• Title/Summary/Keyword: T-test analysis

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Partially confined circular members subjected to axial compression: Analysis of concrete confined by steel ties

  • Eid, R.;Dancygier, A.N.
    • Structural Engineering and Mechanics
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    • v.21 no.6
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    • pp.737-765
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    • 2005
  • This paper presents a theoretical model for the behavior of partially confined axi-symmetric reinforced concrete members subjected to axial load. The analysis uses the theories of elasticity and plasticity to cover the full range of the concrete behavior. Analysis of the elastic range of the problem involves boundary conditions that are defined along a relatively simple geometry. However, extending the analysis into the plastic range involves difficulties that arise from the irregular geometry of the boundary between the plastic zone and the elastic zone, a boundary which is also changing as the axial load increases. The solution is derived by replacing the discrete steel ties with an equivalent tube of thickness $t_{eq}$ and by analyzing the concrete cylinder, which is uniformly confined by the equivalent tube. The equivalency criterion initiates from a theoretical analysis of the problem in its elastic range where further finite element analysis shows that this criterion is valid also for the plastic range of the cylinder material. According to the proposed model, the efficiency of the lateral reinforcement can be evaluated by the equivalent thickness $t_{eq}$. Comparison with published test results of confined reinforced concrete stress-strain curves shows good agreement between the test and the analytical results.

A Study on Effect of Army Risk Assessment System for Preventing Safety Accidents (육군 위험성평가체계의 사고예방효과에 관한 연구)

  • Minsuk Park;Byungho Beak;Seungbae Park;Namjoo Jeon
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.47 no.2
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    • pp.84-92
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    • 2024
  • The purpose of this study is to analyze effect of Army Risk Assessment System(ARAS) which is used to prevent safety accident in ROK army. Based on prior research, we select 4 indicators which are related to accident prevention effect and analyze the differences before and after ARAS operation for each indicators by using Paired-Samples T-Test. Also, we analyze the correlation between degree of ARAS operation and status of safety accidents of 112 ROK Army units. We conduct an evaluation of each function within the system using IPA method. The results of this study are as follows; All 4 indicators are improved compared to before ARAS operation, and the differences are statistically significant. Also, there is negative correlation between the degree of ARAS operation and the occurrence of safety accidents. So, the operation of ARAS has a positive effect on preventing safety accidents. Finally among the 15 functions of ARAS, 4 functions require improvement. The findings of this study have implications for proposing necessity of computerized system in enforcing Risk Assessment. Also, whether or not operating ARAS is important, but it is also important to operate it well. Lastly, We propose improvement plans for each function to operate it well.

Development and Effectiveness of Smartphone Application for the Medication Confirmation of High-alert Medications (고 위험약물의 투약확인을 위한 스마트 폰 어플리케이션의 개발 및 효과)

  • Kim, Myoung Soo
    • Korean Journal of Adult Nursing
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    • v.26 no.3
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    • pp.253-265
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    • 2014
  • Purpose: This study was done to develop and evaluate a smartphone application for the medication confirmation of high-alert medications. Methods: A nonequivalent control group non-synchronized design was used for this study. Participants in the treatment group used the application for four weeks. Data were analyzed using descriptive analysis, ${\chi}^2$-test, and t-test for the homogeneity of participants, and a paired t-test for effectiveness in each group with the SPSS 18.0. Results: Stability of medication administration was estimated by knowledge and certainty, ranged from a score of one to three. A correct answer with high certainty was coded as high stability, low certainty regardless of correct answer was coded as a moderate stability, and incorrect answers with high certainty were rated as low stability. There were no differences in 'knowledge of high alert medication', 'Certainty of knowledge', 'stability of medication administration', 'confidence of single checking medication', and 'medication safety activities' between the treatment group and the comparison group. The treatment group reported a greater difference between pretest and post-test in 'certainty of medication knowledge' (t=3.51, p=.001) than the comparison group. Conclusion: Smartphone application for medication confirmation of high-alert medications will provide an important platform for reducing medication errors risk.

Evaluation of Adhesive Properties Using Cohesive Zone Model : Mode I (Cohesive Zone Model을 이용한 접착제 물성평가 : 모드 I)

  • Lee, Chan-Joo;Lee, Sang-Kon;Ko, Dae-Cheol;Kim, Byung-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.5
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    • pp.474-481
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    • 2009
  • Fracture models and criteria of adhesive with two parameters, namely $G_C$ and ${\sigma}_{max}$, have been developed to describe the fracture process of adhesive joints. Cohesive zone model(CZM) is a representative two parameter failure criteria approach. In CZM, ${\sigma}_{max}$ is a critical, limiting maximum value of the stress in the damage zone ahead of the crack and is assumed to have some physical significance in adhesive failure. Based on CZM and finite element analysis method, the relationship between fracture load and adhesive properties, as $G_{IC)$ and $({\sigma}_{max})_I$, was investigated in adhesively bonded joint tensile test and T-peel test. The two parameters in tensile mode loading were evaluated by using the relationship. The value of $G_{\IC}$ evaluated by proposed method showed close agreement with analytical solution for tapered double cantilever beam(TDCB) test which proposed in an ASTM standard.

The Effects of Foot Reflexology on Pain and Depression of Middle-aged Women with Osteoarthritis (발반사마사지가 골관절염을 가진 중년여성의 통증과 우울에 미치는 효과)

  • Oh, Hyun-Sook;Ahn, Seong-Ah
    • The Korean Journal of Rehabilitation Nursing
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    • v.9 no.1
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    • pp.25-33
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    • 2006
  • Purpose: This study was to examine the effects of foot reflexology on pain and depression of middle-aged women with Osteoarthritis Method: The subjects were 41 osteoarthritis patients resided in the Jinju city from March to May, 2005. The foot reflexology was applied to the experimental group 3 times a week for 4 weeks, 30 minutes eachs. For the data analysis, $X^2$-test was conducted to verify the homogeneity of general characteristics, and t-test was done to verify the homogeneity of pain and depression. To examine the relative efficacy of the intervention, t-test, paired t-test and repeated measures ANOVA were conducted. Results: After foot reflexology, the subjects in experimental group showed significant improvement in pain (F=155.77, p=.000) and depression ((F=20.00, p=.000). Conclusion: The results suggest that the foot reflexology is effective in relieving of pain and depression. Therefore, it is necessary to develop foot reflexology as an independent nursing intervention.

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Development and Implementation of Statistical Edge Detectors on the Web (웹 상에서 통계적 에지검출기 개발 및 구현)

  • Lim, Dong-Hoon
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.4 s.36
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    • pp.133-141
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    • 2005
  • An edge is where the intensity of an image moves from a low value to high value or vice versa. The edges tell where objects are. their shape and size. and something about their texture. Many traditional edge operators are derivative based and perform reasonably well for simple noise-free images. In recent, statistical edge detectors for complex images with noises have been described. This paper compares and analysis the performance of statistical edge detectors based on the T test and Wilcoxon test, and mathematical edge detectors based on Sobel operator, and the well-known Canny detector and Wavelet transformation detector, and provides the implementation of these edge detectors using Java on the web.

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Tensile capacity of mortar-filled rectangular tube with various connection details

  • Kim, Chul-Goo;Kang, Su-Min;Eom, Tae-Sung;Baek, Jang-Woon
    • Steel and Composite Structures
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    • v.44 no.3
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    • pp.339-351
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    • 2022
  • A mortar-filled rectangular hollow structural section (RHS) can increase a structural section property as well as a compressive buckling capacity of a RHS member. In this study, the tensile performance of newly developed mortar-filled RHS members was experimentally evaluated with various connection details. The major test parameters were the type of end connections, the thickness of cap plates and shear plates, the use of stud bolts, and penetrating bars. The test results showed that the welded T-end connection experienced a brittle weld fracture at the welded connection, whereas the tensile performance of the T-end connection was improved by additional stud bolts inserted into the mortar within the RHS tube. For the end connection using shear plates and penetrating stud bolts, ductile behavior of the RHS tube was achieved after yielding. The penetrating bars increased load carrying capacity of the RHS. Based on the analysis of the load transfer mechanism, the current design code and test results were compared to evaluate the tensile capacity of the RHS tube according to the connection details. Design considerations for the connections of the mortar-filled RHS tubes were also recommended.

The Effect of the Structured Education on the Early Rehabilitation Knowledge and Activity Performance of the C.V.A. Patients (구조화된 환자교육이 뇌졸중 환자의 조기재활에 관한 지식과 활동수행에 미치는 영향)

  • 이혜진;이향련
    • Journal of Korean Academy of Nursing
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    • v.27 no.1
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    • pp.109-119
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    • 1997
  • This study has been attempted to set up the strategies of the nursing which can promote the activity performance for early rehabilitation for the patients by examining the effect of the structured patient education on the early rehabilitation knowledge and activity performance of the C.V.A patients. The study method has been done by investigating the experiment group and control group in advance through the question papers and interview and observation on 65 patients who had been hospitalized at oriental medicine hospital of K Medical Center from July 1st 1995 to the end of Sep, 1995. The analysis of the collected material had been done for the homogeneity test in which general characters of experiment group and control group had been tested by X²and the homogeneity test of ADL by t-test. To test the hypothesis the t-test had been given for the difference of the early rehabilitation knowledge and activity performance between the two groups and the correlation between early rehabilitation knowledge and activity performance had been tested by Pearson's Correlation Coefficient. The result of the test of the hypothesis is as the below. 1 The 1st hypothesis “The experiment group which had received the structured education should be higher in the early rehabilitation knowledge than the control group” was supported(t=4.45. p=.000). 2. The 2nd hypothesis “The experiment group which received the structured education should be higher in the early rehabilitation activity performance than the control group”was supported(t=2.11, p=.036). 3. The 3rd hypothesis “The higher the early rehabilitation knowledge of the patient the higher the activity performance degree” was rejected (r=.1546, p=.219). In conclusion, the patients who received the structured education showed the increase in the degree of early rehabilitation knowledge and activity performance, so it has been judged that education has been prerequisite in increasing the knowledge and activity performance of early rehabilitation.

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New index for the gifted students(G-Index) with EEG analysis (뇌파검사 자료를 기반으로 한 과학영재 판별 지수(G-Index) 개발과 적용)

  • Kim, Kyung-Hwa;Kim, Kyu-Han;Lee, Sun-Kil;Hur, Myung;Kim, Yong-Jin
    • Journal of Gifted/Talented Education
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    • v.15 no.1
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    • pp.67-84
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    • 2005
  • In this study we investigated the adequacy of tools for distinction gifted students through the comparison these mutual relation on the basis of data, like paper test, the depths interview score, and the rest data((TTCT: Torrance Tests of Creative Thinking, IQ test, FASP: Find A Shape Puzzle, V.T: Visualization Tests and Exp: experimental ability test), and analysis data of EEG test for examining the adequacy of tools for identification gifted students. So, we developed Brain Wave gifted Index(G-Index) for finding another distinction ability as using brain waves data. The standard of index development use gifted brain characteristic in closed-eyes rest state which is judged like that characteristic of distinction between gifted and normal students is the most clear and consistence. That is, the degree of unified pattern between each object and gifted PCA pattern was defined by Pearson method which added spatial mutual index to weight concept. This refer to mean number of spatial PCA pattern. Searching for the possibility of distinction gifted gave distinction effect in 76%. The result of regression analysis on the basis of mutual relation between the rest data is . The probability formula for distinct gifted group is as follow. $$P=\frac 1{1+e^{-[-0.018(TTCT)+0.057(IQ)+1.916(FASP)+0.682(V.T)+0.088(Exp.)+0.034(G-Index)-57.510]}}$$ The result of this calculation showed that probability for distinct in gifted group was very good(95.0%). On the basis of upper result, tools for identification gifted students should be estimated as using many-sided estimation data whatever possible. And following study about development, and operation of tools for distinction suitable to gifted student in science should be progressed.

Effect of Flipped learning on the Self-directed Learning ability, Learning Attitude, Lesson Satisfaction for Nursing Students of the University (간호대학생의 플립러닝 학습이 자기주도학습능력, 학습태도, 수업만족도에 미치는 영향)

  • Kim Jin;Cha Nam Hyun
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.3
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    • pp.11-17
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    • 2023
  • This study investigates the effects of flipped learning on self-directed learning ability(SDLA), learning attitude, and lesson satisfaction for nursing students of the university. The research participants and data collection were conducted on 41 nursing students in A city from March 1 to June 16, 2022, and the research design is a one-group pretest-posttest design. SDLA, learning attitude, and lesson satisfaction were investigated, and flipped learning lectures were applied to the experimental group as experimental treatment. SPSS 27.0 version was used for statistical analysis and the Paired T-test was applied the effect test before and after the experiment. As a result, the learning attitude of nursing students showed a positive correlation with SDLA and lesson satisfaction, and the flipped learning education method showed SDLA (t=-8.73, p<.001) and learning attitude (t=-6.99, p<.001) and lesson satisfaction (t=-2.17, p<.05) All were statistically significant.