• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2634-2638
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• 2009

The variable structure control(VSC) with sliding mode is the discontinuous control law in leads to undesirable chattering in practice. As a method solving this problem, in this paper, we propose a scheme of the VSC with neural network sliding surface. A neural network sliding surface with boundary layer is employed to solve discontinuous control law. The proposed controller can eliminate the chattering problem of the conventional VSC. The effectiveness of the proposed control scheme is verified by simulation results.

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.169-175
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• 2020

A lot of research has been conducted on a system that collects and observes patients' health information in real time using Internet of Things (IoT) technology, and cares for and supports patients based on this. However, most studies have focused on underlying diseases such as diabetes or cardiovascular disease, and research on IoT systems to cope with respiratory infectious diseases such as COVID-19 is still insufficient. In a COVID-19 situation, the purpose of using an IoT respirator may vary depending on the user. In this paper, we design a system that can adequately cope with respiratory infectious diseases such as COVID-19 by applying IoT technology to respiratory protection. We categorize IoT respirator wearers into patients, medical staff, and self-quarantine persons, and define the purpose and use case of the IoT respirator system according to each classification. The proposed IoT respirator system was designed to achieve each purpose. We developed a prototype system consisting of a smart sensor, a communication module, and a non-motorized hooded respirator to show that the proposed IoT respirator system works.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.10
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• pp.7-12
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• 2011

The effect of frequency interference situation between WiBro and WLAN in TV White Space band was taken into account in this paper. We assumed the using frequency in each system is applied in co-channel. When it comes to co-channel interference case, the minimum distance between WiBro ME and WLAN UE should be at least 210m if the maximum transmitter power of WiBro UE of 25dBm is limited. Analysis results of this paper can provide efficient reference and guideline to make spectrum plan for deploying WiBro and WLAN in TVWS.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.1
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• pp.25-32
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• 2009

The advancements in the infusion of broadcasting and communication and the radio frequency identification technology have made the next generation mobile communication service technology be recognized as an important technology in many different fields and demanded systems of practical service using the technology. Designed in the study was a multimedia platform that would increase the utilization efficiency of limited frequency resources, which made an important part of the next generation mobile communication technology using the radio frequency identification technology, search for vacant frequencies not generating interfering signals to the old frequency users, and consider the growth of infused and complex services. In order to implement the platform, the investigator applied STI as a research model to maximize the functions of a service system and improve reliability. And also suggested IDMA of information required for platform building to maximize the functions of a service system.

• International journal of advanced smart convergence
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• v.8 no.2
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• pp.132-139
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• 2019

We address the problem about forecasting the direction of stock price movement in the Korea market. Recently, the deep neural network is popularly applied in this area of research. In deep neural network systems, proper parameter initialization reduces training time and improves the performance of the model. Therefore, in our study, we propose a novel parameter initialization technique and apply this technique for the stock price movement prediction model. Specifically, we design a framework which consists of two models: a base model and a main prediction model. The base model constructed with LSTM is trained by using the large data which is generated by a large amount of the stock data to achieve optimal parameters. The main prediction model with the same architecture as the base model uses the optimal parameter initialization. Thus, the main prediction model is trained by only using the data of the given stock. Moreover, the stock price movements can be affected by other related information in the stock market. For this reason, we conducted our research with two types of inputs. The first type is the stock features, and the second type is a combination of the stock features and the Korea Composite Stock Price Index (KOSPI) features. Empirical results conducted on the top five stocks in the KOSPI list in terms of market capitalization indicate that our approaches achieve better predictive accuracy and F1-score comparing to other baseline models.

• Journal of Distribution Science
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• v.19 no.4
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• pp.37-51
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• 2021

Purpose: The purpose of this study is to provide a basis for establishing a policy to promote the export of Korean goods through the economic ripple effect of the Korean Wave. From 2001 to 2017, cultural goods exports and consumer goods exports data to 102 countries were used to estimate the effect of cultural goods exports on domestic consumer goods exports. Research design, data and methodology: Based on the Gravity Model, we analyzed the effects of domestic film, publishing, music, broadcasting, clothing, cosmetics, processed food, IT products, and automobiles on the export of consumer goods. Results: The empirical analysis estimated the trade creation effect of exports of cultural products driving exports of consumer goods and found that a 1% increase in exports of cultural products increased 0.136% in exports of consumer goods. Conclusions: The average rate of change in consumer goods exports due to changes in cultural product exports was 22.44, which could be interpreted as an increase of $2,244 in exports of consumer goods such as IT products, cosmetics, clothing, and processed foods. According to the analysis of export-driven effects of each consumer item by dividing cultural products by sector, the effects of export of processed foods, clothing, cosmetics, IT products, and film, music, publishing exports were statistically significant.

• International journal of advanced smart convergence
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• v.11 no.2
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• pp.108-117
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• 2022

The recent development of information and communication technology has a great impact on the audio/video industry. In particular, IP-based AoIP transmission technology and AVB technology are making changes in the audio/video market. Video signal transmission technology has been introduced to the market through a network, but it has not replaced the video switcher function. Video signals in the conference room or classroom are still controlled by the switching device. In order to switch input/output video devices, a cable that is not limited by distance must be connected to the switcher. In addition, the control of the switching device must be performed by a person who has received professional training. In this paper, it is a technology that can be operated even by non-experts by replacing complex video cables (RGB, DVI, HDMI, DP) with LAN cables and enabling IP-based video switching and transmission (Video Mirroring over IP: VMoIP) to replace video switcher equipment. We are going to do this study, I/O videos were controlled in the form of matrix and high-definition videos were transmitted without distortion, and VMoIP is expected to become the standard for video switching systems in the future.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.4
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• pp.349-358
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• 2023

The Satellite-Based Augmentation System (SBAS) plays a significant role in the fields of aviation and navigation: it corrects signal errors of the Global Navigation Satellite System (GNSS) and provides integrity information to facilitate precise positioning. These SBAS systems have been adopted as international standards by the International Civil Aviation Organization (ICAO). In recent SBAS system design, the Minimum Operational Performance Standards (MOPS) defined by the Radio Technical Commission for Aeronautics (RTCA) must be followed. In October 2014, South Korea embarked on the development of a Korean GPS precision position correction system, referred to as Korea Augmentation Satellite System (KASS). The goal is to achieve APV-1 Standard of Service Level (SoL) service level and acquisition of CAT-1 test operating technology. The first satellite of KASS, KASS Prototype 1, was successfully launched from the Guiana Space Centre in South America on June 23, 2020. In December 2022 and June 2023, the first and second service signals of KASS were broadcasted, and full-scale KASS correction signal broadcasting is scheduled to start at the end of 2023. The aim of this study is to analyze the precision of both the GNSS system and KASS system by comparing them. KASS is also compared with Japan's Multi-functional Satellite Augmentation System (MSAS), which is available in Korea. The final objective of this work is to validate the usefulness of KASS correction navigation in the South Korean operational environment.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.7
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• pp.127-138
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• 2012

Unlike the first generation of Korean Wave (Hallyu 1.0), which mainly refers to the exports of Korean TV dramas via broadcasting systems, the New Korean Wave (Hallyu 2.0) era has been brought by K-pop (Korean popular music) via the rapid growth of social media. The purpose of this study is to understand the impact of this significant shift in media on global fans and their way of adopting Korean cultural goods from a social capital perspective, in order to draw some implications for the current Korean content industries. Most global fans of K-pop are young and use social media to access digital content and share their opinions spontaneously. SNS providers such as YouTube and Facebook not only act as information providers to usher the fans to online music retailers; but also function as links between these fans and cultural producers by turning bonding social capital into bridging social capital. Telecommunication and advertising companies participate in this market as a third party by providing funds for supporting digital circulation and distribution. In this multi-sided market with the interdependent agents, it is extremely important to secure a platform that leads the evolution of its business ecology. Without owning the platform, there is also a very little chance to produce linking social capital as a means to maximize the impact of New Korean Wave.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.1-7
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• 2020

In modern society, as technology has advanced and human life area has expanded, there has been an increasing demand for high-quality voice and video communications services without restrictions on time and place. In response to this demand, satellite communications systems that provide a wide range of communications and that offer multiple access are evolving day by day. In satellite communications systems such as Digital Video Broadcasting - Return Channel Via Satellite (DVB-RCS) and Warfighter Information Network-Tactical (WIN-T), the multi-frequency time division multiple access (MF-TDMA) demand assigned multiple access (DAMA) scheme is used for efficient resource allocation. In this scheme, since the satellite terminals periodically request resources from the network controller, and the network controller dynamically allocates resources, it is necessary to arrange resource allocation information from time to time. Shortening of the alignment time is a more important factor in a satellite communications system in which a long transmission delay occurs due to long-distance transmission and reception. In this paper, we propose a sorting algorithm variable-selection scheme that shortens the sorting time by cross-selecting the sorting algorithm based on a threshold value, while setting the number of frames in the MF-TDMA DAMA satellite communications system as the threshold value.