• Journal of Positioning, Navigation, and Timing
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• v.5 no.1
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• pp.29-36
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• 2016

In this paper, performance on receivers of multilateration (MLAT) system that uses ADS-B signal, which is recently becoming popular, was analyzed to overcome shortcomings of existing aircraft flight control systems or reinforce the capabilities. A link budget was analyzed using a channel model in the airport environment with regard to Local Area Multilateration (LAM) for ground-controlled landing around the airport. In order to detect signals that arrived at the receiver successfully, sensitivity of receiver was analyzed using a signal-to-noise ratio (SNR) worksheet, and a method that improves accuracy of the distance measurement was proposed by adopting a peak estimation using sampling signals. Through simulations, optimum specifications of receivers were analyzed to have high precision positioning of LAM, and accuracy of LAM distance measurements was presented.

• Journal of Korea Game Society
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• v.11 no.4
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• pp.3-14
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• 2011

In this paper, affection of jumping motion factors on visual effects are studied for game character's natural motion realization. First, 3 kinds of games that realize natural motions are selected and 4-types of characters jumping motions are captured from it. Then, the motions are measured using four fundamental principles of jumping as takeoff strength, landing impact, landing elasticity and flexibility, and measured in motion factors as time, distance, angle either. Finally, consistent characteristics of visual effects and motion factors on jumping motion are suggested. The study could be used to basic information for realization of character's natural jumping motion.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.1
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• pp.39-45
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• 2007

This paper proposes a method of container position measurement using automatic landing system that is estimated by a laser range finder. In the most of container position measurement methods, CCD cameras or laser scanners have been used to get the source data. However those sensors are not only weak for disturbances, for examples, the light, fog, and rain, but also the system cost is high. When the spreader arrives at the goal position, it is still swung by inertia or by wind effect. In this paper, the spreader swung data have been used to find the container position. The laser range finder is equipped in the front side of spreader. It can measure distance and relative position between spreader and container. This laser range finder can be rotated as desired by a motor. And a tilt sensor is equipped on the spreader to measure spreader sway. The relative position information between the spreader and a container using the laser range finder and tilt sensor is estimated through the geometrical analysis.

• The Journal of Industrial Distribution & Business
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• v.13 no.12
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• pp.9-22
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• 2022

Purpose: Establishing a competitive advantage in the aviation market is essential as the competition among domestic airlines intensifies. Therefore, this study examined the management strategies of both large domestic airlines and low-cost airlines. Research design, data, and methodology: This study classified domestic airlines into Full Service Airlines (FSA) and Low Cost Carriers (LCC), examined each airline's current status and characteristics, and conducted case analyses of FSA and LCC based on Porter's generic competitive strategy. Results: The analyses determined that LCC primarily implemented a cost-advantage strategy, and FSA implemented a differentiation strategy. However, as competition intensified, FSA pursued cost-advantage strategies while establishing LCC through subsidiaries. There are various specific cost reduction methods, including service simplicity, scalability, high utilization, low landing fees, low-cost unit, and point-to-point flight strategies. Conclusions: LCCs are focusing on cost advantage strategies that reduce costs; however, the FSA also runs special price events that are as good as LCCs and are comparable to LCCs on some routes. Furthermore, LCC has recently expanded its mid- and long-distance routes, making competition for long-distance routes with major airlines unavoidable.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.2
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• pp.1-11
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• 2017

In this study, we surveyed the regulations of the Seaplane base and Sea Lane for the Light Sport Aircraft(LSA), and analyzed the water landing/takeoff roll distance of LSA in Korea. Based on the information, we presented the situation of the Sea Lane and the Sea Lane Protection Zone concept, to ensure the Rectangle type Sea Lane and the Omni direction type Sea Lane. We analyzed the availability elements of the safety of Sea Lane for LSA in Korea. A Rectangle type Sea Lane 350 meters long and 40 meters wide, the diameter 350 meters for the An Omni direction type Sea Lane.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.1
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• pp.67-76
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• 2005

In this paper, An analysis on the intelligence system for a biped walking robot(BWR) was made and its results were applied to the BWR. Various sensors were applied to the developed BWR for autonomous and intelligent walk in unknown environments. To measure the distance between the object and BWR, ultrasonic sensor and infrared-rays sensor were used. To identity surrounding environments, vision system was used. Gyro sensor was used to control the posture of BWR. Also, piezoelectricity sensor was used to identity the pressure of foot landing on the surface. Sensors applied to the robot have measurement errors according to noises or walking environments. To improve the function of these sensors, influences of noise or sensing errors were minimized using a sensor fusion scheme. A gait test using the sensor fusion system was performed, and its results are presented.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.30.5-30
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• 2001

This paper describes a new design of blimp having wheeled vehicle part. This system can work both on the ground using wheeled vehicle and in the air using the floating capability of the blimp part. The passive wheeled mechanism in the vehicle part enables the stable taking off, landing on as well as it is greatly helpful to keep a stationary position on the floor. On the other hand, the floating capability enables the wheeled blimp to fly freely regardless of the ground condition or obstacles. The wheeled blimp can be used as an agent robot for the tole-presence application. Using multimedia devices such as camera, speaker, LCD and microphone mounted on the blimp surface, this system can get necessary information at the local site and communicate with person from a distance. As a typical tele-presence application, the wheeled blimp is currently being developed to a tole-guidance robot working in public indoor areas such 35 exhibition halls, departments, hospitals, etc ...

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.162.3-162
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• 2001

The essence of ABS(Anti-skid Brake System) control is to continuously adjust brake pressure to maintain optimum brake torque. This optimum level should balance tire and runway friction its peak value, yielding maximum braking deceleration. It influences not only the deceleration and the taxing distance of an aircraft, but also the strength and the fatigue life of the landing gear. In this paper, an ABS control algorithm is developed with a dynamics model of 5-DOFD(Degree of Freedom). The algorithm is verified by simulations and the simulation results are presented. The dynamics model is simulated by the computer.

• Korean journal of applied entomology
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• v.32 no.1
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• pp.76-82
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• 1993

Phonotaxis of the African mole cricket, Gryllotalpa africana palisot de Beauvois, was investigated in 1990 and 1992 at the agronomy Experiment Station of Korea Ginseng & Tobacco Research Institute in Hwaseong-gun, Kyonggi-do, Male adults produced calling sounds (calling songs) through the openings of subsurface burrows. Intensities of the sound were 77-80 dB at 15 cm above the openings. When tape recordings of male calling songs were broadcasted outdoors at 105-110 dB by two horn speakers installed at the center of a 1.4 m diameter-funnel, flying adults were attracted for 1.5 hours from about 30 minutes after sunset. Among attracted adults, 14.3-16.9% landed in the funnel, and 65.7-74.7% landed on the ground within 2m form the sound source. Females were 66.7-74.3%, which seemed to be due to the sex ratio of the population in the field. Adults landing in the funnel and at the distance of within 2m from the center of the funnel were tend to be a little more than those attracted to a blacklight trap.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.8
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• pp.649-656
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• 2013

High-lift devices have a major influence on takeoff, landing and stall performance of an aircraft. Therefore, a slotted flap design optimization process is proposed in this paper to obtain the most effective flap configuration from supported 2D flap configuration. Flap deflection, Gap and Overlap are considered as main contributors to flap lift increment. ANSYS Fluent 13.0.0$^{(R)}$ is used as aerodynamic analysis software that provides accurate solution at given flight conditions. Optimum configuration is obtained by Sequential Quadratic Programing (SQP) algorithm. Performance of the aircraft with optimized flap is estimated using Aircraft Design Synthesis Program (ADSP), the in-house performance analysis code. Obtained parameters such as takeoff, landing distance and stall speed met KAS-VLA airworthiness requirements.