• Journal of Astronomy and Space Sciences
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• v.20 no.4
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• pp.339-350
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• 2003

Engineering qualification model payload for a communications and broadcasting satellite(CBS) was developed by ETRI from May, 2000 to April, 2003. For. the purpose of functional test and verification of the payload, a real-time hardware-in-the-loop(HITL) CBS simulator(CBSSIM) was also developed. We assumed that the spacecraft platform for the CBSSIM is a geostationary communication satellite using momentum bias three-axis stabilization control technique based on Koreasat. The payload hardware is combined with CBSSIM via Power, Command and Telemetry System(PCTS) of Electrical Ground Support Equipment(EGSE). CBSSIM is connected with PCTS by TCP/IP and the payload is combined with PCTS by MIL-STD-1553B protocol and DC harness. This simulator runs under the PC-based simulation environment with Windows 2000 operating system. The satellite commands from the operators are transferred to the payload or bus subsystem models through the real-time process block in the simulator. Design requirements of the CBSSIM are to operate in real-time and generate telemetry. CBSSIM provides various graphic monitoring interfaces and control functions and supports both pre-launch and after-launch of a communication satellite system. In this paper, the HITL simulator system including CBSSIM, communications payload and PCTS as the medium of interface between CBSSIM and communications payload will be described in aspects of the system architecture, spacecraft models, and simulator operation environment.

• International Journal of Advanced Culture Technology
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• v.11 no.4
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• pp.177-192
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• 2023

A prerequisite for a lasting ceasefire is the emergence of a prevailing view in Moscow and Kyiv that the fighting has reached a hurting stalemate. In sum, they both lose more through continuing warfare than by a ceasefire. This study applies social identity dynamics of nationalism to this escalatory conflict. It generates findings that imply that China as a third-party great power intervening mediator can potentially play a pivotal role. Shifting the respective prevailing views in Moscow and Kyiv of their interaction from a zero-sum foundation requires proffering powerful economic and political third-party incentives. Effective inducement would facilitate national defense, development and prestige for Moscow as well as Kyiv. China arguably has the underutilized potential power capabilities necessary to alter the respective prevailing views of strategic relationships among the great powers within Moscow, Brussels and Washington. A prerequisite for success in striving effectively towards this strategic goal is cooperation with the Beijing despite skepticism from Washington. This study utilizes a process tracing methodological approach. It highlights that the foundations of the Russo-Ukraine war lie in the institutionalization within Euro-Atlantic integration of the Cold War assumption that the USSR was an imperialist revisionist actor. Russia is the USSR's successor state. Moscow's prevailing view is that Russian national self-determination was unjustly circumscribed in the multinational Soviet totalitarian Communist system. The Euro-Atlantic community is perceived as a neocolonial imperial threat by allying with post-1991 Ukrainian nationalism at Russia's expense. The study finds that acknowledging Eurasian regional multipolarity is necessary, if not sufficient, to coopt Beijing into a global political stabilization strategy. It functionally aims to promote international balancing to lessen potentials for horizontal as well as vertical escalation of the Russo-Ukrainian conflict.

• Science of Emotion and Sensibility
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• v.23 no.2
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• pp.3-12
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• 2020

The purpose of this work is to suggest the optimal color temperature, which induces a sense of comfort for autonomous vehicle users through the analysis of biosignal using electroencephalography (EEG) and photoplethysmography (PPG). To achieve this purpose, we applied lighting with a color temperature of 3000 K, 4000 K, 5000 K, and 6000 K to the autonomous driving environment. We experimented in a laboratory equipped with a graphic driving simulator. The experimental procedure is as follows: 1) stabilization (5 min). 2) Uchida-Kraepelin test (3 min). 3) Automatic driving + lighting (3 min). This procedure was repeated four times under different color temperatures. We performed frequency analysis on a collected time-series data and calculated the power value for each frequency band through power spectrum analysis. In the case of EEG, we analyzed α- and β-waves, which are indicators of stability and arousal, respectively. In the case of PPG, we analyzed the sympathetic nervous system activity. To reduce deviations between the subjects, we normalized the data before analysis. The result of the first analysis revealed that α-wave increased only at 5000 K, while the β-wave increased at almost all color temperatures. In addition, in the case of PPG, sympathetic nervous system activity (SNSA) increased under driving conditions. The result of the second analysis revealed that the difference between β-wave and SNSA is insignificant. In conclusion, the increase in α-waves showed that EEG was most stable at 5000 K. The results of this study can be applied to the upcoming autonomous driving era to induce high driver satisfaction. Furthermore, this approach could eventually lead to the acceptance of autonomous vehicles by suggesting a positive effect of autonomous driving.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.568-574
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• 2020

Recently, the installation of energy storage systems (ESSs) that have a range of functions, such as power stabilization of renewable energy sources, demand control, and frequency regulation, has been increasing annually. On the other hand, since the fire accident of ESS occurred at Gochang Power Test Center in August 2017, 29 fire accidents with significant property losses have occurred, including the Gyeongsan substation and Kunsan PV power plant. Because these fire accidents of ESS are arisen regardless of the season and capacity of ESS, an analysis of the fault characteristics in ESS is required to confirm the causes of the fire accidents accurately and ensure the safety of the ESS. This paper proposes the modeling of ESS using PSCAD/EMTDC S/W to identify the fault characteristics and ensure the safety of the ESS. From the simulation results of fault characteristics based on various scenarios, it is clear that the insulation of ESS may be breakdown due to the largely occurring CMV (common mode voltage). Furthermore, the CMV between the PCS and battery can be reduced, and the insulation breakdown of ESS can be prevented if an SPD (surge protect device) is installed in the battery and PCS sides, respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.5
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• pp.597-604
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• 2010

This study focuses on the design of a mechanical joint for a zero moment crane (ZMC), which is a specialized loading/unloading system used in a mobile harbor (MH). The mechanical joint is based on the concept of zero moment point (ZMP), and it plays an important role in stabilizing a ZMC. For effective stabilization, it is necessary to ensure that the mechanical joint is robust to a wide variety of loads; further, the joint must allow the structures connected to it to perform rotational motion with two degrees of freedom By adopting a traditional design process, we designed a new mechanical joint; in this design, a universal joint is coupled with a spherical joint, and then, deformable rolling elements are incorporated. The rolling elements facilitate load distribution and help in decreasing power loss during loading/unloading. Because of the complexity of the proposed system, Kriging-based approximate optimization method is used for enhancing the optimization efficiency. In order to validate the design of the proposed mechanical joint, a structural analysis is performed, and a small-scale prototype is built.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.6
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• pp.51-60
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• 2015

This study conducted shear strength test and plate bearing test to look into the characteristics of bearing capacity using geosynthetics case on forest road surface. The shear strength test showed that the internal friction angle at the time when geosynthetics was used was measured larger on average than that in the unreinforced case. Therefore, using geosynthetics case produced more bearing capacity reinforcement effect. The result from the comparison test of internal friction angle by geosynthetics type revealed that the internal friction angle at the time when geotextile case was used was measured larger. That was attributable to the difference between the area of the total cross section of geotextile made in type of non-woven fabric and its material. Plate bearing test showed that the settlement at the time when geosynthetics was used was measured smaller than that in the unreinforced case. Therefore, using geosynthetics produced more bearing power reinforcement effect. The result from the comparison test showed that geogrid case was measured smaller than geotextile case. Henceforth, It is seemed that it will be necessary to keep studying the reinforcement engineering and process of forest road surface which fits the characteristics and conditions of geosynthetics to prevent forest road demage.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.166-172
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• 2001

A RF wideband receiver for INMARSAT-B satellite communications system was composed of low noise amplifier and high gain amplifier, The low noise amplifier used to the resistive decoupling circuit for input impedance matching and self-bias circuits for low noise. The high gain amplifier consists of matched amplifier type to improve receiver gain. The active bias circuit can be used to provide temperature stability without requiring the large voltage drop or relatively high-dissipated power needed with a bias stabilization resistor. The bandpass filter was used to reduce a spurious level. As a result, the characteristics of the receiver implemented here show more than 60 dB in gain and less than 1.8:1 in input and output voltage standing wave ratio(VSWR), especially the carrier to noise ratio which is input signal level -126.7 dB m at 1537.5 MHz is a 45.23 dB /Hz at a 1.02 kHz.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.147-153
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• 2018

Beacon enables one to measure distance indoors based on low-power Bluetooth low energy (BLE) technology, while GPS (Global Positioning System) only can be used outdoors. In measuring indoor distance using Beacon, RSSI (Received Signal Strength Indication) is considered as the one of the key factors, however, it is influenced by various environmental factors so that it causes the huge gap between the estimated distance and the real. In order to handle this issue, we propose the adaptive ANN (Artificial Neural Network) based approach to measuring the exact distance using Beacon. First, we has carried out the preprocessing of the RSSI signals by applying the extended Kalman filter and the signal stabilization filter into decreasing the noise. Then, we suggest the multi-layered ANNs, each of which layer is learned by specific training data sets. The results showed an average error of 0.67m, a precision of 0.78.

• Journal of Navigation and Port Research
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• v.36 no.10
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• pp.895-904
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• 2012

Today, the competition for hub-port is getting fierce and the shipping liners have enjoyed the increased bargaining power over the terminal operators through the mergers & acquisitions (M&A) and strategic alliances. This result leads the competition among terminal operators to attract liner companies and cargoes in their terminals. In demand side, however, there is a limited container cargo volume to handle because of a steady growth of cargo traffic. While, in supply side, continuous development of port terminals increased more competition among ports or terminals for cargoes. In particular the terminal operating market of Busan port is distorted because of the cargo competition between Busan North-port and Newport. The main purpose of this study is to suggest the stabilization measures of container terminal operating market in Busan port through analysis of the terminal operation market structures and market survey analysis method. For stabilizing the container terminal market, this study suggests the improvement of the legal and institutional system such as improvement in determining and reporting system of stevedoring tariff, establishment of fair competition rules etc., the introduction of port pooling system and adoption of volume-linked terminal lease system with cargo volume ceiling system for each terminal operator.

• The Journal of Korean Philosophical History
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• no.30
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• pp.311-344
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• 2010

Over 100 years in Mainland China, the 'traditional' thought and culture have been transformed from 'the past must be sublated' to 'the heritage must be preserved.' Today, China hopes to deal with the negative effects of industrial development such as the gap between rich and poor, and the absence of common values etc. through the reconstruction of traditional thought and culture, especially that of Confucianism. The Chinese government superficially accepts Confucianism for the purpose of the social stabilization and ongoing economic development while they keep the Socialism as the nation's ideological system. In the private sectors, there is endeavoring move to make the Chinese traditional thought and culture global paralleled to their economic growth. There are also scholars who find the cultural unification and the spiritual comfort from the restoration of the traditional thought and culture. They, so called 'the critical successionists' or 'the cultural conservativists,' believe that the traditional thought and culture could play a role in the Chinese modernization, and the new understanding and interpretation of their tradition could provide an alternative for their future. In my view, we need a careful survey on the view of the critical successionists or the cultural conservativists who regard tradition and culture as a power (力量). With this, we are required to investigate our own problems through the new understanding of our traditional thought and culture.