• 제목/요약/키워드: 적합도 분석

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Analysis of Tree Roughness Evaluation Methods Considering Depth-Dependent Roughness Coefficient Variation (수심별 조도계수 변화를 고려한 수목 조도공식 특성 분석)

  • Du Han Lee;Dong Sop Rhee
    • Ecology and Resilient Infrastructure
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    • v.10 no.3
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    • pp.51-63
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    • 2023
  • Riverine tree management is crucial in realizing a balance between flood control and ecological preservation, which requires an accurate assessment of the impact of trees on river water elevations. In this study, eight different formulas for evaluating vegetation roughness considering the drag force acting on trees, were reviewed, and the characteristics and applicability of these methods were evaluated from a practical engineering perspective. The study compared the characteristics of vegetation roughness measurement methods for calculated roughness coefficients at different water depths and analyzed factors such as effects of tree canopy width, tree density and diameter, and tree stiffness coefficient, and water level estimation results. A comparison of roughness coefficients at the same water depths revealed that the Kouwen and Fathi-Moghadam formulas and the Fischenich formula yield excessive drag coefficients compared to other formulas. Factors such as channel geometry, tree diameter, and tree density showed varying trends depending on the formula but did not exhibit excessive outliers. Formulas considering the tree stiffness coefficient, such as the Freeman et al.'s formula and the Whittaker et al.'s formula, showed significant variations in drag coefficients depending on the stiffness coefficient. When applied to small- and medium-sized virtual rivers in South Korea using the drag coefficient results from the eight formulas, the results indicated a maximum increase in water level of approximately 0.2 to 0.4 meters. Based on this review, it was concluded that the Baptist et al., Huthoff et al., Cheng, Luhar, and Nepf's formulas, which exhibit similar characteristics and low input data uncertainties, are suitable for practical engineering applications.

Characterization and Adsorption Properties of Red Mud/Fly Ash Based Geopolymers Adsorbent with Calcination Temperature (Red mud/fly ash 기반 geopolymer 흡착제의 소성온도에 따른 특성 및 흡착거동)

  • Jin-Yeong Shin;Han-Seong Kim;Hwa-Yeong Kang;Soon-Do Yoon
    • Applied Chemistry for Engineering
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    • v.34 no.4
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    • pp.412-420
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    • 2023
  • In this study, red mud/fly ash based geopolymer adsorbents (RFGPA) were prepared with calcination temperatures of 200, 400, and 600 ℃, and the effects of these calcination temperatures on the adsorption of methylene blue (MB) were investigated. In addition, the prepared RFGPA was characterized using X-ray fluorescence (XRF), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) spectroscopy, and Brunauer-EmmettTeller (BET) analysis. The results of the adsorption kinetics of MB at RFGPA prepared calcination temperatures indicated that the adsorption equilibrium of MB was reached after about 72 h. From the results of the adsorption isotherm, we verified that the degree of adsorption increased with increasing MB concentrations. In addition, the adsorption amount (Q) of MB decreased with an increase in calcination temperature. The experimental adsorption isotherm data were well fitted to the Freundlich and Sips equations compared to the Langmuir equation. In order to verify the effects of photocatalytic decomposition (C/C0) of MB on Fe2O3 present in prepared RFGPA, the degree of decomposition of MB was examined under dark and visible conditions. Results indicated that the decomposition of MB in visible conditions was about 3.0 times faster than that in dark conditions.

A Technology on the Framework Design of Virtual based on the Synthetic Environment Test for Analyzing Effectiveness of the Weapon Systems of Underwater Engagement Model (수중대잠전 교전모델의 무기체계 효과도 분석을 위한 합성환경기반 가상시험 프레임워크 설계 기술)

  • Hong, Jung-Wan;Park, Yong-Min;Park, Sang-C.;Kwon, Yong-Jin(James)
    • Journal of the Korea Society for Simulation
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    • v.19 no.4
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    • pp.291-299
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    • 2010
  • As recent advances in science, technology and performance requirements of the weapons system are getting highly diversified and complex, the performance requirements also get stringent and strict. Moreover, the weapons system should be intimately connected with other systems such as watchdog system, command and control system, C4I system, etc. However, a tremendous amount of time, cost and risk being spent to acquire new weapons system, and not being diminished compared to the rapid pace of its development speed. Defense Modeling and Simulation(M&S) comes into the spotlight as an alternative to overcoming these difficulties as well as constraints. In this paper, we propose the development process of virtual test framework based on the synthetic environment as a tool to analyze the effectiveness of the weapons system of underwater engagement model. To prove the proposed concept, we develop the test-bed of virtual test using Delta3D simulation engine, which is open source S/W. We also design the High Level Architecture and Real-time Infrastructure(HLA/RTI) based Federation for the interoperation with heterogeneous simulators. The significance of the study entails (1)the rapid and easy development of simulation tools that are customized for the Korean Theater of War; (2)the federation of environmental entities and the moving equations of the combat entities to manifest a realistic simulation.

A Study on Landscape Quality Assessment Techniques for Offshore Wind Farms - Focusing on Overseas Guidelines Cases - (해상풍력발전단지 경관의 질 평가 기법에 관한 연구 - 해외가이드라인 사례를 중심으로 -)

  • Jin-Oh Kim;Byoungwook Min;Kyung-Sook Woo;Jin-Pyo Kim
    • Journal of Environmental Impact Assessment
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    • v.32 no.4
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    • pp.230-241
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    • 2023
  • At a time when it is urgent to establish a management system for landscape quality assessment of offshore wind farms in Korea, we analyzed foreign cases to draw implications for improving the landscape quality assessment of offshore wind farms in Korea and to explore the direction of efficient landscape assessment. The main contents derived from the analysis of overseas cases and systems are as follows. First, offshore wind farms are large-scale projects, and it is necessary to consider the landscape from the pre-planning stage, as in overseas cases. Second, the evaluation items for marine landscape quality should be expanded and systematized. Third, a flexible evaluation system that can consider new landscape impacts is required. In order to identify the landscape impacts of offshore wind farm projects, we refer to the landscape assessment items and procedures derived from overseas cases, but reflect them appropriately to the domestic maritime conditions, and specifically introduce a plan to minimize the landscape impacts that may occur during offshore wind farm projects to contribute to the sustainable use of offshore wind power.

Development of Mental Health Self-Care App for University Student (대학생을 위한 정신건강 자가관리 어플리케이션 개발)

  • Kang, Gwang-Soon;Roh, Sun-Sik
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.1
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    • pp.25-34
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    • 2019
  • The purpose of this study is to develop a mobile app for mental health self care of university student. User centered design is a research design that applies the subject's needs assessment, analysis, design, development, evaluation, modification and supplement to suit the subjects. In order to manage the mental health of university students, they consisted of four main areas of mental health problems: drinking, sleeping, depression, and stress. It is designed to enable self test content, analysis and notification of inspection results, and management plan for current status of each area. Based on this, I developed an Android based mental health self-care Application. The subject can enter his or her mental health status data to explain the normal or risk level for each result, and the subject can then select the appropriate intervention method that he or she can perform. In addition, we developed a mental health self care calendar that can display the present status of each of the four areas on a day by day basis, and the current status can be expressed in an integrated manner through animations and status bars. The purpose of this study was to develop a mental health self-care app that can be improved by continuous and improved programs.

Development of Park Performance Assessment Tool (PPAT) for the Qualitative Improvement of Urban Neighborhood Parks (근린공원 서비스의 질적 개선을 위한 공원성능평가도구 개발)

  • Kim, Yong-Gook;Kim, Young-Hyeon;Yoo, Ye-Seul
    • Journal of the Korean Institute of Landscape Architecture
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    • v.51 no.2
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    • pp.120-130
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    • 2023
  • This study aims to develop a Park Performance Assessment Tool (PPAT) to qualitatively evaluate the level of urban neighborhood park services. The Park Performance Assessment Tool (PPAT) development process is as follows. First, a pool of evaluation items was formed by analyzing domestic and foreign cases related to the Park Performance Evaluation Tool (PPAT). Second, evaluation items were refined considering domestic park conditions through expert advisory meetings and pilot evaluations. Third, the reliability of the Park Performance Evaluation Tool (PPAT) was verified through pilot evaluations. Fourth, weights for each evaluation item were derived through an expert survey and AHP analysis. Fifth, a Park Performance Evaluation Tool (PPAT) evaluation table and evaluation guidelines were prepared. The developed Park Performance Assessment Tool (PPAT) was applied to 22 neighborhood parks in Bupyeong-gu, Incheon to evaluate the quality of the physical environment. As a result of the evaluation, several urban neighborhood parks that need improved park services were identified. The Park Performance Evaluation Tool (PPAT) is expected to be used to establish a basic plan for parks and green spaces, select priority and project promotion methods for park maintenance projects, and certify excellent parks

A Case Study of Fashion Illustration Using VR Technology -Focusing on iPad use case and comparative analysis (VR 기술을 활용한 패션일러스트레이션 사례 연구 - 아이패드 활용 사례와 비교분석을 중심으로)

  • Park, Keunsoo
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.1
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    • pp.763-770
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    • 2023
  • In today's modern fashion industry, along with the Fourth Industrial Revolution, the digital fashion industry using new technologies such as AR (Augmented Reality), VR (Virtual Reality), and Metaverse is gradually expanding. Accordingly, in the field of fashion design education, a new form of fashion illustration using VR technology is attracting attention as a new expression method. Recently, the use of digital tools such as iPads is gradually increasing in the field of education at universities majoring in fashion design, and students' interest in new digital tools is continuously increasing in the process of fashion illustration work. Therefore, this study implements fashion illustration using VR technology, which has been commercialized and popularized in the fashion industry, analyzes the differentiated characteristics compared to fashion illustration completed with iPad, and explores the possibility of using VR technology for fashion illustration as a new expression tool. We looked at the limitations. Through this study, it was found that VR is a positive help to fashion illustration to express the conception and overall connectivity in the three-dimensional aspect of fashion design, and the iPad was found to be suitable for specific and delicate fashion illustration expression. The results of this study are intended to provide basic data for fashion illustration education that can increase students' interest and achievement.

Vegetation Classification and Ecological Characteristics of Black Locust (Robinia pseudoacacia L.) Plantations in Gyeongbuk Province, Korea (경북지방 아까시나무 조림지의 식생유형과 생태적 특성)

  • Jae-Soon Song;Hak-Yun Kim;Jun-Soo Kim;Seung-Hwan Oh;Hyun-Je Cho
    • Journal of Korean Society of Forest Science
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    • v.112 no.1
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    • pp.11-22
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    • 2023
  • This study was established to provide basic information necessary for ecological management to restore the naturalness of black locust (Robinia pseudoacacia L.) plantations located in the mountains of Gyeongbuk, Korea. Using vegetation data collected from 200 black locust stands, vegetation types were classified using the TWINSPAN method, the spatial arrangement status according to the environmental gradient was identified through DCA analysis, and a synoptic table of communities was prepared based on the diagnostic species determined by determining community fidelity (Φ) for each vegetation type. The vegetation types were classified into seven types, namely, Quercus mongolica-Polygonatum odoratum var. pluriflorum type, Castanea crenata-Smilax china type, Clematis apiifolia-Lonicera japonica type, Rosa multiflora-Artemisia indica type, Quercus variabilis-Lindera glauca type, Ulmus parvifolia-Celtis sinensis type, and Prunus padus-Celastrus flagellaris type. These types usually reflected differences in complex factors such as altitude, moisture regime, successional stage, and disturbance regime. The mean relative importance value of the constituent species was highest for black locust(39.7), but oaks such as Quercus variabilis, Q. serrata, Q. mongolica, Q. acutissima, and Q. aliena were also identified as important constituent species with high relative importance values, indicating their potential for successional trends. In addition, the total percent cover of constituent species by vegetation type, life form composition, species diversity index, and indicator species were compared.

A Study on Critical Success Factors of Off-Site Construction - By Importance Performance Analysis - (IPA를 통한 OSC 핵심성공요인에 관한 연구 - 국내 PC기반 OSC를 중심으로 -)

  • Jung, Seoyoung;Yu, Jungho
    • Korean Journal of Construction Engineering and Management
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    • v.24 no.2
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    • pp.24-36
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    • 2023
  • OSC is drawing attention to supplement limitations such as productivity problems and on-site safety and quality problems of existing on-site labor-oriented construction production methods. In order to activate the introduction and use of OSC in the domestic construction market, it is important to innovate the technology applied to each stage of OSC process (design and engineering, factory manufacturing, site assembly, and maintenance), but it is also necessary to develop a project management method suitable for OSC method. However, research related to OSC currently being conducted in Korea is mainly in terms of related technology development, and research on deriving project management measures for the success of OSC projects is insufficient. Therefore, it is time for research on deriving a project management plan based on the core success factors of the OSC project. Therefore, by conducting importance-performance analysis on 69 OSC critical success factors derived from the previous study, the study was conducted to derive key improvement factors for OSC introduction and utilization improvement and to provide implications for this. The results of this study are expected to have useful implications for the R&D planning and policy-making process for OSC activation in the future.

A Study on the Optimal Location of the Inclinometer and Strain Gauge in Small-Scale Underground Excavation (소규모 지하굴착에서 지중경사계와 변형률계의 최적 위치 선정에 대한 연구)

  • Gichun Kang;Jinuk Park;Byeongjin Roh;Jiahao Sun;Seong-Kyu Yun
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.2
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    • pp.23-33
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    • 2023
  • Currently, there are cases in Korea where economic damage has occurred due to the ambiguity instrument installation and operation standards in the construction of temporary earth retaining wall, failing to prevent collapse of temporary earth retaining wall at the construction site in advance. Therefore, in this study, a numerical analysis was conducted to find the appropriate installation location of the inclinometer and strain gauge among the installed instruments shown in the design drawing of the temporary earth retaining wall. As a results, It was found that the installation position of the underground inclinometer is the corner of the retaining wall in the case of plane-deformation analysis, and the most displacement occurs in the center of the excavation surface in the case of 3D analysis. When the stress and moment are comprehensively analyzed, the corner is judged to be a vulnerable point. In the case of the strain gauge, In plane-deformation analysis and 3D analysis, the maximum bending stress occurred at the wale connection where the end of the strut and the counter strut are in contact. At this point, it is analyzed that it is necessary to focus on installing and managing the connection to prevent accidents from being vulnerable.