@article{oai:nipr.repo.nii.ac.jp:00010032,
 author = {Kotwa, Ewelina and Lacorte, Silvia and Duarte, Carlos and Tauler, Roma and Kotwa, Ewelina and Lacorte, Silvia and Duarte, Carlos and Tauler, Roma},
 issue = {3},
 journal = {Polar science, Polar science},
 month = {Sep},
 note = {In this paper we examine 2- and 3-way chemometric methods for analysis of Arctic and Antarctic water samples. Standard CTD (conductivity-temperature-depth) sensor devices were used during two oceanographic expeditions (July 2007 in the Arctic; February 2009 in the Antarctic) covering a total of 174 locations. The output from these devices can be arranged in a 3-way data structure (according to sea water depth, measured variables, and geographical location). We used and compared 2- and 3-way statistical tools including PCA, PARAFAC, PLS, and N-PLS for exploratory analysis, spatial patterns discovery and calibration. Particular importance was given to the correlation and possible prediction of fluorescence from other physical variables. MATLAB's mapping toolbox was used for geo-referencing and visualization of the results. We conclude that: 1) PCA and PARAFAC models were able to describe data in a satisfactory way, but PARAFAC results were easier to interpret; 2) applying a 2-way model to 3-way data raises the risk of flattening the covariance structure of the data and losing information; 3) the distinction between Arctic and Antarctic seas was revealed mostly by PC1, relating to the physico-chemical properties of the water samples; and 4) we confirm the ability to predict fluorescence values from physical measurements when the 3-way data structure is used in N-way PLS regression., 2007年7月に北極航海、2009年2月に南極航海を実施して、CTD（電気伝導度、水温、深度）センサーを用い、計174か所で測定を行った。そしてPCA、PARAFAC、PLS、N-PLS手法などを用いてデータの空間分布、校正値の統計比較を行った。MATLABを用いて場所を同定し、可視化して判ったことは、(1) PCAよりPARAFACによる結果表示の方が、解釈が容易、(2) 3階層データに２階層モデルを適用すると、データの共分散構造が平滑化され、情報が失われる、(3) 北極海と南極海の違いは主として水サンプルの物理―化学的性質に関するPC1成分に現れる、(4) 特に重要なのは、N階PLS回帰モデルにおいて３層のデータ構造を適用すると、測定物理量から蛍光量を推定できる、ことである。},
 pages = {242--254},
 title = {Investigation of Arctic and Antarctic spatial and depth patterns of sea water in CTD profiles using chemometric data analysis},
 volume = {8},
 year = {2014}
}