• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.34S no.7
• /
• pp.39-47
• /
• 1997

The mission of the TTC system is to acquire and process the telemetry data from the satellite and to provide mission planning and satellite control for the target stellite system. In this paper, the transmission scheme for the Tracking, Telemetry and Command(TTC) system of satelliteis described and determined according to the recommendation of CCSDS, and the channel characteristics are analyzed according to modulation method. Expecially, we introduced the concepts of carrier vs. telemetry data power ratio which causes the channel performance to degrade, and analyzed the effects of transmission performance according to the power ratio of carrier vs. telemetry data and the modulation index. The channel of the LEO TTC sytem is different with usual satellite communication system. So, we have generalized the link budget of TTC sytem for using the link budget of ground station well-known and proposed the determination method of modultion indices for improveing channel performance.

• Journal of Astronomy and Space Sciences
• /
• v.37 no.2
• /
• pp.117-129
• /
• 2020

In a Satellite communication system, a link budget analysis is the detailed investigation of signal gains and losses moving through a channel from a sender to receiver. It inspects the fading of passed on data signal waves due to the process of spreading or propagation, including transmitter and receiver antenna gains, feeder cables, and related losses. The extent of the proposed tool is to make an effective, efficient, and user-friendly approach to calculate link budget analysis. It is also related to the satellite communication correlation framework by building up a graphical interface link analysis tool utilizing STK^® software with the interface of C# programming. It provides better kinds of graphical display techniques, exporting and importing data files, printing link information, access data, azimuth-elevation-range (AER), and simulation is also possible at once. The components of the link budget analysis tool include transmitter gain, effective isotropic radiated power (EIRP), free space loss, propagation loss, frequency Doppler shift, flux density, link margin, elevation plot, etc. This tool can be useful for amateur users (e.g., CubeSat developers in the universities) or nanosat developers who may not know about the RF communication system of the satellite and the orbital mechanics (e.g., orbit propagators) principle used in the satellite link analysis.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.33 no.3
• /
• pp.93-98
• /
• 2005

STSAT-2 will be launched on December 2007 by the first Korean launch vehicle KSLV-1, and its one of the main instruments is DREAM (Dual Channel Radio Frequency and Environment Atmosphere Monitoring) which detects a signal for atmosphere from the Earth by using micro-wave signal. The STSAT-2 has many units for technology demonstration such as FDSS (Fine Digital Sun Sensor) and DHST (Dual Head Star Tracker) including PPT (Pulsed Plasma Thruster) for attitude control and momentum dumping in the space. In this paper, the power budget analysis for STSAT-2 will be studied and provided for supporting the whole mission life time during the mission of its spacecraft.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.23 no.2
• /
• pp.147-158
• /
• 2020

Korea Ministry of National Defense has directed the state-of-the-art technology Forces troops structures that can respond to security threats in all directions through the Defense Innovation 2.0, which aims to reorganize the personnel and organizations in response to population decline. An implement of effective analysis to maintain combat power is necessary due to possible restrictions on combat power, especially in division of mobilization where reserve manpower is operated frequently. In this study, the normal operations of the reserve officers were investigated, the direct effects of the combat forces of the reserve officers was analyzed using ARENA modeling, and the budget required to operate the innovation and indirect effects of employment of veterans were studied. The result of the simulation proved to be effective in demonstrating unit combat power when the reserve officer was in full-time operations and economic benefits were also significant in terms of efficiency of defense budget management.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.2
• /
• pp.75-83
• /
• 2014

The present study estimated nitrogen budget of South Korea including nitrogen oxides (NOx) in 2011. Emission sources of NOx were calculated with the higher contributors, such as vehicles, businesses, power plants, based on the IPCC and EPA reports. Moreover, nitrogen budget was separated for city, agriculture livestock and forest. Input and output were chemical fertilizer, crop uptake, fixation, irrigation, compost, leaching, volatilization, imported food, denitrification, runoff, and so on. Annual nitrogen input were 1,692,650 ton/yr and output were 837,739 ton/yr which were increased from 2010 budget. In 2011, NOx emissions by vehicles, power plants, and businesses were 308,207 ton/yr, 601,437 ton/yr, and 469,946 ton/yr, respectively. Including nitrogen oxide, total nitrogen input and output in 2011 was calculated as 5,652,366 ton/yr and 1,425,371 ton/yr, respectively.

• Journal of Power Electronics
• /
• v.15 no.4
• /
• pp.1018-1025
• /
• 2015

This paper proposes a methodological scheme for the photovoltaic (PV) simulator design. With the advantages of a digital controller system, linear interpolation is proposed for precise fitting with higher computational efficiency. A novel control strategy that directly tackles two different duty cycles is proposed and implemented to achieve a full-range operation including short circuit (SC) and open circuit (OC) conditions. Systematic design procedures for both hardware and algorithm are explained, and a prototype is built. Experimental results confirm an accurate steady state performance under different load conditions, including SC and OC. This low power apparatus can be adopted for PV education and research with a limited budget.

• 한국디지털정책학회:학술대회논문집
• /
• 2007.06a
• /
• pp.51-58
• /
• 2007

Considering innovation a key to raising living standards, the Ministry of Science and Technology has put in place various measures meeting the needs of the newly promoted Deputy Prime Minister of Science and Technology. Such measures include business process reengineering as streamlining the work process to achieve the improvement in quality and efficiency: building the integrated performance management system to promote performance-or tented environment; and running the 1ifelong learning system for better competitiveness of government officials. Further to the innovation efforts at work, the number of steps of the R&D budget execution is streamlined from eight to five and its payment period is considerably reduced to 15 days from 60 days. In addition, the digitalized R&D budget management systems such as e-Contract System, One-click Processing Monitoring System, and Information Service System through Short Message Service (SMS) will contribute to improving R&D performance. And these systems are efficiently integrated into a portal interface named "Yeon-gu-ma-ru." The Ministry of Science and Technology, spearheading nationwide innovation, will continue efforts to make viable achievements of innovation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.11
• /
• pp.2932-2941
• /
• 1996

Conventional non-regenerative satellite repeaters do not provide anti-jamming capability enough to provide communications between small terminals in jamming environment. In this paper, we analyze the budget and system requirements for Ka-band satellite communication. For the analysis, we modeled and simulated the Ka-band satellite system based on downlink power limited repeater. Assuming that a spread spectrum is applied for anti-jamming purpose, we also analyzed a tolerable jammer-to-signal power ratio under strong up-link jamming in the bit rates of 2.4Kbps and 19.6Kbps.

• Korean Security Journal
• /
• no.1
• /
• pp.135-173
• /
• 1997

We study on the power of local autonomous fire fighting in Korea. Chapter I which sets out purpose, scope and method, is followed by Chapter Ⅱ , dealing largely with the organization, man-power, equipment, activites of local fire fighting administration and the fire fighting environment. Chapter III made a comparative study on the power of autonomous fire fighting, local budget , fire fighting activities, fire present conditions. It is followed by concluding abservation made in Chapter Ⅳ and Chapter V. We indicated a few disputed points on the power of local autonomous fire fighting and suggested several alternatives to improve our fire fighting administration system. The alternatives suggested are as followes : (1) Reinforcement of the man-power, (2) Regulation of the standard fire fighting power, (3) Improvement of the using on fire fighting facilities tax and state finance, (4) Aplication of the local borrowings, (5) Tax reduction and exemption on the fire fighting equip-ment investment, and so forth.

• 한국정보통신설비학회:학술대회논문집
• /
• 2008.08a
• /
• pp.55-58
• /
• 2008

This article describes power supply infrastructure construction methods which are considered from U-City infrastructure. For the eisting city and town, it is one the issue to find an economic method to construct outside infrastructure including ubiquitous service device. Because the economic construction method could minimize the construction budget which cost big portion of U-City. And the power supply infrastructure is the fundamental layer to keep network and service layer stable. This paper suggests several ways to construct methods with keeping pre-constructed underground power cable by attaching inepensive power nodal controller working in zigbee network and introduces how to monitor and mana ge the status of power supply to network and service device.