• 한국가스학회지
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• 제5권2호
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• pp.1-8
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• 2001

공정의 위험성 평가를 위한 이상트리 작성은 많은 시간과 인력을 요하는 작업으로 대규모 화학공장에 적용하기가 매우 힘들다. 본 연구에서는 화학공정의 이상트리 합성을 위해 장치에서 발생할 수 있는 공정변수의 이탈 및 장치이상에 대한 원인-결과 관계를 나타내는데 필요한 객체지향 지식기반의 프레임워크를 제안하였다. 이상에 대한 원인을 탐색하기 위하여 장치의 객체지향 모델링과 장치간의 연결관계를 이용하여 이탈을 전파하고 이를 통해 이상트리를 합성하였다. 제안된 방법론을 질산 냉각 공정에 적용하여 그 유효성을 검증하였다.

• 한국기계가공학회지
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• 제20권5호
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• pp.85-95
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• 2021

Structure design sensitivity was evaluated using the orthogonal array experimental method for passive-type deck support frame (DSF) developed for float-over installation of the offshore plant. Moreover, approximation characteristics were also reviewed based on various meta-models. The minimum weight design of the DSF is significantly important for securing both maneuvering performance and buoyancy of a ship equipped with the DSF and guaranteeing structural design safety. The performance strength of the passive type DSF was evaluated through structure analysis based on the finite element method. The thickness of main structure members was applied to design factors, and output responses were considered structure weight and strength performances. Quantitative effects on the output responses for each design factor were evaluated using the orthogonal array experimental method and analysis of variance. The optimum design case was also identified from the orthogonal array experiment results. Various meta-models, such as Chebyshev orthogonal polynomial, Kriging, response surface method, and radial basis function-based neural network, were generated from the orthogonal array experiment results. The results of the orthogonal array experiment were validated using the meta-modeling results. It was found that the radial basis function-based neural network among the meta-models could approximate the design space of the passive type DSF with the highest accuracy.

• Membrane and Water Treatment
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• 제1권1호
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• pp.61-74
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• 2010

This paper will integrate models at different levels (from filtration, backwashing to chemical cleaning and membrane lifetime) that can be used to minimize overall operating costs of a dead-end ultra filtration process that is used for the purification of surface water. Integration of the models leads to a multi-level optimization problem (at different levels different objectives should be reached). This problem is solved as a MINLP. Systematic modelling and optimization of membrane systems is not extensively discussed in the scientific literature. In this paper the first steps are taken in the formulation of proper models and the use of systems engineering tools to come to real optimal operating conditions. The optimized variables are used to calculate fouling profiles which can subsequently be used as inputs for a control system that actually enforces the profiles to a real pilot plant.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.513-518
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• 2001

As the machining depth increases, the drilling torque increases and fluctuates and the risk of drill failure also increases. Hence, drilling torque control is very important to prevent the drill from failure. In this study, a PID controller was designed to control the drilling torque in a machining center. The plant including the feed drive system, cutting process, and spindle system was modeled for controller design. The Ziegler-Nichols rule was used to determine the controller gain and control action times. The root locus plot was used to tune the controller gain for a certain cutting condition. Also, suggested was a simple method to obtain the tuned controller gain for an arbitrary cutting condition not using the Ziegler-Nichols rule and root locus plot. The cutting torque control, performance of the designed controller and the effect of gain tuning on the control performance were examined.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2001년도 추계산학기술 심포지엄 및 학술대회 발표논문집
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• pp.104-106
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• 2001

This paper presents the usage of software package APM WinMachine for design of train car elements. APM software uses fur maximization of design productivity and efficiency in designing and evaluation machine elements and systems and CAD modeling. In process of machine designing needs make strength calculations of machine parts with complecated design. Will the help of APM software strength calculations can be done quickly. On the Demichovo machine-building plant with the use of APM software were made quickly and effectively strength calculations of the cradle of the suspension of air-conditioner of car train and the mounting brackets of a tank of train toilet.

• 한국산업융합학회 논문집
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• 제22권6호
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• pp.785-795
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• 2019

This paper is a study on the modeling of the quantity estimation model for offshore plant Material handling equipment in FEED(Front End Engineering Design) verification stage using system engineering approach which is an engineering design methods. The relevant engineering execution procedure is not systemized although the operation method and Material handling equipment selection with weight and space constraints is a key part of the FEED. Using the system engineering process, the stakeholder requirements analysis process, the system requirements analysis, and the final system architecture design were sequentially performed, and the process developed through the functional development diagram and Requirement traceability matrix (RTM) was verified. In addition, based on the established process, we propose a Material handling quantity estimation model and Quantity calculation verification Table that can be applied at the FEED verification stage and we verify the applicability through case studies.

• 한국물환경학회지
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• 제24권1호
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• pp.91-98
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• 2008

This work was performed to develop a model possible to predict the influent flow and influent components, which are one of main disturbances causing process problems at the operation of municipal wastewater treatment plant. In this study, artificial neural network (ANN) was used in order to develop a model that was able to predict the influent flow, $COD_{Mn}$, SS, TN 1 day-ahead, 2day-ahead and 3 day ahead. Multi-layer feed-forward back-propagation network was chosen as neural network type, and tanh-sigmoid function was used as activation function to transport signal at the neural network. And Levenberg-Marquart (LM) algorithm was used as learning algorithm to train neural network. Among 420 data sets except missing data, which were collected between 2005 and 2006 at field plant, 210 data sets were used for training, and other 210 data sets were used for validation. As result of it, ANN model for predicting the influent flow and components 1-3day ahead could be developed successfully. It is expected that this developed model can be practically used as follows: Detecting the fault related to effluent concentration that can be happened in the future by combining with other models to predict process performance in advance, and minimization of the process fault through the establishment of various control strategies based on the detection result.

• 한국기계가공학회지
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• 제10권1호
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• pp.87-92
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• 2011

This article proposes a new technique of the dynamic model using multi-body dynamic analysis tool for a flexible main spindle rotor system with a novel phase adjusting control technique for the purpose of an active control of rotor vibration. The dynamic model is used as a plant model. Also in order to make control system, a component parameters and phase controller is composed and simulated by SIMULINK. The vibration is reduced to 50%. Therefore the ADAMS dynamic model for the flexible main spindle rotor and the phase adjusting control techniques may be effective for the suppressing the vibration and helpful for the future active control for rotor vibration.

• KEPCO Journal on Electric Power and Energy
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• 제3권2호
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• pp.127-131
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• 2017

The present paper describes the slagging field data obtained with the one-dimensional process model for the 500 MW tangentially coal fired boiler in Korea. To obtain slagging field data in terms of thermal resistances [$m^2{\cdot}^{\circ}C/kW$], a number of plant data were collected and analyzed with the one-dimensional modelling software at 500 MW full load. The slagging field data for the primary superheater were obtained for six coal blends, and compared with two TMA (Thermo-Mechanical analyzer) slagging indices and the numerical slagging index, along with the conventional slagging indices which were modified with the ash loading. The advanced two TMA indices for six blended coals give a good slagging tendency when comparing them with the slagging field data, while the modified conventional slagging indices give a relatively poor agreement.

• 펄프종이기술
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• 제35권4호
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• pp.57-67
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• 2003

The purpose of the present study is to identify the drying cylinder model in paper plants and to analyze characteristics of process responses for changes in input variables. The model developed in this work is based on actual plant operation data and the steam pressure applied to the cylinder behaves as one the main variables. It is found that heat transfer coefficients from the condensate to the canvas could be represented as empirical relations based on heat conductivities and operation date. The effectiveness of the cylinder model is demonstrated by the measured moisture contents and web temperature. Using transfer functions derived from the cylinder model stability of the drying process is analyzed.