• Title/Summary/Keyword: Age-structure

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Manufacturing technique and provenance Analysis of Bronze Artefacts excavated from Pungnap earthen fortress (풍납토성 출토 청동유물의 제작기술 및 납 원료의 산지추정)

  • Han, Woo Rim;Kim, So Jin;Han, Min-su;Hwang, Jin-ju;Lee, Eun-woo
    • Korean Journal of Heritage: History & Science
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    • v.48 no.2
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    • pp.110-119
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    • 2015
  • Bronzes, Earthenwares and various artifacts were excavated from Pungnap earthen fortress in the early Baekje age in Korea. This study was performed in order to identify the manufacture technology of bronze artefacts and provenance of lead in bronzes. Microstructure and chemical composition results show that 3 of them are Cu-Sn-Pb alloys in which an intentional lead addition was carried out and one is tin bronze showing straight twin structure within crystal grains. Also $CuFeS_2$ or $Cu_5FeS_4$ was used as raw materials through the detection of S and Fe as trace elements. The lead isotope results could be matched with one of the zones of southern Korea and China on the East Asian map. This results shows that data were plotted either in zone 2 or zone 3 of the South Korean galena map. However, one of bronze artifacts was matched with the zone of Northern China.

Carbonation Behavior Evaluation of OPC Concrete Considering Effect of Aging and Loading Conditions (재령 및 하중효과를 고려한 OPC 콘크리트의 탄산화 거동 평가)

  • Hwang, Sang-Hyeon;Yoon, Yong-Sik;Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.1
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    • pp.122-129
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    • 2019
  • The movement of deterioration agents such as a chloride ion, etc. in concrete varies with loading conditions and micro-structure developed by age effect. In this paper, the carbonation behavior by accelerated carbonation test is evaluated considering curing periods(28 days, 91 days, and 365 days) and loading conditions. Carbonation velocity coefficients are obtained referred to KS F 2584. In the control case without loading condition, carbonation velocity coefficient of 91 days decreases to 50.0 % level and that of 365 days decreases to 44.8 % level than that of 28 days curing condition. In 28 curing days, carbonation velocity coefficients changed level of 103.9 ~ 108.8 % in tensile region and 91.9~104.6 % in compressive region by loading conditions. Carbonation velocity coefficients in the 30 % and 60 % tensile loading case at 28 days decreases to 47.3 % and 52.5 % level compared to control case after 1 year. Furthermore, 45.8 % and 44.9 % level of carbonation velocity coefficients are evaluated for 30 % and 60 % compressive loading conditions compared to control case after 1 year. Carbonation velocity coefficient decreases in the 30 % compressive loading level due to effective pore compaction and it increases afterwards due to micro-cracking. In the tensile loading condition, unlike the behavior of compressive region, it linearly increases with increasing loading level.

Research of private landscape architecture of the Tang Era in ancient China -based on excavated excellent articles and a book <洛陽名園記> called Nakyangmyungwonki- (중국 고대 당대(唐代) 민간 조경[사가원림(私家圓林)] 연구 - 출토된 명기(明器)와 낙양명원기를 중심으로 -)

  • Park, Kyung-Ja
    • Korean Journal of Heritage: History & Science
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    • v.38
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    • pp.285-303
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    • 2005
  • Through the excavated excellent articles of the Tang era, we have considered the building techniques and styles of a square pavilion, an octagonal pavilion, a miniature hill, a pond, etc., could read building techniques of the scenic structures on ancient literatures including records and additionally about their poetical life at that time and inquired into the arrangement, structure, building techniques, etc. of a miniature hill, a pond, a pavilion, a flowerplant, etc., on Nakyangmyungwonki. Thus, under the research on the private landscape architecture, especially the nobility gardening, around excavated excellent articles and literatures, 'A miniature hill(假山) and a pond for landscaping views formed the center of a garden, and additionally a pavilion was built and flowerplants were set. The miniature hill of laying stones and having a carven, steeping, stratifying, looking like dyed green and birds' singing among hills and eating water on the lakeshore${\ldots}$' was expressed. The pond of digging in the ground and conducting water had its water system developed. There were several kinds of pavilions such as 廳, 堂, 館, 亭, 臺, 樓, 閣, 榭, etc. As examples of landscaping plants, there were a bamboo, a lotus flower, a peony, aromatic trees a pine, a korean spindle tree, a big cone pine, an empress tree, a wild walnut, a peach, a plum, a Japanese apricot tree, an apricot tree, a chrysanthemum, arrowroot vines, etc. Thus, the garden of the Tang era, abundant, diverse and excellent, enjoyed the prime of the period of prosperity. Due to cultural exchange, it is supposed that the period of united Shilla of the same age would meet with the period of prosperity in the developmental history of Korea landscape, based on the nobility garden system '4 different dwelling-houses every season on a record "四節游宅"'.

Changes in Icthyofauna of Hapcheon Lake and Characteristics of the Bluegill, Lepomis macrochirus Population (합천호의 어류상 변화와 블루길(Lepomis macrochirus) 개체군의 특성)

  • Jang, Chang-Ryeol;Bae, Yang-Seop
    • Korean Journal of Environment and Ecology
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    • v.34 no.6
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    • pp.543-550
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    • 2020
  • This study aimed to identify the characteristics of fish inhabiting Hapcheon Dam and surrounding rivers and the Bluegill population, an invasive species, and provide basic data. The survey of fish living in Hapcheon Dam and surrounding tributaries in the Ulsan area from 2016 to 2017 identified a total of 1,785 individuals of 30 species of 10 families and identified 8 Korea's endemic species (21.8% indigenization rate), 3 exotic species, and 2 ecosystem disturbance species. The comparison of this study with the past survey showed that 36 species of 12 families were reported in the past survey, but 14 species of them were not found in this study. We believe that a more detailed survey of Lake Hapcheon should identify most of them. The analysis of the length-weight relationship for the Bluegill population, identified as the dominant species in the Hapcheon Lake, showed that a large number of populations was in the stage of rapid growth as a large number of populations aged 1 to 2 years was found. Since the obesity level and the length-weight relationship were confirmed to be in good condition, it was necessary to prepare a plan to control the Bluegill population. We expect that this study's results can be useful data for understanding the growth and trends of the Bluegill population inhabiting the Hapcheon Dam and surrounding rivers.

Ecological Characteristics of Tachanovsky's Gudgeon, Ladislabia taczanowskii in Songcheon Stream, Korea (송천에 서식하는 새미(Ladislabia taczanowskii)의 생태 특성)

  • Byeon, Hwa-Keun
    • Korean Journal of Environment and Ecology
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    • v.34 no.6
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    • pp.551-557
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    • 2020
  • This study surveyed the ecological characteristics of Ladislabia taczanowskii at Songcheon Stream from March to November 2019. The species inhabited upstream, where the riverbed structure was mostly covered with boulders and cobbles. The water depth was 31-148 cm, and the stream velocity was fast at 0.94±0.23 (0.51-1.39) m/sec. The gender ratio of females to males was 1 : 0.89. The age according to the total length frequency distribution indicated that the group with 38-70 mm below in total length was one year old, the group with 70-100 mm was two years old, the group with 100-120 mm was three years old, and the group over 120-128 mm was over four years old. The total length of sexually mature fishes was 70 mm for females and 75 mm or more for males. The spawning season was from May to August, and the water temperature was 15.5-20.1℃ during the period. The prosperous spawning season was from June to July, and the water temperature was 15.8-17.2℃ during the period. The spawning ground was where the riffle began in the pool, and its bottom was formed of sand and gravel. The width was about 150 cm, and the water depth was 20 to 50 cm. The average number of eggs in the ovaries was 821 (401-1,314) per matured female, and the matured eggs were yellowish and spherical with a mean diameter of 1.62±0.02 (1.43-2.01) mm. The live foods of L. taczanowskii Cyanophyta, Chlorophyta, Bacillariophyta, Ephemeroptera, and Diptera. The feeding habit of L. taczanowskii is omnivorous, but more than 90% of the stomach content was attached algae.

The Effect of Carbide Precipitation on the High Temperature Deformation of Ni3Al and TiAl

  • Han, Chang-Suk;Kim, Jang-Woo;Kim, Young-Woo
    • Korean Journal of Metals and Materials
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    • v.47 no.3
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    • pp.147-154
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    • 2009
  • The effect of carbon addition on the microstructures and mechanical properties of $Ni_3Al$ and TiAl intermetallic alloys have been characterized. It is shown that carbon is not only an efficient solid solution strengthener in $Ni_3Al$ and TiAl, it is also an efficient precipitation strengthener by fine dispersion of carbide. Transmission electron microscope investigation has been performed on the particle-dislocation interactions in $Ni_3Al$ and TiAl intermetallics containing various types of fine precipitates. In an $L1_2$-ordered $Ni_3Al$ alloy with 4 mol.% of chromium and 0.2~3.0 mol.% of carbon, fine octahedral precipitates of $M_{23}C_6$ type carbide, which has the cube-cube orientation relationship with the matrix, appear during aging. Typical Orowan loops are formed in $Ni_3Al$ containing fine dispersions of $M_{23}C_6$ particles. In the L10-ordered TiAl containing 0.1~2.0 mol.% carbon, TEM observations revealed that needle-like precipitates, which lie only in one direction parallel to the [001] axis of the $L1_0$ matrix, appear in the matrix and preferentially at dislocations. Selected area electron diffraction (SAED) patterns analyses have shown that the needle-shaped precipitate is $Ti_3AlC$ of perovskite type. The orientation relationship between the $Ti_3AlC$ and the $L1_0$ matrix is found to be $(001)_{Ti3AlC}//(001)_{L10\;matrix}$ and $[010]_{Ti3AlC}//[010]_{L10\;matrix}$. By aging at higher temperatures or for longer period at 1073 K, plate-like precipitates of $Ti_2AlC$ with a hexagonal structure are formed on the {111} planes of the $L1_0$ matrix. The orientation relationship between the $(0001)_{Ti2AlC}//(111)_{L10\;matrix}$ is and $[1120]_{Ti2AlC}//[101]_{L10\;matrix}$. High temperature strength of TiAl increases appreciably by the precipitation of fine carbide. Dislocations bypass the carbide needles at further higher temperatures.

Causual Analysis of Public Perception on Opportunity Inequality (기회 불평등에 대한 국민 인식태도의 인과 분석)

  • Lee, Byoung-Hoon
    • 한국사회정책
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    • v.24 no.2
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    • pp.157-179
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    • 2017
  • In Korea, 'spoon class discourse' has attracted public attention in the press and among young people, which reflects that mass awareness that the class status structure is clearly rooted in the society becomes widespread. Although income distribution has been improved since late 2000s, it is interesting that Korean people's subjective perception concerning class mobility and social justice has been worsemed. By using the survey data on people's perception of opportunity inequality, this study finds that Korean people have by and large negative subjective awareness regarding socio-economic opportunity inequality, magnitude of opportunity inequality, and achievement by efforts, and that the degree of the negative perception is greater in accordance with the people's subjective identification. The regression analysis reveals that the social status of respondents and their parents(-), experience of discrimination(+), age(-), and high education of college and above (+) have consistent effect over socio-economic opportunity inequality, magnitude of opportunity inequality, and achievement by efforts with statistical significance. More concretely, as people have lower subjective status identification at the time of parent generation and their own generation, as they have the experience of discriminatory misconduct, and as they are young and highly educated, they have negative or pessimistic perception regarding opportuinity inequality. In addition, it is revealed that the unemployed and non-regular workers have significantly negative perception on socio-economic opportunity inequality, magnitude of opportunity inequality, while negative perception on the magnitude of opportunity inequality and achievement by efforts is noticeable among high and middle income households.

Experimental Study on the Strengthening Effect of External Prestressing Method Considering Deterioration (구조물 노후도를 반영한 외부긴장 보강 효과에 관한 실험적 연구)

  • Kim, Sang-Hyun;Jung, Woo-Tai;Kang, Jae-Yoon;Park, Hee-Beom;Park, Jong-Sup
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.1
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    • pp.1-6
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    • 2021
  • Concrete structures gradually age due to deterioration of materials or excess loads and environmental factors, and their performance decreases, affecting the usability and safety of structures. Although external tension construction methods are widely used among the reinforcement methods of old bridges, it is insufficient to identify the effects and effects of reinforcement depending on the level of aging. Therefore, in this study, a four-point loading experiment was conducted on the subject with the non-reinforced and external tensioning method to confirm the reinforcement effect of the external tensioning method, assuming the aging of the structure as a reduction in the compressive strength and tensile reinforcement of concrete, to analyze the behavior of the reinforcement and confirm the reinforcement effect. As a result of the experiment, it was difficult to identify the amount of reinforcement in the extreme condition due to early elimination of the anchorage. Therefore, compliance with the regulations on anchor bolts is required when applying the external tension reinforcement method. Crack load and yield load increased depending on whether external tension was reinforced, but before the crack, the stiffness before and after reinforcement was similar, making it difficult to confirm the reinforcement effect.

Translation and Cross-Cultural Adaptation Study on a Korean of Sensory Processing Measure Home Form (가정용 Sensory Processing Measure(SPM)의 국내적용을 위한 번역연구)

  • Lee, Hye-Rim;Yoo, Eun-Jung;Kim, Kyeong-Mi
    • The Journal of Korean Academy of Sensory Integration
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    • v.19 no.3
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    • pp.22-31
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    • 2021
  • Purpose : This study aimed to conduct a translation, backtranslation, and content validity test of the Sensory Processing Measure (SPM) for Korean children. Methods : The translation and content validation process involved direct and backward translation; a test of equivalence between the two versions (the original SPM and the Korean version SPM; K-SPM) was performed using content-related evidence collected by a group of experts and a group of parents. Data analysis was carried out using Excel Content validity indices (CVI), mean, and standard deviation were used for the analysis of content validity. Results : The result of the comparison between the original SPM and K-SPM in the group of experts was 3.54 ± .74, the S-CVI/Avg for semanticity was .92, and the S-CVI/Avg for structure was .86. The results for the mean of the understanding test and the S-CVI/Avg were 3.48 ± .63 and .94, respectively. Conclusion : K-SPM will considerately be used as an assessment to identify sensory processing, praxis, and social participation issues for children in Korea. Further studies are suggested to increase the age range and the sample size for a more comprehensive applicability of the K-SPM to Korean children.

An Exploratory Study on the Authenticity Discourse Strategies of Popular Music Audition Programs - Focused on - (대중음악 오디션 프로그램의 진정성 담론 전략에 관한 탐색적 연구 - <미스터트롯>을 중심으로 -)

  • Lie, Jae-Won;Kim, Won-Gyum
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.6
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    • pp.1-13
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    • 2021
  • This study explored the mechanism by which Trot gained a superior position in the broadcasting contents market after the TV Chosun audition program was broadcast. We analyzed the narrative structure of the program to determine what differentiation and popularization strategy the trot audition program took from the existing audition program, and analyzed in-depth interviews with music experts and interviews with the production team. appealed to viewers with a strategy that reversed the success strategy of existing audition programs. First, the strong/non-competent participants did not compete with each other, but rather the strong/skilled players competed against each other. This trot audition set the singing ability as a new 'discourse on sincerity'. Second, we broke away from the 'demon editing', which was considered essential for audition programs, took a strategy of excluding villains. Third, we broke the practice of audition programs that were supposed to show expertise in specific genres, such as idol music, hip-hop, and bands, and combined trot with various genres. Fourth, unlike previous audition programs that mainly targeted specific generations or genders, the strategy was to expand the audience by targeting various age groups. Fifth, it has formed a middle-aged fandom with a 'subtitle strategy' that uses subtitles well to arouse viewers' interest and help empathize.