• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.9
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• pp.884-890
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• 2008

A new guidance law to reach circular target area with grazing angle constraint is proposed as one of midcourse guidance laws of unmanned air vehicles. The purpose of the law is to control the grazing angle between the velocity vector of the vehicle and the line of sight to the aiming point, the center of the circular target area, when the vehicle passes any point on the circle. The optimal solution is derived based on the optimal control theory minimizing a range weighted control energy subject to the nonlinear dynamic equations of the vehicle approaching to the circular target area with grazing angle constraint. The major properties including a convergence of the solution are examined and the performance of the law applied to some typical scenarios is shown by the numerical simulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.11
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• pp.979-987
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• 2012

This paper implements and integrates algorithms for terrain following of UCAVs (Unmanned Combat Aerial Vehicles): trajectory generation, guidance, and navigation. Terrain following is very important for UCAVs because they perform very dangerous missions such as Suppression of Enemy Air Defences while the terrain following can improve the survivability of UCAVs against from the air defence systems of the enemy. To deal with the GPS jamming, terrain referenced navigation based on nonlinear filter is chosen. For the trajectory generation, Voronoi diagram is adopted to generate horizontal plane path to avoid the air defense system. Cubic spline method is used to generate vertical plane path to prevent collisions with ground while flying sufficiently close to surface. Follow-the-Carrot and pure pursuit tracking methods, which are look-ahead point based guidance algorithms, are applied for the guidance. Numerical simulation is performed to verify the performance of the integrated terrain following algorithm.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.2
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• pp.139-144
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• 2004

The flight control system designed for an unmanned airship, which is under development by KARI, is in reduced. First, the dynamic characteristics of the airship are addressed, which are fairly different from those of the nominal aircraft. In order to implement autonomous flight for the unmanned airship, flight control logic is designed including autopilot and guidance law. The autopilot is designed under consideration of the velocity region of the unmanned airship. The guidance laws are implemented in main operational modes such as point navigation, station keeping and spiral up/down for emergency return. Their simulation results are also presented in order to validate performances of the flight control system.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.5
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• pp.277-286
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• 2017

This paper introduces mathematical modelling and control algorithm of expendable mine disposal vehicle. This vehicle has two longitudinal thrusters, one vertical thruster and internal mass moving system which can control pitch rate. Also, the vehicle has an optical camera and forward looking sonar for underwater mine detection and classification. The vehicle is controlled via an optical cable connected with operating console on the mother ship. We describe the vehicle's 6DOF dynamic model and controller which can track the desired trajectory for the way-point tracking. These simulation results shows guidance and maneuvering performance which has other sensor data or not.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.5
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• pp.498-509
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• 2010

In this paper, a waypoint guidance law Line Tracking algorithm is designed for testing an Unmanned Airship. In order to verify, we develop an autonomous flight control and test system of unmanned airship. The flight test system is composed FCC (Flight Control Computer), GCS (Ground Control System), Autopilot & Guidance program, GUI (Graphic User Interface) based analysis program, and Test Log Sheet for the management of flight test data. It contains flight test results of single-path & multi-path following, one point continuation turn, LOS guidance, and safe mode for emergency.

• The Korean Journal of Pain
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• v.20 no.2
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• pp.111-115
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• 2007

Background: Selective diagnostic blocks of the medial branches of the dorsal primary ramus are usually performed under the guidance of fluoroscopic or computed tomography. Recently, however, ultrasound guidance has been suggested as an altemative method. In this study, the distances between the vertebral structures were measured and compared with the values measured using magnetic resonance imaging (MRI) to assess the clinical feasibility of using ultrasound-guided block in Korean patients. Methods: Five male and 15 female patients were enrolled in this study. The target point of the medial branch block in our study was the groove at the base of the superior articular process, We measured the depth from the skin to the target point at the transverse process (d-TP) and to the most superficial point of the superior articular process (d-AP). Results: The d-TP and d-AP values measured under ultrasound guidance were concordant with the values measured using MRI. Conclusions: The images of the bony landmarks obtained under ultrasound examination could be useful for ultrasound-guided lumbar medial branch block.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7897-7903
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• 2015

Background: To explored the value of 3D C-arm CT (CACT) guidance system in performing radiofrequency ablation (RFA) following transarterial chemoembolizationon (TACE) for hepatocellular carcinomas. Materials and Methods: RFA of hepatocellular carcinomas (HCC) were performed on 15 patients (21 lesions) with the assistance of CACT guidance system. Technical success, procedure time, complications and patient radiation exposure were investigated. The puncture performance level was evaluated on a five-point scale (5-1: excellent-poor). Complete ablation rate was evaluated after two months follow-up using enhanced CT scans. Results: The technical success rate of RFA procedure under CACT navigation system was 100 %. Mean total procedure time was $24.24{\pm}6.53min$, resulting in a mean effective exposure dose of $15.4{\pm}5.1mSv$. The mean puncture performance level rated for CACT guided RFA procedure was $4.87{\pm}0.35$. Complete ablation (CA) was achieved in 20 (95.2%) of the treated 21 tumors after the first RFA session. None of patients developed intra-procedural complications. Conclusions: 3D CACT guidance system enables reliable and efficient needle positioning by providing real-time intraoperative guidance for performing RFA on HCCs.

• International Journal of Aeronautical and Space Sciences
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• v.6 no.2
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• pp.64-75
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• 2005

The Stratospheric Airship Platform (SAP) has a capability of performing the autonomous and guidance flight to satisfy given missions. To be used as the High Altitude Platforms (HAPs), the capabilities of controlling platform's accurate position and keeping the station point are the most important features. Under this circumstances Autonomous Flight Control System (AFCS) is a critical system and plays a key role in achieving the given requirements and succeeding in missions. In this paper, the design and analysis results of the AFCS algorithms and controller are presented. The brief summary of the AFCS hardware structure is also explained. The autopilot controller and guidance logics were designed based on the linear dynamics of the unmanned airship platform and the full nonlinear dynamics was considered to evaluate and verify their performances.

• Journal of Wellbeing Management and Applied Psychology
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• v.4 no.2
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• pp.26-34
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• 2021

Purpose: The ultimate purpose of this study is to analyze this survey to understand the overall contents of college career guidance and psychological counseling, and to utilize it to improve the quality of learning and provide career guidance. Research design, data and methodology: The research period and survey subject are approximately one month from 2020.12.01(Tue) to 2021.01.03(Sun). Convenience sampling was conducted using a structured questionnaire composed of a 5-point Likert scale and 5 open-ended questions. As the analysis method, descriptive statistics such as reliability analysis and frequency analysis of Cronbach's α coefficient of internal consistency were mainly used. Data Analysis Statistical program was analyzed using SPSS 25 version. Results: The item with the highest score is that the counseling and counseling-related non-specialized programs offered by the Student Counseling Center are helpful for school life (3.56 points). Conversely, the lowest question is that seminars accompanied by priests are helpful for study (3.38 points). Conclusions: The average score of 5 questions in the career guidance and psychological counseling areas is 3.38 out of 5.

• Journal of the FoodService Safety
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• v.2 no.1
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• pp.36-43
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• 2021

The development of food poisoning prevention guidelines aims to prevent food poisoning in advance and improve the safety of children's meals through hygiene management of children's feeding facilities, especially infants' facilities. Therefore, the composition of the content should be designed so that it can be fully understood from the point of view of the layperson. In terms of meal service management, various standards must be fully reflected and reviewed to increase utilization in the field. Daycare centers and kindergartens have different administrative agencies, similar application laws and guidelines, but different parts exist and various types of facilities, so management standards are often ambiguous. Therefore, such management requires easy guidance, not special guidance, and it should be universally applicable to any facility. Prior studies have shown that the management of meal facilities is the most efficient, but it is difficult to hire and deploy specialists due to the operation of children's meal facilities, so guidance, facilities managers and workers need to voluntarily practice them. It is time to prepare hygiene guidelines that reflect the characteristics of these children's cafeterias, and it is necessary to prepare and utilize guidance suitable for reality until it is institutionalized for the deployment of manpower exclusively for meals.