• International Journal of Aeronautical and Space Sciences
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• 제9권1호
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• pp.66-75
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• 2008

In this work, we explore the feasibility of roll-pitch-yaw integrated autopilots for high angle-of-attack missiles. An investigation of the aerodynamic characteristics of a surface-to-air missile is presented, which reveals the strong effects of cross coupling between the longitudinal and lateral dynamics. Robust control techniques based on $H_{\infty}$ synthesis are employed to design roll-pitch-yaw integrated autopilots. The performance of the proposed roll-pitch-yaw integrated controller is tested in high-fidelity nonlinear five-degree-of-freedom simulations accounting for kinematic cross-coupling effects between the lateral and longitudinal channels. Against nonlinearity and cross-coupling effects of the missile dynamics, the integrated controller demonstrates superior performance when compared with the controller designed in a decoupled manner.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.519-524
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• 2003

In this report, a longitudinal adaptive flight control law is presented for the automatic landing system of a Japanese automatic landing flight experiment vehicle (ALFLEX). The longitudinal adaptive flight control law is designed to track an output of the vehicle to a guidance signal from the guidance portion of the automatic landing system. The proposed adaptive control law in the attitude control portion adjusts the controller gains continuously online as flight conditions change, in spite of the existence of unmodeled dynamics. The number of the controller gains to be adjusted is decreased to 1/2 from the previous studies. Computer simulation involving six-degree-of-freedom (DOF) nonlinear flight dynamics is performed to examine the effectiveness of the proposed adaptive control law. In order to verify the influence of the dispersion of the initial conditions, the Monte Carlo simulation is also applied. The initial conditions are more widely dispersed than the previous studies. As a result, except under the unsuitable initial conditions, the ALFLEX successfully landed on the runway.

• International Journal of Aeronautical and Space Sciences
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• 제12권1호
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• pp.43-56
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• 2011

An integrated system composed of guidance, navigation and control (GNC) system for autonomous proximity operations and the docking of two spacecraft was developed. The position maneuvers were determined through the integration of the state-dependent Riccati equation formulated from nonlinear relative motion dynamics and relative navigation using rendezvous laser vision (Lidar) and a vision sensor system. In the vision sensor system, a switch between sensors was made along the approach phase in order to provide continuously effective navigation. As an extension of the rendezvous laser vision system, an automated terminal guidance scheme based on the Clohessy-Wiltshire state transition matrix was used to formulate a "V-bar hopping approach" reference trajectory. A proximity operations strategy was then adapted from the approach strategy used with the automated transfer vehicle. The attitude maneuvers, determined from a linear quadratic Gaussian-type control including quaternion based attitude estimation using star trackers or a vision sensor system, provided precise attitude control and robustness under uncertainties in the moments of inertia and external disturbances. These functions were then integrated into an autonomous GNC system that can perform proximity operations and meet all conditions for successful docking. A six-degree of freedom simulation was used to demonstrate the effectiveness of the integrated system.

• 산업경영시스템학회지
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• 제18권36호
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• pp.49-59
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• 1995

The vehicle navigation system is developed for helping driver to retrieve driving information more easily and fastly. Navigation System informs driver many pieces of driving information - roadway structure and system, on-line traffic condition, the position of vehicle, route guidance, destination and other information service. As the style of information is diverse and the amount of information is large, driver may have mental and visual overload. The display of information can disturb the driver's attention and this can cause accidents. This state is caused by the defect of human-machine interactions. When the navigation system is designed, human factors - cognitive, judgment, operating - must be considered. The display style must be designed simply and easily, not to be obstacle of human -machine interface. In this study, outside-in view display style and inside-out view display style are compared each other. Two factors are measured. One is cognitive factor-time of cognition on information that is displayed by screen display, cognition error rate. The other is image of screen display - subject's feeling about several styles of display, degree of subject's preference. The prototype of roadway is four kinds - Cross, T-cross, Y-cross and O-cross. Roadway display for test is taken from paper maps. Traffic condition display style, vehicle position display style and route guidance display style are taken from current display style. Traffic condition display style is symbol. Vehicle position display style and route guidance display style are described as color and symbol. The test on screen display is implemented doing given tasks. Then the test is analyzed statistically, The result of test analysis gives the guideline to the designer for the map display of the vehicle navigation system.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1995년도 추계학술대회논문집
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• pp.208-213
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• 1995

The vehicle navigation system is developed for helping driver to retrieve driving information more easily and lastly. Navigation System informs driver many pieces of driving information - roadway structure and system, on-line traffic condition, the position of vehicle, route guidance, destination and other infor- mation service. As the style of information is diverse and the amount of information is large, driver may have mental and visual overload. The display of information can disturb the driver's attention and this can cause accidents. This state is caused by the defect of human-machine interactions. When the navigation system is designed, human factors - cognitive, judgment, operating -must be considered. The display style must be designed simply and easily, not to be obstacle of human - machine interface. In this study, outside- in view display style and inside-out view display style are compared each other. Tow factors are measured. One is cognitive factor-time of cognition on information that is displayed by screen display, cognition error rate. The other is image of screen display - subject's feeling about several styles of display, degree of subject's preference. The prototype of roadway is four kinds -Cross, T-cross and O-cross. Roadway display for test is taken from paper maps. Traffic condition display style, vehicle position display style and route guidance display style are taken from current display style. Traffic condition display style is symbol. vehicle position display style and route guidance display style are described as color and symbol. The test on screen display is implemented doing given tasks. Then the test is analyzed statistically. The result of test analysis gives the guideline to the designer for the map display of the vehicle navigation system.

• 구강회복응용과학지
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• 제25권3호
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• pp.201-210
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• 2009

중심위는 교합적, 교정적, 보존적 관점에서 진단과 치료에 중요한 요소이며, 중심위에 대한 정의와 채득방법에 대하여서는 학자들마다 다양하게 주장하고 있다. 중심위를 채득하는 방법에는 여러 가지가 있고 임상적으로 가장 중요한 부분 중 하나가 재현성과 정확성을 확보하는 것이다. 이에 저자는 중심위 채득시 하악 과두의 운동접번축(kinematic axis)을 인식하는 Arcus $Digma^{(R)}$의 EPA test를 이용하여 중심위 채득 방법에 따른 재현성을 비교하였다. 구강 악안면계의 기능이상이 없으며 교합이 정상이고 치아의 교모 및 마모가 심하지 않은 성인 10명를 대상으로 5가지 중심위 채득 방법 (Self-guided method, Bimanual manipulation, Chin-point guidance, Leaf gauge method, Gothic arch tracer)에 따른 중심위의 재현성을 Arcus $Digma^{(R)}$를 이용하여 비교 연구한 결과 다음과 같은 결론을 얻었다. 첫째, 중심위 채득 방법에 따라 하악과두의 위치는 상이한 양상을 나타냈다. 둘째, 재현성은 bimanual manipulation이 가장 높게 나타났으며 다음으로 chin point guidance, Gothic arch tracer, leaf gauge를 이용한 방법 그리고 unguided method 순이었다. 셋째, 임상에서 양손조작법이나 chin-point guidance이 재현성면에서 비교적 매우 훌륭한 방법이라는 것을 미루어 알 수 있다.

• 한국식생활문화학회지
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• 제34권3호
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• pp.316-324
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• 2019

The purpose of this study was to investigate dietary behavior and nutritional knowledge related to sodium intake in high school students. A questionnaire survey was conducted in 400 high school students (200 boys) in Incheon, Korea. Survey data were analyzed according to gender and degree of obesity. The distribution of the degree of obesity was the highest in 231 normal weight individuals (57.8%), followed by 89 underweight (22.3%), 41 overweight (10.3%), and 39 obese (9.8%). The sodium-related undesirable dietary behavior score was 2.9 points out of 5 points. The detailed dietary behavior scores of 'I eat kimchi when I eat instant noodles or noodles' and 'I like dried fish with salt' were significantly higher in boys than in girls (p<0.05). It was found that boys consumed more frequently high sodium foods, such as pizza, hamburger, and hotdog than girls. According to the degree of obesity, the underweight group consumed more kimchi fried rice and potato chips frequently than the other groups (p<0.05). Preference for salty taste was not significantly different among the groups by gender and degree of obesity. Sodium-related nutritional knowledge score was 5.3 points out of 10 and which was significantly higher in girls or normal weight group than in boys or obesity group. These results suggest that nutritional education on sodium intake is needed because the nutritional knowledge of adolescents is relatively low. Moreover, intensive nutritional guidance is required, especially in boys or adolescents with undesirable degree of obesity.

• 한국학교ㆍ지역보건교육학회지
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• 제4권
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• pp.61-78
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• 2003

This research was conducted to identify the factors that cause school related stress among middle school students, and to develop countermeasures in order to prevent the rebellious acts of middle school students that are on the rise and to pursue after effective guidance measures. To achieve these research objectives, 856 questionnaires were distributed to the two middle schools, situated in Goyang-si, Gyeonggi Province, and these questionnaires were analyzed, using the SPSS statistical package program. The conclusions were as follows; 1. Perceived factors for School Related Stress Overall average of the perceived degree school related stress factors was a level that goes beyond the normalcy. Stress on the grade was the highest Among these, the average of question items that addressed decrease in grade was the highest of all items followed by class factors, teacher-related factors, friend-related factors, and environmental factors. Accordingly, this research demonstrated that the students feel pressured by the university entrace examination and a school life that is focused on grades. The teacher-related factors and class factors were higher than the average, and others were relatively low. 2. School Related Stress according by Individual All the factors for school related stress were statistically significant difference according to the gender, and teacher-related factors, class factors, and environmental factors were statistically significant difference according to their school years. Their grade made their grade factors statistically significant difference, and the number of friends produced a statistically significant difference result on the teacher-related factors. Wheather they had extra classes or not made a statistically significant difference result on the class factors and environmental factors, and especially the time of doing physical exercises produced statistically significant difference on the environmental factors. 3. Countermeasures for School Related Stress according by Individual As for the countermeasures for school related stress according to the individuality, the active reacting was statistically significant difference according to the gender index, and the student's degree to react passively was statistically significant difference according to their grade. The students in different school years showed statistically significant difference reactions in both passive ways and active ways. students tended to react differently in an unreality index. Lastly, Wheather they had extra classes and physical exercises made then to react passively or actively. When the results are compiled, students are most affected by the stress related to grades, which reflected the university entrance examination oriented school life. An alternative is that the development of educational program that factors in the students' talents and aptitude is needed urgently. Moreover, character and career path related guidance and education are just as important as the academics. Given that the stress factors exert some degree of influence on the countermeasures, it is necessary to block the factors in advance and for all the teachers and parents to make an effort to react actively.

• 한국주거학회논문집
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• 제5권1호
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• pp.47-57
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• 1994

The purposes of this study are to serve s$ the bsaic data for the guidance and the dffective preparation of children's room and the children's residing environment in addition, by grasping generally the residential consciousness of children and the consciousness of children's room. For these purposes, the data were collected by using questionnare distributed to 214 5th grade elemantary school children living in Taegu. The data were analyzed using frequency, perecntile, anova, duncan's test, regression analysis. The major findings of this research are as follow: 1. It was found that many children wanted to have their own room because they are quiently able to study without being disturbed in their study. And it is shown that they were generally satisfied with the their own room. 2. There were significant differences in the consciousness of their own room according to the independent variables such as mother's age, father's job, the numbers of room. 3. The residential consciousness of children was variable according to father's age, mother's employment, the order of birth, income, the conditions of housing possession, parent's educational level, housing style, the numbers of room. 4. The mother's employment, father's educational level, the conditions of housing possession, the numbers of room, family numbers were significantly related to the evaluation of their own room. 5. Among the domains of the evaluation of their own room. the degree of width and the degree of convenience were variable to have influence on the satisfaction of their own room

• 한국생활과학회지
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• 제14권3호
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• pp.387-399
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• 2005

The purpose of this study is to investigate the differences of early childhood teachers' job satisfaction and burnout by variables and to analyze the relationship between the two subject matters. Then this study will serve to improve overall quality of early childhood education through fair comprehension about them. We surveyed 333 teachers in total, 171 public/private kindergarten teachers and 162 preschool teachers. A questionnaire by ECJSS of Jord-Bloom(1989) and Fleischer(1985) was used to measure the degree of job satisfaction, along with the version MBI(Maslach Burnout Inventory) by Maslach and Jackson(1981), adjusted by An, youngkil(I992) and Seo, jiyoung(2002), to check the degree of burnout. It was found that job satisfaction was higher among the surveyees of old age or with more education/less working hours. Small salaries, however, was one of the causes of low job satisfaction. Emotional burnout was shown in the surveyees of old age or with good education/career records. On the other hand, exhaustion from a lack of accomplishment was shown in single, young and low paid teachers. Thus, burnout and job satisfaction had a highly negative coefficient of correlation, meaning that job satisfaction gets high when burnout gets low.