• Proceedings of the KIEE Conference
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• summer
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• pp.1278-1280
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• 2004

In this paper, we propose a new diagnosis method of DC/DC converter aging. The method is based on the variations of parasitic resistor for the aging process. We apply an on-line diagnosis of DC/DC converter because the observation is not a device, but a system. This study proposes a method of DC/DC converter diagnosis by analyzing the variations of model on the variations of parasitic resistor.

• Journal of the Korean Society of Food Culture
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• v.16 no.2
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• pp.170-179
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• 2001

Green Tea consists of 15-30% catechins (a type of polyphenol), which act as super antioxidants, inhibitory action against aging process. Antioxidants fight radical-free oxygen, an agent which can begin the process of cancer by damaging essential body chemicals and harming DNA. This study was peformed to develop the elderly diet using Green Tea as an inhibitory action against aging process. Nokchaborijook (Baley gruel added rice powder and Green Tea) was manufactured by various levels of Green Tea(1, 4, 7%) and the grinding period(15, 30, 45 sec). The optimum levels of added Green Tea and grinding periods on Nokchaborijook were determined with the results of sensory evaluation by response surface methodology and analysis of composition. The Anti-oxidant Vitamin A, C, E and Flavonoid were increased with increased levels of Green Tea and grinding periods be decreased. As the levels of Green Tea and grinding periods were increased, the green color and penetrated force became stronger. Among the sensory attributes, Bitterness, Green Tea Flavor and Hashness were greater depending on increasing Green Tea. Jujube flavor was greater relying on decreasing Green Tea. Greenness and spreadability of particles were increased as both the amounts of Green Tea and the grinding period were increased. This result was used to determine the optimum conditions of adding levels of Green Tea and grinding periods. The optimum conditions of Nokchaborijook was established as adding of 5.8% Green Tea grinded for 15 seconds.

• Journal of the Korean Institute of Gas
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• v.23 no.3
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• pp.33-39
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• 2019

in 2010s, many factories are operating without any safety guarantees due to the aging process. Although it is difficult to fundamentally solve the problem of aging process and equipment, Prevent risk by risk assessment in advance. This study targets the corrosion caused by sulfur in the piping in the CDU(Crude Distillation Unit) process desulfurization equipment and conducts the risk assessment by RBI(Risk Based Inspection) referring to API RP 581. RBI expresses the risk by combining frequency and consequence, and creates a risk matrix based on these expression. In this study, the hole size of the pipe was selected as Small and Medium, and the sensitivity of the frequency was selected as 'Low'. You can refer to the Risk Matrix created from the standard to evaluate the risk of corrosion of sulfur from pipes in the piping and to plan future accident prevention. Similarly, prevention of aging in a similar way can prevent large and small incidents that are not visible.

• Proceedings of the Materials Research Society of Korea Conference
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• 2006.05a
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• pp.16.2-16.2
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• 2006

• Archives of Plastic Surgery
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• v.35 no.5
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• pp.581-588
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• 2008

Purpose: It is generally accepted that anatomical structures of the soft tissue in Asian faces are quite different from those in Caucasian. It is presumed that these differences are due to collagen rich thick dermis and durable superficial musculo-apponeurotic system (SMAS) in Asian. We classified the aging lower eyelids and reviewed the operative procedures according to the types of aging lower eyelids in Asian. Methods: We compared preoperative and postoperative photos of 117 patients over 30 years of age, who underwent lower blepharoplasty at the Kyunghee Medical Center from January 2001 to April 2006. We classified the patients based on the degree of skin laxity, presence of nasojugal groove and malar bag, the extent of aging process. We also reviewed the operative procedures according to each type of classification. Results: We classified our patients into four types as following. Type I patients showed minimal skin-muscle excess confined to lower eyelids regardless of the facial line. For these patients, we performed only transcutaneous or transconjunctival blepharoplasty. In type II patients, nasojugal grooves were shown and skin- muscle laxity was limited to the medial side of imaginary vertical line at lateral margin of pupil. In these cases, we performed free fat graft or fat repositioning on nasojugal groove or fat removal and septal duplication confined to medial side. Type III patients displayed more advanced medial bulging and remarkable laxity over the lateral side, the same operation methods as those of type II were applied at the lateral side of the line. Type IV patients demonstrated extensive midfacial aging changes including malar bags and underwent superficial subciliary cheek lift. Conclusion: The lower eyelid aging of Asian is different from those of Caucasian. We think that our classification is useful in selection of appropriate operative procedure to address specific problems for Asian patients.

• Analytical Science and Technology
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• v.24 no.5
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• pp.336-344
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• 2011

The study attempted to find out any effect to prevent photo aging of epoxy resin used for conservation by way of adding UV stabilizer, one of plastic additives. Specimens were made by adding HALS and UVA UV stabilizer as each concentration to 3 kinds of epoxy resin, which are most frequently used for artifacts joining and restoration process, and aging effects were investigated through Color change, SEM, contact angle, FTIR analysis during UV aging experiments. Last, usage suitability was checked when UV stabilizer was added through Universal Tensile strength tester. In result, it is impossible to prevent decomposition of chemical structure in spite of adding UV stabilizer but in the case of epoxy A and R, it is believed that photo aging such as yellowing or crack can be minimized without giving a big influence to adhesive strength of epoxy resin through adding less than 0.1% of UVA. It is expected that above will solve photo aging problem of epoxy resin used for joining and restoration of artifacts and will extend its life as joining and restoration materials.

• Nuclear Engineering and Technology
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• v.43 no.3
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• pp.279-286
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• 2011

The aging degradation and lifetime assessment of a domestic class 1E Ethylene-Propylene-Diene-Monomer (EPDM), which is a popular insulating elastomer for electrical cables in the nuclear power plants, were studied for equipment qualification verification under the Loss of Coolant Accident (LOCA) conditions. The specimens were acceleratively aged, underwent a LOCA environment, as well as tested mechanically, thermo-gravimetrically, and spectroscopically according to the American Society of the Testing of Materials (ASTM) procedures. The tensile test results revealed that the elongation at break gradually decreased with an increasing aging temperature. The lifetime of EPDM aged isothermally at $140^{\circ}C$ was 1,316 hours and reduced to 1,120 hours after experiencing the severe accident test. The activation energies of the elongation reduction were $1.10{\pm}0.196$ eV and $0.93{\pm}0.191$ eV before and after the LOCA condition, respectively. The TGA test results also showed that the activation energy of the aging decomposition decreased from 1.35 eV to 1.02 eV after undergoing the LOCA environment. Although the mechanical property changes were discernibly observed during the aging process, along with the LOCA simulation, the FT-IR analysis showed that the spectroscopic peaks and their intensities did not alter significantly. Therefore, it can be concluded that the degradation of the domestic class 1E EPDM due to aging can be tolerable, even in severe accident conditions such as LOCA, and thus it qualifies as a suitable insulating material for electrical cables in the nuclear power plants.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.1
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• pp.1-15
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• 2008

Objective : Skin aging is commonly observed in patients with diabetes mellitus, which can be accessed by the amount of skin collagen and matrix metalloproteinase-1 (MMP-1). In the present study, anti-skin-aging effects of Root Cortex of Paeonia Suffruticosa Andrews (PSA), which has been widely used to treat diabetes mellitus, are investigated. Methods : Streptozotocin (STZ) was intraperitoneally injected to rats to induce diabetes. Body weights, feed intake, organ weights, blood glucose, and other biochemical index are determined in both normal and diabetic rats. In order to study the effect of PSA on skin aging, the amount of skin collagen was measured in diabetic rats after PSA treatments. Also, MMP-1 synthesis in UVB-irradiated human skin fibroblasts was investigated. Results : 1. When PSA was administered to STZ-induced diabetic rats, feed intake was significantly increased and blood glucose and total cholesterol were decreased in a dose-dependent manner. However, there are no differences in individual organ weights, GOT, and GPT. 2. A decrease of skin collagen in diabetic rats was significantly suppressed when PSA was treated. 3. PSA also inhibited MMP-1 synthesis in UVB-irradiated normal human skin fibroblasts, similar to retinoid, a well-known effective anti-skin-aging substance. Conclusion: PSA suppressed a collagen decrease in diabetic rats and inhibited MMP-1 synthesis in UVB-irradiated human skin fibroblasts. Therefore, the treatment of PSA is very effective to slow down the skin aging process.

• BMB Reports
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• v.57 no.5
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• pp.256-261
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• 2024

In the context of aging, the susceptibility to infectious diseases increases, leading to heightened morbidity and mortality. This phenomenon, termed immunosenescence, is characterized by dysregulation in the aging immune system, including abnormal alterations in lymphocyte composition, elevated basal inflammation, and the accumulation of senescent T cells. Such changes contribute to increased autoimmune diseases, enhanced infection severity, and reduced responsiveness to vaccines. Utilizing aging animal models becomes imperative for a comprehensive understanding of immunosenescence, given the complexity of aging as a physiological process in living organisms. Our investigation focuses on Cisd2, a causative gene for Wolfram syndrome, to elucidate on immunosenescence. Cisd2 knockout (KO) mice, serving as a model for premature aging, exhibit a shortened lifespan with early onset of aging-related features, such as decreased bone density, hair loss, depigmentation, and optic nerve degeneration. Intriguingly, we found that the Cisd2 KO mice present a higher number of neutrophils in the blood; however, isolated neutrophils from these mice display functional defects. Through mass spectrometry analysis, we identified an interaction between Cisd2 and Calnexin, a protein known for its role in protein quality control. Beyond this function, Calnexin also regulates calcium homeostasis through interaction with sarcoendoplasmic reticulum calcium transport ATPase (SERCA). Our study proposes that Cisd2 modulates calcium homeostasis via its interaction with Calnexin and SERCA, consequently influencing neutrophil functions.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.22 no.3
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• pp.36-46
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• 2009

Objective : Recently, the demands for the effective and safe depigmentating and anti-aging agents of the skin have increased due to the medical, pharmaceutical and cosmetic reasons. The aim of this study is to search new materials from the traditional herbal medicines which inhibit the aging process of skin in vitro. Methods : herbal medicines(80% ethanol or water extracts) were screened for their inhibitory activities against elastase. Results : Rheum undulatum (final concentrstion 1 mg/ml) appeared over 30% of inhibition of elastase activity. so we are investigated anti wrinkle effects of Rheum undulatum look through MMP-1 inhibition activity. also Extracts of Rheum undulatum showed higher anti tyrosinase activity than arbutin (final concentration 1 mg/ml). Conclusion : These results suggest that herbal medicines could be strong potential sources of inhibition of anti-aging and whitening effects for the skin.