• Journal of Korean Society of Steel Construction
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• v.29 no.5
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• pp.341-352
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• 2017

Well designed group bolted connections can exhibit excellent ductile behavior through the bearing mechanism until the occurrence of shear rupture in the bolt or in the connecting plate. This excellent ductility can be utilized in favor of economical connection design. In this study, comprehensive tests on single-bolt bearing connections were conducted and analyzed considering bearing boundary conditions. The primary objective was to propose a generalized bearing strength and load-deformation relationship that can be used for designing group-bolted connections. To this end, new bearing strength formula, deformation limits as well as new load-deformation relationship were first proposed. Especially the proposed load-deformation relationship can reflect the stiffness, strength, and geometrical boundary conditions of the joint. The proposed formula and relationship are validated based on test results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4A
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• pp.383-389
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• 2010

The concrete structural design provisions in Korea are based on ultimate strength design. Up to service load stage, it is assumed a linear stress-strain relation, but there is no stress-strain relationship for a concrete material from service load stage to limat state. According to the current provisions, an independent method is provided for the each calculation of deflection and crack width. In EC2 provisions based on limit state design, however, a stress-strain relationship of concrete is provided. Thereby, it is able to calculate a strength as well as a deflection directly from concrete stress-strain relationship. In this paper the moment-curvature relationship is directly calculated from a material law using equilibrium and compatibility conditions. Then strength and deflection are formulated. These results are compared with the values from the current provisions in Korea. From the results, the deflection based on a moment-curvature relationship is well agreed with experimental results and it is appeared that the deflection after the yielding of steel is also possible.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.649-655
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• 2010

Unsaturated compressive tests are performed to evaluate the effect of matric suction on the strength and the deformation characteristics for statically compacted natural kaolin in Korea. Under different conditions of the initial degree of saturation in kaolin, the relationship between suction and the degree of saturation at failure can be expressed by unique soil-water characteristic curve. These results demonstrate that the newly established constant water content type unsaturated shear strength test equipment can be used for estimating the relationship between suction and the compressive strength.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.468-474
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• 1997

High strength concrete is a more effective material for columns subject to axial force and moment than for other structural elements. The purpose of this study is to review strength calculation methods for high strength concrete columus by comparison of analytical values and experimental results. The variables of column test under eccentric loading were concrete compressive strength, longitudinal steel ratio, and eccentricity of load. The tied column sections of 120×120mm and 210×210mm were tested and the eccentricity of load varied in the range from 0.16 times to 0.54 times the column depth. The analytical results using the stress-strain relationship to 0.54 times the column depth. The analytical results using the stress-strain relationship as well as the ACI's rectangular block, Zia's modified block, and the trapezoidal block are compared with experimentally obtained data, and discussed in this paper.

• The Journal of Economics, Marketing and Management
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• v.10 no.2
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• pp.15-22
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• 2022

Purpose: This study explores the effect of employee's growth needs strength on counterproductive work behaviors. Perceived job insecurity was also examined as a moderating variable on the relationship between the two variables. Research Design, data and methodology: This study collected 108 data samples from working individuals from South Korea. The Exploratory Factor Analysis (EFA) and the hierarchical regression analysis were used to analyze the data. Hierarchical regression analysis was performed using SPSS 24.0. Results: Our research results indicated that employee's growth needs strength has a negative effect on counterproductive work behaviors. Perceived job insecurity moderates the relationship between the two variables. Conclusions: Organizations should focus on creating growth opportunities for employees, since facilitating employee's growth need strength will counteract the desire to engage in behaviors that can be detrimental to the organization. and its members.

• International Journal of Highway Engineering
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• v.7 no.3 s.25
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• pp.63-69
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• 2005

For many years, the compressive strength of concrete has been regarded as an important index in determining concrete pavement quality. The compressive strength of the sample cores from the field has been used as quality index of concrete pavement. However, this process is time consuming and requires a lot of labor. Recently, the M-E Design Methodology in the pavement design based on the elastic modulus has been adopted. Therefore, several NDT methodologies have been adopted for QA/QC in the field and for the pavement design. Among various NDT methods, the wave propagation method can be used to measure the elastic modulus of concrete because the wave velocity is directly related to the elastic modulus. Therefore, in this study the wave propagation method was used for estimating the concrete modulus. The relationship between the compressive strength measured in he laboratory and the elastic modulus measured by the wave propagation method was analyzed, and the compressive strength was estimated from the elastic modulus for various mix types. The results showed that the relationship between the elastic modulus and the compressive strength was observed and the relationship varied depending on the aggregate types.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.11 no.2
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• pp.91-96
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• 2005

Determination of safety factor of corrugated fiberboard boxes used for agricultural products is very complicated process due to nature of living products. Moisture content is one of the most critical factors to determine overall physical strength of paper, so its influences on strength properties of corrugated board made from different raw materials must be quantified. The results obtained from the study were summarized as follows; 1. Results show a detrimental effect on bursting strength and compressive strength of liners with increasing relative humidity of environment and moisture content of liners. 2. The relevance of equilibrium moisture content at varying relative humidity levels was proved and its relationship was used as an important factor to estimate box compression strength. 3. Test results was statistically used for establish the relationship between relative humidity and moisture content of liners. Estimated compression strength of boxes at varying moisture content was similar to results of theoretical equations such as Kellicutt's. Further study could be carried out in order to determine a optimum safety factors of various corrugated board boxes for agricultural products.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.4
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• pp.27-33
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• 2018

PURPOSE: This study was conducted to identify the relationships among stress response inventory, hospital anxiety and depression, muscle tone and stiffness, and hand strength in chronic stroke patients. METHODS: A total of 14 chronic stroke patients voluntarily agreed to this experiment and were included in this study. All measurements were performed in one day and in a room without noise. The tests conducted in this study were as follows: muscle tone and stiffness of the upper trapezius hand grip measurement. Subjects were also asked to complete surveys describing the following: stress response inventory and hospital anxiety and depression scale. RESULTS: There were significant correlations among stress response inventory and hospital anxiety and depression, stress response inventory and hand strength, and hospital anxiety and depression and hand strength (P<.05). There were high positive correlations between stress response inventory and hospital anxiety and depression (r=.979), while there were moderate negative correlations between stress response inventory and hand strength (r=-.415) and between hospital anxiety and depression and hand strength (r=-.420). CONCLUSION: The results of the present study indicate that there is a relationship among stress response inventory, hospital anxiety and depression, and hand strength in patients with chronic stroke.

• Tribology and Lubricants
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• v.20 no.1
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• pp.7-13
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• 2004

High strength steels are widely used as tribo-materials in the field. Previous study revealed that for mild steel, the states of strain on the worn surface measured by X-ray diffraction has a good relationship with the state of wear. The objective of this study is to identify the relationship between the state of strain on the worn surface and the state of wear in high strength steels. Sliding wear tests were carried out using several hardened steels. X-ray diffraction tests were conducted to analyze the state of strain on the worn surface during wear. The experimental results indicated that the state of strain on worn surface in the hardened steel shows the same tendency as in the mild steel. It is clear that change of half value width on the worn surface as a function of sliding speeds is broadly similar in shape to wear characteristics curve and its magnitude has a good relationship with the wear rate at two different wear modes in the hardened steel.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.834-839
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• 2003

Previous research has been conducted on an ultrasonic wave reflection method that utilizes a steel plate embedded in the concrete to measure the reflection loss of shear waves at the steel-concrete interface. The reflection loss has been shown to have a linear relationship to compressive strength at early ages. The presented investigations continue this research by examining the fundamental relationship between the reflection loss, measured with shear waves, and the hydration kinetics of Portland cement mortar, represented by dynamic elastic moduli, compressive strength and degree of hydration. Dynamic elastic moduli are measured by fundamental resonant frequency and degree of hydration is determined by thermogravimetric analysis. The water/cement ratio was varied for the tested mixture compositions. The results presented herein show that compressive strength, dynamic shear modulus and degree of hydration have a linear relationship to the reflection loss for the tested mortars at early ages.