• Journal of Korean Society for Quality Management
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• v.47 no.1
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• pp.187-198
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• 2019

Purpose: In this study, a reliability prediction based reliability growth management is suggested especially for the early development phase of a system and the case study of surveillance system is given. Methods: The proposed reliability prediction based reliability growth management procedures consists of 7 Steps. In Step 1, the stages for reliability growth management are classified according to the major design changes. From Step 2 to Step 5, system reliability is predicted based on reliability structures and the predicted reliabilities of subsystems (Level 2) and modules (Level 3). At each stage, by comparing the predicted system reliability with that of the previous stage, the reliability growth of the system is checked in Step 6. In Step 7, when the predicted value of sustem reliability does not satisfy the reliability goal, some design alternatives are considered and suggested to improve the system reliability. Results: The proposed reliability prediction based reliability growth management can be an efficient alternative for managing reliability growth of a system in its early development phase. The case study shows that it is applicable to weapon system such as a surveillance system. Conclusion: In this study, the procedures for a reliability prediction based reliability growth management are proposed to satisfy the reliability goal of the system efficiently. And it is expected that the use of the proposed procedures would reduce, in the test and evaluation phase, the number of corrective actions and its cost as well.

• Journal of Wetlands Research
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• v.25 no.4
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• pp.274-283
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• 2023

Buffer zones, an example of nature-based solutions, offer wide range of environmental, social and economic benefits due to their multifunctionality when applied to watershed areas promoting blue-green connectivity. This study evaluated the effects of buffer zone application to the water quality of Yongdam reservoir tributaries. Particularly, the challenges and improvement of the buffer zone design were identified and suggested, respectively. Water and soil samples were collected from a total of six sites in Yongdam reservoir from September 2021 to April 2022. Water quality analyses revealed that among the sites monitored, downstream of Sangjeonmyeon Galhyeonri (SG_W_D2) was found to have the highest concentration for water quality parameters turbidity, total suspended solids (TSS), chemical oxygen demand (COD), total phosphorus (TP) and total nitrogen (TN). This finding was attributed to the algal bloom observed during the sampling conducted in September and October 2021. It was found through the soil analyses that high TN and TP concentrations were also observed in all the agricultural land uses implying that nutrient accumulation in agricultural areas are high. Highest TN concentration was found in the agricultural area of Jeongcheonmyeon Wolpyeongri (JW_S_A) followed by Jucheonmyeon Sinyangri (JS_S_A) while the lowest TN concentration was found in the original soil of Sangjeonmyeon Galhyeonri (SG_S_O). Among the types of buffer zones identified in this study, Type II-A, Type II-B and Type III were found to have blue-green connectivity. However, initially, blue-green connectivity in these buffer zone types were not considered leading to poor design and poor performance. As such, improvement in the design considering blue-green network and renovation must be considered to optimize the performance of these buffer zones. The findings in this study is useful for designing buffer zones in the future.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.5
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• pp.650-659
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• 2013

To investigate the effects of facial blood flow rates(FBFR) and facial skin temperature(FST) generated by Gagam-Jawoonaek(GJ) application(appl.) after Miso Facial Rejuvenation Acupuncture(MFRA). Ten people in their twenties to fifties with no skin diseases were recruited. We randomly divided subjects two groups(A, B) and set the GJ appl. site(group A - right side, group B - left side). MFRA was performed on both sides of their face. Immediately after acupuncture treatment(AT treat.), GJ was applied only half of the face. We measured their FBFR using Laser Doppler Perfusion Imaging(LDPI) and FST using Digital Infrared Thermal Imaging(DITI) at pre-AT treat., immediately after AT treat., twenty and sixty minutes after GJ appl.. We analyzed data using Mann-Whitney test and Wilcoxon test(p < 0.05). After MFRA treat., FBFR on both sides increased. Twenty minutes after JW appl., the changes of FBFR on GJ appl. side($122.9{\pm}43.1PU$) were bigger than GJ non-appl. side($80.9{\pm}38.4PU$), a statistically significant decrease. Sixty minutes after application, FBFR on both sides were recovered almost at the same level as that of pre-AT treat. After MFRA treat., FST on both sides increased. Twenty minutes after GJ appl., the changes of FST on GJ appl. side($1.1{\pm}0.6^{\circ}C$) were comparable to that of GJ non-appl. side($1.2{\pm}0.5^{\circ}C$). Sixty minutes after application, FST on both sides were recovered almost at the same level as that of pre-AT treat.. Gagam-Jawoonaek could decrease facial blood flow rates.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.11
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• pp.4705-4710
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• 2015

Background: Though a large proportion of cancer survivors are assumed to be commonly affected by sleep disturbance, few studies have focused on short sleep problems and its correlates among Korean cancer survivors. The purpose of this study was to evaluate the prevalence of short sleep in adult cancer survivors from a nationwide population-based sample and to identify risk factors for short sleep duration. Materials and Methods: Based on the fourth and fifth Korea National Health and Nutrition Examination Surveys (2007-2012), 1,045 cancer survivors and 33,929 non-cancer controls were analyzed. The prevalence of short sleep was compared between these two groups. Associations between short sleep and its correlates were evaluated using multiple logistic regression among cancer survivors: odds ratios (ORs) and 95% confidence intervals (95%CIs) were estimated after adjusting for sociodemographic factors, lifestyle factors, psychological conditions, and cancer-related factors. Results: About 8.1% of cancer survivors slept for less than 5 hours per day (6.2% men and 9.3% women), whereas this was the case for only 3.7% of non-cancer controls. Cancer survivors who had the lowest household income level showed a significantly higher likelihood for short sleep (adjusted OR 2.82, 95%CI 1.06-7.54). Self-reported poor health and depressive symptoms were found to be associated with significantly increased likelihood for short sleep in cancer survivors (adjusted OR 3.60, 95%CI 1.40-9.26 and adjusted OR 2.00, 95%CI 1.17-3.42). Gastric cancer survivors had a 3.97-fold increased risk for short sleep (95%CI 1.60-9.90). Conclusions: The prevalence of short sleep occurs at a high rate among the Korean cancer survivors, which may indicate a poorer quality of life and a higher risk of future complications in survivorship. Targeted interventions that can assist cancer survivors to cope with sleep disturbances as well as ensuring psychological stability are warranted to reduce the latent disease burden.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.3
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• pp.233-240
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• 2014

An in vitro study on cariogenic potential of four over-the-counter nutritional supplements for children was performed. The experimental groups were four over-the-counter nutritional supplements. The positive control group was 10% sucrose solution (S), and the negative control group was artificial saliva (T). The pH of each group, the buffering capacities, acid production, the microhardness changes of the bovine teeth specimens were measured. The pH of all experimental groups were lower than critical pH 5.5 where enamel demineralization starts. The buffering capacity of the Hama Vitamin Pharm (Hamsoa Pharm Co., Korea) was highest, and the Smart Chewable Vitamin A (JW Pharm Co., Korea) had the lowest buffering capacity. The reduction rates of the pH of the experimental groups were significantly higher than that of the negative control group (p < 0.05). The microhardness of enamel of all experimental groups and the positive control group significantly decreased. In contrast, the microhardness of enamel of the negative control group significantly increased after experiment (p < 0.05). The reduction rate of the microhardness of enamel of the Hama Vitamin Pharm (Hamsoa Pharm Co., Korea) was significantly higher and Hikid Plus (Sanga Pharm Co., Korea) was significantly lower than the other experimental groups.

• KSBB Journal
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• v.10 no.5
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• pp.475-481
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• 1995

The effect of metallothionein expression on the metal resistance and removal by recombinant Saccharomyces cerevisiae containing the plasmid pJW9 was investigated. The recombinant strain S. cerevisiae BZ-pJ was constructed by transforming the host strain S. cerevisiae BZ3l-1-7Ba with the gene coding for a metal-binding protein, metallothionein. Introduction of the MT gene yielded an increase in the minimum inhibitory concentration (MIC) of copper more than three times compared with the host strain. The minimum inhibitory concentrations of $Cr^{2+}, Znr^{2+} and Pb^{2+}, $ were not different for the two strains. The recombinant yeast grown in a medium containing 8mM CuSO4 was able to remove copper with a capacity of 18.9mg $Cu^{2+}$/g dry cell. In a mixture of copper and zinc, the presence of copper relieved the toxic effects caused by zinc, resulting in an enhancement of the final cell density and the specific growth rate of the recombinant yeast. The capability to remove copper by the recombinant yeast was linearly proportional to the copper concentrations in the medium. The efficiency of copper removal was rather constant regardless of the initial copper concentrations. The specific removal of zinc was dependent on the zinc concentrations in media, though, and such dependence was not so pronounced as the concentration of copper.

• Nutrition Research and Practice
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• v.12 no.3
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• pp.258-264
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• 2018

BACKGROUND/OBJECTIVES: Diet quality scores or indices, based on dietary guidelines, are used to summarize dietary intake into a single numeric variable. The aim of this study was to examine the association between the modified diet quality index for Koreans (DQI-K) and mortality among Health Examinees-Gem (HEXA-G) study participants. SUBJECTS/METHODS: The DQI-K was modified from the original diet quality index. A total of 134,547 participants (45,207 men and 89,340 women) from the HEXA-G study (2004 and 2013) were included. The DQI-K is based on eight components: 1) daily protein intake, 2) percent of energy from fat, 3) percent of energy from saturated fat, 4) daily cholesterol intake, 5) daily whole-grain intake, 6) daily fruit intake, 7) daily vegetable intake, and 8) daily sodium intake. The association between all-cause mortality and the DQI-K was examined using Cox proportional hazard regression models. Hazard ratios and confidence intervals were estimated after adjusting for age, gender, income, smoking status, alcohol drinking, body mass index, and total energy intake. RESULTS: The total DQI-K score was calculated by summing the scores of the eight components (range 0-9). In the multivariable adjusted models, with good diet quality (score 0-4) as a reference, poor diet quality (score 5-9) was associated with an increased risk of all-cause mortality (hazard ratios = 1.23, 95% confidence intervals = 1.06-1.43). Moreover, a one-unit increase in DQI-K score resulted in a 6% higher mortality risk. CONCLUSIONS: A poor diet quality DQI-K score was associated with an increased risk of mortality. The DQI-K in the present study may be used to assess the diet quality of Korean adults.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.482-488
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• 2022

In this study, the durability of ultra rapid hardening mortar for sewage pipe was evaluated by type of mortar binder. As a result of analyzing the internal structure for each type of mortar, it was confirmed that Al₂(OH)₃ was generated in the internal structure of the CAC-based mortar, and its corrosion resistance was superior to that of other types of mortar. As a result of the compressive strength test, OPC had the tsmallest strength, followed by CAC100 > CAC100P > CAC80. This trend was similar to the previous study results. Chloride ion penetration resistance and freeze-thaw test showed similar trends. That is, CAC and C12A7 were better than OPC, and CSA was worse than OPC. This is mostly beacuse of cracks caused by expansion of CSA-based mortar. CAC100P mix showed the best chemical resistance. It is thought that this is because the alumina gel formed inside the mortar and the polymer combine to make the internal structure more dense.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.62-69
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• 2023

Re-damage is frequently occurring for various reasons, including material factors, external factors, and factors caused by poor construction in concrete cross-section restoration work, so it is necessary to identify the cause and improve it. Cement-based materials are the most commonly used maintenance materials for concrete structures, and in particular, additional cross-sectional restoration work may be carried out due to re-damage such as cracks and excitement due to dry contraction of the repair material. In this study, a basic study was conducted to identify the characteristics of concrete while diversifying the maximum dimensions and assembly rate of thick aggregates to examine the effects of using thick aggregates in repair materials. As a result, the slump of concrete increased as the maximum size of thick aggregates increased, and the amount of air content was measured 1.88 to 2.35 times higher in the mixing using aggregates with a maximum aggregate size of 5 mm or more compared to the mixing group with a maximum aggregate size of 10 mm or more. It was found that compressive strength was greatly affected by the performance rate of thick aggregates. The compressive strength was measured the highest in the mixture using thick aggregates with the highest performance rate of 20 mm, and the compressive strength of the mixture with the lowest performance rate was more than 45%. As a result of the dry shrinkage measurement, the dry shrinkage was the lowest as the performance rate of the thick aggregate increased according to the change in the maximum dimensions and assembly rate of the thick aggregate, and the lowest performance rate was the largest in the mix. Through this study, it was confirmed that adjusting the particle size by diversifying the maximum dimensions and assembly rate of thick aggregates used in concrete structure repair materials can improve strength and workability and reduce dry shrinkage.

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.193-201
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• 2016

This study was carried out to analyze the nutritional composition, bioactive components, antioxidant activity, and cytotoxic assay of cancer cells on Rubus crataegifolius (RC) : R. crataegifolius from Jangseong (RC-J), R. crataegifolius from Hwaseong (RC-H), R. crataegifolius from Ulsan (RC-U), R. crataegifolius from Sunchang (RC-S), and R. crataegifolius from Pohang (RC-P). The peroximate composition had the largest amount of carbohydrate content among all kinds of RC. As far as the mineral contents of RC, Calcium comprised the highest amount ($996.6{\mu}g/g{\pm}0.8%$) and Natrium the lowest ($6.2{\mu}g/g{\pm}1.0%$). A total of 26 kinds of free amino acids and 18 kinds of component amino acids were analyzed in RC. The results of electron donating were high scavenging effects of 80% in water extract (RC-UW) and 82.6% in ethanol extract (RC-UE) in $500{\mu}g/ml$ concentration from RC-U. Also, the cytotoxic effects of cancer cells B16F10 (RC-UW and RC-PE), H1299 (RC-SW and RC-PE), and MCF-7 (RC-JW and RC-SE) appeared in RC. Therefore, we confirmed that new varieties may possibly be developed with functional materials.