• 제목/요약/키워드: year-to-year variation

검색결과 1,206건 처리시간 0.034초

서울지역 사무소 건물의 환경부하에 관한 연구 (A study on the environmental load of office buildings in Seoul)

  • 이상형;이윤규;양관섭;안태경;이승언;박효순
    • 설비공학논문집
    • /
    • 제11권2호
    • /
    • pp.244-249
    • /
    • 1999
  • This study is to examine the emission rate of $CO_2$gas as the environmental load in office buildings. After the investigation of monthly consumption of each energy source(electricity and natural gas), it is analyzed that the $CO_2$emission rate of 34 office buildings surveyed is 22.4kg-$c/m^2$.year, which consists of 17.5kg-$c/m^2$.year by consuming electricity, and 4.9kg-$c/m^2$.year by consuming natural gas. And the $CO_2$emission rate of each load in those buildings consists of 68% emitted by general electricity, 16% by cooling load and 16% by heating load. It is also proposed that the $CO_2$emission rate of cooling and heating load is profoundly pertinent to the variation of outdoor temperature.

  • PDF

ISM Code 도입에 따른 국내 해양사고 및 보험율 변화에 관한 연구 (A Study on the Change of Domestic Marine Accidents and Insurance rates According to Enforcement of ISM Code)

  • 양형선;노창균
    • 해양환경안전학회:학술대회논문집
    • /
    • 해양환경안전학회 2006년도 추계학술발표회
    • /
    • pp.47-51
    • /
    • 2006
  • 선박에서 발생하는 각종 사고의 처리와 손해배상은 선박보험료와 P&I 보험료에 영향을 마치게 되므로, 해양사고와 선박보험료의 증감은 선박의 ISM code 도입의 효과를 측정하는 직접적인 평가척도가 될 수 있다. 따라서 본 연구에서는 ISM Code 국내도입 1년 전에서 부터 도입 후 8년 동안에 변화하는 해양사고 및 선박보험율의 분석을 통해 ISM 시행에 따른 성과를 파악하였다. 분석결과 해양사고는 ISM 이행 1년 전에 비해 ISM 이행 8년차에는 약 14.4% 가 감소하였고 보험율도 감소하는 경향을 나타내었다.

  • PDF

Managing Within-Field Spatial Yield Variation of Rice by Site-Specific Prescription of Panicle Nitrogen Fertilizer

  • Ahn Nguyen Tuan;Shin Jin Chul;Lee Byun-Woo
    • 한국작물학회지
    • /
    • 제50권4호
    • /
    • pp.238-246
    • /
    • 2005
  • Rice yield and protein content have been shown to be highly variable across paddy fields. In order to characterize this spatial variability of rice within a field, two-year experiments were conducted in 2002 and 2003 in a large-scale rice field of $6,600m^2$ In year 2004, an experiment was conducted to know if variable rate treatment (VRT) of N fertilizer, that was prescribed for site-specific management at panicle initiation stage, could reduce spatial variation in yield and protein content of rice while increasing yield compared to conventional uniform N topdressing (UN, 33kg N/ha at PIS) method. VRT nitrogen prescription for each grid was calculated based on the nitrogen (N) uptake (from panicle initiation to harvest) required for target rice protein content of $6.8\%$, natural soil N supply, and recovery of top-dressed N fertilizer. The required N uptake for target rice protein content was calculated from the equations to predict rice yield and protein content from plant growth parameters at panicle initiation stage (PIS) and N uptake from PIS to harvest. This model· equations were developed from the data obtained from the previous two-year experiments. The plant growth parameters for the calculation of the required N were predicted non-destructively by canopy reflectance measurement. Soil N supply for each grid was obtained from the experiment of year 2003, and N recovery was assumed to be $60\%$ according to the previous reports. The prescribed VRT N ranged from 0 to 110kg N/ha with an average of 57kg/ha that was higher than 33 kg/ha of UN. The results showed that VRT application successfully worked not only to reduce spatial variability of rice yield and protein content but also to increase rough rice yield by 960kg/ha. The coefficient of variation (CV) for rice yield and protein content was reduced significantly to $8.1\%$ and $7.1\%$ in VRT from $14.6\%$ and $13.0\%$ in UN, respectively. And also the average protein content of milled rice in VRT showed very similar value of target protein content of $6.8\%$. In conclusion the procedure used in this paper was believed to be reliable and promising method for reducing within-field spatial variability of rice yield and protein content. However, inexpensive, reliable, and fast estimation methods of natural N supply and plant growth and nutrition status should be prepared before this method could be practically used for site-specific crop management in large-scale rice field.

TANK모델에 의한 낙동강 유입오염 부하량의 계절변동 예측 (Seasonal Variation Prediction of Inflow Pollutant Loads of Nakdong river by using Tank Model)

  • 김종렬;이인철
    • 한국해양공학회:학술대회논문집
    • /
    • 한국해양공학회 2004년도 학술대회지
    • /
    • pp.210-215
    • /
    • 2004
  • The Purpose of this study are to develop the simulation(Tank model, Rainfall-runoff model) for the estimation of wily river discharge and for evaluation of wily pollutant loads from the watersheds of the objected basin area. As apply this constructed Tank model to Nakdong river region, we evaluated the wily river discharge of Nakdong river from use-land conditions, precipitation and evaporation data of 3 years(from 1998 to 2000) and investigate the seasonal fluctuation of SS, COD, TN, TP inflowing into Nakdong river. The result shows that summer has high pollutant level than winter in seasonal characteristic and the down stream has high pollutant level than the upper stream. The annual average of SS, COD, TN, TP flawing in Nakdong river(Samranjin) was estimated each 691ton-COD/year, 1854.2ton-SS/year, 382.8ton-TN/year and 13.0ton- TP/year.

  • PDF

측정-상관-예측법을 이용한 장기간 풍속 및 설비이용률의 예측 (Prediction of long-term wind speed and capacity factor using Measure-Correlate-Predict method)

  • 고경남;허종철
    • 한국태양에너지학회 논문집
    • /
    • 제32권6호
    • /
    • pp.37-43
    • /
    • 2012
  • Long-term variations in wind speed and capacity factor(CF) on Seongsan wind farm of Jeju Island, South Korea were derived statistically. The selected areas for this study were Subji, having a year wind data at 30m above ground level, Sinsan, having 30-year wind data at 10m above ground level and Seongsan wind farm, where long-term CF was predicted. The Measure-Correlate-Predict module of WindPRO was used to predict long-tem wind characteristics at Seongsan wind farm. Eachyear's CF was derived from the estimated 30-year time series wind data by running WAsP module. As a result, for the 30-year CFs, Seongsan wind farm was estimated to have 8.3% for the coefficien to fvariation, CV, and-16.5% ~ 13.2% for the range of variation, RV. It was predicted that the annual CF at Seongsan wind farm varied within about ${\pm}4%$.

대기중 입자상물질에 있어서 이온성분의 입도별 계절변동 (Seasonal variation in size distributions for ionic components in the atmospheric aerosol)

  • 김희강;조기철;이주희;최민규;마창진;강충민;여현구
    • 한국환경보건학회지
    • /
    • 제22권4호
    • /
    • pp.55-61
    • /
    • 1996
  • Measurements of the seasonal variations of concentration and size distribution of TSP, $SO_4^{2-}, NO_3^-, Cl^-, NH_4^+, Na^+, K^+, Ca^{2+}$ and $Mg^{2+}$ were made by Andersen air sampler from May 1995 to April 1996 in Seoul. The size distribution of these ions was divided into four patterns. 1) Distribution was concentrated on fine particles over a year such as $NO_3^-$ component, 2) Distribution was predominated in coarse particles fraction over a year such as $Mg^{2+}$ and $Ca^{2+}$ components, 3) Distribution was differerent from various seasons such as $NH_4^+, SO_4^{2-}, Cl^-$ and $K^+$ components, 4) Distribution was bi-modal such as $Na^+$.

  • PDF

연도별 기상데이터를 활용한 건물의 냉.난방부하 특성 비교 (Comparative Studies on Heating and Cooling Loads' of a Building Varied by Annual Weather Data)

  • 이지훈;황광일
    • 한국항해항만학회지
    • /
    • 제35권3호
    • /
    • pp.265-270
    • /
    • 2011
  • 본 연구는 건물에너지 효율 향상을 위한 목적으로 기상데이터 변화에 따른 건물 냉 난방부하량을 예측하고 결과를 비교 분석한 것으로, 연구 성과는 다음과 같다. 1)기상청에서 입수데이터를 평가툴인 ESP-r에 활용할 수 있도록 항목별 기상데이터를 개발하였다. 표준기상 데이터의 외기온도, 습도, 풍속은 대부분의 경우 기상청데이터 보다 크거나 높았다. 수평면전일사량은 기상청데이터가 높았고, 직달일사량은 겨울철에는 표준기상데이터가, 여름철에는 기상청데이터가 많은 것으로 나타났다. 2)대학교 캠퍼스 내에 신축된 후생복지관을 대상으로 한 시뮬레이션 결과, 최대난방부하의 경우 표준년도, 2006년, 2009년이 비슷한 반면 2007년은 표준년도 대비 81%, 2008년은 96% 수준이었고, 연간난방부하는 2006년, 2008년의 순으로 난방수요가 많았다. 한편, 냉방부하의 경우에는, 상대적으로 최대냉방부하가 큰 2007년, 2009년의 연간 냉방부하보다 최대냉방부하가 가장 적은 2008년의 연간냉방부하가 더 큰 결과를 보였다. 3)냉 난방기기의 상당시간가동률을 평가한 결과, 표준년도의 최대부하대비 상당시간가동률은 2006~2009년이 표준년도에 비해 대부분 가동률이 낮았다.

진해만에 있어서의 COD의 시공간적인 특성 및 결정인자 (The Determining factors and Temporal and Spatial Characteristics of Chemical Oxygen Demand in Jinhae Bay)

  • 김종구;조은일
    • 한국환경과학회지
    • /
    • 제8권2호
    • /
    • pp.189-195
    • /
    • 1999
  • Determining factors and temporal & spatial characteristics of COD(Chemical Oxygen Demand) at the sea surface in Jinhae bay have been examined by using seasonal data, taken at twenty six stations over the whole bay during 1989~1994 by NERDA. The data have been analyzed in terms of long term means, anomalously large values. Jinhae bay is divided into three regions based on the time mean : mouth of Jinhae bay, inner sea of Masan bay, western sea of Jinhae bay called region 1,2 and 3, respectively. The horizontal distribution of the long term mean of COD at each station is similar to those of nitrogen and phosphorus. Characteristics of whole mean variation in the year shows high range of variation in region 2. It was appear to decreases every year in whole trend. Factors determining seasonal variation in whole COD mean are relative to salinity and nutrient, affected by precipitation in summer. Spatial variation shows high range of fluctuation in region 2 compare to other region. Factors determining of spatial variation of COD was appear to nutrient, affected by pollutant load of land area and bottom sediment. The long term mean of COD at each station is closely related with thats of nutrients. The correlation coefficient between COD and nitrogen, phosphate phosphorus was found to be high as 0.75, 0.78, respectively. Anomalously large COD was observed 14 times at 6 stations. These stations are located in inner sea of Masan bay(Region 2) and Songjeong bay(Region 1). The seasonal frequency of the observed anomalous COD is large in April, and other seasons are much the same.

  • PDF

표고별 파종시기가 서로다른 두과 - 화본과 혼파초지에서 두과목초의 생육 및 건물수량에 미치는 영향 (Effect of Sowing Season on the Growth and Dry Matter Yield Legumes in Different Legume-Grass Mixtures according to Altitude)

  • 정의수;김현섭
    • 한국초지조사료학회지
    • /
    • 제12권3호
    • /
    • pp.153-160
    • /
    • 1992
  • 본 시험은 고령지 두과목초의 적응성을 구명하기 위하여 표고가 다른 3개지역(600,800,1000m a.s.l)에서 주구를 파종시기(추파.추파), 세구를 혼파조명(알팔파-화본과, 레드크로바-화본과, 화이트크로바-화본과)으로 두고 분할구 배치 3반복으로 수행하였다. 1.600m에서 두과목초의 적응성을 보면 알팔파, 레드클러버 및 화이트클로버 공히 추파를 했을 때 연차간 악화없이 약 30%를 유지하여 적응성이 매우 양호하였다.2. 800m에서는 화치트클로버를 춘파하므로써 연차간에 심한 감소없이 최종 예취시 약 14.0%를 점유하고 있었으며 또한 10a당 건물수량이 가장 많았다. 3. 1000m에서도 800m와 비슷한 경향으로 화이트클로버를 춘파했을 경우 어느정도 적응이 가능하였다. 4. 표고별 두과목초의 비솔 및 수량이 표고가 증가 할수록 현저하게 감소하였으며 알팔파는 800m 이상에서는 생육이 거의 불가능하였다.

  • PDF