bluuebunny/crossref_metadata_2025 huggingface dataset:
Variational principle for one-dimensional inviscid flow
Authors: Liu Xian-Yong , Liu Yan-Ping , Wu Zeng-Wen
Published: July 2022

A family of variational principles is obtained for the 1-D inviscid flow by
Ji-Huan He?s semi-inverse method. The invalidy of the Lagrange multiplier
method, e. g., the Lagrange crisis, is also discussed to eliminate
constraints of a constrained variational principle. Two approaches to the
elimination of the crisis are elucidated.
Thermodynamics of the coal dust explosion: Main factors and optimal control
Authors: Ban Tao , Chao Jiang-Kun , Cheng Lei , Zhang Sheng-Qi , Shao Hong-Yuan , He Xiang
Published: July 2022

The explosion intensity and the low explosion limit of the coal dust explosion are affected by the calorific value and the heat transfer rate of the coal dust, which are closely related to the coal quality index. This paper studies experimentally the low explosive limit of the coal dust with different coal quality indexes. Based on the principal component analysis, the main factors affecting the low explosive limit are obtained by extracting the principal components from the coal quality indexes. Through comparative analysis, a regression model is proposed to predict the low explosive limit for practical applications.
Optimal design of homogeneous ignition of biomass by pulse ignition technique
Authors: Li Xiaomin , Sun Kunfeng , Cao Kan , Meng Zhaofeng
Published: July 2022

The volatile matters in biomass have an essential effect on their ignition
stabilization. In the present work, the homogeneous ignition of seven kinds
of biomass and eight kinds of coals is studied by the pulse ignition
technique. At ignition, the flame brightness of biomass appears more faintly
than that of coal. The flame color appears in bluish violet for biomass and
yellowish red for coal. The homogeneous ignition temperature ranges from
270?C to 310?C for biomass and 390-500?C for coal, respectively, and it
decreases with the decrease of the particle size. A theoretical model is
established to predict the homogeneous ignition temperature by the thermal
balance method and the thermal explosion theory. Based on the theoretical
prediction, a quasi-linear model and a non-linear model are developed
through the least square algorithm.
Effect of temperature on the bubble-electrospinning process and its hints for 3-D printing technology
Authors: Zuo Yuting , Liu Hongjun
Published: July 2022

The temperature will significantly affect the surface tension of a bubble. By
suitable control of the inside and outside temperature of the spun bubble,
the surface tension can be vanished entirely. This zero-tension phenomenon
is extremely helpful in the bubble electrospinning process. An experiment is
designed to study the effect of the inside and outside temperature on the
nanofibers diameter, and the theoretical prediction agrees well with the
experimental data. This paper sheds a bright light on controlling the
spinning process by temperature and hinting at a new trend in the 3-D
printing technology.
Novel free surface electrospinning for preparing nanofibers and its mechanism study
Authors: Yin Jing , Xu Lan
Published: July 2022

In order to meet the increasing demand for nanofibers and overcome the
disadvantages of traditional electrospinning technology, it is necessary to
research an electrospinning device that can produce nanofibers efficiently.
In this paper, a free surface electrospinning device was improved, and a
spherical section free surface electrospinning device was developed to
prepare high-quality polyacrylo-nitrile nanofibers in batches. Meanwhile,
MAXWELL 3-D software was used to simulate the electric field distribution of
the spherical section free surface electro-spinning with solution reservoirs
of different spherical radii. The influence of the spherical radius on the
spinning effect was analyzed to study the spinning mechanism. The results
showed that when the applied voltage was 40 kV, the electric field
distribution of the spherical section free surface electrospinning with a
larger spherical radius was more uniform, the nanofiber diameter was
larger, the nanofiber diameter distribution was more uniform, and the yield
of nanofibers was higher. When the spherical radius was 75 mm, the quality
of nanofibers was better, and the yield could reach the maximum value of
14.35 g per hour, due to its higher average electric field intensity and
uniform electric field distribution.
Two analytical methods for time fractional Caudrey-Dodd-Gibbon-Sawada-Kotera equation
Authors: Chen Bin , Lu Jun-Feng
Published: July 2022

This paper focuses on solving the time fractional
Caudrey-Dodd-Gibbon-Sawada-Kotera equation (FCDGSKE). We propose two
analytical methods based on the fractional complex transform, the
variational iteration method and the homotopy perturbation method. The
approximated solutions to the initial value problems associated with FCDGSKE
are provided without linearization and complicated calculation. Numerical
results show the main merits of the analytical approaches.
Variational iteration method for two fractional systems with boundary conditions
Authors: Xu Bo , Zhang Yufeng , Zhang Sheng
Published: July 2022

Under investigation in this paper are two local fractional partial
differential systems, one is the homogeneous linear partial differential
system with initial values, and the other is the inhomogeneous non-linear
partial differential system with initial and boundary values. To solve
these two local fractional systems, we employ the local fractional
variational iteration method and obtain exact solutions. It is shown that
the method provides an effective mathematical tool for solving linear and
non-linear local fractional partial differential systems with initial and
boundary values.
Vapor injection technology for heat-pump air conditioner of electric bus in an extreme environment
Authors: Cui Siqi , Bai Jing , Su Zhiyong , Zhang Chao , Qin Chang , Geng Shuwei
Published: July 2022

In order to solve the problems of a heat pump air conditioner for an electric
bus under extreme conditions, such as the large compression ratio, the high
discharge temperature, the reduced system performance, the frequent
shutdown of the compressor due to the overheat protection, this paper
proposes a vapor injection technology with an economizer, and carries out a
theoretical analysis of the process to reveal the effect of the vapor
injection technology on the performance of the air conditioner. The results
show that at ultra-low temperature heating operating conditions, when the
compressor speed increases from 2000 rpm to 5000 rpm, the heating capacity
of the vapor injection system increases from 16.2% to 22.7%, and the heating
performance coefficient increases from 2.8% to 14.2%.
Thermo-physiological comfort properties of different woven fabrics used in sportswear for outdoor activities
Authors: Lu Xin , Wu Shigang
Published: July 2022

In this study, the thermo-physiological wear comfort is mainly characterized
by the thermal and water vapor resistance performance of the woven fabrics
used as sportswear for outdoor activities. The commonly used twill woven
fabric with different thicknesses, weight, and density are selected for the
experimental analysis, and it finds that fabric weight and thickness have
crucial effects on the thermal resistance, and the water vapor resistance
depends linearly on density and thickness. The present study gives an
optimal design of sportswear for outdoor activities with low thermal and
water vapor resistance.
Research on energy storage characteristics of composite phase change material in a heating transfer system
Authors: Liu Enhai , Zhang Wenyun , Gong Yajun , Li Wei , Qian Yingzhi , Yu Zhang , Wei Xiaotong
Published: July 2022

Aiming at the problems of lack of energy in undeveloped areas with low
low-density residents and few heating users, and large heat loss, we
propose a heating energy vehicle connected with mobile energy storage to
assist the operation of district heating. Using paraffin-expanded graphite
as the phase change material for energy storage, this paper studies the
effect of expanded graphite on energy storage characteristics and finds that
10% expanded graphite can shorten the heat storage time and heat release
time by 50% and 36.4%, respectively. Two economic operation modes are
recommended for auxiliary district heating and synergetic coupling.
Research on quasi-two-stage compression cycle characteristics of refrigeration system for cold storage
Authors: Yang Fengye , Su Zhiyong , Wang Chunyan , Li Haijun
Published: July 2022

In view of the current test methods and evaluation indicators for the
performance of cold storage freezing systems, a cold storage experimental
platform with a micro-channel heat exchanger is designed using the inject
technology, and the power consumption and cooling performance are tested
under different conditions of the internal and external environment
temperatures, vapor injecting flux, compressor speed, and vapor inject
pattern. The experimental results provide us with a useful source for the
optimization or improvement of cold storage freezing systems.
Hydrothermal synthesis of TiO2/BiOBr composites with enhanced photocatalytic activity
Authors: Wang Kuang , Qi Zhenming , Chen Yujie , Chen Jiayi , Yu Ren , Wang Chunxia
Published: July 2022

The hydrothermal method is used to fabricate the TiO2/BiOBr composite. The
X-ray diffraction, SEM, X-ray photoelectron spectroscopy, and
ultraviolet-visible diffuse reflectance spectroscopy are employed to
characterize its crystal structure, physical morphology, chemical
composition, and light absorption. Its photocatalytic performance and
stability are analyzed by the photocatalytic degradation rate of rhodamine
B solution under sunlight irradiation. The composite exhibits the optimal
photocatalytic effect when the Ti:Bi molar ratio is 4:1.
Enthronement of the invisible. Understanding the origin and evolution of the iconography of empty thrones and hetoimasia in the late antique period
Authors: Vranesevic Branka , Spehar Olga
Published: July 2022

The motif of hetoimasia is one of the most widespread and most complex in
medieval iconography, and it has its roots in the Graeco-Roman and Jewish
empty thrones of an invisible or absent deity. It gradually developed during
the Late Antique period, and experienced its full flourishing in the Middle
Ages. It has been appearing in the scenes of the Last Judgment since the
eleventh century and, as such, inherits an eschatological connotation (Ps.
9: 7-8). Besides a survey of the earlier ways of percieving this problem,
this paper offers alternative possibilities for interpreting the origin and
development of the motifs of empty thrones and hetoimasia in Late Antiquity.
The cult of Saint Zotikos Orphanotrophos and his images in Byzantium and beyond
Authors: Tomic Marka
Published: July 2022

St. Zotikos Orphanotrophos acquired great renown in Constantinople owing to
his efforts in the establishment of two singularly important philanthropic
institutions in the Byzantine Empire - Orphanotropheion (??????????????) on
the Acropolis of Constantinople and the Leprosarium in Pera (Golden Horn at
Elaiones). The paper discusses an underexplored aspect of the veneration of
St. Zotikos - his representations in art. It uses available liturgical
sources, hagiographical testimonies and the scarce visual evidence to
investigate and determine the reach of the cult of St. Zotikos
Orphanotrophos, first in the wider framework of Eastern Christian art and
then in Serbian medieval art.
A reassessment of middle Byzantine monumental painting on Mount Athos. Patronage, dating and style
Authors: Vapheiades Konstantinos
Published: July 2022

Our view of Middle Byzantine monumental painting on Mount Athos remains
fragmentary, mainly due to the absence of textual sources on workshops and
patronage. Thus, the attribution of pictorial ensembles to this period
largely depends on their association with the artistic environments of
Komnenian Constantinople and Thessalonike. Based on epigraphic, iconographic
and stylistic evidence, the following article will offer an overall
assessment of the extant fragments raising new questions as to their style,
dating and patrons.
Mileseva, Sinai and “Crusader art”. A contribution to the study of thirteenth-century Byzantine painting
Authors: Zivkovic Milos
Published: July 2022

The paper proposes a stylistic link between the earliest wall paintings in
the Church of the Ascension at the Mileseva Monastery, previously usually
attributed to Thessalonian painters, and several icons from St. Catherine?s
monastery on Mount Athos. Based on their visual similarity, it questions the
earlier attributions of those Sinai icons, rejecting the view that they were
painted by Western Crusader artists. Furthermore, their ascription to
Byzantine artists is also supported by certain iconographic parallels with
corresponding details on the frescoes of Mileseva.
Investigation on laser forming of open cell aluminum foam
Authors: Changdar Anirban , Shrivastava Ankit , Chakraborty Shitanshu Shekhar , Dutta Samik
Published: July 2022

Open cell aluminum foam having high porosity has the potential to increase the efficiency of a heat exchanger and also to be used for diverse other functions. However, being prone to fail easily under tensile mechanical load, their thermal forming using a laser has been proposed in the literature. This work investigates the effect of laser parameters, orientation-position-curvature of scan path, the number of scans, and foam thickness on the bending angle achieved while forming 95% porous pure aluminum (99.7% aluminum) open cell foam plates using a diode laser. Furthermore, the capability of laser forming to produce developable and nondevelopable surfaces out of this foam has been demonstrated. Higher line energy gave a higher bending angle. Under the same line energy, the combination of higher power-higher scan speed produced a higher bending angle. In contradiction to laser forming of the sheet metal, no saturation or reduction in bending angle per scan pass was observed with an increase in scan pass number. This observation could be explained with the help of cell densification by previous scan passes leading to an increase in the coupling of more thermal energy for subsequent scan passes. Scan paths with increased curvature (or less radius) also produced higher bending due to a higher amount of cell collapse in the irradiated region.
International Copyright Flexibilities for Prevention, Treatment and Containment of COVID-19
Authors: Flynn Sean , Nkrumah Erica , Schirru Luca
Published: July 2022

Most policymaking attention with respect to intellectual property barriers toCOVID-19 prevention, treatment and containment has been focused on patents.This focus is reflected in the World Trade Organisation (WTO) Ministerial Decisionon the TRIPS Agreement, adopted on 17 June 2022, which provides a limited waiverof TRIPS rules on compulsory licences for production of COVID-19 vaccines. Theoriginal WTO proposal for a TRIPS waiver, however, explicitly applied to all formsof intellectual property, including copyright. This article outlines the numerous waysin which copyright can create barriers to addressing COVID-19. It also provides adescription of international copyright treaty provisions that permit uses of copyrightmaterials in response to the barriers identified, despite the exclusion of copyrightfrom the final TRIPS waiver.
K problematike pečatného symbolu a erbu mesta Krupina
Authors: Lukáč Miroslav
Published: July 2022

The author discusses the existence and dating of the Krupina town’s seals and the motivations for accepting the seal symbol (later the coat of arms as well) of the Lamb of God of Krupina, whereas based on the analogies of towns in Hungary or abroad he contemplates the influence of the paradigm of medieval society and its focus on eternal life that leads to the Kingdom of heaven to the Savior, Jesus Christ. The author points to the possible connection of the symbol with the church dedication of the main parish church of the Blessed Virgin Mary. He also deals with the view of older literature, which derived its acceptance into the seals of the town from the coins of Hungarian rulers who were associated with the origins of the town of Krupina. Jesus Christ (symbolically depicted as the Lamb of God) is an attribute of the Virgin Mary in Christian iconography and was constantly depicted together with the mother, Virgin Mary, similarly to the fashion it was implemented in Krupina. At the same time, the Lamb was a symbol of the heavenly Jerusalem, a perfect city, which was a model and ideal of the earthly city, and thus of the community of the Krupina townspeople. The authority of the Savior is thus symbolically linked to the authority of the king and also to the authority of the burghers, as well as to the legal force of the documents they issued. This could have been one of the motivations of the Krupina townspeople to adopt this symbol into the seals of the town. At the same time, it is possible to assume an increase in the influence of rectors of the main parish church in the town, who probably performed the duties of the first notaries of the town of Krupina.
“…It is impossible to endure the above mentioned serious matters and grievous injuries…” Misunderstandings between István II. Koháry, General-Captain of Fiľakovo and the Nobility (1667-1682)
Authors: Komjáti Zoltán Igor
Published: July 2022

In the 17th century Fiľakovo was not only the base for the royal garrison, but at the same time the fort was the seat of three counties: Novohrad, Pest-Pilis-Solt and Heves and Külső-Szolnok earlier fleeing before the Ottomans. By the common sense and the practical reason, we could believe that the dependency on each other, the mutual national interest and the patriotic solidarity would bring about cooperation between the border soldiers and the nobility. The stark reality was, however, that they could not agree: mutual accusations, disagreements, atrocities, severe debates — occasionally with the intention to kill — characterised the relationship of the Fiľakovo troops and the nobility residing or temporarily staying in the border castle. The main problem was the lack of supplies for the army. As the border soldiers did not receive their dues, they procured food and goods needed for their living and clothing from the nearby settlements in the county, which was ever so often violent. The county nobility was deeply harmed by the attacks of the soldiers that not only hindered their living, but they saw it as the derogation of their ancient noble rights and their sanctity, which they could not tolerate. As a result the nobility had to limit the privileges of the Fiľakovo border soldiers that the other party could not stand, either. The war between the two social strata both regarding themselves privileged precipitated in legal debates: who is to accuse and punish the guilty and captured border soldiers? who has the right to call to account and punish the guilty captured soldiers? whose jurisdiction is stronger and in what case? Heves and Külső-Szolnok County sent their representatives either together with other counties or on its own to Pál Esterházy, Ferenc Nádasdy, then from 1670 to Ádám Forgách, Chief Judge of Hungary, but they could have even presented their grievances to the Emperor. The other frontline of the confrontation between the two parties manifested in the use of violence. People were treated roughly by the soldiers due to the mutual conflict, but the village inhabitants instigated by the County Magistrate did not hold themselves back when capturing a soldier. This way, there were often human casualties. When a person of noble origin committed an atrocity, no matter how significant it was he was treated carefully and judgement was very slow. This is shown in the study through the case of Menyhért Ebeczky, the Deputy-Lord-Lieutenant of Novohrad County and Noble Judge of Heves and Külső-Szolnok County from 1678.
PATHOGENETIC FEATURES OF PREECLAMPSIA CLINICAL COURSE CONTROL IN PREGNANT WOMEN AND ITS EFFECT ON THE CARDIOVASCULAR SYSTEM (LITERATURE REVIEW)
Authors: Babiy N.V. , Yuzko O.M.
Published: July 2022

Objective – to analyze modern views on the pathogenetic features of control over theclinical course of preeclampsia in pregnant, NT-proBNP role and its pathogenesis andthe possibilities of prevention.Conclusion. The necessity of further investigation of this problem, with the aim of prolongingthe term of pregnancy in women with preeclampsia to avoid preterm labor, has been shown.
Social Representations of LGBT Old Age and Sex Workers in Brazilian Adults
Authors: Lima Filho Gutemberg De Sousa , Gomes de Alcântara Jéssica , Da Silva Alves Mateus Egilson , Fernandes de Araújo Ludgleydson , Mendes da Silva Sousa Evair , De Lima Bezerra Igor Eduardo , Lima Silva Maria Fernanda
Published: July 2022

Background: The number of elderly people in the world is growing significantly, so there is an urgent need to ensure that this population can live a full life, especially taking into account the current COVID-19 pandemic scenario. Objective: To analyze the social representations of LGBT old age for male and female sex workers through the pandemic. Method: A qualitative, descriptive, and exploratory research conducted with 10 male and 10 female sex workers aged between 18 and 48. Sociodemographic questionnaires and semi-structured interviews were administered using Google Forms and then analyzed by descending hierarchical classification through the IRaMuTeQ software. Results: The analysis showed three classes: (1) «Social understanding of the topic LGBT old age,» (2) «Stigma of genders and sexual orientations,» and (3) «Physical transformations and their accompanying obstacles». Conclusions: The representations are associated with the difficulties that elderly people have with aging in society, as well as debating LGBT old age. There are also greater obstacles regarding aging of female sex workers. In this way, the study seeks to contribute to broaden the knowledge of the psychosocial aspects of LGBT aging and old age, especially those of sex workers.
Streptococcus canis sequence type 43 may be associated with treatment failure in dogs with corneal ulceration
Authors: Leis Marina L. , Sandmeyer Lynne S. , Costa Matheus O.
Published: July 2022

OBJECTIVE

To profile Streptococcus canis isolates obtained from corneal ulcers in dogs.

ANIMALS

10 dogs.

PROCEDURES

Medical records were searched to identify dogs diagnosed with ulcerative keratitis by a veterinary ophthalmologist and having a positive corneal culture for S canis during the year 2020. For each case, clinical findings and outcome were determined, antimicrobial resistance and sensitivity panels were summarized, whole genome sequencing was performed, and isolates were typed using multi-locus sequence typing and genome-based proteome phylogenetic analysis.

RESULTS

10 S canis isolates were included from dogs diagnosed with ulcerative keratitis. Dogs were either treated surgically via keratectomy and conjunctival grafting (n = 6) or treated medically (4). Three of 10 corneas failed to heal and required enucleation (2/6 conjunctival grafts and 1/4 medically managed corneal ulcers). All three corneal ulcers that failed to heal were associated with S canis sequence type (ST) 43. Sequence types identified from successfully treated cases included ST8 (n = 1), ST50 (1), ST2 (2), ST27 (1), and ST15 (1). One ST43 isolate was obtained from a dog that healed following a conjunctival graft, however this was the only dog that received an oral antibiotic in addition to topical antibiotics.

CLINICAL RELEVANCE

Based on this small dataset, S canis ST43 may be associated with increased virulence and contribute to conjunctival graft failure and progressive corneal collagenolysis. The postoperative administration of an oral antimicrobial may protect against conjunctival graft rejection in dogs specifically due to S canis ST43.
Enhancement Photocatalytic Activity of Mn Doped Cds/Zno Nanocomposites for the Degradation of Methylene Blue Under Solar Light Irradiation
Authors: Sivaranjani Kaliyappan , Sivakumar Santhanam , Dharmaraja Jaganathan
Published: July 2022

In this study, Mn doped CdS/ZnO nanocomposites synthesized by co-precipitation method and its photocatalytic activity was tested using methylene blue under solar light irradiation. The prepared hybrid nanocomposites are characterized by using different physicochemical techniques including XRD, FESEM, EDX, TEM, UV-vis DRS and PL analysis. From the XRD analysis, Mn doped ZnO/CdS nanocomposite diffraction peaks only reflect the binary crystalline structures of ZnO and CdS. However, there is no characteristic peak of Mn is found that may be because of low content of Mn doped on ZnO/CdS. But Mn (2.9 wt%) was detected in the Mn doped ZnO/CdS nanocomposite, which was measured by EDX analysis. The FESEM and TEM results exhibit the surface particle of Mn doped ZnO/CdS nanocomposite which have spherical nature and confirmed the formation of Mn doped ZnO/CdS nanocomposites. The photocatalytic degradation results have revealed that the Mn doped CdS/ZnO nanocomposites exhibit admirable activity toward the photocatalytic degradation of the MB. The reason for excellent photocatalytic activity of Mn doped CdS/ZnO nanocomposites indicates the absorbance band shifted to red region and reduction of recombination of photogenerated electron-hole, which is in good agreement with UV-visible DRS analysis and PL study results. The fitted kinetic plots showed a pseudo-first-order reaction model and the appropriate rate constants were found to be 0.0068 min−1, 0.00846 min−1, and 0.0188 min−1, for ZnO, 25 % CdS/ZnO, and 0.8 mol% Mn doped CdS/ZnO nanocomposites, respectively. The maximum photocatalytic activity was achieved by 0.8 mol% Mn doped CdS/ZnO nanocomposites with a 95% degradation efficiency of MB. Hydroxyl and superoxide radicals, having a vital role in the degradation of MB, confirmed scavenging experiments. In addition, the recycling tests displays that the Mn doped CdS/ZnO nanocomposites have shown good stability and long durability. The enhanced photodegradation activity of Mn doped CdS/ZnO nanocomposites indicates the potential of the nanocomposite for the treatment of organic pollutants from the textile wastewater.
Pier abutment: Bridge the gap with non rigid connector - A clinical case report
Authors: Sharma Vineet , Meena Kamal Kumar , Gurjar Balwant Singh , Nagar Ramawatar
Published: July 2022

Pier abutment is defined as a freestanding abutment with edentulous space on both sides. This case report described the rehabilitation of a patient who presented to the department with the primary complaint of missing teeth and difficulty in mastication. Intraoral examination revealed missing right maxillary canine and the second premolar, with the lone standing first premolar acting as a pier abutment. To reduce the stress transferred to the abutment and prosthetic assembly, a non-rigid (Tenon-mortise) connector was used in the case, with a keyway (mortise) distal to the pier abutment and a key (Tenon) mesial to the distal pontic.
Robotic Process Automation (RPA) Adoption: A Systematic Literature Review
Authors: Costa Diogo António da Silva , Mamede Henrique São , Mira da Silva Miguel
Published: July 2022

Robotic process automation (RPA) is a recent technology that has recently become increasingly adopted by companies as a solution for employees to focus on higher complexity and more valuable tasks while delegating routine, monotonous and rule-based tasks to their digital colleagues. The increased interest, reflected in the increasing number of articles regarding approaches and test cases, has triggered the necessity for a summary that could extract the more generalisable ideas and concepts about these software robots. This paper used a Systematic Literature Review (SLR) approach to find and synthesise information from articles obtained on this subject. This research identified the most general implementation approaches of successful RPA adoption cases, observed benefits, challenges commonly faced by organisations, characteristics that make processes more suitable for RPA, and research gaps in the current literature. The findings presented in this paper have two purposes. The first is to provide a way for companies and organisations to become more familiar with good practices regarding the adoption of robotic process automation. The second is to foster further research on the subject by complementing the current knowledge and proposing new paths for research.
Turnover-Mitigating Effect of Servant Leadership on Job Performance
Authors: Bieńkowska Agnieszka , Koszela Anna , Ludwikowska Kamila , Tworek Katarzyna
Published: July 2022

Job performance is an extremely complex factor affecting organisational performance. The literature recognises factors impacting job performance positively and negatively. This article aims to verify the turnover-mitigating effect on the relationship between servant leadership and job performance. The developed moderated mediation model is empirically verified based on the data collected from 263 managers working in Poland’s for-profit organisations. The results were analysed using Macro for IBM SPSS Statistics. It has been shown that employee turnover is a mediator in the job performance model based on turnover-mitigating servant leadership. Additionally, the influence of employees’ dynamic capabilities has been analysed. The study revealed the significance of servant leadership in influencing job performance and the disruptive relationship between employee turnover and the impact of employees’ dynamic capabilities in reducing employee turnover. This research provides practical implications for managers and organisations regarding selecting the right leadership style to improve employee job performance.
Sentimentos Negativos de Empreendedores e a Covid-19: Uma Análise de Tweets
Authors: Pagotto Daniel , Barbosa Rodrigo , Borges Cândido , Nassif Vânia
Published: July 2022

Objetivo: A presente pesquisa teve como objetivo analisar a interferência da pandemia da COVID-19 nos sentimentos negativos dos empreendedores.

Metodologia/Abordagem: Para alcançar o objetivo proposto, foram utilizadas postagens feitas por empreendedores na rede social Twitter no primeiro semestre de 2020, início da pandemia. Uma análise de sentimento foi realizada nos tweets obtidos, com um enfoque nos sentimentos negativos de repugnância, tristeza, medo e raiva.

Originalidade/Relevância: Estudos anteriores demonstraram que pandemias podem gerar impactos negativos na saúde psicológica e emocional das pessoas. Nesse contexto, a sobrevivência do negócio dos empreendedores pode ser prejudicada, pois um quadro de baixa saúde mental pode resultar na diminuição da capacidade de planejamento, resolução de problemas e tomada de decisões.

Principais Conclusões: Os sentimentos de tristeza e medo apresentaram o maior aumento percentual entre os empreendedores analisados no período. Esses sentimentos podem levar a doenças físicas e emocionais. Pesquisas futuras podem aplicar algoritmos que consigam ampliar a classificação dos sentimentos, inclusive adicionando à análise sentimentos de valência positiva.

Contribuições teóricas/metodológicas: O presente trabalho contribui ao introduzir uma técnica que tem sido apontada como promissora nos estudos de administração e empreendedorismo no contexto desafiador da pandemia causada pelo coronavírus.
Unsupervised Multi-Modal Medical Image Registration via Discriminator-Free Image-to-Image Translation
Authors: Chen Zekang , Wei Jia , Li Rui
Published: July 2022

In clinical practice, well-aligned multi-modal images, such as Magnetic Resonance (MR) and Computed Tomography (CT), together can provide complementary information for image-guided therapies. Multi-modal image registration is essential for the accurate alignment of these multi-modal images. However, it remains a very challenging task due to complicated and unknown spatial correspondence between different modalities. In this paper, we propose a novel translation-based unsupervised deformable image registration approach to convert the multi-modal registration problem to a mono-modal one. Specifically, our approach incorporates a discriminator-free translation network to facilitate the training of the registration network and a patchwise contrastive loss to encourage the translation network to preserve object shapes. Furthermore, we propose to replace an adversarial loss, that is widely used in previous multi-modal image registration methods, with a pixel loss in order to integrate the output of translation into the target modality. This leads to an unsupervised method requiring no ground-truth deformation or pairs of aligned images for training. We evaluate four variants of our approach on the public Learn2Reg 2021 datasets. The experimental results demonstrate that the proposed architecture achieves state-of-the-art performance. Our code is available at https://github.com/heyblackC/DFMIR.
DANet: Image Deraining via Dynamic Association Learning
Authors: Jiang Kui , Wang Zhongyuan , Wang Zheng , Yi Peng , Jiang Junjun , Xiao Jinsheng , Lin Chia-Wen
Published: July 2022

Rain streaks and background components in a rainy input are highly correlated, making the deraining task a composition of the rain streak removal and background restoration. However, the correlation of these two components is barely considered, leading to unsatisfied deraining results. To this end, we propose a dynamic associated network (DANet) to achieve the association learning between rain streak removal and background recovery. There are two key aspects to fulfill the association learning: 1) DANet unveils the latent association knowledge between rain streak prediction and background texture recovery, and leverages it as an extra prior via an associated learning module (ALM) to promote the texture recovery. 2) DANet introduces the parametric association constraint for enhancing the compatibility of deraining model with background reconstruction, enabling it to be automatically learned from the training data. Moreover, we observe that the sampled rainy image enjoys the similar distribution to the original one. We thus propose to learn the rain distribution at the sampling space, and exploit super-resolution to reconstruct high-frequency background details for computation and memory reduction. Our proposed DANet achieves the approximate deraining performance to the state-of-the-art MPRNet but only requires 52.6\% and 23\% inference time and computational cost, respectively.
ER-SAN: Enhanced-Adaptive Relation Self-Attention Network for Image Captioning
Authors: Li Jingyu , Mao Zhendong , Fang Shancheng , Li Hao
Published: July 2022

Image captioning (IC), bringing vision to language, has drawn extensive attention. Precisely describing visual relations between image objects is a key challenge in IC. We argue that the visual relations, that is geometric positions (i.e., distance and size) and semantic interactions (i.e., actions and possessives), indicate the mutual correlations between objects. Existing Transformer-based methods typically resort to geometric positions to enhance the representation of visual relations, yet only using the shallow geometric is unable to precisely cover the complex and actional correlations. In this paper, we propose to enhance the correlations between objects from a comprehensive view that jointly considers explicit semantic and geometric relations, generating plausible captions with accurate relationship predictions. Specifically, we propose a novel Enhanced-Adaptive Relation Self-Attention Network (ER-SAN). We design the direction-sensitive semantic-enhanced attention, which considers content objects to semantic relations and semantic relations to content objects attention to learn explicit semantic-aware relations. Further, we devise an adaptive re-weight relation module that determines how much semantic and geometric attention should be activated to each relation feature. Extensive experiments on MS-COCO dataset demonstrate the effectiveness of our ER-SAN, with improvements of CIDEr from 128.6% to 135.3%, achieving state-of-the-art performance. Codes will be released \url{https://github.com/CrossmodalGroup/ER-SAN}.
RePFormer: Refinement Pyramid Transformer for Robust Facial Landmark Detection
Authors: Li Jinpeng , Jin Haibo , Liao Shengcai , Shao Ling , Heng Pheng-Ann
Published: July 2022

This paper presents a Refinement Pyramid Transformer (RePFormer) for robust facial landmark detection. Most facial landmark detectors focus on learning representative image features. However, these CNN-based feature representations are not robust enough to handle complex real-world scenarios due to ignoring the internal structure of landmarks, as well as the relations between landmarks and context. In this work, we formulate the facial landmark detection task as refining landmark queries along pyramid memories. Specifically, a pyramid transformer head (PTH) is introduced to build both homologous relations among landmarks and heterologous relations between landmarks and cross-scale contexts. Besides, a dynamic landmark refinement (DLR) module is designed to decompose the landmark regression into an end-to-end refinement procedure, where the dynamically aggregated queries are transformed to residual coordinates predictions. Extensive experimental results on four facial landmark detection benchmarks and their various subsets demonstrate the superior performance and high robustness of our framework.
Dite-HRNet: Dynamic Lightweight High-Resolution Network for Human Pose Estimation
Authors: Li Qun , Zhang Ziyi , Xiao Fu , Zhang Feng , Bhanu Bir
Published: July 2022

A high-resolution network exhibits remarkable capability in extracting multi-scale features for human pose estimation, but fails to capture long-range interactions between joints and has high computational complexity. To address these problems, we present a Dynamic lightweight High-Resolution Network (Dite-HRNet), which can efficiently extract multi-scale contextual information and model long-range spatial dependency for human pose estimation. Specifically, we propose two methods, dynamic split convolution and adaptive context modeling, and embed them into two novel lightweight blocks, which are named dynamic multi-scale context block and dynamic global context block. These two blocks, as the basic component units of our Dite-HRNet, are specially designed for the high-resolution networks to make full use of the parallel multi-resolution architecture. Experimental results show that the proposed network achieves superior performance on both COCO and MPII human pose estimation datasets, surpassing the state-of-the-art lightweight networks. Code is available at: https://github.com/ZiyiZhang27/Dite-HRNet.
IDPT: Interconnected Dual Pyramid Transformer for Face Super-Resolution
Authors: Shi Jingang , Wang Yusi , Dong Songlin , Hong Xiaopeng , Yu Zitong , Wang Fei , Wang Changxin , Gong Yihong
Published: July 2022

Face Super-resolution (FSR) task works for generating high-resolution (HR) face images from the corresponding low-resolution (LR) inputs, which has received a lot of attentions because of the wide application prospects. However, due to the diversity of facial texture and the difficulty of reconstructing detailed content from degraded images, FSR technology is still far away from being solved. In this paper, we propose a novel and effective face super-resolution framework based on Transformer, namely Interconnected Dual Pyramid Transformer (IDPT). Instead of straightly stacking cascaded feature reconstruction blocks, the proposed IDPT designs the pyramid encoder/decoder Transformer architecture to extract coarse and detailed facial textures respectively, while the relationship between the dual pyramid Transformers is further explored by a bottom pyramid feature extractor. The pyramid encoder/decoder structure is devised to adapt various characteristics of textures in different spatial spaces hierarchically. A novel fusing modulation module is inserted in each spatial layer to guide the refinement of detailed texture by the corresponding coarse texture, while fusing the shallow-layer coarse feature and corresponding deep-layer detailed feature simultaneously. Extensive experiments and visualizations on various datasets demonstrate the superiority of the proposed method for face super-resolution tasks.
Domain Adaptation via Maximizing Surrogate Mutual Information
Authors: Zhao Haiteng , Ma Chang , Chen Qinyu , Deng Zhi-Hong
Published: July 2022

Unsupervised domain adaptation (UDA), which is an important topic in transfer learning, aims to predict unlabeled data from target domain with access to labeled data from the source domain. In this work, we propose a novel framework called SIDA (Surrogate Mutual Information Maximization Domain Adaptation) with strong theoretical guarantees. To be specific, SIDA implements adaptation by maximizing mutual information (MI) between features. In the framework, a surrogate joint distribution models the underlying joint distribution of the unlabeled target domain. Our theoretical analysis validates SIDA by bounding the expected risk on target domain with MI and surrogate distribution bias. Experiments show that our approach is comparable with state-of-the-art unsupervised adaptation methods on standard UDA tasks.
Test-time Fourier Style Calibration for Domain Generalization
Authors: Zhao Xingchen , Liu Chang , Sicilia Anthony , Hwang Seong Jae , Fu Yun
Published: July 2022

The topic of generalizing machine learning models learned on a collection of source domains to unknown target domains is challenging. While many domain generalization (DG) methods have achieved promising results, they primarily rely on the source domains at train-time without manipulating the target domains at test-time. Thus, it is still possible that those methods can overfit to source domains and perform poorly on target domains. Driven by the observation that domains are strongly related to styles, we argue that reducing the gap between source and target styles can boost models’ generalizability. To solve the dilemma of having no access to the target domain during training, we introduce Test-time Fourier Style Calibration (TF-Cal) for calibrating the target domain style on the fly during testing. To access styles, we utilize Fourier transformation to decompose features into amplitude (style) features and phase (semantic) features. Furthermore, we present an effective technique to Augment Amplitude Features (AAF) to complement TF-Cal. Extensive experiments on several popular DG benchmarks and a segmentation dataset for medical images demonstrate that our method outperforms state-of-the-art methods.
Accelerated Multiplicative Weights Update Avoids Saddle Points Almost Always
Authors: Feng Yi , Panageas Ioannis , Wang Xiao
Published: July 2022

We consider nonconvex optimization problem with constraint that is a product of simplices. A commonly used algorithm in solving this type of problem is the Multiplicative Weights Update (MWU), an algorithm that is widely used in game theory, machine learning and multi agent systems. Despite it has been known that MWU avoids saddle points, there is a question that remains unaddressed: ``Is there an accelerated version of MWU that avoids saddle points provably?'' In this paper we provide a positive answer to above question. We provide an accelerated MWU based on Riemannian Accelerated Gradient Descent, and prove that the Riemannian Accelerated Gradient Descent, thus the accelerated MWU, avoid saddle points.
Using Constraint Programming and Graph Representation Learning for Generating Interpretable Cloud Security Policies
Authors: Kazdagli Mikhail , Tiwari Mohit , Kumar Akshat
Published: July 2022

Modern software systems rely on mining insights from business sensitive data stored in public clouds. A data breach usually incurs significant (monetary) loss for a commercial organization. Conceptually, cloud security heavily relies on Identity Access Management (IAM) policies that IT admins need to properly configure and periodically update. Security negligence and human errors often lead to misconfiguring IAM policies which may open a backdoor for attackers. To address these challenges, first, we develop a novel framework that encodes generating optimal IAM policies using constraint programming (CP). We identify reducing dormant permissions of cloud users as an optimality criterion, which intuitively implies minimizing unnecessary datastore access permissions. Second, to make IAM policies interpretable, we use graph representation learning applied to historical access patterns of users to augment our CP model with similarity constraints: similar users should be grouped together and share common IAM policies. Third, we describe multiple attack models and show that our optimized IAM policies significantly reduce the impact of security attacks using real data from 8 commercial organizations, and synthetic instances.
An Exact MaxSAT Algorithm: Further Observations and Further Improvements
Authors: Xiao Mingyu
Published: July 2022

In the maximum satisfiability problem (MaxSAT), given a CNF formula with m clauses and n variables, we are asked to find an assignment of the variables to satisfy the maximum number of clauses. Chen and Kanj showed that this problem can be solved in O*(1.3248^m) time (DAM 2004) and the running time bound was improved to O*(1.2989^m) by Xu et al. (IJCAI 2019). In this paper, we further improve the result to O*(1.2886^m). By using some new reduction and branching techniques we can avoid several bottlenecks in previous algorithms and get the improvement on this important problem.
TiRGN: Time-Guided Recurrent Graph Network with Local-Global Historical Patterns for Temporal Knowledge Graph Reasoning
Authors: Li Yujia , Sun Shiliang , Zhao Jing
Published: July 2022

Temporal knowledge graphs (TKGs) have been widely used in various fields that model the dynamics of facts along the timeline. In the extrapolation setting of TKG reasoning, since facts happening in the future are entirely unknowable, insight into history is the key to predicting future facts. However, it is still a great challenge for existing models as they hardly learn the characteristics of historical events adequately. From the perspective of historical development laws, comprehensively considering the sequential, repetitive, and cyclical patterns of historical facts is conducive to predicting future facts. To this end, we propose a novel representation learning model for TKG reasoning, namely TiRGN, a time-guided recurrent graph network with local-global historical patterns. Specifically, TiRGN uses a local recurrent graph encoder network to model the historical dependency of events at adjacent timestamps and uses the global history encoder network to collect repeated historical facts. After the trade-off between the two encoders, the final inference is performed by a decoder with periodicity. We use six benchmark datasets to evaluate the proposed method. The experimental results show that TiRGN outperforms the state-of-the-art TKG reasoning methods in most cases.