• 산업기술연구
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• 제25권A호
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• pp.123-131
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• 2005

Semantic object model has widely been recognized as an alternative data modeling approach to entity-relationship model for database system design. In this study, we have presented a semantic object model for intermediary type shopping mall consisting of multiple buyers and sellers. Essential processes and information with regard to the customer management, product management, price estimation, product order etc. have been considered for this study. Upon careful examination and analysis of them, a detailed semantic objects and attributes have been drawn and structured into semantic object diagrams. The final objects were converted into an entity-relationship diagram so that intuitive comparison could be made for relational database design. The results in this study may form a conceptual framework for both academic concerns and more complicated system applications.

• 경영과학
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• 제12권3호
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• pp.135-161
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• 1995

This paper is concerned with a conceptual design of a knowledge-based modeler for network analysis. The "knowledge-based modeler" approach is suggested as a method for incorporating the user's qualitative knowledge and subjective decison in the course of the mathematical modeling and the subsequent solution procedure. The submodules of the proposed modeler such as database, model/algorithm base and functional knowledge bases are identified and the flows of information between the submodules are sequentially defined. A prototype system is implemented for experimental purpose by using the application software GURU.ware GURU.

• 한국CDE학회논문집
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• 제11권4호
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• pp.265-272
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• 2006

For the design and analysis of 3D object featuring complexity and irregularity in shape, sectional digital images measured by an industrial CT scanner are employed to generate a finite element model with uniform voxels. The voxel model plays a key role in developing an integrated reverse engineering system including geometric modeling, simulation and optimization. Design examples applied to topology optimization show that the proposed approach can provide a remarkable reduction in time cost at the conceptual and detail design stages.

• 한국농공학회논문집
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• 제56권6호
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• pp.45-53
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• 2014

This study presents a system dynamics modeling approach to simulate daily streamflow in a watershed including wastewater treatment plant which contributes to irrigation water supply. The conceptual system dynamics model considering the complex and dynamic hydrological processes in the watershed was developed. The model was calibrated and validated each for two years based on observed flow data. Model performances in terms of $E_{NS}$, RSR, PBIAS, and $R^2$ were 0.64, 0.60, -3.6 %, and 0.64 for calibration period, and 0.66, 0.58, -2.6 %, and 0.66 for validation period, respectively, showing an applicability on generating the daily streamflow. System dynamics modeling approach could help better understand the hydrological behavior of the watershed being reused wastewater for agriculture, by providing graphical dynamics of the hydrological processes as well as conventional rainfall-runoff model results.

• Wind and Structures
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• 제38권5호
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• pp.355-366
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• 2024

Severe natural multi-hazard events can cause damage to infrastructure and economic losses of billions of dollars. The challenges of modeling these losses include dependency between hazards, cause and sequence of loss, and lack of available data. This paper presents and explores multi-hazard loss modeling in the context of the combined wind and rain vulnerability of mid/high-rise buildings during hurricane events. A component-based probabilistic vulnerability model provides the framework to test and contrast two different approaches to treat the multi-hazards: In one, the wind and rain hazard models are both decoupled from the vulnerability model. In the other, only the wind hazard is decoupled, while the rain hazard model is embedded into the vulnerability model. The paper presents the mathematical and conceptual development of each approach, example outputs from each for the same scenario, and a discussion of weaknesses and strengths of each approach.

• International Journal of Aeronautical and Space Sciences
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• 제16권3호
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• pp.370-379
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• 2015

Handling constantly evolving configurations of aircraft can be inefficient and frustrating to design engineers, especially true in the early design phase when many design parameters are changeable throughout trade-off studies. In this paper, a physics-based design framework using parametric modeling is introduced, which is designated as DIAMOND/AIRCRAFT and developed for structural design of transport aircraft in the conceptual and preliminary design phase. DIAMOND/AIRCRAFT can relieve the burden of labor-intensive and time-consuming configuration changes with powerful parametric modeling techniques that can manipulate ever-changing geometric parameters for external layout of design alternatives. Furthermore, the design framework is capable of generating FE model in an automated fashion based on the internal structural layout, basically a set of design parameters describing the structural members in terms of their physical properties such as location, spacing and quantities. The design framework performs structural sizing using the FE model including both primary and secondary structural levels. This physics-based approach improves the accuracy of weight estimation significantly as compared with empirical methods. In this study, combining a physics-based model with parameter modeling techniques delivers a high-fidelity design framework, remarkably expediting otherwise slow and tedious design process of the early design phase.

• 한국정보과학회논문지:데이타베이스
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• 제32권2호
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• pp.111-119
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• 2005

전자카타로그는 상품에 관한 풍부한 의미를 포함하며 온톨로지가 적용될 여지가 높은 영역이다. 온톨로지는 사물의 본질과 사물간의 관계를 나타내는데, 전자카탈로그를 형식적(formal)인 온톨로지로 표현하는 것은 전자상거래 영역에서 중요하다. DL(Description Logic)은 현재 사용되는 여러 온톨로지 언어의 이론적 기반을 제공한다. 본 논문은 DL 언어를 사용해 전자카타로그를 형식적으로 온톨로지 모델링 한다. 기본적인 모델링 구성요소 집합은 화장 개체 관계(Extended Entity Relationship)로 개념적으로 나타내고, DL 언어로 대응해서 변환한다. EER로 나타낼 수 없는 부가적인 의미적 지식은 직접 DL언어로 표현한다. 논문에서 제시하는 모델링 언어는 언어의 표현력과 복잡도를 고려할 때, 현실적으로 추론에 적합하다고 알려져 있는 SHIQ(d) 언어 범위에 기반하고 있다. 모델링한 온톨로지 e-카타로그의 활용 이해를 돕기 위해 시나리오를 제시하고, 실제 DL 추론 도구를 통해 그 시험적 검증을 한다.

• 한국수자원학회논문집
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• 제45권6호
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• pp.597-606
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• 2012

DEM(Digital Elevation Model) 크기의 변화에 따라 특정 지역에 많은 규격의 수문 데이터가 존재할 수 있기 때문에, 어느 지역, 어느 기상 데이터에도 작동할 수 있는 수문 모형의 개발이 절실히 필요하게 되었다. 이와 같은 필요성을 설명하기 위해서 객체지향(object-oriented)적인 프로그래밍 기술을 적용한 GHISMO(Geographic and Hydrologic Information System Modeling Objects)라는 수문모형(hydrologic model)을 개발하였다. GHISMO의 가장 핵심적인 수문학적 접근방법은 저류-배출(storage-release)과 지표면 유효 강수량을 구하기 위하여 SCS curve number 방법을 사용한 것이다. 이 연구에서 수문모형의 모의실험 결과를 제공할 것이다.

• 품질경영학회지
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• 제30권4호
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• pp.58-67
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• 2002

Since the inception of off-line quality control, it has drawn a particular attention from research community and it has been implemented in a wide variety of industries mainly due to its extensive applicability to numerous real situations. Emphasizing design issues rather than control issues related to manufacturing processes, off-line quality control has been recognized as a cost-effective approach to quality improvement. It mainly consists of three design stages: system design, parameter design, and tolerance design which are implemented in a sequential manner. Utilizing experimental designs and optimization techniques, off-line quality control is aimed at achieving product performance insensitive to external noises by reducing process variability. In spite of its conceptual soundness and practical significance, however, off-line quality control has also been criticized to a great extent due to its heuristic nature of investigation. In addition, it has also been pointed out that the process optimization procedures are inefficient. To enhance the current practice of off-line quality control, this study proposes an integrated optimization model by utilizing a well-established statistical tool, so called response surface methodology (RSM), and a tolerance - cost relationship.

• 한국수자원학회논문집
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• 제43권8호
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• pp.709-720
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• 2010

본 연구에서는 개념적인 토양수분 모형을 이용하여 가뭄에 대한 기후변화의 영향을 모형화하고, 모형으로부터의 결과를 분석하고 있다. 미래 기후자료로서 A2 온실가스 배출 시나리오에 따라 CCCma CGCM3-T63에 의해 도출된 자료가 이용되며, 일별 강수분포 및 월별 강수량 및 잠재증발산량의 변화를 고려하기 위하여 일별 스케일링 기법이 적용된다. 모형으로부터 도출된 주요결과로부터 미래에는 우리나라에 보다 잦은 가뭄이 있을 수 있음을 살펴볼 수 있다.