• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.27-36
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• 2004

Contemporary objectives for steel rod rolling processing are increasingly complex and often contrasting i.e. obtaining a desired product with optimum combination of properties such as strength, toughness and formability at lower cost. Low-alloy steel rods have been produced with several heat treatments for drawing and forging processes at room temperature. In order to reduce these heat treatments much of the researches concerning of high temperature mechanical behavior of steel rods have been conducted at wire rod mill of POSCO. In this present work, optimizations of rolling temperature and cooling rate for JS-SCM435 are performed to eliminate softening heat treatment(Low Temperature Annealing) for drawing process. The results from the optimization changed the microstructure of rods after rod rolling from Bainite with high tensile strength of 1000Mpa to Pearlite and Ferrite with appropriate strength of 750Mpa that is equivalent tensile strength after softening heat treatment.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.2
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• pp.433-438
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• 2019

This paper proposes a method of improving deep learning based numbers and characters recognition performance on parts of drawing through image preprocessing. The proposed character recognition system consists of image preprocessing and 7 layer deep learning model. Mathematical morphological filtering is used as preprocessing to remove the lines and shapes which causes false recognition of numbers and characters on parts drawing. Further.. Further, the used deep learning model is a 7 layer deep learning model instead of VGG-16 model. As a result of the proposed OCR method, the recognition rate of characters is 92.57% and the precision is 92.82%.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.2
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• pp.59-66
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• 2018

The purpose of this study is to investigate the method on improving the frequency of use and satisfaction rate of the community facilities and to evaluate relation between improving the frequency of use and satisfaction rate of the community facilities and improving the sense of community in apartments. The research subjects of this study is the four public lease apartments which is built around same period with same design guide. The survey method is a questionnaire survey, a experimental study, focus group interview, an analysing drawing. The result of study is as follows. The first, the frequency of use and satisfaction rate have been effected by the operation management system as well as the physical circumstance. The second, The frequency of use and satisfaction rate of the community facilities have had positive correlation with sense of community. The third, multimedia room and conference room with low usability need to change a multipurpose space such as cafe, classroom for learning on artistic topic with high demand from occupant. Finally, a mindset shift is required for architects to inspire community facilities as an important mediated space improving the sense of community by suggesting spaces for leisure and hobby activities.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.11 no.5
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• pp.197-202
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• 2001

The influence of thermal treatment and cold drawing was investigated for poly(ethy1ene terephthalate) films fabricated with various experimental conditions. Samples were elongated at room temperature under stepwise-drawing condition with the cross-head speed kom 0.5 to 500 mrdmin in an universal tester. Stress oscillation was observed in the stress-stnin curve of the samples heat-treatd at 50, 72 and $129^{\circ}C$ for 30 min, but it was not observed in the samples heat-treatd at $83^{\circ}C$ for 30 min. Thermal analyses of the samples were carried out in differential scanning calorimeter at the heating rate df $10^{\circ}C$/min/min, and the glass transition temperature, crystallization peak, enthalpy of fusion and degree of crystallinity were measured. The dynamic mechanical analyses of the samples were also carried out in a multiplefimction internal kiction pendulum at 1 Hz with the heating rate of $1.5^{\circ}C$/min, and it was found that the elastic modulus increases in the order of non-treated, heat-treated, and elongated samples.

• Land and Housing Review
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• v.8 no.4
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• pp.257-266
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• 2017

LH has been using ultra high strength reinforcing bars (SD500 and SD600), since 2011. Such a change requires an adjustment of the old extra rates of bar splice to reflect use of ultra high strength reinforcing bars, as these rates had been set based on SD400 bars. It is particularly difficult to calculate precisely rebar lap-splice locations for large areas, such as those in apartment buildings. This research aims to adjust the extra rates of bar splice to reflect a reasonable rate; the rebar lap-splice length is not an exact estimation, but instead, an extra rates of bar splice is set and the rebar lap-splice length is increased by 2% (D 10) - 7% (025) depending on the bar size. The subjects of this study are LH apartments undergoing frame construction. We studied the quantity estimations from the design drawings, and analyzed the settlement quantities of construction field. The results of the study revealed that, when each of the quantities are analyzed, consider adjusting the extra rates of bar splice of some rebar to 1% - 3.5%. This was caused by an overuse of reinforcing bars in onsite construction and the use of supporting bars that have not been reflected in the documents, among other reasons. Based on the results of our study, an improvement plan for the current extra rates of bar splice seems to be necessary, cutting or raising the rate depending on the analysis of the data. Through this study, we expect to contribute to the calculation of reasonable construction costs, improvements in the quality of rebar work, and improvements in the capacity of design techniques for apartment buildings.

• Journal of the Korea Convergence Society
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• v.10 no.5
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• pp.85-94
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• 2019

This study was aimed to identify a study on the effect of chest compressions combined with abdominal drawing-in technique on prevention of back pain and chest compression quality. We tested motion analysis, electromyography, and chest compression quality of 15 paramedics. Data were normalized to SPSS 21.0 (Kolmogorov-Smirnov and Shapiro-Wilk test). The paired t-test was used for the pre- and post-test chest compressions, the one-way ANOVA was used for the analysis of the measurement point-in-time differences, and LSD was used for the post-test. The results of the study showed significant difference in muscle activity and chest compression success rate when the chest pressure was applied with abdomen drawing-in. Therefore, it is necessary to study cardiopulmonary resuscitation education which can increase the chest compression success rate while preventing the back pain of the paramedics in the future.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.546-551
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• 1997

In sheet metal forming, since the surface area of workpiece is apparently larger than the volume of it, the surface condition of the sheet metal is much varied. The formability of sheet metal is decided by the forming limit and the macroscopic suface defect as like fracture and wrinkle, and microscopic asponent, The factors affected in forming limit are stain herdening exponent, strain-rate scnsitivity exponent, anisotropic coefficient. The increasing of surface roughness is decresed the forming limit curve. It is known that the greater plastic deformation the more surface roughness by Kienzle, Osadaka. The purpose of this study is to investigate the influences of surface roughness in a uniaxial tension and the traperzoidal-shaped box drawing.

• Korean Management Science Review
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• v.34 no.2
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• pp.57-66
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• 2017

The purpose of this study is to analyze the multidimensional productivity of the shipbuilding performance and to explain the role of different factors, such as man-hour, dock period, number of building block, launching process rate, automatic welding percent, and drawing fault rate which are important production-related variables in most shipbuilding companies. The shipbuilding productivity is obtained using Data Envelopment Analysis (DEA) approach. Then, a Tobit model is considered to measure the influence of different factors on the measured productivity. The results reveal that this productivity measure can substitute a representative shipbuilding productivity index (CGT/man-hour) in shipbuilding industries. Also, this multidimensional productivity analysis using DEA and Tobit reveals complex relationships between production-related variables and CGT and sale.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1996.10a
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• pp.38-47
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• 1996

Sectional analysis program for plane strain or axisymmetric geometry of aluminum alloy sheet metals was developed. For modeling the anomalous behavior of aluminum alloy, Barlat's strain rate potential and Hill's 1990 non-quadratic yield theory arranged under the plane stress assumption were employed. 2-D rigid-viscoplastic FEM formulation based on the bending-augmented membrane theory was derived, solving simultaneously force equilibrium as well as non-penetration condition. Isotropic hardening law was also assumed for yielding behavior. To verify the validity and availability of the developed program, 2-D stretch/draw forming process for plane strain geometry and cylindrical cup deep drawing process for axisymmetric geometry were simulated.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.10a
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• pp.44-54
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• 1994

A variational formulation and the associated finite elemet equations have been derived for general three-dimensional deformation of a planar anisotropic rigid-plastic sheet metal which obeys the strain-rate potential proposed by BARLAT et al [13]. By using the natural convected coordinate system, the effect of geometric change and the rotation of planar anisotropic axes are considered efficiently. In order to check the validity of present formulation, a cylindrical cup and a square cup deep drawing test was modeled. good agreement was found between the FE simulation and the experiment. The results have shown that the present formulation for planar anisotropic deformation can be efficiently applied to the analysis of sheet metal working processes for planar anisotropic nonferrous metals.