Verification of Simulation of Surface Texturing on Planar Surface By Grinding

김호찬,고태조 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

Surface texturing is a means of pattern generation on a workpiece surface to provide functionality or for aesthetic reasons. Grindingis one of the various technology used for surface texturing. Compared with other methods (such as lasers, abrasive jet machining,mechanical cutting or rolling, and etching), grinding has some advantages for large-area texturing. In texturing by grinding, thegrinding wheel needs particular shapes such as helical grooves on the peripheral surface of the wheel, depending on the shape ofpatterns to be generated on a workpiece. A grinding wheel with a helical groove generates patterns on the workpiece by the relativemotion of the wheel and the workpiece. The pattern shapes are determined according to the combination of the grinding wheel speedand feed rate, as well as the geometry of the helical groove of the wheel. Before texturing, it is important to predict the texturedpatterns with a mathematical model. If the textured patterns are predictable, the shape of the grinding wheel and the grindingparameters can be determined. This paper proposes a mathematical model for the prediction of pattern generation, and verificationof texturedpatterns based on the simulation resultsis given.

과대망상을 보이는 Wilson씨 병 사례

김호찬,이창영,오동원 고신대학교 의학부 1990 高神大學校 醫學部 論文集 Vol.6 No.2

The authors experienced a case of Wilson's disease coincidentally occured in brothers. The younger manifested grandiose delusion, elevated mood, visual hallucination and emotional lability, impulsive behavior. The elder showed non-specific symptoms. The patient was treated with small dosage of antipsychotics, D-penicillamine and oral zinc, low copper diet When sloped antipsychotics, the psychotic symptoms relapsed. We reported this patient and reviewed the related articles.

Cannabinoid Receptor Agonist가 만성 저산소환경에 의한 두뇌 겉질 신경세포의 자멸사에 미치는 영향

김호찬 고신대학교 의과대학 2009 고신대학교 의과대학 학술지 Vol.24 No.1

Chronic hypoxia has been associated with change in neurovascular behavior. The expression of cannabinoid receptors in brain has been well established and their agonists are thought to modulate neuronal activity and have the neuroprotective function in animal models of hypoxic-ischemia. In this work, we investigated the influence of cannabinoid receptor agonist (win 55.212.2) on cell death progress induced by chronic hypoxia. Rats were incubated in hypoxia conditions consisted of a mixture of 2% O2, 5%CO2, 93% N2. The solution containing WIN55.212.2 was injected into rats twice a day (every 12h) for 7 days. Synthetic cannabinoid receptor agonist, WIN55.212.2 inhibits the cell death by chronic hypoxia. Also it inhibits neuron apoptosis. These data support that WIN55.212.2 would rescues neurons from apoptosis by chronic hypoxia. Also it suggests that WIN55.212.2 may be therapeutic drug for neuronal death by chronic hypoxia.

역공학에서의 Delaunay 삼각형 분할에 의한 STL 파일 생성

김호찬,허성민,이석희 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.5

선형 SISO 시스템의 공분산 배치이론에 관한 연구

김호찬 濟州大學校 産業技術硏究所 1998 산업기술연구소논문집 Vol.9 No.1

In this paper, an alternate method for state-covariance assignmer for SISO(sing1e input single output) linear systems is proposed. This method is based on the inverse solution of the Lyapunov matrix equation and the resulting formulas are similar in structure to the formulas for pole placement. Further. the set of all assignable covariance matrices to a SISO linear system is also characterized.

과모델된 선형시불변 시스템을 대상으로한 견실한 적응제어

金豪贊 濟州大學校工科大學産業技術硏究所 1996 尖端技術硏究所論文集 Vol.7 No.2

We design a robust adaptive controller based on the internal model control (IMC) structure for stable plants. The order of the controller can be lower than that of the plant. Some robustness properties of the IMC structure against modeling errors are presented and the concept of gain margin is utilized to make the adaptive system robust. In addition. we prove the stability of the proposed adaptive control algorithm. Simulation result shows the relation between performance and the order of the controller.

닫힌형태의 그래미언을 사용한 불안정한 SISO 시스템의 모델축소

김호찬 濟州大學校工科大學産業技術硏究所 1996 尖端技術硏究所論文集 Vol.7 No.1

This paper develops a simple approach to balanced model reductions for unstable linear continuous-time SISO systems. First, the controllability, observability, and cross Gramians are directly obtained from the coefficients of the transfer function using the Routh array in a closed-form. Based on these Gramians, a simple algorithm is proposed to compute a reduced order model based on balancing and truncation technique for unstable SISO systems. This algorithm is simpler and numerically more efficient in computing the Gramians than presently existing algorithms. If the unstable system can be balanced, then the proposed algorithm gives a reduced order model which has the same number of unstable poles as the original model.

복소수이미지 방법을 이용한 겉보기 대지저항률 계산

김호찬,부창진,강민제 한국전기전자학회 2019 전기전자학회논문지 Vol.23 No.1

The apparent soil resistivity is used for estimating multilayer soil parameters, such as, layer’s depth and soilresistivity. The apparent soil resistivity can be measured, and also can be calculated if soil parameters are given,becacuse the apparent soil resistivity is a function of these parameters. Therefore, any optimization algorithms can beused to find these parameters which make the calculated apparent soil resistivity close to the measured one. Theequation for calculating the apparent soil resistivity is complicated and time consumed, because it is composed of aninfinite integral which includes a zero order Bessel’s function of the first kind. In this paper, a fast algorithm forcalculating the apparent soil resistivity of horizontal multilayer earth structure has been presented using complex imagemethod. 겉보기대지저항률은 층의 깊이와 대지저항률과 같은 다층 대지파라미터들을 추정하는 데 사용된다. 겉보기대지저항률은측정 될 수 있으며, 또한 겉보기대지저항률은 이들 파라미터들의 함수이기 때문에 주어진 대지 파라미터들로 계산 될 수 있다. 따라서 모든 최적화 알고리즘을 사용하여 계산된 겉보기대지저항률을 측정된 대지저항률에 가깝게 만드는 이들 파라미터들을 찾을 수 있다. 겉보기대지저항률을 계산하기위한 방정식은 0 차 Bessel함수를 포함하는 무한 적분으로 구성되어 있기때문에 복잡하고 시간 소모적이다. 본 논문에서는 수평 다층 구조의 겉보기대지저항률을 계산하기 위한 빠른 알고리즘이 복소수이미지 방법을 사용하여 제시되었다.

Additive manufacturing of smart insole by direct printing of pressure sensitive material

김호찬,박성철,이인환 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.12

3D printing technology is gaining attention as one of the key technologies that will lead the fourth industrial revolution. In addition, the field of application is from trial production to mass production of products. However, in many cases, the application area is limited to the geometrical shape building of products. This paper shows an example of application technology for manufacturing the smart insole by applying 3D printing technology for the purpose of giving various functions as well as making geometric shape. In the production of smart insole, 3D printing technology is applied to direct printing of pressure sensitive sensor and highly conductive wire as well as flexible insole object itself. The materials used in the production of flexible products, conductors and sensor are different, and in order to produce the sensor by 3D printing, suitable materials have been directly manufactured and used. This paper shows that the 3D printing technology can be directly applied to the manufacturing of multi functional products through the above manufacturing process as well as the experimental results after the actual production.

과대망상을 보이는 Wilson씨 병 사례

김호찬,이창영,오동원 高神大學 醫學部 1990 高神大學醫學部 論文集 Vol.6 No.2