• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.1006-1013
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• 2002

The multiplicity of operating systems brings about a choice problem to the end-user and a multi-fold intensity to the competing developer. This study intends to provide guidelines solving the problems for both the end-user and the developers of operating systems. For the purpose, we adopt an appropriate evaluation model in terms of user-perceived quality through the applicable criteria and an evaluation method. Briefly, reliability and portability are key factors to contribute to the perceived duality. The empirical study also illustrates a comparative analysis on the dominant products. Microsoft Windows and Linux, in Korea.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.357-364
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• 1997

After the buyer purchases the product, the seller's role does not end. If the product fails to function properly before the end of the warranty period, the seller is responsible for its repair or replacement under the seller's warranty policy. There are two common types of warranty policies: the free replacement warranty and the rebate warranty. Under the free replacement warranty policy, replacement or repairs during the warranty period are provided by the seller free of charge to the buyer. Under the rebate warranty policy, a failed item is replaced by a new one or is repaired at a cost to the age of the failed item. The rebate warranty is most often used for items such as a battery or an automobile tire which wear out and must be replaced at failure. This paper proposes a easy way of estimating the warranty cost under the free replacement warranty policy assuming an exponential product failure function on repairable products.

• Journal of Korean Society for Quality Management
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• v.27 no.1
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• pp.195-210
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• 1999

The multiplicity of software packages brings about a choice problem to the end-user and a multi-fold intensity to the competing developer. This study intends to provide guidelines solving the problems for both the end-user and the developer of packages for automatic statistical analyses. For the purpose, we adopt an appropriate evaluation model in terms of user-perceived quality through the applicable criteria and an evaluation method. The result of empirical study is described, which shows that the weight of each criterion is dynamic along usage levels. Briefly, functionality, usability, and reliability are key factors to contribute to the perceived quality. The empirical study also illustrates a comparative analysis on the dominant products, SAS and SPSS, in Korea.

• Fisheries and Aquatic Sciences
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• v.25 no.10
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• pp.517-524
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• 2022

Over production of methylglyoxal (MGO) a highly reactive dicarbonyl compound, has been associated in progressive diabetes with vascular complication. Therefore, we investigated whether hot water extract of Loliolus beka meat (LBM-HWE) presents a preserve effect against MGO-induced cellular damage in human umbilical vein endothelial cells (HUVECs). The LBM-HWE extract showed to inhibit MGO-induced cytotoxicity. Additionally, the LBM-HWE reduced mRNA expression of pro-inflammatory cytokines, and reduced MGO-induced advanced glycation end product (AGEs) formation. Furthermore, LBM-HWE induced glyoxalase-1 mRNA expression and reduced MGO-induced carbonyl protein formation in HUVECs. The results implicate that LBM-HWE has protective ability against MGO-induced HUVECs toxicity by preventing AGEs formation. In conclusion, LBM-HWE could be used as a potential treatment material for the prevention of vascular complications of diabetes.

• Analytical Science and Technology
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• v.35 no.1
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• pp.8-14
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• 2022

Many studies have shown that advanced glycation end-products (AGEs) and glycation adducts are significantly linked to aging and disease. Particularly, the level of glycation in human milk is important because the AGE intake is closely related to AGE levels in infants. In this study, we used human milk samples obtained from four primiparae and four multiparae. We isolated proteins using acetone and trichloroacetic acid (TCA) precipitation. A total of 67 glycated proteins and 122 glycated peptides was quantified; among them, 19 glycated peptides were differentially expressed. We confirmed that the degree of glycation differed according to fertility. The study provides a foundation for using proteomics to evaluate the mother's milk quality and link between maternal health and human milk quality.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.179-186
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• 1998

Dextransucrase hyper-producing Leuconostoc mesenteroides B-512FMCM and dextransucrase constitutive mutants B-742CB and B-1355C catalyzed the transfer of glucose from sucrose to other carbohydrates which were present or were added to the reaction digests. When the acceptor was a maltose, gentiobiose, lactose or raffinose, there was produced a series of oligosaccharide acceptor products or single product based on the kinds of enzymes and reaction conditions. To obtain the quantitative information about the yield and the distribution of acceptor products and dextran two experimental parameters were studied: a) the ratio of acceptor to sucrose and b) the amount of enzyme at constant carbohydrate concentration (100 mM). As the amount of enzyme increased, the synthesis of acceptor products (of maltose or gentiobiose) increased, and the formation of dextran decreased. As the ratio of acceptor to sucrose increased, the amount of dextran and the number of acceptor-products decreased and the amount of acceptor-products increased. When maltose or gentiobiose was an acceptor, the glucose from sucrose was transferred to the C-6 hydroxyl group of the nonreducing-end glucose residue of accepters to give a homologous series of isomaltosyl dextrins. In case of lactose or raffinose, there was produced only one acceptor product from B-512FMCM dextransucrase reaction. In the lactose acceptor reaction, the glucose from sucrose was transferred to the C-2 hydroxyl of the reducing end glucose residue of lactose. To get a series of oligosaccharides from lactose or raffinose acceptor reaction we used B-742CB dextransucrase or B-1355C alternansucrase with 500 mM sucrose in reaction digest.

• Korean Journal of Pharmacognosy
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• v.37 no.2 s.145
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• pp.103-109
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• 2006

Advanced glycation end products (AGEs) formation plays an important role in the progression of diabetic complications. To develop effective herbal formulations with suppression of diabetic nephropathy, a common complication in diabetic patients, we evaluated inhibitory activities of KIOM-79, a new herbal prescription, on the formation of AGEs using in vitro and in vivo model systems. Effects of KIOM-79 on the expression of AGEs, RAGEs (receptor for Advanced glycation end products), type IV collagen and renal $TGF-{\beta}1$ mRNA was also examined in streptozotocon (STZ)-induced diabetic rats. STZ-induced diabetic rats were treated orally with KIOM-79 (250 and $500\;kg^{-1}$ once a day for 13 weeks). In vitro system KIOM-79 suppressed the formation of AGEs $(18.12\;{\mu}g/ml)$. In STZ-induced diabetic rats showing accumulation of AGE and RAGE, pathological examination revealed that KIOM-79 prevented AGE and RAGE deposition in the kidney. In STZ induced diabetic rats, the expansion of mesangial matrix and the glomerular tufts seemed to be larger than those in normal rats. Howεver, after administration with KIOM-79, mesangial metrix and glomerular volume were decreased, and overexpression of type IV collagen was also decreased. Overexpression of renal $TGF-{\beta}1$ mRNA was inhibited significantly. These results suggest that the KIOM-79 might be an effective herbal prescription to prevent or alleviate the progression of diabetic nephropathy.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.2
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• pp.147-153
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• 2021

Collagen hydrolysate (CH) is known to prevent skin aging by stimulating skin dermal fibroblasts to promote synthesis of extracellular matrix such as collagen and elastin. Recently, among the various factors that cause skin aging, advanced glycation end products (AGEs) have received particular attention. However, the effect of CH on AGE accumulation has not been studied. Since CH could affect AGE accumulation by promoting production of skin structural proteins, clinical trial was performed using low molecule collagen peptide (LMCP), which were CH containing 25% tripeptide and 4% Gly-Pro-Hyp. Skin autofluorescence (SAF) values were measured using an AGE reader to evaluate accumulation of AGE in skin. As a result of applying 0.5% and 1.0% LMCP solutions to the subject's forearm for 8 weeks, the SAF value at the test site significantly decreased compared to the control site. Additionally, in vitro test was performed using CCD-986sk to evaluate the promotion of collagen synthesis in skin fibroblasts by LMCP. As a result, 800 ㎍/mL of LMCP significantly increased synthesis of human pro-collagen Iα1 (COL1A1) in CCD-986sk. Through this study, we have confirmed that tropical LMCP applications can promote collagen synthesis to help anti-glycation effects, suggesting that LMCP has potential as an anti-aging cosmetic material.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.6
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• pp.445-453
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• 2021

Objectives: Periodontitis is the most common chronic disease that causes tooth loss and is related to systemic diseases such as cardiovascular disease and diabetes. An objective indicator of the current activity of periodontitis is necessary. Soluble forms of the receptor for advanced glycation end products (sRAGE) are markers that reflect the status of inflammatory diseases. In this study, the relationship between sRAGE and periodontitis was analyzed to determine whether it can be used to diagnose the current state of periodontitis. Patients and Methods: Eighty-four patients without any systemic diseases were diagnosed with periodontitis using three classifications of periodontitis. Demographics and oral examination data such as plaque index (PI), bleeding on probing (BOP) index, and probing pocket depth (PPD) were analyzed according to each classification. In addition, correlation and partial correlation between sRAGE and the values indicating periodontitis were analyzed. Results: In each classification, the level of sRAGE tended to decrease if periodontitis was present or severe, but this change was not statistically significant. sRAGE and periodontitis-related variables exhibited a weak correlation, among which the BOP index showed a relatively strong negative correlation (ρ=-0.20). Based on this, on analyzing the correlation between the BOP index and sRAGE in the group with more severe periodontitis (PPD≥5 mm group, severe group of AAP/CDC [American Academy of Periodontology/Centers for Disease Control and Prevention], periodontitis group of López), the correlation further increased (ρ=-0.23, -0.40, -0.50). Partial correlation analysis of the sRAGE and BOP index showed a stronger negative correlation (ρ=-0.36, -0.55, -0.45). Conclusion: sRAGE demonstrated a tendency to decrease upon increased severity of periodontitis according to the classifications used. Above all, the correlation with the BOP index, which reflects the current state of periodontitis, was higher in the group with severe periodontitis. This indicates that the current status of periodontitis can be diagnosed through sRAGE.

• Journal of Nutrition and Health
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• v.55 no.3
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• pp.348-358
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• 2022

Purpose: Hyperglycemia accelerates the formation of advanced glycation end products (AGEs), a group of compounds formed via non-enzymatic glycation/glycoxidation. Type 2 diabetes mellitus (T2DM) is related to oxidative stress, resulting in some overgeneration of AGEs. The accumulation of AGEs in T2DM patients leads to increased inflammation, DNA damage, tissue damage, progression of diabetic microvascular disease, and nephropathy. Heme oxygenase-1 (HO-1) is an intracellular enzyme that catalyzes the oxidation of heme. Expression of HO-1 in the endothelium and in muscle monocytes/macrophages was upregulated upon exposure to reactive oxygen species or oxidized low-density lipoprotein. Cells activated by oxidative stress are reported to release HO-1 in the serum. In the current study, we discuss the oxidative status according to the level of AGEs and the association of HO-1 with AGEs or urinary DNA damage marker in type 2 diabetic Korean patients. Methods: This study enrolled 36 diabetic patients. Subjects were classified into two groups by serum AGEs level (Low AGEs group: < 0.85 ng/mL serum AGEs; High AGEs group: ≥ 0.85 ng/mL serum AGEs). Body composition was measured using bioelectrical impedance analysis. Blood and urinary parameters were measured using commercial kits. Results: No significant differences were observed in the general characteristics and body composition between the two groups. Serum HO-1 concentration was significantly higher in the High AGEs group than in the Low AGEs group. After adjustment of age and gender, a correlation was performed to assess the association between serum HO-1 and serum AGEs or urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG). Our results indicate that serum HO-1 is positively correlated with serum AGEs and urinary 8-OHdG. Conclusion: Taken together, our results indicate that in diabetes patients, a high level of HO-1 is associated with a high concentration of AGEs and 8-OHdG, probably reflecting a protective response against oxidative stress.