Search results

The purpose of this paper is to present issues related to the design of a modern lighting system based on LED technology. The developed system provides lighting with a high colour rendering index (up to 98); it also has many innovative functions, which make its implementation bring significant energy savings and increase the comfort of work.

In contrast to typical solutions, the dynamic synthesis of white light from six component colours was used in the presented project. This process is controlled by a microcontroller, and there is a colour temperature sensor in the feedback loop. The communication between smart luminaires and sensor modules is provided by means of a ZigBee wireless network.

The correctness of the proposed methodology has been proved by measurements and laboratory tests.

The process of improving the lighting system is continued and significant changes in the spectrum of used sensors are expected.

The proposed system based on mixing light from six components is an innovative solution that besides undoubted advantages entails a more elaborate electronic circuitry. However, good characteristics of the obtained light, as well as the possibility of compensating for changes in colour temperature of natural light and reducing the impact of aging of LEDs, in the authors’ opinion, make the proposed solution find its place on the market.

The proposed solution is original, both in terms of the light mixing technique and advanced functionality offered by the system.

Distribution research was an important field of research in Germany especially in the 1920s and 50s. After that, the major research interests in the area of marketing and internal trade shifted to other topics. Retailing and wholesaling institutions became more powerful and new technologies supporting physical distribution activities began to attract researchers to deal with distribution problems. Distribution as treated in this synopsis covers the areas of retailing, wholesaling, industrial selling and physical distribution.

The longitudinal impact of media multitasking on the development of executive function has been understudied, as most of the existing studies are cross-sectional. This longitudinal study addresses this research gap and uses multiple measures, i.e. behavioral and self-reported, to explore the impact of media multitasking on the executive function of Chinese adolescents.

This study followed 99 Chinese adolescents (M_age = 14.41, SD = 1.10; 42 boys and 57 girls) for one year using both behavioral (2-back, Stroop Color and Number-letter tasks) and self-reported (questionnaire) measures. The adolescents were categorized as either heavy/high media multitaskers (HMMs; 19 boys and 29 girls) or light/low media multitaskers (LMMs; 23 boys and 28 girls). They were tested at baseline, 6 months later and 12 months later.

The results indicated that the accuracy scores for all cognitive tasks differed with age, but the switch-cost in the shifting task and the self-reported measures of executive function did not. And there were consistent differences between the HMMs and LMMs in the self-reported measures and 2-back accuracy. However, the interaction effect was found only in shifting ability, indicating a decline in the LMMs' self-reported problematic shifting behavior in daily life.

This study used behavioral and self-reported measures to confirm the longitudinal impact of media multitasking on executive function. The impact of media multitasking on executive function is more apparent in daily-life behavior than in cognitive task performance.