• 제목/요약/키워드: Scaling factors

검색결과 487건 처리시간 0.025초

한국형 스켈링공포(KSF 1.0)의 측정도구 개발 및 관련요인 (Development of Measurement Scale for Korean Scaling Fear-1.0 and Related Factors)

  • 조명숙;이성국
    • 치위생과학회지
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    • 제9권3호
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    • pp.327-338
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    • 2009
  • 본 연구는 한국의 문화와 실정에 맞는 한국형 스켈링공포에 관한 측정도구를 개발하기 위해 2008년 11월 연구 대상자 720명을 대상으로 개방형 질문을 통해 문항을 수집하였고( 1차 조사), 2008년 12월과 2009년 1월에 스켈링 환자 110명을 대상으로 사전조사를 실시하여 측정도구의 영역설정 및 문항선정을 통해 1차 도구를 개발하였으며 (2차 조사), 2009년 2~3월에 연구대상자 720명에게 설문조사하여 최종적으로 4개 영역과 19개 문항을 결정함으로서 최종적으로 측정도구를 개발하였다. 문항수준 분석결과에서 결측치는 0.003%로 기준의 20%보다 낮아 양호했고, 검사-재검사 신뢰도 검중에서 상관계수가 0.92 이상으로 높았으며, 짝비교 t-검증도 조사 전후 간에 유의한 차이가 없어 신뢰도가 높았다. 문항 내적일치도 역시 전체 영역 내 상관계수 범위가 0.39~0.95로 높았으며, 항목판별타당도는 영역 간 상관계수가 0.56이하로 유의하였다. 영역수준의 분석결과 3개 영역의 평균 범위는 2.06~2.33 이었고 예상치 못한 신체반응의 공포영역은 1.29 이었다. 각 영역의 바닥치와 천장치는 각각 4.3%와 6.8%로 기준의 20% 보다 낮아 적합했고, 요인분석에서 일부 영역의 요인이 단일요인으로 묶이는 것을 제외하연, 각 영역별 문항이 동일 요인으로 묶여졌으며, 확인적 요인분석 결과에서 전반적으로 모형 합치도가 높았다. 스켈링 경험유무별 스켈링공포의 종속변수에 유의하게 영향을 미치는 연수분석에서 스켈링 경험자는 성별과 칫솔방법이 유의성이 있었고, 비 경험자는 성별, 교육수준, 칫솔방법, 그리고 일주 당 운동량 등이 유의했다. 이상으로 본 연구는 스켈링공포에 관한 측정도구를 총 4개 영역 19개 문항을 개발하였다. 향후 개발된 도구는 여러 집단을 대상으로 재평가를 받아 일반화 되어야 할 것이며, 이들 환자들에게 적용함으로서 정기적인 스켈링을 통한 구강보건향상에 기여할 것으로 판단된다.

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Structural behavior of arch dams considering experimentally validated prototype model using similitude and scaling laws

  • Altunisik, Ahmet Can;Kalkan, Ebru;Basaga, Hasan B.
    • Computers and Concrete
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    • 제22권1호
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    • pp.101-116
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    • 2018
  • As one of the most important engineering structures, arch dams are huge constructions built with human hands and have strategical importance. Because of the fact that long construction duration, water supply, financial reasons, major loss of life and material since failure etc., the design of arch dams is very important problem and should be done by expert engineers to determine the structural behavior more accurately. Finite element analyses and non-destructive experimental measurements can be used to investigate the structural response, but there are some difficulties such as spending a long time while modelling, analysis and in-situ testing. Therefore, it is more useful to conduct the research on the laboratory conditions and to transform the obtained results into real constructions. Within the scope of this study, it is aimed to determine the structural behavior of arch dams considering experimentally validated prototype laboratory model using similitude and scaling laws. Type-1 arch dam, which is one of five arch dam types suggested at the "Arch Dams" Symposium in England in 1968 is selected as reference prototype model. The dam is built considering dam-reservoir-foundation interaction and ambient vibration tests are performed to validate the finite element results such as dynamic characteristics, displacements, principal stresses and strains. These results are considered as reference parameters and used to determine the real arch dam response with different scales factors such as 335, 400, 416.67 and 450. These values are selected by considering previously examined dam projects. Arch heights are calculated as 201 m, 240 m, 250 m and 270 m, respectively. The structural response is investigated between the model and prototype by using similarity requirements, field equations, scaling laws etc. To validate these results, finite element models are enlarged in the same scales and analyses are repeated to obtain the dynamic characteristics, displacements, principal stresses and strains. At the end of the study, it is seen that there is a good agreement between all results obtained by similarity requirements with scaling laws and enlarged finite element models.

Quantitative Comparison of Activity Calculation Methods for the Selection of Most Reliable Radionuclide Inventory Estimation

  • Hwang, Ki-Ha;Lee, Sang-Chul;Lee, Kun-Jai;Jeong, Chan-Woo;Ahn, Sang-Myeon;Kim, Tae-Wook;Kim, Kyoung-Doek;Herr, Y.H.
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2003년도 가을 학술논문집
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    • pp.322-327
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    • 2003
  • It is important to know the accurate radionuclide inventory of radioactive waste for the reliable management. However, estimation of radionuclide concentrations in drummed radioactive waste is difficult and unreliable because of difficulties of direct detection, high cost, and radiation exposure of sampling personnel. In order to overcome these difficulties, scaling factors (SFs) have been used to assess the activities of radionuclides that could not be directly analyzed. A radionuclide assay system has been operated at KORI site since 1996 and consolidated scaling factor method has played a dominant role in determination of radionuclides concentrations. However, some problems are still remained such as uncertainty of estimated scaling factor values, inaccuracy of analyzed sample values, and disparity between the actual and ideal correlation pairs and the others. Therefore, it needs to improve the accuracy of scaling factor values. The scope of this paper is focused on the improvement of accuracy and representativeness of calculated scaling factor values based on statistical techniques. For the selection of reliable activity determination method, the accuracy of estimated SF values for each activity determination method is compared. From the comparison of each activity determination methods, it is recommended that SF determination method should be changed from the arithmetic mean to the geometrical mean for more reliable estimation of radionuclide activity. Arithmetic mean method and geometric mean method are compared based on the data set in KORI system.

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한국 중장년의 치면세마 필요와 구강 및 전신건강행동의 관련성 (Association between needs for scaling and oral and general health behaviors in middle-aged people)

  • 한수진
    • 한국융합학회논문지
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    • 제11권5호
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    • pp.51-59
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    • 2020
  • 본 연구는 국민건강영양조사 제7기에 참여한 우리나라 중장년층 대표표본에서 치석제거를 필요로 하는 치주건강상태와 구강 및 전신 건강행동의 관련성을 확인하는 것이다. 제7기 국민건강영양조사에 참여한 40-64세 중장년 5,120명을 대상으로 하였고, 다변량 로지스틱 회귀분석을 수행하였으며, 인구사회학적 특성과 구강 및 전신건강상태에 대해 보정하였다. 현재 흡연(OR=1.593), 치과방문안함(OR=1.578), 현재 음주(OR: 1.420), 구강검진 비수검(OR: 1.304), 구강관리용품 비사용(OR: 1.2942)의 치면세마 필요에 대한 OR이 유의하게 높았으며, 성별 하위그룹분석 결과 성별에 따라 유의한 요인이 달랐다. 연구결과 중장년층 치주건강의 유지, 증진에 효과적인 구강 및 전신 건강행동을 확인하였다.

도시 이미지 분석 기법에 관한 연구 : MDS(Multidimensional Scaling)에 의한 도시 간 이미지 비교 (A Study on the Analysis Method of City Image : Focusing on the Image Comparison between Cities by MDS)

  • 임승빈;최형석;변재상
    • 한국조경학회지
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    • 제32권1호
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    • pp.47-56
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    • 2004
  • Rapid economic development in Korea caused functions of city functions such as concentration of population, deterioration of the quality of living environment and traffic congestion. Korean cities have lost their identity becausr they are merged functionally and physically with neighboring cities, forming one mesa-city. Unified shape and disorganized streets of cities often cause confusion among foreigners and visitors. It is very difficult for them to find their image in strange cities. It is, however, important to correctly analyze the image and meaning of cities for understanding its identity. The purpose of this study is to develop a method to analyze the city image by focusing on some of the main cities in Korea. For this purpose, the adjective questionnaire and multi-dimension scaling (MDS) are applied to the analysis of city image. Image analysis graph by MDS can visually present the general and integrate images. The results of this study are summarized as follows: The important factors for interpretation of city image are historical and industrial character. Seoul, Taegu and Pusan have industrial and complex city images. Kongju has historical city image, while Changwon has a modern image. Chuncheon belongs to a soft and small image. Each city has an alternative solution against a negative image, according to the image analysis graph.

다차원척도법을 이용한 귀비탕변증설문지(歸脾湯辨證設問紙)와 관련 설문지와의 비교 연구 (Comparison between Guibi-tang Questionnaire and Related Questionnaires using Multidimensional Scaling)

  • 이병희;박영재;오환섭;이상철;김민용;박영배
    • 대한한의진단학회지
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    • 제15권2호
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    • pp.169-174
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    • 2011
  • Objectives: Seven Emotions consist of Joy(喜), Anger(怒), Anxiety(憂), Thought(思), Sorrow(悲), Fear(恐), Fright(驚). If Seven Emotions are excessive, their extreme mental stimulations cause physical illness. The aim of the research is to make a proposal on the concept of Seven Emotions by a statistical comparison between guibi-tang questionnaire and health related questionnaires. Methods: We studied the similarities among three factors of guibi-tang questionnaire and three health related questionnaires(subjective symptoms of fatigue test, beck depression inventory, state-trait anxiety inventory, etc.) using multidimensional scaling. Results and Conclusions: 1. Physical-Emotion Dimension and Chronic-Acute Dimension were labelled in two-dimensional solution. 2. Seven Emotions and Fatigue have a high correlation. 3. Seven Emotions and Trait-Anxiety have a high correlation.

외연적과 내연적 유한요소법에 의한 자동차 로어암의 하이드로포밍 공정해석 (Analysis of Hydroforming Process for an Automobile Lower Arm by Using Explicit and Implicit FEM)

  • 김정;최한호;강범수
    • 한국정밀공학회지
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    • 제19권9호
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    • pp.74-81
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    • 2002
  • Recently tube hydroforming has been widely applied to the automotive industries due to its several advantages over conventional methods. In this paper, attention is paid to comparison of an implicit and an explicit finite element method widely used for numerical simulation of a hydroforming process. For an explicit FEM, a huge amount of computational time is required because of the very small time increment to solve a quasi-static problem. Hence, when an explicit FEM is used fDr a hydroforming process, it is general to convert the real problem to a virtual problem with a different processing time and mass density by appropriate scaling factor. However it is difficult to figure out how large the scaling should be adopted enough to ignore the dynamic effects and maintain the desired accuracy. In this paper, the comparison of the results obtained from both methods focus on the accuracy of the predicted geometrical shape and the stress with various scaling factors which are applied to analyze hydroforming process of an automobile lower arm.

이산요소법을 이용한 수치해석에서의 상사성 이론의 적용성 검토 (Feasibility Study on Similarity Principle in Discrete Element Analysis)

  • 윤태영;박희문
    • 한국도로학회논문집
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    • 제18권2호
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    • pp.51-60
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    • 2016
  • PURPOSES : The applicability of the mechanics-based similarity concept (suggested by Feng et al.) for determining scaled variables, including length and load, via laboratory-scale tests and discrete element analysis, was evaluated. METHODS: Several studies on the similarity concept were reviewed. The exact scaling approach, a similarity concept described by Feng, was applied in order to determine an analytical solution of a free-falling ball. This solution can be considered one of the simplest conditions for discrete element analysis. RESULTS : The results revealed that 1) the exact scaling approach can be used to determine the scale of variables in laboratory tests and numerical analysis, 2) applying only a scale factor, via the exact scaling approach, is inadequate for the error-free replacement of small particles by large ones during discrete element analysis, 3) the level of continuity of flowable materials such as SCC and cement mortar seems to be an important criterion for evaluating the applicability of the similarity concept, and 4) additional conditions, such as the kinetics of particle, contact model, and geometry, must be taken into consideration to achieve the maximum radius of replacement particles during discrete element analysis. CONCLUSIONS : The concept of similarity is a convenient tool to evaluate the correspondence of scaled laboratory test or numerical analysis to physical condition. However, to achieve excellent correspondence, additional factors, such as the kinetics of particles, contact model, and geometry, must be taken into consideration.

한국 청소년의 치아우식증과 치주질환에 대한 예방행위 경험 관련요인 (Related factors of preventive behavior experiences toward dental caries and periodontal disease in Korean adolescents)

  • 박신영;한여정;류소연
    • 한국치위생학회지
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    • 제16권3호
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    • pp.417-426
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    • 2016
  • Objectives: The objective of the study was to investigate the related factors of preventive behavior experience toward dental caries and periodontal disease in Korean adolescents. Methods: The study subjects were 72,060 adolescents in 800 schools who completed 2014 Korean Youth Risk Behavior Web-based survey. Dependent variables included general characteristics of the subjects, oral health behavior, and oral disease experience. The experience rate of sealant and scaling showed the prevention behavior of dental caries and periodontal disease. Data were analyzed by IBM SPSS statistics 20.0. Results: The experience rate of sealant accounted for 26.9%. The experience of sealant was related with gender, school, maternal education level, economic status, vigorous physical activity, smoking, usual stress, fruit consumption, milk consumption, soda consumption, snack consumption, tooth brushing, oral health education experience, periodontal bleeding and pain, mucosal disorders, and bad breath. The experience rate of scaling was 22.6%. The experience of scaling was related with gender, school, city division, learning achievement, maternal education level, economic status, residential type, vigorous physical activity, usual stress, fruit consumption, milk consumption, tooth brushing, oral health education experience, periodontal bleeding and pain, mucosal disorders, and bad breath. Conclusions: To expand preventive oral health behavior in the adolescents, it is necessary to support the systematic policy making and monetary establishment in the future.

다차원척도법으로 알아본 음료 TV광고 인식구조: 주의 속성을 중심으로 (Cognitive structure of TV drink advertisement based on multidimensional scaling)

  • 김은영;이훈재;정상철
    • 인지과학
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    • 제25권1호
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    • pp.25-49
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    • 2014
  • 본 연구는 한 제품 군(음료)의 다양한 TV 광고들을 대상으로 광고 수용자들이 어떤 속성을 중심으로 광고를 인식하는지 알아보고자 하였다. 이를 위해 다차원척도법을 사용하여, 14개의 음료 광고들의 각 쌍에 대한 광고 수용자의 유사성 평정에 근거한 광고들의 포지셔닝 맵을 도출하였다. 광고 수용자의 인식 구조를 반영하는 포지셔닝 맵의 차원을 알아보고자 각 광고에 대한 주의 요소, 태도, 구매의도에 대한 평정치와 포지셔닝 맵 상의 각 광고 위치 좌표 간의 상관을 조사하였다. 실험 결과, 음료 광고인식 차원은 내용에 대한 주의, 색상, 움직임에 대한 주의 요소와 높은 상관을 보였다. 특히, 주의 요소들 중 내용에 대한 주의가 강조될수록 광고에 대한 감성적, 행동적 태도가 긍정적으로 형성되었으며, 구매 의도도 증가하였다. 이러한 결과는 주의를 끄는 내용이 담긴 광고가 소비자의 긍정적인 태도와 관련이 높음을 시사한다.