• Title/Summary/Keyword: Model dimension

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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
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    • v.2 no.4
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    • pp.233-238
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    • 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.

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

  • Choi, Miae;Park, Sunghee
    • Child Health Nursing Research
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    • v.26 no.2
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    • pp.222-237
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    • 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.

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

  • Hong, Do-Kwan;Woo, Byung-Chul;Jeong, Yeon-Ho;Koo, Dae-Hyun;Ahn, Chan-Woo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.9
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    • pp.963-968
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    • 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
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    • v.6 no.2
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    • pp.49-61
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    • 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.

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

  • 함세영;임정웅
    • The Journal of Engineering Geology
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    • v.4 no.2
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    • pp.219-229
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    • 1994
  • Since groundwater flow in fractured rocks is controlled by the distribution of fractures irregu1arly developed in space, it is not possible to understand the hydraulic characteristics of fractured aquifers using Theis equation which is applicable only to homogeneous isotropic confined aquifer. This study deals with the theoretical background of the fractal groundwater flow model with leakage, the methodology of calculation of the hydraulic parameters, and the application of the developed model to field data. From the result of the application of the fractal model to two field data in Hongcheon and Yusung areas, we obtained a good match between theoretical curves and observed curves, with the same hydraulic parameters at the pumping well and the observation well. In the two pumping test analyses, we have determined 1.9 of the fractal dimension. This means that the dimension of groundwater flow at these two sites is slightly smaller than radial flow.

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

  • Choi, Hyeon-Rak;Jang, Deok-Ho
    • Journal of Digital Convergence
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    • v.16 no.11
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    • pp.57-67
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    • 2018
  • The purpose of this study is to examine the issues of school arts & culture education policy in Korea, using the four dimensional model of Cooper, Fusarelli, & Randall(2004). Research method is literature analysis, the accumulated policy documents and academic papers were used as the basis data. As a result, the followings are required for effective policy outcome: From the normative dimension, overcoming the pursuit of national growth ideology and bureaucratic rationality; from the structural dimension, securing of practical forms and content through the reform to the teacher mandate system in curriculum operation; from the constituentive dimension, clear division of roles among members through the change of awareness about arts & culture education; and finally from the technical dimension, rational allocation of resources based on firm educational criteria. Building upon the results, promotion of basic academic research, accepting the opinions of arts & culture education parties concerned, expansion of opportunities for cultural art experience of teachers, building up the integrated arts & culture education teacher training system, the reorganization of the teacher training system, and raising the professionalism of teaching artists.

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
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    • v.7 no.1
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    • pp.71-80
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    • 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.

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

  • Um Young-Rhan;Suh Yeon-Ok;Song Rha-Yun;June Kyung-Ja;Yoo Kyung-Hee;Cho Nam-Ok
    • The Journal of Korean Academic Society of Nursing Education
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    • v.4 no.2
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    • pp.220-235
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    • 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.

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