| 1. |
- Crnkovic, Ivica, et al.
(författare)
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Software Engineering in East and South Europe (SEESE'08)
- 2008
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Ingår i: ICSE'08 PROCEEDINGS OF THE THIRTIETH INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING. - New York, New York, USA : ACM Press. - 9781605580791 ; , s. 1077-1077
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Konferensbidrag (populärvet., debatt m.m.)abstract
- East and South European countries are going through a process of intensive changes and ICT plays an important role in supporting these changes. Most of the East and South European countries have a tradition of high quality education, in particular in natural and traditional technical sciences and thus have a good potential to take the new challenges. Today there is a strong need for advances and excellence in Software Engineering education and research, which are crucial for effective development of software industry in the region.
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| 2. |
- Jiang, Zhiheng, et al.
(författare)
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Use of software-defined radio receivers in two-way satellite time and frequency transfers for UTC computation
- 2018
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Ingår i: Metrologia. - : IOP Publishing. - 0026-1394 .- 1681-7575. ; 55:5, s. 685-698
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Tidskriftsartikel (refereegranskat)abstract
- Two-way satellite time and frequency transfer (TWSTFT) is a primary technique for the generation of coordinated universal time (UTC). About 20 timing laboratories around the world continuously operate TWSTFT using satellite time and ranging equipment (SATRE19) modems for remote time and frequency comparisons in this context. The precision of the SATRE TWSTFT as observed today is limited by an apparent daily variation pattern (diurnal) in the TWSTFT results. The observed peak-to-peak variation have been found as high as 2 ns in some cases. Investigations into the origins of the diurnals have so far provided no complete understanding about the cause of the diurnals. One major contributor to the diurnals, however, could be related to properties of the receive part in the modem. In 2014 and 2015, it was demonstrated that bypassing the receive part and the use of software-defined radio (SDR) receivers in TWSTFT ground stations (SDR TWSTFT) instead could considerably reduce both the diurnals and the measurement noise. In 2016, the International Bureau of Weights and Measures (BIPM) and the Consultative Committee for Time and Frequency (CCTF) working group (WG) on TWSTFT launched a pilot study on the application of SDR receivers in the TWSTFT network for UTC computation. The first results of the pilot study were reported to the CCTF WG on TWSTFT annual meeting in May 2017, demonstrating that SDR TWSTFT shows superior performance compared to that of SATRE TWSTFT for practically all links between participating stations. In particular, for continental TWSTFT links, in which the strongest diurnals appear, the use of SDR TWSTFT results in a significant suppression of the diurnals by a factor of between two and three. For the very long inter-continental links, e.g. the Europe-to-USA links where the diurnals are less pronounced, SDR TWSTFT achieved a smaller but still significant gain of 30%. These findings are supported by an evaluation of some of the links with an alternate technique based on GPS signals (GPS IPPP) as reported in this paper. Stimulated by these results, the WG on TWSTFT prepared a recommendation for the 21st CCTF meeting, which proposed the introduction of SDR TWSTFT in UTC generation. With CCTF approval of the recommendation, a roadmap was developed for the implementation of SDR TWSTFT in UTC generation. In accordance with the roadmap, most of the stations that participated in the pilot study have updated the SDR TWSTFT settings to facilitate the use of SDR TWSTFT data in UTC generation. In addition, the BIPM conducted a final evaluation to validate the long-term stability of SDR TWSTFT links, made test runs using the BIPM standard software for the calculation of UTC, now including SDR TWSTFT data, and started to calculate SDR TWSTFT time links as backup from October 2017. The use of SDR TWSTFT in UTC generation will begin in 2018.
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| 3. |
- Ochodek, Miroslaw, et al.
(författare)
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Mining Task-Specific Lines of Code Counters
- 2023
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Ingår i: IEEE Access. - 2169-3536. ; 11, s. 100218-100233
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Tidskriftsartikel (refereegranskat)abstract
- Context: Lines of code (LOC) is a fundamental software code measure that is widely used as a proxy for software development effort or as a normalization factor in many other software-related measures (e.g., defect density). Unfortunately, the problem is that it is not clear which lines of code should be counted: all of them or some specific ones depending on the project context and task in mind? Objective: To design a generator of task-specific LOC measures and their counters mined directly from data that optimize the correlation between the LOC measures and variables they proxy for (e.g., code-review duration). Method: We use Design Science Research as our research methodology to build and validate a generator of task-specific LOC measures and their counters. The generated LOC counters have a form of binary decision trees inferred from historical data using Genetic Programming. The proposed tool was validated based on three tasks, i.e., mining LOC measures to proxy for code readability, number of assertions in unit tests, and code-review duration. Results: Task-specific LOC measures showed a "strong" to "very strong" negative correlation with code-readability score (Kendall's $\tau $ ranging from -0.83 to -0.76) compared to "weak" to "strong" negative correlation for the best among the standard LOC measures ( $\tau $ ranging from -0.36 to -0.13). For the problem of proxying for the number of assertions in unit tests, correlation coefficients were also higher for task-specific LOC measures by ca. 11% to 21% ( $\tau $ ranged from 0.31 to 0.34). Finally, task-specific LOC measures showed a stronger correlation with code-review duration than the best among the standard LOC measures ( $\tau $ = 0.31, 0.36, and 0.37 compared to 0.11, 0.08, 0.16, respectively). Conclusions: Our study shows that it is possible to mine task-specific LOC counters from historical datasets using Genetic Programming. Task-specific LOC measures obtained that way show stronger correlations with the variables they proxy for than the standard LOC measures.
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