• 제목/요약/키워드: pillars

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A review of experimental and numerical studies on crack growth behaviour in rocks with pre-existing flaws

  • G. Sivakumar;V.B. Maji
    • Geomechanics and Engineering
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    • 제35권4호
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    • pp.333-366
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    • 2023
  • Rock as a mass generally exhibits discontinuities, commonly witnessed in rock slopes and underground structures like tunnels, rock pillars etc. When these discontinuities experiences loading, a new crack emerges from them which later propagates to a macro scale level of failure. The failure pattern is often influenced by the nature of discontinuity, geometry and loading conditions. The study of crack growth in rocks, namely its initiation and propagation, plays an important role in defining the true strength of rock and corresponding failure patterns. Many researchers have considered the length of the discontinuity to be fully persistent on rock or rock-like specimens by both experimental and numerical methods. However, only during recent decades, there has been a substantial growth in research interest with non-persistent discontinuities where the crack growth and its propagation phenomenon were found to be much more complex than persistent ones. The non-persistence fractures surface is generally considered to be open and closed. Compared to open flaws, there is a difference in crack growth behaviour in closed or narrow flaws due to the effect of surface closure between them. The present paper reviews the literature that has contributed towards studying the crack growth behaviour and its failure characteristics on both open and narrow flaws subjected to uniaxial and biaxial compression loading conditions.

Enhanced Smart Tourism and its Role in Reshaping the Tourism Industry

  • Ulrike Gretzel;Hyunae Lee;Eunji Lee;Namho Chung;Chulmo Koo
    • Journal of Smart Tourism
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    • 제3권4호
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    • pp.23-31
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    • 2023
  • This paper explores the concept of enhanced smart tourism as a response to the challenges and opportunities arising in the post-pandemic tourism landscape. The COVID-19 pandemic has not only halted the global tourism industry but also prompted a reevaluation of its sustainability, technological integration, and impact on local communities. The need for a paradigm shift in tourism is emphasized, focusing on digitalization, innovation, and resilience. Enhanced smart tourism is characterized by a shift from traditional practices to innovative governance models, increased emphasis on sustainability, and the integration of technology for better management and visitor experiences. The paper discusses the four pillars of enhanced smart tourism - Technology, Sustainability, Accessibility/Mobility, and Innovation/Creativity, and their expansion in the post-pandemic era. Furthermore, the significant role of data in smart tourism is examined, highlighting the importance of data valuation, management, and ethics. The paper proposes frameworks and methods for data valuation and emphasizes the necessity of a comprehensive approach to data within the smart tourism ecosystem. The conclusion points to the need for further empirical and conceptual research to fully realize the potential of enhanced smart tourism.

국제경영 분야에 관한 연구동향 분석 (Review on Literatures of International Management)

  • 권기환;권재현
    • 무역학회지
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    • 제45권6호
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    • pp.227-258
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    • 2020
  • The field of international management has consistently been recognized as one of the key research pillars in the grand scope of trade studies. In this paper, we conducted critical review on literatures of international management, which were published in Korea Trade Review from 1975 to 2019. Especially, this paper analyzed 'when did research results in the field of international management appear in Korea Trade Review for the first time?', 'how many papers in the field of international management have been published in Korea Trade Review so far?', 'what topics have the papers in the field of international management published in Korea Trade Review mainly described?', and 'what research methods have the papers in the field of international management published in Korea Trade Review adopted?' In particular, this paper compared the similarities and differences between the research issues in leading global journals and those of international management research papers published in Korea Trade Review. In addition, some implications for future research would be suggested regarding what characteristics of international management studies will be meaningful to be published in the Korea Trade Review.

수중 유속 및 유향의 동시 측정을 위한 이미지 분석 기술에 관한 연구 (Image Analysis for the Simultaneous Measurement of Underwater Flow Velocity and Direction)

  • 서동민;오상우;변성훈
    • 센서학회지
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    • 제32권5호
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    • pp.307-312
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    • 2023
  • To measure the flow velocity and direction in the near field of an unmanned underwater vehicle, an optical measurement unit containing an image sensor and a phosphor-integrated pillar that mimics the neuromasts of a fish was constructed. To analyze pillar movement, which changes with fluid flow, fluorescence image analysis was conducted. To analyze the flow velocity, mean force analysis, which could determine the relationship between the light intensity of a fluorescence image and an external force, and length-force analysis, which could determine the distance between the center points of two fluorescence images, were employed. Additionally, angle analysis that can determine the angles at which pixels of a digital image change was selected to analyze the direction of fluid flow. The flow velocity analysis results showed a high correlation of 0.977 between the external force and the light intensity of the fluorescence image, and in the case of direction analysis, omnidirectional movement could be analyzed. Through this study, we confirmed the effectiveness of optical flow sensors equipped with phosphor-integrated pillars.

거리 기반 적응형 임계값을 활용한 강건한 3차원 물체 탐지 (Robust 3D Object Detection through Distance based Adaptive Thresholding)

  • 이은호;정민우;김종호;이경수;김아영
    • 로봇학회논문지
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    • 제19권1호
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    • pp.106-116
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    • 2024
  • Ensuring robust 3D object detection is a core challenge for autonomous driving systems operating in urban environments. To tackle this issue, various 3D representation, including point cloud, voxels, and pillars, have been widely adopted, making use of LiDAR, Camera, and Radar sensors. These representations improved 3D object detection performance, but real-world urban scenarios with unexpected situations can still lead to numerous false positives, posing a challenge for robust 3D models. This paper presents a post-processing algorithm that dynamically adjusts object detection thresholds based on the distance from the ego-vehicle. While conventional perception algorithms typically employ a single threshold in post-processing, 3D models perform well in detecting nearby objects but may exhibit suboptimal performance for distant ones. The proposed algorithm tackles this issue by employing adaptive thresholds based on the distance from the ego-vehicle, minimizing false negatives and reducing false positives in the 3D model. The results show performance enhancements in the 3D model across a range of scenarios, encompassing not only typical urban road conditions but also scenarios involving adverse weather conditions.

Gemas: Enhancing the Distribution of Integrated Eco-Friendly Marketing Strategies towards Digital Transformation and Global Competitiveness

  • Diana AQMALA;Febrianur Ibnu Fitroh Sukono PUTRA
    • 유통과학연구
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    • 제22권5호
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    • pp.39-57
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    • 2024
  • Purpose: Various policies continue to be strengthened to develop Micro, Small and Medium Enterprises (MSMEs), which have a strategic role in the economy through the pillars of corporatization, capacity and financing to support strong and inclusive economic growth. Efforts to transform MSMEs marketing strategies are undertaken through eco-friendly digitalization to increase resilience and more productive and innovative capacity. Research design, data and methodology: This research is an exploratory qualitative approach taken to investigate the transformation of eco-friendly marketing strategies for MSMEs to increase competitiveness at the global level. The samples obtained were 425 MSMEs assisted by the DKI Jakarta, Bali, Java, Borneo, and Sumatera. The data collection technique used non-probability sampling (snowball sampling). Data is analyzed through collection, reduction, analysis, validity testing, presentation and conclusion. Results: This research shows the transformation of eco-friendly digital-based MSME marketing strategies occurred through four stages, namely production and institutional activities, expanding market share, digitalization and financing, and export market access. Conclusions: Eco-friendly digital transformation allows MSMEs competencies to be refined to improve business processes and business competitiveness at the international level. The contribution of this marketing strategy transformation is expanding MSMEs access to financial institutions (fintech), marketplaces, and QRIS (QR Code Indonesian Standard) digital payments.

Study on damage law and width optimization design of coal pillar with the discrete element method

  • Chuanwei Zang;Bingzheng Jiang;Xiaoshan Wang;Hao Wang;Jia Zhou;Miao Chen;Yu Cong
    • Geomechanics and Engineering
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    • 제37권6호
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    • pp.555-563
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    • 2024
  • The reasonable setting of coal pillar width plays a key role in guaranteeing the steadiness of surrounding rock of fully mechanized caving gateroad driving along the next goaf. Based on the engineering background of the Bayangaole mine, the discrete element method was used to simulate the fracture evolution of coal pillars with different pillar widths. The results show that the damage rate of the coal pillar increases with the decrease in the width of the coal pillar. Once the coal pillar width is smaller than 6 m, cracks run through the coal pillar, and the coal pillar is completely damaged. In the middle of the coal pillar, which has a width of 6 m and above, there is a relatively complete area with low damage. The results show that the pillar width of 6 m is the most appropriate. Field tests prove that the reserved width of a 6 m small coal pillar can effectively control the surrounding rock deformation, ensuring the overall steadiness of the gateroad in the thick coal seam. It is hoped that this study will offer some reference for the determination of the reasonable size of the coal pillar.

조선 세종대(世宗代) 앙부일구의 특징 (CHARACTERISTICS OF ANGBU-ILGU DURING THE REIGN OF KING SEJONG OF THE JOSEON DYNASTY)

  • 민병희;이기원;박지원;김상혁
    • 천문학논총
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    • 제39권2호
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    • pp.69-87
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    • 2024
  • This study analyzes the characteristics of the Angbu-ilgu, a Korean sundial resembling a concave hemisphere, which was crafted in 1434 during the sixteenth reign of King Sejong (r. 1418-1450) of the Joseon Dynasty, although no remains of it exist today. We draw upon historical documents, such as the Sejong-Sillok (Veritable Records of King Sejong), Donggyeong-Jiji (Chorography of the Joseon Dynasty), and Yuanshi (History of the Yuan Dynasty), as well as related extant relics. The primary features of King Sejong's Angbu-ilgu were as follows. First, celestial-circumference degrees were intricately engraved along the meridian line. Second, 12 double-hours were represented by images corresponding to their respective animal divinities. Third, a plate was affixed to the end of the gnomon, which stood perpendicular to the alidade, serving as a handle, rotated along two axes, and included a pinhole. Fourth, the diameter of the hemisphere measured 414 mm, approximately 1.5-2.1 times larger than extant Angbu-ilgu relics. Finally, four pillars supporting the Angbu-ilgu were positioned at four cardinal points. In conclusion, this study holds significance for restoring the Angbu-ilgu from the era of King Sejong.

마리오 보타 작품에서 보여지는 실내공간의 특성에 관한 연구 - 공공건물을 중심으로 - (A Study on the Characteristics of Interior Space in the Works of Mario Botta -Focused on Public Buildings-)

  • 김용립
    • 한국실내디자인학회논문집
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    • 제28호
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    • pp.33-43
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    • 2001
  • Mario Botta is one of the modern architects who established his own architectural world on the basis of the architectural spirit of Modernism. His works have been a good theme not only for those who study architecture but also for those who study the relationship between architecture and the surrounding environment and there have been many published papers and reports on his works. However, most of them stressed on the importance of the external appearance of architecture or on the relationship between architecture and the surrounding environment. There have been relatively few studies that have dealt intensively with interior space. The aim of this study is to find the characteristics of interior space in public buildings that were designed by Botta and to analyze them from the view design principles and design elements. For this purpose, the five most important public buildings were selected and the public space of the building like the central hall, the lobby, and the foyer were analyzed. Through this study, the followings are realized. A) Spatial features: $\circled1$ Refined and graceful interiors where the principle of symmetry was applied, $\circled2$ Centripetal interiors surrounded by thick walls, $\circled3$ Interior design lit by skylights above the central area, B) Formative features: $\circled1$ The shapes of the external and internal spaces are identical, $\circled2$ Simple geometrical shapes were applied in defining the shapes of internal spaces, $\circled3$ Skylights and light wells were combined and were utilized as form elements, $\circled4$ Architectural vocabularies of Corbusier such as stairs, round pillars, and bridges were developed and utilized, $\circled5$ Utilized the geometry that resembled his architecture as a form element to the furniture, C) material pattern features: $\circled1$ Plainly expressed the patterns of bricks that appear in the course of construction, $\circled2$ Made and used horizontal stripe patterns using stones of different colors.

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발파진동 및 비산충격에 대한 광주 안정성 분석 (Analysis of Pillar Stability for Ground Vibration and Flyrock Impact in Underground Mining Blasting)

  • 박현식;김지수;류복현;강추원
    • 화약ㆍ발파
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    • 제30권2호
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    • pp.9-20
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    • 2012
  • 최근 광업계는 지하개발이 주로 이루어지며, 대형 굴착장비의 보급으로 인해 갱도 및 채굴공동이 지하심 부화되고 있다. 채광설계 시 채굴공동의 붕락방지와 채광작업의 안전성 확보를 위해 채굴공동 및 광주의 설계가 매우 중요하게 대두되고 있다. 이에 본 연구는 지하채굴공동의 발파진동계측을 통한 발파진동 예측식 도출을 수행하였고, 채굴공동의 발파시 발생되는 비산석의 파쇄입도 분석과 비산거리 측정을 통하여 광주에 가해지는 이론적인 충격진동을 산정하였다. 지하채굴공동의 발파에 따른 광주의 영향을 검토하기 위하여 유한요소해석을 수행하여 발파진동 예측식과 비교하였으며, 채굴공동의 발파로 인해 발생되는 비산석이 광주에 충격이 가해졌을 때의 충격진동과 이론적인 충격진동을 비교, 분석하였다.