• Journal of Ship and Ocean Technology
• /
• 제5권3호
• /
• pp.27-35
• /
• 2001

In this research, hybrid method with case-based reasoning and rule-based reasoning is applied. Using case-based reasoning, design experts'experience and know-how are effectively represented in order to obtain a proper configuration of midship section in the initial ship design stage. Since there is not sufficient domain knowledge available to us, traditional case-adaptation algorithms cannot be applied to our problem, i.e., creating the configuration of midship section. Thus, new case-adaptation algorithms not requiring any domain knowledge are developed antral applied to our problem. Using the knowledge representation of DnV rules, rule-based reasoning can perform deductive inference in order to obtain the scantling of midship section efficiently. The results from the case-based reasoning and the rule-based reasoning are examined by comparing the results with various conventional methods. And the reasonability of our results is verified by comparing the results wish actual values from parent ship.

• 한국해양공학회지
• /
• 제29권6호
• /
• pp.463-469
• /
• 2015

Fatigue in the metal used as hull material has always been an important issue. The fatigue phenomenongenerally occurs suddenly in a ship hull, and always causesa large number of casualties and economic losses. This paper presents a study of an assessment method for the fatigue life based on Li’s approach using MSC Fatigue. The details of Li’s approach based on MSC Fatigue are provided. Based on the results of this study, it can be concluded that Li’s approach has several advantages: (1) it allows the wide application of different structural details, (2) is easy to use, and (3) provides accurate results. Finally, Li’s approach can be proven to be feasible for a ship’s fatigue analysis.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2000년도 가을 학술발표회논문집
• /
• pp.182-189
• /
• 2000

This paper presents a simple and reliable constitutive model for predicting the nonlinear response of reinforced concrete subjected to general membrane loadings. Based on the concept of equivalent uniaxial strain, constitutive relations of concrete are presented in the axes of orthotropy. The behavior of cracked concrete is described by a system of orthogonal cracks, which follows the principal strain directions and rotates according to the loading history. Simple hysteretic rules defining the cyclic stress-strain curves of concrete and steel are used. In addition, the stiffness and strength degradation of cracked concrete is included in the formulation. Correlation studies between analytical results and experimental values from idealized shear panel tests are conducted with the objective to establish the validity of the proposed model.

• Steel and Composite Structures
• /
• 제11권6호
• /
• pp.505-524
• /
• 2011

Steel girder web panels have been subjected in recent decades, to a number of experimental and numerical studies but the mechanisms that regulate the behaviour of the panels composed by two subpanels with different thickness were not deeply studied. Furthermore specific design rules regarding the estimation of the buckling coefficient for panels with variable thickness are not included in the codes even if this is a common situation particularly for steel bridge girders with beams having significant height. In this framework,this work aims to investigate buckling behaviour of steel beams with webs composed of panels with different thicknesses subjected to both in-plane axial compression and bending moment and gives some simplified equations for the estimation of the buckling coefficient.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1990년도 봄 학술발표회 논문집
• /
• pp.6-11
• /
• 1990

Inelastic behavior of reinforced concrete members is very complex and affected by many factors. Therefore, though using the finite element method which is good to predict the response of R/C member, it has to be proceeded to model these factors appropriately which have influence on the behavioral characteristics of reinforced concrete members. The proposed model consists of the physical single component model having the finite size of plastic regions and the hysteretic rules, by regressing experimental data, which can idealize the hysteretic behavior of R/C member under inelastic cyclic loads. This study confirms the accuracy of the developed analytical model through comparison with the test results of R/C members having a variety of shear-to-depth ratio and maximum shear stress.

• Structural Engineering and Mechanics
• /
• 제14권1호
• /
• pp.57-70
• /
• 2002

This work presents an iterative mesh partitioning approach to improve the efficiency of parallel substructure finite element computations. The proposed approach employs an iterative strategy with a set of empirical rules derived from the results of numerical experiments on a number of different finite element meshes. The proposed approach also utilizes state-of-the-art partitioning techniques in its iterative partitioning kernel, a cost function to estimate the computational cost of each submesh, and a mechanism that adjusts element weights to redistribute elements among submeshes during iterative partitioning to partition a mesh into submeshes (or substructures) with balanced computational workloads. In addition, actual parallel finite element structural analyses on several test examples are presented to demonstrate the effectiveness of the approach proposed herein. The results show that the proposed approach can effectively improve the efficiency of parallel substructure finite element computations.

• 정보기술과데이타베이스저널
• /
• 제7권1호
• /
• pp.55-65
• /
• 2000

Information semantics is a well-known issue in areas of information systems researches. It describes what data mean, how they are created, where they can be applied to ; thus, it provides indispensable information for management of data. This article proposes to formalize information semantics by the processes that data are created or transformed. A scheme is proposed to describe an information production structure, which is called an information structure graph. An information structure graph is a directed graph, whose leaves are primary input data objects and whose root and internal nodes are output objects. Information semantics is derived from an information structure graph that has data as its root. For this, rules are proposed to manipulate and compare graphs. The structural relationships among information structure graphs are mapped into semantic relationships among data.

• Journal of Information Processing Systems
• /
• 제11권3호
• /
• pp.450-464
• /
• 2015

In linguistics, stemming is the operation of reducing words to their more general form, which is called the 'stem'. Stemming is an important step in information retrieval systems, natural language processing, and text mining. Information retrieval systems are evaluated by metrics like precision and recall and the fundamental superiority of an information retrieval system over another one is measured by them. Stemmers decrease the indexed file, increase the speed of information retrieval systems, and improve the performance of these systems by boosting precision and recall. There are few Persian stemmers and most of them work based on morphological rules. In this paper we carefully study Persian stemmers, which are classified into three main classes: structural stemmers, lookup table stemmers, and statistical stemmers. We describe the algorithms of each class carefully and present the weaknesses and strengths of each Persian stemmer. We also propose some metrics to compare and evaluate each stemmer by them.

• 산업공학
• /
• 제13권2호
• /
• pp.188-194
• /
• 2000

A pattern recognition system is proposed to recognize characters in any type of Giro. The system consist of the character segmentation and the character recognition. Positional features from two round markers at the upper-right part and lower-left part of Giro is used for extracting character strings from images and RLE analysis is used if there are no round markers. A multi step combined method, which use a structural method and a statistical method, is used to improve recognition. The structural method apply rules on each characters, whereas a statistical method gives a different weighting vector to each pixel for improving the classification performance in regard to noises and distortions. The experimental results show that the proposed combined method has higher recognition rate, over than 98% even in cases that images are rotated about 10 degrees as well as have noises.

• 한국구조물진단유지관리공학회 논문집
• /
• 제3권2호
• /
• pp.233-240
• /
• 1999

Even though the recent construction safety disasters not only result in the loss inside construction sites but also become to a large public disasters, safety activities are managed in an irrational way and safety rules are ignored in the construction sites which leads to occur same type of disasters repeatedly. In this paper, a fuzzy set theoretic approach to risk analysis is proposed as an alternative to the techniques currently used in the general construction projects safety. Then the concept of risk evaluation using linguistic representation of the likelihood, exposure and consequences is introduced. A risk assessment model using approximate reasoning technique base on fuzzy logic is presented to drive fuzzy values of risk and numerical example for risk analysis is also presented to illustrate the results.