• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.46 no.10
• /
• pp.845-855
• /
• 2018

Cross section design of a prop-blade is carried out for VTOL(Vertical Takeoff and Landing) Quad Tilt Prop-rotor UAV with a maximum takeoff weight of 55 kg and a maximum cruising speed of 180 km/h. Design procedure for cross section design is established and design requirements for prop-blade are identified. Through the procedure, cross section design is carried out to meet the identified requirements. Main design factors including stiffness, weight per unit length, and elastic axis are obtained by using a finite element section analysis program, and the design weight of the prop-blade is predicted. The obtained design factors are used along with the rotor system analysis program CAMRAD II to evaluate the dynamic stability of prop-blade in operating environment. In addition, the prop-blade load is obtained by CAMRAD II software, and it is used to verify the safety of the prop-blade structure. If the design results are not satisfactory, design changes are made in an iterative manner until the results satisfy the design requirements.

• Knowledge Management Research
• /
• v.22 no.1
• /
• pp.105-120
• /
• 2021

Recently, there has been a dramatic change in real estate markets with the development of information technology. The word, Proptech, is defined as the real estate transaction innovation motivated by various types of information technology including artificial intelligence, sensing technology and big data. The objective of this study is to provide a value-creation framework for Proptech business based on the understanding of how and what types of values are created and shared, which gives organization to develop strategies and business models. And a new classification scheme of Proptech business is also suggested based on the recognition of created values along the development of Proptech business. Then, the proposed matrix is applied to derive the business value such as intangibility value, relational value and enhancement value with the case analysis on the each components of Proptech business.

• Knowledge Management Research
• /
• v.22 no.2
• /
• pp.289-300
• /
• 2021

Proptech, which has applied information technology to the real estate market, is leading real estate transaction innovation by presenting various value creation models. This study categorizes and understands values that are created and shared in proptech-based businesses, and develops evaluation data that reflects the relative importance of individual value areas. To this end, the dimension of value creation of proptech was hierarchically constructed, and the degree of relative value creation of the sub-industries of the proptech industry was evaluated. In order to grasp the relative importance of the proposed indicators, AHP analysis was conducted for industry and academic experts. In the first stage, intangible values, relational values, and advanced values were presented. It was derived as weights between indicators through two-way comparison. This study aims to improve and develop the value-creation capability of the entire Korean proptech ecosystem in the future by evaluating the value-created competence of each sector of the proptech industry.

• Journal of the KSME
• /
• v.29 no.6
• /
• pp.594-600
• /
• 1989

항공기용 원동기는 항공기를 추진시키기 위한 동력장치이다. 항공기가 추진력을 얻기 위해서는 프로펠러를 회전시켜 대량의 공기를 뒤로 가속시켜 그 반작용을 이용하는 방법과, 단순히 배기 가스를 뒤로 고속분사시켜 그 반작용을 이용하는 방법이 있다. 피스톤 엔진은 전자를, 터보 제트 엔진은 후자를 대표하고 있는데 두 가지 방법을 절충하여 터빈으로 프로펠러를 회전시키는 터보 프롭엔진과, 헬리콥터의 로우터를 회전시키는 터보 샤프트 엔진도 있다. 또 터보 제트 엔진과 터보 프롭 엔진의 증간성능을 꾀한 터보 팬 엔진이 있는데 효율이 아주 좋기 때문에 급속히 발 전되어 항공기용 원동기의 대명사격으로 현재 군용이나 민간기용으로 널리 사용되고 있다. 최 근에는 터보팬 엔진과 터보 프롭 엔진을 절충한 새로운 터보 프롭 APT (advanced turbo prop) 엔진의 실용화가 추진되고 있다. 이상과 같은 종류의 엔진 이외에도 항공기용 원동기에는 극히 제한된 용도에 쓰이는 램 제트와 펄스 제트 엔진 그리고 로켓 엔진 등이 있다. 원동기는 그 용 도에 따라 개발, 활용되는 것이기 때문에 오랜 역사를 지닌 피스톤 엔진은 아직까지도 경항공 기용 원동기의 주류를 이루고 있고, 앞으로도 터보 프롭 엔진과 더불어 나름대로 계속 활용될 것으로 전망된다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.11a
• /
• pp.371-377
• /
• 2009

The propulsion system of turboprop has been rarely used in the large aircraft due to the limitation of the maximum velocity of the propeller, the power limitation by the reduction gear, etc. Recently, the demand on turboprop aircraft continues to increase because of economical efficiency and environmental factors. In this paper, turboprop propulsion system which is composed of a Pratt & Whitney 127F turboprop engine and a Hamilton Standard 568F propeller was modeled by using the Gasturb11 software. The result of the performance analysis on this propulsion system model showed that the propulsion system model was evaluated to have been successfully builded.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2001.04a
• /
• pp.76-79
• /
• 2001

SIMULINK^{$\circledR}$를 이용하여 항공기용 터보프롭 엔진을 모델링한 후 현재 KT-1의 추진기관인 PT6A-62 분리축 터보프롭엔진의 성능을 해석하였다. SIMULINK^{$\circledR}$ 모델의 검증을 위하여 상용해석프로그램인 GASTURB 와 비교한 결과 최대오차율 1.07% 이내로 확인되었다. 지상정지 조건에서 블리드 공기유량을 0에서 5%, 보기류 구동에 따른 출력손실을 0에서 20 hp로 가정하고 해석한 결과 축마력은 최대 0.68%감소하며 비연료소모율은 거의 영향을 받지 않음을 알 수 있었다.

• Aerospace Industry
• /
• s.94
• /
• pp.34-37
• /
• 2007

헬리콥터와 터보프롭기가 만나면 과연 어떤 모습일까? 물론 애써 상상할 필요는 없다. 우리가 상상해야 할 수고를 덜어줄 기종이 이미 나와 있기 때문이다. 바로 V-22 오스프리(Osprey)이다.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.33 no.9
• /
• pp.16-26
• /
• 2005

The aerodynamic design of a proprotor for the Smart UAV adopting tiltrotor aircraft concept is conducted in this study. Since proprotor of tiltrotor aircraft is operated at both rotary and fixed wing mode with single configuration rotor, the proprotor has to be designed to meet performance requirements for both flight modes. The aerodynamic design of proprotor is accomplished by combining three sources of data - the proprotor performance data, the aerodynamic data of vehicle, and the performance data of engine. The performance analysis code for proprotor is based on the combined momentum and blade element theory and validated by comparison with the TRAM data. In order to design configuration for a proprotor satisfying requirements for both rotary and fixed wing mode, various kind of performance maps are constructed for many performance and configuration parameters. From the analysis the twist angle of 38 degrees and the solidity of 0.118 are decided to be the optimal geometric parameters for both operating conditions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.648-651
• /
• 2010

Propeller shall have high efficiency and improved aerodynamic characteristics to get the thrust to fly at high speed for the FAR25 turboprop aircraft. That is way Clark-Y airfoil which is used to conventional turboprop aircraft propeller is selected as a blade airfoil. Javaprop program based on the Adkins method is used for aerodynamic design and analysis of propeller, Adkins method is based on the vortex-blade element theory which design the propeller to satisfy the condition for minimum energy loss. Slipstream displacement don't change and consider a rigid body. High efficiency propeller geometry is generated by varying chord length and pitch angle at design point of FAR25 turboprop aircraft. The propeller design results indicate that could be applied to the FAR25 turboprop aircraft, through analysis of propeller aerodynamic characteristics using the CFD(Computational Fluid Dynamic).

• The Journal of the Korea Contents Association
• /
• v.11 no.10
• /
• pp.69-76
• /
• 2011

As a smallest unit of the game story, quest needs to be analyzed in terms of structure in order to study quest storytelling. This thesis introduces structuralist theory of narrative function of folk-tale by Propp to determine the structure of the quest. Propp proposed immutable elements of the characters as 31 kinds of Folk-tale functions. I analyzed assigning quests in MMORPG. As a result, 13 essential functions of the Quest, and 5 add-ons were drawn and the order among functions was figured out. Most quests in MMORPG followed the order of the essential functions and optional add-ons and showed a repeating pattern. The essential and optional functions and its order can be utilized to arrange appropriate element for quest storytelling and to strengthen and lead the various ways of the quest storytelling.