• 한국수학교육학회지시리즈D:수학교육연구
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• 제19권4호
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• pp.267-278
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• 2015

The study is about the influence of literal, symbolic and graphics languages on mathematics reading. The results show that the scores of symbolic language volume are significantly lower than that of literal language volume. The abstractness of the mathematical symbols will not have a significant impact on the students with excellent mathematical academic, but as for the medium and poor students, abstract mathematics symbols will cause their cognitive impairment. Due to picture-superiority-effect, the test scores of the graphics language volume are significantly higher than that of the symbolic language volume. Graphics language will have a significant impact on the excellent and medium students, but has no impact on the poor students.

• 한국게임학회지
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• 제8권1호
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• pp.32-38
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• 2011

수학적 명제들을 사용하는 수학교육용 게임의 학습 도움말이나 안내말은 그래픽 우선 인지스타일을 가진 게임세대의 학습자를 위해 그래픽적인 형태로 표현하는 것이 필요하다. 본 논문에서는 수학 명제들에 대한 객체 기반 비주얼적 표현방법을 제안하였다. 이 표현방법은 단어들과 함께 그래픽적 기호들과 수학적 기호들 사용하여 객체 기반적인 표현방법의 규칙을 갖고 있다. 그래서 수학적 의미를 정확하게 표현하거나 이해하기가 쉽다. 그리고 학습자가 내용을 빠르게 읽을 수 있다. 제안된 방법은 게임 세대 학습자들에게 교육용 게임을 통해 수학 학습의 스캐폴딩으로써 도움을 받기가 좋다.

• 제어로봇시스템학회논문지
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• 제9권11호
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• pp.917-924
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• 2003

Recurrent neural networks have been successfully applied to communications channel equalization. Major disadvantages of gradient-based learning algorithms commonly employed to train recurrent neural networks are slow convergence rates and long training sequences required for satisfactory performance. In a high-speed communications system, fast convergence speed and short training symbols are essential. We propose decision feedback equalizers using a recurrent neural network trained with Kalman filtering algorithms. The main features of the proposed recurrent neural equalizers, utilizing extended Kalman filter (EKF) and unscented Kalman filter (UKF), are fast convergence rates and good performance using relatively short training symbols. Experimental results for two time-varying channels are presented to evaluate the performance of the proposed approaches over a conventional recurrent neural equalizer.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(4)
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• pp.41-44
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• 2001

Variable length coding (VLC) has been used in many well known standard video coding algorithms such as MPEG and H.26x. However, VLC can not be processed parallelly because of its sequentiality. This sequentiality is a big barrier for implementing a real-time software video codec since parallel schemes can not be applied. In this paper, we propose a new fast VLD (Variable Length Decoding) method based on the probabilistic distribution of symbols in VLC tables used in MPEG as well as H.263 standard codecs. Even though MPEG suggests the table partitioning method, they do not show theoretically why the number of partitioned tables is two or three. We suggest the method for deciding the number of partitioned tables. Applying our scheme to several well-known MPEG-2 test sequences, we can reduce the computational time up to about 10% without any sacrificing video quality

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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• pp.222-225
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• 2000

Human frequently communicate non-linguistic information with gesture. So, we must develop efficient and fast gesture recognition algorithms for more natural human-computer interaction. However, it is difficult to recognize gesture automatically because human's body is three dimensional object with very complex structure. In this paper, we suggest a method which is able to detect key frames and frame changes, and to classify image sequence into some gesture groups. Gesture is classifiable according to moving part of body. First, we detect some frames that motion areas are changed abruptly and save those frames as key frames, and then use the frames to classify sequences. We symbolize each image of classified sequence using Principal Component Analysis(PCA) and clustering algorithm since it is better to use fewer components for representation of gestures. Symbols are used as the input symbols for the Hidden Markov Model(HMM) and recognized as a gesture with probability calculation.

• The Journal of the Acoustical Society of Korea
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• 제22권1E호
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• pp.26-32
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• 2003

We propose new time-frequency (TF) tools for analyzing linear time-varying (LTV) systems and nonstationary random processes showing hyperbolic TF structure. Obtained through hyperbolic warping the narrowband Weyl symbol (WS) and spreading function (SF) in frequency, the new TF tools are useful for analyzing LTV systems and random processes characterized by hyperbolic time shifts. This new TF symbol, called the hyperbolic WS, satisfies the hyperbolic time-shift covariance and scale covariance properties, and is useful in wideband signal analysis. Using the new, hyperbolic time-shift covariant WS and 2-D TF kernels, we provide a formulation for the hyperbolic time-shift covariant TF symbols, which are 2-D smoothed versions of the hyperbolic WS. We also propose a new interpretation of linear signal transformations as weighted superposition of hyperbolic time shifted and scale changed versions of the signal. Application examples in signal analysis and detection demonstrate the advantages of our new results.

• 대한수학회논문집
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• 제32권2호
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• pp.287-304
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• 2017

Motivated mainly by certain interesting recent extensions of the generalized hypergeometric function [Integral Transforms Spec. Funct. 23 (2012), 659-683] by means of the incomplete Pochhammer symbols $({\lambda};{\kappa})_{\nu}$ and $[{\lambda};{\kappa}]_{\nu}$, we first introduce incomplete Fox-Wright function. We then define the families of incomplete extended Hurwitz-Lerch Zeta function. We then systematically investigate several interesting properties of these incomplete extended Hurwitz-Lerch Zeta function which include various integral representations, summation formula, fractional derivative formula. We also consider an application to probability distributions and some special cases of our main results.

• Journal of Information Processing Systems
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• 제12권2호
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• pp.322-331
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• 2016

Image compression is an essential technique for saving time and storage space for the gigantic amount of data generated by images. This paper introduces an adaptive source-mapping scheme that greatly improves bit-level lossless grayscale image compression. In the proposed mapping scheme, the frequency of occurrence of each symbol in the original image is computed. According to their corresponding frequencies, these symbols are sorted in descending order. Based on this order, each symbol is replaced by an 8-bit weighted fixed-length code. This replacement will generate an equivalent binary source with an increased length of successive identical symbols (0s or 1s). Different experiments using Lempel-Ziv lossless image compression algorithms have been conducted on the generated binary source. Results show that the newly proposed mapping scheme achieves some dramatic improvements in regards to compression ratios.

• ETRI Journal
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• 제39권4호
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• pp.514-524
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• 2017

In this paper, we propose a spatial modulation (SM) scheme referred to as complex quadrature SM (CQSM). In contrast to quadrature SM (QSM), CQSM transmits two complex signal constellation symbols on the real and quadrature spatial dimensions at each channel use, increasing the spectral efficiency. To achieve that, signal symbols transmitted at any given time instant are drawn from two different modulation sets. The first modulation set is any of the conventional QAM/PSK alphabets, while the second is a rotated version of it. The optimal rotation angle is obtained through simulations for several modulation schemes and analytically proven for the case of QPSK, where both results coincide. Simulation results showed that CQSM outperformed QSM and generalized SM by approximately 5 dB and 4.5 dB, respectively, for the same transmission rate. Its performance was similar to that of QSM; however, it achieved higher transmission rates. It was additionally shown numerically and analytically that CQSM outperformed QSM for a relatively large number of transmit antennas.

• 한국컴퓨터정보학회논문지
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• 제9권1호
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• pp.25-30
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• 2004

본 논문은 지휘자의 지휘 동작으로부터 일련의 영상들을 추출하여 지휘자가 지휘하는 박자를 인식하는 방법을 제안하고 있다 색상판별에 의해서 손의 위치를 감지하였으며 양자화를 통해서 그 위치를 기호화함으로써 지휘 동작을 일련의 기호로 표현하였다. 변형을 포함하는 기호열의 인식에 좋은 결과를 보이는 HMM(Hidden Markov Model)을 사용함으로써 표현된 기호열을 지휘박자로 인식하도록 하는 시스템을 구성하였다.