Self-organizing maps (SOM) have been recognized as a powerful tool in data exploratoration, especially for the tasks of clustering on high dimensional data. However, clustering on categorical data is still a challenge for SOM. This paper aims to extend standard SOM to handle feature values of categorical type. A batch SOM algorithm (NCSOM) is presented concerning the dissimilarity measure and u...

Polycyclic aromatic hydrocarbons (PAHs), abundant in mixed contaminant sites, often coexist with heavy metals. The fate and remediation of PAHs depend heavily on the sorption and desorption behavior of these contaminants. The sorption behavior can in turn be highly affected by certain soil components and properties, such as soil organic matter (SOM) and the presence of heavy metals. Through rev...

Some reports have outlined many different treatment strategies for superior oblique myokymia (SOM) that attempt to reduce or eliminate patients' symptoms of monocular oscillopsia and/or diplopia. Most treatment strategies have focused solely on oral medications or invasive surgery. The following is a current and critical review of SOM along with its clinical findings/symptoms, demographics, the...

Cortical interneurons are classified into several subtypes that contribute to cortical oscillatory activity. Parvalbumin (PV)-expressing cells, a type of inhibitory interneuron, are involved in the gamma oscillations of local field potentials (LFPs). Under ketamine-xylazine anesthesia or sleep, mammalian cortical circuits exhibit slow oscillations in which the active-up state and silent-down st...

In many terrestrial ecosystems plant productivity is limited by the availability of mineral nitrogen, which is produced by soil microbial transformations of organic N in soil organic matter (SOM-N). Mineral N availability results from two opposing processes, 1) gross mineral N production (gross ammonification/ gross nitrification) and 2) microbial N immobilization. These processes can be influe...

Vad kännetecknar en text av god kvalitet och hur starkt påverkar textens utformning, sammansättning och uppbyggnad ifall en avhandling eller rapport uppfattas som högkvalitativ? Dessa frågor har aktualiserats med anledning av Högskoleverkets utvärderingssystem av utbildningar, som lägger stor vikt vid skriftliga rapporter producerade i samband med examensarbeten. Detta nummer av Lärande i LTH h...

Both the Self-Organizing Map (SOM) and fuzzy ARTMAP neural network are trained based upon the competitive mechanism and use the “winner-take-all” rule. Previous studies developed soft classification algorithms for the SOM. This paper introduces the idea and proposes non-parametric measures for the fuzzy ARTMAP computational neural networks to handle spatial uncertainty in remotely sensed imager...

Yores hensigt vil her va::re at konstruere dele af et direkte afbildende sprog, som vil sa::tte os i stand til at repra::sentere virkelighedens mest generelle strukturer. Vi skal ikke her benytte os af de logiske standard-behandlinger af epistemiske tilstande, der sa::dvanligvis opfatter disse som domme (propositioner). Vi vil i stedet genoptage den ikke mindre a::rva::rdige, men nutildags noge...

This paper modified the mechanism of weight adjusting of the Self-Organizing Mapping network (SOM) for solving the problems of topology preserving and clarifying boundary of clustering graph for the clustering analysis. The modified SOM is named the Multiple Clustering Centers SOM (MCC-SOM). The MCC-SOM changed the competitive learning mechanism of “winner takes all” to allow the more one clust...