89,470 research outputs found
Migrant and non-migrant domestic workers in Hanoi: the segmentation of domestic service
Nguyen M. Migrants and Non-migrant Domestic Workers in Hanoi. The Segmentation of Domestic Service. DEV Working Paper Series. Vol 22. Norwich: School of International Development, UEA; 2010
THE YIELD CURVE AS A LEADING INDICATOR ACROSS COUNTRIES AND TIME: THE EUROPEAN CASE
With the increasing demand for a better understanding about the relationship between yield curve and economic activities, this paper analyzes the data sets of seven countries in the European Union: Germany, France, Belgium, Spain, the United Kingdom, Sweden and Poland using quantitative analytical method. Based on previous literature, the expected hypothesis is: there is a strong relationship between the yield curve and the chance of an incoming economic contraction. The inverted yield curve, or the negative yield curve spread is considered as the tool to forecast the incoming contraction. Having been used as a rule of thumb for future reference of a contraction, whether yield curve and interest rates can be an accurate tool to predict the movement of business cycles should be studied more thoroughly, which will help not only the governments to reduce the loss from recession, but also equip financial sector valuable information to adjust itself before a contraction takes place. Further findings in this paper present a comparison between a group of Eurozone members and a group of non-Eurozone members. The similarities and differences give a broad idea of how the creation of the Eurozone has affected the area in the last decade
Phase ambiguity resolution for offset QPSK modulation systems
A demodulator for Offset Quaternary Phase Shift Keyed (OQPSK) signals modulated with two words resolves eight possible combinations of phase ambiguity which may produce data error by first processing received I(sub R) and Q(sub R) data in an integrated carrier loop/symbol synchronizer using a digital Costas loop with matched filters for correcting four of eight possible phase lock errors, and then the remaining four using a phase ambiguity resolver which detects the words to not only reverse the received I(sub R) and Q(sub R) data channels, but to also invert (complement) the I(sub R) and/or Q(sub R) data, or to at least complement the I(sub R) and Q(sub R) data for systems using nontransparent codes that do not have rotation direction ambiguity
Enhanced thermoelectric figure of merit in vertical graphene junctions
In this work, we investigate thermoelectric properties of junctions
consisting of two partially overlapped graphene sheets coupled to each other in
the cross-plane direction. It is shown that because of the weak van-der Waals
interactions between graphene layers, the phonon conductance in these junctions
is strongly reduced, compared to that of single graphene layer structures,
while their electrical performance is weakly affected. By exploiting this
effect, we demonstrate that the thermoelectric figure of merit can reach values
higher than 1 at room temperature in junctions made of gapped graphene
materials, for instance, graphene nanoribbons and graphene nanomeshes. The
dependence of thermoelectric properties on the junction length is also
discussed. This theoretical study hence suggests an efficient way to enhance
thermoelectric efficiency of graphene devices.Comment: 6 pages, 4 figures, submitte
Characterisation of anisotropic etching in KOH using network etch rate function model: influence of an applied potential in terms of microscopic properties
Using the network etch rate function model, the anisotropic etch rate of p-type single crystal silicon was characterised in terms of microscopic properties including step velocity, step and terrace roughening. The anisotropic etch rate data needed have been obtained using a combination of 2 wagon wheel patterns on different substrate and 1 offset trench pattern. Using this procedure the influence of an applied potential has been investigated in terms of microscopic properties. Model parameter trends show a good correlation with chemical/electrochemical reaction mechanism and mono- and dihydride terminated steps reactivity difference. Results also indicate a minimum in (111) terrace roughening which results in a peak in anisotropic ratio at the non-OCP applied potential of −1250 mV vs OCP
Coarse-Graining and Renormalization of Atomistic Binding Relations and Universal Macroscopic Cohesive Behavior
We present two approaches for coarse-graining interplanar potentials and
determining the corresponding macroscopic cohesive laws based on energy
relaxation and the renormalization group. We analyze the cohesive behavior of a
large---but finite---number of interatomic planes and find that the macroscopic
cohesive law adopts a universal asymptotic form. The universal form of the
macroscopic cohesive law is an attractive fixed point of a suitably-defined
renormalization-group transformation.Comment: 15 pages, 6 figures, submitted to the Journal of the Mechanics and
Physics of Solid
The impact of NRZ data asymmetry on the performance of a space telemetry system
The telemetry data asymmetry due to rising and falling voltage transitions can cause undesired spectral components at the output of a spacecraft transmitter. The performance of a space telemetry system can potentially degrade because of these undesired components. Here, an expression is derived for the power spectral density of an asymmetric nonreturn-to-zero (NRZ) data stream. This formula is then used to investigate how the data bandwidth varies with data asymmetry. At the receiver end, the threshold levels of undesired spectral components that fall into the carrier-tracking-loop bandwidth are determined by examining the derived spectral density. Further, based on this formula, a simple technique is developed for the computation of bit signal-to-noise ratio (SNR) degradation due to data asymmetry. The telemetry bit SNR degradations derived using this technique are compared with results obtained previously and with measurements by the Electronic Systems Test Laboratory (ESTL) at the Lyndon B. Johnson Space Center
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