• 산업경영시스템학회지
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• 제46권spc호
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• pp.61-67
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• 2023

Special equipment used for snow removal is only used in the winter and must be moved into storage during non-winter seasons. However, when moving heavy equipment using a forklift within a limited space, safety accidents may occur due to deformation and damage due to the worker's limited visibility and excessive loading of heavy objects. In this study, the scissors boom of the developed heavy load transporter was conducted in two cases: link structural analysis and position-based structural analysis. In detail, the link structural analysis covers four cases of stress and safety factor according to material and thickness to optimize the specifications of the material selected during development, and the structural analysis according to position covers two cases before and after the lift, when maximum stress concentration is achieved. Safety was evaluated through finite element analysis. As a result of the study, when manufacturing a scissors boom type heavy load transporter that can withstand a load of 10 tons, the link showed safety at SS400 4.5mm or higher, and reinforcement is needed in the upper and lower structures, so it is judged to be useful in applying materials according to the load.

• 한국지반공학회논문집
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• 제20권4호
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• pp.29-38
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• 2004

본 연구에서는 복합 경계면요소를 이용한 비선형 응력-변형 모델을 이용하여 쓰레기 매립지의 안정성해석을 수행하였다. 쓰레기 매립층의 응력-변형 거동 특성은 국내외 쓰레기의 삼축압축 강도시험 수행결과로써 결정하였고, 경계면 요소의 모델 변수 값은 여러 가지 차수재의 전단시험 결과를 적용하였다. 해석방법에 대한 검증을 위하여 국내 페기물 관리법에 준하는 매립지 모델을 선정하여 안정성해석을 실시하였다. 쓰레기에 대한 삼축압축시험과 토목섬유재에 대한 응력-변형 특성을 분석한 결과 쓰레기는 선형거동을 그리고 토목섬유는 비선형거동을 나타내는 것으로 나타났다. 경계면요소를 이용한 복합차수층 매립지의 안정성 해석결과 매립지 바닥면과 사면의 경계부에서 응력집중과 차수계의 전단변위가 크게 나타나 토목섬유라이너가 포설된 복합차수층의 경우는 복합 경계면 요소가 적용된 해석이 필요함을 알 수 있었다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.77-82
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• 1997

The CANDU-6 transition core refuelled from 37-element fuel to CANFLEX-NU fuel has been evaluated by an 100full power day time-dependent fuel-management simulation to find the core compatibility with the CANFLEX fuel loading. The simulation calculations for the transition core were carried out with the RFSP code, provided by the cell averaged fuel properties obtained from the POWDERPUFS-V code. The simulation results were compared with those of the current 37-element fuel loading only. The results show that the CANFLEX-NU fuel bundles will be compatible with the CANDU-6 reactor because the core physics characteristics of CANFLEX-NU fuel are very similar to those of the 37-element fuel bundle.

• Computers and Concrete
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• 제18권6호
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• pp.1097-1112
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• 2016

Fire loading causes a critical collapse of RC (Reinforced Concrete) Structures since the embedded steels inside are relative week against high elevated temperature. Several numerical frameworks for fire resistance have been proposed, however they have limitations such as unstable convergence and long calculation period. In the work, 2-D nonlinear FE technique is proposed using Galerkin method for RC structures under fire loading. Closed-form element stiffness with a triangular element is adopted and verified with fire test on three RC slabs with different fire loading conditions. Several simulations are also performed considering fire loading conditions, water contents, and cover depth. The proposed numerical technique can handle time-dependent fire loading, convection, radiation, and material properties. The proposed technique can be improved through early-aged concrete behavior like moisture transport which varies with external temperature.

• Computers and Concrete
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• 제23권6호
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• pp.399-408
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• 2019

Structural health monitoring is important for the safety of lives and asset management. In this study, numerical models were developed for the piezoresistive behavior of smart concrete based on finite element (FE) method. Finite element models were calibrated with experimental data collected from compression test. The compression test was performed on smart concrete cube specimens with 75 mm dimensions. Smart concrete was made of cement CEM II 42.5 R, silica fume, fine and coarse crushed limestone aggregates, brass fibers and plasticizer. During the compression test, electrical resistance change and compressive strain measurements were conducted simultaneously. Smart concrete had a strong linear relationship between strain and electrical resistance change due to its piezoresistive function. The piezoresistivity of the smart concrete was modeled by FE method. Twenty-noded solid brick elements were used to model the smart concrete specimens in the finite element platform of Ansys. The numerical results were determined for strain induced resistivity change. The electrical resistivity of simulated smart concrete decreased with applied strain, as found in experimental investigation. The numerical findings are in good agreement with the experimental results.

• Journal of Forest and Environmental Science
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• 제29권1호
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• pp.99-108
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• 2013

This study was conducted to evaluate the non-timber forest functions of the Research Forest area of Kangwon National University. In this study, forest recreation function was investigated through survey method answered by forest management experts. The evaluation factors for forest recreation function were separated into external and internal factors. Each factor was classified into intermediate element and detailed element. Therefore in this study, the evaluation factors of forest recreation function were divided into two groups which are the potential of external factors and the suitability of internal factors. Potential of the external factors were divided into accessibility, location, landscape and induction factors while the suitability of internal factor was divided into stand structure, forest structure and human impact. The priority of the potential of external factors was in order that location, accessibility, induction factors and landscape. The most important factors for the location, accessibility, induction and landscape factors are based on regional characteristics.

• 가족자원경영과 정책
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• 제10권4호
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• pp.65-85
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• 2006

The purposes of this study are to classify housewives based on their perception of benefits sought of preschool child education commodity and to identify the characteristics of each type. For empirical analysis, the data for this study were collected from 400 full-time housewives with preschool child living in Seoul. The statistical methods adopted fur data analysis are cluster analysis, one-way ANOVA, Duncan's multiple range test and discriminant analysis. The major findings of this study are as follows : First, four housewives' types can be categorized by the level of those 3 dimensions. The name fur the types was given as 'sticking to one's belief type', 'taking importance to early stimulation type' 'conforming to and imitating others type', and 'believing blindly in education commodity type'. Second, the result of discriminant analysis shows that 'housewives' education level and their education-related values' element was the most crucial in classifying the housewives, and 'considering child's characteristics and educational home environment' element was the next. The results of this study suggest several implications fur the education of parents with preschool child. Parents' education programs differentiated by the objects and the problems should be developed : which are suitable for each housewives' type.

• 정보관리학회지
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• 제22권4호통권58호
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• pp.97-109
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• 2005

본 연구에서는 정보자원의 메타데이터 작성시 메타데이터 간 의미의 일관성을 유지하기 위한 메타데이터 명명 방법론과 이를 실제 분야에 적용할 수 있는 메타데이터 명명 규칙의 실험적 모형을 제시하였다. 이를 위해 우선적으로 ISO/IEC 11179에서 제시하고 있는 메타데이터 레지스트리 메타모형과 데이터의 기본 속성 및 개념을 논의하였으며, 이러한 논의를 토대로 객체용어(object term)와 속성용어(property term) 및 표현(presentation)에 관한 명명 규칙의 실제 적용 사례를 제시하였다. 객체용어의 생성은 자료유형의 엔터티-관계(I-R) 모형에 근거한 휴리스틱 분석을 통해 이루어졌으며, 속성용어의 명명은 더블린코어의 메타데이터 셋을 기반으로, 표현은 SHOE 1.0 버전을 기반으로 하였다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.121-124
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• 1996

In general, cellular manufacturing system can be constructed by the following two steps. The first step forms machine cells and part families, and the second step determines cell layout based on the result of first step. Cell layout has to be considered when cell is formed becauese the result of cell formation affects it. This paper presents a cell formation algorithm and proposes an integrated mathematical model for cell formation and cell layout. The cell formation algorithm minimizes the number of exceptional element in cellular manufacturing system. New concept for similarity and incapability is introduced, based on machine-operation incidence matrix and part-operation incidence matrix. One is similarity between the machines, the other is similarity between preliminary machine cells and machines. The incapability identifies relations between machine cells and parts. In this procedure, only parts without an exceptional element are assigned to machine cell. Bottleneck parts are considered with cell layout design in an integrated mathematical model. The integrated mathematical model determines cell layout and assigns bottleneck parts to minimize the number of exceptional element and intercell moving distance, based on linearixed 0-1 integer programming. The proposed algorithm is illustrated by using numerical examples.

• 디지털산업정보학회논문지
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• 제11권1호
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• pp.1-8
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• 2015

Recently, a high strength concrete(HSC) in excess of 80 MPa is popular to use in the domestic construction field. But there is no design standard of high strength concrete. It is reason why a study about structural behaviors of thin walls is required. In this paper, the accurate Finite Element Method as a virtual test is suggested considering material properties, which are concrete and steel, and the experimental fractural model suggested by Kupfer. It is conducted the comparison evaluation of the ultimate failure loads, lateral-displacements and crack propagation patterns between the results of experimental approach, which were carried on Saheb's test for normal strength concrete and Lee's test for high strength concrete. Therefore it is suggested to use the accurate virtual simulation test method and Ubiquitous Sensor Network(USN) by Finite Element Method for Internet of Things(IoT).