• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.75-83
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• 2014

Most warship combat systems inquire human operator to control several sensor and another equipments as well as decision-modeling. For this reason, many researches with multi-agent based M&S (Modeling and Simulation) have been increasingly conducted. However there cannot find any researches of M&S based analysis for anti-submarine warfare that requires a high level of mission complexity between multiple platforms. In this research, we have been developed various combat platform models such as warship, submarine and helicopter, etc. In order to apply the multi-agent-based M&S technology to the anti-submarine warfare i.e. a HVU (High Value Unit) escort mission scenario. Then we have successfully analyzed the measures of effectiveness according to the different tactics and different situations. In future, the defence engineer maybe employ our methodology and tools to analyze actual tactical problem by simply inserting actual data into our agent model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.4
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• pp.363-372
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• 2016

SIGMA(Scientific cubesat with Instruments for Global Magnetic field and rAdiation) CubeSat has been developed for magnetic field measurement of the Earth and space radiation measurement at Kyung Hee university. The flight software plays important roles in controlling the satellite and processing the data in the space mission. In this paper, the Flight Software has been implemented to process all the tasks in the one thread without RTOS(Real Time Operating System). This is an effective mothed not only to concentrate the space mission of CubeSat but also to reduce the overhead of the Flight Software by considering the mission perform procedures and the system control methods.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.54.1-54.1
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• 2014

Kyung Hee University has been developing a CubeSat for the space science mission called SIGMA (Scientific cubesat with Instrument for Global Magnetic field and rAdiation), which includes TEPC (Tissue Equivalent Proportional Counter) and a magnetometer. SIGMA has a 3-unit CubeSat, and the weight is about 3.2 kg. The main payload is TEPC which can measure the Linear Energy Transfer (LET) spectrum and calculate the equivalent dose for the complicated radiation field in the space. The magnetometer is a secondary payload using a miniaturized fluxgate magnetometer. We expect it to have a 1 nT resolution in the dynamic range of ${\pm}65535$ nT. An Attitude Control System (ACS) spins the SIGMA spacecraft 4 rpm with the spin axis perpendicular to the ecliptic plane. Full duplex communication is consists of VHF uplink and S-band and UHF downlink. In this paper, we introduce the system design and the scientific purpose of the SIGMA CubeSat mission.

• Journal of Astronomy and Space Sciences
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• v.33 no.4
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• pp.323-333
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• 2016

In this study, the uncertainty requirements for orbit, attitude, and burn performance were estimated and analyzed for the execution of the $1^{st}$ lunar orbit insertion (LOI) maneuver of the Korea Pathfinder Lunar Orbiter (KPLO) mission. During the early design phase of the system, associate analysis is an essential design factor as the $1^{st}$ LOI maneuver is the largest burn that utilizes the onboard propulsion system; the success of the lunar capture is directly affected by the performance achieved. For the analysis, the spacecraft is assumed to have already approached the periselene with a hyperbolic arrival trajectory around the moon. In addition, diverse arrival conditions and mission constraints were considered, such as varying periselene approach velocity, altitude, and orbital period of the capture orbit after execution of the $1^{st}$ LOI maneuver. The current analysis assumed an impulsive LOI maneuver, and two-body equations of motion were adapted to simplify the problem for a preliminary analysis. Monte Carlo simulations were performed for the statistical analysis to analyze diverse uncertainties that might arise at the moment when the maneuver is executed. As a result, three major requirements were analyzed and estimated for the early design phase. First, the minimum requirements were estimated for the burn performance to be captured around the moon. Second, the requirements for orbit, attitude, and maneuver burn performances were simultaneously estimated and analyzed to maintain the $1^{st}$ elliptical orbit achieved around the moon within the specified orbital period. Finally, the dispersion requirements on the B-plane aiming at target points to meet the target insertion goal were analyzed and can be utilized as reference target guidelines for a mid-course correction (MCC) maneuver during the transfer. More detailed system requirements for the KPLO mission, particularly for the spacecraft bus itself and for the flight dynamics subsystem at the ground control center, are expected to be prepared and established based on the current results, including a contingency trajectory design plan.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.116-122
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• 2020

Human and material resource planning is one representative example of Operations Research. Resource planning is important not only in civilian settings but also in military ones. In the Air Force, flight scheduling is one of the primary issues that must be addressed by the personnel who are connected to flight missions. However, although the topic is of great importance, relatively few studies have attempted to resolve the problem on a scientific basis. Each flight squadron has its own scheduling officers who manually draw up the flight schedules each day. While mistakes may not occur while drafting schedules, officers may experience difficulties in systematically adjusting to them. To increase efficiency in this context, this study proposes a mathematical model based on a binary variable. This model automatically drafts flight schedules considering pilot's mission efficiency. Furthermore, it also recommends that schedules be drawn up monthly and updated weekly, rather than being drafted from scratch each day. This will enable easier control when taking the various relevant factors into account. The model incorporates several parameters, such as matching of the main pilots and co-pilots, turn around time, availability of pilots and aircraft, monthly requirements of each flight mission, and maximum/minimum number of sorties that would be flown per week. The optimal solution to this model demonstrated an average improvement of nearly 47% compared with other feasible solutions.

• Advances in aircraft and spacecraft science
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• v.5 no.4
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• pp.459-475
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• 2018

In the field of aerospace engineering, accurate control of a spacecraft's orientation is often very important to mission success. Therefore, attitude control is a technically plentiful and extensively studied subject in controls literature during recent decades. This investigation of spacecraft attitude control is assumed to address two important aspects of the problem solutions. One sliding mode anti-disturbance control for utilization of faulty actuator components and another one disturbance observer based control to improve the pointing accuracy in the absence of anti-vibration equipment for the elastic appendages like a solar panel. Simultaneous occurrence of vibration due to flexible appendages and reaction degradation due to failure in attitude actuators complicates this case. The advantage of this method is acquisition proper control by the combination of disturbance observer and sliding mode compensation that form a fault tolerant control for the concerned satellite attitude control system. Furthermore, the proposed composite method indicates that occurrence the failure in actuators and even elastic solar panel vibration effect may be handled directly without reconfiguring the control components or providing piezoelectric devices. It's noteworthy, attitude quaternion and angular velocity commands are robustly tracked via controllers to become inclined to zero.

• International Journal of Computer Science & Network Security
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• v.24 no.3
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• pp.151-159
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• 2024

Twin clutch model enables the power-shifts as conventional planetary automatic transmission and eradicates the disadvantages of single clutch trans- mission. The automatic control of the dual clutches is a problem. Particularly to control the clutching component that engages when running in one direction of revolution and disengages when running the other direction, which exchange the torque smoothly during torque phase of the gearshifts on planetary-type automatic transmissions, seemed for quite a while hard to compensate through clutch control. Another problem is to skip gears during multiple gearshifts. However, the twin clutch gear control described in ["M Goetz, M C Levesley and D A Crolla. Dynamics and control of gearshifts on twin clutch transmissions, Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 2005"], a significant improvement in twin clutch gear control system is discussed. In this research our objective is to formally specify the twin clutch gear control system and verify it with the help of formal methods. Formal methods have a high potential to give correctness estimating techniques. We use UPPAAL for formal specification and verification. Our results show that the twin clutch gear control model partially fulfills its functional requirements.

• 시스템엔지니어링워크숍
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• s.4
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• pp.17-22
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• 2004

This paper present the brief generation process of system requirements or mart UAV from a development obejective. The current Snart UAV requirements deal with the restricted life cycle from development to test and verification exclusive of full life cycle beacuse of the new technology demonstration research program funded by goverments. The Smart UAV system consists of flight vechicle, avionics, communication link, payload, ground control stationand ground supporting system. In thus paper, top-down flown requirememts are intoduced how to allocate to each sub-system.

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.29-32
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• 2002

This paper suggest target detection algorithm for mobile robot control using color and shape recognition. In many cases, ultrasonic sensor(USS) is used in mobile robot system to measure the distance between obstacles. But with only USS, it may have many restrictions. So we attached CCD camera to mobile robot to overcome its restrictions. If visual information is given to robot system then robot system will be able to accomplish more complex mission successfully. With acquired vision data, robot looks for target by color and recognize its shape.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.389-392
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• 2008

The thrust axis alignment of the launch vehicle is very important because of the misalignment causes the unstable attitude control and results in mission failure. Generally, optical methods such as digital theodolite and laser tracker and mechanical method such as turn table method are used to thrust axis alignment. This article deals with the simple method of thrust axis alignment of Kick Motor.