• 제목/요약/키워드: Probability and statistics

검색결과 1,183건 처리시간 0.026초

Innovation Capability and Sustainable Competitive Advantage: An Entrepreneurial Marketing Perspective

  • TEGUH, Sriwidadi;HARTIWI, Prabowo;RIDHO, Bramulya Ikhsan;BACHTIAR, Simamora H.;SYNTHIA, Atas Sari;NOOR, Hazlina Ahmad
    • The Journal of Asian Finance, Economics and Business
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    • 제8권5호
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    • pp.127-134
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    • 2021
  • This study aims to determine the role of innovative capabilities as a mediator in analyzing entrepreneurial marketing's effect on sustainable competitive advantage in food and beverage micro-, small-, and medium- enterprises (MSMEs). Data was obtained from a food and beverage store manager in Tangerang City, comprising 119 samples. Furthermore, the G⁎Power, a tool used to calculate statistical power analysis for various t-tests, F tests, χ2 tests, z tests, and several exact tests, was used to determine the number of research samples, the α error probability of 5%, and 3 variables. The data collection method used questionnaires with Likert Scale 1-5 to indicate strongly disagree to strongly agree. To analyze data, we used Path Analysis supported by SmartPLS statistics software. Path analysis is a form of multiple regression statistical analysis that is used to evaluate causal models by examining the relationships between a dependent variable and two or more independent variables. It aims to provide estimates of the magnitude and significance of hypothesized causal connections between sets of variables. The data processing process took place in two stages, namely the estimation model testing with validity and reliability, and the structural model testing to decide the impact or correlation between variables utilizing the t-test. The result showed a positive and significant effect of entrepreneurial marketing to innovative capability and competitive advantage through the innovative capability of MSMEs.

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.

고차확률가중모멘트법에 의한 지역화빈도분석과 GIS기법에 의한 설계강우량 추정(I) -동질성의 지역구분 방법을 중심으로- (Estimation of Design Rainfall by the Regional Frequency Analysis using Higher Probability Weighted Moments and GIS Techniques(I))

  • 이순혁;박종화;류경식;지호근;전택기;신용희
    • 한국농공학회지
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    • 제43권4호
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    • pp.57-68
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    • 2001
  • It is matter of common knowledge to give impetus to the water resources development to cope with increasing demand and supply for the water utilization project including agricultural living and industrial water owing to the economic and civilization development in recent years. Regional design rainfall is necessary or the design of the dam reservoir levee and drainage facilities for the development of various kinds of essential waters including agricultural water. For the estimation of the regional design rainfall classification of the climatologically an geographically homogeneous regions should be preceded preferentially This study was mainly conducted to derive the optimal regionalization of the precipitation data which can be classified by the climatologically and geographically homogeneous regions all over the regions except Cheju and Wulreung islands in Korea. A total of 65 rain gauges were used to regional analysis of precipitation. Annual maximum series for the consecutive durations of 1, 3, 6, 12, 24, 36, 48 and 72hr were used for various statistical analysis. Both K-means clustering and mean annual precipitation methods are used to identify homogeneous regions all over the regions. Nine and five homogeneous regions for the precipitation were classified by the K-means clustering and mean annual methods, respectively. Finally, Five homogeneous regions were established by the trial and error method with homogeneity test using statistics of $\chi$$^2$ distribution.

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한국 물리치료사 국가 면허시험 합격 여부의 예측요인 탐색 (Exploring the Predictive Factors of Passing the Korean Physical Therapist Licensing Examination)

  • 김소현;조성현
    • 대한통합의학회지
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    • 제10권3호
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    • pp.107-117
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    • 2022
  • Purpose : The purpose of this study was to establish a model of the predictive factors for success or failure of examinees undertaking the Korean physical therapist licensing examination (KPTLE). Additionally, we assessed the pass/fail cut-off point. Methods : We analyzed the results of 10,881 examinees who undertook the KPTLE, using data provided by the Korea Health Personnel Licensing Examination Institute. The target variable was the test result (pass or fail), and the input variables were: sex, age, test subject, and total score. Frequency analysis, chi-square test, descriptive statistics, independent t-test, correlation analysis, binary logistic regression, and receiver operating characteristic (ROC) curve analyses were performed on the data. Results : Sex and age were not significant predictors of attaining a pass (p>.05). The test subjects with the highest probability of passing were, in order, medical regulation (MR) (Odds ratio (OR)=2.91, p<.001), foundations of physical therapy (FPT) (OR=2.86, p<.001), diagnosis and evaluation for physical therapy (DEPT) (OR=2.74, p<.001), physical therapy intervention (PTI) (OR=2.66, p<.001), and practical examination (PE) (OR=1.24, p<.001). The cut-off points for each subject were: FPT, 32.50; DEPT, 29.50; PTI, 44.50; MR, 14.50; and PE, 50.50. The total score (TS) was 164.50. The sensitivity, specificity, and the classification accuracy of the prediction model was 99 %, 98 %, and 99 %, respectively, indicating high accuracy. Area under the curve (AUC) values for each subject were: FPT, .958; DEPT, .968; PTI, .984; MR, .885; PE, .962; and TS, .998, indicating a high degree of fit. Conclusion : In our study, the predictive factors for passing KPTLE were identified, and the optimal cut-off point was calculated for each subject. Logistic regression was adequate to explain the predictive model. These results will provide universities and examinees with useful information for predicting their success or failure in the KPTLE.

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.

보건조사연구에서 다변량결측치가 내포된 자료를 효율적으로 분석하기 위한 통계학적 방법 (Statistical Methods for Multivariate Missing Data in Health Survey Research)

  • 김동기;박은철;손명세;김한중;박형욱;안재형;임종건;송기준
    • Journal of Preventive Medicine and Public Health
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    • 제31권4호
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    • pp.875-884
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    • 1998
  • Missing observations are common in medical research and health survey research. Several statistical methods to handle the missing data problem have been proposed. The EM algorithm (Expectation-Maximization algorithm) is one of the ways of efficiently handling the missing data problem based on sufficient statistics. In this paper, we developed statistical models and methods for survey data with multivariate missing observations. Especially, we adopted the EM algorithm to handle the multivariate missing observations. We assume that the multivariate observations follow a multivariate normal distribution, where the mean vector and the covariance matrix are primarily of interest. We applied the proposed statistical method to analyze data from a health survey. The data set we used came from a physician survey on Resource-Based Relative Value Scale(RBRVS). In addition to the EM algorithm, we applied the complete case analysis, which uses only completely observed cases, and the available case analysis, which utilizes all available information. The residual and normal probability plots were evaluated to access the assumption of normality. We found that the residual sum of squares from the EM algorithm was smaller than those of the complete-case and the available-case analyses.

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이동형 위성단말을 위한 20 GHz 대역 채널 특성 분석 (Analysis of Channel Characteristics at Around 20 GHz for Satellite On-The-Move Terminal)

  • 권건섭;허종완;황기민;임철민;유흥균
    • 한국전자파학회논문지
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    • 제25권2호
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    • pp.223-234
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    • 2014
  • 본 논문은 위성통신 시스템에서 OTM(On-The-Move: 이동형) 위성단말이 운용되는 지역의 채널 특성을 분석한 결과를 다룬다. 무궁화 5호 위성의 20 GHz 대역 수신 신호를 이용하여 대전~대천까지 실 주행시험을 수행하였고, 측정 결과를 고속도로 환경과 국도 환경 두 부분으로 구분하여 통계적 분석을 수행하였다. 통계적 분석에는 확률밀도 함수와 Markov 모델을 이용하여 위성 채널의 특성을 분석하였고, 더불어 국도 환경과 고속도로 환경에서 수신 전력의 임계값 설정에 따른 ACD(Average Connection Duration), AFD(Average Fade Duration), LCR(Level Crossing Rate)을 각각 제시하고, 서로 비교하였다.

LPG BLEVE 피해분석 및 안전거리 설정에 관한 연구 (A Study on Damage Analysis Safety Distance Setting for LPG BLEVE)

  • 김종혁;이병우;김정욱;정승호
    • 한국안전학회지
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    • 제35권6호
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    • pp.25-31
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    • 2020
  • Boiling Liquid Expanding Vapor Explosion(BLEVE) can cause not only economic damage to the plant but also serious casualties. LPG accidents account for 89.6 percent of all accidents caused by gas leaks in Korea over the past nine years, while casualties from accidents also account for 73 percent of all accidents, according to statistics from the Korea Gas Safety Corporation. In addition, a potential explosion and a fire accident from one LPG storage tank may affect the nearby storage tanks, causing secondary and tertiary damage (domino effect). The safety distance standards for LPG used by LPG workplaces, charging stations, and homes in Korea have become stricter following the explosion of LPG charging stations in Bucheon. The safety distance regulation is divided into regulations based on the distance damage and the risk including frequency. This study suggests two approaches to optimizing the safety distance based on the just consequence and risk including frequencies. Using the Phast 7.2 Risk Assessment software by DNV GL, the explosion overpressure and heat radiation were derived according to the distance caused by BLEVE in the worst-case scenario, and accident and damage probability were derived by considering the probit function and domino effect. In addition, the safety distance between LPG tanks or LPG charging stations was derived to minimize damage effects by utilizing these measures.

안전한 항공기 운항을 위한 현업 전지구예보모델 기반 깊은 대류 예측 지수: Part 2. 계절별 최적화 및 사례 분석 (Aviation Convective Index for Deep Convective Area using the Global Unified Model of the Korean Meteorological Administration, Korea: Part 2. Seasonal Optimization and Case Studies)

  • 박이준;김정훈
    • 대기
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    • 제33권5호
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    • pp.531-548
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    • 2023
  • We developed the Aviation Convective Index (ACI) for predicting deep convective area using the operational global Numerical Weather Prediction model of the Korea Meteorological Administration. Seasonally optimized ACI (ACISnOpt) was developed to consider seasonal variabilities on deep convections in Korea. Yearly optimized ACI (ACIYrOpt) in Part 1 showed that seasonally averaged values of Area Under the ROC Curve (AUC) and True Skill Statistics (TSS) were decreased by 0.420% and 5.797%, respectively, due to the significant degradation in winter season. In Part 2, we developed new membership function (MF) and weight combination of input variables in the ACI algorithm, which were optimized in each season. Finally, the seasonally optimized ACI (ACISnOpt) showed better performance skills with the significant improvements in AUC and TSS by 0.983% and 25.641% respectively, compared with those from the ACIYrOpt. To confirm the improvements in new algorithm, we also conducted two case studies in winter and spring with observed Convectively-Induced Turbulence (CIT) events from the aircraft data. In these cases, the ACISnOpt predicted a better spatial distribution and intensity of deep convection. Enhancements in the forecast fields from the ACIYrOpt to ACISnOpt in the selected cases explained well the changes in overall performance skills of the probability of detection for both "yes" and "no" occurrences of deep convection during 1-yr period of the data. These results imply that the ACI forecast should be optimized seasonally to take into account the variabilities in the background conditions for deep convections in Korea.

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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