• Title/Summary/Keyword: cycling system

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A Systemic Model for the Gifted Education (체제적인 영재교육을 위한 Renzulli의 전교 심화학습 모형(SEM)의 개성방안)

  • Park, Eun-Young
    • Journal of Gifted/Talented Education
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    • v.10 no.2
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    • pp.1-23
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    • 2000
  • The Schoolwide Enrichment Model(SEM) is a representative model for the gifted education. As the model seems to be more conceptual in nature, it is hard to respond to the different interests and changing needs of the gifted learners. Also it does not provide specific procedures and prescriptions in teaching-learning processes for the teachers. Therefore, SEM needs to be modified into a Systemic Model that is more flexible and procedural. The paper proposes an Instructional Systems Design(ISD) model for SEM. The Systemic Model for SEM consists of 5 major steps. These are as follows: Planning, Diagnosis, Prescription, Implementation, Evaluation. In Planning step, there is a six-stage procedure for initiating the implementation of the SEM. In Diagnosis step, there are two-phases in identifying students for participation in the SEM and assessing strengths, interests, and talents of the learners and recording in The Total Talent Portfolio(TTP). In Prescription step, Curriculum Compacting is administered as a systematic procedure for modifying thecurriculum for above-average ability students. In Implementation step, Enrichment Learning and Teaching is an instructional strategy designed to promote active engagement in learning for teachers and students. Whenever each step has completed, Evaluation step should be followed. These 5 steps are repetitive, cycling and interactive. That is, each one becomes input for the next step, process for itself, and output for the previous step. Each step is monitored through the process of Review and Revision step. In conclusion, the paper suggests six strengths of the Systemic Model for SEM; The Model (1) provides the specific procedure in teaching-learning process; 92) has interactive relations with each component; (3) can be revised continuously for creation of the most effective system; (4) can be implemented more flexibly; (5) can be developed as an unique system for each school; (6) facilitates communications between teachers and students.

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Development of a Silicon Carbide Large-aperture Optical Telescope for a Satellite (SiC를 이용한 대구경 위성용 망원경 제작)

  • Bae, Jong In;Lee, Haeng Bok;Kim, Jeong Won;Lee, Kyung Mook;Kim, Myung-Whun
    • Korean Journal of Optics and Photonics
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    • v.33 no.2
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    • pp.74-83
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    • 2022
  • The entire process, from the raw material to the final system qualification test, has been developed to fabricate a large-diameter, lightweight reflective-telescope system for a satellite observation. The telescope with 3 anastigmatic mirrors has an aperture of 700 mm and a total mass of 66 kg. We baked a silicon carbide substrate body from a carbon preform using a reaction sintering method, and tested the structural and chemical properties, surface conditions, and crystal structure of the body. We developed the polishing and coating methods considering the mechanical and chemical properties of the silicon carbide (SiC) body, and we utilized a chemical-vapor-deposition method to deposit a dense SiC thin film more than 170 ㎛ thick on the mirror's surface, to preserve a highly reflective surface with excellent optical performance. After we made the SiC mirrors, we measured the wave-front error for various optical fields by assembling and aligning three mirrors and support structures. We conducted major space-environment tests for the components and final assembly by temperature-cycling tests and vibration-shock tests, in accordance with the qualifications for the space and launch environment. We confirmed that the final telescope achieves all of the target performance criteria.

Introduction of a New Method for Total Organic Carbon and Total Nitrogen Stable Isotope Analysis of Dissolved Organic Matter in Aquatic Environments (수환경 내 용존성 유기물질의 총 유기탄소 및 총 질소 안정동위원소 신규 분석법 소개)

  • Si-yeong Park;Heeju Choi;Seoyeon Hong;Bo Ra Lim;Seoyeong Choi;Eun-Mi Kim;Yujeong Huh;Soohyung Lee;Min-Seob Kim
    • Korean Journal of Ecology and Environment
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    • v.56 no.4
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    • pp.339-347
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    • 2023
  • Dissolved organic matter (DOM) is a key component in the biogeochemical cycling in freshwater ecosystem. However, it has been rarely explored, particularly complex river watershed dominated by natural and anthropogenic sources, such as various effluent facility and livestock. The current research developed a new analytical method for TOC/TN (Total Organic Carbon/Total Nitrogen) stable isotope ratio, and distinguish DOM source using stable isotope value (δ13C-DOC) and spectroscopic indices (fluorescence index [FI] and biological index [BIX]). The TOC/TN-IR/MS analytical system was optimized and precision and accuracy were secured using two international standards (IAEA-600 Caffein, IAEA-CH-6 Sucrose). As a result of controlling the instrumental conditions to enable TOC stable isotope analysis even in low-concentration environmental samples (<1 mgC L-1), the minimum detection limit was improved. The 12 potential DOM source were collected from watershed, which includes top-soils, groundwater, plant group (fallen leaves, riparian plants, suspended algae) and effluent group (pig and cow livestock, agricultural land, urban, industry facility, swine facility and wastewater treatment facilities). As a result of comparing characteristics between 12 sources using spectroscopic indices and δ13C-DOC values, it were divided into four groups according to their characteristics as a respective DOM sources. The current study established the TOC/TN stable isotope analyses system for the first time in Korea, and found that spectroscopic indices and δ13C-DOC are very useful tool to trace the origin of organic matter in the aquatic environments through library database.

The Origin of Records and Archives in the United States and the Formation of Archival System: Focusing on the Period from the Early 17th Century to the Mid 20th (미국의 기록(records) 및 아카이브즈(archives)의 역사적 기원과 관리·보존의 역사 17세기 초부터 20세기 중반까지를 중심으로)

  • Lee, Seon Ok
    • The Korean Journal of Archival Studies
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    • no.80
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    • pp.43-88
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    • 2024
  • The National Archives and Records Administration (NARA) is a relatively quiet latecomer to the traditional archives of the Western world. Although the United States lacks a long history of organized public records·archives management, it has developed a modern system optimized for the American historical context. This system focuses on the systematic management and preservation of the vast amount of modern records produced and collected during the tumultuous 20th century. As a result, NARA has established a modern archival system that is optimized for the American historical context. The U.S. public records·archives management system is based on the principle that records·archives are the property of the American people and belong to the public. This concept originated during the British colonial era when records were used to safeguard the rights of the colonies as self-governing citizens. For Americans, records and archives have long been a symbol of the nation's identity, serving as a means of protecting individual freedoms, rights, and democracy throughout the country's history. It is natural, therefore, that American life and history should be documented, and that the recorded past should be managed and preserved for the nation's present and future. The public records·archives management system in the United States is the result of a convergence of theories, practices, lessons learned, and ideas that have been shaped by the country's history, philosophies, and values about records, and its unique experience with records management. This paper traces the origins of records and archives in the United States in a historical context to understand the organic relationship between American life and records. It examines the process of forming a modern public records management system that is both uniquely American and universal to the American context without falling into the two forms of traditions that reflect the uniqueness of American history.

Electrochemical Characteristics of $V_2O_5$ based All Solid State Thin Film Microbattery by Ex-situ Sputtering Method (Ex-situ 스퍼터링법에 의한 $V_2O_5$ 전 고상 박막전지의 전기화학적 특성)

  • Lim Y.C.;Nam S.C.;Jeon E.J.;Yoon Y.S.;Cho W.I.;Cho B.W.;Chun H.S.;Yun K.S.
    • Journal of the Korean Electrochemical Society
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    • v.3 no.1
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    • pp.44-48
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    • 2000
  • Amorphous $V_2O_5$ cathode thin films were prepared by DC-magnetron sputtering at room temperature and the thin film rechargeable lithium batteries were fabricated with the configuration of $V_2O_5/LIPON/Li$ using sequential ex-situ thin film deposition techniques. The electrochemical characteristics of $V_2O_5$ cathode materials Prepared at 80/20 of $Ar/O_2$ ratio showed high capacity and cycling behaviors by half cell test. LIPON solid electrolytes films were prepared by RF-magnetron sputtering using the self-made $Li_3PO_4$ target in pure $N_2$ atmosphere, and it was very stable for lithium contact in the range of 1.2-4.0 V vs. Li. Metallic lithium were deposited on LIPON electrolyte by thermal evaporation methode in dry room. Vanadium oxide based full cell system showed the initial discharge capacity of $150{\mu}A/cm^2{\mu}m$ in the range of $1.2\~3.5V$.

Effects of Donor Cell Treatments on the Production of Transgenic Cloned Piglets (공여세포 처리 조건이 형질전환 복제돼지 생산에 미치는 영향)

  • Kwon, Dae-Jin;Kwak, Tae-Uk;Oh, Keon-Bong;Kim, Dong-Hoon;Yang, Byoung-Chul;Im, Gi-Sun;Kim, Jin-Hoi;Park, Jin-Ki;Hwang, Seong-Soo
    • Reproductive and Developmental Biology
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    • v.35 no.3
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    • pp.197-201
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    • 2011
  • This study was conducted to investigate the effects of donor cell treatments on the production of transgenic cloned piglets. Ear fibroblast cell obtained from NIH MHC Inbred minipig was used as control. The GalT knock-out/CD45 knock-in (GalT/CD46) transgenic cell lines were established and used as donor cells. The reconstructed GalT/CD46 embryos were surgically transferred into oviduct of naturally cycling surrogate sows (Landrace ${\times}$ Yorkshire) on the second day of standing estrus. Unlike control (1.2 kV/cm, 75.4%), the fusion rate of the GalT/CDl6 donor cells was significantly higher in 1.5 kV/cm, (84.5%) than that of 1.25 kV/cm, (20.2%) (p<0.01). When the number of the transferred embryos were more than 129, the pregnancy and delivery rates were increased to 13/20 (65%) and 5/20 (25%) compared to less then 100 group [1/6 (16.7%) and 0/6 (0%)], respectively. To analyze the effect of donor cell culture condition on pregnancy and delivery rates, the GalT/CD46 donor cells were cultured with DMEM or serum reduced medium. In serum reduced medium group, the pregnancy and delivery rates were improved to 8/12 (66.7%) and 5/12 (41.7%) compared to DMEM group [3/7 (42.9%) and 0/7 (0%)], respectively. In conclusion, it can be postulated that an appropriate fusion condition and culture system is essential factors to increase the efficiency of the production of transgenic cloned piglets.

The Activation Plan of Resource Circulation of Copper through Analysis of Waste Resources Circulation Flow (동의 폐자원흐름분석을 통한 자원순환 활성화 방안)

  • Lee, Hi Sun;Woo, Jeong-Hun;Lee, Jae-Chun
    • Resources Recycling
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    • v.23 no.2
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    • pp.26-36
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    • 2014
  • The materials flow of copper can be analyzed into up-stream and down-stream stages based on the literature survey. Discharge and recycling stages in the down-stream have been particularly analyzed through the field survey. The waste nickel resources circulation flow may conveniently be grouped into 4 stages discharge import, collection disuse, resource recovery and product production export, the resources mainly consist of copper scrap and stainless steel scrap in 2010. The resource circulation rate of 36.83% is obtained from the above flow. Various plans are therefore, suggested in each stage to increase resource circulation rate. At discharge import stage, it is suggested to consider this kind of waste as an important resources if it is appropriately classified in detail, basides applying quota tariff to this kind of waste. At collection disuse stage, the plan of stabilizing supply and demand is suggested through the improvement of bidding system. Resources professional cycling stage crushing and grinding companies foster coexistence between large and small plans and strategies were suggested. At product production export stage, the integrated approval is suggested approval for licensing to register units as waste-treating facilities instead of exempting registration under the present condition to activate recycling industries.

Effects of organic matter sources on nitrogen supply potential in arable land (농경지에서 유기물 시용에 의한 질소 공급 효과)

  • Lee, Ye-Jin;Yun, Hong-Bae;Song, Yo-Sung;Lee, Chang-Hoon;Sung, Jwa-Kyung;Ha, Sang-Keun
    • Korean Journal of Agricultural Science
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    • v.42 no.4
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    • pp.431-437
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    • 2015
  • Recently, assessment of nitrogen balance has been required for environmental agriculture. Nutrient management using organic matters in farmlands has been strongly required as a means of extending resource-cycling agriculture and reduction of nitrogen balance. Organic matters-derived nutrients and soil-available nitrogen should be necessarily considered to manage nutrient balance in soil-plant system. In this study, we reviewed the amount of N supply according to types of organic matter such as livestock compost and green manure in arable land. In case of applied livestock compost in soil, nitrogen mineralization was influenced by nitrogen amount of livestock manure and mixed materials. And nitrogen mineralization of green manure in arable land was influenced by types of crop and return period of green manure because of change of C/N ratio. Also, nitrogen supply by organic matter in arable land can be changed by environmental factors such as temperature, moisture in soil. Therefore, nitrogen supply according to C/N ratio of organic matter and analysis method for estimation of soil nitrogen supply availability should be evaluated to set up the nutrient management model.

The Impact of Public Transit Accessibility on the Car-sharing Use Demand (대중교통 접근성이 카셰어링 이용수요에 미치는 영향)

  • Kim, Suk-Hee;LEE, Kyu-Jin
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.15 no.4
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    • pp.1-11
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    • 2016
  • The purpose of this study is to analyze the effect of public transit accessibility on the Carsharing use demand. By utilizing the rental historical DB of Greencar which is operated in Suwon city and public transit GIS DB, the use demand models for Carsharing by rental offices are built and analyzed in accordance with public transit accessibility. The result indicates 73% of walking as a majority, 3% cycling, and 20% using buses and urban railways to access Carsharing rental offices. The goodness of fit of Carsharing use models reflecting accessibility to buses and railways is verified as 0.818 which proves that public transit accessibility is a significant variable. Therefore, it is verified that installing Carsharing rental offices where public transit transfer is convenient can possibly increase the use demand. Especially, while accessibility to buses is verified as a significant variable out of other public transit means, the accessibility to urban railways is verified as not significant. This suggests that a variety of complementary policies such as transfer discount policy and one-way transfer return policy are necessary in between urban railways and Carsharing in order to promote mutual use demand in accordance with the other public transit means. This study result is yet the basic research on Carsharing, however it is expected to contribute to improvement of transfer demand in between different public transit means.

Seasonal Nutrient Analysis of Paddy Soils in Korean Type of Large Scale Environment-friendly Agricultural District (한국형 광역친환경 논 농업단지 토양의 시기별 양분 분석)

  • Choi, Hyun-Sug;Jung, Seok-Kyu
    • Korean Journal of Organic Agriculture
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    • v.25 no.2
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    • pp.373-386
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    • 2017
  • The study was conducted to investigate seasonal nutrient dynamics in rice-cultivated soils collected from farmhouses of three large-scale environment-friendly agricultural districts (LEAD), Jangheung, Suncheon, and Okcheon in which environmental-friendly agriculture has been exemplarily practiced in Korea. Among three districts, Crop- livestock cycling organic farming system had been introduced only in Jangheung. pH and EC of farmhouse soils of three LEADs were ranged between 5.5 - 6.7 and $0.4-1.0dS\;m^{-1}$ from March to September, respectively. T-N was observed to be high on the farmhouse soil in Suncheon and K was observed to be lowest on farmhouse soil in Okcheon. Concentration of $NH_4-N$ in soil was observed to be highest on June, in particular on the farmhouse in Jangheung, but rapidly decreased due to the loss of fertilizer applied in Spring. Yield and harvest index were the highest on the farmhouse in Okcheon in which total annual gross production $ha^{-1}$ was nearly three time higher than those of other two farmhouses. Farmhouse soil of Okcheon was maintained the highest seasonal nutrient balance due to the high input of fertilizer. It was estimated that K balance in the farmhouse soil in Suncheon dropped to $-60kg\;ha^{-1}$ on September, and it might have some effect on the less rice productivity due to K deficiency. Farmhouse soil in Jangheung was maintained low seasonal balance of T-N and P but showed the highest N use efficiency in the rice grain. Based on above-mentioned results, we think Jangheung farmhouse can be recommended as a model farmhouse of LEADs.