• Title/Summary/Keyword: OER

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Study on the problems and improvement directions of OER systems (국내 OER(Open Educational Resource) 현황 분석 및 발전방향 탐색)

  • Jung, Hyojung;Kwon, Sukjin;Cho, Hangchol;Kim, Dongsik
    • Proceedings of the Korea Contents Association Conference
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    • 2011.05a
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    • pp.223-224
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    • 2011
  • 본 연구에서는 국내 OER의 현황을 분석하고, OER의 교육적 가치를 극대화하고 지속가능성을 확보하기 위한 발전 방향을 탐색하였다. 현황 분석 결과 국내 OER은 주로 기존의 전통적인 교육 콘텐츠를 무료로 제공하고 확산시키는 것에 초점을 맞추고 있다. 이는 더욱 넓은 의미에서 논의되고 있는 OER의 정의와 해외 동향을 살펴볼 때에 제한적이다. 본 연구는 본질적 의미에서의 '개방'을 실천하고, 사용자들의 '참여'를 유도함으로써 OER 활용을 촉진함으로써 더욱 진화된 형태의 OER을 실현할 수 있는 방안에 대하여 제안하였다.

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An Analysis of the Status of OER(Open Educational Resources) Usage in Asia (아시아지역의 공개교육자원 활용현황 분석)

  • Lee, Eunjung;Kim, Yong
    • Journal of Internet Computing and Services
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    • v.13 no.6
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    • pp.41-53
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    • 2012
  • Open educational resources(OER) enable the spread of mutual information exchange and provide advantages to both their users and institutions, such as reducing costs, improving content quality, and establishing relationships. The recent research on OER was about their connection to formal education, copyright trends, and corporate e-learning. There have been very few studies, however, on the utilization of OER and on the problems related to their practical use. Thus, this study was conducted for the purposes of analyzing the status of OER usage in education-related institutions and of providing suggestions for institution operation based on the analysis results, to promote the use of OER. A survey was conducted among more than 200 institutions in Asia, and the survey results showed that 'images and visual materials' are the most commonly used materials in Asia, and that the factors barring OER usage in the said region are 'lack of awareness', 'lack of skills', 'the absence of a reward system', and poor cooperation in participation. To promote OER usage, each institution should provide training courses about awareness, utilization skills, and copyrights. There is also a need to provide support for the establishment of reward systems and environments for OER usage. Finally, more active participation is required for inter-agency cooperation in OER sharing.

A study on analysis of OER service in University Libraries (국내 대학도서관 OER 현황분석에 관한 연구)

  • Han, Sun-Young;Hwang, Hee-Lim
    • Proceedings of the Korean Society for Information Management Conference
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    • 2016.08a
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    • pp.81-86
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    • 2016
  • 공개자원운동의 일환으로 등장한 OER, OCW 컨텐츠를 정보자원으로서 관리해야 할 필요성이 커지고 있다. 이에 본 연구는 국내 대학도서관 OER 현황분석을 하고자 한다. 이를 위해 성균관대학교, 숙명여자대학교, 부산대학교를 분석대상으로 선정하였으며, 컨텐츠 및 컨텐츠 품질, 홍보, 플랫폼 세 항목을 기준으로 분석하였다. 그 결과 첫째, OER을 정보자원으로서 체계적으로 수집 관리해야 할 대상으로 보고 있지 않았다. 둘째, OER 서비스 활성화를 위해 적극적으로 홍보가 이루어지지 않고 있었다. 셋째, 이용자들이 참여할 수 있는 OER 플랫폼은 구축되어 있으나 이용자들이 쉽게 접근할 수 있는 수준이라 보기 어려웠다. 이에 대한 해결 방안을 모색하여 대학도서관이 교내정보자원의 통합관리기관으로서 역할제고 방안에 대해 고찰하는 것에 의의가 있다.

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Nitrogen-doped Nickel Oxide Catalysts for Oxygen-Evolution Reactions (알칼라인 조건에서의 산소발생반응을 위한 N-doped NiO 촉매)

  • Lee, Jin Goo;Jeon, Ok Sung;Shul, Yong Gun
    • Korean Chemical Engineering Research
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    • v.57 no.5
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    • pp.701-705
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    • 2019
  • Oxygen-evolution reaction (OER) in alkaline media has been considered as a key process for various energy applications. Many types of catalysts have been developed to reduce high overpotential in OER, such as metal alloys, metal oxides, perovskite, or spinel. Nickel oxide (NiO) has high potential to increase OER activity according to volcano plots. The exact mechanisms for OER has not been discovered, but defects such as cation or anion vacancy typically act as an active site for diverse electrochemical reactions. In this study, nitrogen was doped into NiO by using ethylenediamine for formation of Ni vacancy, and the effects of N doping on OER activity and stability was studied.

Design Guidelines for Teachers' Professional Development Program that Help Improve Self-Regulated Learning Skills through OER (공개교육자원(OER)을 활용한 자기조절학습능력 향상을 위한 웹기반 교원연수 프로그램 설계 전략)

  • Cha, HyunJin;Park, TaeJung
    • The Journal of Korean Association of Computer Education
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    • v.16 no.5
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    • pp.69-83
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    • 2013
  • This study aims towards developing design guidelines for teachers' professional development programs (PDP) that help to improve self-regulated learning skills through OER (Open Educational Resources). To achieve the research objective, first, literature review and case studies about famous OER collections were conducted, and from these reviews, twenty-six guidelines according to ten categories suggested by Zimmerman & Martinez-Pons were derived and finalized into fifteen items in nine categories through review of five experts. Based on the guidelines, a prototype of a teacher's PDP was implemented and evaluated by seven teachers. Results of the usability evaluation proved that the design strategies implemented in the prototype might contribute to improving teacher's self-regulated learning skills and helped to find the teacher's needs based on their PDP.

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Heat-treatment effects on oxygen evolution reaction of nickel-cobalt layered double hydroxide

  • Lee, Jung-Il;Ko, Daehyeon;Mhin, Sungwook;Ryu, Jeong Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.31 no.3
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    • pp.143-148
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    • 2021
  • Alkaline oxygen evolution reaction (OER) electrocatalysts have been widely studied for improving the efficiency and green hydrogen production through electrochemical water splitting. Transition metal-based electrocatalysts have emerged as promising materials that can significantly reduce the hydrogen production costs. Among the available electrocatalysts, transition metal-based layered double hydroxides (LDHs) have demonstrated outstanding OER performance owing to the abundant active sites and favorable adsorption-desorption energies for OER intermediates. Currently, cobalt doped nickel LDHs (NiCo LDHs) are regarded as the benchmark electrocatalyst for alkaline OER, primarily owing to the physicochemical synergetic effects between Ni and Co. We report effects of heat-treatment of the as-grown NiCo LDH on electrocatalytic activities in a temperature range from 250 to 400℃. Electrocatalytic OER properties were analysed by linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). The heat-treatment temperature was found to play a crucial role in catalytic activity. The optimum heat-treatment temperature was discussed with respect to their OER performance.

Electrocatalytic properties of Nd1.5Ba1.5CoFeMnOx for water splitting (수전해용 Nd1.5Ba1.5CoFeMnOx 전기촉매 특성 분석)

  • Lee, Ho Jun;Cho, Kyungwon;Ryu, Jeong Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.30 no.1
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    • pp.17-20
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    • 2020
  • Developing effective and earth-abundant electrocatalyst for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is critical for the commercialization of a water splitting system. In particular, the overpotential of the OER is relatively higher than the HER, and thus, it is considered that one of the important methods to enhance the performance of the electrocatalyst is to reduce the overpotential of the OER. In this work, we present a simple synthetic route for triple perovskite Nd1.5Ba1.5CoFeMnOx with high performance OER and HER activity. This triple perovskite structure which shows high crystallinity through combustion method shows superior bifunctional catalytic performance in alkaline media. We believe that the prepared triple provskite with high performance OER and HER activity can give further feasibility for the commercialization of a water splitting system.

Association between Optic Nerve Sheath Diameter/Eyeball Transverse Diameter Ratio and Neurological Outcomes in Patients with Aneurysmal Subarachnoid Hemorrhage

  • Jinsung Kim;Hyungoo Shin;Heekyung Lee
    • Journal of Korean Neurosurgical Society
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    • v.66 no.6
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    • pp.664-671
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    • 2023
  • Objective : The optic nerve sheath diameter (ONSD)/eyeball transverse diameter (ETD) ratio is a more reliable marker of intracranial pressure than the ONSD alone. We aimed to investigate the predictive value of the ONSD/ETD ratio (OER) for neurological outcomes in patients with aneurysmal subarachnoid hemorrhage (aSAH). Methods : Adult patients with aSAH who visited the emergency department of a tertiary hospital connected to a South Korean university between January 2015 and December 2021 were included. Data on patient characteristics and brain computed tomography scan findings, including the ONSD and ETD, were collected using a predefined protocol. According to the neurological outcome at hospital discharge, the patients were divided into the unfavorable neurological outcome (UNO; cerebral performance category [CPC] score 3-5) and the favorable neurological outcome (FNO; CPC score 1-2) groups. The primary outcome was the association between the OER and neurological outcomes in patients with aSAH. Results : A total of 171 patients were included in the study, of whom 118 patients (69%) had UNO. Neither the ONSD (p=0.075) nor ETD (p=0.403) showed significant differences between the two groups. However, the OER was significantly higher in the UNO group in the univariate analysis (p=0.045). The area under the receiver operating characteristic curve of the OER for predicting UNO was 0.603 (p=0.031). There was no independent relationship between the OER and UNO in the multivariate logistic regression analysis (adjusted odds ratio, 0.010; p=0.576). Conclusion : The OER was significantly higher in patients with UNO than in those with FNO, and the OER was more reliable than the ONSD alone. However, the OER had limited utility in predicting UNO in patients with aSAH.

Low-iridium Doped Single-crystalline Hydrogenated Titanates (H2Ti3O7) with Large Exposed {100} Facets for Enhanced Oxygen Evolution Reaction under Acidic Conditions ({100} 단결정 수소화 티타네이트(H2Ti3O7)를 활용한 저함량 Irridium 수전해 양극 촉매 개발)

  • Sun Young Jung;HyukSu Han
    • Journal of the Microelectronics and Packaging Society
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    • v.30 no.1
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    • pp.79-89
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    • 2023
  • Development of efficient and stable electrocatalysts for oxygen evolution reaction (OER) under acidic conditions is desirable goal for commercializing proton exchange membrane (PEM) water electroyzer. Herein, we report iridium-doped hydrogenated titanate (Ir-HTO) nanobelts as a promising catalyst with a low-Ir content for the acidic OER. Addition of low-Ir (~ 3.36 at%) into the single-crystalline HTO nanobelts with large exposed {100} facets significantly boost catalytic activity and stability for OER under acidic conditions. The Ir-HTO outperforms the commenrcial benchmark IrO2 catalyst; an overpotential for delivering 10 mA cm-2 current density was reduced to about 25% for the Ir-HTO. Moreover, the catalytic performance of Ir-HTO is positioned as the most efficient electrocatalyst for the acidic OER. An improved intrinsic catalytic activity and stability are also confirmed for the Ir-HTO through in-depth electrochemical characterizations. Therefore, our results suggest that low-Ir doped single-crystalline HTO nanobelts can be a promising catalyst for efficient and durable OER under acidic conditions.

Size Effects of MoS2 on Hydrogen and Oxygen Evolution Reaction

  • Ghanashyam, Gyawali;Jeong, Hae Kyung
    • Journal of Electrochemical Science and Technology
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    • v.13 no.1
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    • pp.120-127
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    • 2022
  • Molybdenum disulfide (MoS2) has been widely used as a catalyst for the bifunctional activities of hydrogen and oxygen evolution reactions (HER and OER). Here, we investigated size dependent HER and OER performance of MoS2. The smallest size (90 nm) of MoS2 exhibits the lowest overpotential of -0.28 V at -10 mAcm-2 and 1.52 V at 300 mAcm-2 with the smallest Tafel slopes of 151 and 176 mVdec-1 for HER and OER, respectively, compared to bigger sizes (2 ㎛ and 6 ㎛) of MoS2. The better HER and OER performance is attributed to high electrochemical active surface area (6 × 10-4 cm2) with edge sites and low charge transfer resistance (18.1 Ω), confirming that the smaller MoS2 nanosheets have the better catalytic behavior.