고유한 리듬을 이룬다. 이 글에서는 우리말 소리의 길이에 영향을 미치는 주요변수를 실험음성학적 결과와 함께 살펴본다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.8
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• pp.754-763
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• 2002

This paper discusses the improved power performances of the size-reduced amplifier using defected ground structure (DGS). The slow-wave effect and enlarged electrical length occur due to the additional equivalent circuit elements of DGS. Using these properties, it is possible to reduce the length of transmission lines in order to keep the same original electrical lengths by inserting DGS on the ground plane. The matching and performances of the amplifier are preserved even after DGS patterns have been inserted. While there is no loss in the size-reduced transmission lines at the operating frequency, but there exists loss to some extent at harmonic frequencies. This leads to the more excellent inherent capability of harmonic rejection of the size-reduced amplifier. Therefore, it is expected tile harmonics of the size-reduced amplifier are smaller than those of the original amplifier. The measured second harmonic, third order intermodulation distortion (IMD3), and adjacent channel power ratio (ACPR) of the size-reduced amplifier are smaller than those of the original amplifier by 5 dB, 2~6 dB, and 1~4 dB, respectively, as expectation.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.147-150
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• 2013

본 논문에서는 A/V라우터, SDI to HDMI 비압축신호변환기 등 방송장비에서 주로 사용되는 SDI(Serial Digital Interface) 신호의 입력감도 특성이 케이블 길이에 따라 특성이 어떻게 변화되는가를 분석하기 위해 케이블 길이에 따른 신호의 특성을 분석하였다. 특성의 확인을 위해 ITU 및 SMPTE 표준에서 규정하는 Rise/Fall Time, Timing/Alignment Jitter 값과 PSNR 값을 활용하였다. 본 논문은 전송률에 따른 케이블 길이 변화를 비교 시험하여 방송장비 제조사에서 권고하는 케이블 길이에 대한 신뢰도 확인 및 실 사용 환경에서의 케이블 길이 고려 등을 위해 필요한 데이터를 추출하였으며, 향후 시험규격개발에 중요한 자료로 활용될 것으로 기대된다.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.14-21
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• 2013

In satellite operations and space exploration missions, a ranging is one of the most essential technologies to get its navigational information of space probes. Recently, the importance of cross-support between space agencies is increasing for more fine performance of space mission. For cross-support, mutually compatible ranging system between space agencies is recommended. For these reasons, the consultative committee for space data systems (CCSDS) recommends pseudo noise (PN) ranging as a digital standard ranging system. The length of PN sequence in CCSDS standard is proper for deep space missions, however, it is too long to use for ranging in near earth missions. In this paper, we propose Variable Length PN sequence schemes suitable for ranging of near earth satellites, such as low-earth orbit (LEO), medium-earth orbit (MEO) and Geostationary orbit (GEO). Therefore we propose variable length PN sequence ranging system including CCSDS standard for multiple missions.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.08a
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• pp.192-197
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• 1998

• Journal of the Korean Society of Radiology
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• v.10 no.5
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• pp.359-365
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• 2016

Fluoroscopy is performed when tissue or organ in the human body is examined, and it is used for diagnosis and procedure in back ailments. With regard to fluoroscopy equipment, distortion occurs on the peripheral part of fluoroscopic image rather than on its central part. This study measured distortion factors of vertical spacing ratio and distortion factor of diagonal spacing ratio before and after correction by applying a correction algorithm. According to measuring the vertical spacing ratio, post-correction standard deviation decreased by 0.04 in comparison with pre-correction one. Also measuring the diagonal spacing ratio, post-correction standard deviation decreased by 0.06 in comparison with pre-correction one. Consequently, the distortion of fluoroscopic image decreased after correction. A decrease in the distortion of image through the application of correction algorithm and the improvement of performance will be helpful in finding a correct position of lumbar puncture in nucleoplasty to treat lumbar disc herniation in the future.

• Korean Journal of Ichthyology
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• v.32 no.2
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• pp.55-62
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• 2020

The Relative weight index is an index for evaluating nutritional condition of fish by calculating a ratio of observed weight to standard weight. The purpose of this study is estimating standard Length-Weight relationships (standard LWRs) to calculate standard weight for application of relative weight index and analyze frequency distribution of relative weight index of 10 freshwater fish in the South Korea. The standard LWRs for each species was calculated by the Length-Weight data sets from 798 times of captures at 141 sites. The correlation of determination (r²) for all species was over 0.9 and values of parameter b were within the expected range according to Froese (2006). We calculated in increments of 10 from 10 to 90 percentile of relative weight index for each species, and it could be used as a standard for quantitative assessment of nutritional condition of freshwater fish.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.4
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• pp.104-108
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• 1993

The linear length measurements are most frequently performed and should be most accurate among other parts in dimensional metrology. We developed the linear measuring system using a laser interferometer to improve the accuracy and to shorten the calibration time. The uncertainty of the system is 0.01 .mu. for 500mm steel gage block. The range of the measurement and resolution of the system are 1000mm and 0.01 .mu. m, respectively.

• Tunnel and Underground Space
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• v.19 no.1
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• pp.52-63
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• 2009

This is a study on large-scale rock joint roughness measurements using LIDAR (light detection and ranging) and the Split-FX point cloud processing software. The large-scale rock Joint Roughness Coefficient (JRC) is calculated using the maximum amplitude of joint asperities over the profile length on large-scale Joint surfaces of rock. As the profile length increases, JRC decreases due to scale-effects of rock specimens and is non-stationary. Also JRC shows anisotropy depending on the profile direction. The profile direction is measured relative to either dip or strike of the large-scale joint.