• Title/Summary/Keyword: Model validation

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A Comparison of Pan-sharpening Algorithms for GK-2A Satellite Imagery (천리안위성 2A호 위성영상을 위한 영상융합기법의 비교평가)

  • Lee, Soobong;Choi, Jaewan
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.4
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    • pp.275-292
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    • 2022
  • In order to detect climate changes using satellite imagery, the GCOS (Global Climate Observing System) defines requirements such as spatio-temporal resolution, stability by the time change, and uncertainty. Due to limitation of GK-2A sensor performance, the level-2 products can not satisfy the requirement, especially for spatial resolution. In this paper, we found the optimal pan-sharpening algorithm for GK-2A products. The six pan-sharpening methods included in CS (Component Substitution), MRA (Multi-Resolution Analysis), VO (Variational Optimization), and DL (Deep Learning) were used. In the case of DL, the synthesis property based method was used to generate training dataset. The process of synthesis property is that pan-sharpening model is applied with Pan (Panchromatic) and MS (Multispectral) images with reduced spatial resolution, and fused image is compared with the original MS image. In the synthesis property based method, fused image with desire level for user can be produced only when the geometric characteristics between the PAN with reduced spatial resolution and MS image are similar. However, since the dissimilarity exists, RD (Random Down-sampling) was additionally used as a way to minimize it. Among the pan-sharpening methods, PSGAN was applied with RD (PSGAN_RD). The fused images are qualitatively and quantitatively validated with consistency property and the synthesis property. As validation result, the GSA algorithm performs well in the evaluation index representing spatial characteristics. In the case of spectral characteristics, the PSGAN_RD has the best accuracy with the original MS image. Therefore, in consideration of spatial and spectral characteristics of fused image, we found that PSGAN_RD is suitable for GK-2A products.

A Study on Digital Documentation of Precise Monitoring for Microscale Displacements within the Tomb of King Muryeong and the Royal Tombs in Gongju, Korea (공주 무령왕릉과 왕릉원 내부 미세변위 정밀모니터링을 위한 디지털 기록화 연구)

  • Choi, Il Kyu;Yang, Hye Ri;Lee, Chan Hee
    • Journal of Conservation Science
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    • v.37 no.6
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    • pp.626-637
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    • 2021
  • The tomb complex of the royal family from the period of the Ungjin Baekje Kingdom (475 to 538 AD) in Gongju, Korea, contains the tomb of King Muryeong and other royal tombs. After the excavation of the tomb of King Muryeong in 1971, these tombs were opened up to the public, without the establishment of systems for their safety, conservation and management. The tombs have consequently experienced rapid environmental changes and suffered various damages. In this study, specific vulnerable parts inside the tombs were selected for deviation analysis using 3D scanning, and 3D image models were constructed on this basis. Progressive displacement was identified in tomb No. 5, and basic data for future investigations was acquired from tomb No. 6 and the tomb of King Muryeong. In the deviation analysis for the southern plastered wall of tomb No. 5, the damage was not found to exceed the ranges of ±18 mm and ±2 mm. However, the lintel stone was found to be sagging by 0.32 mm on average, and the distance between the walls to have increased by 0.36 mm on average. Direct water seepage occurring in tomb No. 5 is considered to be increasing the damage within the tomb, such as the dropping and sagging of the lintel. The 3D image models constructed in this study will play an important role as baseline data for future research, and can be used to discuss a secure conservation scheme for the tombs through cross-validation with precise measurement monitoring.

Multi-fidelity uncertainty quantification of high Reynolds number turbulent flow around a rectangular 5:1 Cylinder

  • Sakuma, Mayu;Pepper, Nick;Warnakulasuriya, Suneth;Montomoli, Francesco;Wuch-ner, Roland;Bletzinger, Kai-Uwe
    • Wind and Structures
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    • v.34 no.1
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    • pp.127-136
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    • 2022
  • In this work a multi-fidelity non-intrusive polynomial chaos (MF-NIPC) has been applied to a structural wind engineering problem in architectural design for the first time. In architectural design it is important to design structures that are safe in a range of wind directions and speeds. For this reason, the computational models used to design buildings and bridges must account for the uncertainties associated with the interaction between the structure and wind. In order to use the numerical simulations for the design, the numerical models must be validated by experi-mental data, and uncertainties contained in the experiments should also be taken into account. Uncertainty Quantifi-cation has been increasingly used for CFD simulations to consider such uncertainties. Typically, CFD simulations are computationally expensive, motivating the increased interest in multi-fidelity methods due to their ability to lev-erage limited data sets of high-fidelity data with evaluations of more computationally inexpensive models. Previous-ly, the multi-fidelity framework has been applied to CFD simulations for the purposes of optimization, rather than for the statistical assessment of candidate design. In this paper MF-NIPC method is applied to flow around a rectan-gular 5:1 cylinder, which has been thoroughly investigated for architectural design. The purpose of UQ is validation of numerical simulation results with experimental data, therefore the radius of curvature of the rectangular cylinder corners and the angle of attack are considered to be random variables, which are known to contain uncertainties when wind tunnel tests are carried out. Computational Fluid Dynamics (CFD) simulations are solved by a solver that employs the Finite Element Method (FEM) for two turbulence modeling approaches of the incompressible Navier-Stokes equations: Unsteady Reynolds Averaged Navier Stokes (URANS) and the Large Eddy simulation (LES). The results of the uncertainty analysis with CFD are compared to experimental data in terms of time-averaged pressure coefficients and bulk parameters. In addition, the accuracy and efficiency of the multi-fidelity framework is demonstrated through a comparison with the results of the high-fidelity model.

The Validation Study of the Korean Version of Zero-sum Belief Scale (한국판 제로섬 신념 척도 타당화 연구)

  • Joeng, Ju-Ri
    • Korean Journal of Culture and Social Issue
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    • v.27 no.3
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    • pp.285-303
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    • 2021
  • The purpose of this study was to investigate the reliability and validity of the Korean version of the zero-sum belief scale among a sample of Korean adults. The original scale was developed by Różycka-Tran, Boski, and Wojciszke (2015) based on the Belief in a Zero-Sum Game (BZSG) model. A total of 508 participants (252 college students and 256 non-student adults) completed an online survey comprised of the scales of zero-sum belief, social trust, subjective socioeconomic status, individualistic-collectivistic tendencies, and social comparison orientation. Results of the exploratory factor analysis and the confirmatory factor analysis indicated that zero-sum belief scale has one factor. The internal consistency of the zero-sum belief scale was good. The Zero-sum belief scale did not have a significant relationship with social trust and subjective socioeconomic status. However, the scale was positively associated with vertical individualistic and vertical collectivistic tendencies and negatively associated with horizontal collectivistic tendencies. There was no significant relationship between zero-sum belief and horizontal individualistic tendencies, but there was a significant positive relationship between zero-sum belief and social comparison orientation. However, the results from the college student sample and the non-student adult sample were different. Lastly, this study could facilitate future research on zero-sum belief in South Korea, and future studies are needed to reveal the predictors and effects of zero-sum belief.

The Effect of Early Morning Delivery Service Quality of Online Shopping on Customer Satisfaction and Customer Behavior (Reuse Intention) (온라인 쇼핑의 새벽배송 서비스품질이 고객만족도와 고객행동(재이용의도)에 미치는 영향)

  • Chung, Chong Woo;Kim, Chul Soo
    • Journal of Service Research and Studies
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    • v.13 no.3
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    • pp.57-69
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    • 2023
  • Early morning delivery possesses distinct characteristics that differentiate it from standard delivery services. This service typically involves delivering products to customers during the early morning hours, primarily before 7 AM. While online early morning delivery offers various advantages from a customer perspective, it also presents challenges that sellers and online shopping companies need to overcome. The early morning delivery market is experiencing significant growth in the online food retail sector, incorporating both PC-based online shopping and mobile shopping. The objective of this research is to identify the factors influencing customer satisfaction and the intention to reuse in the context of early morning delivery for online shopping. To model the online shopping environment with early morning delivery, independent factors were categorized into three types: System Properties, Product Characteristics, and Delivery Characteristics. This study examined the relationships among these three independent factors, the mediating factor of customer satisfaction, and the dependent variable of the intention to reuse. To conduct this research, empirical validation of the research hypotheses was carried out using the final dataset for analysis. Within this study, the previously explored System Properties, Product Characteristics, and Delivery Characteristics were established. Summarizing the findings of the analysis, it was discovered that System Properties and Product Characteristics played a significant role in determining the quality of early morning delivery services for online shopping. While product diversity and convenience had a positive impact, it is noteworthy that Delivery Characteristics did not influence customer satisfaction. Consequently, it can be concluded that there is no effect on the intention to reuse.

Statistical Techniques to Detect Sensor Drifts (센서드리프트 판별을 위한 통계적 탐지기술 고찰)

  • Seo, In-Yong;Shin, Ho-Cheol;Park, Moon-Ghu;Kim, Seong-Jun
    • Journal of the Korea Society for Simulation
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    • v.18 no.3
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    • pp.103-112
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    • 2009
  • In a nuclear power plant (NPP), periodic sensor calibrations are required to assure sensors are operating correctly. However, only a few faulty sensors are found to be calibrated. For the safe operation of an NPP and the reduction of unnecessary calibration, on-line calibration monitoring is needed. In this paper, principal component-based Auto-Associative support vector regression (PCSVR) was proposed for the sensor signal validation of the NPP. It utilizes the attractive merits of principal component analysis (PCA) for extracting predominant feature vectors and AASVR because it easily represents complicated processes that are difficult to model with analytical and mechanistic models. With the use of real plant startup data from the Kori Nuclear Power Plant Unit 3, SVR hyperparameters were optimized by the response surface methodology (RSM). Moreover the statistical techniques are integrated with PCSVR for the failure detection. The residuals between the estimated signals and the measured signals are tested by the Shewhart Control Chart, Exponentially Weighted Moving Average (EWMA), Cumulative Sum (CUSUM) and generalized likelihood ratio test (GLRT) to detect whether the sensors are failed or not. This study shows the GLRT can be a candidate for the detection of sensor drift.

Development and Validation of the Scale of Care Competence for Adolescent (청소년 돌봄역량 측정도구의 개발 및 타당화)

  • Lee, Jisun;Choi, Saeeun
    • Journal of Korean Home Economics Education Association
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    • v.35 no.2
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    • pp.111-132
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    • 2023
  • The objective of this research is to conceptualize care competences for adolescents and to develop a valid measurement tool based on this conceptualization. The primary aim is to establish a solid foundation for effective communication in teaching care competences within the domain of home economics education. To achieve this, a comprehensive review of relevant literature and previous studies was conducted, and consultations with experts were undertaken to assess content and criterion-related validity. Furthermore, exploratory and confirmatory factor analyses were performed. The findings from these analyses resulted in a set of 34 items, which were categorized into five distinctive factors representing care competences in adolescents. These factors encompassed four items of care thinking, seven items of care emotion, six items of care behavior, seven items of self-care and ten items of community-care. Additionally, a reliability analysis was performed on the model, confirming the stability and consistency of the five factor structure and the 34 item scale, which assess care competences in adolescents.

Development and Validation of Psychological Difficulties Scale of Working Moms (워킹맘 심리적 어려움 척도 개발 및 타당화: 대졸이상 고학력 워킹맘 중심으로)

  • Jung, Hyun;Tak, Jinkook
    • The Korean Journal of Coaching Psychology
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    • v.4 no.2
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    • pp.1-26
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    • 2020
  • The purpose of this study was to develop and validate the Psychological Difficulties Scale of Working Moms(PDSWM). In the first study, 69items and 17 factors of the inventory were obtained based on interview, open-ended questionnaires. In the second study, the on-line surveys from 306 working mom was carried to analyze factor structure of the PDSWM. The final result showed that the 12 factor model with 64 items was appropriate. The third study was collected from 638 working mom and in order to make certain the cross-validity of the inventory, the group was divided into two groups (each group with 319 employees). The results of exploratory factor analyses using data of group 1 showed that the 8 factor structure with 48 items was appropriate. Also the results of confirmatory factor analysis using data of group 2 showed that the 8 factor structure indicated a satisfactory fit. Final 8 factors were as follows: 1) Feeling Apologetic to family members 2) Discrimination at workplace 3) burnt-out: both body and mind 4) Unequal distribution of child-rearing and house chore labor 5) Conflict with the babysitter/grandparents 6) Limit in further strengthening work competency 7) Social prejudice 8) Difficulty being on time for work. The PDSWM was significantly correlated with various criteria such as organizational commitment, life satisfaction, and work engagement. Based on such findings, implications, limitations, and the suggestions for future study were discussed.

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Vehicle Collision Simulation for Roadblocks in Nuclear Power Plants Using LS-DYNA (LS-DYNA를 이용한 원자력발전소의 로드블록에 대한 차량 충돌 시뮬레이션)

  • SeungGyu Lee;Dongwook Kim;Phill-Seung Lee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.2
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    • pp.113-120
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    • 2023
  • This paper introduces a simulation method for the collision between roadblocks and vehicles using LS-DYNA. The need to evaluate the performance of anti-ram barriers to prepare for vehicle impact has increased since vehicle impact threats have been included as a design criterion for nuclear power plants. Anti-ram barriers are typically certified for their performance through collision experiments. However, because Koreas has no performance testing facilities for anti-ram barriers, their performance can only be verified through simulations. LS-DYNA is a specialized program for collision simulation. Various organizations, including NCAC, distributes numerical models that have been validated for their accuracy with collision tests. In this study, we constructed a finite element model of the most critical vehicle barrier module and simulated collision between roadblocks and vehicles. The calculated results were verified by applying the validation criteria for vehicle safety facility collision simulations of NCHRP 179.

Analysis of Relative Importance of Board Game Development Models (보드게임 개발 모형의 상대적 중요도 분석)

  • Kim, Ji-Hye;Ho, Ryu Seuc
    • Journal of Digital Convergence
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    • v.20 no.1
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    • pp.257-263
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    • 2022
  • In the current era of Corona, the positive potential of board games is emerging as the 'untact' is accelerating. This situation can be seen as an opportunity to have a positive impact on the development of the board game industry depending on how to develop board games in a more interesting, high-quality and educational way than before. To this end, this study intends to present a methodology for deriving the relative importance of important factors in board game development among the preceding studies and methodologies for more advanced board game development by board game developers and experts. This study is to derive the relative importance of important factors in board game development. To this end, important factors in board game development for board game developers and experts were derived through the Delphi method, and the Delphi method in the ranking format was used to rank the relative importance of the derived factors. This study focused on the development model of playing cards among board games. Priority analysis result, development and planning composition, prior research analysis, draft production, production, validation, application, and review in order of importance were derived(were derived in the order of importance). The results of this study are expected to provide practical guidelines for companies to prioritize and utilize development according to their importance when developing board games.