Indicators for merge conflicts in the wild: survey and empirical study

While the creation of new branches and forks is easy and fast with modern version-control systems, merging is often time-consuming. Especially when dealing with many branches or forks, a prediction of merge costs based on lightweight indicators would be desirable to help developers recognize problematic merging scenarios before potential conflicts become too severe in the evolution of a complex software project. We analyze the predictive power of several indicators, such as the number, size or scattering degree of commits in each branch, derived either from the version-control system or directly from the source code. Based on a survey of 41 developers, we inferred 7 potential indicators to predict the number of merge conflicts. We tested corresponding hypotheses by studying 163 open-source projects, including 21,488 merge scenarios and comprising 49,449,773 lines of code. A notable (negative) result is that none of the 7 indicators suggested by the participants of the developer survey has a predictive power concerning the frequency of merge conflicts. We discuss this and other findings as well as perspectives thereof.     

Computer-drawn trajectories of particles in mutual and external fields — An application of computers in university physics teaching

A software system is described which allows the simulation of a large variety of physics phenomena in the computer and the output of results in graphical form. It is designed for interactive use by a class of students working on display terminals. Great care is taken to design the simulation and the display part of the program as flexible as possible. Several examples of simulation are presented and future extensions of the method are discussed.     

5,6-Dihydro-2,4,6-trimethyl-4H-1,3,5-dithiazine – an aroma-active compound formed in course of the Likens–Nickerson extraction

 5,6-Dihydro-2,4,6-trimethyl-4H-1,3,5-dithiazine (thialdine) is an aroma-active compound that has been isolated from different species of meat. In this study we have investigated the formation of thialdine using the simultaneous distillation–extraction according to Likens–Nickerson for the extraction of aroma compounds. Three isomers of thialdine were identified in the aroma extract of cooked and dried hen meat. It was shown that these compounds are not genuine substances from the sample examined, but that they are artefacts formed during sample preparation. Received: 30 October 1996     

Outlook for the global economy

The end of the 1970s also brought to a close a growth phase of the world economy which had lasted more than 20 years and been interrupted only by relatively mild reverses. Although, after a recession of somewhat longer than 2 years, the preconditions have now improved for a return to the path of economic recovery, at least in most industrial countries, there is no cause for an excessive measure of optimism. Due to their high mountains of debt to other nations, a majority of the large newly emerging industrial countries (the so-called threshold nations) and of the developing countries will be forced to assign first priority to an improvement in their balances of payments over the next few years and will therefore largely fail to act as additional customers for foreign goods. In many industrial countries—again as a result of voluminous indebted-ness—narrow limits have been placed on an expansive economic policy course. Besides, the markets served by these nations exhibit a high degree of saturation. In such an environment, the best growth prospects are held by those industries which succeed in creating new requirements and demands on their traditional markets. This is one of the principal reasons why innovation will play an even more important part in the future than it has already played in the past. It can be fairly estimated that the consumer goods industries and the service sector will develop more favorably within the span of the next 12–18 months than the capital goods industries. From a geographic viewpoint it can be assumed on the basis of the existing evidence that during this period economic performance will be stronger in the USA and Japan than in Western Europe. Prospects for an economic comeback in Europe are best in Great Britain, the Federal Republic of Germany and in Italy.