검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 3,080

        141.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Special equipment used for snow removal is only used in the winter and must be moved into storage during non-winter seasons. However, when moving heavy equipment using a forklift within a limited space, safety accidents may occur due to deformation and damage due to the worker's limited visibility and excessive loading of heavy objects. In this study, the scissors boom of the developed heavy load transporter was conducted in two cases: link structural analysis and position-based structural analysis. In detail, the link structural analysis covers four cases of stress and safety factor according to material and thickness to optimize the specifications of the material selected during development, and the structural analysis according to position covers two cases before and after the lift, when maximum stress concentration is achieved. Safety was evaluated through finite element analysis. As a result of the study, when manufacturing a scissors boom type heavy load transporter that can withstand a load of 10 tons, the link showed safety at SS400 4.5mm or higher, and reinforcement is needed in the upper and lower structures, so it is judged to be useful in applying materials according to the load.
        4,000원
        142.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to examine the architectural characteristics of Hak-seong Lee Family's Geun-jae-gong Historic House located in Seok-cheon-ri, Ung-chon-myeon, Ulju-gun, Ulsan. The house is said to have been rebuilt in the early 20th century after it was built in the 18th century, and now there are nine buildings left, including the An-chae, Sa-rang-chae, Sa-dang, storehouses and etc. This house is a large-scale house that is difficult to find similar cases in near region. The division of areas on each building is clear, and it is evaluated that it retains the typical characteristics of the head family in the late Joseon Dynasty in terms of its overall size and layout. In addition, the current wooden structure, which is said to have been rebuilt in the early 20th century, shows the composition method and space utilization method of the 3-Dori type upper structure, which have become more diverse since the late Joseon Dynasty. This has not been dealt with in the previous survey, and should be considered in detail through this paper.
        4,000원
        143.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study aims to analyze the geometric characteristics of the pointed arches proposed by Al-Kāshī in his book "Miftāḥ al-Ḥisāb" (Key of Arithmetic) and investigate their planning principles, architectural application, and typological characteristics. Al-Kāshī completed this significant work in 1427 and dedicated it to Ulugh Beg, a Timurid Sultan in Samarkand. In the ninth chapter, titled "Al-‘Imārāt wa al-Abnīya" (Amīr’s Mansion and Building), Al-Kāshī sought to measure the surface areas and volumes of barrel vaults (Azaj) and domes (Qubba). To achieve this, he proposed five kinds of pointed arches (Ṭāq) and analyzed their drawing methods and composition principles. The Īwān and Qubba structures, which are curved architectural elements, hold significant importance in Islamic architecture. However, previous research has predominantly focused on comparing the drawings in Al-Kāshī's book with historical buildings, neglecting the inherent characteristics of the drawings themselves. This study intends to contribute to a deeper understanding of Al-Kāshī's remarkable work and shed light on the geometric aspects of monumental structures in the Timurid Period.
        4,000원
        144.
        2023.10 구독 인증기관·개인회원 무료
        Understanding the landscapes and the elements that make up the landscapes can help us understand the entire natural ecosystems and biodiversity. Landscape ecology has been studied since the past. however, many studies are conducted on single landscapes, and comparative studies between landscapes are few. We compared insect species diversity and community structure within a single plant community across landscapes and habitat. Additionally, identify environmental factors that affect diversity. Our results showed that above-ground and below-ground insect communities were clearly distinguished. Additionally, species diversity was high below-ground in all landscapes. Insect community structures across landscapes did not differ in above-ground. However, below-ground, the urban was differentiated from the forest and agricultural land. We identified the urbanization indices GMIS and PHBASE as factors responsible for these difference.
        145.
        2023.10 구독 인증기관·개인회원 무료
        Riptortus pedestris has established symbiotic interactions with specific bacteria from soil environment in every generations. The soil environment is extremely heterogeneous with microbial diversity, suggesting that bacterial composition of the R. pedestris can be affected by surrounding environments. Therefore, we investigated spatiotemporal variation of bacterial communities in wild R. pedestris collected from five mainland areas and Jeju Island in South Korea across insect generations. Among the 390 R. pedestris adults collected, we detected a total of 28 bacterial genera from the symbiotic region of insects. Among the bacterial genera, genus Caballeronia bacteria was the most abundantly detected regardless of sampling site and generation. Nevertheless, bacterial richness varied among the insect generations with 10 genera detected in overwintered generation, 15 genera in the 1st generation and 18 genera in the 2nd generation. Moreover, we found five bacterial genera that were exclusively detected from the Jeju island compared to the mainland areas surveyed.
        156.
        2023.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study we examine variations in the structure of perovskite compounds of LaBa2Cu2O9, LaBa2CaCu3O12 and LaBa2Ca2Cu5O15 synthesized using the solid state reaction method. The samples’ compositions were assessed using X-ray fluorescence (XRF) analysis. The La: Ba: Ca: Cu ratios for samples LaBa2Cu2O9, LaBa2CaCu3O12 and LaBa2Ca2Cu5O15 were found by XRF analysis to be around 1:2:0:2, 1:2:1:3, and 1:2:2:5, respectively. The samples’ well-known structures were then analyzed using X-ray diffraction. The three samples largely consist of phases 1202, 1213, and 1225, with a trace quantity of an unknown secondary phase, based on the intensities and locations of the diffraction peaks. According to the measured parameters a, b, and c, every sample has a tetragonal symmetry structure. Each sample’s mass density was observed to alter as the lead oxide content rose. Scanning electron microscope (SEM) images of the three phases revealed that different Ca-O and Cu-O layers can cause different grain sizes, characterized by elongated thin grains, without a preferred orientation.
        4,000원
        157.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        BNKT Ceramics, one of the representative Pb free based piezoelectric ceramics, constitutes a perovskite(ABO3) structure. At this time, the perovskite structure (ABO3) is in the form where the corners of the octahedrons are connected, and in the unit cell, two ions, A and B, are cations, A ion is located at the body center, B ion is located at each corner, and an anion O is located at the center of each side. Since Bi, Na, and K sources constituting the A site are highly volatile at a sintering temperature of 1100℃ or higher, it is difficult to maintain uniformity of the composition. In order to solve this problem, there should be suppression of volatilization of the A site material or additional compensation of the volatilized. In this study, the basic composition of BNKT Ceramics was set to Bi0.5(Na0.78K0.22)0.5TiO3 (= BNKT), and volatile site (Bi, Na, and K sources) were coated in the form of a shell to compensate additionally for the A site ions. In addition, the physical and electrical properties of BNKT and its coated with shell additives(= @BNK) were compared and analyzed, respectively. As a result of analyzing the crystal structure through XRD, both BNKT(Core) and @BNK(Shell) had perovskite phases, and the crystallinity was almost similar. Although the Curie temperature of the two sintered bodies was almost the same (TC = 290 ~ 300 ℃), it was confirmed that the d33 (piezoelectric coefficient) and Pr (residual polarization) values were different. The experimental results indicated that the additional compensation for a shell additive causes the coarsening, resulting in a decrease in sintering density and Pr(remanent polarization). However, coating shell additives to compensate for A site ion is an effective way to suppress volatilization. Based on these experimental results, it would be the biggest advantage to develop an eco-friendly material (Lead-free) that replaced lead (Pb), which is harmful to the human body. This lead-free piezoelectric material can be applied to a biomedical device or products(ex. earphones (hearing aids), heart rate monitors, ultrasonic vibrators, etc.) and skin beauty improvement products (mask packs for whitening and wrinkle improvement).
        4,000원
        158.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examines the textual structure and speech acts within the inaugural addresses of the ministers in the Yoon Suk Yeol Government’s first cabinet. These addresses typically follow a three-part structure: introduction, development, and closing. The introduction features an opening greeting, while the development stage outlines the main service and missions, and presents requests to organizational members. The closing stage concludes the address. The introduction and closing are often simple enumerations of contents, whereas the development stage is logically and coherently structured. In terms of speech acts, the introductory stage predominantly features expressive acts. The development stage is marked by announcements and requests, while the closing e ncompasses various acts including statements, promises, and solicitations.
        6,700원
        159.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, Free-Form and Irregular Shape high-rise buildings are constructed by IT technology development. Tilted shaped high-rise building which is one of Irregular shape high-rise buildings can cause lateral displacement by gravity load and lateral load due to tilted elevation shape. Therefore, it is necessary to review the behavior and structural aspects of the Tilted shape high-rise building by gravity load. In this paper, the dynamic characteristics of a tilted structure with a dual-core were analyzed with the core location as a design variable, and response behavior, vulnerable members, and vulnerable layers to earthquake loads were analyzed. As a result of the analysis, as the location of the core moved in an tilted direction, the eccentric distance and eccentric load decreased, reducing the axial force of the vertical members. However, the location of the core had little effect on the response.
        4,000원
        160.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Reliable, inexpensive, environment-friendly, and durable properties of carbon materials with unique and outstanding photoelectric performance is highly desired for myriad of applications such as catalysis and energy storage. Since lattice modulation is a vital method of surface modification of materials, which form by an external force during the synthesis process, causing the internal compression and stretching, leading to lattice sliding event. In this review, we present a summary of different methods to tailor the lattice modulation in 2D carbon-based materials, including grain/twin boundary, lattice strain, lattice distortion, and lattice defects. This overview highlights the implication control of the diverse morphologies of nanocrystals and how to tailor the materials properties without adding any polymers. The improvement in the performance of 2D carbon materials ranges from the enhancement of charge transport and conductivity, structural stability, high-performance of light absorption capacity, and efficient selectivity promote the future prospect of 2D carbon materials broaden their applications in terms of energy conversion and storage. Finally, some perspectives are proposed on the future developments and challenges on 2D carbon materials towards energy storage applications.
        4,200원