1,884 research outputs found
Empirical research on the evaluation model and method of sustainability of the open source ecosystem
The development of open source brings new thinking and production modes to software engineering and computer science, and establishes a software development method and ecological environment in which groups participate. Regardless of investors, developers, participants, and managers, they are most concerned about whether the Open Source Ecosystem can be sustainable to ensure that the ecosystem they choose will serve users for a long time. Moreover, the most important quality of the software ecosystem is sustainability, and it is also a research area in Symmetry. Therefore, it is significant to assess the sustainability of the Open Source Ecosystem. However, the current measurement of the sustainability of the Open Source Ecosystem lacks universal measurement indicators, as well as a method and a model. Therefore, this paper constructs an Evaluation Indicators System, which consists of three levels: The target level, the guideline level and the evaluation level, and takes openness, stability, activity, and extensibility as measurement indicators. On this basis, a weight calculation method, based on information contribution values and a Sustainability Assessment Model, is proposed. The models and methods are used to analyze the factors affecting the sustainability of Stack Overflow (SO) ecosystem. Through the analysis, we find that every indicator in the SO ecosystem is partaking in different development trends. The development trend of a single indicator does not represent the sustainable development trend of the whole ecosystem. It is necessary to consider all of the indicators to judge that ecosystem’s sustainability. The research on the sustainability of the Open Source Ecosystem is helpful for judging software health, measuring development efficiency and adjusting organizational structure. It also provides a reference for researchers who study the sustainability of software engineering
Enhanced oxidation resistance of active nanostructures via dynamic size effect.
A major challenge limiting the practical applications of nanomaterials is that the activities of nanostructures (NSs) increase with reduced size, often sacrificing their stability in the chemical environment. Under oxidative conditions, NSs with smaller sizes and higher defect densities are commonly expected to oxidize more easily, since high-concentration defects can facilitate oxidation by enhancing the reactivity with O2 and providing a fast channel for oxygen incorporation. Here, using FeO NSs as an example, we show to the contrary, that reducing the size of active NSs can drastically increase their oxidation resistance. A maximum oxidation resistance is found for FeO NSs with dimensions below 3.2 nm. Rather than being determined by the structure or electronic properties of active sites, the enhanced oxidation resistance originates from the size-dependent structural dynamics of FeO NSs in O2. We find this dynamic size effect to govern the chemical properties of active NSs
Restricted phase space thermodynamics of Einstein-power-Yang-Mills AdS black hole
We consider the thermodynamics of the Einstein-Power-Yang-Mills AdS black
holes in the context of the gauge-gravity duality. Under this framework, the
Newton's gravitational constant and the cosmological constant are varied in the
system. We rewrite the thermodynamical first law in a more extended form
containing both the pressure and the central charge of the dual conformal field
theory, i.e., the restricted phase transition formula. A novel phenomena
arises: the dual quantity of pressure is the effective volume, not the
geometric one. That is leading to a new behavior of the Van de Waals-like phase
transition for this system with the fixed central charge: the supercritical
phase transition. From the Ehrenfest's scheme perspective, we check out the
second-order phase transition of the EPYM AdS black hole. Furthermore the
effect of non-linear Yang-Mills parameter on these thermodynamical properties
is also investigated
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