• Title/Summary/Keyword: 편차지수

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Analysis of Promising Country for Seawater Desalination Plant Using Delphi Method (Delphi 기법을 이용한 해수담수화 플랜트 유망 국가 분석)

  • Yang, Jeong-Seok;Kim, Il-Hwan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.6
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    • pp.2351-2357
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    • 2013
  • An index was developed for analyzing the promising countries for seawater desalination plant and related data sets were collected and analyzed. Each indicators was standardized by scale readjustment method and Delphi method was used to calculate the weights for indicators from questionnaire survey by experts in seawater desalination plant field. Twenty three indicators were selected and they were classified into three groups, economic, social, and environmental indicator groups. Eleven countries (Saudi Arabia, UAE, Kuwait, Iran, Qatar, China, Singapore, India, Algeria, Turkey, United States) were selected considering present data availability and index for each country was calculated. The results show United States and China took the first (0.537) and second (0.490) place for the most promising country for seawater desalination plant. However it will not be easy to play a significant role in the markets because of present seawater desalination technology level and national policy, etc. Saudi Arabia took the third (0.329) place and other countries which has more than 0.2 index value can be considered as a promising countries for seawater desalination plant. We can establish a strategy to export our seawater desalination technology and plant using the result of this study. The developed index can be applied to other countries, which were not included in this study, when their data is available.

Corruption and Government Expenditure Volatility (부패와 정부지출의 변동성)

  • Lim, Eung-Soon;Hwang, Jin-Young;Song, In-Sang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.1
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    • pp.188-194
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    • 2011
  • Using cross-section of 83 countries, this paper empirically examines the relationship between corruption and government expenditure volatility. A country's corruption is denoted by either control of corruption, compiled by Kaufmann et al. (2008), or corruption perceptions index, provided by Transparency International. In addition, a country's government expenditure volatility is measured by the standard deviation of the change ratio of government expenditure from 1990 to 2005. Regression results suggest that a country's control of corruption and corruption perceptions index (higher ratings signifying more transparency) are significantly and negatively associated with the volatility of government expenditure. However, the estimated coefficients of corruption perceptions index show somewhat reduced statistical significances. The results are robust to the sub-sample of countries excluding European OECD countries. Therefore, the regression results suggest corrupt bureaucrats are able to periodically change economic rules of the game, which results in the possibility of a higher variance in government expenditure.

The Climatological Characteristics of Monthly Precipitation over Han- and Nakdong-river Basins: Part I. Variability of Area Averaged Time Series (한강과 낙동강 유역평균 월강수량의 기후 특성: I. 유역평균 시계열의 변동)

  • Baek, Hee-Jeong;Kwon, Won-Tae
    • Journal of Korea Water Resources Association
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    • v.38 no.2
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    • pp.111-119
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    • 2005
  • The climatological characteristics of the area averaged monthly precipitation over the Han- and Nakdong-river basins were investigated. The data used for this study is monthly precipitation data from 51 meteorological stations for the period of 1954 to 2002. The magnitude of area averaged precipitation in the Han-river basin was about 10% larger than that in the Nakdong-river basin. However, the variability of two monthly precipitation time series exhibited similar characteristics: April precipitation tends to decrease and August precipitation increase significantly, while there was no significant trend for the other months. There were some indications of abrupt change around the 1970's in the periodicity of precipitation and relationship with El Nino index. September precipitation showed negative correlation with NINO3 index but November precipitation, positive correlation with NINO3 index, indicating a possible connection with the global-scale phenomena.

Freezing Depth Analysis Considering Environmental Factors and Physical Properties of Pavement Materials (환경변수 및 도로재료의 특성을 고려한 동결깊이 분석)

  • Kim, Suk Myung;Rhee, Suk Keun;Kim, Suk Nam
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1D
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    • pp.55-61
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    • 2009
  • In this research freezing depth analyses were performed for the recent 9 project field sites using FrostAM which is a freezing analysis model developed recently within the country and a model based on regional environmental factors and physical properties of pavement materials. The environmental factors needed for freezing depth analysis were obtained from the meteorological agency website. And there were laboratory tests and analyses using a measuring device for properties of unsaturated soil for the field site samples across country to obtain hydrographical properties among physical properties. The freezing depths analyzed by FrostAM were deeper in the range of 14cm~44cm than those based on freezing index. It is considered that the freezing depths based on freezing index were overestimated. And there are considerable differences among the freezing depths based on freezing index which were designed by different designers.

Estimating Stem Volume Table of Quercus Acutissima in South Korea using Variable Exponent Equation (변량지수식을 이용한 전국 상수리나무의 입목수간재적표 추정)

  • Ko, Chi-Ung;Kim, Dong-Geun;Kang, Jin-Taek
    • Journal of Korean Society of Forest Science
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    • v.108 no.3
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    • pp.357-363
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    • 2019
  • This study was conducted to develop a stem volume table for Quercus acutissima in Korea by using Kozak's stem taper equation. In total, 2700 tree samples were collected around the country, and growth performance was investigated through compiling data on diameters by stem height and stem analysis. In order to test the stem taper equation's fitness, the fitness index (FI), bias, and mean absolute deviation (MAD) were analyzed. The fitness of the equation was estimated at 97%, bias as 0.017, and MAD turned out to be 1.118, respectively. Furthermore, there was a statistically significant volume difference between the current volume table and the new volume table (p = 0.0008, <0.005). The result indicates that using the new volume table that reflects the actual forest will reduce the loss when assessing wood resources and will improve the accuracy of forest statistics for national and local governments. A stem volume table, the main result of this research, which is utilized in the estimated stem taper equation, will provide growth information for Quercus acutissima, one of the main broadleaf species in Korea, and will function as a management indicator for rational forest management.

Development of Line Density Index for the Quantification of Oceanic Thermal Fronts (해양의 수온전선 정량화를 위한 선밀도 지수 개발)

  • Cho, Hyun-Woo;Kim, Kye-Hyun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.2
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    • pp.227-238
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    • 2006
  • Line density index(LDI) was developed to quantify a densely isothermal line rate as standard index in the ocean environment. Theoretical background on the LDI development process restricting index range 0 to 100 was described. And validation test was done for the LDI application condition that total line length is not greater than 1/10 of unit area. NOAA SST(Sea Surface Temperature) data were used for the experimental application of LDI in the South Sea of Korea. Using GIS, $0.1^{\circ}C$ isothermal lines were linearized as vector data form SST raster data, and unit area were built as polygon data. For the LDI calculation, spatial overlapping(line in polygon) was implemented. To analyze the effect of unit area size for the LDI distribution, two cases of unit area size were designed and descriptive statistics was calculated including performing normality test. The results showed no change of LDI's essential characteristics such as mean and normality except for the range of value, variance and standard deviation. Accordingly, it was found that complex structure of thermal front and even smaller scale of front width than unit area size could influence on the LDI distribution. Also, correlation analysis performed between LDI and difference of temperature(${\Delta}T^{\circ}C$), and horizontal thermal gradient(${\Delta}T^{\circ}C/km$) on the front was obtained from linear regression model. This obtained value was compared with the results from previous researches. Newly developed LDI can be used to compare the thermal front regions changing spatio-temporally in the ocean environment using absolute index value. It is considered to be significant to analyze the relationship between thermal front and marine environment or front and marine organisms in a quantitative approach described in this study.

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Exploiting GOCI-II UV Channel to Observe Absorbing Aerosols (GOCI-II 자외선 채널을 활용한 흡수성 에어로졸 관측)

  • Lee, Seoyoung;Kim, Jhoon;Ahn, Jae-Hyun;Lim, Hyunkwang;Cho, Yeseul
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1697-1707
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    • 2021
  • On 19 February 2020, the 2nd Geostationary Ocean Color Imager (GOCI-II), a maritime sensor of GEO-KOMPSAT-2B, was launched. The GOCI-II instrument expands the scope of aerosol retrieval research with its improved performance compared to the former instrument (GOCI). In particular, the newly included UV band at 380 nm plays a significant role in improving the sensitivity of GOCI-II observations to the absorbing aerosols. In this study, we calculated the aerosol index and detected absorbing aerosols from January to June 2021 using GOCI-II 380 and 412 nm channels. Compared to the TROPOMI aerosol index, the GOCI-II aerosol index showed a positive bias, but the dust pixels still could be clearly distinguished from the cloud and clear pixels. The high GOCI-II aerosol index coincided with ground-based observations indicating dust aerosols were detected. We found that 70.5% of dust and 80% of moderately-absorbing fine aerosols detected from the ground had GOCI-II aerosol indices larger than the 75th percentile through the whole study period.

Stand Volume Estimation of Pinus Koraiensis Using Landsat TM and Forest Inventory (Landsat TM 영상과 현장조사를 이용한 잣나무림 재적 추정)

  • Park, Jin-Woo;Lee, Jung-Soo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.1
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    • pp.80-90
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    • 2014
  • The objective of this research is to estimate the stand volume of Pinus koraiensis, by using the investigated volume and the information of remote sensing(RS), in the research forest of Kangwon National University. The average volume of the research forest per hectare was $307.7m^3/ha$ and standard deviation was $168.4m^3/ha$. Before and after carrying out 3 by 3 majority filtering on TM image, eleven indices were extracted each time. Independent variables needed for linear regression equation were selected using mean pixel values by indices. The number of indices were eleven: six Bands(except for thermal Band), NDVI, Band Ratio(BR1:Band4/Band3, BR2:Band5/Band4, BR3:Band7/Band4), Tasseled Cap-Greeness. As a result, NDVI and TC G were chosen as the most suitable indices for regression before and after filtering, and R-squared was high: 0.736 before filtering, 0.753 after filtering. As a result of error verification for an exact comparison, RMSE before and after filtering was about $69.1m^3/ha$, $67.5m^3/ha$, respectively, and bias was $-12.8m^3/ha$, $9.7m^3/ha$, respectively. Therefore, the regression conducted with filtering was selected as an appropriate model because of low RMSE and bias. The estimated stand volume applying the regression was $160,758m^3$, and the average volume was $314m^3/ha$. This estimation was 1.2 times higher than the actual stand volume of Pinus koraiensis.

Multivariate Process Capability Indices for Skewed Populations with Weighted Standard Deviations (가중표준편차를 이용한 비대칭 모집단에 대한 다변량 공정능력지수)

  • Jang, Young Soon;Bai, Do Sun
    • Journal of Korean Institute of Industrial Engineers
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    • v.29 no.2
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    • pp.114-125
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    • 2003
  • This paper proposes multivariate process capability indices (PCIs) for skewed populations using $T^2$rand modified process region approaches. The proposed methods are based on the multivariate version of a weighted standard deviation method which adjusts the variance-covariance matrix of quality characteristics and approximates the probability density function using several multivariate Journal distributions with the adjusted variance-covariance matrix. Performance of the proposed PCIs is investigated using Monte Carlo simulation, and finite sample properties of the estimators are studied by means of relative bias and mean square error.

Aggregation of Hyperion Spectral Band Using Landsat-7 ETM+ Spectral Characteristic - NDVI Application (Landsat-7 ETM+ 센서 분광특성을 이용한 Hyperion 영상의 밴드 조합 - NDVI 적용을 중심으로)

  • Kim, Dae-Sung;Kim, Yong-Il;Yu, Ki-Yun
    • 한국공간정보시스템학회:학술대회논문집
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    • 2005.05a
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    • pp.339-344
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    • 2005
  • 하이퍼스펙트럴 데이터의 효과적인 분석을 위해 밴드 추출(Feature Extraction)이나 밴드선택(Feature Selection)에 대한 연구가 최근 많이 이루어지고 있다. 본 연구는 상대적으로 많은 밴드를 가지는 하이퍼스펙트럴 영상을 식생지수(Vegetation Index)와 같은 특수한 목적에 적용하기 위해 같은 파장대의 밴드를 조합(Band Aggregation)하여 Landsat ETM+ 영상 밴드와 동일한 영상 생성을 목적으로 한다. 이를 위해 NASA에서 제공하는 밴드별 분광특성 자료를 이용하여 밴드 조합을 위한 가중치 계산식에 적용하였으며, 밴드 선택을 위한 유효 파장대를 추출해 보았다 데이터 간 편차를 줄이기 위해 실제 1분 간격으로 촬영된 동일지역의 Hyperion과 ETM+ 영상을 사용하여 알고리즘에 적용하였고, 그 결과를 영상 간 상관계수와 NDVI 영상을 이용하여 비교 분석하였다.

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