• Title/Summary/Keyword: First-and Second-Order Sensitivity

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Analysis of Resident-oriented Management Process & It's Participants Subjectivities in Maha Ecotourism, Pyeongchang-gun (평창 마하생태관광지의 주민 주도 운영 과정과 참여자의 태도에 관한 주관성 분석)

  • Lee, Jae-Hyuck;Son, Yong-Hoon
    • Journal of Korean Society of Rural Planning
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    • v.21 no.1
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    • pp.63-75
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    • 2015
  • In analyzing the issues of ecotourism, collecting opinions of local residents and participants is an essential process because ecotourism needs to keep ecological sensitivity and respect local residents' ecological lives. Thus, the objective of this study is to analyze the local participants' attitude in resident-oriented ecotourism. Maha ecotourism site, as a study site, is located in Pyeongchang-gun, one of the twelve ecotourism sites designated by the Ministry of Environment. This site has drawn attention since the local government of Pyeongchang-gun transferred its management right on Maha ecotourism sit to the organization of local residents in 2013. This study uses Q methodology which is the most popular research method in analyzing people's subjectivity, that is, viewpoint and attitude. This study have found that there are four features in the subjectivities of participants toward ecotourism site: first group is the people who want more autonomous management right of local residents on Maha ecotourism site. Second group is the people who only want to stand by the ecotourism management. Third group is the people who focus on the migration of talented persons into their neighborhood owing to the program. Lastly, fourth group is the people who focus on the quality of the ecotourism program. In case of the second group, though they have negative opinions of the program, they have much interest in successful cases in other countries managed similar programs with Maha ecotourism. It would be effective for the group to have opportunities to experience successful ecotourism cases in other countries. On top of it, having seminars regarding ecotourism or holding community councils frequently would be very helpful for encouraging the second group of people to join in the ecotourism program actively like other groups of people. Supplying more manpower and developing various programs are also necessary in order to support other three groups.

Probabilistic seismic assessment of structures considering soil uncertainties

  • Hamidpour, Sara;Soltani, Masoud;Shabdin, Mojtaba
    • Earthquakes and Structures
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    • v.12 no.2
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    • pp.165-175
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    • 2017
  • This paper studies soil properties uncertainty and its implementation in the seismic response evaluation of structures. For this, response sensitivity of two 4- and 12-story RC shear walls to the soil properties uncertainty by considering soil structure interaction (SSI) effects is investigated. Beam on Nonlinear Winkler Foundation (BNWF) model is used for shallow foundation modeling and the uncertainty of soil properties is expanded to the foundation stiffness and strength parameters variability. Monte Carlo (MC) simulation technique is employed for probabilistic evaluations. By investigating the probabilistic evaluation results it's observed that as the soil and foundation become stiffer, the soil uncertainty is found to be less important in influencing the response variability. On the other hand, the soil uncertainty becomes more important as the foundation-structure system is expected to experience nonlinear behavior to more sever degree. Since full This paper studies soil properties uncertainty and its implementation in the seismic response evaluation of structures. For this, response sensitivity of two 4- and 12-story RC shear walls to the soil properties uncertainty by considering soil structure interaction (SSI) effects is investigated. Beam on Nonlinear Winkler Foundation (BNWF) model is used for shallow foundation modeling and the uncertainty of soil properties is expanded to the foundation stiffness and strength parameters variability. Monte Carlo (MC) simulation technique is employed for probabilistic evaluations. By investigating the probabilistic evaluation results it's observed that as the soil and foundation become stiffer, the soil uncertainty is found to be less important in influencing the response variability. On the other hand, the soil uncertainty becomes more important as the foundation-structure system is expected to experience nonlinear behavior to more sever degree. Since full probabilistic analysis methods like MC commonly are very time consuming, the feasibility of simple approximate methods' application including First Order Second Moment (FOSM) method and ASCE41 proposed approach for the soil uncertainty considerations is investigated. By comparing the results of the approximate methods with the results obtained from MC, it's observed that the results of both FOSM and ASCE41 methods are in good agreement with the results of MC simulation technique and they show acceptable accuracy in predicting the response variability.

PIV study of the flow around a 5:1 rectangular cylinder at moderate Reynolds numbers and small incidence angles

  • Guissart, Amandine;Elbaek, Erik;Hussong, Jeanette
    • Wind and Structures
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    • v.34 no.1
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    • pp.15-27
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    • 2022
  • This work comes within the framework of the "Benchmark on the Aerodynamics of a Rectangular Cylinder" that investigates a rectangular cylinder of length-to-depth ratio equal to 5. The present study reports and discusses velocity fields acquired using planar Particle Image Velocitmetry for several angles of attack and Reynolds numbers. In particular, for a cylinder depth-based Reynolds number of 2 × 104 and zero incidence angle, the flow features along the lateral (parallel to the freestream) upper and lower surfaces of the cylinder are reported. Using first and second order statistics of the velocity field, the main flow features are discussed, especially the size and location of the time-averaged flow structures and the distribution of the Reynolds stresses. The variation of the flow features with the incidence is also studied considering angles of attack up to 6°. It is shown that the time-averaged flow is fully detached for incidence higher than 2°. For an angle of attack of 0°, the effects of the Reynolds number varying between 5 × 103 and 2 × 104 are investigated looking at flow statistics. It is shown that the time-averaged location of the reattachment point and the shape and position of the time-averaged main vortex are mostly constant with the Reynolds number. However, the size of the inner region located below the time-averaged shear layer and just downstream the leading edge corner appears to be strongly dependent on the Reynolds number.

A Case Studies on the Sustainable Fashion Trend and Design as ESG Practice in the Post-Corona New Normal Period (포스트코로나 뉴노멀 시대의 ESG 실천 방안으로서의 지속가능한 패션경향 및 디자인 방향성 연구)

  • Lee, Dal A;Kim, Chan Ho
    • Journal of the Korea Fashion and Costume Design Association
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    • v.24 no.3
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    • pp.169-184
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    • 2022
  • This study aims to discuss sustainable fashion trends and sustainable design directions that fashion companies are practicing with ESG in the post-corona new normal era. As a research method, this study examined sustainable fashion trends and ESG practices through empirical case studies focusing on each fashion brand's website, including previous research and literature research, using materials such as newspapers and magazines. As for ESG practice plans, they were divided into four categories: technology orientation, design orientation, consumption orientation, and social value pursuit orientation. The sustainable fashion trends were also divided into four categories. First, the trend exhibits cyclical sustainability using pro-environmental materials, such as pro-environmental fibers, recycled fibers, biodegradable fibers. Second, high sensitivity and rare value sustainability were shown using reuse and upcycling. Third, consumption-oriented trends were promoted through slow fashion. Fourth, in order to realize eco-friendly sustainable fashion and ESG as practical ways to pursue social values, there is a trend of integrating sustainability through changes in perception considering people, society, and the environment. Beyond spreading concern about value consumption trends and the environment, it presents a direction for future industries concerning core values with social roles, responsibility, and ethical awareness from various perspectives.

Dynamic Analysis of Francis Runners - Experiment and Numerical Simulation

  • Lais, Stefan;Liang, Quanwei;Henggeler, Urs;Weiss, Thomas;Escaler, Xavier;Egusquiza, Eduard
    • International Journal of Fluid Machinery and Systems
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    • v.2 no.4
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    • pp.303-314
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    • 2009
  • The present paper shows the results of numerical and experimental modal analyses of Francis runners, which were executed in air and in still water. In its first part this paper is focused on the numerical prediction of the model parameters by means of FEM and the validation of the FEM method. Influences of different geometries on modal parameters and frequency reduction ratio (FRR), which is the ratio of the natural frequencies in water and the corresponding natural frequencies in air, are investigated for two different runners, one prototype and one model runner. The results of the analyses indicate very good agreement between experiment and simulation. Particularly the frequency reduction ratios derived from simulation are found to agree very well with the values derived from experiment. In order to identify sensitivity of the structural properties several parameters such as material properties, different model scale and different hub geometries are numerically investigated. In its second part, a harmonic response analysis is shown for a Francis runner by applying the time dependent pressure distribution resulting from an unsteady CFD simulation to the mechanical structure. Thus, the data gained by modern CFD simulation are being fully utilized for the structural design based on life time analysis. With this new approach a more precise prediction of turbine loading and its effect on turbine life cycle is possible allowing better turbine designs to be developed.

Metamodel based multi-objective design optimization of laminated composite plates

  • Kalita, Kanak;Nasre, Pratik;Dey, Partha;Haldar, Salil
    • Structural Engineering and Mechanics
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    • v.67 no.3
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    • pp.301-310
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    • 2018
  • In this paper, a multi-objective multiparameter optimization procedure is developed by combining rigorously developed metamodels with an evolutionary search algorithm-Genetic Algorithm (GA). Response surface methodology (RSM) is used for developing the metamodels to replace the tedious finite element analyses. A nine-node isoparametric plate bending element is used for conducting the finite element simulations. Highly accurate numerical data from an author compiled FORTRAN finite element program is first used by the RSM to develop second-order mathematical relations. Four material parameters-${\frac{E_1}{E_2}}$, ${\frac{G_{12}}{E_2}}$, ${\frac{G_{23}}{E_2}}$ and ${\upsilon}_{12}$ are considered as the independent variables while simultaneously maximizing fundamental frequency, ${\lambda}_1$ and frequency separation between the $1^{st}$ two natural modes, ${\lambda}_{21}$. The optimal material combination for maximizing ${\lambda}_1$ and ${\lambda}_{21}$ is predicted by using a multi-objective GA. A general sensitivity analysis is conducted to understand the effect of each parameter on the desired response parameters.

Study on the Effect of the Health Lifestyle on Customer Satisfaction, Repurchase Intention and Recommendation Intention: Focused on Protein Beverage Customers (건강 라이프스타일이 만족, 재구매 의도, 추천 의도에 미치는 영향: 단백질 음료 소비자를 대상으로)

  • Lee, Seung-Yeop;Kim, Yong-Il;Nam, Jang-Hyeon
    • Asia-Pacific Journal of Business
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    • v.13 no.2
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    • pp.169-182
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    • 2022
  • Purpose - The purpose of this study was to investigate influence relationship among health lifestyle, customer satisfaction, repurchase intention and recommendation intention in the protein beverage market. Design/methodology/approach - This study collected 286 survey data from customers who had experience buying and drinking the protein beverage. The Exploratory Factor Analysis (EFA) and the multiple regression analysis were hired in order to analyze the data. Findings - First, four dimensions of health lifestyle("health confidence," "health sensitivity," "health intention," and "health eating habit") were found to be valid and reliable. Second, all four dimensions of health lifestyle had a positive effect on customer satisfaction. Third, customer satisfaction had a positive effect on repurchase intention. Lastly, customer satisfaction had a positive effect on recommendation intention. Research implications or Originality - This study provided research model among health lifestyle, customer satisfaction, repurchase intention and recommendation. Furthermore, the results of this study were useful for identifying the role of health lifestyle in estimating customer satisfaction and the strategies for strengthening customer satisfaction in the protein beverage market.

An intelligent health monitoring method for processing data collected from the sensor network of structure

  • Ghiasi, Ramin;Ghasemi, Mohammad Reza
    • Steel and Composite Structures
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    • v.29 no.6
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    • pp.703-716
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    • 2018
  • Rapid detection of damages in civil engineering structures, in order to assess their possible disorders and as a result produce competent decision making, are crucial to ensure their health and ultimately enhance the level of public safety. In traditional intelligent health monitoring methods, the features are manually extracted depending on prior knowledge and diagnostic expertise. Inspired by the idea of unsupervised feature learning that uses artificial intelligence techniques to learn features from raw data, a two-stage learning method is proposed here for intelligent health monitoring of civil engineering structures. In the first stage, $Nystr{\ddot{o}}m$ method is used for automatic feature extraction from structural vibration signals. In the second stage, Moving Kernel Principal Component Analysis (MKPCA) is employed to classify the health conditions based on the extracted features. In this paper, KPCA has been implemented in a new form as Moving KPCA for effectively segmenting large data and for determining the changes, as data are continuously collected. Numerical results revealed that the proposed health monitoring system has a satisfactory performance for detecting the damage scenarios of a three-story frame aluminum structure. Furthermore, the enhanced version of KPCA methods exhibited a significant improvement in sensitivity, accuracy, and effectiveness over conventional methods.

Observation on power system characteristic changes in case of outage (주요설비 휴전시 계통 특성변화 고찰)

  • Lee, Woon-Hee;Lee, Chang-Gun;Joo, Hang-Roe;Jang, Sung-Ik
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.429-430
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    • 2007
  • The enlargement of an electric power system network gives us much challenges concerning with network operation. In addition to it, the fast aging process of network equipments requires more chance to check and maintenance, and also the increase of heavy loaded facilities and the increase of the fault current in the network need to exchange with the larger facilities in capacity. Due to these reasons, outages trend to increase. Network solution studies for outages are performed mainly for two purposes. The first one is to find the countermeasures when the outage causes a violation of the network reliability criteria. And the second one is to minimize network constraints due to outages. There are so many outages around 400 for only one month. Therefore, in order to do case studies for outage, not only skilled persons are needed, but also many available tools to help properly. Concerning with proper tools, we will introduce a program which we developed to get informations concerned with network sensitivity, and an example to apply that program.

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Identification of key elements for stable flight of drones and horizontal space compartment in urban area (드론의 안정적 비행을 위한 핵심요소와 도시 수평 공간 구획)

  • Kim, Jung-Hoon;Kim, Hong-Bae
    • Journal of Korea Planning Association
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    • v.53 no.7
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    • pp.39-48
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    • 2018
  • The purpose of this study is to verify the stable flight conditions of drones within a limited urban area by using the ICAO(International Civil Aviation Organization) reich model which is using to evaluate civil aircraft stability. The results of the study are summarized as follows. First, in order for the drones flying stably, the horizontal safety separation distance between a drone and another should be at least 1,852M. Second, assuming that no obstacles within 1,852M of horizontal space, two drones can be fly into upper and lower spaces. However there are obstacles such as buildings, it is impossible to secure a 1,852M distance between drones. Third, sensitivity analysis point out that the separation interval($s_x$) of drone aviation has the greatest influence on the TLS(Target Level of Safety). If future research is conducted to lower the numerical values, the safety distance between a drone and another drone will be drastically reduced, allowing more detailed urban space division, and will be presented as a scientific numerical value for establishing a dedicated path for the drones.