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        검색결과 522

        1.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Many school buildings are vulnerable to earthquakes because they were built before mandatory seismic design was applied. This study uses machine learning to develop an algorithm that rapidly constructs an optimal reinforcement scheme with simple information for non-ductile reinforced concrete school buildings built according to standard design drawings in the 1980s. We utilize a decision tree (DT) model that can conservatively predict the failure type of reinforced concrete columns through machine learning that rapidly determines the failure type of reinforced concrete columns with simple information, and through this, a methodology is developed to construct an optimal reinforcement scheme for the confinement ratio (CR) for ductility enhancement and the stiffness ratio (SR) for stiffness enhancement. By examining the failure types of columns according to changes in confinement ratio and stiffness ratio, we propose a retrofit scheme for school buildings with masonry walls and present the maximum applicable stiffness ratio and the allowable range of stiffness ratio increase for the minimum and maximum values of confinement ratio. This retrofit scheme construction methodology allows for faster construction than existing analysis methods.
        4,000원
        2.
        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
        7.
        2024.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, we undertook detailed experiments to increase hydrogen production efficiency by optimizing the thickness of titanium dioxide (TiO2) thin films. TiO2 films were deposited on p-type silicon (Si) wafers using atomic layer deposition (ALD) technology. The main goal was to identify the optimal thickness of TiO2 film that would maximize hydrogen production efficiency while maintaining stable operating conditions. The photoelectrochemical (PEC) properties of the TiO2 films of different thicknesses were evaluated using open circuit potential (OCP) and linear sweep voltammetry (LSV) analysis. These techniques play a pivotal role in evaluating the electrochemical behavior and photoactivity of semiconductor materials in PEC systems. Our results showed photovoltage tended to improve with increasing thickness of TiO2 deposition. However, this improvement was observed to plateau and eventually decline when the thickness exceeded 1.5 nm, showing a correlation between charge transfer efficiency and tunneling. On the other hand, LSV analysis showed bare Si had the greatest efficiency, and that the deposition of TiO2 caused a positive change in the formation of photovoltage, but was not optimal. We show that oxide tunneling-capable TiO2 film thicknesses of 1~2 nm have the potential to improve the efficiency of PEC hydrogen production systems. This study not only reveals the complex relationship between film thickness and PEC performance, but also enabled greater efficiency and set a benchmark for future research aimed at developing sustainable hydrogen production technologies.
        4,000원
        8.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        원자력발전소(원전) 시스템 내진성능 평가를 위하여 구조물내응답스펙트럼(ISRS)은 필수적으로 요구된다. 특히, 원전 부지 고유 스펙트럼 변경 시 새로운 ISRS 도출이 요구될 경우 지진 재해석 등의 상당한 비용을 필요로 하게 된다. 따라서 이 연구는 지진 재해석 이 필요 없는 ISRS 스케일링 근사 방법에 대한 여러 가지 접근법을 제공한다. 이러한 접근법으로 도출한 ISRS는 정확한 ISRS와 비교 한다. 근사 방법의 ISRS 가 원전 주요 시스템 지진응답 및 내진성능에 미치는 영향을 분석한다. 결과적으로 본 연구에서 제시한 ISRS 스케일링 근사 방법은 저주파에서 비교적 유사하게 ISRS를 도출하지만, 고주파에서는 그 정확도가 감소하였다. ISRS 스케일링 근사 방법이 시스템 지진응답/내진성능 산출 정확도에 미치는 영향은 방법의 시스템 주요 모드 응답 유사도 산출 정도에 따라 결정된 것을 확인할 수 있었다.
        4,000원
        9.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구는 셰이머스 히니의 나무 시에 등장하는 물, 땅, 공기의 상징적 의미를 시인의 개인적인 경험 및 글쓰기 공간과 견주어 탐색한다. 그의 아버지에게 헌정된 기념 시집 『사물 보기』에 수록된 「물푸레나무」와 「제곱화 41」은 어린 시절의 추억이 담긴 풍경인 모욜라 강변에서 발견되는 물푸레나무와 버드나무를 신화화하여 원초적인 존재이자 전통적인 농기구와 재료의 상징으로 묘사한다. 지하철 노선의 도시적 배경과 오리나무의 자연적 영역을 대조하는 히니의 후기 작품인 『구역과 원』의 「오리나무를 심으며」도 분석 대상이다. 또 「자작나무 숲」은 영국인 지인의 정원에 있는 나무를 관조한다. 라이너 마리아 릴케의 시를 번역한 히니는 시적 과정의 필수 요소인 불의 이미지와 과일의 상징성을 각각 강조하며 나무를 관조한다.
        5,400원
        10.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we investigated the time signal devices of Deungnu (circa 1270) and Gungnu (1354), the water clocks produced during the Yuan Dynasty (1271–1368). These clocks influenced Heumgyeonggaknu (1438) of the Joseon Dynasty (1392–1910), exemplifying the automatic water clocks of the Yuan Dynasty. Deungnu, Gungnu, and Heumgyeonggaknu can be considered as automatic mechanical clocks capable of performances. The Jega-Yeoksang-Jip (Collection of Calendrical and Astronomical Theories of Various Chinese Masters) contains records of Deungnu extracted from the History of the Yuan Dynasty. We interpreted these records and analyzed reproduction models and technical data previously produced in China. The time signal device of Deungnu featured a four-story structure, with the top floor displaying the four divine constellations, the third floor showcasing models of these divinities, the second floor holding 12-h jacks and a 100-Mark ring, and the first floor with four musicians and a 100-Mark Time-Signal Puppet providing a variety of visual attractions. We developed a 3D model of Deungnu, proposing two possible mechanical devices to ensure that the Time-Signal Puppet simultaneously pointed to the 100-Mark graduations in the east, west, south, and north windows: one model reduced the rotation ratio of the 100-Mark ring to 1/4, whereas the other model maintained the rotation ratio using four separate 100-Mark rings. The power system of Deungnu was influenced by Suunuisangdae (the water-driven astronomical clock tower) of the Northern Song Dynasty (960–1127); this method was also applied to Heumgyeonggaknu in the Joseon Dynasty. In conclusion, these automatic water clocks of East Asia from the 13th to 15th centuries symbolized creativity and excellence, representing scientific devices that were the epitome of clock-making technology in their times.
        4,300원
        12.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        바이폴라막은 양이온교환층과 음이온교환층 및 양극접합층으로 이루어진 이온교환막으로 물 분해 특성을 기반으 로 하여 프로톤과 수산화 이온을 생성시키는 막이다. 이러한 특성을 이용하여 화학 산업, 식품 가공, 환경 보호, 에너지 변환 및 저장과 같은 다양한 응용 분야에서 연구가 되고 있다. 본 논문에서는 바이폴라막 기술에 대한 종합적인 이해를 제공하기 위해 바이폴라막의 개념 및 물 분해 메커니즘과 물 분해 촉매에 대한 조사하였다. 마지막으로 최근 에너지 기술에 적용되고 있는 바이폴라막 프로세스를 조사하였다.
        4,000원
        13.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Organoleptic parameters such as color, odor, and flavor influence consumer perception of drinking water quality. This study aims to evaluate the taste of the selected bottled and tap water samples using an electronic tongue (E-tongue) instead of a sensory test. Bottled and tap water's mineral components are related to the overall preference for water taste. Contrary to the sensory test, the potentiometric E-tongue method presented in this study distinguishes taste by measuring the mineral components in water, and the data obtained can be statistically analyzed. Eleven bottled water products from various brands and one tap water from I city in Korea were evaluated. The E-tongue data were statistically analyzed using multivariate statistical tools such as hierarchical clustering analysis (HCA), principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA). The results show that the E-tongue method can clearly distinguish taste discrimination in drinking water differing in water quality based on the ion-related water quality parameters. The water quality parameters that affect taste discrimination were found to be total dissolved solids (TDS), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), sulfate (SO4 2-), chloride (Cl-), potassium (K+) and pH. The distance calculation of HCA was used to quantify the differences between 12 different types of drinking water. The proposed E-tongue method is a practical tool to quantitatively evaluate the differences between samples in water quality items related to the ionic components. It can be helpful in quality control of drinking water.
        4,200원
        14.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 PEBAX/PVDF 복합막을 제조하고 에탄올/물 혼합액에 대한 투과증발 성능을 평가하였다. 또한 PVDF 지지체 표면에 ZIF-8 층을 형성하여 복합막의 투과증발 성능을 향상시키고자 하였고, PEBAX 선택층 두께에 따른 성능 비교 를 통해 최적의 막을 선정하였다. 제작된 복합막을 물과 에탄올이 95/5 중량비로 혼합된 공급액에 대하여 투과증발 실험을 수행하였다. 그 결과 ZIF-8 충이 형성된 PVDF 지지체를 사용한 복합막의 경우 플럭스 1.98 kg/m2h, 분리 계수 3.88로 일반 PVDF 지지체를 사용한 복합막보다 투과량과 선택도가 모두 높은 값을 나타내었다.
        4,000원
        15.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Numerous studies have established a correlation between sociodemographic characteristics and water usage, identifying population as a primary independent variable in mid- to long-term demand forecasting. Recent dramatic sociodemographic changes, including urban concentration-rural depopulation, low birth rates-aging population, and the rise in single-person households, are expected to impact water demand and supply patterns. This underscores the necessity for operational and managerial changes in existing water supply systems. While sociodemographic characteristics are regularly surveyed, the conducted surveys use aggregate units that do not align with the actual system. Consequently, many water demand forecasts have been conducted at the administrative district level without adequately considering the water supply system. This study presents an upward water demand forecasting model that accurately reflects real water facilities and consumers. The model comprises three key steps. Firstly, Statistics Korea’s SGIS (Statistical Geological Information System) data was reorganized at the DMA level. Secondly, DMAs were classified using the SOM (Self-Organizing Map) algorithm to consider differences in water facilities and consumer characteristics. Lastly, water demand forecasting employed the PCR (Principal Component Regression) method to address multicollinearity and overfitting issues. The performance evaluation of this model was conducted for DMAs classified as rural areas due to the insufficient number of DMAs. The estimation results indicate that the correlation coefficients exceeded 0.9, and the MAPE remained within approximately 10% for the test dataset. This method is expected to be useful for reorganization plans, such as the expansion and contraction of existing facilities.
        4,200원
        16.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Water utilities are making various efforts to reduce water losses from water networks, and an essential part of them is to recognize the moment when a pipe burst occurs during operation quickly. Several physics-based methods and data-driven analysis are applied using real-time flow and pressure data measured through a SCADA system or smart meters, and methodologies based on machining learning are currently widely studied. Water utilities should apply various approaches together to increase pipe burst detection. The most intuitive and explainable water balance method and its procedure were presented in this study, and the applicability and detection performance were evaluated by applying this approach to water supply pipelines. Based on these results, water utilities can establish a mass balance-based pipe burst detection system, give a guideline for installing new flow meters, and set the detection parameters with expected performance. The performance of the water balance analysis method is affected by the water network operation conditions, the characteristics of the installed flow meter, and event data, so there is a limit to the general use of the results in all sites. Therefore, water utilities should accumulate experience by applying the water balance method in more fields.
        4,800원
        17.
        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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