Miracle-dz/UniFAR-FTUs huggingface dataset:
Microsecond Atomic-Scale Molecular Dynamics Simulations of Polyimides

We employ microsecond atomic-scale molecular dynamics simulations to get insight into the structural and thermal properties of heat-resistant bulk polyimides. As electrostatic interactions are essential for the polyimides considered, we propose a two-step equilibration protocol that includes long (microsecond-scale) MD simulations of polymer melt with partial atomic charges switched off, followed by relatively short runs (100 ns) of the polymer system with full electrostatics. We demonstrate that macroscopic characteristics of a polyimide sample (such as the glass transition temperature and density) are not particularly sensitive to the degree of equilibration. However, great caution should be paid when local structural characteristics are considered: proper equilibration of the local polymer structure (monitored through the radius of gyration and the end-to-end distance of individual chains) is found to require simulations on a microsecond time scale. Finally, we found a dramatic impact of electrostatic interactions on the properties of the bulk polyimides considered: when intra- and intermolecular dipole–dipole interactions come into play we witness compaction of individual polymer coils and eventually an increase in the glass transition temperature and polymer density.
Optimal Design of Mechanisms for Robot Hands

Scientific progress has been very important in the last two centuries, from the invention of the steam machine until the electronic age. Robots design has also suffered an important progress in the last decades and many approaches deal with this issue. Our approach carries out an optimal design of planar 1 DoF mechanisms which are used for robot hands or grippers. These kinds of mechanisms are amply used because of their simplicity and they only need one motor to move them, so many robots use this kind of mechanism as grippers. We studied a new technique to carry out an optimal design of a gripper in this work. A searching procedure is developed, which applies genetic algorithms based on an evolutionary approach. The new method has proved to solve synthesis problems of planar mechanisms and has been used for testing a hand robot mechanism, showing that the solutions are accurate and valid for all cases. Different techniques have been used for mechanism synthesis. In graphical techniques the use of the coupler curve atlas (Hrones & Nelson, 1951) who developed the four-bar mechanisms atlas with almost 10,000 curves is especially remarkable. The solution by (Zhang et al., 1984) focused on five-bar geared linkages. These methods are easy and fast to use but at a low precision rate. The first reference addressing analytical methods was made by (Sandor, 1959), followed by (Erdman, 1981), (Kaufman, 1978) and (Loerch et al.,1975). References about the subject by (Freudenstein, 1954), (Beyer, 1963), (Hartenberg & Denavit, 1964) also exist, solving the synthesis problem using precision points to be reached by the coupler point of the mechanism, but these methods restrict the number of precision points in order to allow the solution of the mathematical system to be closed and show problems caused by wrong sequence of the precision points followed. The great increase in computer power has permitted the recent development of routines that apply numerical methods to the minimization of a goal function. One of the first authors who studied these methods was (Han, 1966), whose work was later improved by (Kramer & Sandor, 1975), (Sohoni & Haug, 1982). They optimized one of the most common goal functions: the error between the points tracked by the coupler and its desired trajectory. The approach to mechanism synthesis presented in this work deals with evolutionary algorithms based on a differential evolution technique. These kinds of algorithms were first introduced by (Holland, 1973,1975), whose work is included in Goldberg’s book (Goldberg, 1989), and they have been extensively and successfully applied to different optimization problems. These methods define a starting population that is improved by approximations to the goal function making use of natural selection mechanisms and natural genetic laws.
Synthesis of some heterocyclic compounds and application thereof inelectroluminescent cells

Introduction Until the late 60s of the last century, electronics were dominated by materials of inorganic origin. This situation began to change when it was discovered that some organic materials are capable of conducting electricity. The importance of this discovery was accentuated in 2000 when Heeger, MacDiarmid and Shirakawa were awarded the Nobel Prize for their research on organic conductive polymers. Nowadays organic materials are used in the construction of photoelements, capacitors, diodes, batteries, chemical sensors, polymer lasers, NLO devices and transistors [1]. One of the fastest developing disciplines is the electroluminescence (EL) of organic compounds. The phenomenon has been known since the early 60s of the last century, but it had not found practical application, as the organic EL diodes of that time could not compete with their inorganic counterparts. The breakthrough came in 1987, when results of work on a double-layered high performance EL cell were published [2]. The device comprised vacuum deposited films of an 8-hydroxyquinoline aluminium complex (AlQ3), which served as the electron transporting layer (ETL) and of an aromatic amine constituting the Hole Transporting Layer (HTL). In 1990 Friend reported on his work on a cell based on poly(p-phenylene vinylene) (PPV) [3]. One of the most important achievements in this area was the discovery of electrophosphorescence, which enables increasing the internal quantum yield up to nearly 100%, whereas the maximum yield in traditional cells, based on the host-guest design, reaches 25% only [4]. These and subsequent discoveries have indicated that EL displays can be constructed with the use of organic compounds. These displays are now becoming increasingly common due to the high colour saturation they offer, low supply voltage, low weight, possibility of creating large luminous surfaces, wide angle of view, high contrast and the fact that they emit light a feature for which liquid crystal displays require an additional layer. At present OLED (Organic Light Emitting Diode) displays are widely used in electronic equipment such as mobile telephones, digital cameras, car audio systems, electrical shavers, prototype 20-inch TV screens. However, it will take some time before TVs with OLED or PHOLED (Phosphorescent Organic Light Emitting Diode) screens arrive at shops. This is because there are problems with uneven ageing of luminescent materials used in their manufacture. University and industrial laboratories around the world are working on improving the materials used for the manufacture of these devices and on improving their performance, so that the requirements of the industry and of everyday applications are met. Perhaps, traditional light bulbs will in the future be substituted by lighting planes emitting white light. One company, Universal Display Corporation, announced that they have developed a PHOLED technology that allows 100% transformation of electrical energy into light [5].
Water competition, variability and river basin governance: a critical analysis of the Great Ruaha River, Tanzania.

This chapter analyses historical irrigation and river basin developments and narratives to demonstrate particular dimensions of water competition in the Great Ruaha River basin in southern Tanzania. Alongside this, we identify three interrelated scalar and emergent dynamic behaviours revealed as a part of basin development. These ‘systems’ behaviours relate to the growth and coalescing of areas of smallholder irrigated farms since the late 1950s. The three concepts are termed ‘parageoplasia’,1 ‘nonequilibrium behaviour’ and ‘share modification’. These insights provide additional layers to the ideas captured in Molle’s (2003) conceptual framework for river basin development, specifically on the demand–supply equation, where we bring additional thinking to his allocation ‘third way’ and on the nature of basin development. While exploring the broad narrative of growth in water demand, we explore further dimensions arising from a highly variable inter-/intra-annual water availability, which affects the distribution of water and impacts of this growth curve, as informed by a sub-Saharan environment. As well as explaining the concepts terms, we argue that the ideas revealed by this case study might have application to smallholder irri gation elsewhere in savannah agro-ecologies in Africa. The chapter explores how this analysis leads to new insights – particularly in relation to adaptation to climatic change expressed through increased variability of rainfall and river flow (Milly et al., 2008).
Model Predictive Control of Ride-sharing Autonomous Mobility-on-Demand Systems

This paper presents a model predictive control (MPC) approach to optimize routes for Ride-sharing Autonomous Mobility-on-Demand (RAMoD) systems, whereby self-driving vehicles provide coordinated on-demand mobility, possibly allowing multiple customers to share a ride. Specifically, we first devise a time-expanded network flow model for RAMoD. Second, leveraging this model, we design a real-time MPC algorithm to optimize the routes of both empty and customer-carrying vehicles, with the goal of optimizing social welfare, namely, a weighted combination of customers’ travel time and vehicles’ mileage. Finally, we present a real-world case study for the city of San Francisco, CA, by using the micro-scopic traffic simulator MATSim. The simulation results show that a RAMoD system can significantly improve social welfare with respect to a single-occupancy Autonomous Mobility-on-Demand (AMoD) system, and that the predictive structure of the proposed MPC controller allows it to outperform existing reactive ride-sharing coordination algorithms for RAMoD.
User Personalization based Product Ranking using Sentimental Reviews

The internet has dramatically changed the life of people by creating a new way for expressing their views and opinions on products of various domains. There are millions of products sold online by various merchants every year. These merchants allow their consumers to post their reviews on different products. The consumer reviews contribute to obtain quality information of the products. There is huge collection of consumer reviews are now available on the internet. This makes it difficult for the consumers to take wise decision on purchasing product. The consumer reviews are disorganized in nature due to that it creates difficulties in information navigation and knowledge acquisition in product reviews. In this case, the aspect gives the clear vision on the quality of the product. The existing methods are used to identify and rank product aspects automatically based on their weights and aspect rating. In this paper, we have personalized aspect ranking of the product by taking personnel preferences of the consumers. The proposed modified user personalization based product ranking approach solves the problem of meaningless reviews. This approach allows consumers to post reviews in the form of text review, sentimental review and product rating. The experimental results confirm that the proposed modified technique is highly effective. It outperforms the existing methods consequently.
Infiltration from an impoundment for coal‐bed natural gas, Powder River Basin, Wyoming: Evolution of water and sediment chemistry

Development of coal‐bed natural gas (CBNG) in the Powder River Basin, Wyoming, has increased substantially in recent years. Among environmental concerns associated with this development is the fate of groundwater removed with the gas. A preferred water‐management option is storage in surface impoundments. As of January 2007, permits for more than 4000 impoundments had been issued within Wyoming. A study was conducted on changes in water and sediment chemistry as water from an impoundment infiltrated the subsurface. Sediment cores were collected prior to operation of the impoundment and after its closure and reclamation. Suction lysimeters were used to collect water samples from beneath the impoundment. Large amounts of chloride (12,300 kg) and nitrate (13,500 kg as N), most of which accumulated naturally in the sediments over thousands of years, were released into groundwater by infiltrating water. Nitrate was more readily flushed from the sediments than chloride. If sediments at other impoundment locations contain similar amounts of chloride and nitrate, impoundments already permitted could release over 48 × 106 kg of chloride and 52 × 106 kg of nitrate into groundwater in the basin. A solute plume with total dissolved solid (TDS) concentrations at times exceeding 100,000 mg/L was created in the subsurface. TDS concentrations in the plume were substantially greater than those in the CBNG water (about 2300 mg/L) and in the ambient shallow groundwater (about 8000 mg/L). Sulfate, sodium, and magnesium are the dominant ions in the plume. The elevated concentrations are attributed to cation‐exchange‐enhanced gypsum dissolution. As gypsum dissolves, calcium goes into solution and is exchanged for sodium and magnesium on clays. Removal of calcium from solution allows further gypsum dissolution.
Preliminary and Incomplete Comments Welcome Early Test Scores , Socioeconomic Status and Future Outcomes

This paper uses data from the National Child Development Survey of an entire cohort of children born in Britain in one week in 1958. We show that test scores measured as early as age 7 have significant effects on future educational and labor market outcomes, even after a wide array of observable characteristics have been controlled for. The effects are similar or larger than those of other observed characteristics of the children. Perhaps unsurprisingly, it is easier to predict future test scores given past test scores, than to predict schooling attainments or labor market outcomes. A striking result is that among men, early test scores are better predictors of wages and employment at age 33 than at age 23. Among women, one observes the same pattern for wages, but it is generally more difficult to predict employment at age 33 than at age 23, presumably because many women take time out of labor market careers to care for children. We test several hypotheses about the interactions between socioeconomic status and high or low test scores at age 7. Compared to other children (and in terms of educational attainments), lowSES children reap both larger gains from having high age 7 test scores and smaller losses from having low age 7 test scores. The opposite is true among high-SES children who suffer large losses from low scores and small gains from high scores. The hypothesis of systematic test bias against low-SES students offers one way to interpret these results. Janet Currie Duncan Thomas UCLA and NBER RAND and UCLA Dept. of Economics, UCLA 1700 Main St. 405 Hilgard Ave. Santa Monica CA 90403 Los Angeles 90095-1477 dt@rand.org currie@simba.sscnet. ucla.edu
Different morphology of Nuphar lutea in two contrasting aquatic environments and its effect on ecosystem engineering

Aquatic plants (macrophytes) can have a large effect on river hydraulics and geomorphology. Though, the extent to how plant morphological plasticity actively influences these feedbacks has received little scientific attention. The nymphaeid macrophyte species Nuphar lutea (L.) Smith is characterized by a distinct leaf duality. Floating leaves shade most of the submerged leaves thereby limiting light penetration in the water. Despite their apparent negligible photosynthetic role, submerged leaves of N. lutea remain intact during summer and contribute a significant part to the total biomass. Our results indicate that the submerged leaves are crucial in plant–flow interactions and hence in the engineering potential of the plant, i.e. the capacity to locally reduce flow velocities and to promote sedimentation, including organic matter deposition. Plant individuals growing in running river water were compared to individuals from adjacent oxbow lake water. The number and size of submerged leaves were significantly higher for river standing individuals and the accumulated sediment contained significantly more organic matter, total nitrogen and total phosphorus, and was characterized by a lower carbon/nitrogen ratio and a finer grain size. We therefore argue that the submerged N. lutea canopy in rivers has the ability to create a high‐nutrient, low hydrodynamic environment, resembling the conditions found in oxbow lakes. Copyright © 2014 John Wiley & Sons, Ltd.
In Situ Filtration Rates of Blue Mussels ( Mytilus edulis ) Measured by an Open-Top Chamber Method

Blue mussels, Mytilus edulis , form dense beds of both commercial and ecological importance, and many attempts have been made to determine their filtration rate. The total time in which mussels actually utilise their filtration capacity in nature varies greatly, making in situ methods for filtration rate measurements relevant. Further, it is being debated to what extend filtration rates measured in the laboratory using cultivated algal cells may apply for mussels in nature. In the present study, we have used an open-top chamber setup in order to allow repeated in situ filtration rate measurements of M. edulis using ambient natural phytoplankton and free-living bacteria. We found that the in situ measured filtration rates are comparable to filtration rates obtained in laboratory studies using different methods and controlled diets of cultivated algal cells. Further, we found that the retention efficiency of free-living bacteria was between 22.2% and 29.9%, in good agreement with values from laboratory studies. Our findings support the assumption that mussels in nature tend to use their filtration capacity when the phytoplankton concentration is above a certain lower trigger level.
Multi-objective ranking and selection: Optimal sampling laws and tractable approximations via SCORE

ABSTRACT Consider the multi-objective ranking and selection (MORS) problem in which we select the Pareto-optimal set from a finite set of systems evaluated on three or more stochastic objectives. Toward determining how to allocate a simulation budget among the systems, we characterise the asymptotically optimal sample allocation that maximises the misclassification-probability decay rate, and we provide an implementable allocation called MO-SCORE. The MO-SCORE allocation simultaneously controls the probabilities of misclassification by exclusion and inclusion, identifies phantom Pareto systems crucial for computational efficiency, and models dependence between the objectives. The MO-SCORE allocation is fast and accurate for problems with three objectives or a small number of systems. For problems with four or more objectives and a large number of systems, we propose independent MO-SCORE (iMO-SCORE). Our numerical experience is extensive and promising: MO-SCORE and iMO-SCORE can be used to solve MORS problems involving several thousand systems in three and four objectives.
Evaluation of the Town Energy Balance (TEB) Scheme with Direct Measurements from Dry Districts in Two Cities

Abstract The Town Energy Balance (TEB) model of Masson simulates turbulent fluxes for urban areas. It is forced with atmospheric data and radiation recorded above roof level and incorporates detailed representations of the urban surface (canyon geometry) to simulate energy balances for walls, roads, and roofs. Here the authors evaluate TEB using directly measured surface temperatures and local-scale energy balance and radiation fluxes for two “simple” urban sites: a downtown area within the historic core of Mexico City, Mexico (stone buildings five to six stories in height), and a light industrial site in Vancouver, British Columbia, Canada (flat-roofed, single-story warehouses). At both sites, vegetation cover is less than 5%, which permits direct evaluation of TEB in the absence of a coupled vegetation scheme. Following small modifications to TEB, notably to the aerodynamic resistance formulations, the model is shown to perform well overall. In Mexico City, with deep urban canyons and stone walls, almos.
Sensing Precipitable Water Vapor (PWV) using GPS in Turkey – Validation and Variations

In the last two decades, the Global Positioning System (GPS) has been widely used in naviga‐ tion, positioning, timing and related sciences. However, GPS observations are subject to several sources of error, such as clock biases, multi-path delay, and ionospheric and tropo‐ spheric delays. Particularly, the tropospheric delay significantly affects the GPS signals and causes errors of several meters in positioning. Since the GPS signal is sensitive to the tropo‐ spheric refractive index, which is dependent on the pressure, temperature and moisture, GPS can be used for sensing these properties in the troposphere, e.g.,tropospheric water vapor [12, 13]. Although studies have demonstrated to successfully estimate PWV from GPS within 1-2 mm of accuracy at 15-minute temporal resolution, a number of factors still affect PWV accuracies, e.g., mapping functions and Earth’s tide models, [14, 11].
Challenges and Proposals for Enabling Dynamic Heterogeneous Execution of Big Data Frameworks

The efficient execution of Big Data applications requires a large quantity of compute and memory resources. Typically, these resources are in the form of data centres with numerous processing elements connected through a computer network. Although initially the majority of data centers were utilizing only CPU resources, nowadays we can find heterogeneous accelerators such as GPUs and FPGAs. Ideally, Big Data frameworks and applications should exploit those diverse hardware resources in order to push their performance boundaries or increase resource utilization. Despite ongoing work to enable such functionality, the majority of the solutions revolve around external libraries that provide pre-compiled kernels for heterogeneous accelerators. This fact imposes programmability and code fragmentation challenges that can only be addressed by enabling Big Data platforms to dynamically compile and execute their code on such devices. In this paper we analyze and discuss the major challenges for programming and executing Big Data processing applications on distributed systems with heterogeneous hardware. In addition, we present our work-in-progress towards providing a heterogeneous programming framework for running Big Data applications on systems that include diverse hardware resources including CPUs, GPUs, and FPGAs. In contrast to existing approaches, our envisioned solution employs JIT compilation and runtime support, integrated in the data flow engine, enabling the automatic acceleration of Big Data platforms completely transparently to the user and without sacrificing programmability.