• Journal of Welding and Joining
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• v.5 no.2
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• pp.53-59
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• 1987

The effect of applied stress, current density and heat-treatment after welding on the time to fracture, fracture behavior was investigated by the method of constant load tensile testing under catholic charging with hydrogen in E.B. welded 250,300 Grade 18% Ni Maraging steel sheet. The main results obtained are as follows: 1. All specimen showed the characteristic delayed failure and the time to fracture showed decreasing tendency with the increase in current density and applied stress. 2. Hydrogen embitterment susceptibility of notched specimen after solution-treatment and aging after welding was more increased than that of aged smooth specimen and as welded specimen. 3. Fracture surface showed a typical intergranular fracture on the border, a dimple pattern in the center of specimen and some quasi-cleavage fracture between the intergranular and the dimple.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.481-486
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• 1998

In this paper, elastic and inelastic behavior of exterior joint of moment-resisting R.C frame with non-seismic detail subjected to reversed cyclic lateral load such as earthquake excitations was investigated. 1/2-scals subassemblage exterior beam-column joint including slab was manufactured based on similitude law. Then, pseudo static test under the displacement control was performed. The results of 1)crack pattern and failure mode, 2)degradation stiffness and strength, energy dissipation capacity from load-displacement hysteresis curve, 3)strain of steel were analysed.

• Journal of the Korean housing association
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• v.10 no.2
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• pp.185-193
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• 1999

This study aims to identify the usage behavior of An-bang space in apartment dwellers through the perception, the residential life style and the use of furniture. The data is collected from interviewing housewives through questionnaire designed for this study. The 210 date were analyzed by using Frequencies, Mean, Factor analysis, ${\chi}^2-test$, t-test, one-way ANOVA and scheffe-test. The main results of the study are as follows: (1) It is called An-bang' or 'large room' rather than 'master's bedroom' although it is recognized as exclusively couple-oriented space. And are founded to be different designation and perception on An-bang space. (2) The residential life style in An-bang is classified as family-centered gathered, rest entertainment, make-up fitting and hobby. And it has significant differences among dwellers according to their personal characteristics. (3) The furniture style and arrangement pattern are mostly modern ones and 'ㄷ' type.

• Journal of the Korean housing association
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• v.10 no.2
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• pp.259-268
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• 1999

This study aims to recognize the importance of the outdoor environment for the improvement in the residents' quality of life and analyze residents' outdoor behavior(physical and psychological) pattern in terms of relation to outdoor environment in Multi-Housing Complexes. Our survey was performed to the residents of 6 Multi-Housing Complexes located in Pusan, and analyzed residents' consciousness, use and evaluation in relation to outdoor space according to the characteristics of the Multi-Housing Complexes. The results are as follows: l. The outdoor space is classified into resting space, green space, parking space, play space and sport space. Most of residents recognize that green space and parking space are the most important of the outdoor space. 2. Mainly, wives use for stroll and talk, husbands use for sports and stroll, and children use for sports and play. 3. The parking space is the highest score and sport space is the lowest score according to the residents' evaluation of the outdoor space, and yet sport space must be considered in planning of outdoor space because the residents' needs are high.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.2
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• pp.261-269
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• 2003

This study examined the effects of store density levels on consumers'crowding perception and the effects of perceived retail crowding on consumer emotions and in turn shopping behavior. In addition, the study investigated the effects of perceived price value and store type on the segmented dimensions of perceived retail crowding. Results of an experimental test with 3 density levels and 2 store types confirmed the effects of density on social crowding and spatial crowding. While social crowding positively affected arousal, spatial crowding negatively did pleasure which in turn affected approach-avoidance behavior. Though two store types showed the same pattern in such relationships, the effect of perceived price value on retail crowding was different by store type.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.97-99
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• 2004

To understand the geochemical processes controlling the distribution of nitrate and other agricultural constituents in an alluvial aquifer, hydrogeological and hydro geochemical studies were carried out in an agricultural area within Cheonan. In this selected field, nitrate concentrations were very wide in range but was locally attenuated significantly down to very low levels (<1.0 mg/L). Abrupt removal of nitrate coincided with the pattern of redox change and thus indicated that geochemical processes occurring during and after recharge events control the behavior and distribution of nitrate and other redox-sensitive chemical species.

• Computational Structural Engineering
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• v.9 no.4
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• pp.165-172
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• 1996

For thin elastic structures such as beams, arches, plates and shells, there may exist the boundary layer in the narrow thin region neighborhood of boundaries, where the solution displays the singular behavior exponentially decaying in the normal direction to the boundary. In the finite element analysis of these structures, finite element mesh patterns have a significant role to capture this singularity. This paper introduces the analytic study of this problem and provides a guideline to construct optimal mesh patterns together with numerical experiments.

• Nuclear Engineering and Technology
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• v.28 no.5
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• pp.467-481
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• 1996

An integrated framework of modeling the human operator cognitive behavior during nuclear power plant accident scenarios is presented. It incorporates both plant and operator models. The basic structure of the operator model is similar to that of existing cognitive models, however, this model differs from those existing ones largely in too aspects. First, using frame and membership function, the pattern matching behavior, which is identified as the dominant cognitive process of operators responding to an accident sequence, is explicitly implemented in this model. Second, the non-task-related human cognitive activities like effect of stress and cognitive biases such as confirmation bias and availability bias, are also considered. A computer code, OPEC is assembled to simulate this framework and is actually applied to an SGTR sequence, and the resultant simulated behaviors of operator are obtained.

• Journal of the Korea Concrete Institute
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• v.11 no.5
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• pp.107-118
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• 1999

10 RC bridge piers have been made on a 1/3.4 scale model, and six piers of them were retrofitted with glassfiber. The have been tested in the quasi-static cyclic load so as to investigate their seismic enhancement before and after retrofitting with glassfibers. The objective of this experimental study is to investigate how to strength the ductility of reinforced concrete bridge piers which have been nonseismically designed and constructed in Korea before 1992. Important test parameters are axial load, load pattern, retrofit type. Glassfiber sheets were used for retrofitting in the plastic hinge region of concrete piers. The nonlinear behavior of bridge columns have been evaluated through their yield and ultimate strength, energy dissipation, displacement ductility and load-deflection characteristics under quasi-static cyclic loads. It can be concluded from the test that concrete piers strengthened with glassfibers have been enhanced for their ductile behavior by approximate 50%.

• Korea-Australia Rheology Journal
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• v.12 no.3_4
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• pp.181-186
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• 2000

Rheological Properties of polypropylenes having different molecular structures (linear polypropylene (PPL) and branched one (PPB)) were studied. Both the extensional flow and oscillatory shear flow properties were checked. Especially, the melt strength of polypropylenes having various shear history were investigated by using in-house-made Rheometer (called SMER). Compared to linear polypropylene, the branched polypropylene shows enhanced melt strength during extensional flow due to the retarded relaxation of molecules. When the slope of melt tension was plotted against take up speed of melt strand, the characteristic peak was observed in case of branched polypropylene, while the linear polypropylene shows only monotonously decreasing pattern. This entanglement was partially disrupted by physical forces such as shear during melt extrusion. However, the melt strength of PPB after multiple extrusion is still higher than PPL, implying the loss of elasticity during multiple extrusion is not so comprehensive. On dynamic experiments, PPB shows typical shear thinning behavior and the tangent delta of PPB is lower than PPL, reflecting high elasticity of PPB.