6,877 research outputs found
The profitability of technical analysis in the Taiwan-U.S. forward foreign exchange market
Based on technical analysis and White's and Hansen's data-snooping-robust tests, we examine the efficiency of the Taiwan-U.S. forward foreign exchange market and find that, unlike the spot market, the forward market is inefficient even under a very high transaction cost, suggesting that the failure of forward rate unbiasedness documented in the literature may be due to forward market inefficiency.data snooping, forward exchange rate unbiasedness, market efficiency, profitability, reality check, technical analysis
An alternative simplified model of tensile membrane action of slabs in fire
This paper presents an initial re-examination of the mechanisms of tensile membrane action of thin concrete floor slabs. The study is based on a large-deflection plastic analysis, which can apply to either isolated or continuous slabs at ambient or high temperatures. The basic calculation method considers plain flat slabs, but is in no way limited to these, or to isotropic reinforcement. The new method is compared against the generic Bailey-BRE method, indicating for some typical examples that the actual enhancement of yield-line capacity due to TMA can be over-estimated by the latter
Further study on heredity of liquid aluminum modified by electric pulse
The remarkable heredity of liquid aluminum modified by electric pulse (EP, EPM) has been uncovered. For better understanding from all aspects on the hereditary properties, the present research deals with the heredity destruction and the secondary EPM procedure. It is shown that the secondary EPM is capable of preventing the heredity reduction of EP-modified liquid aluminum, and that the final refining effect has a close relationship with technique parameters of the secondary EPM. Furthermore, at a certain superheated temperature depending on the initial EPM technique parameters, the heredity relationship of EP-modified liquid aluminum can be cut off during remelting. High temperature X-ray diffraction combining with the DSC tests also indicates that the EP-induced structure changes have almost disappeared at an elevated remelting temperature
Deformation monitoring of high-latitude permafrost region of northeastern China with time series inSAR technique
Abstract. Permafrost distributed in northeast China is the only high-altitude permafrost in China. The deformation monitoring over this permafrost region is of great importance to local climate change and ecological environments. This study focuses on the deformation monitoring of high-latitude permafrost in northeast China with time series InSAR technique. The spatial distribution characteristics, the annual deformation rates and the temporal deformation evolutions of permafrost could be retrieved from multi-temporal InSAR processing with Sentinel-1 TOPS datasets. This work concludes that time series InSAR technique could help to retrieve a comprehensive and reliable permafrost deformation, while a long time-series of displacements facilitated to better understand permafrost kinematics.</p
Smartphone Use and Psychological Well-Being among College Students in China: A Qualitative Assessment
Background: Problematic smartphone use is widespread, and college-age youth faces an especially high risk of its associated consequences. While a promising body of research has emerged in recent years in this area, the domination of quantitative inquiries can be fruitfully and conceptually complemented by perspectives informed through qualitative research. Toward that end, this study aimed to interrogate the myriad behavioral, attitudinal, and psychological tendencies as a side effect of college students’ engagement with the smartphone in their everyday lived experience through in-depth interviews.
Methods: We recruited 70 participants from seven college campuses hailing from different geographic regions in China, and conducted semi-structured in-depth virtual interviews via WeChat in November and December 2020. Subjective experiences, personal narratives and individual perceptions in the context of routine interaction with the smartphone were thematically analyzed through a reiterative process in an effort to detect prevailing threads and recurring subthemes.
Results: The smartphone has established a pervasive presence in college students’ everyday life. Time-based use characteristics generated a typology of four distinct user groups: hypo-connected antagonists, balanced majority, hyper-connected enthusiasts, and indulgent zealots. Habitual usage falls on predictable patterns matched onto temporal, locale-based and contextual cues and triggers. Students’ dependency relationships with the smartphone have both functional and emotional dimensions, as prominently manifested in occasions of detachment from the device. Self-regulatory effort in monitoring and limiting use is significantly impacted by mental focus and personal goal setting. Perspectives from our qualitative data suggest the need for taking into account a variety of contextual cues and situational factors in dissecting psychological and emotional outcomes of smartphone use and abuse
The global geometrical property of jet events in high-energy nuclear collisions
We present the first theoretical study of medium modifications of the global
geometrical pattern, i.e., transverse sphericity () distribution of
jet events with parton energy loss in relativistic heavy-ion collisions. In our
investigation, POWHEG+PYTHIA is employed to make an accurate description of
transverse sphericity in the p+p baseline, which combines the next-to-leading
order (NLO) pQCD calculations with the matched parton shower (PS). The Linear
Boltzmann Transport (LBT) model of the parton energy loss is implemented to
simulate the in-medium evolution of jets. We calculate the event normalized
transverse sphericity distribution in central Pb+Pb collisions at the LHC, and
give its medium modifications. An enhancement of transverse sphericity
distribution at small region but a suppression at large
region are observed in A+A collisions as compared to their p+p references,
which indicates that in overall the geometry of jet events in Pb+Pb becomes
more pencil-like. We demonstrate that for events with 2 jets in the final-state
of heavy-ion collisions, the jet quenching makes the geometry more sphere-like
with medium-induced gluon radiation. However, for events with ~jets,
parton energy loss in the QCD medium leads to the events more pencil-like due
to jet number reduction, where less energetic jets may lose their energies and
then fall off the jet selection kinematic cut. These two effects offset each
other and in the end result in more jetty events in heavy-ion collisions
relative to that in p+p.Comment: 9 pages, 9 figure
Superimposed Training-Aided Channel Estimation for Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing Systems over High-Mobility Environment
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