Miracle-dz/UniFAR-FTUs huggingface dataset:
Aerosol optical characteristics and their vertical distributions under enhanced haze pollution events: effect of the regional transport of different aerosol types over eastern China

Abstract. The climatological variation of aerosol properties and the planetary boundary layer (PBL) during 2013–2015 over the Yangtze River Delta (YRD) region were investigated by employing ground-based Micro Pulse Lidar (MPL) and CE-318 sun-photometer observations. Combining Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite products, enhanced haze pollution events affected by different types of aerosol over the YRD region were analyzed through vertical structures, spatial distributions, backward trajectories, and the potential source contribution function (PSCF) model. The results show that aerosols in the YRD are dominated by fine-mode particles, except in March. The aerosol optical depth (AOD) in June and September is higher due to high single scattering albedo (SSA) from hygroscopic growth, but it is lower in July and August due to wet deposition from precipitation. The PBL height (PBLH) is greater (means ranging from 1.23 to 1.84 km ) and more variable in the warmer months of March to August, due to the stronger diurnal cycle and exchange of heat. Northern fine-mode pollutants are brought to the YRD at a height of 1.5 km . The SSA increases, blocking the radiation to the surface, and cooling the surface, thereby weakening turbulence, lowering the PBL, and in turn accelerating the accumulation of pollutants, creating a feedback to the cooling effect. Originated from the deserts in Xinjiang and Inner Mongolia, long-range transported dust masses are seen at heights of about 2 km over the YRD region with an SSA440 nm below 0.84, which heat air and raise the PBL, accelerating the diffusion of dust particles. Regional transport from biomass-burning spots to the south of the YRD region bring mixed aerosol particles at a height below 1.5 km , resulting in an SSA440 nm below 0.89. During the winter, the accumulation of the local emission layer is facilitated by stable weather conditions, staying within the PBL even below 0.5 km .
Maneuvering Target Detection Based on JRC System in Gaussian and Non-Gaussian Clutter

Aimed at the problem of detecting maneuvering targets in the Gaussian and sea clutter environments and based on the established motion state model, this paper proposed a new scheme that uses a joint radar-communication (JRC) system with Kalman filter to accurately detect the target with the generalized likelihood ratio test (GLRT) theory and a constant false alarm rate (CFAR) based threshold. Also, the theoretical threshold and probability function of GLRT target detection based on CFAR were given. Moreover, target detection probability of the new JRC system in Weibull and distribution clutter is deduced. In addition to theoretical considerations, simulations and measurement results of the new JRC systems demonstrate excellent detection performance for maneuvering targets in the Weibull and distribution channel.
Micrometeorological and chamber methods for measurement of nitrous oxide fluxes between soils and the atmosphere : overview and conclusions

Emissions of N20 from agricultural grassland fertilized with 185 kg N ha -1 have been measured using a range of chamber and micrometeorological methods at a common site in the lowlands of Scotland. Measurements were made over similar periods (30 to 60 min) by all methods, but the areas over which the fluxes were measured ranged from 0.008 m 2 for the smallest chambers to 104 to 10 5 m 2 for the micrometeorological methods. The fluxes measured using chambers ranged from less than 10 to more than 1700 ng N20-N m -2 s -l' they were a factor of 3 larger from a previously grazed area than from the remainder. Fluxes showed great spatial variability and also a general decline with time following a peak after fertilization. Micrometeorological measurements were made by eddy correlation using fast-response tunable diode laser absorption spectroscopy (TDLAS) and by aerodynamic (flux gradient) methods using Fourier transform infrared spectroscopy (FTIR), gas chromatography (GC), and TDLAS. All of the flux gradient methods provided similar fluxes of N20 over the ungrazed section of the field, with averages over the measurement period in the range 52 to 55 ng N20-N m -2 s -1 . Eddy correlation measurements with the TDL averaged 85 and 43 ng m -2 s -1 on the two days when measurements were made. Mean fluxes from the chamber methods, using GC, FTIR, and long-path infrared spectroscopy to detect N20, were larger than those from the micrometeorology and ranged from 280 ng N20-N m -2 s -1 for the smallest chambers to 210 ng N2,O-N m -2 s -1 for the 0.13/0.49 m 2 chambers and 300 ng N20-N m -2 s -1 for the 62 mchamber. The different techniques employed averaged over different spatial scales, and the measurements related to different areas of the field. Nonetheless, the different micrometeorological methods gave similar fluxes. The higher values obtained by the chamber methods may have been due either to the spatial variability of the fluxes at the site, with the chambers being located in regions of relatively greater source strength, or to factors associated with the methods themselves.
Who is claiming for fixed-term contracts?

The present study aims to contribute to the debate concerning the effects on economic performance and the structure of the labor market of regulations that combine high Employment Protection Legislations (EPL) with consent for the use of fixed-term contracts (FTC). Using a Rajan and Zingales (1998) difference-in-difference empirical technique in a panel of 45 countries, we explore the response of industries that differ in their "intrinsic need" of worker turnover when they face different levels of EPL and how the possibility of using FTC might change the outcome. Our approach suggests an original demand side explanation of the claiming of FTC.
Maximum Power Point Tracking Algorithms for Solar Photovoltaic Systems

Actualmente la poblacion crece a una gran velocidad provocando un aumento en el consumo energetico y, por otro lado, surge la necesidad de reducir las emisiones de gases contaminantes provocadas por las fuentes combustibles. La aparicion de las energias renovables da respuesta a estas cuestiones y, por ello, este proyecto se centra en la energia solar, desarrollada desde hace aproximadamente 40 anos y cuyo potencial excede las posibles necesidades futuras y, en concreto, la energia solar fotovoltaica (PV), que transforma la radiacion solar en electricidad. La transformacion de energia solar en electricidad es debida al efecto fotoelectrico, que tiene lugar en la union de un semiconductor tipo P y uno tipo N. Por ello, la celula solar se puede modelar mediante un circuito electrico formado por una fuente de intensidad y un diodo, junto a resistencias parasitas que representan las posibles perdidas Debido a la influencia de las condiciones atmosfericas, es necesario el seguimiento del punto de maxima potencia (MPP), a traves de los algoritmos de seguimiento (MPPT). Por ello, este proyecto se ha centrado en la recopilacion de los algoritmos MPPT mas utilizados para, posteriormente, realizar el modelado y simulacion de algunos de ellos. Con el objetivo de contrastar las caracteristicas definidas previamente de algunos metodos, se ha procedido a su modelado en Simulink R. En conclusion, bajo las condiciones simuladas, los algoritmos convencionales presentan resultados muy similares y, por otro lado, se aprecia una mayor extraccion de potencia mediante el Metodo Beta, a pesar de que su complejidad sea superior.
A field experiment on the reproductive success of the invasive clam Mya arenaria (Bivalvia) in the Tagus estuary: coexistence with the native clam Scrobicularia plana

A three month field experiment with tidal level (upper, middle, lower) and treatment (excavated and not excavated plots) as categorical experimental factors showed that the invasive clam Mya arenaria has reached a more advanced stage in the invasion process in the Tagus estuary. As we observed the smallest recruited juveniles of Mya arenaria (2 mm) throughout the study period, we concluded that the clam is capable of reproducing in the new habitat. Juveniles of both Mya arenaria and the bivalve Scrobicularia plana were found to avoid excavated experimental plots, showing a significantly higher abundance in the control plots. These data, strongly suggest that the recruited bivalves actively avoid unsuitable substrata. Juvenile specimens of Mya arenaria were more abundant in the mid-intertidal zone. However, juvenile specimens of Scrobicularia plana were mainly distributed in the upper intertidal level, which suggests that they have a different settlement behaviour from that observed for the juveniles of the invasive clam. Despite the divergent distribution between the juveniles of the two species in the study site, the possible interaction between these two species is considered and discussed.
Transport Phenomena of Solid Particles in Pulsatile Pipe Flow

The transportation mechanism of single solid particles in pulsating water flow in a vertical pipe was investigated by means of videography and numerical simulations. The trajectories of alumina particles were observed experimentally by stereo videography. The particle diameter was 3 mm or 5 mm, and the pipe diameter was 18 mm or 22 mm. The frequency of flow pulsation was less than or equal to 6.67 Hz. It was found that the critical minimum water flux at which the particle can be transported upward depended on the pulsating pattern. Two types of numerical simulations were conducted, namely, one-dimensional simulations for tracking the vertical motion of the solid particles and two-dimensional simulations of the pulsating pipe flows in an axisymmetric coordinate system. The computer simulations of axisymmetric pipe flows revealed that the time-averaged radial velocity profile of water in the pulsating flows was very different from that in steady pipe flows. The motion of the particles is discussed in detail for a better understanding of the physics of the transport phenomena.
Global Ground Truth Data Set with Waveform and Improved Arrival Data

Abstract : The main objective of this three-year research project is to produce a quality-controlled global GTO-5 event set, accompanied with waveform and groomed arrival time data sets. Our efforts are directed toward developing and refining methodologies for generating new ground-truth(GT) events through multiple-event location analysis. To accomplish this goal, we have developed the hybrid HDC-RCA (hypocentroidal decomposition and reciprocal cluster analysis) methodology. The HDC analysis determines accurate event location patterns relative to a provisional cluster centroid using regional and telesesmic phases. The RCA analysis then determines the accurate location of the cluster centroid using local phases only. RCA accomplishes this by keeping the event and station patterns fixed and relocates the station centroid using the events as fictitious stations. Because both relative station and relative event patterns are fixed and multiple events are typically recorded at each station, solving for the cluster hypocentroid represents an over determined inversion problem that is robust with respect to strong local seismic-velocity biases.
Exploring issues underlying citizen adoption of eGovernment initiatives in developing countries: The case of Tanzania

Adoption plays an important role in the success of eGovernment initiatives. Low adoption, particularly by citizens, indicates inadequate utilization and rejection of the initiatives by the intended users. This may lead into failure of eGovernment initiatives. This is particularly important in the context of developing countries such as Tanzania where eGovernment is a newly imported innovation. It is therefore imperative to understand and proactively consider issues underlying citizen adoption of eGovernment initiatives in that context. This study aimed at identifying issues underlying adoption of eGovernment initiatives in Tanzania, a typical developing country. The results are important for designing, deploying, and evaluating of the initiatives in the country. In this paper, we present research results concerning issues influencing adoption of eGovernment initiatives by citizens in Tanzania. Using the case study approach as our strategy, we investigated the adoption of three government organisations. We found that the adoption of eGovernment initiatives in Tanzania is determined by (1) perceived organisational preparedness (2) citizen preparedness (3) service intrinsic issues, (4) access limitations, and (5) organisational context. We perceive that it is possible to achieve higher degree of citizen adoption of eGovernment initiatives in Tanzania. However, the government need appropriate strategies to overcome challenges posed by the issues identified in this study.
Hydraulic performance evaluation of mini sprinkler system

Irrigation system performance assessment is of high priority in irrigation research to solve the problem of irrigation development and management. It is obvious that many irrigation systems are performing below their capacity. This situation may lead to non-uniform and unreliable water distribution. The mini sprinkler systems recently introduced for irrigation needs to be evaluated for their performance. A mini sprinkler system was evaluated for its hydraulic performance. Experiment was conducted to evaluate the hydraulic performance using a mini sprinkler system having double nozzle-full circle sprinkler at various sprinkler spacings (8 m × 8 m, 10 m × 10 m and 12 m × 12 m) at three operating pressures (1.0, 1.5 and 2.0 kg/cm2). The index of jet break up was obtained in all the three operating pressures in the range of 2.63 to 4.65, however ideal value of index of jet break up was obtained close to 4.0 at 1.5 kg/cm2. Uniformity coefficient for all the system arrangements was in the range of 79.14 to 87.68%. The uniformity coefficients were obtained at par for 8 m × 8 m spacing at 2.0 kg/cm2 and 10 m × 10 m spacing at 1.5 kg/cm2. The spacing of 10 m × 10 m at operating pressure of 1.5 kg/cm2 showed better hydraulic performance with economical feasibility. Key words: Mini sprinker, uniformity coefficient, distribution uniformity, index of jet break up, hydraulic performance.
Observational Signatures of the Warm-Hot Intergalactic Medium and X-ray Absorption Lines by the Halo of our Galaxy

Approximately 30% to 50% of the total baryons of the present universe are considered to take a form of warm/hot intergalactic medium (WHIM) and to have evaded direct detection. The WHIM of T = 106-107K is most likely detected through absorption and emission lines of O VII and O VIII. The equivalent widths of the absorption lines are typically 0.4eV, which is consistent with the absorption lines having redshifts indistinguishable from zero observed in the spectra of a few bright active galactic nuclei (AGN). However, from the midplane O VII density estimated from O VII absorption line in the Galactic X-ray source, 4U1820-303, we consider that a significant fraction of warm/hot plasma responsible for the AGN absorption lines is located in our Galaxy rather than in the local group. For a systematic study of the WHIM, survey-type observations detecting emission lines are necessary. While the typical surface brightness O VII and O VIII emission lines is below the detection limit of present and proposed future missions, an unambiguous detection will be feasible with a small X-ray mission dedicated for this purpose. Our proposed mission, DIOS (Diffuse Intergalactic Oxygen Surveyor), is sensitive to the WHIM of temperatures T = 106-107K and can survey about 0.1sr area to the depth of cosmological redshift z < 0.3 in two years.
Improving robustness of pose estimation in AR using motion segmentation

Recent improvements in mobile technology have allowed computationally intensive augmented reality systems to become increasingly ubiquitous. As will be shown in this thesis an increasing number of companies have started developing markerless AR systems that can be used professionally. Robust pose estimation is essential for such systems to convey users into a believable AR experience by excluding outlying and erroneous tracked features. Robust statistics can detect and reject large percentages of outliers but in highly dynamic scenes more dedicated motion segmentation is required. In this thesis a motion segmentation algorithm is presented that is designed to increase robustness in a vision based marker-less stereo AR framework, to improve pose estimation and mapping. This is based on a motion segmentation method that has successfully been tested on PTAM [1]. We believe that by expanding this to stereo vision, improvements can be made by utilizing the extra visual information obtained by the second camera. By modeling the stereo triangulation error we could use the Mahalanobis distance for clustering features and correct for their error distribution, which increases with distance from the camera. Initial visual inspection showed that this improved the dynamic feature rejection with respect to the Euclidean distance and with that also the accuracy of pose estimation. This is shown in the test results. By using the 3D distribution in the scoring of each set, the correct labeling of a set of clustered features as being static was improved. This is because static features are more likely to be arbitrarily spread over the 3D scene while dynamic features belonging to the same moving object are more likely to be grouped in a relatively planar configuration. Stereo vision provides 2.5 D information (in contrast with X-ray images) and moving objects are generally smaller than the 3D scene in which the user resides itself.
www.econstor.eu Markov Switching in Disaggregate Unemployment Rates∗

We develop a dynamic factor model with Markov switching to examine secular and business cycle fluctuations in U.S. unemployment rates. We extract the common dynamics among unemployment rates disaggregated for seven age groups. The framework allows analysis of the contribution of demographic factors to secular changes in unemployment rates. In addition, it allows examination of the separate contribution of changes due to asymmetric business cycle fluctuations. We find strong evidence in favor of the common factor and of the switching between high and low unemployment rate regimes. We also find that demographic adjustments can account for a great deal of the secular change in the unemployment rate, particularly the abrupt increase in the 1970s and 1980s and the subsequent decrease.
Comfort-oriented social force model and learned lessons

In this paper, we propose a new Social Force Model (SFM), called COSFM (Comfort-Oriented Social Force Model), that maximizes the comfort of people when robots navigate around them. We describe a navigation system that allows robots to reach their target in small human environments like a flat or small corridors in a safe and comfortable manner. More precisely, the proposed approach is tested with a 3D version of the Social Force Model (SFM) for aerial robots with some restrictions in order to maximize the comfort of nearby humans. To accomplish this commitment, we include a navigation scheme that predicts the humans motion and intention so the robot can safely avoid people. Moreover, to avoid surprises, robots will never go faster than human motion velocity. This contrasts with other conventional works where the environment is neither so tight or close with people and walls. This work is based on previous works of SFM [1] applied to robots that come from an older framework for understanding human movements in crowds [2]. However, we must advise that even if the first results are quite good there is still much work to do to obtain a fully comfortable model. The current model shows great potential to solve difficult decisions, even scale on many elements in close environments.Finally, the results are good enough to think it is an appropriate model for indoor human close environments with applications such as delivering goods or reaching people for help in buildings.
Electoral Systems and the Influence of the Median Voter: Quasi-Experimental Evidence from popular and parliamentary votes #

When moving from a plurality rule to a proportional system, members of national parliament have more incentives to diverge from the median voter’s preferences. We match voting behavior concerning legislative proposals of Swiss members of parliament with real referenda outcomes on the same issues for the years 1996 to 2009. This quasi-experimental data allows us to identify whether differences in electoral systems induce members of parliament to diverge from the choices of the median voter. Empirical results indicate that members of parliament from districts with proportional representation tend to diverge significantly more from the median voter’s preferences than members of parliament from districts with plurality rule.
Enhancing the Adoption of E-Government Systems through Open Government and Open Government Data (OGD) Initiatives in Qatar

The present study aimed to analyze the status of e-government in developing countries, and particularly at Qatar. It also aimed to analyze the status of Open Government Data (OGD) in Qatar in order to identify the main motives that prompted the Qatari government to launch Open Government Data initiatives. In order to cover the research objectives effectively; the researcher used two main methods in order to cover the study objectives. The researcher used the qualitative method to achieve the goals of the study optimally and by reference to all sources on the subject of the study of previous studies, books and references. The researcher also used the analytical method through analyzing the status of e-government in developing countries, and particularly at Qatar. It also aims to analyze the status of Open Government Data (OGD) in Qatar in order to identify the main motives that prompted the Qatari government to launch Open Government Data initiatives. The research concluded that although Qatar is trying to develop e-government systems in various citizen transactions, and while trying to keep pace with the developed countries in the development of open data, Qatar still needs many steps and initiatives to promote e-government by relying on Open Government Data. The reliance of Qatar's Government on open data would encourage individuals to participate in decision-making, facilitate citizens' access to the required information, and increase citizen adoption of e-government. The research also concluded that Open Government Data (OGD) represents a new stage in activating the implementation of the e-government of Qatar, as it helps in achieving the basic objectives that the e-government seeks to achieve. The application of OGD initiatives may be a challenge for developing countries, due to several reasons, such as poor coordination among various government agencies, poor quality of published data, and the absence of laws and regulations that govern and control the nature of such initiatives. The research recommended in developing an Open Government Data strategy. This strategy will represent the road map for the Qatari government to activate the application of OGD initiatives. The research also recommended in establishing a framework for OGD, develop a legislative framework for OGD initiatives to control these initiatives and raise their success rate and enhancing the use of Web 2.0 regarding its significant benefits, since this web allowing the user for data modification and access to it when needed. Keywords : e-government, Open Government, Open Government Data (OGD).