• 제목/요약/키워드: Model dimension

검색결과 1,508건 처리시간 0.034초

Development of Preliminary Design Model for Ultra-Large Container Ships by Genetic Algorithm

  • Han, Song-I;Jung, Ho-Seok;Cho, Yong-Jin
    • International Journal of Ocean System Engineering
    • /
    • 제2권4호
    • /
    • pp.233-238
    • /
    • 2012
  • In this study, we carried out a precedent investigation for an ultra-large container ship, which is expected to be a higher value-added vessel. We studied a preliminary optimized design technique for estimating the principal dimensions of an ultra-large container ship. Above all, we have developed optimized dimension estimation models to reduce the building costs and weight, using previous container ships in shipbuilding yards. We also applied a generalized estimation model to estimate the shipping service costs. A Genetic Algorithm, which utilized the RFR (required freight rate) of a container ship as a fitness value, was used in the optimization technique. We could handle uncertainties in the shipping service environment using a Monte-Carlo simulation. We used several processes to verify the estimated dimensions of an ultra-large container ship. We roughly determined the general arrangement of an ultra-large container ship up to 1500 TEU, the capacity check of loading containers, the weight estimation, and so on. Through these processes, we evaluated the possibility for the practical application of the preliminary design model.

혼종 모형을 이용한 간호대학생의 사회적 지지에 대한 개념 분석 (Concept Analysis of Social Support of Nursing Students Using a Hybrid Model)

  • 최미애;박성희
    • Child Health Nursing Research
    • /
    • 제26권2호
    • /
    • pp.222-237
    • /
    • 2020
  • Purpose: The purpose of this study was to analyze the concept of social support of nursing students using a hybrid model and to derive a definition and attributes of social support through theoretical, fieldwork, and final analysis stages. Methods: Twenty-nine studies were analyzed in the theoretical stage. Seventeen in-depth interviews were conducted with nursing students in the fieldwork stage. In the final analysis stage, the concept of social support was defined and the attributes were derived by integrating the theoretical and fieldwork stages. Results: The attributes of social support of nursing students identified in the final analysis consisted of two dimensions and eight attributes. The two dimensions were structural and functional support. The eight attributes were social network, educational, emotional, informational, economic, positive evaluation, self-esteem support, and support by providing a role model provision. The structural dimension included the social network support attribute. The functional dimension included the remaining seven attributes. Educational support and support by providing of a role model provision were newly derived attributes that reflected specific characteristics of nursing students. Conclusion: Based on the results of this study, we suggest that researchers should attempt to develop a scale to measure the social support of nursing students.

초고속기용 열박음 로터 제작을 위한 로터의 치수에 따른 가열온도의 해석적 예측 (Analytical Prediction of Heating Temperature to Manufacture Rotor with Shrink Fit for Ultra High Speed Motor According to Change Dimension of Rotor)

  • 홍도관;우병철;정연호;구대현;안찬우
    • 대한기계학회논문집A
    • /
    • 제33권9호
    • /
    • pp.963-968
    • /
    • 2009
  • This paper deals with shrink fit analysis of rotor by 2D cross-section, 2D axis-symmetry, and 3D FEM model. And this paper presents 2nd order approximation function of thermal expansion displacement by design variables (shape dimension, heating temperature, sleeve length, interference etc.), table of orthogonal array and RSM(response surface methodology). The possibility of the rotor with shrink fit is evaluated by thermal expansion displacement. If thermal expansion displacement is larger than interference, shrink fit enable to make the rotor. 2D axis-symmetry model and 3D model are more reasonable than 2D cross-section model, because stress and strain is different along length of shaft.

A NUMERICAL STUDY ON CHARACTERISTICS OF FLUID FLOW AND SOLUTE TRANSPORT IN A SELF-AFFINE VARIABLE-APERTURE FRACTURE UNDER NORMAL COMPLIANCE EFFECT

  • JEONG WOOCHANG;HWANG MANHA;KO ICKHWAN;SONG JAIWOO
    • Water Engineering Research
    • /
    • 제6권2호
    • /
    • pp.49-61
    • /
    • 2005
  • This paper presents the numerical study to examine characteristics of fluid flow and solute transport in a rough fracture subject to effective normal stresses. The aperture distribution is generated by using the self-affine fractal model. In order to represent a nonlinear relationship between the supported normal stress and the fracture aperture, we combine a simple mechanical model with the local flow model. The solute transport is simulated using the random walk particle following algorithm. Results of numerical simulations show that the flow is significantly affected by the geometry of aperture distribution varying with the effective normal stress level while it is slightly affected by the fractal dimension that determines the degree of the fracture surface roughness. However, solute transport is influenced by the effective normal stress as well as the fracture surface roughness.

  • PDF

누수를 포함하는 지하수 유동의 프락탈 모델 적용에 의한 균열 암반 대수층의 수리상수 산출 (Computing Hydraulic Parameters of Fractured Aquifers Using Fractal Model of Groundwater Flow with Leakage)

  • 함세영;임정웅
    • 지질공학
    • /
    • 제4권2호
    • /
    • pp.219-229
    • /
    • 1994
  • 균열 암반내 지하수 흐름은 공간적으로 불규칙하게 분포하는 균열 발달 상태에 영향을 받으므로 균질의 등방성 피압 대수층에 적용이 가능한 Theis식으로는 균열 암반 대수층의 수리지질학적 특성을 똑바로 이해할 수 없다. 본 연구에서는 지하수 흐름의 프락탈(Fractal)모델을 발전시킨 누수를 포함하는 프락탈모델의 이론적은 배경 및 수리상수 산출 방법을 제시하고,개발된 모델을 야외자료에 적용시켰다. 상기 모델은 홍천과 유성지역에서 수행된 양수시험 자료에 적용시킨 결과, 동일한 수리상수 값으로 양수정과 관측정에서의 관측된 수위하강 곡선과 이론적인 수위하강 곡선이 잘 일치하는 결과를 얻었다. 홍천 지역과 유성 지역의 시험공 주위의 프락탈 차원은 1.9로 구해졌으며, 이것은 이들 지역의 지하수 흐름이 2차원보다 약간 작은 프락탈 차원을 보인다는 것을 지시한다.

  • PDF

현행 학교 문화예술교육 정책의 맥락에 관한 탐색 연구 : Cooper 등의 4차원 정책분석 모형 적용 (A Study on the Exploration of the School Arts & Culture Education Policy : Application of Cooper's Four Dimension Model)

  • 최현락;장덕호
    • 디지털융복합연구
    • /
    • 제16권11호
    • /
    • pp.57-67
    • /
    • 2018
  • 본 연구는 Cooper, Fusarelli와 Randall(2004)의 4차원 정책분석 모형을 활용하여 학교 문화예술교육 정책을 둘러싼 핵심 쟁점을 규범적, 구조적, 구성적, 기술적 차원별로 분석하고, 개선을 위한 시사점을 제시하였다. 연구방법은 문헌분석으로서 그동안 축적된 정책문서와 학술논문 등을 근거자료로 활용하였다. 분석결과, 학교 문화예술교육 정책의 효과적 추진을 위해 규범적 차원에서는 국가성장 이데올로기 및 과도한 관료적 합리성 추구의 극복이, 구조적 차원에서는 교사수권형 교육과정으로의 개혁을 통한 실질적 형식과 내용의 확보가, 구성적 차원에서는 문화예술교육에 대한 인식 변화를 통한 구성원 간의 명확한 역할 구분이, 그리고 기술적 차원에서는 확고한 교육학적 기준에 근거한 자원의 합리적 배분이 요청된다. 이상의 연구결과를 바탕으로 국가의 기초학술연구 진흥, 교육당사자의 의견수용, 교원의 문화경험기회 확대, 통합적 문화예술교육 연수체제 구축, 교원양성체제 정비, 예술강사의 교육전문성 강화 등을 향후 연구 및 실천과제로 제시하였다.

Dimension Reduction of Solid Models by Mid-Surface Generation

  • Sheen, Dong-Pyoung;Son, Tae-Geun;Ryu, Cheol-Ho;Lee, Sang-Hun;Lee, Kun-Woo
    • International Journal of CAD/CAM
    • /
    • 제7권1호
    • /
    • pp.71-80
    • /
    • 2007
  • Recently, feature-based solid modeling systems have been widely used in product design. However, for engineering analysis of a product model, an ed CAD model composed of mid-surfaces is desirable for conditions in which the ed model does not affect analysis result seriously. To meet this requirement, a variety of solid ion methods such as MAT (medial axis transformation) have been proposed to provide an ed CAE model from a solid design model. The algorithm of the MAT approach can be applied to any complicated solid model. However, additional work to trim and extend some parts of the result is required to obtain a practically useful CAE model because the inscribed sphere used in the MAT method generates insufficient surfaces with branches. On the other hand, the mid-surface ion approach supports a practical method for generating a two-dimensional ed model, even though it has difficulties in creating a mid-surface from some complicated parts. In this paper, we propose a dimension reduction approach on solid models based on the midsurface abstraction approach. This approach simplifies the solid model by abbreviating or removing trivial features first such as the fillet, mounting, or protrusion. The geometry of each face is replaced with mid-patches from the simplified model, and then unnecessary topological entities are deleted to generate a clean ed model. Also, additional work, such as extending and stitching mid-patches, completes the generation of a mid-surface model from the patches.

실무수행능력 중심의 교육모형 및 측정도구 개발 (The Development of Nursing Education Model and The Instrument for Improving Clinical Competence)

  • 엄영란;서연옥;송라윤;전경자;유경희;조남옥
    • 한국간호교육학회지
    • /
    • 제4권2호
    • /
    • pp.220-235
    • /
    • 1998
  • The revolution of nursing curriculum has been focused on clinical competency for nursing graduates to flexibly respond to changes in societal health needs and disciplinary requirements. In this trend, the study was designed to identify basic concepts of nursing education that reflects the changes in societal needs and nursing discipline, and to develop the instrument to measure performance level in each dimension of clinical competency. The study was conducted in two phases. In phase 1, principal concepts consisted of nursing education were determined through literature review as well as series of discussion sessions on nursing philosophies and educational objectives among researchers. Though the process, the conceptual framework of competency based nursing curriculum was constructed with nursing process and professional role as horizontal threads, client, health needs, and nursing interventions as vertical threads. Then, items were developed to represent each dimension of competency : client and health need, nursing process, professional role, and nursing interventions. The total of 273 items were included as to represent clinical competency required for BSN graduates. In phase 2, questionnaires were distributed to nursing faculties of 41 BSN programs to validate the 273-item Instrument developed to measure competency. The total of 34 subjects returned the questionnaire with 81% of response rates. The subjects of the study had an average of 42 months of clinical experience and 13 years of education experience in various nursing areas with an age range of 30 to 52 years. The data were analyzed by utilizing SPSSWIN and the results are as follows. 1) The mean score of the nursing process dimension was supported most with the mean of 3.60(SD=0.32) compared to client and health need dimension(M=3.49, SD=.40), professional role(M=3.41, SD=.44), and nursing interventions(M=3.57, SD=.34). 2) The dimensions of competency were moderately correlated to each other with a range of r=.433 to r=.829, confirming that four dimensions of competency were related but distinct concepts. 3) The items of each dimension were analyzed based on its appropriateness. 'Assessing risk factors of the clients' were most highly supported in client and health need dimension. Most items of nursing process dimension were considered appropriate, while items related to efficient communication were well supported in professional role dimension. In nursing intervention dimension, items on basic nursing skills were highly supported while items on specific nursing interventions such as music therapy or art therapy were considered relatively inappropriate to competency for BSN graduates. The findings clearly showed that the current nursing education more emphasizes nursing interventions based on nursing process than other dimensions of competency. There is a need to reconceptualize nursing curriculum that is able to reflect more of nursing professional role and client/health need dimensions. Further research to validate the instrument by confirming competency dimensions of nursing graduates who are currently working at the hospital has been suggested.

  • PDF