• 대한지구과학교육학회지
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• 제5권3호
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• pp.245-255
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• 2012

The purposes of this research are to analyze preservice elementary teachers' degree of difficulty in classes of seasonal variation and suggest the measures of classes so that preservice elementary teachers can progress classes of seasonal variation effectively. To achieve them, the research was conducted for 90 first graders completing teaching method of elementary science in P university of education from Sep. to Dec. 2012. This research was conducted, based on the results of in-depth interview for 9 preservice elementary teachers who performed classes of seasonal variation, survey on the degree of class difficulty and evaluation of classes on 8 classes theme of Earth sector in elementary science. The results of this research are as follows. The first, preservice elementary teachers had relatively high class difficulty for teaching seasonal variation among the sector of the earth in elementary science. The second, in the evaluation of preservice elementary teachers' classes, the more the subject showed high class difficulty, the more the score of class evaluation was low. The reason is analyzed that high class difficulty reduces teacher's confidence. The third, preservice elementary teachers had insufficient knowledges and concepts which are basically necessary for the classes of seasonal variation. Especially, it was more serious for preservice elementary teachers who didn't learn Earth-science during their high school time. The fourth, it is necessery that concrete and systematical teaching method should be developed so as to improving preservice elementary teachers' teaching method for the classes of seasonal variation.

• 대한원격탐사학회지
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• 제26권6호
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• pp.665-673
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• 2010

The role of remote sensing in phenological studies is increasingly regarded as a key in understanding large area seasonal phenomena. This paper describes the application of Moderate Resolution Imaging Spectroradiometer (MODIS) time series data for vegetation classification using seasonal variation patterns. The vegetation seasonal variation phase of Seoul and provinces in Korea was inferred using 8 day composite MODIS NDVI (Normalized Difference Vegetation Index) dataset of 2006. The seasonal vegetation classification approach is performed with reclassification of 4 categories as urban, crop land, broad-leaf and needle-leaf forest area. The BISE (Best Index Slope Extraction) filtering algorithm was applied for a smoothing processing of MODIS NDVI time series data and fuzzy classification method was used for vegetation classification. The overall accuracy of classification was 77.5% and the kappa coefficient was 0.61%, thus suggesting overall high classification accuracy.

• Communications for Statistical Applications and Methods
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• 제16권2호
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• pp.335-348
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• 2009

Fuzzy regression is used as a complement or an alternative to represent the relation between variables among the forecasting models especially when the data is insufficient to evaluate the relation. Such phenomenon often occurs in seasonal time series data which require large amount of data to describe the underlying pattern. Semiparametric model is useful tool in the case where domain knowledge exists about the function to be estimated or emphasis is put onto understandability of the model. In this paper we propose fuzzy semiparametric support vector regression so that it can provide good performance on forecasting of the seasonal time series by incorporating into fuzzy support vector regression the basis functions which indicate the seasonal variation of time series. In order to indicate the performance of this method, we present two examples of predicting the seasonal time series. Experimental results show that the proposed method is very attractive for the seasonal time series in fuzzy environments.

• 응용통계연구
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• 제36권5호
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• pp.457-471
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• 2023

월별 시계열은 일별 시계열의 월별 합이지만, 일별 시계열을 대체로 관측할 수 없어서 요일구성변동, 명절·공휴일변동 등 달력변동을 가상적으로 가정한 가변수를 포함한 RegARIMIA 모형을 이용하여 추정하고 있다. 일별 시계열을 관측할 수 있다면 요일구성변동, 명절·공휴일변동 등 달력변동을 일별 시계열을 바탕으로 추정할 수 있고 이를 이용하여 월별 시계열의 계절조정을 개선할 수 있다. 이 논문에서는 일별 시계열의 달력변동 추정을 이용하여 월별 시계열의 계절조정을 개선하는 방법을 제안하고, 이 방법을 적용하여 3개의 월별 시계열을 계절조정하고 기존의 X-13ARIMA-SEATS를 이용한 계절조정과 비교하였다.

• Journal of Radiation Protection and Research
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• 제31권4호
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• pp.197-201
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• 2006

Daily and seasonal variations of the ambient gamma ray exposure rates were measured by using a pressurized ion chamber from January 2003 to December 2005 in the CheongJu Regional Radiation Monitoring Post and the patterns of the distributions were studied. The annual average of the daily variation of the exposure rate was $\sim0.17{\mu}R/h$. The exposure rate was found to be maximum during 8:00 am to 9:00 am and minimum during 8:00 pm to 10:00 pm. For the annual data, the exposure rate was the minimum during the month of February. The exposure rate increased from February to mid-October (except during the period from May to July with no change) and decreased from October to February. The seasonal variation was found to be about $1{\mu}R/h$. Most of the measured values (96%) of the exposure rates fell under the normal distribution with a deviation of less than 4.8% and the remaining 4% had large fluctuations caused mainly by the rainfalls.

• 대한환경공학회지
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• 제39권6호
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• pp.311-317
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• 2017

본 연구에서는 농법 및 시기에 따른 논토양의 화학성을 비교 분석하였다. 이를 위하여 관행논 11개 필지와 유기논 24개 필지에 대하여 3월, 5월, 8월, 10월에 토양 시료 채취 및 분석을 수행하였고, 실험 분석 결과에 대해 통계 분석을 수행하였다. 분산분석 결과 농법에 의한 유의미한 차이가 나타난 항목은 $NH_4-N$와 $P_2O_5$이었지만, 시기에 따른 차이는 모든 항목에서 높은 유의성 있는 차이를 보였다. 주성분 분석 결과 또한 토양내 질소 및 인의 농도는 농법에 의한 영향보다는 시료 채취시기에 따른 영향이 더 크게 나타났다. 토양의 전기전도도는 3월에서 10월로 감에 따라서 값이 증가하였다. 토양 유기물은 3월 및 5월에 비하여 8월과 10월에 높게 나타났다. T-N는 3월에서 10월로 지남에 따라서 감소하는 경향을 나타냈다. $NH_4-N$ 및 $NO_3-N$ 농도는 관행논 및 유기논 모두 5월에 가장 높게 나타났다. T-P 농도는 8월에 가장 높은 값을 나타낸 반면에, $P_2O_5$의 경우에는 8월에 가장 낮은 값을 나타내었다. 본 연구 결과 논토양의 화학적 특성은 농법에 의한 차이보다는 시기에 의한 차이가 더 크게 나타났다. 따라서 토양 환경 특성에 대한 분석 및 비교시 시기에 대한 고려가 반드시 필요한 것으로 판단된다.

• 농촌의학ㆍ지역보건
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• 제26권1호
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• pp.115-119
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• 2001

사회적 통계 작성할 때 계절변동효과는 자료에 많은 영향을 미친다. 농촌의 의료기관에 내원한 환자들의 수도 계절에 영향을 많이 받는다. 1994년에서 2000년까지 농촌 보건지소에 내원한 환자 수를 분석하여 계절지수를 구하였다. 의료고유의 요인을 제거하기 위하여 감기 환자를 제외하고 계절지수를 구하였다. 각각의 계절지수는 다음과 같다. 1. 전체지수는 1월에서 12월 0.96, 1.08, 1.23, 0.83. 0.82, 0.75, 1.01, 0.99, 1.02, 1.05, 1.13, 1.13이다. 2. 감기환자를 제외한 지수는 0.94, 0.90. 1.42, 0.94, 0.91, 0.77, 1.13, 0.92, 0.84, 1.07, 1.10, 1.06이다. 위의 결과를 보면 봄, 초여름에 환자 수가 감소하고 한여름과 겨울에 환자가 증가한다. 이것은 감기 환자를 제외하고 분석하여도 같은 결과이다. 또한 이것은 농사의 주기와도 일치한다. 계절변동 지수를 잘 활용한다면 농촌을 대상으로 한 보건 연구나 사업계획에 많은 도움이 될 것이다.

• 천문학논총
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• 제23권1호
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• pp.1-12
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• 2008

Understanding of the basic characteristics of an astronomical instrument is a prerequisite to obtaining reliable data from the instrument. We have analyzed more than 1,000 calibration images from the Fairchild 486 CCD (hereafter the Maidanak 4k CCD system) attached to the AZT-22 1.5m telescope at Maidanak Astronomical Observatory in Uzbekistan. The Maidanak 4k CCD system supports three readout modes through 1, 2, or 4 amplifiers. In most cases observers use 4-amplifier readout mode to save time. We have tested the stability and seasonal variation of zero levels and confirm that two quadrants of the images (Amp 1 & 2) show no appreciable seasonal variation. but the other two quadrants (Amp 3 & Amp 4) show an evident seasonal variation in the bias level. The Cryo Tiger, the cooling system used at the Maidanak 4k CCD system, maintains the CCD temperature at -108'E, and effectively suppresses the dark electrons. The mean value versus the variance plot of the flat images does not show the expected relation for an ideal Poisson noise distribution and this is attributed to the large variation in quantum efficiency between different pixels. In addition, we confirm that there is no appreciable difference in gain between readout amplifiers, but there is a large variation in quantum efficiency across CCD chip especially in U. Due to the finite length of shutter opening and closing time, the effective exposure time varies across the science images. We introduce two parameters to quantify the effect of this uneven illumination and present a method to remove these effects. We also present a method to remove the interference patterns appearing in the images obtained with longer wavelength filters and investigate the spatial variation of the point spread function.

• 한국방재학회 논문집
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• 제1권2호
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• pp.93-101
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• 2001

본 연구에서는 계절에 따른 온도 변화를 고려한 건조수축의 예측모델을 제시하여, 실제구조물에서의 계절에 따른 온도변화에 대한 장기 거동 특성을 보다 향상된 방법으로 파악할 수 있는 방법을 제시하였다. 본 연구에서 사용된 건조수축 보정계수식은 계절에 따른 온도변화를 포함한 건조수축의 실제 실험적 데이터들을 사용하여 제안되었으며, FCM 교량의 장기 거동 조사는 현장에서 건조수축의 수치해석 결과를 적용할 수 있는지 없는지를 결정하기 위해 수행되었다. 본 연구에서 채택된 수치해석 방법은 실제 변형율과 차이가 발생하는 일반적인 방법과는 달리 실제 구조물의 거동특성을 매우 유사하게 모사할 수 있는 것으로 나타났다. 결과적으로 본 연구에서 제안된 방법은 FCM 교량의 장기 처짐에 대한 예측을 향상 시킬 것이다.

• 수산해양기술연구
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• 제47권2호
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• pp.118-127
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• 2011

This study was investigated seasonal variation and species composition of fish species at artificial reefs (octangle three-stage compartment type and dice type)and natural rock in the Shinyang-Ri coastal waters off Jeju Island with visual census method in January 2009, April 2009, July 2009, September 2009, December 2009, March 2010, June 2010, and September 2010. A total of 44 fish species was occurred, and the dominant fish species were Apogon semilineatus, Chromis notata, Trachurus japonicus, Sebastes thompsoni and Apogon doederleini. The number of individuals of fishes was higher at April 2009 and March 2010, however, lower at June 2010 and September 2010. The number of fish speices was higher at artificial reefs than those of at natural rock. Apogon semilineatus was dominant at octangle three-stage compartment type and the dice type artificial reefs, whereas Chromis notata was for natural rock. These results indicated that artificial reefs were good habitats for a variety of fish species in the Shinyang-Ri coastal waters off Jeju Island.