bluuebunny/crossref_metadata_2025_split huggingface dataset:
PV Inverter with Decoupled Active and Reactive Power Control to Mitigate Grid Faults
Authors: Talha M , Raihan S. R. S. , Rahim N.A. 
Published: April 2021

Abstract
Low power distributed Photovoltaic (PV) systems would be a dominant power generator in future grids. This PV penetration significantly influence the grid stability, especially in an event of grid faults. Traditional PV inverters disconnect themselves from grid on detecting a low voltage at their point of common coupling (PCC). A temporary low voltage grid fault can lead to outage, if PV inverters are not equipped with low voltage ride through (LVRT) feature. During a low voltage grid fault PV inverter can assist the grid recovery process by not only staying connected to grid but also injecting reactive power into the grid. Many grid code standards have issued guidelines to inject reactive power during a low voltage fault. Development of low voltage ride through inverters require decoupled power flow control. In addition to maximum power point operation and standardized current injection to the grid, modern PV inverters should be able to deal with LVRT and loss of grid (LoG) ride through features, as demanded by the regulating grid codes. Reduction in grid outages can be achieved, if the PV inverters stay connected during LVRT, LoG and short circuit faults. Most of previous studies on LVRT control of PV inverters have not short circuit faults and loss of grid faults at PCC. This work proposed a PV inverter controller capable of controlling complex power into the grid. A decoupled current regulator with feed forward compensation is modelled. A short circuit grid fault is also tested with the developed PV inverter. It is found that the PV inverter ride through the low voltage and short circuit faults. The system is simulated in MATLAB(Simulink), the designed controller can provide decoupled active and reactive power to the grid during the fault events.
Investigate the Effect of Artificial Neural Network Parameters to Improve Fault Distance and Impedance Accuracy
Authors: Ali Mohd Syukri , Bakar Ab Halim Abu , Nasrudin Abd Rahim 
Published: April 2021

Abstract
This paper investigates the effect of artificial neural network (ANN) parameters against the ANN accuracy on cable fault location. The investigation is conducted through the fault impedance and distance estimations during the occurrence of high impedance fault (HIF) in the distribution system. The measured three-phase voltage and current signals are utilized and fed into the ANN to estimate the fault impedance and distance. The accuracy of the estimated fault impedance and distance is evaluated with respect to the variation of ANN parameters. Based on the analysis, it shows that more accurate results can be obtained by utilizing the optimal value of ANN parameters.
Parametric Evaluation of 11kV Zinc Oxide Surge Arrester using Finite Element Analysis Model
Authors: Nurul A.A. Latiff , Sameh Z.A. Dabbak , Hazlee A. Illias , Bakar Ab H.A. 
Published: April 2021

Abstract
A surge arrester on transmission line is used to deflect lightning surge to ground, avoiding power systems from destruction. During normal condition, there is a leakage current flow through surge arresters where it is one of the main causes of surge arrester humiliation. Thus, monitoring the surge arrester condition is very significant. In this work, the effect of several parameters in a 11kV zinc oxide surge arrester design based on leakage current distribution has been studied. A comparison is made between measurements and modelling in order to validate the model that has been developed using finite element analysis. This work found that the benefit of using FEA-based model where the design parameters that affect the leakage current can be identified. Through this study, a well knowledge of leakage current can be achieved and also help in zinc oxide surge arrester design.
Design of a small scale fluidized-bed incinerator for MSW with ability to utilize HHO as auxiliary fuel
Authors: Butt Osama Majeed , Ahmad Muhammad Shakeel , Che Hang Seng , Rahim Nasrudin Abd 
Published: April 2021

Abstract
Waste incineration has become a mature technology and widely accepted due to its environment friendliness, easy operation and ability to reduce more than 95% mass fraction. There are some inherent limitations associated with incinerators such as high fuel consumption and cite feasibility. In this study, we propose a novel design concept of small scale fluidized bed incinerator for household use, with the ability to consume brown’s gas (HHO) as primary fuel for incinerate waste. In principle, the HHO gas generated through photovoltaic (PV) integrated water electrolysis system would be feed from the bottom to provide heat energy to the waste. Theoretical design of fluidized bed type incinerator has been presented with water electrolyzer system. It was calculated that 150 lph of hydrogen is required for this proposed incinerator system which can handle 5 kg of waste.
Photovoltaic performances and lifetime analysis of TiO2/rGO DSSCs sensitized with Roselle and N719 dyes
Authors: Omar A , Fakir M S , Hamdan K S , Rased N H , Rahim N A 
Published: April 2021

AbstractTwo titanium dioxide/reduced graphene oxide (TiO2/rGO) based dye-sensitized solar cells (DSSCs) were fabricated and separately sensitized with natural dye extracted from Roselle flowers and ruthenium-based dye of N719. The current-voltage (I-V) performances were measured using Visiontec Solar I-V tester at standard illumination of AM1.5 and irradiance level of 100 mW/cm2. The lifetime of the TiO2/rGO based DSSCs were furtherly investigated by measuring the I-V performances of the cells on the 5thday and 15thday. The highest power conversion efficiency (PCE) of 1.233 % was measured for the photoanode sensitized with N719 dye on the 15thday. The PCE of Roselle dye dropped from 0.992 % on the 5thday to 0.897 % on the 15thday. Dye degradation and low electron injection have influenced the unstable photovoltaic performances of Roselle dye even with the presence of electron conducting path provided by the rGO particles.
P(HEMA-co-EA) as host polymer for flexible dye-sensitized solar cell (DSSC) electrolyte
Authors: Rased N H , Raihan S R S , Rahim N A 
Published: April 2021

AbstractAn electrolyte is the main component of a dye-sensitized solar cell (DSSC) which influences the efficiency of the DSSC. In order to prevent leakage problem and adhesive problem, new solid-state polymer electrolyte proposed rather than using a liquid electrolyte. For this research, new copolymers using 2-hydroxyethyl methacrylate (HEMA) and Ethyl Acrylate (EA) monomers are randomly copolymerized via UV-cure polymerization method with different ratio of each monomer (10,30,50,70,90) towards development as a solid-state electrolyte in flexible DSSC. In this study, the best ratio of the copolymer HEMA-co-EA will be the host polymer for electrolyte in DSSC. The most promising characteristics as a host in polymer electrolytes are due to its smooth cross-sectional surface and lowest glass transition temperature. Therefore, a best ratio of p(HEMA-co-EA) will be stirred with sodium iodide (NaI), Tetrahydro folic acid (THF) and iodine crystal for 24 hours to form a homogenous solution of an electrolyte. This p(HEMA-co-EA) will incorporate with different weight ratios of sodium iodide (NaI). This research reported that after 1500 s only three ratios of new host polymer p(HEMA-co-EA) were successfully copolymerized completely. All three ratio will be characterized by physical appearance, FTIR, DSC and XRD. By naked eyes, only 3 ratios of monomer (50HEMA:50EA, 70HEMA:30EA and 90HEMA:10EA) gave brittle structure which proved the copolymerization process completely success. For FTIR, those three ratios show the breakdown of a double bond at the HEMA monomer structure proved the complete copolymerization process. DSC shows that all three ratio shows the glass transition temperature (Tg) and only 50HEMA:50EA gave melting temperature (Tm) at 192.49°C and XRD confirmed the phase structure and crystallinity of three ratios. All these characterizations show that HEMA and EA monomers can be successfully random copolymerize with a three suitable ratio of each monomer and been used as an electrolyte for flexible DSSC.
(Quasi-)Quantization of the electrical, thermal, and thermoelectrical conductivities in two and three dimensions
Authors: Noky Jonathan , Gooth Johannes , Sun Yan , Felser Claudia 
Published: April 2021

Abstract
The quantum Hall effect in a 2D electron system expresses a topological invariant, leading to a quantized conductivity. The thermal Hall and thermoelectric Nernst conductances in two dimensions are also reported to be quantized in specific systems. However, a comprehensive study of these quantities within one formalism for quantum Hall systems is so far elusive. In this work, we investigate the Hall, thermal Hall, and Nernst effects analytically and numerically in 2D and 3D. In addition to the quantized values for the Hall and thermal Hall conductances in two dimensions, we also find quasi-quantized values in three dimensions, which are the related 2D quanta scaled by a characteristic length. The Nernst conductivity is not generally quantized. Instead, an integration in energy is required to obtain a universally (quasi-)quantized thermoelectric quantity.
Conformations and diffusion of flexibly linked colloidal chains
Authors: Verweij Ruben W , Moerman Pepijn G , Huijnen Loes P P , Ligthart Nathalie E G , Chakraborty Indrani , Groenewold Jan , Kegel Willem K , van Blaaderen Alfons , Kraft Daniela J 
Published: April 2021

Abstract
For biologically relevant macromolecules such as intrinsically disordered proteins, internal degrees of freedom that allow for shape changes have a large influence on both the motion and function of the compound. A detailed understanding of the effect of flexibility is needed in order to explain their behavior. Here, we study a model system of freely-jointed chains of three to six colloidal spheres, using both simulations and experiments. We find that in spite of their short lengths, their conformational statistics are well described by two-dimensional Flory theory, while their average translational and rotational diffusivity follow the Kirkwood–Riseman scaling. Their maximum flexibility does not depend on the length of the chain, but is determined by the near-wall in-plane translational diffusion coefficient of an individual sphere. Furthermore, we uncover shape-dependent effects in the short-time diffusivity of colloidal tetramer chains, as well as non-zero couplings between the different diffusive modes. Our findings may have implications for understanding both the diffusive behavior and the most likely conformations of macromolecular systems in biology and industry, such as proteins, polymers, single-stranded DNA and other chain-like molecules.
Adaptive partial scanning transmission electron microscopy with reinforcement learning
Authors: Ede Jeffrey M 
Published: April 2021

Abstract
Compressed sensing can decrease scanning transmission electron microscopy electron dose and scan time with minimal information loss. Traditionally, sparse scans used in compressed sensing sample a static set of probing locations. However, dynamic scans that adapt to specimens are expected to be able to match or surpass the performance of static scans as static scans are a subset of possible dynamic scans. Thus, we present a prototype for a contiguous sparse scan system that piecewise adapts scan paths to specimens as they are scanned. Sampling directions for scan segments are chosen by a recurrent neural network (RNN) based on previously observed scan segments. The RNN is trained by reinforcement learning to cooperate with a feedforward convolutional neural network that completes the sparse scans. This paper presents our learning policy, experiments, and example partial scans, and discusses future research directions. Source code, pretrained models, and training data is openly accessible at https://github.com/Jeffrey-Ede/adaptive-scans.
MPGVAE: improved generation of small organic molecules using message passing neural nets
Authors: Flam-Shepherd Daniel , Wu Tony C , Aspuru-Guzik Alan 
Published: April 2021

Abstract
Graph generation is an extremely important task, as graphs are found throughout different areas of science and engineering. In this work, we focus on the modern equivalent of the Erdos–Rényi random graph model: the graph variational autoencoder (GVAE) (Simonovsky and Komodakis 2018 Int. Conf. on Artificial Neural Networks pp 412–22). This model assumes edges and nodes are independent in order to generate entire graphs at a time using a multi-layer perceptron decoder. As a result of these assumptions, GVAE has difficulty matching the training distribution and relies on an expensive graph matching procedure. We improve this class of models by building a message passing neural network into GVAE’s encoder and decoder. We demonstrate our model on the specific task of generating small organic molecules.
The nilpotent cone for classical Lie superalgebras
Authors: Jenkins L. , Nakano Daniel 
Published: April 2021

In this paper the authors introduce an analogue of the nilpotent cone,

N

{\mathcal N}

, for a classical Lie superalgebra,

g

{\mathfrak g}

, that generalizes the definition for the nilpotent cone for semisimple Lie algebras. For a classical simple Lie superalgebra,

g

=

g

0
¯

⊕

g

1
¯

{\mathfrak g}={\mathfrak g}_{\bar 0}\oplus {\mathfrak g}_{\bar 1}

with

Lie

G

0
¯

=

g

0
¯

\text {Lie }G_{\bar 0}={\mathfrak g}_{\bar 0}

, it is shown that there are finitely many

G

0
¯

G_{\bar 0}

-orbits on

N

{\mathcal N}

. Later the authors prove that the Duflo-Serganova commuting variety,

X

{\mathcal X}

, is contained in

N

{\mathcal N}

for any classical simple Lie superalgebra. Consequently, our finiteness result generalizes and extends the work of Duflo-Serganova on the commuting variety. Further applications are given at the end of the paper.
Heights of points on elliptic curves over ℚ
Authors: Griffin Michael , Ono Ken , Tsai Wei-Lun 
Published: April 2021

In this note we obtain effective lower bounds for the canonical heights of non-torsion points on

E
(

Q

)

E(\mathbb {Q})

by making use of suitable elliptic curve ideal class pairings

Ψ

E
,
−
D

:

E
(

Q

)
×

E

−
D

(

Q

)
↦

C
L

(
−
D
)
.

\begin{equation*} \Psi _{E,-D}: \ E(\mathbb {Q})\times E_{-D}(\mathbb {Q})\mapsto \mathrm {CL}(-D). \end{equation*}

In terms of the class number

H
(
−
D
)

H(-D)

and

T
E

(
−
D
)

T_E(-D)

, a logarithmic function in

D
D

, we prove

h
^

(
P
)
>

|

E

t
o
r

(

Q

)

|

2

(
H
(
−
D
)
+

|

E

t
o
r

(

Q

)

|

)

2

⋅

T
E

(
−
D
)
.

\begin{equation*} \widehat {h}(P)> \frac {|E_{\mathrm {tor}}(\mathbb {Q})|^2}{\left ( H(-D)+ |E_{\mathrm {tor}}(\mathbb {Q})|\right )^2}\cdot T_E(-D). \end{equation*}
Inertial manifolds for a singularly non-autonomous semi-linear parabolic equations
Authors: Li Xinhua , Sun Chunyou 
Published: April 2021

This paper devotes to the existence of an

N
N

-dimensional inertial manifold for a class of singularly, i.e.

A
(
t
)

A(t)

may degenerate to

0
0

at some time

t
t

, non-autonomous parabolic equations

∂

t

u
+
A
(
t
)
u
=
F
(
t
,
u
)
+
g
(
x
,
t
)
,

t
>
τ
;

u

|

t
=
τ

=

u

τ

(
x
)
,

x
∈
Ω
,

\begin{equation*} \partial _{t}u+A(t)u=F(t,u)+g(x,t),\;t>\tau ;\; \; u|_{t=\tau }=u_{\tau }(x),\;x\in \Omega , \end{equation*}

where

A
(
t
)
≥
0

A(t)\geq 0

for any

t
≥
τ

t\geq \tau

, and

Ω
⊂

R

d

\Omega \subset \mathbb {R}^{d}

is a bounded domain with smooth boundary. Since the operator

A
(
t
)

A(t)

may degenerate, a compatibility condition for the operator

A
(
t
)

A(t)

and the nonlinear term

F
(
t
,
u
)

F(t,u)

was proposed to construct the inertial manifolds.
Cause-specific mortality prediction in older residents of São Paulo, Brazil: a machine learning approach
Authors: do Nascimento Carla Ferreira , dos Santos Hellen Geremias , de Moraes Batista André Filipe , Roman Lay Alejandra Andrea , Duarte Yeda Aparecida Oliveira , Chiavegatto Filho Alexandre Dias Porto 
Published: April 2021

Abstract

Background
Populational ageing has been increasing in a remarkable rate in developing countries. In this scenario, preventive strategies could help to decrease the burden of higher demands for healthcare services. Machine learning algorithms have been increasingly applied for identifying priority candidates for preventive actions, presenting a better predictive performance than traditional parsimonious models.

Methods
Data were collected from the Health, Well Being and Aging (SABE) Study, a representative sample of older residents of São Paulo, Brazil. Machine learning algorithms were applied to predict death by diseases of respiratory system (DRS), diseases of circulatory system (DCS), neoplasms and other specific causes within 5 years, using socioeconomic, demographic and health features. The algorithms were trained in a random sample of 70% of subjects, and then tested in the other 30% unseen data.

Results
The outcome with highest predictive performance was death by DRS (AUC−ROC = 0.89), followed by the other specific causes (AUC−ROC = 0.87), DCS (AUC−ROC = 0.67) and neoplasms (AUC−ROC = 0.52). Among only the 25% of individuals with the highest predicted risk of mortality from DRS were included 100% of the actual cases. The machine learning algorithms with the highest predictive performance were light gradient boosted machine and extreme gradient boosting.

Conclusion
The algorithms had a high predictive performance for DRS, but lower for DCS and neoplasms. Mortality prediction with machine learning can improve clinical decisions especially regarding targeted preventive measures for older individuals.
De Novo Identification and Visualization of Important Cell Populations for Classic Hodgkin Lymphoma Using Flow Cytometry and Machine Learning
Authors: Simonson Paul D , Wu Yue , Wu David , Fromm Jonathan R , Lee Aaron Y 
Published: April 2021

AbstractObjectivesAutomated classification of flow cytometry data has the potential to reduce errors and accelerate flow cytometry interpretation. We desired a machine learning approach that is accurate, is intuitively easy to understand, and highlights the cells that are most important in the algorithm’s prediction for a given case.MethodsWe developed an ensemble of convolutional neural networks for classification and visualization of impactful cell populations in detecting classic Hodgkin lymphoma using two-dimensional (2D) histograms. Data from 977 and 245 clinical flow cytometry cases were used for training and testing, respectively. Seventy-eight nongated 2D histograms were created per flow cytometry file. Shapley additive explanation (SHAP) values were calculated to determine the most impactful 2D histograms and regions within histograms. SHAP values from all 78 histograms were then projected back to the original cell data for gating and visualization using standard flow cytometry software.ResultsThe algorithm achieved 67.7% recall (sensitivity), 82.4% precision, and 0.92 area under the receiver operating characteristic. Visualization of the important cell populations for individual predictions demonstrated correlations with known biology.ConclusionsThe method presented enables model explainability while highlighting important cell populations in individual flow cytometry specimens, with potential applications in both diagnosis and discovery of previously overlooked key cell populations.
Association of Overactive Bladder With Hypertension and Blood Pressure Control: The Multi-Ethnic Study of Atherosclerosis (MESA)
Authors: Akbar Aelia , Liu Kiang , Michos Erin D , Bancks Michael P , Brubaker Linda , Markossian Talar , Durazo-Arvizu Ramon , Kramer Holly 
Published: April 2021

Abstract

BACKGROUND
The sudden urge to urinate, also known as overactive bladder (OAB), may reflect higher sympathetic activity and associate with higher blood pressure (BP).

METHODS
This cross-sectional analysis utilized data from sixth follow-up exam (2015–2016) of Multi-Ethnic Study of Atherosclerosis to examine the association of OAB with systolic (SBP) and diastolic blood pressure (DBP) levels, hypertension, and BP control. Information on urinary symptoms was obtained with the International Consultation on Incontinence Questionnaire (ICIQ). Sex-stratified regression models were constructed to examine differences in BP, hypertension prevalence, and BP control while adjusting for demographic factors, comorbidities, and medication use.

RESULTS
Among the 1,446 men and 1,628 women who completed the ICIQ (mean age 73.7 years [SD 8.4]), OAB was present in 31.6% of men and 38.9% of women. With no antihypertensive medication use, OAB was not associated with SBP or DBP in both men and women after adjusting for covariates. However, among the 894 men and 981 women on antihypertensive medication, OAB was associated with higher SBP among men (4.04 mm Hg; 95% confidence interval [CI] 1.02, 7.06) but not among women (−0.67 mm Hg; 95% CI −3.79, 2.46) while DBP did not differ by OAB presence in men or women. In addition, OAB was also associated with lower odds of BP control among men (odds ratio [OR] 0.69; 95% CI 0.49, 0.96) but not women (OR 0.96; 95% CI 0.71, 1.30).

CONCLUSIONS
Among men, OAB is associated with lower odds of BP control which suggests that OAB may impede hypertension management.
Evidence of Browning of White Adipocytes in Poorly Survived Fat Grafts in Patients
Authors: Liu Tong , Fu Su , Wang Qian , Cheng Hao , Mu Dali , Luan Jie 
Published: April 2021

Abstract

Background
Browning adipocytes induced by burn and cancer were assumed less viable and more prone to necrosis for their hypermetabolic properties. Recent studies have shown browning of white adipose after fat engraftment in mice.

Objectives
The authors sought to evaluate whether fat transfer could induce browning biogenesis in fat grafts in humans and if it is associated with graft necrosis.

Methods
Necrotic adipose grafts were excised from 11 patients diagnosed with fat necrosis after fat grafting or flap transfer. Non-necrotic fat grafts were from 5 patients who underwent revisionary surgeries after flap transfer. Histology and electronic microscopy as well as protein and gene expression of browning-related marker analyses were performed.

Results
Fat grafts with necrosis demonstrated a higher gene expression level of uncoupling protein-1 (greater than fivefold increase, **P &lt; 0.01), a master beige adipocyte marker, than non-necrotic fat grafts. Electronic microscopy and histology showed that browning adipocytes were presented in necrotic adipose in patients.

Conclusions
Fat transfer induced browning adipocytes in patients and was evident in patients with postgrafting necrosis.

Level of Evidence: 5
Metaphors as a Tool for Understanding of Lived Experience of Social Work Practitioners in the Contemporary Czech Society
Authors: Petrucijová Jelena , Glumbíková Kateřina 
Published: April 2021

Abstract
The paper aims to understand lived experience of social work practitioners in contemporary Czech society through the use of the potential of metaphors. Metaphors are seen as a tool for bringing implicit knowledge and experience to the surface (especially where they are encountered certain barriers to verbalisation); as an area of connecting lived experience and its essential meaning. Using the phenomenological hermeneutical method of thematic narrative analysis and structural thematic analysis of metaphorical narratives, new ways of structuring reality by participants and new coherences are revealed, thus re-describing reality that shows the tension, if not conflict, between the concept of social work based on technically conceived rationality as officially carried out and required institutional policy in social services and social work as a value-oriented profession The implication for social work: the social workers should reflect the impacts of the revealed conflict on the practice and reconsider the further role and development of social work.