http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Монголын бурханы шашны дуу <Цагаан дарь эхийн залбирал> гүр дууны судалгаа
박상후(Sanghu Park) 단국대학교 몽골연구소 2022 몽골지역연구 Vol.7 No.2
This paper is a comparative analysis on the ancient music score and sound source of the Mongolian Buddhist song, Gur Duu. For the comparative analysis, this paper used the ancient music score from 1897 owned by Aimag Folk Museum at Bayankhongor, Mongolia and transcribed the staff by using the sound source recorded in 1979 with the same title, ‘Tsagaan dara ehiin zalbiral’, owned by Institute of Language and Literature, Mongolian Academy of Science. The manuscript from 1897 includes total of 64 Gur duu pieces and each piece is divided into 3 keys of upper key, lower key, and Chakhar. ‘Tsagaan dara ehiin zalbiral’ Gur duu analyzed in this paper falls under the upper key of 10-string yatgalig. The register for ‘Tsagaan dara ehiin zalbiral’ Gur duu in the manuscript covers from the low octave sol(g) to higher octave la(a) in fa(F) major. Meanwhile, ‘Tsagaan dara ehiin zalbiral’ in the recorded sound source is do (C)major and its register covers from low la(a) note to high do(c) with 10 intervals. In the ancient music score of ‘Tsagaan dara ehiin zalbiral’ Gur duu, the ancient music score was composed of 6 limes while the recorded sound source included 8 phrases. Each song was sang in both closed and open sets. In the comparative analysis on the ancient music score and sound source that were preserved in the form of written record and oral tradition with 100-year gap, the ancient music score and sound source showed the same key while involving difference in melody and lyrics. It is assumed that the beat got faster over time. This study holds significance in comparing the written tradition and oral tradition by using the ancient music score and sound source.
Study on Structural Design of Archimedes Wind-Power Mill
박상후(Sanghu Park),양성문(Sungmon Yang),지호성(Hosung Ji) Korean Society for Precision Engineering 2018 한국정밀공학회지 Vol.35 No.4
We have designed the structural shapes of a spiral blade and the frame to be used in an Archimedes wind-power system with the objective of increasing its mechanical strength. A conical roll-bending forming process was introduced to fabricate a metallic spiral blade, based on an incremental stepwise approach. From this process, the complicated spiral blade was constructed, and it could be applied to the wind-power mill. We proposed a few structural design concepts for improvement of the mechanical strength of the blade and frame. Fixing rods between the blades increased the natural frequency of the blades three-fold, compared to the original model with no rods. Also, the strength of the frame was increased by introducing edge-flanges with a height greater than 20 mm. This study will be helpful to industrial engineers interested in the structural design of a wind-power system in understanding the structural design process.
진칭예(Qingye Jin),연시모(Simo Yeon),손용(Yong Son),박상후(Sanghu Park) Korean Society for Precision Engineering 2021 한국정밀공학회지 Vol.38 No.9
With the development of Additive Manufacturing process, lattice structures have recently been fabricated with fine quality. Lattice structures have unique performances which encompass various elastic responses. In this study, shear characteristics of the lattice structures (BCC and OTC) fabricated by SLM process, under optimized manufacturing conditions, were analyzed by 1/4 compression tests. As a result, several fracture modes and elastic configurations were found by comparing the compression test results of various lattice structures. In addition, the lattice structures possessed certain shear elasticity and normal elasticity among different types of lattices at elastic region when shearing. As the 1/4 compression test was simulating the lattice structure on concentrate load or shearing load, the test represented shock introspection characteristics of the lattice inner structure.
우위팅(Yu-Ting Wu),진진(Zhen Qin),이윤승(Yunseung Lee),류성기(Sungki Lyu),백승호(Seoungho Back),박상후(Sanghu Park) 대한기계학회 2021 大韓機械學會論文集A Vol.45 No.8
분말을 친환경적이고 정량적으로 공급하기 위하여 본 논문에서는 노벨 분말 공급 장치의 설계를 제안하고 그 메커니즘 설계 원리에 대해 분석한다. 장치내 분말의 유동 특성을 관찰하기 위하여 분유를 연구 대상으로 선정하였다. 분말 입자 사이의 공극률과 충돌효과를 고려하여 유동영역 내에서 고밀도의 입자 유동 모델을 구축하였으며 Fluent를 활용하여 순간적인 CFD 시뮬레이션을 수행하였다. 무거운 하중을 받는 장치의 구조적 안전성을 고려하여 일련의 유한요소법 기반 구조 강도의 시뮬레이션을 실시하고 메커니즘의 신뢰성을 검증하였다. 또한 3D 프린터를 활용하여 분말 공급 장치의 시제품을 제작하였으며 섭취량 실험을 수행하였다. 결론적으로 제안된 분말 공급 장치는 내부 유동 특성, 구조적 안전성, 실제 분말 공급의 정량 정밀성 등 측면에서 만족스럽다고 평가할 수 있다. 본 연구에서 사용된 설계 및 검증 방법과 다양한 메커니즘의 설계를 위한 유용한 이론을 제시하였다. To precisely feed powders or particles in an environmentally friendly manner, a novel apparatus for powder feeding is proposed. The kinematics and design principles of the mechanism were analyzed. To observe the flow characteristics of the powder in the apparatus, milk powder was selected as the study object. By considering the voidage and collision effect between particles, the dense discrete phase method–discrete element method collision model was established and investigated based on the commercial computational fluid dynamics software ANSYS Fluent. To observe the structural stability of the proposed apparatus under an extreme load condition, a series of finite-element-method-based structural simulations were implemented and the reliability of the design was verified. A prototype was made based on three-dimensional printing technology, and the feeding precision was compared with that of the traditional measuring spoon. The design was satisfactory in terms of flow characteristics, structural safety, and quantitative feeding. The design and investigation methods used in this study can provide an important theoretical reference for the design of a variety of apparatus.
Process Design of Conical Roll-Shaping for Fabrication of Variable Curvature Spiral Blade
양성문(Sungmoon Yang),심도식(Dosik Shim),지호성(Hoseong Ji),백준호(Joonho Baek),김봉식(Bongsik Kim),안석영(Seokyoung Ahn),박상후(Sanghu Park) Korean Society for Precision Engineering 2016 한국정밀공학회지 Vol.33 No.11
A conical roll-shaping process was proposed for fabrication of a metallic spiral blade applied to a small-scale wind turbine system. A spiral blade has continuously different curvatures, with a range of 100 to 350 ㎜ radius. To fabricate this complex shape, we developed a conical rollshaping process having two main conical rollers for feeding a blank sheet, and two cylindrical side rollers for control of local bending. For clear understanding of the process parameters, numerical analyses were conducted using a commercial code, Pam-Stamp. This study optimized the effects of process parameters, such as gap and angle between the main rollers and side rollers, and also the movement of side rollers. In order to increase the forming efficiency, a central rotation point was also calculated by the analytical approach. This developed rolling process can thus be utilized in a sheet metal forming process for obtaining spirally curved sheet metal shapes.
우위팅(Yu-Ting Wu),진진(Zhen Qin),김남용(Namyong Kim),전남술(Namsool Jeon),박상후(Sanghu Park),류성기(Sungki Lyu) 대한기계학회 2021 大韓機械學會論文集A Vol.45 No.1
항공기 견인봉은 주로 지상에서 항공기의 견인 작업 및 유지보수 목적으로 사용된다. 작동 중에 과부하, 인적 요인으로 작업 과실 및 환경(지면) 요인의 영향으로 인하여 견인봉 굽힘 또는 파손과 같은 고장 문제가 자주 발생하여 항공기의 정상적인 비행 스케줄에도 영향을 미친다. 이러한 종류의 문제는 비행 중에 발생하지 않지만 높은 발생 빈도로 인하여 항공산업에서는 견인봉의 설계단계에서 구조적 안정성을 매우 중요시하고 있다. 본 연구에서는 소형 무장헬기용 견인봉을 기반으로 모델링 및 수치 연구를 수행하여 최적의 견인봉 구조설계 방법에 대하여 고찰하였다. 실제 작업 극한 조건을 고려하여 각각 특성이 있는 tubular 식 및 solid 식 견인봉에 대하여 구조 강도 평가, 좌굴 임계 하중 분석 및 전단핀 설계를 수행하였다. 본 논문에서 사용한 연구 방법은 다양한 작업 조건 및 견인봉 모델 개발에 적용이 가능하며 항공기의 견인 작업의 안전성을 보장하기 위하여 중요한 설계 이론을 적용하였다. Mainly an aircraft tow bar is used for the operation and maintenance of an aircraft on the ground. Failure problems such as tow bar bending and fracture frequently occur owing to the influences of overload conditions, man-made destruction, and environmental factors. These problems may even affect the normal flight mission of the aircraft during the operation. Although this type of problem does not occur during flight, owing to the high occurrence frequency of this problem, the structural stability of the tow bar in the design stage is of importance to the aerospace industry. In this study, a series of modeling and numerical analyses were carried out to investigate the optimal design method with a high structural stability based on a tow bar for small military helicopters. A structural strength evaluation, ultimate buckling load analysis, and design of the breakaway pin were performed for tubular and solid bar-type tow rods with specific characteristics by considering the actual extreme working conditions and different characteristics of the tubular and solid tow bars. The method used in this study is applicable under various working conditions and for tow bar model development. It provides an important design theory reference to ensure the safety of the towing operation of the aircraft.