• 상하수도학회지
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• 제25권4호
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• pp.489-495
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• 2011

Silt Density Index (SDI) has been used as a fouling index for reverse osmosis (RO) processes for decades. In order to decrease RO fouling, feed water should meet SDI standard, which was used to select a proper pretreatment system for RO processes. However, SDI is supposed to be sensitive only to particles larger than 0.45 ${\mu}m$ in terms of diameters while nanoparticles and dissolved organic matter can be potent foulants for RO processes. Our study started from the suspected performance of SDI as a RO fouling index. SDI data from pilot plants located world wide including South Korea were collected and analyzed. Suspended partcle concentration (i.e., turbidity and particle counts), and dissolved organic matter concentration (i.e., dissolved orgnaic carbon (DOC) concentration) data were also collected and compared to SDI values of same water samples. We found that SDI values were not only affected by suspended particle concentration but also by dissolved organic matter concentration. Therefore SDI can be used as a reasonable fouling index for RO feed water because the main foulants for RO processes are suspended particle and dissolved organic matter.

• 한국통신학회논문지
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• 제30권1C호
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• pp.35-43
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• 2005

본 논문에서는 팔레트 기반 이미지(palette-based image) 또는 인덱스 이미지(indexed image)라고 불리는 256색의 이미지에 대한 압축 성능 향상을 위한 새로운 알고리즘을 소개한다. 제안한 방식은 현재 색상이 갖는 인덱스 값을 중심으로 다음에 나오는 색상의 인덱스가 얼마나 발생하는지를 측정하고, 발생 빈도를 정렬하여 순위를 구한 후에, 색상에 대한 인덱스 값을 순위로 표현하여 원래의 인덱스 이미지를 대체한다. 그렇게 변화된 순위 인덱스이미지(ranked index image)의 인덱스 분포에서는 순위가 높은 곳에 같은 인덱스들이 더 많이 존재하기 때문에 데이터 중복성(redundancy)을 높일 수 있어, 압축 효율을 기대할 수 있다. 실험 결과에서는, 기존의 산술부호화 방식, 휘도 성분 기반의 JPEG-LS 방식 그리고 인덱스 기반의 GIF 방식들과 비교할 때, 원 이미지에 대한 압축률이 최대 22.5까지 향상되어 제안한 방식의 압축 성능이 훨씬 뛰어나다는 것을 보여준다.

• Journal of Nutrition and Health
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• 제45권1호
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• pp.80-93
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• 2012

Recent studies have reported that the glycemic index (GI) has an effect on developing the risk for metabolic abnormalities such as diabetes, dyslipidemia, and obesity. As there are no reliable GI values for common Korean foods, only a few studies have been carried out using the dietary GI for Korean adults. The aim of this study was to establish a table of GI values for common Korean foods and evaluate dietary glycemic index (DGI) and dietary glycemic load (DGL) among the Korean adult population. International tables of GI values and other published values were used to tabulate GI values for common Korean foods. Among 653 food items, 149 (22.8%) were adapted from published data, 60 (9.2%) were imputed from similar foods, and 444 (68.0%) were assigned a zero. Data from 7,940 subjects aged 20 years and older in the 2007-2008 Korea National Health and Nutrition Examination Survey were obtained, and DGI and DGL were calculated. The average DGI was 60.0 and the average DGL was 182.5 when the reference food GI value was glucose. After adjusting for potential confounding variables, DGI and DGL increased significantly according to age group (p for trend < 0.001). The food group that contributed most to DGL was grain and its products supplying 85.3% of total DGL, whereas the mean GI value in grain and its products was 72.6. Fruits and potatoes also contributed to DGL (5.8 and 2.9%, respectively), and their GIs were high (67.7 for potatoes and 45.8 for fruits). For individual food items, white rice supplied 66.7% of total GI followed by glutinous rice (2.3%) and steamed white rice cakes (2.0%). In conclusion, a table of GI values for 653 common food items was established in which white rice was the most contributing item to DGL. Our results will be useful to examine the relationships between DGI, DGL, and metabolic abnormalities in the Korean population.

• 복식문화연구
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• 제11권1호
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• pp.153-164
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• 2003

For this study, 148 female adults between the ages of 20 and 60 who satisfied the plus-size judgment criteria took part in this study. Criteria were Rohrer index is higher than 1.5, bust girth larger than 90cm, and RBW(relative body weight) index higher than 110. Using anthropometric measurement values, indirect measurement values, and index values, this study analyzed frequencies, Duncan multiple range, and ANOVA to obtain information on characteristics that determine a representative body shape, by age, 1'3r Plus-sized women. The results are as follows: Physical Characteristics of Pius-Sized Women by Their Age: Women in their 20s md 30s had broader shoulders with smaller waists, with large buttocks and thighs. Among women in their 50s and 60s, body fat level increased significantly in regions such as the chest and abdomen, which made their upper body heavier.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.75-78
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• 2003

This study is to present a method of land cover change detection by the typhoon RUSA (August 1 - September 4, 2002) using Landsat 7 ETM+ images. For the Namdae-cheon watershed in Gangreung, two images of Sept. 29, 2000 and Nov. 22, 2002 were prepared. To identify the damaged areas, firstly, the NDVI (Normalized Difference Vegetation Index) of each image was computed, secondly, the NDVI values were reclassified as two categories that the negative index values including zero are the one and the positive index values are the other, thirdly the reclassified image before typhoon is subtracted from the reclassified image after typhoon to get DNDVI (Differential NDVI). From the DNDVI image, the flooded and damaged areas could be extracted.

• 한국소음진동공학회논문집
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• 제20권9호
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• pp.834-840
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• 2010

The Sound reduction indices(SRIs) of interior door with 13 different size apertures are measured in acoustic chamber. Also, as a theoretical approach, the SRIs are estimated using Gomperts' theory. In this study, the aperture of interior door is focused on the lower part of door leaf which is well known as a main cause to deteriorate the sound insulation performance of door. The results show that the SRI of door strongly depends on the aperture width and the dip in the measured sound reduction index curve by the resonance effect within aperture is observed at high-frequency. On the whole, the values calculated by theory are in good agreement with the measured values including the position of resonance dip. The average difference between the measured and the calculated values is 0.9 dB for 13 doors with different size aperture in terms of the weighted SRI.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2004년도 학술발표회
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• pp.1300-1304
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• 2004

This study is to present a method of flood damaged area detection by the typhoon RUSA (August 31 - September 1, 2002) using Landsat 7 ETM+ and Landsat 5 TM images. Two images of Sept. 29, 2000 and Sept. 11, 2002 (path 115, row 34) were prepared for Gangreung, To identify the damaged areas, firstly, the NDVI (Normalized Difference Vegetation Index) of each image was computed, secondly, the NDVI values were reclassified as two categories that the negative index values including zero are the one and the positive index values are the other, thirdly the reclassified image before typhoon is subtracted from the reclassified image after typhoon to get DNDVI (Differential NDVI). Some part of urban and agricultural were classified into damaged area due to typhoon RUSA in Gangreung, $18.8km^2$ and $17.7km^2$ respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제3권5호
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• pp.527-547
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• 2009

Moving object management is widely used in traffic, logistic and data mining applications in ubiquitous environments. It is required to analyze spatio-temporal data and trajectories for moving object management. In this paper, we proposed a novel index structure for spatio-temporal aggregation of trajectory in a constrained network, named aCN-RB-tree. It manages aggregation values of trajectories using a constraint network-based index and it also supports direction of trajectory. An aCN-RB-tree consists of an aR-tree in its center and an extended B-tree. In this structure, an aR-tree is similar to a Min/Max R-tree, which stores the child nodes' max aggregation value in the parent node. Also, the proposed index structure is based on a constrained network structure such as a FNR-tree, so that it can decrease the dead space of index nodes. Each leaf node of an aR-tree has an extended B-tree which can store timestamp-based aggregation values. As it considers the direction of trajectory, the extended B-tree has a structure with direction. So this kind of aCN-RB-tree index can support efficient search for trajectory and traffic zone. The aCN-RB-tree can find a moving object trajectory in a given time interval efficiently. It can support traffic management systems and mining systems in ubiquitous environments.

• 한국측량학회지
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• 제32권6호
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• pp.607-615
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• 2014

RVI (Radar Vegetation Index) has shown some promise in the vegetation fields, but its relationship with MVI (Multispectral Vegetation Index) is not known in the context of various land covers. Presented herein is a comparative analysis of the MVI values derived from the LANDSAT-8 and RVI values originating from the RADARSAT-2 quad-polarimetric SAR (Synthetic Aperture Radar) data. Among the various multispectral vegetation indices, NDVI (Normalized Difference Vegetation Index) and SAVI (Soil Adjusted Vegetation Index) were used for comparison with RVI. Four land covers (urban, forest, water, and paddy field) were compared, and the patterns were investigated. The experiment results demonstrated that the RVI patterns of the four land covers are very similar to those of NDVI and SAVI. Thus, during bad weather conditions and at night, the RVI data could serve as an alternative to the MVI data in various application fields.

• 한국농공학회지
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• 제37권6호
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• pp.103-111
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• 1995

Drought index calculation based on the principal hydrological parameters, such as rainfall and reservoir storage, can estimate the duration and intensity of drought in irrigation reservoirs. It is difficult to build up a drought criteria since the conditions change variously by the reliability of rainfall. Because of the increasing water demands, it is urgent to prepare a generalized positive countermeasure to overcome drought. Water demands can at calculated but the estimation of drought characteristics, and the effective water management method can be established. The purpose of this study is to obtain a drought index and build up a data-base on the reservoir basins for establishing the fundamental hydrological data-base. This Index can observe the behavior of the WSI(Water Supply Index) and the component indices. The results summarized through this study are as follows. 1. WSI value of zero does not correspond to 100% in average due to the skewness in the probability distributions. 2. WSI is not a linear index; that is, given change in terms of water volume or percentage of average does not result in a proportional change on the WSI scale. 3. WSI is not always between the reservoir and the rainfall index in magnitude. This is only true if the component indices are of opposite sign. If they are of the same sign, the SWSI will often have a mangitude greater than either of the component indices. This is easily understood, because the concurrence of extreme values of the same sign for the two components is rarer than the occurrence of extreme values for either of the two components individually.