나눔마당 : 세아해암학술상 수상자 -박종진 교수

박종진 대한금속재료학회 2016 재료마당 Vol.29 No.1

하이힐 굽 높이에 따른 보행 시 족저압 변화 비교 분석

박종진 한국운동역학회 2009 한국운동역학회지 Vol.19 No.4

We aimed to determine the effect of heel height on foot pressure by comparing and analyzing data on foot pressure in shoes with different heel heights. On the basis of a previous study, we selected 3cm and 7cm as the shoe heel heights preferred by female college students. We divided 10 female students into forefoot and hindfoot to measure vertical force, maximum pressure, and average pressure. The average pressure on the forefoot was higher and that on the hindfoot was lower in the case of 7cm high-heeled shoes. The maximum pressure on the forefoot was significantly higher in the case of the 7cm heel height (p<.05). The vertical force, maximum pressure, and average pressure on the hindfoot were also significantly higher in the case of the 7cm heel height (p<.05). The results showed that wearing 7cm high-heeled shoes exerted greater maximum pressure on the forefoot and greater vertical force, maximum pressure, and average pressure on the hindfoot. This leads to increase in confining pressure caused by high pressure distribution over the forefoot and increase in the pressure on the hindfoot, which may cause deformation of toes and heel pain over a long period. Therefore, female college students who wish to wear high heels are recommended to wear 3cm high-heeled shoes rather than 7cm high-heeled shoes. 본 연구는 구두 굽 높이 변화에 따른 보행 시 족저압력을 비교, 분석함으로써 구체적인 데이터를 정량화하여 높은 굽을 착용함으로 인한 전족부의 압력 증가가 발에 미치는 영향을 알아보고자 한다. 본 연구에 사용된 구두는 선행연구를 바탕으로 여대생이 선호하는 구두 굽 높이 3cm, 7cm를 선택하였으며 여대생 10명을 대상으로 발을 전족부와 후족부로 나누어 수직힘, 최대압력, 평균압력을 측정하였다. 그 결과 전족부에서의 평균압력은 7cm 높이 구두가 높게 나타났으며, 후족부에서는 7cm 높이 구두가 낮게 나타났다. 통계처리 결과 전족부위에서는 3cm 굽 높이와 7cm 굽 높이의 최대압력 비교에서 유의한 차이가 나타났으며(p<.05), 후족부위에서는 수직힘, 최대압력, 평균압력 모두 유의한 차이가 나타났다(p<.05). 이상과 같이 구두를 착용함으로서 전족부의 최대압력이 높아지는 것은 물론이고 후족부위의 수직힘, 최대압력, 평균압력도 높아지는 것을 알 수 있었다. 이러한 현상은 전족부위에 높은 압력분포로 구속압이 증가하여 발가락의 변형을 유발할 수 있으며 후족부위에 압력증가는 장시간 착용 시 뒤꿈치의 통증을 유발할 수 있다. 따라서 굽이 있는 구두를 착용할 때 굽 높이가 7cm일 때 보다는 3cm일 때, 굽 높이가 낮을수록 전족부의 변형 예방과 후족부의 통증을 줄일 수 있을 것으로 기대된다.

Finite-Element Analysis of Radial Extrusion for a Thin Disk with Severe-Plastic Deformation

박종진 대한금속·재료학회 2012 METALS AND MATERIALS International Vol.18 No.3

Severe plastic deformation is an effective method to obtain fine or ultrafine grains in metallic materials. In the present study, a radial extrusion of a round bar was investigated for the capability of producing a thin disk by severe plastic deformation by the rigid-plastic finite-element method. Similar to the deformation mechanism in the ECAP, the shear deformation was observed to develop at the corner of the container; its magnitude increases as the radius of the corner decreases. Additional plastic deformation was obtained as the material flowed in the radial direction. However, waviness of the sheet in the radial direction and occurrence of cracking were observed at the periphery of the disk. To resolve these problems, the bottom surface of the container was conically designed in order to provide an inclination angle along the radial direction. This process was further modified to a radial extrusion of a pipe for a hollow disk or thin ring with severe-plastic deformation.

교육시설분야의 건축계획 연구동향 분석

박종진,소갑수,김승제,Park, Jong-Jin,So, Kab-Soo,Kim, Seung-Je 한국교육시설학회 2012 교육시설 Vol.19 No.6

According to the reports by the OECD and UN in 2012, Korea is evaluated highly of its enthusiasm and level of education compared to other evaluation indices. This result implies that Korea has much more interest in education than other countries. In reality however, the nation does not provide an adequate condition in other aspects such as the quality of life of citizens and its educational environment. For this reason, our country currently promotes and operates various policies and environmental improvements in an effort to coincide with the timely demands and to cope up with the advanced educational system. Researches in particular are being implemented on Korea's current educational policies by specialists related to their specific fields. This study is to understand the periodic trends of the educational facilities according to the specialist-oriented articles and apply it as a basic resource to the future researches on the corresponding field.

Finite-Element Analysis of a Vertical Twin-Roll Casting

박종진 대한금속·재료학회 2014 METALS AND MATERIALS International Vol.20 No.2

Metallic strips can be produced by twin-roll casting, in which the melt is cooled, solidified, and rolled to aspecific thickness. In the present study, the rigid-thermoviscoplastic finite-element method was applied tothe analysis of complex phenomena including melt flow, heat transfer, solidification, and plastic deformationoccurring in a vertical twin-roll casting of magnesium alloy AZ31. The melt was found to be confined in rotationalmotions of two symmetric vortexes developed at the roll entrance, and thus only the melt near the nozzlewall became solidified and rolled to a sheet. As the nozzle thickness increased, the vortex increased in sizeresulting in more bifurcation and instability, which are definitely adverse to material properties of the strip. The maximum cooling rate of 600 °C/s was found at the centerline as solidification took place at the rollexit. Other findings are also discussed including roll force, roll torque, and pressure distribution, which weregreatly dependent upon the plastic deformation after solidification.

耳性帶狀疱疹의 5例

朴鍾珍 대한이비인후과학회 1973 대한이비인후과학회지 두경부외과학 Vol.16 No.-

초등학교 검도 수련생들의 정서 및 사회성 경향

박종진 한국스포츠리서치 2006 한국 스포츠 리서치 Vol.17 No.2

시간 지연 연속 시간 시스템의 디지털 모델링

박종진,최규석,박인규,강정진 한국인터넷방송통신학회 2012 한국인터넷방송통신학회 논문지 Vol.12 No.1

Control Theory for continuous-time system has been well developed. Due to the development of computer technology, digital control scheme are employed in many areas. When delays are in control systems, it is hard to control the system efficiently. Delays by controller-to-actuator and sensor-to-controller deteriorate control performance and could possibly destabilize the overall system. In this paper, a new approximated discretization method and digital design for control systems with multiple state, input and output delays and a generalized bilinear transformation method with a tunable parameter are also provided, which can re-transform the integer time-delayed discrete-time model to its continuous-time model. Illustrative example is given to demonstrate the effectiveness of the developed method. 연속시간 시스템의 제어 이론은 잘 개발되어 왔다. 컴퓨터 기술의 발달로 인해 디지털 제어 기법이 여러 분야에 적용되어 왔다. 제어 시스템에 시간 지연이 있는 경우는 시스템을 효율적으로 제어하는 것이 어렵다. 제어기와 액츄에이터 그리고 센서와 제어기 간에 있는 지연은 제어 성능을 떨어뜨리고 전체 시스템을 불안정하게 할 수 있다. 본 논문에서는 다중의 상태, 입력 그리고 출력 지연을 가지는 제어 시스템을 위한 새로운 근사 이산화 방법과 디지털 설계 그리고 조정가능한 계수를 가지는 일반화된 쌍선형 변환 방법을 제안한다. 이 방법은 정수의 시간 지연을 가지는 이산 시간 모델을 동일한 연속 시간 모델로 다시 변환할 수 있다. 실제적인 예제를 통해 제안된 방법의 효율성을 증명한다.

쓰러기 소각로의 연소제어를 위한 퍼지모델 예측제어기 설계

박종진,강신준,남의석,김여일,우광방 한국지능시스템학회 1997 한국지능시스템학회논문지 Vol.7 No.2

Refuse incineration plant operations involve many kinds of uncertain factors, such as the variable physical properties of refuse as fuel and the complexity of the burning phenomenon. This makes it very dificult to apply conventional control methods to the combustion control of the refuse. So most of the refuse incineration plant are operated by operators. In this paper, an multi-variable fuzzy model predictive controller is proposed for the combustion control of the re:fuse. Adaptive network based fuzzy inference system is used for modeling of the refuse incineration plant and multi-variable fuzzy model predictive controller is designed based on the identified fuzzy model. And computer simulation was carried out to evaluate performance of the proposed controller.

소결분말금속의 항복함수

박종진 대한기계학회 1993 대한기계학회논문집 Vol.17 No.5

Several yield criteria for porous materials are compared with each other, defining the apparent yield stress as the yield stress of the porous material in simple compression. It was found that the plastic Poisson's ratio is the parameter needed to define the yield criterion, rather than the relative density. The plastic Poisson's ratio is regarded as a material characteristic that is obtained from a simple compression test. A new form of yield criterion was suggested, and it was applied to hydrostatic compression as well as uniaxial strain compression of sintered Al-2024 powder. The crossover point in the mean stress vs volume change curves of the processes was predicted. It is presented that the flow stress of the fully densed material can be obtained from that of the porous material using relations obtained from the yield criterion.