The self-organizing map (SOM) has been widely used as a software tool for visualization of high-dimensional data. Important SOM features include information compression while trying to preserve topological and metric relationship of the primary data items. The assumption of topological preservation in SOMs is not true for many data mappings involving dimension reduction. With the automation of ...

Abstract. Random Forest (RF) is a powerful ensemble method for classification and regression tasks. It consists of decision trees set. Although, a single tree is well interpretable for human, the ensemble of trees is a black-box model. The popular technique to look inside the RF model is to visualize a RF proximity matrix obtained on data samples with Multidimensional Scaling (MDS) method. Here...

Self-organizing maps (SOM) have been successfully applied in many fields of research. In this paper, we demonstrate the use of SOM-based method for the analysis of Expandable PolyStyrene (EPS) batch process. To this end, a data set of EPS-batch process was used for training a SOM. Reference vectors of the SOM were then classified by K-means algorithm into six clusters, which represent product t...

Digitala resurser i undervisningen, flexibelt lärande och lärandesituationen för utländska studenter står i fokus i aprilnumret av Lärande i LTH. I den första artikeln presenterar sig Genombrottets gästprofessor Linda Price, som forskar och undervisar om användning av digitala resurser inom högre utbildning. Linda Price har vid LTH ansvar för kursen ”Supporting Learning through Digital Resource...

Studying the influence of climatic and/or site-specific factors on soil organic matter (SOM) along an elevation gradient is important for understanding the response of SOM to global warming. We evaluated the composition of SOM and structure of humic acids along an altitudinal gradient from 600 to 1400 m in moso bamboo (Phyllostachys edulis) plantations in central Taiwan using NMR spectroscopy a...

Somatostatin (Som), one of the most concentrated neuropeptides in the brain, is highly expressed in the olfactory bulb (OB). However, the temporal profile by which OB somatostatin-expressing (Som+) interneurons are produced and the molecular mechanisms controlling this profile are totally unknown. In the present study, we found that all the Som+ interneurons in the mouse external plexiform laye...

We analyzed relations between the content of total organic carbon (TOC) and the content of soil organic matter (SOM) in 47 soil profiles dug out in dry coniferous forests, fresh coniferous forests, and mixed deciduous-coniferous forests. Soils in the analyzed sites are derived from sands. In each soil horizon, bulk density (BD), pH, soil texture, and TOC and SOM were determined. Correlation bet...

In this study, a multistage modular self-organizing map (SOM) model is proposed for parallel web text clustering. In the first stage, the large textual datasets are divided into some small disjoint datasets (i.e., task decomposition). In the second stage, each small data set is input into different unitary SOM models for word clustering map (i.e., modularization learning). In this stage, differ...

This paper is a short presentation of the SOM (Semantic Object Model) approach. SOM was created to fulfill two main objectives. The first objective is the revision of the traditional data modeling techniques in order to integrate them within an object oriented framework, without sacrificing the main object-oriented principles, namely encapsulation, extendibility and reusability. The paper advoc...

Generally, conceptual data models, such as E-R, NIAM, ORM, and UML, are used for modeling relational database schema. Another object database schema design, e.g. Semantic Object Model (SOM), is employed. We use SOM in our research work. The reasons, SOM can capture more meaning of an application environment and provides richer data structuring capabilities. Therefore, it is a powerful approach ...