• 한국수산과학회지
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• 제36권2호
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• pp.120-128
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• 2003

Fishes were caught by a set net in the coastal waters off Yosu, Korea from April to October, 2001, and seasonal variation of abundance and species composition were studied. Fifty two species were identified as fish $(89\%)\;cephalopods\;(10\%)\;and\;crustaeans\;(1\%).$ Of the fishes Engraulis japonicus, Trachurus japonicus and Trichiurus lepturus were dominant species representing $64.1\%$ in total number of individuals. The number of species was high in spring and low in summer; number of individuals was high in spring and low in autumn. The diversity index (H') was 0.4-0.7 The abundance and species composition fluctuated seasonally. Occurrence of the various stages of fishes indicated that Scombia japonicus, T. japonicus and E japonicus utilized in the area as spawning ground, Conger myriaster larvae, Ammodytes personatus and Seriola quinqueradiata as nursery ground, and T. lepturus and Ilisha elongata as spawning and nursery grounds.

• 한국식품영양과학회지
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• 제27권4호
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• pp.775-784
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• 1998

This study was conduced to investigate the seasonal variation of dietary intake and quality obtained by 24 hour recall method in Korean adults living in rural area. The mean daily intakes of 4 seasons were 1,692kcal for energy, 63g(14.8% of energy) for protein, 30g(15.7% of energy) for fat, 257g(60.7% of energy) for carbohydrate. Mean daily intakes were significantly highest in winter for most of the nutrients, and lower in summer for energy, fat, calcium, iron. Mena adequacy ratio(MAR), an index of overall nutritional quality was 0.65 in winter, 0.67 in spring, 0.65 in summer and 0.72 in autumn and nutrient adequacy ratio(NAR) was significantly different fro vitamin C agmong different seasons. Subjects consumed usually 15.3 different foods in winter, 14.5 in summer, 13.9 in spring and 13.7 in autumn. The number of food consumed was positively correlated with intake of most nutrients, especially in autumn. For variety among the five major food groups(grain, meat, dairy, fruit, vegetable) with a dietary diversity scores(DDS) calculated, the average socre of DDS was 3 in all seasons and omitted food groups were usually dariy and fruit. In conclusion, dietary intake and quality of Korean adults were different according to seasons.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.741-749
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• 2021

The research paper endeavors to investigate the presence of seasonal anomalies in the Indian equity market. It also aims to verify the notion that equity markets are for long-term investors. The study employs daily index data of Sensex, Bombay Stock Exchange, to understand its volatility for the period ranging from January 2001 to August 2020. To analyze the seasonal effects in the stock market of India, multiple regression techniques along with descriptive analysis, graphical analysis and various statistical tests are used. The study also employs the rolling returns at different time intervals in order to understand the underlying risks and volatility involved in equity returns. The results from the analysis reveal that daily and monthly seasonality is not present in Sensex returns i.e., investors cannot earn abnormal returns by timing their investment decisions. Hence, the major finding of this study is that the Indian stock market performance is random, and the returns are efficient. The other major conclusion of the research is that the equity returns are profitable in the long run providing investors a hope that they can make gains and compensate for the loss in one period by a superior performance in some other periods.

• 한국산림과학회지
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• 제100권1호
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• pp.124-130
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• 2011

본 연구는 국립공원 탐방 수요예측에 적합한 모형을 추정하고, 계절 ARIMA Model을 이용하여 국립공원 탐방수요를 예측하였다. 분석 자료는 2003년 1월부터 2010년 12월까지 우리나라 18개 국립공원의 월별 탐방객 수 자료를 이용하였다. 분석결과 $ARIMA(1,0,0)(1,1,0)_{12}$모형이 국립공원 탐방수요를 예측하는데 적합한 모형으로 선정되었으며, MAPE를 이용한 사후평가 결과에서도 모형의 정확도가 높은 것으로 나타났다. 따라서 본 연구 결과는 국립공원 탐방수요 예측기법의 신뢰성 및 타당성 향상과 함께 국립공원 관리전략 수립에 기여할 것으로 판단된다.

• 대한원격탐사학회지
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• 제40권2호
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• pp.123-139
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• 2024

Forest vertical structure is vital for comprehending ecosystems and biodiversity, in addition to fundamental forest information. Currently, the forest vertical structure is predominantly assessed via an in-situ method, which is not only difficult to apply to inaccessible locations or large areas but also costly and requires substantial human resources. Therefore, mapping systems based on remote sensing data have been actively explored. Recently, research on analyzing and classifying images using machine learning techniques has been actively conducted and applied to map the vertical structure of forests accurately. In this study, Sentinel-2 and digital surface model images were obtained on two different dates separated by approximately one month, and the spectral index and tree height maps were generated separately. Furthermore, according to the acquisition time, the input data were separated into cases 1 and 2, which were then combined to generate case 3. Using these data, forest vetical structure mapping models based on random forest, support vector machine, and extreme gradient boost(XGBoost)were generated. Consequently, nine models were generated, with the XGBoost model in Case 3 performing the best, with an average precision of 0.99 and an F1 score of 0.91. We confirmed that generating a forest vertical structure mapping model utilizing bi-seasonal data and an appropriate model can result in an accuracy of 90% or higher.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.192-193
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• 2015

Construction Cycle Trend Survey, which survey total value of orders and realized amounts monthly, is a valuable statistics that used to quick grasp or forecast the trend of domestic construction business. In recent periodical survey quality diagnoses, few professional users named a problem that Construction Cycle Trend Survey could not get together with the current state of the construction industry. This study examined weather Construction Cycle Trend Survey reflects the economic sentiment of construction business or not. Paired t test was performed between Construction Cycle Trend Survey and Construction Business Survey Index (CBSI), and significant differences were verified.

• 한국농공학회지
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• 제31권4호
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• pp.81-89
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• 1989

This study is to determine seasonal consumptive use of water of a design year during growing period (June-September) for paddy rice in Suwon. To obtain Dry flay Index which is defined as the number of probable dry days occurring at a design year, Slade Partly Un- symmetrical Distribution Function was adopted. Dry Day Index was analysed with 5, 10 and 30 day-term. And each of them was evaluated with recurrence intervals of 1, 3, 5, 10 and 20 year using 49 years daily rainfall data('35-'83). Their singnificance were tested at 1% level by X$^2$ test. On the basis of these values, Probable Evapotranspiration (ET) which is the daily average ET for the sum of both ET on dry days and ET on rainy days were esti- mated using 5 years daily actual ET data(' 82-' 86). Their Crop Coefficients were also de- termined by the modified Penman equation(1977) proposed by Doorenbos & Pruitt.

• The Korean Journal of Ecology
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• 제20권6호
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• pp.461-470
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• 1997

There are 7 classes, 17 orders, and 141 species of benthic macroinvertebrates at the 5 study sites from Feb, '91 to May, '92. Total species frequency number has less variations among sites than seasonal changes. Not considering seasonal changes this indicates that there are some influences from outside pollution sources. Seasonally, Ortho chadiinae sp. 2 take 21.2% share of total species. It was the dominant species in Feb. '91. With total average level Ephemeroptera take 51.3% of total species as first dominant species. Diptera 27.8% as second dominant species and Trichoptera 16.7% as third dominant species. Through these biological indexes, they appear to have unstable living environments in summer at sites 1 and 5. One can see that site 1 is more polluted than site 3 because site 1 has more pollution sources such as pastures and recreation areas.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1483-1485
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• 2003

Multitemporal approaches using sequential data acquired over multiple years are essential for satisfactory discrimination between many land cover classes whose signatures exhibit seasonal trends. At any particular time, the response of several classes may be indistinguishable. Using the estimates of periodogram which are obtained from sequential images, the periodicity of the process have been incorporates into multitemporal classification. The Normalized Difference Vegetation Index (NDVI) was computed for seven-day composites of the Advanced Very High Resolution Radiometer (AVHRR) imagery over the Korean peninsula for 1996 - 2000 using a dynamic technique.

• 한국수산과학회지
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• 제46권6호
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• pp.878-885
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• 2013

Seasonal variation in marine macroalgal community structure was examined at the intertidal zones of Heuksando and Hongdo, Shinan, Korea, from July 2008 to May 2009. In total, 86 macroalgal species were identified, including 12 green, 19 brown, and 55 red algae; 67 species at Heuksando and 70 species at Hongdo, were observed. Annual seaweed biomass was 252.44 g dry $wt/m^2$ at Heuksando and 217.67 g dry $wt/m^2$ at Hongdo. The dominant seaweed in importance value (IV > 15) differed between the sites: Sargassum thunbergii at Heuksando and Corallina pilulifera at Hongdo. The vertical distribution pattern of seaweeds from the upper to lower intertidal zones at Heuksando was Gloiopeltis spp., Ulva spp. - S. thunbergii, S. fusiforme, Hildenbrandia rubra - S. thunbergii, C. pilulifera. On the rocky shore of Hongdo, seaweed zonation was distinct: Porphyra yezoensis, Gloiopeltis spp., Ulva spp. - C. pilulifera, S. fusiforme, Myelophycus simplex - Chondrus ocellatus, C. pilulifera, and Carpopeltis affinis. Annual seaweed coverage, richness index (R), evenness index (J'), and diversity index (H') values were greater at Hongdo (41.35%, 12.82, 0.59, and 2.50 respectively) than at Heuksando (31.54%, 11.93, 0.44, and 1.87 respectively), which may indicate that the seaweed community at Hongdo is more stable relative to the one at Heuksando.