• Korea-Australia Rheology Journal
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• v.16 no.3
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• pp.141-146
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• 2004

Shear-induced damage of Red Blood Cell (RBC) is an imminent problem to be solved for the practical application of artificial organs in extra corporeal circulation, as it often happens and affects physiological homeostasis of a patient. To design and operate artificial organs in a safe mode, many investigations have been set up to correlate shear and shear-induced cell damage. Most studies were focused on hemolysis i.e. the extreme case, however, it is important as well to obtain a clear understanding of pre-hemolytic mechanical damage. In this study, the change in deformability of RBC was measured by ektacytometry to investigate the damage of RBC caused by shear. To a small magnitude of pre-shear, there is little difference, but to a large magnitude of pre-shear, cell damage occurs and the effect of shear becomes significant depending on both the magnitude and imposed time of shearing. The threshold stress for cell damage was found to be approximately 30 Pa, which is much less than the threshold of mechanical hemolysis but is large enough to occur in vitro as in the extra corporeal circulation during open-heart surgery or artificial heart. In conclusion, it was found and suggested that the decrease of deformability can be used as an early indication of cell damage, in contrast to measuring plasma hemoglobin. As cell damage always occurs during flow in artificial organs, the results as well as the approach adopted here will be helpful in the design and operation of artificial organs.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.6 s.177
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• pp.1446-1455
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• 2000

Fatigue crack initiation and propagation behavior under cyclic biaxial loading has been investigated using thin-walled tubular specimen with a hole. Two types of biaxial loading system, i.e. cyclic tensile loading with super-imposed static torsional load and cyclic torsional loading with superimposed static tensile load, with various values of the biaxial loading ratio, $\tau$ s/ $\sigma$ max (or $\tau$ max/ $\sigma$s) were employed. Fatigue tests show that fatigue crack near the hole initiates and propagates at 900 and 450 direction to the longitudinal direction of the specimen under cyclic tensile and torsion loading with static biaxial stress, respectively, and the static biaxial stress doesn't have any great influence on fatigue crack initiation and growth direction. Stress analysis near the hole of the specimen shows that the crack around the hole initiates along the plane of maximum tangential stress range. Fatigue crack growth rates were evaluated as functions of equivalent stress intensity factor range, strain energy density factor range and crack tip opening displacement vector, respectively. It is shown that the biaxial mode fatigue crack growth rates can be relatively consistently predicted with these cyclic parameters.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.8-13
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• 2008

Emissions from automobiles have long been considered a prime source of pollutants involved in smog formation and ozone production. Especially VOCs are associated with serious environmental problems such as photo-chemical smog as well as human health effects. Since motor vehicles are a major source of VOCs, estimating of emission from mobile source is the most important factor to control VOCs. VOCs are emitted from various pollution like motor vehicles, mobile and stationary source that has characteristics of toxicity, cancer-causing, bio-accumulation, durability in air and diffusion can exert a bad influence upon human health and environment. However we don't have any standard or regulation about VOCs emissions. This study is summarized as VOCs emission characteristics from in-use light-duty diesel and LPG fueled vehicles. The vehicle exhaust-gas test mode is CVS cycle and nier-10 cycles that developed on EPA and National Institute of Environmental Research. TO-14 method (Toxic Organic) was chosen for VOCs analysis from EPA in USA. This study results will be useful when make a emission factor and rule making of emission standard about domestic VOCs emission for the improve to air condition.

• The Korean Journal of Pharmacology
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• v.18 no.1
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• pp.17-22
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• 1982

Zizyphus seed(Zizyphus vulgaris Lamark var. Spinosus Bunge) has long been used as hypnotics and sedatives in oriental medicine, and it is reported that the Zizyphus seed elicited a variety of pharmacologic actions besides CNS depression. Present study was undertaken to investigate the effects of Zizyphus seed on the central nervous system and on the blood pressure. The effect of Zizyphus seed on the central nervous system was measured by the influence of thiopental sleeping time and by inhibition of chemical convulsion (strychnine and pentylenetetrazol induced). Blood pressure changes by Zizyphus extract and its mode of action were investigated. The ground Zizyphus seed was extracted with hexane and methanol, consecutively and the supernatants were discarded. The precipitate was re-extracted with distilled water and the supernatant was evaporated to a dark-brownish sticky liquid, which was used as Zizyphus seed extract in this study after dissolving in saline prior to experiment. The results are as follows. 1) Zizyphus seed extract caused marked prolongation of the thiopental sleeping time in mice. 2) The chemical convulsion by strychnine and pentylenetetrazol, and the mortality by them in chicks were not affected by pretreatment of Zizyphus seed extract. 3) Zizyphus seed extract produced transient fall of blood pressure in the cat, and this hypotentive effect was blocked partially by atropine but not affected by bilateral vagotomy and/or hexamethonium, nor propranolol and, chlorpheniramine and/or cimetidine. With the above results, it may be suggested that the water extract of Zizyphus seeds contains components producing CNS depression and hypotension. Furthermore it is felt that the cholinergic effect, but not the adrenergic or histaminergic, is partly responsible for the hypotensive effect of Zizyphus seed extract.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.169-179
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• 2010

Satisfying the same probability of loss of control and essentially two fail operative performance with a triplex computer architecture requires a lot of modification of the conventional redundancy management design techniques, previously employed in quadruplex digital flight control computer. T-50 FCS for triplex redundancy management design applied an advanced digital flight control architecture with an I/O controller which is functionally independent of the digital computer to achieve the same reliability and special failure analysis and isolation schemes for fail operational goals with a triplex configuration. The analysis results indicated that the triplex flight control system is to satisfy the safety requirement utilizing the advanced flight control techniques and the system performance of the implemented flight control system was verified by failure mode effect test.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10397-10400
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• 2015

Stigmalactam, an aristolactam-type alkaloid extracted from Orophea enterocarpa, exerts cytotoxicity against several human and murine cancer cell lines, but the molecular mechanisms remain elusive. The aims of this study were to identify the mode and mechanisms of human cancer cell death induced by stigmalactam employing human hepatocellular carcinoma HepG2 and human invasive breast cancer MDA-MB-231 cells as models, compared to normal murine fibroblasts. It was found that stigmalactam was toxic to HepG2 and MDA-MB-231 cells with $IC_{50}$ levels of $23.0{\pm}2.67{\mu}M$ and $33.2{\pm}4.54{\mu}M$, respectively, using MTT assays. At the same time the $IC_{50}$ level towards murine normal fibroblast NIH3T3 cells was $24.4{\pm}6.75{\mu}M$. Reactive oxygen species (ROS) production was reduced in stigmalactam-treated cells dose dependently after 4 h of incubation, indicating antioxidant activity, measured by using 2',7',-dichlorohydrofluorescein diacetate and flow cytometry. Caspase-3 and caspase-9 activities were increased in a dose response manner, while stigmalactam decreased the mitochondrial transmembrane potential dose-dependently in HepG2 cells, using 3,3'-dihexyloxacarbocyanine iodide and flow cytometry, indicating mitochondrial pathway-mediated apoptosis. In conclusion, stigmalactam from O. enterocarpa was toxic to both HepG2 and MDA-MB-231 cells and induced human cancer HepG2 cells to undergo apoptosis via the intrinsic (mitochondrial) pathway.

• Journal of the Korean Society for information Management
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• v.4 no.2
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• pp.47-61
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• 1987

Main advantages of an analytico-synthetic scheme are its flexibility and its ability to cope with new subjects as they arise. Accordingly the synthetic scheme can keep pace with changes in knowledge more easily than an enumerative scheme because new subjects often merely involve fresh combinations of basic unit parts already listed. The findings of the study are as follows: 1. Each part of the components of a complex subject is called phase in CC and we are able to obtain three levels of phase relations such as intra-facet phase relation, intra-array - phase relation and inter-subject phase relation. 2. Different digits are used in CC to represent different varieties of phase relation in each levels. 3. The mode of phase relation may be taken to indicate the strength of bond between the phase and may form a new main subject. 4. In the rules and grammar of the phase relation the extension of two-phase subject is possible up to any extent theoritically. 5. Phase relation in DDC was introduced in the 18th edition, but there was no provision for the kind and the level of phase relation. 6. Colon(:) of the UDC is used to represent phase relation but there was also no provision for the kind and the level of phase relation.

• Clinical and Experimental Pediatrics
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• v.55 no.9
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• pp.350-353
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• 2012

An 18-year-old boy was admitted with chest discomfort, nausea, and dyspnea at rest. At the age of 3 years, he underwent muscle biopsy and dystrophin gene analysis owing to an enlarged calf muscle and elevated serum kinase level (6,378 U/L) without overt weakness; based on the results, Becker muscular dystrophy (BMD) was diagnosed. The dystrophin gene showed deletion of exons 45 to 49. He remained ambulant and could step upstairs without significant difficulties. A chest roentgenogram showed cardiomegaly (cardiothoracic ratio, 54%), and his electrocardiogram (ECG) showed abnormal ST-T wave, biatrial enlargement, and left ventricular hypertrophy. The 2-dimensional and M-mode ECGs showed a severely dilated left ventricular cavity with diffuse hypokinesis. The systolic indices were reduced, including fractional shortening (9%) and ejection fraction (19%). Despite receiving intensive medical treatment, he died from congestive heart failure 5 months after the initial cardiac symptoms. We report a case of BMD with early-onset dilated cardiomyopathy associated with deletion of exons 45 to 49. Early cardiomyopathy can occur in BMD patients with certain genotypes; therefore, careful follow-up is required even in patients with mild phenotypes of BMD.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.698-702
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• 2007

Recently, it isn't hard to find split screen effects in films, TV dramas and commercial films which composes a screen with different frames of images. The TV series '24' which was produced in USA in the year 2001 and is expecting the release of its 7th series next year frequently exhibits such split screen methods. '24' is a TV drama of the events taking place in one day which is produced in the form of real-time mode and consists of 24 episodes which is an hour long. Using split screen method, the drama effectively delivers the events simultaneously taking place at different locations. Moreover, the divided frames of each screen relates to one another by means of collision, synthesis and ect. which captures the vision of the spectators. This study aims at analysing the relationships between the frames which consists split screen scenes in the drama '24' and discover its eye capturing attractions using film montage theories.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.1
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• pp.69-76
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• 2010

While increased use of motor cycles in the recent years for various demands could worsen air quality, only few studies have been conducted on estimation of emission factors and characterization of emissions from motorcycle. In this study, emissions from selected six models of motorcycle based on largest market share and production rate were investigated. To investigate gaseous and carbonaceous air pollutants, such as carbon monoxide (CO), total hydrocarbon (THC), nitrogen oxide ($NO_x$), elemental carbon (EC) and organic carbon (OC), total 124 motorcycles between 2003 and 2007 model year were tested with regulatory driving conditions, such as CVS-40 and CVS-47 mode. These motorcycles were further sub-categorized based on their displacement (< 50 cc, 50~150 cc, and $\geq$ 150 cc), type of stroke (2- and 4 strokes) and model year (2003~2005 and 2006~2007). Tested motorcycles with recent model year (2006~2007) exhibited less emissions of regulatory gaseous and carbonaceous air pollutants compared to old model year (2003~2005). Chemical analysis showed that CO present in highest concentration followed by THC and $NO_x$ for all tested motorcycles. Interestingly, two strokes motorcycle produced higher THC emission but less CO and $NO_x$ than those of four strokes. For all types of displacement and stroke, emission factors (gram per kilometer) of THC and CO except $NO_x$ with recent model year (2006~2007) showed decreased trend compared to old model year (2003~2005). In addition to this, due to mixed combustion between gasoline fuel and lubricant, two strokes motorcycle showed OC > EC emission trend.