한국 합기도의 태동과 발전사: 대동류합기유술(大東流合氣柔術)을 중심으로

황종대 ( Jong Dae Hwang ),주동진 ( Dong Jin Joo ),김동규 ( Dong Kyu Kim ) 대한무도학회 2012 대한무도학회지 Vol.14 No.1

한국의 ``합기도(Hapkido)``와 일본의 ``아이기도(Aikido)``는 ``대동류합기유술(大東流合氣柔術)``에서 그 근원을 찾을 수 있다. 그러나 현대 합기도의 역사는 한국은 한국대로, 일본은 일본대로 각기 다른 형식으로 발전되어 왔다. 그리하여 이 연구는 ``대동류합기유술``이 한국의 고대 국가인 신라에 기반하며, 일본에서 다케다 소카쿠(武田□角, 1859-1943)로부터 대동류합기유술을 배워 귀국한 최용술(崔龍述, 1899-1986)에 의해 한국 합기도가 창안되고 전파되어 오늘에 이르렀음을 확인하고자 하였다. 이와 함께 태동부터 전환기에 이르는 역사적 맥락과 과제를 탐색하였다. 그 동안 합기도의 역사는 문헌이나 사료(史料)의 부족으로 인해 끊임없는 시비가 이어졌다. 그러나 최근 이와 관련한 연구와 다량의 자료들이 발굴되고 제시됨으로써 한국 합기도의 역사가 명확해지기 시작하였다. 따라서 이 연구에서는 한국 합기도와 일본 아이기도의 기원이 되는 ``대동류합기유술``에 대한 고찰을 통하여 합기도의 역사적 정체성을 찾을 수 있는 발판을 마련하고자 하였다. 즉 한국 합기도의 ``정체성 혼란``이라는 시비의 도가니에서 벗어날 수 있는 계기를 마련하고자 한 것이 이 연구의 목적이다. It is a realistic issue for Korean Hapkido to establish its existence and the fact that it is different from Japanese Aikido. The purpose of this study was to discuss the historical context of Korean martial arts and the development of Korean Hapkido in search of the tradition and historical root of Korean Hapkido. The following are the results of this study: there is a reliable ancient text that states that Daedongryu Hapkiyusul, the root of Korean Hapkido, has originated from Shilla. Korean Hapkido was created by Sillasaburo Yosimitsch and was transmitted to Choi Yong Sul(1899-1986) by Takeda Sokaku(1859-1943) to take its present form. Korean Hapkido, reestablished by Choi Yong Sul after the Korean independence, roots from practical Korean martial arts. Many generations of his pupils have also developed and succeeded Korean Hapkido until today.

공구경로 및 자세의 선정과 이송률 제어를 통한 임펠러 표면조도 개선에 관한 연구

황종대(Jong Dae Hwang),오지영(Ji Young Oh),정윤교(Yoon Gyo Jung) 대한기계학회 2008 大韓機械學會論文集A Vol.32 No.12

5-axis NC machining has a good advantage of the accessibility of tool motion by adding two rotary axes. It offers numerous advantages such as expanding machining fields in parts of turbo machineries like impeller, propeller, turbine blade and rotor, reasonable tool employment and great reduction of the set-up process. However, as adding two rotary axes, it is difficult to choose suitable machining conditions in terms of tool path, tool posture, feedrate control at a tool tip and post-processing. Therefore in this paper, it is proposed to decide suitable machining condition through an experimental method such as adopting various tool paths, tool postures, and feedrate types. Machining experiment on AL7075 for impeller is performed to define suitable machining condition, and measurement of surface roughness on machined surfaces depended on each machining condition is performed. By defining suitable machining condition, we should have conclusion as improving the surface quality in the aspect of surface roughness and machined shape of surface.

기하학적 형상정보와 벡터망을 이용한 임펠러의 5축가공

황종대(Jong-Dae Hwang),윤일우(Il-Woo Yun) 한국기계가공학회 2020 한국기계가공학회지 Vol.19 No.3

Two rotational motions of the 5-axis machine tool maximize the degree of freedom of the tool axis vector, which improves tool accessibility; however, this lowers feed speed and rigidity, which impairs machining stability. In addition, cutting efficiency is lowered when compared with a flat end mill because typically, the ball-end mill is used when machining by rotational motion. This study increased cutting efficiency by using a corner radius flat end mill during impeller roughing. Furthermore, we proposed a fixed controlled machining of the rotary motion using geometric shape information to improve the feed speed and machining stability. Finally, we proposed a finishing tool path generation method using a vector net to increase the convenience and practicality of tool path generation. To verify its effectiveness, we compared the machining time, shape accuracy, and surface quality of the proposed method and an existing dedicated module.

편심구동장치 시제품 개발을 위한 3D프린팅-5축가공 복합기술

황종대(Jong-Dae Hwang),양준석(Jun-Seok Yang),윤성환(Sung-Hwan Yun),정윤교(Yoon-Gyo Jung) 한국기계가공학회 2016 한국기계가공학회지 Vol.15 No.2

Since a 5-axis machine tool has two rotary axes, it offers numerous advantages, such as flexible accessibility, longer tool life, better surface finish, and more accuracy. Moreover, it can conduct whole machining by rotating the rotary feed axes while setting the fixture at once without re-fixing in contrast to conventional 3-axis machining. However, it is difficult to produce complicated products that have a hollow shape. In contrast, 3D printing can produce an object with a complicated hollow shape easily and rapidly. However, because of layer thickness and shrinkage, its surface finish and dimensional accuracy are not adequate. Therefore, this study proposes hybrid technology by integrating the advantages of these two manufacturing processes. 3D printing was used as the additive manufacturing rapidly in the whole body, and 5-axis machining was used as the subtractive manufacturing accurately in the joining and driving places. The reliability of the proposed technology was verified through a comparison with conventional technology in the aspects of processing time, surface roughness. and dimensional accuracy.

고효율 LED 식물재배 시스템 개발

황종대(Jong-Dae Hwang),고동수(Dong-Su Ko) 한국기계가공학회 2014 한국기계가공학회지 Vol.13 No.4

This study was carried out to develop an efficient plant growth system that can be controlled by altering the wavelength and illumination using a LED module. If it is possible to develop a system that can be controlled in this manner, utilizing different characteristics in the meaningful wavelength band depending on the growth time or type of plant, the plant growth conditions can be optimized. In order to this, red, green, blue and white LEDs are arrayed in a rectangle, consisting of LED modules which can be combined with each other. Consequently, the array can be used to select the optimal light conditions with monochromatic red, green, blue and white LEDs, or mixed LEDs, for plant growth. Experiments on the characteristics of the wavelengths to evaluate the efficiency of the plant growth system were performed. The usefulness of the system was demonstrated through a cultivation test involving several special plants.

LED광원의 광파장 특성에 따른 식물의 성장도 평가

황종대(Jong-Dae Hwang),고동수(Dong-Su Ko) 한국기계가공학회 2014 한국기계가공학회지 Vol.13 No.5

This study was carried out to evaluate the plant growth rate according to the wavelength characteristics of LED light sources. In order to achieve this, red, green, blue and white LEDs were arrayed in a rectangle array consisting of LED modules which can be combined with each other.. This can facilitate the selection of the optimal characteristics of the light from monochromatic red, green, blue and white LEDs or mixed LEDs for plant growth. Experiments to evaluate the growth rate according to the wavelength characteristics of the LEDs with several plants, in this case ice plants, lettuce, barley, broccoli and chives, were performed.

스크류 유량계의 개발 및 정밀 성능평가에 관한 연구

황종대(Jong Dae Hwang),오지영(Ji Young Oh),정윤교(Yoon Gyo Jung),이상렬(Sang Ryul Lee) Korean Society for Precision Engineering 2009 한국정밀공학회지 Vol.26 No.5

드릴, 보링 공정복합형 스텝 커터의 개발

황종대(Jong Dae Hwang),허윤녕(Yun Nyoung Heo),오지영(Ji Young Oh),정윤교(Yoon Gyo Jung),조성림(Sung Lim Cho) 한국기계가공학회 2008 한국기계가공학회지 Vol.7 No.3

As demands for being economical, precise drilling process is on the increase. Therefore, the objective of this study is to develop a step cutter that can be controllable through micro dimension and can be changed from separate manufacturing processes of drilling and boring into an integrated one. In order to attain this object the step cutter is designed with a 3D geometric modeling and the design could be modified easily by using parametric modeling methodology. Also, collision is not occurred during manufacturing process because of cutting simulation. The step cutter is assembled by parts made up of 5-axis machining and sintering. Validation tests are accomplished. They show that developed cutter has characteristics such as reduction of machining time as well as the good surface roughness of the machined hole. Indeed, reliability could be obtained from a durability test.

기하학적 특성을 이용한 프로펠러의 효율적인 5축가공

황종대(Jong-Dae Hwang),윤일우(Il-Woo Yun) 한국기계가공학회 2020 한국기계가공학회지 Vol.19 No.4

The rotary feed axes of a 5-axis machine tool can increase the freedom of the tool posture, while reducing feed speed and rigidity. In addition, as a ball-end mill is inevitably used during machining by rotational feed, the step-over length is reduced compared to the flat-end mill, thereby reducing the material removal rate. Therefore, this study attempts to improve the material removal rate, feed speed, and machining stability using the corner radius flat-end mill and a fixed controlled machining method for the rotary feed axes during roughing. In addition, the tapered ball-end mill and simultaneously controlled machining method for the rotary feed axes were used for finishing to improve the propeller"s 5-axis machining efficiency by enhancing the surface quality. In order to create the tool path effectively and easily, we propose a specific approach for using the propeller"s geometric properties and evaluate the effectiveness of the proposed method by comparing it with the method of the dedicated module.

MC-Space 알고리즘을 이용한 역공학 효율성 증대에 관한 연구

황종대(Jong-Dae Hwang),정윤교(Yoon-Gyo Jung),정종윤(Jong-Yoon Jung) 한국생산제조학회 2005 한국공작기계학회 추계학술대회논문집 Vol.2005 No.-

This study deals with the improvement of efficiency in the aspect of accuracy and time reduction in the reverse engineering. For this, two main strategies are applied in this paper. One is the path smoothness strategy, the other is the collision free strategy. Path smoothness strategy adopts modified B-spline algorithm that is constructed with altered control vertices. It allows improvement of accuracy of reverse engineering with faired surface. Collision free strategy adopts configuration space algorithm defined by two parameters which determine the probe posture. It allows a time reduction of reverse engineering without collision. So this two strategies are named, MC-Space algorithm.