• Journal of the Korea Safety Management & Science
• /
• v.6 no.2
• /
• pp.251-262
• /
• 2004

There is boner process of stone manufacturing to become quality down of stone to consolidated micro crack appearance of stone surface and biotite by fire that is to be route process in stone surface by flame of LPG. And then, it is develop that stone surface process equipment by automation for the work method of boner process can be substitute work method by shotball blasting. To developement of equipment, There is to be down noise and dust. Acording to remove calamity growth hazardous substance in the work environment, there is to solve workplace avoidance factor. We have taken Taguchi's parameter design approch, specifically orthogonal array, and determined the optimal levels of stone surface through analysis of the experimental results using SIN ratio.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.7
• /
• pp.198-204
• /
• 1996

Electron beam lithography is one of the importnat technologies which can delineate deep submicron patterns. REcently, electron beam lithography is being applied in delineating the critical layers of semiconductor device fabrication. In this paper, we present a development simulation program for electron beam lithography and study the development profiles of resist when resist is exposed by the electron beam. Experimentally, the development parameter of positive and negative resists are measured and the data is applied to input parameter of the simulation program. Also simulation results are compared of the process results in the view of resist profiles. As a result, for PMMA and SAL 601 resist, the trend of simulation to the values of process parameters agree with real process results very well, so that the process results can be predicted by the simulation.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.37 no.1
• /
• pp.151-156
• /
• 2014

Control charts are generally used for process control, but the role of traditional control charts have been limited in case of a contaminated process. Traditional $\bar{x}$ control charts have not been activated well for such a problem because of trying to control processes as center line and control limits changed by the contaminated value. This paper is to propose robust $\bar{x}$ control charts which is considering a location parameter in order to respond to contaminated process. In this paper, we consider $\bar{x}_{\alpha}$, that is trimmed rate; typically ten percent rate is used. By comparing with p, ARL value, the responding results are decided. The comparison resultant results of proposed two control charts are shown and are well contrasted.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.7
• /
• pp.178-187
• /
• 1999

In order to identify a transfer function model with noise, penalty function method has been widely used. In this method, estimation process for possible model parameters from low to higher order proceeds the model identification process. In this study, based on linear estimation method, a new approach unifying the estimation and the identification of ARMAX model is proposed. For the parameter estimation of a transfer function model with noise, linear estimation method by noise separation is suggested instead of nonlinear estimation method. The feasibility of the proposed model identification and estimation method is verified through simulations, namely by applying the method to time series model. In the case of time series model with noise, the proposed method successfully identifies the transfer function model with noise without going through model parameter identification process in advance. A new algorithm effectively achieving model identification and parameter estimation in unified frame has been proposed. This approach is different from the conventional method used for identification of ARMAX model which needs separate parameter estimation and model identification processes. The consistency and the accuracy of the proposed method has been verified through simulations.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.1012-1015
• /
• 2003

Recently technologies have created new principle and theory but the PID control system remains its popularity as the PID controller contains simple structure, including maintenance and parameter adjustment being so simple. The adjust parameter of PID to achieve best response of process which be using time and may be error if user are not expert. Nowadays this problem was solved by develop PID controller which can analysis and auto tune parameter are appropriate with process which used principle of Ziegler ? Nichols but it are expensive and designed for each task. Thus, this paper proposes auto tune PID based on FPGA by use principle of Dahlin which maximum overshoot not over 5 percentages and do not fine tuning again. It have performance in control process are neighboring controller in industrial and simple to use. Especially, It can use various process and low price. The auto tune digital PID processor embedded on chip FPGA XC2S50-5tq-144. The digital PID processor was designed by fundamental PID equation which architectures including multiplier, adder, subtracter and some other logic gate. It was verified by control model of temperature control system.

• Membrane Journal
• /
• v.26 no.3
• /
• pp.187-196
• /
• 2016

Pressure-assisted forward osmosis (PAFO) process has recently been under spotlight for its potential to improve forward osmosis (FO) process performance by applying low hydraulic pressure on the feed side. Structure parameter, one of the governing factors in estimating water flux and solute flux across FO membranes in the solution-diffusion model (S-D model), determines solute resistivity in FO and PAFO processes. This study aims to estimate the trend of structure parameter change with respect to varying additional hydraulic pressure condition in PAFO.

• Korean Journal of Food Science and Technology
• /
• v.23 no.1
• /
• pp.81-87
• /
• 1991

To examine the effect of the individual operational variables on extrusion process, test trials of the fractional factorial design of the three process variables at three levels, including feed rate, screw speed and die openings, were carried out by using a laboratory scale twin-screw extruder with three different screw configuration for corn grit with the water addition fixed at 15% of the powder feed rate. As the increase of feed rate, while extrusion temperature(ET), specific mechanical energy input (SME), and residence time(RT) were showed the tendency to decrease, extrusion pressure(EP) was increased and as the increase of screw speed, ET, SME and EP were showed the tendency to increase, but RT was decreased. However, as increase the number of die hole, all system parameters were showed the tendency to decrease. The influence of the change in each process parameters was increased as the increase of the number of reverse element in screw configuration. In case of using the screw configuration with increasing number of reverse element at the condition of same process parameters, ET, SME and RT was increased, but EP was decreased. The functional relationships of the system parameters to the process parameters can be quantified by using multiple regression equations(mostly R-sq>0.90) and maped on suface response diagrams to expedite evaluation.

• Journal of Korean Society on Water Environment
• /
• v.25 no.4
• /
• pp.530-538
• /
• 2009

The Oxic-Settling-Anaerobic (OSA) treatment process, a modified Conventional Activated Sludge (CAS) process, was developed for the purpose of sludge reduction. The insertion of a sludge holding tank into a sludge return line, an anaerobic reactor, forming an OSA process, may provide a cost-effective way of reducing excess sludge production during a process. The OSA process was evaluated for its sludge reduction ability by kinetic parameter and mass balance, with an observed excess sludge reduction of 63.5%, as $P_{X.VSS}$, compared with the conventional activated sludge process.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.23 no.3
• /
• pp.195-203
• /
• 2020

Selective laser melting(SLM) is one of the powder bed fusion(PBF) processes, which enables quicker production of nearly fully dense metal parts with a complex geometry at a moderate cost. However, the process still lacks knowledge and the experimental evaluation of possible process parameter sets is costly. Thus, this study presents a finite element analysis model of the SLM process to predict the melt pool characteristics. The physical phenomena including the phase transformation and the degree of consolidation are considered in the model with the effective method to model the volume shrinkage and the evaporated material removal. The proposed model is used to predict the melt pool dimensions and validated with the experimental results from single track scanning process of Ti-6Al-4V. The analysis result agrees with the measured data with a reasonable accuracy and the result is then used to evaluated each of the process parameter set.

• Journal of the Korean Society of Safety
• /
• v.34 no.4
• /
• pp.59-67
• /
• 2019

Since it is really hard to construct process models based on prior process knowledges, various statistical approaches have been employed to build fault diagnosis models. However, the crucial drawback of these approaches is that the solutions may vary according to the fault magnitude, even if the same fault occurs. In this study, the parameter monitoring approach is suggested. When a fault occurs in a chemical process, this leads to trigger the change of a process model and the monitoring parameters of process models is able to provide the efficient fault diagnosis model. A few important variables are selected and their predictive models are constructed by partial least square (PLS) method. The Euclidean norms of parameters of PLS models are estimated and a fault diagnosis can be performed as comparing with parameters of PLS models based on normal operational conditions. To improve the monitoring performance, cumulative summation (CUSUM) control chart is employed and the changes of model parameters are recorded to identify the type of an unknown fault. To verify the efficacy of the proposed model, Tennessee Eastman (TE) process is tested and this model can be easily applied to other complex processes.