• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.923-926
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• 2001

In this paper, we investigate a new approach pilot-symbol-aided channel estimation for orthogonal frequency division multi-plexing (OFDM) systems. Until now, lots of channel estimation methods are proposed. The pilot symbol assisted modulation (PSAM) has good performance. But, our proposed Algorithm has more good performance than the conventional PSAM system. Our algorithm is that channel estimation performance using the less inserted pilot-symbols systems is almost same to the two times inserted pilot-symbols system. The proposed method is highly robust to fast Rayleigh fading channel. Simulation results are presented to demonstrate the performance of our proposed algorithm.

• Research in Mathematical Education
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• v.8 no.1
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• pp.31-37
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• 2004

This study explores the relations between mathematics and the natural human language. At the very outset, a general definition of language was, given while it was attempted to make some comparisons between the words of natural language and mathematical symbols at that. Besides, the occupation of natural language functions within mathematics was handled. Consequently, it was tried to manifest that the language of mathematics enjoys the features of natural language as well. Mathematics makes use of many functional and structural features. The fact that fundamental ingredient of mathematics is symbols does not change this reality.

• Bulletin of the Korean Mathematical Society
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• v.48 no.3
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• pp.617-625
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• 2011

In [6], it was shown that hyponormality for Toeplitz operators with polynomial symbols can be reduced to classical Schur's algorithm in function theory. In [6], Zhu has also given the explicit values of the Schur's functions ${\Phi}_0$, ${\Phi}_1$ and ${\Phi}_2$. Here we explicitly evaluate the Schur's function ${\Phi}_3$. Using this value we find necessary and sufficient conditions under which the Toeplitz operator $T_{\varphi}$ is hyponormal, where ${\varphi}$ is a trigonometric polynomial given by ${\varphi}(z)$ = ${\sum}^N_{n=-N}a_nz_n(N{\geq}4)$ and satisfies the condition $\bar{a}_N\(\array{a_{-1}\\a_{-2}\\a_{-4}\\{\vdots}\\a_{-N}}\)=a_{-N}\;\(\array{\bar{a}_1\\\bar{a}_2\\\bar{a}_4\\{\vdots}\\\bar{a}_N}\)$. Finally we illustrate the easy applicability of the derived results with a few examples.

• MALSORI
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• no.39
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• pp.43-51
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• 2000

The aim of this paper is to present a phonetically oriented keyboard array for the International Korean Phonetic Alphabet (IKPA). IKPA is a phonetic alphabet devised on the basis of Hangout (Korean alphabet) (Lee, 1999). Every computer has a keyboard as its input device and the English keyboard array is hewn as 'QWERTY' system, which represents the first six letters of the second line of the keyboard. This array is a traditional one devised to protect the congestion of the keys of the mechanical typewriter. To improve the anay of the keyboard, another system named 'Dvorak' has been devised. Likewise, a serious attempt has been made by the authors to work out an efficient keyboard for IKPA representing the manner of vowel and consonant classification. In the phonetic keyboard, the consonant symbols are arranged in the left hand side according to the Place and mauler of the articulation and the vowel symbols in the right hand side according to the vowel quadrilateral.

• Journal for History of Mathematics
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• v.26 no.5_6
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• pp.355-370
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• 2013

Thomas Harriot has been introduced in middle school textbooks as a great mathematician who created the sign of inequality. This study is about Harriot's symbolism and the theory of equation. Harriot made symbols of mathematical concepts and operations and used the algebraic visual representation which were combinations of symbols. He also stated solving equations in numbers, canonical, and by reduction. His epoch-making inventions of algebraic equation using notation of operation and letters are similar to recent mathematical representation. This study which reveals Harriot's contribution to general and structural approach of mathematical solution shows many developments of algebra in 16th and 17th centuries from Viete to Harriot and from Harriot to Descartes.

• Communications of the Korean Mathematical Society
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• v.17 no.2
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• pp.349-361
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• 2002

The ill-posed elliptic wave propagation problems can be transformed into well-posed initial value problems of the reflection and transmission operators characterizing the material structure of the given model by the combination of wave field splitting and invariant imbedding methods. In general, the derived scattering operator equations are of first-order in range, nonlinear, nonlocal, and stiff and oscillatory with a subtle fixed and movable singularity structure. The phase space and path integral analysis reveals that construction and reconstruction algorithms depend crucially on a detailed symbol analysis of the scattering operators. Some information about the singularity structure of the scattering operator symbols is presented and analyzed in the transversely homogeneous limit.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1010-1014
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• 2009

Acceleration of the globalization process as they are internationally accepted, standardized. A lot of somebody started to feel tired of the standards symbols, and like to pursuit the original and natural, and hope that the new interest in the emergence of visual symbols. Dongba (東巴文字) text are Naxi(納西族) Dongba pictograph (象形文字) of a concrete nature in china, Characterized by simplicity, abstraction, associative, interesting, decorative, symbolic etc. These features can quickly identify and satisfy to the people's demand for special aesthetic.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2967-2969
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• 2005

2003년에 영상압축의 표준으로 제시된 H.264/AVC의 압축성능은 대부분 Context-based Adaptive Binary Arithmetic Codes (CAHAC)라는 새로운 엔트로피 코딩에 기인한 것이다. 그러나, CABAC의 뛰어난 성능에도 불구하고 복잡한 처리과정 때문에 하드웨어로 구현하기가 상당히 곤란하다. 곱셈기가 없는 알고리즘임에도 불구하고 영역(range), 오프셋(offset), 그리고 컨텍스트 변수들(context varivales)을 순차적으로 구해야 하기 때문이다. 이 논문에서는 한번에 최대 두 비트를 디코딩 할 수 있는 예측기법을 통하여 CARAC의 전체적인 디코딩 시간을 줄일 수 있는 방법을 제안한다. 한 비트를 디코딩하기 위해서는 두 개의 심볼(a set of binary symbols)에 대한 확률분포를 사전에 알아야 하지만, 제안된 방법에서는 두 비트를 동시에 디코딩할 수 있도록 네 개의 심볼(two sets of binary symbols)에 대한 확률 분포를 예측하여 디코더에 제공한다. 제안된 예측기법을 CABAC 디코더에 적용한 결과, 기존보다 10-13%의 복호시간을 단축하는 효과를 가졌다. 논문에서 제안된 예측기법을 통한 고속디코더의 구현은 확률을 기반으로 하는 신호처리에 사용되어 고속의 시스템을 구성하는데 효과적으로 적용될 수 있다.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.577-580
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• 1998

In this paper, we psresent the design strategy of the assistive communication system for the mute and speech disorder to be able to communicate with people under the restricted circumstances. First, it should be used conventiently in daily life and a specific domain should be set accoridng to the circumstance. Second, proper words in each domain should be selected according to the physical and mental ability of users. This paper seeks to highlight some of the issues involved in using semantic compaction in adynamic environment. (e.g. noun and verb explorable system). In additon, symbols are used in this system in order to make users recognize clearly the meaning of a words. The sentences are compounded from symbols. The compounded sentences are shown on the display monitor in letter,s and synthesized naturally in voice in order to be understood easily.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.65-75
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• 1996

The probability distributio function (pdf) of transmitted symbols should be asymmectric for recovering the received data in the 3rd order blind equalizer system. In this paper, we hav edesigned the blind equalizer using symmetric-asymmetric (SA) and asymmetric-symmetric (AS) transforms for less computational complexities and robustness in the noisy environments. The method of SA and AS transform was peformed using natural logarithmic operation. This paper proves that the proposed in this paper can be performed as real time operation. This paper proves that the compression factor k has no effet on transmitted symbols. Also 3rd order equalization method proposed in this paper can be performed as real time operation. As a result of computer simulatio, the computational complexity of proposed algorithm is reduced to be an half of 4th order method and MSE is enhanced as 10dB at the case of 4-PAM and 15dB at the case of 8-PAM respectivley. Conclusively, we have found that 3rd order blind equalizer can be implemented when the pdf of transmitter is asymmetric.