• International Journal of Contents
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• 제10권3호
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• pp.1-8
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• 2014

In this paper, we collect and analyze the status of mobile phone applications (hereafter apps) in the healthcare and fitness category of the Apple iTunes App Store and Google Play Store. We determine the number of apps and analyze statistical aspects such as classifications, age rating, fees, and user evaluation of the popular items. As of September 30, 2013, there were 236 popular apps available from iTunes. Google Play offered 720 apps. We discover that apps for healthcare and fitness are diverse. Apps for physical exercise have the greatest popularity. The proportions of apps that are suitable for all ages among the Google and iTunes popular apps are 55.8% and 89.4%, respectively. The user evaluation of apps in iTunes is relatively less positive. We determine that the proportion of paid apps to free apps in Google is higher than that of the apps in iTunes. We perform hypothesis tests and find statistically significant differences in age rating and perceived satisfaction between the apps of the Apple iTunes App Store and Google Play Store. However, we find no meaningful differences in the classification and price of the apps between the two app stores. We perform hypothesis tests to verify the differences in age rating and perceived satisfaction between the paid and free apps within and across the Google Play Store and iTunes App Store. There are statistically significant differences in the age rating between the paid and free apps in the Google play store, between the Google free and iTunes free apps, between the Google paid and iTunes paid apps, between the Google free and iTunes paid apps, and between the Google paid and iTunes free apps. There are statistically significant differences in the perceived satisfaction between the Google free and iTunes free apps, between the Google paid and iTunes paid apps, between the Google free and iTunes paid apps, and between the Google paid and iTunes free apps.

• 대한공간정보학회지
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• 제7권1호
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• pp.29-40
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• 1999

벡터 GIS에서 자연선형체는 통상 일련의 직선분(line segments)에 의해 표시되나 그 대안으로 곡선분(curve segments) 역시 사용될 수 있다. 곡선분은 스플라인보간법에 의해 생성가능하며 이를 위해 Bezier방법과 신보간법(유기윤, 1998)이 사용될 수 있는데 본 연구에서는 신보간법의 퍼포먼스를 테스트해 보았다. 테스트는 두 가지에 촛점을 두었는데 (1) 새보간법에 의해 생성된 선형분이 직선분 보다 정확하게 자연선형체를 표현할 수 있는지 여부와 (2) 새보간법에 의해 생성된 선형분이 Bezier방법에 의해 생성된 선형분 보다 자연선형체를 정확하게 표현할 수 있는지 여부에 대한 검정이다. 이를 위해 t-테스트에 의한 가설검정법이 이용되었으며 자료로는 미 지질조사국의 7.5분 지형도가 이용되었다. 테스트결과 새보간법과 Bezier방법에 의해 생성된 선형분이 직선분 보다 자연선 형체를 정확하게 표현하였으며 새보간법에 의해 생성된 선형분이 Bezier방법에 의해 생성된 선형분보다 정확하게 표현하였다.

• 자원ㆍ환경경제연구
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• 제21권2호
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• pp.271-299
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• 2012

환경과 경제성장과의 관계는 환경경제학 분야에서 오랜 동안 논란이 되어왔으며, 논란의 핵심은 두 변수간의 내생성(endogeneity)과 생략변수(omitted variables)들에 관한 문제들이다. 본 연구는 논란의 핵심들을 고려하여 우리나라의 1981년~2008년까지의 시계열자료를 바탕으로 $CO_2$ 배출량과 경제성장 간의 인과관계 및 에너지믹스의 영향을 실증적으로 분석하였다. 에너지믹스와 계량경제학 문제들을 고려한 대부분의 모형에서 $CO_2$ 배출량과 경제성장의 관계가 역 U자형이라는 EKC 가설을 확인할 수 있었으며, 에너지믹스가 국내 온실가스 감축에 크게 기여하는 것으로 나타났다. 에너지믹스가 $CO_2$ 배출에 미치는 영향은 원자력에너지가 다른 에너지원에 비해 $CO_2$ 배출량 감축에 가장 큰 기여를 하였으나, 신재생에너지는 $CO_2$ 감축에 거의 기여하지 못한 것으로 분석되었다. 이는 지금까지 국내에서 신재생에너지 비중이 다른 에너지원에 비해 적었기 때문이다. 또한 최종 에너지 소비부문은 $CO_2$ 증가와 수송부문의 연관성이 통계적으로 유의한 것으로 나타났다.

• 한국과학교육학회지
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• 제28권8호
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• pp.779-785
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• 2008

이 연구에서는 연소 개념 학습에서 변칙 사례의 역할을 인지적 동기적 측면에서 조사했다. 중학교 2학년 학생 433명을 대상으로 선개념 검사와 변칙 사례에 대한 반응 검사, 상황 흥미 검사를 실시했다. 연소 개념 학습을 실시한 후, 사후 검사로 주의집중, 노력, 개념 이해도 검사를 실시했다. 목표 오개념을 지닌 것으로 판별된 208명의 응답을 분석한 결과, 거부와 배제 반응의 비율은 밀도에 대한 선행연구의 결과와 비교하여 상대적으로 높은 반면, 신념 변화 반응의 비율은 낮은 것으로 나타났다. 경로 분석 결과, 대안 가설 제시 후의 상황 흥미가 직접적으로 또는 주의집중과 노력을 매개로 개념 이해도에 영향을 주는 것으로 나타났다. 변칙 사례에 의해 유발된 상황 흥미는 대안 가설 제시 후의 인지 갈등에 직접적으로 영향을 미치기도 했다.

• Journal of the Korean Data and Information Science Society
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• 제7권2호
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• pp.235-245
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• 1996

확률변수 (X,Y)가 이변량 정규분포를 따르는 경우, 모상관계수 ${\rho}$에 관한 여러 가설들 중에서 $H_{0}:{\rho}={\rho}_{0}$인 경우에는 알려진 분포를 이용한 통계적 추론을 하기가 어렵다. 이러한 경우 Fisher에 의해 제안된 Z-변환을 이용한 근사적 검정법이 사용되어 오고 있으나 근사적인 방법이기 때문에 주어진 표본의 크기가 충분히 많지 않은 경우에는 적용에 무리가 있을 수 있다. 그래서 본 논문에서는 먼저 표본 상관계수 R의 분포를 모의실험을 통하여 직접 구하여 검정한 정확 검정법과, 붙스트랩(bootstrap) 방법을 이용하여 구한 붙스트랩 검정법을 제시하고, Fisher의 방법의 효율성과 실제성을 검토하고 제시된 방법들과 서로 비교하고자 한다.

• Structural Engineering and Mechanics
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• 제82권5호
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• pp.557-569
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• 2022

The retrofit of existing structures in high seismic zones is a crucial issue in the earthquake engineering field. The interest of the research community is particularly high for the structures that do not respect current seismic codes and present structural deficiencies such as poor detailing and lack of capacity design provisions. A reinforced concrete (RC) school building is used as case study to show the influence of different knowledge levels on the seismic retrofitting cost assessment. The safety assessment of the case study building highlights deficiencies under both vertical and seismic loads. By considering all the possible knowledge levels defined by the Italian such as by the European codes in order to derive the mechanical properties of the school building constitutive materials, the retrofit operations are designed to achieve different seismic safety thresholds. The retrofit structural costs are calculated and summed up to the costs for in-situ in tests. The paper shows how for the case study building the major costs spent for a large number of in-situ tests allows to save a consistent amount of money for retrofit operations. The hypothesis of demolition and reconstruction of the building is also compared in terms of costs with all the analyzed retrofit options.

• Journal of Photoscience
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• 제1권1호
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• pp.69-73
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• 1994

Sporangiophores (spphs) of Phycomyces blakesleeanus are positively phototropic to unilateral visible (blue) light over a range of fluence rates 10$^{-9}$ to 1 W/m$^2$. The maximal bending angle is always 70-75$\circ$ from the vertical. Many mutants with abnormal phototropism have been isolated. Complementation tests revealed that the genetic grouping is completely consistent with the phenotypic classification scheme, based on sensory responses other than those to light. The spph of the piloboloid mutant, the growth zone of which gradually ceases elongation but expands spherically, and the $\beta$-carotene-overproducing mutant show negative phototropism, in contrast to the wild type spph. We hypothesized that the phototropic orientation of spph is determined by the ratio of the maximal light fluenee rate at the proximal side to that at the distal side of the spph. Based on this hypothesis, we found that the maximal bending angle was larger in thin spphs than in thick ones, and larger in spphs containing smaller amount of $\beta$-carotene than in carotene-rich spphs. In addition to our hypothesis, gravitropic experiments revealed that the maximal bending angle of the wild type spph results from a balance among positive phototropism, negative gravitropism, and the optical properties of the spph. For further advancement of this study, we developed a mutant with a high proportion of uninucleate spores, and designed an efficient microinjection method for obtaining transformants.

• Industrial Engineering and Management Systems
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• 제7권3호
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• pp.228-244
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• 2008

ISO9000 set of standards has been widely applied in Iranian Automotive manufacturing industry. Regarding the effects of TQM and ISO9000 set of standards various studies have been conducted and different quantitative conclusions have been made. Due to lack of quantitative information, in many of the cases, using qualitative information becomes the best option. The qualitative nature of data in such cases, requires qualitative analysis methods that might lead to some challenging computational issues. This paper examines the impact of ISO9000: 2000 certification and its perceived benefits for an automotive manufacturing company. Using an empirical approach, the paper seeks to ascertain if certification has indeed improved the performance of the company. Our null hypothesis rotates around the effect of ISO9000: 2000 on the 4W's of an enterprise. To carry out the research, first we developed a couple of questionnaires including all criteria of ISO9000 and 4W's. Second, the questionnaires were discussed with two researchers knowledgeable in the field, and then submitted to the quality practitioners and executives of Iran Khodro Enterprise-a leading company in Iranian automotive manufacturing industry. Finally the null hypothesis was tested and the technology improvement dimensions were ranked through nonparametric tests. The results illustrated a reasonable cause and effect relationship, suggesting that ISO9000: 2000 has positive effect on the 4W's of company result. In this work we investigate the effect as technology improvement viz., the improvement of techno-ware, human-ware, info-ware, and organ-ware.

• Journal of the Korean Data and Information Science Society
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• 제28권6호
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• pp.1547-1555
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• 2017

This paper studies Bayesian test of homogeneity in contingency tables made by discretizing a continuous variable. Sometimes when we are considering events of interest in small area setup, we can think of discretization approaches about the continuous variable. If we properly discretize the continuous variable, we can find invisible relationships between areas (groups) and a continuous variable of interest. The proper discretization of the continuous variable can support the alternative hypothesis of the homogeneity test in contingency tables even if the null hypothesis was not rejected through k-sample tests involving one-way ANOVA. In other words, the proportions of variables with a particular level can vary from group to group by the discretization. If we discretize the the continuous variable, it can be treated as an analysis of the contingency table. In this case, the chi-squared test is the most commonly employed method. However, further discretization gives rise to more cells in the table. As a result, the count in the cells becomes smaller and the accuracy of the test becomes lower. To prevent this, we can consider the Bayesian approach and apply it to the setup of the homogeneity test.

• 유통과학연구
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• 제18권10호
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• pp.101-110
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• 2020

Purpose: The study investigates the implementation of corporate social responsibility (CSR) in the real estate sector of the UAE by collecting the opinions of both the real estate companies and different tenants on the execution of CSR. Research design, data, and methodology: Using a sample of 300 different types of UAE real estate consumers and twenty real estate firms, the researchers collected the opinions of targeted subjects by administering two types of questionnaires. The Cronbach's Alpha and the Kaiser-Meyer-Olkin (KMO) tests were employed to check the internal consistency and validity of the questionnaires. The selected hypotheses were tested using the Kruskal-Wallis (K-W) hypothesis testing technique. Results: The findings revealed that all types of UAE real estate consumers expressed their discontentment over the implementation of socially responsible actions by the real estate companies. Whereas UAE real estate companies expressed their confidence in the ideal implementation of social actions towards all stakeholders in general and tenants. Conclusion: Even though more than 50 percent of realty customers are dissatisfied with the company's implementation of CSR, a little over 54.80 percent are willing to recommend the company to their family and friends. Implications have been provided for UAE real estate companies who wish to promote their business to all categories of UAE real estate consumers successfully.