• Aerospace Engineering and Technology
• /
• v.2 no.1
• /
• pp.140-152
• /
• 2003

Scenario is a guiding principle of launch operation and control for rocket and ground support system. Therefore, developing a scenario is the first step to prepare for rocket launch, which is a critical task for success of KSR-III flight test. The launch scenario for KSR-III flight test is a procedural sequence of command and control signals to be given to rocket and ground support systems. In this paper, the UML object modeling method is applied to development of a launch scenario. First, the subsystems of the launch system are modeled by objects, and then the interfaces between each two subsystems are modeled by association links. The finally obtained object diagram of KSR-III launch system is used to analyzing flow of data and commands and control signals, and interactions. The scenario includes the sequences of pre-launch/launch operations and emergency operations.

• Journal of Korean Society on Water Environment
• /
• v.35 no.6
• /
• pp.470-480
• /
• 2019

The Doam lake watershed was designated as a non-point pollution management area in 2007 to improve water quality based on watershed management implementation. There have been studies of non-point source reduction with respect to the watershed management impacting the pollutant transport of the reservoir. However, a little attention has been focused on the impact of water quality improvement by the management of the dam operation or the guidelines on the dam operation. In this study, the impact of in-lake management practices combined with watershed management is analyzed, and the appropriate guidelines on the operation of the dam are suggested. The integrated modeling system by coupling with the watershed model (HSPF) and reservoir water quality model (CE-QUAL-W2) was applied for analyzing the impact of water quality management practices. A scenario implemented with sedimentation basin and suspended matter barrier showed decrease in SS concentration up to 4.6%. The SS concentration increased in the scenarios adjusting withdrawal location from EL.673 m to the upper direction(EL.683 m and EL.688 m). The water quality was comparably high when the scenario implemented all in-lake practices with water intake at EL.673 m. However, there was improvement in water quality when the height of the water intake was moved to EL.688 m during the summer by preventing sediments inflow after the rainfall. Therefore, to manage water quality of the Doam lake, it is essential to control the water quality by modulating the height of water intake through consistent turbidity monitoring during rainfall.

• Journal of the Society of Naval Architects of Korea
• /
• v.59 no.5
• /
• pp.252-261
• /
• 2022

The present study concerns assessing the operability of a surface combatant, based on the Percent-Time-Operable (PTO). For validation of the seakeeping analysis in the regular waves, the model test is first conducted in a towing tank. The seakeeping analysis results in the regular waves are expanded to the irregular waves, considering the wave spectra around the Korean peninsula and in North Pacific. The seakeeping criteria of the surface combatant in transit, combat, replenishment operation, and survival condition are defined by the literature review. An annual operation scenario of the surface combatant in two operation areas, i.e., advance speed and wave direction, are combined with the seakeeping analysis results to assess PTO. The main constraints of operability of the surface combatant are identified as the pitch angle and vertical velocity at the helicopter deck.

• Journal of the Korean Institute of Gas
• /
• v.21 no.1
• /
• pp.34-42
• /
• 2017

We developed the safety training methods which improve the current methods by overcoming the single scenario-based one-way communication between trainee and training system. We improved the design and implementation of the safety training scenarios, which is one of the most important components of the plant safety training system for safe operation of the city gas governor. The diversity and training effects of the training scenarios can be improved by interactive training between the plant safety training system and operators. The interactive training methods were developed based on Finite State Machine model which is applicable to and based on plant safety training platform. We could see the possibility of applying this method of safety training scenario system to other domain of plant safety training system.

• Journal of Aerospace System Engineering
• /
• v.16 no.5
• /
• pp.49-56
• /
• 2022

S-STEP is a small SAR satellite mission that monitors time-limited emergency targets and military anomalies in areas of interest, achieving the average revisit in less than 30 minutes by deploying a constellation of 32 satellites in low orbit at an altitude of 510 km. The mission operation mode of S-STEP is divided into normal mode, observation mode, communication mode, and orbit maintenance mode. Further,, the attitude control mode is subdivides into initial detumbling, sun pointing, target pointing, ground station pointing, and thrust direction maintenance. Based on the preliminary mission operational scenario and the satellite's characteristics, this study analyzed the attitude control performance during initial detumbling and observation modes. It verifies that each mode's attitude control accuracy requirements within the time allotted by the scenario of the S-STEP achieved.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2002.02a
• /
• pp.56-59
• /
• 2002

Since the KSTAR magnet structure should be maintained at cryogenic temperature of about 4.5 K, even a small amount of heat might be a major cause of the temperature rising of the superconducting magnet structure. The Joule heating by eddy current induced on the magnet structure during the KSTAR operation was found to be a critical parameter for designing the cooling scheme of the magnet structure as well as defining the requirements of the refrigerator for the cryogenic system. Based on the Joule heating calculation, it was revealed that the bulk temperature rising of the magnet coil structure was less than 1 K. The local maximum temperature especially at the inboard leg of the TF coil structure increase as high as about 21 K for the plasma vertical disruption scenario. For the CS coil structure maximum temperature of 8.4 K was obtained from PF fast discharging scenario.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.8
• /
• pp.729-734
• /
• 2016

The current domestic railway wireless communication networks transmit and receive data using several communication schemes such as VHF, TRS-ASTRO, and TRS-TETRA depending on the specific region. Recently, LTE scheme has been adopting in railway wireless communication systems to provide various services and increase reliability. It is critical to support the network interoperability between the existing communication schemes and new communication scheme for seamless data transmission. In this paper, we propose two interoperability schemes in railway communications networks, i.e., network oriented scheme and terminal oriented scheme. We consider the operation scenario for each scheme and compare two interoperability schemes. The practical implementation issues are also discussed based on suggested schemes.

• Journal of Korean Society of Water and Wastewater
• /
• v.31 no.5
• /
• pp.409-414
• /
• 2017

In this study, we divided the process operation scenarios into three categories based on raw water temperature and turbidity. We will select and operate the process operation scenario according to the characteristics of the raw water. The number of algae in the DAF treated water has been analyzed to be less than 100 cells/mL. These results indicated that the DAF process is effective in removing the algae. In addition, the scenario of the integrated management decision algorithm of the DAF process was developed. DAF pilot plants ($500m^3/day$) process has shown a constantly sound performance for the treatment of raw water, yielding a significantly low level of turbidity (DAF treated water, 0.21~1.56 NTU).

• Journal of the military operations research society of Korea
• /
• v.28 no.1
• /
• pp.29-46
• /
• 2002

This study focuses primarily on the construction of the wartime sealift operation model from US to Korea. There are some uncertainties in the process of sealift operation such as the procurement rate of materiel in US, the distribution of KFS on four initial position locations at the start of the activation, and the number of ports and berths in the SPOES and SPODS. The sealift capability, based on the allocation of sealift assets such as the number of vessels, berths, and ports, is evaluated through simulation. The simulation is executed with a baseline wartime scenario and then the results are analyzed through a sensitivity analysis. The military planner may use of this model as a standard for establishing effective and concrete sealift operation plan in the near future.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.22 no.5
• /
• pp.27-43
• /
• 2019

This study applied the LANDIS-II model to the forest vegetation of the study area in Yeongdong-gun, Korea to identify climate effects on ecosystems of forest vegetation. The main purpose of the study is to examine the long-term changes in forest aboveground biomass(AGB) under three different climate change scenarios; The baseline climate scenario is to maintain the current climate condition; the RCP 4.5 scenario is a stabilization scenario to employ of technologies and strategies for reducing greenhouse gas emissions; the RCP 8.5 scenario is increasing greenhouse gas emissions over time representative with 936ppm of $CO_2$ concentration by 2100. The vegetation survey and tree-ring analysis were conducted to work out the initial vegetation maps and data for operation of the LANDIS model. Six types of forest vegetation communities were found including Quercus mongolica - Pinus densiflora community, Quercus mongolica community, Pinus densiflora community, Quercus variabilis-Quercus acutissima community, Larix leptolepis afforestation and Pinus koraiensis afforestation. As for changes in total AGB under three climate change scenarios, it was found that RCP 4.5 scenario featured the highest rate of increase in AGB whereas RCP 8.5 scenario yielded the lowest rate of increase. These results suggest that moderately elevated temperatures and $CO_2$ concentrations helped the biomass flourish as photosynthesis and water use efficiency increased, but huge increase in temperature ($above+4.0^{\circ}C$) has resulted in the increased respiration with increasing temperature. Consequently, Species productivity(Biomass) of trees decrease as the temperature is elevated drastically. It has been confirmed that the dominant species in all scenarios was Quercus mongolica. Like the trends shown in the changes of total AGB, it revealed the biggest increase in the AGB of Quercus mongolica under the RCP 4.5 scenario. AGB of Quercus mongolica and Quercus variabilis decreased in the RCP 4.5 and RCP 8.5 scenarios after 2050 but have much higher growth rates of the AGB starting from 2050 under the baseline scenario. Under all scenarios, the AGB of coniferous species was eventually perished in 2100. In particular they were extinguished in early stages of the RCP 4.5 and RCP 8.5 scenarios. This is because of natural selection of communities by successions and the failure to adapt to climate change. The results of the study could be expected to be effectively utilized to predict changes of the forest ecosystems due to climate change and to be used as basic data for establishing strategies for adaptation climate changes and the management plans for forest vegetation restoration in ecological restoration fields.