• Title/Summary/Keyword: impact coefficient

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Translation and validation of the Turkish version of the Psychosocial Impact of Dental Aesthetics Questionnaire

  • Aglarci, Cahide;Baysal, Asli;Demirci, Kadir;Dikmen, Ferhan;Aglarci, Ali Vasfi
    • The korean journal of orthodontics
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    • v.46 no.4
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    • pp.220-227
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    • 2016
  • Objective: The aim of this study was to translate the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) into Turkish, validate the questionnaire, and provide a cross-cultural adaptation. Methods: The translation process included the following steps, which were performed by a translation committee: (1) translation into Turkish, (2) back translation into English, (3) pretesting, and (4) cross-cultural adaptation. The Turkish version of the PIDAQ was produced subsequent to the translation process. Validity and reliability were measured using the Perception of Occlusion Scale and the aesthetic component of the Index of Orthodontic Treatment Need. The questionnaire was administered to 260 individuals (age range, 18-30 years; mean age, $20.50{\pm}1.9$ years). Structural validity was assessed via factor analysis, and internal consistency was measured using Cronbach's alpha coefficient. Results: Factor analysis revealed a four-factor structure, with factor loadings for included items ranging from 0.380 to 0.868. Few questions were shuffled among domains various factor loadings. Cronbach's alphas for the Turkish version of the PIDAQ ranged from 0.534 to 0.904. Mean scores for the PIDAQ subscale and total scores differed significantly according to Index of Orthodontic Treatment Need and Perception of Occlusion Scale scores. Conclusions: This study provided a Turkish version of the PIDAQ, which could be a useful tool in the evaluation of the psychosocial impact of malocclusion in young Turkish adults.

Study on the Improving Penetration Performance of Tungsten Heavy Alloy Penetrator by Heat Treatment (열처리 공정을 통한 텅스텐 중합금 관통자의 관통능력 향상에 관한 연구)

  • Kim, Myunghyun;Noh, Jooyoung;Lee, Youngwoo;An, Daehee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.2
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    • pp.322-327
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    • 2020
  • An Armor Piercing Fin Stabilized Discarding Sabot (APFSDS), which penetrates and sabotages the target by physical energy, consists of a general penetrator using Depleted Uranium (DU) or Tungsten Heavy Alloy (THA) but THA is preferable because of manufacturing and environmental issues. On a THA penetrator, the penetration performance is determined mainly by self-sharpening depending on the hardness and toughness of materials. In particular, the tensile strength and impact strength work as key factors. The correlation coefficient for the penetration performance of the tensile strength was 0.721 and the impact strength was -0.599. The improved penetration performance by additional heat treatment was proven experimentally. Therefore, maintaining elongation over 9 % and tensile strength over 123 kg/㎟ is desirable, and the impact strength should be less than 6.8 kg·m/㎠ for good penetration performance.

Method for Determining Thickness of Rubber Fenders of a Tripod Type Offshore Wind Turbine Substructure (해상풍력 삼각지주형 하부구조물의 충격손상방지용 고무펜더의 두께결정 방법)

  • Lee, Kang-Su
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.4
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    • pp.490-496
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    • 2012
  • The main object of this research is to minimize the shock effects which frequently result in fatal damage in offshore wind turbine on impact of barge. The collision between offshore wind turbine and barge is generally a complex problem and it is often impractical to perform rigorous finite element analyses to include all effects and sequences during the collision. On applying the impact force of a barge to the offshore wind turbine, the maximum acceleration, internal energy, and plastic strain are calculated for each load case using the finite element method. A parametric study is conducted with the experimental data in terms of the velocity of barge, thickness of the offshore wind turbine, and thickness and Mooney-Rivlin coefficient of the rubber fender. Through the analysis proposed in this study, it is possible to determine the proper size and material properties of the rubber fender and the optimal moving conditions of barge.

Development of Instrument for Korean Osteoarthritis Impact Measurement Scale (KAIMS) in Hip and Knee Osteoarthritis (한국형 골관절염영향측정척도(KAIMS) 도구개발 - 무릎 및 엉덩관절의 골관절염환자 중심 -)

  • Yi, Seung-Ju;Kim, Jin-Seop
    • The Journal of Korean Physical Therapy
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    • v.26 no.2
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    • pp.82-89
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    • 2014
  • Purpose: This study was conducted in order to develop an instrument for the Korean Osteoarthritis Impact Measurement scale (KAIMS) in hip and knee osteoarthritis patients. Methods: A sample of 426 subjects was recruited in Ulsan metropolitan city (six hospitals and clinics) and Andong city (five hospitals and clinics) from June 2010 to May 2011. Item internal consistency and item discriminant validity were analyzed on the item-level, and floor (%) and ceiling (%) effect were analyzed on the scale-level. Exploratory factor analysis was performed for construction of items in the KAIMS instrument; confirmative factor analysis was also performed to test the fit of the model. Results: In 426 respondents, age was 64.3 years. The reliability for r coefficient 0.90 (mobility) and 0.89 (pain and stiffness) (Cronbach's alpha 0.95, 0.95 respectively) was high in the test-retest, and there was no significant difference in paired t-test (p>0.05). Item internal consistency (${\alpha}=0.92$, ${\alpha}=0.87$ respectively) was also high. It was constructed of two factors (mobility, pain and stiffness dimension) and nine items in explanatory factor analysis; results of confirmatory factor analysis also indicated that the dimensional structure model was fitted well in the test of model fit (${\chi}^2=83.83$, df=26, p=0.000; RMR=0.05; GFI=0.96; AGFI=0.83). Conclusion: In conclusion, the results of this study showed that the KAIMS that was developed was a reliable and valid instrument for measurement of osteoarthritis (OA) patients. We recommend further research for additional development of the instrument on OA in Korea.

Analysis of Impact Acoustic Property of Apple Using Piezo-Polymer Film Sensor (고분자 압전 박막 센서를 이용한 사과의 충격 음파 특성 분석)

  • Kim, Man-Soo;Lee, Sang-Dae;Park, Jeong-Hak;Kim, Ki-Bok
    • Journal of the Korean Society for Nondestructive Testing
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    • v.28 no.2
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    • pp.144-150
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    • 2008
  • In this study, the PVDF (polyvinylidene fluoride) piero-film sensor was applied to measure the internal quality of apple. The developed sensor detected the response signal through apple after mechanical impact on the surface of apple. The acoustical parameters at time domain such as rise time (RT), ring down count (RC), energy (EN), event duration (ED) and peak amplitude (PA) and acoustical parameter at frequency domain such as spectral density (SE) were analyzed. The size of waveform decreased as storage time of apple increased. The frequency at maximum magnitude was shifted to lower frequency band according to the storage time. The acoustical parameters showed strong relationship with storage time. The multiple linear regression equation was developed to estimate storage time of apple using the acoustical parameters at time domain and its coefficient of determination was 0.97. The internal quality of apple according to storage time is predictable using developed PVDF sensor and acoustical parameters defined in this study.

Graphical method for evaluating the impact of influential observations in high-dimensional data (고차원 자료에서 영향점의 영향을 평가하기 위한 그래픽 방법)

  • Ahn, Sojin;Lee, Jae Eun;Jang, Dae-Heung
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.6
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    • pp.1291-1300
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    • 2017
  • In the high-dimensional data, the number of variables is very larger than the number of observations. In this case, the impact of influential observations on regression coefficient estimates can be very large. Jang and Anderson-Cook (2017) suggested the LASSO influence plot. In this paper, we propose the LASSO influence plot, LASSO variable selection ranking plot, and three-dimensional LASSO influence plot as graphical methods for evaluating the impact of influential observations in high-dimensional data. With real two high-dimensional data examples, we apply these graphical methods as the regression diagnostics tools for finding influential observations. It has been found that we can obtain influential observations with by these graphical methods.

COVID-19 and the Korean Economy: When, How, and What Changes?

  • Park, ChangKeun;Park, JiYoung
    • Asian Journal of Innovation and Policy
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    • v.9 no.2
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    • pp.187-206
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    • 2020
  • Under the on-going evolution of the COVID-19 pandemic, estimating the economic impact of the pandemic is highly uncertain and challenging. This situation makes it difficult for policymakers, governors, and economic entities to formulate appropriate responses and decision makings. To provide useful information about the effect of the COVID-19 pandemic on the Korean economy, this study examined macroeconomic impact analysis stemming from the pandemic shocks with different scenarios for the Korean economy. Based on three scenarios using the growth rate of 2020 GDP and consumer expenditure patterns, the 2021 GDP by industry sector was forecast with two new approaches. First, the recovering process of the Korean economy from the shock was analyzed by applying a Flex-IO method. Second, a new forecasting approach combined with an IO coefficient matrix was applied to forecast the future GDP changes. The findings of this study are summarized as follows: First, the total GDP growth rate under the Pessimistic Scenario demonstrates less rebound from the shock than that of the Base Scenario. Second, agriculture, culture, and tourism-related sectors that are suffering from the severe losses of COVID-19 showed lower resilience than other different industries. Third, information and communications technology (ICT) industry maintains a stable growth trend and is expected to take the leading role for the Korean economy in the post-COVID-19 and the Industry 4.0 eras. The findings deliver that it needs to analyze how government expenditure responding the shock into the forecasting model, which can be more useful and reliable to simulate the resilience from the pandemic.

Preparation and Properties Enhancement of Epoxy Resin Employing Poly(amic acid) (PAA) (Poly(amic acid) (PAA)를 함유한 에폭시 수지의 제조 및 물성 향상)

  • 이용택;배성호;박병천
    • Polymer(Korea)
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    • v.25 no.2
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    • pp.254-262
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    • 2001
  • Epoxy resin based upon the N,N'-diglycidylaniline which is widely used in optic, electronic and composite material. We modified this epoxy resin with poly(amic acid) (PAA) that is a precursor of polyimide. To improve the mechanical property we controlled PAA content and imidization ratio. PI-modified epoxy blends were prepared for the formation of IPN structure. The possible reaction in the epoxy resin/PAA blends were investigated by FT-IR and inherent viscosity techniques. Thermal properties are measured by TGA, DSC, and TMA. Mechanical properties are measured by UTM and impact test machine. Morphology is investigated by SEM. Thermal stability improved with increasing the content of PAA in blends. As the content of PAA increases in blend, the glass transition temperature and thermal expansion coefficient decreases. Increasing impact strengths in J/m in the range of 920∼2412 were observed in blends. The PAA segment may act as a toughening agent in the epoxy networks, thus contributing the impact strength improvement of the blends.

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A Study on the Effect of Job Distribution on Quality of Life for Good Job Behavior

  • Kim, Yong-Min;Yong, Tae-Hee
    • Journal of Distribution Science
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    • v.16 no.9
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    • pp.25-33
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    • 2018
  • Purpose - The purpose of the study is to analyze the empowerment intermediary role on the relationship between the job distribution and the quality of life. A research on empowerment and social service staffs' job distribution also should be conducted to improve the quality of their lives. Because empowerment, particularly, affects the quality of life, it should be taken a detail discussion for empowerment improvement. Research design, data, and methodology - This paper conducted a questionnaire survey. In total, 722 copies of the structural questionnaire were analyzed. Five parameter subsets were selected to measure the empowerment such as task significance, role performance capability, self-determination, task impact, then, the survey consists of 10 questions. For data analysis, confirmatory factor analysis, discriminant and concentration validity analysis, path coefficient significance, and mediation effectiveness verification were employed. Results - As evidenced from the data analysis, job distribution variables such as job impact, job autonomy, and feedback affect the quality of their lives. Empowerment also affects the quality of their lives. Next, the empowerment functions as meditating role in the relationships with job impact, job autonomy, feedback and the quality of their lives. On the other hand, the empowerment do not function as meditating role in the relationships with social service staffs' function diversity and the quality of their lives. Conclusions - It is necessary to conduct ways for various job performance and outside educational facilities to improve social service staffs' function diversity. The mission, vision, strategic purposes, detailed execution goals need to be set by all their organization members' participation. Empowerment also requires social welfare facilities' drastic delegation on their authority and responsibilities with their active decentralization in the organization.

A Study on the Effect of Small and Medium Enterprise Workers' Welfare Environment on Job Satisfaction (중소기업 근로자의 복지환경이 직무 만족도에 미치는 영향)

  • Kwak, No-Hag;Kim, Moon-Jun
    • Industry Promotion Research
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    • v.1 no.1
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    • pp.19-25
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    • 2016
  • This study is to determine the status of satisfaction and well-being and work environment aimed at SME workers, deficiencies is to improve the overall satisfaction improvement. As a result of the confidence analysis to verify the reliability of the measurement tool, all of the factors is somewhat higher reliability coefficient was found to less than 0.6. Job factors, relationship factors, compensating factors are subjected to multiple regression analysis as job satisfaction and welfare duties factors to determine the impact on satisfaction, relationship factors, the compensation factor as an independent variable and dependent of each job satisfaction and welfare satisfaction variable result of three factors, job factors and compensation factors, two factors had significant influence on job satisfaction. When the job factor ${\beta}$ value(0.584), the compensation factor(0.369) showed a net impact on job satisfaction big. By improving the business environment and well-being through improved employee satisfaction, it came to a positive attitude to business is expected to have a positive impact on the satisfaction of external customers.