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        검색결과 427

        3.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        태풍은 지구 시스템 내의 해양-대기-육상 상호작용을 일으키는 매우 중요한 현상으로 특히 태풍의 특성 인자 중 하나인 풍속은 중심 기압, 이동 경로, 해수면 온도 등의 매개변수에 의해 복잡하게 변화하여 실제 관측 자료를 기반으 로 이해하는 것이 중요하다. 2015 개정 교육과정 기반 중등학교 교과서에서 태풍 풍속은 본문 내용 및 삽화의 형태로 제시되고 있어 풍속에 대한 심층적 이해가 가능한 탐구활동이 무엇보다 필요한 실정이다. 본 연구에서는 교수-학습 과 정에서 간단한 조작만으로도 태풍의 풍속을 이해할 수 있도록 그래픽 사용자 인터페이스(GUI)를 기반으로 한 데이터 시각화 프로그램을 개발하였다. 2023년 발생한 태풍 마와르, 구촐, 볼라벤의 천리안 위성 2 A호 RGB (Red-Green-Blue) 영상 자료를 입력 자료로 활용하였다. 태풍 주변의 구름 이동 좌표를 입력하여 태풍의 풍속을 산출하고 태풍 중심 기 압, 폭풍 반경, 최대 풍속 등의 매개 변수를 입력하여 태풍 풍속 분포를 시각화 할 수 있도록 설계하였다. 본 연구에서 개발된 GUI 기반 프로그램은 천리안 위성 2 A호로 관측 가능한 태풍에 대해 오류 없이 적용 가능하며 교과서의 시공 간적 한계를 벗어난 실제 관측 자료 기반의 과학탐구활동이 가능하다. 학생과 교사는 별도의 유료 프로그램 및 전문적 인 코딩 지식이 없어도 실제 관측 자료를 수집, 처리, 분석, 시각화하는 과정을 경험할 수 있으며, 이를 통해 미래 정보 화 사회에서의 필수 역량인 디지털 소양을 함양시킬 수 있을 것으로 기대된다.
        5,400원
        6.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The secondary growth model for Salmonella was developed based on the artificial neural network (ANN) with data collected from ComBase and FoodData Central. In addition to the existing secondary model variables (temperature, pH, Na+, and water contents), more input variables (sugar, carbohydrate, lipid, and protein contents) were considered. The output variables were microbial growth parameters (lag phase duration [l] and maximum growth rate [mmax]). A commercial ANN program (NeuralWorks Predict) was utilized with training at 80%, validation at 10%, and test data at 10%. ANN models were created using all data and cleansed data. Using the cleansed data, the training/testing root mean square error (RMSE) for mmax improved from 0.14/0.16 to 0.11/0.14, whereas the RMSE for l was still not acceptable, from 11.94/33.03 to 7.09/4.18. The l data were divided into two ranges with high and low goodness of fit, whereas the ANN model for each field was built, resulting in an optimally low RMSE.
        4,000원
        7.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The waste secondary battery contains a significant amount of valuable metals, making its recycling highly desirable. However, conventional chemical methods for recycling are environmentally unfriendly and cost-ineffective. Rather than the chemical method, this paper deals with a mechanical method for recovering electrode materials from waste secondary batteries by blowing pressurized air onto the interface area between the electrode and the separator. Especially, in this study, the effective blowing angle were searched by simulating the separation of the electrode material from the separator through 1-way fluid structure interaction analysis based on the Cohesive Zone Modeling technique.
        4,000원
        8.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated quality characteristics and functionality of rose sparkling wine that were manufactured by secondary fermentation after inoculation of yeast strains. The pH of the samples ranged from 3.96 to 4.05 and total acidity ranged from 0.23 to 0.32%. The alcohol contents of wines ranged from 6.4 to 6.6% and the CO2 pressure ranged from 2.0 to 2.6 bar. The brightness of rose wines ranged from 84.72 to 87.36, the redness from 9.28 to 14.15, and the yellowness from 9.50 to 19.20. The hue value of wines ranged from 1.137 to 1.513 and color intensity ranged from 0.724 to 0.882. Aroma analysis identified 14 alcohols, 22 esters, 4 ketones, 4 acids, and 17 miscellaneous compounds. The total tannin contents and total polyphenol contents of wines were 11.28~12.43 mg% and 24.79~28.20 mg%, respectively. The DPPH radical scavenging activity of wines ranged 63.33 to 67.89% and the ABTS radical scavenging activity of wines 82.16~86.06%. The results of this study provide a basis for establishing the brewing process of rose sparkling wines yeast strains.
        4,200원
        9.
        2023.11 구독 인증기관·개인회원 무료
        Heavy water primary system decontamination technology is essential to reduce worker exposure and improve safety during maintenance and decommissioning of nuclear facilities. Advanced decontamination technology development aims to secure controlled decontamination technologies that can reduce the cost of radiation exposure and dramatically reduce the amount of secondary waste generated when decontaminating large equipment and large-area facilities. We conducted a study to identify candidate corrosion inhibitors through the literature and analyze the degree of corrosion of carbon steel samples. Countries with advanced nuclear technology have developed chemical decontamination technology for the entire nuclear power generation system and applied it to the dismantling and maintenance of nuclear power plants. In the decontamination process, the corrosion oxide film must be removed. If the base metal is corroded by the decontaminant in this process, additional secondary waste is generated and treatment costs increase. Therefore, it is necessary to develop a corrosion inhibitor that inhibits the corrosion of the carbon steel base metal in the decontamination process to generate a secondary waste liquid that is favorable for waste reduction and treatment. In this presentation, a study was conducted to analyze the extent of corrosion on a carbon steel base material and identify candidate materials for corrosion inhibition testing. Samples were analyzed using optical microscopy and EPMA analysis to determine the thickness of the corroded oxide film. EPMA analysis also allowed us to map the elemental distribution of the carbon steel corrosion layer, which we plan to quantify in the future. The candidate materials for organic-based corrosion inhibitor were also selected based on their inhibition mechanism; having high electronegative elements for coordinate covalent bonding at metal surface and hydrophobic nonpolar group for preventing access of corrosive substances.The selection of candidate materials for corrosion inhibition testing was based on the mechanism of the corrosion inhibitor. Organic-based corrosion inhibitors are adsorbed by donor-acceptor interactions between metal surfaces and highly electronegative elements. Corrosion can also be inhibited by arranging hydrophobic nonpolar groups on metal surfaces in the solution direction to prevent access of corrosive substances.
        10.
        2023.11 구독 인증기관·개인회원 무료
        Kori Unit 1 nuclear power plant is a pressurized water reactor type with an output of 587 Mwe, which was permanently shut down on June 18, 2017. Currently, the final decommissioning plan (FDP) has been submitted and review is in progress. Once the FDP is approved, it is expected that dismantling will begin with the secondary system, and dismantling work on the primary system of Kori Unit 1 will begin after the spent nuclear fuel is taken out. It is expected that the space where the secondary system has been dismantled can be used as a temporary storage place, and the entire dismantling schedule is expected to proceed without delay. The main equipment of the secondary system is large and heavy. The rotating parts is connected to a single axis with a length of about 40 meters, and is complexly installed over three floors, making accessibility very difficult. A large pipe several kilometers long that supplies various fluids to the secondary system is installed hanging from the ceiling using a hanger between the main devices, and the outer diameter of the pipe is wrapped with insulation material to keep warm. In nuclear secondary system decommissioning, it is very important to check for radiation contamination, establish and implement countermeasures, and predict and manage safety and environmental risks that may occur when cutting and dismantling large heavy objects. So we plan to evaluate the radiation contamination characteristics of the secondary system using ISOCS (In- Situ Object Counting System) to check for possible radioactive contamination. According to the characteristics results, decommissioning plans and methods for safe dismantling by workers were studied. In addition, we conducted research on how to safely dismantle the secondary system in terms of industrial safety, such as asbestos, cutting and handling of heavy materials and so on. This study proposes a safe decommissioning method for various risks that may occur when dismantling the secondary system of Kori Unit 1 nuclear power plant.
        11.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examines the characteristics of berries from secondary bearing shoots of ‘Scintilla’ southern highbush blueberry, grown hydroponically in the Jinju, Gimhae, and Uiryeong regions of Gyeongnam Province. Typically, ‘Scintilla’ forms flower buds at the tips of regular bearing shoots during the previous season, yielding berries in the current season. However, under heated cultivation, we observed a proliferation of secondary bearing shoots that produce berries in the same growing season. Flowering and harvesting on secondary bearing shoots were delayed by 52 and 36 days, respectively, compared to regular bearing shoots. However, these shoots exhibited a 54% increase in diameter and a 10% increase in length. We found no significant difference in berry size and soluble solid content between the two types of shoots. Notably, berries from the secondary bearing shoots had higher potassium and lower calcium and magnesium concentrations. We conclude that berries from secondary bearing shoots could be marketable, provided the bushes are healthy. These findings provide valuable insights for optimizing cultural practices to improve the yield and quality of blueberries under specific environmental conditions.
        4,000원
        12.
        2023.10 구독 인증기관·개인회원 무료
        The beet armyworm, Spodoptera exigua, is one of the worldwide distributed agricultural pest insects and has been known to show high resistance to conventional chemical insecticides. Since it has been reported that secondary metabolites from actinomycetes show insecticidal activities against various insect pests, actinomycetes could be a potential source of insecticidal compounds. In this study, culture extracts of Streptomyces strains were tested for their insecticidal activity against Spodoptera exigua. Among them, culture extracts of IMBL-0003 strain which was identified as Streptomyces celluloflavus showed a high insecticidal activity (more than 90% mortality). These results suggested that secondary metabolites of this isolate could have potentials to be a efficient eco-friendly pesticide for controling Spodoptera exigua.
        15.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate preservice teachers’ understanding of democratic citizenship. This study utilized the democratic citizenship frame to assess 17 participants’ comprehension of this concept. The researcher designed a method course where participants in groups analyzed science activities to identify democratic citizenship components. Through the analysis of two science activities—one on energy and the other on climate change—and the development of science panels addressing various global issues, preservice teachers' understanding of democratic citizenship was enhanced. Preservice teachers showed a good understanding of critical thinking, communication and collaboration, and STS (science, technology, and society); and the most enhanced understanding of empathy, which was the least perceived in pre-survey, component of democratic citizenship. The democratic citizenship frame proved to be a valuable tool for teaching and learning this topic, particularly when applied to socioscientific issues in the classroom. More research-based revisions of the science curriculum are necessary, and more systematic practices with reflections are essential in teacher education.
        5,100원
        16.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2023년 3월, EU는 안전하고 다양하며 저렴하고 지속 가능한 주요 원 자재 공급에 접근하는 포괄적인 조치인 핵심 원자재법(CRMA:Critical Raw Materials Act)을 채택하였다. CRMA의 핵심은 총 4가지로 구분 할 수 있다. EU전체 연간 소비량 대비 최소 10%이상을 역내에서 채굴 하고 핵심원자재 역내 가공량을 최대 40%이상으로 하며 핵심원자재 역 내 재활용 비율을 최소 15%까지 끌어올리기로 목표한 것이다. 또한 모 든 가공 단계에서 특정 국가에 대한 수입량을 EU연간 소비량의 65%를 제한 하였다. CRMA의 출현에 따라 중동부유럽 내에서 선전하고 있는 우리 자동차 기업과 배터리 생산기업에도 변화가 있을 것이며 핵심원자 재 법에 따른 대응방안을 강구해야 할 필요가 있다. 따라서 본 논문에서 는 중동부유럽 2차전지 기업 현황을 살펴보고 EU 핵심원자재법 출현에 따른 대응방안을 제시해 보고자 한다.
        6,100원
        17.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : In this study, we aim to broaden the understanding of the factors influencing the accuracy of WIM systems for overload enforcement. Particularly, we explored the proportions and causes of secondary influencing factors (driving path, vehicle class, and acceleration), which have been relatively less studied and reduced the accuracy of the WIM system. METHODS : Overload enforcement data were recorded by the WIM system, and enforcement officers were gathered. The ratios of each data point, which are the relative errors, are used to estimate the accuracy of the WIM system. These relative errors were classified into four driving-path groups, four vehicle-class groups, and three acceleration groups. The change in the accuracy of the WIM system caused by each influencing factor was analyzed by comparing the difference in the average relative error between the classified groups. Analysis of variance (ANOVA) and Welch's ANOVA were used to determine significant differences between groups. RESULTS : Vehicles departing from a normal driving path make it difficult for the GVW compensation algorithm of the WIM system to operate properly. For these abnormal paths, the standard deviation of the average GVW relative error was 22%. There was no specific trend in the difference in accuracy by vehicle class. However, we found that the rear axle and retractable axle were the main causes of the reduced GVW accuracy in each vehicle class. The average GVW relative error remained the same regardless of the acceleration, but the average FAW relative error of the accelerated vehicle was approximately 2.5% lower than that of the unaccelerated vehicle. CONCLUSIONS : An abnormal driving path, lifting of a retractable axle, and rapid acceleration (or deceleration) reduce the accuracy of WIM systems. Intelligent transportation systems, such as traffic signals, telematics devices, and applications that induce desirable driving are required for effective overload enforcement. Additionally, it is necessary to smoothen the road pavement to minimize the dynamic effects on the rear axle.
        4,200원
        18.
        2023.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 실험은 마이크로웨이브 처리가 상추 유묘의 생육 변화와 이차대사산물 함량의 변화를 알아보고자 수행되었다. 파종 후 3주째 상추 유묘에 2.45GHz 주파수와 200W의 마이크로 웨이브를 0, 4, 8 및 12초 동안 처리하고, 4주간 식물공장에서 재배한 후 생육 및 성분 분석을 수행하였다. 지하부와 지상부 의 생체중과 건물중, 엽면적, 엽장 및 엽수는 마이크로웨이브 처리시간이 증가할수록 감소하였다. 4초 처리구와 비교하여 12초 처리구에서 chlorophyll a, chlorophyll b 및 총 carotenoids 의 함량이 증가되었으며 총 페놀 함량은 감소하였다. 무처리 구와 비교하여 8초 처리구에서 총 플라보노이드 함량이 감소 하였다. 이러한 결과들은 산화적 스트레스에 의해 이차대사 산물 함량이 변화된 것으로 사료된다. 총 플라보노이드 함량 을 제외한 이차대사산물 함량은 각 처리구에서 무처리구와 비 교하여 유의한 차이가 없었지만, 각 처리구 사이의 유의한 차 이는 200W와 2.45GHz의 마이크로웨이브 처리가 4주 후 상 추의 이차대사산물 함량에 영향을 줄 수 있다는 것을 시사한다.
        4,000원
        19.
        2023.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This paper presents a case study of developing a blended reading program for Korean EFL middle school students using a process drama methodology to generate intrinsic motivation to read, improve reading comprehension and language fluency, and foster twenty-first-century skills such as creativity, communication, and cooperation. For the development of the reading program, a needs analysis was conducted using student questionnaires and diagnostic tests. From results of the needs analysis, sample lessons were designed based on the process drama methodology following its planning principles and strategies. Based on feedback from teachers and students after piloting the sample lessons, the blended reading program was finalized. The proposed blended reading program is expected to help Korean EFL middle school students build a positive attitude toward reading English books and develop reading comprehension, language fluency, and 21st-century core competencies. It will also encourage English teachers to use innovative teaching methods in English education.
        8,300원
        20.
        2023.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To develop a high capacity lithium secondary battery, a new approach to anode material synthesis is required, capable of producing an anode that exceeds the energy density limit of a carbon-based anode. This research synthesized carbon nano silicon composites as an anode material for a secondary battery using the RF thermal plasma method, which is an ecofriendly dry synthesis method. Prior to material synthesis, a silicon raw material was mixed at 10, 20, 30, 40, and 50 wt% based on the carbon raw material in a powder form, and the temperature change inside the reaction field depending on the applied plasma power was calculated. Information about the materials in the synthesized carbon nano silicon composites were confirmed through XRD analysis, showing carbon (86.7~52.6 %), silicon (7.2~36.2 %), and silicon carbide (6.1~11.2 %). Through FE-SEM analysis, it was confirmed that the silicon bonded to carbon was distributed at sizes of 100 nm or less. The bonding shape of the silicon nano particles bonded to carbon was observed through TEM analysis. The initial electrochemical charging/ discharging test for the 40 wt% silicon mixture showed excellent electrical characteristics of 1,517 mAh/g (91.9 %) and an irreversible capacity of 133 mAh/g (8.1 %).
        4,000원
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