• Title/Summary/Keyword: Model validation

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Enhancement of Geomorphology Generation for the Front Land of Levee Using Aerial Photograph (항공영상을 연계한 하천 제외지의 지형분석 개선 기법)

  • Lee, Geun Sang;Lee, Hyun Seok;Hwang, Eui Ho;Koh, Deuk Koo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3D
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    • pp.407-415
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    • 2008
  • This study presents the methodology to link with aerial photos for advancing the accuracy of topographic survey data that is used to calculate water volume in urban stream. First, GIS spatial interpolation technique as Inverse Distance Weight (IDW) and Kriging was applied to construct the terrain morphology to the sand-bar and grass area using cross-sectional survey data, and also validation point data was used to estimate the accuracy of created topographic data. As the result of comparison, IDW ($d^{-2}_{ij}$, 2nd square number) in Sand-bar area and Kriging Spherical model in grass area showed more efficient results in the construction of topographic data of river boundary. But the differences among interpolation methods are very slight. Image classification method, Minimum Distance Method (MDM) was applied to extract sand-bar and grass area that are located to river boundary efficiently and the elevation value of extracted layers was allocated to the water level point value. Water volume with topographic data from aerial photos shows the advanced accuracy of 13% (in sand-bar) and 12% (in grass) compared to the water volume of original terrain data. Therefore, terrain analysis method in river linking with aerial photos is efficient to the monitoring about sand-bar and grass area that are located in the downstream of Dam in flooding season, and also it can be applied to calculate water volume efficiently.

The Effects of Franchise Firm's Reputation on Trust and Loyalty (외식프랜차이즈 기업의 평판이 신뢰와 충성도에 미치는 영향)

  • Kim, Hye-Rim;Han, Young-Wee;Cho, Hye-Duck
    • The Korean Journal of Franchise Management
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    • v.8 no.2
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    • pp.37-47
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    • 2017
  • Purpose - Recently, the food service franchise market is experiencing rapid growth and competition is intensifying. Therefore, consumer choice has expanded, and reputation management has become important as a strategy for survival of corporations. Based on previous studies, this research proposed the theoretical framework about the structural relationships among reputation, trust(cognitive trust, affective trust), and loyalty. Research design, data, and methodology - This study examined the structural relationship between reputation, trust, and loyalty from the customer's perspective. Based on comprehensive validation procedures across nine food service Franchise firm types, This study found support for a five-dimensional scale with the following dimensions: Customer Orientation, Employer Brand, Reliable and Financially Strong Company, Product and Service Quality, and Social and Environmental Responsibility. In order to verify the research purposes, research model and hypotheses were developed. The data were collected from 227 food service franchise consumers through online survey. The data was analyzed with SPSS 24.0 and Amos 23.0 statistical program. Result - The results of the study are as follows. First, customer orientation, reliable·financially strong company and product·service quality have significant impact on corporate cognitive trust. And employer brand, product/service quality and social·environmental responsibility have significant impact on corporate affective trust. Second, cognitive trust and affective trust have significant impacts on consumer loyalty. Conclusions - The implications of this study are following as: From the theoretical perspective, this study considers trust as two dimensions such as cognitive and affective, not a single dimension, and identify what dimensions of franchise firms affect consumers' reputation perception and in turn lead cognitive and affective trust, and loyalty. This study also provides several managerial implications. In the franchise market where competition is intensifying, it is very important to analyze the attitudes of consumers in order to gain an advantage in competition with other competitors. In this study, it is meaningful that the study was conducted on consumers who have experience using a restaurant franchise company. Also, reputation is necessary to pay attention to the company because it is an important variable that strengthens with customer through confidence in food service franchise business, and leads loyalty and consumer consumption. Therefore, marketers should develop marketing strategies considering various reputation factors.

Feasibility of a Linear Diode Array Detector for Commissioning of a Radiotherapy Planning System

  • Seung Mo Hong;Uiseob Lee;Sung-woo Kim;Youngmoon Goh;Min-Jae Park;Chiyoung Jeong;Jungwon Kwak;Byungchul Cho
    • Progress in Medical Physics
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    • v.34 no.1
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    • pp.1-9
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    • 2023
  • Purpose: Although ionization chambers are widely used to measure beam commissioning data, point-by-point measurements of all the profiles with various field size and depths are time-consuming tasks. As an alternative, we investigated the feasibility of a linear diode array for commissioning a treatment planning system. Methods: The beam data of a Varian TrueBeam® radiotherapy system at 6 and 10 MV with/without a flattening filter were measured for commissioning of an Eclipse Analytical Anisotropic Algorithm (AAA) ver.15.6. All of the necessary beam data were measured using an IBA CC13 ionization chamber and validated against Varian "Golden Beam" data. After validation, the measured CC13 profiles were used for commissioning the Eclipse AAA (AAACC13). In addition, an IBA LDA-99SC linear diode array detector was used to measure all of the beam profiles and for commissioning a separate model (AAALDA99). Finally, the AAACC13 and AAALDA99 dose calculations for each of the 10 clinical plans were compared. Results: The agreement of the CC13 profiles with the Varian Golden Beam data was confirmed within 1% except in the penumbral region, where ≤2% of a discrepancy related to machine-specific jaw calibration was observed. Since the volume was larger for the CC13 chamber than for the LDA-99SC chamber, the penumbra widths were larger in the CC13 profiles, resulting in ≤5% differences. However, after beam modeling, the penumbral widths agreed within 0.1 mm. Finally the AAALDA99 and AAACC13 dose distributions agreed within 1% for all voxels inside the body for the 10 clinical plans. Conclusions: In conclusion, the LDA-99SC diode array detector was found to be accurate and efficient for measuring photon beam profiles to commission treatment planning systems.

Validation of the Korean Version of the Continuing Bonds Scale (한국판 지속 유대 척도의 타당화)

  • Kyeyang Kim ;Jongwon Park ;Wan-Suk Gim
    • Korean Journal of Culture and Social Issue
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    • v.22 no.2
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    • pp.263-283
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    • 2016
  • The present study aimed at examining the factor structure, reliability and validity of the Korean version of the Continuing Bonds Scale (K-CBS). In study 1, exploratory factor analysis was administered to 293 bereaved adults who had experienced the death of a loved one, and it revealed a single factor structure with 10 items that explained 52.59% of the total variance. The K-CBS showed good internal consistency with Cronbach's alpha of .92. In study 2, confirmatory factor analysis in a different sample of 200 bereaved adults indicated satisfactory standardized regression weights of all items. However, one item had a squared multiple correlation less than .40, hence, this item was discarded, and 9 items remained for the final scale. The single factor model with 9 items displayed a good fit. The K-CBS had strong positive correlation with grief symptoms, and weak positive correlation with depression. After controlling for grief, however, the K-CBS was predictive of a decrease in depression. The K-CBS was positively associated with posttraumatic growth. In addition, significant differences in scores of the K-CBS were shown among groups based on the deceased's relation to the bereaved and expectedness of loss. These results suggest that the K-CBS is a reliable and valid instrument to measure continuing bonds. Finally, implications, limitations, and directions for future research were discussed.

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Development of BIM and Augmented Reality-Based Reinforcement Inspection System for Improving Quality Management Efficiency in Railway Infrastructure (철도 인프라 품질관리 효율성 향상을 위한 BIM 기반 AR 철근 점검 시스템 구축)

  • Suk, Chaehyun;Jeong, Yujeong;Jeon, Haein;Yu, Youngsu;Koo, Bonsang
    • Korean Journal of Construction Engineering and Management
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    • v.24 no.6
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    • pp.63-65
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    • 2023
  • BIM and AR technologies have been assessed as a means of enhancing productivity within the construction industry, through the provision of effortless access to critical data on site, achieved via the projection of 3D models and associated information onto actual structures. However, most of the previous researches for applying AR technology in construction quality management has been performed for construction projects in general, resulting in only overall on-site management solutions. Also, a few previous researches for the application of AR in the quality management of specific elements like reinforcements focused only on simple projection, so conducting specific quality inspection was impossible. Hence, this study aimed to develop a practically applicable BIM-based AR quality management system targeted for reinforcements. For the development of this system, the reinforcement inspection items on the quality checklist used at railway construction sites were analyzed, and four types of AR functions that can effectively address these items were developed and installed. The validation result of the system for the actual railway bridge showed a degradation of projection stability. This problem was solved through model simplification and enhancement of the AR device's hardware performance, and then the normal operation of the system was validated. Subsequently, the final developed reinforcement quality inspection system was evaluated for practical applicability by on-site quality experts, and the efficiency of inspection would significantly increase when using the AR system compared to the current inspection method for reinforcements.

A Groundwater Potential Map for the Nakdonggang River Basin (낙동강권역의 지하수 산출 유망도 평가)

  • Soonyoung Yu;Jaehoon Jung;Jize Piao;Hee Sun Moon;Heejun Suk;Yongcheol Kim;Dong-Chan Koh;Kyung-Seok Ko;Hyoung-Chan Kim;Sang-Ho Moon;Jehyun Shin;Byoung Ohan Shim;Hanna Choi;Kyoochul Ha
    • Journal of Soil and Groundwater Environment
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    • v.28 no.6
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    • pp.71-89
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    • 2023
  • A groundwater potential map (GPM) was built for the Nakdonggang River Basin based on ten variables, including hydrogeologic unit, fault-line density, depth to groundwater, distance to surface water, lineament density, slope, stream drainage density, soil drainage, land cover, and annual rainfall. To integrate the thematic layers for GPM, the criteria were first weighted using the Analytic Hierarchical Process (AHP) and then overlaid using the Technique for Ordering Preferences by Similarity to Ideal Solution (TOPSIS) model. Finally, the groundwater potential was categorized into five classes (very high (VH), high (H), moderate (M), low (L), very low (VL)) and verified by examining the specific capacity of individual wells on each class. The wells in the area categorized as VH showed the highest median specific capacity (5.2 m3/day/m), while the wells with specific capacity < 1.39 m3/day/m were distributed in the areas categorized as L or VL. The accuracy of GPM generated in the work looked acceptable, although the specific capacity data were not enough to verify GPM in the studied large watershed. To create GPMs for the determination of high-yield well locations, the resolution and reliability of thematic maps should be improved. Criterion values for groundwater potential should be established when machine learning or statistical models are used in the GPM evaluation process.

Ecological Risk Assessment of 4,4'-Methylenedianiline (4,4'-Methylenedianiline의 환경매체별 위해성평가)

  • Hyun Soo Kim;Daeyeop Lee;Kyung Sook Woo;Si-Eun Yoo;Inhye Lee;Kyunghee Ji;Jungkwan Seo;Hun-Je Jo
    • Journal of Environmental Health Sciences
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    • v.49 no.6
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    • pp.334-343
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    • 2023
  • Background: South Korea's Act on Registration and Evaluation, etc. of Chemicals (known as K-REACH) was established to protect public health and the environment from hazardous chemicals. 4,4'-Methylenedianiline (MDA), which is used as a major intermediate in industrial polymer production and as a vulcanizing agent in South Korea, is classified as a toxic substance under the K-REACH act. Although MDA poses potential ecological risks due to industrial emissions and hazards to aquatic ecosystems, no ecological risk assessment has been conducted. Objectives: The aim of this study is to assess the ecological risk of MDA by identifying the actual exposure status based on the K-REACH act. Methods: Various toxicity data were collected to establish predicted no effect concentrations (PNECs) for water, sediment, and soil. Using the SimpleBox Korea v2.0 model with domestic release statistical data and EU emission factors, predicted environmental concentrations (PECs) were derived for ten sites, each referring to an MDA-using company. Hazard quotient (HQ) was calculated by ratio of the PECs and PNECs to characterize the ecological risk posed by MDA. To validate the results of modeling-based assessment, concentration of MDA was measured using in-site freshwater samples (two to three samples per site). Results: PNECs for water, sediment, and soil were 0.000525 mg/L, 4.36 mg/kg dw, and 0.1 mg/kg dw, respectively. HQ for surface water and sediment at several company sites exceeded 1 due to modeling data showing markedly high PEC in each environmental compartment. However, in the results of validation using in-site surface water samples, MDA was not detected. Conclusions: Through an ecological risk assessment conducted in accordance with the K-REACH act, the risk level of MDA emitted into the environmental compartments in South Korea was found to be low.

Validation of the Effectiveness of Education for Obtaining Consent in Clinical Study (임상연구 동의서 교육 시행의 효용성 검증)

  • Ji Eun Kim;Mi Sung Lee;Sul Hwa Kim;Ji Hye Yang;Seung Ah Go;Cho Long Lee;Soo Yeon Yang;Hae Joo Shin;Bo Ah Kim;Jong Woo Chung
    • The Journal of KAIRB
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    • v.5 no.2
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    • pp.51-58
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    • 2023
  • Purpose: To validate the effectiveness of obtaining consent education on errors in the consent process and to develop the education program for researchers. Methods: From February 2019 to February 2022, a 30-minute, 1:1 face-to-face consent education developed using the ADDIE model was conducted on 78 nurses as principal investigators. An informed consent audit tool, which includes 6 items developed by Asan Medical Center Human Research Protection Center, was used to analyze errors in obtaining informed consent process. Data analysis was performed using the SPSS ver. 25.0, and the Mann-Whitney U-test and χ2-test were utilized to verify the difference in errors between the experimental and control groups. Results: The participants consisted of 42 in the experimental group and 36 in the control group, with no statistically significant difference between the 2 groups. Both 2 groups showed the highest frequency of documentation errors, followed by format errors, errors related to a suitability of investigator, participant, or participant's legally acceptable representative, witness and confidentiality issues. After education, there was a significant decrease in both format errors (p=0.002) and documentation errors (p<0.001) in the experimental group. The proportion of participants without any errors in all items was higher in the experimental group (35.7%) compared to the control group (5.6%), and this difference was statistically significant (p=0.001). Conclusion: The obtaining consent education program was found to be effective in reducing informed consent errors. This study emphasizes the importance of education, suggesting the need for its expansion and accessibility, as well as the necessity for all researchers conducting clinical studies to receive the obtaining consent education.

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A Study on Real-time Autonomous Driving Simulation System Construction based on Digital Twin - Focused on Busan EDC - (디지털트윈 기반 실시간 자율주행 시뮬레이션 시스템 구축 방안 연구 - 부산 EDC 중심으로 -)

  • Kim, Min-Soo;Park, Jong-Hyun;Sim, Min-Seok
    • Journal of Cadastre & Land InformatiX
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    • v.53 no.2
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    • pp.53-66
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    • 2023
  • Recently, there has been a significant interest in the development of autonomous driving simulation environment based on digital twin. In the development of such digital twin-based simulation environment, many researches has been conducted not only performance and functionality validation of autonomous driving, but also generation of virtual training data for deep learning. However, such digital twin-based autonomous driving simulation system has the problem of requiring a significant amount of time and cost for the system development and the data construction. Therefore, in this research, we aim to propose a method for rapidly designing and implementing a digital twin-based autonomous driving simulation system, using only the existing 3D models and high-definition map. Specifically, we propose a method for integrating 3D model of FBX and NGII HD Map for the Busan EDC area into CARLA, and a method for adding and modifying CARLA functions. The results of this research show that it is possible to rapidly design and implement the simulation system at a low cost by using the existing 3D models and NGII HD map. Also, the results show that our system can support various functions such as simulation scenario configuration, user-defined driving, and real-time simulation of traffic light states. We expect that usability of the system will be significantly improved when it is applied to broader geographical area in the future.

Accuracy of posteroanterior cephalogram landmarks and measurements identification using a cascaded convolutional neural network algorithm: A multicenter study

  • Sung-Hoon Han;Jisup Lim;Jun-Sik Kim;Jin-Hyoung Cho;Mihee Hong;Minji Kim;Su-Jung Kim;Yoon-Ji Kim;Young Ho Kim;Sung-Hoon Lim;Sang Jin Sung;Kyung-Hwa Kang;Seung-Hak Baek;Sung-Kwon Choi;Namkug Kim
    • The korean journal of orthodontics
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    • v.54 no.1
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    • pp.48-58
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    • 2024
  • Objective: To quantify the effects of midline-related landmark identification on midline deviation measurements in posteroanterior (PA) cephalograms using a cascaded convolutional neural network (CNN). Methods: A total of 2,903 PA cephalogram images obtained from 9 university hospitals were divided into training, internal validation, and test sets (n = 2,150, 376, and 377). As the gold standard, 2 orthodontic professors marked the bilateral landmarks, including the frontozygomatic suture point and latero-orbitale (LO), and the midline landmarks, including the crista galli, anterior nasal spine (ANS), upper dental midpoint (UDM), lower dental midpoint (LDM), and menton (Me). For the test, Examiner-1 and Examiner-2 (3-year and 1-year orthodontic residents) and the Cascaded-CNN models marked the landmarks. After point-to-point errors of landmark identification, the successful detection rate (SDR) and distance and direction of the midline landmark deviation from the midsagittal line (ANS-mid, UDM-mid, LDM-mid, and Me-mid) were measured, and statistical analysis was performed. Results: The cascaded-CNN algorithm showed a clinically acceptable level of point-to-point error (1.26 mm vs. 1.57 mm in Examiner-1 and 1.75 mm in Examiner-2). The average SDR within the 2 mm range was 83.2%, with high accuracy at the LO (right, 96.9%; left, 97.1%), and UDM (96.9%). The absolute measurement errors were less than 1 mm for ANS-mid, UDM-mid, and LDM-mid compared with the gold standard. Conclusions: The cascaded-CNN model may be considered an effective tool for the auto-identification of midline landmarks and quantification of midline deviation in PA cephalograms of adult patients, regardless of variations in the image acquisition method.