• The Journal of the Acoustical Society of Korea
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• v.40 no.5
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• pp.428-438
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• 2021

For long-range communication in deep water, low carrier frequency is efficient due to a decrease in transmission loss. However, there is a limitation in that the data rate decreases due to a narrow bandwith. In order to increase the data rate in an environment with a limited bandwidth, it is necessary to design a higher-order modulation scheme. This paper analyzes the long-range communication data modulated by higher-order modulation schemes. The long-range communication experiment (23 km ~) was conducted in East Sea in October 2020. During the experiment, a vertical line array was utilized and communication sequences were modulated by Phase Shift Keying (PSK) and Quadrature Amplitude Modulation (QAM) schemes and transmitted by a towed source. In more detail, PSK modulation consists of quadrature PSK and 8PSK, QAM modulation consists of 8QAM and 16QAM. Time reversal processing is applied to mitigate inter-symbol interference by utilizing the correlation between received signals and channel impulse responses. All modulation schemes show successful results at 23 km range, demonstrating the feasibility of higher-order modulation in long-range communication.

• Journal of Advanced Navigation Technology
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• v.25 no.5
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• pp.357-362
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• 2021

UWB(ultra wide band) communication systems employ short pulses to transmit information which spreads the signal energy over a very wide frequency spectrum. Received signal-to-noise power ratio of UWB signals is an important factor in determining the accuracy of a positioning system. As the signal to noise power ratio gets higher, positioning errors decrease since noise becomes less effective. Calculation of signal to noise power ratio as a function of communication distance provides important guidelines for the system design. And the performance of a positioning system also depends heavily on the channel model. As a result of the analysis, it was found that the performance of the received signal to noise power ratio according to the communication distance was better in the LOS channel environment than in the Non LOS(line of sight) channel environment. And as the symbol interval of the preamble signal increases at a specific communication distance, the channel capacity of the UWB system increases.

• Journal of the Daesoon Academy of Sciences
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• v.35
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• pp.477-508
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• 2020

Awareness of grievances and the concept of "grievances (冤)" itself are both universal and essential among East Asian countries. Grievances have become a cultural symbol that has repeatedly appeared in the Han culture of later generations. The way new religious groups interpret "grievances" and face disasters, which are seen as having been brought by grievances, reflects the circumstances and historical backgrounds that Eastern nations hold in common. This paper aims to discuss the concept of "grievances" in Taiwan's Weixin Shengjiao and Korea's Daesoon Jinrihoe, which are represented doctrinally as "The Resolution of Grievances and Altruism" (in Weixin Shengjiao) and "The Resolution of Grievances for Mutual Beneficence" (in Daesoon Jinrihoe). How these two tenets are fulfilled in modern society will likewise be examined. Weixin Shengjiao takes solving the hatred among the Three Ancestors as a premise for achieving world peace and commits to stabilizing people's lives amid the capitalistic design of modern society. Daesoon Jinrihoe deems the "Reordering Works" to be the only way to unify the earthly energies to achieve balance in the universe. They also developed the "Three Major Works" to contribute to modern society. These two new religious orders share many similarities, but are distinct in their interpretations and practices. Both orders demonstrate the features and meaning of "Solving Grievances" as it relates to the process of modernization in East Asia.

• Fashion & Textile Research Journal
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• v.24 no.1
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• pp.42-52
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• 2022

The goal of this study is to analyze the value of Kanga as an ethos of the Swahili culture. The theoretical background of the research method was the analysis of the domestic and foreign literature, journals, and research data from various internet sites related to the subject, and the conclusion was drawn based on these studies. With the spread Pan-Africanism, the interest in African ethos has become a source of inspiration for contemporary fashion. Moreover, as a symbol of Swahili culture in East Africa, Kanga has been developed by embracing its own diverse cultures, The unique feature of Kanga is that it can easily be transformed created ceaselessly and creatively. Consequently, the following results were obtained based on the theoretical content. Firstly, as a representative of Women's Voice, Kanga serves as an outlet for the voices of women coming from a poor social status under the political background in East Africa. Secondly, as a Reliable Advocate, Kanga performs the positive functions as a medium of communication through its traditional usage and distinctive arrangement of clothes. Thirdly, as a Versatile Messenger, the uniqueness of Kanga with the external elements in most interestingly and active mannerly, and it has become the value of communication channel which clearly inspired the fashion designers. I believe that it will be interesting and meaningful to study the strategies on the social role of Kanga in the future which has started receiving more attention in the 21st century. And it can be said that Kanga's unique identity lies in the attraction and value which influences contemporary fashion.

• International Journal of Computer Science & Network Security
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• v.23 no.5
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• pp.172-178
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• 2023

In this paper, performance of autoencoder based OFDM communication systems is compared with IEEE 802.11a Wireless Lan System (Wi-Fi). The proposed autoencoder based OFDM system is composed of the following steps. First, one sub-carrier's transmitter - channel - receiver system is created by autoencoder. Then learning process of the one sub-carrier autoencoder generates constellation map. Secondly, using the plural sub-carrier autoencoder systems, parallel bundle is configured with inserting IFFT and FFT before and after the channel to configure OFDM system. Finally, the receiver part of the OFDM communication system was updated by re-learning process for adapting channel condition such as multipath channel. For performance comparison, IEEE802.11a and the proposed autoencoder based OFDM system are compared. For channel estimation, Wi-Fi uses initial long preamble to measure channel condition. but Autoencoder needs re-learning process to create an equalizer which compensate a distortion caused by the transmission channel. Therefore, this autoencoder based system has basic advantage to the Wi-Fi system. For the comparison of the system, additive random noise and 2-wave and 4-wave multipaths are assumed in the transmission path with no inter-symbol interference. A simulation was performed to compare the conventional type and the autoencoder. As a result of the simulation, the autoencoder properly generated automatic constellations with QPSK, 16QAM, and 64QAM. In the previous simulation, the received data was relearned, thus the performance was poor, but the performance improved by making the initial value of reception a random number. A function equivalent to an equalizer for multipath channels has been realized in OFDM systems. As a future task, there is not include error correction at this time, we plan to make further improvements by incorporating error correction in the future.

• Journal of Digital Convergence
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• v.20 no.1
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• pp.185-190
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• 2022

Bluetooth is a common wireless technology that is widely used as a connection medium between various consumer electronic devices. The Bluetooth receiver usually adopts a Viterbi algorithm to improve signal-to-noise ratio performance, but requires complex hardware and calculations for continuous search and estimation for the irrational modulation indexes at the transmission. This paper proposes a non-coherent maximum estimation based 8-State Viterbi FSM to solve these complexity problems. The proposed optimal Viterbi FSM can detect Gaussian frequency-shfit keying symbol without any prior information and estimation for the modulation indexes. The HV1/HV2 packets are used for the estimation of the proposed algorithm and the simulation results have shown performance improvements with about 2dB for 10^-3 BER compared to other ideal approaches such as decision direct method.

• Journal of Fashion Business
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• v.28 no.2
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• pp.76-91
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• 2024

This study analyzed the colors used in the logos of infants' and children's clothing brands, comparing them based on brand type and the pursued image. A total of 34 brands with the highest recent sales rates were selected. Among these, 17 were large-sized enterprise brands found in department stores, and the other 17 were in-house production enterprise brands. All colors used in the logos of the selected brands were extracted from the brand logo images. In addition, the study classified the pursued images of the selected brands using emotional adjectives in order to assess variations in different color attributes of the logos according to the brand type and pursued image. The study found that in-house production enterprise brands used lighter and more varied colors compared to department store brands. For both brand types, reddish-to-yellowish hues were most commonly used. Brands projecting a 'cute' and 'gorgeous' image exhibited a greater array of colors in their logos, while brands with a 'neat', 'modern', and 'luxurious' image used less saturated colors. In terms of logo type, symbol logos used the most colors with a moderate level of lightness, while typographic logos used the fewest colors with a low level of lightness.

• Korean Journal of Psychosomatic Medicine
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• v.20 no.1
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• pp.50-58
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• 2012

Objectives : This study examined the selective deficits of executive function in patients with mild traumatic brain injury that in normal range of general intelligence level and aimed to analysis of the correlation between K-WAIS result and executive function. Methods : 59 subjects were included in this study, who were diagnosed as mild traumatic brain injury(MTBI) and they have visited in neuropsychiatric department of Wonkwang University Hospital during from March, 2005 to September, 2010. For measurement of general intelligence quotient, the Korean-Wechsler Adults Intelligence Scale(K-WAIS) was administered and for measurement of executive intelligence quotient(EIQ), Executive Intelligence Test(EXIT) was administered. Results : Of patients, 50.8% included at abnormal EIQ group. The patients of abnormal EIQ showed poorer full scale IQ(FIQ), performance IQ(PIQ) and in subscale that picture arrangement, digit symbol, digit span, block design, object assembly and comprehension were significantly different. In terms of relationships between K-WAIS and EIQ, FIQ and PIQ have positive correlation with EIQ. And in subscale, picture arrangement, digit symbol, digit span, block design, object assembly and comprehension show positive correlation with EIQ. Conclusion : This study suggest that MTBI patients with have normal range of general intelligence level may have deficit of executive function is common. The decline of FIQ, PIQ and some subscales of K-WAIS may suggest executive dysfunction in MTBI patients.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.1
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• pp.107-118
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• 2016

The Seoul metropolitan government announced an open design competition for reconfiguring the annex building of the National Tax Service Building site on Sejong-daero as a space for citizens to commemorate the 70th anniversary of Korea's liberation. The site, built during the Japanese colonial period, has been in use ever since. This study, as one of the entries for the competition, described the strategy and design contents by drawing the concept and main points of the design through an analysis of the historical context of the site. As the guidelines instructed to consider the value of the Sejong-daero area and the cultural heritage through a comprehensive analysis, this study specified the site as a place connecting the past, present and future. Since the foundation of the Joseon dynasty, the Korean Empire and the Japanese colonial period, Sejong-daero has been a main site for important events and activities along with the change of the city structure. Jungdong, to the rear of the site, was a place for adopting new culture during the beginnings of modern Korea, while adjacent places like Duksugung, the Anglican church, and the Seoul City Council building have also been historic urban landscapes of the historical layers of time as the city has changed. When Gojong announced the Korean Empire, the city structure was remodeled with this site as the center along with Sogong-ro, Wongudan and so forth. In this study, public interest stated in the guidelines was focused and the relevance of the road and the plaza was considered from the view of an historic urban landscape by a comprehensive analysis with Sejong-daero as the center. The restoration of public interest was to be drawn as the concept of the object site by considering the current status and the change around the site and Jungdong at the rear. Returning the site to the public is ambiguous with the relevance of the restoration of public interest and as the symbol of the idea of the Korean Empire by Gojong's announcement. The object site, having the characteristic of being returned to the public, must ensure public interest and therefore the design strategy has been established with the keywords of openness, connection and void. As a result of a review of the alternatives, a plan for a square has an 8% slope, just as the original site does, and provides ramps for convenient access for all, including the disabled and the elderly, and is connected to the grounds adjacent. No construction is allowed at the terrace square of the Anglican church level and the main square connected to the pedestrian street, so a variety of modern city utilization can be done. The value of the site at which this design is aimed shall be given back to the public with the concepts of modern democracy, independence, and the vision of Gojong by reinterpreting the space from a modern viewpoint. This study focused on the processes of establishing a main concept and strategy rather than the content of the design details, and the suggestion is meaningful in that the design for the object site with historic backgrounds and the layers of time can continue to be grown.

• The Research Journal of the Costume Culture
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• v.7 no.6
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• pp.129-139
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• 1999

This paper analyzes the trend of fashion and make-up in 1990s and their relevancy to each other. Based on the chronological analysis, we propose a new category for the fashion and make-up trend in 1990s, which is 1) traditional ecology period(1990∼1994), 2) versatile trial or decadent period(1995∼1997), and 3) soft landing period based on the minimal neo-ecology and romanticism(1998∼2000). Between 1990 and 1994, there was no differentiation in seasons. It appeared that spring/summer and fall/winter trend have had no big differences. At the beginning in 1990s, it was basically based on ecology concept that emphasizes the natural image. However after 1995, seasonal differences in trend are appeared and there were various make-up designs. The trends of spring/summer in 1996 could be named as color revolution period that emphasized the unique and individual expression of each person. In 1997, black, pastel, and brown colors were the result of reinterpreting the classic and sexy images of 1960s to natural and modernistic image of 1997. Purple color started to be introduced to us. In 1998, pastel tone, pink, and purple color expresses the glamorous look based on the romantic feminism. S/S of 1999 is mainly represented by minimalism and avant garde. For fall/winter trends, brown color lines make-up comes to mix with romantic image and developed into wine, orange, neon colors in 1995 and 1996. These colors were the symbol of property and sentiment. Gold make-up emphasizing the eye area was the tendency of that period. In 1997, the fear of coming end of century was expressed as decadent image. At that time, ethnic and romantic image appeared with vivid color lines, gold, red and violet. In 1998, romanticism was popular again with modernism and ethnic mood. It expressed the romantic elegant image. The trend has returned to the ecology mood again in 1999. This ecology is somewhat different from the previous ecology. It adds a sofistaiced feeling and sportic fashion. To express natural and sportic image, they choose pink blush. In coming 2000 as a new millennium, the yellow color will be main the stream to express vision, dream, and happiness in both fashion and make-up as an accent color. The minimal design and minimal tools will be used for the design and make-up, respectively. In addition, the fusion concept will dominate the fashion and make-up industry in the globalized and boundariless age. Through this paper, we hope that make-up can be accepted as a part of total fashion in its relationship with other elements such as shoes, clothes and accessory and that it can be considered as a independent art that has direct influence on people and industry.