복합적층 원뿔형 쉘의 링 보강효과 연구

박원태,최재진,손병직 한국안전학회 2004 한국안전학회지 Vol.19 No.1

In this study, composite laminated conical shells with ring stiffeners are analyzed. A versatile 4-node shell element which is useful for the analysis of conical shell structures is used. An improved flat shell element is established by the combined use of the addition of non-conforming displacement modes and the substitute shear strain fields. The proposed element has six degrees of freedom per node and permits an easy connection to other types(beam element) of finite elements. And 3-D beam element is used for ring stiffeners. Optimum location and optimum section properties of ring stiffeners are obtained. It is shown that the thickness of conical shell is reduced about 201/o by optimum ring stiffeners.

Solution-Processed High Performance Amorphous Metal Oxide Thin Film Transistors by Water Vapor Annealing

박원태,손인영,Yong Xu,김동윤,신을룡,이태권,노용영 한국고분자학회 2015 한국고분자학회 학술대회 연구논문 초록집 Vol.2015 No.4

원격조종항공기 드론 조종기모드 표준화 연구 : 드론 조종기모드 선호도를 중심으로

박원태 한국산업경영시스템학회 2019 한국산업경영시스템학회지 Vol.42 No.4

Remotely Piloted Aircraft (RPA) controls as a type of unmanned aerial vehicle (drone) is growing rapidly and its flight controller stick disposition is required standardization. We should standardize RPA drone flight control disposition because the flight pilot of RPA is hard to be trained so the flight controller stick differences impairs safety and wastes time and effort of flight controller industry. So this study researches the on-going standardization of RPA drone flight control disposition in Korea and foreign countries. Also this paper analyzes and researches of expert about RPA drone flight controller function and application of flight control mode. I accomplished expert research about standardization plan of unmanned flight control mode and confirm the necessity. Nowadays mode1 and 2 are mostly used in Korea so I carried out preference investigation for two modes. There were 4 preferences choices of RPA drone control mode necessity (importance) and recommendation of standardization modes. They answered that necessity of standardization is important considering pilot training, flight safety and positive development of drone industry. The result of standardization mode preference is that they prefer mode 2 (drone maker 86%, training facilities and research facilities 58%, government bureau 60%). Overall preference result shows that mode 1 24%, mode 1&2 16%, mode 2 60%. So they preferred mode 2 by 60%. The differences between two modes are the direction of throttle and pitch. Direction of throttle and pitch operate opposite way. They prefer mode 2 because mode 2 has similarities of manned flight control mode. Significance of this study is that it showed the necessity of standardization and flight control preference in a quantitative way. It will help drone standardization in related industries and development direction near future.

비행교관의 변혁적 리더십이 학생조종사의 심리적 안정감과 학업만족에 미치는 영향

박원태 한국항공운항학회 2020 한국항공운항학회지 Vol.28 No.3

This research is accomplished to verify objectively how flight instructor’s transformativeleadership affects student pilot’s psychological stabilities and learning satisfactions. Flightinstructor’s transformative leadership factor divided into individual consideration, intellectualstimulus and charisma from exploring factor analysis. Psychological stability factor subdivided into happiness, concentration and satisfaction. Learning satisfaction factor subdivided into participation, recommendation, persistence, accomplishment and relationship. According to the analysis of flight instructor’s transformative leadership effect on psychological stability, it showed that it has statistical significance on happiness, concentration and satisfaction. It also has positive influence on happiness and concentration. The result from regression analysis showed that individual consideration and charisma affected happiness and concentration in order. However, satisfaction from individual consideration, intellectual stimulus and charisma didn’t show statistical significance to student pilot’s satisfaction. Analysis of flight instructor’s transformative leadership on student pilot’s learning satisfaction showed statistical significance between them. Intellectual stimulus and charisma had positive influence on student pilot’s learning satisfaction. Regression analysis showed charisma and intellectual affect student pilot’s learning satisfaction in order.

무인항공기시스템 사고요인 분석을 통한 안전 운용방안 고찰

박원태 한국항공운항학회 2023 한국항공운항학회지 Vol.31 No.1

This study investigated the accident cases of the U.S. Air Force and the R.O.K. Army. It analyzed the accident factors of the unmanned aircraft system using case analysis on unmanned aircraft system operators of the R.O.K. Air Force. Following the analysis this paper suggested safety operation plans for the R.O.K. Air Force. The risk factors of unmanned aircraft system were summarized by collecting and analyzing accident cases of unmanned aircraft system by the U.S. Air Force, collecting and analyzing accident risk factors of RQ-4 operators of the R.O.K. Air Force. Through the analyzed risk factors, a safety operation plan for the semi-automatic unmanned aircraft system and the fully automatic unmanned aircraft system was presented.

비행교관의 변혁적 리더십과 학생조종사의 심리적 안정감 관계에서 지도자 신뢰의 매개효과

박원태,Park, Wontae 한국항공운항학회 2021 한국항공운항학회지 Vol.29 No.1

This thesis researched student pilots at certified flying school to prove several things as follows. First, this study tried to find out the influence of instructor's leader trust to student pilot. Second, this study also tried to investigate the influence of student pilot's psychological stability from leader trust. Third, this study tried to prove the mediation effect of leader trust between flight instructor's transformation leadership and the student pilot psychological stability. The result of empirical research are as follows. First, the result of the verification of the relationship between transformative leadership and trust of leader showed that transformative leadership has a positive (+) influence to trust of leader. Second, the result of verification between leader trust and psychological stability relationship showed that trust of leader gives positive(+) influence to psychological stability. Third, the result of verification between transformative leadership and psychological stability showed that trust of leader gives positive(+) influence to psychological stability. I discussed implication from this study at the end and presented future research direction.

비등방성 원뿔형 쉘의 안정성에 관한 연구

박원태,손병직 한국안전학회 2001 한국안전학회지 Vol.16 No.5

In this paper, stability analysis is carried out far the out of plane behaviors under compressive loads to the conical direction. It is not easy to obtain the analytic solutions about the stability analysis of anisotropic conical shells consisted of composite materials. For solving this problems, this paper used the finite difference method which is one of the numerical methods. The characteristics of the buckling behaviors of anisotropic laminated composite conical shells may be different according to a variety of causes, that is, the change of fiber angle, material arrangement, radius ratio, shape ratio and so on. The objective of this study is to analyze buckling behaviors of circular conical shells with shear deformation effects and to prove the advantage of composite materials.

관용헬기 가동률 향상방안 연구 : 가동률과 운용유지비 분석을 중심으로

박원태 청주대학교 산업과학연구소 2021 産業科學硏究 Vol.39 No.1

Aircraft owned by government are fire fighting aircraft and forestry aircraft. There are also official helicopters used by government which are police and marine police helicopters. Public usage of these helicopters in the air safety rules are for police activity, marine guard, fire fighting, forestry disaster prevention, emergency medical care helicopters. They are operated by National Police Agency, Ocean National Police Agency, National Fire Agency and Korea Forest Service. Each Agency has its own operation rules for specific models. But because of different operating concepts, different types of aircraft model, operations limitations, operating rate and information exchange, there was lack of response when the agencies had to deal with national disasters such as SeWol Ferry accident together. This thesis is a initial study of national disaster response effectiveness. I analyze domestic public use helicopters status and present optimized helicopter model in the economic point of view.

고리의 어제와 내일

박원태 한국원자력산업회의 1984 원자력산업 Vol.4 No.5

직교이방성 박판 및 후판의 해석연구

박원태,최재진 한국산학기술학회 2003 한국산학기술학회논문지 Vol.4 No.2

본 연구에서는 직교이방성 박판 및 후판의 휨문제에 대한 해석결과를 제시하였다. 수치해석방법으로는 유한요소법을 사용하였으며, 직교이방성판 휨문제에 대한 지배방정식은 Kirchhoff 가정에 의한 박판이론과 Mindlin 가정에 의한 후판이론을 이용하여 유도하였으며 판의 폭-두께비의 변화에 따른 해석결과를 비교 검토하였다. In this study, it is presented analysis results of bending problems in the orthotropic thick plates and the orthotropic thin plates. Finite element method in this analysis was used. Both Kirchoff’s assumptions and Mindlin assumptions are used as the basic governing equations of bending problems in the orthotropic plates. The analysis results are compared between the orthotropic thick plates and the orthotropic thin plates for the variations of thickness-width ratios.