• Title/Summary/Keyword: Skewness factor

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Development of an Instrument for Measuring Action Competence on Climate Change within High School Students (고등학생 기후변화 대응 실천역량 검사도구의 개발)

  • Baek, Seongheui;Shin, Hyeonjeong;Kim, Chan-Jong
    • Journal of The Korean Association For Science Education
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    • v.41 no.6
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    • pp.533-542
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    • 2021
  • This study aims to develop an instrument for measuring high school students' action competence on climate change (ACoCC). The instrument is defined as the construct comprised of seven factors and thirty-five items and takes approximately 15 minutes to fill out. A panel of experts and students' content validation were undertaken to modify the items. Five hundred and twenty-eight first and second graders in Korean high schools participated in the instrument survey. To assess the reliability and validity of ACoCC instrument, item analysis (mean, skewness, kurtosis, item-total correlation), internal consistency estimate, and confirmatory factor analysis were used. It was appropriate to use the 7-dimensional ACoCC instrument (knowledge about climate change, climate change sensibility, reflection, communication, integrated thinking, willingness, decision making), with 35 items for high school students. The following instrument was self-report given in the 5-point Likert scale (1=strongly disagree, 2=disagree, 3=neutral, 4=agree, 5=strongly agree). The internal consistency coefficient was shown as a whole was shown as 0.953, and the subscale's internal consistency coefficient ranged from 0.786 to 0.862.

Non-Gaussian wind features over complex terrain under atmospheric turbulent boundary layers: A case study

  • Hongtao, Shen;Weicheng, Hu;Qingshan, Yang;Fucheng, Yang;Kunpeng, Guo;Tong, Zhou;Guowei, Qian;Qinggen, Xu;Ziting, Yuan
    • Wind and Structures
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    • v.35 no.6
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    • pp.419-430
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    • 2022
  • In wind-resistant designs, wind velocity is assumed to be a Gaussian process; however, local complex topography may result in strong non-Gaussian wind features. This study investigates the non-Gaussian wind features over complex terrain under atmospheric turbulent boundary layers by the large eddy simulation (LES) model, and the turbulent inlet of LES is generated by the consistent discretizing random flow generation (CDRFG) method. The performance of LES is validated by two different complex terrains in Changsha and Mianyang, China, and the results are compared with wind tunnel tests and onsite measurements, respectively. Furthermore, the non-Gaussian parameters, such as skewness, kurtosis, probability curves, and gust factors, are analyzed in-depth. The results show that the LES method is in good agreement with both mean and turbulent wind fields from wind tunnel tests and onsite measurements. Wind fields in complex terrain mostly exhibit a left-skewed Gaussian process, and it changes from a softening Gaussian process to a hardening Gaussian process as the height increases. A reduction in the gust factors of about 2.0%-15.0% can be found by taking into account the non-Gaussian features, except for a 4.4% increase near the ground in steep terrain. This study can provide a reference for the assessment of extreme wind loads on structures in complex terrain.

Development a Measurement Scale for Analysis on Factors Influencing College Choice of College Freshman's (전문대학 신입생들의 대학선택 영향 요인 분석을 위한 측정도구 개발)

  • Kim, Myung-Eun;Jang, Won-Seok
    • The Journal of the Korea Contents Association
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    • v.16 no.7
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    • pp.50-62
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    • 2016
  • The aim of this study was to develop scale of test taker to affect on process of selection of college. The study procedures were performed as follow : establish of study model, item generation, verification of content validity, 1st and 2nd pilot test and verification of construct validity and reliability. In order to verification of validity and reliability, 230 freshman were surveyed and the data were analyzed by mean, standard deviation, skewness. kurtosis, Pearson correlation, Verimax factor analysis and Cronbach's ${\alpha}$. As result of factor analysis, the 15 factors(61 items) that explain 68.37% of the total variance were extracted and each factors were classified by attribution as follow : Information collection-mass media(4items), college activity (3items), support and environment(4items), education(5items), Influential person on decision making(3items), education quality(4items), education service(5items), reputation(3items), accessibility(2items), personal circumstances(2items), college's mass media(5items), promotion (4items), on-line(4items), person's PR (3items), College image(10items). Cronbach's ${\alpha}$ of total items was 0.916 and Cronbach's ${\alpha}$ of each factors were showed range between 0.694~0.878. Measurement scale of this study may be utilized to collect basic data be required to establish policy strategy of local college be faced with difficulty of admission recruitment.

The Structural relationship among Commitment to Change, Needs of Technology Education Innovation, Communication and Self-Efficacy of Technology Teachers (교육환경 변화에 따른 기술교사의 변화몰입과 기술교육혁신 요구, 커뮤니케이션 및 자기효능감의 구조적 관계 분석)

  • Kim, Yong-lk
    • 대한공업교육학회지
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    • v.36 no.2
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    • pp.111-130
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    • 2011
  • The purpose of this study was to identify a causal relationship among commitment to change, needs of technology education innovation, communication and self-efficacy of technology teachers. A total of 300 copies of questionnaires were used for data analysis except for 117 copies like the one where insincerely responds to any question was found. To ensure the reliability and validity of questions, I performed technical statistics like average, standard deviation, skewness, and kurtosis via PASW 18.0, item-total correlation and the totality, and reliability analysis. I undertook a confirmatory factor analysis via AMOS 7.0 to ensure the validity of items together with a structural analysis to perform a path analysis among variables and assess the suitability of model. The major finding of this study were as follows: First, because fit index of hypothetical model generally met standards in this study, a hypothetical model was judged appropriately. Second, needs of technology education innovation had a positive effect on communication and commitment to change of technology teachers. And, communication among technology teachers had a positive effect on commitment to change of technology teachers. This result means that communication among technology teachers is important to activation of technology education. Third, self-efficacy had a positive effect on commitment to change of technology teachers. This result means that it needs to raise self-efficacy level through teacher education.

The Analysis of Long Term Performance of Initial Public Offerings in KOSDAQ Market (코스닥시장에서의 신규공모주의 장기성과 분석 -수요예측제도 도입 후를 중심으로-)

  • Shin, Yeon-Soo;Sheo, Chung-Won;Shin, Young-Jae
    • Management & Information Systems Review
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    • v.28 no.1
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    • pp.25-44
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    • 2009
  • This study examines long term performance of initial public offerings(IPO) after book building was introduced in KOSDAQ market. We use event time portfolio approach and calendar time portfolio approach to test if the performance of IPO is fair or not in long term. We estimate the performance by using the BHAR(buy and hold abnormal return), CAR(cumulative abnormal return), WR(wealth relatives) model in event time portfolio approach. And we calculate the performance by using Fama-French three factor model, CTAR(calendar time abnormal return), RATS(Return Across Time and Securities approach) model in calendar time portfolio approach. This study shows that the long term performance of IPO is positive with statistical significance as the results of the analysis through the various research method and all windows in all kinds of firms and total firms.

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Association between the self-reported periodontal health status and oral health-related quality of life among elderly Koreans (한국노인의 자가보고 치주건강상태와 구강건강관련 삶의 질의 연관성)

  • Jang, Moon-Sung;Kim, Hae-Young;Shim, Yeon-Su;Rhyu, In-Chul;Han, Soo-Boo;Chung, Chong-Pyoung;Ku, Young
    • Journal of Periodontal and Implant Science
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    • v.36 no.3
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    • pp.591-600
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    • 2006
  • Purpose: This study assessed the impact of self-reported periodontal health on the oral health-related quality of life among elderly Koreans. Methods: Four hundred twenty one elderly Koreans in Seoul and suburban areas were selected with a cluster (institution) sampling method, and were requested to take oral examinations and finish questionnaires on the Oral Health Impact Profile-14(OHIP-14). and self-reported periodontal health status, such as periodontal symptoms, self-rated periodontal health and periodontal treatment need. As the dependent variable, OHIP-14 showed a positive skewed distribution (skewness: 1.17), we transformed to square-root form to apply parametric analyses. Bivariate analysis by t-test and ANOVA, and multivariate analysis with the two-level regression model accounting clusters were implemented. Results: Mean age of the subjects was 74.6 years and 66.5% were women. Fourteen items of OHIP-14 were summarized to one factor explaining 78.6% of total variance and produced the Chronbach alpha coefficient of 0.92. Results from the multivariate model, adjusting for age, sex, type of institutions, ability to pay, and number of teeth present, showed significantly lower OHIP-14 with reporting less than 3 periodontal symptoms (p(O.OOO1), rating their own periodontal health as above average level (p=O.0144), and thinking they don't need any periodontal treatments in the near future (p=O.0148), than their counterparts. The intraclass-corrrelation estimated by the final model was 0.028. Conclusion: This study demonstrates a significant association between self-reported periodontal health status and the oral health-related quality of life.

Calibration of Thermal Camera with Enhanced Image (개선된 화질의 영상을 이용한 열화상 카메라 캘리브레이션)

  • Kim, Ju O;Lee, Deokwoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.4
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    • pp.621-628
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    • 2021
  • This paper proposes a method to calibrate a thermal camera with three different perspectives. In particular, the intrinsic parameters of the camera and re-projection errors were provided to quantify the accuracy of the calibration result. Three lenses of the camera capture the same image, but they are not overlapped, and the image resolution is worse than the one captured by the RGB camera. In computer vision, camera calibration is one of the most important and fundamental tasks to calculate the distance between camera (s) and a target object or the three-dimensional (3D) coordinates of a point in a 3D object. Once calibration is complete, the intrinsic and the extrinsic parameters of the camera(s) are provided. The intrinsic parameters are composed of the focal length, skewness factor, and principal points, and the extrinsic parameters are composed of the relative rotation and translation of the camera(s). This study estimated the intrinsic parameters of thermal cameras that have three lenses of different perspectives. In particular, image enhancement based on a deep learning algorithm was carried out to improve the quality of the calibration results. Experimental results are provided to substantiate the proposed method.

The Mediating Effect of Ego Resilience in the Relationship between Children's Academic Stress and School Adjustment (아동의 학업 스트레스와 학교 적응간의 관계에서 자아탄력성의 매개효과)

  • Jeong Yeong Mi
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.2
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    • pp.99-104
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    • 2023
  • The purpose of this study was to examine the effect of children's academic stress on school adaptation and to verify whether ego-resilience plays a mediating role in the relationship between academic stress and school adaptation. Based on the data from the 12th year of the Korean Children's Panel (2019), the general characteristics of the main subjects and the mean, standard deviation, skewness and kurtosis of the main variables were confirmed through basic statistical analysis, and correlation analysis was conducted between variables. In addition, to examine whether ego-resilience mediated the effect of academic stress on school adaptation, a three-step regression analysis was conducted following the procedure of Baron and Kenny. The results of this study were as follows. First, it was found that children's academic stress, school adaptation, and ego resilience were all significantly correlated. The higher the academic stress, the lower the ego-resilience and school adaptability. Second, it was confirmed that ego-resilience has a partial mediating effect in the relationship between children's academic stress and school adjustment. Ego resilience in the academic stress situation means that it acts as an important mediating factor to flexibly adapt to school life by objectively grasping and coping with the stress situation. Therefore, we need to recognize the need for flexible and resilient individual characteristics so that children can reduce academic stress and adapt well to school life, and seek active interest and intervention plans.

Effect of Hair and Beauty Professionals' Self-Management on Job Performance and Intention to Continue Their Duties: Mediated Verification of Self-Efficacy (헤어미용전문가의 자기관리가 직무성과 및 미용지속의도에 미치는 영향: 자기효능감의 매개검증)

  • Jeong-Hwa Cho
    • Journal of the Korean Applied Science and Technology
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    • v.40 no.5
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    • pp.1149-1162
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    • 2023
  • The purpose of this study is to study the mediating verification of self-efficacy in the effect of self-management of hair beauty experts on job performance and beauty continuity intention. The subjects of the study were surveyed and used for analysis of 256 beauty experts working as hair beauty experts in Seoul and Gyeonggi Province. The SPSS 28.0 and AMOS 28.0 statistical package programs were used for the analysis method, and descriptive statistics of mean, standard deviation, kurtosis, skewness, confirmatory factor analysis and reliability analysis, correlation, and mediating effect analysis were analyzed using bootstrapping techniques. The results of the study showed that the self-management of hair beauty experts had a significant positive (+) effect on self-efficacy, job performance, and intention to continue beauty. The self-efficacy of hair beauty experts had a significant (+) effect on job performance and beauty continuity intention. It was confirmed that there was a mediating effect of self-efficacy in the relationship between self-management and job performance of hair beauty experts. The statistical significance level is p<.It was analyzed by setting it at the level of 05.

Evaluating the usefulness of BinkieRTTM (oral positioning stent) for Head and Neck Radiotherapy (두경부암 환자 방사선 치료 시 BinkieRTTM(구강용 고정장치)에 대한 유용성 평가)

  • GyeongJin Lee;SangJun Son;GyeongDal Lim;ChanYong Kim;JeHee Lee
    • The Journal of Korean Society for Radiation Therapy
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    • v.34
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    • pp.21-30
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    • 2022
  • Purpose: The purpose of this study is to evaluate the effectiveness of oral positioning stent, the BinkieRTTM in radiation treatment for head and neck cancer patients in terms of tongue positions reproducibility, tongue doses and material properties. Materials and Methods: 24 cases using BinkieRTTM during radiation treatments were enrolled. The tongue was contoured on planning CT and CBCT images taken every 3 days during treatment, and then the DSC and center of tongue shift values were analyzed to evaluate the reproducibility of the tongue. The tongue dose was compared in terms of dose distribution when using BinkieRTTM and different type of oral stents (mouthpiece, paraffin wax). Randomly selected respective 10 patients were measured tongue doses of initial treatment plan for nasal cavity and unilateral parotid cancer. Finally, In terms of material evaluation, HU and relative electron density were identified in RTPS. Results: As a result of DSC analysis, it was 0.8 ± 0.07, skewness -0.8, kurtosis 0.61, and 95% CI was 0.79~0.82. To analyze the deviation of the central tongue shift during the treatment period, a 95% confidence interval for shift in the LR, SI, and AP directions were indicated, and a one-sample t-test for 0, which is an ideal value in the deviation(n=144). As a result of the t-test, the mean and SD in the LR and SI directions were 0.01 ± 0.14 cm (p→.05), 0.03 ± 0.25 cm (p→.05), and -0.08 ± 0.25 cm (p ←.05) in the AP direction. In the case of unilateral parotid cancer patients, the Dmean to the tongue of patients using BinkieRTTM was 16.92% ± 3.58% compared to the prescribed dose, and 23.99% ± 10.86% of patients with Paraffin Wax, indicating that the tongue dose was relatively lower when using BinkieRTTM (p←.05). On the other hand, among nasal cavity cancer patients, the Dmean of tongue dose for patients who used BinkieRTTM was 4.4% ± 5.6%, and for those who used mouthpiece, 5.9% ± 6.8%, but it was not statistically significant (p→.05). The relative electron density of Paraffin Wax, BinkieRTTM and Putty is 0.94, 0.99, 1.26 and the mass density is 0.95, 0.99 and 1.32 (g/cc), Transmission Factor is 0.99, 0.98, 0.96 respectively. Conclusion: The result of the tongue DSC analysis over the treatment period was about 0.8 and Deviation of the center of tongue shifts were within 0.2 cm, the reproducibility was more likely excellent. In the case of unilateral head and neck cancer patients, it was found that the use of BinkieRTTM rather than Paraffin Wax or Putty can reduce the unnecessary dose irradiated to the tongue. This study might be useful to understand of BinkieRTTM's properties and advantages. And also it could be another considered option as oral stent to keep the reproducibility of tongue and reducing dose during head and neck radiation treatments.