Asymmetric Volatility and Risk in Equity Markets

It appears that volatility in equity markets is asymmetric: returns and conditional volatility are negatively correlated. We provide a unified framework to simultaneously investigate asymmetric volatility at the firm and the market level and to examine two potential explanations of the asymmetry: leverage effects and time-varying risk premiums. Our empirical application uses the market portfolio and portfolios with different leverage constructed from Nikkei 225 stocks, extending the empirical evidence on asymmetry to Japanese stocks. Although volatility asymmetry is present and significant at the market and the portfolio levels, its source differs across portfolios. We find that it is important to include leverage ratios in the volatility dynamics but that their economic effects are mostly dwarfed by the volatility feedback mechanism. Volatility feedback is enhanced by a phenomenon that we term covariance asymmetry: conditional covariances with the market increase only significantly following negative market news. We do not find significant asymmetries in conditional betas.

Heavy-quark potential in Gribov-Zwanziger approach around deconfinement phase transition

The interaction potential between a pair of heavy quarks is calculated with resummed perturbation method in Gribov-Zwanziger approach at finite temperature. The resummed loop correction makes the potential complex. While the real part is, as expected, screened and becomes short-ranged in hot medium, the strength of the imaginary part increases with temperature and is comparable with the real part, which is very different from the previous calculation in HTL approach. This means that, both the color screening and Landau damping play important role in the dissociation of heavy flavor hadrons in hot medium.Comment: 6 pages, 7 figure

Effects of Cryogenic Treatment after Annealing of Ti-6Al-4V Alloy Sheet on Its Formability at Room Temperature

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This is an Open Access article made available under the terms of the Creative Commons Attribution licence CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.In this article, the effects of cryogenic treatment after annealing on the formability of Ti-6Al-4V alloy sheet were experimentally studied. The Ti-6Al-4V titanium alloy was treated by cryogenic treatment after annealing (ACT). Tensile tests were carried out using a universal machine at room temperature. The microstructure evolution of Ti-6Al-4V subjected to ACT was also investigated using an optical microscope (OM). Both the shearing performance and drawing formability were analyzed by punch shearing tests and deep drawing tests, respectively. Results showed that after ACT, the tendency of the β phase can be apparently changing into stable β’ and α’ phases. The elastic modulus is lower than that of the untreated material. It was found that both the yield strength and tensile strength are declined slightly, whereas the ductility is increased significantly. The shear strength in punch shearing is decreased at room temperature and cryogenic temperature. The ratio of smooth zone on the section after ACT3 is much larger than the others. The rollover diameters are not obviously greater than those of the untreated. Additionally, the height of the burr shows a decreasing trend after ACT. During deep drawing, drawing depth is deeper than that of the untreated material, the drawing load after ACT is reduced, and the decreasing tendency of the drawing load slows down. It is noted that the micro-cracks occur at the bottom of the sample.Peer reviewe

A LightGBM-Based EEG Analysis Method for Driver Mental States Classification

Fatigue driving can easily lead to road traffic accidents and bring great harm to individuals and families. Recently, electroencephalography- (EEG-) based physiological and brain activities for fatigue detection have been increasingly investigated. However, how to find an effective method or model to timely and efficiently detect the mental states of drivers still remains a challenge. In this paper, we combine common spatial pattern (CSP) and propose a light-weighted classifier, LightFD, which is based on gradient boosting framework for EEG mental states identification. ,e comparable results with traditional classifiers, such as support vector machine (SVM), convolutional neural network (CNN), gated recurrent unit (GRU), and large margin nearest neighbor (LMNN), show that the proposed model could achieve better classification performance, as well as the decision efficiency. Furthermore, we also test and validate that LightFD has better transfer learning performance in EEG classification of driver mental states. In summary, our proposed LightFD classifier has better performance in real-time EEG mental state prediction, and it is expected to have broad application prospects in practical brain-computer interaction (BCI)

Perbedaan Pengaruh Penerapan Metode inquiri dan Eksperimen terhadap Hasil Belajar IPA ditinjau dari Keaktifan Siswa Kelas IV SD di Dabin V Kecamatan Purwodadi Tahun Pelajaran 2012/2013

Penelitian ini bertujuan untuk mengetahui perbedaan pengaruh penggunaan metode inquiry dan metode eksperimen terhadap hasil belajar  ditinjau dari keaktifan belajar siswa kelas IV pada mata pelajaran IPA SD Negeri  Dabin V Kec. Purwodadi Kab. Grobogan.Subjek dalam penelitian ini adalah siswa kelas IV SD Negeri 1 Candisari  tahun ajaran 2012/2013 yang berjumlah 85 siswa, yang terdiri dari 27 siswa SD Negeri I Candisari  dengan perlakuan metode eksperimen, 30 Siswa dari SD Negeri II Candisari dengan menggunakan metode Inquiry sedangkan untuk kelas Uji coba dari SD Negeri I Genuksuran dengan jumlah Siswa 28. Teknik pengumpulan data yang digunakan adalah menggunakan tes.Data penelitian dianalisis dengan menggunakan teknik analisis kuantitatif.Hasil penelitian menunjukan bahwa metode inquiry dan eksperimen berpengaruh terhadap hasil belajar yang di tinjau dari keaktifan belajar siswa kelas IV pada mata pelajaran IPA SD Negeri Dabin V. Hal ini ditunjukan dari hasil perhitungan dengan menggunakan Uji Anava 2X3. Keyword: metode inquiry ,metode eksperimen, mata pelajaran IP

Environmental economic impact assessment in China: Problems and prospects

The use of economic valuation methods to assess environmental impacts of projects and policies has grown considerably in recent years. However, environmental valuation appears to have developed independently of regulations and practice of environmental impact assessment (EIA), despite its potential benefits to the EIA process. Environmental valuation may be useful in judging significance of impacts, determining mitigation level, comparing alternatives and generally enabling a more objective analysis of tradeoffs. In China, laws and regulations require the use of environmental valuation in EIA, but current practice lags far behind. This paper assesses the problems and prospects of introducing environmental valuation into the EIA process in China. We conduct four case studies of environmental economic impact assessment (EEIA), three of which are based on environmental impact statements of construction projects (a power plant, a wastewater treatment plant and a road construction project) and one for a regional pollution problem (wastewater irrigation). The paper demonstrates the potential usefulness of environmental valuation but also discusses several challenges to the introduction and wider use of EEIA, many of which are likely to be of relevance far beyond the Chinese context. The paper closes with suggesting some initial core elements of an EEIA guidelineEnvironmental impact assessment; Environmental valuation; China; Economic analysis

Detecting uber-operons in prokaryotic genomes

We present a study on computational identification of uber-operons in a prokaryotic genome, each of which represents a group of operons that are evolutionarily or functionally associated through operons in other (reference) genomes. Uber-operons represent a rich set of footprints of operon evolution, whose full utilization could lead to new and more powerful tools for elucidation of biological pathways and networks than what operons have provided, and a better understanding of prokaryotic genome structures and evolution. Our prediction algorithm predicts uber-operons through identifying groups of functionally or transcriptionally related operons, whose gene sets are conserved across the target and multiple reference genomes. Using this algorithm, we have predicted uber-operons for each of a group of 91 genomes, using the other 90 genomes as references. In particular, we predicted 158 uber-operons in Escherichia coli K12 covering 1830 genes, and found that many of the uber-operons correspond to parts of known regulons or biological pathways or are involved in highly related biological processes based on their Gene Ontology (GO) assignments. For some of the predicted uber-operons that are not parts of known regulons or pathways, our analyses indicate that their genes are highly likely to work together in the same biological processes, suggesting the possibility of new regulons and pathways. We believe that our uber-operon prediction provides a highly useful capability and a rich information source for elucidation of complex biological processes, such as pathways in microbes. All the prediction results are available at our Uber-Operon Database: , the first of its kind

Study on the oasification process and its effects on soil particle distribution in the south rim of the Tarim Basin, China in recent 30 years

AbstractOasification is an important geography process in arid areas, although little research attention has been paid to the process compared to desertification. In fact, studying oasification not only directly reveals its effects on the environment, but can also uncover causes of desertification through examination of oasification causes and processes. In this study, oases located on the south rim of Tarim Basin in Xinjiang, China, were selected as a regional study area. For assessing changes in oases area over the past 30years, four images taken in September in 1977, 1992, 2000 and 2010 were used. To further investigate the effects of oasification on the environment, the Cele Oasis was specifically selected as a representative study area, and soil particle-size distributions (PSD) were analyzed. The results indicated that the oasification process was unmistakable and should receive more attention in the southern marginal zone of the Tarim Basin. In addition, the results also revealed that oasification can have positive effects on the soil environment. In terms of management implications, it is essential that farmland remain in continuous use after reclamation; otherwise, reclamation will weaken oasification and intensify desertification