• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.8
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• pp.2879-2899
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• 2021

The tone reservation (TR) scheme is an attractive method to reduce peak-to-average power ratio (PAPR) in the filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) systems. However, the high PAPR of FBMC signal will severely degrades system performance. To address this issue, a cyclic shift based TR (CS-TR) scheme with embedding side information (SI) is proposed to reduce the PAPR of FBMC signals. At the transmitter, four candidate signals are first generated based on cyclic shift of the output of inverse discrete Fourier transform (IDFT), and the SI of the selected signal with minimum peak power among the four candidate signals is embedded in sparse symbols with quadrature phase-shift keying constellation. Then, the TR weighted by optimal scaling factor is employed to further reduce PAPR of the selected signal. At the receiver, a reliable SI detector is presented by determining the phase rotation of SI embedding symbols, and the transmitted data blocks can be correctly demodulated according to the detected SI. Simulation results show that the proposed scheme significantly outperforms the existing TR schemes in both PAPR reduction and bit error rate (BER) performances. In addition, the proposed scheme with detected SI can achieve the same BER performance compared to the one with perfect SI.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.105-112
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• 2021

This study aims to find empirical evidence of the effect of increasing income on the potential transfer of wealth from manufacturing companies that go public to stakeholders. Earnings management with an accrual approach with the Modified Jones model is an identifier of the availability of earnings management practices, without paying attention to both positive and negative symbols. The interpretation of the results of the discretionary accrual measurement between positive and negative symbols has different meanings. Positive discretionary accruals indicate that management uses income-increasing techniques. Meanwhile, negative discretionary accruals indicate that management uses income-reducing techniques. Income-increasing techniques tend to be viewed as opportunistic behavior of managers. This study used 111 data from manufacturing companies listed on the IDX (Indonesia Stock Exchange) from 2015-2018. Path analysis is used to test the hypothesis. The results of this study are in line with the point of view of management strategy, increasing income is used as a way to transfer potential welfare from the company to stakeholders. Social welfare (tax) and managerial remuneration are proven to be mediators in increasing the effect of increasing income on future company value. Further research can complete the potential welfare transfer against the shareholders related to income-increasing strategy.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.6 no.4
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• pp.3-38
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• 1996

The mobile station shall convolutionally encode the data transmitted on the reverse traffic channel and the access channel prior to interleaving. Code symbols output from the convolutional encoder are repeated before being interleaved except the 9600 bps data rate. All the symbols are then interleaved, 64-ary orthogonal modulation, direct-sequence spreading, quadrature spreading, baseband filtering and QPSK transmission. The sync, paging, and forward traffic channel except the pilot channel in the forward CDMA channel are convolutionally encoded, block interleaved, spread with Walsh function at a fixed chip rate of 1.2288 Mcps to provide orthogonal channelization among all code channels. Following the spreading operation, the I and Q impulses are applied to respective baseband filters. After that, these impulses shall be transmitted by QPSK. Authentication in the CDMA system is the process for confirming the identity of the mobile station by exchanging information between a mobile station and the base station. The authentication scheme is to generate a 18-bit hash code from the 152-bit message length appended with 24-bit or 40-bit padding. Several techniques are proposed for the authentication data computation in this paper. To protect sensitive subscriber information, it shall be required enciphering ceratin fields of selected traffic channel signaling messages. The message encryption can be accomplished in two ways, i.e., external encryption and internal encryption.

• ETRI Journal
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• v.42 no.6
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• pp.859-871
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• 2020

A spectrally encapsulated (SE) orthogonal frequency-division multiplexing (OFDM) precoding scheme for wireless short packet transmission, which can suppress the out-of-band emission (OoBE) while maintaining the advantage of the cyclic prefix (CP)-OFDM, is proposed. The SE-OFDM symbol consists of a prefix, an inverse fast Fourier transform (IFFT) symbol, and a suffix generated by the head, center, and tail matrices, respectively. The prefix and suffix play the roles of a guard interval and suppress the OoBE, and the IFFT symbol has the same size as the discrete Fourier transform symbol in the CP-OFDM symbol and serves as an information field. Specifically, as the center matrix generating the IFFT symbol is orthogonal, data and pilot symbols can be allocated to any subcarrier without distinction. Even if the proposed precoder is required to generate OFDM symbols with spectral efficiency in the transmitter, a corresponding decoder is not required in the receiver. The proposed scheme is compared with CP-OFDM in terms of spectrum, OoBE, and bit-error rate.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1388-1391
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• 2010

In this paper, we present a design and implementation of U-learning system using pen based augmented reality approach. Student has been given a smart pen and a smart study book, which is similar to the printed material already serviced. However, we print the study book using CMY inks, and embed perceptually invisible dot patterns using K ink. Smart pen includes (1) IR LED for illumination, IR pass filter for extracting the dot patterns, and (3) camera for image captures. From the image sequences, we perform topology analysis which determines the topological distance between dot pixels, and perform error correction decoding using four position symbols and five CRC symbols. When a student touches a smart study books with our smart pen, we show him/her multimedia (visual/audio) information which is exactly related with the selected region. Our scheme can embed 16 bit information, which is more than 200% larger than previous scheme, which supports 7 bits or 8 bits information.

• Industry Promotion Research
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• v.8 no.1
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• pp.135-141
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• 2023

Snakes are objects that appear in religions, folktales, and folktales of various countries, and have had a great influence on human spirit and culture since ancient times. In this study, we focused on the shedding of skin in the ecology of snakes and dealt with related symbols. In the process of shedding its skin, the snake overcomes difficulties and pains, grows, and escapes death to gain a new life. This has the meaning of individuation through the process of psychological transformation by overcoming hardships. This shedding of skin was recognized as a symbol of wisdom, transformation, rebirth, and healing in myths, religions, and folktales, and settled in people's unconscious.

• East Asian mathematical journal
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• v.40 no.2
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• pp.209-229
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• 2024

In this study, we design a teaching unit that constructs Pascal graphs and extended Pascal triangles to explore number patterns inherent in them. This teaching unit is designed to consider the diachronic process of teaching-learning by combining Dörfler's theoretical generalization model with Wittmann's design science ideas, which are applied to the didactical practice of mathematization. In the teaching unit, considering the teaching-learning level of prospective teachers who studied discrete mathematics, we generalize the well-known Pascal triangle and its number patterns to extended Pascal triangles which have directed graphs(called Pascal graphs) as geometric models. In this process, the use of symbols and the introduction of variables are exhibited as important means of generalization. It provides practical experiences of mathematization to prospective teachers by going through various steps of the generalization process targeting symbols. This study reflects Wittmann's intention in that well-understood mathematics and the context of the first type of empirical research as structure-genetic didactical analysis are considered in the design of the learning environment.

• School Mathematics
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• v.17 no.2
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• pp.257-272
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• 2015

This study is related to reinforcement of the continuity between Nuri curriculum and elementary mathematics curriculum emphasized by 2015 revised national curriculum. Considering that teachers tend to rely much more on textbooks than on curriculum, we analyzed the continuity between math-related activities of Nuri manuals for teachers and the elementary mathematics textbooks and aimed to suggest several ways for securing the continuity based on the result of analyses. To do this, we compared and analyzed Nuri manuals (for ages three to five) for teachers and the first and second grade mathematics textbooks in three aspects: mathematical contents, mathematical terms and symbols, and mathematical processes. We adopted the same analysis framework including continuity, discontinuity and reverse continuity as the study on the continuity between Nuri curriculum and elementary mathematics curriculum. As a result, the results of analyses were revealed in three aspects, respectively. We also discussed the results and suggested some implications for securing the continuity of Nuri manuals for teachers and the elementary mathematics textbooks and for revising curriculum and its materials such as textbooks, workbooks or manuals for teachers.

• Journal of the Korean association of regional geographers
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• v.9 no.4
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• pp.576-591
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• 2003

This study examined how historical facts of the past were established as a symbol or identity of a region and reorganized in the present local communities. Janseong has reorganized regional symbols through a regional festival named Hong-gil-dong Festival based on its tradition and cultural resources and used them as a strategy for the regional revitalization. Jangseong was known as "a district of noble scholars" represented by the Philam Seowon(local school) enshrining Kim In-hoo, a superior one of the Confusion scholars of Joseon period. And it was considered as "a place of justice" because of historical fact that it was an important base of Donghak movement and the struggle by righteous soldiers who fought for the country in the late Joseon period. Moreover, as the place which is assumed as a birthplace of Hong Gil-dong, a hero of the Hong Gil-dong story was excavated, the local government has reorganized Mr. Hong as a symbol of the region and has held the Hong Gil-dong festival for its development. In spite of its short history, the festival was established as a representative of Janseong. It also created various regional cultural attractions such as regional logos of Hong Gil-dong and a tourist attraction of his birthplace. Jangseong reorganized its tradition for the regional revitalization through a business-oriented property of the event strategy enforcing a dynamic and external image. In the aspects of tradition reorganization and use for actual development, it is sure that the Hong Gil-dong Festival will work for true integration and revitalization of the region by providing experiences of reorganized regional tradition and culture along with various regional landscapes.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.96-107
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• 2011

Recently, studies of 3D HDTV broadcasting technology have been processed actively. Korea is making efforts to modify Advanced Television Systems Committee (ATSC) 8-Vestigial Side Band (8-VSB) systems for terrestrial 3D HDTV broadcasting services. We intend to adopt a new frame structure to use PN (Pseudo-Noise) sequence as frame header, and VSB modulation. PN sequence is used to recover carrier freqeuncy offset, carrier phase error. In this paper, we will describe this system as the modified ATSC systems. The receiver of the modified ATSC system should be able to estimate and recover carrier frequency offset exactly. A existing ATSC systems inserts pilot to recover carrier frequency offset, on the other hand the modified ATSC systems use PN sequence to recovery carrier frequency offset without the use of pilot. In this paper, we introduce carrier frequency recovery (CFR) scheme for the modified ATSC systems. The proposed CFR scheme is composed of coarse CFR scheme using Fitz algorithm and fine CFR scheme using a simple PN sequence correlation algorithm. And, the symbol information of QAM modulated signal is contained in both In-phase (I)channel and Quadrature-phase (Q)channel. However the symbol information of VSB modulated signal is contained in I channel, and Q channel is just Hilbert transform of I channel. For the reason, VSB modulated symbols can not have fixed phase like QAM modulated symbols, and VSB modulated symbols is more sensitive to carrier frequency offset. Therefore we perform phase correction of received PN sequence to improve performance.