• Communications for Statistical Applications and Methods
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• 제25권6호
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• pp.619-631
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• 2018

Functional data analysis continues to attract interest because advances in technology across many fields have increasingly permitted measurements to be made from continuous processes on a discretized scale. Particulate matter is among the most harmful air pollutants affecting public health and the environment, and levels of PM10 (particles less than 10 micrometers in diameter) for regions of California remain among the highest in the United States. The relatively high frequency of particulate matter sampling enables us to regard the data as functional data. In this work, we investigate the dominant modes of variation of PM10 using functional data analysis methodologies. Our analysis provides insight into the underlying data structure of PM10, and it captures the size and temporal variation of this underlying data structure. In addition, our study shows that certain aspects of size and temporal variation of the underlying PM10 structure are associated with changes in large-scale climate indices that quantify variations of sea surface temperature and atmospheric circulation patterns.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제22권1호
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• pp.1-11
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• 2015

The present paper is concerned with the notions of Lipschitz and asymptotic for perturbed functional differential system knowing the corresponding stability of functional differential system. We investigate Lipschitz and asymptotic stability for perturbed functional differential systems. The main tool used is integral inequalities of the Bihari-type, and all that sort of things.

• 한국주거학회논문집
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• 제16권1호
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• pp.65-72
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• 2005

With the changing consciousness of community people and the rising standard of living, there has recently been an emphasis on the creation of public facilities' new functions and their role as local community facilities. This changing trends are accordingly requiring a change in spatial structure of the public facilities. In this study, an analysis was conducted with 24 public facilities situated in the Buk-gu district of Daegu to identify the adequacy of their space scale after functional variation. The results of this study are summarized as follows. 1) The site area of public facilities has been being widened after functional variation since more spaces are needed to provide an outdoor resting space with community people, expand a parking space, and operate a community center. 2) The factors that had a direct effect on the change in the use of space are the reduced space for administrative work and the expanded scope of the community center's function. Specifically, the areas of activities for civil service and administrative work and for reserve forces have been reduced due to reduction of function, and floor division by each function group has been becoming stricter due to addition of a community center's function. 3) It was shown that in terms of the space for functions of public facilities, spaces for civil service and waiting have increased mostly after function variation. After functional variation, the scale of spaces for civil service and administrative work has been being planned within the range of $200\~300 m^2$, regardless of the number of population to be covered by public facilities. 4) The space for public use is showing the greatest increase in public facilities which have been built after functional variation. The major factors seem to be the increased moving passages, the expanded convenient facilities for community people, and the increased convenient facilities for disabled. Facilities scale plans have been being made more systematically, compared to the conventional facilities.

• 비교문화연구
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• 제25권
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• pp.649-678
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• 2011

The purpose of this work is to explain categorial correlations between indirect evidentiality and epistemic modality on the basis of semantic, pragmatic usages of Russian so-called non-specialized lexical markers of evidentiality, such as kazhetsja, naverno, vidimo, poxozhe, dolzhno byt' etc. To do this, firstly I concentrated on the parameter of internal functional variation of a given parenthetic word. Secondly, I approached this topic from a typological perspective. Thirdly, I accepted Sweeter(1990)'s methodological assumption that etymological prototype of a given word plays a great role in grammatical, semantic, pragmatic changes. As a result, I could postulate general tendencies of grammaticalizations (or semantic, pragmatic, funtional changes) in the direction from epistemic modality to indirect evidentialty, which consists of inferentives, presumptives, and quotatives. For example, such a parenthetic word as kazhetsja can functions not only as a marker of epistemic modality of uncertainty, but also as inferentives. Besides, it is very interesting that this word lately has started to function as quotatives, too. This kind of functional variations are very characteristic in these spheres.

• 대한수학회논문집
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• 제10권3호
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• pp.643-652
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• 1995

We use a semi-variational method to obtain necessary condition for a linear functional L to attain its extrema at certain elementary products. This is applied to obtain an answer to the long-standing question of determining explicit extreme points of the normalised Spirallike functions of order $\alpha$.

• Journal of applied mathematics & informatics
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• 제33권1_2호
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• pp.219-228
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• 2015

In this paper, we investigate Lipschitz and asymptotic stability for perturbed functional differential systems.

• 대한수학회보
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• 제61권1호
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• pp.281-290
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• 2024

We consider the total scalar curvature functional, and show that if the second variation in the transverse traceless tensor direction is negative, then the metric is Einstein. We also find the relation between the second variation and the Lichnerowicz Laplacian.

• 대한산업공학회지
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• 제36권3호
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• pp.154-163
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• 2010

Process monitoring of output variables affecting final performance have been mainly executed in semiconductor manufacturing process. However, even earlier detection of causes of output variation cannot completely prevent yield loss because a number of wafers after detecting them must be re-processed or cast away. Semiconductor manufacturers have put more attention toward monitoring process inputs to prevent yield loss by early detecting change-point of the process. In the paper, we propose the method to efficiently monitor functional input variables in multi-phase semiconductor manufacturing process. Measured input variables in the multi-phase process tend to be of functional structured form. After data pre-processing for these functional input data, change-point analysis is practiced to the pre-processed data set. If process variation occurs, key variables affecting process variation are selected using contribution plot for monitoring efficiency. To evaluate the propriety of proposed monitoring method, we used real data set in semiconductor manufacturing process. The experiment shows that the proposed method has better performance than previous output monitoring method in terms of fault detection and process monitoring.

• 한국수자원학회논문집
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• 제48권5호
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• pp.379-391
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• 2015

국내 4대강에 설치된 다기능보는 하천을 횡단하는 수공구조물로써 고정보와 가동보로 구분되어 설치되었으며, 각 다기능보의 수문운영 방식에 따라 유량이 변화하여 하상변동 및 유사이동 형태의 변화 가능성이 있다. 본 연구에서는 다기능보의 수문운영에 따른 장기 하상변동을 금강유역을 중심으로 연구하였다. 연구결과, 금강에서는 다기능보의 설치 및 수문운영 시나리오에 따라서 최심하상고의 변화가 연평균하상고의 변화에 비해서 상대적으로 큰 것으로 나타났다. 최심하상고의 하상저하는 최대 2.79 m, 하상상승은 최대 1.90 m까지 발생하는 것으로 나타났으며, 연평균하상고의 하상저하는 최대 2.16 m, 하상상승은 최대 1.24 m까지 발생하는 것으로 나타났다. 또한 하상변동에 따른 홍수위 분석 결과, 다기능보 설치 후에 홍수위가 대부분 상승하는 것으로 나타났으며, 최대 2.23 m까지 상승하는 것으로 나타났다. 이러한 결과로 인해서 제방의 여유고를 상회하는 홍수위가 발생할 가능성이 있기 때문에, 하천의 유사관리 및 하천계획수립을 함에 있어서 다기능보의 수문운영을 고려해야 한다고 판단된다. 또한 본 연구결과는 향후 하천계획을 수립함에 있어서 종단적 하도관리 및 안정하상 채택 등을 위해서 기초자료로 활용될 수 있을 것으로 본다.

• 한국작물학회지
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• 제54권1호
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• pp.24-28
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• 2009

This study was conducted to evaluate the growth characters and yield components of 18 collected sesame cultivars to get basic information on the variation for the sesame breeding using principal component analysis. All characters except days to flowering, days to maturity and 1,000 seed weight showed significantly different. Seed weight per 10 are showed higher coefficient of variance. Capsule bearing stem length and liter weight showed positive correlation with seed yield per 10 are. The principal components analysis grouped the estimated sesame cultivars into four main components which accounted for 83.7% of the total variation at the eigenvalue and its contribution to total variation obtained from principal component analysis. The first principal component ($Z_1$) was applicable to increase plant height, capsule bearing stem length and 1,000-seed weight. The second principal component ($Z_2$) negatively correlated with days to flowering and maturity by which it was applicable to shorten flowering and maturity date of sesame. At the scatter diagram, Yangbaek, Ansan, M1, M2, M4, M7 and M9 were classified as same group, but M10, Yanghuk, Kanghuk, M5, M6, M12 and M13 were classified as different group. This results would be helpful for sesame breeder to understand genetic relationship of some agronomic characters and select promising cross lines for the development of new sesame variety.