• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.2
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• pp.402-407
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• 1995

The effects of room temperature and strain aging treatment are discussed on the critical condition for the onset of growth of non-propagating cracks on 0.15% C low carbon steel, with special emphasis on the length of the critical non-propagating crack and on the crack opening displacement(COD) at the crack tip. It is found from the experimental analysis that room temperature and strain aging of a fatigue pre-cracked specimen introduced the closure of a crack tip of the pre-crack and the reduction of crack opening displacement at the wake of crack, together with an improvement in crack growth resistance of the microstructure. This may cause an increase in the endurance limit of the specimen, through the enhancement of effective stress for the onset of growth of the critical non-propagating crack.

• Transactions of Materials Processing
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• v.8 no.3
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• pp.294-305
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• 1999

A vision-based surface-strain measurement system has been still improved since the authors devel-oped the first version of it. New algorithms for the subpixel measurement and surface smoothing are introduced to improve the accuracy and precision in the present study. The effects of these algorithms are investigated by error analysis. And the equations required to calculate 3D surface-strain of a shell element are derived from the shape function of a linear solid finite-element. The influences of external factors on the measurement error are also examined, and several trials are made to obtain possible optimal condition which may minimize the error.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.106-112
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• 2008

International conferences to block the spread of Avian bird flu occurred in Beijing, 2006 and others warned of the seriousness of the H5N1 strain. The meetings succeeded in generating billions of dollars from USA, EU and World Bank. Migratory birds seem to play a major role in the spread of the aggressive strain globally from Asia to Europe and Africa. Experiences of tolerance breeding of maize (Zea mays L.) for four decades against 20 biotic stresses suggest that the prime cause of the occurrence of H5N1 strain was due to the human beings' counter-efforts against nature. Excessive use of chemicals (spray and injection) in the commercial poultry farms had created high selection pressure on virus. The new strain had mutated for survival. Attempting to eliminate the virus by chemicals for 100% control is a dangerous way to control biotic stresses. This can create more aggressive strains. A solution would be to build up tolerability of the commercial animals against the virus. Improvement of poultry cage environments and respect for nature must be integrated. Potential foes must be watched.

• Korean Journal of Poultry Science
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• v.17 no.1
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• pp.7-15
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• 1990

The present study was undertaken to determine the effect of different body hair color (Native type) and commercial white laying hen (Improvement, Nick Chick strain) on cholesterol, triglyceride and protein concentration in serium. Experimental hens were selected out of yellow-brown body hair color strain (10 heads), green-black body hair color strain (13 heads), white body hair color strain (7 heads), black-bone strain (10 heads) as native type and commercial white laying hen (30 head,3) as improved variety. Experimental diet was fed identically for 4 weeks in total groups. The results of the experiment obtained were summerized as follows：1. Serium cholesterol contents were the highest in commercial white laying hen ($172.50\pm$13.45 mg/100 $m\ell$) (p＜0.01;, and higher in white color strains than body hair color strain groups. Body hair color strain groups were similar in serium cholesterol contents. 2, Serium triglyceride concentration also showed no response among native type groups, however commercial white laying hen group shelved significatly difference. (p＜0.01) 3. Serium protein contents were the highest in commercial white laying hen group ($6.24\pm$0.23 mg/100 $m\ell$). (p＜0,01) Increasing the serium cholesterol, triglyceride and protein contents in commercial white laying hen group than color strain group of native type was considered to improved grade.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.1-11
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• 2016

The information about the deformations of high-aspect-ratio wings is needed for the real-time monitoring of structural responses. Wing deformation in flight can be predicted by using relationship between the curvatures and the strains on the wing skin. It is also necessary to consider geometric nonlinearity when the large deformation of wing is occurred. The strain distribution on fixed-end is complex in the chordwise direction because of the geometric shape of fixed-wings on fuselages. Hence, the wing displacement can be diversely predicted by the location of the strain sensing lines in the chordwise direction. We conducted a study about prediction method of displacements regardless of the chordwise strain sensing locations. To correct spanwise strains, the ratio of spanwise strain to chordwise strain, Poisson's ratio, and the ratio of the plate strain to the beam strain were used. The predicted displacements using the strain correction were consistent with those calculated by the FEA and verified through the bending testing.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.312-315
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• 2002

This paper summarizes the results of a numerical study conducted to analyze the effect of selected process parameters on material flow and thread profile in thread rolling of large diameter blanks. Based on the previous work where a plane strain mode was found to provide a reasonable approximation of the thread rolling process, the effect of varying thread form, friction factor, flow stress, and blank diameter on effective strain and thread height was analyzed using the finite element code DEFORM. This study show that effective strain for flank angle, that blank diameter had important effect on the as-rolled thread while flow stress, friction factor, and crest round of dies had significant impact on effective strain at the thread root and crest and load of thread rolling. While the rate of strain harding was found to have an effect on the crest profile, the results indicate that it is the primary factor responsible for seam formation in rolled threads.

• Microbiology and Biotechnology Letters
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• v.23 no.4
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• pp.461-471
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• 1995

The heterofermentative Leuconostoc mesenteroides, which is propagated from the initial to the intermediate stage of Kimchi fermentation, produces organic acids and carbon dioxide to impart refreshment, weak acid taste to Kimchi. But owing to lactic acid production by the homofermentative Lactobacillus Plantarum, Kimchi finally reaches its acidified state. So, Leu. mesenteroides was isolated from Kimchi and identified and was improved by mutation for carbon dioxide production at low pH, and for the high total acceptability. We tested with a wild-type strain K-1 and its improved mutant strain M-10 of Leu. mesenteroides. The wild-type strain K-1 could grow in pH 4.2 at 30$\circ$C or 20$\circ$C, and in pH 5.0 at 10$\circ$C. But the mutant strain M-10 could grow in pH 3.3 at 10$\circ$C. In the respect of total acceptability, mutant strain M-10 inoculated Kimchi was ever better than any others. Mutant M-10 inoculated Kimchi prolonged the optimum ripening period of Kimchi up to two times as compared with the control group.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.525-530
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• 2003

Recently an automobile industry is concerned about an automobile wiring harness system. It means that development of component modules is on the increase. An importance of the connector in one part of the modules will be enhanced. A connector is made of P.B.T. (Poly Butylene Terephthalate). PBT is resistant to the high temperature. This paper deals with thermal strain of connector. According as temperature increase, effects of the temperature and thermal strains give an analysis of the deformation using ABAQUS. This apparent thermal strain results actually from the variation of temperature. Being based on this analysis, axiomatic design applies to design parameters of the connector. As compared with CAE analysis, a performance improvement makes certain of the truth of the matter.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4784-4789
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• 2014

This paper evaluated the structural improvements and new product development of cleaning machines. A cleaning machine was redesigned for structural improvements and new product development using a 3-D design program CATIA. In addition, structural analysis was conducted on the modeled cleaning machine using the ANSYS program. The total deformation, stress and strain were obtained by the pressure change. This result was applied to the new product development of cleaning machines.

• Land and Housing Review
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• v.2 no.1
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• pp.79-85
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• 2011

The bearing capacity of a soil can be improved by conventional ground improvement techniques such as stabilization and compaction methods. Recently, the use of geotextiles in improving the bearing capacity of soils has become popular because of the availability of durable and strong geosynthetic materials. In this paper, through the laboratory model tests on sandy ground reinforced by geotextiles with the strip footing under plane strain condition, the effects of bearing capacity improvement on the sandy ground and its behaviour were investigated.