The aim of this study was to develop athletics health guidance (AHG) aimed at supporting coaches and parents involved in organized child athletics by providing practical advice and tools for the management of the most common health problems experienced in athletics by the 12‐ to 15‐year olds. The study used participatory action research (PAR) and an established health service guideline development procedure modified to fit AHG development in child athletics. A sequential process consisting of four steps with associated subgoals was employed. The collected data were structured according to the AHG development steps and analyzed using qualitative methods. The most common health concern identified was injuries related to growth and overuse. No randomized controlled studies investigating injury prevention programs or any existing concepts/guidelines in child athletics were found that could be used in the development of the AHG. A requirements document was instead defined in a nominal group process and used for the AHG development. The areas included in the final AHG were as follows: training youth athletes, growth and puberty, recovery, injury prevention, injuries and illnesses, mental illness, safe sport, and anti‐doping. The evidence regarding health issues in child athletics is limited, indicating that actions to support good health in the sport are currently based essentially on best practice. The long‐term aim of the AHG and associated website is to systematically create and introduce conditions that can bridge the "know‐do gap" and provide coaches and parents with easy‐to‐access and up‐to‐date knowledge in the field of child athlete health in athletics.

Purpose -The purpose of this paper is to design a tool for IIR digital filters obtained from analog prototypes, which preserves simultaneously the amplitude and the group delay response. Design/methodology/approach -A new s-to-z transform is developed based on a second order formula used for numerical integration of differential equations. Stability of the newly obtained transfer functions in the z-domain is proved to be preserved. Distortions introduced by the new transform into the original amplitude and group delay responses are studied. Findings -The new formula, when implemented to all-pole prototypes, exhibits lower selectivity than the original while reducing the pass-band group delay distortions. In the same time its structure is importantly simpler than the functions obtained by the well-known bilinear transform. When implemented to a prototype having "all kinds" of transmission zeros the resulting filter has almost ideally the same characteristic as the prototype.Research limitations/implications -The new transform may be used exclusively to synthesize even order filters. The new function is twice the order of the analog prototype. This kind of transformations are used to design IIR digital filters only. Low-pass transfer functions were studied being prototypes for all other cases. Originality/value -This is a new result never mentioned in the literature. Its effectiveness is confined to a niche problem when simultaneous sharp selectivity and low group delay distortions are sought.

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Concerning the fact that the design of contemporary integrated circuits (IC) is practically impossible without using sophisticated Electronic Design Automation (EDA) software, this paper gives some interesting thoughts and considerations about that issue. As technology processes advances on year basis consequently EDA industry is forced to follow this trend as well. This, on the other hand, requires IC designer to frequently and efficiently accommodate to new working environments. Authors of this paper suggest a method for high level circuit analysis that is based on using common (open source or low cost) circuit simulators but precise and fast enough to meet requirements imposed by demanding mixed-signal blocks. The paper demonstrates the proposed EDA procedure on an example of second order ?? modulator design. It illustrates considerable simulation time saving which is more than welcome in a world of analogue and mixed-signal design. [Projekat Ministarstva nauke Republike Srbije, br. TR32004: Advanced technologies for measurement, control, and communication on the electric grid]

This paper presents transistor level design of operational transconductance amplifier in CMOS technology. Custom designed, circuit is to be built-in into the mixed-signal, switched capacitor circuit. Amplifier targets relatively high slewrate and moderate open loop gain with megahertz order gainbandwidth. Adopted architecture is discussed appreciating application in switched capacitor circuits. Circuit behavior is examined through set of simulations. Obtained results confirmed desired behavior. Target technology process is TSMC 350nm.