Understanding Lorentz violation with Rashba interaction

Rashba spin orbit interaction is a well studied effect in condensed matter physics and has important applications in spintronics. The Standard Model Extension (SME) includes a CPT-even term with the coefficient H_{\mu \nu} which leads to the Rashba interaction term. From the limit available on the coefficient H_{\mu \nu} in the SME we derive a limit on the Rashba coupling constant for Lorentz violation. In condensed matter physics the Rashba term is understood as resulting from an asymmetry in the confining potential at the interface of two different types of semiconductors. Based on this interpretation we suggest that a possible way of inducing the H_{\mu \nu} term in the SME is with an asymmetry in the potential that confines us to 3 spatial dimensions.Comment: 13 pages, minor corrections. Version to appear in IJMP

Crystal nucleation mechanism in melts of short polymer chains under quiescent conditions and under shear flow

We present a molecular dynamics simulation study of crystal nucleation from undercooled melts of n-alkanes, and we identify the molecular mechanism of homogeneous crystal nucleation under quiescent conditions and under shear flow. We compare results for n-eicosane(C20) and n-pentacontahectane(C150), i.e. one system below the entanglement length and one above. Under quiescent conditions, we observe that entanglement does not have an effect on the nucleation mechanism. For both chain lengths, the chains first align and then straighten locally. Then the local density increases and finally positional ordering sets in. At low shear rates the nucleation mechanism is the same as under quiescent conditions, while at high shear rates the chains align and straighten at the same time. We report on the effects of shear rate and temperature on the nucleation rates and estimate the critical shear rates, beyond which the nucleation rates increase with the shear rate. We show that the viscosity of the system is not affected by the crystalline nuclei.Comment: 9 page

The role of effective communication and trustworthiness in determining guests’ loyalty

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.This study investigates the role of trustworthiness and effective communication in the development of guests’ loyalty within the hotel sector. We propose and test a conceptual model that differentiates between two types of loyalty: attitudinal and behavioral. As hotels can control and manage how they communicate their desired characteristics to guests, we posit effective communication and a hotel’s trustworthiness as the key concepts in building loyalty. This study reports on the findings of a study based on 322 hotel guests. Data were analyzed using structural equation modeling. The results reveal that implementing effective communication methods leads to a trustworthy image, which in turn has a positive impact on attitudinal and behavioral loyalty. This research provides hotel managers with strategic directions for cultivating guest loyalty

Multi-GCN: Graph Convolutional Networks for Multi-View Networks, with Applications to Global Poverty

With the rapid expansion of mobile phone networks in developing countries, large-scale graph machine learning has gained sudden relevance in the study of global poverty. Recent applications range from humanitarian response and poverty estimation to urban planning and epidemic containment. Yet the vast majority of computational tools and algorithms used in these applications do not account for the multi-view nature of social networks: people are related in myriad ways, but most graph learning models treat relations as binary. In this paper, we develop a graph-based convolutional network for learning on multi-view networks. We show that this method outperforms state-of-the-art semi-supervised learning algorithms on three different prediction tasks using mobile phone datasets from three different developing countries. We also show that, while designed specifically for use in poverty research, the algorithm also outperforms existing benchmarks on a broader set of learning tasks on multi-view networks, including node labelling in citation networks

The Structure Performance Hypothesis and The Efficient Structure Performance Hypothesis-Revisited: The Case of Agribusiness Commodity and Food Products Truck Carriers in the South

Two competing hypotheses on market structure and performance of firms are the traditional structure-conduct-performance (SCP) paradigm and the efficiency structure hypothesis. This paper reveals the profits made by firms in the trucking industry were because of greater efficiencies than their competitors and not because of collusive activities.Public Economics,

Guidance and Counseling Based on Sûrat Al-Fãtihah

Among the forms of guidance and counseling development there is the emergence of Islamic variety based models of guidance and counseling. One of them is model of al-Fãtihah-Based Guidance and Counseling (FBGC). The model was developed from the belief that science in the study of the Qur\u27an, especially al-Fãtihah has its own place, both in the study of its name and its content. Because it was developed from sũrat al-Fãtihah, all the elements of the service, starting from the philosophical basis, guidance objective, material, procedures, counselors\u27 competencies and evaluation as well as indicators of the success of the service all are extracted from the contextualization of sũrat al-Fãtihah. This paper was developed from a study of literatures. After doing the library study, the writer concluded that the FBGC can be used as complementary service in the implementation of guidance and counseling at Islamic school to support the embodiment of the golden generation after one hundred years of Indonesian independence in 2045