• Title/Summary/Keyword: Range of period

Search Result 3,867, Processing Time 0.033 seconds

Genetic Programming Based Compensation Technique for Short-range Temperature Prediction (유전 프로그래밍 기반 단기 기온 예보의 보정 기법)

  • Hyeon, Byeong-Yong;Hyun, Soo-Hwan;Lee, Yong-Hee;Seo, Ki-Sung
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.61 no.11
    • /
    • pp.1682-1688
    • /
    • 2012
  • This paper introduces a GP(Genetic Programming) based robust technique for temperature compensation in short-range prediction. Development of an efficient MOS(Model Output Statistics) is necessary to correct systematic errors of the model, because forecast models do not reliably determine weather conditions. Most of MOS use a linear regression to compensate a prediction model, therefore it is hard to manage an irregular nature of prediction. In order to solve the problem, a nonlinear and symbolic regression method using GP is suggested. The purpose of this study is to evaluate the accuracy of the estimation by a GP based nonlinear MOS for 3 days temperatures in Korean regions. This method is then compared to the UM model and has shown superior results. The training period of 2007-2009 summer is used, and the data of 2010 summer is adopted for verification.

The Application of the GWLF model for Agricultural Small Watershed (농촌 소유역에 대한 GWLF 모형의 적용성 검토)

  • Hwang, Sye-Woon;Park, Seung-Woo
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2005.10a
    • /
    • pp.667-672
    • /
    • 2005
  • The objective of the study is to investigate the application of the mid-range model for agricultural ungaged small watershed. In this study, the need for the selection of an optimal model was presented, and the Feasibility of the GWLF(Generalized Watershed Loading Function) model was examined for agricultural small watershed. The study watershed covers 384ha, and the hydrologic and water quality data were monitored from 1996 to 2004. In the results of the simulation for the calibration period $(1996{\sim}1999)$ and verification $(2002{\sim}2004)$, $R^2$ were $0.70{\sim}0.91$ and RMSE was $2.11{\sim}5.71$. Then, the results of water quality simulation for SS, TN and TP, show that $R^2$ were 0.58, 0.47 and 0.62 respectively. This results were compared with the other research using the detailed models (SWAT, HSPF) for the same watershed and this showed the feasibility of mid-range model for the small watershed.

  • PDF

A Study on the Long-Wave Effective Floating Breakwater I: On Trapezoid and Prominence Cross Section (장주기파에 효율적인 부유식방파제에 대한 연구 I: 사다리꼴과 요철 단면형상에 대하여)

  • 김도영;안용호
    • Journal of Ocean Engineering and Technology
    • /
    • v.15 no.1
    • /
    • pp.7-11
    • /
    • 2001
  • In this paper, trapezoid sections and prominence sections were examined to improve the performance of floating breakwater in long waves. The linear potential theory is used and the boundary element method with a matching boundary is employed for numerical computation. The effects of the side slope of the trapezoid section and the geometry ratio of the prominence section on the floating breakwater were examined. It was found that trapezoid sections show lower transmission coefficients than the rectangular sections in the long wave range. In prominence sections the size of the sides are more important than the size of the top. Proper choices of the pontoon type geometry may move the local minimum point of the wave transmission coefficient toward the longer wave ranges and improve the performance of the floating breakwater in the long wave range for a given wave period.

  • PDF

Quasi-Periodic Oscillations of Off-Limb Flaring Arcade Loops observed in the SDO/HMI Continuum

  • Cho, Il-Hyun;Nakariakov, Valery;Moon, Yong-Jae;Lee, Jin-Yi;Kashapova, Larisa;Cho, Kyung-Suk
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.46 no.1
    • /
    • pp.43.2-43.2
    • /
    • 2021
  • In this study, we report oscillations of the total intensity of white light loops in the off-limb solar flare observed in 2017-Sep-10 with the SDO/HMI. The total intensity oscillations are correlated with the area of the flaring loop in the plane of the sky. The oscillatory pattern is well fitted by two consecutive damped oscillations. The period and damping time of the first oscillation are 12.9 minutes and 9.9 minutes, respectively. Those of the second oscillation are 11.7 minutes and 15.4 minutes. The excitation of the oscillations coincides with two consecutive type III radio bursts observed in meter range. Assuming the oscillations are magnetoacoustic waves in the flaring loops with the loop lengths ranging from 30 to 90 Mm, the temperature of the white light emitting loops could be in the range from 0.3 MK to 2.6 MK.

  • PDF

The Riboflavin Status in Insulin-Dependent Diabetes Mellitus During Growing Period (성장기 인슐린 의존성 당뇨병 환자의 리보플라빈 영양상태)

  • 이정희
    • Journal of Nutrition and Health
    • /
    • v.27 no.7
    • /
    • pp.729-739
    • /
    • 1994
  • Riboflavin status of 17 insulin-dependent diabetic mellitus(IDDM) patients in growing period was evaluated as a function of energy intake and expenditure, biochemical nutritional status and diabetic control indicators. Compared with recommended dietary allowances for Koreans(RDA, 1989), only 35.3% of subjects was at good levels of all nutrients intakes and 52.9% of subjects was below normal level of height and weight. Nutrients consumed below RDA levels were energy(=88.5% of subjects), niacin(64.7%), iron(52.9%) and protein(23.5%) respectively. The riboflavin status was within normal range by urinary riboflavin excretion but 17.6% of subjects was evaluated as showed riboflavin deficiency by erythrocyte glutathione reductase activity coefficient(EGRAC). Correlation between riboflavin intake, urinary riboflavin excretion, EGRA level and diabetic duration were not statistically significant. Correlation analyses indicated that EGRA level was inversely correlated with thiamin, niacin and cabohydrate intake. No significant correlations were found between the EGRA and glycosylated hemoglobin A1(HbA1) (r=-0.464, p=0.129). From this study, it is suggested that IDDM subjects need to maintain balanced diet containing nutrients above RDA for individual activity during growing period. It needs more study whether the current recommended riboflavin allowance is adequate for diabetic patients.

  • PDF

Results of the key comparison in absolute pressure from 1 Pa to 1000 Pa

  • Hong, Seung-Soo;Shin, Yong-Hyeon;Chung, Kwang-Hwa;A. P. Miiller
    • Journal of Korean Vacuum Science & Technology
    • /
    • v.6 no.3
    • /
    • pp.109-115
    • /
    • 2002
  • This paper describes a CCM key comparison of low absolute-pressure standards at seven National Measurement Institutes that was carried out during the period March 1998 to September 1999 in order to determine their degrees of equivalence at pressures in the range 1 Pa to 1000 Pa. The Korea Research Institutes of Standards and Science(KRISS) participated from 10 Pa to 1000 Pa pressure range in 1999. The primary standards, which represent two principal measurement methods, included five liquid-column manometers and four static expansion systems. The transfer standard package consisted of four high-precision pressure transducers, two capacitance diaphragm gauges to provide high resolution at low pressures, and two resonant silicon gauges to provide the required calibration stability.

  • PDF

The Analysis on the Types of Remodeling in Preference Group -Focused on the Internet Remodeling site- (리모델링 선호집단의 형태 분석 연구 -인터넷 리모델링 상담 사이트를 중심으로)

  • Park, Hyun-Ok;Lee, Jong-Suk
    • Journal of The Korean Digital Architecture Interior Association
    • /
    • v.3 no.2
    • /
    • pp.1-7
    • /
    • 2003
  • Remodeling has improved through many interests of people and governmental positive support. Accordingly, this study precedes definition and typology of remodeling. As well, it analyzed the type of remodeling preference group who asked consulting on internet following items and researched a special feature of construction case. - Area, Age, Size and Type of Building, Prospective Cost, Constructing Period, Range of Remodeling- Then, remodeling will have a big effect and be needed lasting evaluation.

  • PDF

Numerical Weather Prediction and Forecast Application (수치모델링과 예보)

  • Woo-Jin Lee;Rae-Seol Park;In-Hyuk Kwon;Junghan Kim
    • Atmosphere
    • /
    • v.33 no.2
    • /
    • pp.73-104
    • /
    • 2023
  • Over the past 60 years, Korean numerical weather prediction (NWP) has advanced rapidly with the collaborative effort between the science community and the operational modelling center. With an improved scientific understanding and the growth of information technology infrastructure, Korea is able to provide reliable and seamless weather forecast service, which can predict beyond a 10 days period. The application of NWP has expanded to support decision making in weather-sensitive sectors of society, exploiting both storm-scale high-impact weather forecasts in a very short range, and sub-seasonal climate predictions in an extended range. This article gives an approximate chronological account of the NWP over three periods separated by breakpoints in 1990 and 2005, in terms of dynamical core, physics, data assimilation, operational system, and forecast application. Challenges for future development of NWP are briefly discussed.

Inter-Region Relative Price Convergence in Korea

  • Moon, Seongman
    • East Asian Economic Review
    • /
    • v.21 no.2
    • /
    • pp.123-146
    • /
    • 2017
  • This paper examines the persistence of relative consumer price indices for 15 regions in Korea including 6 metropolitan cities and 9 provinces over the period of 1990-2016. In particular, we ask if relative regional price indices contain a common stochastic trend and find that they are not. We then investigate how quickly these relative prices converge to their long run value and find that a half-life of a deviation from the long run value is in the range of 13 to 22 months for the aggregate consumer price indices and in the range of 7 to 13 months for the tradable goods price indices, which is much quicker than the estimates of previous studies. These estimates suggest that existing monetary models with the realistic duration of price rigidities can generate the persistence in relative price indices.

Composting Greenhouse using The Forced Aeration Method

  • Hong, Ji-Hyung;Park, Keum-Joo;Sohn, Bo-Kyoon
    • Proceedings of the Korean Society for Agricultural Machinery Conference
    • /
    • 1996.06c
    • /
    • pp.685-691
    • /
    • 1996
  • Recent research in composting greenhouse has focused on some of the fundamental properties during the process such as temperature , carbon dioxide content and odors which change as the composting progresses. The composting greenhouse of cattle manure with rice hulls by a forced aeration method without turning is available for the practical proposition. The control of a predetermined temperature range(45-65$^{\circ}C$) is possible if intermittent aeration is used. The carbon dioxide concentration was maintained in the range from 400 to 2650 ppm by the intermittent aeration. The ammonia emission rose rapidly leading to a temperature increase of composting material up to more than 60$^{\circ}C$ for six days. Ammonia emission declined quickly and could hardly be detected after 10 days of running period.

  • PDF