Stress is a universal element at work and all human beings have to face stress in all walks of life. The consequences of stress are a deviation from the existing physical and psychological condition of human life. The aim of this paper is to identify the cause of work stress among tile factory workers in Kannur district in Kerala. The research design undertaken for the study was descriptive res...

We present here an elementary construction of an aperiodic tile set. Although there already exist dozens of examples of aperiodic tile sets we believe this construction introduces an approach that is different enough to be interesting and that the whole construction and the proof of aperiodicity are hopefully simpler than most existing techniques. Aperiodic tile sets have been widely studied si...

Molecular self-assembly appears to be a promising route to bottom-up fabrication of complex objects. Two major obstacles are how to create structures with more interesting organization than periodic or finite arrays, and how to reduce the fraction of side products and erroneous assemblies. Algorithmic self-assembly provides a theoretical model for investigating these questions: the growth of ar...

We know that tilesets that can tile the plane always admit a quasiperiodic tiling [4, 8], yet they hold many uncomputable properties [3, 11, 21, 25]. The quasi-periodicity function is one way to measure the regularity of a quasiperiodic tiling. We prove that the tilings by a tileset that admits only quasiperiodic tilings have a recursively (and uniformly) bounded quasi-periodicity function. Thi...

While algorithmic DNA self-assembly is, in theory, capable of forming complex patterns, its experimental demonstration has been limited by significant assembly errors. In this paper we describe a novel protection/deprotection strategy to strictly enforce the direction of tiling assembly growth to ensure the robustness of the assembly process. Tiles are initially inactive, meaning that each tile...

Article history: Received 28 January 2014 Accepted 6 June 2014 Available online 23 June 2014 Communicated by D.-Z. Du