nils-herrmann/clean_scirepeval huggingface dataset:
Single-Carrier Frequency Domain Equalization for Hammerstein Communication Systems Using Complex-Valued Neural Networks

Single-carrier (SC) block transmission with frequency-domain equalization (FDE) offers a viable transmission technology for combating the adverse effects of long dispersive channels encountered in high-rate broadband wireless communication systems. However, for high-bandwidth efficiency and high-power-efficiency systems, the channel can generally be modeled by the Hammerstein system, which includes the nonlinear distortion effects of the high-power amplifier (HPA) at transmitter. For such nonlinear Hammerstein channels, the standard SC-FDE scheme no longer works. This paper advocates a complex-valued (CV) B-spline neural-network-based nonlinear SC-FDE scheme for Hammerstein channels. Specifically, we model the nonlinear HPA, which represents the CV static nonlinearity of the Hammerstein channel, by a CV B-spline neural network, and we develop two efficient alternating least squares schemes for estimating the parameters of the Hammerstein channel, including both the channel impulse response coefficients and the parameters of the CV B-spline model. We also use another CV B-spline neural network to model the inversion of the nonlinear HPA, and the parameters of this inverting B-spline model can easily be estimated using the standard least-squares algorithm based on the pseudo training data obtained as a natural byproduct of the Hammerstein channel identification. Equalization of the SC Hammerstein channel can then be accomplished by the usual one-tap linear equalization in the frequency domain as well as the inverse B-spline neural network model obtained in the time domain. Extensive simulation results are included to demonstrate the effectiveness of our nonlinear SC-FDE scheme for Hammerstein channels.

Field of study: Engineering
Simulation of the Recent Multidecadal Increase of Atlantic Hurricane Activity Using an 18-km-Grid Regional Model

In this study, a new modeling framework for simulating Atlantic hurricane activity is introduced. The model is an 18-km-grid nonhydrostatic regional model, run over observed specified SSTs and nudged toward observed time-varying large-scale atmospheric conditions (Atlantic domain wavenumbers 0–2) derived from the National Centers for Environmental Prediction (NCEP) reanalyses. Using this “perfect large-scale model” approach for 27 recent August–October seasons (1980–2006), it is found that the model successfully reproduces the observed multidecadal increase in numbers of Atlantic hurricanes and several other tropical cyclone (TC) indices over this period. The correlation of simulated versus observed hurricane activity by year varies from 0.87 for basinwide hurricane counts to 0.41 for U.S. landfalling hurricanes. For tropical storm count, accumulated cyclone energy, and TC power dissipation indices the correlation is ~0.75, for major hurricanes the correlation is 0.69, and for U.S. landfalling tropical st...

Field of study: Environmental science
On investigating overlay service topologies

Recently, a moderate amount of work has been reported on the use of overlay networks to support value-added network services, such as multicasting, Quality-of-Service (QoS), security, etc. To design an overlay network, the first step is to choose an overlay topology connecting all the overlay service nodes. When considering overlay topologies, several questions need to be answered first: How overlay topologies affect overlay routing performance? Which topologies can provide satisfactory performance? How can we construct efficient overlay topologies connecting all the overlay nodes? 
 
In this paper, we focus on the overlay network topology construction issue. First, we evaluate and compare the performance and overhead of the existing overlay topologies. Second, we formalize the overlay topology construction problem and propose two new heuristic methods to construct efficient overlay topologies. Simulation results have demonstrated the efficiency of the two proposed approaches. It is shown that overlay service performance varies significantly with respect to different overlay topologies. Thus, it is important to choose an appropriate overlay network topology. The knowledge of IP-layer topology information also benefits significantly in constructing efficient overlay topologies as inferred from the results.

Field of study: Computer science
Purification of protein from a crude mixture through SDS-PAGE transfer method.

SDS-polyacrylamide gel electrophoresis (SDS-PAGE) transfer method was used for purification and enrichment of the protein from crude sample. Coomassie bluc/ZnSO4 stained protein band(s) containing intact polyacrylamide gel were loaded on to another polyacrylamide gel either alone or as pooled gel bands. Two/three bands were combined together and arranged tightly over one another, sealed with stacking gel and ran in another gel, which was quite useful for enrichment and purification of a particular protein from a complex mixture. Recovery of protein by gel transfer method was found to be 70% in case of ZnSO4 staining, whereas around 30% recovery was possible, following Coomassie blue staining. The method described here for purification of protein(s) from a complex mixture, following gel transfer procedure could be useful for further characterization of the desired protein.

Field of study: Biology, Chemistry, Physics
Carbon dioxide laser for detrusor tunnel creation in robot-assisted laparoscopic extravesical ureteral reimplant.

Demonstrate and report initial results using a carbon dioxide (CO2) laser for detrusor tunnel creation in robot-assisted laparoscopic extravesical ureteral reimplant (RALUR).



Retrospective chart review was performed for cases of RALUR from 2011 to 2014. Patients undergoing complex reconstruction (ureteral tailoring, dismembered reimplant, concomitant ureteroureterostomy), and those who had incomplete follow-up were excluded. Variables, including use of the CO2 laser, were collected and correlated with outcomes.



23 patients representing 40 ureteral units were included for analysis. A CO2 laser was used in 9/23 (39%) patients and 16/40 (40%) ureteral units. Intraoperative mucosotomy was reported in 3/14 (21%) patients for the electrocautery group and 1/9 (11%) patients for the CO2 laser group. Resolution of VUR was observed in 11/14 (79%), and 9/9 (100%) of patients for the electrocautery group and the CO2 laser group, respectively. Two complications were identified in the electrocautery group of patients: ileus (Clavien 2), and transient bilateral ureteral obstruction requiring placement of ureteral stents (Clavien 3B). There were no complications in the CO2 laser group.



Creation of the detrusor tunnel with a CO2 laser is safe and effective, and is associated with a lower rate of failure and complication in this cohort.

Field of study: Medicine
Complex interactions between day length and diurnal patterns of gene expression drive photoperiodic responses in a perennial C4 grass.

Photoperiod is a key environmental cue affecting flowering and biomass traits in plants. Key components of the photoperiodic flowering pathway have been identified in many species, but surprisingly few studies have globally examined the diurnal rhythm of gene expression with changes in day length. Using a cost-effective 3'-Tag RNA sequencing strategy, we characterize 9,010 photoperiod responsive genes with strict statistical testing across a diurnal time series in the C4 perennial grass, Panicum hallii. We show that the vast majority of photoperiod responses are driven by complex interactions between day length and sampling periods. A fine-scale contrast analysis at each sampling time revealed a detailed picture of the temporal reprogramming of cis-regulatory elements and biological processes under short- and long-day conditions. Phase shift analysis reveals quantitative variation among genes with photoperiod-dependent diurnal patterns. In addition, we identify three photoperiod enriched transcription factor families with key genes involved in photoperiod flowering regulatory networks. Finally, coexpression networks analysis of GIGANTEA homolog predicted 1,668 potential coincidence partners, including five well-known GI-interacting proteins. Our results not only provide a resource for understanding the mechanisms of photoperiod regulation in perennial grasses but also lay a foundation to increase biomass yield in biofuel crops.

Field of study: Environmental science
The Weusi Artists

This essay outlines the formation of the Weusi Artists, begun in Harlem in 1965 as an African American artists’ collective. The word Weusi translates as “blackness” in Swahili. Together the artists founded a gallery and academy of fine arts and studies, both of which became great motivating forces in the development, production, and dissemination of black art during the 1960s and 1970s.

Field of study: Art
A variable refractive null lens.

Null lenses, for use with rotationally symmetric but nonspherical surfaces, are extremely useful for testing during production. In general, each different system to be tested requires a different null lens. A variable null lens is proposed which consists of two aspheric plates, each of which introduces approximately fourth- or sixth-order spherical aberration. When the plates are inserted in a diverging beam, the effect on the wavefront may be changed by varying the plate spacing. The system may be used to test parabolas and other nonspherical mirrors at center of curvature, aspheric plates in conjunction with spherical mirrors, and various other systems. Once the two plates have been produced and measured, the spacing of the plates used may be determined for each test. This would normally be done by computer, using any of the optimization techniques for lens design. Examples are shown, and an estimate of obtainable accuracy is given.

Field of study: Physics
Research and Development of Rapid Casting Process

The rapid casting process,which is an integration of rapid prototyping and the casting process,is introduced.the expandable patterns,die of expandable patterns,pattern,pattern plate,casting mould,casting cores and mould shells can be made directly or indirectly by rapid prototyping,then the metal castings can be manufactured rapidly by conventional casting technology.By introducing the principle of the rapid prototyping into the moulding process,the binders and catalyst are sprayed on the moulding sands or ceramics powders,the casting mould can be obtained after curing and coated by refractory coating,then can be used for pouring of liquid metals.Rapid casting processes can increase the production efficiency and is suited for the small batch of various complicated components.Hence,it has a good prospect.

Field of study: Materials science
Study in vitro of the down--regulating effects of As_(2)O_(3) on secretion of immunosuppressive molecules from Colon26 tumor cells

To study in vitro the down-regulating effects of As_2O_3 on secretion of immunosuppressive molecules from Colon26 tumor cells.  Re-cultured supernatants of Colon26 after treated by As_2O_3 and the corresponding supernatants of Colon26 treated without As_2O_3 as control were collected. The concentrations of five immunosuppressive molecules(including TGF-β1, VEGF, IL-4, IL-6 and IL-10) in different supernatants were measured by quantitative ELISA. The effects of different supernatants on five immunofunctions of murine splenocytes(including NK killing and transformation induced by Con A detected by MTT, and expression levels of IL-2Rα, CD3e~+ζ~+ and CD3e~-ζ~+ detected by FCM) were determined.  For supernatants of Colon26 treated without As_2O_3, all of five immunosuppressive molecules were found, the concentration of TGF-β1 was highest, and the significant inhibitions of five immunofunctions of murine splenocytes were showed. For Colon26 after treated by As_2O_3, the concentrations of five immunosuppressive molecules in the first re-cultured supernatant and its inhibition of the four immunofunctions except of CD3e~-ζ~+ expression decreased greatly. Compared with the first re-cultured supernatant, the concentrations of TGF-β1, VEGF and IL-4 in the second re-cultured supernatant and its inhibition of NK killing, transformation induced by Con A and CD3e~+ζ~+ expression increased highly, and others had no changes. The analysis of correlation indicated the positive correlations existed between TGF-β1 or IL-10 and inhibition of transformation induced by Con A or IL-2Rα expression, between IL-4 and inhibition of NK killing or transformation induced by Con A or CD3e~+ζ~+ expression, and not between VEGF or IL-6 and inhibition of five immunofunctions.  As_2O_3 can down-regulate secretion of immunosuppressive molecules by Colon26.The down-regulating effects on secretions of TGF-β1, VEGF and IL-4 can last for 48 h, and on secretions of IL-6 and IL-10 can last for 96 h at least. This effect should be one of anti-tumor mechanisms of As_2O_3.

Field of study: Biology
Organic inverter: Theoretical analysis using load matching technique

This paper reports the analysis of key parameters affecting voltage transfer characteristics of pseudo PMOS organic inverters. Pentacene has been used as active material for PMOS Organic Thin Film transistor (OTFT). We have used two different inverter configurations for thorough analysis. Each configuration comprises of an enhancement mode driver ( V Threshold  = −9.7 V) and a depletion mode load ( V Threshold  = 11.7 V). First configuration has its source and gate terminals shorted. While, second configuration differs with its drain and gate terminals shorted. In order to surmise the theoretical performance of the inverters, we have used load matching technique. After investigating various parameters such as inverting gain, noise margin values (immunity to noise error signals) and threshold voltage value, influencing the voltage inverting efficiency of the two configurations mentioned above, it was found that an inverter with shorted source-gate load configuration is better of the two due to privileges such as saturation mode operation of load, low driver current with early saturation of enhancement mode driver, which facilitates full swing output voltage operation. Second configuration with shorted drain-gate load, lacks saturation mode operation of load and fails to deliver high voltage swing along with acceptable noise margin values and inverting gain.

Field of study: Engineering
TH‐C‐303A‐08: Prostate Localization Using Daily Cone‐Beam Computed Tomography Imaging: Assessment of Accuracy Using Similarity Metrics and Observation‐Based Measures

To estimate the accuracy of daily CBCT/CT prostate rigid‐body registrations using different similarity metrics (SM) and observation‐based measures, and to determine the tradeoffs of these methods.  Daily CBCTimages of 29 prostate cancer patients were retrospectively analyzed; 14 patients with calcifications in the prostate (calcification dataset) and 15 patients without calcifications (no‐calcification dataset). Three groups of test registrations were performed. , and compared using the calcification mismatch vector length as an end‐point. Test2: Using the 4 best SMs based on Test1, 75 CBCT/CT pairs from the no‐calcification dataset were registered using visual comparison as the endpoint (300 registrations), i.e. the accuracy of prostate contour overlays on CBCTimages were visually ranked. Test3: For the top ranked SM based on the above 2 tests, the registration accuracy was estimated from 356 CBCT/CT registrations from 11 patients in the calcification dataset with and without calcification filtering from registrations.  Test1: Incremental‐sign‐correlation (ISC), gradient‐correlation (GC), gradient‐difference (GD), and normalized‐cross‐correlation (NCC) were the SMs with the least vector length errors (μ±σ: 1.6±0.9∼2.9±2.1 mm).  Using visual criteria, 2 of the 3 reviewers ranked GC slightly higher than the other SMs.  Using GC, 96% of registrations (341/356 registrations) showed less than 3 mm error when calcifications were filtered. Corresponding errors were L/R:0.1±0.5 mm, A/P:0.8±1.0 mm, and S/I: 0.5±1.1 mm. Existence of prostate calcifications increased the number of successful registrations to 97%.  The estimated <3mm error was approximately 96% (1.1 mm SD) using GC, ISC and GD similarity measures. These measures offer a relatively quick and accurate means of assessing CBCT/CT registrations in the routine clinical setting. User observation is a necessary requirement in the overall QA of the process.

Field of study: Medicine, Physics
Cobalt Doped Orthorhombic LiMnO2 as Cathode Materials for Lithium-Ion Batteries

Orthorhombic type LiCoxMn1−xO2 (0 ≤ x ≤ 0.14) oxides have been synthesized by hydrothermal treatment of (CoxMn1−x)3O4 precursors and LiOH aqueous solution at 170 °C. As-synthesized powders showed well-ordered β-NaMnO2 structures, and the products were single crystalline particle oxides from TEM observations. The particle size decreased with increasing the amount of Co substituent. Much more improved capacity upon 100 cycling was clearly seen in orthorhombic LiCo0.1Mn0.9O2, comparing to orthorhombic LiMnO2.

Field of study: Chemistry
Notions of Human Capital and Academic Identity in the PhD: Narratives of the Disempowered

An important component of PhD students’ educational experiences is the understanding they develop of their academic identity. In this study, we explore PhD students’ expectations and lived realities during their studies through the lens of Bourdieu’s theory of practice. We show that doctoral students perceive the PhD as an all-consuming endeavor and, at the same time, a degree of competing demands. Importantly, several doctoral students’ academic identities were laden with conceptions of marginalization, which evoked feelings of disempowerment and lead to a lack of agency. Therefore, this study advocates for a doctoral environment where different forms of human capital are valued and the voices of PhD students are respected within the academy. This will ensure that future scholars are able to enter the academy with a strong sense of who they are and where they fit within their field.

Field of study: Education
Kinetics of ultrasonic degradation of polysaccharide from Porphyra yezoensis

Due to some deficiencies of the polysaccharides degradation by the methods of chemical,thermal or enzymatic treatment,sonication was introduced for the degradation of Porphyra yezoensis polysaccharide(PYPS).The Mark-Houwink equation,showing the relationship between molecular weight and intrinsic viscosity,was set up.It was found from the results of the degradation dynamics that there was an exponential relation between the rate constant and treatment time of sonication,different from the traditional chemical,thermal or enzymatic treatment.The activation energy of the degradation was 52.13 kJ·mol-1,and it could be preliminarily concluded that ultrasonic degradation was better than the enzymatic ones.

Field of study: Chemistry, Environmental science
Contradictions of Green Development: Human Rights and Environmental Norms in Light of Belo Monte Dam Activism

This paper offers a historical examination of the ways in which advocacy strategies and tactics have shifted in relation to political opportunities, using a case study of a hydroelectric dam project in the Brazilian Amazon, known as the Belo Monte Dam. Drawing on over three decades of resistance by transnational activist coalitions, the paper looks at how new tactics and political alignments have altered the dynamics of activism and norm diffusion in Brazilian domestic environmental, human rights and development policies. The paper argues that current theories of norm diffusion inadequately explain backslides and tend to underestimate the complexity of domestic political alignments. The case adds political insight to our understanding of the relationship of transnational advocacy strategy to environmental and human rights political realities in Brazil.  Este artículo ofrece un examen histórico de las formas en las que las tácticas y estrategias de defensa al medio ambiente han variado según las oportunidades políticas, utilizando como caso de estudio el proyecto de una hidroeléctrica en la Amazonia brasileña conocida como la presa de Belo Monte. Basándose en más de tres décadas de resistencia de parte de coaliciones de activistas transnacionales, este material se pregunta cómo las nuevas tácticas y nuevos alineamientos políticos han alterado las dinámicas del activismo y la difusión de normas en las políticas brasileñas relacionadas al medio ambiente, a los derechos humanos, y al desarrollo. El material señala que las actuales teorías de difusión de normas explican inadecuadamente los retrocesos y tienden a subestimar la complejidad de los alineamientos políticos domésticos. El caso contribuye a entender mejor, en términos políticos, la relación entre las estrategias transnacionales de activismo y las actuales realidades políticas medioambientales y de derechos humanos en Brasil.  Este artigo apresenta um exame histórico das maneiras pelas quais estratégias e táticas de defesa de direitos têm mudado em relação às oportunidades políticas, utilizando como estudo de caso o projeto de uma hidrelétrica na Amazônia brasileira conhecida como Belo Monte. Usando como base mais de três décadas de resistência por coalizões de ativistas transnacionais, este artigo discute como novas táticas e alinhamentos políticos têm alterado as dinâmicas de ativismo e difusão de normas nas políticas brasileiras em relação ao meio ambiente, aos direitos humanos e ao desenvolvimento. O artigo argumenta que teorias atuais de difusão de normas explicam os retrocessos de maneira inadequada e tendem a subestimar a complexidade dos arranjos políticos domésticos. O caso insere conhecimento político ao nosso entendimento da relação entre estratégias transnacionais de ativismo e as realidades políticas, ambientais e de direitos humanos atuales no Brasil.

Field of study: Political science
Historical Dictionary of Mesoamerica by Walter R. T. Witschey and Clifford T. Brown (review)

The market for dictionaries, handbooks, and guides to ancient Mesoamerica seems to be a busy one, since hardly a year goes by without another entry into the crowded marketplace. The latest entry is this historical dictionary, part of a series of similar works from Scarecrow Press, an imprint of Rowman and Littlefield. This volume contains some 900 entries on important aspects of ancient Mesoamerica, from Acalan (Campeche) to Zempoala (Veracruz). It includes sites, civilizations, deities, themes (for example, medicine and flowers), and individuals, such as Pacal (ruler of Palenque). Unfortunately the title is a bit misleading, as the dictionary focuses significantly on the Maya with only passing entries for the other civilizations of ancient Mesoamerica.

Field of study: History
Leisure-rich and leisure-poor: the leisure patterns of young adults

Some of the results of an investigation into the leisure patterns and lifestyles of 200 ‘young adults’ living in the Potteries are presented. On the basis of selected attributes of their leisure behaviour, respondents were classified into six leisure activity types and ordered along a spectrum from ‘leisure-rich’ to ‘leisure-poor’. While some of the results correspond with what might be expected from previous work, there are also interesting differences. In particular, high levels of participation in leisure activities do not necessarily equate directly with high levels of satisfaction. Moreover, by differentiating groups in this way, it is also possible to begin to identify those who are ‘at risk’ or ‘at benefit’ in what has traditionally been regarded as a homogeneous and non-problematic phase of the life cycle.

Field of study: Sociology