• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.3-17
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• 2007

This paper provides an introduction to life-span simulation and numerical approach to support the performance design processes of reinforced concrete structures. An integrated computational system is proposed for life-span simulation of reinforced concrete. Conservation of moisture, carbon dioxide, oxygen, chloride, calcium and momentum is solved with hydration, carbonation, corrosion, ion dissolution. damage evolution and their thermodynamic/mechanical equilibrium. Coupled analysis of mass transport and damage mechanics associated with steel corrosion is presented for structural performance assessment of reinforced concrete. Multi-scale modeling of micro-pore formation and transport phenomena of moisture and ions are mutually linked for predicting the corrosion of reinforcement and volumetric changes. The interaction of crack propagation with corroded gel migration can also be simulated. Two finite element codes. multi-chemo physical simulation code (DuCOM) and nonlinear dynamic code of structural reinforced concrete (COM3) were combined together to form the integrated simulation system. This computational system was verified by the laboratory scale and large scale experiments of damaged reinforced concrete members under static loads, and has been applied to safety and serviceability assessment of existing structures. Based on the damage details predicted by the nonlinear finite element analytical system, the life-span-cost of RC structures including the original construction costs and the repairing costs for possible damage during the service life can be evaluated for design purpose.

• Journal of Sasang Constitutional Medicine
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• v.14 no.3
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• pp.7-16
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• 2002

Purpose The goal of this study tried to provide aging and life span in Sasang Constitutional Medicine. Methods It was researched Master Dong-Mu's documentary records about aging and the life span represented by ${\ulcorner}$Dongyi Soose Bowon Sasang Chobongyun${\lrcorner}$ and ${\ulcorner}$Dongyi Soose Bowon${\lrcorner}$ published in 1901. Results & conclusion 1. A principal of regimen according to Sasang Constitutional Medicine isn't medicational method but non-medicational method. There are control mind and upright oneself. 2. Dong-Mu's the views of the span of life represented by 'Inherent vitality' that a term means health promoting and forecasting length of the life. He also emphasizied a natural power of recovery from damaged vitality. 3. Greed is reduced one's lifetime. It is originated by bias for 'joy-anger -sorrow-pleasure'. The other example is 'Liquor-Sex-Property- Authority'. 4. The way of prolonging lifetime what managed small visceral intestines through constitutional upright oneself. This is found on pathology, care of health and constitutional 'Knowledge and Deed'.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1012-1020
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• 2006

The crack that occurs on the wheels of railroad cars can be categorized into a surface crack that starts from the surface or a subsurface crack that starts from the inside and can be detrimental to safe railroad operations. Therefore, estimating the growth life span of this type of crack is very important. In this research, the stress distributions, displacements, and the growth-life spans of both surface cracks and subsurface cracks have been studied. By using the finite element analysis, especially in the life span prediction process, the stress conditions and the stress intensity factors of the crack tip have been discovered. The Paris formula has been used to analyze the growth-life span prediction.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2005.11a
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• pp.43-49
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• 2005

The purpose of this study was to provide the fundamental data for the gradual apartment management plan. Through the questionnaire survey, residential satisfactions and maintenance consciousness were investigated. As the result of statistic analysis, the residents' needs for improvement according to the life span of apartment communities were found out. And we can also compare the differences about maintenance consciousness to the life span of apartment. The major research findings are as follows. First, the satisfaction averages according to the life span of apartment communities were classified two groups, less than 10 years' and over than 10 years'. By the requirement for improvement according as the life span apartment communities, habitability factors was demanded in less tham 10 years' group and safety factors was required in over than 10 years' group, Second, dwellers have high preference about remodeling to reconstruction. Especially we have to pay attention to the result that positive consciousness of remodeling and long term reparative marked highly in the group which has the short elapsed years. These results represent the possibility gradual step-by-step remodeling. In other words, the object of remodeling is not only odeteriorated apartments but also new apartments to have short elapsed years.

• Journal of Radiation Protection and Research
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• v.9 no.2
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• pp.67-75
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• 1984

As a part of studies on acute effects of high dose irradiation the present report was carried out to evaluate the changes of the leukocyte life span in the Newzealand white male rabbits by a single whole body exposure to gamma rays from $^{60}Co$ teleirradiation unit. The exposure was done in dose levels of 100, 300, 550 and 1,000 rad to each experimental group of 10 rabbits. The life span and apparent half survival time of leukocytes, and the elution rate of leukocytes in the circulating blood were measured by McMillan method using $^{51}Cr$. 1. As a critical indicator of radiation hazards of the Newzealand male rabbits, the LD 50/30 and LD 100/30 after whole body exposure was estimated as 550 and 1,000 rads respectively. 2. The life span of leukocyte in the circulation after irradiation was slightly shortened in the 100 rad irradiated group, as compared with the unirradiated control group, but markedly shortened in the 300, 550 and 1,000 rads irradiated group. 3. After irradiation, decrease of leukocyte half survival time in the circulation showed the same pattern as that of leukocytes life span. 4. As the irradiation doses increased, the elution rate of $^{51}Cr$ loss from $^{51}Cr$ tagged leukocytes in the circulation were markedly increased gradually. 5. The life span shortening of leukocytes in the circulation after irradiation seems to occure by two processes of senescence acceleration and early destruction.

• Journal of Life Science
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• v.26 no.6
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• pp.646-650
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• 2016

The influence of chromosome number on cell growth and cell aging was investigated in various yeast strains that have many artificial chromosomes constructed using a chromosome manipulation technique. Host strain FY833 and the YKY18, YKY18R, YKY24, and YKY30 strains harboring 16 natural chromosomes, 18 chromosomes, 18 chromosomes containing rDNA chromosome, 24 chromosomes, and 30 chromosomes, respectively, were used, and the specific growth rate of each strain was compared. The specific growth rates in the YKY18 and YKY24 strains were indistinguishable from that in the host strain, while those of the YKY18R and YKY30 strains were reduced to approximately 25% and 40% of the host strain level, respectively. Subsequently, the replicative life span was examined to investigate the relationship between the number of chromosomes and cell aging, and the life span was decreased to approximately 14% and 45% of the host strain level in the YKY24 and YKY30 strains, respectively. Moreover, telomere length, well known as a senescence factor, was shorter and more diversified in the strain, showing decreased life span. Therefore, these results suggest the possibility that an increase in the number of chromosomes containing artificial chromosomes caused cell aging, and we expected these observations would be applied to improve industrial strain harboring of versatile and special artificial chromosomes.

• Journal of Life Science
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• v.14 no.2
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• pp.209-214
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• 2004

Cytotoxic anticancer chemotherapeutic agents generally produce severe side effects, while reducing host resistance to cancer and infections, especially through the destruction of lymphoid and bone marrow cells. In this study, we have investigated the effect of chitosan on cytotoxic activity against cancer cells and life span in mice. The direct cytotoxicity of chitosan or chitosan-combinated chemotherapeutic agents for tumor cells was observed. In addition, the effect of life span extention was counted on sarcoma 180 mice injected with chitosan-combinated mitomycin C. The effect of growth inhibion for cancer cells, K562 and Yac-1 was shown in the cytotoxicity test of chitosan or chitosan-combinated chemotherapeutic agents. Also, the effect of life span extension was observed on sarcoma 180 mice injected with chitosan-combinated mitomycin C. Our results suggest that life span extension in sarcom 180 mice exposed with chitosan-combinated chemotherapeutic agents showed the probability of its usefulness for cancer therapy if more research results were accumulated.

• The Journal of Health Technology Assessment
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• v.6 no.2
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• pp.133-141
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• 2018

Objectives: In the past, the pharmaceutical drug heparin was mostly used as the anticoagulant for continuous renal replacement therapy (CRRT), but the duration time is long to have the risk of a bleeding adverse effect, and in that case the drug therapy Nafamostat mesilate was utilized instead, as it is more safe in this case, with a short half-life and is increasing in use to permit lower concerns for bleeding incidents. However, there are insufficient number of large-scale studies on the comparison of Nafamostat mesilate and heparin. Methods: In this study, a systematic review are used to compare the bleeding risk of Nafamostat mesilate and Heparin, as subjected to patients and procedures for measuring risks performed with a CRRT, and the filter life span is to be evaluated as well in this patients. Results: As a result of literature review search, a total of 6 studies were included in systematic review. The reducing risk of bleeding and filter life span was analyzed. The retrospective cohort studies confirm that Nafamostat mesilate is less at risk of bleeding than heparin. And a cohort study confirms that Nafamostat mesilate is longer filter lifespan than heparin and randomized controlled trial studies show that Nafamostat mesilate is longer filter lifespan than not using the anticoagulants. Conclusion: Nafamostat mesilate is considered to be a good therapeutic option because it has a longer filter life span as well as the advantage of reducing bleeding.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1574-1579
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• 2006

This study was performed to determine the developmental potentials of nuclear transfer (NT) embryos using life-span extended cells transfected with a foreign gene as donor cells. A life-span extended bovine embryonic fibroblast cell line was transfected with an expression vector in which the human type II collagen (BOMAR) and ear fibroblasts were used as a donor cell. Cytogenetic analysis was performed to analyze the chromosomal abnormality of donor cells. The fusion rate of 1.8 kV/cm for $15{\mu}sec$ given twice was significantly higher than that of other groups (p<0.05) and the embryos lysed were significantly higher after 1.8 kV/cm for $20{\mu}sec$ given once compared to other groups (p<0.01). The blastocyst development in the ear cell group was statistically significant compared to both BOMAR groups (p<0.01). Both BOMAR groups cultured more than 40 passages (>40 passages) had a lower number of chromosomes; however, fresh granulosa cell (GC) and BOMAR groups cultured less than 20 passages had normal chromosome numbers. Both >40 passages BOMAR groups had numerous obscure debris in metaphase spreads. The transfected foreign gene was expressed in all BOMAR groups, but not in the GC group. Based on these results, the lower developmental potential of NT embryos using life-span extended donor cells transfected with a foreign gene might be a cause of chromosomal abnormality in donor cells.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.4
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• pp.1-11
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• 2006

A citation-based method of estimating the life span of a patented technology is proposed In this study. The suggested framework Includes : (1) estimation of citation frequency of an individual patent within a technology group. (2) calculation of a mutual citation frequency between citing patent and cited patents, (3) calculation of the period for cited patents from the year of registration to the year of being cited most recently and (4) description for technology group using descriptive statistics such as mean, median, mode, etc. The framework suggested in this study was applied to the US patent data between 1976 and 2004 for 5 communications areas.