국제사료명에 있어서의 부위(항목2) 에 대한 용어 설명

박홍석,최진호 한국영양사료학회 1981 韓國營養飼料學會誌 Vol.5 No.1

DESIGN OF CONFORMAL COOLING CHANNELS FOR AN AUTOMOTIVE PART

박홍석,N. H. PHAM 한국자동차공학회 2009 International journal of automotive technology Vol.10 No.1

The cooling system plays a crucial role in determining the bproductivity and quality of an injection molding process. With the current growth of Solid Freeform Fabrication (SFF) techniques, mold designers have been striving for not only improvement in cooling system performance but also for a method to do so automatically. In this paper, a method is proposed for developing a conformal cooling system that facilitates uniform cooling over the entire mold surface with minimum cycle time. Based on the temperature distribution after the filling stage, the mold surface is split into zones which will be cooled by optimized subconformal channels obtained from the optimization process. The optimization process in which the objective function is stated as minimization of the cooling time with boundaries ensuring a realistic design will optimize the cooling system layout in terms of cooling channel size and location. Finally, all subcooling channels are combined to generate the entire conformal cooling system for the injection mold. The cooling system plays a crucial role in determining the bproductivity and quality of an injection molding process. With the current growth of Solid Freeform Fabrication (SFF) techniques, mold designers have been striving for not only improvement in cooling system performance but also for a method to do so automatically. In this paper, a method is proposed for developing a conformal cooling system that facilitates uniform cooling over the entire mold surface with minimum cycle time. Based on the temperature distribution after the filling stage, the mold surface is split into zones which will be cooled by optimized subconformal channels obtained from the optimization process. The optimization process in which the objective function is stated as minimization of the cooling time with boundaries ensuring a realistic design will optimize the cooling system layout in terms of cooling channel size and location. Finally, all subcooling channels are combined to generate the entire conformal cooling system for the injection mold.

진화형 제조시스템 실현을 위한 생체 모방 기술

박홍석,박진우,Tran Ngoc-Hien,김동훈,송준엽 대한전자공학회 2011 전자공학회지 Vol.38 No.3

DEVELOPMENT OF A FIBER-REINFORCED PLASTIC ARMREST FRAME FOR WEIGHT-REDUCED AUTOMOBILES

박홍석,X. P. DANG 한국자동차공학회 2011 International journal of automotive technology Vol.12 No.1

This paper presents the design optimization process of a short fiber-reinforced plastic armrest frame to minimize its weight by replacing the steel frame with a plastic frame. The analysis was carried out with the equivalent mechanical model and design of experiment (DOE) method. Instead of considering the whole structure, it is divided into three simpler regions to reduce the complexity of the problem through examining its structural characteristics and load conditions. The maximum stress and deflection of the regions that carry the normal load are calculated by the analytical mathematical form derived from an equivalent model. The other regions loaded by contact stress are handled by FEM (finite element method), the DOE method, and the RSM (response surface model). To optimize the design variables in both cases, the object functions derived from these calculations are solved with a CAE (computer aided engineering) tool. This method clearly shows the mechanical and mathematical representation of structural optimization and reduces the computing costs. After design optimization, the weight of the optimum plastic-based armrest frame is reduced by about 18% compared to the initial design of a plastic frame and is decreased by 50% in comparison with the steel frame. Some prototypical armrest frames were also made by injection molding and tested. The research results fulfilled all of the design requirements.

A New Approach for Molding Multi Component Parts

박홍석,Dinh Ba Hung Anh 한국정밀공학회 2010 International Journal of Precision Engineering and Vol. No.

Injection molding has gained an enormous importance over the last twenty years. This is due both to the development of sophisticated products and to the efforts being generally made to the reduction of product weight specially in automobile industry. Developments aimed at creating innovative products are expected to broaden industrial implementation of their techniques. Establishment then requires the progressive development of existing mold techniques and engineering knowledge. This paper describes a successive process for molding multi component complicated products such as door trim, instrument panel and so on. Using an analytical model, the orthogonal experiment method (Taguchi method) and numerical simulation, an optimal process for simultaneous injection molding with “core-back” and “co-injection” technique is presented to produce such innovative products. Through practical tests, this process was verified in terms of applicability.

비강내 발생한 연골-골화성 선종양 과오종 1예

박홍석,최장원,송창윤,구수권 대한비과학회 2011 Journal of rhinology Vol.18 No.2

Hamartoma is a non-malignant malformation or developmental anomaly of tissue development that may occur anywhere in the body but is rarely reported in the nasal cavity, paranasal sinuses, or nasopharynx. Chondro-osseous respiratory epithelial adenomatoid hamartoma (CO-REAH) of the nasal cavity is exceedingly rare, and can be confused both grossly and microscopically with more serious sinonasal tumors. We present the case of a 58-year-old man with a nasal cavity mass, which was removed by an endonasal approach. Radiographic and histological studies permitted a diagnosis of CO-REAH in this case. KEY WORDS:

Reduction of Heat Losses for the In-line Induction Heating System by Optimization of Thermal Insulation

박홍석,Xuan-Phuong Dang 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

Improving the electrical energy efficiency of the manufacturing process is the imperative task to resolve the cost-saving pressure and environmental legislations. This paper focuses on a study on the thermal efficiency of the in-line induction heating systems that are using in the hot forging applications. Besides optimizing the process parameters that increase the electromagnetic and thermal efficiency, reducing the heat losses to the surrounding air is one of the practical ways to save the operating energy. The weakness of the current in-line induction heating systems were pointed out, and we proposed an insulating system to reduce the heat losses caused by convection and radiation. The analytical model of the heat transfer and the simulation model were built to calculate and verify the thermal efficiency of the insulating covers. The results show that using insulating covers at the open spaces between adjacent heaters of an in-line induction heating for automotive crankshaft forging can approximately reduce 9% of heat losses compared with the energy stored in the workpiece. The best values of the geometrical design parameters of the insulating cover were determined by solving the constrained optimization that considers some technological aspects of the proposed insulating system. This work is intended as a contribution to make the hot forging industry become greener and more efficient in terms of saving operating energy.

제품개발 지원을 위한 협업 시스템

박홍석,최홍원,Park, Hong-Seok,Choe, Hong-Won 대한기계학회 2007 기계저널 Vol.47 No.4

공정 지향적인 프로그래밍 시스템

박홍석 한국경영과학회 1996 한국경영과학회 학술대회논문집 Vol.- No.1

This paper presents an algorithmic approach used in the development of a task-level off-line programming system for the efficient application of robot. In the method, robot tasks are graphically described with manipulation functions. By applying robot language these graphic robot tasks are converted into commands for the robot. A programming example demonstrates the potentiality of task-oriented robot programming.

Optimization of bending sequence in roll forming using neural network and genetic algorithm

박홍석,Tran-Viet Anh 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.8

In the roll forming process, the bending sequence plays a major role in the product quality. The optimal bending sequence results in the smallest number of passes and the flawless process. This paper presents a new optimization procedure of bending sequence in a roll forming process. The multilayer perceptron is used to build the neural network (NN), which models the variation of longitudinal strain in process while the genetic algorithm (GA) is employed to optimize the bending sequence. The data used for training the network is automatically obtained by the integration between CAD and CAE. The values of peak longitudinal strains are maximized while the number of passes is reduced to the smallest and the constraint conditions being set on the maximal longitudinal strain to avoid buckling. The overbending at final pass after spring back is also considered in this paper. Two roll forming processes are optimized in order to prove applicability and efficiency of the optimization procedure. This method maintains the longitudinal strain less than the buckling limit,whereas reducing the number of passes to the smallest. Thus, the advantages of the proposed method show the high applicability in designing and optimizing the bending sequence in the roll forming process.