Characterizing dissolved organic matter fractions using spectral fluorescent signatures and post processing by principal component analysis

2000 ◽  
Vol 366 (1) ◽  
pp. 22-25 ◽  
Author(s):  
T. F. Marhaba ◽  
R. L. Lippincott ◽  
D. Van
Keyword(s):  
Principal Component Analysis ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Principal Component ◽  
Component Analysis ◽  
Post Processing ◽  
Organic Matter Fractions

scholarly journals Characterization of soil chemical properties of strawberry fields using principal component analysis

2013 ◽  
Vol 37 (1) ◽  
pp. 168-176 ◽  
Author(s):  
Gláucia Oliveira Islabão ◽  
Marília Alves Brito Pinto ◽  
Lisiane Priscila Roldão Selau ◽  
Ledemar Carlos Vahl ◽  
Luís Carlos Timm
Keyword(s):  
Principal Component Analysis ◽  
Organic Matter ◽  
Soil Fertility ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Principal Component ◽  
Component Analysis ◽  
Soil Chemical Properties ◽  
Available Phosphorus ◽  
Very High

One of the largest strawberry-producing municipalities of Rio Grande do Sul (RS) is Turuçu, in the South of the State. The strawberry production system adopted by farmers is similar to that used in other regions in Brazil and in the world. The main difference is related to the soil management, which can change the soil chemical properties during the strawberry cycle. This study had the objective of assessing the spatial and temporal distribution of soil fertility parameters using principal component analysis (PCA). Soil sampling was based on topography, dividing the field in three thirds: upper, middle and lower. From each of these thirds, five soil samples were randomly collected in the 0-0.20 m layer, to form a composite sample for each third. Four samples were taken during the strawberry cycle and the following properties were determined: soil organic matter (OM), soil total nitrogen (N), available phosphorus (P) and potassium (K), exchangeable calcium (Ca) and magnesium (Mg), soil pH (pH), cation exchange capacity (CEC) at pH 7.0, soil base (V%) and soil aluminum saturation(m%). No spatial variation was observed for any of the studied soil fertility parameters in the strawberry fields and temporal variation was only detected for available K. Phosphorus and K contents were always high or very high from the beginning of the strawberry cycle, while pH values ranged from very low to very high. Principal component analysis allowed the clustering of all strawberry fields based on variables related to soil acidity and organic matter content.

scholarly journals Post-processing techniques and principal component analysis for regional wind power and solar irradiance forecasting

Solar Energy ◽  
2016 ◽  
Vol 134 ◽  
pp. 327-338 ◽  
Author(s):  
Federica Davò ◽  
Stefano Alessandrini ◽  
Simone Sperati ◽  
Luca Delle Monache ◽  
Davide Airoldi ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Wind Power ◽  
Solar Irradiance ◽  
Principal Component ◽  
Component Analysis ◽  
Post Processing ◽  
Processing Techniques

A German version of the Intermittent Claudication Questionnaire (ICQ): cultural adaptation and validation

VASA ◽  
2012 ◽  
Vol 41 (5) ◽  
pp. 333-342 ◽  
Author(s):  
Kirchberger ◽  
Finger ◽  
Müller-Bühl
Keyword(s):  
Principal Component Analysis ◽  
Intermittent Claudication ◽  
Completion Time ◽  
Short Form ◽  
Principal Component ◽  
Component Analysis ◽  
German Version ◽  
Average Completion Time ◽  
Sf 36 ◽  
Related Quality

Background: The Intermittent Claudication Questionnaire (ICQ) is a short questionnaire for the assessment of health-related quality of life (HRQOL) in patients with intermittent claudication (IC). The objective of this study was to translate the ICQ into German and to investigate the psychometric properties of the German ICQ version in patients with IC. Patients and methods: The original English version was translated using a forward-backward method. The resulting German version was reviewed by the author of the original version and an experienced clinician. Finally, it was tested for clarity with 5 German patients with IC. A sample of 81 patients were administered the German ICQ. The sample consisted of 58.0 % male patients with a median age of 71 years and a median IC duration of 36 months. Test of feasibility included completeness of questionnaires, completion time, and ratings of clarity, length and relevance. Reliability was assessed through a retest in 13 patients at 14 days, and analysis of Cronbach’s alpha for internal consistency. Construct validity was investigated using principal component analysis. Concurrent validity was assessed by correlating the ICQ scores with the Short Form 36 Health Survey (SF-36) as well as clinical measures. Results: The ICQ was completely filled in by 73 subjects (90.1 %) with an average completion time of 6.3 minutes. Cronbach’s alpha coefficient reached 0.75. Intra-class correlation for test-retest reliability was r = 0.88. Principal component analysis resulted in a 3 factor solution. The first factor explained 51.5 of the total variation and all items had loadings of at least 0.65 on it. The ICQ was significantly associated with the SF-36 and treadmill-walking distances whereas no association was found for resting ABPI. Conclusions: The German version of the ICQ demonstrated good feasibility, satisfactory reliability and good validity. Responsiveness should be investigated in further validation studies.

Sign in / Sign up

Export Citation Format

Share Document