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In this paper, we use quarterly stock price index data to test the weak form of the efficient market hypothesis for 13 art market indices. The fact that hypotheses can be efficiently tested by performing unit root tests is well known. The conventional unit root test results show that most art indices have unit roots, which means that these art markets are efficient. However, the results of the non-linear quantile unit root tests we conduct over a range of quantiles lead us to reject the null of the unit root test for several art markets. To acquire more information, we perform the test over sub-quantile intervals, finding asymmetric market efficiency between the low and high quantile intervals: we cannot reject the unit root null in upper quantile intervals for most art price indices. [ABSTRACT FROM AUTHOR]

Purpose: A daily quality assurance (QA) check in proton therapy is ensuring that the range of each proton beam energy in water is accurate to 1 mm. This is important for ensuring that the tumor is adequately irradiated while minimizing damage to surrounding healthy tissue. It is also important to verify the total charge collected against the beam model. This work proposes a time-efficient method for verifying the range and total charge of proton beams at different energies using a multilayer Faraday collector (MLFC). Methods: We used an MLFC-128-250 MeV comprising 128 layers of thin copper foils separated by thin insulating KaptonTM layers. Protons passing through the collector induce a charge on the metallic foils, which is integrated and measured by a multichannel electrometer. The charge deposition on the foils provides information about the beam range. Results: Our results show that the proton beam range obtained using MLFC correlates closely with the range obtained from commissioning water tank measurements for all proton energies. Upon applying a range calibration factor, the maximum deviation is 0.4 g/cm2. The MLFC range showed no dependence on the number of monitor units and the source-to-surface distance. Range measurements collected over multiple weeks exhibited stability. The total charge collected agrees closely with the theoretical charge from the treatment planning system beam model for low- and mid-range energies. Conclusions: We have calibrated and commissioned the use of the MLFC to easily verify range and total charge of proton beams. This tool will improve the workflow efficiency of the proton QA. [ABSTRACT FROM AUTHOR]

This study tests for the weak-form market efficiency of 15 cryptocurrency prices. The conventional unit root tests and stationary test results reveal that most cryptocurrency markets are efficient markets. However, the non-linear quantile unit root test proposed by Li and Park (2018) rejects the unit root null hypothesis over the whole quantile level. To derive more informative ideas, we split the whole quantile interval to several sub-intervals and find asymmetric behaviour of the market efficiency across the lower and upper sub-intervals in several cryptocurrency markets. Moreover, non-linear quantile unit root tests for Chainlink, Bitcoin Cash, Binance Coin, EOS, Tron, and Stellar indicate that markets for these cryptocurrencies are efficient at the upper sub-intervals. [ABSTRACT FROM AUTHOR]

In this paper, we empirically test the convergence of income and energy intensity for 61 countries using an augmented spatial growth model that includes energy and urbanization variables. We test an income convergence model to understand how energy use affects economic growth, and reveal that developing countries have energy constraints on their economic development. We show that energy is an essential component of economic growth in the early stages of development and that energy intensity converges between countries. It is consistent with the OLS estimation results that the convergence rate of energy intensity in developing countries of the spatial panel data model is still higher than in developed countries. However, the spatial panel data model shows that the gap between the two convergence rates is narrowed when spatial dependence is included. This implies that a country's steady state is influenced by the neighbouring countries and emphasizes the importance of international cooperation policies for reducing energy intensity. Since the effects of economic variables on the reduction of energy intensity are different in developed and developing countries, a country-specific energy policy rather than an internationally uniform policy is required. [ABSTRACT FROM AUTHOR]

This study uses the Vietnam Access to Resources Household Survey (VARHS) data from 2008 to 2014 to analyse the relationship between socio-political capital and household income in rural Vietnam. We consider six types of socio-political capital (connections with others that create access to useful information and/or benefits) namely Communist Party membership, membership in mass organizations (MOs) and voluntary groups, connections with officials, financial assistance, and trust. Communist Party membership and financial assistance have significant positive effects on household income in the pooling, random, and fixed effects models and at all quantile levels. The effect of trust is also positive and significant in all models but only significant at high quantile levels. Whereas connections with officials show significantly positive effects in the pooling and random effects models and at most quantile levels, the effects of MOs and voluntary groups are negative and significant for some models. [ABSTRACT FROM AUTHOR]