• 대한기계학회논문집A
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• 제23권7호
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• pp.1139-1146
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• 1999

Reliability analysis of structures based on fracture mechanics requires knowledge on statistical characteristics of the parameter C and m in the fatigue crack growth law, $da/dN=C({\Delta}K)^m$. The purpose of the present study is to investigate if it is possible to predict fatigue crack growth rate by only the fluctuation of the parameter C. In this study, Paris-Erdogan law is adopted, where the author treat the parameter C as random and m as constant. The fluctuation of crack growth rate is assumed only due to the parameter C. The growth resistance coefficient of material to fatigue crack growth (Z=1/C) was treated as a spatial stochastic process, which varies randomly on the crack path. The theoretical crack growth rates at various stress intensity factor range are discussed. Constant ${\Delta}K$ fatigue crack growth tests were performed on the structural steel, SM45C. The experimental data were analyzed to determine the autocorrelation function and Weibull distributions of the fatigue crack growth resistance. And also, the effect of the parameter m of Paris' law due to variation of fatigue crack growth resistance was discussed.

• Journal of Ginseng Research
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• 제47권3호
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• pp.469-478
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• 2023

Background: Nitrogen (N) is an essential macronutrient for plant growth and development. To support agricultural production and enhance crop yield, two major N sources, nitrate and ammonium, are applied as fertilizers to the soil. Although many studies have been conducted on N uptake and signal transduction, the molecular genetic mechanisms of N-mediated physiological roles, such as the secondary growth of storage roots, remain largely unknown. Methods: One-year-old P. ginseng seedlings treated with KNO₃ were analyzed for the secondary growth of storage roots. The histological paraffin sections were subjected to bright and polarized light microscopic analysis. Genome-wide RNA-seq and network analysis were carried out to dissect the molecular mechanism of nitrate-mediated promotion of ginseng storage root thickening. Results: Here, we report the positive effects of nitrate on storage root secondary growth in Panax ginseng. Exogenous nitrate supply to ginseng seedlings significantly increased the root secondary growth. Histological analysis indicated that the enhancement of root secondary growth could be attributed to the increase in cambium stem cell activity and the subsequent differentiation of cambium-derived storage parenchymal cells. RNA-seq and gene set enrichment analysis (GSEA) revealed that the formation of a transcriptional network comprising auxin, brassinosteroid (BR)-, ethylene-, and jasmonic acid (JA)-related genes mainly contributed to the secondary growth of ginseng storage roots. In addition, increased proliferation of cambium stem cells by a N-rich source inhibited the accumulation of starch granules in storage parenchymal cells. Conclusion: Thus, through the integration of bioinformatic and histological tissue analyses, we demonstrate that nitrate assimilation and signaling pathways are integrated into key biological processes that promote the secondary growth of P. ginseng storage roots.

• International Journal of Internet, Broadcasting and Communication
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• 제11권4호
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• pp.65-70
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• 2019

We are looking the impact associated with globalization in favor of small and medium enterprises (SMEs) growth and how helped to reduce the obstacle facing SMEs growth. We used empirical analysis in order to examine the relationship underlying the globalization and its impact to SME growth. We employed primarily data from Tanzania SMEs. Further we seeks to explain the negative notion that has been created that globalization is not friendly to SME growths. We employed primary data from Tanzania SMEs. The partial least squares (PLS) was used for analysis. The conclusion has indicated that globalization has a relationship with SMEs growth and has contributed to the reduction of obstacles that inhibit SMEs growth. However study confirmed controversial result on part of availability of managers and manpower with global perspectives to influence SMEs growth. The test accepted that globalization has influenced availability of managers with global perspectives but reject the availability of these managers influences the SMEs growth The results give a clear outlook to help policy maker in policy review process, formulate base for extensive study on issues for manager perspectives and draw intervention.

• 한국생산제조학회지
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• 제8권2호
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• pp.27-34
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• 1999

The growth-strain method was used for shape optimization, which carries out the optimization by distributing uniformly the distributed parameter such as von Mises stress and shear strain energy density. Shape optimization is carried out by iteration of stress analysis and growth strain analysis. In this study, the effect of growth ratio in the method was investigated and then the range of the adequate value of the growth ratio was determined. Also the growth-strain method was improved by applying the linear PID control theory in order to control volume required by a designer. Finally, an automatic shape optimization system was built up by the improved growth-strain method with a commercial software using finite element method. The effectiveness and practicability of the developed shape optimization system was verified by some examples.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제11권9호
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• pp.355-362
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• 2022

농업에 정보 통신 기술을 접목한 스마트팜은 단순한 생육 환경 모니터링에서 벗어나 작물 생육을 위한 최적의 환경을 발견하고 자율제어가 가능한 농업의 형태로 나아가고 있다. 이를 위해서는 관련 데이터를 수집하는 것도 중요하지만, 재배 경험과 지식을 가진 농업인 사용자들이 수집된 데이터를 다양한 관점에서 분석하여 작물 생육 환경 제어에 유용한 정보를 도출해야 할 필요가 있다. 본 연구에서는 작물 생육과 관련된 데이터를 가지고 필요한 정보를 얻고자 하는 농업인 사용자가 쉽게 데이터 분석을 할 수 있는 웹 서비스를 개발하였다. 개발한 웹 기반 데이터 분석 서비스는 데이터 분석을 위하여 R 언어를 사용하며 Node.js를 위한 익스프레스 웹 애플리케이션 프레임워크를 기반으로 개발하였다. 데이터 분석 서비스를 운영 중인 생육 환경 모니터링 시스템과 함께 적용해 본 결과 사용자는 웹 상에서 CSV 형식의 파일을 입력하거나 직접 데이터 입력함으로써 서버가 제공하는 데이터 분석을 위한 R 스크립트를 실행하여 데이터 분석을 수행할 수 있었다. 서비스 제공자는 다양한 데이터 분석 서비스를 쉽게 제공할 수 있었고, R 스크립트만 새로 추가하면 애플리케이션에 대한 수정 없이 새로운 데이터 분석 서비스 추가가 용이함을 확인하였다.

• 수산경영론집
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• 제42권2호
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• pp.85-96
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• 2011

Oliver flounder population density affect Oliver flounder growth and mortality rate. In laboratory pilot experiment, Oliver flounder growth rate is inversely proportional to stocking density. But previous study has not proved external validity. This study is aimed to analyze the effect of stocking density on the Oliver flounder culture farms in Jeju Island. In order to do this, I selected 13 farms in Jeju island as a sample. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows. First, in case of the Oliver flounder culture farms, Bertalanffy equation is not applicable to the Oliver flounder growth. Second, the Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, is preferred to density definition defined as the weight of Oliver flounder per $m^2$ of water surface area on the Oliver Flounder Culture Farms case. Third, growth rate and production weight on the Oliver flounder culture farms are inversely proportional to stocking density on spearman rank correlation test. When extensive comparable biological and culture condition data become available, analysis model can be easily modified to yield more accurate results.

• Korean Chemical Engineering Research
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• 제59권1호
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• pp.138-151
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• 2021

The effect of a reactant ratio on the growth of a buoyancy-driven instability in an irreversible A+B→C reaction system is analyzed theoretically and numerically. Taking a non-stoichiometric reactant ratio into account, new linear stability equations are derived without the quasi-steady state assumption (QSSA) and solved analytically. It is found that the main parameters to explain the present system are the Damköhler number, the dimensionless density difference of chemical species and the ratio of reactants. The present initial grow rate analysis without QSSA shows that the system is initially unconditionally stable regardless of the parameter values; however, the previous initial growth rate analysis based on the QSSA predicted the system is unstable if the system is physically unstable. For time evolving cases, the present growth rates obtained from the spectral analysis and pseudo-spectral method support each other, but quite differently from that obtained under the conventional QSSA. Adopting the result of the linear stability analysis as an initial condition, fully nonlinear direct numerical simulations are conducted. Both the linear analysis and the nonlinear simulation show that the reactant ratio plays an important role in the onset and the growth of the instability motion.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1997년도 Proceedings of the 12th KACG Technical Meeting and the 4th Korea-Japan EMGS (Electronic Materials Growth Symposium)
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• pp.203-206
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• 1997

• 한국전산구조공학회논문집
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• 제23권6호
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• pp.607-613
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• 2010

FRANC3D is a program for simulating arbitrary three-dimensional crack growth. Recently, a completely new version of the program, FRANC3D/NG, has been created. Unlike previous versions, which relied largely on boundary element analysis, the new version of the program works with finite element analysis exclusively and is designed to work with general-purpose commercial finite element packages. This paper presents the theoretical underpinnings of the procedures to adaptively modify the geometry and mesh of a model to simulate crack growth.

• 대한치과교정학회지
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• 제18권2호
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• pp.343-366
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• 1988

Craniofacial complex is influenced by numerical skeletal elements. Though the analysis of growth change has been done by various analytical methods, it was dependent on any method of registration and superimposition, based on reference plane and reference point. However, the craniofacial growth is composed of a number of local growth elements. Therefore, it will be necessary to use a clinically useful method for estimating craniofacial skeletal growth independently. The author analysed longitudinal cephalometric roentgenogram of 15 Korean males and 15 Korean females aged from 6 to 12 years by the finite element method and results were as follows : 1. The finite element method for craniofacial skeletal complex and soft tissue made it possible to analyze the independent local growth. 2. Regression equations from the value of each strain will make it possible to predict the craniofacial growth. 3. The growth of anterior cranial base was different from that of other facial bone. 4. The growth of posterior cranial base influenced the growth of upper pharyngeal region, midfacial region, maxilla and posterior region of mandible. 5. The growth of maxillary complex was vertical rather than horizontal. 6. The growth direction of ramus, mandibular body, alveolar bone was various. 7. The relation between hard tissue and soft tissue by finite element method was variant.