• Title/Summary/Keyword: T-test analysis

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Structural Behavior of Composite Basement Wall According to Shear Span-to-Depth Ratio and FE Analysis Considering the Condition of Contact Surface (전단경간비에 따른 합성지하벽의 거동과 접촉면의 조건을 고려한 유한요소 해석)

  • Seo, Soo Yeon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.6
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    • pp.118-126
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    • 2011
  • The objective of this paper is to study the structural behavior of Composite Basement Wall (CBW) according to shear span-to-depth ratio through an experiment and predict the nonlinear behavior of CBW by using ADINA program widely has been being used for FE analysis. Especially, this study focuses on the part of CBW in which the Reinforced Concrete (RC) is under compression stress; At the region of CBW around each floor, RC part stresses by compressive force when lateral press by soil acts on the wall. The contact condition between RC wall and steel (H-Pile) including stud connector is main factor in the analysis since it governs overall structural behavior. In order to understand the structural behavior of CBW whose RC part is under compressive stress, an experimental work and finite element analysis were performed. Main parameter in the test is shear span-to-depth ratio. For simplicity in analysis, reinforcements were not modeled as a seperated element but idealized as smeared to concrete. All elements were modeled to have bi-linear relation of material properties. Three type of contact conditions such as All Generate Option (AGO), Same Element Group Option with Tie(SEGO-T) and Same Element Group Option with Not tie(SEGO-NT) were considered in the analysis. For each analysis, the stress flow and concentration were reviewed and analysis result was compared to test one. From the test result, CBW represented ductile behavior by contribution of steel member even if it had short shear span-to-depth ration which is close to "1". The global composite behavior of CBW whose concrete wall was under compressive stress could be predicted by using contact element in ADINA program. Especially, the modeling by using AGO and SEGO-T showed more close relation on comparing with test result.

The Canopy Transparency Coating Study of Cockpit Temperature Effect Verification (조종실 온도 영향성 검증을 위한 캐노피 투명체 코팅 연구)

  • Nam, Yongseog;Kim, Taehwan;Kim, Yunhi;Woo, Seongjo;Kim, Myungho
    • Journal of Aerospace System Engineering
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    • v.2 no.2
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    • pp.42-45
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    • 2008
  • Under the non-operating exposure condition in the hot area, the T-50 cockpit temperature is expected over the requirement according to T-50 environmental criteria. So it is necessary to protect the cockpit from the high temperature condition during the non-operating exposure because the high temperature of the cockpit may result in the cockpit equipment malfunction. In this study, the transparency coating is selected as the method for protecting the cockpit from the high temperature exposure and analyzed the effect on the cockpit heat load attenuation. Some kinds of cockpit coating were reviewed and selected and the analysis was performed about the effect before and after coating application under 1% hot day condition based on the T-50 FSD hot soaking test data. The result of analysis show transparency coating is so effective to attenuate the heat load of T-50 cockpit.

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Relationship between Health Promotion Behavior and Marriage Value View

  • Kim, Jungae;Seo, Eunhui
    • International Journal of Advanced Culture Technology
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    • v.8 no.3
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    • pp.10-17
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    • 2020
  • This study was cross sectional descriptive survey study to analysis the relationship between marriage value view and health promotion behavior among university students. Questionnaires from those who voluntary agreed to the study were collected online, and the collection period was from May 20, 2020 to June 10, 2020. Research tools for analyzing marriage value view was used by RR lee, and health promotion behavior research tools was developed by Walker., The data analysis was performed using SPSS 18.0 as frequency, Pearson correlation, t-test, and Multiple regression analysis. According to the analysis, women had high passive (p<0.05) and exclusive (p<0.01) marriage value view, while men had high active (p<0.01) and instrumental (p<0.05) marriage value view. According to the analysis, it turns out that people who value interpersonal relationships during health promotion have a positive effect on romantic (t=2.383, R2=.257, p=.019) and instrumental (t=2.201, R2=.120, p=.030) marriage value view. Hygiene has been appeared to affect Passive marriage value view (t=3.001, R2=.111, p=.003) and Exclusive marriage value view (t=3.765, R2=.122, p=.000). Nutrition has been appeared to affect conservative marriage value view (t=2.086, R2=.118, p=0.039). Exercise has been appeared to affect conservative marriage value view (t=2.456, R2=.118, p=0.015) and active marriage value view (t=2.261, R2=.168, p=0.025). Through this study, in order to increase for the desire of marriage, marriage values need to be organized differently between men and women in marriage value programs and it suggested that health promotion behavior be included in programs that enhance the value of marriage.

Vibration Characteristics of the Tower Structure of a 750kW Wind Turbine Generator (750kW 풍력발전기 타워 구조의 진동 특성)

  • Kim, Seokhyun;Nam, Y.S.;Eun, Sungyoung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.2 s.95
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    • pp.219-224
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    • 2005
  • Vibration response of the tower structure of a 750kW wind turbine (W/T) generator is investigated by measurement and analysis. Acceleration response of the W/T tower under various operation condition is monitored in real time by the vibration monitoring system using LabVIEW. Resonance state of the tower structure is diagnosed in the operating speed range. Resonance frequency range of the test model is investigated with the wind speed data of the test site. To predict the tower resonance frequency, tower is modeled as an equivalent beam with a lumped mass and Rayleigh energy method is applied. Calculated tower bending frequency is in good agreement with the measured value and the result shows that the simplified model can be used in the design stage of the W/T tower.

Strength Evaluation of Adhesive Bonded Joint for Light Weight Structure by T-Peel Joint Test (T형 이음 접합에 의한 경량구조물용 접착이음강도의 평가)

  • 이강용;공병석;우형표
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.4
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    • pp.56-65
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    • 1998
  • The bonding strength evaluation of the light weight materials for an electrical vehicle has been performed through the T-peel joint test in which the design paramete- rs such as joint style, adherend type, adherend thickness, adhesive thickness, and adhesive type are considered. It is experimentally observed that the peel strength of joint increases with the increase of the adherend thickness. With the increase of the adhesive thickness, however, the peel strength of joint increases a little. Aluminum-FRP adherend combination shows such higher peel strength than that of Aluminum-Aluminum adherend combination. For the adhesive bonded joint, the results of FEM analysis agree with those of experiment. The adhesive bonded joint reinfored with a rivet gives higher peel strength than that of the joint without rivet.

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Compressive performance with variation of yield strength and width-thickness ratio for steel plate-concrete wall structures

  • Choi, Byong-Jeong;Kim, Won-Ki;Kim, Woo-Bum;Kang, Cheol-Kyu
    • Steel and Composite Structures
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    • v.14 no.5
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    • pp.473-491
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    • 2013
  • The primary objectives of this paper are to describe the buckling patterns and to determine the squash load of steel plate-concrete (SC) walls. The major variables in this study were the width-thickness (B/t) ratio and yield strength of surface steel plates. Six SC walls were tested, and the results include the maximum strength, buckling pattern of steel plates, strength of headed studs, and behavior of headed studs. Based on the test results, the effects of the B/t ratio on the compressive strength are also discussed. The paper also presents recommended effective length coefficients and discusses the effects of varying the yield strength of the steel plate, and the effects of headed studs on the performance of SC structures based on the test results and analysis.

Changes in the visual display terminal syndrome of college students in online classes during the COVID-19 pandemic (COVID-19 팬데믹 상황에서 온라인 수업 중인 대학생의 영상표시단말기 증후군의 변화)

  • Jang, Keong Sook;Jung, Young-Mi
    • The Journal of Korean Academic Society of Nursing Education
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    • v.29 no.1
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    • pp.60-71
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    • 2023
  • Purpose: The purpose of this study was to identify changes in the experience rate and level of symptoms of visual display terminal syndrome in college students attending online classes during the COVID-19 pandemic. Methods: Data were collected from February 22 to June 8, 2021 at three measurement points. A total of 117 college students were administered a visual display terminal syndrome survey just before online classes (T1), one month after the start of online classes (T2), and three months after the start of online classes (T3). The collected data were analyzed by frequency and percentage, paired t-test, McNemar test, and repeated measures analysis of variance using the IBM SPSS 25.0 program. Results: The intensity of college students' visual display terminal syndrome during online classes increased at T2 and T3 compared to T1. The rate of experiencing back discomfort or pain increased abruptly at T2 compared to T1. The intensity of college students' eye related symptoms and skin related symptoms increased at T2 and T3 compared to T1, while the intensity of college students' psychological symptoms, general body discomfort, and musculoskeletal symptoms increased at T3 compared to T1. Conclusion: The results of this study suggest that self-care programs are needed to prevent visual display terminal syndrome in college students who are in long-term online classes.

Consolidation of Cu-based amorphous particles (Cu계 비정질 입자의 가압 성형)

  • Kang E. Y.;Chung Y. H.;Yoo H. G.;Park J. W.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.10a
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    • pp.273-276
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    • 2005
  • Packing characteristics of amorphous alloy particles were investigated by scanning electron microscopy, compositional analysis, micro-hardness test and finite element method (FEM). Electroless Ni-plating was made on the surface of the Cu-based amorphous particles before consolidation in ambient atmosphere at an intermediate region of glass transition and crystallization temperatures $(T_g\;and\;T_x)$. Some parts of the Ni-layer in the interfaces of the consolidated particles disappeared, while some of them still remained without appreciable change in compositions. No cracks or fractures were found in the particles, which may occur at low temperatures below or near $T_g$ as anticipated by the FEM analysis. Crystallization and change in hardness were not observed after consolidation.

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Analysis of Web Site Usability for Interface Improvement Using T-Model Procedure

  • Abdulhak, Sami Abduljalil;Kang, Dae-Ki
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.192-194
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    • 2011
  • With the huge tendency of users toward online web sites, many issues regarding the user behavior interacting with these websites are yet still underestimated and not addressed in all aspects from software developers or business organizations. In this paper, we solely focus on the usability analysis of social network websites to enhance and improve the use of these social websites for more effective and motivational interaction. We use T-Model procedure as a mechanism of this research. Subjects with variation of expertise are contributed to the research of this paper. Minor quantitative analysis will be employed to test the hypothetical of this research in the further research. Result and its implications will be discussed profoundly at the end of this research.

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