• 응용통계연구
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• 제28권5호
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• pp.1025-1034
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• 2015

1920년대에 소개되었던 Shewhart 관리도는 관측치가 서로 독립임을 가정했다. 오늘날은 데이터 측정과 자료수집 기술이 발전하면서 자기상관 공정 데이터가 많이 발생하고 있으며, 이것은 통계적 공정 관리의 성능에 부정적인 영향을 끼치게 된다. 자기상관이 존재하는 데이터에 대하여 가장 쉽게 접근할 수 있는 관리도는 먼저 자기상관구조를 모형화할 수 있는 적절한 시계열 모형을 가정한 다음 잔차를 구하여, 그 잔차에 기반한 Shewhart 관리도를 적용하는 것이다. 실제 문제에서 시계열 모형의 참 모수값은 알려져 있지 않으므로, 이 값은 일단계 표본(과거의 관리상태 표본)으로부터 추정된다. 본 논문에서는 이러한 모수추정이 이단계 표본을 모니터링하는데 어떠한 영향이 있는지 살펴보았다.

• Nuclear Engineering and Technology
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• 제49권2호
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• pp.349-359
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• 2017

During the past 25 years, in the context of probabilistic safety assessment, efforts have been directed towards establishment of comprehensive pipe failure event databases as a foundation for exploratory research to better understand how to effectively organize a piping reliability analysis task. The focused pipe failure database development efforts have progressed well with the development of piping reliability analysis frameworks that utilize the full body of service experience data, fracture mechanics analysis insights, expert elicitation results that are rolled into an integrated and risk-informed approach to the estimation of piping reliability parameters with full recognition of the embedded uncertainties. The discussion in this paper builds on a major collection of operating experience data (more than 11,000 pipe failure records) and the associated lessons learned from data analysis and data applications spanning three decades. The piping reliability analysis lessons learned have been obtained from the derivation of pipe leak and rupture frequencies for corrosion resistant piping in a raw water environment, loss-of-coolant-accident frequencies given degradation mitigation, high-energy pipe break analysis, moderate-energy pipe break analysis, and numerous plant-specific applications of a statistical piping reliability model framework. Conclusions are presented regarding the feasibility of determining and incorporating aging effects into probabilistic safety assessment models.

• 한국컴퓨터정보학회논문지
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• 제22권1호
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• pp.71-76
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• 2017

Recently, there are various researches using inaudible high frequencies like as wireless communication based smart devices, data transmission algorithm, indoor positioning trace technologies. However, when they use high frequencies of inaudible range, they have a problem that the accuracy of data transmission with high frequencies was low because of interference from ambient noise in our real life. To solve this problem, in this paper, we proposed an application based on smart phone and server system for collection of ambient noise and detection of robust high frequency range. The server system could detect the robust high frequency range from statistical analysis of collected noise and the robust high frequency could avoid interference from ambient noise. We tested the proposed application's ability to gather noise and high frequencies for a certain period of time to evaluate performance. According to the testing results, we confirmed that the proposed application and server system could detect a robust high-frequency range via noise analysis in real life. Therefore, the proposed application and server could be a useful technology for future research on inaudible high frequencies.

• 유통과학연구
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• 제11권5호
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• pp.17-24
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• 2013

Purpose - Taxes are a critical source of government revenue, particularly for aiding development and progress in a society. Today, taxes are viewed as a tool for growth and stability and for reducing inequalities; a country's citizens play a vital role in realizing this objective through their participation. Research design, data, and methodology - In Iran, tax collection and preparation are always of great concern and represent the most important responsibilities of the government. This study seeks to investigate the administrative barriers in taxpayer participation and highlights the challenges regarding timely tax collection faced during 2011, from the point of view of both tax expertsand taxpayers. Results - Sixty-six questionnaires from taxpayers and tax experts in the Zanjan province were collected and tested using statistical tools. Conclusions - The results indicate that there are no obstacles in taxpayer participation; moreover, both taxpayers and tax experts have similar opinions regarding this issue.

• 응용통계연구
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• 제17권2호
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• pp.359-371
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• 2004

우리나라 대학들은 최근에 여러 환경 변화의 소용돌이 속에 몸살을 않고 있다. 이러한 환경에서 통계학과는 과연 안전지대에 놓여 있는가\ulcorner 이러한 변화 속에서 살아남기 위한 자구적인 노력은 얼마나 존재했는가\ulcorner 본 연구는 통계학과의 현황과 문제점을 진단하고, 그 해결방안을 탐색해보는데 목적이 있다.

• 응용통계연구
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• 제27권4호
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• pp.577-588
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• 2014

자료의 수집과 저장이 수월해 지면서 대용량의 자료들이 존재하고 특히 개체 보다 변수가 더 많은 자료들이 생산되고 있다. 변수들이 증가하면서 다중공선성 같은 문제들이 발생하여 분석의 어려움에 봉착하게 된다. 이러한 문제를 해결하는 방법들이 많이 연구되었지만 다소간의 정보의 손실을 감내하고 연속형 자료를 범주형 자료로 변환하면 나름 유용한 분석이 가능하다고 본다. 대용량 범주형 자료의 대표적인 사례로 유전자 염기 서열 자료가 있고 이를 분석하기 위한 많은 기술들이 발달되어 있다. 본 논문에서는 국내 은행들이 생산해 낸 다양한 지표들을 분석하기 위해 유전자 염기 서열 분석 기법을 적용하여 분석하였고 나름 유용한 정보를 얻을 수 있음을 보였다. 본 논문에서 사용한 자료는 11개의 은행과 5개의 저축은행과 관련된 78개 재정 지표를 갖는 자료로서 심각한 다중 공선성이 존재하여 자료를 범주화하고 분석한 결과 몇 가지 유용한 결과를 도출하였다.

• Journal of the Korean Data and Information Science Society
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• 제20권6호
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• pp.1075-1083
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• 2009

과학적 연구 방법은 가설을 세우고 실험이나 관찰을 통해 얻은 자료를 이용한 경험적 사실을 바탕으로 가설을 추상화하는 과정을 거치게 된다. 이 과정에서 자료를 획득하는 방법이 추상화의 최초 과정이 되고 많은 경우 서베이 리서치라는 구조화된 문항을 통한 방법이 사용 된다. 자료가 획득된 후에는 회귀분석, 선형구조방정식 등 고급 통계 기법들을 사용하여 가설들을 추상화하는 과정을 거치게 된다. 여기서, 설문지를 통해 많은 수 의 문항들의 응답이 획득되고 추상화를 위해 차원 축소라는 과정을 거치게 된다. 하지만 차원 축소된 정보들이 때때로 실제 현상을 이해하는데 있어서 현실감을 떨어지게 하는 경우도 존재하고 추상화 보다는 설문지 자체에서 어떤 지식을 얻기가 요구되기도 한다. 본 연구에서 설문지의 문항들 중에서 과연 어떤 문항들이 연구하고자 하는 문제의 해답을 줄 수 있는 핵심적인 문항인지를 찾아내고 이들 핵심 문항들로 모델을 구축하는 방법을 제시하였다. 강의 평가 자료를 예제로 사용하여 보다 나은 강의 평가를 받기 위한 전략들을 구상하여 보았다.

• Computers and Concrete
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• 제12권2호
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• pp.109-129
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• 2013

This work presents an approach to model concrete shrinkage. The goal is to permit the concrete industry's experts to develop independent prediction models based on a reduced number of experimental data. The proposed approach combines fuzzy logic and genetic algorithm to optimize the fuzzy decision-making, thereby reducing data collection time. Such an approach was implemented for an experimental data set related to self-compacting concrete. The obtained prediction model was compared against published experimental data (not used in model development) and well-known shrinkage prediction models. The predicted results were verified by statistical analysis, which confirmed the reliability of the developed model. Although the range of application of the developed model is limited, the genetic-fuzzy approach introduced in this work proved suitable for adjusting the prediction model once additional training data are provided. This can be highly inviting for the concrete industry's experts, since they would be able to fine-tune their models depending on the boundary conditions of their production processes.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1049-1051
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• 2003

This study investigated the use of airborne image data to provide estimates of within -field variability in soil properties and crop growth as an alternative to extensive field data collection. Hyperspectral and multispectral images were acquired in 2000, 2001, and 2002 for central Missouri experimental fields. Data were converted to reflectance using chemically-treated reference tarps with known reflectance levels. Geometric distortion of the hyperspectral pushbroom sensor images was corrected with a rubber sheeting transformation. Statistical analyses were used to relate image data to field-measured soil properties and crop characteristics. Results showed that this approach has potential; however, it is important to address a number of implementation issues to insure quality data and accurate interpretations.

• 한국의류산업학회지
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• 제13권4호
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• pp.461-471
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• 2011

Jewelry has recognized as a part of independent formative arts of fashion with the change modern man's cognition for the fashion. It is a great important section to express fashion image. So, many corporations design and develop the jewelry by themselves to maxmize their fashion image. Among the so many kinds of jewelry, especially the necklace is located beneath the face and linked as a part of fashion, so it frequently has showed in Fashion Collection. Like this Fashion and jewelry enact each other and share their esthetic features but, it is insufficient the study of fashion linked with the jewelry. In this study, we defined the words which is using confusedly according to jewelry forms what researched by others. In addition, we tend to study the effect of that the form, hue and character of materials of necklace that is expressed in fashion collection influence fashion image. The method of this study is comprised with precedent studies and analysis of necklace photos in fashion collection. For the analysis of data, we implement content analysis and statistical analysis using SPAW Statistics 18(frequency analysis, percentage, cross-tabulations, $X^2$-test). Because the hue and the form of necklace take a great role to make fashion image with the sense of its eyesight, its effective coordination go up the delicate feelings with the form, hue and quality of the fashion. Especially, the hue is the essential element of formative characteristics to express visual image. The necklace had coordinated more frequently in S/S than F/W, it means that more light and simple fashion let ornamental beauty could express by the necklace. So, it is very effective things that we predict the trend of fashion, then, coordinate with well-matched necklace.