• Title/Summary/Keyword: HyperSAS

Search Result 4, Processing Time 0.019 seconds

HyperSAS Data for Polar Ocean Environments Observation and Ocean Color Validation (극지 해양환경 관측 및 고위도 해색 검보정을 위한 초분광 HyperSAS 자료구축)

  • Lee, Sungjae;Kim, Hyun-cheol
    • Korean Journal of Remote Sensing
    • /
    • v.34 no.6_2
    • /
    • pp.1203-1213
    • /
    • 2018
  • In Arctic and Antarctic ocean, remote sensing is the most effective observation for environmental changes due to the inaccessibility of the regions. Even though satellite, UAV (Unmanned Aerial Vehical) are well known remote sensing platforms, and research vessel also used for automatic measurement on the regions, varied environment of Polar regions require time series and wide coverage of data. Especially, in high latitude, apply an optical satellite remote sensing is not easy due to low sun altitude. In this paper, we introduce an operation of hyper-spectrometer (HyperSAS/Satlantic inc.) which is mounted on Ice Breaker Research Vessel ARAON of Korea Polar Research Institute since 2010, to acquire an above water reflectance atomatically through every research cruise on Arctic and Antarctic ocean and transit both regions. In addition to, auxiliary data for the remotely acquired data, in situ water sampling were also obtained. The above water reflectance and in situ water sampling data are continuously acquired since 2010 will contribute to improve an Ocean Color algorithm in the high latitude and help to understand ocean reflectances over from high latitude through low latitude. Preliminary result from above water reflectance showed characteristics of Arctic ocean and Antarctic Ocean and used to develop algorithms for estimating various ocean factors such as chlorophyll and suspended sediment.

Prelaunch Study of Validation for the Geostationary Ocean Color Imager (GOCI) (정지궤도 해색탑재체(GOCI) 자료 검정을 위한 사전연구)

  • Ryu, Joo-Hyung;Moon, Jeong-Eon;Son, Young-Baek;Cho, Seong-Ick;Min, Jee-Eun;Yang, Chan-Su;Ahn, Yu-Hwan;Shim, Jae-Seol
    • Korean Journal of Remote Sensing
    • /
    • v.26 no.2
    • /
    • pp.251-262
    • /
    • 2010
  • In order to provide quantitative control of the standard products of Geostationary Ocean Color Imager (GOCI), on-board radiometric correction, atmospheric correction, and bio-optical algorithm are obtained continuously by comprehensive and consistent calibration and validation procedures. The calibration/validation for radiometric, atmospheric, and bio-optical data of GOCI uses temperature, salinity, ocean optics, fluorescence, and turbidity data sets from buoy and platform systems, and periodic oceanic environmental data. For calibration and validation of GOCI, we compared radiometric data between in-situ measurement and HyperSAS data installed in the Ieodo ocean research station, and between HyperSAS and SeaWiFS radiance. HyperSAS data were slightly different in in-situ radiance and irradiance, but they did not have spectral shift in absorption bands. Although all radiance bands measured between HyperSAS and SeaWiFS had an average 25% error, the 11% absolute error was relatively lower when atmospheric correction bands were omitted. This error is related to the SeaWiFS standard atmospheric correction process. We have to consider and improve this error rate for calibration and validation of GOCI. A reference target site around Dokdo Island was used for studying calibration and validation of GOCI. In-situ ocean- and bio-optical data were collected during August and October, 2009. Reflectance spectra around Dokdo Island showed optical characteristic of Case-1 Water. Absorption spectra of chlorophyll, suspended matter, and dissolved organic matter also showed their spectral characteristics. MODIS Aqua-derived chlorophyll-a concentration was well correlated with in-situ fluorometer value, which installed in Dokdo buoy. As we strive to solv the problems of radiometric, atmospheric, and bio-optical correction, it is important to be able to progress and improve the future quality of calibration and validation of GOCI.

Development of Alarm Processing Algorithm for SAS (변전소 자동화를 위한 Alarm Processing 방법 개발)

  • Jin, B.G.;Hyun, S.H.;Lee, S.J.
    • Proceedings of the KIEE Conference
    • /
    • 2006.07a
    • /
    • pp.161-162
    • /
    • 2006
  • There are many alarms in Substation Automation System because of data types and quantities increasing, so it is very difficult for operators to know the actual situations. In order to help operators easily make decision, some unnecessary alarms should be removed or combined as one. In this paper, alarm processing is using the structure of substation system and the relation of measured data and events to make some rules. Conventional alarm processing just gives data, but proposed alarm processing gives the whole information. In a simulation model system, the data such as voltage, current and CB status are collected by HyperSim and saved in DB, then proposed alarm processing has been testified using those data based on real-time simulation.

  • PDF

Association of Hypertension with Cluster of Obesity, Abnormal glucose and Dyslipidemia in Korean Urban Population (한국인의 일부 도시인에서 비만, 이상혈당, 이상지질혈증의 집락과 고혈압의 관련성)

  • Lee, Kang-Sook;Kim, Jeong-Ah;Park, Chung-Yill
    • Journal of Preventive Medicine and Public Health
    • /
    • v.31 no.1 s.60
    • /
    • pp.59-71
    • /
    • 1998
  • To examine the association of hypertension with cluster of obesity, abnormal glucose and dyslipidemia in Korean urban population, we conducted this cross-sectional study among 3027 men and 2127 women age 20-85 years who visited a prevention center between May 1991 and June 1995 for a multiphasic health check at St. Mary's Hospital, Seoul. By the self-administered questionnaire, the informations of educational attainments, monthly income, alcohol consumption, cigarette smoking, and physical excercise level were obtained. Height, weight, and blood pressure were measured by a trained nurse. The fasting blood sugar (FBS), total cholesterol, high density lipoprotein (HDL) cholesterol and triglyceride were tested by enzyme method. Low density lipoprotein (LDL) cholesterol was calculated by 'total cholesterol - HDL cholesterol - triglyceride/5'. For testing the differences of cardiovascular risk factors between hypertension and normotension group, 1-test and $\chi^2$-test were performed. For the age adjusted odds ratios of hypertension in persons with obesity, abnormal glucose, and dyslipidemia compared with normal, logistic regression was performed by using SAS pakageprograme. The results obtained were as follows: 1. Age, weight, body mass index(BMI), blood glucose, total cholesterol, LDL cholesterol, and triglyceride of hypertension group in men and women were significantly higher than normotension group, but height and HDL cholesterol of hypertension group only in women significantly lower than normotension group. The frequency of obesity $(BMI\geq25kg/m^2)$, abnormal glucose $(\geq\;120mg/dl)$, hypercholesterolemia $(\geq\;240mg/dl)$, lower HDL cholesterol (<45 mg/dl in women only), higher LDL cholesterol $(\geq\;160mg/dl)$, and hyper hypertriglyceridemia $(\geq\;250mg/dl)$ in hypertension group of men and women were significantly higher than normotension group. 2. Systolic and diastolic blood pressure were negatively correlated with hight, but positively with age, weight, BMI, total cholesterol, LDL cholesterol, and triglyceride in men and women. BMI was positively correlated with fasting blood sugar, total cholesterol, LDL cholesterol and triglyceride but negatively with HDL cholesterol. 3. The age adjusted odds ratios of hypertension were as follows in men and women : among persons who were obese compared with those nonobese, 2.53 (95% Confidence Intervals [C.I.] 2.08-3.07) and 2.22 (95%C.I. 1.71-2.87): among persons who were abnormal glucose compared with those normoglycemic, 1.43 (95%C.I 1.13-1.82) and 2.01 (95%C.I 1.36-2.94): and among persons who were dyslipidemia (hypercholesterolemia or lower HDL cholesterol or higher LDL cholesterol or hypertriglyceridemia) compared with those normal lipid, 1.59 (95%C.I 1.30-1.95) and 1.51 (95%C.I 1.16-1.96). After combined more than one risk factor, the odds ratios were increased. Among persons with cluster of obesity, abnormal glucose, and dyslipidemia, the odds ratio of hypertension was 2.25 (95%C.I 1.47-3.37) in men and 3.02 (95%C.I 1.71-5.30) in women. In conclusion, it was suggested that hypertension was associated with cluster of obesity, abnormal glucose, dyslipidemia in this Korean urban population.

  • PDF