• 제목/요약/키워드: variance structure

검색결과 539건 처리시간 0.03초

전역 민감도 분석을 이용한 건물 에너지 성능평가의 합리적 개선 (Rational Building Energy Assessment using Global Sensitivity Analysis)

  • 유영서;이동혁;김선숙;박철수
    • 대한건축학회논문집:구조계
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    • 제36권5호
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    • pp.177-185
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    • 2020
  • The building energy performance indicator, called Energy Performance Index (EPI), has been used for the past decades in South Korea. It has a list of design variables assigned with weighting factors (a, b). Unfortunately, the current EPI method is not performance-based but very close to a prescriptive rating. With this in mind, this study aims to propose a new performance-based EPI method. For this purpose, a global sensitivity analysis method, Sobol, is employed. The Sobol method is suitable for complex nonlinear models and can decompose all the output variance due to every input. The Sobol sensitivity index of each variable is defined as 0 to 1 (0 to 100%), and the sum of all sensitivity indices is equal to 1 (100%). In this study, an office building was modeled using EnergyPlus and then the Latin Hypercube Sampling (LHS) was conducted to generate a surrogate model to EnergyPlus. The sensitivity index was suggested to replace weight (a) in the existing EPI. In addition, the discrete weight (b) in the existing EPI was replaced by a set of continuous regression functions. Due to the introduction of the sensitivity index and the continuous regression functions, the new proposed approach can provide far more accurate outcome than the existing EPI (R2: 0.83 vs. R2: 0.01 for cooling, R2: 0.66 vs. R2: 0.01 for total energy). The new proposed approach proves to be more rational, objective and performance-based than the existing EPI method.

Comparison of the Isometric Hip Flexors Strength in Supine Position in Subjects With and Without Weak Isometric Core Strength

  • Jeon, In-Cheol
    • 한국전문물리치료학회지
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    • 제28권1호
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    • pp.59-64
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    • 2021
  • Background: Hip flexor muscles are very important in the hip joint structure as a mover and stabilizer. In addition, isometric hip flexor strength in the supine position needs to be considered with isometric core strength (WICS) to measure a precise strength in a clinical way. Objects: We compared isometric hip flexor strength in the supine position in subjects with and without WICS (between factors) and conditions with and without an external support (within factors). Methods: A total of 34 subjects (16 with WICS, 18 without WICS) participated in this study. We used the double-bent leg-lowering test to divide the subjects in two groups according to the presence of WICS. Isometric hip flexor strength was evaluated in the supine position both with and without an external support condition. The two-way mixed analysis of variance was applied to identify significant differences between groups (with vs. without WICS: between factors) and conditions (with vs. without an external support: within factors). Statistical significance was set at α = 0.05. Results: In subjects with WICS, isometric hip flexor strength was greater with an external support than without it (p = 0.0064). In subjects without WICS, there were no significant differences in isometric hip flexor strength in the presence or absence of an external support (p = 0.075). The isometric hip flexor strength was significantly greater with an external support condition in particular in subjects with WICS. Conclusion: The findings of this study reported that an external support condition in individuals with WICS may contribute to the improvement of isometric hip flexion strength in the supine position. Therefore, isometric core strength should be evaluated to distinguish the weakness between core region and hip flexors.

다변량 분석을 이용한 건설업 발주자의 안전보건조치 의무 도입 필요성 분석 (Analysis of the Necessity of Introducing the Obligation to Take Safety and Health Measures for Construction Orderers using Multivariate Analysis)

  • 임세종;서재민;원정훈;김창원
    • 한국안전학회지
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    • 제37권1호
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    • pp.20-29
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    • 2022
  • To stem the ever-prevalent occurrence of industrial accidents in the construction industry, which is emerging as a social problem, efforts must be invested by various stakeholders. Specifically, among stakeholders, the orderer is at the top of a project's decision-making structure. Therefore, the orderer's awareness of safety and health directly affects the process of securing the safety of the overall construction site. In this light, the present study aims to identify differences in the perceptions of each stakeholder regarding the obligatory safety and health measures for clients that have recently been introduced. In addition, it suggests specific implementation plans in the Korean context. The data used for analysis were collected through a survey targeting stakeholders such as orderers, safety managers, and site managers, and the collected data were quantitatively reviewed by using multivariate analysis methods such as analysis of variance. As a result of the analysis, the introduction of safety and health obligations for the owner was found to be necessary, and the designation and operation of safety and health experts as an action plan was deemed reasonable. The authors expect that the results of this study can be used as basic data for revising the related regulations in Korea. Moreover, as a further study, a review of the effectiveness after improving regulations would contribute strongly to the domain.

Seed Dispersal by Water, Wind, Birds, and Bats in the Caliraya Watershed, Laguna

  • Giancarlo Pocholo L. Enriquez;Lillian Jennifer V. Rodriguez
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제4권1호
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    • pp.28-42
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    • 2023
  • Seed dispersal supports community structure, maintains genetic connectivity across fragmented landscapes, and influences vegetation assemblages. In the Philippines, only two seed dispersal studies have compared different dispersal agents. We examined the seed dispersal patterns of water, wind, birds, and bats in the Caliraya Watershed, Philippines. We aimed to determine the floral species that were dispersed and how the forest characteristics influenced seed dispersal. By running seed rain traps and drift litter collection from March to June 2022, we analyzed 14,090 seeds in a privately owned study site within the watershed. Water did not exclusively disperse any species and acted as a secondary disperser. Seed density (seeds/trap) was significantly higher for bird-dispersed (n=166) and bat-dispersed (n=145) seeds than for wind-dispersed (n=79) seeds (One-way analysis of variance [ANOVA]: F2,87=16.21, P<0.0001). Species number (species/trap) was significantly higher for bird-dispersed (n=3.7) and bat-dispersed (n=3.9) seeds than for wind-dispersed (n=0.2) seeds (One-way ANOVA: F2,87 =16.67, P<0.0001). Birds dispersed more species because they are more diverse and access a wider variety of fruits, unlike bats. Birds and bats target different fruits and provide separate seed dispersal services. Generalized linear model analyses revealed that the number and basal area of fleshy fruit trees most strongly influenced the bird seed dispersal patterns. Therefore, we recommend a three-way approach to restoration efforts in the Caliraya Watershed: (1) ensure the presence of fleshy fruit trees in restoration zones, (2) assist the establishment of mid-successional and wind-dispersed trees, and (3) intensify the conservation efforts for both flora and faunal diversity.

한국어판 난임 낙인 측정도구의 타당도와 신뢰도 (The Reliability and Validity of Korean Version of the Infertility Stigma Scale (K-ISS))

  • 김미옥;반민경
    • 대한간호학회지
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    • 제52권6호
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    • pp.582-597
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    • 2022
  • Purpose: This study aimed to translate the Infertility Stigma Scale (ISS) into Korean and to evaluate its reliability and validity in the Korean context. Methods: Data were collected from 350 women who underwent in vitro fertilization (IVF). Data were analyzed using SPSS WIN 25.0 and AMOS 22.0. Content validity was analyzed using the item-level content validity index (I-CVI) and scale-level content validity index/averaging (S-CVI/Ave). The preliminary survey was conducted on 20 women who had experienced IVF at least once to check the level of understanding of the tool and the time required to fill out the questionnaire. Exploratory and confirmatory factor analyses were used to test construct validity. Additionally, hypothesis-testing construct validity were tested. Cronbach's α was used to assess the reliability. Results: The Korean-ISS (K-ISS) consists of 25 items, excluding two items from the original ISS questionnaire. Exploratory factor analysis identified four factors, which explained 75.6% of the total variance. The four distinct factors were infertility stigma with self-devaluation (56.8%), public stigma (8.1%), social withdrawal (6.5%), and family stigma (4.2%). In the confirmatory factor analysis, the 25 items in the four-factor structure were validated (χ2 /df ≤ 3, RMSEA ≤ 10). The hypothesis-testing construct validity of K-ISS against FPI (r = .58~.71, p < .001) and FQI (r = - .49~- .65, p < .001) was tested and found to be significant. The internal consistency reliability of the K-ISS, assessed using Cronbach's α, was .97. Conclusion: The K-ISS has satisfactory construct validity and reliability; therefore, it can help minimize the negative impact of stigma by measuring the stigma associated with women experiencing infertility.

지속 가능 패션 디자인의 이미지 요소에 관한 연구 - 업사이클링 가방 상품 중심으로 - (A Study on the Image Elements of Sustainable Fashion Design - Focusing on up-cycling bags products -)

  • 유흔;정재윤
    • 한국의상디자인학회지
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    • 제25권2호
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    • pp.1-16
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    • 2023
  • Due to the current seriousness of environmental pollution and the eco-friendly movement of the fashion industry, research on sustainable fashion design is being actively conducted. In this study, consumer perception of upcycling products, are divided into image, function, and meaning; and image is further divided into shape, color, and material. It was redefined as pattern, and image recognition was evaluated among men and women in their 20s and 30s, and men and women in their 40s and 50s used as subjects. First, factors that determine each image were extracted based on qualitative analysis of the precedent cases of upcycling bags, and quantitative analysis of the subjects was induced through a questionnaire. As a result of the analysis of evaluation items related to image association, the average frequency analysis of all subjects for each stimuli and the cognitive variance of the frequency analysis by generation by gender were found to be similar. However, awareness of some stimuli by generation showed a significant difference. Overall, in the three stimuli with high overall preference, common features, such as the basic box-shaped symmetrical structure, the monochromatic color of the Munsell system, solid and practical texture, and appropriate use of patterns were identified. In addition, it was confirmed that there was a difference with factors such as femininity, simplicity, touch, and splendor in the measurement factors. In conclusion, it is considered that the main significance of this study is that it excluded the recognition and meaning of upcycling products and explored the original design and image elements of products. Therefore, it is expected that this study will be used as a basic data for responding to the gender image of each generation as an alternative method of sustainable fashion design, and it will be an opportunity to expand the scope of the study to a detailed study beyond the biased topic.

Effect of internal structures on the accuracy of 3D printed full-arch dentition preparation models in different printing systems

  • Teng Ma;Tiwu Peng;Yang Lin;Mindi Zhang;Guanghui Ren
    • The Journal of Advanced Prosthodontics
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    • 제15권3호
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    • pp.145-154
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    • 2023
  • PURPOSE. The objective of this study was to investigate how internal structures influence the overall and marginal accuracy of full arch preparations fabricated through additive manufacturing in different printing systems. MATERIALS AND METHODS. A full-arch preparation digital model was set up with three internal designs, including solid, hollow, and grid. These were printed using three different resin printers with nine models in each group. After scanning, each data was imported into the 3D data processing software together with the master cast, aligned and trimmed, and then put into the 3D data analysis software again to compare the overall and marginal deviation whose results are expressed using root mean square values and color maps. To evaluate the trueness of the resin model, the test data and reference data were compared, and the precision was evaluated by comparing the test data sets. Color maps were observed for qualitative analysis. Data were statistically analyzed by one-way analysis of variance and Bonferroni method was used for post hoc comparison (α = .05). RESULTS. The influence of different internal structures on the accuracy of 3D printed resin models varied significantly (P < .05). Solid and grid models showed better accuracy, while the hollow model exhibited poor accuracy. The color maps show that the resin models have a tendency to shrink inwards. CONCLUSION. The internal structure design influences the accuracy of the 3D printing model, and the effect varies in different printing systems. Irrespective of the kind of printing system, the printing accuracy of hollow model was observed to be worse than those of solid and grid models.

향토음식점의 스토리텔링이 구매행동에 미치는 영향 (The Effect of Storytelling on Purchase Behavior in Local Food Restaurant)

  • 박아름;조미숙
    • 한국식생활문화학회지
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    • 제25권6호
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    • pp.764-769
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    • 2010
  • The aim of this study was to examine how customers perceive storytelling at a real local restaurant and to understand how consumption reflects their evaluation by understanding their values. Participants received information from a real local restaurant in the Gangneung area to examine the effects of storytelling and to evaluate their affective attitudes towards local restaurant stories, word-of-mouth intentions, and purchasing intentions using a seven-point Likert scale. A total of 310 consumers were used. A factor analysis was performed to identify consumption value characteristics and factor structure, which consisted economic value, emotional value, and epistemic value. To test whether local restaurant consumers could be classified into homogenous groups based on their consumption values, a three cluster solution was selected, and a Kmeans cluster analysis was performed. As a result, three groups were identified and labeled appropriate for their scores based on each of the consumption values; emotional value-oriented consumers to cluster 1, epistemic value-oriented consumers to cluster 2, and economic value-oriented consumers to cluster 3. An analysis of variance was used to examine the differences in the affective attitudes towards storytelling at the local restaurant, purchasing intentions, and word-of-mouth intentions across the three clusters. The epistemic value-oriented consumers had the highest score for all three variables. In contrast, economic value-oriented consumers had the lowest scores for the three variables. A regression analysis revealed that affective attitudes towards storytelling were significantly affected by these three consumption values. It also showed that positive affective attitudes towards storytelling were associated with higher purchasing intention and word-of-mouth. The significance of this study was to show how customers perceive storytelling at a real restaurant and reflect on their evaluation by understanding their consumption values. As a result, this study examined the potential power of storytelling as an effective marketing communication tool for local restaurants.

포말건조 조건에 따른 애플망고 분말의 건조 가공 특성 (Drying Characteristics of Mango Powder according to Foam-Mat Drying Conditions)

  • 오현빈;백채완;곽태호;장현욱;김하윤;조용식
    • 한국식품영양학회지
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    • 제36권6호
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    • pp.496-505
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    • 2023
  • This study explored a method to enhance the drying process usability of local mangoes by producing foam-mat dried powder under varying drying temperatures (50, 60, 70℃) and foam thicknesses (3, 6, 9 mm). The drying process period ranged from 60 to 390 minutes based on the set conditions, with higher temperatures and thinner foams accelerating drying. Powder chromaticity (L*,(L*, a*, and b*) demonstrated a declining trend with increasing drying temperature and foam thickness, exhibiting notable variance in chroma values. The water absorption index varied significantly, between 3.08 to 4.24, under different drying conditions, although the water solubility index remained consistent across foam-dried samples. Powder moisture content ranged from 2.53% to 3.83%, with hygroscopicity escalating with temperature and foam thickness. Vitamin C structure was compromised during the hot air drying process, especially at temperatures above 60℃. Electronic nose analysis distinguished foam-dried powder from freeze-dried powder; however, a thicker foam yielded a scent profile closer to that of freeze-dried powder. The findings provide fundamental data on mango foam drying, which is expected to improve processing and storage tech for local mangoes.

교육 현장에서 시행된 임상 술기 시험의 다면적 타당도 분석 (Multifaceted validity analysis of clinical skills test in the educational field setting)

  • 채한;이민정;김명호;김규석;조은별
    • 대한한의학회지
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    • 제45권1호
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    • pp.1-16
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    • 2024
  • Introduction: The importance of clinical skills training in traditional Korean medicine education is increasingly emphasized. Since the clinical skills tests are high-stakes tests that determine success in national licensing exams, it is essential to develop reliable multifaceted analysis methods for clinical skills tests in actual education settings. In this study, we applied the multifaceted validity evaluation methods to the evaluation results of the cardiopulmonary resuscitation module to confirm the applicability and effectiveness of the methods. Methods: In this study, we used internal consistency, factor analysis, generalizability theory G-study and D-study, ANOVA, Kendall's tau, descriptive statistics, and other statistical methods to analyze the multidimensional validity of a cardiopulmonary resuscitation test in clinical education settings over the past three years. Results: The factor analysis and internal consistency analysis showed that the evaluation rubric had an unstable structure and low concordance. The G-study showed that the error of the clinical skills assessment was large due to the evaluator and unexpected errors. The D-study showed that the variance error of the evaluator should be significantly reduced to validate the evaluation. The ANOVA and Kendall's tau confirmed that evaluator heterogeneity was a problem. Discussion and Conclusion: Clinical skills tests should be continuously evaluated and managed for validity in two steps of pre-production and actual implementation. This study has presented specific methods for analyzing the validity of clinical skills training and testing in actual education settings. This study would contribute to the foundation for competency-based evidence-based education in practical clinical training.