• 제목/요약/키워드: Model dimension

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A fractal fracture model and application to concrete with different aggregate sizes and loading rates

  • Chang, Kug Kwan;Xi, Yunping;Roh, Y.S.
    • Structural Engineering and Mechanics
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    • 제23권2호
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    • pp.147-161
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    • 2006
  • Recent developments in fractal theory suggest that fractal may provide a more realistic representation of characteristics of cementitious materials. In this paper, the roughness of fracture surfaces in cementitious material has been characterized by fractal theory. A systematic experimental investigation was carried out to examine the dependency of fracture parameters on the aggregate sizes as well as the loading rates. Three maximum aggregate sizes (4.76 mm, 12.7 mm, and 19.1 mm) and two loading rates (slow and fast loading rate) were used. A total of 25 compression tests and 25 tension tests were performed. All fracture parameters exhibited an increase, to varying degrees, when aggregates were added to the mortar matrix. The fracture surfaces of the specimens were digitized and analyzed. Results of the fractal analysis suggested that concrete fracture surfaces exhibit fractal characteristics, and the fractal geometry provide a useful tool for characterizing nonlinear fracture behavior of concrete. Fractal dimension D was monotonically increased as maximum aggregate sizes increase. A new fractal fracture model was developed which considers the size and shape of aggregate, and the crack paths in the constituent phases. Detailed analyses were given for four different types of fracture paths. The fractal fracture model can estimate fractal dimension for multiphase composites.

구동륜(驅動輪)의 성능예측(性能豫測)에 적합한 토양변수(土壤變數)의 차원해석(次元解析)을 위한 차륜(車輪)-토양(土壤) 시스템의 상사성(相似性) 연구(硏究)(II) -침하량(沈下量) 예측(豫測) 분석(分析)- (A Similitude Study of Soil-Wheel System for Inentifying the Dimension of Pertinent Soil Parameter (II) -Sinkage Prediction Analysis-)

  • 이규승;정창주
    • Journal of Biosystems Engineering
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    • 제14권3호
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    • pp.158-167
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    • 1989
  • This study was conducted to investigate the applicability of true model theory in a powered lugged wheel-soil system and to examine the possibility of using principles of similitude in investigating the dimensions of soil parameters pertinent to a powered lugged wheel-soil system concerning the sinkage prediction. The following conclusions were derived from the study; 1) The sinkage of prototype wheels proved to be predicted by those of the model wheels for the range of the dynamic weight tested. 2) A conditional equation which can be used for the prediction of sinkage of prototype by model test was derived as $n_f=n{_\ell}{^{-b}}$. The range of the numerical value of b, which is the exponent on the length dimension of the soil property ${\alpha}$, was found to be -1.48~-2.54. 3) Considering a relatively wide variation of b values, it was concluded that there are several soil properties which are pertinent to the powered lugged-wheel soil system concerning the sinkage prediction.

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The Development of Information Science in Ibero-America

  • Araujo, Carlos Alberto Avila
    • Journal of Information Science Theory and Practice
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    • 제7권4호
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    • pp.6-19
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    • 2019
  • The purpose of this article is to problematize the existence of a possible Ibero-American informational thinking. It was initially observed that a relative absence of Ibero-America in the international presentations and mappings of information science exists. Below, the reality of the 22 countries that compose Ibero-America is discussed, a region that can be understood from a sociocultural and geopolitical perspective. Then, a mapping of the information science research in these countries is made. The main research topics found are: epistemological studies, relationships with library science, information literacy, representation and organization, bibliometric studies, information management, user studies, technological dimensions, and relationships with archival science and museum studies. Finally, a general epistemological configuration of information science is presented at a global level, highlighting the great trends of study of information that marked the decades of the 1960s and 1970s (physical model), 1980s and 1990s (cognitive model), and the 21st century (sociocultural model), and which manifested themselves in the different subareas that make up the field. The most recent research in information science, in addition to addressing information transfer (physical dimension) and its relationship with data and knowledge (cognitive dimension), has also incorporated aspects related to the social effects of information, its role in the constitution of identities and culture, and the importance of its material conformations. Such expansion reflects attempts to address the complexity of informational phenomena. Therefore, it is concluded that it is important to place the specific contributions of Ibero-America in this context.

Modeling for the strap combined footings Part I: Optimal dimensioning

  • Aguilera-Mancilla, Gabriel;Luevanos-Rojas, Arnulfo;Lopez-Chavarria, Sandra;Medina-Elizondo, Manuel
    • Steel and Composite Structures
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    • 제30권2호
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    • pp.97-108
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    • 2019
  • This paper presents a new model for the strap combined footings to obtain the most economical contact surface on the soil (optimal dimensioning) to support an axial load and moment in two directions to each column. The new model considers the soil real pressure, i.e., the pressure varies linearly. Research presented in this paper shows that can be applied to the T-shaped combined footings and the rectangular combined footings. The classical model uses the technique of test and error, i.e., a dimension is proposed, and subsequently, the equation of the biaxial bending is used to obtain the stresses acting on each vertex of the strap combined footing, which must meet the conditions following: The minimum stress should be equal or greater than zero, and maximum stress must be equal or less than the allowable capacity that can withstand the soil. Numerical examples are presented to obtain the optimal area of the contact surface on the soil for the strap combined footings subjected to an axial load and moments in two directions applied to each column. Appendix shows the Tables 4 and 5 for the strap combined footings, the Table 6 for the T-shaped combined footings, and the Table 7 for the rectangular combined footings.

Analyzing the Business Model Canvas and Marketability of Heritage Sites in Central Luzon: A Public Sector Perspective

  • Delia LUMIWES;Gi Ho JEONG
    • 융합경영연구
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    • 제11권6호
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    • pp.35-41
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    • 2023
  • Purpose: This study aims to determine the marketability of the heritage sites in Region III, Philippines. More specifically, it will obtain information on the: (a) profile of the heritage sites in Central Luzon; (b) dimensional issues of their marketability along social, environmental, and economic lines; (c) quality of services in terms of tangibility, responsiveness, empathy, assurance, and reliability; and (d) its business model canvas. Research design, data, and methodology: This will utilize a descriptive survey of the heritage sites in Central Luzon, namely: Aurora, Nueva Ecija, Bulacan, Pampanga, Tarlac, Zambales, and Bataan. There will be 60 respondents, including 5 facilitators, 24 residents, and 31 tourists. The results will be statistically measured through the measures of central tendencies, dispersion, and the test of significance. Result and conclusion: This study will comprehensively examine the local tourism sector, benefiting various stakeholders. It serves as a valuable resource for tourists by providing insights into destination marketing strategies and enhancing heritage tourism experiences. Administrators benefit from coping strategy evaluations, aiding in the formulation of effective strategies aligned with industry goals. Tourism businesses align with industry objectives and the study streamlines ordinances for site protection for local government units. Additionally, the community gains empowerment through insights into employable activities and potential businesses, influencing assessments of the justification for local preservation ordinances.

낙엽송 제재에 따른 이용재적 산출 모델의 개발 (Development of a Wood Recovery Estimation Model for the Tree Conversion Processes of Larix kaempferi)

  • 권기범;한희;설아라;정혜진;정주상
    • 한국산림과학회지
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    • 제102권4호
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    • pp.484-490
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    • 2013
  • 본 연구는 낙엽송 개체목의 가공처리 과정에서 생산되는 제재목 및 제재 부산물의 양을 분석하기 위한 시뮬레이션 모델을 개발하고자 수행되었다. 이 모델에서는 수간곡선 추정식을 이용하여 개체목의 전간재적을 산출하고 절동된 원목에 대한 목재 가공 시뮬레이션을 통해 판재 및 각재, 원주목의 규격에 따른 최대 생산가능량을 예측하였다. 또한 제재목 가공처리 과정에서 생산되는 톱밥 및 죽데기의 잔존재적에 대한 분석을 수행하였다. 그 결과 흉고직경 12 cm 이상부터 제재목의 생산이 가능한 것으로 나타났고, 제재목의 생산이 가능한 경우에는 보다 큰 규격의 판재와 각재를 생산하는 것이 상대적으로 작은 규격의 판재와 각재 혹은 원주목을 생산하는 것에 비해 더 많은 생산량을 얻을 수 있었다. 향후 이 모델은 낙엽송의 이용재적 산출을 통한 산림의 경제적 가치평가는 물론, 최근 목질계 바이오에너지 자원으로서 그 중요성이 점차 높아지고 있는 톱밥과 같은 제재 부산물의 양을 예측하는 데에도 활용될 수 있을 것이다.

엔터프라이즈 아키텍처 지향 모델 개발: 연계와 통합 관점에서 본 엔터프라이즈 현재와 미래 아키텍처 사상 (Toward Developing An Enterprise Architecture Orientation Model: Mapping the Present and Future Enterprise Architecture from the Alignment and Integration Perspective)

  • 손정순;전성현
    • 경영정보학연구
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    • 제12권2호
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    • pp.1-23
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    • 2010
  • 엔터프라이즈 정보화를 추진하는데 있어서 가장 심각한 문제 중 하나는 서로 연계 통합되지 않은 사일로(Silo) 시스템 문제이다. 정보전략계획(Information Strategy Planning)은 비즈니스에 필요한 개별시스템 기능성 도출에 국한되어 오히려 이러한 사일로 문제를 가중시키고 있다. 본 연구는 엔터프라이즈 사일로 문제가 엔터프라이즈 제반 요소들이 가지는 관계에 대한 총체적 시각, 곧 '아키텍처적 시각'이 부재하기 때문이라고 보고, 이러한 엔터프라이즈 요소간 관계를 정의하고 체계화할 수 있는 '엔터프라이즈 아키텍처 지향 모델'을 제안한다. 이를 위해 본 연구는 엔터프라이즈 제반 구성요소들 상호간에 수직적, 수평적 관계성을 부여하고 엔터프라이즈가 이들 관계에 있어서 거치는 진화의 단계를 설정한다. 엔터프라이즈 아키텍처 지향 모델에서 수직적 관계는 Kaplan과 Norton의 연구로부터 도출된 성과, 역량, 전략이라는 세 요소가 조직 상하간에 전략적 관리적 측면에서 '연계(Alignment)'되어야 함을 의미한다. 수평적 관계는 Ross 등이 통합 대상으로 다룬 정보기술, 데이터/프로세스, 비즈니스 컴포넌트 요소들이 수평 조직간에 기능적 실행적 측면에서 '통합(Integration)'되어야 함을 강조한다. 본 모델은 엔터프라이즈의 현재와 미래 아키텍처를 사상하는 개념공간으로서 엔터프라이즈의 현재 모습을 파악하고 엔터프라이즈가 지향하는 미래 모습을 도출하며 현재에서 미래로의 이행을 인도하는 개념적 틀로서 작용하게 된다. 끝으로 본 모델의 적용 사례를 들고 모델의 적용이 각 엔터프라이즈가 지향하는 엔터프라이즈 모습에 따라 어떻게 달라질 수 있는지를 논의한다.

Bayesian Variable Selection in the Proportional Hazard Model

  • Lee, Kyeong-Eun
    • Journal of the Korean Data and Information Science Society
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    • 제15권3호
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    • pp.605-616
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    • 2004
  • In this paper we consider the proportional hazard models for survival analysis in the microarray data. For a given vector of response values and gene expressions (covariates), we address the issue of how to reduce the dimension by selecting the significant genes. In our approach, rather than fixing the number of selected genes, we will assign a prior distribution to this number. To implement our methodology, we use a Markov Chain Monte Carlo (MCMC) method.

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비례위험모형에서 비례성 가정에 대한 검정: 도산모형에의 응용

  • 남재우;김동석;이회경
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2004년도 추계학술대회 및 정기총회
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    • pp.615-618
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    • 2004
  • The previous quantitative bankruptcy prediction models cannot include time dimension. To overcome this limit, various dynamic models using survival analysis are developed recently. This paper emphasizes that the proportionality assumption must be adapted with caution when the Cox's proportional hazard model is used to explain bankruptcy. It is shown that a non-proportional hazard model including a change point model is a proper alternative, when the proportionality assumption is violated by the change of macroeconomic environment, such as the financial crisis in 1997.

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중국인의 지역별 특성에 의한 직무특징, 조직효과성 관계 모델 개발 (Development of Job Characteristics, Organizational Effectiveness Model for Chinese by Province and City)

  • 최성운;백봉기
    • 대한안전경영과학회지
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    • 제5권4호
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    • pp.245-256
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    • 2003
  • Job characteristics have influence on the organizational effectiveness. The job characteristics are the core job dimension and organizational effectiveness. Aptitude and personality also act on job characteristics. In this study, we investigate chinese characters by province and city. The purpose of this study is to develop the job characteristics and organizational effectiveness model for chinese by province and city. Consequently, we suggest to be applied the model to korean finns strategically, which push into China, by view of improvement of organizational effectiveness and adaptation in China.