Codeshare-Allianzen bei Fluggesellschaften

The paper juxtaposes the challenges that airline codeshare alliances create for analytical information systems on the one hand and their motivation from a marketing perspective on the other. The authors review the state-of-the-art literature on potential marketing benefits and analyze the impact on airline planning systems. In this regard, revenue management systems are of particular interest. Based on a simulation study, the authors infer a severe impact of decentralized codeshare controls as currently widely implemented in the industry on revenue management performance. In the scenarios examined, complementary codesharing reduces alliance-wide revenues by up to 1 %. Losses increase when a carrier experiences high local demand or a high degree of codeshare demand, and disseminate over the whole network. Virtual codeshares also cause losses of 0.3 % to 1.5 % depending on the discount level offered by the marketing carrier and on the demand structure. Finally, the authors formulate a set of managerial implications based on these findings.     

Computer game development as a literacy activity

This study examined computer game development as a pedagogical activity to motivate and engage students in curriculum-related literacy activities. We hypothesized that as a consequence, students would improve their traditional reading and writing skills as well as develop new digital literacy skills. Eighteen classes of grade 4 students were assigned to either an experimental or control group. Both groups studied the same curriculum unit over a 10 week period, however, in addition the experimental group developed computer games related to the unit using a game development shell. An analysis of pre- and post-unit scores on two standardized literacy test batteries revealed that the experimental students performed significantly better on one of the subtests, a measure of logical sentence construction (p = .002). Field notes and teacher interview data indicated that game development helped improve student content retention, ability to compare and contrast information presented, utilize more and different kinds of research materials including digital resources, editing skills, and develop an insight into questioning skills.     

Advancing the Water Footprint into an Instrument to Support Achieving the SDGs – Recommendations from the “Water as a Global Resources” Research Initiative (GRoW)

Water Resources Management - The water footprint has developed into a widely-used concept to examine water use and resulting local impacts caused during agricultural and industrial...     

SDN-based teleprotection and control power systems: A study of available controllers and their suitability

With the popularization of the smart grid paradigm, substation automation technology has gradually been upgraded with additional processing and communication capabilities within control and protection devices. Hence, the research community is pressured to find new, efficient, and reliable communication solutions for such a scenario. That task is complicated by the stringent temporal requirements defined by the International Electrotechnical Commission (IEC) 61850 standard for power system communication comprising teleprotection schemes. Further compounding the issue is the critical nature of the power grid, in which availability is definitely a strong requirement. Software-defined networking (SDN) may provide powerful tools to fulfill those requirements at acceptable costs. As such, this paper surveys and compares several available SDN controllers and their applicability to the teleprotection scenario. It further evaluates controllers in terms of capacity and resilience through experiments in an emulated environment.     

Ensemble Learning for Fetal Health Classification

: Cardiotocography (CTG) represents the fetus’s health inside the womb during labor. However, assessment of its readings can be a highly subjective process depending on the expertise of the obstetrician. Digital signals from fetal monitors acquire parameters (i.e., fetal heart rate, contractions, acceleration). Objective:: This paper aims to classify the CTG readings containing imbalanced healthy, suspected, and pathological fetus readings. Method:: We perform two sets of experiments. Firstly, we employ five classifiers: Random Forest (RF), Adaptive Boosting (AdaBoost), Categorical Boosting (CatBoost), Extreme Gradient Boosting (XGBoost), and Light Gradient Boosting Machine (LGBM) without over-sampling to classify CTG readings into three categories: healthy, suspected, and pathological. Secondly, we employ an ensemble of the above-described classifiers with the over-sampling method. We use a random over-sampling technique to balance CTG records to train the ensemble models. We use 3602 CTG readings to train the ensemble classifiers and 1201 records to evaluate them. The outcomes of these classifiers are then fed into the soft voting classifier to obtain the most accurate results. Results:: Each classifier evaluates accuracy, Precision, Recall, F1-scores, and Area Under the Receiver Operating Curve (AUROC) values. Results reveal that the XGBoost, LGBM, and CatBoost classifiers yielded 99% accuracy. Conclusion:: Using ensemble classifiers over a balanced CTG dataset improves the detection accuracy compared to the previous studies and our first experiment. A soft voting classifier then eliminates the weakness of one individual classifier to yield superior performance of the overall model.     

Empirical evaluation of the effects of experience on code quality and programmer productivity: an exploratory study

Context

There is a widespread belief in both SE and other branches of science that experience helps professionals to improve their performance. However, cases have been reported where experience not only does not have a positive influence but sometimes even degrades the performance of professionals.

Aim

Determine whether years of experience influence programmer performance.

Method

We have analysed 10 quasi-experiments executed both in academia with graduate and postgraduate students and in industry with professionals. The experimental task was to apply ITLD on two experimental problems and then measure external code quality and programmer productivity.

Results

Programming experience gained in industry does not appear to have any effect whatsoever on quality and productivity. Overall programming experience gained in academia does tend to have a positive influence on programmer performance. These two findings may be related to the fact that, as opposed to deliberate practice, routine practice does not appear to lead to improved performance. Experience in the use of productivity tools, such as testing frameworks and IDE also has positive effects.

Conclusion

Years of experience are a poor predictor of programmer performance. Academic background and specialized knowledge of task-related aspects appear to be rather good predictors.

     

Comparison of the performance of latent heat flux products over southern hemisphere forest ecosystems: estimating latent heat flux error structure using in situ measurements and the triple collocation method

ABSTRACT

In this study, we compared different remote-sensing (RS)-based land surface models (LSM) and reanalysis latent heat flux (LE) products over different forest ecosystems. We analysed the performance of three RS products, the MOD16A2, the Breathing Earth System Simulator (BESS) model, and a combined optical-microwave model (COM) in their ability to replicate eddy covariance (EC) flux observations of LE at eight southern hemisphere forest ecosystems and compared their results to simulated LE from the offline LSM (GLDAS/NOAH) and a reanalysis LE dataset (MERRA). To determine spatial uncertainties, we used the triple collocation (TC) method, which does not require a priori knowledge of the true LE value, at selected Australian EC locations and over an area without in situ measurement (the Dry Chaco Forest (DCF), Argentina). The spatial pattern of the TC results was commensurable with uncertainties calculated using EC observations, indicating that the TC method is a robust technique to estimate spatial uncertainties. As global products have been validated with EC measurement from Ozflux stations, we hypothesized and found, using the TC model, that LE products achieve a better performance over areas with EC from networks than over sites without ground-based measurements and may reflect over-calibration of models or a need for a more diverse representation of ecosystems at flux tower networks.