• Journal of Communications and Networks
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• 제18권5호
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• pp.725-734
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• 2016

For multi-mode radar signals in complex electromagnetic environment, different modes of one emitter tend to be deinterleaved into several emitters, called as "extension", when processing received signals by use of existing sorting methods. The "extension" problem inevitably deteriorates the sorting performance of multi-mode radar signals. In this paper, a novel method based on spatial data mining is presented to address above challenge. Based on theories of data field, we describe the distribution information of feature parameters using potential field, and makes partition clustering of parameter samples according to revealed distribution features. Additionally, an evaluation criterion based on cloud model membership is established to measure the relevance between different cluster-classes, which provides important spatial knowledge for the solution of the "extension" problem. It is shown through numerical simulations that the proposed method is effective on solving the "extension" problem in multi-mode radar signal sorting, and can achieve higher correct sorting rate.

• 식품과학과 산업
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• 제52권1호
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• pp.20-31
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• 2019

Sensory perception of food/beverage products is one of the most important quality factors to determine consumer acceptability and thus sensory discrimination methodology has been a vital tool for quality management. Signal detection theory(SDT) and Thurstonian modeling provide the most advanced psychometric approach to modeling various discrimination methods. In these theories, perceptual and cognitive decisional factors are considered so that, a fundamental measure of sensory difference (d') can be computed, independent of test methods used. In this paper, sensory discrimination analysis based on SDT and Thurstonian modeling is introduced for more accurate and systematic applications of sensory and hedonic quality management in industry. Ways to realize the statistical power and relative sensitivity of sensory discrimination methods theorized in SDT and Thurstonian modeling in practice, are also discussed by using a case study of the Nongshim quality management program for drinking water in which SDT A-Not A test methodology was further optimized.

• 천문학논총
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• 제39권1호
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• pp.1-12
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• 2024

In this study, we investigated the time signal devices of Deungnu (circa 1270) and Gungnu (1354), the water clocks produced during the Yuan Dynasty (1271-1368). These clocks influenced Heumgyeonggaknu (1438) of the Joseon Dynasty (1392-1910), exemplifying the automatic water clocks of the Yuan Dynasty. Deungnu, Gungnu, and Heumgyeonggaknu can be considered as automatic mechanical clocks capable of performances. The Jega-Yeoksang-Jip (Collection of Calendrical and Astronomical Theories of Various Chinese Masters) contains records of Deungnu extracted from the History of the Yuan Dynasty. We interpreted these records and analyzed reproduction models and technical data previously produced in China. The time signal device of Deungnu featured a four-story structure, with the top floor displaying the four divine constellations, the third floor showcasing models of these divinities, the second floor holding 12-h jacks and a 100-Mark ring, and the first floor with four musicians and a 100-Mark Time-Signal Puppet providing a variety of visual attractions. We developed a 3D model of Deungnu, proposing two possible mechanical devices to ensure that the Time-Signal Puppet simultaneously pointed to the 100-Mark graduations in the east, west, south, and north windows: one model reduced the rotation ratio of the 100-Mark ring to 1/4, whereas the other model maintained the rotation ratio using four separate 100-Mark rings. The power system of Deungnu was influenced by Suunuisangdae (the water-driven astronomical clock tower) of the Northern Song Dynasty (960-1127); this method was also applied to Heumgyeonggaknu in the Joseon Dynasty. In conclusion, these automatic water clocks of East Asia from the 13th to 15th centuries symbolized creativity and excellence, representing scientific devices that were the epitome of clock-making technology in their times.

• 전자공학회논문지SC
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• 제44권5호
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• pp.45-54
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• 2007

시/주파수 분석은 생체 신호 처리에서 널리 사용되어왔다. 전기 생리학적 신호로부터 중요한 특징들을 추출함으로써 이 방법들은 특정 질병의 임상 병리학적 기전 해석이 가능하다. 하지만 이 방법은 신호가 안정하다는 가정 아래 적용되었으며 불안정한 시스템에서의 적용은 제한이 되어 있다. 본 연구에서는 비선형적이고 비정상적인 심실세동 심전도 파형의 분석을 위해 Hilbert-Huang 변환을 사용한 새로운 신호처리 방법을 제안하였다. Hilbert-Huang 변환은 경험모드분리법(EMD)과 힐버트 변환으로 크게 두 가지로 구성된다. Hilbert-Huang 변환은 EMD를 사용하여 각각의 특성을 지니고 있는 독립적인 내부모드함수들로 나누어지며, 힐버트 변환에 의해 순간 주파수와 크기를 구할 수 있게 된다. 이런 특성으로 신호의 국부적인 작용에 대하여 정확하게 설명할 수 있게 된다. 본 연구에서는 Hilbert-Huang 변환을 기반으로 심실세동 심전도 파형으로부터 두 종류의 파라미터(EMD-IF, EMD-FFT)를 추출하고 서포트 벡터 머신(Support Vector Machine)을 이용하여 소생성공 및 실패 여부 예측에 관하여 연구하였다. 평균적으로 민감도와 특이도는 각각 87.57%와 76.92%로 나타났다. Hilbert-Huang 변환은 더욱 정확하게 심실세동에서의 소생성공 예측을 가능하게 하였다.

• 한국군사과학기술학회지
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• 제18권5호
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• pp.538-547
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• 2015

The goal of this study is to develop an algorithm to propose optimal deployment of detection sensor nodes in the target area, based on a performance surface, which represents detection performance of active and passive acoustic sonar systems. The performance surface of the active detection system is calculated from the azimuthal average of maximum detection ranges, which is estimated with a transmission loss and a reverberation level predicted using ray-based theories. The performance surface of the passive system is calculated using the transmission loss model based on a parabolic equation. The optimization of deployment configurations is then performed by a hybrid method of a virtual force algorithm and a particle swarm optimization. Finally, the effectiveness of deployment configurations is analyzed and discussed with the simulation results obtained using the algorithm proposed in this paper.

• 융합신호처리학회논문지
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• 제6권3호
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• pp.157-162
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• 2005

본 논문은 미지의 마찰력을 갖는 로봇 매니퓰레이터에 대하여 퍼지시스템을 이용한 적응보상기를 제안한다. 일반적인 로봇제어이론에서는 대부분 마찰력을 무시하거나 단순히 다이나믹 마찰력만을 고려한다. 본 논문에서는 다이나믹 마찰력뿐만 아니라 비스코스 마찰력까지도 고려한 제어방식이다. 마찰력이 관절마다 결부되지 않는다는 성질을 이용하여 각 관절에 해당하는 마찰력을 SISO 퍼지시스템으로 근사하며 전체제어시스템이 안정도를 Lyapunov 안정도 이론을 이용하여 증명하고 적절한 적응법칙을 설계한다. 제안된 제어방식의 타당성을 보이기 위해 2-링크 로봇 매니퓰레이터에 대하여 컴퓨터 시뮬레이션을 보이고 각 링크에 대한 마찰력을 퍼지시스템이 잘 근사한다는 것을 보인다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1284-1287
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• 1987

A method of quantitative electrocardiogram analysis, based on concepts drawn from syntactic pattern recognition theories, is described. The algorithm can be used for removing the Interference noises and base line drift as a filter function, and for reducing the number of points representing the digitized ECG waveform. The Parsing is performed with simple finite state automata inferred by experiments and suitable to be updated during experiment execution. Two parameters are utilized for defining the noise and these make the algorithm flexible. The examples for testing the algorithm is real ECG waveforms with noise. Some experimental results lire presented.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1685-1690
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• 2007

Wave and following checking cycle arbor in the mountains form that examine various theories that decide checking cycle and data and application possibility that can acquire actually were presented. If see in standpoint that breakdown detects singularity availability before change happening, problem is advanced how action of device may do ordinary times supervision (monitoring) or checking cycle. In checking cycle decision, situation of latency breakdown that can not know that cause breakdown before device that is using examines can exist. Example such as car examination, faur and equitable spirit health examination, security device etc. can be fatal the time. Therefore, study and examined arbor in the mountains room of family proper checking cycle.

• 한국자기공명학회논문지
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• 제19권3호
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• pp.124-131
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• 2015

Hyperpolarization methods are the most emerging techniques in the field of magnetic resonance (MR) researches since they make a contribution to overcoming sensitivity limitation of MR spectroscopy and imaging, leading to new fields of researches, real-time in vivo metabolic/molecular imaging and MR analysis of chemical/biological reactions in non-equilibrium conditions. Make use of enormous signal enrichments, it becomes feasible to investigate various chemical and biochemical systems with low ${\gamma}$ nuclei in real-time. This review deals with the theoretical principals of common hyperpolarization methods and their experimental features. In addition, more detailed theories, mechanisms, and applications of dissolution dynamic nuclear polarization (D-DNP) are discussed.

• 한국통신학회논문지
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• 제21권7호
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• pp.1777-1786
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• 1996

This paper describes theories and implementation techniques of a digital high-definition television(HDTV) modem based on 32-QAM for terrestrial broadcasting. We proposed a digital demodulation scheme and a symbol timing recovery structure based on the band edge component maximization(BECM) method. The adaptive equalizer has 256 complex taps to remove the multipath of delays ranging from -2.mu.s~+24.mu.s with a new T/2-spaced blind equalization algorithm. computer simulation results reveal that the proposed algorithm outperforms other conventional blind equalization algorithm a digital HDTV modem with 4.91MHz symobol rate is implemented by utilizing the proposed algorithms. All processings for modem operations such as demodulation, estimation of symbol timing phase error, adaptive equalization, and carrier recovery except IF signal processing and sampling phase control part of the AD converter are done in digital domain. Especially, the carrier recovery loop can track a carrier offset of upto .+-.350KHz.