Refine
Year of publication
Document Type
Has Fulltext
- no (25)
Is part of the Bibliography
- no (25)
Keywords
- eye tracking (4)
- visual expertise (3)
- code reviews (2)
- expertise (2)
- BEHAVIOR (1)
- BLENDS (1)
- Exhaust gas recirculation (1)
- IGNITION (1)
- INJECTION (1)
- Jatropha oil (1)
Institute
Begutachtungsstatus
- peer-reviewed (11)
esearch was and still is involved in the controversial issue about innate talent or extensive practice as the determinants of excellent performance in a range of domains. This study aims to contribute by presenting an analysis of practice activities in a domain that appears to be particularly suitable—orchestral conducting. Most conductors usually attain expertise in instrument playing prior to commencing conducting studies. Twenty-seven students of German study programs of orchestral conducting (approximately 18.7% of the population) responded to a questionnaire about their practice activities in conducting programs and their instrumental experiences. Descriptive results show the wealth of prestudy experiences conducting students have. A clear influence on practice activities cannot be stated. During study, students rated conducting-specific practice activities as more demanding and devoted more time to them than to general music practice activities. Therefore, conducting-specific practice activities might have been practiced more deliberately than general music practice activities.
Rainer Schliermann, Irmgard Schroll-Decker, Julia Schuder und Hans Gruber unternehmen mit ihrer empirisch-quantitativen Studie den Versuch herauszufinden, welche Auswirkungen studien- und praxisbezogene Interkulturalitäts-Begegnungen auf den Erwerb Interkultureller Sensibilität der Studierenden der Studiengänge Soziale Arbeit haben. Die untersuchten Rahmenbedingungen wurden in personen-, ausbildungs- und berufsbezogene interkulturelle Erfahrungsbildung eingeteilt, wobei unterstellt wurde, dass diese Erfahrungsbildung den Erwerb Interkultureller Sensibilität fördert.
To investigate the combustion and emission behavior of straight vegetable oils (SVO), jatropha oil, soybean oil, and diesel fuel were tested. For this research, a 2.2L common-rail engine with a two-stage turbocharging concept was equipped with a cylinder pressure indication system, an exhaust-gas analyzer, an AVL Micro Soot sensor and a Scanning Mobility Particle Sizer 3936 (SMPS) device to detect the particle-size-distribution (PSD). At a low and mid-load engine-operating point (EOP), the thermodynamic and emissions were investigated under various exhaust gas recirculation (EGR) rates with respect to the PSD. Moreover, the injection behavior of the three test fuels was analyzed separately using an injection rate analyzer. This procedure facilitates the thermodynamic investigations of the engine process and allows the calculation of the hydraulic delay (HD) as well as the ignition delay (ID). The ID of the SVO fuels compared to diesel fuel was found to be lower at all engine-operating modes, while jatropha oil always showed the shortest ID. In the particulate-nitrogen oxide (NOX) trade-off, the SVO fuels showed higher particulate matter (PM) emissions at the low-load EOP, whereas the PM emissions of diesel fuel overtop the SVO fuels at a higher engine load. With increased EGR-rates, a rise in the particle size was observed for all fuels. At the low-load EOP, the SVO fuels showed larger particles for high EGR-rates. This effect also changed by increasing the engine-load to the mid-load EOP, wherein the particle size of the diesel fuel emissions is higher by applying elevated EGR-rates.
An effective way to reduce greenhouse gas emissions (GHGs) is to use rurally produced straight jatropha oil as a substitute for diesel fuel. However, the different physical and chemical properties of straight vegetable oils (SVOs) require a customized setup of the combustion engine, particularly of the injection timing and quantity. Therefore, this study demonstrates the differences in the injection and combustion processes of jatropha oil compared to diesel fuel, particularly in terms of its compatibility with exhaust gas recirculation (EGR).
A 2.2 l common-rail diesel engine with a two-stage turbocharging concept was used for testing. To examine the differences in injection rate shaping of diesel fuel and jatropha oil, the injector was tested with an injection rate analyzer using both the fuels. To investigate the combustion process, the engine was mounted at an engine test bench and equipped with a cylinder pressure indication system. All limited emissions, as well as fuel consumption, were measured.
Various injection strategies, boost and rail pressure levels were tested at different EGR rates in terms of their impact on the combustion process. EGR in particular offers a great potential in the case of jatropha oil combustion due to its oxygen content. In addition, the investigation of injection rate shaping in combination with cylinder pressure analysis allowed a detailed thermodynamic evaluation of the combustion process. Ignition delay (ID) was also analyzed using a new method to calculate the start of combustion (SOC)
This study uses holistic models of image perception to analyze and interpret eye movements during a code review. 23 participants (15 novices and 8 experts) take part in the experiment. The subjects’ task is to review six short code examples in C programming language and identify possible errors. During the experiment, their eye movements are recorded by an SMI 250 REDmobile. Additional data is collected through questionnaires and retrospective interviews. The results implicate that holistic models of image perception provide a suitable theoretical background for the analysis and interpretation of eye movements during code reviews. The assumptions of these models are particularly evident for expert programmers. Their approach can be divided into different phases with characteristic eye movement patterns. It is best described as switching between scans of the code example (global viewing) and the detailed examination of errors (focal viewing).
This study uses holistic models of image perception originating from radiology and psychology to analyze and interpret eye movements during code reviews in the C++ programming language. The study design is based on former experiments, but is supplemented by approaches from expertise research. The study utilizes a sample of 34 subjects whose eye movements are recorded by a Tobii Pro Spectrum 600 Hz. The results show that the holistic models of image perception are suitable for application to source code. In addition, it can be observed that the code reviews are conducted in phases, which are characterized by certain strategies (e.g. scan, error detection, ...). Furthermore, experience-related differences can be detected between experts and novices, which emphasize that experts use elaborate strategies and have a comparatively better ability to collect and process information from source code
Despite being a well-structured domain, software engineering lacks standardized definitions, metrics, and theories for analyzing eye movements in domain-specific tasks. This gap can be addressed by adapting models from other fields, such as radiology and psychology. In particular, the holistic models of image perception provide a suitable framework for software engineering applications. This paper introduces a unified model of visual perception focused on eye movements during code reviews. It is based on prior research, findings from other studies, and cross-domain theories. Empirical studies on C and C++ code reviews confirm a phase-based process, where experts switch between global scanning and focal viewing. In addition, significant differences in the fixation rate, fixation duration, number of saccades, and AOI-specific metrics highlight the role of expertise in visual processing. The proposed model offers a structured framework for eye-tracking analysis in software engineering, defining relevant metrics and supporting future refinements across various software engineering tasks.
Eye tracking technology offers valuable insights into how developers and users interact with software artifacts, tools, and interfaces. However, conducting empirical eye tracking research comes with a number of challenges. To assist researchers and students new to the field, this article provides a concise summary of the background as well as the key considerations. As an additional resource, we present a detailed checklist along with its application. Note that both the outline and the checklist are specifically tailored to, but not limited to, the context of software engineering research.
