• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.6
• /
• pp.160-165
• /
• 1999

In surface grinding, the conditions of the grinding wheel give a significant effect on the ground workpieces comparing with other metal removal provesses. In this paper, to assist the development, a non-contacting optical method by the laser beam is introduced. The in-process measurement of scattering intensities has been made during surface grinding processes and the surface textures of wheel working surfaces are captured. Also, in order to determine the dressing time monitoring method of a grinding wheel, a three-dimensional computer simulation of the grinding operation has been attempted based on the contact mechanism and the surface-shaping system between the grinding wheel and the workpiece. The optimal dressing time is determined by the amount of the grain wear and work surface roughness.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.818-821
• /
• 2004

With a rapid development in the area of micro and ultra precision technology, the micro surface machining of small size parts are explosively increased. Especially, to improve efficiency of various beams in lens and reflector, non-rotational symmetric form and several mm level heights changeable surface can be machined at a time. These geometric complex 3D surface cannot be machined by general short stroke FTS. The long stroke FTS if firmly needed to move directly several mm and have nm level positioning accuracy for the complex surface form. The long stroke FTS used linear motors to drive moving unit long and fine, aero static bearings to decrease friction and moving errors in guide way, optical linear scale with nm level resolution to measure position of FTS. Furthermore, to increase the performance of acceleration of FTS, the light material, such as AL is used for the structure and the high stiffness box type structure is selected. In this paper, the genetic algorithm approach is described to determine a set of design parameters for auto tuning. The authors have attempted to model the design problem with the objective of minimizing the error, such as variable pattern change. This method can give the better alternative than existing other method.

• Proceedings of the KSME Conference
• /
• 2001.11b
• /
• pp.897-902
• /
• 2001

SBOS(Soot blower Optimum System) analyzes the accumulated fouling rate of a coal-fired boiler plant at short intervals, compares it with a reference data, and determines the optimal time of soot blowing. In this paper, ANFIS algorithm which is an optimal algorithm to detect variation of boiler performance with time, updating the reference data and to eliminate the effects of noise in field signal is used to clean heating surface and to reduce steam needed to blow the soot.

• Journal of the Korean Dietetic Association
• /
• v.24 no.1
• /
• pp.31-47
• /
• 2018

The purpose of this research was to provide basic information for cookies made with black soybeans, chick peas, lentils, oatmeal, and brewer's yeast and to establish the optimum formula for the development of low glycemic index (GI) cookies with high biotin content for lactating women. This study was performed to determine the optimal composite recipe of oatmeal cookies with two different concentrations levels of bean powder (black soybeans, chick peas, lentils) and brewer's yeast using a central composite design. In addition, the mixing conditions of oatmeal cookies were optimized using response surface methodology of sensory evaluation and mechanical and physicochemical analysis. As a result, mechanical and physicochemical analyses showed significant values for lightness, redness, yellowness, hardness, and water content (P<0.05), while sensory evaluation showed significant values for flavor, taste, crispness, and overall acceptability (P<0.05). The optimal sensory combination was suggested to be 3.73 g of bean powder and 1.59 g of brewer's yeast. Considering all outcomes obtained throughout the experiments, brewer's yeast, black soybeans, chick peas, lentils, and oatmeal are suitable ingredients for increasing functionality and consumer acceptability of cookies. In addition, these results are expected to be useful in producing cookies of optimal quality, contributing to the development of various nutritious foods, and improving the food industry for lactating women.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.4 no.1
• /
• pp.36-40
• /
• 1999

Optimal lyophilization process was developed for manufacturing the dried product of Lactobacillus acidophilus with high cell viability. Three major factors, freezing rate, specific surface area of samples, and stabilizer type and their synergy were shown to play a crucial role in the development of an effective lyophilization process. Finally we found an optimal combination among three process parameters mentioned above; an exceptionally high cell survival percentage of 90% was achieved using the 8.28 cm-1 specific surface area of samples, slow freezing rate, and a stabilizer composition of 4% skim milk +1% glycerol +0.1% calcium chloride.

• Proceedings of the KSME Conference
• /
• 2001.06c
• /
• pp.580-585
• /
• 2001

A response surface method(RSM) is utilized for structural optimization and implemented on a parametric CAD platform. Once an approximation of the performance function is made, no formal design sensitivity analysis is necessary. The approximation gives the designer the sensitivity information and furthermore intuition on the performance functions. The scheme for the design of experiment chosen for the RSM has a large influence on the accuracy of converged solutions and the amount of computation. The D-optimal design criterion as implemented in this paper is found efficient for the structural optimization. The program is developed on a parametric CAD platform and tested using several shape design problems of such as a torque arm and a belt clip. It is observed that the RSM used provides a faster convergence than other approximation methods for design sensitivity.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.04a
• /
• pp.111-117
• /
• 2004

The tool geometry parameters and cutting process have complex relationships. Until now, various cutting test were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process. In high speed machining. Using various tools with different geometry, relationships between tool geometry parameter (rake angle, clearance angle, length of cutter) and cutting process (cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining and developed tool geometry design S/W.

• International Journal of Precision Engineering and Manufacturing
• /
• v.4 no.1
• /
• pp.23-29
• /
• 2003

Stencil is used normally as a mask for solder pasting on pad of a printed circuit board (PCB). The objective of this study is to develop a stencil cutting system and determine the optimal conditions to make good-quality stencil by using a Nd:YAG laser. The effects of process parameters such as laser power, type of mask, gas pressure, cutting speed and pulse duration on the cut edge quality were investigated. In order to analyze the cut surface characteristics (roughness, kerfwidth, dross) optical microscopy, SEM microscopy and roughness measurements were used. As a result, the optimal conditions of cutting process parameters were determined, and the practical feasibility of the proposed system was also examined by using a commercial Gerber file for PCB stencil manufacturing.

• IE interfaces
• /
• v.10 no.1
• /
• pp.155-167
• /
• 1997

The purpose of this study is to develop the program for efficient operation of a multi-functional surface mounting device(SMD) which mount various components on a printed circuit board(PCB). These components are provided by diverse types of feeders such as cassette, stick and tray feeders. The SMD has one or two heads. In the SMD, the positions of PCB and feeders and fixed, and the head moves to pick up a component from a feeder and to mount it on the PCB. The number of lanes occupied by each feeder and the nozzle used for each component can be different. We develop an off-line program to minimize the cycle-time of the SMD by studying the optimal assignment of feeders and the optimal mounting sequence of components. Graphical User Interface(GUI) is also developed. Additionally, we consider the line balancing problem which appears when two SMDs are used sequentially.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.989-992
• /
• 1997

The objective of this study is to develop stencil cutting process and determine optimal conditions which make good-quality stencil by using a Nd:YAG laser. The effects of process parameters such as laser power, type of mask, gas pressure, cutting speed and pulse width on the cut edge quality were investigated. In order to analyze the cut surface characteristics(roughness, kerf width, dross) optical microscopy, SEM photography and roughness test were used. A a results, the optimal conditions of process parameters were determined, and the practical feasibility of the proposed system is also examined by using a commercial gerber file for PCB stencil manufacturing.