• Title/Summary/Keyword: Point Sampling

Search Result 821, Processing Time 0.026 seconds

Location of Sampling Points in Optical Reflectance Measurements of Chinese Cabbage and Kale Leaves

  • Ngo, Viet-Duc;Kang, Sin-Woo;Ryu, Dong-Ki;Chung, Sun-Ok;Park, Sang-Un;Kim, Sun-Ju;Park, Jong-Tae
    • Journal of Biosystems Engineering
    • /
    • v.40 no.2
    • /
    • pp.115-123
    • /
    • 2015
  • Purpose: A sampling scheme may significantly affect the accuracy of a sensor. This study was conducted to investigate the effects of sampling point locations on optical reflectance measurements of Chinese cabbage and kale plant leaves. Methods: Variability and similarity of multiple measurements for different parts of the leaves were compared. Results: The results indicate that the variability between the average and individual reflectance spectra was smaller for the blade part than for the vein part. Furthermore, the reflectance for the blade part over the upper leaf area was greater and more stable than those for the other parts for both the cabbage and kale leaf samples. Conclusions: The results provide guidelines for optical reflectance measurements of Chinese cabbage and kale plants. The effects of the number of sampling points, the number of leaves, and the relationships between optical reflectance and leaf components remain to be investigated in the future.

Analysis of Organic Molecular Markers in Atmospheric Fine Particulate Matter: Understanding the Impact of "Unknown" Point Sources on Chemical Mass Balance Models

  • Bae, Min-Suk;Schauer, James J.
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.25 no.3
    • /
    • pp.219-236
    • /
    • 2009
  • Particle-phase organic tracers (molecular markers) have been shown to be an effective method to assess and quantify the impact of sources of carbonaceous aerosols. These molecular markers have been used in chemical mass balance (CMB) models to apportion primary sources of organic aerosols in regions where the major organic aerosol source categories have been identified. As in the case of all CMB models, all important sources of the tracer compounds must be included in a Molecular Marker CMB (MM-CMB) model or the MMCMB model can be subject to biases. To this end, the application of the MM-CMB models to locations where reasonably accurate emissions inventory of organic aerosols are not available, should be performed with extreme caution. Of great concern is the potential presence of industrial point sources that emit carbonaceous aerosols and have not been well characterized or inventoried. The current study demonstrates that emissions from industrial point sources in the St. Louis, Missouri area can greatly bias molecular marker CMB models if their emissions are not correctly addressed. At a sampling site in the greater St. Louis Area, carbonaceous aerosols from industrial point sources were found to be important source of carbonaceous aerosols during specific time periods in addition to common urban sources (i.e. mobile sources, wood burning, and road dust). Since source profiles for these industrial sources have not been properly characterized, method to identify time periods when point sources are impacting a sampling site, needs to avoid obtaining biases source apportionment results. The use of real time air pollution measurements, along with molecular marker measurements, as a screening tool to identify when point sources are impacting a receptor site is presented.

Registration of Aerial Image with Lines using RANSAC Algorithm

  • Ahn, Y.;Shin, S.;Schenk, T.;Cho, W.
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.25 no.6_1
    • /
    • pp.529-536
    • /
    • 2007
  • Registration between image and object space is a fundamental step in photogrammetry and computer vision. Along with rapid development of sensors - multi/hyper spectral sensor, laser scanning sensor, radar sensor etc., the needs for registration between different sensors are ever increasing. There are two important considerations on different sensor registration. They are sensor invariant feature extraction and correspondence between them. Since point to point correspondence does not exist in image and laser scanning data, it is necessary to have higher entities for extraction and correspondence. This leads to modify first, existing mathematical and geometrical model which was suitable for point measurement to line measurements, second, matching scheme. In this research, linear feature is selected for sensor invariant features and matching entity. Linear features are incorporated into mathematical equation in the form of extended collinearity equation for registration problem known as photo resection which calculates exterior orientation parameters. The other emphasis is on the scheme of finding matched entities in the aide of RANSAC (RANdom SAmple Consensus) in the absence of correspondences. To relieve computational load which is a common problem in sampling theorem, deterministic sampling technique and selecting 4 line features from 4 sectors are applied.

Assessment of heavy metals in sediments of Shitalakhya River, Bangladesh

  • Al-Razee, A.N.M.;Abser, Md. Nurul;Mottalib, Md. Abdul;Rahman, Md. Sayadur;Cho, Namjun
    • Analytical Science and Technology
    • /
    • v.32 no.5
    • /
    • pp.210-216
    • /
    • 2019
  • Concentrations of Cu, Zn, Fe, Mn, Ni and Cr have been estimated in sediments of the Shitalakhya River at Polash-Ghorashal area, Narsingdi, Bangladesh. 36 samples of sediments from nine sampling point at different locations of Shitalakhya River were collected to determine the concentration of Cu, Zn, Fe, Mn, Ni, Cr and the samples were analyzed by atomic absorption spectrophotometer (AAS). The obtained results were compared with national and international guidelines. The levels of heavy metal concentrations in sediments were found to decrease in the order of Fe > Mn > Zn > Ni > Cu > Cr, respectively. The heavy metal concentration in sediment of Shitalakhya was below the recommended safe limits of heavy metals by WHO, FAO and other international standards. Contamination factor (CF) of Zn and Cu at sampling point Fsd2 show higher (> 1) values due to the influence of external discrete sources like wastage catalysts of ZnO and CuO. Geo-accumulation index values of the study indicate as non-contaminated to moderately contaminate.

Land-use Change Assessment by Permanent Sample Plots in National Forest Inventory (국가산림자원조사 고정표본점 자료를 이용한 토지이용변화 평가)

  • Yim, Jong-Su;Kim, Rae Hyun;Lee, Sun Jeoung;Son, Yeong Mo
    • Journal of Climate Change Research
    • /
    • v.6 no.1
    • /
    • pp.33-40
    • /
    • 2015
  • Forests are to be recognized as an important carbon sink under the UNFCCC that consist of above- and below-biomass, dead organic matter (DOM) such as dead wood and litter, and soil organic matter (SOM). In order to asses for DOM and SOM, however, it is relevant to land-use change matrices over last 20 years for each land-use category. In this study, a land-use change matrix was produced and its uncertainty was assessed using a point sampling technique with permanent sample plots in national forest inventory at Chungbuk province. With point sampling estimated areas at 2012 year for each land-use category were significantly similar to the true areas by given six land-use categories. Relative standard error in terms of uncertainty of land-use change among land-use categories ranged in 4.3~44.4%, excluding the other land. Forest and cropland covered relatively large areas showed lower uncertainty compared to the other land-use categories. This result showed that selected permanent samples in the NFI are able to support for producing land-use change matrix at a national or province level. If the $6^{th}$ NFI data are fully collected, the uncertainty of estimated area should be improved.

A Study on Building Identification from the Three-dimensional Point Cloud by using Monte Carlo Integration Method (몬테카를로 적분을 통한 3차원 점군의 건물 식별기법 연구)

  • YI, Chaeyeon;AN, Seung-Man
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.23 no.4
    • /
    • pp.16-41
    • /
    • 2020
  • Geospatial input setting to represent the reality of spatial distribution or quantitative property within model has become a major interest in earth system simulation. Many studies showed the variation of grid resolution could lead to drastic changes of spatial model results because of insufficient surface property estimations. Hence, in this paper, the authors proposed Monte Carlo Integration (MCI) to apply spatial probability (SP) in a spatial-sampling framework using a three-dimensional point cloud (3DPC) to keep the optimized spatial distribution and area/volume property of buildings in urban area. Three different decision rule based building identification results were compared : SP threshold, cell size, and 3DPC density. Results shows the identified building area property tend to increase according to the spatial sampling grid area enlargement. Hence, areal building property manipulation in the sampling frameworks by using decision rules is strongly recommended to increase reliability of geospatial modeling and analysis results. Proposed method will support the modeling needs to keep quantitative building properties in both finer and coarser grids.

$^1H$ NMR-Based Urinary Metabolic Profiling of Gender and Diurnal Variation in Healthy Korean Subjects (성별 및 채뇨 시각별 $^1H$ NMR 기반 뇨 대사체 프로파일링 연구)

  • Jeong, Jin-Young;Hwang, Geum-Sook;Park, Jong-Chul;Kim, Dong-Hyun;Ha, Mi-Na
    • Environmental Analysis Health and Toxicology
    • /
    • v.25 no.4
    • /
    • pp.295-306
    • /
    • 2010
  • Objectives : This study was undertaken to examine the metabolomic changes due to gender and diurnal variation at sampling time and to identify an appropriate time point for urine sampling in epidemiologic studies using metabolomic profiles. Methods : Urine samples were collected twice a day (morning and afternoon) from 20 healthy Korean adults after fasting for 8 hours. The metabolomic assay was investigated using $^1H$ NMR spectroscopy coupled with the principal components analysis (PCA) and partial least squares discriminant analysis (PLS-DA). The metabolites responsible for differentiation between groups were identified through the loading plot of PLS-DA and quantified using Chenomx NMR Suite with a 600 MHz library. Results : Metabolites responsible for differentiation in gender and sampling time were creatinine, trimethyl anine oxide (TMAO), hippurate, mannitol, citrate and acetoacetate. Dimethylamine showed difference only as a factor of diurnal time. The level of creatinine was higher in men compared to women, and the levels of citrate, TMAO, hippurate, mannitol, and acetoacetate were higher in women compared to men. The levels of creatinine, TMAO, hippurate, dimethylamine and mannitol were higher in the morning rather than the afternoon while those of citrate and acetoacetate were higher in the afternoon rather than the morning. Conclusions : Since urinary metabolomic profiles varied by gender and diurnal cycle, urine sampling should be performed at the same time point for all participants in epidemiologic studies using metabolomic profiles.

A Comparative Study on Obesity Judgment Indices for Body Characteristics Analysis in Korean Obese Women (비만 여성의 체형 특성 분석을 위한 비만 판정 지수의 비교)

  • Yi, Kyong-Hwa
    • The Research Journal of the Costume Culture
    • /
    • v.17 no.6
    • /
    • pp.1141-1154
    • /
    • 2009
  • As a preliminary research of body characteristics analysis of Korean obese woman, this study aims to select optimal obesity judgment tools for reliable sampling of obese subjects from 2,425 female measurement data out of 2004 Size Korea project's raw data. From previous researches related to obesity, 7 obesity judgment tools were chosen. 2007 obesity rate(26.3%) of Korean female adults was refered in selecting optimal obesity judgment criteria in the study. The results are as follows. Firstly, it was verified that BMI was the most suitable in judging and sampling the obese subjects by the percentile analysis. R$\ddot{o}$hrer index was also reliable in grouping the obese subjects from a population. Secondly, it was concluded that the obesity ratios of relative weight 120 and higher group, R$\ddot{o}$hrer index 1.6 and higher group and waist girth 80cm and higher group were the most similar to obesity rate of Korean female adults by 2007 National Health & Nutrition Survey. Thirdly, 30 direct measurements, age, 2 drop values and 6 ratios of 7 groups by the obesity judgment tools showed the significance each other at p<0.001 level. On the other hand, "bust point to bust point" and "waist to hip length" measurements didn't show the significant differences among 7 groups. Conclusively, 4 to 5 satisfactions out of 7 obesity judgment criteria were adequate and sufficient in sampling the obese subjects. If it is needed the strict criteria for judging the obesity, 5 satisfactions and higher group will be the best choice as the obese subjects. However 4 satisfactions and higher group generally, will be adequate for sampling of the obese subjects.

  • PDF

A Nonuniform Sampling Technique and Its Application to Speech Coding (비균등 표본화 기법과 음성 부호화로의 응용)

  • Iem, Byeong-Gwan
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.24 no.1
    • /
    • pp.28-32
    • /
    • 2014
  • For a signal such as speech showing piece-wise linear shape in a very short time period, a nonuniform sampling method based on the inflection point detection (IPD) is proposed to reduce data rate. The method exploits the geometrical characteristics of signal further than the existing local maxima/minima detection (MMD) based sampling method. As results, the reconstructed signal by the interpolation of the IPD based sampled data resembles the original speech more. Computer simulation shows that the proposed IPD based method produces about 9~23 dB improvement over the existing MMD method. To show the usefulness of the IPD technique, it is applied to speech coding, and compared to the continuously variable slope delta modulation (CVSD). The nonuniformly sampled data is binary coded with one bit flag set "1". Noninflection samples are not sent, but only flag bits set 0 are sent. The method shows 0.3 ~ 9 dB SNR and 0.5 ~ 1.3 mean opinion score (MOS) improvements over the CVSD.

Algorithm Development of Human Body Bio-Signal Measurement based on Sampling Time using Doppler Radar Information (도플러 레이더 정보를 이용한 샘플링 시점 기반의 생체 신호 측정 알고리즘 개발)

  • Ryu, Jae-Chun;Lee, Myung-Eui
    • Journal of Advanced Navigation Technology
    • /
    • v.24 no.4
    • /
    • pp.322-327
    • /
    • 2020
  • Recently, a research on obtaining a vital signal using a Doppler radar has been developed and is used as a technology applied to patients in bed. However, in the case of the measured pulse, the respiration signal is generated as noise, resulting in a problem of lowering accuracy. In this paper, we propose a bio-signal measurement algorithm based on the sampling point to improve the accuracy of the signal for measuring the pulse rate when measuring bio-signals using a Doppler radar. The proposed algorithm improves the accuracy of the measured bio-signal by removing noise generated when measuring biosignals based on two sampling points. Compared with actual medical equipment and existing bio-signal algorithms, it is more than 90% similar to medical equipment. In addition, it was confirmed that severe amplitude change was minimized compared to the existing algorithm.