• 상하수도학회지
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• 제24권5호
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• pp.617-628
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• 2010

The operation performance of sewer rehabilitation projects conducted with Build-Transfer- Lease contract in Korea will be evaluated using the index of infiltration and inflow (I/I). Though I/I obtained at the fourth year should be initially evaluated based on the I/I values observed for the previous three years after the completion of sewer construction, the concrete methodology have not been proposed to rely on the so called 'performance evaluation committee'. This study suggests two statistical methodology to evaluate the I/I performance; the confidence interval method and the hypothesis-testing method. Assumed ten I/I values in each year for 20 years are used in this study. Two cases are analyzed and compared; case I to use as control data all I/I values for all years obtained before the evaluation year and case II to use I/I values for only 3 years before the evaluation year. As a result, case II tends to have relatively higher scores than case I, reflecting the low mean I/I values at the initial years.

• 천문학회지
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• 제41권4호
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• pp.99-107
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• 2008

When a new counting experiment is proposed, it is crucial to predict whether the desired source signal will be detected, or how much observation time is required in order to detect the signal at a certain significance level. The concept of the a priori prediction of the detection limit in a newly proposed experiment should be distinguished from the a posteriori claim or decision whether a source signal was detected in an experiment already performed, and the calculation of statistical significance of a measured source signal. We formulate precise definitions of these concepts based on the statistical theory of hypothesis testing, and derive an approximate formula to estimate quickly the a priori detection limit of expected Poissonian source signals. A more accurate algorithm for calculating the detection limits in a counting experiment is also proposed. The formula and the proposed algorithm may be used for the estimation of required integration or observation time in proposals of new experiments. Applications include the calculation of integration time required for the detection of faint emission lines in a newly proposed spectroscopic observation, and the detection of faint sources in a new imaging observation. We apply the results to the calculation of observation time required to claim the detection of the surface thermal emission from neutron stars with two virtual instruments.

• 대한지리학회지
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• 제43권2호
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• pp.253-262
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• 2008

이 논문의 주요 목적은 정규성 가정 하에 일변량 공간 연관성 측도의 첫 번째 네 적률을 구해내는 일반화된 추출 절차를 정식화하고, 그것을 바탕으로 각 측도의 가설 검정을 위해 정규근사가 갖는 가능성과 한계를 평가하는 것이다. 중요 연구 결과는 다음과 같다. 첫째, 이전의 연구에 기반함으로써, 정규성 가정 하에 전역적 측도와 국지적 측도에 모두 적용될 수 있는 일반화된 적률 추출절차가 도출되었다. 개별 공간 연관성 측도를 위한 필수적인 메트릭스가 적절히 정의되었을 때, 일반화된 유의성 검정 방법은 각 공간 연관성 측도의 기대값과 분산은 물론 첨도와 왜도를 효과적으로 산출하였다. 둘째, 첫 번째 두 적률에 근거한 정규근사 방법은 전역적 통계량에 대해서는 유효한 것으로 판명되었지만, 국지적 통계량에 대해서는 매우 높은 왜도와 첨도로 말미암아 그 유효성이 현저히 떨어지는 것으로 드러났다.

• 한국도로학회논문집
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• 제16권4호
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• pp.63-74
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• 2014

PURPOSES: This research is to evaluate the mechanical performance of different types of Hot Mix Asphalt (HMA) pavement cells prepared for MN/Road field testing section through an extensive experimental analysis of air voids and simple statistical evaluation tools (i.e. hypothesis test). METHODS: An extensive experimental work was performed to measure air voids in 82 asphalt mixture cores (238 samples in total) obtained from nine different types of road cell located in MN/Road testing field. In order to numerically and quantitatively address the differences in air voids among the different test Cells built in MN/Road, a simple statistical test method (i.e. t-test) with 5% significance was used. RESULTS: Similar trends in air voids content were found among the mixtures including conventional HMA, Reclaimed Asphalt Pavement (RAP) and Warm Mix Asphalt (WMA) combined with taconite aggregate this provides support to the use of RAP and WMA technology in the constructions of asphalt pavement. However, in case of acid modified HMA mixtures, significant differences in air void content were observed between on the wheel path and between wheel path location, which implies negative performances in rutting and thermal cracking resistances. Conclusions : It can be concluded that use of RAP and WMA technology in the construction of conventional asphalt pavement and the use of PPA (Poly Phosphoric Acid) in combinations with SBS (Styrene Butadiene Styrene) in asphalt binder production provide satisfactory performance and, therefore, are highly recommended.

• 대한영상의학회지
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• 제84권4호
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• pp.866-878
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• 2023

의학 논문을 작성할 때 통계학은 필수적인 요소로 알려져 있고 중요성이 강조되고 있지만 많은 논문에서 통계적 오류가 발생하고 있다. 의학 논문에서 발생할 수 있는 통계적 오류는 설계 단계에서의 오류, 분석 단계에서의 오류, 작성과 해석 단계에서의 오류로 분류할 수 있다. 설계 단계에서는 연구의 가설이나 자료의 수집 및 분석 계획이 명확하지 않으면 오류가 발생한다. 분석 단계에서는 연구의 목적과 자료의 특성을 충분히 고려하지 않고 올바른 분석 방법을 적용하지 않으면 오류가 발생한다. 분석을 수행한 후에는 결과를 해석하여 논문을 작성하게 되고, 이 단계에서 분석 방법을 잘못 작성하거나 결과를 올바르게 해석하지 못하면 오류가 발생한다. 본 논문에서는 의학 논문에서 흔히 발생하는 통계적 오류에 대해 고찰하고 오류를 줄이는데 기여하고자 한다.

• 유통과학연구
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• 제19권6호
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• pp.5-19
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• 2021

Purpose: O2O Service is a major internet-based distribution industry. The purpose of this study is to confirm the effects of positive psychological capital on job intensity, customer orientation, and the mediating effects of trust of O2O employee. Research design, data and methodology: This study aims to identify the effect of positive psychological capital on customer orientation and job intensity through empirical analysis. 475 questionnaires were used for the final analysis using random sampling methods from O2O employees working at leading distribution companies for hypothesis verification. The analysis methods used for hypothesis testing in this study were analyzed using the SPSS 21.0 statistical package. Results: Empirical analysis shows that it is an important factor in increasing job intensity and customer orientation, and that company trust has a significant influence through mediating effects among variables. Conclusions: In order to enhance job intensity and customer orientation for O2O distribution workers, it is necessary to change efforts with management efforts for positive psychological factors and trust. It is also believed that company trust should be considered as an important factor in the future leadership competency development system in that it can promote positive psychological capital, further strengthening job intensity and customer orientation.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.349-362
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• 2021

This study aims to examine the effect of environmental performance, independent board of commissioners, and firm size on environmental disclosure measured by the Indonesian environmental index. The population in this study is manufacturing and coal mining companies that follow "PROPER" and are listed on the Indonesia Stock Exchange (IDX) from 2017 to 2019. This research was conducted by reviewing annual reports to collect information on environmental disclosures. The sampling used in this study was purposive sampling technique and obtained a sample of 117. Also, the data analysis technique used was multiple linear regression analysis with statistical hypothesis testing. The results showed that environmental performance and firm size had a positive effect on financial performance. Meanwhile, the independent board of commissioners does not affect financial performance. Furthermore, environmental performance, firm size, and financial performance have a positive effect on environmental disclosure. While the independent board of commissioners does not affect environmental disclosure. The findings of this research suggest that environmental performance has a significant positive effect on financial performance. The hypothesis is accepted, meaning that companies that are sensitive to environmental problems and run eco-efficiency operations will strengthen the company's profitability.

• 응용통계연구
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• 제25권2호
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• pp.311-319
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• 2012

수명시간 분석에서 가장 간단하고 또한 자주 이용되는 분포는 지수분포이다. Koziol과 Green (1976)은 Cram$\acute{e}$r-von Mises 통계량을 Kaplan-Meier의 product limit 경험분포함수를 이용하여 임의중도절단자료에 대해서 일반화하였다. 그러나 이 통계량은 모수의 값이 주어진 단순귀무가설을 가정하고 있으므로 실제 자료에 적용하기에는 어려운 점이 있다. 본 논문에서는 척도모수가 미지인 지수분포의 적합도 검정에 모수를 추정하여 Koziol-Green 통계량을 적용하였다. 그리고 같은 방법으로, 전통적인 Kolmogorov-Smirnov 검정통계량을 일반화하고 두 가지 통계량의 검정력을 모의실험을 통하여 비교하였다. 그 결과 전반적으로 일반화된 Koziol-Green 통계량이 Kolmogorov-Smirnov 통계량보다 지수분포의 검정에 있어서는 좀 더 좋은 검정력을 보여주었다.

• 산업경영시스템학회지
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• 제41권3호
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• pp.11-20
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• 2018

Recently companies have increased the new projects to improve and innovate the business process in order to adopt the advanced technologies such as IoT (Internet of Things), Big Data Analysis, Cloud Computing, mobile and artificial intelligence technologies for sustainable competitive advantages under rapid technological and socioeconomic external environmental changes. However, there are obstacles to achieve the project goals, corporate's strategy and objectives due to various kind of risks based on characteristics of projects and conflicts of stakeholders participated on projects. Hence, the solutions are required to resolve the various kind of risks and conflicts of stakeholders. The objectives of this study are to investigate the impact of the project governance, agency conflicts on the project success based on agency theory by using the statistical hypothesis testing the relationship among those variables. As a result of hypothesis testing, we could find that the project governance impacts positively on project success and negatively on the agency conflicts. Further, the agency conflicts impacts negatively on the project success. Finally, we could find that the agency conflicts such as goal conflict, different risk attitude and information asymmetry between project manager and team members impact negatively on the project success. Meanwhile, the project governance impact positively on the project success, negatively impact on the agency conflicts such as goal conflict, different risk attitude and information asymmetry between project manager and project team members. In order to increase the project success rate, the project governance institutions such as PGB (Project Governance Board), EPMO (Enterprise Project Management Office), PSC (Project Steering Committee) are needed to prevent or reduce the agency conflicts between project manager and team members.

• 대한간호학회지
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• 제4권1호
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• pp.38-49
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• 1974

Presently, the performance level of the college student has received a great deal of attention, particularly in the area of professional education. The problem of under achievement, especially in areas dealing with science and technology, has gone through considerable investigation by numerous Psychologists and Educators. Thus for, however, they have not been successful in determining conclusively the non-intellectual factors involved. The maladjustment problem of these students has been a thorn in the side of nursing education for some time. This topic has been discussed among nursing educators without any tangible results. Furthermore, the fact that the number of students who withdraw from nursing education programs before graduation has increased. This represents a major problem for nursing education. This problem area had increased attention drawn to it on October 1957, when Russia successfully launched to first satellite "Sputnik" into space. Various studies seem to indicate that factors related to over achievement and under.achievement can be found in the motivation of the students. This study is aimed at testing 3 hypotheses which hopefully will lead to a better understanding of the learning activities of nursing students and to determine some of their nonintellectually personality traits. Hypothesis I: learning activities in nursing students and persona1ity are correlated, there will be significant differences in personality need structures between 4 classes of nursing collegiate students. Sub-hypothesis: There will also be significant differences in the degree of student satisfaction in her major subject. Hypothesis I: If there is a special personality need structure which is required for the clinical learning activity in general, then there will be significant differences between the personality need structures of under-achievers and overachiever. Hypothesis II : If each clinical nursing subject requires different personality need structures, then there will be differences in personality need structure between the different clinical groups Methodology: 1. Tool: A Korean translation and correction of the Edwards Personal Preference Schedule of U.S.A. was used. 2. Subject and Test Method: Subjects were nursing students at Yonsei University, who enrolled for Fall semester of 1971. The Researcher herself executed the test for the test for the class as a group, and the absent students were tested indidually. Out of 307 students, 293 students (95.4%) were reported. 3. Statistical treatment: The mean and standard deviation for each of the 15 personality need variables were computed and the value of T-test was obtained to determine the differences in the personality need structures between each group. Results: 1, For the first hypothesis, the personality need structures between each of the 4 classes and the reported degree of satisfaction in major subject showed significant differences. Therefore the hypothesis I was accepted. 2. The comparison of personality need structure of under-achievers and over-achievers in clinical fields showed significant differences. Thus hypothesis II was accepted. 3. Personality need structure between clinical subject groups showed significant differences therefore the 3rd hypothesis was accepted.