Miracle-dz/UniFAR-FTUs huggingface dataset:
A Cooperative Mobile Satellite Communication System with the Dynamic Space-Time Coding

Channels of mobile satellite communications are affected by multipath fading and shadowing attenuation. At the same time, diversity gains are believed to improve the transmission reliability in fading channels. Considering that the traditional Space-Time Coding (STC) is not suitable for the cooperative mobile satellite communication, in this paper, a new cooperative mobile satellite communication system is proposed based on the Dynamic Space-Time Coding (D-STC). The transmitting energy of the proposed scheme is saved by avoiding forwarding erroneous signals in cooperative users. Meanwhile, this system benefits from diversity gains and the transmission is robust. Additionally, a closed-form expression of the outage probability for the proposed scheme is derived, and then it is demonstrated that this scheme is much better than the existing noncooperative scheme and schemes with traditional STCs in the outage performance. Finally, the analytical result is supported and validated by numerical simulations.
Analysis of TCP Performance over a Low-Delay MAC Protocol Designed for Satellite-based Sensor Networks

Advances in terrestrial network technology such as fibre optic cables have significantly increased data rates and reduced cost, making it highly attractive for high-speed data networks. However, satellite communication remains competitive for certain applications where it has clear advantages over other technologies including fibre optic cables. The point to multipoint broadcast capability of a satellite is an important characteristic that allows multiple sub-networks or nodes to be controlled simultaneously by a single transmission. Similarly, multiple sub-networks or nodes can send data to a central point through a common channel, instead of using multiple point-to-point channels. This facilitates implementation of unique supervisory control and data acquisition systems such as a sensor network to monitor oil and gas pipelines or for agricultural purposes. One important problem in design of a satellite data network is how uncoordinated sources can share the common satellite channel. A multiple access control protocol is required to achieve efficient sharing of the channel while meeting the user traffic constraints. This paper investigates effects TCP performance when used with a new low-delay protocol that integrates Random Access and Bandwidth-on-Demand techniques.
Role of remittances on labor force participation in Haiti

Do remittances affect the household's labor supply in developing countries? In this paper we analyze the differences in the effect of remittances on the labor supply of women and men in Haiti in 2012. We show that the response of the individuals to remittances can vary between those household in the primary, private informal, private formal, and public sector even conditional on region, age, level of education among others. We decompose changes in outcomes into different sub-samples of the Haitian populations. We find significantly lower labor participation of headships of recipient remittance households as well as lower number of hours worked per week being men more sensitive than women. Such results are opposite to other findings for the region such as in Nicaragua and in Jamaica. We also found little evidence that remittances affect the share of participation in the household and in the total amount of hours devoted to work by the household. We proposed here four models to analyze this issue : a probabilistic model where outcomes are the decision of participation and ratio of household in the labor market, and a IV-tobit specification which models the number working hours of headship and aggregated working hours in the household.
A Run on Oil: Climate Policy, Stranded Assets, and Asset Prices

I study the dynamic implications of uncertain climate policy on macroeconomic outcomes and asset prices. Focusing particularly on the oil sector, I find that accounting for uncertain climate policy in an otherwise standard climate-economic model with oil extraction generates a run on oil; meaning oil firms accelerate extraction as climate change increases and oil reserves decrease due to the risk of future climate policy actions stranding oil reserves. Furthermore, the risk of uncertain climate policy, and the run on oil it causes, leads to a downward shift and dynamic decrease in the oil spot price and value of oil firms compared to the setting without uncertain policy. Ignoring the impact of uncertain climate policy would therefore lead to an overvaluation of the oil sector or “carbon bubble. ” Empirical evidence suggests observable market outcomes are consistent with the model predictions about the effects of uncertain climate policy.
Optimized design of Wastewater stream treatment processes by membrane technologies

Optimized Design of Wastewater Stream Treatment Processes by Membrane Technologies Marco Stoller*, Javier Miguel Ochando Pulido, Olga Sacco a Department of Chemical Materials Environmental Engineering, ‘La Sapienza’ University of Rome, Rome, Italy b Department of Chemical Engineering, University of Granada, Granada, Spain c Department of Chemical Engineering, University of Salerno, Salerno, Italy marco.stoller@uniroma1.it
TURBULENT MAGNETOHYDRODYNAMIC RECONNECTION MEDIATED BY THE PLASMOID INSTABILITY

It has been established that the Sweet–Parker current layer in high Lundquist number reconnection is unstable to the super-Alfvénic plasmoid instability. Past two-dimensional magnetohydrodynamic simulations have demonstrated that the plasmoid instability leads to a new regime where the Sweet–Parker current layer changes into a chain of plasmoids connected by secondary current sheets, and the averaged reconnection rate becomes nearly independent of the Lundquist number. In this work, a three-dimensional simulation with a guide field shows that the additional degree of freedom allows plasmoid instabilities to grow at oblique angles, which interact and lead to self-generated turbulent reconnection. The averaged reconnection rate in the self-generated turbulent state is of the order of a hundredth of the characteristic Alfvén speed, which is similar to the two-dimensional result but is an order of magnitude lower than the fastest reconnection rate reported in recent studies of externally driven three-dimensional turbulent reconnection. Kinematic and magnetic energy fluctuations both form elongated eddies along the direction of the local magnetic field, which is a signature of anisotropic magnetohydrodynamic turbulence. Both energy fluctuations satisfy power-law spectra in the inertial range, where the magnetic energy spectral index is in the range from −2.3 to −2.1, while the kinetic energy spectral index is slightly steeper, in the range from −2.5 to −2.3. The anisotropy of turbulence eddies is found to be nearly scale-independent, in contrast with the prediction of the Goldreich–Sridhar theory for anisotropic turbulence in a homogeneous plasma permeated by a uniform magnetic field.
Viscosity Approximation Methods with Errors and Strong Convergence Theorems for a Common Point of Pseudocontractive and Monotone Mappings: Solutions of Variational Inequality Problems

We introduce two proximal iterative algorithms with errors which converge strongly to the common solution of certain variational inequality problems for a finite family of pseudocontractive mappings and a finite family of monotone mappings. The strong convergence theorems are obtained under some mild conditions. Our theorems extend and unify some of the results that have been proposed for this class of nonlinear mappings.
Seismic and mechanical studies of the artificially triggered rockfall at Mount Néron (French Alps, December 2011)

Abstract. The eastern limestone cliff of Mount Neron (French Alps) was the theater for two medium-size rockfalls between summer and winter 2011. On 14 August 2011, a ~2000 m3 rock compartment detached from the cliff, fell 100 m below and propagated down the slope. Although most of the fallen rocks deposited on the upper part of the slope, some blocks of about 15 m in size were stopped by a ditch and an earthen barrier after a run-out of 800 m. An unstable overhanging ~2600 m3 compartment remained attached to the cliff and was blasted on 13 December 2011. During this artificially triggered event, 7 blocks reached the same ditch, with volumes ranging from 0.8 to 12 m3. A semi-permanent seismic array located about 2.5 km from the site recorded the two events, providing a unique opportunity to understand and to compare the seismic phases generated during natural and artificially triggered rockfalls. Both events have signal duration of ~100 s with comparable maximum amplitudes recorded at large distances (computed local magnitude of 1.14 and 1.05, respectively), most of the energy lying below 20 Hz. Remote sensing techniques (photogrammetry and lidar) were employed before and after the provoked rockfall, allowing the volume and fracturing to be characterized. This event was filmed by two video cameras, and the generated ground motions were recorded using two temporary 3C seismic sensors and three seismic arrays deployed at the slope toe. Videos and seismogram processing provided estimates of the propagation velocity during the successive rockfall phases, which ranges from 12 to 30 m s−1. The main seismic phases were obtained from combined video and seismic signal analyses. The two most energetic phases are related to the ground impact of fallen material after free fall, and to individual rock block impacts into the ditch and the earthen barrier. These two phases are characterized by similar low-frequency content but show very different particle motions. The discrete element technique allowed reproducing the key features of the rockfall dynamics, yielding propagation velocities compatible with experimental observations.
Interest Rate and Foreign Exchange Sensitivity of Bank Stock Returns: Evidence from China

This study employs a GARCH model to investigate the effects of interest rate and foreign exchange rate changes on Chinese banks’ stock returns. The results suggest that market movement and foreign exchange rate changes are statistically significant in explaining banks’ stock returns, despite different reactions from different bank portfolios in regard to risks. Interest rate fluctuations, on the other hand, appear to be insignificant factors in equity pricing. The results confirm the link between market risks and stock returns and highlight the need for further interest rate liberalization.
Chemometrics-assisted spectrophotometry for simultaneous determination of sodium benzoate and citric acid in beverage products

The development and validation of chemometrics-assisted spectrophotometry have been successfully performed for determination of sodium benzoate and citric acid that have overlapping of ultra violet absorption spectra. The study aimed to develop, validate, and apply spectrophotometric method with chemometrics approach for determination of both compounds in beverage products simultaneously. The analytical method was performed by making a calibration model using 16 training sets and 10 test sets of mixed solution followed by absorbance measurenment at wavelength of 190 nm up to 400 nm. In addition, the absorbance data was processed by multivariate calibration models of principal component regression (PCR) and partial least square-1 (PLS-1) and validated internally and externally to obtain optimum model. Validation of analytical methods was done by evaluating some parameters such as linearity and ranges, accuracy, precision, detection limits and quantification limits. The results showed that the optimum wavelength was 235 nm to 250 nm for sodium benzoate and 220 nm to 240 nm for citric acid with the selected optimum principal components (PCs) value were 6 (PCR) and 4 (PLS-1) for sodium benzoate and PCs 2 (PCR and PLS-1) for citric acid. The parameters of the analytical method validation developed were suitable and the analytical methods could be applied for the determination of the sodium benzoate and citric acid contents simultaneously in the beverage products.
The Relationship between Demographic towards the Achievement of a Successful Muslim Entrepreneur in Malaysia

Previous studies have shown that demographics factors are among the factors that influence the success of an entrepreneur. Therefore, this research aims to examine the relationship between demographic variable that comprises of ages, the length of running a business and business capital towards the achievement of a successful Muslim entrepreneur in Malaysia. Pearson Correlation test is used to identify the relationship between ages, the length of running a business and business capital, whereas ANOVA Test and T Test is used to used to determine the relationship differences between ages, the length of running a business and business capital towards the achievement of a successful Muslim entrepreneur in Malaysia. This research verified that there is a significant relationship between ages, the length of running a business and business capital towards the achievement of a successful Muslim entrepreneur in Malaysia. However, only age and business capital has a significant effect with the achievement of successful entrepreneur in Malaysia. Therefore, the results of this study demonstrate that demographic factors influence the achievement of successful Muslim entrepreneur in Malaysia
Benefits of donkeys in rural and urban areas in northwest Nigeria

The objective of this study is to explore the benefits of donkeys for rural and urban smallholder farmers in northwest Nigeria. We visited 112 smallholder donkey farmers located in rural and urban areas from four states in northwest Nigeriathrough four focus group meetings, interviews with individual farmers and in depth interview with 12 key informants. In addition, 80 citizens were interviewed about their perception on donkeys. Donkeys were used more intensively in urban than in rural areas. The number of donkeys was higher (p<0.001) in urban (4.1) than in rural areas (1.9). The number of days per week working with donkeys was also higher (p<0.05) in urban (6.4) than in rural (2.9) areas. However, farm sizes werelower (p<0.001) in urban (0.5 ha) than in rural (1.0 ha) areas. Farmers in urban areas received 16% higherannual income from their donkeys than those in rural areas. Donkeys were mainly appreciated by farmers for their low purchasing price, low-cost equipment, ease of management, and role in ceremonies. The main constraints facing the farmers were lack of information on donkey keeping, lack of access to clean water and proper feed, and lack of money to expand the business. About 50% of citizens associated donkeys with poverty.It was concluded that donkeys play important socio-economic roles in the farming systems and should therefore be included in future livestock policy planning in Nigeria.
Positron and nanoindentation study of helium implanted high chromium ODS steels

Abstract Three oxide dispersion strengthened (ODS) steels with different chromium content (MA 956, MA 957 and ODM 751) were studied as candidate materials for new nuclear reactors in term of their radiation stability. The radiation damage was experimentally simulated by helium ion implantation with energy of ions up to 500 keV. The study was focused on surface and sub-surface structural change due to the ion implantation observed by mostly non-destructive techniques: positron annihilation lifetime spectroscopy and nanoindentation. The applied techniques demonstrated the best radiation stability of the steel ODM 751. Blistering effect occurred due to high implantation dose (mostly in MA 956) was studied in details.
Vegetational versus topographical effects on forest bird communities: a test in the cantabrian mixed forest ecoregion (Spain)

La fisonomia y composicion floristica de la vegetacion conforman la estructura de las comunidades de aves a escala local. Sin embargo, la utilidad de estos rasgos para identificar areas apropiadas para las aves puede quedar oscurecida por la accion de otros factores, como la altitud, el clima y la estructura del paisaje a escala regional. Estos factores actuan a grandes escalas espaciales (en gradientes latitudinales), pero tambien a escalas menores (regiones montanosas). En este trabajo se explora la influencia de la topografia y la vegetacion sobre las comunidades de aves nidificantes e invernantes en la �ecorregion de bosque mixto cantabrico� (Espana), un area donde muchos pajaros forestales palearticos alcanzan el borde suroeste de su area de distribucion. El trabajo se realizo en nueve bosques extensivos semi-naturales localizados en la ladera norte de la cordillera Cantabrica, con alturas comprendidas entre 400 m y 1.300 m. Los pajaros se censaron en 78 transectos lineales de 500 m de longitud, en los que tambien se estimaron 10 variables de vegetacion. Los efectos de esta, y de la altitud y orientacion de la ladera sobre la riqueza y abundancia de pajaros se analizaron mediante el concurso de analisis de componentes principales y modelos generales lineales. Los resultados demuestran que, a la escala del estudio, los efectos de la vegetacion sobre las comunidades aviares son muy escasos y limitados a un efecto positivo de las manchas de robles sobre la riqueza invernal. La altitud es un predictor destacado de la distribucion aviar, especialmente en invierno, cuando los bosques localizados en las areas mas bajas mantienen las mayores abundancias y riquezas de aves. Este patron difirio entre pajaros con distintos nichos de forrajeo, ya que las especies que explotan los troncos apenas fueron afectadas por la altitud, mientras que la abundancia de los pajaros que comen en el suelo descendio drasticamente en niveles altos y medios. La conservacion de las comunidades de pajaros forestales de las montanas cantabricas exige la proteccion estricta de todo el gradiente boscoso altitudinal, en especial de los bosques que todavia persisten en las cotas bajas. Asi mismo, es urgente la conservacion de todos los robledales.
Coupled Fixed Point Theorems For Symmetric (ϕ,ψ) -weakly Contractive Mappings In Ordered Partial Metric Spaces

We establish some coupled fixed point theorems for symmetric (���� ,���� )-weakly contractive mappings in ordered partial metric spaces. Some recent results of Berinde (Nonlinear Anal. 74 (2011), 7347-7355; Nonlinear Anal. 75 (2012), 3218-3228) and many others are extended and generalized to the class of ordered partial metric spaces.
A semi-empirical model for mesospheric and stratospheric NO y produced by energetic particle precipitation

Abstract. The MIPAS Fourier transform spectrometer on board Envisat has measured global distributions of the six principal reactive nitrogen (NOy) compounds (HNO3, NO2, NO, N2O5, ClONO2, and HNO4) during 2002–2012. These observations were used previously to detect regular polar winter descent of reactive nitrogen produced by energetic particle precipitation (EPP) down to the lower stratosphere, often called the EPP indirect effect. It has further been shown that the observed fraction of NOy produced by EPP (EPP-NOy) has a nearly linear relationship with the geomagnetic Ap index when taking into account the time lag introduced by transport. Here we exploit these results in a semi-empirical model for computation of EPP-modulated NOy densities and wintertime downward fluxes through stratospheric and mesospheric pressure levels. Since the Ap dependence of EPP-NOy is distorted during episodes of strong descent in Arctic winters associated with elevated stratopause events, a specific parameterization has been developed for these episodes. This model accurately reproduces the observations from MIPAS and is also consistent with estimates from other satellite instruments. Since stratospheric EPP-NOy depositions lead to changes in stratospheric ozone with possible implications for climate, the model presented here can be utilized in climate simulations without the need to incorporate many thermospheric and upper mesospheric processes. By employing historical geomagnetic indices, the model also allows for reconstruction of the EPP indirect effect since 1850. We found secular variations of solar cycle-averaged stratospheric EPP-NOy depositions on the order of 1 GM. In particular, we model a reduction of the EPP-NOy deposition rate during the last 3 decades, related to the coincident decline of geomagnetic activity that corresponds to 1.8 % of the NOy production rate by N2O oxidation. As the decline of the geomagnetic activity level is expected to continue in the coming decades, this is likely to affect the long-term NOy trend by counteracting the expected increase caused by growing N2O emissions.
Ice velocity measurements of Langjökull, Iceland, from interferometric synthetic aperture radar (InSAR)

Abstract We have computed the velocity of Langjökull ice cap (LIC), Iceland, using InSAR data acquired by the European Remote-sensing Satellite in 1994 and an ice-surface elevation model derived from a GPS survey conducted in 1997. The velocity map covers 68% of the 925 km2 of LIC. Eight principal outlet glaciers were identified, along which ice velocities increased from zero at the ice divide to a maximum of 75 m a−1. When the InSAR velocity dataset is compared with surface GPS measurements of ice flow determined in summer 2001, there is generally good agreement, suggesting interannual and seasonal stability for much of the ice cap during this period. However, non-zero ice velocities at the termini of four of the eight glaciers surveyed suggest that these glaciers were advancing in 1994. Comparison of our GPS and InSAR velocities suggests that Sudurjökull experienced elevated velocity in late February 1994, which, when other studies are considered, appears to be consistent with a glacier surge.
A Reference Architecture for Virtual Research Environments

This paper describes the Reference Architecture of the enhanced VRE (e-VRE), a Virtual Research Environment defined in the context of the VRE4EIC Project, funded by EU H2020 e-Infrastructure program. e-VRE is designed to overcome limits of existing VREs with respect to a number of orthogonal dimensions: improving the quality of VRE user experience by providing user centered, secure, privacy compliant, sustainable environments for accessing data, composing workflows and tracking data publications; increasing VRE usage in multidisciplinary research domains by abstracting and reusing building blocks and workflows from existing VRE initiatives; improving the interoperability of heterogeneous discovery, contextual and detailed metadata across all layers of the VRE.
Conformal growth of Mo/Si multilayers on grating substrates using collimated ion beam sputtering

Deposition of multilayers on saw-tooth substrates is a key step in the fabrication of multilayer blazed gratings (MBG) for extreme ultraviolet and soft x-rays. Growth of the multilayers can be perturbed by shadowing effects caused by the highly corrugated surface of the substrates, which results in distortion of the multilayer stack structure and degradation of performance of MBGs. To minimize the shadowing effects, we used an ion-beam sputtering machine with a highly collimated atomic flux to deposit Mo/Si multilayers on saw-tooth substrates. The sputtering conditions were optimized by finding a balance between smoothening and roughening processes in order to minimize degradation of the groove profile in the course of deposition and at the same time to keep the interfaces of a multilayer stack smooth enough for high efficiency. An optimal value of energy of 200 eV for sputtering Kr+ ions was found by deposition of test multilayers on flat substrates at a range of ion energies. Two saw-tooth substrates we.