• Title/Summary/Keyword: strength index

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The Effect of Yoga and Health Calisthenics Program in the Middle Aged Women on Physiological Index and Life Satisfaction (요가와 건강체조 프로그램이 중년여성의 생리적 지수와 생활만족도에 미치는 효과)

  • Min, Soon;Jang, Sook-Hee;Kim, Hye-Sook;Ha, Yun-Ju;Chung, Kyoung-A;Jung, Sun-Ju
    • Journal of Korean Biological Nursing Science
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    • v.12 no.2
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    • pp.97-105
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    • 2010
  • Purpose: The purpose of this study was to examine the effect of yoga and health calisthenics program in the middle aged women on physiological index and life satisfaction. Methods: This research was an one group pretest-posttest design. A pre and post measurement tool of the program was applied to measure body weight, obesity, rate of body fat, vital capacity, inhalation rate of oxygen, sit-up, grasping power, total physical response, body anteversion, body mass index (BMI), total physical strength, physical strength, health age, life satisfaction. Data collected from this tool was analyzed by SPSS in paired t-test. Results: The results were summarized as follows: yoga program group, the body weight, obesity, BMI, %body fat of the decreased. The results of pulmonary yoga group, vital capacity and inhalation rate of oxygen, total physical strength examination results showed a significant difference. Conclusion: In this study, the yoga program was effective in positive on body composition and physical strength, life satisfaction in middle aged women.

Stabilization of expansive soil using industrial wastes

  • Mohanty, Soumendra K.;Pradhan, Pradip K.;Mohanty, Chitta R.
    • Geomechanics and Engineering
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    • v.12 no.1
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    • pp.111-125
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    • 2017
  • Swelling and shrinkage characteristics of expansive fine grained soil cause volumetric changes followed by distress and damage to the structures. Soil stabilization can be explained as the alteration of the soil properties by chemical, mechanical or any other means in order to enhance the engineering properties of the soil. Utilization of industrial wastes in soil stabilization is cost effective and environment friendly. This paper presents an experimental study on stabilization of expansive soil using industrial wastes, viz. fly ash and dolochar. The paper includes the evaluation of engineering properties like unconfined compressive strength and California bearing ratio (CBR) of expansive soil collected from Balasore district of Odisha stabilized with fly ash and dolochar in different proportions and to predict the influence of these additives on engineering properties and strength characteristics of expansive soil. Both fly ash and dolochar were found to increase the CBR and decrease many index properties such as liquid limit, plastic limit, plasticity index, swelling index and UCS, thus enhancing the strength parameters of expansive soil.

Engineering Characteristics of the Sedimentary Rocks on Compressive Strength and Weathering Grade (압축강도와 풍화도에 관련된 퇴적암의 공학적 특성)

  • 이영휘;김영준;박준규
    • Journal of the Korean Geotechnical Society
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    • v.16 no.1
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    • pp.5-17
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    • 2000
  • The physical and mechanical properties of the sedimentary rocks deposited in Taegu and Kyongbuk region have been measured in the laboratory and at the field. Four kinds of rocks such as the shale, the mudstone, the siltstone and the sandstone were the object of this study. In sedimentary rock joint, bedding made it impossible to extract cores for uniaxial compressive test. Some correlations between the uniaxial compressive strength and the other characteristic values such as Point load index, Schmidt hammer rebound, Brazilian strength, P-wave velocity and Absorption ratio are made. The chemical and mineral compositions are also investigated by the XRF and XRD analysis. In addition, the weathering grade of rocks are classified by the quantitative indices of Point load index, Schmidt hammer rebound and Absorption ratio.

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A study on the strength of mechanically fastened composite joint using the linear analysis (선형해석을 이용한 복합재료 기계적 체결부의 강도평가에 관한 연구)

  • Chun, Young-Jun;Choi, Jin-Ho;Kweon, Jin-Hwe;Lee, Sang-Chan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.9
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    • pp.49-56
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    • 2004
  • With the wide application of fiber-reinforced composite material in aero-structures and mechanical parts, the design of composite joint have become a very important research area because they are often the weakest areas in composite structures. In this paper, the linear finite element analyses in which the pin of the composite joint was assumed to be the frictionless rigid body were performed and predict the strength of the mechanically fastened composite joint using the failure area index method. By the failure area index method, the strength of the mechanically fastened composite joint which has the specimen of different shape, hole size and stacking sequence could be predicted within 12.2%.

Experimental and numerical investigation of the effect of sample shapes on point load index

  • Haeri, Hadi;Sarfarazi, Vahab;Shemirani, Alireza Bagher;Hosseini, Seyed Shahin
    • Geomechanics and Engineering
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    • v.13 no.6
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    • pp.1045-1055
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    • 2017
  • Tensile strength is considered key properties for characterizing rock material in engineering project. It is determined by direct and indirect methods. Point load test is a useful testing method to estimate the tensile strengths of rocks. In this paper, the effects of rock shape on the point load index of gypsum are investigated by PFC2D simulation. For PFC simulating, initially calibration of PFC was performed with respect to the Brazilian experimental data to ensure the conformity of the simulated numerical models response. In second step, nineteen models with different shape were prepared and tested under point load test. According to the obtained results, as the size of the models increases, the point load strength index increases. It is also found that the shape of particles has no major effect on its tensile strength. Our findings show that the dominant failure pattern for numerical models is breaking the model into two pieces. Also a criterion was rendered numerically for determination of tensile strength of gypsum. The proposed criteria were cross checked with the results of experimental point load test.

Performance Test of a Real-Time Measurement System for Horizontal Soil Strength in the Field

  • Cho, Yongjin;Lee, DongHoon;Park, Wonyeop;Lee, Kyouseung
    • Journal of Biosystems Engineering
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    • v.41 no.4
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    • pp.304-312
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    • 2016
  • Purpose: Soil strength has been measured using a cone penetrometer, which is making it difficult to obtain the spatial data required for precision agriculture. Our objectives were to evaluate real-time horizontal soil strength (RHSS) to measure soil strength in real time while moving across the field. Using the RHSS data, the tillage depth was determined, and the power consumption of a tractor and rotavators were compared. Methods: The horizontal soil-strength index (HSSI) obtained by the RHSS was compared with the cone index (CI), which was measured using a cone penetrometer. Comparison analysis in accordance with the measurement depth that increased at 5-cm interval was conducted using kriged maps at six sensing depths. For tillage control and evaluation of the power consumption, the system was installed with a potentiometer for tillage depth, a torque sensor from the rear axle, and a power take-off (PTO) shaft. Results: The HSSI was lower than the CI, but they were the same at 54.81% of the total grids for the 5-cm depth and at 3.85% for the 10-cm depth. In accordance with the recommended tillage map, tillage operations between 0 and 15 cm left 2.3% and 7% residue cover on the soil, and that between 20 and 10 cm covered a wider utilization of 3% and 18.4%, respectively. When the tillage depth was 15 cm, the comparison result of the power requirements between the PTO and rear axle in terms of control performance revealed that the maximum power requirements of the axle and PTO were 44.63 and 23.24 kW, respectively. Conclusions: An HSSI measurement system was evaluated by comparison with the conventional soil strength measurement system (CI) and applied to a tractor to compare the tillage power consumption. Further study is needed on its application to various farm works using a tractor for precision agriculture.

Assessment of compressive strength of high-performance concrete using soft computing approaches

  • Chukwuemeka Daniel;Jitendra Khatti;Kamaldeep Singh Grover
    • Computers and Concrete
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    • v.33 no.1
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    • pp.55-75
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    • 2024
  • The present study introduces an optimum performance soft computing model for predicting the compressive strength of high-performance concrete (HPC) by comparing models based on conventional (kernel-based, covariance function-based, and tree-based), advanced machine (least square support vector machine-LSSVM and minimax probability machine regressor-MPMR), and deep (artificial neural network-ANN) learning approaches using a common database for the first time. A compressive strength database, having results of 1030 concrete samples, has been compiled from the literature and preprocessed. For the purpose of training, testing, and validation of soft computing models, 803, 101, and 101 data points have been selected arbitrarily from preprocessed data points, i.e., 1005. Thirteen performance metrics, including three new metrics, i.e., a20-index, index of agreement, and index of scatter, have been implemented for each model. The performance comparison reveals that the SVM (kernel-based), ET (tree-based), MPMR (advanced), and ANN (deep) models have achieved higher performance in predicting the compressive strength of HPC. From the overall analysis of performance, accuracy, Taylor plot, accuracy metric, regression error characteristics curve, Anderson-Darling, Wilcoxon, Uncertainty, and reliability, it has been observed that model CS4 based on the ensemble tree has been recognized as an optimum performance model with higher performance, i.e., a correlation coefficient of 0.9352, root mean square error of 5.76 MPa, and mean absolute error of 4.1069 MPa. The present study also reveals that multicollinearity affects the prediction accuracy of Gaussian process regression, decision tree, multilinear regression, and adaptive boosting regressor models, novel research in compressive strength prediction of HPC. The cosine sensitivity analysis reveals that the prediction of compressive strength of HPC is highly affected by cement content, fine aggregate, coarse aggregate, and water content.

The Study on Technology competitiveness of Domestic Engineering Enterprise based on the Quantitative Patent Analysis (정량적 특허데이터 분석에 기반한 국내 엔지니어링기업의 기술경쟁력 연구)

  • Kwon, Jeong Hwi
    • Journal of the Korea Safety Management & Science
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    • v.15 no.4
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    • pp.295-309
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    • 2013
  • In order to investigate of technology competitiveness for domestic engineering enterprise, using the quantitative and objective patent. In these result, the technology competitiveness(Patent Activity Index, Patent Family Size Index, Patent Impact Index, Technology strength) of our enterprise is far inferior to another country. So we should try to achieve our superiority in competitive power, we devote ourself to put through technical improvements of our domestic engineering enterprise in many ways.

Study on the Novel Materials Containing Nanoparticles and Isocyanate Group for Strength Improvement of Hydrogel Ophthalmic Lens

  • Lee, Min-Jae;Sung, A-Young
    • Journal of Integrative Natural Science
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    • v.11 no.2
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    • pp.113-120
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    • 2018
  • This study was planned to prepare the high strength hydrogel ophthalmic lens containing isocyanate group and nanoparticles. HDI with carbon nanoparticles were used as additives for the basic combination of HEMA, MA and MMA, and the materials were copolymerized with EGDMA as the cross-linking agent and AIBN as the initiator. The mixture was heated at $100^{\circ}C$ for an hour to produce the high performance hydrogel ophthalmic lens by cast mold method. Measurement of the physical characteristics of the produced material showed that the refractive index was in the range of 1.4027~1.4600, water content 25.21~44.01%, contact angle $54.18{\sim}72.94^{\circ}$, visible light transmittance 53.03~92.09%, and tensile strength 0.1024~0.2359 kgf and breaking strength was 0.0872~0.2825 kgf. The results showed an increase of refractive index while the decrease in water content. And also, the breaking strength was highest when the addition ratio of HDI was 5%(wt). As a result of the absorbance measurement, no significant difference was observed in all the samples, so it can be judged that the stabilization of nanoparticles in the polymer was maintained.

A Study on Relationship between Point Load Strength Index and Abrasion Rate of Sediment Particle (퇴적물 입자의 점하중강도지수와 마식율의 관계에 대한 연구)

  • Kim, Jong-Yeon
    • Journal of the Korean Geographical Society
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    • v.43 no.6
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    • pp.808-823
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    • 2008
  • Sediment abrasion in rivers is caused by the interaction between bedrock channel bed and sediment particles transported through the river. Abrasion rate of sediment particles in rivers is controlled by two major factors; Sediment transport conditions including hydraulic conditions form the erosive forces and physical and chemical strengths of the particles form a resistance force against abrasion and other erosional processes. Physical experiments were performed to find the role of each variable on sediment abrasion process. Total 266 sediment particles were used in this experiment. All sediment particles were divided into 11 independent sediment groups with sediment particle size and sediment loads. Each sediment groups were abraded in tumbling mill for up to 8 hours. Changes in weight were recorded by run and total: 2,128 cases of abrasion rate were recoded. Physical strength of rock particles was measured with point load strength index. It is found that sediment abrasion rate has a negative functional relationship point load strength index ($I_{a(50)}$) ($R^2=0.22$). It was suggested that physical strength of sediment particles set the "maximum possible abrasion rate'. As sediment flux increases, abrasion rates of sediment particles with similar point load strength index were changed. It could be concluded that not only physical characteristics of sediment particles, but also sediment transport conditions control sediment abrasion rates.