CO2 Storage Capacity Assessment of Aquifers in South Africa

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Convergence of the weak K\"ahler-Ricci Flow on manifolds of general type

We study the K\"ahler-Ricci flow on compact K\"ahler manifolds whose canonical bundle is big. We show that the normalized K\"ahler-Ricci flow has long time existence in the viscosity sense, is continuous in a Zariski open set, and converges to the unique singular K\"ahler-Einstein metric in the canonical class. The key ingredient is a viscosity theory for degenerate complex Monge-Amp\`ere flows in big classes that we develop, extending and refining the approach of Eyssidieux-Guedj-Zeriahi.Comment: Final version, to appear in IMR

Memcapacitive Devices in Logic and Crossbar Applications

Over the last decade, memristive devices have been widely adopted in computing for various conventional and unconventional applications. While the integration density, memory property, and nonlinear characteristics have many benefits, reducing the energy consumption is limited by the resistive nature of the devices. Memcapacitors would address that limitation while still having all the benefits of memristors. Recent work has shown that with adjusted parameters during the fabrication process, a metal-oxide device can indeed exhibit a memcapacitive behavior. We introduce novel memcapacitive logic gates and memcapacitive crossbar classifiers as a proof of concept that such applications can outperform memristor-based architectures. The results illustrate that, compared to memristive logic gates, our memcapacitive gates consume about 7x less power. The memcapacitive crossbar classifier achieves similar classification performance but reduces the power consumption by a factor of about 1,500x for the MNIST dataset and a factor of about 1,000x for the CIFAR-10 dataset compared to a memristive crossbar. Our simulation results demonstrate that memcapacitive devices have great potential for both Boolean logic and analog low-power applications

The China A shares follow random walk but the B shares do not

The China A-Share stocks and the China B-Share stocks are common stocks issued by companies incorporated in China. These two classes of common stocks differ in the nationality of the investors each is restricted to by law. For the most part, the A shares, quoted in the Chinese yuan, or renminbi, are for Chinese nationals while the B shares, quoted in foreign currencies, are for non-Chinese nationals and residents of Macau, Hong Kong and Taiwan. This paper identified eighty-six companies issuing both the A and B shares and tested if these shares weekly returns follow a random walk. Employing the Lo and MacKinlay variance ratio test statistics, it is discovered that five times more B shares rejected the random walk as did the A shares. Moreover, both the Shenzhen and Shanghai B-Share indexes reject the random walk while neither the Shenzhen nor Shanghai A-Share index reject the random walk.

The Taiwan stock market does follow a random walk

Applying the Lo and MacKinlay variance ratio test on the weekly returns from the Taiwan stock market from 1990 to mid 2006, I obtained results strongly indicative of the fact that not only does the Taiwan composite stock index move in a random walk fashion, returns for the individual stocks do so as we. Previous authors employing the same methodology obtained opposite results, namely, that the movements of the Taiwan stock composite index do not follow a random walk.random walk