• 한국전산구조공학회논문집
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• 제30권1호
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• pp.77-86
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• 2017

Industry Foundation Classes(IFC)는 Building Information Modeling(BIM)을 위한 표준 데이터 스키마로 정보의 상호운용성 확보를 위한 핵심이지만, 건물만을 대상으로 하고 있어 토목 시설물에 적용하기에는 한계가 있다. 이에 따라 기존 IFC에 토목 시설물을 위한 새로운 요소를 추가하는 연구가 진행되었지만, 상용 소프트웨어가 해당 기능을 추가하기 전에는 새로운 스키마를 활용할 수 없다. 본 연구에서는 토목 시설물에 적용하기 위한 IFC 데이터 스키마 활용 방안을 제시하고, 토목시설물을 위한 확장 요소와 기존 IFC 요소와의 정보 매핑을 통한 확장 IFC기반의 토목 시설물 정보모델링 방법을 제시하였다. 그리고 철도의 궤도 및 침목에 대한 IFC 확장 스키마를 제시하고 제시한 방법을 적용하여 그 활용성을 검증하였다.

• 한국CDE학회논문집
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• 제12권1호
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• pp.8-14
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• 2007

In the product design process computer-aided engineering and optimization tolls are widely utilized in order to reduce the total development time and cost. Since several simulation tools are involved in the process, information losses, omissions, or errors are common and the importance of seamless information exchange among the tools has been increased. In this work, ISO STEP standards are adopted to represent the neutral format for structural analysis and optimization. The schema of AP209 defined the information of finite element analysis is used and the new schema is proposed to describe the information of structural optimization based on the STEP methodology. The schema is implemented by EXPRESS, information modeling language, and ST-Developer is employed to generate C++ classes and STEP Rose Library by using the schema denoted. To substantiate the proposed approach, the information access interfaces of the finite element modeling software (FEMAP), structural optimization software(GENESIS) and in-house topology optimization program are developed. Examples are shown to validate the information exchange of finite element analysis and structural optimization using STEP standards.

• 한국조경학회지
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• 제28권1호
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• pp.29-36
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• 2000

Leisure constraints mean the factor to constrain individual's leisure activity. Leisure constraints are composed of interpersonal constraints, interpersonal constraints and structural constraints. The purposes of this study are to show that intrapersonal leisure constraints have a strong effect on leisure preference, and leisure constraints are sequential and hierachical process. Intrapersonal constraints effect on leisure constraints in first step. And then interpersonal constraints and structural constraints effect on leisure participation. Those three leisure constraints are all linked together and come out step by step. Regarding adults as a population, who are more than 20-year-old and live in Seoul, 9 dongs were chose after dividing into upper and lower classes according to the value of their residence. The questionnaire consists of 4 parts: intrapersonal constraints, interpersonal constraints, structural constraints, and demographic characteristics. Results of this paper is that people who have strong intrapersonal constraints normally have problems caused from social structure. Intrapersonal constraints and structural constrains come out not seperately but together. Then, it can be said that structural constraints have an influence over intrapersonal constraints. So, it's necessary to solve structural problems to increase preferences and participations of them.

• 한국산림과학회지
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• 제96권5호
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• pp.572-579
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• 2007

Tree species diversity is an important aspect of forest ecosystem stability. Tree species inventories at defined sites and in minimum diameter classes give a reliable indicator of the diversity level as well as the structural stability level of a study site. This study was conducted to investigate the species composition and the stand structure of the natural forest, timber-harvested forest (logged-over forest) and degraded forest of the Oak-twin Township in the Bago Yoma Region of Myanmar. Natural forest showed the highest family and species richness in all the investigated forests. At the family level, Verbenaceae occupied the highest importance value index (IVI) in all the forest stands while teak (Tectona grandis Linn. f.) occupied the highest IVI at the species level. However, the small diameter classes of T. grandis and other commercial species were less than those of big diameter classes in all the investigated forests. This abnormal pattern of diameter distribution could be a problem for the sustainable production of commercial timber species in the near future.

• 한국언어정보학회지:언어와정보
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• 제14권1호
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• pp.165-196
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• 2010

The primary goal of this paper is to propose methods of enriching two heterogeneous ontologies: Sejong Semantic Classes (SJSC) and KorLexNoun 1.5 (KLN). In order to achieve this goal, this study introduces the pros and cons of two ontologies, and analyzes the error patterns found during the fine-grained manual mapping processes between them. Error patterns can be classified into four types: (1) structural defectives involved in node branching, (2) errors in assigning the semantic classes, (3) deficiency in providing linguistic information, and (4) lack of the lexical units representing specific concepts. According to these error patterns, we propose different solutions in order to correct the node branching defectives and the semantic class assignment, to complement the deficiency of linguistic information, and to increase the number of lexical units suitably allotted to their corresponding concepts. Using the results of this study, we can obtain more enriched ontologies by correcting the defects and errors in each ontology, which will lead to the enhancement of practicality for syntactic and semantic analysis.

• 한국IT서비스학회지
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• 제19권1호
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• pp.159-172
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• 2020

The purpose of this study is to examine the structural relationship among factors affecting learning engagement, satisfaction, continuance intention in China-MOOC. For this study, data were collected from 334 students who were taking MOOC classes. and structural equation model ling analyses were employed to examine the causal relationships among variables. From the results of this study, First, self-regulated learning and interaction significantly affected learning engagement. Second, interaction had direct effects on satisfaction. Third, satisfaction significantly affect continuance intention. Furthermore, satisfaction mediated relationships between interaction and continuance intention. These results imply that self-regulated learning, interaction, learning engagement should be considered for designing and implementing China-MOOC learning. Further implication are discussed in the study.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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• pp.305-312
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• 2003

Recently, with a progressive development of hardware of computer, the internet and network technology, the environment of construction varies rapidly due to increase the complex form in structure shape and system. With variations, the CAD system for design and products also varies from 2D system to 3D system. This study mainly deals with the methodology of automatic connection design of 3D CAD system, steel connection system (XSteel) using macro. First, using design program in the steel connection system, Xsteel, the joint connection macro will be made up and established the detail classes of design. The next, Database Program (Converter Program) related to the general structural analysis program (MIDAS) and the steel connection program (Xsteel) is constructed for data interface between two programs. From this study, if the merits of 3D CAD system and converter program are utilized well, it is expected that the time needed in modeling and the amounts due to material loses decrease gradually.

• Bulletin of the Korean Chemical Society
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• 제18권5호
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• pp.501-509
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• 1997

In recent papers[Bull. Kor. Chem. Soc. 1996, 17, 735; ibid 1997, 18, 478] we reported results of molecular dynamics (MD) simulations for the thermodynamic, structural, and dynamic properties of liquid normal alkanes, from n-butane to n-heptadecane, using three different models. Two of the three classes of models are collapsed atomic models while the third class is an atomistically detailed model. In the present paper we present results of MD simulations for the corresponding properties of liquid branched-chain alkanes using the same models. The thermodynamic property reflects that the intermolecular interactions become weaker as the shape of the molecule tends to approach that of a sphere and the surface area decreases with branching. Not like observed in the straight-chain alkanes, the structural properties of model Ⅲ from the site-site radial distribution function, the distribution functions of the average end-to-end distance and the root-mean-squared radii of gyration are not much different from those of models Ⅰ and Ⅱ. The branching effect on the self diffusion of liquid alkanes is well predicted from our MD simulation results but not on the viscosity and thermal conductivity.

• Structural Engineering and Mechanics
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• 제12권1호
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• pp.85-100
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• 2001

In this paper, an analytical procedure for solving several static and dynamic problems of non-uniform beams is proposed. It is shown that the governing differential equations for several stability, free vibration and static problems of non-uniform beams can be written in the from of a unified self-conjugate differential equation of the second-order. There are two functions in the unified equation, unlike most previous researches dealing with this problem, one of the functions is selected as an arbitrary expression in this paper, while the other one is expressed as a functional relation with the arbitrary function. Using appropriate functional transformation, the self-conjugate equation is reduced to Bessel's equation or to other solvable ordinary differential equations for several cases that are important in engineering practice. Thus, classes of exact solutions of the self-conjugate equation for several static and dynamic problems are derived. Numerical examples demonstrate that the results calculated by the proposed method and solutions are in good agreement with the corresponding experimental data, and the proposed procedure is a simple, efficient and exact method.

• BMB Reports
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• 제31권6호
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• pp.525-535
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• 1998

A critical step in the faithful translation of genetic information is specific tRNA recognition by aminoacyl-tRNA synthetases. These enzymes catalyze the covalent attachment of particular amino acids to the terminal adenosine of cognate tRNA substrates. In general, there is one synthetase for each of the twenty amino acids and each enzyme must discriminate against all of the cellular tRNAs that are specific for the nineteen noncognate amino acids. Primary sequence information combined with structural data have resulted in the division of the twenty synthetases into two classes. In recent years, several high-resolution co-crystal structures along with biochemical data have led to an increased understanding of tRNA recognition by synthetases of both classes. The anticodon sequence and the amino acid acceptor stem are the most common locations for critical recognition elements. This review will focus on acceptor stem discrimination by class II synthetases. In particular, the results of in vitro aminoacylation assays and site-directed and atomic group mutagenesis studies will be discussed. These studies have revealed that even subtle atomic determinants can provide signals for specific tRNA aminoacylation.