• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.6
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• pp.505-516
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• 2011

The concept of the IGC(Integrated Guidance and Control) has been introduced to overcome the performance limit of the SGC(Separated Guidance and Control) loop. A new type of IGC with impact angle constraint has been proposed in this paper. Angle of attack, pitch angle rate, pitch angle and line of sight angle are considered as state variables. A controllability analysis and equilibrium point analysis have been carried out to investigate the control characteristic of the prposed IGC. The LQR(Linear Quadratic Regulator) has been adopted for the control law and detailed explanations about the adoption has been provided. The performance comparison between the IGC and the SGC has been carried out. The result of numerical simulations shows that the IGC guarantees better guidance performance than the SGC when the agile maneuver is needed for a specific guidance geometry.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.8
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• pp.637-648
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• 2021

This paper aims to propose new reentry guidance for Korean Space plane (KSP). Similar to the Space Shuttle guidance concept, a reference drag profile is first determined to satisfy several flight path constraints and boundary conditions, and the proposed guidance commands are realized in a way to track the predetermined reference drag profile. To this end, the drag dynamics is examined. The investigation uncovers that the dynamics characteristics of the drag and the flight path angle are considerably different. Based on this fact, the proposed guidance commands are determined using the time-scale separation technique and the feedback linearization methodology. The key feature of the proposed guidance lies in its simple structure and a clear working mechanism. Therefore, the proposed method is simple to implement compared to existing methods. Numerical simulations are performed to investigate the performance of the proposed method.

• Korean Journal of Child Education & Care
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• v.19 no.2
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• pp.165-176
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• 2019

Objective: The purpose of this study is to develop a measure of the Early Childhood Teacher's Guidance Efficacy Scale based on guidance and teacher-efficacy theory. Methods: This subjects were 243 teachers in Seoul and Gyeonggi-do. Results: An exploratory factor analysis was conducted on the data collected of 4 factors, namely, guidance efficacy for problem behavior, children understanding, home-connected, basic life habits. In addition, there are significant positive correlations between the sub-area score and the overall in the early childhood teacher's guidance efficacy scale(r = .26 ~ .72, p < .001). Internal consistency and split-half reliability of each sub scale were reasonably accept. Conclusion/Implications: 'The guidance efficacy scale for early childhood teachers' developed in this study is an appropriate tool. Therefore, the developed scale can become a useful tool to measure the overall guidance efficacy level of early childhood teachers.

• Human Ecology Research
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• v.61 no.3
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• pp.415-427
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• 2023

The Family Education Guidance Service is a public service developed by the government to give guidance and service to parents on educating their children in China. Recently, the service has attracted increasing attention from scholars, as well as from the Chinese Government. To assess the current status of research on the Family Education Guidance Service, this paper firstly introduces the policy history and clarifies the definition of the Family Education Guidance Service and other relevant terms used in China. It then presents a review of studies on the Family Education Guidance Service published in journals with high-grade ratings and analyzes the characteristics of current research in terms of year of publication, author affiliations, research themes, research methods, and target groups. Based on these, it makes suggestions for future development. Overall, 43 papers are reviewed, the findings of which reveal that related research is at the beginning of an upswing. Most authors belong to education colleges and law colleges of universities. The themes studied most often are the strategy exploration and legal construction of the Family Education Guidance Service. The parents of primary- and middle-school students are the most commonly studied group, followed by schoolteachers. The results indicate that despite the growing number of publications, research in this field is still in its early stages and many aspects require further exploration.

• Journal of Aerospace System Engineering
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• v.18 no.2
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• pp.1-11
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• 2024

This paper applies a relative impact angle control guidance law to a communication-based multi-missile network system with uncertainties and disturbances. The multi-missile network system is represented as a transitive reduction directed acyclic graph. Furthermore, this paper introduces both centralized and decentralized guidance laws based on the graph's structure. The relationship between these guidance laws is analyzed by comparing them based on the communication structure and the presence of system noise. To analyze the effects of decentralized optimal cooperative guidance law, this paper assumes uncertainty in missile dynamics and predicted impact point information for the relative impact angle control mission. Monte Carlo simulations are conducted for various mission environments to analyze the impact of communication and its structure on the system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.308-309
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• 2016

This paper deals with ship's track keeping methods which is crucial part of automatic navigation control systems. In this paper, we mainly discuss the performance of different guidance methods including way point guidance, enclosure-based steering guidance and lookahead-based steering guidance system. As a controller, a PID control system is employed to control ship's rudder angle during track-keeping. Finally, the performance of three methods are discussed through some simulation results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.8
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• pp.662-670
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• 2017

This paper proposes an optimization-based procedure to determine the parameters of the Apollo guidance law for Korean lunar lander mission. A lunar landing mission is formulated as a trajectory optimization problem to minimize the fuel consumption and the reference trajectory for the lander is obtained by solving the problem in the pre-flight phase. Some parameters of the Apollo guidance, which are coefficients of the polynomial used to define the guidance command, are selected based on the reference trajectory obtained in the pre-flight phase. A case study for the landing guidance of Korean lunar lander mission using the proposed procedure is conducted to demonstrate its effectiveness.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.4
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• pp.430-435
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• 2011

In this paper, a navigation technology of an unmanned vehicle using relative localization and magnetic guidance is proposed. Magnetic guidance system had been developed as a robust autonomous driving technology as long as magnetic fields on the path are detected. Otherwise, if magnetic fields were not detected due to some reasons, the vehicle could not drive. Therefore, in order to overcome the drawback, we propose that relative localization would be combined to magnetic guidance system. To validate the usefulness of the proposed method, a robotic vehicle was set up with the magnetic guidance system and the relative localization. In addition, the unmanned driving test was realized on the road without the magnetic fields so that the proposed method is verified by the experiment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.7
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• pp.69-75
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• 2004

An avoidance/guidance problem of an aircraft against moving obstacle is considered in two dimensional space. The aircraft is modelled as a point mass flying with constant speed. The lateral acceleration is assumed the control input. Artificial potential functions are applied to the terminal point and moving obstacles in order that repulsive forces and an attractive force are produced by the obstacles and the terminal point respectively. A real time guidance/avoidance law is proposed by using the potential forces and relative velocity. The guidance law for a logarithm potential function results the well-known proportional navigation law. The avoidance control command is inverse proportional to the time-to-go to the obstacle and turns the aircraft toward the negative direction of the line-of-sight change. The performance of the proposed guidance/avoidance law is verified with simulations.

• Journal of Service Research and Studies
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• v.1 no.1
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• pp.81-90
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• 2011

The unemployed graduates who got a higher education aggravate unstable employment in our society. However, the existing College of education in employment guidance course still get the effect of students' direct employment and the stale, simply an information delivery functionality of college students after graduation could not serve the needs of industries.. Thus, this paper suggests a mentoring service, which will be proceeding for career guidance and college life guidance. The expert and field evaluation were frequently executed so that the systematic and continuous mentoring activities to occur. These mentoring service model for work guidance are expected to improve the employment rate of University as well as to decline the rate of jobless.