• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.04a
• /
• pp.160-165
• /
• 2004

At this research, we examined probability of light bulb's life span value and prediction on purpose to inquire out the span of repeat velocity as fracture probability by executing the fatigue test, which is considered property of Tungsten filament's thermal fatigue used as an automobile bulb. As a result we can confirm what the most suitable solution is weibull distribution and log normal distribution. Tungsten filament's span gets longer as the fatigue repeat velocity gets shorter And, repeat span is about 15%~40% shorter than sequence life span.

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

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

• Molecules and Cells
• /
• v.37 no.1
• /
• pp.51-57
• /
• 2014

NOG1 is a nucleolar GTPase that is critical for 60S ribosome biogenesis. Recently, NOG1 was identified as one of the downstream regulators of target of rapamycin (TOR) in yeast. It is reported that TOR is involved in regulating lifespan and fat storage in Caenorhabditis elegans. Here, we show that the nog1 ortholog (T07A9.9: nog-1) in C. elegans regulates growth, development, lifespan, and fat metabolism. A green fluorescence protein (GFP) promoter assay revealed ubiquitous expression of C. elegans nog-1 from the early embryonic to the adult stage. Furthermore, the GFP-tagged NOG-1 protein is localized to the nucleus, whereas the aberrant NOG-1 protein is concentrated in the nucleolus. Functional studies of NOG-1 in C. elegans further revealed that nog-1 knockdown resulted in smaller broodsize, slower growth, increased life span, and more fat storage. Moreover, nog-1 over-expression resulted in decreased life span. Taken together, our data suggest that nog-1 in C. elegans may be an important player in regulating life span and fat storage via the insulin/IGF pathway.

• Structural Engineering and Mechanics
• /
• v.78 no.1
• /
• pp.87-102
• /
• 2021

Long span cross-rope suspension structure is an innovative structural system evolved from typical Cross-Rope Suspension (CRS) guyed tower, a type of supporting system with short span suspension cable supporting overhead power transmission lines. In mountainous areas, the span length of suspension cable was designed to be extended to hundreds or over one thousand meters, which is applicable for crossing deep valleys. Vortex Induced Vibration (VIV) of overhead power transmission lines was considered to be one of the major factors of its fatigue and service life. In this paper, VIV and its controlling by Stockbridge damper for long span CRS was discussed. Firstly, energy balance method and finite element method for assessing VIV of CRS were presented. An approach of establishing FE model of long span CRS structure with dampers was introduced. The effect of Stockbridge damper for overall vibration of CRS was compared in both theoretical and numerical approaches. Results indicated that vibration characteristics of conductor in long span CRS compared with traditional tower-line system. Secondly, analysis on long span CRS including Stockbridge damper showed additional dampers installed were essential for controlling maximum dynamic bending stresses of conductors at both ends. Moreover, factors, including configuration and mass of Stockbridge damper, span length of suspension cable and conductor and number of spans of conductor, were assessed for further discussion on VIV controlling of long span CRS.

• Steel and Composite Structures
• /
• v.23 no.4
• /
• pp.435-444
• /
• 2017

In the past, the progressive collapse resulting from local failures during accidents has caused many tragedies and loss of life. Although long-span spatial grid structures are characterised by a high degree of static indeterminacy, the sudden failure of key members may lead to a catastrophic progressive collapse. For this reason, it is especially necessary to research the progressive collapse resistance capacity of long-span spatial grid structures. This paper presents an evaluation method of important members and a novel dynamic analysis method for simulating the progressive collapse of long-span spatial grid structures. Engineering cases were analysed to validate these proposed method. These proposed methods were eventually implemented in the progressive collapse analysis of the main stadium for the Universiade Sports Center. The roof of the structure was concluded to have good resistance against progressive collapse. The novel methods provide results close to practice and are especially suitable for the progressive collapse analysis of long-span spatial grid structures.

• Journal of Information Management
• /
• v.35 no.1
• /
• pp.93-112
• /
• 2004

This study is intend to analyze the cited patent life time of US patent data via more objective way. It is based on exploratory approach which is one of various methods for technology forecasting. The life spans of cited patents of specific technological field are deduced from using informetric analysis of USPA database of KISTI, which is composed of US patent data covered from 1972 to present. The statistics of the results may help to estimate the economic life span of the specific technological area for technology valuation.

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

• Current Research on Agriculture and Life Sciences
• /
• v.32 no.1
• /
• pp.30-33
• /
• 2014

A simulation model was developed to monitor food contamination during the ripening process of Kimchi on a factory scale. The cabbages were divided into three groups: control (without salt or red pepper), samples with added salt, and samples with added salt and red pepper. The processed Kimchi was left to ripen in a refrigerator at $4^{\circ}C$ and five frog heads (contaminant) left on the surface of the cabbages in each group. For the control, the contaminant exhibited a long life span of 10 days or more, however, for the samples with salt and samples with salt and red pepper, the contaminant showed a relatively short life span. In particular, for the processed Kimchi that included salt and red pepper, the life-span of the contaminant was dramatically decreased to around 3 days. Therefore, the present results suggest that the proposed simulation trial is suitable for monitoring contamination during Kimchi production. Moreover, since the contaminant could not survive more than 3 days, this suggests that the salt concentration in the Kimchi damaged the permeability of the skin and other tissue membranes.

• Journal of the Korean Society of Safety
• /
• v.29 no.5
• /
• pp.97-103
• /
• 2014

To ensure durability and light weight of bridges, high-strength concrete is required for long-span deck slabs. Such a technology eventually extends the life of bridges and improves the economic efficiency. The results of this study suggests a formula for calculating the minimum thickness of long-span deck slabs built with high strength concrete. The minimum thickness is proposed based on the limit states indicated in the CEB-FIP Model Code and the Korean Highway Bridge Design Code(limit state design). The design compressive strength of concrete used for the study is 80MPa. Moreover, the required thickness for satisfying the flexural capacity and limiting deflection is estimated considering the limit state load combination. The formula for minimum thickness of deck slabs is proposed considering the ultimate limit state(ULS) and the serviceability limit state(SLS) of bridges, and by comparing the Korean Highway Bridge Design Code and similar previous studies. According to the research finding, the minimum thickness of long-span deck slab is more influenced by deflection limit than flexural capacity.