• Journal of the Korean Society of Safety
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• v.26 no.2
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• pp.1-5
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• 2011

In order to evaluate fatigue endurance for an ultra-light weight inline skate frame, FEM analysis was performed. Tensile properties and a S-N curve were determined through tensile and fatigue tests on a modified Al-7075+$S_c$ alloy. The yield and ultimate tensile strengths were 553.3 MPa and 705.5 MPa, respectively. The fatigue endurance limit of this alloy was 201.2 MPa. For evaluating the fatigue endurance of the inline skate frame, the S-N data were compared with the stress analysis results through FEM analysis of the frame. The maximum Von-Mises stress of the frame was determined 106 MPa through FEM analysis of the frame, assuming that the rider weight is 75 Kg. Conclusively, on the basis of fatigue limit, the inline skate frame has a safety factor of approximately 2.0.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.159-167
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• 2006

The impact time history of human body with K2 rifle on stand shooting posture is analyzed and compared with experimental results. Analysis model is Korean 50% tile of twenties and height, weight is 174 cm, 62 kgf respectively. The muscle and bone human model of Korean man's twenties 50% tile is applied. ADAMS program is used for kinematic analysis and human model is developed by Life Mod program. The effect of the ground support condition, grip position and human weight factor are studied. Maximum impact force of shoulder is 784 N. The horizontal displacement of K2 rifle muzzle is 2.9 cm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.1
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• pp.7-11
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• 2017

In this study, we develop the exact field of mode I in an infinitely deep crack in a half-plane. Using this field, we obtain the exact stress intensity factor $K_{I}$. From the tractions on the crack faces induced by exact field, we calculate the stress intensity factor of this field. We compare the results with the stress intensity factor calculated using Bueckner's weight function formula and that calculated by using Tada's formula listed in "The Stress Analysis of Cracks Handbook" It was found that Bueckner's formula yields accurate results. However, the results obtained using Tada's formula exhibit inaccurate behavior.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1894-1898
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• 2007

Conventional 3-phase AC-DC converter is frequently in the industrial world. In this paper, the high power factor 3-phase AC-DC converter which can reduce its weight and volume is proposed. The high power factor 3-phase AC-DC converter without LC filter can realize light weight and low-cost. In spite of elimination of LC filter, the performance of the high power 3-phase AC-DC converter is almost the same as conventional 3-phase AC-DC converter. Finally, this result can be expected to be applied to aviation and the space industry with high power density and high power factor.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.201-211
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• 2013

This study compares Customer Satisfaction Index(CSI) and the weight for each dimension by applying various methods of weight calculation and attempts to suggest some implications. For the purpose, the study classified the methods of weight calculation into the subjective method and the statistical method. Constant sum scale was used for the subjective method, and the statistical method was again segmented into correlation analysis, principal component analysis, factor analysis, structural equation model. The findings showed that there is difference between the weights from the subjective method and the statistical method. The order of the weights by the analysis methods were classified with similar patterns. Besides, the weight for each dimension by different methods of weight calculation showed considerable deviation and revealed the difference of discrimination and stability among the dimensions. Lastly, the CSI calculated by various methods of weight calculation showed to be the highest in structural equation model, followed by in the order of regression analysis, correlation analysis, arithmetic mean, principal component analysis, constant sum scale and factor analysis. The CSI calculated by each method showed to have statistically significant difference.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.532-537
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• 2005

Increasing of body weight has been one of the important economic factors in the poultry industry. Insulin-like growth factor (IGF)-I is a polypeptide that serves to regulate muscle development and body growth. Moreover, IGF-I is related to feed efficiency. However, there are few studies regarding the regulatory roles of chicken IGF-I/-II compared with that of mammals. Especially, the Korean Native Ogol Chicken (KNOC) has a lean body growth and its body weight is generally lighter than the broiler chicken. Therefore, this study was conducted to investigate associations among serum IGF-I/-II concentration, feed efficiency, and body growth in KNOC. The body weight and feed intake of KNOC were recorded from 20 to 36 weeks at 2 weeks intervals, and blood was taken every 2 weeks. Serum IGF-I/-II were measured by RIA. Chickens were divided into two groups, high and low serum IGF-I concentration. Generally, feed efficiency and growth performance (body weight and weight gain) in the high serum IGF-I group were higher than those of the low group during the experimental period. In particular, the body weight of the IGF-I high group were significantly different from those of the IGF-I low group at 34 and 36 weeks, respectively (p<0.05). Moreover, body weight, weight gain, and feed efficiency had a significant correlation with serum IGF-I at several weeks (p<0.05 and p<0.01). These results show that IGF-I plays an important role in body growth and suggests a possibility that serum IGF-I could be used as a selection marker for body growth in KNOC.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.393-399
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• 1997

Single-phase and three-phase AC to DC power converters are becoming frequently used for high voltage/high power applications such as telecommunications. They often require input/output transformer isolation for safety, a unity input power factor for minimum reactive power, free input harmonic currents fed back to the AC Power distribution system and, finally, high efficiency and high power density for minimum weight and volume. The proposed boost converter for power factor correction (PFC) provides an unity input power factor, low harmonic distortion and high efficiency along with reduced volume and weight. Single-phase 220VAC input/380VDC 1KW output prototype is constructed and experimental results will be verified with those of PSpice simulation.

• Biomolecules & Therapeutics
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• v.3 no.1
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• pp.80-84
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• 1995

Effects of titrated extract of Centella asiatica (TECA) and epidermal growth factor (EGF) isolated from the urine of pregnant horse on the proliferation of human epidermal keratinocyte in culture were studied. An increase in the number of keratinocyte was observed with the treatment of TECA at the concentration ranges from 1 $\mu\textrm{g}$/mι to 100 $\mu\textrm{g}$/mι. Effects of low molecular weight EGF (LEGF) and high molecular weight EGF (HEGF) on the proliferation of keratinocyte in culture were also studied. The number of keratinocyte in culture was significantly increased with LEGF and HEGF respectively at the concentration of 10 ng/mι. Simultaneous treatment of the keratinocyte with LEGF, HEGF and TECA led to the increased proliferation of keratinocytes resulting 96% of the effect of a positive control, EGF isolated from mouse submaxillary glands.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.3
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• pp.1-11
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• 1997

This study aims to estimate the relative importance of quality management items through the defect analysis in the landscape construction process. The RIQMI are decided by the defect coefficient and it's cause weight. The defect items in the landscape construction process were classified by 56 items based on the classification form of '96 landscape architectural construction standard and the cause pattern were categorized 4 types as design, material, construction, and environment factors. To analyze the defect coefficient and the aucse weight by defect, the researcher surveyed the questionnaires on the 103 engineers and the 31 experts on the landscape architectural construction. The result of this study are as follows. The relative importance by facilities pattern turn out to be much higher construction, material fator than design. environment factor in wood facilities, paving facilities, and steel facilities, the RIQMI is very high in timber crack, timber vending, faulty of timber against decay, welding faulty of steel facilities in material factor, and timber crack, faulty of timber against decay, finish faulty of steel facilities, welding faulty of steel facilities in construction factor.

• Journal of information and communication convergence engineering
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• v.15 no.2
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• pp.73-78
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• 2017

A general linearly constrained broadband adaptive array is examined in the eigenvector space with respect to the optimal weight vector and the adaptive algorithm. The optimal weight vector and the general adaptive algorithm in the eigenvector space are obtained by eigenvector matrix transformation. Their operations are shown to be the same as in the standard coordinate system except for the relevant transformed vectors and matrices. The nulling performance of the general linearly constrained broadband adaptive array depends on the gain factor such that the constraint plane is shifted perpendicularly to the origin by an increase in the gain factor. The general linearly constrained broadband adaptive array is observed to perform better than a conventional linearly constrained adaptive array in a coherent signal environment, while the former performs similarly to the latter in a non-coherent signal environment.