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        검색결과 480

        1.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study explored the process-structure-property (PSP) relationships in Ti-6Al-4V alloys fabricated through direct energy deposition (DED) additive manufacturing. A systematic investigation was conducted to clarify how process variables—specifically, manipulating the cooling rate and energy input by adjusting the laser power and scan speed during the DED process—influenced the phase fractions, pore structures, and the resultant mechanical properties of the samples under various processing conditions. Significant links were found between the controlled process parameters and the structural and mechanical characteristics of the produced alloys. The findings of this research provide foundational knowledge that will drive the development of more effective and precise control strategies in additive manufacturing, thereby improving the performance and reliability of produced materials. This, in turn, promises to make significant contributions to both the advancement of additive manufacturing technologies and their applications in critical sectors.
        4,000원
        2.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        1993년 형성된 비아 캄페시나(Vía Campesina)는 근대화되고 세계화 된 식량 생산 체제(food regime)의 발전 과정에서 소외되고 배제된 토 지, 물, 종자, 산림 등과 같은 생태 환경뿐만 아니라 그 과정에서 배제 혹은 착취되어 온 영세 농민들의 권리 회복을 주창해 온 전 세계적 농 민 조직이다. 특히 20세기 후반 이후 비아 캄페시나의 ‘농민의 삶’ 회 복 주장에 전 세계의 농민과 다양한 농민 조직들이 동참한 배경에는 식량 생산 체제의 세계화에 따라 농민의 삶이 회복하기 어려울 정도로 파괴되어 농촌과 도시의 빈민층으로 전락하거나, 곳곳에서 생태 환경이 파괴됨을 공동으로 목격하고 경험하였기 때문이다. 본 연구의 목적은 볼리비아의 전통적 농업 지역인 알티플라노(altiplano) 지역에서 전통 적으로 자가소비를 위해 생산되어 온 생계 작물인 퀴노아(quinoa)가 상업 작물로서 전환되는 기회를 맞이하면서, ‘농민의 삶’ 회복을 시도 한 알티플라노 농민들이 처한 딜레마에 관해 분석하는 것이다. 즉, 그 동안 글로벌 식량 체제는 농민들의 삶을 유지하는 데 부정적인 영향을 미치는 주된 요인으로 다뤄져 왔는데, 글로벌 식량 체제 아래서 새롭게 만들어진 기회 구조가 농민의 삶 회복에 어떤 영향을 미쳤는지, 그 과 정에서의 딜레마는 무엇인지에 대해 논의한다.
        5,400원
        3.
        2024.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Hydrogen cyanide (HCN) and hydrogen isocyanide (HNC) are isomers with similar chemical properties. However, HNC can be converted into other molecules by reactions with atomic hydrogen (H) and atomic oxygen (O), resulting in a variation of the HCN/HNC abundance ratio. These reaction rates are sensitive to gas temperature, resulting in different abundance ratios in different temperature environments. The emission of HCN and HNC was found to distribute along ring structures in the protoplanetary disk of V883 Ori. HCN exhibits a multi-ring structure consisting of inner and outer rings. The outer ring represents a genuine chemical structure, whereas the inner ring appears to display such characteristics due to the high dust continuum optical depth at the center. However, HNC is entirely depleted in the warmer inner ring, while its line intensity is similar to that of HCN in the colder outer ring. In this study, we present a chemical calculation that reproduces the observed HCN/HNC abundance ratio in the inner and outer rings. This calculation suggests that the distinct emission distribution between HCN and HNC results from a currently ongoing outburst in V883 Ori. The sublimation of HCN and HNC from grain surfaces and the conversion of HNC to HCN determine their chemical distribution in the heated, warm inner disk.
        4,000원
        4.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        5.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 현대 중국어 ‘刚才+V+了’ 구문에 사용된 동사 ‘V’의 의미 기능과 제약조 건을 분석하였다. 일반적으로 구문에 사용되는 동사 ‘V’는 구문에서 ‘관계’, ‘심리’, ‘동 작’, ‘종결’, ‘순간’의 의미자질로 구분된다. 그러나 이러한 의미자질을 가진 동사가 ‘刚 才+V+了’ 구문에 모두 사용할 수 있는 것은 아니다. 사실 ‘刚才+V+了’ 구문이 필요 로 하는 동사는 일정한 사용조건이 필요하다. 이를 밝히기 위하여 본고는 우선 ‘刚才 +V+了’ 구문에 사용된 ‘V’를 의미질의 특징에 따라 유형별로 분류하였다. 이를 토대 로 ‘刚才+V+了’ 구문의 의미와 ‘了’의 의미 기능 그리고 구문에 사용된 동사 ‘V’의 제 약에 대해 분석하였다. 이를 기초로 하여 의미자질을 유형별로 비교한 후 사용조건 에 부합되는지를 우선 분석하였다. 그 결과, 동사는 의미자질에 따라 다음과 같은 조 건에 부합되는 경우 구문이 성립되었다. 첫째, ‘刚才’가 ‘了’와 결합하지 않는 경우이 다. 이 경우 출현할 수 있는 동사는 동작의 시작점과 종결점, 지속의 과정을 모두 가진 동사이어야 구문이 성립되었다. 둘째, 시간명사 ‘刚才’와 ‘了’가 결합할 경우, 중간 에 출현할 수 있는 동사는 사건 시간량이 ‘刚才’의 시간량보다 짧아야 성립될 수 있 었다. 또한 동사의 의미자질이 시작, 지속, 종결을 지닌 경우, 그리고 지속, 종결만을 가진 경우, 시작과 종결이 일치한 동사가 지속성이 없이 순간성을 지닌 동사이어야 구문이 성립된다는 결론을 얻었다. 셋째, ‘刚才+V’와 ‘刚才+V+了’ 중 ‘V’의 공통점은 동사의 시간량이 ‘刚才’보다 [+短时]여야 성립되었으며, ‘了’의 결합 여부에 따라 강조 되는 정도가 달랐다. 다시 말해, ‘刚才+V’ 구문의 강조점은 시작점이고, ‘刚才+V+了’ 구문의 강조점은 동작의 종결점이었다.
        5,500원
        6.
        2024.06 구독 인증기관 무료, 개인회원 유료
        This paper attempts to show that the word sì 巳(祀) used after the negative wù 勿 or wú 毋 functions as a “Vintransitive” (all the abbreviations and references used in this paper are given at the end of Part I). As such, it forms a VP, 勿/毋 V1 (=巳) V2, where V2 is frequently, but not always, one of the six “Type-A ritual Vs”—one being dăo 禱 ‘to pray’ and the rest given in the paper; when V2 is a “Type-B non-ritual V”—one being diàn 田(甸) ‘to hunt’ and the rest inexhaustible. A major reason for the use of V2 is to contrast with the preceding V1. This is deduced from closely examining the semantic relationship between V1 and V2. The details will be explained with examples. There are also inscriptions in which V1 (巳/祀) is used before yú 于, a “multidirectional” preposition. This is labelled as “Nloc in the sense of ‘in, at’, not ‘to, for’ when preceded by the V1 or in the construction given in the title. The paper accounts for its motivating principle. The paper argues that 巳/祀 is a Vaction meaning “conduct sì-providential ritual”. It was done at a place to seek divine direction and guidance from the deity or Power believed to have dwelt in situ. Originally presented in Takashima (2009a), this paper delves further into linguistic, philological, and cultural aspects of the 巳-ritual couched in the VP, 勿/毋 V1 (=巳/祀) V2. Part I has covered “Examination I: Zhū Shēngyù’s Questions and Zhāng Yùjīn’s Interpretation”. The paper answers the former and evaluates the latter. Part II begins with “Examination II: Qiú Xīguī’s Interpretation” and ends with the conclusions of the entire paper.
        5,700원
        8.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to predict the process window of laser powder bed fusion (LPBF) for printing metallic components, the calculation of volumetric energy density (VED) has been widely calculated for controlling process parameters. However, because it is assumed that the process parameters contribute equally to heat input, the VED still has limitation for predicting the process window of LPBF-processed materials. In this study, an explainable machine learning (xML) approach was adopted to predict and understand the contribution of each process parameter to defect evolution in Ti alloys in the LPBF process. Various ML models were trained, and the Shapley additive explanation method was adopted to quantify the importance of each process parameter. This study can offer effective guidelines for fine-tuning process parameters to fabricate high-quality products using LPBF.
        4,000원
        9.
        2024.04 구독 인증기관·개인회원 무료
        Parasites have co-evolved with their host for a long period of time, resulting in unique parasitic systems tailored to each host species. This makes them suitable for research on physiological function control through cross-species molecules like miRNA. The body louse, a vector of bacterial pathogens, is particularly valuable as a model insect due to their frequent feeding on human blood, which results in the continuous ingestion of human-derived miRNA and injection of salivary gland-derived miRNA into the human body. In this study, we conducted miRNA sequencing on body lice with mixed stages and identified 105 miRNAs, including 50 novel miRNAs. Sequence analysis of human miRNAs remaining in body lice and the functional analysis of these miRNAs are in progress.
        10.
        2024.04 구독 인증기관·개인회원 무료
        This presentation explores the application of Artificial Intelligence (AI) in entomology beyond traditional image analysis. It highlights AI's potential in auditory and olfactory analysis, areas less explored in entomological research. Utilizing machine learning, AI enhances insect classification and ecosystem assessment through improved analysis of existing data. The discussion includes AI's capability in developing indices for habitat evaluation using insects as bioindicators, emphasizing its versatility across different research areas within entomology. This approach aims to broaden the scope of AI applications, promoting a deeper understanding of ecological dynamics through entomological studies.
        11.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study analyzes the fifth edition of the enhanced spelling of the Indonesian language (EYD V) by comparing it with the original Indonesian spelling system (EBI) in terms of the use of character and punctuation. Specifically, it presumes that the frequent occurrence of errors in the Indonesian spelling systems is related to both indifference in Indonesian orthography and recurrent orthographic revisions. Based on this premise, it investigates differences between the original EBI, officially announced in 2015, and EYD V, the latest Indonesian spelling system, in terms of the use of character and punctuation. The analytic results found that EYD V includes several new elements, such as the introduction of a monophthong eu and the use of consonants q, x, and y at the end of words. Furthermore, it was found that EYD V provides the revised and supplemented contents compared to the original EBI from multiple perspectives by implementing enhanced consistency and timeliness in descriptions and error correction. The outcomes of this study are expected to serve as essential data for Indonesian writing education and as comparative data for discussions on Malay orthography in relation to Indonesian orthography.
        7,800원
        12.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study contrasted the response relationship and constraints of the Chinese phrase ‘S+給+NP1+V+NP2’ between ‘给’ and Korean ‘에 게’. Both ‘给’ and Korean ‘에게’ have something in common that they can lead to the objects of grant, communication, or benefit, but there were also certain constraints on the response relationship. In order to clarify this constraint, this study first classified semantic items according to the following nouns and trailing predicates of the phrase ‘S+給+NP1+V+NP2’ and their semantic relationships. Based on this, this paper compares Chinese ‘给’ with Korean ‘에게’ and analyzes the differences between the two. As a result of the analysis, the correspondence between the two was affected by the following constraints. First, the correspondence is established if the object ‘에 게1’ and ‘给1’ are living beings. Second, when ‘에게1’ contains [+benefit] or [+transmission] positive semantics, it is impossible to communicate with ‘给2’ to each other. Third, when both the subject of action and the posterior object are living things, there is a correspondence between ‘에게3’ and ‘给5’. However, there is a difference in the meaning of ‘给5’ and ‘에게3’ in Korean. ‘给5’ has a function that emphasizes the posterior predicate, but ‘에게3’ in Korean does not have such a function.
        6,300원
        13.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study explores the profound impact of varying oxygen content on microstructural and mechanical properties in specimens HO and LO. The higher oxygen concentration in specimen HO is found to significantly influence alpha lath sizes, resulting in a size of 0.5-1 μm, contrasting with the 1-1.5 μm size observed in specimen LO. Pore fraction, governed by oxygen concentration, is high in specimen HO, registering a value of 0.11%, whereas specimen LO exhibits a lower pore fraction (0.02%). Varied pore types in each specimen further underscore the role of oxygen concentration in shaping microstructural morphology. Despite these microstructural variations, the average hardness remains consistent at ~370 HV. This study emphasizes the pivotal role of oxygen content in influencing microstructural features, contributing to a comprehensive understanding of the intricate interplay between elemental composition and material properties.
        4,000원
        14.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The towing distance, which is speed over the ground, and the water flow quantity, which is speed through the water, were used when estimating the amount of Metapenaeus joyneri resources that rose to the surface at night using the swept area method in order to compare and analyze the difference. It was conducted using a shrimp dredge, trial fishing gear for catching Metapenaeus joyneri. Catch during the entire survey period was 188.9 kg. Monthly catch ranged from 3.1 to 109.2 kg, highest in June and lowest in September. The swept volume calculated using the speed over the ground was about 13% higher than using the speed through the water. Metapenaeus joyneri resources estimated using the towing distance ranged from 320.1 to 14,649.8 kg. Resources estimated using the water flow quantity ranged from 278.5 to 12,886.3 kg. Therefore, the amount of Metapenaeus joyneri resources estimated using the speed over the ground was about 14% higher than the method using the speed through the water, indicating that the amount of resources was overestimated.
        4,000원
        15.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Photoanode optimization is a fascinating technique for enlightening the power conversion efficiency (PCE) of dye-sensitized solar cells (DSSCs). In this present study, V2O5/ ZnO and reduced graphene oxide (rGO)-V2O5/ZnO nanocomposites (NCs) were prepared by the solid-state technique and used as photoanodes for DSSCs. A wet chemical technique was implemented to generate individual V2O5 and ZnO nanoparticles (NPs). The structural characteristics of the as-synthesized NCs were investigated and confirmed using powder X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), and Scanning electron microscope (SEM) with energy dispersive X-ray (EDX) analysis. The average crystallite size (D) of the as-synthesized V2O5/ ZnO and rGO-V2O5/ZnO NCs was determined by Debye-Scherer’s formula. The bandgap (eV) energy was calculated from Tauc’s plots, and the bonding nature and detection of the excitation of electrons were investigated using the Ultra violet (UV) visible spectra, Fourier Transform infrared (FTIR) and photoluminescence (PL) spectral analysis. Electrical studies like Hall effect analysis and the Nyquist plots are also described. The V2O5/ ZnO and rGO-V2O5/ZnO NCs based DSSCs exhibited 0.64% and 1.27% of PCE and the short circuit current densities and open circuit voltages improved from 7.10 to 11.28 mA/cm2 and from 0.57 to 0.68 V, respectively.
        4,300원
        16.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Titanium constitutes approximately 60% of the weight of steel and exhibits strength comparable to steel's but with a higher strength-to-weight ratio. Titanium alloys possess excellent corrosion resistance due to a thin oxide layer at room temperature; however, their reactivity increases above 600°C, leading to oxidation and nitridation. Welding titanium alloys presents challenges such as porosity issues. Laser welding minimizes the heat-affected zone (HAZ) by emitting high output in a localized area for a short duration. This process forms a narrow and deep HAZ, reducing the deterioration of mechanical properties and decreasing the contact area with oxygen. In this study, fiber laser welding was conducted on 8.0mm thick Ti-6Al-4V alloy using the Bead On Plate (BOP) technique. A total of 25 welding conditions were experimented with to observe bead shapes. The results demonstrated successful penetration within the 0.792mm to 8.000mm range. It was concluded that this experimental approach can predict diverse welding conditions for Ti-6Al-4V alloys of various thicknesses.
        4,000원
        17.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        High-entropy alloys (HEAs) are characterized by having five or more main elements and forming simple solids without forming intermetallic compounds, owing to the high entropy effect. HEAs with these characteristics are being researched as structural materials for extreme environments. Conventional refractory alloys have excellent hightemperature strength and stability; however, problems occur when they are used extensively in a high-temperature environment, leading to reduced fatigue properties due to oxidation or a limited service life. In contrast, refractory entropy alloys, which provide refractory properties to entropy alloys, can address these issues and improve the hightemperature stability of the alloy through phase control when designed based on existing refractory alloy elements. Refractory high-entropy alloys require sufficient milling time while in the process of mechanical alloying because of the brittleness of the added elements. Consequently, the high-energy milling process must be optimized because of the possibility of contamination of the alloyed powder during prolonged milling. In this study, we investigated the hightemperature oxidation behavior of refractory high-entropy alloys while optimizing the milling time.
        4,000원
        18.
        2023.12 구독 인증기관 무료, 개인회원 유료
        This paper attempts to show that the word sì 巳(祀) used after the negative wù 勿 or wú 毋 functions as a “Vintransitive” (all the abbreviations and references used in this paper are given at the end of Part I). As such, it forms a VP, 勿/毋V1V2, where V2 is always one of the six “Type-A ritual Vs”—one being dăo 禱 ‘to pray’, the rest given in the paper. The semantic relationship between V1 (巳/祀) and V2 is closely examined. There are also inscriptions in which V1 is used before yú 于, a “multidirectional” preposition. This is labelled as “Nloc in the sense of ‘in, at’ (not ‘to, for’)” in the construction given in the title. The paper accounts for its motive principle. The paper argues that 巳/祀 is a Vaction meaning “conduct sì-providential ritual”. It was done at a place to seek divine direction and guidance from the deity or Power believed to have dwelt in situ. Originally presented in Takashima (2009a), this paper delves further into linguistic, philological, and cultural aspects of the 巳-ritual couched in the VP, 勿/毋V1(=巳/祀)V2. A major reason for its use is to contrast the 巳-ritual with other rituals and sacrifices. The details will be explained with examples. Part I covers “Examination I: Zhū Shēngyù’s Questions and Zhāng Yùjīn’s Interpretation”. The paper answers the former and evaluates the latter. Part II begins with “Examination II: Qiú Xīguī’s Interpretation” and ends with the conclusions of the entire paper.
        8,600원
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