• International Journal of Precision Engineering and Manufacturing
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• 제2권1호
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• pp.26-32
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• 2001

An ecpert system for rotationally symmetric deep drawing products has been developed. The application for non-axisymmetric components, however, has not been reported yet. This study construsctus and expert system for non-axisymmetric motor frame which shape is classified into ellipse in deep draqing process and investigates process sequence design with elliptical shape. The developed system consists of four modules. The first is recognition of calculate surface area for non-axisymmetric products. The third is blank design module the creates an oval-shaped blank with the same surface area. The fourth is a processplanning module based on production rules that play the best important roles in an expert system for manufacturing .The production rules are generated and upgraded by interviewing field engineers. Especially, drawing coefficient, punch and die radii for elliptical shape products are considered as main design parameters. The constructed system for elliptical deep drawing product would be very useful to reduce lead time and improve accuracy for products.

• 대한조선학회논문집
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• 제45권2호
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• pp.151-156
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• 2008

It is necessary to perform the research works on the general structural designs and optimum structural designs of double hull tankers and bulk carriers due to the newly built Common Structural Rules(CSR). In this study, an optimum structural design of a mid-ship part of double hull oil tanker was carried out by using the CSR. An optimum structural design program was developed by using the Pareto optimal based multi-objective function method. The hull weight and fabrication cost obtained by the single and multi-objective function methods were compared with existing ship by the consideration of CSR and material cost which is recently increasing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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• pp.800-802
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• 2000

In this paper, we propose the Self-Organizing Networks(SON) based on competitive Fuzzy Polynomial Neuron(FPN) for the optimal design of nonlinear process system. The SON architectures consist of layers with activation nodes based on fuzzy inference rules. Here each activation node is presented as FPN which includes either the simplified or regression Polynomial fuzzy inference rules. The proposed SON is a network resulting from the fusion of the Polynomial Neural Networks(PNN) and a fuzzy inference system. The conclusion part of the rules, especially the regression polynomial uses several types of high-order polynomials such as liner, quadratic and modified quadratic. As the premise part of the rules, both triangular and Gaussian-like membership functions are studied. Chaotic time series data used to evaluate the performance of our proposed model.

• Steel and Composite Structures
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• 제36권3호
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• pp.273-291
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• 2020

Two-storey X-bracings are currently very popular in European practice, as respect to chevron and simple X bracings, owing to the advantages of reducing the bending demand in the brace-intercepted beams in V and inverted-V configurations and optimizing the design of gusset plate connections. However, rules for two-storey X braced frames are not clearly specified within current version of EN1998-1, thus leading to different interpretations of the code by designers. The research presented in this paper is addressed at investigating the seismic behaviour of two-storey X concentrically braced frames in order to revise the design rules within EN1998-1. Therefore, five different design criteria are discussed, and their effectiveness is investigated. With this aim, a comprehensive numerical parametric study is carried out considering a set of planar frames extracted from a set of structural archetypes that are representative of regular low, medium and high-rise buildings. The obtained results show that the proposed design criteria ensure satisfactory seismic performance.

• 대한조선학회논문집
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• 제47권4호
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• pp.598-605
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• 2010

The structural design of oil tankers and bulk carriers should be performed based on the Common Structural Rules(CSR) which were recently established by the International Association Classification Societies(IACS). At first, in the structural design viewpoint, the scantling and hullweight based on the CSR should be compared with those of existing rules, and then a minimum weight/cost design should be performed by considering the variation of the number of web and the material property. In this study, the optimum web space and material property will be proposed by performing a minimum weight/cost design of a large oil tanker, and the results will be compared with those of existing ship. The longitudinal members are determined by SeaTrust-Holdan developed by the Korean Register of Shipping(KR), and the transverse members are determined by NASTRAN and PULS.

• Journal of Ship and Ocean Technology
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• 제9권2호
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• pp.29-36
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• 2005

A hull form of Baltic ice class IA Aframax tanker has been developed taking into consideration of powering performance in brash ice channels based on IA class rules. Speed performance of the ship hull form in normal seagoing has been validated through model tests in a towing tank. The hull form design developed in this work has demonstrated good speed performance in normal seagoing although the ship design is entitled to ice class IA.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.89-96
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• 2003

This research presents a methodology for processing design provisions by representing the provisions and also by checking the conformance of design entities with the provisions via STEP information technology, which is considered as a canonical component for implementing CALS. The provisions of standards are represented in the .form of EXPRESS schema including various entities, algorithms, global rules, and local rules, while the schema are managed on EXPRESS engine called EXPRESSO.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.1149-1152
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• 1999

In this paper we analyzed each region of specific points and ｅ-Δｅphase plane in order to make fuzzy rule base. After we composed the fuzzy control rules which can decrease rise time, delay time, maximum overshoot than basic fuzzy control rules. The composed method are converged more rapidly than single rule base in convergence region. Proposed method is alternately use at specific points of ｅ-Δｅphase plane with two fuzzy control rules, that is one control rule occruing the steady state error used in transient region and another fuzzy control rule use to decrease the steady state error and rapidly converge at the convergence region. Two fuzzy control rules in the ｅ-Δｅ phase plane decide the change time according to response characteristics of plants. As the results of simulation through the second order plant and the delay time plan, Proposed dual fuzzy control rules get the good response compare with the basic fuzzy control rule.

• 대한산업공학회지
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• 제20권3호
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• pp.35-53
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• 1994

Orthographic views ore traditionally used for engineering drawings. This paper presents a methodology for 3D parametric design using orthographic views. The parametric design technique, which is used to design 2D orthographic views, is based on production rules. In the production rule-base, several view interrelation rules and over 50 geometric rules are included. An efficient algorithm is also developed to expedite the reasoning process. For 3D object construction from orthographic views, the approach known as bottom-up geometrical approach is used. The approach consists of 4 steps : 1) generation of wire-frame, 2) construction of face from wire frame, 3) formation of 3D subobjects from faces, and 4) construction of final 3D objects. Curvilinear solids as well as planar solids can be constructed. A method of converting existing 2D CAD data to parametric 3D CAD data is also presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.992-994
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• 1995

FLC has a good performance for complication system or unknown model by using human linguistic method but many part control design are based on expert knowledge or trial-error method and it is difficult to prove stability and robustness of controller. In this paper we improve this problem by setting fuzzy rules by dividing phase plane of error and rate of error change by switching surface. We can guarantee the stability in nonlinear system, and also in fuzzy PID type controller the complexity of controller design is increased by increasing the number of input variables and defining more range of operation if we want performance of more specific rules, thus we need to fine the method to decrease the number of control rules used in FLC design. In this paper the algorithm is validated by simulation using conventional FLC and proposed method.