• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.7
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• pp.81-89
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• 2002

Guidance laws can be conceptually classified into three categories although their mathematical representations are various and different. In this paper, a generalized conceptual guidance law including the concepts of the above categories is proposed. The aim angle is introduced using the geometry of the collision triangle. The aim angle represents the arbitrary angle between the pursuit angle and the expected collision angle. The objective of the proposed guidance law is to make the aim angle zero asymptotically. It can be shown that the aim angle error response for the considered system is same as that of the first order system. When the autopilot of the missile system has slow dynamics, autopilot time lag may deteriorate the performance of the guidance law performance. In this case, another new guidance law compensating the autopilot time lag effect is proposed. To verify the proposed guidance laws, several numerical simulations are performed.

• 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.

• Fire Science and Engineering
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• v.33 no.5
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• pp.78-85
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• 2019

In complex buildings, Way-finding is the most important factor for safe evacuation. Recently, evacuation guidance systems using smartphones have been developed. However, smartphone evacuation guidance maps used in these studies appear different from those used in previous studies due to the lack of established standards. Therefore, in this study, we conducted a preference survey of evacuation guidance maps as a basic research for establishing evacuation guidance maps using smartphones. The components of smartphone evacuation guidance maps were selected using regulations and analyses conducted in previous studies, and preference surveys were conducted using the size of each component. Through this research, we suggested a method to create a high preference for each component of an evacuation guidance map.

• 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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.10
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• pp.709-716
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• 2022

In this paper the Gamma guidance law, which was used for IUS (Inertial Upper Stage), is applied for solid-motor guidance of a upper stage of a satellite launch vehicle. The RCS (Reaction Control System), which activates after burnout of the upper stage, is employed for the convergence of the guidance algorithm and compensation of velocity errors induced by the solid motor. The algorithm is also simplified by replacing the time-consuming numerical integration process to predict final vehicle states with Keplerian trajectories. The performance of the algorithm is evaluated by conducting 3-DOF computer simulations for off-nominal flight conditions. The numerical results show that Gamma guidance can reduce the orbit injection accuracy in comparison with that obtained by applying open-loop commands.

• 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.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.12
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• pp.1217-1224
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• 2014

This paper presents a modified track guidance algorithm for formation flight of multiple UAVs. The suggested guidance algorithm is the spatial version of the first order dynamic characteristics for a time-dependent system so the algorithm is able to generate a path without overshoot to track the desired line. A crucial design parameter is a spatial constant that controls the shape of the convergence to an assigned flight path similarly to a time constant. Reference flight trajectories are designed based on a two-dimensional vehicle model, and the performance of the proposed guidance law is verified by numerical simulation using rigid body UAV dynamics with MATLAB/Simulink Aerosim Blockset.

• Journal of the Korean Data and Information Science Society
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• v.14 no.2
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• pp.223-235
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• 2003

Using internet, most of students are still exposed to unreasonable commercial information and even tend to consumptive behaviors. Various programs have been mobilized to keep it with a blockade system against the noxious information. But guidance is more instructive than blockade in respect of education. Thus, the focus of this study is to induce and motivate their self-directed learning activities with internet guide contents. We develope a learning guidance material as one of the information platforms. Furthermore, we consider the availability of such learning guidance materials through interview and observation. We find that easy and meaningful internet access and utilizing environment influence the children's self-directed learning ability.