• Journal of Distribution Science
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• v.14 no.3
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• pp.31-38
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• 2016

Purpose - This paper reviews the change of steel export-import structure between Japan and China by the courtesy of international business reference index and stress to analyze comparative advantage under the circumstance of time-series evaluating database by 3 indexes. Research design, data, methodology - Per economic phase, both China-Japan have mutually a complementary base. Under this kind of view point, the reason why to conduct this study is to realize how this 2 country's trade competitiveness should be improved and strengthened. Results - Under this research data and analysis outcomes, bilateral intra-economy's potential supplementation is enormous. Additionally, expected benefits from here are so sufficiently assured as we compare them with any other regional economic integrated society. Conclusions - When we review our economic point of view, Northeast economic cooperations between China and Japan can provide a chance for industrial technological cooperations not only in steel business but also in other business areas. Come to think of the circumstance to accelerate competitions between 2 country's industries past time and acknowledge concrete resource supplier including expanding export market and diversification.

• Computers and Concrete
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• v.1 no.2
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• pp.189-209
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• 2004

Several extensions to the Thelandersson phenomenological model for concrete under transient high temperatures are explored. These include novel expressions for the temperature degradation of the elastic modulus and the temperature dependency of the coefficient of the free thermal strain. Furthermore, a coefficient of thermo mechanical strain is proposed as a bi-linear function of temperature. Good qualitative agreement with various test results taken from the literature is demonstrated. Further extensions include the effects of plastic straining and temperature dependent Poisson's ratio. The models performance is illustrated on several simple benchmark problems under uniaxial and biaxial stress states.

• Journal of Ocean Engineering and Technology
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• v.22 no.3
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• pp.89-95
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• 2008

Fatigue cracked components often needs to be repaired during service. Standard repair schemes involve strengthening the component by connecting reinforcing members by means of rivets or welding by reducing the crack-tip stress intensity factors. Recent technological advances in fiber reinforced composite materials and adhesive bonding have led to the development of efficient repair schemes. In this study, the influence of various shape parameters on fatigue crack growth in the CCT type uniform thickness plates and the thin-ta-thick type stiffened panels repaired with woven fabric type Kevlar-Epoxy composite patch are studied experimentally.

• Structural Engineering and Mechanics
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• v.19 no.6
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• pp.603-618
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• 2005

The split Hopkinson pressure bar (SHPB) technique is widely used to characterize the dynamic mechanical response of engineering materials at high strain rates. In this paper, attendant problems associated with testing 70 mm diameter concrete specimens are considered, analysed and resolved. An adaptation of a conventional solid circular striker bar, as a means of achieving reliable and repeatable SHPB tests, is then proposed. In the analysis, a pseudo one-dimensional model is used to analyse wave propagation in a non-uniform striker bar. The stress history of the incident wave is then obtained by using the finite difference method. Comparison was made between incident waves determined from the simplified model, finite element solution and experimental data. The results show that the simplified method is adequate for designing striker bar shapes to overcome difficulties commonly encountered in SHPB tests. Using two specifically designed striker bars, tests were conducted on 70 mm diameter steel fibre reinforced concrete specimens. The results are presented in the paper.

• Journal of Applied Reliability
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• v.6 no.4
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• pp.255-274
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• 2006

Recently firms become largely changed because of rapid technological innovation and serious global competition. It induces job stress of workers and finally leads to job burnout. This study aims to find the effects of job demands and job resources on job burnout. Job demands contains role ambiguity, role conflict, role overload and job characteristics. Job resources contains job control and feedback, involvement in decision making, learning opportunity and social support. The result reveals that job demands raises job burnout and job resources decreases job burnout. And it reveals that the effects of job demands and job resources on job burnout differs slightly according to job categories.

• International Commerce and Information Review
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• v.16 no.2
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• pp.69-88
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• 2014

This study examines the effect of external environments such as technological change and competitive intensity on standardization. It was empirically tested by a Korean sample to verify the validity of the research framework. The empirical result confirms that external environments increase the odds of marketing standardization and technology standardization. The result also indicates that technology change and global standardization are related. The data support that firms facing a high rate of technology change stress marketing and technology standardization. The result also confirms that competitive intensity directly influences marketing standardization.

• Structural Engineering and Mechanics
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• v.5 no.6
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• pp.743-754
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• 1997

A three-dimensional constitutive modeling for reinforced concrete is presented for finite element nonlinear analysis of reinforced concrete. The targets of interest to the authors are columns confined by lateral steel hoops, RC thin shells subjected to combined in-plane and out-of-plane actions and massive structures of three-dimensional (3D) extent in shear. The elasto-plastic and continuum fracture law is applied to pre-cracked solid concrete. For post cracking formulation, fixed multi-directional smeared crack model is adopted for RC domains of 3D geometry subjected to monotonic and reversed cyclic actions. The authors propose a new scheme of decomposing stress strain fields into sub-planes on which 2D constitutive laws can be applied. The proposed model for 3D reinforced concrete is experimentally verified in both member and structural levels under cyclic actions.

• International Journal of High-Rise Buildings
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• v.6 no.3
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• pp.249-259
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• 2017

The use of high-strength steels in construction of highrise and mega building structures can bring about many technological advantages from fabrication to erection. However, key design criteria such as local and lateral stability in current steel design specifications were developed based on tests of ordinary steels which have stress-strain characteristics very different from that of high strength steels. A series of tests on 800 MPa tensile strength steel (HSA800) members are summarized in this paper which were conducted to investigate the appropriateness of extrapolating current ordinary-steel based design criteria to high strength steels. 800 MPa I-shape beam specimens designed according to flange local buckling (FLB) criteria of the AISC Specification developed a sufficient strength for elastic design and a marginal rotation capacity for plastic design. It is shown that, without introducing distinct and significant yield plateau to the stress-strain property of high-strength steel, it is inherently difficult to achieve a high rotation capacity even if all the current stability limits are met. 800 MPa I-shape beam specimens with both low and high warping rigidity exhibited sufficient lateral torsional buckling (LTB) strength. HSA800 short-column specimens with various edge restraint exhibited sufficient local buckling strength under uniform compression and generally outperformed ordinary steel specimens. The experimental P-M strength was much higher than the AISC nominal P-M strength. The measured residual stresses indicated that the impact of residual stress on inelastic buckling of high-strength steel is less. Cyclic seismic test results showed that HSA800 members have the potential to be used as non-ductile members or members with limited ductility demand in seismic load resisting systems. Finally, recent applications of 800 MPa high strength steel to highrise and mega building structures in Korea are briefly presented.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.93-96
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• 2003

Laser beam welding process is a relatively new process in comparison with arc welding process, but it is expected to apply widely because of the many advantages, and research and development of that process is being progressed actively for the practical use. the application of this welding process has been restricted due to the high initial investment and the need of precise processing against the material, but cost reduction and thick plate welding in high speed have become practial by recent technological development, and this welding process to not only small parts in automobile, machinery and physicochemical field, but also a large structure and pipe line are being applied. In order to utilize this welding process appropriately to a steel structure, the properties of welding residual stresses and fracture toughness in welded joints are to be investigated for relibilty. On this study, after performing the finite element analysis, thermal and residual stress properties have been examined to the general structural steel (HT50) by laser beam welding. Besides, the property of fracture toughness has been investigated by the Charpy impact test and 3-points bending CTOD test carried out in the range of temperature between $-60^{\circ}C$ and $20^{\circ}C$. From the research results it is revealed that the maximum residual stress appears in the center of plate thickness and the fracture toughness is influenced by strength mis-match.

• Journal of Digital Convergence
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• v.13 no.3
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• pp.137-153
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• 2015

Technostress- a term coined by Craig Brod- refers to a modern disease of adaptation caused by an inability to cope with new technologies. Stress is a person's adaptive response to a stimulus that places excessive psychological or physical demands on that person. In a similar vein, technostress can affect a variety of side effect such as low work productivity and resistance against new technology. The purpose of this study is thus to investigate of differences of technostressors using demographic informations such as gender, age, computer use skill, and industrial types. To do this, we conducted independence t-test and analysis of variance. We found that demographic characteristics can affect the differences of technostressors. Conclusions and implications are discussed in the last section of this paper.