• Journal of Christian Education in Korea
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• v.69
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• pp.77-104
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• 2022

The purpose of this study was to investigate the research trend of forest play. The purpose of this study is to provide basic data for the vitalization of forest play research by analyzing the research period, research content, and research methods. For this study, 57 domestic master's and doctoral dissertations were extracted through the National Assembly Library and the Research Information Sharing Service(RISS) with the keywords of 'forest', 'play', and 'forest play'. The frequency and percentage were calculated by analyzing forest play research based on four criteria: research period, research content, research method, and research subject. As a result of the research, first, the trend of forest play research by period is from 2011 to 2021, with 49 articles (85.9%) for master's degrees and 8 articles (14.1%) for doctor's degrees. Second, the trend by research content was found to be 16 basic studies (28.1%) and 41 practical studies (71.9%). Forest play research is being actively conducted centered on practical research. Third, the trends by research method were in the order of 39 quantitative studies (68.4%), 17 qualitative studies (29.8%), and 1 literature study (1.8%). Forest play research is focused on quantitative research, and comparatively qualitative research and literature research account for a low proportion. Fourth, the trend by study subject was 56 single subject studies (98.2%). The single subjects were 52 children (91.2%), 3 teachers (5.2%), and 1 parent (1.8%). As for the mixed subjects, there is one study (1.8%) targeting children and parents, and it is necessary to conduct a study with mixed subjects. As for the study of material subjects, 42 articles (73.7%) in the natural environment, 13 articles (22.8%) in educational institutions, and 2 articles (3.5%) in the media were found in the order. Research on the home environment related to forest play is insufficient, so research on parents, children-parents, and home environment related to forest play should be conducted in the future.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.85-103
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• 2023

The in-situ remediation of a solidified stratum containing a large amount of fine-texture material like clay or organic matter in contaminated soil faces limitations such as increased remediation cost resulting from decreased purification efficiency. Even if the soil conditions are good, remediation generally requires a long time to complete because of non-uniform soil properties and low permeability. This study assessed the remediation effect and evaluated the field applicability of a methodology that combines pneumatic fracturing, vacuum extraction, and plasma blasting (the PPV method) to improve the limitations facing existing underground remediation methods. For comparison, underground remediation was performed over 80 days using the experimental PPV method and chemical oxidation (the control method). The control group showed no decrease in the degree of contamination due to the poor delivery of the soil remediation agent, whereas the PPV method clearly reduced the degree of contamination during the remediation period. Remediation effect, as assessed by the reduction of the highest TPH (Total Petroleum Hydrocarbons) concentration by distance from the injection well, was uncleared in the control group, whereas the PPV method showed a remediation effect of 62.6% within a 1 m radius of the injection well radius, 90.1% within 1.1~2.0 m, and 92.1% within 2.1~3.0 m. When evaluating the remediation efficiency by considering the average rate of TPH concentration reduction by distance from the injection well, the control group was not clear; in contrast, the PPV method showed 53.6% remediation effect within 1 m of the injection well, 82.4% within 1.1~2.0 m, and 68.7% within 2.1~3.0 m. Both ways of considering purification efficiency (based on changes in TPH maximum and average contamination concentration) found the PPV method to increase the remediation effect by 149.0~184.8% compared with the control group; its average increase in remediation effect was ~167%. The time taken to reduce contamination by 80% of the initial concentration was evaluated by deriving a correlation equation through analysis of the TPH concentration: the PPV method could reduce the purification time by 184.4% compared with chemical oxidation. However, the present evaluation of a single site cannot be equally applied to all strata, so additional research is necessary to explore more clearly the proposed method's effect.

• Korean Journal of Plant Resources
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• v.36 no.2
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• pp.107-121
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• 2023

This study analyzed the polyphenol, flavonoid contents, antioxidant activity, anti-aging activity and phenol component contents of Saccharina japonica (SJ), Costaria costata (CC) extracts with hot water, 95% methanol, 95% prethanol for investigating possible utilization of SJ and CC extracts. The result revealed that the SJ and CC methanol extracts showed the highest polyphenol and flavonoid contents, 4.63 mg TAN/g, and 4.19 mg QUE/g respectively. Also, the SJ and CC methanol extracts showed higher antioxidant activity than prethanol and hot water extracts, whereas the ABTS radical scavenging activities were the highest in prethanol extracts (IC₅₀ = 15.4, 10.3 ㎍/µL). In anti-aging activity for evaluating the anti-wrinkle activity and skin whitening activity, the CC methanol extracts had high collagenase inhibitory activity (88.3%), and the SJ prethanol extracts showed higher elastase inhibitory activity (19.0%) compared to other extracts. Then the tyrosinase inhibitory activity was significantly higher in the SJ and CC methanol extracts (41.8, 30.3%, respectively), whereas prethanol extracts were the lowest. To identify the phenol component contents of SJ and CC extracts, 4-hydroxybenzoic acid, naringenin, naringin and nicotinic acid were measured using LC-MS/MS. As a result, the phenol contents were the highest in SJ methanol extract (4-hydroxybenzoic acid), SJ and CC prethanol extract (naringin and naringenin) and CC prethanol extract (nicotinic acid). Lastly, the antioxidant activity of SJ and CC showed high correlations with polyphenol and flavonoid contents (R = -0.946~0.883). These results suggest that prethanol or methanol extracts of SJ and CC have higher antioxidant activities, anti-aging activity and the potential to be used as material for health functional food and cosmetics.

• Korean Journal of Plant Resources
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• v.36 no.1
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• pp.1-14
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• 2023

This study measured the antioxidant activity and phytochemical content of 192 Boehmeria nivea var. tenacissima (Gaudich.) Miq. collected from six regions in order to identify the possibility of its industrial application. Two antioxidant activity assay (DPPH radical scavenging activity and ABTS radical scavenging activity) and two phytochemical content assay (total polyphenol content (TPC) and total flavonoid content (TFC)) of 192 samples were analyzed. The results showed that the DPPH radical scavenging activity of 192 samples was ranged from 0.02 to 1.35 mgAAE/g, and among them, the samples collected from Goheung (0.53 ± 0.37) and Ulleungdo (0.52 ± 0.28) showed the highest activity. The ABTS radical scavenging activity was showed the ranged from 0.07 to 1.81 mgAAE/g, and the samples collected at Ulleungdo (0.47 ± 0.36) showed the highest activity. The total polyphenol content of 192 samples was 18.6 to 234.8 ugGAE/g, and the samples collected at Mokpo (93.4 ± 34.7) and Jindo (90.4 ± 24.5) showed the highest content. The total flavonoid content was 0.10 to 1.22 mgQE/g and the samples collected at Ulleungdo (0.49 ± 0.31) showed the highest content. In the correlation analysis, there was no significant relationship between the environmental conditions and the antioxidant activity. The total polyphenol content showed a positive correlation with daily temperature difference, and negative correlation with average wind speed and average humidity, and total flavonoid content showed negative correlations with the average temperature, maximum temperature, and minimum temperature. This result can be used as a basic data establish the cultivation conditions of B. nivea var. tenacissima (Gaudich.) Miq. as a functional raw material to increase the usefulness of B. nivea var. tenacissima (Gaudich.) Miq..

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.4
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• pp.1-15
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• 2023

This research intended to reveal the special characteristics of the vegetation structure and the tendency of change of -landfill slope districts, which are reclaimed land, through an investigationsinto the presently existent vegetation and plant community structure of the World Cup Park landfill slope district. For the analysis of changes in vegetation, this study compared the results of field surveys in 1999, 2003, 2005, 2007, 2008, 2012, 2016, and 2021. For the investigation into the plant community structure, a field investigation was carried out in 2021 with six fixed investigation districts designated in 1999 as subjects. To analyze the change in the plant community structure, the past data on the population, the number of the species, and the species diversity by the layer in 2021 were compared and analyzed in the landfill slope district, which is reclaimed land. The changes of the vegetation distribution and the power had been affected by typhoons (Kompasu). Above the plantation foundation, which had been dry and poor, Salix koreensis, marsh woody plants that had formed the community, decreased greatly. The Robinia pseudoacacia community, after the typhoon in 2010, decreased in the number of species and population. Afterward, it showed a tendency to rebound. Regarding the Ailanthus altissima-Robinia pseudoacacia-Paulownia tomentosa community, the number of the species and the population had shown a change similar to the Robinia pseudoacacia community. The Paulownia tomentosa and the Ailanthus altissima have been culled. The slope was predicted as a Future Robinia pseudoacacia forest. The Salix pseudolasiogyne community has been transitioning to a Robinia pseudoacacia forest. Only some enumeration districts, the Robinia pseudoacacia forests and the Salix pseudolasiogyne, had been growing. However, most had been in been declining. It was predicted that this community will be maintained as a Robinia pseudoacacia forest in the future. As these vegetation communities are the representative vegetation of the landfill slope districts, which is reclaimed land, there is a need to understand the ecosystem changes of the community through continuous monitoring. The results of this research can be utilized as a basic material for the vegetation restoration of reclaimed land.

• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.56-70
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• 2022

Tombs No. 39 and No. 63 in Gyo-dong, Changnyeong, are unique in the Changnyeong area in that they do not have additional burials because they are hoenggu-style tombs with an entrance on the north side. This study tried to understand the nature and meaning of the two separate stone walls at the entrance of the tomb along with the burial process of the tomb. These two stone walls mark small tombs built independently within a large tomb, with stone wall No. 39 stone wall No. 3 (No.39-3) and No. 63 stone wall No. 3 (No. 63-3). Both units are located in the middle of the northern wall of the burial body part and share one wall with the burial body part wall stone. All animal fluids inside the stone wall were identified. In particular, it was estimated that at least three dogs were buried as a result of identification of animal fluids No. 63-3. Above all, these animals have their heads facing outward with their backs to the main occupants, and do not overlap in a limited space and are placed side by side. Changnyeong Gyo-dong No. 39-3 and 63-3 were created in the process of building the burial body, and although they are independent relics, they form a subordinate relationship in that they were built along the main burial within one tomb. In addition, it is coercive in that it is placed in an orderly manner according to a certain direction in a state that has not been dismantled after killing an animal. Therefore, It is understood to be the SHUNJANG of dogs. Studies on animal fluids excavated from tombs in the Three Kingdoms period are interpreted as animal stewardship, sacrificial collection, and animal sacrifice depending on their location, and this is known as a series of animal sacrifice rites, namely, animal stewardship and sacrifice. This recognition is based on material objectification of animals, such as food or sacrifices. However, Changnyeong Gyo-dong No. 39-3 and 63-3 are different in that they recognize animals as spiritual beings in the process of funeral rites and are closely related to the ideology that there is life after death. In addition, analysis of the location and directionality of the remains is also required from multiple angles. These two SHUNJANG correspond to the entrance to the tomb, and the location is the most open space at the entrance. The appearance of a dog looking outward, etc., can also be interpreted as the meaning of protecting the tombs and byeoksa. This appearance can be compared with the dog depicted in a mural in a Goguryeo tomb that reflects the ancient world's thought and stone figures excavated from the tomb of King Muryeong of Baekje, and it is also consistent with the meaning of the JINMYOSU protecting the ancient tombs. This suggests that a multifaceted study on animal fluid burial remains is needed in the future.

• Korean Journal of Heritage: History & Science
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• v.56 no.2
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• pp.80-98
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• 2023

In the late Joseon Dynasty, when the bride would ride a palanquin when she went to live with her in-laws, it was a custom to cover the palanquin with tiger skin to ward off misfortunes that may come her way. The higher classes used tiger skin or leopard skin for this purpose, but the common people had to substitute this expensive item with a tiger pattern painted on a blanket. Such blankets were called hotanja, hogu, hoguyok and the like. The term "hotanja" is a pure Korean word. It is not known when the cover for the bridal palanquin was first used, but it was popular from the end of the 19^th century and then gradually disappeared. This is due to the introduction of new Western style weddings that eliminated the need for a bridal palanquin. The tiger print blanket was used not only to cover the bride's palanquin but also to cover a table or floor during the wedding ceremony. This study ran a material analysis on nine pieces of tiger print blankets. All of the blanket artifacts examined in this study had an outer cover and a lining made of fabric that used cotton thread for the warp and wool thread for the weft. Two kinds of wool were found in the weft thread in the outer covers: fat-tailed sheep hair from China and goat hair for carpets from the Hebei province, China. Records show that "blankets with painted tiger patterns" were imported from Russia, and the imported blankets were from Russia and China. The outer cover can be categorized into six types, and the lining into three types depending on the weave and direction of the thread twist. The hem facing can be divided into four types. The lining and outer cover use the full width of the fabric, which was woven in wide widths of 135 cm or wider. The tiger pattern on the blanket was made by stenciling. The stencil design of the body and tail of the tiger were placed on a red blanket to be painted in white, and then the background color of the tiger, which is yellow, would be painted over the white, and then black stripes would be added. The pattern of the tiger varies, which shows that the blankets were made by various craftspeople. The pattern of the tiger print blanket is usually of a tiger lying down, but there were tiger print blankets with a tiger standing up. The pattern of the tiger grew smaller over time, and flower patterns were added in the background. Decorative elements were gradually added to the tiger print blanket patterns, but its function as a palanquin cover became lost. By taking the features of tiger print blankets into consideration, it can be assumed that there are imported pieces among the remaining pieces, and were produced in various places because it was popular at that time.

• Analytical Science and Technology
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• v.21 no.6
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• pp.487-494
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• 2008

An experiment was performed for zone refined Re-filament and normal (nonzone refined) Re-filament to reduce the background effect on the measurement of low level uranium samples. From both filaments, the signals which seemed to come from a cluster of light alkali elements, $(^{39}K_6)^+$, $(^{39}K_5+^{41}K)^+$ and $PbO_2$ were identified as the isobaric effect of the uranium isotopes. The isobaric effect signal was completely disappeared by heating the filament about $2000^{\circ}C$ at < $10^{-7}$ torr of vacuum for more than 1.5 hour in zone refined Refilaments, while that from the normal Re-filaments was not disappeared completely and was still remained as 3 pg. of uranium as the impurities after the degassing treatment was performed for more than 5 hours at the same condition of zone refined filaments. A threshold condition eliminating impurities were proved to be at 5 A and 30 minutes of degassing time. The uranium content as an impurity in rhenium filament was checked with a filament degassing treatment using the U-233 spike by isotope dilution mass spectrometry. A 0.31 ng of U was detected in rhenium filament without degassing, while only 3 pg of U was detected with baking treatment at a current of 5.5 A for 1 hr. Using normal Re-filaments for the ultra trace of uranium sample analysis had something problem because uranium remains to be 3 pg on the filament even though degassed for long hours. If the 1 ng uranium were measured, 0.3% error occurred basically. It was also conformed that ionization filament current was recommended not to be increased over 5.5 A to reduce the background. Finally, the contents of uranium isotopes in uranium standard materials (KRISS standard material and NIST standard materials, U-005 and U-030) were measured and compared with certified values. The differences between them showed 0.04% for U-235, 2% for U-234 and 2% for U-236, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.565-575
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• 2009

In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast load is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, normal strength concrete structures require higher strength to improve their resistance against impact and blast loads. Therefore, a new material with high-energy absorption capacity and high resistance to damage is needed for blast resistance design. Recently, Ultra High Strength Concrete(UHSC) and Reactive Powder Concrete(RPC) have been actively developed to significantly improve concrete strength. UHSC and RPC, can improve concrete strength, reduce member size and weight, and improve workability. High strength concrete are used to improve earthquake resistance and increase height and bridge span. Also, UHSC and RPC, can be implemented for blast resistance design of infrastructure susceptible to terror or impact such as 9.11 terror attack. Therefore, in this study, the blast tests are performed to investigate the behavior of UHSC and RPC slabs under blast loading. Blast wave characteristics including incident and reflected pressures as well as maximum and residual displacements and strains in steel and concrete surface are measured. Also, blast damages and failure modes were recorded for each specimen. From these tests, UHSC and RPC have shown to better blast explosions resistance compare to normal strength concrete.

• Journal of Korea Entertainment Industry Association
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• v.13 no.5
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• pp.263-271
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• 2019

The recent phenomenon of job "Miss Match", which is inconsistent with knowledge in the demand of educational training institutes and industries, has spread to an increase in private education costs for reeducation and employment of new hires, resulting in weak individual job competency and poor employment capability, as well as economic and material waste at the national level. To compensate for these problems, the National Competency Standards(NCS), which are available immediately in practice and look for a standard point of national job competency with the aim of fostering human resources sought by industries, were developed, and even the NCS-based qualification system was launched in line with the stream of times. This study is intended to look into the importance and priority of competency units and competency unit elements at the NCS-based qualification L3 level in the skin care field for an overall check of the NCS-based qualification level at a time when educational institutes are organizing and operating the school curriculums according to the NCS and NCS-based qualification level. And it is attempted to provide basic data for the development of curriculum in fostering professional human resources required by industries. To analyze the needs for competency units and competency unit elements at the L3 level, a survey using AHP method was carried out to a group of field experts and a group of education experts. In addition, the SPSS(Statistical Package for Social Science) ver. 21.0 and Expert Choice 2000, an AHP-only solution was used to do statistical processing through the processes of data coding and data cleaning. The findings showed that there was a partial difference of opinion between a group of field experts and a group of education experts. This indicates that the inconsistencies between educational training institutes and industrial sites should be resolved at this time of change with the aim of fostering field customized human resources with professional skills. Consequently, the solution is to combine jobs at industrial sites and standardized educations of educational institutes with human resources required at industrial sites.