• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.44-51
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• 2019

Designing sophisticate ship structures that satisfy several design criteria simultaneously with minimum weight and cost is an important engineering issue. For a ship structure composed of a shell and stiffeners, this issue is more serious because their mutual effect has to be addressed. In this study, a two-stage optimization method is proposed for the conceptual design of stiffeners in a ship's prow. In the first stage, a topology optimization method is used to determine a potential stiffener distribution based on the optimal results, whereupon stiffeners are constructed according to stiffener generative theory and the material distribution. In the second stage, size optimization is conducted to optimize the plate and stiffener sections simultaneously based on a parametric model. A final analysis model of the ship-prow structure is presented to assess the validity of this method. The analysis results show that the two-stage optimization method is effective for stiffener conceptual design, which provides a reference for designing actual stiffeners for ship hulls.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.12 s.159
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• pp.1661-1671
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• 2006

Many researchers have studied the process of retail evolution in the United States and in Europe. Although extensively studied(e.g., Agergaard, Olsen & Allpass, 1970; Oren, 1989), used in conceptual work(e.g., Cist, 1968), and applied as foundation in empirical work(e.g., HcNair, 1958), some limitations exist as follows: inability to cover multiple types of retail institutions and limited quantification. The purpose of this study is to build a conceptual framework combining existing retail evolution theories to overcome existing limitations. Data collection and analysis followed a qualitative research design, specifically a grounded theory type of design with a constant comparative analysis method. As a result of the study, a conceptual framework was built by synthesizing aspects of retail evolution theories and showed retail institution types in a change process.

• English Language & Literature Teaching
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• v.13 no.3
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• pp.41-56
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• 2007

This paper, drawing on various secondary sources related to bilingualism and bilingual education, proposes a semi-CLIL (Content and Language Integrated Learning) model as an initial option for Korea's ELT instruction at a primary level, with a subsequent application to a secondary level in mind. It is reported that the current pedagogy focused on early English education and communicative language teaching does not meet the needs of students' EFL proficiency. The main reasons for this are considered to lie in the social and educational environment which impedes EFL students' meaningful and authentic communication in target language. Thus, by exploring a conceptual approach to such a problem, this paper suggests a paradigm of integrating content and language for a reasonable solution.

• ETRI Journal
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• v.18 no.2
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• pp.87-106
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• 1996

This paper proposes a new model as a framework for forecasting demand and technological substitution, which can accommodate different patterns of technological change. This model, which we named, "Adaptive Diffusion Model", is formalized from a conceptual framework that incorporates several underlying factors determining the market demand for technological products. The formulation of this model is given in terms of a period analysis to improve its explanatory power for dynamic processes in the real world, and is described as a continuous form which approximates a discrete derivation of the model. In order to illustrate the applicability and generality of this model, time-series data of the diffusion rates for some typical products in electronics and telecommunications market have been empirically tested. The results show that the model has higher explanatory power than any other existing model for all the products tested in our study. It has been found that this model can provide a framework which is sufficiently robust in forecasting demand and innovation diffusion for various technological products.

• Management & Information Systems Review
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• v.1
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• pp.229-268
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• 1997

Recently, object-oriented concepts and technology are on the leading edge of programming language and database systems research, and their usefulness in those contexts has been successfully demonstrated. The adoption of object-oriented concept to the design of model bases has several benefits. From the perspectives of object-oriented approach, models in a model base are viewed as object which encapsulate their states and behaviors. This paper focuses on the design of an object-oriented model base that handles various resources of DSS(data, knowledge, models, solvers) in a unified fashion. For the design of a model base, we adopted Object Modeling Techniques(OMT). An object model of OMT can be used for the conceptual design of an overall model base schema. The object model of OMT provides several advantages over the conventional approaches in model base design. The main advantage are model reuse, hierarchical model construction, model sharing, meta-modeling, and unified model object management.

• Journal of Environmental Science International
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• v.31 no.10
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• pp.845-859
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• 2022

The natural environment of the modern society does not simply reflect damage, but is a complex and grave reality that threatens the Earth. To solve this problem, various aspects related to the natural environment have been explored around the world, and a number of studies are ongoing to balance the development and preservation of the natural environment in Korea. However, no clear category exists for the natural environment and the related terms are ambiguous, rendering the overall evaluation system is in efficient. Therefore, the present study attempted to set the scope of application of a comprehensive evaluation system based on terms similar to the natural environment, concepts of the natural environment viewed from a value-based perspective and a capacitive perspective. In addition, by examining the concept of ecosystem services, a conceptual model for efficient application of the evaluation system of the natural environment through the association between categories of the natural environment is presented to derive implications for practical operation in the future.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.233-234
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• 2018

• Journal of Ocean Engineering and Technology
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• v.32 no.1
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• pp.9-20
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• 2018

The present study deals with the conceptual design of a motion reduction device for a floating wave-offshore wind hybrid power generation platform. A damping plate attached to the bottom of a column of a large semi-submersible is introduced to reduce the motion of the platform. Performance analyses on various shapes and configurations of damping plates were performed using the potential flow solver, and the appropriate configuration and size of the damping plate were selected based on the numerical results. In order to see the effect of viscous damping, a small scale model test was performed in a 2D wave flume. The performances of five different damping plates were measured and discussed based on the results of free decay tests and regular wave tests.

• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.4
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• pp.19-26
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• 2003

In this paper, the result of the conceptual study of a tipjet driven propulsion system is presented. The concept of a tipjet driven propulsion system is to employ tipjet as power source to drive a rotor Because the vehicle is supposed to takeoff and land vertically, a rotor system, which has tipjet nozzles, is adopted to fly like a helicopter. Exhaust gas, which is generated by an engine, Passes through an internal duct system and divided into four blade ducts. The design code is consists of two parts, engine model and internal duct model. Inside a rotating duct, compressible flow is affected by two additional force terms, centrifugal force and coriolis force and they govern the performance in rotary mode, The intention of this paper is to address the issues associated with sizing and optimizing configurations of a tipjet driven propulsion system especially in rotary wing mode.

• Journal of Korean Society for Quality Management
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• v.25 no.4
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• pp.71-78
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• 1997

In this paper, we consider a hierarchical Bayes estimation of the parameter, the reliability and failure rate functions based on type-II censored samples from a Burr type-？ failure time model. The Gibbs sampler a, pp.oach brings considerable conceptual and computational simplicity to the calculation of the posterior marginals and reliability. A numerical study is provided.