목표비행체 연속 추적을 위한 자세틀 유지비행에 관한 연구

박영웅(Young-Woong Park),방효충(Hyo-Choong Bang) 한국항공우주학회 2009 韓國航空宇宙學會誌 Vol.37 No.1

본 논문에서는 목표비행체의 궤도운동 특성과 정지궤도에 있는 추적위성의 자세운동 특성을 결합하여 목표비행체를 추적하는 것과 동시에 지상국과 항상 교신할 수 있는 자세틀을 형성할 수 있는 관계식을 유도하였다. 형성되는 자세틀을 유지하기 위해서 추적위성이 고기동 자세변환을 수행할 수 있으므로 고기동에서도 특이점을 갖지 않는 MRP 변수를 사용하였다. 또한, 여러 목표비행체에 대해 연속 추적이 가능하도록 자동으로 자세틀을 변환할 수 있는 관계식을 제시하고 시뮬레이션을 통해 자세틀 유지비행과 연속 추적 성능을 확인하였다. 본 논문에서 제시한 자세틀 유지비행은 고정밀 센서를 이용하지 않아도 지상장비를 통해 목표비행체 궤도만 제공되면 추적위성이 항상 지상과 교신하면서 목표비행체를 추적할 수 있음을 보였다. This paper derives the equation of coordinated attitude formulation taking into account the orbital dynamics of a target vehicle and the attitude of a tracking satellite in geostationary orbit. The coordinated attitude is always to communicate with the ground station during the target tracking. Because the tracking satellite could perform high angle maneuver, MRP parameters having no singular point are used. Also for the sequential tracking of several target vehicles, the equation automatically making a coordinated attitude is suggested. Coordinated attitude flying and sequential tracking are confirmed through simulations. In short, this paper shows that a satellite could track a target vehicle and communicate with ground station simultaneously using the derived equation of coordinated attitude even though without a accuracy sensor.

Chattering Free Distributed Consensus Control for Attitude Tracking of Spacecraft Formation System with Unmeasurable Angular Velocity

Miao Xu,Yi-ming Fang,Jian-Xiong Li,Xiaodong Zhao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.9

In this paper, the attitude tracking control of spacecraft formation is studied when the velocities of spacecrafts are unmeasurable. Firstly, a Finite-Time Extended State Observer (FTESO) is constructed to estimate the unmeasured angular velocity and compensate the external disturbance for each spacecraft. Secondly, a chattering free distributed consensus controller which did not require inversion of Laplacian matrix is proposed based on FTESO and Integral Nonsingular Terminal Sliding Mode (INTSM). It is proved that the proposed consensus controller can realize finite-time attitude tracking control of spacecraft by the Lyapunov stability theory. Finally, a simulation example with one leader and four followers is given. The simulation results show that the proposed consensus controller can eliminate system chattering, and provide fast finite-time convergence performance and high precision Tracking.

고등학생의 성별 계열과 메타인지 및 과학적 태도의 관계

안근재 ( Keun Jae Ahn ),강경희 ( Kyung Hee Kang ) 경북대학교 과학교육연구소 2014 科學敎育硏究誌 Vol.38 No.2

The purpose of this study was to analyze of high school students` metacognition and scientific attitude according to gender and academic track. Also it was to investigate relationship between metacognition and scientific attitude. Data were gathered through questionnaires of 220 high school students. In the result of analysis on metacognition according to gender, the mean of male group was higher than the score of female group. The result of t-test wasn`t showed statistically significant difference of two groups. In analysis on metacognition according to academic track, the score of science track students were higher than its liberal art track. And the difference between two groups was significant. The result of analysis on scientific attitude according to gender showed no difference between male group and female group. But there was significant difference between two groups in analysis on scientific attitude according to academic track. Also there was high correlation between sub-elements of metacognition and scientific attitude. The result of multiple regression analysis revealed the influence of moniter, regulation, criticism and openness. The results of this study can be utilized as basic data to develop teaching-learning strategy for cultivating high school students` metacognition and scientific attitude. Follow-up studies are needed for analyzing the relations of factors on science learning.

시선추적 실험을 통한 미적 지각의 요인 분석

문지원(Moon Chi Won) 한국미술교육학회 2018 美術敎育論叢 Vol.32 No.4

본 연구에서는 미적 지각의 요인을 실증적으로 밝히기 위해 사실적 드로잉과말하기에서 나타나는 예술가와 비예술가의 안구 운동 패턴의 차이를 시선 추적을통해 직접 탐색하였다. 두 집단의 안구 운동 패턴은 탐색 전략과 관심 영역에 대한응시시간의 양적 자료를 중심으로 드로잉 결과인 질적 자료와 함께 통합적으로분석되었다. 결론적으로, 사실적 드로잉에서 나타난 예술가의 미적 지각의 핵심적인요인은 관조적 태도, 관계 지각, 예민한 감수성, 선택적 주의로 요약할 수 있다. 이 중 핵심은 관조적 태도라 할 수 있다. 관조적 태도 없이 미적 지각은 발생하지않으며, 미적 지각과 일상적 지각의 차이는 수집된 정보에 대한 인식의 차이라고할 수 있다. 따라서 미술 교육에서 미적 지각의 교육은 결국 관조적 태도의 교육이그 핵심이며 기초라고 할 수 있으며, 관조적 태도는 다양한 자극을 대상으로 하는미적 표현의 의식적 학습 과정을 통해 발달될 수 있다. In this study, we explored the difference of eye movement pattern between artists and non-artists in realistic drawing and speaking in order to empirically identify the factors of aesthetic perception. The eye movement patterns of the two groups were analyzed integrally with the qualitative data of the drawing, focusing on the quantitative data of the search strategy and the gaze time on the areas of interest. In conclusion, key factors of artist’s aesthetic perception in realistic drawing can be summarized as contemplative attitude, perception of relationship, sensitive sensibility, and selective attention. The core of these is contemplative attitude. Aesthetic perception does not occur without a contemplative attitude, and the difference between aesthetic perception and everyday perception is the difference in perception of collected information. Therefore, education of aesthetic perception in art education can be regarded as the core and foundation of contemplative attitude, and contemplative attitude can be developed through the process of conscious learning of aesthetic expressions that are subject to various stimuli.

Sliding Mode Backstepping Control for Variable Mass Hexa-Rotor UAV

Nam-Sik. Kim,Tae-Yong. Kuc 제어로봇시스템학회 2020 제어로봇시스템학회 국제학술대회 논문집 Vol.2020 No.10

The mass of an Unmanned Aerial Vehicles (UAV) alters while picking up or dropping off a mass. The variable mass will deteriorate the control performance of the UAV. This deteriorated control performance generates unstable motor output and leads to power loss. To solve this problem, a mathematical model considering variable mass in real time is proposed in this paper. Based on the established model, taking position and attitude tracking control problem into consideration, a robust control scheme is then designed via Sliding Mode Control (SMC). Backstepping method is used to track the attitude of UAV underactuated system. The proposed controller adapts to the change of mass to control the UAV and stabilizes the position error and the attitude tracking error along the desired trajectory for the position tracking. Stabilized position, attitude and reduced errors are verified through simulation.

Attitudes Formation by Small but Meaningful Personal Information

Jaejoong Kim,SangWon Lee,Minwook Kwak,Kyueun Lee,Bumseok Jeong 대한신경정신의학회 2017 PSYCHIATRY INVESTIGATION Vol.14 No.3

Objective-People often evaluate others using fragmentary but meaningful personal information in recent days through social media. It is not clear that whether this process is implicit or explicit and what kind of information is more important in such process.We examined the effects of several meaningful fragmentary information onattitude. Methods-Thirty three KAIST students were provided four fragmentary information about four virtual people that are meaningful in evaluating people and frequently seen in real life situations, and were asked to imagine that person during four follow-up sessions. Explicit and Implicit attitudes were measured using Likert scale and Implicit Association Test respectively. Also, eye tracking was done to find out the most important information. Results-Strong explicit attitudes, were formed toward both men and women, and weak but significant implicit attitudes, were generated toward men only. Eyetracking results showed that people spent more time reading morality information. Conclusion-Our results indicate that explicit attitudes are made by propositional learning, which is the main component for evaluating others with several meaningful fragmentary information, and implicit attitudes are formed by top down process. And as well as those of previous studies, morality information was suggested as the most important factor in developing attitudes.

Development of Hovering AUV Test-bed for Underwater Explorations and Operations

Byun, Seung-Woo,Choi, Hyeung-Sik,Kim, Joon-Young Korean Society of Ocean Engineers 2013 International journal of ocean system engineering Vol.3 No.4

This paper describes the design and control of a hovering AUV test-bed and analyzes the dynamic performance of the vehicle using simulation programs. The main purpose of this vehicle is to carry out fundamental tests of its station keeping, attitude control, and desired position tracking. Its configuration is similar to the general appearance of an ROV for underwater operations, and its dimensions are $0.75m{\times}0.5m{\times}0.5m$. It has four 450-W thrusters for longitudinal/lateral/vertical propulsion and is equipped with a pressure sensor for measuring the water depth and a magnetic compass for measuring its heading angle. The navigation of the vehicle is controlled by an onboard Pentium III-class computer, which runs with the help of the Windows XP operating system. This provides an appropriate environment for developing the various algorithms needed for developing and advancing a hovering AUV.

GAFC 비선형 제어기법을 적용한 쿼드로터의 자세 및 고도제어

김영욱(Young-Ouk Kim),박성용(Seong-Yong Park),이현재(Henzeh Leeghim) 제어로봇시스템학회 2016 제어·로봇·시스템학회 논문지 Vol.22 No.10

A nonlinear control law for the quad-rotor of a low-complexity, global approximation-free from system uncertainties and external disturbances are described in this paper. The control law guarantees convergence to a small bounded error using a prescribed performance function. The stability of the proposed nonlinear control system is also proven by the Lyapunov stability theorem. The advantage of this technique is that it has a simpler form than any other nonlinear compensators and is applicable to any nonlinear systems without precise knowledge of the systems. In this paper, the proposed approach is applied to attitude/altitude control of a quad-rotor. Numerical simulations are performed to investigate the proposed nonlinear attitude control law by applying it to an uncertain quadcopter system with external disturbances.

Development of a Hovering AUV for Underwater Explorations

Byun, Seung-Woo,Kim, Joon-Young The Society of Naval Architects of Korea 2007 Journal of ship and ocean technology Vol.11 No.2

This paper describes the design and development of a hovering AUV constructed at Cheju National University and analyses the dynamic performance of the vehicle using simulation programs. The main purpose of this AUV is to carry out fundamental tests in its station keeping, attitude control, and desired position tracking. Its configuration is similar to the general ROV appearance for underwater works and its dimensions are 0.75m*0.5m*0.5m. It has 4 thrusters of 450 watts for longitudinal/lateral/vertical propulsion and is equipped with a pressure sensor for measuring water depth and a magnetic compass for measuring heading angle. The navigation of the vehicle is controlled by an on-board Pentium III-class computer, which runs with the help of the Windows XP operating system. These give us an appropriate environment for developing various algorithms needed for developing and advancing Hovering AUV.

남자고등학생의 학교 계열이 양성평등 의식과 성 태도에 미치는 영향

김진주(Jin-ju Kim),박재원(Jae-won Park),신형진(Hyoung-jin Shin) 경북대학교 사회과학연구원 2014 사회과학 담론과 정책 Vol.7 No.1

본 연구는 남학생의 양성평등의식이 여학생보다 현저히 낮다는 기존의 많은 연구에 기초해서 성별을 통제하여 대구광역시에 거주하는 남자 고등학생을 대상으로 양성평등 의식에 영향을 미치는 요인들을 파악하고자 실시한 설문조사 결과를 분석하였다. 계열화 교육 이 상이한 학생문화를 형성하고 그 결과로 양성평등 의식을 포함하는 광범위한 가치관의 차이를 불러올 수 있다는 기존 연구에 기초하여 중심 설명변수로는 학교 계열을, 통제변수로는 학교 성적, 가족 배경, 대학 진학 목표, 종교, 이성 교제, 성 태도 등을 포함시켜 양성 평등 의식을 종속변수로 한 다중회귀분석을 실시하였다. 분석 결과, 학교 계열, 학교 성적, 대학 진학 목표, 이성 교제 경험, 성 태도가 통계적으로 유의미한 영향력을 미치는 것으로 나타났다. 특히, 학교 계열은 양성평등 의식을 설명하는 가장 중요한 변수로 밝혀졌는데, 실업계 남고 학생들보다 인문계 남고 학생들의 양성평등 의식이 현저히 높은 것으로 나타나 계열별 교육과정이 상이한 사회화 과정을 통해 양성평등 의식에 영향을 미친다는 가설이 지지되었다. 또한 양성평등 의식을 설명하는 예측 변인이었던 성 태도가 인과관계의 방 향을 바꾸어 종속변수가 될 수 있음에 착안하여 동일한 예측 변인으로 성 태도를 종속변수로 한 분석도 실시하였는데, 여기에서도 학교 계열이 성 태도를 설명하는 가장 영향력 있 는 변수라는 것이 주목되었다. 이 연구는 남자고등학생의 양성평등 의식 향상과 올바른 성 태도 함양을 위한 정책을 위해서는 계열별 교과과정의 양성성 지향 정도, 계열별 상이한 학교문화 등을 포함하여 구체적으로 어떤 상이한 교육 환경이 학생들의 양성평등 의식과 성 태도의 차이를 일으키는지에 대한 후속 연구가 필요하다는 점을 시사하고 있다. This study analyzed survey data collected from three different high schools in Daegu, South Korea to examine the predictors of gender equality consciousness and sexual attitudes among male students. Based on the hypothesis that the tracking system in Korean high schools creates different subcultures that lead to different levels of gender equality consciousness and sexual attitudes, we adopted multivariate regression models which included the variables of self-reported academic achievement, family background, plans after high school, and having a girlfriend. Statistical results indicated that different tracking systems were the strongest predictors of gender equality consciousness and sexual attitudes among male high school students when controlling for other factors. Future studies must identify specific characteristics of the tracking system that creates different student subcultures and leads to variations in gender equality consciousness and sexual attitudes among students of different tracks.