• Journal of information and communication convergence engineering
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• v.14 no.2
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• pp.78-83
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• 2016

In underwater acoustic communication, the transmitted signals are severely influenced by the reflections from both the sea surface and the sea bottom. As very large reflection signals from these boundaries cause an inter-symbol interference (ISI) effect, the communication quality worsens. A channel estimation-based equalizer is usually adopted to compensate for the reflected signals under the acoustic communication channel. In this study, a feed-forward equalizer (FFE) with the least mean squares (LMS) algorithm was applied to a quadrature phase-shift keying (QPSK) transmission system. Two different types of equalizers were adopted in the QPSK system, namely a real-coefficient equalizer and a complex-coefficient equalizer. The performance of the complex-coefficient equalizer was better than that of two real-coefficient equalizers. Therefore, a Hilbert transform was applied to the real-coefficient binary phase-shift keying (BPSK) system to obtain a complex-coefficient BPSK system. Consequently, we obtained better results than those of a real-coefficient equalizer.

• Journal of Communications and Networks
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• v.10 no.3
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• pp.253-257
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• 2008

In this paper, the performance of generic orthogonal space-time block codes (OSTBCs) introduced by Alamouti [2], Tarokh [3], and Su and Xia [11] is analyzed. We first define one-dimensional component symbol error function (ODSEF) from the exact expression of the pairwise error probability of an OSTBC. Utilizing the ODSEF and the bit error probability (BEP) expression for quadrature amplitude modulation (QAM) introduced by Cho and Yoon [9], the exact closed-form expressions for the BEP of linear OSTBCs with QAM in quasi-static Rayleigh fading channel are derived. We also derive the exact closed-form of the BEP for some OSTBCs which have at least one message symbol transmitted with unequal power via all transmit antennas.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.12
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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.

• Journal of electromagnetic engineering and science
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• v.4 no.2
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• pp.63-67
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• 2004

DAM(Delay-And-Multiplier) intercept receiver usually detects the symbol rate of the transmitted DS spread spectrum signal for the feature extraction. It is important for secure communication to reduce the normalized output signal-to-noise ratio that is generated at the DAM intercept receiver as a measure of detectability. In this paper, several kinds of chip waveforms are novelly analyzed for LPI(Low-Probability of Intercept) communication against DAM intercept receiver. Consequently, it is shown that the rectangular chip waveform shows the best LPI performance in the bandwidth of 2/$T_c$TEX>, 4/$T_c$TEX>, and 6/$T_c$TEX>/. Except the rectangular waveform, kaiser chip waveform show better LPI performance than the other waveforms in the bandwidth of 4/$T_c$TEX> and 6/$T_c$TEX>.

• SUVANNABHUMI
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• v.15 no.1
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• pp.129-148
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• 2023

Using sociohistorical approaches, the paper shows that before the 15th century, myths of Hùng Kings, considered to be the descendants of the Dragon race and ancestors of the Vietnamese people, may have existed locally. Vietnamese rulers and people strongly supported the integration of these myths into indigenous culture to form a new belief: the worship of Hùng Kings. By way of discovering the transformation process from the founding myths to the modern national beliefs of the Vietnamese, this paper attempts to demonstrate that both myths and worship of Hùng Kings were politically created and encouraged. The article also focuses on the reasons why these myths and worship reached a broad public as these were integrated into Vietnamese culture.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.14 no.1
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• pp.81-94
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• 2003

Objectives：Developmental reading disorder is a condition which manifests significant developmenttal delay in reading ability or persistent errors. About 3-7% of school-age children have this condition. The purpose of the present study was to validate the diagnostic values of Word/Nonword Reading Test and Letter-Symbol Discrimination Task for the purpose of overcoming the caveats of Basic Learning Skills Test. Methods：Sixty-three reading-disordered patients(mean age 10.48 years old) and sex, age-matched 77 normal children(mean age 10.33 years old) were selected by clinical evaluation and DSM-IV criteria. Reading I and II of Basic Learning Skills Test, Word/Nonword Reading Test, and Letter-Symbol Discrimination Task were carried out to them. Word/Nonword Reading Test：One hundred usual highfrequency words and one hundred meaningless nonwords were presented to the subjects within 1.2 and 2.4 seconds, respectively. Through these results, automatized phonological processing ability and conscious letter-sound matching ability were estimated. Letter-Symbol Discrimination Task：mirror image letters which reading-disordered patients are apt to confuse were used. Reliability, concurrent validity, construct validity, and discriminant validity tests were conducted. Results：Word/Nonword Reading Test：the reliability(alpha) was 0.96, and concurrent validity with Basic Learning Skills test was 0.94. The patients with developmental reading disorders differed significantly from normal children in Word/Nonword Reading Test performances. Through discriminant analysis, 83.0% of original cases were correctly classified by this test. Letter-Symbol Discrimination Task：the reliability(alpha) was 0.86, and concurrent validity with Basic Learning Skills test was 0.86. There were significant differences in scores between the patients and normal children. Factor analysis revealed that this test were composed of saccadic mirror image processing, global accuracy, mirror image processing deficit, static image processing, global vigilance deficit, and inattention-impulsivity factors. By discriminant analysis, 87.3% of the patients and normal children were correctly classified. Conclusion：The patients with developmental reading disorders had deficits in automatized visuallexical route, morpheme-phoneme conversion mechanism, and visual information processing. These deficits were reliably and validly evaluated by Word/Nonword Reading Test and Letter-Symbol Discrimination Task.

• Journal of architectural history
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• v.15 no.3
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• pp.7-25
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• 2006

This research examines symbolic meanings of architectural style of Japanese ruling era of Korea through analysis of Expo buildings. Expo buidings of Joseon Product Evaluation Expo(1915), Joseon Expo(1929), and Joseon Grand Expo(1940) are chosen as subjects of this research. Expos held in Korea since 1945 were creatures of colonial reign and their objectives are advertising the advancement of Japan. New and latest architectural styles of Western countries were used as a symbol of advancement in non-western countries. Renaissance style and Secession style in Joseon Product Evaluation Expo and Modernism style in Joseon Expo were introduced as architectural styles that symbolize advancement. On the contrary, the traditional architectural style of Joseon Dynasty was distorted as symbol of backwardness. Latest Western Architectural Styles were used elaborately and Intentionally to symbolize advancement and industrialization by Japanese ruling power and companies. Specially, Modernism style operating as 'symbol of advancement' is characteristic of non-western society in attempt to proceed Modernization through Westernization. Also, it can be suggested that architectures in Modernism style are used in ways to symbolize the advancement of the colonial reign authorities within the colonial society.

• Journal of the Korea Fashion and Costume Design Association
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• v.16 no.1
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• pp.65-76
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• 2014

The purpose of this study is to examine the influence of conspicuous consumption on wearing attitude of jeans and analyze the difference of purchasing behavior in jeans by gender. Questionnaires were administered to 386 college students living in Deagu and Busan province. Frequency, factor analysis, reliability analysis, regression analysis, t-test, and $X^2$-test were used for data analysis. Conspicuous consumption were categorized into 5 factors such as famous brand preference, brand conspicuous, fashion pursuit, symbol of social position, and imported goods pursuit. Wearing attitude of jeans was categorized into fashion information leadership, fashion innovation, and pursuit of economic. The result of this study showed brand conspicuous, fashion pursuit, symbol of social position, and imported goods pursuit had significant effect of fashion information leadership and brand conspicuous, fashion pursuit, and imported goods pursuit had significant effect of fashion innovation. Brand conspicuous, and symbol of social position had significant effect of pursuit of economic. The indicates that men showed high brand conspicuous of conspicuous consumption and fashion innovation of wearing attitude of jeans. Gender of college students showed significant differences in purchasing place, purchasing price.

• Journal of the Korean Society of Costume
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• v.20
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• pp.93-104
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• 1993

The purpose of this study is to clarify the adap-tation of traditional beauty of dress in Baek Eui for the establishment of tradition of dress culture. Especially, the color of the traditional dress rep-resent a symbol which is connedted with the na-tional character and the evvironment. But it is hard to examine closely because color preference are transformend with the times. This study is framed within the limits of the next themes : the origin, history and meaning of the Baek Eui ; the philosophical theory of cosmic Five Elements and the Prohibition of Baek Eui ; the beauty of Baek Eui. As the national character is indicative of the conservativeness and the purity, Koreans have kept up wearing Baek Eui spite of the occasional prohibition. Since the color of the dress represen-tatived the signs of the social class and the power, over the eighty persent of the common people put on the Beak Eui : ramie and flax fabrics that has it's own color in Chosun-Dynasty. I think that the use of natural color harmony is prominent and the beauty of Baek Eui is the naturality and the non-artificiality. The meaning of the symbol on the Korean Beak Eui is the divinity, the holiness, the purity, the cleanliness, the modesty, the frugality, the integ-rity, the constancy, the elegance, the simplicity.

• Journal of the Korean Society of Clothing and Textiles
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• v.14 no.3 s.35
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• pp.196-207
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• 1990

The western heraldry influenced by the style of periodic art, the lion and the eagle charges were expressed simply and laconically in Romanesque period, laconically but forcibly in Gothic period, and elegantly and elaborately in the period of the Renaissance. The symbolical character of each charge expressed in the heraldry in the process of the changes of the times can be summarized as follows: 1) The ferocious beast like the eagle or the lion in the heraldry is symbolic of a majestic appearance of sovereign's. 2) The legendary or mythical monster in the heraldry is the symbol of holding sacred the heraldry owner endowed superhuman ability from him, or the symbol of coercion or menace to the other party on the appearance of being sized with fear. 3) The domestic animals or the poultry in the heraldry are chiefly symbolic of intrepidity, bravery, sacrifice, or faithfulness, which can be supposed a subject's loyalty to his sovereign. 4) The lamb or the cross in the heraldry is the charge concerned with Christ who brought a fundamantal thought in the middles ages. So they can be said the symbol of Christianity.