• 한국초등과학교육학회지:초등과학교육
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• 제25권3호
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• pp.244-256
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• 2006

Elementary teachers should lower their levels of expectation and indeed perspectives to those of elementary students. Even in relation to basic symbols, such as an arrow, can be read differently by teachers or students. Semiotics deals with the creation of meaning in rotation to symbols and signs. This study introduces semiotic analysis to the study of science textbooks. Elementary science textbooks contain a great many inscriptions, such as photographs and cartoons, even more than texts, such as words and sentences. Inscriptions employ various social conventions such as arrows, auxiliary lines, etc. Some conventional signs, however, hold different or indeed multiple meanings than the textbook author intended the sign to have. The arrows used in science textbook, mainly in the inscriptions, were analyzed and classified according to their intended meaning. The results indicated that teachers should use such arrows more carefully in lessons with elementary students.

• 한국조경학회지
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• 제33권2호
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• pp.92-99
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• 2005

The main gate of a university is a element of landscape which improves the quality of campus as well as demarcates the boundary and publicizes the image of university. Therefore, each university strives to differentiate its main gate from that of other universities with a unique form. This research investigates the signs and symbols shown at the university's main gate of 18 universities in Korea, and also presents useful design tips with the objective of bearing the spirit of the campus and its founding ideology. The results of this research as follows: Icons of Sign for 18 universities can be classified into five separate categories: things, human, animal, character, and metaphor. Examples of the 'things' icons include a pen nib, the sun, the cross, a big bell, and so on. Also, the meaning of the represented symbols can be grouped in three separate categories: university's development, contribution to society, and mining of knowledge. From the three category, university development symbol is the most likely to be used.

• Journal of information and communication convergence engineering
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• 제8권3호
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• pp.267-272
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• 2010

For the last decade, recurrent neural networks (RNNs) have been commonly applied to communications channel equalization. The major problems of gradient-based learning techniques, employed to train recurrent neural networks are slow convergence rates and long training sequences. In high-speed communications system, short training symbols and fast convergence speed are essentially required. In this paper, the derivative-free Kalman filter, so called the unscented Kalman filter (UKF), for training a fully connected RNN is presented in a state-space formulation of the system. The main features of the proposed recurrent neural equalizer are fast convergence speed and good performance using relatively short training symbols without the derivative computation. Through experiments of nonlinear channel equalization, the performance of the RNN with a derivative-free Kalman filter is evaluated.

• 한국통신학회논문지
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• 제32권4C호
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• pp.379-388
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• 2007

In this paper, we propose an adaptive turbo decoding algorithm for high order modulation scheme combined with originally design for a standard rate-1/2 turbo decoder for B/QPSK modulation. A transformation applied to the incoming I-channel and Q-channel symbols allows the use of an off-the-shelf B/QPSK turbo decoder without any modifications. Adaptive turbo decoder process the received symbols recursively to improve the performance. As the number of iterations increase, the execution time and power consumption also increase as well. The source of the latency and power consumption reduction is from the combination of the radix-4, dual-path processing, parallel decoding, and early-stop algorithms. We implemented the proposed scheme on a field-programmable gate array (FPGA) and compared its decoding speed with that of a conventional decoder. From the result of implementation, we confirm that the decoding speed of proposed adaptive decoding is faster than conventional scheme by 6.4 times.

• 복식문화연구
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• 제14권2호
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• pp.177-191
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• 2006

The purpose of this study was to analyze the signification system between logo and brand concept systematically in sportswear brands. For this purpose, 37 apparel brands focused on sportswear brand were selected and the results of the study were following : First, the sportswear brands that symbolize a specific sports used a related supplies such as a golf ball or tennis ball, etc to express sports or concept that pursuit each brand. Second, the sportswear brands used the brand logo that represent or symbolize a specific animal, plant and natural world to express a strong spirit of sports and active energy. Third, the sportswear brands used the word mark or symbol that design a brand name in dynamic or speedy typeface to represent a speed and progressive spirit of sports. Fourth, the sportswear brands used the symbols that represent a concrete object, person such as a mast, shield, etc to emphasize the brand concept. Fifth, the sportswear brands used the symbols of a graphic or geometric style to represent the special quality of brand in type.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.775-779
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• 1999

This paper presents design of AGC(Automatic Gain Control) and DC offset remover suitable for cable modem which makes use of QAM(Quadrature Amplitude Modulation) scheme. Since QAM has multi-level signal characteristic, for high-order QAM, the constellation is dense and the distance of decision boundary between adjacent symbols is short. So AGC and DC offset remover must be designed optionally for preventing performance degradation. AGC is designed into feedback type and is related to the STR(Symbol Timing Recovery)and Paff interpolation algorithm. Whereas AGC need to perform average power detection during many symbols by comparison with the reference power, DC offset remover uses only the instant polarity decision such that simple implementation can be achieved with good performance. Though the AGC and DC offset remover are simulated here only for 256 QAM scheme for convenience'sake, it can be applied to other multi-level QAM or PSK modulation scheme.

• 전자공학회논문지B
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• 제31B권4호
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• pp.9-17
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• 1994

The incremental parsing techniques are essential part of language-based environment which allow incremental construction of programs, as reparsing of modified part of the program alone enhances the system performance. A number of methods and algorithms have been proposed for incremental parsing and for the construction of incremental parsers. The purpose of this paper is to review the earlier incremental parsing algorithms which are too expensive in both time and space, and to present an efficient incremental LR parsing algorithm which is more efficient than the previous ones. In this paper, we generate automatically an extended LR parsing tables which allow the nonterminal symbols as well as terminal symbols for the input, and apply them to our efficient incremental LR parsing algorithm. Using these extended LR parsing tables. we suggest several methods to reduce its memory spaces and parsing steps as well. The algorithms described here were implemented in C language and YACC on a SUN UNIX OS, and were tested with several grammars and strings.

• ETRI Journal
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• 제34권5호
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• pp.719-726
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• 2012

Messages are generally selected with the same probability in the encoding scheme of rateless codes for equal error protection. In addition, a belief propagation (BP) decoding scheme is generally used because of the low computational complexity. However, the probability of recovering a new message by BP decoding is reduced if both the recovered and unrecovered messages are selected uniformly. Thus, more codeword symbols than expected are required for the perfect recovery of message symbols. Therefore, a new encoding scheme with a nonuniform selection of messages is proposed in this paper. In addition, a BP-Gaussian elimination hybrid decoding scheme that complements the drawback of the BP decoding scheme is proposed. The performances of the proposed schemes are analyzed and compared with those of the conventional schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권12호
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• pp.4872-4891
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• 2015

Orthogonal frequency division multiplexing (OFDM) signals suffer from the problem of high peak-to-average power ratio (PAPR), which complicates the design of analog front-end of the system. Companding is a well-known PAPR reduction technique that involves transforming signal amplitudes using a deterministic function. OFDM signal amplitude, on average, is Rayleigh distributed but the distribution can vary significantly from symbol to symbol, especially when constellation size increases. In this paper, a new adaptive companding scheme is proposed along with its design methodology aiming at optimizing the compander performance by accommodating this variation in its design. This is achieved by designing compander parameters separately for statistically dissimilar symbols in OFDM waveform and making the compander select from these parameters, during run-time, according to the features of input symbols.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.239-242
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• 2003

Transmit diversity using STBC(Space Time Block Code) provides the same diversity gain as MRRC(Maximal Ratio Receiver Combining), when the fading channel is constant across two consecutive symbols. But, when the channel condition is changed for the two consecutive symbols, the transmit diversity using STBC does not offer good performance due to the large doppler shift. In this paper, we have proposed a interference cancellation scheme for performance enhancement in transmit diversity using STBC over time selective fading channel. Simulation results for various doppler shift rates are presented for the transmit diversity using the proposed scheme.