• 제목/요약/키워드: Models, statistical

검색결과 3,012건 처리시간 0.028초

Calculating the collapse margin ratio of RC frames using soft computing models

  • Sadeghpour, Ali;Ozay, Giray
    • Structural Engineering and Mechanics
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    • 제83권3호
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    • pp.327-340
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    • 2022
  • The Collapse Margin Ratio (CMR) is a notable index used for seismic assessment of the structures. As proposed by FEMA P695, a set of analyses including the Nonlinear Static Analysis (NSA), Incremental Dynamic Analysis (IDA), together with Fragility Analysis, which are typically time-taking and computationally unaffordable, need to be conducted, so that the CMR could be obtained. To address this issue and to achieve a quick and efficient method to estimate the CMR, the Artificial Neural Network (ANN), Response Surface Method (RSM), and Adaptive Neuro-Fuzzy Inference System (ANFIS) will be introduced in the current research. Accordingly, using the NSA results, an attempt was made to find a fast and efficient approach to derive the CMR. To this end, 5016 IDA analyses based on FEMA P695 methodology on 114 various Reinforced Concrete (RC) frames with 1 to 12 stories have been carried out. In this respect, five parameters have been used as the independent and desired inputs of the systems. On the other hand, the CMR is regarded as the output of the systems. Accordingly, a double hidden layer neural network with Levenberg-Marquardt training and learning algorithm was taken into account. Moreover, in the RSM approach, the quadratic system incorporating 20 parameters was implemented. Correspondingly, the Analysis of Variance (ANOVA) has been employed to discuss the results taken from the developed model. Additionally, the essential parameters and interactions are extracted, and input parameters are sorted according to their importance. Moreover, the ANFIS using Takagi-Sugeno fuzzy system was employed. Finally, all methods were compared, and the effective parameters and associated relationships were extracted. In contrast to the other approaches, the ANFIS provided the best efficiency and high accuracy with the minimum desired errors. Comparatively, it was obtained that the ANN method is more effective than the RSM and has a higher regression coefficient and lower statistical errors.

직장 내 괴롭힘이 정서적 고갈 및 조직몰입에 미치는 영향에 관한 연구 - 사회적 지원의 역할 (A Study on the Effects of Workplace Bullying on Emotional Depletion and Organizational Commitment-The Role of Social Support)

  • 정해숙;김현;현병환
    • 한국콘텐츠학회논문지
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    • 제21권12호
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    • pp.463-476
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    • 2021
  • 본 연구는 직장 내 괴롭힘이 정서적 고갈 및 조직몰입에 미치는 영향에 유의한 차이를 살펴보고, 사회적 지원에 따른 유의한 차이가 있을 것인가를 고찰해 보고자 400부의 설문지를 활용하였다. 분석 방법으로 표본 특성에는 SPSS 24를 사용, 확인적 요인 분석, 신뢰도 및 타당도, 경로 분석, 구조방정식 모형에는 SmartPLS 3 통계 프로그램을 사용하였다. 연구 결과로는, 직장 내 괴롭힘은 정서적 고갈에 유의한 정(+)에 영향을 미치며, 정서적 고갈은 조직몰입에 유의한 부(-)의 영향을 미치는 것으로 나타났다. 직장 내 괴롭힘과 조직몰입 사이의 영향 관계에서 정서적 몰입은 부(-)의 방향으로 부분 매개하였고, 정서적 고갈이 조직몰입에 미치는 영향은 사회적 지원의 조절에 유의한 차이가 있는 것으로 나타났다. 시사점으로는 직장 내 괴롭힘은 정서적 고갈에 영향을 미치므로 괴롭힘을 예방하는 기업의 노력이 절실히 요구되며, 조직 내 상사와의 의사소통을 증진할 수 있는 제도나 커뮤니티를 활용하여 종사자들의 조직몰입을 향상할 수 있음을 시사해 주고 있다.

Does the palatal vault form have an influence on the scan time and accuracy of intraoral scans of completely edentulous arches? An in-vitro study

  • Osman, Reham;Alharbi, Nawal
    • The Journal of Advanced Prosthodontics
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    • 제14권5호
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    • pp.294-304
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    • 2022
  • PURPOSE. The purpose of this study was to evaluate the influence of different palatal vault configurations on the accuracy and scan speed of intraoral scans (IO) of completely edentulous arches. MATERIALS AND METHODS. Three different virtual models of a completely edentulous maxillary arch with different palatal vault heights- Cl I moderate (U-shaped), Cl II deep (steep) and Cl III shallow (flat)-were digitally designed using CAD software (Meshmixer; Autodesk, USA) and 3D-printed using SLA-based 3D-printer (XFAB; DWS, Italy) (n = 30; 10 specimens per group). Each model was scanned using intraoral scanner (Trios 3; 3ShapeTM, Denmark). Scanning time was recorded for all samples. Scanning accuracy (trueness and precision) were evaluated using digital subtraction technique using Geomagic Control X v2020 (Geomagic; 3DSystems, USA). One-way analysis of variance (ANOVA) test was used to detect differences in scanning time, trueness and precision among the test groups. Statistical significance was set at α = .05. RESULTS. The scan process could not be completed for Class II group and manufacturer's recommended technique had to be modified. ANOVA revealed no statistically significant difference in trueness and precision values among the test groups (P=.959 and P=.658, respectively). Deep palatal vault (Cl II) showed significantly longer scan time compared to Cl I and III. CONCLUSION. The selection of scan protocol in complex cases such as deep palatal vault is of utmost importance. The modified, adopted longer path scan protocol of deep vault cases resulted in increased scan time when compared to the other two groups.

Factors affecting maxillary sinus pneumatization following posterior maxillary tooth extraction

  • Lim, Hyun-Chang;Kim, Sangyup;Kim, Do-Hyup;Herr, Yeek;Chung, Jong-Hyuk;Shin, Seung-Il
    • Journal of Periodontal and Implant Science
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    • 제51권4호
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    • pp.285-295
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    • 2021
  • Purpose: The aims of the present study were 1) to quantitatively evaluate the extent of sinus pneumatization and 2) to determine the factors affecting sinus pneumatization. Methods: Based on implant treatment records, a list of patients who underwent implant placement on the posterior maxilla was obtained. Among them, patients with pre-extraction and post-extraction (before implant placement) panoramic radiographs were selected. After excluding radiographs with low resolution and image distortion, the radiographs before and after extraction were superimposed using computer software. Subsequently, the extent of sinus pneumatization (the vertical change of the sinus floor) was measured. Simple and multiple mixed models were used to determine the factors affecting sinus pneumatization. Results: A total of 145 patients were eligible for the present investigation. The average extent of sinus pneumatization was 1.56±3.93 mm at 176 tooth sites. Male sex, single tooth extraction, extraction of an endodontically compromised tooth, a class I root-sinus relationship, and sinus membrane thickening >10 mm favored pneumatization, but without statistical significance. The maxillary second molar presented the greatest pneumatization (2.25±4.39 mm) compared with other tooth types. This finding was confirmed in the multiple mixed model, which demonstrated a statistically significant impact of the extraction of a second molar compared with the extraction of a first premolar. Conclusions: Maxillary sinus pneumatization was 1.56±3.93 mm on average. The extraction of a second molar led to the greatest extent of pneumatization, which should be considered in the treatment plan for this tooth site.

Empirical Analysis of Effect of Entrepreneurship on Export Performance: Focusing on the Mediated Effect of Technology Capability and Export Support Policy of Start-Ups

  • Joo, Se-Hwan;Shin, Gun-Hoon
    • Journal of Korea Trade
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    • 제24권6호
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    • pp.173-193
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    • 2020
  • Purpose - This study aims to examine the effect of entrepreneurship of start-ups on export performance when the business closure rate is higher than business start-up rate in Korea. Thus, this study analyzes various factors for start-ups established within the past seven years and uses export performance as an indicator. Prior to analysis of factors, the study defines the concepts of start-up factors based on various studies. Design/methodology - In order to analyze the export performance of startups, this study conducted an empirical analysis using statistical analysis. Theories were established based on previous studies, and hypotheses and research models were designed based on the established theories. Subsequently, in order to verify the research hypothesis and research model, factor analysis such as validity and reliability, and structural equation modeling were analyzed. Findings - As a result of analysis based on previous studies, we found that there is a difference between theoretical and practical aspects. Whereas previous studies showed that market orientation, technology orientation, and social capital have a direct impact on export performance, the present study analyzed that there is no such impact, and that technology capabilities were important as a result of the unique traits of start-ups. Originality/value - Existing studies have limitations in understanding the overall characteristics of a company by using market orientation, technology orientation, and social capital as individual independent variables. In addition, the existing researches have been analyzed in relation to corporate performance, whereas this study has been limited to export performance, so it can be regarded as different from other studies.

Estimation of co-variance components, genetic parameters, and genetic trends of reproductive traits in community-based breeding program of Bonga sheep in Ethiopia

  • Areb, Ebadu;Getachew, Tesfaye;Kirmani, MA;G.silase, Tegbaru;Haile, Aynalem
    • Animal Bioscience
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    • 제34권9호
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    • pp.1451-1459
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    • 2021
  • Objective: The objectives of the study were to evaluate reproductive performance and selection response through genetic trend of community-based breeding programs (CBBPs) of Bonga sheep. Methods: Reproduction traits data were collected between 2012 and 2018 from Bonga sheep CBBPs. Phenotypic performance was analyzed using the general linear model procedures of Statistical Analysis System. Genetic parameters were estimated by univariate animal model for age at first lambing (AFL) and repeatability models for lambing interval (LI), litter size (LS), and annual reproductive rate (ARR) traits using restricted maximum likelihood method of WOMBAT. For correlations bivariate animal model was used. Best model was chosen based on likelihood ratio test. The genetic trends were estimated by the weighted regression of the average breeding value of the animals on the year of birth/lambing. Results: The overall least squares mean±standard error of AFL, LI, LS, and ARR were 375±12.5, 284±9.9, 1.45±0.010, and 2.31±0.050, respectively. Direct heritability estimates for AFL, LI, LS, and ARR were 0.07±0.190, 0.06±0.120, 0.18±0.070, and 0.25±0.203, respectively. The low heritability for both AFL and LI showed that these traits respond little to selection programs but rather highly depend on animal management options. The annual genetic gains were -0.0281 days, -0.016 days, -0.0002 lambs and 0.0003 lambs for AFL, LI, LS, and ARR, respectively. Conclusion: Implications of the result to future improvement programs were improving management of animals, conservation of prolific flocks and out scaling the CBBP to get better results.

암 환자의 영적 디스트레스 측정도구 개발 (The Development of a Tool for Assessment of Spiritual Distress in Cancer Patients)

  • 김진숙;고일선;고수진
    • 대한간호학회지
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    • 제52권1호
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    • pp.52-65
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    • 2022
  • Purpose: This study was conducted to develop a scale to measure spiritual distress in cancer patients. Methods: A total of 69 preliminary items for the spiritaul distress assessment tool (SDAT) were compiled, based on a literature review, selection of empirically relevant items through concept analysis of hybrid models, confirmation of content validity by experts, cognitive interviews, and a pretest. Self-administered questionnaires were collected between April 1 and July 31, 2018, from 225 cancer patients at four medical institutions and one nursing home. The data were analyzed using item analysis, exploratory factor analysis, convergent and discriminant validity, and Pearson correlation for criterion validity. Reliability was tested by Cronbash's α coefficient. Results: The final version of the SDAT consisted of 20 items. Five-factors, loss of peace, burden of family, avoidance of confronting death, guilt and remorse, regret for not being able to apololgize and forgive were extracted, and showed 62.8% of total variance. The factors were confirmed through convergent and discriminant validity. Criterion validity was confirmed by functional assessment chronic illness therapy spiritual well-being scale 12 (FACIT-Sp12). The overall Cronbach's α was .91, and the coefficients of each subscale ranged from .78~.83. Conclusion: The SDAT for cancer patients is valid and reliable. It is suggested that the tool can be used to measure spiritual distress in cancer patients.

Sustainable controlled low-strength material: Plastic properties and strength optimization

  • Mohd Azrizal, Fauzi;Mohd Fadzil, Arshad;Noorsuhada Md, Nor;Ezliana, Ghazali
    • Computers and Concrete
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    • 제30권6호
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    • pp.393-407
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    • 2022
  • Due to the enormous cement content, pozzolanic materials, and the use of different aggregates, sustainable controlled low-strength material (CLSM) has a higher material cost than conventional concrete and sustainable construction issues. However, by selecting appropriate materials and formulations, as well as cement and aggregate content, whitethorn costs can be reduced while having a positive environmental impact. This research explores the desire to optimize plastic properties and 28-day unconfined compressive strength (UCS) of CLSM containing powder content from unprocessed-fly ash (u-FA) and recycled fine aggregate (RFA). The mixtures' input parameters consist of water-to-cementitious material ratio (W/CM), fly ash-to-cementitious materials (FA/CM), and paste volume percentage (PV%), while flowability, bleeding, segregation index, and 28-day UCS were the desired responses. The central composite design (CCD) notion was used to produce twenty CLSM mixes and was experimentally validated using MATLAB by an Artificial Neural Network (ANN). Variance analysis (ANOVA) was used for the determination of statistical models. Results revealed that the plastic properties of CLSM improve with the FA/CM rise when the strength declines for 28 days-with an increase in FA/CM, the diameter of the flowability and bleeding decreased. Meanwhile, the u-FA's rise strengthens the CLSM's segregation resistance and raises its strength over 28 days. Using calcareous powder as a substitute for cement has a detrimental effect on bleeding, and 28-day UCS increases segregation resistance. The response surface method (RSM) can establish high correlations between responses and the constituent materials of sustainable CLSM, and the optimal values of variables can be measured to achieve the desired response properties.

Development Web-based Arabic Assessments for Deaf and Hard-of-Hearing Students

  • Atwan, Jaffar;Wedyan, Mohammad;Abbas, Abdallah;Gazzawe, Foziah;Alturki, Ryan
    • International Journal of Computer Science & Network Security
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    • 제22권5호
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    • pp.359-367
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    • 2022
  • Arabic skills are the tools by which children are prepared for the educational procedures on which their life depends. Deaf and hard of hearing students (DHH), must be able to grasp the same Arabic terms as hearing students and their different meanings in a context of different sentences less than what they are supposed to be due to their inability. However, problems arise in the same Arabic word and their different meanings in a context for (DHH) students since the way of comprehending such words does not meet the needs and circumstances of (DHH) students. Therefore, researchers introduce web-based method for Arabic words and their meanings in a context prototype that can overcome those problems. Methodology: The study sample consists of 30 (DHH) students at Al Amal City of Palestine, Gaza Region (GR). Those participants that agreed to take part in this study were recruited using a purposeful sampling method. Additionally, to examine the survey information descriptively, the Statistical Packages for social Sciences (SPSS) version 24.0 was used. A sign language teaching movie is utilized in the prototype to standardize the process and verify that Arabic vocabulary and their implications are comprehended. The Evolutionary Process Model of Prototype technique was utilized to create this system. Finding: The findings of this study show that the prototype built is workable and has the ability to help DHHS differentiate between phrases that have the same letters but distinct meanings. The findings of this study are expected to contribute to a better understanding and application of Development of Web-based Arabic Assessments for (DHH) Students in developing countries, which will help to increase the use of Development of Web-based Arabic for (HDD) students in those countries. The empirical models of Web-based Arabic for (DHH) students are established as a proof of concept for the proposed model. The results of this study are predicted to have a significant impact to the information system practitioners and to the body of knowledge.

Electronic Media and New Configurations of the Content of Modern Educational Practices

  • Skurativskyi, Vadym;Shyrman, Roman;Sharolapova, Nina;Nehreskul, Ihor;Molokanova, Olha
    • International Journal of Computer Science & Network Security
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    • 제22권4호
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    • pp.401-407
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    • 2022
  • Electronic media are an integral part of modern civilization; educational practices are no exception, which should change the content orientations, structures and methodological approaches in accordance with the requirements of the educational market. This makes it relevant to find effective and successful configurations in the process of implementing modern educational practices. The purpose of the research lies in determining the basic principles of electronic media and their place in modern education, identifying the effectiveness of teaching disciplines with application of electronic media, as well as establishing the level of assessment by students of the need to involve different types of electronic media in the educational process and professional practice. The research methodology is complex; the descriptive method and methods of observation, analysis and synthesis have been used in the academic paper. The method of pedagogical experiment has become the principal one; the method of questionnaires and statistical methods have been also used. The hypothesis of the academic paper lies in the fact that the involvement of electronic media in the educational process makes it more effective and requires conceptual changes in educational practices. The result of the research manifests in the identification of new opportunities for the use of electronic media, leading to conceptual shifts in the framework of modern educational policies. In the future, it will be appropriate to consider the theoretical aspects of changing worldview models in education and the use of new media in the educational process, their effectiveness and relevance.