• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1516-1519
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• 1997

With disseminationof Distributed Control Systems(DCS), the huge amounts of process operation data could have been available and led to figure out process behaviors better on the statistical basis. Until now, the statistical modeling technology has been susally applied to process monitoring and fault diagnosis. however, it has been also thought that these process information, extracted from statistical analysis, might serve a great opportunity for process operation improvements and process improvements. This paper proposed a general methodolgy for process operation improvements including data analysis, backing up the result of analysis based on the methodology, and the mapping physical physical phenomena to the Principal Components(PC) which is the most distinguished feature in the methodology form traditional statistical analyses. The application of the proposed methodology to the Balst Furnace(BF) process has been presented for details. The BF process is one of the complicated processes, due to the highly nonlinear and correlated behaviors, and so the analysis for the process based on the mathematical modeling has been very difficult. So the statisitical analysis has come forward as a alternative way for the useful analysis. Using the proposed methodology, we could interpret the complicated process, the BF, better than any other mathematical methods and find the direction for process operation improvement. The direction of process operationimprovement, in the BF case, is to increase the fludization and the permeability, while decreasing the effect of tapping operation. These guide directions, with those physical meanings, could save fuel cost and process operator's pressure for proper actions, the better set point changes, in addition to the assistance with the better knowledge of the process. Open to set point change, the BF has a variety of steady state modes. In usual almost chemical processes are under the same situation with the BF in the point of multimode steady states. The proposed methodology focused on the application to the multimode steady state process such as the BF, consequently can be applied to any chemical processes set point changing whether operator intervened or not.

• 한국멀티미디어학회논문지
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• 제17권7호
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• pp.858-865
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• 2014

In the case of system like MES, various sensors collect the data in real time and save it as a big data to monitor the process. However, if there is big data mining in distributed computing system, whole processing process can be improved. In this paper, system to analyze the cause of operation deviation was built using the big data which has been collected from deasphalting process at the two different plants. By applying multivariate statistical analysis to the big data which has been collected through MES(Manufacturing Execution System), main cause of operation deviation was analyzed. We present the example of analyzing the operation deviation of deasphalting process using the big data which collected from MES by using multivariate statistics analysis method. As a result of regression analysis of the forward stepwise method, regression equation has been found which can explain 52% increase of performance compare to existing model. Through this suggested method, the existing petrochemical process can be replaced which is manual analysis method and has the risk of being subjective according to the tester. The new method can provide the objective analysis method based on numbers and statistic.

• International Journal of Automotive Technology
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• 제8권2호
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• pp.243-248
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• 2007

The durability of a cylinder head is influenced by the thermal and mechanical history during the manufacturing process, as well as engine operation. In order to improve the durability of cylinder head, both load from engine operation and the preload conditions from the manufacturing process must be considered. The aluminum cylinder head used for a HSDI diesel engine is investigated to reduce the possibility of high cycle fatigue crack in this study. FE analysis is performed to elucidate the mechanism of high cycle fatigue crack in the HSDI diesel cylinder head. Two separate approaches to increase the durability of the cylinder head are discussed: reducing load from engine operation and re-arranging preload conditions from the manufacturing process at the critical location of the cylinder head. Local design changes of the cylinder head and modification of pretension load in the cylinder head bolt were investigated using FE analysis to relieve load at the critical location during engine operation. Residual stress formed at the critical location during the manufacturing process is measured and heat treatment parameters are changed to re-arrange the distribution of residual stress. Results of FE analysis and experiments showed that thorough consideration of the manufacturing process is necessary to enhance the durability of the cylinder head.

• 상하수도학회지
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• 제19권6호
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• pp.781-790
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• 2005

Granular Activated Carbon(GAC) is widely used in drinking water treatment. Many of the problems occurring in the GAC process are associated with the operation goal and performance. The purpose of this study were to evaluate the design, operation, and performance of granular activated carbon process in D water treatment plant. The optimal operation conditions of GAC process such as backwashing condition, granular activated carbon replacement time were discussed. The design, operation and performance of GAC process is influenced by their raw water characteristics and placement within the treatment process sequence. A critical analysis of plants experience and the information from the literature identifies the effectiveness of GAC process and indicates where modifications in design and operation could lead to improved performance. It would be useful to evaluate and optimize the GAC process in other treatment plant.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1024-1030
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• 1993

In manufacturing press die with free surface, grinding operation is an important post process for surface finish and dimensional accuracy. With the advancement of NC technology. surface grinding operation is increasingly replaced by the gantry type manipulator. As the mechanics for grinding operation is different from machining operation, conventional CAM system for machining operation is hard to apply. In this. paper, we develop a five-axis CAM system by which an efficient gantry trajectory can be planned and verified. The developed system consists of four conceptual modules; namely CAD, PROCESS. CAM, and ANALYSIS. In the CAD module, the machined surface is represented by CL-data or surface modeler, and process parameters are specified by the PROCESS module. Then, the CAM module generates a series of grinding paths based on the grinding mechanics together with process databases for tool spaces and grinding conditions. The generated paths are verified via ANALYSIS module. Validation via real experiments is left for further study.

• Nuclear Engineering and Technology
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• 제41권5호
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• pp.739-746
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• 2009

This paper introduces facility operation modeling and simulation based primarily on a discrete event system modeling scheme. Many modern industrial facilities are so complex that their operational status cannot be estimated by simple calculations. In general, a facility can consist of many processes and transfers of material between processes that may be modeled as a discrete event system. This paper introduces the current status of studies on operation modeling and simulation for typical nuclear facilities, along with some examples. In addition, this paper provides insights about how a discrete event system can be applied to a model for a nuclear facility. A headend facility is chosen for operation modeling and the simulation, and detailed procedure is thoroughly described from modeling to an analysis of discrete event results. These kinds of modeling and simulation are very important because they can contribute to facility design and operation in terms of prediction of system behavior, quantification of facility capacity, bottleneck identification and efficient operation scheduling.

• 공업화학
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• 제16권2호
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• pp.217-225
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• 2005

H사의 유로변경식 고도하수처리 공법의 제어 변수가 DO와 수온 등으로 한정되어 있어 효율성의 만족도를 충족시켜주지 못하는 현재의 상황을 개선하고자 세 가지 개선방향을 설정하여 Simulation을 통한 Operation Data의 분석 및 장치구성과 실험을 통한 최적제어 Logic을 연구하여 이를 다시 S하수처리장에 설치 적용한 결과이다. 본 실험을 통해서 수온과 유량에 근간한 Operation Mode 변경의 최적화와 이를 통한 동력비 절감을 이루었고 암모니아성 질소의 농도에 따른 Operation Mode의 변경에서 일반 Normal Mode와 병행하여 Save Mode를 새로 적용하여 동력비 절감을 이루었다. 또한 DO 값을 송풍량과 수중폭기기의 교반속도에 의해 비례제어하고 유출수의 암모니아 농도에 따라 DO 값을 제어하여 안정적인 질산화를 이루었다. 이러한 결과는 공정효율의 극대화와 운영 및 유지관리비의 절감을 이루었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.341-343
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• 2012

This study introduces a method for computation of process and operation gap in the specific construction operation(i.e., RC frame construction applying a block-grouping scheme) using CYCLONE-based simulation modeling and analysis technique. Since uncertainty of construction environment exists, a thoughtful production planning is required to effectively deal with a risk resulting in schedule delay in advance. This study presents the concepts of a time delay occurred in a process level and operation level in a operation model, and a method of measuring gap-times in each level while the simulation progresses. It helps a site manager to decide how many segmentation in a construction block is suitable for eliminating unproductive time-delays under the constrained resources (e.g., laborer, equipment). A case study presents a network model representing a three segmented RC frame work, and result obtained from the simulation experiment.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.91-97
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• 2012

In this study, cost analysis of electrokinetic (EK) restoration process for desalination of saline agricultural land was performed for field application based on a pilot scale field application. For reasonable cost analysis, EK process was classified into three major parts: system design, installation and operation. Cost of system installation consists of materials and installation for electrode/electric wire, power supply and data monitoring, drainage system, etc. Operation cost was calculated based on electrical consumption and water charges for EK process. Total cost for EK process was 2,943,013 won for $1000m^2$ in greenhouse area. Cost for system installation was 2,553,786 won, that is, 87% of total cost, while cost for system operation was 389,229 won, that is, 13% of total cost.

• Korean Chemical Engineering Research
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• 제46권2호
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• pp.383-388
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• 2008

화학공정의 안전하고 효율적인 운전에 관심이 커지면서 공정이상의 원인을 조기에 진단하기 위한 다양한 이상진단방법이 연구되어 왔다. 최근에는 통계적 모델 등 정량적 데이터에 기반한 이상진단방법이 많이 연구되고 있으나, 특정 조업영역에서 얻어진 통계적 모델을 다른 조업영역에 적용하면 오진단이 많아지게 된다. 따라서 공정특성상 다양한 조업영역이 존재하는 화학공정에 데이터기반 방법론을 적용하기에는 어려움이 있어 화학공정의 조업영역 판별법이 요구되고 있다. 이 연구에서는 유클리드 거리(Euclidean distance), FDA(Fisher's discriminant analysis), PCA(principal component analysis)의 통계모델과 이 모델들에 공정변수의 동특성을 반영한 모델을 제안하였다. 6개의 조업모드를 가진 TE(tennessee eastman) 공정에 대한 사례연구를 통해 동특성을 반영한 PCA 모델의 성능이 가장 우수함을 확인하였다.