• Title/Summary/Keyword: secondary materials

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Investigating Teachers' Perception of the Educational Resource Sharing System in Korea: A Qualitative Research

  • Sewon JOO;Innwoo PARK
    • Educational Technology International
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    • v.24 no.2
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    • pp.115-141
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    • 2023
  • The aim of this research is to understand the perceptions of primary and secondary teachers regarding educational resource sharing systems(ERS) by using a qualitative approach. This study conducted Focus Group Interview(FGI) with 20 primary and secondary school teachers. Interview data were analyzed through inductive content analysis method. The results are as follows. First, teachers placed significant emphasis on high-quality, convenient functions, and reward system for sharing resources. Specifically, teachers identified the necessity for a diverse array of materials, systematic categorization of these resources, and the provision of monetary compensation as essential components. Second, the study participants advocated strategies for revitalizing ERS including enhancing accessibility, constructing user-friendly features, increasing awareness, and establishing a reward system to incentivize the resource sharing. In particular, teachers proposed strategies such as developing mobile-based services and AIdriven data recommendation system. These results provide actionable insights for stakeholders engaged in the design, implementation, and evaluation of resource sharing platforms.

Development and Implementation of STEM -Identification of Mathematics Teachers' Beliefs- (융합 프로그램의 개발과 적용 -수학 교사의 신념을 중심으로-)

  • Noh, Jihwa
    • East Asian mathematical journal
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    • v.39 no.4
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    • pp.377-392
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    • 2023
  • The purpose of this research was to investigate mathematics teachers' beliefs regarding the implementation of STEM approaches in secondary school mathematics classes and to identify the factors influencing their beliefs. A survey on teachers' beliefs about applying STEM in mathematics classes was developed and distributed online to mathematics teachers from middle and high schools in two metropolitan areas. Eighty-two surveys were returned from the teachers. Factor analysis revealed that the items were distributed among five main aspects. The findings indicated that most teachers believed in the necessity of implementing STEM education. However, some teachers expressed concerns about the effectiveness of implementation due to the lack of materials, resources, and equipment needed for STEM implementation.

Stomach Cancer Secondary to Hematologic Diseases (혈액질환에 속발하는 이차성 위암)

  • Kim, Ji-Hoon;Jee, Sung-Bae;Huh, Hoon;Chin, Hyung-Min;Kim, Wook;Kim, Dong-Wook;Lee, Jong-Wook;Min, Woo-Sung;Kim, Choon-Choo;Jeon, Hae-Myung
    • Journal of Gastric Cancer
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    • v.7 no.4
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    • pp.237-241
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    • 2007
  • Purpose: Patients with hematologic diseases such as chronic myeloid leukemia (CML) or chronic lymphoid leukemia (CLL) are known to have an increased chance of acquiring a secondary neoplasm. Stomach cancer is one of the most common malignant diseases in Korea, and we investigated whether the incidence of secondary stomach cancer in patients with a hematologic disease increases, in order to determine if a more intensive screening program for detecting secondary gastric cancer was required. We also investigated the safety of performing a gastrectomy in hematologic disease patients. Materials and Methods: From 1992 to 2006, the medical records of 8376 patients diagnosed with one of the six common hematologic diseases were reviewed. Results: Nine secondary stomach cancers were found among the 8376 patients during the 15-year observation period. No surgical-related complications occurred, and there was no recurrence of stomach cancer if detected early. Conclusion: It seems that a more intensive screening program for detecting secondary gastric cancer in hematologic disease patients is not required, and surgery is not risky in these patients.

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Influence of PVP on the Thickness of Ferroelectric (Na,K)NbO3 Film by Sol-Gel (솔-젤 법을 통해 제조된 강유전체 (Na,K)NbO3 막의 두께에 미치는 PVP의 영향)

  • Kim, Dae-Gun;Yoo, In-Sang;Kim, Sae-Hoon;Kim, Jin-Ho
    • Korean Journal of Materials Research
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    • v.22 no.12
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    • pp.696-700
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    • 2012
  • (Na, K) $NbO_3$ thick film was successfully achieved using a sol-gel coating process with the addition of polyvinylpyrrolidone (PVP) to a metal alkoxide solution. The transparent coating solution, mixed with Nb:PVP = 1:1 in a molar ration, was synthesized by evaporating the solvent to over 62.5 wt%. Additive PVP increased the viscosity of the solution so that the coating thickness could be enhanced. The thickness of the (Na, K) $NbO_3$ film assisted by PVP was ca. 320 nm at the time of deposition; this value is four times thicker than that of the sample fabricated without PVP. Also, due to PVP binding with the OH groups of the metal alkoxide, the condensation reaction in the film was suppressed. The crystalline size of the (Na, K) $NbO_3$ films assisted by PVP was ca. 15 nm smaller than that of the film fabricated without PVP. After the sintering process at $700^{\circ}C$, the (Na, K) $NbO_3$ films were mainly composed of randomly oriented (Na, K) $NbO_3$ phase of perovskite crystal structure, including a somewhat secondary phase of $K_2Nb_4O_{11}$. However, by adding PVP, the content of the secondary phase became quite smaller than that of the sample without PVP. It was thought that the addition of PVP might have the effect of restraining the loss of potassium and that PVP could hold metalloxane by strong hydrogen bonding before complete decomposition. Therefore, the film thickness of the (Na, K) $NbO_3$ films could be considerably advanced and made more crack-free by the addition of PVP.

A Study on the Effect of Graphene Substrate for Growth of Vanadium Dioxide Nanostructures (이산화바나듐 나노구조물의 성장에서 그래핀 기판의 영향에 관한 연구)

  • Kim, Ki-Chul
    • Journal of Convergence for Information Technology
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    • v.8 no.5
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    • pp.95-100
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    • 2018
  • The metal oxide/graphene nanocomposites are promising functional materials for high capacitive electrode material of secondary batteries, and high sensitive material of high performance gas sensors. In this study, vanadium dioxide($VO_2$) nanostructrures were grown on CVD graphene which was synthesized on Cu foil by thermal CVD, and exfoliated graphene which was exfoliated from highly oriented pyrolytic graphite(HOPG) using a vapor transport method. As results, $VO_2$ nanostructures on CVD graphene were grown preferential growth on abundant functional groups of graphene grain boundaries. The functional groups are served to nucleation site of $VO_2$ nanostructures. On the other hand, 2D & 3D $VO_2$ nanostructures were grown on exfoliated graphene due to uniformly distributed functional groups on exfoliated graphene surface. The characteristics of morphology controlled growth of $VO_2$/graphene nanocomposites would be applied to fabrication process for high capacitive electrode materials of secondary batteries, and high sensitive materials of gas sensors.

Manufacture of magnetite (Fe3O4) electrode and its electrochemical properties (마그네타이트 (Fe3O4) 전극의 제조와 전기화학 특성)

  • Kim, Myong-Jin;Kim, Dong Jin;Kim, Hong Pyo
    • Corrosion Science and Technology
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    • v.14 no.1
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    • pp.19-24
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    • 2015
  • Flow Accelerated Corrosion (FAC) causes unexpected accidents in a secondary side of a nuclear power plant. The secondary side pipes are mainly carbon steel tubes that have a protective magnetite ($Fe_3O_4$) layer on the inner surface. The stability of the protective magnetite layer depends on the parameters related to the FAC phenomena such as pH, temperature, flow rate, surface roughness etc. The dissolution of magnetite is basically the electrochemical reaction, but the most of the experiments of magnetite dissolution were carried out thermodynamically to determine the solubility of magnetite. The knowledge of the electrochemical properties of magnetite is required to understand the dissolution process of magnetite. This paper reviews the manufacture of the magnetite ($Fe_3O_4$) electrode, and summaries the electrochemical properties of the magnetite.

Study of Merchandising Process of Fur Clothing (모피의류의 상품화과정에 관한 연구)

  • Kim, Ji-Young
    • Journal of the Korea Fashion and Costume Design Association
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    • v.16 no.3
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    • pp.135-149
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    • 2014
  • Fur clothing as fashion items is expanding into casual & ladies's wear market as well as fur market. The interest of fur fashion is rising. So this study compares and analyzes the merchandising process of textile clothing also it of fur clothing by merchandising steps. Fur clothing has so many change factors at time of purchase by scarcity of raw material, price fluctuation, exchange rate and others. Therefore it is primarily about securing of raw material. As soon as plan of product is finished, the purchase of fur raw material has to be started while progress of design products for commercializing the fur clothing. The design of fur clothing is consist of material design, color design and shape design. And It makes a new trend & market as we are developing new & various treatments. The some of imported materials are transferred to the factory for being treated first dressing, fabric treatments and dyeing processing according to the design. The first treated materials are transferred to the sewing factory again for secondary treatments and finally inspected and shipped. During secondary treatments the fur has gone through various manufacturing process for using like fabric materials and it takes long time because almost work is running manually. Unlike fabric clothing, fur clothing's manufacturing method is complicated and various from material process to shape process as per feature. Therefore the merchandising with fur cannot make mass production also needs detail craftsmanship depending by expert's skills. On this wise the fur clothing takes long time to the completion thus it has been risky and costly.

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Evaluation of the Effectiveness of 3D Printing Shielding Devices using Monte Carlo Simulation in Plain Radiography (일반영상 검사 시 몬테칼로 시뮬레이션을 이용한 3D 프린팅 차폐기구의 효용성 평가)

  • Cho, Yong In;Kim, Jung Hoon
    • Journal of the Korean Society of Radiology
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    • v.14 no.3
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    • pp.303-311
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    • 2020
  • Scattering-ray generated during plain radiography can cause secondary exposure to organs and tissues other than the target area. Currently, Shielding devices used to reduce radiation exposure are mostly used for radiation protection of workers, and radiation protection of patients is rarely performed. Therefore, this study intends to evaluate the organ dose by scattered-rays and the effectiveness 3D printing materials as a radiation shielding device during plain radiography through simulation. As a result, the absorbed dose for each organ at the time of examination showed a high effect due to the secondary scattering-ray as the distance from the source was close and the organ closer to the skin surface. The dose reduction effect due to the use of 3D printing shielding devices to protect this showed a higher shielding effect in the case of mixed printing materials compared to plastics.

Development of Model Turtle Boat for Teaching-Learning in the Elementary and Secondary Schools (초·중등학교 교수-학습용 모형 거북선 개발)

  • Choi, Jun-Seop;Park, Sang-Jin
    • 대한공업교육학회지
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    • v.33 no.2
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    • pp.154-169
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    • 2008
  • The purpose of this study was to develop learning model turtle boat of teaching-learning materials in order for the students to enhance knowledge, skill and attitude and give interest in transportation technology, and also to recognize the legacy of Korean history. The model turtle boat was developed through three major phases; preparation, development and improvement. The main results of this study were as follows: First, the model turtle boat was developed for students to cultivate design, fabrication, process abilities, and also technological literacy by experimenting and fabricating for themselves. Second, the learning model turtle boat developed is equipped with the sail using natural energy, the linkage and screw applying a mechanical energy and solar cell using solar energy among driving energy. Third, in order to increase interest and attitude regarding a ship in transportation technology, the model turtle boat was developed for students to be able to operate with wireless transceiver on water. Fourth, the model turtle boat was developed to apply the teaching and learning materials for the classes of experiment and practice in primary and secondary schools.

Characteristics of Plasma Sprayed BSCCO Superconductor Coatings with Annealing Time After Partial Melt Process (BSCCO 플라즈마 용사피막의 부분용융열처리 후 어닐링 시간에 따른 초전도 특성)

  • Park, Jeong-Sik;Lee, Seon-Hong;Park, Kyeung-Chae
    • Korean Journal of Materials Research
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    • v.24 no.2
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    • pp.116-122
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    • 2014
  • $Bi_2Sr_2CaCu_2O_x$(Bi-2212) and $Bi_2Sr_2Ca_2Cu_3O_y$(Bi-2223) high-Tc superconductors(HTS) have been manufactured by plasma spraying, partial melt process(PMP) and annealing treatment(AT). A Bi-2212/2223 HTS coating layer was synthesized through the peritectic reaction between a 0212 oxide coating layer and 2001 oxide coating layer by the PMP-AT process. The 2212 HTS layer consists of whiskers grown in the diffusion direction. The Bi-2223 phase and secondary phase in the Bi-2212 layer were observed. The secondary phase was distributed uniformly over the whole layer. As annealing time goes on, the Bi-2212 phase decreases with mis-orientation and irregular shape, but the Bi-2223 phase increases because a new Bi-2223 phase is formed inside the pre-existing Bi-2212 crystals, and because of the nucleation of a Bi-2223 phase at the edge of Bi-2212 crystals by diffusion of Ca and Cu-O bilayers. In this study the spray coated layer showed superconducting transitions with an onset Tc of about both 115 K, and 50 K. There were two steps. Step 1 at 115 K is due to the diamagnetism of the Bi-2223 phase and step 2 at 50 K is due to the diamagnetism of the Bi-2212 phase.