• Title/Summary/Keyword: Validity Analyses

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Development of Network and Digital creation tools Curriculum Model to consider understanding concepts and learning activity (개념이해와 학습활동을 고려한 네트워크 및 디지털 창작도구 교육과정 모델 개발)

  • Sung, Younghoon;Jeong, Youngsik;Park, Namje
    • Journal of The Korean Association of Information Education
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    • v.20 no.6
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    • pp.563-574
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    • 2016
  • This paper is a research on the curriculums of network and digital creation tools among SW education in order to apply them to SW curriculum in education fields. For doing so, a curriculum model was developed by extracting main key words through the analyses of domestic and foreign SW curriculum, and reorganization of concept understanding and learning activity elements was made so as to be fit to characteristics of each curriculum. And curriculums were remodeled by curriculum such like concept understanding was focussed in network, activities in digital creation tools and its validity was suggested through expert verification by composing contents elements based on the results. Also, this model was proposed so that each school could recompose it easily by combining contents elements of other curriculums. Therefore, the suggested model could be utilized as a basic research data in applying domestic SW curriculum standard model.

Static behavior of a laterally loaded guardrail post in sloping ground by LS-DYNA

  • Woo, Kwang S.;Lee, Dong W.;Yang, Seung H.;Ahn, Jae S.
    • Geomechanics and Engineering
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    • v.15 no.5
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    • pp.1101-1111
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    • 2018
  • This study aims to present accurate soil modeling and validation of a single roadside guardrail post as well as a single concrete pile installed near cut slopes or compacted sloping embankment. The conventional Winkler's elastic spring model and p-y curve approach for horizontal ground cannot directly be applied to sloping ground where ultimate soil resistance is significantly dependent on ground inclination. In this study, both grid-based 3-D FE model and particle-based SPH (smoothed particle hydrodynamics) model available in LS-DYNA have been adopted to predict the static behavior of a laterally loaded guardrail post. The SPH model has potential to eliminate any artificial soil stiffness due to the deterioration of the node-connected Lagrangian soil mesh. For this purpose, this study comprises two parts. Firstly, only 3-D FE modeling has been tested to show the numerical validity for a single concrete pile in sloping ground using Mohr-Coulomb material. However, this material option cannot be implemented for SPH elements. Nevertheless, Mohr-Coulomb model has been used since this material model requires six input soil data that can be obtained from the comparative papers in literatures. Secondly, this work is extended to compute the lateral resistance of a guardrail post located near the slope using the hybrid approach that combines Lagrange FE elements and SPH elements by the suitable node-merging option provided by LS-DYNA. For this analysis, the FHWA soil material developed for application to road-base soils has been used and also allows the application of SPH element.

Development of a Shop Manager Training Program for Vocational Education High School Students (직업 역량 강화를 위한 고등학생 대상 샵 매니저 교육 프로그램 개발)

  • Lee, Jisoo;Lee, Yoon-Jung;Noh, Hyekyun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.42 no.4
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    • pp.599-611
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    • 2018
  • This study develops a training program for vocational high school students. This study implemented the ADDIE teaching-learning model and was conducted in the sequence of analyses, design, development, implementation and evaluation. In the analysis phase, the existing studies related to vocational competency training were analyzed along with an analysis of the current education programs and suitability assessment. Based on the analysis, the education program was designed and contents were determined. The program consisted of 5 chapters and 17 unit hours of instruction. Reigeluth's (1987) theory was used as the framework for organizing educational materials in the development phase. The programs were implemented on students and evaluated by students as well as experts. Students evaluated the program in terms of the degree of motivation for learning, comprehension of learning content, perceptions of lessons in classes as well as the advantages and disadvantages of the program. Experts evaluated the program in terms of program validity. The results indicate the developed program was useful for training students vocational competencies as shop managers. This study contributes to the field of fashion education, by presenting an example of systematic development of an educational program in connection with industry.

Development Rapid Analytical Methods for Inositol as a Trace Component by HPLC and LC-MS/MS in Infant Formula

  • Shin, Jin-Ho;Park, Jung-Min;Kim, Ha-Jung;Ahn, Jang-Hyuk;Kwak, Byung-Man;Kim, Jin-Man
    • Food Science of Animal Resources
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    • v.35 no.4
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    • pp.466-472
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    • 2015
  • A rapid and simple analytical method, using liquid chromatography tandem mass spectrometry (LC-MS/MS), was developed to detect myo-inositol (MI) in infant formulas. For protein removal: acid hydrolysis and lipid removal through organic solvent extraction. The operating conditions for instrumental analysis were determined based on previously reported analogous methods that used LC-MS/MS. Quantitative analysis was used for the detection limit test, infant formula recovery test, and standard reference material (SRM) 1849a to verify the validity of our LC-MS/MS analytical method, which was developed to quantify MI. For validation, the results of our method were compared with the results of quantitative analyses of certified values. The test results showed that the limit of detection was 0.05 mg/L, the limit of quantitation was 0.17 mg/L, and the method detection limit was 17 mg/kg. The recovery test exhibited a recovery between 98.07-98.43% and a relative standard deviation between 1.93-2.74%. Therefore, the result values were good. Additionally, SRM 1849a was measured to have an MI content of 401.84 mg/kg and recovery of 98.25%, which is comparable to the median certified value of 409 mg/kg. From the aforementioned results, we judged that the instrumental analysis conditions and preparation method used in this study were valid. The rapid analytical method developed herein could be implemented in many laboratories that seek to save time and labor.

Clinical Observation on Blood Flow of Facial Acupuncture Points in Bell's Palsy Patients by Doppler Ultrasound (도플러 초음파검사를 이용한 안면마비 환자의 안면부 경혈의 혈류 관찰)

  • Yin, Chang-Shik;Bae, Young-Min;Choi, Yang-Sik;Ko, Jeong-Min;Kim, Sergey;Kang, Uk;Lee, Sang-Hoon
    • Journal of Acupuncture Research
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    • v.26 no.2
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    • pp.49-58
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    • 2009
  • Objectives : The aim of this study was to investigate whether Doppler ultrasound device is applicable for the evaluation of facial palsy patients. Methods : A total of 25 patients participated in the first assessment and 22 of them finished a follow-up assessment one week later. An assessment comprised of a Minimax-Doppler-K device examination on bilateral acupoints $ST_5$, $SI_{19}$, $ST_2$, and $BL_1$, House-Brackmann grading, and subjective symptom questionnaire. Measurement reliability was assessed and clinically meaningful variations of Doppler measurement values were explored. Results : Doppler ultrasound examination revealed a significant difference of some measurement values between values of the symptom side and the contralateral side, between groups of severe paralysis and moderate paralysis, and between groups of short duration(0-3 weeks) and long duration (3 weeks-5 months) by non-parametric analyses (p<0.05). Several re-examination values showed a significant correlation with the first examination values by Spearman's correlation tests (p<0.05). Conclusions : This study revealed several possibilities for the clinical application of this device. Further validity tests and device improvements for a user's convenience would be helpful for its practical application.

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Development of a Safety Assessment Method using Detailed Structural Analysis for Iron-Manufacturing Plant Structures (상세구조해석을 이용한 제철설비구조물 안전성 평가 기술개발)

  • Lee, Man-Seung;Lee, Jae-Myung;Paik, Jeom-Kee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.18 no.1
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    • pp.93-99
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    • 2005
  • Up to date, the life extension of industrial plant structures has been strongly required in the field of iron-manufacturing company, atomic or power generation company and so on. Fault monitoring, maintenance of aging structural components, safety assessment and residual life prediction may be recognized as typical and/or practical methods in terms of life extension methods. Based on the construction of damage scenario, precise analysis method and development of the risk or reliability assessment, a number of studies have been carried out in this viewpoint. In conjunction with the finite element analysis technique, a practical procedure for the safety assessment of iron-manufacturing plant structures was developed in this paper with a particular interest in furnace. By virtue of the detailed finite element analyses for blust furnace under an operational condition, the validity of the proposed procedure for safety assessment was presented.

Finite Element Analyses of Cylinder Problems Using Pseudo-General Plane Strain Elements(Planar Constraint) (유사 평면변형률 유한요소를 사용한 실린더 문제의 해석)

  • KWON YOUNG-DOO;KWON HYUN-WOOK;SHIN SANG-MOK;LEE CHAN-BOK
    • Journal of Ocean Engineering and Technology
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    • v.17 no.5 s.54
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    • pp.66-75
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    • 2003
  • Long cylinder, subjected to internal pressure, is important in the analysis and design of nuclear fuel rod structures. In many cases, long cylinder problems have been considered as a plane strain condition. However, strictly speaking, long cylinder problems are not plane strain problems, but rather a general plane strain (GPS) condition, which is a combination of a plane strain state and a uniform strain state. The magnitude of the uniform axial strain is required, in order to make the summation of the axial force zero. Although there has been the GPS element, this paper proposes a general technique to solve long cylinder problems, using several pseudo-general plane strain (PGPS) elements. The conventional GPS elements and PGPS elements employed are as follows: axisymmetric GPS element (GA3), axisymmetric PGPS element (PGA8/6), 2-D GPS element (GIO), 3-D PGPS element (PG20/16), and reduced PGPS elements (RPGA6, RPG20/16). In particular, PGPS elements (PGA8/6, PG20/16) can be applied in periodic structure problems. These finite elements are tested, using several kinds of examples, thereby confirming the validity of the proposed finite element models.

Stochastic Analysis in the Generation of Floor Response Spectra for Liner Systems with Proportional Damping (추계학적(推計學的) 해석법(解析法)에 의한 선형비례감쇠(線形比例減衰) 시스템의 층응답(層應答)스펙트럼)

  • Park, Young Suk;Seo, Jeong Moon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.8 no.1
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    • pp.77-85
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    • 1988
  • A stochchastic analysis procedure of generating floor response spectra for proportionally damped linear systems subject to earthquake loading is presented. Theories of random vibration and mode acceleration method are used in the formulation of governing equations. The structure-oscillator interaction is not considered. It is assumed that the input motions and oscillator responses are stationary Gaussian processes with mean zero. The nonstationary characteristics of earthquake motion are incorporated in the peak factor which is based on Vanmarcke's theory. Floor response spectra for both resonance and non-resonance cases are calculated under the assumption that the peak factors for structure and oscillator are equal to that for ground response spectrum. The validity of this method is demonstrated by comparing the results obtained by proposed method with those by time history analyses. The results obtained by this method are conservative and accurate with tolerable precision. This method saves much computing time compared with time history analysis method.

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Analysis of Vertical and Horizontal Behavior of Helical Piles in Sands Varying Helix Shapes and Locations (사질토에서의 헬릭스 형상 및 위치에 따른 헬리컬 파일의 수직 및 수평 거동 분석)

  • Bae, Jonghwan;Lee, Junwon;Shin, Sehee;Kim, Dongwook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.40 no.4
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    • pp.393-400
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    • 2020
  • Axial and lateral behavior of helical piles is generally influenced by number, diameter, helix pitch, and locations of helices. In this study, axial and horizontal behavior of helical piles with three helices was investigated varying helices' locations, diameter, and pitch. Especially, due to the spiral shapes of helices, the effect of lateral load directions at pile heads on their lateral behavior was investigated. Axial load test of small-scale helical pile was conducted in laboratory, and its results were compared with numerical analysis results of the same model for cross check of validity of both results. Furthermore, diverse numerical analyses were performed for different shapes of helical piles. Consequently, it was found that, for the given analysis conditions, the helix diameter was the most influential factor on the horizontal and vertical behavior of helical piles.

Elasto-plastic Analysis of Circular Tunnel with Consideration of Strain-softening of GSI Index (GSI 지수의 변형률 연화를 고려한 원형터널의 탄소성 해석)

  • Lee, Youn-Kyou;Park, Kyung-Soon
    • Tunnel and Underground Space
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    • v.20 no.1
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    • pp.49-57
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    • 2010
  • For the elasto-plastic analysis of a circular tunnel driven in a strain-softening rock mass subjected to a hydrostatic in-situ stress condition, this study suggests a convenient elasto-plastic analysis scheme which takes the strain-softening of GSI index into account and demonstrates its potential as a numerical tool in designing a circular tunnel. The suggested numerical scheme was developed by modifying the previous elasto-plastic procedure proposed by Lee & Pietruszczak(2008). With the assumption that GSI index of rock mass adjacent to the tunnel surface may be degraded due to the damage caused by the blasting and excavation, the concept of the strain-softening of GSI index was invoked. The concept provides a useful tool considering the strain-softening of the strength parameters appearing in the generalized Hoek-Brown criterion because these parameters can be evaluated empirically by use of GSI. In order to check the validity of the proposed scheme, the elasto-plastic analyses for circular tunnels were performed in various analysis conditions and the results were discussed.