• Title/Summary/Keyword: concrete cutting

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Development of a Theoretical Model for STEAM Education (융합인재교육(STEAM)을 위한 이론적 모형의 제안)

  • Kim, Sung-Won;Chung, Young-Lan;Woo, Ae-Ja;Lee, Hyun-Ju
    • Journal of The Korean Association For Science Education
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    • v.32 no.2
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    • pp.388-401
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    • 2012
  • This study attempted to propose a theoretical model for STEAM education, entitled to the Ewha-STEAM education model, which could provide more concrete guidelines for science educators and curriculum developers to execute STEAM ideas. We identified key knowledge and key competencies to nurture future creative/convergent human resources. Key knowledge included an understanding of core ideas cutting across traditional disciplinary boundaries as well as the nature of different disciplines. And additionally, key competencies implied such abilities as to explore the scientific world, to resolve problems, and to communicate and collaborate with others. We also added creativity and character as an essential part of key competencies. In order to provide more specific guidelines when developing, implementing, and evaluating STEAM curriculum, we suggested three elements of convergence to consider: 1) unit of convergence (i.e. concept/skills, problem/phenomenon, activity), 2) degree of convergence (i.e. multi-disciplinary, inter-disciplinary, extra-disciplinary), and 3) context of convergence (i.e. personal, societal, global). It is expected that the Ewha-STEAM education model would contribute towards diverse education communities understanding the direction of STEAM education and its educational potentials.

Shattering Grain Loss in Relation to the Impulse During Harvest and Year-Variation of Grain Tensile Strength in Rice (벼 수확시 충격에 의한 탈립 손실과 탈립성의 년차간 변이)

  • Yong Woong, Kwon;Jin Chul, Shin
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.28 no.4
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    • pp.419-424
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    • 1983
  • Tensile strength and shattering losses of rice grains in a binder harvest and in a free falling test were examined. Indica$\times$Japonica varieties, Milyang 23, Hangangchal, and Taebaek, and a Japonica variety, Jinheung were used for this study. The average tensile strength varied with varieties, showing 0.743N (Newton) in Milyang 23, 1.078N in Hangangchal, 1.573 N in Taebaek, and 1.775 N in Jinheung. Extrapolation of the average tensile strength for the zero field loss of grain indicated about 1.7 N. Moisture content of straw at the cutting position in a binder harvest was 76.0 to 86.7% in culm and 76.7 to 77.8% in leaf sheath. The percent loss of grains occurring in binder barvest in the field was equivalent to the degree of shattering in the panicle-falling test onto the concrete floor at the height of about 40cm. The grain shattering (Y) was closely related to the impulse (X), the change in momentum: Y=-25.73+4958.4X, ($r^2$=0.987) for Milyang 23, Y=-12.97+2258.3X, ($r^2$=0.979) for Hanagangchal, Y=-5.24+840.4X, ($r^2$ =0.976) for Taebaek. The tensile strengths of grains and their variance varied singnificantly yearly even in the same variety. The magnitude of year-variance was somewhat smaller for the easily shattering variety.

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Development of Dry Process Caisson Method for Maintenance of Submerged Harbor Structure (수중 항만구조물의 유지보수를 위한 건식 케이슨 공법 개발)

  • Lee Joong-Woo;Oh Dong-Hoon;Kwak Seung-Kyu;Kim Sung-Tae
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.06b
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    • pp.163-170
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    • 2006
  • Together with the trend of enhancement in domestic industrial development and economic progress due to import and export, the demand for construction of the roads, bridges, especially port facilities, and several coastal protection and ocean structures is increasing rapidly. MOMAF of Korean Government is driving construction of 9 new ports and renovation of the existing fishery ports. Among these structures most of bridge base, wharves, dolphins, quays, and jetties are being newly built of steel or concrete pile. As the base, supporting bulkheads, and piles are underwater after construction, it is difficult to figure out the status of structures and not enough to get maintenance and strengthen the structures. Every year, moreover, these works suck the government budget due to higher incomplete maintenance expense for protection from corrosions of structures and increased underwater construction period. For the purpose of cutting down the expense of government budget, it is necessary to extend the life cycle of the existing structures. Therefore, we developed a new method for maintenance of submerged structures near the waterline by allowing dry work environment with the floating caisson. The method shows easy to move around the working area and handle. It also showed not only a significant reduction maintenance expenses and time for anti-corrosion work but also better protection. This will be a milestone to reduce the maintenance and construction expenses for the shore and water structures.

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The Efficiency and Improvement of the Highway Wild-Life Fences for Decrease of Mammals Road-kill - In Case of Manjong~Hongchun Section on Jungang Highway - (포유류 로드킬 저감을 위한 고속도로 유도울타리 효율성 및 개선방안 연구 - 중앙고속도로 만종~홍천 구간을 사례로 -)

  • Song, Jeong-Seok;Lee, Kyong-Jae;Ki, Kyong-Seok;Jun, Ik-Yo
    • Korean Journal of Environment and Ecology
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    • v.25 no.5
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    • pp.649-657
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    • 2011
  • This study had targeted the Manjong Junction~Hongchun interchange section of Jungang highway in order to analyze the efficiency and improvement of the highway wild-life fences. Being analyzed wild-life fence as an effective facility for the prevention of road-kill, it had founded that the wild animals did not jump over even the two layer guardrail, concrete barrier and noise barrier, fence for rock fall. For the section with high road-kill decrease effect after installing the wild-life fence, the effect was higher at wild-life fence with the height of 1.0m where the door had not been installed and the well connected points of road facility than the area with fence height of 1.5m. The road-kill decrease effect was also high at the well managed areas even if the door has not been installed. Also, road-kill had occurred by concentrating around the end of wild-life fence after installing the fence, Moreover road-kill had also occurred around the cutting section. The door of wild-life fence had higher amount of road-kill occurrence as the installation interval was closer. it was analyzed that the door management has a lot of effect on road-kill decrease. The fence for rock fall, two layer guardrail and concrete barrier having the effect of wild-life fence installed on the road would have to be installed by connecting with wild-life fences through proper facility improvement. Although the door should not be installed if possible, it should be installed as automatic door or gravity door to prevent the door from leaving the door open. An escape route has to be formed for the prompt escape away from the road for the animals entered through the ending section of the fence. The eco-corridor has to be made by restoring the soil layer of dual purpose eco-corridor forming a planting area. Also, the dead body after the accident has to be disposed to the outer section of the road immediately in order to prevent the secondary road-kill by the predator from the road-kill. The fence has to be installed as 500m or longer in both ways, in other words 1,000m or longer, from the targeted spot of minimum accident prevention while connecting up to the bridge or box culvert, etc that are next road facilities if possible to guide wild animals safely to the eco-corridor.

A Study on the Formation Process and the Settling Period of the Gwandong-Palkyung by the Thematic Exploration of Joseon Landscape Poetry and Paintings (옛 시문과 그림으로 살핀 관동팔경(關東八景)의 형상화 및 정착시기)

  • Rho, Jae-Hyun;Son, Hee-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.35 no.1
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    • pp.10-24
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    • 2017
  • The research takes note of the formation process and settling period of Gwandong-Palkyung(關東八景, Eight Sites of Eastern Korea), the representative palgyeong(prominent eight sites) and jipgyeong(集景, landscape collection of scenic beauty), and investigates the time of formation regarding the palkyung and jipgeyong of Gwandong's scenic beauty through the analysis and interpretation of bibliographic data, and reference data. The result of the study is as follows. As the first document that records the terminology of "Gwandong-Palkyung" is "Daphongeunggil(答洪應吉)" of Yi, Hwang(李滉), Gwandong-Palkyung is inferred to be settled within the recognition of the people even before the 16th century. The geographic analysis result including "Sinjeung Donggukyeojiseungram(新增東國輿地勝覽)", Gwandong-Palkyung expanded as Gwandong-Sipkyung in early to middle of the 16th century. The first confirmed landscape collection regarding Gwandong-Palkyung in this study is confirmed in Shin Zup(申楫)'s "Yeonggwandong-Palkyung(詠關東八景)", thus, the terminology of Gwandong-Palkyung existed before 16th century at the latest. The settlement time of current "Palkyung" collection is estimated to be early 17th century at the latest. Poetries regarding Gwandong-Palkyung, and the frequency on the appearance of Gwandong scenic beauties are analyzed as making clear of the concentrated phenomenon on the sceneries of Gwandong-Palkyung. On the other hand, the collection of Gwandong-Palkyung in the domain of arts is confirmed initially in the ${\ll}$Gwandongpalkyungdobyeong(關東八景圖屛)${\gg}$ of Heo, Pil(許泌). Gwandong-Palkyung, expressed as the actual scene landscape painting shows similar tendencies of the conditions in the jipgyeong from the poetry, but the appearance rate of the painting subject was more prominent in visual solidarity and cohesion due to the reflection of the importance on icon(圖像) of the art works produced with particular meaning in the case of fixed ideal system. From late Joseon to modern times, ${\ll}$palpokbyeongpung(八幅屛風)${\gg}$ of various forms of folk painting is a corroborative evidence notifying that the cultural phenomenon of Gwandong-Palkyung has entered the universal period of embrace. Also, the 13 scenic beauties of Gangwon-Do appearing in the games of Namseungdo and Myeongseungyuramdo include Gwandong-Palkyung, which confirms the settlement of Gwandog-Palkyung even within the culture of games in late Joseon. Such results demonstrate the existence of awareness regarding Gwandong-Palkyung from the first half of the 15th century, which is presumed to have completely settled in the 17th century through the continuous development of formative process in the 16th century. Ultimately, Gwandong-Palkyung is the concrete formation of regional scenic beauties that individually gained its reputations as scenery from the Koryo Dynasty to late 17th century. Gwandong-Palkyung of the scenic beauty of Gwandong is a unique cultural scenery of the region that have germinated and formed through the process of cutting and polishing of long time to collect the best eight of scenic beauty from the many participation of sightseeing culture.

The Effect of Stage of Maturity on the Composition and Feeding Value of Silage (생육시기가 Silage의 사용가치에 미치는 영향)

  • 신정남;윤익석
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.4 no.1
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    • pp.41-60
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    • 1983
  • Experiments were conducted to study the effect of stage of maturity at harvest on the quality of silage. Herbage samples taken from the barley plant, rye plant, wheat plant, oat plant, Orchardgrass, Italian ryegrass, a mixed grass sward of Orchardgrass and Italian ryegrass and corn plant at different stages of maturity and ensiled in order to evaluate the effect of maturity on the chemical composition and feeding value as well as digestibility using sheep. Forage material were ensiled in small concrete silo. 1. The dry matter yield per 10a increased with advancing the maturity. Yield of brarley plant was 404, 635 and 900 kg at heading, milk and milk dough stage, respectively. Rye plant yield was 279, 589, 708, 10,000, 1,265, 1,376 and 1,492 kg at booting, before heading, early heading, late heading, early flowering, late flowering and after flowering stage, respectively. Italian ryegrass yield was 355, 613, 844 and 1,109 kg at vegetative, booting, heading and flowering, respectively. Orchardgrass/Italian ryegrass production was 477, 696, 891 and 1,027 kg at before was 458, 1,252, 1,534, 1,986 and 2,053 kg at tassel, early milk, yellow ripe and ripe stage, respectively. 2. Dry matter content increased with advancing maturity, but crude protein declined markedly. The NFE content decreased with advancing maturity of all the herbages except corn plant where NFE content increased, but corn plant increased. The content of crude fiber increased with advancing maturity except corn plant. The content of crude ash decreased with advancing maturity. In the rye plant, the content of neutral detergent fiber (NDF), acid detergent fiber (ADF) and cellulose increased with advancing maturity. 3. In vitro dry matter digestibilities of the rye plant was 53.6, 54.1, 50.7, 47.1, 44.9, 40.1 and 38.9% booting, before hcading, early heading, late heading, early flowering, late flowering and after flowering stage, respectively. The regression equation was $Y=56.22-0.74X+0.009X^2$ (X=cutting date from the first cut, Y=dry matter digestibilities). 4. In vitro digestible dry matter yield (kg/10a) of rye plant increased with advancing maturity, but declined from the flowering stage. The regression equation was $Y=168.88+26.09X-0.41X^2$ (X=cutting date from the first cut). 5. In vitro digestibility of dry matter in the corn plant was 69.2, 71.5, 69.8 and 69.9% at tassel, early milk, milk and yellow ripe stage, respectively. 6. The digestibility of crude protein and crude fiber of all plants decreased with advancing matuity, but NFE of the barley and corn generally increased. 7. The TDN contents on the dry matter basis decreased, but those of barley and corn silage were not different. TDN content of barley was 57.8, 57.1 and 57.9% at heading, milk and milk dough stage, respectively. That of rye silage was 50.0, 27.2 and 43.7% at early flowering, after flowering and milk stage, respectively. Italian ryegrass silage was 67.9, 63.7, and 54.9% at before heading, early heading and after heading, respectively. In case of Orchardgrass silage the TDN was 54.8, 52.9 and 46.1% at after heading, after flowering and milk, respectively. Corn shows TDN value of 59.5, 62.8 and 61.6% at milk, yellow ripe and ripe, respectively. 8. The pH value increased slightly by advancing maturity. 9. the content of organic acid decreased by advancing maturity and also increasing the DM content.

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