Search results

Search:
in the keywords: response time

Sort By:

Limit search:

Simulations of AlGaAs/GaAs heterojunction phototransistors

100%

Ściana B., Panek M., Borczuch A., Tłaczała M.

Open Physics

2011

vol. 9

issue 4

1114-1121

Heterojunction bipolar phototransistors, based on GaAs technology, are widely used in optoelectronic integrated circuits. One of the methods to improve phototransistor performance is applying a delta-doped thin base, which causes both a higher current gain and a better time response. There is a lack of information about this kind of device in the literature. Our work presents the results of computer simulations of AlGaAs/GaAs n-p-n phototransistors, with a bulk-doped and delta-doped base working as two- and threeterminal devices. The characteristics and device parameters obtained clearly show that phototransistors with delta-doped base have higher sensitivity and a better time response compared to the structures with a bulk-doped base. Based on simulation results, we modified the epitaxial phototransistor structure with a double delta-doped base that should improve device performance.

Reaction time and stress tolerance of police officers in specific and non-specific tests in professional self-defence training

86%

Vit M., Houdek M., Sebera M.

Physical Activity Review

2019

issue 7

193-200

The police forces performance is demanding on well-timed and quick reaction. Single reaction time and choice reaction time are crucial when the jeopardy appears. Performing under stress in life-threatening situations needs a good level of stress tolerance. In our study, we used two nonspecific, and two specific (shooting) tests to analyse the reactivity of police officer under different conditions. Material and methods: The research sample consisted of n=18 male Czech police training instructors. The group is unique as these police officers are specialised in the professional self-defence with focus on the coercive means use and shooting skills. Two standardized non-specific tests administrated with the Vienna Test System (VTS) by Schuhfried GmbH were used for data gathering. Single reaction time (SRT) was measured by the Reaction test, stress tolerance and choice reaction time (CRT) was measured by the Determination test. Two practical non-standardized shooting tests were used for the reactivity analysis in the goal oriented environment (shooting range). Results: The single reaction time among police training instructors was M=261.56±33.60 ms, which corresponds to the 66.28 percentile of age norm. Performance in the stress tolerance test also matches the average performance in population (M=45.56 percentile of correct reactions, M=61.67 percentile of incorrect reactions, M=51.44 percentile of skipped signals). According to the Pearson correlation coefficient, there is no correlation between single reaction time in the Reaction test and choice reaction time in the Determination test (r=-0.03). There is no correlation between single reaction time in the nonspecific Reaction test and performance in the specific Shooting test 1 (r=0.06) and Shooting test 2 (r=-0.01). Conclusions: There is no relation between the results in the specific and non-specific reaction tests. Nonspecific tests of single reaction time and choice reaction time are suitable for a general assessment of motor abilities. Specific tasks need specific training and specific evaluation methods.

Refine search results

1 Open Physics

1 Physical Activity Review

1 2019

1 2011

1 Borczuch A.

1 Houdek M.

1 Panek M.

1 Sebera M.

1 Tłaczała M.

1 Vit M.

1 Ściana B.

Search results

Simulations of AlGaAs/GaAs heterojunction phototransistors

Reaction time and stress tolerance of police officers in specific and non-specific tests in professional self-defence training