bluuebunny/crossref_metadata_2025 huggingface dataset:
Data-Driven Energy Efficiency and Part Geometric Accuracy Modeling and Optimization of Green Fused Filament Fabrication Processes
Authors: Alizadeh Morteza , Esfahani Mehrnaz Noroozi , Tian Wenmeng , Ma Junfeng
Published: September 2019

Nowadays, increasing awareness of environmental protection has evoked the adoption of green technologies in design and manufacturing. As a revolutionizing manufacturing technology that produces components in a layer-by-layer fashion, additive manufacturing (AM) has followed this trend. Among a variety of AM processes, fused filament fabrication (FFF) is one of the most commonly used technologies. However, AM (including FFF) is inherently energy expensive and energy inefficient compared with the conventional manufacturing. Thus, an urgent investigation is needed to reduce the energy consumption for AM production. On the other hand, part geometric accuracy is an important aspect for the quality of additively manufactured components. It is not meaningful to improve AM’s energy consumption performance with compromised part geometric accuracy. Therefore, it is necessary to jointly consider energy consumption as well as part geometric accuracy in the AM process design. This study applies the statistical regression approach to model AM energy consumption and part geometric accuracy. The nondominated sorting genetic algorithm II (NSGA-II) and the technique for order of preference by similarity to ideal solution (TOPSIS) method together are used to locate the compromised optimal solution for AM process parameter settings. The effectiveness of the proposed approach is demonstrated through a case study developed with the FFF process and a specific part design. The results of this study are significant to both AM energy consumption and part geometric accuracy in terms of qualitative and quantitative analyses. Furthermore, the study can potentially guide the future AM sustainability model development and be extended to future AM process improvement.
Effects of Bio-Inspired Micro-Scale Surface Patterns on the Profile Losses in a Linear Cascade
Authors: Liu Qiang , Zhong Shan , Li Lin
Published: September 2019

In this paper, we investigated the effects of herringbone riblets, a type of bio-inspired micro-scale surface patterns, on pressure losses and flow turning angles in a linear cascade over a range of low Reynolds numbers from 0.50 × 105 to 1.50 × 105 and at three different incidence angles. Our experiments showed that despite their micro-scale size, herringbone riblets produced a significant reduction in pressure loss and a substantial increase in flow turning angle except at the low end of the Reynolds numbers tested. In comparison to the baseline case without riblets, the highest reduction in the zone-averaged pressure loss coefficient behind one flow passage was 36.4% which was accompanied by a 4.1 deg increase in the averaged turning angle. The loss reduction was caused by a decrease in γmax at α = −1 deg, a narrower wake zone at α = 9 deg and a mixture of both at α = 4 deg due to the suppression of flow separation on the blade suction surface. It was also noted that such a significant improvement was always accompanied by the appearance of a serrated wake structure in the contours of pressure loss coefficient in which the region with a higher loss reduction occurring directly behind the divergent region of herringbone riblets. The observed improvement in cascade performance was attributed to the secondary flow motion produced by herringbone riblets which energizes the boundary layer. Overall, this work has produced convincing experimental evidence that herringbone riblets could be potentially used as passive flow control devices for reducing flow separation in compressors at low Reynolds numbers.
A New Ultrasonic Testing Method for Residual Strain Measurement With Laser Grating
Authors: Pei Cuixiang , Kou Xing , Liu Tianhao , Chen Zhenmao
Published: September 2019

In this paper, a new and noncontact ultrasonic testing (UT) method using laser grating is proposed for the residual strain measurement. In this method, the laser grating technique is utilized to generate coherent surface waves with a specific wavelength in the narrow frequency band. A numerical method based on the finite element model is established to simulate the coherent surface waves generated by the laser grating in prestrained media to determine the capability and sensitivity of this method. The relationship between the strain and frequency spectrum of the coherent surface wave is studied. Finally, an experiment validation of the laser grating-based UT of residual strain is carried out using specimen with different plastic strains by the tensile test.
An Experimental Evaluation of the Effects of Filtercake in Wellbore Strengthening: Filtercake Rupture Resistance and Fracture Sealing Time
Authors: Yang Mingzheng , Chen Yuanhang
Published: September 2019

Recent research studies have indicated that filtercakes play a role in preventing fracture initiation, blocking pre-existing narrow fractures, and isolating drilling-induced fractures at the initiation stage. The ability of the filtercakes to effectively strengthen the wellbore expectedly depends on its capability in maintaining its integrity and providing the barrier to isolate pressure and fluid transmission between the wellbore and fractures. In this research, a modified permeability apparatus was used to evaluate the quality of drilling fluid filtercakes. A new criterion defined as filtercake rupture resistance is proposed to characterize the filtercake quality regarding its ability to sustain pressure over an open fracture. Experimental tests were conducted to investigate how filtercake thickness and filtercake yield strength affect the rupture resistance. The mechanism of filtercake in sealing the narrow fractures is explored, and it was observed that solid's plugging/bridging plays the vital role in this mechanism. A thicker and stronger filtercake also contributes to a faster establishment of complete fracture seal. The results of this research can be utilized as a reference that guides the optimization of drilling fluid for continuously strengthening the wellbore.
Combined interpolation, scale change, and noise reduction in spectral analysis
Authors: Le Van L. , Kim Tae J. , Kim Young D. , Aspnes David E.
Published: September 2019

The authors present a simple, convenient, and accurate noise-reduction approach for interpolating spectra, in particular, for converting those available as discrete points equally spaced in wavelength, acquired, for example, by a photodiode-array detector, to equivalent spectra equally spaced in energy, as needed for analysis. Based on continuum mathematics, the algorithm uses Gaussian kernels and capitalizes on the fact that trapezoidal-rule integration is accurate to fourth order in the ratio of point separation to width when applied to Gaussian functions. The approach can be expanded to perform differentiation and other operations. Examples include false-data verification, wavelength-to-energy conversion of near-bandgap interference oscillations of a GaN film, and calculation of the second energy derivative of monolayer MoS2 in the exciton region.
Phenology and population structure of the Mediterranean stripe-necked terrapin Mauremys leprosa (Schweigger, 1812) in the Reghaïa Lake (northern Algeria)
Authors: Escoriza Daniel , Bakhouche Badis , Ghoulam Tiar , Imed Djemadi , Khalil Draidi
Published: September 2019

The Mediterranean stripe-necked terrapin is a freshwater turtle widely distributed in southwestern Europe and northwestern Africa, but whose natural history is little known. In this study we investigated the ecology of a population in northern Algeria (Reghaïa Lake Ramsar Reserve), with special emphasis on its phenology, demographic structure and diet, based on capture and recapture methods. Our results indicated that there is a short inactivity period in January and possibly the activity is also reduced during the month of August. The best Jolly-Seber model indicated that the population within the survey station had a minimum size of 653 specimens. The population contained a higher proportion of males (0.68 - 0.76) and a proportion of juveniles between 0.02 - 0.16. Females were larger and relatively heavier than males. Analysis of stomach contents showed that M. leprosa feeds with high frequency on aquatic arthropods. Specifically, we found insects: Diptera (Chironomidae, Culicidae, Dixidae, Syrphidae), Heteroptera (Corixidae, Notonectidae) and Coleoptera (Dytiscidae), crustaceans (Branchiopoda, Ostracoda), plant matter (Typha angustifolia), fish (Gambusia holbrooki), and unidentified materials.
What’s in a Sport Class? The Classification Experiences of Paraswimmers
Authors: Van Dornick Kirsti , Spencer Nancy L.I.
Published: September 2019

The purpose of this study was to examine the classification experiences (perspectives and reflections) of paraswimmers. Classification provides a structure for parasport, with the goal of reducing the impact of impairment on the outcome of competition. Guided by interpretive description, nine paraswimmers ranging in swimming experience and sport class were interviewed. Reflective notes were also collected. Transcribed interviews were analyzed inductively, followed by a deductive analysis using Nordenfelt’s dignity framework. Three themes represent the findings: access, diversity, and (un)certainty. Despite several positive experiences, paraswimmers also discussed inconsistencies in the process leading them to question competition fairness and classification accuracy. These findings suggest that continued efforts to improve the classification system are required. In addition, paraswimmers and their allies (e.g., coaches) require more information about the classification process to better understand the outcomes and to effectively advocate for their needs.
Reactivity to Accelerometer Measurement of Children With Visual Impairments and Their Family Members
Authors: Zhu Xihe , Haegele Justin A.
Published: September 2019

The purpose of this study was to examine reactivity to accelerometer measurement in children with visual impairments (VI), their sighted siblings, and their parents. A sample of 66 participants (including 22 children with VI, 22 siblings, and 22 parents) completed a demographic survey and wore triaxial accelerometers for at least 4 consecutive days for 8 hr. An analysis of covariances with repeated measures was conducted, controlling for participant gender. Children with VI had 8.1% less moderate to vigorous physical activity time on Day 1 than Days 2–4 average. Their sighted siblings and parents had 7.8% and 7.1% more moderate to vigorous physical activity time on Day 1 than their Days 2–4 average, respectively. The reactivity percentage for parents and children without VI is consistent with existing literature. However, an inverse reactivity for children with VI was found, which is a unique contribution to the literature and will have implications for researchers using accelerometers for this population.
Not All Play Equipment Is Created Equal: Associations Between Equipment at Home and Children’s Physical Activity
Authors: Moss Katrina M. , Dobson Annette J. , Edwards Kimberley L. , Hesketh Kylie D. , Chang Yung-Ting , Mishra Gita D.
Published: September 2019

Background: Play equipment at home could be targeted in interventions to increase children’s physical activity (PA), but evidence is mixed, potentially because current methods do not reflect children’s lived experience. This study investigated associations between combinations of equipment and PA. Methods: Data were from the Mothers and their Children’s Health study and the Australian Longitudinal Study on Women’s Health. Mothers (n = 2409) indicated the types of fixed active (eg, trampolines), portable active (eg, bicycles), and electronic (eg, computers) equipment at home, and the number of days children (n = 4092, aged 5–12 y, 51% boys) met PA guidelines. Latent class analysis was used to identify combinations of equipment, and linear regressions were used to investigate associations with PA. Results: Compared with children with high active (fixed and portable) and medium electronic equipment, children with portable active and medium (B = −0.53; 95% confidence interval, −0.72 to −0.34) or high (B = −0.58; 95% confidence interval, −0.83 to −0.33) electronic equipment met the guidelines on fewer days. Children with similar active equipment (but more electronic equipment) met the PA guidelines on fewer days (mean difference = −0.51, SE = 0.14, P = .002). Conclusion: Having the right combination of play equipment at home may be important for children’s PA.
Lead by Example
Authors: Todaro Elaine , Davis Liz
Published: September 2019

A growing national interest in physical fitness has presented a variety of challenges for the recreational sports professional. Questions such as, which activities provide the greatest fitness benefits, how can I promote interest in physical fitness, and which activities need to be added and/or eliminated are common today. The trend in physical fitness for better health is real and here to stay, and only by finding the best answers to the above questions can professionals hope to serve all of their clientele (Lamke, 1980, p.4).
Community-Acquired Respiratory Viruses in Transplant Patients: Diversity, Impact, Unmet Clinical Needs
Authors: Ison Michael G. , Hirsch Hans H.
Published: September 2019

Patients undergoing solid-organ transplantation (SOT) or allogeneic hematopoietic cell transplantation (HCT) are at increased risk for infectious complications. Community-acquired respiratory viruses (CARVs) pose a particular challenge due to the frequent exposure pre-, peri-, and posttransplantation.
Induction of
Rhodobacter capsulatus
Gene Transfer Agent Gene Expression Is a Bistable Stochastic Process Repressed by an Extracellular Calcium-Binding RTX Protein Homologue
Authors: Ding Hao , Grüll Marc P. , Mulligan Martin E. , Lang Andrew S. , Beatty J. Thomas
Published: September 2019

GTAs catalyze horizontal gene transfer (HGT), which is important for genomic evolution because the majority of genes found in bacterial genomes have undergone HGT at some point in their evolution. Therefore, it is important to determine how the production of GTAs is regulated to understand the factors that modulate the frequency of gene transfer and thereby specify the tempo of evolution. This work describes a new type of genetic regulation in which an extracellular calcium-binding protein homologue represses the induction of the
Rhodobacter capsulatus
GTA, RcGTA.
Serological Array-in-Well Multiplex Assay Reveals a High Rate of Respiratory Virus Infections and Reinfections in Young Children
Authors: Kazakova Anna , Kakkola Laura , Päkkilä Henna , Teros-Jaakkola Tamara , Soukka Tero , Peltola Ville , Waris Matti , Julkunen Ilkka
Published: September 2019

The multiplex immunoassay was successfully used to simultaneously detect antibodies against seven different viruses. The developed serological microarray is a new promising tool for diagnostic, epidemiological, and seroprevalence analyses of virus infections.
Global Transcriptomic Analysis of the Candida albicans Response to Treatment with a Novel Inhibitor of Filamentation
Authors: Romo Jesus A. , Zhang Hao , Cai Hong , Kadosh David , Koehler Julia R. , Saville Stephen P. , Wang Yufeng , Lopez-Ribot Jose L.
Published: September 2019

These results from whole-genome transcriptional profiling provide further insights into the biological activity and mode of action of a small-molecule inhibitor of
C. albicans
filamentation. This information will assist in the development of novel antivirulence strategies against
C. albicans
infections.
Association of napping with incident cardiovascular events in a prospective cohort study
Authors: Häusler Nadine , Haba-Rubio Jose , Heinzer Raphael , Marques-Vidal Pedro
Published: September 2019

Objective

There is controversy regarding the effect of napping on cardiovascular disease (CVD), with most studies failing to consider napping frequency. We aimed to assess the relationship of napping frequency and average nap duration with fatal and non-fatal CVD events.

Methods

3462 subjects of a Swiss population based cohort with no previous history of CVD reported their nap frequency and daily nap duration over a week, and were followed over 5.3 years. Fatal and non-fatal CVD events were adjudicated. Cox regressions were performed to obtain HRs adjusted for major cardiovascular risk factors and excessive daytime sleepiness or obstructive sleep apnoea.

Results

155 fatal and non-fatal events occurred. We observed a significantly lower risk for subjects napping 1–2 times weekly for developing a CVD event (HR 0.52, 95% CI 0.28 to 0.95) compared with non-napping subjects, in unadjusted as well as adjusted models. The increased HR (1.67, 95% CI 1.10 to 2.55) for subjects napping 6–7 times weekly disappeared in adjusted models (HR 0.89, 95% CI 0.58 to 1.38). Neither obstructive sleep apnoea nor excessive daytime sleepiness modified this lower risk. No association was found between nap duration and CVD events.

Conclusion

Subjects who nap once or twice per week have a lower risk of incident CVD events, while no association was found for more frequent napping or napping duration. Nap frequency may help explain the discrepant findings regarding the association between napping and CVD events.
Amelioration of estrogen-induced endometrial hyperplasia in female rats by hemin via heme-oxygenase-1 expression, suppression of iNOS, p38 MAPK, and Ki67
Authors: Ali Fatma F. , Abdelzaher Walaa Yehia , Ibrahim Randa Ahmed , Elroby Ali Doaa Mohamed
Published: September 2019

Although heme oxygenase-1 (HO-1) is part of an endogenous defense system implicated in the homeostatic response, its role in cell proliferation and tumor progression is still controversial. Endometrial hyperplasia (EH) is associated with high risk of endometrial cancer (EC). Therefore, we aimed to evaluate the effect of hemin, a HO-1 inducer, against EH. Thirty-two female rats (60–70 days old) were divided into 4 groups treated for 1 week: vehicle control group, hemin group (25 mg/kg; i.p. 3 times/week), estradiol valerate (EV) group (2 mg/kg per day, p.o.), and hemin plus EV group. Sera were obtained for reduced glutathione level. Uterine malondialdehyde, superoxide dismutase, total nitrite/nitrate, and interleukin-1β levels were estimated. HO-1 and p38 mitogen-activated protein kinase expressions were obtained in uterine tissue. Uterine histological and immunohistochemical assessment of iNOS and Ki67 were also done. Results demonstrated that upregulation of HO-1 expression in hemin plus EV rats led to amelioration of EH which was confirmed with histological examination. This was associated with significant decrease in oxidative stress parameters, p38 mitogen-activated protein kinase expression, and interleukin-1β level. Also, uterine iNOS and Ki67 expressions were markedly suppressed. In conclusion, upregulation of HO-1 expression via hemin has ameliorative effect against EH through its antioxidant, anti-inflammatory, and antiproliferative actions.
Cosmological test on viscous bulk models using Hubble parameter measurements and type Ia supernovae data
Authors: Hernández-Almada A.
Published: September 2019

From a phenomenological point of view, we analyze the dynamics of the Universe at late times by introducing a polynomial and hyperbolic bulk viscosity into the Einstein field equations respectively. We constrain their free parameters using the observational Hubble parameter data and the Type Ia Supernovae dataset to reconstruct the deceleration q and the jerk j parameters within the redshift region $$0<z<2.5$$0<z<2.5. At current epochs, we obtain $$q_0 = -\,0.680^{+0.085}_{-0.102}$$q0=-0.680-0.102+0.085 and $$j_0 = 2.782^{+1.198}_{-0.741}$$j0=2.782-0.741+1.198 for the polynomial model and $$q_0 = -\,0.539^{+0.040}_{-0.038}$$q0=-0.539-0.038+0.040 ($$-\,0.594^{+0.056}_{-0.056}$$-0.594-0.056+0.056) and $$j_0 = 0.297^{+0.051}_{-0.050}$$j0=0.297-0.050+0.051 ($$1.124^{+0.196}_{-0.178}$$1.124-0.178+0.196) for the tanh (cosh) model. Furthermore, we explore the statefinder diagnostic that gives us evident differences with respect to the concordance model (LCDM). According to our results this kind of models is not supported by the data over LCDM.
Semileptonic decays of the scalar tetraquark $$Z_{bc;\overline{u}\overline{d}}^{0}$$
Authors: Sundu H. , Agaev S. S. , Azizi K.
Published: September 2019

We study semileptonic decays of the scalar tetraquark $$Z_{bc;\overline{u} \overline{d}}^{0}$$Zbc;u¯d¯0 to final states $$T_{bs;\overline{u}\overline{d} }^{-}e^{+}\nu _{e}$$Tbs;u¯d¯-e+νe and $$T_{bs;\overline{u}\overline{d}}^{-}\mu ^{+}\nu _{\mu }$$Tbs;u¯d¯-μ+νμ , which run through the weak transitions $$c\rightarrow se^{+}\nu _{e}$$c→se+νe and $$c\rightarrow s\mu ^{+}\nu _{\mu }$$c→sμ+νμ, respectively. To this end, we calculate the mass and coupling of the final-state scalar tetraquark $$T_{bs;\overline{u}\overline{d} }^{-} $$Tbs;u¯d¯- by means of the QCD two-point sum rule method: these spectroscopic parameters are used in our following investigations. In calculations we take into account the vacuum expectation values of the quark, gluon, and mixed operators up to dimension ten. We use also three-point sum rules to evaluate the weak form factors $$G_{i}(q^2)$$Gi(q2) ($$i=1,~2$$i=1,2) that describe these decays. The sum rule predictions for $$G_{i}(q^2)$$Gi(q2) are employed to construct fit functions $$F_{i}(q^2)$$Fi(q2), which allow us to extrapolate the form factors to the whole region of kinematically accessible $$q^2$$q2. These functions are required to get partial widths of the semileptonic decays $$\Gamma \left( Z_{bc}^{0}\rightarrow Te^{+}\nu _{e}\right) $$ΓZbc0→Te+νe and $$\Gamma \left( Z_{bc}^{0}\rightarrow T\mu ^{+}\nu _{\mu }\right) $$ΓZbc0→Tμ+νμ by integrating corresponding differential rates. We analyze also the two-body nonleptonic decays $$Z_{bc;\overline{u}\overline{d}}^{0} \rightarrow T_{bs;\overline{u}\overline{d }}^{-}\pi ^{+}$$Zbc;u¯d¯0→Tbs;u¯d¯-π+ and $$Z_{bc;\overline{u}\overline{d}}^{0} \rightarrow T_{bs;\overline{u }\overline{d}}^{-}K^{+}$$Zbc;u¯d¯0→Tbs;u¯d¯-K+, which are necessary to evaluate the full width of the $$Z_{bc;\overline{u}\overline{d}}^{0}$$Zbc;u¯d¯0. The obtained results for $$\Gamma _{\mathrm {full}}=(3.18\pm 0.39)\times 10^{-11}~{\mathrm {MeV}}$$Γfull=(3.18±0.39)×10-11MeV and mean lifetime $$20.7_{-2.3}^{+2.9}~{\mathrm {ps}}$$20.7-2.3+2.9ps of the tetraquark $$Z_{bc;\overline{u} \overline{d}}^{0}$$Zbc;u¯d¯0 can be used in experimental investigations of this exotic state.
Relaxation dynamics and crystallization study of glass-forming chiral-nematic liquid crystal S,S-2,7-bis(4-pentylphenyl)-9,9-dimethylbutyl 9H-fluorene (5P-Am*FLAm*-P5)
Authors: Jasiurkowska-Delaporte Małgorzata , Rozwadowski Tomasz , Juszyńska-Gała̧zka Ewa , Krawczyk Jan , Dmochowska Ewelina , Kula Przemysław , Massalska-Arodź Maria
Published: September 2019

The chiral nematic S,S-2,7-bis(4-pentylphenyl)-9,9-dimethylbutyl9H-fluorene (5P-Am*FLAm*-P5) liquid crystal shows a complex phase diagram strongly dependent on thermal treatment as identified by Polarizing Optical Microscopy (POM) and differential scanning calorimeter (DSC). The molecular dynamics in various thermodynamics states was studied by means of broadband dielectric spectroscopy (BDS). The vitrification of a chiral nematic phase (N*) is manifested by a Vogel-Fulcher-Tammann (VFT)-type temperature dependence of structural relaxation time ($\tau_{\alpha}$τα). Three dielectric relaxation processes exhibiting Arrhenius-like thermal activation were found in conformationally disordered (condis) Cr1 and Cr2 structures. The isothermal cold crystallization process of Cr2 occurs in the metastable N* phase; however, in the non-isothermal experiments, the Cr2 phase is formed in the isotropic phase obtained on heating the metastable N* phase. The findings for the isothermal process were compared with those regarding non-isothermal crystallization.

Graphical abstract
Modeling an HPGe detector response to gamma-rays using MCNP5 code
Authors: Prozorova I. V. , Sabitova R. R. , Ghal-Eh N. , Bedenko S. V.
Published: September 2019

The response function is the important information for the precise interpretation of experimental data and also for characterizing the developing nuclear instruments. Measurement of the response function normally requires a number of mono-energetic gamma-ray sources, a long acquisition time and an appropriate experimental setup. The Monte Carlo method, as an alternative to response function measurement, has widely been used and recommended. In this study, a computational model of an HPGe detector has been developed by using the MCNP5 code. To validate the simulated model, the simulations from mono-energetic sources have been compared to the corresponding measured data. Any deviation from the measurement could be attributed to the unmodeled details of the detector crystal, so they needed adjustment. Moreover, an analysis has been undertaken on the dependency of detection efficiency on the dead layer thickness of the germanium crystal. Having developed a computational model of the crystal, a set of correction factors was extracted to take into account the gamma-ray self-absorption within the source volume. The simulated model of the HPGe detector in this study can be used to calculate the detection efficiency when the samples are not of the standard geometry which require self-absorption considerations.
A computational study of solitary wave solutions of Kawahara-type equations by meshless spectral interpolation method
Authors: Hussain Manzoor , Haq Sirajul
Published: September 2019

In this paper, a meshless spectral radial point interpolation (MSRPI) method using weighted [Formula: see text]-scheme is formulated for the numerical solutions of a class of nonlinear Kawahara-type evolutionary equations. The formulated method is applied for simulation of single and double solitary waves motion, wave generation and oscillatory shock waves propagation. Quality of approximation is measured via discrete [Formula: see text], [Formula: see text] and [Formula: see text] error norms. Three invariant quantities corresponding to mass, momentum and energy are also computed for the method validation. Stability analysis of the proposed method is briefly discussed and verified computationally. Comparison of the obtained results are made with other existing results in the literature revealing the method superiority.
A 2.3 mW Multi-Frequency Clock Generator with −137 dBc/Hz Phase Noise VCO in 180 nm Digital CMOS Technology
Authors: Sahani Jagdeep Kaur , Singh Anil , Agarwal Alpana
Published: September 2019

A fast phase frequency detector (PFD) and low gain low phase noise voltage-controlled oscillator (VCO)-based phase-locked loop (PLL) design are presented in this paper. PLL works in the frequency range of 0.025–1.6[Formula: see text]GHz, targeting various SoC applications. The proposed PFD, designed using CMOS dynamic logic, is fast and improves the locking time, dead zone and blind zone in the PLL. The standard CMOS inverter gate-based pseudo differential VCO is used in the PLL. Also, CMOS inverter is used as variable capacitor to tune the frequency of VCO with control voltage. The proposed PLL is designed in a 180[Formula: see text]nm CMOS process with supply voltage of 1.8[Formula: see text]V. The phase noise of VCO is [Formula: see text][Formula: see text]dBc/Hz at an offset frequency of 100[Formula: see text]MHz. The reference clock of 25[Formula: see text]MHz synthesizes the output clock of 1.6[Formula: see text]GHz with rms jitter of 0.642[Formula: see text]ps.
Hardware Reduction and Statistical Verification of Cryptographic Standard Cell Resistant to SCA
Authors: Mirković Milena Stanojlović , Milić Miljana , Mirković Dejan , Litovski Vančo
Published: September 2019

This paper presents results regarding the progress achieved in the design of a customized encrypted multiplexer cell. The focus of our interest is the no short-circuit dynamic differential logic method that demonstrates high immunity of a standard logic cell to the side channel attacks (SCAs). Three innovative solutions are examined and the best one is proposed for the encrypted multiplexer cell. Designed cells are realized to the layout masks level targeting the 350[Formula: see text]nm CMOS process. The post-layout simulations showed high resistivity to the SCA for all designed cells. The resistance to the SCA of the proposed design was statistically verified at the transistor level. The verification is performed using the Monte Carlo (MC) simulation in which widths and lengths of the transistor channel were varied according to the Gaussian distribution. The designed encrypted cell will be the part of a more complex crypto system for power consumption metering which should increase overall system’s data security.
On the reality of Hawking radiation
Authors: Qadir Asghar
Published: September 2019

Hawking radiation caught the imagination of the public and physicists alike, because it seemed so counter-intuitive. By their very definition, black holes were supposed to endlessly absorb, but never emit, matter and energy. Yet, Hawking argued that taking Quantum Theory into account, they would radiate. The further belief was that Bekenstein and Hawking had developed the field of Black Hole Thermodynamics. Here I want to correct this impression and give due credit to Roger Penrose for founding the subject. Further, I discuss the question of whether Hawking radiation should be expected to really exist, arguing that there is reason to doubt it.
Study on the compound nucleus fusion probability PCN in 12C +93Nb reaction at above barrier energies using different degrees-of-freedom
Authors: Chopra Sahila , Kaur Hemdeep , Kundra Aastha
Published: September 2019

In this work, we extend our earlier study [S. Chopra, Hemdeep, A. Kaur and R. K. Gupta, Phys. Rev. C 93 (2016) 024603] of [Formula: see text] reaction at below- and near- to above-barrier energies for both coplanar ([Formula: see text]) and noncoplanar ([Formula: see text]) degrees-of-freedom. Our main aim is to see the texture of variation of compound nucleus (CN) fusion probability [Formula: see text] at all the experimentally available center-of-mass energies ([Formula: see text]) in the range 41–69[Formula: see text]MeV, using the dynamical cluster-decay model (DCM). In this study, we worked for both degrees-of-freedom, having compact configurations ([Formula: see text]) and including higher multipole deformations (quadrupole to hexadecapole, [Formula: see text]) of nuclei. In the work of above-mentioned reference, for [Formula: see text]Ag[Formula: see text] (weakly fissioning nuclear system), we found a discrepancy in [Formula: see text], i.e., increasing function with increasing [Formula: see text], belongs to superheavy nuclei for the case of [Formula: see text] [see Fig. Fig.4 of [A. Kaur, S. Chopra and R. K. Gupta, Phys. Rev. C 90 (2014) 024619], but this erroneous result moved to correct one after the inclusion of [Formula: see text] (decreasing with increasing [Formula: see text], weakly fissioning class), which encouraged us to check the trend of [Formula: see text] at all available energies. Our evaluation framework shows the noncoplanar configuration, with higher multipole deformations [Formula: see text] included, as the most probable configuration for studying the heavy-ion reactions [S. Chopra, Hemdeep, P. Kaushal and R. K. Gupta, Phys. Rev. C 98 (2018) 041603(R)]. Second, our interest is to check the consistency of experimental data, where the experimentalists have given the data with the mixing of three different experiments for same reaction. In this study, we have found that our results are in good agreement and consistent with only the latest experimental data at five [Formula: see text]’s (=41.097, 47.828, 54.205, 60.051 and 65.454[Formula: see text]MeV), i.e., showing large ([Formula: see text]90%) noncompound nucleus contribution (or equivalently quasi-fission/Incomplete fusion) in the (total) fusion cross-section.
Investigation of breakup fusion in 16O + 124Sn system and its correlation with various entrance channel parameters
Authors: Singh D. , Linda Sneha B. , Giri Pankaj K. , Mahato Amritraj , Kumar Harish , Tali Suhail A. , Afzal Ansari M. , Kumar R. , Muralithar S. , Singh R. P.
Published: September 2019

Forward recoil range distribution of evaporation residues (ERs) populated through complete fusion (CF) and incomplete fusion (ICF) dynamics in [Formula: see text]O + [Formula: see text]Sn system have been measured. Different full and partial linear momentum transfer components have been observed. The results indicate the occurrence of ICF involving break-up of [Formula: see text]O into 4He + [Formula: see text]C and 8Be + 8Be. However, the present data shows that the ERs are populated through both CF and ICF. A systematic study was performed which shows that the ICF fraction rises exponentially with the established entrance channel parameters and their various combinations. Moreover, these present results clearly show that [Formula: see text] is able to explain the ICF dynamics more conclusively than combined parameter [Formula: see text] for the systems having spherical or slightly deformed target. Further, the dependence of ICF dynamics on target structure has also been studied through a new parameter [Formula: see text] of the target. The parameter [Formula: see text] is directly associated with the target structure and has been found more effective and sensitive than existing parameters to investigate the target structure effect on ICF dynamics. Thus, the present observations suggest that [Formula: see text] ratio of the target should also be considered as an important entrance channel parameter which strongly affects the ICF dynamics.
Fuzzy Spatio-Spectro-Temporal Ontology for Remote Sensing Image Annotation and Interpretation: Application to Natural Risks Assessment
Authors: Messaoudi Wassim , Farah Mohamed , Farah Imed Riadh
Published: September 2019

This research deals with semantic interpretation of Remote Sensing Images (RSIs) using ontologies which are considered as one of the main challenging methods for modeling high-level knowledge, and reducing the semantic gap between low-level features and high-level semantics of an image. In this paper, we propose a new ontology which allows the annotation as well as the interpretation of RSI with respect to natural risks, while taking into account uncertainty of data, object dynamics in natural scenes, and specificities of sensors. In addition, using this ontology, we propose a methodology to (i) annotate the semantic content of RSI, and (ii) deduce the susceptibility of the land cover to natural phenomena such as erosion, floods, and fires, using case-based reasoning supported by the ontology. This work is tested using LANDSAT and SPOT images of the region of Kef which is situated in the north-west of Tunisia. Results are rather promising.
Fuzzy Network Based Framework for Software Maintainability Prediction
Authors: Wang Xiaowei , Gegov Alexander , Farzad Arabikhan , Chen Yuntao , Hu Qiwei
Published: September 2019

Software metrics based maintainability prediction is leading to development of new sophisticated techniques to construct prediction models. This paper proposes a new software maintainability prediction framework, which bases on Fuzzy Network, a novel exploratory modeling technique. The proposed framework utilizes both the metric data collected from software system and the subjective appraisals from experts. An application example of the framework is shown. In comparison to the Standard Fuzzy System based models, Fuzzy Network based models improves the transparency more than 71.3% and the accuracy more than 11.0%. It is confirmed that Fuzzy Network based framework is more appropriate for constructing SMP model.
A Concise Survey of Matching Preclusion in Interconnection Networks
Authors: MAO YAPING , CHENG EDDIE
Published: September 2019

The matching preclusion number of a graph is the minimum number of edges whose deletion results in a graph that has neither perfect matchings nor almost-perfect matchings. There are other related parameters and generalization including the strong matching preclusion number, the conditional matching preclusion number, the fractional matching preclusion number, and so on. In this survey, we give an introduction on the general topic of matching preclusion.
Connectivity and Matching Preclusion for Leaf-Sort Graphs
Authors: WANG SHIYING , WANG YANLING , WANG MUJIANGSHAN
Published: September 2019

A multiprocessor system and interconnection network have a underlying topology, which is usually presented by a graph, where nodes represent processors and links represent communication links between processors. The (conditional) matching preclusion number of a graph is the minimum number of edges whose deletion leaves the resulting graph (with no isolated vertices) that has neither perfect matchings nor almost perfect matchings. In this paper, we prove that (1) the connectivity (edge connectivity) of the leaf-sort graph CFn is [Formula: see text] for odd n and [Formula: see text] for even n; (2) CFn is super edge-connected; (3) the matching preclusion number of CFn is [Formula: see text] for odd n and [Formula: see text] for even n; (4) the conditional matching preclusion number of CFn is 3n – 5 for odd n and n ≥ 3, and 3n – 6 for even n and n ≥ 4.
Matching Preclusion for Enhanced Pyramid Networks
Authors: WEI XIAQI , ZHANG SHURONG , YANG WEIHUA
Published: September 2019

The matching preclusion number of a graph is the minimum number of edges whose deletion leaves the resulting graph that has neither perfect matchings nor almost perfect matchings. This concept was introduced as a measure of robustness in the event of edge failure in interconnection networks. The pyramid network is one of the important networks applied in parallel and distributed computer systems. Chen et al. in 2004 proposed a new hierarchy structure, called the enhanced pyramid network, by replacing each mesh in a pyramid network with a torus. An enhanced pyramid network of n layers is denoted by EPM(n). In this paper, we prove that the matching preclusion number of EPM(n) is 9 where n ≥ 4.
Conditional Matching Preclusion for Folded Hypercubes
Authors: LIN RUIZHI , ZHANG HEPING
Published: September 2019

Let G be a graph with an even number of vertices. The matching preclusion number of G is the minimum number of edges whose deletion leaves the resulting graph without a perfect matching, and the conditional matching preclusion number of G is the minimum number of edges whose deletion results in a graph with no isolated vertices and without a perfect matching. Matching preclusion number was introduced for measuring the robustness of a network when there is a link failure. In this paper, we focus on conditional matching preclusion for folded hypercube FQn, an important variant of hypercube. We show that conditional matching preclusion number of FQn is 2n and all optimal conditional matching preclusion sets are trivial for n ⩾ 5.
COMPUTATIONAL MODELING WITH UNCERTAINTY OF FREQUENT USERS OF E-COMMERCE IN SPAIN USING AN AGE-GROUP DYNAMIC NONLINEAR MODEL WITH VARYING SIZE POPULATION
Authors: BURGOS C. , CORTÉS J. C. , MARTÍNEZ-RODRÍGUEZ D. , VILLANUEVA R. J.
Published: September 2019

Electronic commerce (EC) has numerous advantages. It allows saving time when we purchase an item, offers the possibility of review without depending on the schedules of traditional stores, access to a wider variety and quantity of articles, in many cases, with lower prices, etc. Based upon mathematical epidemiology tenets strongly related to social behavior able to describe the influence of peers, in this paper we propose an age-group dynamic model with population varying size based on a system of difference equations to study the evolution of the frequent users of EC over time in Spain. Using data from surveys retrieved from the Spanish National Statistics Institute, we use and design computational algorithms to perform a probabilistic estimation of the model parameters that allow the model output to capture the data uncertainty. Then, we will be able to perform a precise prediction with uncertainty.
Machining and Characterization of Micro-Channels Generated on Phosphor Bronze Using μ-EDM
Authors: Raju Leera , Hiremath Somashekhar S.
Published: September 2019

Micro-Electro Discharge Machining ([Formula: see text]-EDM) is one of the nonconventional micro-machining processes in which electrical discharges are produced between the micro-sized electrodes — tool and workpiece immersed in dielectric fluid. The electrical discharges thus produced remove the workpiece material through melting and vaporization process and results in the creation of micro-craters. This paper focuses on machining of micro-channels on copper alloy — phosphor bronze plate using [Formula: see text]-EDM. Various micro-channels have been machined on phosphor bronze with input parameters: voltage, capacitance and pulse on-time varied at four levels. The experimental layout plans were designed with robust design technique — Taguchi-based L[Formula: see text] orthogonal array and the process parameters were optimized using optimization technique — Grey Relational Analysis (GRA). The dimensional aspects — depth, width, profile and surface roughness of machined channels were selected as output responses. The experimental results show that the parameters have individual and combined effect on responses. Analysis of Variance (ANOVA) technique has been used to explore the effect of parameters on responses. Detailed surface morphology of the machined features has also been analyzed using scanning electron microscope (SEM) and noncontact optical profiler images. As an extension of machining channels, Y-shaped channel has been machined on copper alloy which can be used for micro-fluidic applications.
Investigation of GFRP Gear Accuracy and Surface Roughness Using Taguchi and Grey Relational Analysis
Authors: Sharma Atul , Aggarwal M. L. , Singh Lakhwinder
Published: September 2019

Glass fiber reinforced polymer (GFRP) composite gear is used in a number of applications where fine motion transmission and silent rotation is required. In order to increase its usage there is a need to increase the quality of gear. Shrinkage problem is associated with injection molded gear. In present case blank is prepared by injection molding and teeth are cut on gear shaper by which metrology can be controlled by optimizing the machining parameters. An analysis of variance was applied on 27 experiments to validate the process and found out that rotary feed is at rank 1 which is 0.15[Formula: see text]mm/stroke, cutting fluid ratio is at rank 2 which is 12%, cutting speed is at rank 3 which is 240 stroke/min, fluid flow rate is at rank 4 which is 30 ml/min. By using these parameters optimum performance obtained is 0.213[Formula: see text]mm root diameter deviation (RD), 0.165[Formula: see text]mm tooth thickness variation (TT) and 1[Formula: see text][Formula: see text]m roughness average (Ra) with grey relational grade of 0.8318. The optimum response provided the best value of RD, TT and Ra for the range included in experimental results which is 0.138 to 0.416[Formula: see text]mm, 0.012 to 0.187[Formula: see text]mm and 1.2 to 2.43[Formula: see text][Formula: see text]m respectively. Surface roughness improvement in this work is 49.8% higher as compared to result available in literature.
Classifying Attention Types with Thermal Imaging and Eye Tracking
Authors: Abdelrahman Yomna , Khan Anam Ahmad , Newn Joshua , Velloso Eduardo , Safwat Sherine Ashraf , Bailey James , Bulling Andreas , Vetere Frank , Schmidt Albrecht
Published: September 2019

Despite the importance of attention in user performance, current methods for attention classification do not allow to discriminate between different attention types. We propose a novel method that combines thermal imaging and eye tracking to unobtrusively classify four types of attention: sustained, alternating, selective, and divided. We collected a data set in which we stimulate these four attention types in a user study (N = 22) using combinations of audio and visual stimuli while measuring users' facial temperature and eye movement. Using a Logistic Regression on features extracted from both sensing technologies, we can classify the four attention types with high AUC scores up to 75.7% for the user independent-condition independent, 87% for the user-independent-condition dependent, and 77.4% for the user-dependent prediction. Our findings not only demonstrate the potential of thermal imaging and eye tracking for unobtrusive classification of different attention types but also pave the way for novel applications for attentive user interfaces and attention-aware computing.
To Mask or Not to Mask?
Authors: Alharbi Rawan , Tolba Mariam , Petito Lucia C. , Hester Josiah , Alshurafa Nabil
Published: September 2019

Activity-oriented cameras are increasingly being used to provide visual confirmation of specific hand-related activities in real-world settings. However, recent studies have shown that bystander privacy concerns limit participant willingness to wear a camera. Researchers have investigated different image obfuscation methods as an approach to enhance bystander privacy; however, these methods may have varying effects on the visual confirmation utility of the image, which we define as the ability of a human viewer to interpret the activity of the wearer in the image. Visual confirmation utility is needed to annotate and validate hand-related activities for several behavioral-based applications, particularly in cases where a human in the loop method is needed to label (e.g., annotating gestures that cannot be automatically detected yet). We propose a new type of obfuscation, activity-oriented partial obfuscation, as a methodological contribution to researchers interested in obtaining visual confirmation of hand-related activities in the wild. We tested the effects of this approach by collecting ten diverse and realistic video scenarios that involved the wearer performing hand-related activities while bystanders performed activities that could be of concern if recorded. Then we conducted an online experiment with 367 participants to evaluate the effect of varying degrees of obfuscation on bystander privacy and visual confirmation utility. Our results show that activity-oriented partial obfuscation (1) maintains visual confirmation of the wearer's hand-related activity, especially when an object is present in the hand, and even when extreme filters are applied, while (2) significantly reducing bystander concerns and enhancing bystander privacy. Informed by our analysis, we further discuss the impact of the filter method used in activity-oriented partial obfuscation on bystander privacy and concerns.
Back to Real Pictures
Authors: Axtell Benett , Munteanu Cosmin
Published: September 2019

Personal pictures storage is currently split between a myriad of physical and digital tools. Cloud photo storage and social networks are seeing increasing adoption, and are being recommended to families (especially older generations) as digital pictures solutions. The ubiquity of these platforms raises the question of whether the design of their photo-based operations consider the mental models of their cross-generational users. Understanding mental models is a key factor for the usability (and adoption) of these technologies. Previous works have observed that perceptions of digital storage limit adoption, especially for older users. However, we do not yet understand users' mental models of these applications. This impedes efforts to design applications better matching diverse user needs. We present here a cross-generational investigation of users' mental models of ubiquitous picture technologies, including cloud storage and social sharing. We find that mental models are split (both between generations and domains), contributing to lower adoption by older adults. Our analysis reveals that digital tools need to understand their roots in physical pictures and bridge this divide by including physical concepts as an aspect of use, if we are to support cross-generational interactions with personal and family pictures.