• Korean Journal of Construction Engineering and Management
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• v.23 no.1
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• pp.64-72
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• 2022

The retaining wall structure is essential for construction work that performs underground excavation. Displacement management of the retaining wall structure is important regardless of the size of the construction. However, in the case of small-scale construction sites with an excavation depth of less than 10m, displacement management of retaining wall structure not properly performed due to problems such as 1) companies' smallness, 2) lack of capacity of construction managers, 3) complexity of installation, dismantling and displacement of measuring instruments. As a result of analyzing previous research, it was analyzed that it is difficult to apply this to a small - scale construction site because most of the previous research has problems in using an expensive 3D scanner or installing many measuring instruments. This study aims to propose a conceptual design of a displacement measurement system for retaining wall structure based on laser sensor and to verify the displacement recognition performance of core technology applied to the conceptual design. A conceptual design was proposed using a 2D laser scanner. As a result of verifying the displacement recognition of the 2D laser scanner, a displacement of 15mm was analyzed to be sufficiently understandable. In the future, if the proposed conceptual design is developed and applied to the small-scale construction site, it is thought that it will contribute to the reduction of safety accidents at small-scale construction sites.

• Journal of the Korean School Mathematics Society
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• v.11 no.4
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• pp.595-608
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• 2008

The purpose of this study is to address the teachers' knowledge bases for effective mathematics teaching and especially to provide the various definitions and the structures of mathematics knowledge which is the most important one of the knowledge bases. The conceptual understanding about teachers' knowledge bases for effective mathematics teaching and the structure of mathematics knowledge may be used in evaluating effective mathematics teaching and teachers as well as in developing a new conceptual framework for the structure of mathematical knowledge.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.179-184
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• 2005

In the present study, conceptual design of the main wing for 20 seats WIG{wing in Ground Effect) flight vehicle, which will be a high speed maritime transportation system for the next generation, was performed. The high stiffness and strength Carbon-Epoxy material was used for the major structure and the skin-spar with a foam sandwich structural type was adopted for improvement of lightness and structural stability. As a design procedure for this study, firstly the design load was estimated with maximum flight load, and then flanges of the front and the rear spar from major bending load and the skin structure and the webs of the spars were preliminarily sized using the netting rules and the rule of mixture. In order to investigate the structural safety and stability, stress analysis was performed by Finite Element Codes such as NASTRAN/PA TRAN[6] and NISA II [7]. From the stress analysis results, it was confirmed that the upper skin structure between the front spar and rear spar was very unstable for the buckling. Therefore in order to solve this problem, a middle spar and the foam sandwich structure at the upper skin and the web were added. After design modification, even thought the designed wing weight was a little bit heavier than the target wing weight, the structural safety and stability of the final design feature was confirmed. Moreover, in order to fix the wing structure at the fuselage, the insert bolt type structure with six high strength bolts was adopted for easy assembly and removal.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.4
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• pp.383-395
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• 2014

According to the requirement of wing weight estimation and frequent adjustments during aircraft conceptual design, a wing weight estimation method considering the constraints of structural strength and stiffness is proposed to help designers make wing weight estimations rapidly and accurately. This method implements weight predictions on the basis of structure weight optimization with stiffness constraints and strength constraints, which include achievement of wing shape parametric modeling, rapid structure layout, finite element (FE) model automated generation, load calculation, structure analysis, weight optimization, and weight computed based on modeling. A software tool is developed with this wing weight estimation method. This software can realize the whole process of wing weight estimation with the method and the workload of wing weight estimation is reduced because much of the work can be completed by the software. Finally, an example is given to illustrate that this weight estimation method is effective.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.157-163
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• 2015

XML has become one of the most influential standard language for representing and exchanging data on internet. However, XML itself has a ability to represent a logical structure for storing and managing data, it is inadequate to use as a conceptual modeling tool because of its complexity for representing the document structures. In this paper, we propose the graphical form of conceptual modeling techniques for representing the structure of the XML schema documents using an extended entity relationship diagram. For this, extended entity relationship model is presented for representing the XML schema structure, transformation rules are presented for transforming extended entity relationship model into XML schema document to show the completeness of the proposed model.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.4
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• pp.1-15
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• 2000

Information systems (IS) failures still continue and are prevalent everywhere. When considering an enormous amount of budget currently invested on IS technology in many organizations, these continuing failures can be critical culprits to failures of the organizations themselves. However, the meaning and definition of IS failures are not unified among IS researchers as well as IS practitioners although there have been a lot of conceptual research regarding the concept of IS failures. Previous empirical studies are not enough yet and thus we anticipate further empirical studies to be performed which will validate previous conceptual research. In this regards, by analyzing IS practitioners perception toward IS failures in a more detailed manner, this research extends conceptual and empirical research in the past which previously identified the structure of information systems (IS) failures. Further, this current study identified the interrelationships among the categories. The data was analyzed using a multidimensional scaling program and fourteen categories of problems were identified as to constitute the IS failure structure. It was found that about a half of categories identified were related to technical failures such as network and system infrastructure, costs, data/information, and program errors. The other remaining categories were related with organizational or social problems such as business success, human resources, relationships, communication, and user skills.

• Journal of Korean Elementary Science Education
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• v.37 no.1
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• pp.39-53
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• 2018

The purpose of this study was to investigate the conceptual structure of subjects related to matter having pre-service elementary school teachers by applying semantic network analysis (SNA). The analyzed concepts in the subjects of matter were 6 words such as 'atom', 'molecule', 'ion', 'electron', 'matter' and 'particle'. The results of SNA of the concepts are as follows : 1. In the semantic network of 'atom', words having a high betweenness centrality were linked with the words based on both the scientific context and the everyday context. 2. The network of 'molecule' was analyzed to be more organized than the network of the 'atom'. 3. In the network of 'ion', the group of words of the scientific context was distinguished from the group of words of the everyday context. 4. The network of 'electron' was analyzed to be more oriented on electricity and magnetism in the field of physics. 5. In the network of 'matter', the words related to compounds were linked with knowledge of history of science. 6. The network of 'particle' was not structured with words based on particulate nature of matter.

• International Journal of Computer Science & Network Security
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• v.21 no.9
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• pp.247-260
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• 2021

Data modeling is a process of developing a model to design and develop a data system that supports an organization's various business processes. A conceptual data model represents a technology-independent specification of structure of data to be stored within a database. The model aims to provide richer expressiveness and incorporate a set of semantics to (a) support the design, control, and integrity parts of the data stored in data management structures and (b) coordinate the viewing of connections and ideas on a database. The described structure of the data is often represented in an entity–relationship (ER) model, which was one of the first data-modeling techniques and is likely to continue to be a popular way of characterizing entity classes, attributes, and relationships. This paper attempts to examine the basic ER modeling notions in order to analyze the concepts to which they refer as well as ways to represent them. In such a mission, we apply a new modeling methodology (thinging machine; TM) to ER in terms of its fundamental building constructs, representation entities, relationships, and attributes. The goal of this venture is to further the understanding of data models and enrich their semantics. Three specific contributions to modeling in this context are incorporated: (a) using the TM model's five generic actions to inject processing in the ER structure; (b) relating the single ontological element of TM modeling (i.e., a thing/machine or thimac) to ER entities and relationships; and (c) proposing a high-level integrated, extended ER model that includes structural and time-oriented notions (e.g., events or behavior).

• The Journal of Information Systems
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• v.7 no.1
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• pp.181-208
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• 1998

In many literatures of model management, various schemes for representing model base schema have proposed. Ultimately, the goal is to arrive at a set of mutually supportive and synergistic methodologies and tools for the modeling problem domain and model base design. This paper focus on how best to structure and represent conceptual model of problem domain and schema of model base. Semantic concepts and modeling constructs are valuable conceptual tools for understanding the structural relationships and constraints involved in an model management environment. To this end, we reviewed the model management literature, and analyzed the constructs of modeling tools of data model management graph-based approach. Although they have good tools but most of them are not enough for the representation of structural relationships and constraints. So we wanted more powerful tools which can represent diverse constructs in a decision support modeling and model base schema design. For the design of a model base, we developed object modeling framework which uses Object Modeling Techniques (OMT). In Object Modeling Framework, model base schema are classified into conceptual schema, logical schema, and physical schema. The conceptual schema represents the user's view of problem domain, and the logical schema represents a model formatted by a particular modeling language. The schema design, this paper proposes an extension of Object Model to overcome some of the limitations exhibited by the OMT. The proposed tool, Extended Object Model(EOM) have diverse constructs for the representation of decision support problem domain and conceptual model base schema.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.4
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• pp.452-459
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• 1998

The purpose of this study was to discover a conceptual framework and evaluation process of apparel quality by means-end chain theory. The theoretical study was conducted to find out a conceptual framework and build a hypothetical evaluation process model of apparel quality. Apparel quality was perceived associative network called a means-end chain and was evaluated in several stages. A conceptual framework of apparel quality evaluation was organized into hierarchical relationships among four different dimensions: physical attribute, physical function, instrumental performance, and expressive performance. The means-end structure linked tangible physical attributes and function to more abstract instrumental and expressive performance. A hypothetical evaluation process model linked dimensions of apparel quality to the selected means-end relationship. Different consumers had different means-end chains for the same apparel. Therefore different subjects are likely to have different evaluation paths. From this study we can suggest an evaluation process model of apparel quality.