• 제목/요약/키워드: Monthly variations

검색결과 365건 처리시간 0.027초

Distribution Pattern of Zooplankton in the Han River Estuary with respect to Tidal Cycle

  • Youn, Seok-Hyun;Choi, Joong-Ki
    • Ocean Science Journal
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    • 제43권3호
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    • pp.135-146
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    • 2008
  • The monthly distribution of zooplankton communities in Han River estuary was investigated at two stations from July 1998 to June 1999. Monthly mean abundance of total zooplankton varied remarkably, with the range from 20 $indiv.{\cdot}m^{-3}$ to 19,600 $indiv.{\cdot}m^{-3}$. During the study period, dominant species of zooplankton community were dinoflagellate Noctiluca scintillans, copepods Paracalanus indicus, Paracaanus crassirostris, Acartia hongi, Acartia ohtsukai, and meroplanton cirriped larvae. According to tidal states, relative high abundance occurred at high tide without regard to season. The temporal distribution of abundance implied that the reduced salinity probably limited the zooplankton populations and the fluctuations of salinity were an important factor in the variation of abundance. However, the results of salinity tolerance test shows that the variations in salinity do not directly influence the decrease of abundance. This study shows that the relatively high abundance of zooplankton near high tide seems to be related with the expansion of abundant zooplankton inhabiting Incheon coastal waters through tidal currents.

ARIMA 모형을 이용한 진양호 수질의 장래예측 (Forecasting of Water Quality in Chinyang Reservoir Using ARIMA Model)

  • 김종오;유환희;김옥선;박증석
    • 한국습지학회지
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    • 제1권1호
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    • pp.17-28
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    • 1999
  • The purpose of this study was to analysis water quality monitoring data and to estimate future trends using ARIMA model of time series analysis. Water quality data in Chin yang reservoir were used with monthly monitoring interval during past 7 years. The variations of water quality parameters with periodicity and trend could be estimated by multiplicative ARIMA models and the statistical tests showed a good agreement with the observed data. Therefore, the monthly values of water quality parameters could be forecasted using these models.

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기상통계분석에 의한 제주도 풍력자원 데이터베이스 구축 (Establishment of The Wind Resource Database of Jejudo by Meteo-Statistical Analysis)

  • 김현구;장문석;경남호
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 춘계학술대회
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    • pp.296-297
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    • 2006
  • In order to support wind power development, the wind resource database of Jejudo has been established by meteo-statistical analysis on meteorological-mast measurements of KIER. Analysis processes contain correlation of monthly wind speed and power-law exponent among neighboring sites, Measure-Correlated-Predict for long-term correlation, classification of exposure category using satellite image and so forth. It is found that the monthly variations of wind speed and power-law exponent depend on seasonal winds and characterize wind system of Jejudo.

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풋고추 품종별 가격 및 규모 신축성 분석 (An Analysis of the Price and Scale Flexibilities on Different Varieties of Green Pepper)

  • 최세현;노수정;조재환
    • 한국유기농업학회지
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    • 제25권1호
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    • pp.37-52
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    • 2017
  • Three varieties of green pepper - Chungyang pepper, Cucumber-taste pepper and Nokgwang pepper - are competing with one another in consumption due to the overlapping shipment period. The objective of this study is to analyze the influence of monthly variations of shipment quantities on the wholesale market prices. A Linear Approximated Inverse Almost Ideal Demand System (LA/IAIDS) is employed with monthly data set of three different varieties of green pepper consumption. The results show that if there is an excess supply in the market, the rate of the price decline is larger for forcing culture Chungyang pepper than other pepper varieties. On the contrary, change in supply of cucumber-taste pepper and Nokgwang pepper has little effect on the price of Chungyang pepper. The results of this study can be utilized as a basic information for enhancing the farm income and promoting agricultural policies related to the establishment of self-help funds by Chungyang pepper producer groups in Gyeongnam region.

Precipitation Anomalies Around King Sejong Station, Antarctica Associated with E1Niño/Southern Oscillation

  • Kwon, Tae-Yong;Lee, Bang-Yong
    • Ocean and Polar Research
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    • 제24권1호
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    • pp.19-31
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    • 2002
  • Precipitation variability around King Sejong Station related with E1 $Ni\~{n}o$/Southern Oscillation (ENSO) is evaluated using the gauge-based monthly data of its neighboring stations. Though three Ant-arctic Stations of King Sejong (Korea), Frei (Chile), and Artigas (Uruguay) are all closely located within 10 km, their precipitation data show mostly insignificant positive or rather negative correlations among them in the annual, seasonal and monthly precipitation. This result indicates that there are locally large variations in the distribution of precipitation around King Sejong Station. The monthly data of Frei Station for 31 years (1970-2000) are analyzed for examining the ENSO signal in precipitation because of its longer precipitation record compared to other two stations. From the analysis of seasonal precipitation, it is seen that there is a tendency of less precipitation than the average during E1 $Ni\~{n}o$ events. This dryness is more distinct in fall to spring seasons, in which the precipitation decreases down to about 30% of seasonal mean precipitation. However, the precipitation signal related with La $Ni\~{n}a$ events is not significant. From the analysis of monthly precipitation, it is found that there is a strong negative correlation during 1980s and in the late 1990s, and a weak positive correlation in the early 1990s between normalized monthly precipitation at Frei Station and Sea Surface Temperature (SST) anomalies in the $Ni\~{n}o$ 3.4 region. However, this relation may be not applied over the region around King Sejong Station, but at only one station, Frei.

한국 근해 수온의 주기적 변화(II). 삼도와 중지도 해역 표면수온의 년주변화 및 장주기 변화 (Periodic Variations Of Water Temperature In The Seas Around Korea(II). Annual And Long Term Variations Of Surface Water Temperature In The Regions Of Mishima And Okinoshima)

  • 한상복
    • 한국해양학회지
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    • 제5권2호
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    • pp.41-51
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    • 1970
  • 수권(Hydrosphere)은 기권(Atmosphere)과 암권(Lithosphere)의 중간에 있으며 이에 대한 연구는 지구 물리학 분야에서 가장 중요하게 다루어 지는 것 중의 하나이다. 특히 수권의 70% 이상을 차지하고 있는 해양에서의 환경 변화를 조사하는 것은 해황의 변동을 예측하여 수산업이나 기타의 해중 시설물을 설치하는 데 중요한 자료를 제공해 주는 기초 적인 분야이다.

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가리비, Patinopecten yessoensis 소화맹낭의 계절변화 (Seasonal Variations of Digestive Diverticula in the Scallop, Patinopecten yessoensis)

  • 장영진
    • 한국양식학회지
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    • 제4권1호
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    • pp.19-30
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    • 1991
  • 가리비, Patinopecten yesso두냔의 소화맹낭 및 그 상피세포의 지방에 대한 계절변동과 생식소 발달과의 관계를 알아보기 위하여, 일본 북해도의 오호츠크해에 면한 망주만산 방류양식 개체를 1982년 9월부터 1984년 5월까지 월별로 채집하여 조사한 결과는 다음과 같다. 1. 소화맹낭의 지수는 $5{\~}6$월에 가장 높았으며, 12월 및 유빙에 최저치를 나타냈다. 2. 소화맹낭의 조직단면적 1 $mm^{2}$당 세관수는 $9{\~}10$월에 최소치를 나타냈으나, 3월에 최다치를 보였다. 3. 생식소 지수(X)와 소화맹낭의 지방세관 비율(Y)은 $Y=145.6X^{-0793}$의 역지수함수적 관계를 나타냈다. 4. 소화맹낭의 지방은 생식소의 발달과 함께 생식소로 전이되는 계절변동을 보였다.

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Data analysis for improving population management in animal shelters in Seoul

  • Cho, Yoon Ju;Lee, Young-Ah;Hwang, Bo Ram;Kim, Hyung Joon;Han, Jin Soo
    • 대한수의학회지
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    • 제55권2호
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    • pp.125-131
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    • 2015
  • A total of 11,395 animals were impounded in shelters in Seoul in 2013. The Animal Protection Division of the Seoul metropolitan government has annual contracts with local veterinary associations as well as Korean animal rescue and management organizations for providing shelter to animals, and collects monthly statistics from these groups. In 2013, the collected intake and outcome data for 25 districts were reviewed to analyze shelter capacity in terms of housing capacity (monthly daily average intake, required holding capacity, and adoption-driven capacity), staff capacity (staff hours required for daily care), and live release rate. Seasonal variations in the monthly daily average intake were observed, indicating that management of these shelters requires various strategies. This study was performed to analyze and interpret meaningful statistics for improving the efficiency of animal shelters in Seoul. However, inconsistent collection of animal statistics limited data compilation. Creation of a basic animal statistics matrix with reference to well-designed matrices from recognized professional animal shelters is essential. These complied statistical data will help plan for future animal shelter needs in Seoul.

Statistics of Ionospheric Storms Using GPS TEC Measurements Between 2002 and 2014 in Jeju, Korea

  • Chung, Jong-Kyun;Choi, Byung-Kyu
    • Journal of Astronomy and Space Sciences
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    • 제32권4호
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    • pp.335-340
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    • 2015
  • Using the Total Electron Content (TEC) data from the Global Navigation Service System (GNSS) site in Jeju, operated by the Korea Astronomy and Space Science Institute (geographic location: $33.3^{\circ}N$, $126.5^{\circ}E$; geomagnetic location: $23.6^{\circ}N$) for 2002-2014 in Korea, the results of the statistical analysis of positive and negative ionospheric storms are presented for the first time. In this paper, ionospheric storms are defined as turbulences that exceed 50% of the percentage differential Global Positioning System (GPS) TEC ratio (${\Delta}TEC$) with monthly median GPS TEC. During the period of observations, the total number of positive ionospheric storms (${\Delta}TEC$ > 50%) was 170, which is greater than five times the number of negative ionospheric storms (${\Delta}TEC$ < - 50%) of 33. The numbers of ionospheric storms recorded during solar cycles 23 and 24 were 134 and 69, respectively. Both positive and negative ionospheric storms showed yearly variation with solar activity during solar cycle 23, but during solar cycle 24, the occurrence of negative ionospheric storms did not show any particular trend with solar activity. This result indicates that the ionosphere is actively perturbed during solar cycle 23, whereas it is relatively quiet during solar cycle 24. The monthly variations of the ionospheric storms were not very clear although there seems to be stronger occurrence during solstice than during equinox. We also investigated the variations of GPS positioning accuracy caused by ionospheric storms during November 7-10, 2004. During this storm period, the GPS positioning accuracies from a single frequency receiver are 3.26 m and 2.97 m on November 8 and 10, respectively, which is much worse than the quiet conditions on November 7 and 9 with the accuracy of 1.54 m and 1.69 m, respectively.

금강산(金剛山)에서 관측한 미세먼지 농도 - 2007년 9월부터 2008년 5월까지 - (PM10 Mass Concentration at Keumgangsan, North Korea - from September 2007 to May 2008 -)

  • 김정은;심원보;임재철;전영신
    • 대기
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    • 제21권4호
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    • pp.447-454
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    • 2011
  • As dust storms originated in Neimongu Plateau and Manchuria became more frequent in Korea, there was a growing need for Asian Dust (Hwangsa) monitoring stations in North Korea, which is a pathway of Asian Dust to South Korea. The South Korean and the North Korean Governments agreed to build the Automatic Weather System and the PM10 measurement instruments in the Gaeseong Industrial Zone and the Keumgangsan Tourist Region, North Korea in 2007. PM10 mass concentration data in the Keumgangsan Tourist Region could be collected only during the period from September 2007 to May 2008. In this study, daily, monthly and diurnal variations of PM10 mass concentration of the Keumgangsan are analyzed and compared with those of Sokcho and Gwangdeoksan. Three sites show similar variations in daily and monthly means. Correlation coefficients (r) between Sokcho and Keumgangsan, and between Gwangdeoksan and Keumgangsan are 0.89 and 0.67, respectively. But diurnal variation at Keumgangsan has a distinct feature compared to the other sites. Diurnal PM10 variation shows two peaks around 8 AM and 4-5 PM and very low at night. The difference between the daily maximum and minimum is $20{\sim}60{\mu}g\;m^{-3}$ during September to November 2007. Temperature, relative humidity and wind speed from the Keumgangsan AWS data were compared with those from the Changjon station, and showed good correlation each other except wind speed.