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        검색결과 169

        21.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Human and material resource planning is one representative example of Operations Research. Resource planning is important not only in civilian settings but also in military ones. In the Air Force, flight scheduling is one of the primary issues that must be addressed by the personnel who are connected to flight missions. However, although the topic is of great importance, relatively few studies have attempted to resolve the problem on a scientific basis. Each flight squadron has its own scheduling officers who manually draw up the flight schedules each day. While mistakes may not occur while drafting schedules, officers may experience difficulties in systematically adjusting to them. To increase efficiency in this context, this study proposes a mathematical model based on a binary variable. This model automatically drafts flight schedules considering pilot’s mission efficiency. Furthermore, it also recommends that schedules be drawn up monthly and updated weekly, rather than being drafted from scratch each day. This will enable easier control when taking the various relevant factors into account. The model incorporates several parameters, such as matching of the main pilots and co-pilots, turn around time, availability of pilots and aircraft, monthly requirements of each flight mission, and maximum/minimum number of sorties that would be flown per week. The optimal solution to this model demonstrated an average improvement of nearly 47% compared with other feasible solutions.
        4,000원
        22.
        2020.12 구독 인증기관 무료, 개인회원 유료
        This paper compares the preceding study on the development of evaluation indicator for ATOs for mechanics and vocational ability evaluation system implemented by the Ministry of Employment and Labor to support various vocational training. This paper also examines the systems for the protection and possible options of the consumer through disclosed notification and evaluation cases such as the traffic service evaluation system in the aviation sector. By extension, in order to ensure quality management and enhanced capability of flight schools, this paper aims to present a methodology for introducing an evaluation model certified by ATOs for pilots that emerges from comparing the preceding study on various vocational training applied with the CIPP evaluation model of Stufflebeam and the procedures for the designation of ATOs for pilots and follow-up management thereon in Korea, dividing it into four stages, which are the preparation stage, screening stage, designation stage and management stage, and applying the items and performance indicators to be carried out at each stage.
        4,300원
        23.
        2020.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        At ship design stage, the maneuverability is generally estimated based on the empirical formula or the computational fluid dynamic (CFD), which is one of the numerical simulation methods. Using the hydrodynamic derivatives derived through these methods can quantitatively estimate the maneuverability of target vessels and evaluate indirect maneuverability. Nevertheless, research on estimating maneuverability is insufficient for ships not subject to IMO maneuverability standard, especially fishing vessels, and even at the design stage, the empirical formula developed for merchant ships is applied without modification. An estimation error may occur due to the empirical formula derived from the regression analysis results of a model test if the empirical formula developed for merchant ships with different hull shapes is applied to fishing vessels without any modification. In this study, the modified empirical formula that can more accurately estimate the fishing vessel's maneuverability was derived by including the hull shape parameter of target fishing trawlers in the regression analysis process that derives Kijima et al. (1990) formula. As a result, the modified empirical formula showed an average estimation error of 6%, and the result improved the average error of 49% of Kijima et al. (1990) formula developed for merchant ships.
        4,000원
        24.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a motion control problem for the vessel towed by towing ship on the sea is considered. The towed vessel does not have self-control capabilities such that its course stability totally depends on the towing ship. Especially, in the narrow canal, river and congested harbor area, extreme tension is required during the towing operation. The authors, therefore, propose a new control system design method in which the rudder is activated to provide its maneuverability. Based on the leader following system configuration, a nonlinear mathematical model is derived and a backstepping control is designed. By experiment results with nonlinear control framework, the usefulness and effectiveness of the proposed strategy are presented.
        4,000원
        26.
        2020.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to offer specific information needed to assist in operation of a ship with same type rudder through evaluating the maneuverability of training ship A-Ra with flapped rudder, sea trials based full scale for turning test, zig-zag test with rudder angle 10° and 20°, and spiral test at service condition were carried out on starboard and port sides around Jeju Island according to the standards of maneuverability of IMO. As a result, the angular velocity of port turn was higher than that of starboard turn. Therefore, the size of turning circle was longer on the starboard side. In addition, variation of the transfer due to various factors was more stable than those of the others. In the Z-test results, the mean of 1st and 2nd overshoot angles were 9.8°, 6.3° and 15.3°, 9.2° respectively when the port and starboard was 10°; the 1st overshoot angle were 18°, 13.7° when using 20°. Her maneuverability index Tˊ and Kˊ can be easily determined by using a computer with the data obtained from Z-test where Kˊ and Tˊ are dimensionless constants representing turning ability and responsiveness to the helm, respectively. In the Z-test under flap rudder angle 10°, the obtained Kˊ value covered the range of 2.37-2.87 and Tˊ was 1.74-3.45. Under the flap rudder angle 20°, Kˊ and Tˊ value showed 1.43-1.63, 1.0-1.73, respectively. In the spiral test, the loop width was unstable at +0.3° and –0.5°-0.9° around the midship of flap rudder. As a result, course stability was comparatively good. From the sea trial results, training ship ARA met the present criterion in the standards of maneuverability of IMO.
        4,200원
        27.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        30.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The most important role of air defense system is to attack the air target of enemy to defend the important military unit or facilities. In order to attack the target as soon as it is detected, fast and precise fire signal transfer using the fire control stick is very important. However, it was found that firing is not conducted in the test for fire control stick. In order to find the reason of such problem and improve life cycle of fire control stick, the test was conducted and it was found that chattering occurred and this led to malfunction of signal transfer from control stick to fire control unit of air defense system. In order to draw resolution for this problem, two contact plate made of beryllium copper is suggested to add to the control stick to enhance the contact and reduce chattering effect. The four fire switch prototypes were tested for 100,000 times and it showed its reliability of use.
        4,000원
        33.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 동력수상레저기구 조종면허의 기존 수기채점방식을 전자채점방식으로 전환할 수 있도록 실기시험항목을 분석하여 현재의 실기시험 시스템의 개념을 해치지 않는 범위 내에서 디지털화할 수 있는 방안을 모색하고, LiDAR센서와 WAVE통신을 통한 전자채점 시스템을 개발했다. 연구를 통해 얻은 결과는 다음과 같다. 첫째, 시험선에서는 LiDAR 및 시험관 평가입력장치를 통해 입력된 채점 데이터가 통합처리장치에서 WAVE통신을 통해 육상 관제센터로 전송되어 응시자의 데이터를 저장/관리할 수 있는 시스템을 구축 및 검증했다. 둘째, 사행 과제를 평가함에 있어서 기존에 목시관측 또는 막대기를 사용한 것을 대신하여 LiDAR를 이용함으로써 정확한 거리측정이 가능해졌고, 정확한 거리정보를 시험선 통합처리장치를 통해 시험관 평가입력장치에 신속하게 표출했다. 셋째, 시험선에서 취 득한 평가점수 데이터를 육상 관제센터로 유실없이 고속으로 전송하기 위해 활용한 WAVE통신에서 원활한 전송 및 처리가 가능함을 확인했다.
        4,000원
        40.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pilot Aptitude Research Equipment (PARE) is a simulator developed to measure or research pilot aptitude and train for student pilots. Design of an ergonomic PARE operation console is required to operate the equipment effectively. This study carried out five steps : (S1) operator questionnaire survey, (S2) anthropometric design formula development, (S3) usability evaluation, (S4) improvement design, and (S5) validation considering both Physical User Interface (PUI) and Graphic User Interface (GUI) of PARE operation console. The operator questionnaire surveyed needs for each PUI and GUI part of the console from two PARE actual operators. In terms of PUI, the anthropometric design formula was developed by using design variables, body dimensions, target population characteristics, and reference posture related to the PARE console. In terms of GUI, the usability evaluation was conducted by three usability testing experts with a 7-point scale (1 : very low, 4 : neutral, 7 : very high) on GUI of the PARE operation console by seven usability criteria. The improved PARE operation console was designed to reflect the optimal values of design variables calculated from design formula, the results from usability testing, and the operator’s needs. The improvement effect was observed by 20 people who had experience with the PARE operation console. As a result of the validation, monitor visibility and cockpit visibility for the improved PUI design and visibility and efficiency for the improved GUI design were significantly increased by more than 90% respectively. The improved design of the PARE operation console in this study can contribute to enhance operation performance of the PARE.
        4,000원
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