• 제목/요약/키워드: probability.statistics

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온도기반의 Beta Distribution Model 을 이용한 후지 사과의 성숙기 예측 (Predicting Harvest Maturity of the 'Fuji' Apple using a Beta Distribution Phenology Model based on Temperature)

  • 최인태;심교문;김용석;정명표
    • 한국환경과학회지
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    • 제26권11호
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    • pp.1247-1253
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    • 2017
  • The Fuji variety of apple, introduced in Japan, has excellent storage quality and good taste, such that it is the most commonly cultivated apple variety in Gunwi County, North Gyeongsang Province, Korean Peninsula. Accurate prediction of harvest maturity allows farmers to more efficiently manage their farm in important aspects such as working time, fruit storage, market shipment, and labor distribution. Temperature is one of the most important factors that determine plant growth, development, and yield. This paper reports on the beta distribution (function) model that can be used to simulate the the phenological response of plants to temperature. The beta function, commonly used as a skewed probability density in statistics, was introduced to estimate apple harvest maturity as a function of temperature in this study. The model parameters were daily maximum temperature, daily optimum temperature, and maximum growth rate. They were estimated from the input data of daily maximum and minimum temperature and apple harvest maturity. The difference in observed and predicted maturity day from 2009 to 2012, with optimal parameters, was from two days earlier to one day later.

라이센스 제품의 구매 촉진을 위한 프로 스포츠 서비스 품질과 동일시에 관한 연구 (A Study of Service Quality and Identity on Professional Sports for Promoting Licensing Product Intentions)

  • 박배진;박선영
    • 벤처창업연구
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    • 제11권3호
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    • pp.189-197
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    • 2016
  • 본 연구의 목표는 프로 스포츠 산업에서 라이센싱 제품의 소비 촉진을 위해 서비스 품질을 통해서 필요한 기초 자료를 제공하는 것이다. 특히 현재 연구는 프로스포츠에서 서비스 품질과 라이센스 상품의 구매의도와의 영향력을 조사하고, 동일시의 조절효과를 평가하고자 한다. 이를 위해 서울과 중소도시에 거주하는 사람을 모집단으로 설정한 후 편의표본추출법을 이용하여 총271명의 자료를 실제 분석에 사용하였다. 이를 통해 얻어진 결론은 다음과 같다. 첫째, 프로스포츠의 서비스품질은 라이센스 제품의 구매의도에 정적인 영향을 미치는 것으로 나타났으나, 그러나 단독으로 동일시는 유의미한 영향력이 나타나지 않았다. 둘째. 조절변수로서 동일시의 효과를 검증한 결과 서비스 품질의 스타플레이어와 라이센스 제품의 구매의도의 관계에서 정적인 영향을 미치는 것으로 나타났다. 따라서 프로스포츠에 스폰서로 참여하는 기업은 성적, 매력성, 스타플레이어 그리고 지역연고와 같은 프로스포츠 서비스품질에 의해 스포츠팬과 동일시됨으로서 라이센스 제품의 구매의도를 촉진시킬 수 있음을 입증하였다.

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Optimization of the construction scheme of the cable-strut tensile structure based on error sensitivity analysis

  • Chen, Lian-meng;Hu, Dong;Deng, Hua;Cui, Yu-hong;Zhou, Yi-yi
    • Steel and Composite Structures
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    • 제21권5호
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    • pp.1031-1043
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    • 2016
  • Optimization of the construction scheme of the cable-strut tensile structure based on error sensitivity analysis is studied in this paper. First, the element length was extracted as a fundamental variable, and the relationship between element length change and element internal force was established. By setting all pre-stresses in active cables to zero, the equation between the pre-stress deviation in the passive cables and the element length error was obtained to analyze and evaluate the error effects under different construction schemes. Afterwards, based on the probability statistics theory, the mathematical model of element length error is set up. The statistical features of the pre-stress deviation were achieved. Finally, a cable-strut tensile structure model with a diameter of 5.0 m was fabricated. The element length errors are simulated by adjusting the element length, and each member in one symmetrical unit was elongated by 3 mm to explore the error sensitivity of each type of element. The numerical analysis of error sensitivity was also carried out by the FEA model in ANSYS software, where the element length change was simulated by implementing appropriate temperature changes. The theoretical analysis and experimental results both indicated that different elements had different error sensitivities. Likewise, different construction schemes had different construction precisions, and the optimal construction scheme should be chosen for the real construction projects to achieve lower error effects, lower cost and greater convenience.

한국어판 플러턴 어드밴스드 균형 척도의 라쉬분석 (Application of Rasch Analysis to the Korean Version of the Fullerton Advanced Balance Scale)

  • 김경모
    • 한국전문물리치료학회지
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    • 제23권1호
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    • pp.46-54
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    • 2016
  • Background: Rasch analysis estimates the probability that a respondent will endorse an item and select a particular rating for that item. It has the advantage of placing both the items and the person along a single ration scale and calibrates person ability and item difficulty onto an interval scale by logits. In addition, Rasch analysis is a useful tool for exploring the validity of questionnaires that have been developed using traditional methods. Therefore, it has been recommended as a method for developing and evaluating functional outcome measures. Objects: The purpose of this study was to investigate the item fit, item difficulty, and rating scale of the Korean version of the Fullerton Advanced Balance Scale (KFAB) using Rasch analysis. Methods: Total 97 subjects (39 males and 58 females) with dwelling elderly adults were participated, but 3 people were excluded for misfit persons. Rasch analysis was then done by means of the Winsteps program to determine the item fit, item difficulty, rating scale, and reliability of the KFAB. Results: In this study, the 'standing with feet together and eyes closed', 'two-footed jump', 'walk with head turns', and 'stand on foam, eyes closed' items shown misfit statistics. The most difficult item was 'stand on one leg', whereas the easiest item was 'turn in full circle'. The rating scale was acceptable with all criteria. Both item and person separation indices and reliability showed acceptable values. This would indicated that each domain covers a useful range of item difficulty that is appropriate for measuring a person with a wide range of functional ability. Conclusion: The KFAB has been proven reliable, valid and an appropriate tool with which to evaluate the balance of the elderly people.

학령 전 아이들의 사칙연산 문장제 해결 능력과 방법 분석 (An Analysis on the Competence and the Methods of Problem Solving of Children at the Before of School Age in Four Operations Word Problems)

  • 이대현
    • 한국학교수학회논문집
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    • 제13권3호
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    • pp.381-395
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    • 2010
  • 학령 전 아이들은 형식적인 교육을 받지 않고서도 일상적인 경험이나 비형식적인 방법으로 수를 익히고, 계산을 한다. 따라서 학령 전 아이들의 수학적 능력에 대한 이해는 유치원 교육과 초등학교 저학년의 수학 학습 지도에 시사점을 줄 수 있다는 변에서 중요하다. 본 연구에서는 학령 전인 만 5세의 아이들이 사칙연산 문장제의 의미론적 측면의 문제 유형에 어느 정도의 해결 능력과 방법을 보이는가를 조사하였다. 연구 결과, 만 5세의 학령 전 아이들은 5보다 크고 10보다 작은 수로 구성된 사칙연산 문장제에 대하여 구체물을 이용한 비형식적 연산의 수행과 정신적 암산을 수행하는 방법을 통하여 문제를 해결할 수 있는 능력을 가지고 있음을 알 수 있었다. 이것은 학령 전 아이들의 수학적 경험을 위한 교육과정이나 프로그램을 체계적으로 구성하여 제시할 필요성을 제기한다.

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초등수학에서 직관적 원리에 의한 교육 내용 분석 (An Analysis on the Instructional Contents by Intuitive Principles in Elementary Mathematics)

  • 이대현
    • 한국초등수학교육학회지
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    • 제15권2호
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    • pp.283-300
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    • 2011
  • 이 연구는 초등학교 수학 지도에서 직관적 원리의 중요성을 인식하고, 교육과정과 그 해설서, 그리고 교과서에 제시된 직관적 원리에 의한 교육 내용을 분석하였다. 이를 위해 초등학교 교육과정과 그 해설서에 제시된 교육 내용에서 직관적 원리에 의한 내용을 추출하고, 이 내용이 교과서에 어떻게 구현되었는가를 분석하였다. 분석결과, 교육과정의 수학 교과의 성격에서는 직관적 원리에 의한 지도를 제시하고 있었으나, 목표와 학습 방법, 평가에서는 직관적 원리에 의한 지도 내용을 제시하지 않고 있었다 또한 내용영역에서는 교육과정 문서에는 직관적 원리에 의한 지도 내용을 제시하지 않았고, 교육과정 해설서에만 도형 영역 12개, 측정 영역 1개, 확률과 통계영역 2개가 제시되어 있었다. 그리고 본 연구에서 제시한 직관적 지도 원리 6가지 중에서 특정 원리에 치중되어 있었다. 이러한 결과를 바탕으로 교육과정 구안과 교과서 집필에 필요한 직관적 원리에 따른 수학 지도의 시사점을 도출하였다.

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평가 문항을 활용한 중학교 수학 교육과정의 내용 및 인지행동의 위계성 조사 (Investigating the Hierarchical Nature of Content and Cognitive Domains in the Mathematics Curriculum for Korean Middle School Students via Assessment Items)

  • 송미영;김선희
    • 대한수학교육학회지:학교수학
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    • 제9권2호
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    • pp.223-240
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    • 2007
  • 본 연구는 중학생들의 수학 성취를 국가수준에서 평가한 경험적 자료를 활용하여 우리나라 중학교 수학과 교육과정의 내용과 수학에서의 인지행동이 위계적으로 구성되어 있는지를 조사하였다. 전반적으로 교육과정의 내용 제시 순서는 난이도 순위와 통계적으로 유의한 상관관계가 나타나지 않은 반면, 인지행동의 위계는 난이도 순위와 통계적으로 유의한 상관관계가 있었다. 이러한 결과에서 검사 문항의 난이도 순위가 학교에서 배운 수학 교과 내용의 순서보다는 문항에서 요구하는 인지행동의 수준과 더 관련이 있음을 알 수 있었다. 그리고 내용 위계와 인지행동의 위계 간 상관관계가 유의하게 나타나, 교육과정에서 늦게 등장하는 내용일수록 요구되는 인지 행동도 높은 수준임을 발견할 수 있었다. 내용 및 인지행동의 위계와 난이도 순위 간 상관분석에서 특이한 양상을 나타낸 문항에 대해서는 그 특성을 분석하였다.

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관성 및 다양성추구 상태의 비대칭성에 관한 연구 - 구간통합 다항로짓분석을 활용하여 (The Study on the Asymmetry of Inertia and Variety-Seeking State - Using Section-Aggregated Multinomial Logit Analysis)

  • 이승연
    • 지식경영연구
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    • 제14권1호
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    • pp.73-94
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    • 2013
  • Customer's purchase state consists of purchase inertia and variety-seeking. As the growing brand familiarity triggers the increase of brand attractiveness, customers purchase state will be of inertia. However the excessively growing brand familiarity ignites the decrease of brand attractiveness. Followingly the purchase state will be tend to plunge into the variety-seeking state. The main topic of this study is to validate the asymmetric formation of customer's purchase states between inertia and variety-seeking. In order to follow up the main topic, this article introduces a model to freely describe the velocity of value changes depending upon the purchase states. This model will help overcome the limitation of the past studies having been based on the symmetric value changes. Based on this approach marketer will be able to decide the timing of sales promotions. This research utilized local telecommunication carrier's database of smartphone application purchase/download records. This database was collected from two years (2009 and 2010) span, the time when the smartphones started commodifying in Korea whilst most of the past studies had used purchase data of maturity stage products. From this approach utilizing the introduction stage data in the product life cycle, the probability of brand choice depending upon the purchase state on the early-stage can be probed. Moreover, this study tries to expand the research methodology from the other areas of research by knowledge sharing. Here this study introduces the methodology of section-aggregated multinomial logit to simultaneously estimate the parameters that were included in the plural multinomial logit functions while the plural functions were inter-connected. This adoption of section-aggregated multinomial logit model procedures from the computerized statistics areas is expected to nourish the marketing research for more precise analysis and estimation of effects of marketing activities.

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FMEA에서 공통원인고장이 포함될 경우의 고장원인에 대한 위험평가 절차 (A Risk Evaluation Procedure in FMEA for Failure Causes including Common Cause Failures)

  • 김병남;권혁무;홍성훈;이민구
    • 품질경영학회지
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    • 제46권2호
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    • pp.327-338
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    • 2018
  • Purpose: A risk evaluation procedure is proposed for common failure causes in FMEA(Failure Mode and Effects Analysis). The conventional FMEA does not provide a proper means to compare common failure causes with other failure causes. This research aims to develop a risk evaluation procedure in FMEA where common failure causes and other failure causes exist together. Methods: For each common failure cause, the effect of each combination of its resulting failures is recommended to be reevaluated considering their interactive worsening effect. And the probability that each combination of failures is incurred by the same common cause is also considered. Based on these two factors, the severity of each common cause is determined. Other procedures are similar to the conventional method. Results: The proposed procedure enables to compare and prioritize every failure cause. Thus, the common causes, each of which incurring two or more failures, and other causes, each of which is corresponding to one failure, can be fairly compared. Conclusion: A fair and proper way of comparing the common failure causes and other causes is provided. The procedure is somewhat complicated and requires more works to do. But it is worth to do.

ICD-10을 이용한 ICISS의 타당도 평가 (Validation of the International Classification of Diseases 10th Edition Based Injury Severity Score(ICISS))

  • 정구영;김창엽;김용익;신영수;김윤
    • Journal of Preventive Medicine and Public Health
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    • 제32권4호
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    • pp.538-545
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    • 1999
  • Objective : To compare the predictive power of International Classification of Diseases 10th Edition(ICD-10) based International Classification of Diseases based Injury Severity Score(ICISS) with Trauma and Injury Severity Score(TRISS) and International Classification of Diseases 9th Edition Clinical Modification(ICD-9CM) based ICISS in the injury severity measure. Methods : ICD-10 version of Survival Risk Ratios(SRRs) was derived from 47,750 trauma patients from 35 Emergency Centers for 1 year. The predictive power of TRISS, the ICD-9CM based ICISS and ICD-10 based ICISS were compared in a group of 367 severely injured patients admitted to two university hospitals. The predictive power was compared by using the measures of discrimination(disparity, sensitivity, specificity, misclassification rates, and ROC curve analysis) and calibration(Hosmer-Lemeshow goodness-of-fit statistics), all calculated by logistic regression procedure. Results : ICD-10 based ICISS showed a lower performance than TRISS and ICD-9CM based ICISS. When age and Revised Trauma Score(RTS) were incorporated into the survival probability model, however, ICD-10 based ICISS full model showed a similar predictive power compared with TRISS and ICD-9CM based ICISS full model. ICD-10 based ICISS had some disadvantages in predicting outcomes among patients with intracranial injuries. However, such weakness was largely compensated by incorporating age and RTS in the model. Conclusions : The ICISS methodology can be extended to ICD-10 horizon as a standard injury severity measure in the place of TRISS, especially when age and RTS were incorporated in the model. In patients with intracranial injuries, the predictive power of ICD-10 based ICISS was relatively low because of differences in the classifying system between ICD-10 and ICD-9CM.

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