• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.568-576
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• 2017

As interest in functionality and environmentally friendly cosmetics is growing in recent years, materials that use safe and effective plant extracts have been developed. Therefore, this study also attempted to check the possibility of the graviola extract, which is known to have various efficacy mainly as a health functional material as a functional cosmetic material. In order to find out the antioxidant activity of graviola, we measured total polyphenol, total flavonoid content and DPPH radical scavenging activity and measured the ROS activity inhibition effect and cytoprotective effect on oxidative stress by treating HDF with hydrogen peroxide cells at an appropriate concentration after checking cytotoxicity in HDF cells. Based on the results of this experiment, the graviola extract was found to contain as high as 26.6 mg(CA)/100g, 14.3 mg(Q)/100g of total polyphenol and flavonoid, which are the antioxidant indexes and to have the high radical scavenging activity. The cell survival rate of the HDF cells was measured, and as a result, no significant cytotoxicity was observed at all concentrations and the experiment was carried out at a concentration of $100{\mu}g/mL$ afterwards. Inhibition of ROS activity in HDF cells induced by hydrogen peroxide was measured and the concentration-dependent inhibition of ROS activity was found and the cell protection effect of graviola was measured after hydrogen peroxide was treated for 4, 24 and 48 hours. As a result, the cell protection effect as high as 89.92% was confirmed at a $25{\mu}g/mL$ concentration up to 24 hours. As these results show that the graviola extract has excellent antioxidant activity, almost no toxicity to HDF cells, an effective activity inhibitory effect on active oxygen generated by hydrogen peroxide and excellent cytoprotective effect, the possibility as various functional materials with antioxidant and cytoprotective effects was confirmed.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.2
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• pp.13-19
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• 2019

Purpose Tc-99m HMPAO is widely used radiopharmaceutical for brain perfusion SPECT. Tc-99m HMPAO is chemically unstable and is liable to show deterioration of labeling efficiency due to high incidence of secondary Tc-99m HMPAO complex, free pertechnetate and reduced-hydrolyzed Tc-99m. In this study, we investigated whether sialogogues administration could reduce the impurities of Tc-99m HMPAO. Materials and Methods In thirty subjects(20 male and 10 female, age range 19~89 years, mean age $60.7{\pm}14.5years$), brain perfusion SPECT were performed at basal and citric acid stimulation states consecutively after injection of 555 MBq of Tc-99m HMPAO. In the salivary glands, the uptake coefficient was calculated using Siemens processing program. Statistical comparison between before and after the citric acid stimulation performed paired t-test. P value less than 0.05 was regarded as statistically significant. Results Salivary glands uptake was $12900{\pm}3101$ counts in basal and $10677{\pm}2742$ counts in citric acid stimulation states. Unnecessary impurities in the body is much decreased after citric acid administration(t=10.78, P<0.05). The image quality was much improved after administration of citric acid and the regional cerebral perfusion was clearly from demarcated the background. Conclusion The impurity is distributed throughout the body particularly in the salivary glands and nasal mucosa when Tc-99m HMPAO brain perfusion SPECT is performed. If this impurities is not removed, the quality of the image may deteriorate, resulting in errors in visual evaluation. The use of sialogogues could be helpful for decreasing unnecessary impurities in the body.

• Journal of Science and Technology Studies
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• v.19 no.3
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• pp.247-289
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• 2019

By examining the experiences of three social economy organizations who participated in the social problem-solving R&D projects, we discuss the conditions which may encourage the participation of civil society in national R&D programs in South Korea. By calling for the inclusion of social economy organizations along with the living-lab, the social problem-solving R&D projects introduced a new type of civic participation in the national R&D programs. It is the requirement in the RFP of the social problem-solving R&D which led PIs to inviting social economy organizations into their projects. But the invites occurred rather abruptly and accidently without adequate mutual understanding between scientific experts and social economy organizations. While helping social economy organizations participate in R&D processes, this form of institutional arrangement also led them into a position in subordination to scientific experts. Social economy organizations were supposed to coordinate the living lab in the social problem-solving R&D projects which they felt familiar as an extension of what they have been doing. In contrast, they felt administrative work such as accounts following complicate administrative rules as the most unfamiliar challenge. The difference in their emphases between scientific experts and social economy organizations was also evident. Social economy organizations viewed that, while they and ordinary people are primarily interested in a practical use of the developed products or services, scientific experts tend to focus on research and development. Not only did such difference produce a friction in the R&D processes but also it had social economy organizations view the R&D projects they participated in as unsuccessful. Nevertheless, all these experiences provided a great opportunity for the social economy organizations for learning and growing as a new actor in the national R&D.

• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.642-651
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• 2013

This study sought to evaluate the daily intakes of sodium saccharin and sucralose for individuals in Korea with average and high levels of consumption of both these substances. The estimated daily intake of both sweeteners was determined from analytical data and dietary intake data collected as part of the Korean National Health and Nutrition Survey. Analysis of the data showed that sodium saccharin was found in 53 (15.6%) of 339 processed foods analyzed, whereas sucralose was found in 141 (23.9%) of 590 processed foods analyzed. The average intake of sodium saccharin was 1.18% of the acceptable daily intake (ADI) defined by the Joint FAO/WHO Expert committee on Food Additives (JECFA). The average intake of sucralose was 0.55% of ADI. The 95th percentile intakes of sodium saccharin and sucralose were 5.29% and 15.66% of ADI, respectively. Children 6 years old and younger consumed more sodium saccharin and sucralose than did children from any of the other age groups tested. In conclusion, the average daily intakes of sodium saccharin and sucralose within members of the Korean population fall within safe levels.

• The Journal of the Convergence on Culture Technology
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• v.10 no.5
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• pp.367-372
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• 2024

It was intended to explore the relationship between motivation for participation in hair education, program satisfaction, and lifelong learning happiness index for adult learners at the Lifelong Education Center, and to provide basic data for revitalizing lifelong education programs. Today, universities have conditions as a comprehensive educational institution with practicality that can meet various and high-quality lifelong educational needs. The university-affiliated Lifelong Education Center plays a role in ensuring the right to learn for all citizens as well as fulfilling the social service function and greatly expanding educational opportunities, which is one of the essential functions of universities, by making good use of the excellent transfer material resources of universities. Adults should now seek professional self-identity through retraining, and respond flexibly to various social situations such as increasing roles, expanding responsibility, and uncertainty in the job and employment structure toward professional socialization in the professional world The subject of the study was to collect data by distributing 90 questionnaires to adult learner hair education subjects in G area, and 85 copies were finally used for SPSS 26.0 for Windows analysis, excluding questionnaires with insufficient responses. The survey period was from November 1 to December 27, 2023. First, it was found that adult learners' motivation to participate in hair education has an effect on the lifelong learning happiness index. Second, it was found that adult learners' satisfaction with the program of hair care workers has an effect on the lifelong learning happiness index. Through this study, it is judged that it is necessary to understand what can maximize the high lifelong learning happiness index, and to meet the learning needs of modern people living in the age of 100, increase their potential, help them design a second life, contribute to self-realization and society, and help them have steady, self-directed lifelong learning opportunities.

• Korean Journal of Heritage: History & Science
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• v.40
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• pp.357-386
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• 2007

At present, thirteen Buddhist bells of Unified Silla are known to the world: Six in Korea, five in Japan and two other bells, and three out of them are impossible to make out its original form. Therefore, we divided the form of Unified Silla Buddhist bells based on the ten other bells, and we tried out to prove the manufacturing technology by the comparison of the research material of Uncheon-dong bell and existing research materials of other bells, in other to find their linkage based on the alloy elemental composition. We divided Unified Silla Buddhist bell into two types: Type I has symmetric apsaras and regular patterns on its face and it was made in early Silla period; type II has asymmetric apsaras and irregular pattern arrangement and made in late Silla period. In particular, Uncheon-dong Buddhist bells is very similar to Komyoji[光明寺] temple bell from ninth century in Japan. It is peculiar that the apsaras on Uncheon-dong bell play vertical music instruments that are never seen in Unified Silla Buddhist bell. Most of Unified Silla Buddhist bell are compounded with Cu-Sn or Cu-Sn-Pb system. From eighth and ninth century, bells were cast with even composition of copper, tin and lead, and the bronze alloy ratio was similar to the record in Gogonggi[考工記], Jurye[周禮], a book from ancient China. Particularly, Uncheon-dong bell is in a rare case of Cu-Sn-Pb-As system. As had been rarely used in Unified Silla Buddhist bells, so we presented the relative research materials. As has the same nature as Pb. Because As easily volatilize at high temperature, it is hard to use. But it has its merit of solidity and durability. Pb enhances fluidity and thereby expresses the patterns more distinct; As makes the bell stronger. The result of lead isotope ratio could not exactly reveal a concrete producing center. However, over the analysis of our samples, hereby we suggest Uncheon-dong bell was made of materials from just one ore deposit.

• Journal of Korea Game Society
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• v.4 no.4
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• pp.11-18
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• 2004

The on-line games in the past were played by only two persons exchanging data based on one-to-one connections, whereas recent ones (e.g. MMORPG: Massively Multi-player Online Role-playings Game) enable tens of thousands of people to be connected simultaneously. Specifically, Korea has established an excellent network infrastructure that can't be found anywhere in the world. Almost every household has a high-speed Internet access. What made this possible was, in part, high density of population that has accelerated the formation of good Internet infrastructure. However, this rapid increase in the use of on-line games may lead to surging traffics exceeding the limited Internet communication capacity so that the connection to the games is unstable or the server fails. expanding the servers though this measure is very costly could solve this problem. To deal with this problem, the present study proposes the load distribution technology that connects in the form of local clustering the game servers divided by their contents used in each on-line game reduces the loads of specific servers using the load balancer, and enhances performance of sewer for their efficient operation. In this paper, a cluster system is proposed where each Game server in the system has different contents service and loads are distributed efficiently using the game server resource information such as CPU utilization. Game sewers having different contents are mutually connected and managed with a network file system to maintain information consistency required to support resource information updates, deletions, and additions. Simulation studies show that our method performs better than other traditional methods. In terms of response time, our method shows shorter latency than RR (Round Robin) and LC (Least Connection) by about 12%, 10% respectively.

• Clean Technology
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• v.30 no.2
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• pp.134-144
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• 2024

In this study, the mechanical stability of red mud was improved for its commercial use as a catalyst to effectively decompose HFC-134a, one of the seven major greenhouse gases. Red mud is an industrial waste discharged from aluminum production, but it can be used for the decomposition of HFC-134a. Red mud can be manufactured into a catalyst via the crushing-preparative-compression molding-firing process, and it is possible to improve the catalyst performance and secure mechanical stability through calcination. In order to determine the optimal heat treatment conditions, pellet-shaped compressed red mud samples were calcined at 300, 600, 800 ℃ using a muffle furnace for 5 hours. The mechanical stability was confirmed by the weight loss rate before and after ultra-sonication after the catalyst was immersed in distilled water. The catalyst calcined at 800 ℃ (RM 800) was found to have the best mechanical stability as well as the most catalytic activity. The catalyst performance and durability tests that were performed for 100 hours using the RM 800 catalyst showed thatmore than 99% of 1 mol% HFC-134a was degraded at 650 ℃, and no degradation in catalytic activity was observed. XRD analysis showed tri-calcium aluminate and gehlenite crystalline phases, which enhance mechanical strength and catalytic activity due to the interaction of Ca, Si, and Al after heat treatment at 800 ℃. SEM/EDS analysis of the durability tested catalysts showed no losses in active substances or shape changes due to HFC-134a abasement. Through this research, it is expected that red mud can be commercialized as a catalyst for waste refrigerant treatment due to its high economic feasibility, high decomposition efficiency and mechanical stability.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.25 no.3
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• pp.79-87
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• 2019

The degree of cosmetic's oxidation depends on the storage conditions and external conditions when using the product. The microbial contamination and oxygen exposure often results in the quality deterioration of cosmetics. In addition, the problem is that consumers often use cream-type cosmetics, which have short expiration period (6-12 months), even after the product is expired. When using the deteriorated cosmetics, it can be fatal to consumers' safety including some symptoms such as folliculitis, rashes, edema, and dermatitis. Therefore, it is necessary to develop sealed smart packaging for cosmetics to prevent the deterioration of cosmetics and improve consumer safety. In this study, we have developed smart packaging design for cosmetics that can measure the surrounding environment and expiration date for the cosmetics in the real time. In addition, the smart packaging includes sensor, which are linked to the mobile application. Users can find out the measurement results through the application. Also, the packaging design and functions were set up based on the survey results by the user and feasible model can be produced based on user choice. The measurement in the three environment has been done after manufactured the sensor, PCB, and mobile application. As a result, it works normally within a certain range under all three environmental conditions. It is believed that the information on expiration dates and storage environment can be efficiently delivered to the consumers through developed cosmetics smart packaging and applications. The development of UI/UX design for consumer is further studied. The UX/UI design of the application plays an essential role in achieving this goal through the commercialization the cosmetic products in the wide range.

• Journal of Technology Innovation
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• v.17 no.2
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• pp.1-23
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• 2009

The Survey on the Industrial Research and Development(R&D) is the primary source of information on R&D performed by Korea industrial sector. The results of the survey are used to assess trends in R&D expenditures. Government agencies, corporations, and research organizations use the data to investigate productivity determinants, formulate tax policy, and compare individual company performance with industry averages. Recently, Korea Industrial Technology Association(KOITA) has collected the data by complete enumeration. Koita has, currently, considered sample survey because the number of R&D institutions in industry has been dramatically increased. This study develops survey design for the industrial research and development(R&D) statistics by introducing a sample survey. Companies are divided into 8 groups according to the amount of R&D expenditures and firm size or type. We collect the sample from 24 or 8 sampling strata and compare the results with those of complete enumeration survey. The estimates from 24 sampling strata are not significantly different to the results of complete enumeration survey. We propose the survey design as follows: Companies are divided into 11 groups including the companies of which R&D expenditures are unknown. All large companies are included in the survey and medium and small companies are sampled from 70% and 3%. Simple random sampling (SRS) is applied to the small company partition since they show uniform distribution in R&D expenditures. The independent probability proportionate to size (PPS) sampling procedure may be applied to those companies identified as 'not R&D performers'. When respondents do not provide the requested information, estimates for the missing data are made using imputation algorithms. In the future study, new key variables should be developed in survey questionnaires.