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        검색결과 61

        1.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        According to previous studies, the El Niño Southern Oscillation (ENSO) does not appear to regulate TC activity over Korea. By dividing the TC season into two sub-seasons, i.e. summer and autumn, we found the opposite response of TC activity over Korea to ENSO phases between the sub-seasons. In summer, about 1.2 more TCs affect Korea during El Niño than during La Niña, while about 1.2 fewer TCs do so in autumn. The opposite responses to ENSO could reduce the statistical significance of the relationship between ENSO and TC activity over Korea when the entire TC season (July to October) is considered. In summer, the southerly anomaly over the southern sea of the Korean peninsula due to the eastward retreating subtropical high allows a greater number of TCs to approach Korea during El Niño compared to La Niña. On the other hand, in autumn, the northwesterly anomaly due to the westward extension of the subtropical high leads to a smaller number of TC approaches.
        4,000원
        2.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study introduces a novel approach for identifying potential failure risks in missile manufacturing by leveraging Quality Inspection Management (QIM) data to address the challenges presented by a dataset comprising 666 variables and data imbalances. The utilization of the SMOTE for data augmentation and Lasso Regression for dimensionality reduction, followed by the application of a Random Forest model, results in a 99.40% accuracy rate in classifying missiles with a high likelihood of failure. Such measures enable the preemptive identification of missiles at a heightened risk of failure, thereby mitigating the risk of field failures and enhancing missile life. The integration of Lasso Regression and Random Forest is employed to pinpoint critical variables and test items that significantly impact failure, with a particular emphasis on variables related to performance and connection resistance. Moreover, the research highlights the potential for broadening the scope of data-driven decision-making within quality control systems, including the refinement of maintenance strategies and the adjustment of control limits for essential test items.
        4,000원
        4.
        2023.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigates the influence of the type of lipid phase (corn oil [CO], palm oil [PO], MCT oil [MO], lemon oil [LO]) on the physical characteristics and bioactive peptide (BP) encapsulation in food-grade water-in-oil-in-water (W/O/W) double emulsions. The stabilities of the double emulsions were analyzed for droplet size characteristics, viscosity, dynamic rheological properties, encapsulation efficiency (EE), and release rate of BP (at different temperatures: 4, 25, 37, and 60oC) for 28 days. The encapsulated BP acts as an active substance in the osmotic balance and destabilization of the double emulsion system. For the effect of the oil phase, double emulsions prepared with PO showed the best droplet stability without phase separation (D50 < 1 m) and high BP retention (EE > 60%). In the release rate at high temperatures (60oC), the BP released from double emulsions was in the order of MO > CO > LO > PO over time. In contrast, the BP release from double emulsions at low temperatures (< 37oC) had no difference depending on the oil type. Therefore, the information obtained from this work is useful for preparing stable, functional food or cosmetic products from double emulsions using a BP.
        4,000원
        5.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study focused on improving the phase stability and mechanical properties of yttria-stabilized zirconia (YSZ), commonly utilized in gas turbine engine thermal barrier coatings, by incorporating Gd2O3, Er2O3, and TiO2. The addition of 3-valent rare earth elements to YSZ can reduce thermal conductivity and enhance phase stability while adding the 4-valent element TiO2 can improve phase stability and mechanical properties. Sintered specimens were prepared with hot-press equipment. Phase analysis was conducted with X-ray diffraction (XRD), and mechanical properties were assessed with Vickers hardness equipment. The research results revealed that, except for Z10YGE10T, most compositions predominantly exhibited the t-phase. Increasing the content of 3-valent rare earth oxides resulted in a decrease in the monoclinic phase and an increase in the tetragonal phase. In addition, the t(400) angle decreased while the t(004) angle increased. The addition of 10 mol% of 3-valent rare-earth oxides discarded the t-phase and led to the complete development of the c-phase. Adding 10 mol% TiO2 increased hardness than YSZ.
        4,000원
        6.
        2023.06 구독 인증기관 무료, 개인회원 유료
        The words for the moon phase in the inscriptions on bronze wares in the Zhou dynasty are open to different interpretations, and the calculation of the moon phase dates clarifies the ambiguities of the bronze moon phase words. Calculation of the time interval between the calendar solunar dates in two bronze ware inscriptions can be made, because the calendar solunar dates (gan-zhi 干支) were in a constant cycle of 60 days. Calculation of the date interval between the two moon phases on the same two bronze ware inscriptions also can be made , because the moon phase is also in cycles. The narrative tradition in the inscriptions of the Shang and Zhou dynasties includes a date series: the day in the solunar cycle, the month and the year of a king’s reign, and the day in the moon phase cycle. By comparing whether the two intervals meet or not, one can verify whether the bronze moon-phase idioms are meaningful, and it can also be confirmed whether the chronology of the kings of Zhou compiled by the previous scholars is resonable and create a new chronology through iterative calculation. The time intervals calculated in this paper chronicle every imperial event from the Zhou dynasty to the Shang dynasty, which rebuild a new chronology for the Xia, Shang, and Zhou dynasties. All modern attempts are hindered by a basic assumption, that the bone calendar of the Shang Dynasty is the same as the bronze calendar of the Zhou Dynasty, but it is completely different from the bronze calendar of Zhou, when reading the Bronze Annals (this paper) alongside the Bone Annals (last paper) and as seen in Table 24. In addition, although the inscriptions related to the lunar phases are extremely difficult to understand, through computation, the records of three lunar eclipses on bronze vessels in the Zhou and Shang dynasties are newly recognized, which helps to reconstruct a new chronological list of the kings of Zhou.
        11,900원
        7.
        2022.12 구독 인증기관 무료, 개인회원 유료
        Modern attempts to decipher the Shang bone scripts have been hampered by the fundamental assumption that the scripts are recordings of the sound of the language and not ideas. Some phonetic “translations” could be proposed without the possibility of verification, and some graphic “translations” without meanings are seen as the names of sacrificial rituals by previous scholars. Actually, a character is derived from a thought, and the thought is derived from a figuration, while the figuration itself is derived from the graphed object or event. Therefore, the same character can be used in different dialects or languages to depict the same concepts. Based on the bone scripts being ideograms, several bone scripts used frequently for the names of the day were assumed to be the moon phases; thus, the time interval between two corresponding days with its moon phase was calculated for verification. Extensionally, according to the time interval between the two days, and the moon phase recorded on the bone tablets (or bronze wares) and the chronological table of the kings of Shang compiled by the pre vious scholars, the assumptions of the moon phase characters are attested by the calculations of the numbering days of the solunar date. Solunar dates (Chinese: Gan-Zhi 干支) were used to record dates with a cycle of 60 days. Conversely, on consideration of the dates and moon phases for the bone inscription events, the prevous chronology is improved with iterative methed, and we propose new chronology for Shang kings. In addition, through computation, three records of a lunar eclipse on the Shang bronze inscriptions and on the Zhou bronze vessels are newly recognized, which helps to reconstruct the years of the kings of Shang and of the kings of Zhou; the Shang bone calendar’s New Year started from the summer solstice of the year, from the full moon of the lunar phase and from the dawn of the day.
        13,700원
        10.
        2021.09 구독 인증기관 무료, 개인회원 유료
        The physicochemical properties of crystalline titanium dioxide nanoparticles (TiO2 NPs) were investigated by comparing amorphous (amTiO2), anatase (aTiO2), metaphase of anatase-rutile (arTiO2), and rutile (rTiO2) NPs, which were prepared at various calcination temperatures (100℃, 400℃, 600℃, and 900℃). X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses confirmed that the phase-transformed TiO2 had the characteristic features of crystallinity and average size. The surface chemical properties of the crystalline phases were different in the spectral analysis. As anatase transformed to the rutile phase, the band of the hydroxyl group at 3,600–3,100 cm–1 decreased gradually, as assessed using Fourier transform infrared spectroscopy (FT-IR). For ultraviolet-visible (UVVis) spectra, the maximum absorbance of anatase TiO2 NPs at 309 nm was blue-shifted to 290 nm at the rutile phase with reduced absorbance. Under the electric field of capillary electrophoresis (CE), TiO2 NPs in anatase migrated and detected as a broaden peak, whereas the rutile NPs did not. In addition, anatase showed the highest photocatalytic activity in an UV-irradiated dye degradation assay in the following order: aTiO2 > arTiO2 > rTiO2. Overall, the phases of TiO2 NPs showed characteristic physicochemical properties regarding size, surface chemical properties, UV absorbance, CE migration, and photocatalytic activity.
        4,000원
        11.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        예이츠의 가이어는 예이츠의 또 다른 중요한 상징 원 또는 대차륜과 밀접한 관련이 있다. 예이츠의 대차륜은 달의 28개 월상(月像)으로 구성되어 있으며 각각의 상은 인간의 서로 다른 성품을 구현하고 있다. 본 연구의 목적은 『환상록』에 나오는 기하학적인 상징체계인 달에 대하여 살펴보므로 예이츠의 작품을 이해하는 데 도움을 주는 데 있다. 이를 위해 달의 28 국면을 예이츠의 상징체계에 영향을 준 것과 관련시켜 다루고자 한다.
        5,100원
        13.
        2020.11 구독 인증기관 무료, 개인회원 유료
        This study reviews two decades of literature on three (i.e., resource, investment and integrative) phases of marketing, identifies the marketing capability gaps from the phases and applies the insights to an emerging market context. The study found that there are unique marketing capability gaps at each of the three marketing phases. While marketing managers try to close the gaps, the fast changing socio-demographic, economic, technological environments, and even the growing power of emerging markets created more gaps. The gaps are wider in emerging markets alongside opportunities these markets provide. The findings and suggested solutions are summarized in a conceptual model.
        4,800원
        14.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구의 목적은 실제 관찰의 맥락을 강조한 달의 위상 변화 문제를 해결하는 과정에서 드러나는 초등 예비교사의 설명 유형과 그 특징을 파악하여 초등 교사 양성 프로그램에서 고려해야 할 부분에 대한 시사점을 제공하는데 있다. 이를 위해 초등 예비교사 30명이 관찰 가능한 달의 위상을 설명한 내용을 분석하였으며, 주요한 연구 결과는 다음 과 같다. 첫째, 달의 위상 변화에 대해 현상의 관찰과 이에 대한 과학적 추론에 바탕을 두기 보다는 달의 위상별 출몰 시간표를 도입하여 설명하는 경우가 많았다. 둘째, 태양이 뜨면 달이 보이지 않거나 또는 달이 떠 있다면 무조건 달을 관찰할 수 있다고 생각하는 유형의 대안 개념이 확인되었다. 셋째, 달을 관찰할 수 있는 시각과 방위에 대해서는 태양의 위치와 무관하게 관찰할 수 있다거나 남중할 때 관찰할 수 있다고 설명하는 경우도 있었다. 또한 달을 관찰하는 날짜는 음력으로 상정하여 접근하는 방식도 볼 수 있었다. 이상의 결과로부터 교육학적인 시사점을 논의하였다.
        4,600원
        15.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        One of the promising candidates for accident-tolerant fuel (ATF), a ceramic microcell fuel, which can be distinguished by an unusual cell-like microstructure (UO2 grain cell surrounded by a doped oxide cell wall), is being developed. This study deals with the microstructural observation of the constituent phases and the wetting behaviors of the cell wall materials in three kinds of ceramic microcell UO2 pellets: Si-Ti-O (STO), Si-Cr-O (SCO), and Al-Si-Ti-O (ASTO). The chemical and physical states of the cell wall materials are estimated by HSC Chemistry and confirmed by experiment to be mixtures of Si-O and Ti-O for the STO; Si-O and Cr-O for SCO; and Si-O, Ti-O, and Al-Si-O for the ASTO. From their morphology at triple junctions, UO2 grains appear to be wet by the Si-O or Al-Si-O rather than other oxides, providing a benefit on the capture-ability of the ceramic microcell cell wall. The wetting behavior can be explained by the relationships between the interface energy and the contact angle.
        4,000원
        16.
        2019.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The microstructure, phase, and mechanical properties of three aged porcelain insulators which were manufactured in different years (1973, 1995 and 2008) and which were used in the field for different amounts of time, were investigated. With X-ray 3D computed tomography (CT), defects with ~mm size can be detected without destroying the aged insulators. Defects of small specimens, which are cut from the aged insulators and polished, are analyzed with optical and scanning electron microscopy (OM and SEM), and defects of um size are detected by OM and SEM. The number and size of defects in all the aged insulators are similar. Porcelain insulators manufactured in 1973 contain more SiO2 (quartz and cristobalite) than those manufactured in 2008. Those manufactured in 2008 contain more Al2O3 than those manufactured earlier. The Vickers hardness of the insulator manufactured in 1973 has the lowest value. The formation of the cristobalite (SiO2) in the insulator manufactured in 1973 which can come from the phase transformation of quartz can cause stress in the insulator by formation of microcracks, which can lead to the low hardness of the insulator.
        4,000원
        18.
        2018.10 구독 인증기관·개인회원 무료
        본 연구는 산림, 하천, 자연 녹지 등 자연생태환경과 격리된 도심 속의 생태적 패치를 분석하고 이해하여 생태적 가치가 높은 생태 환경을 조성하는 방안을 모색해 보고자 실시하였다. 분석 대상지역은 도심 속의 생태적 패치로 다양한 입지 조건으로 조성되어 활용되고 있는 국립과천과학관(경기도 과천시 상하벌로 110일원) 일대를 중심으로 선정하였다. 생태적 패치(patch) 입지별 4개의 구역으로 구분하였고 각 조사 구역 별 결과에서 곤충상은 Ⅰ구역에서 61과 135종, Ⅱ구역에서 31과 46종, Ⅲ구역에서 31과 42종, Ⅳ구역에서 13과 14종 등으로 구분되었다. 전체 조사구역의 군집 분석 결과, 다양성 지수 4.30, 종풍부도 22.74, 균등도 0.84 등으로 구분되었다. 조사 결과, 수환경과 키 작은 수목을 중심으로 하고 경작 및 원예가 재배되는 Ⅰ구역에서 종 조성이 다양하게 분포하였고 소규모 생태적패치를 조성할 경우 수환경과 원예화원, 소규모 경작지 등이 분포할때 종 다양성이 높고 생태적으로 안정된 양상이 될 것으로 기대된다.
        19.
        2018.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Hydrothermal synthesis of highly crystalline TiO2 nanorods is a well-developed technique and the nanorods have been widely used as the template for growth of various core-shell nanorod structures. Magneli/CdS core-shell nanorod structures are fabricated for the photoelectrochemical cell (PEC) electrode to achieve enhanced carrier transport along the metallic magneli phase nanorod template. However, the long and thin TiO2 nanorods may form a high resistance path to the electrons transferred from the CdS layer. TiO2 nanorods synthesized are reduced to magneli phases, TixO2x-1, by heat treatment in a hydrogen environment. Two types of magneli phase nanorods of Ti4O7 and Ti3O5 are synthesized. Structural morphology and X-ray diffraction analyses are carried out. CdS nano-films are deposited on the magneli nanorods for the main light absorption layer to form a photoanode, and the PEC performance is measured under simulated sunlight irradiation and compared with the conventional TiO2/CdS core-shell nanorod electrode. A higher photocurrent is observed from the stand-alone Ti3O5/CdS coreshell nanorod structure in which the nanorods are grown on both sides of the seed layer.
        4,000원
        20.
        2017.11 구독 인증기관·개인회원 무료
        Korea is the second largest coffee consuming country in Asia after the Philippines. For modern people, coffee has jumped over a favorite food and grown into a single culture. There are many processing ways to make coffee. In this study, we utilized magnetic resonance imaging(MRI) based on the principles of nuclear magnetic resonance(NMR) and achieved to acquire images with an non-destructive and non-invasive way. The samples we used in the experiment were ‘Robusta’ coffee bean(Congo). Magnetic resonance(MR) image sets were acquired using a MRI system, installed at Institution for Agricultural Machinery & ICT Convergence at Chonbuk National University. From the raw phase(Green Bean stage) to the roasted phase, we obtained MR images from each phase to monitor the internal changes. We divided experiment into 5 stages, starting with ‘Green Bean’ phase to ‘Roasted’ phase. We obtained images every 6 hours during the ‘Fermentation’ phase and every 3 hours during the ‘Dry’ phase. In MRI, we used a gradient echo pulse sequence to scan fast and to take images right after each experiment stage ends. The direction of imaging plane was coronal 30 images with 64 mm x 64 mm field of view(FOV). As MRI uses the magnetic properties of nuclei which especially hydrogen nuclei from water molecules, images could see clearly with sufficient moisture, but in ‘Dry’ phase, images obtained with noise involved. These result suggested that MRI technique was an efficient method to monitor the moisture distribution changes inside the coffee beans.
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